Beadex Function in the Motor Neurons Is Essential for Female Reproduction in Drosophila melanogaster
Kairamkonda, Subhash; Nongthomba, Upendra
2014-01-01
Drosophila melanogaster has served as an excellent model system for understanding the neuronal circuits and molecular mechanisms regulating complex behaviors. The Drosophila female reproductive circuits, in particular, are well studied and can be used as a tool to understand the role of novel genes in neuronal function in general and female reproduction in particular. In the present study, the role of Beadex, a transcription co-activator, in Drosophila female reproduction was assessed by generation of mutant and knock down studies. Null allele of Beadex was generated by transposase induced excision of P-element present within an intron of Beadex gene. The mutant showed highly compromised reproductive abilities as evaluated by reduced fecundity and fertility, abnormal oviposition and more importantly, the failure of sperm release from storage organs. However, no defect was found in the overall ovariole development. Tissue specific, targeted knock down of Beadex indicated that its function in neurons is important for efficient female reproduction, since its neuronal knock down led to compromised female reproductive abilities, similar to Beadex null females. Further, different neuronal class specific knock down studies revealed that Beadex function is required in motor neurons for normal fecundity and fertility of females. Thus, the present study attributes a novel and essential role for Beadex in female reproduction through neurons. PMID:25396431
Chapter 11.18 - Neuroendocrine Control of Female Reproduction.
The hypothalamus and pituitary are known to play roles in reproductive function. A growing body of evidence indicates that environmental toxicants can alter female reproductive function by disrupting hypothalamic control of the pituitary and subsequently the endocrine control of ...
Santos-del-Blanco, L; Climent, J; González-Martínez, S C; Pannell, J R
2012-11-01
The study of local adaptation in plant reproductive traits has received substantial attention in short-lived species, but studies conducted on forest trees are scarce. This lack of research on long-lived species represents an important gap in our knowledge, because inferences about selection on the reproduction and life history of short-lived species cannot necessarily be extrapolated to trees. This study considers whether the size for first reproduction is locally adapted across a broad geographical range of the Mediterranean conifer species Pinus pinaster. In particular, the study investigates whether this monoecious species varies genetically among populations in terms of whether individuals start to reproduce through their male function, their female function or both sexual functions simultaneously. Whether differences among populations could be attributed to local adaptation across a climatic gradient is then considered. Male and female reproduction and growth were measured during early stages of sexual maturity of a P. pinaster common garden comprising 23 populations sampled across the species range. Generalized linear mixed models were used to assess genetic variability of early reproductive life-history traits. Environmental correlations with reproductive life-history traits were tested after controlling for neutral genetic structure provided by 12 nuclear simple sequence repeat markers. Trees tended to reproduce first through their male function, at a size (height) that varied little among source populations. The transition to female reproduction was slower, showed higher levels of variability and was negatively correlated with vegetative growth traits. Several female reproductive traits were correlated with a gradient of growth conditions, even after accounting for neutral genetic structure, with populations from more unfavourable sites tending to commence female reproduction at a lower individual size. The study represents the first report of genetic variability among populations for differences in the threshold size for first reproduction between male and female sexual functions in a tree species. The relatively uniform size at which individuals begin reproducing through their male function probably represents the fact that pollen dispersal is also relatively invariant among sites. However, the genetic variability in the timing of female reproduction probably reflects environment-dependent costs of cone production. The results also suggest that early sex allocation in this species might evolve under constraints that do not apply to other conifers.
Santos-del-Blanco, L.; Climent, J.; González-Martínez, S. C.; Pannell, J. R.
2012-01-01
Background and Aims The study of local adaptation in plant reproductive traits has received substantial attention in short-lived species, but studies conducted on forest trees are scarce. This lack of research on long-lived species represents an important gap in our knowledge, because inferences about selection on the reproduction and life history of short-lived species cannot necessarily be extrapolated to trees. This study considers whether the size for first reproduction is locally adapted across a broad geographical range of the Mediterranean conifer species Pinus pinaster. In particular, the study investigates whether this monoecious species varies genetically among populations in terms of whether individuals start to reproduce through their male function, their female function or both sexual functions simultaneously. Whether differences among populations could be attributed to local adaptation across a climatic gradient is then considered. Methods Male and female reproduction and growth were measured during early stages of sexual maturity of a P. pinaster common garden comprising 23 populations sampled across the species range. Generalized linear mixed models were used to assess genetic variability of early reproductive life-history traits. Environmental correlations with reproductive life-history traits were tested after controlling for neutral genetic structure provided by 12 nuclear simple sequence repeat markers. Key Results Trees tended to reproduce first through their male function, at a size (height) that varied little among source populations. The transition to female reproduction was slower, showed higher levels of variability and was negatively correlated with vegetative growth traits. Several female reproductive traits were correlated with a gradient of growth conditions, even after accounting for neutral genetic structure, with populations from more unfavourable sites tending to commence female reproduction at a lower individual size. Conclusions The study represents the first report of genetic variability among populations for differences in the threshold size for first reproduction between male and female sexual functions in a tree species. The relatively uniform size at which individuals begin reproducing through their male function probably represents the fact that pollen dispersal is also relatively invariant among sites. However, the genetic variability in the timing of female reproduction probably reflects environment-dependent costs of cone production. The results also suggest that early sex allocation in this species might evolve under constraints that do not apply to other conifers. PMID:23002272
Effects of Environmental Toxicants on the Neuroendocrine Control of Female Reproduction
The hypothalamus and pituitary are known to play key roles in reproductive function. A growing body of evidence indicates that environmental toxicants can alter female reproductive function by disrupting hypothalamic control of the pituitary and subsequently, the endocrine contro...
Hormonally mediated effects on the female reproductive system may manifest in pathologic changes of endocrine-responsive organs and altered reproductive function. Identification of these effects requires proper assessment, which may include investigative studies of female reprod...
Fanson, Kerry V; Parrott, Marissa L
2015-11-01
This article is part of a Special Issue "SBN 2014". Chronic stress is known to inhibit female reproductive function. Consequently, it is often assumed that glucocorticoid (GC) concentrations should be negatively correlated with reproductive success because of the role they play in stress physiology. In contrast, a growing body of evidence indicates that GCs play an active role in promoting reproductive function. It is precisely because GCs are so integral to the entire process that disruptions to adrenal activity have negative consequences for reproduction. The goal of this paper is to draw attention to the increasing evidence showing that increases in adrenal activity are important for healthy female reproduction. Furthermore, we outline several hypotheses about the functional role(s) that GCs may play in mediating reproduction and argue that comparative studies between eutherian and marsupial mammals, which exhibit some pronounced differences in reproductive physiology, may be particularly useful for testing different hypotheses about the functional role of GCs in reproduction. Much of our current thinking about GCs and reproduction comes from research involving stress-induced levels of GCs and has led to broad assumptions about the effects of GCs on reproduction. Unfortunately, this has left a gaping hole in our knowledge about basal GC levels and how they may influence reproductive function, thereby preventing a broader understanding of adrenal physiology and obscuring potential solutions for reproductive dysfunction. Copyright © 2015 Elsevier Inc. All rights reserved.
Ovarian function's role during cancer cachexia progression in the female mouse.
Hetzler, Kimbell L; Hardee, Justin P; LaVoie, Holly A; Murphy, E Angela; Carson, James A
2017-05-01
Cachexia is a debilitating condition that occurs with chronic disease, including cancer; our research has shown that some regulation of cancer cachexia progression is affected by sex differences. The Apc Min/+ mouse is genetically predisposed to develop intestinal tumors; IL-6 signaling and hypogonadism are associated with cachexia severity in the male. This relationship in the female warrants further investigation, as we have shown that the ability of IL-6 to induce cachexia differs between the sexes. Since ovarian reproductive function relies on a complex system of endocrine signaling to affect whole body homeostasis, we examined the relationship between ovarian reproductive function and progression of cancer cachexia in the female Apc Min/+ mouse. Our study of ovarian reproductive function in female Apc Min/+ mice showed disease-related cessation of estrous cycling (acyclicity) in 38% of mice. Acyclicity, including morphological and functional losses and enhanced muscle inflammatory gene expression, was associated with severe cachexia. Interestingly, ovariectomy rescued body weight and muscle mass and function but increased muscle sensitivity to systemic IL-6 overexpression. In conclusion, our results provide evidence for a relationship between ovarian reproductive function and cachexia progression in female Apc Min/+ mice. Copyright © 2017 the American Physiological Society.
Effect of elevation on distribution of female bats in the Black Hills, South Dakota
Cryan, P.M.; Bogan, M.A.; Altenbach, J.S.
2000-01-01
Presumably, reproductive female bats are more constrained by thermoregulatory and energy needs than are males and nonreproductive females. Constraints imposed on reproductive females may limit their geographic distribution relative to other bats. Such constraints likely increase with latitude and elevation. Males of 11 bat species that inhabit the Black Hills were captured more frequently than females, and reproductive females typically were encountered at low-elevational sites. To investigate the relationship between female distribution and elevation, we fitted a logistic regression model to evaluate the probability of reproductive-female capture as a function of elevation. Mist-net data from 1,197 captures of 7 species revealed that 75% of all captures were males. We found a significant inverse relationship between elevation and relative abundance of reproductive females. Relative abundance of reproductive females decreased as elevation increased. Reproductive females may be constrained from roosting and foraging in high-elevational habitats that impose thermoregulatory costs and decrease foraging efficiency. Failure to account for sex differences in distributional patterns along elevational gradients may significantly bias estimates of population size.
Ovarian function’s role during cancer cachexia progression in the female mouse
Hetzler, Kimbell L.; Hardee, Justin P.; LaVoie, Holly A.; Murphy, E. Angela
2017-01-01
Cachexia is a debilitating condition that occurs with chronic disease, including cancer; our research has shown that some regulation of cancer cachexia progression is affected by sex differences. The ApcMin/+ mouse is genetically predisposed to develop intestinal tumors; IL-6 signaling and hypogonadism are associated with cachexia severity in the male. This relationship in the female warrants further investigation, as we have shown that the ability of IL-6 to induce cachexia differs between the sexes. Since ovarian reproductive function relies on a complex system of endocrine signaling to affect whole body homeostasis, we examined the relationship between ovarian reproductive function and progression of cancer cachexia in the female ApcMin/+ mouse. Our study of ovarian reproductive function in female ApcMin/+ mice showed disease-related cessation of estrous cycling (acyclicity) in 38% of mice. Acyclicity, including morphological and functional losses and enhanced muscle inflammatory gene expression, was associated with severe cachexia. Interestingly, ovariectomy rescued body weight and muscle mass and function but increased muscle sensitivity to systemic IL-6 overexpression. In conclusion, our results provide evidence for a relationship between ovarian reproductive function and cachexia progression in female ApcMin/+ mice. PMID:28292759
Fort, Douglas J; Mathis, Michael; Fort, Chelsea E; Fort, Hayley M; Bacon, Jamie P
2015-06-01
A modified tier 1 Endocrine Disruptor Screening Program (EDSP) 21-d fish short-term reproduction assay (FSTRA) was used to evaluate the effects of sediment exposure from freshwater and brackish ponds in Bermuda on reproductive fecundity and endocrine function in fathead minnow (Pimephales promelas) and killifish (Fundulus heteroclitus). Reproductively active male and female fish were exposed to control sediment and sediment from 2 freshwater ponds (fathead minnow) and 2 marine ponds (killifish) contaminated with polyaromatic hydrocarbons and metals via flow-through exposure for 21 d. Reproductive fecundity was monitored daily. At termination, the status of the reproductive endocrine system was assessed by the gonadosomatic index, gonadal histology, plasma steroids (estrogen [E2], testosterone [T], and 11-ketotestosterone [11-KT]), steroidogenic enzymes (aromatase and combined 3β/17β -hydroxysteroid dehydrogenase [3β/17β-HSD]), and plasma vitellogenin (VTG). Decreased reproductive fecundity, lower male body weight, and altered endocrinological measures of reproductive status were observed in both species. Higher plasma T levels in female minnows and 11-KT levels in both male and female minnows and female killifish exposed to freshwater and brackish sediments, respectively. Decreased female E2 and VTG levels and gonadal cytochrome P19 (aromatase) activity were also found in sediment exposed females from both species. No effect on female 3β/17β-HSD activity was found in either species. The FSTRA provided a robust model capable of modification to evaluate reproductive effects of sediment exposure in fish. © 2015 SETAC.
Vitamin D is necessary for reproductive functions of the male rat.
Kwiecinski, G G; Petrie, G I; DeLuca, H F
1989-05-01
The effect of vitamin D deficiency on the fertility and reproductive capacity of male rats was investigated. Male weanling rats were fed vitamin D-deficient or vitamin D-replete diets until maturity, and mated to age-matched, vitamin D-replete females. Vitamin D-deficient males were capable of reproduction. However, successful matings, i.e., presence of sperm in the vaginal tract of the female, by vitamin D-deficient males were reduced by 45% when compared to matings by vitamin D-replete males. Fertility (successful pregnancies in sperm-positive females) was reduced by 73% in litters from vitamin D-deficient male inseminations when compared to litters from females inseminated by vitamin D-replete males. These results demonstrate that vitamin D and its metabolites are necessary for normal reproductive functions in the male rat.
Differences in Patterns of Reproductive Allocation between the Sexes in Nicrophorus orbicollis.
Smith, Ashlee N; Creighton, J Curtis; Belk, Mark C
2015-01-01
Organisms are selected to maximize lifetime reproductive success by balancing the costs of current reproduction with costs to future survival and fecundity. Males and females typically face different reproductive costs, which makes comparisons of their reproductive strategies difficult. Burying beetles provide a unique system that allows us to compare the costs of reproduction between the sexes because males and females are capable of raising offspring together or alone and carcass preparation and offspring care represent the majority of reproductive costs for both sexes. Because both sexes perform the same functions of carcass preparation and offspring care, we predict that they would experience similar costs and have similar life history patterns. In this study we assess the cost of reproduction in male Nicrophorus orbicollis and compare to patterns observed in females. We compare the reproductive strategies of single males and females that provided pre- and post-hatching parental care. There is a cost to reproduction for both males and females, but the sexes respond to these costs differently. Females match brood size with carcass size, and thus maximize the lifetime number of offspring on a given size carcass. Males cull proportionately more offspring on all carcass sizes, and thus have a lower lifetime number of offspring compared to females. Females exhibit an adaptive reproductive strategy based on resource availability, but male reproductive strategies are not adaptive in relation to resource availability.
ERIC Educational Resources Information Center
Manpower Administration (DOL), Washington, DC. Job Corps.
This self-study program for the high-school level contains lessons in the following subjects: Plants and Photosynthesis; The Human Digestive System; Functions of the Blood; Human Circulation and Respiration; Reproduction of a Single Cell; Reproduction by Male and Female Cells; The Human Reproductive System; Genetics and Heredity; The Nervous…
Nguyen, Philip V; Kafka, Jessica K; Ferreira, Victor H; Roth, Kristy; Kaushic, Charu
2014-01-01
The male and female reproductive tracts are complex microenvironments that have diverse functional demands. The immune system in the reproductive tract has the demanding task of providing a protective environment for a fetal allograft while simultaneously conferring protection against potential pathogens. As such, it has evolved a unique set of adaptations, primarily under the influence of sex hormones, which make it distinct from other mucosal sites. Here, we discuss the various components of the immune system that are present in both the male and female reproductive tracts, including innate soluble factors and cells and humoral and cell-mediated adaptive immunity under homeostatic conditions. We review the evidence showing unique phenotypic and functional characteristics of immune cells and responses in the male and female reproductive tracts that exhibit compartmentalization from systemic immunity and discuss how these features are influenced by sex hormones. We also examine the interactions among the reproductive tract, sex hormones and immune responses following HIV-1 infection. An improved understanding of the unique characteristics of the male and female reproductive tracts will provide insights into improving clinical treatments of the immunological causes of infertility and the design of prophylactic interventions for the prevention of sexually transmitted infections. PMID:24976268
Goldsammler, Michelle; Merhi, Zaher; Buyuk, Erkan
2018-05-09
Besides being a risk factor for multiple metabolic disorders, obesity could affect female reproduction. While increased adiposity is associated with hormonal changes that could disrupt the function of the hypothalamus and the pituitary, compelling data suggest that obesity-related hormonal and inflammatory changes could directly impact ovarian function. To review the available data related to the mechanisms by which obesity, and its associated hormonal and inflammatory changes, could affect the female reproductive function with a focus on the hypothalamic-pituitary-ovarian (HPO) axis. PubMed database search for publications in English language until October 2017 pertaining to obesity and female reproductive function was performed. The obesity-related changes in hormone levels, in particular leptin, adiponectin, ghrelin, neuropeptide Y and agouti-related protein, are associated with reproductive dysfunction at both the hypothalamic-pituitary and the ovarian levels. The pro-inflammatory molecules advanced glycation end products (AGEs) and monocyte chemotactic protein-1 (MCP-1) are emerging as relatively new players in the pathophysiology of obesity-related ovarian dysfunction. There is an intricate crosstalk between the adipose tissue and the inflammatory system with the HPO axis function. Understanding the mechanisms behind this crosstalk could lead to potential therapies for the common obesity-related reproductive dysfunction.
Role of leptin in female reproduction.
Pérez-Pérez, Antonio; Sánchez-Jiménez, Flora; Maymó, Julieta; Dueñas, José L; Varone, Cecilia; Sánchez-Margalet, Víctor
2015-01-01
Reproductive function is dependent on energy resources. The role of weight, body composition, fat distribution and the effect of diet have been largely investigated in experimental female animals as well as in women. Any alteration in diet and/or weight may induce abnormalities in timing of sexual maturation and fertility. However, the cellular mechanisms involved in the fine coordination of energy balance and reproduction are largely unknown. The brain and hypothalamic structures receive endocrine and/or metabolic signals providing information on the nutritional status and the degree of fat stores. Adipose tissue acts both as a store of energy and as an active endocrine organ, secreting a large number of biologically important molecules termed adipokines. Adipokines have been shown to be involved in regulation of the reproductive functions. The first adipokine described was leptin. Extensive research over the last 10 years has shown that leptin is not only an adipose tissue-derived messenger of the amount of energy stores to the brain, but also a crucial hormone/cytokine for a number of diverse physiological processes, such as inflammation, angiogenesis, hematopoiesis, immune function, and most importantly, reproduction. Leptin plays an integral role in the normal physiology of the reproductive system with complex interactions at all levels of the hypothalamic-pituitary gonadal (HPG) axis. In addition, leptin is also produced by placenta, where it plays an important autocrine function. Observational studies have demonstrated that states of leptin excess, deficiency, or resistance can be associated with abnormal reproductive function. This review focuses on the leptin action in female reproduction.
Chapter 22: Female Reproductive Toxicology
The female reproductive system provides multiple targets for environmental toxicants with the hypothalamic-pituitary-ovarian axis. Moreover, the functional impact of a chemical can differ, depending on the species involved and the parameters of exposure. While cross-species compa...
Growth Hormone and Reproduction: A Review of Endocrine and Autocrine/Paracrine Interactions
Hull, Kerry L.; Harvey, Steve
2014-01-01
The somatotropic axis, consisting of growth hormone (GH), hepatic insulin-like growth factor I (IGF-I), and assorted releasing factors, regulates growth and body composition. Axiomatically, since optimal body composition enhances reproductive function, general somatic actions of GH modulate reproductive function. A growing body of evidence supports the hypothesis that GH also modulates reproduction directly, exerting both gonadotropin-dependent and gonadotropin-independent actions in both males and females. Moreover, recent studies indicate GH produced within reproductive tissues differs from pituitary GH in terms of secretion and action. Accordingly, GH is increasingly used as a fertility adjunct in males and females, both humans and nonhumans. This review reconsiders reproductive actions of GH in vertebrates in respect to these new conceptual developments. PMID:25580121
Experimental reduction of intromittent organ length reduces male reproductive success in a bug
Dougherty, Liam R.; Rahman, Imran A.; Burdfield-Steel, Emily R.; Greenway, E. V. (Ginny); Shuker, David M.
2015-01-01
It is now clear in many species that male and female genital evolution has been shaped by sexual selection. However, it has historically been difficult to confirm correlations between morphology and fitness, as genital traits are complex and manipulation tends to impair function significantly. In this study, we investigate the functional morphology of the elongate male intromittent organ (or processus) of the seed bug Lygaeus simulans, in two ways. We first use micro-computed tomography (micro-CT) and flash-freezing to reconstruct in high resolution the interaction between the male intromittent organ and the female internal reproductive anatomy during mating. We successfully trace the path of the male processus inside the female reproductive tract. We then confirm that male processus length influences sperm transfer by experimental ablation and show that males with shortened processi have significantly reduced post-copulatory reproductive success. Importantly, male insemination function is not affected by this manipulation per se. We thus present rare, direct experimental evidence that an internal genital trait functions to increase reproductive success and show that, with appropriate staining, micro-CT is an excellent tool for investigating the functional morphology of insect genitalia during copulation. PMID:25972470
Novel function of LHFPL2 in female and male distal reproductive tract development.
Zhao, Fei; Zhou, Jun; Li, Rong; Dudley, Elizabeth A; Ye, Xiaoqin
2016-03-11
Congenital reproductive tract anomalies could impair fertility. Female and male reproductive tracts are developed from Müllerian ducts and Wolffian ducts, respectively, involving initiation, elongation and differentiation. Genetic basis solely for distal reproductive tract development is largely unknown. Lhfpl2 (lipoma HMGIC fusion partner-like 2) encodes a tetra-transmembrane protein with unknown functions. It is expressed in follicle cells of ovary and epithelial cells of reproductive tracts. A spontaneous point mutation of Lhfpl2 (LHFPL2(G102E)) leads to infertility in 100% female mice, which have normal ovarian development, ovulation, uterine development, and uterine response to exogenous estrogen stimulation, but abnormal upper longitudinal vaginal septum and lower vaginal agenesis. Infertility is also observed in ~70% mutant males, which have normal mating behavior and sperm counts, but abnormal distal vas deferens convolution resulting in complete and incomplete blockage of reproductive tract in infertile and fertile males, respectively. On embryonic day 15.5, mutant Müllerian ducts and Wolffian ducts have elongated but their duct tips are enlarged and fail to merge with the urogenital sinus. These findings provide a novel function of LHFPL2 and a novel genetic basis for distal reproductive tract development; they also emphasize the importance of an additional merging phase for proper reproductive tract development.
Species Comparison of the Role of p38 MAP Kinase in the Female Reproductive System.
Radi, Zaher A; Marusak, Rosemary A; Morris, Dale L
2009-06-01
The p38 mitogen-activated protein kinases (MAPKs) are members of discrete signal transduction pathways that have significant regulatory roles in a variety of biological processes, depending on the cell, tissue and organ type. p38 MAPKs are involved in inflammation, cell growth and differentiation and cell cycle. In the female reproductive system, p38 MAPKs are known to regulate various aspects of the reproductive process such as mammalian estrous and menstrual cycles as well as early pregnancy and parturition. p38 MAPKs have also been implicated in alterations and pathologies observed in the female reproductive system. Therefore, pharmacologic modulation of p38 MAPKs, and inter-connected signaling pathways (e.g., estrogen receptor signaling, c-fos, c-jun), may influence reproductive physiology and function. This article provides a critical, comparative review of available data on the roles of p38 MAPKs in the mammalian female reproductive system and in reproductive pathophysiology in humans and preclinical species. We first introduce fundamental differences and similarities of the mammalian female reproductive system that should be considered by toxicologists and toxicologic pathologists when assessing the effects of new pharmacologic agents on the female reproductive system. We then explore in detail the known roles for p38 MAPKs and related molecules in female reproduction. This foundation is then extended to pathological conditions in which p38 MAPKs are thought to play an integral role.
Prostaglandins and reproduction in female farm animals.
Weems, C W; Weems, Y S; Randel, R D
2006-03-01
Prostaglandins impact on ovarian, uterine, placental, and pituitary function to regulate reproduction in female livestock. They play important roles in ovulation, luteal function, maternal recognition of pregnancy, implantation, maintenance of gestation, microbial-induced abortion, parturition, postpartum uterine and ovarian infections, and resumption of postpartum ovarian cyclicity. Prostaglandins have both positive and negative effects on reproduction; they are used to synchronize oestrus, terminate pseudopregnancy in mares, induce parturition, and treat retained placenta, luteinized cysts, pyometra, and chronic endometritis. Improved therapeutic uses for prostaglandins will be developed when we understand better their involvement in implantation, maintenance of luteal function, and establishment and maintenance of pregnancy.
Heme oxygenase/carbon monoxide in the female reproductive system: an overlooked signalling pathway
Němeček, David; Dvořáková, Markéta; Sedmíková, Markéta
2017-01-01
For a long time, carbon monoxide (CO) was known for its toxic effect on organisms. But there are still many things left to discover on that molecule. CO is formed directly in the body by the enzymatic activity of heme oxygenase (HO). CO plays an important role in many physiological processes, such as cell protections (against various stress factors), and the regulation of metabolic processes. Recent research proves that CO also operates in the female reproductive system. At the centre of interest is the importance of CO for gestation. During the gestation period, CO is an important element affecting the proper function of the feto-placental unit and generally affects fetal survivability rates. Gestation is one of the most important processes of successful reproduction, although there are more relevant processes that need to be researched. While already proven that CO influences steroidogenesis and the corpus luteum survivability rate, our knowledge concerning the function and importance of CO in the reproductive system is still relatively limited. As an example, our knowledge of CO function in an oocyte, the most important cell for reproduction, is almost non-existent. The aim of this review is to summarize our current knowledge concerning the function of CO in the female reproductive system. PMID:28123837
Lu, Huijie; Cui, Yong; Jiang, Liwen; Ge, Wei
2017-07-01
Estrogens signal through both nuclear and membrane receptors with most reported effects being mediated via the nuclear estrogen receptors (nERs). Although much work has been reported on nERs in the zebrafish, there is a lack of direct genetic evidence for their functional roles and importance in reproduction. To address this issue, we undertook this study to disrupt all three nERs in the zebrafish, namely esr1 (ERα), esr2a (ERβII), and esr2b (ERβI), by the genome-editing technology clustered regularly interspaced short palindromic repeats and its associated nuclease (CRISPR/Cas9). Using this loss-of-function genetic approach, we successfully created three mutant zebrafish lines with each nER knocked out. In addition, we also generated all possible double and triple knockouts of the three nERs. The phenotypes of these mutants in reproduction were analyzed in all single, double, and triple nER knockouts in both females and males. Surprisingly, all three single nER mutant fish lines display normal reproductive development and function in both females and males, suggesting functional redundancy among these nERs. Further analysis of double and triple knockouts showed that nERs, especially Esr2a and Esr2b, were essential for female reproduction, and loss of these two nERs led to an arrest of folliculogenesis at previtellogenic stage II followed by sex reversal from female to male. In addition, the current study also revealed a unique role for Esr2a in follicle cell proliferation and transdifferentiation, follicle growth, and chorion formation. Taken together, this study provides the most comprehensive genetic analysis for differential functions of esr1, esr2a, and esr2b in fish reproduction. Copyright © 2017 Endocrine Society.
GnRH and GnRH receptors in the pathophysiology of the human female reproductive system.
Maggi, Roberto; Cariboni, Anna Maria; Marelli, Marina Montagnani; Moretti, Roberta Manuela; Andrè, Valentina; Marzagalli, Monica; Limonta, Patrizia
2016-04-01
Human reproduction depends on an intact hypothalamic-pituitary-gonadal (HPG) axis. Hypothalamic gonadotrophin-releasing hormone (GnRH) has been recognized, since its identification in 1971, as the central regulator of the production and release of the pituitary gonadotrophins that, in turn, regulate the gonadal functions and the production of sex steroids. The characteristic peculiar development, distribution and episodic activity of GnRH-producing neurons have solicited an interdisciplinary interest on the etiopathogenesis of several reproductive diseases. The more recent identification of a GnRH/GnRH receptor (GnRHR) system in both the human endometrium and ovary has widened the spectrum of action of the peptide and of its analogues beyond its hypothalamic function. An analysis of research and review articles published in international journals until June 2015 has been carried out to comprehensively summarize both the well established and the most recent knowledge on the physiopathology of the GnRH system in the central and peripheral control of female reproductive functions and diseases. This review focuses on the role of GnRH neurons in the control of the reproductive axis. New knowledge is accumulating on the genetic programme that drives GnRH neuron development to ameliorate the diagnosis and treatment of GnRH deficiency and consequent delayed or absent puberty. Moreover, a better understanding of the mechanisms controlling the episodic release of GnRH during the onset of puberty and the ovulatory cycle has enabled the pharmacological use of GnRH itself or its synthetic analogues (agonists and antagonists) to either stimulate or to block the gonadotrophin secretion and modulate the functions of the reproductive axis in several reproductive diseases and in assisted reproduction technology. Several inputs from other neuronal populations, as well as metabolic, somatic and age-related signals, may greatly affect the functions of the GnRH pulse generator during the female lifespan; their modulation may offer new possible strategies for diagnostic and therapeutic interventions. A GnRH/GnRHR system is also expressed in female reproductive tissues (e.g. endometrium and ovary), both in normal and pathological conditions. The expression of this system in the human endometrium and ovary supports its physiological regulatory role in the processes of trophoblast invasion of the maternal endometrium and embryo implantation as well as of follicular development and corpus luteum functions. The GnRH/GnRHR system that is expressed in diseased tissues of the female reproductive tract (both benign and malignant) is at present considered an effective molecular target for the development of novel therapeutic approaches for these pathologies. GnRH agonists are also considered as a promising therapeutic approach to counteract ovarian failure in young female patients undergoing chemotherapy. Increasing knowledge about the regulation of GnRH pulsatile release, as well as the therapeutic use of its analogues, offers interesting new perspectives in the diagnosis, treatment and outcome of female reproductive disorders, including tumoral and iatrogenic diseases. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Cecchetto, Nicolas Rodolfo; Naretto, Sergio
2015-10-01
Body temperature is a key factor in physiological processes, influencing lizard performances; and life history traits are expected to generate variability of thermal preferences in different individuals. Gender, body size and reproductive condition may impose specific requirements on preferred body temperatures. If these three factors have different physiological functions and thermal requirements, then the preferred temperature may represent a compromise that optimizes these physiological functions. Therefore, the body temperatures that lizards select in a controlled environment may reflect a temperature that maximizes their physiological needs. The tegu lizard Tupinambis merianae is one of the largest lizards in South America and has wide ontogenetic variation in body size and sexual dimorphism. In the present study we evaluate intraspecific variability of thermal preferences of T. merianae. We determined the selected body temperature and the rate at which males and females attain their selected temperature, in relation to body size and reproductive condition. We also compared the behavior in the thermal gradient between males and females and between reproductive condition of individuals. Our study show that T. merianae selected body temperature within a narrow range of temperatures variation in the laboratory thermal gradient, with 36.24±1.49°C being the preferred temperature. We observed no significant differences between sex, body size and reproductive condition in thermal preferences. Accordingly, we suggest that the evaluated categories of T. merianae have similar thermal requirements. Males showed higher rates to obtain heat than females and reproductive females, higher rates than non-reproductive ones females. Moreover, males and reproductive females showed a more dynamic behavior in the thermal gradient. Therefore, even though they achieve the same selected temperature, they do it differentially. Copyright © 2015 Elsevier Ltd. All rights reserved.
Stahlschmidt, Zachary R; Lourdais, Olivier; Lorioux, Sophie; Butler, Michael W; Davis, Jon R; Salin, Karine; Voituron, Yann; DeNardo, Dale F
2013-01-01
Current reproductive effort typically comes at a cost to future reproductive value by altering somatic function (e.g., growth or self-maintenance). Furthermore, effects of reproduction often depend on both fecundity and stage of reproduction, wherein allocation of resources into additional offspring and/or stages of reproduction results in increased costs. Despite these widely accepted generalities, interindividual variation in the effects of reproduction is common-yet the proximate basis that allows some individuals to mitigate these detrimental effects is unclear. We serially measured several variables of morphology (e.g., musculature) and physiology (e.g., antioxidant defenses) in female Children's pythons (Antaresia childreni) throughout reproduction to examine how these traits change over the course of reproduction and whether certain physiological traits are associated with reduced effects of reproduction in some individuals. Reproduction in this capital breeder was associated with changes in both morphology and physiology, but only morphological changes varied with fecundity and among specific reproductive stages. During reproduction, we detected negative relationships between morphology and self-maintenance (e.g., increased muscle allocation to reproduction was related to reduced immune function). Additionally, females that allocated resources more heavily into current reproduction also did so during future reproduction, and these females assimilated resources more efficiently, experienced reduced detriments to self-maintenance (e.g., lower levels of oxidative damage and glucocorticoids) during reproduction, and produced clutches with greater hatching success. Our results suggest that interindividual variation in specific aspects of physiology (assimilation efficiency and oxidative status) may drive variation in reproductive performance.
Elle, Elizabeth; Meagher, Thomas R
2000-12-01
According to Bateman's principle, male fitness in entomophilous plant species should be limited by mating opportunity, which is influenced by the size or number of flowers. We determined male-specific fitness consequences of floral phenotype in andromonoecious Solanum carolinense, examined the relationship between male and female reproductive success within plants, and evaluated the distribution of functional gender among plants. A maximum likelihood-based paternity analysis, based on multilocus allozyme phenotypes of parents and offspring from four experimental plots, was used to determine male reproductive success and its relationship to floral phenotype. Male success was enhanced by an increase in the proportion of male flowers produced but not by an increase in total flower number, even though all flowers contain male parts. Larger flower size increased male success in only one plot. Male and female reproductive success were negatively correlated, and plants varied in functional gender from completely female to completely male. This gender specialization may occur because hermaphroditic and male flowers differ in their ability to contribute to male and female success. Although sex allocation theory predicts a positive relationship between the size or number of plant parts and reproductive success, this study indicates that aspects of floral morphology that affect gender specialization should also be considered.
Peroxisome Proliferator-Activated Receptors in Female Reproduction and Fertility
Carta, Gaspare; Artini, Paolo Giovanni
2016-01-01
Reproductive functions may be altered by the exposure to a multitude of endogenous and exogenous agents, drug or environmental pollutants, which are known to affect gene transcription through the peroxisome proliferator-activated receptors (PPARs) activation. PPARs act as ligand activated transcription factors and regulate metabolic processes such as lipid and glucose metabolism, energy homeostasis, inflammation, and cell proliferation and differentiation. All PPARs isotypes are expressed along the hypothalamic-pituitary-gonadal axis and are strictly involved in reproductive functions. Since female fertility and energy metabolism are tightly interconnected, the research on female infertility points towards the exploration of potential PPARs activating/antagonizing compounds, mainly belonging to the class of thiazolidinediones (TZDs) and fibrates, as useful agents for the maintenance of metabolic homeostasis in women with ovarian dysfunctions. In the present review, we discuss the recent evidence about PPARs expression in the hypothalamic-pituitary-gonadal axis and their involvement in female reproduction. Finally, the therapeutic potential of their manipulation through several drugs is also discussed. PMID:27559343
Sitnik, Jessica L; Francis, Carmen; Hens, Korneel; Huybrechts, Roger; Wolfner, Mariana F; Callaerts, Patrick
2014-03-01
Members of the M13 class of metalloproteases have been implicated in diseases and in reproductive fitness. Nevertheless, their physiological role remains poorly understood. To obtain a tractable model with which to analyze this protein family's function, we characterized the gene family in Drosophila melanogaster and focused on reproductive phenotypes. The D. melanogaster genome contains 24 M13 class protease homologs, some of which are orthologs of human proteases, including neprilysin. Many are expressed in the reproductive tracts of either sex. Using RNAi we individually targeted the five Nep genes most closely related to vertebrate neprilysin, Nep1-5, to investigate their roles in reproduction. A reduction in Nep1, Nep2, or Nep4 expression in females reduced egg laying. Nep1 and Nep2 are required in the CNS and the spermathecae for wild-type fecundity. Females that are null for Nep2 also show defects as hosts of sperm competition as well as an increased rate of depletion for stored sperm. Furthermore, eggs laid by Nep2 mutant females are fertilized normally, but arrest early in embryonic development. In the male, only Nep1 was required to induce normal patterns of female egg laying. Reduction in the expression of Nep2-5 in the male did not cause any dramatic effects on reproductive fitness, which suggests that these genes are either nonessential for male fertility or perform redundant functions. Our results suggest that, consistent with the functions of neprilysins in mammals, these proteins are also required for reproduction in Drosophila, opening up this model system for further functional analysis of this protein class and their substrates.
Sitnik, Jessica L.; Francis, Carmen; Hens, Korneel; Huybrechts, Roger; Wolfner, Mariana F.; Callaerts, Patrick
2014-01-01
Members of the M13 class of metalloproteases have been implicated in diseases and in reproductive fitness. Nevertheless, their physiological role remains poorly understood. To obtain a tractable model with which to analyze this protein family’s function, we characterized the gene family in Drosophila melanogaster and focused on reproductive phenotypes. The D. melanogaster genome contains 24 M13 class protease homologs, some of which are orthologs of human proteases, including neprilysin. Many are expressed in the reproductive tracts of either sex. Using RNAi we individually targeted the five Nep genes most closely related to vertebrate neprilysin, Nep1-5, to investigate their roles in reproduction. A reduction in Nep1, Nep2, or Nep4 expression in females reduced egg laying. Nep1 and Nep2 are required in the CNS and the spermathecae for wild-type fecundity. Females that are null for Nep2 also show defects as hosts of sperm competition as well as an increased rate of depletion for stored sperm. Furthermore, eggs laid by Nep2 mutant females are fertilized normally, but arrest early in embryonic development. In the male, only Nep1 was required to induce normal patterns of female egg laying. Reduction in the expression of Nep2-5 in the male did not cause any dramatic effects on reproductive fitness, which suggests that these genes are either nonessential for male fertility or perform redundant functions. Our results suggest that, consistent with the functions of neprilysins in mammals, these proteins are also required for reproduction in Drosophila, opening up this model system for further functional analysis of this protein class and their substrates. PMID:24395329
Chen, Chen; Song, Xiaolei; Wei, Weixia; Zhong, Huanzi; Dai, Juanjuan; Lan, Zhou; Li, Fei; Yu, Xinlei; Feng, Qiang; Wang, Zirong; Xie, Hailiang; Chen, Xiaomin; Zeng, Chunwei; Wen, Bo; Zeng, Liping; Du, Hui; Tang, Huiru; Xu, Changlu; Xia, Yan; Xia, Huihua; Yang, Huanming; Wang, Jian; Wang, Jun; Madsen, Lise; Brix, Susanne; Kristiansen, Karsten; Xu, Xun; Li, Junhua; Wu, Ruifang; Jia, Huijue
2017-10-17
Reports on bacteria detected in maternal fluids during pregnancy are typically associated with adverse consequences, and whether the female reproductive tract harbours distinct microbial communities beyond the vagina has been a matter of debate. Here we systematically sample the microbiota within the female reproductive tract in 110 women of reproductive age, and examine the nature of colonisation by 16S rRNA gene amplicon sequencing and cultivation. We find distinct microbial communities in cervical canal, uterus, fallopian tubes and peritoneal fluid, differing from that of the vagina. The results reflect a microbiota continuum along the female reproductive tract, indicative of a non-sterile environment. We also identify microbial taxa and potential functions that correlate with the menstrual cycle or are over-represented in subjects with adenomyosis or infertility due to endometriosis. The study provides insight into the nature of the vagino-uterine microbiome, and suggests that surveying the vaginal or cervical microbiota might be useful for detection of common diseases in the upper reproductive tract.Whether the female reproductive tract harbours distinct microbiomes beyond the vagina has been a matter of debate. Here, the authors show a subject-specific continuity in microbial communities at six sites along the female reproductive tract, indicative of a non-sterile environment.
Experimental evidence of a risk-sensitive reproductive allocation in a long-lived mammal.
Bårdsen, Bard-Jørgen; Fauchald, Per; Tveraa, Torkild; Langeland, Knut; Yoccoz, Nigel Gilles; Ims, Rolf Anker
2008-03-01
When reproduction competes with the amount of resources available for survival during an unpredictable nonbreeding season, individuals should adopt a risk-sensitive regulation of their reproductive allocation. We tested this hypothesis on female reindeer (Rangifer tarandus), which face a trade-off between reproduction and acquisition of body reserves during spring and summer, with autumn body mass functioning as insurance against stochastic winter climatic severity. The study was conducted in a population consisting of two herds: one that received supplementary winter feeding for four years while the other utilized natural pastures. The females receiving additional forage allocated more to their calves. Experimental translocation of females between the herds was conducted to simulate two contrasting rapid alterations of winter conditions. When females receiving supplementary feeding were moved to natural pastures, they promptly reduced their reproductive allocation the following summer. However, when winter conditions were improved, females were reluctant to increase their reproductive allocation. This asymmetric response to improved vs. reduced winter conditions is consistent with a risk-averse adjustment in reproductive allocation. The ability of individuals to track their environment and the concordant risk-sensitive adjustment of reproductive allocation may render subarctic reindeer more resilient to climate change than previously supposed.
Lourdais, O; Brischoux, F; DeNardo, D; Shine, R
2004-07-01
In many species the high energetic demands of reproduction induce a negative energy balance, and thus females must rely on tissue catabolism to complete the reproductive process. Previous works have shown that both fat and protein are energy resources during prolonged fasting in vertebrates. While many ecological studies on energy costs of reproduction have focused on variations in fat stores, the impact of protein investment on the female has not been thoroughly investigated. Notably, as there is no specialized storage form for proteins, intense catabolism is likely to entail structural (musculature) loss that may compromise maternal physical performance after reproduction. Measurements on captive rainbow boas ( Epicrates cenchria maurus) confirm that reproducing females undergo significant protein catabolism (as indicated by elevated plasma uric acid levels) and show considerable musculature loss during gestation (as detected by reduced width of the epaxial muscles). Protein mobilization entailed a significant functional loss that was illustrated by decrements in tests of strength and constriction after parturition. In wild situations, such effects are likely to decrease the snakes' ability to forage and apprehend prey. Hence, the time period needed to recover from reproduction can be extended not only because the female must compensate losses of both fat stores and functional muscle, but also because the ability to do so may be compromised. Performance alteration is likely to be of equal or greater importance than reduced energy stores in the physiological mediation of elevated post-reproduction mortality rates and infrequent reproductive bouts (e.g. biannual or triannual), two common ecological traits of female snakes.
Lancaster, L T; Hazard, L C; Clobert, J; Sinervo, B R
2008-03-01
Life history trade-offs are often hierarchical with decisions at one level affecting lower level trade-offs. We investigated trade-off structure in female side-blotched lizards (Uta stansburiana), which exhibit two evolved strategies: yellow-throated females are K-strategists and orange-throated are r-strategists. Corticosterone treatment was predicted to differentially organize these females' reproductive decisions. Corticosterone-treated yellow females suppressed reproduction but survived well, and augmented egg mass without decreasing clutch size. Conversely, corticosterone enhanced mortality and reproductive rates in orange females, and increased egg mass only after lengthy exposure. Corticosterone did not affect post-laying condition, suggesting that corticosterone increased egg mass through enhanced energy acquisition (income breeding). Corticosterone enhanced survival of lightweight females, but decreased survival of heavy females, introducing a foraging vs. predation trade-off. We conclude that rather than being a direct, functional relationship, observed trade-offs between offspring size and number represent evolved differences in hierarchical organization of multidimensional trade-offs, particularly in response to stress.
Leptin and its potential interest in assisted reproduction cycles.
Catteau, A; Caillon, H; Barrière, P; Denis, M G; Masson, D; Fréour, T
2016-04-01
Leptin, an adipose hormone, has been shown to control energy homeostasis and food intake, and exert many actions on female reproductive function. Consequently, this adipokine is a pivotal factor in studies conducted on animal models and humans to decipher the mechanisms behind the infertility often observed in obese women. A systematic PubMed search was conducted on all articles, published up to January 2015 and related to leptin and its actions on energy balance and reproduction, using the following key words: leptin, reproduction, infertility, IVF and controlled ovarian stimulation. The available literature was reviewed in order to provide an overview of the current knowledge on the physiological roles of leptin, its involvement in female reproductive function and its potential interest as a prognostic marker in IVF cycles. Animal and human studies show that leptin communicates nutritional status to the central nervous system and emerging evidence has demonstrated that leptin is involved in the control of reproductive functions by acting both directly on the ovaries and indirectly on the central nervous system. With respect to the clinical use of leptin as a biomarker in IVF cycles, a systematic review of the literature suggested its potential interest as a predictor of IVF outcome, as high serum and/or follicular fluid leptin concentrations have correlated negatively with cycle outcome. However, these preliminary results remain to be confirmed. Leptin regulates energy balance and female reproductive function, mainly through its action on hypothalamic-pituitary-ovarian function, whose molecular and cellular aspects are progressively being deciphered. Preliminary studies evaluating leptin as a biomarker in human IVF seem promising but need further confirmation. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Reproductive toxicity: Male and female reproductive systems as targets for chemical injury
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mattison, D.R.; Plowchalk, D.R.; Meadows, M.J.
On the basis of current knowledge of reproductive biology and toxicology, it is apparent that chemicals affecting reproduction may elicit their effects at a number of sites in both the male and the female reproductive system. This multiplicity of targets is attributable to the dynamic nature of the reproductive system, in which the hypothalamic-pituitary-gonadal axis is controlled by precise positive and negative feedback mechanisms among its components. Interference by a xenobiotic at any level in either the male or the female reproductive system may ultimately impair hypothalamic or pituitary function. Normal gonadal processes such as spermatogenesis or oogenesis, ejaculation ormore » ovulation, hormone production by Leydig or granulosa cells, and the structure or function of the accessory reproductive structures (e.g., epididymis, fallopian tube) also appear vulnerable to xenobiotics. The reproductive system is a complex one that requires local and circulating hormones for control. This brief review illustrates a system for characterizing the mechanism of action of reproductive toxicants, as well as for defining the sites available for disruption of reproduction. Unfortunately, at present, data addressing the actual vulnerability of reproduction are sorely lacking. However, when experiments have been conducted and combined with epidemiologic data or clinical observation, it has been possible to demonstrate impairment of reproductive processes by xenobiotics. The role of environmental exposure to xenobiotics in the increase in infertility that has been observed remains to be defined. 87 references.« less
Similar Gender Dimorphism in the Costs of Reproduction across the Geographic Range of Fraxinus ornus
Verdú, Miguel; Spanos, Kostas; čaňová, Ingrid; Slobodník, Branko; Paule, Ladislav
2007-01-01
Background and Aims The reproductive costs for individuals with the female function have been hypothesized to be greater than for those with the male function because the allocation unit per female flower is very high due to the necessity to nurture the embryos until seed dispersal occurs, while the male reproductive allocation per flower is lower because it finishes once pollen is shed. Consequently, males may invest more resources in growth than females. This prediction was tested across a wide geographical range in a tree with a dimorphic breeding system (Fraxinus ornus) consisting of males and hermaphrodites functioning as females. The contrasting ecological conditions found across the geographical range allowed the evaluation of the hypothesis that the reproductive costs of sexual dimorphism varies with environmental stressors. Methods By using random-effects meta-analysis, the differences in the reproductive and vegetative investment of male and hermaphrodite trees of F. ornus were analysed in 10 populations from the northern (Slovakia), south-eastern (Greece) and south-western (Spain) limits of its European distribution. The variation in gender-dimorphism with environmental stress was analysed by running a meta-regression between these effect sizes and the two environmental stress indicators: one related to temperature (the frost-free period) and another related to water availability (moisture deficit). Key Results Most of the effect sizes showed that males produced more flowers and grew more quickly than hermaphrodites. Gender differences in reproduction and growth were not minimized or maximized under adverse climatic conditions such as short frost-free periods or severe aridity. Conclusions The lower costs of reproduction for F. ornus males allow them to grow more quickly than hermaphrodites, although such differences in sex-specific reproductive costs are not magnified under stressful conditions. PMID:17098751
Effects of Parental Status on Male Body Mass in the Monogamous, Biparental California Mouse
Saltzman, Wendy; Harris, Breanna N.; de Jong, Trynke R.; Nguyen, Pauline P.; Cho, Julia T.; Hernandez, Mindy; Perea-Rodriguez, Juan P.
2014-01-01
Studies of biparental mammals demonstrate that males may undergo systematic changes in body mass as a consequence of changes in reproductive status; however, these studies typically have not teased apart effects of specific social and reproductive factors, such as cohabitation with a female per se, cohabitation with a breeding female specifically, and engagement in paternal care. We aimed to determine whether California mouse (Peromyscus californicus) fathers undergo systematic changes in body mass and if so, which specific social/reproductive factor(s) might contribute to these changes. We compared mean weekly body masses over a 5-week period in 1) males housed with another male vs. males housed with a non-reproductive (tubally ligated) female; 2) males housed with a tubally ligated female vs. males housed with a female that was undergoing her first pregnancy; and 3) experienced fathers housed with vs. without pups during their mate’s subsequent pregnancy. Body mass did not differ between males housed with another male and those housed with a non-reproductive female; however, males housed with a non-reproductive female were significantly heavier than those housed with a primiparous female. Among experienced fathers, those housed with pups from their previous litter underwent significant increases in body mass across their mates’ pregnancy, whereas fathers housed without pups did not. These results suggest that male body mass is reduced by cohabitation with a breeding (pregnant) female, but not by cohabitation with a non-reproductive female, and that increases in body mass across the mate’s pregnancy are associated with concurrent care of offspring rather than cohabitation with a pregnant female. Additional work is needed to determine the mechanisms and functional significance, if any, of these changes in male body mass with reproductive condition. PMID:26005292
Gap junction connexins in female reproductive organs: implications for women's reproductive health.
Winterhager, Elke; Kidder, Gerald M
2015-01-01
Connexins comprise a family of ~20 proteins that form intercellular membrane channels (gap junction channels) providing a direct route for metabolites and signalling molecules to pass between cells. This review provides a critical analysis of the evidence for essential roles of individual connexins in female reproductive function, highlighting implications for women's reproductive health. No systematic review has been carried out. Published literature from the past 35 years was surveyed for research related to connexin involvement in development and function of the female reproductive system. Because of the demonstrated utility of genetic manipulation for elucidating connexin functions in various organs, much of the cited information comes from research with genetically modified mice. In some cases, a distinction is drawn between connexin functions clearly related to the formation of gap junction channels and those possibly linked to non-channel roles. Based on work with mice, several connexins are known to be required for female reproductive functions. Loss of connexin43 (CX43) causes an oocyte deficiency, and follicles lacking or expressing less CX43 in granulosa cells exhibit reduced growth, impairing fertility. CX43 is also expressed in human cumulus cells and, in the context of IVF, has been correlated with pregnancy outcome, suggesting that this connexin may be a determinant of oocyte and embryo quality in women. Loss of CX37, which exclusively connects oocytes with granulosa cells in the mouse, caused oocytes to cease growing without acquiring meiotic competence. Blocking of CX26 channels in the uterine epithelium disrupted implantation whereas loss or reduction of CX43 expression in the uterine stroma impaired decidualization and vascularization in mouse and human. Several connexins are important in placentation and, in the human, CX43 is a key regulator of the fusogenic pathway from the cytotrophoblast to the syncytiotrophoblast, ensuring placental growth. CX40, which characterizes the extravillous trophoblast (EVT), supports proliferation of the proximal EVTs while preventing them from differentiating into the invasive pathway. Furthermore, women with recurrent early pregnancy loss as well as those with endometriosis exhibit reduced levels of CX43 in their decidua. The antimalaria drug mefloquine, which blocks gap junction function, is responsible for increased risk of early pregnancy loss and stillbirth, probably due to inhibition of intercellular communication in the decidua or between trophoblast layers followed by an impairment of placental growth. Gap junctions also play a critical role in regulating uterine blood flow, contributing to the adaptive response to pregnancy. Given that reproductive impairment can result from connexin mutations in mice, it is advised that women suffering from somatic disease symptoms associated with connexin gene mutations be additionally tested for impacts on reproductive function. Better knowledge of these essential connexin functions in human female reproductive organs is important for safeguarding women's reproductive health. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Smith, Adam R; Kapheim, Karen M; Pérez-Ortega, Betzi; Brent, Colin S; Wcislo, William T
2013-01-01
The evolution of eusociality is hypothesized to have involved de-coupling parental care from reproduction mediated by changes in endocrine regulation. While data for obligately eusocial insects are consistent with this hypothesis, we lack information from species representative of the transition from solitary reproduction to eusociality. Here we report the first evidence for a link between endocrine processes and social behavior in a facultatively eusocial bee, Megalopta genalis (Halictidae). Using females that varied in social, reproductive, and ecological context, we measured juvenile hormone (JH), a major regulator of colony caste dynamics in other eusocial species. JH was low at adult emergence, but elevated after 10 days in all nesting females. Females reared in cages with ad lib nutrition, however, did not elevate JH levels after 10 days. All reproductive females had significantly more JH than all age-matched non-reproductive females, suggesting a gonadotropic function. Among females in established nests, JH was higher in queens than workers and solitary reproductives, suggesting a role for JH in social dominance. A lack of significant differences in JH between solitary reproductives and non-reproductive workers suggests that JH content reflects more than reproductive status. Our data support the hypothesis that endocrine modifications are involved in the evolutionary decoupling of reproductive and somatic effort in social insects. These are the first measurements of JH in a solitary-nesting hymenopteran, and the first to compare eusocial and solitary nesting individuals of the same species. Published by Elsevier Inc.
GnRH in the Human Female Reproductive Axis.
Limonta, Patrizia; Marelli, Marina Montagnani; Moretti, Roberta; Marzagalli, Monica; Fontana, Fabrizio; Maggi, Roberto
2018-01-01
Gonadotropin-releasing hormone (GnRH) is recognized as the central regulator of the functions of the pituitary-gonadal axis. The increasing knowledge on the mechanisms controlling the development and the function of GnRH-producing neurons is leading to a better diagnostic and therapeutic approach for hypogonadotropic hypogonadisms and for alterations of the puberty onset. During female life span, the function of the GnRH pulse generator may be affected by a number of inputs from other neuronal systems, offering alternative strategies for diagnostic and therapeutic interventions. Moreover, the identification of a GnRH/GnRH receptor system in both human ovary and endometrium has widened the spectrum of action of the peptide outside its hypothalamic functions. The pharmacological use of GnRH itself or its synthetic analogs (agonists and antagonists) provides a valid tool to either stimulate or block gonadotropin secretion and to modulate the female fertility in several reproductive disorders and in assisted reproduction technology. The use of GnRH agonists in young female patients undergoing chemotherapy is also considered a promising therapeutic approach to counteract iatrogenic ovarian failure. © 2018 Elsevier Inc. All rights reserved.
Aubret, Fabien; Bonnet, Xavier; Shine, Richard; Lourdais, Olivier
2002-09-01
Reproduction is energetically expensive for both sexes, but the magnitude of expenditure and its relationship to reproductive success differ fundamentally between males and females. Males allocate relatively little to gamete production and, thus, can reproduce successfully with only minor energy investment. In contrast, females of many species experience high fecundity-independent costs of reproduction (such as migration to nesting sites), so they need to amass substantial energy reserves before initiating reproductive activity. Thus, we expect that the relationship between energy reserves and the intensity of reproductive behavior involves a threshold effect in females, but a gradual (or no) effect in males. We tested this prediction using captive vipers (Vipera aspis), dividing both males and females into groups of high versus low body condition. Snakes from each group were placed together and observed for reproductive behavior; sex-steroid levels were also measured. As predicted, females in below-average body condition had very low estradiol levels and did not show sexual receptivity, whereas males of all body condition indices had significant testosterone levels and displayed active courtship. Testosterone levels and courtship intensity increased gradually (i.e., no step function) with body condition in males, but high estradiol levels and sexual receptivity were seen only in females with body reserves above a critical threshold. Copyright 2002 Elsevier Science (USA)
Hussain, Mona A.; Abogresha, Noha M.; Tamany, Dalia A.; Lotfy, Mariam
2016-01-01
Introduction Globally, the prevalence of overweight and obesity is increasing, predisposing females to health hazards including compromised reproductive capacity. Our objective was to investigate the effect of ad libitum, isocalorically and hypocalorically restricted high-fat diet (HFD) feeding on reproductive function in diet-induced obese female rats. Material and methods Twenty female albino Sprague Dawley rats were used; 5 rats were kept on a standard pellet animal diet to serve as a control group (A) and 15 rats were fed a HFD for 9 weeks to induce obesity. The HFD fed animals were equally divided into three groups: an ad libitum HFD group (B), an isocalorically restricted HFD group (C), and a hypocalorically restricted HFD group (D). Estrous cyclicity, hormonal levels, ovarian histopathology and caspase-3 immunoreactivity were evaluated. Results The HFD-fed rats in groups B, C and D had significant irregularity in estrous cyclicity Vs group A (p = 0.001, 0.003 and 0.034 respectively). Groups C and D had significant reduction in serum progesterone level (p = 0.006 and 0.018 Vs A). Isocaloric restriction of HFD feeding significantly increased serum LH. Groups B and C had a significant increase in caspase-3 expression in the ovary (p < 0.001). Conclusions Ad libitum HFD interfered with the normal estrous cycle and enhanced apoptosis of luteal cells in obese female rats. The HFD restriction interfered with the normal estrous cycle and caused functional insufficiency of the corpus luteum in obese female rats. These results suggest that HFD feeding determinately affects female reproductive function independently of caloric intake. PMID:27478474
Impact of bariatric surgery on female reproduction.
Merhi, Zaher O
2009-11-01
To evaluate the current literature on the impact and potential mechanisms of surgical weight loss on female reproduction, with a focus on changes in reproductive hormone profile, fertility status, measures of ovarian reserve, efficacy of oral contraception, sexuality, and pregnancy. Appraisal of articles relevant to surgical weight loss and female reproduction. The altered reproductive hormone profile associated with morbid obesity seems to reverse, either partially or totally, after surgical weight loss. Although bariatric surgery seems to improve fertility status and many of the complications associated with obesity in pregnancy, it may be linked to oral contraceptive failure. Although müllerian-inhibiting substance is a direct measure of ovarian reserve, its level changes with obesity and after surgical weight loss. There is a decrease or no change in the risk of miscarriage after bariatric surgery. An improvement in sexual function may follow dramatic surgical weight reduction; however, the possibility of a detrimental influence afterward can occur. The increasing popularity of bariatric surgery in reproductive-age women calls for greater clinician awareness of its impact on female reproduction.
Steinberg, Rebecca M.; Walker, Deena M.; Juenger, Thomas E.; Woller, Michael J.; Gore, Andrea C.
2009-01-01
Perinatal exposures to endocrine-disrupting chemicals such as polychlorinated biphenyls (PCBs) can cause latent effects on reproductive function. Here, we tested whether PCBs administered during late pregnancy would compromise reproductive physiology in both the fetally-exposed female offspring (F1 generation), as well as in their female offspring (F2 generation). Pregnant Sprague-Dawley rats were treated with the PCB mixture Aroclor (A) 1221 (0, 0.1, 1 or 10 mg/kg) on embryonic days 16 and 18. Somatic and reproductive development of F1 and their F2 female offspring were monitored, including ages of eye opening, pubertal landmarks, and serum reproductive hormones. The results showed that low doses of A1221 given during this critical period of neuroendocrine development caused differential effects of A1221 on F1 and F2 female rats. In both generations, litter sex ratio was skewed towards females. In the F1 generation, additional effects were found including a significant alteration of serum luteinizing hormone (LH) in the 1 mg/kg A1221 group. The F2 generation showed more profound alterations, particularly with respect to fluctuations in hormones and reproductive tract tissues across the estrous cycle. On proestrus, the day of the preovulatory GnRH/gonadotropin surge, F2 females whose mothers had been perinatally exposed to A1221 exhibited substantially suppressed LH and progesterone concentrations, and correspondingly smaller uterine and ovarian weights on estrus, compared to F2 decendants of control rats. These latter changes suggest a dysregulation of reproductive physiology. Thus, low levels of exposure to PCBs during late fetal development cause significant consequences on the maturation and physiology of two generations of female offspring. These findings have implications for reproductive health and fertility of wildlife and humans. PMID:18305224
Minireview: Metabolism of Female Reproduction: Regulatory Mechanisms and Clinical Implications
Babayev, Elnur; Collins, Stephen C.; Nemeth, Gabor; Horvath, Tamas L.
2014-01-01
Female fertility is highly dependent on successful regulation of energy metabolism. Central processes in the hypothalamus monitor the metabolic state of the organism and, together with metabolic hormones, drive the peripheral availability of energy for cellular functions. In the ovary, the oocyte and neighboring somatic cells of the follicle work in unison to achieve successful metabolism of carbohydrates, amino acids, and lipids. Metabolic disturbances such as anorexia nervosa, obesity, and diabetes mellitus have clinically important consequences on human reproduction. In this article, we review the metabolic determinants of female reproduction and their role in infertility. PMID:24678733
Minireview: Metabolism of female reproduction: regulatory mechanisms and clinical implications.
Seli, Emre; Babayev, Elnur; Collins, Stephen C; Nemeth, Gabor; Horvath, Tamas L
2014-06-01
Female fertility is highly dependent on successful regulation of energy metabolism. Central processes in the hypothalamus monitor the metabolic state of the organism and, together with metabolic hormones, drive the peripheral availability of energy for cellular functions. In the ovary, the oocyte and neighboring somatic cells of the follicle work in unison to achieve successful metabolism of carbohydrates, amino acids, and lipids. Metabolic disturbances such as anorexia nervosa, obesity, and diabetes mellitus have clinically important consequences on human reproduction. In this article, we review the metabolic determinants of female reproduction and their role in infertility.
Cherwin, Tamara S.; Plakke, Melissa S.; Hill, Jason; Small, Brandon S.; Goetz, Breanna J.; Wheat, Christopher W.; Morehouse, Nathan I.
2017-01-01
Male ejaculates are often structurally complex, and this complexity is likely to influence key reproductive interactions between males and females. However, despite its potential evolutionary significance, the molecular underpinnings of ejaculate structural complexity have received little empirical attention. To address this knowledge gap, we sought to understand the biochemical and functional properties of the structurally complex ejaculates of Pieris rapae butterflies. Males in this species produce large ejaculates called spermatophores composed of an outer envelope, an inner matrix, and a bolus of sperm. Females are thought to benefit from the nutrition contained in the soluble inner matrix through increases in longevity and fecundity. However, the indigestible outer envelope of the spermatophore delays female remating, allowing males to monopolize paternity for longer. Here, we show that these two nonsperm-containing spermatophore regions, the inner matrix and the outer envelope, differ in their protein composition and functional properties. We also reveal how these divergent protein mixtures are separately stored in the male reproductive tract and sequentially transferred to the female reproductive tract during spermatophore assembly. Intriguingly, we discovered large quantities of female-derived proteases in both spermatophore regions shortly after mating, which may contribute to spermatophore digestion and hence, female control over remating rate. Finally, we report evidence of past selection on these spermatophore proteins and female proteases, indicating a complex evolutionary history. Our findings illustrate how structural complexity of ejaculates may allow functionally and/or spatially associated suites of proteins to respond rapidly to divergent selective pressures, such as sexual conflict or reproductive cooperation. PMID:28630352
Russell, J E; Stouthamer, R
2011-01-01
Parthenogenesis-inducing (PI) Wolbachia belong to a class of intracellular symbionts that distort the offspring sex ratio of their hosts toward a female bias. In many PI Wolbachia-infected species sex ratio distortion has reached its ultimate expression-fixation of infection and all-female populations. This is only possible with thelytokous PI symbionts as they provide an alternative form of reproduction and remove the requirement for males and sexual reproduction. Many populations fixed for PI Wolbachia infection have lost the ability to reproduce sexually, even when cured of the infection. We examine one such population in the species Trichogramma pretiosum. Through a series of backcrossing experiments with an uninfected Trichogramma pretiosum population we were able to show that the genetic basis for the loss of female sexual function could be explained by a dominant nuclear effect. Male sexual function had not been completely lost, though some deterioration of male sexual function was also evident when males from the infected population (created through antibiotic curing of infected females) were mated to uninfected females. We discuss the dynamics of sex ratio selection in PI Wolbachia-infected populations and the evolution of non-fertilizing mutations. PMID:20442735
Russell, J E; Stouthamer, R
2011-01-01
Parthenogenesis-inducing (PI) Wolbachia belong to a class of intracellular symbionts that distort the offspring sex ratio of their hosts toward a female bias. In many PI Wolbachia-infected species sex ratio distortion has reached its ultimate expression-fixation of infection and all-female populations. This is only possible with thelytokous PI symbionts as they provide an alternative form of reproduction and remove the requirement for males and sexual reproduction. Many populations fixed for PI Wolbachia infection have lost the ability to reproduce sexually, even when cured of the infection. We examine one such population in the species Trichogramma pretiosum. Through a series of backcrossing experiments with an uninfected Trichogramma pretiosum population we were able to show that the genetic basis for the loss of female sexual function could be explained by a dominant nuclear effect. Male sexual function had not been completely lost, though some deterioration of male sexual function was also evident when males from the infected population (created through antibiotic curing of infected females) were mated to uninfected females. We discuss the dynamics of sex ratio selection in PI Wolbachia-infected populations and the evolution of non-fertilizing mutations.
Heifetz, Yael; Lindner, Moshe; Garini, Yuval; Wolfner, Mariana F
2014-03-31
Upon mating, regions of the female reproductive tract mature and alter their function [1-3], for example to facilitate storage of sperm or control the release of eggs [4-6]. The female's nervous system and neuromodulators play important roles in her responses to mating [7-13]. However, it is difficult to reconcile the reproductive tract's many changing but coordinated events with the small set of neuromodulators present [14-18]. We hypothesized that each part of the reproductive tract contains a characteristic combination of neuromodulators that confer unique identities on each region and that postmating changes in these combinations coordinate subsequent actions. We examined the presence, locations, and levels of neuromodulators and related molecules ("signaling molecules") in the reproductive tract of Drosophila melanogaster females before and after mating: the biogenic amine octopamine, which regulates ovulation rate in Drosophila and locusts [7, 14-20]; serotonin, which regulates muscle contraction in locust oviducts [21]; and the FMRF amide dromyosuppressin, which regulates contraction of Drosophila heart muscle [22] and may regulate muscle contractions in the reproductive tract, if it is expressed there. We find that separate aspects of mating (sperm, seminal proteins, and physical effects) independently modulate the release of signaling molecules. Each reproductive tract subregion displays a characteristic combination of signaling molecule release, resulting in a unique functional identity. These patterns, and thus functions, change reproducibly after mating. Thus, one event (mating) promotes new combinations of signaling molecules that endow different parts of the reproductive tract with unique temporal and spatial identities that facilitate many aspects of fertilization. Copyright © 2014 Elsevier Ltd. All rights reserved.
Koppik, Mareike; Fricke, Claudia
2017-12-01
Senescence is accompanied by loss of reproductive functions. Here, we studied reproductive ageing in Drosophila melanogaster males and asked whether the expected decline in male reproductive success is due to diminished functionality of the male accessory gland (AG). The male AG produces the majority of seminal fluid proteins (SFPs) transferred to the female at mating. SFPs induce female postmating changes and are key to male reproductive success. We measured age-dependent gene expression changes for five representative SFP genes in males from four different age groups ranging from 1 to 6 weeks after eclosion. Simultaneously, we also measured male reproductive success in postmating traits mediated by transfer of these five SFPs. We found a decreased in male SFP gene expression with advancing age and an accompanying decline in male postmating success. Hence, male reproductive senescence is associated with a decline in functionality of the male AG. While overall individual SFP genes decreased in expression, our results point towards the idea that the composition of an ejaculate might change with male age as the rate of change was variable for those five genes. © 2017 John Wiley & Sons Ltd.
Co-regulation of female sexual behavior and pregnancy induction: an exploratory synthesis.
Erskine, Mary S; Lehmann, Michael L; Cameron, Nicole M; Polston, Eva K
2004-08-31
This paper will review both new and old data that address the question of whether brain mechanisms involved in reproductive function act in a coordinated way to control female sexual behavior and the induction of pregnancy/pseudopregnancy (P/PSP) by vaginocervical stimulation. Although it is clear that female sexual behavior, including pacing behavior, is important for induction of P/PSP, there has been no concerted effort to examine whether or how common mechanisms may control both functions. Because initiation of P/PSP requires that the female receive vaginocervical stimulation, central mechanisms controlling P/PSP may be modulated by or interactive with those that control female sexual behavior. This paper presents a synthesis of the literature and recent data from our lab for the purpose of examining whether there are interactions between behavioral and neuroendocrine mechanisms which reciprocally influence both reproductive functions.
Role of pigment epithelium-derived factor in the reproductive system.
Chuderland, Dana; Ben-Ami, Ido; Bar-Joseph, Hadas; Shalgi, Ruth
2014-10-01
The physiological function of the female reproductive organs is hormonally controlled. In each cycle, the reproductive organs undergo tissue modifications that are accompanied by formation and destruction of blood vessels. Proper angiogenesis requires an accurate balance between stimulatory and inhibitory signals, provided by pro- and anti-angiogenic factors. As with many other tissues, vascular endothelial growth factor (VEGF) appears to be one of the major pro-angiogenic factors in the female reproductive organs. Pigment epithelium-derived factor (PEDF) is a non-inhibitory member of the serine protease inhibitors (serpin) superfamily, possessing potent physiologic anti-angiogenic activity that negates VEGF activity. The role of PEDF in decreasing abnormal neovascularization by exerting its anti-angiogenic effect that inhibits pro-angiogenic factors, including VEGF, has been investigated mainly in the eye and in cancer. This review summarizes the function of PEDF in the reproductive system, showing its hormonal regulation and its anti-angiogenic activity. Furthermore, some pathologies of the female reproductive organs, including endometriosis, ovarian hyperstimulation syndrome, polycystic ovary syndrome, and others, are associated with a faulty angiogenic process. This review illuminates the role of PEDF in their pathogenesis and treatment. Collectively, we can conclude that although PEDF seems to play an essential role in the physiology and pathophysiology of the reproductive system, its full role and mechanism of action still need to be elucidated. © 2014 Society for Reproduction and Fertility.
Design: Reviewed articles indexed in PubMed from 1999-2007 addressing environment and puberty, menstrual and ovarian function, fertility, and menopause. Results: The strongest evidence of environmental contaminant exposures interfering with healthy reproductive function in adu...
Chelini, Marie Odile Monier; Palme, Rupert; Otta, Emma
2011-10-24
In many mammal species, reproduction is not shared equally among the members of a social unit. Even though reproductive skew seems unlikely in females of solitary species, this phenomenon could result from environmental factors. Although solitary in the wild, captive Syrian hamsters (Mesocricetus auratus) are generally housed in groups. We investigated whether social stress produces some degree of reproductive skew in this solitary species and whether female reproductive success varies as a function of social rank. To assess the physiological relationship between social stress and fertility, we monitored reproductive hormones and glucocorticoids of solitary and pair-housed females during pregnancy by means of recently established non-invasive methods for measuring hormone metabolites in the feces. The patterns of fecal progesterone, estrogen and glucocorticoid metabolites were similar to those found in blood and reported in the literature for pregnant hamsters. As expected, dominant females had higher breeding success than subordinate females. However the rate of reproductive failure was also very high among the singly housed females of our control group. The number of pups per litter, the average sex-ratio in each group, and the mean weight of pups did not differ significantly among groups. Glucocorticoid concentrations were unaffected by housing and social rank and the few differences between the endocrine profiles of singly- and pair-housed females are not sufficient to explain the observed difference in breeding success. It is likely that social isolation impairs reproduction in the same manner as subordination. Our findings suggest that social isolation of animals accustomed to group living was equally as disturbing as cohabitation with an unknown conspecific. Copyright © 2011 Elsevier Inc. All rights reserved.
Lutterschmidt, William I; Lutterschmidt, Deborah I; Mason, Robert T; Reinert, Howard K
2009-08-01
Data addressing adrenocortical modulation across taxonomic groups are limited, especially with regard to how female reproductive condition influences the sensitivity of the hypothalamus-pituitary-adrenal axis. We investigated seasonal and reproductive variation in basal and stress-induced hormone profiles in a population of free-ranging timber rattlesnakes (Crotalus horridus) in north-central Pennsylvania during spring (i.e., May), summer (i.e., July), and early fall (i.e., September). Baseline corticosterone concentrations varied seasonally and were significantly lower during the summer sampling period in July. We observed a significant negative relationship between baseline corticosterone and testosterone in male snakes, while baseline corticosterone and estradiol tended to be positively correlated in females. Treatment of snakes with 1 h of capture stress significantly increased corticosterone across all seasons. However, there was a significant interaction between corticosterone responses to capture stress and season, suggesting that adrenocortical function is modulated seasonally. Because elevated corticosterone may be associated with reproduction, we asked whether hormonal stress responses vary with female reproductive condition. Although sample sizes are low, reproductive snakes had significantly higher baseline and stress-induced corticosterone concentrations than non-reproductive or post-parturient females. Further, despite similar baseline corticosterone concentrations between non-reproductive and post-parturient rattlesnakes, post-parturient females responded to capture stress with a significantly higher increase in corticosterone. Collectively, these data suggest that the sensitivity of the hypothalamus-pituitary-adrenal axis varies both seasonally and with changing reproductive states.
Flores, Heather A.; Bubnell, Jaclyn E.; Aquadro, Charles F.; Barbash, Daniel A.
2015-01-01
Many reproductive proteins from diverse taxa evolve rapidly and adaptively. These proteins are typically involved in late stages of reproduction such as sperm development and fertilization, and are more often functional in males than females. Surprisingly, many germline stem cell (GSC) regulatory genes, which are essential for the earliest stages of reproduction, also evolve adaptively in Drosophila. One example is the bag of marbles (bam) gene, which is required for GSC differentiation and germline cyst development in females and for regulating mitotic divisions and entry to spermatocyte differentiation in males. Here we show that the extensive divergence of bam between Drosophila melanogaster and D. simulans affects bam function in females but has no apparent effect in males. We further find that infection with Wolbachia pipientis, an endosymbiotic bacterium that can affect host reproduction through various mechanisms, partially suppresses female sterility caused by bam mutations in D. melanogaster and interacts differentially with bam orthologs from D. melanogaster and D. simulans. We propose that the adaptive evolution of bam has been driven at least in part by the long-term interactions between Drosophila species and Wolbachia. More generally, we suggest that microbial infections of the germline may explain the unexpected pattern of evolution of several GSC regulatory genes. PMID:26291077
NASA Astrophysics Data System (ADS)
Briones-Fourzán, Patricia; Barradas-Ortíz, Cecilia; Negrete-Soto, Fernando; Lozano-Álvarez, Enrique
2010-08-01
Heterocarpus ensifer is a tropical deep-water pandalid shrimp whose reproductive features are poorly known. We examined reproductive traits of a population of H. ensifer inhabiting the continental slope (311-715 m in depth) off the Yucatan Peninsula, Mexico (SW Gulf of Mexico). Size range of the total sample ( n=816) was 10.4-38.9 mm carapace length. Females grow larger than males, but both sexes mature at 57% of their maximum theoretical size and at ˜30% of their total lifespan. Among adult females, the proportion of ovigerous females was high in all seasons, indicating year-round reproduction. Most females carrying embryos in advanced stages of development had ovaries in advanced stages of maturation, indicating production of successive spawns. In the autumn, however, the proportion of ovigerous females and the condition index of these females were lower compared to other seasons. This pattern potentially reflects a reduction in food resources following the summer minimum in particulate organic carbon flux to the deep benthos, as reported in previous studies. Spawns consisting of large numbers (16024±5644, mean±SD) of small eggs (0.045±0.009 mm 3) are consistent with extended planktotrophic larval development, an uncommon feature in deep-water carideans. Egg number increased as a power function of female size but with substantial variability, and egg size varied widely within and between females. There was no apparent trade-off between egg number and egg size and neither of these two variables was influenced by female condition. These results indicate iteroparity and a high and variable reproductive effort, reflecting a reproductive strategy developed to compensate for high larval mortality. The present study provides a baseline to compare reproductive traits between Atlantic populations of this tropical deep-water pandalid.
Evidence for bisphenol A-induced female infertility - Review (2007–2016)
Ziv-Gal, Ayelet; Flaws, Jodi A.
2016-01-01
We summarized the scientific literature published from 2007 to 2016 on the potential effects of bisphenol A (BPA) on female fertility. We focused on overall fertility outcomes (e.g., ability to become pregnant, number of offspring), organs that are important for female reproduction (i.e., oviduct, uterus, ovary, hypothalamus, and pituitary), and reproductive related processes (i.e., estrous cyclicity, implantation, and hormonal secretion). The reviewed literature indicates that BPA may be associated with infertility in women. Potential explanations for this association can be generated from experimental studies. Specifically, BPA may alter overall female reproductive capacity by affecting the morphology and function of the oviduct, uterus, ovary, and hypothalamus-pituitary-ovarian axis in animal models. Additionally, BPA may disrupt estrous cyclicity and implantation. Nevertheless, further studies are needed to better understand the exact mechanisms of action and to detect potential reproductive toxicity at earlier stages. PMID:27417731
Two-generation reproductive toxicity study of tributyltin chloride in female rats.
Ogata, R; Omura, M; Shimasaki, Y; Kubo, K; Oshima, Y; Aou, S; Inoue, N
2001-05-25
A two-generation reproductive toxicity study of the effects of tributyltin chloride (TBTCl) was conducted in female rats using dietary concentrations of 5, 25, and 125 ppm TBTCl. Reproductive outcomes of dams (number and body weight of pups and the percentage of live pups) and the growth of female pups (the day of eye opening and body weight gain) were significantly decreased in the 125 ppm TBTCl group. A delay in vaginal opening and impaired estrous cyclicity were also observed in the 125 ppm TBTCl group. However, an increase in anogenital distance was found in all TBTCl groups on postnatal d 1. A dose-effect relationship was observed in TBTCl-induced changes in anogenital distance. These results indicate that the whole-life exposure to TBTCl affects the sexual development and reproductive function of female rats. In addition, the TBTCl-induced increase in anogenital distance seems to suggest it may exert a masculinizing effect on female neonates. However, the concentrations of TBTCl used in this study are not environmentally relevant.
Avila, Frank W; Cohen, Allie B; Ameerudeen, Fatima S; Duneau, David; Suresh, Shruthi; Mattei, Alexandra L; Wolfner, Mariana F
2015-08-01
Within the mated reproductive tracts of females of many taxa, seminal fluid proteins (SFPs) coagulate into a structure known as the mating plug (MP). MPs have diverse roles, including preventing female remating, altering female receptivity postmating, and being necessary for mated females to successfully store sperm. The Drosophila melanogaster MP, which is maintained in the mated female for several hours postmating, is comprised of a posterior MP (PMP) that forms quickly after mating begins and an anterior MP (AMP) that forms later. The PMP is composed of seminal proteins from the ejaculatory bulb (EB) of the male reproductive tract. To examine the role of the PMP protein PEBme in D. melanogaster reproduction, we identified an EB GAL4 driver and used it to target PEBme for RNA interference (RNAi) knockdown. PEBme knockdown in males compromised PMP coagulation in their mates and resulted in a significant reduction in female fertility, adversely affecting postmating uterine conformation, sperm storage, mating refractoriness, egg laying, and progeny generation. These defects resulted from the inability of females to retain the ejaculate in their reproductive tracts after mating. The uncoagulated MP impaired uncoupling by the knockdown male, and when he ultimately uncoupled, the ejaculate was often pulled out of the female. Thus, PEBme and MP coagulation are required for optimal fertility in D. melanogaster. Given the importance of the PMP for fertility, we identified additional MP proteins by mass spectrometry and found fertility functions for two of them. Our results highlight the importance of the MP and the proteins that comprise it in reproduction and suggest that in Drosophila the PMP is required to retain the ejaculate within the female reproductive tract, ensuring the storage of sperm by mated females. Copyright © 2015 by the Genetics Society of America.
Dynamic digestive physiology of a female reproductive organ in a polyandrous butterfly
Plakke, Melissa S.; Deutsch, Aaron B.; Meslin, Camille; Clark, Nathan L.; Morehouse, Nathan I.
2015-01-01
ABSTRACT Reproductive traits experience high levels of selection because of their direct ties to fitness, often resulting in rapid adaptive evolution. Much of the work in this area has focused on male reproductive traits. However, a more comprehensive understanding of female reproductive adaptations and their relationship to male characters is crucial to uncover the relative roles of sexual cooperation and conflict in driving co-evolutionary dynamics between the sexes. We focus on the physiology of a complex female reproductive adaptation in butterflies and moths: a stomach-like organ in the female reproductive tract called the bursa copulatrix that digests the male ejaculate (spermatophore). Little is known about how the bursa digests the spermatophore. We characterized bursa proteolytic capacity in relation to female state in the polyandrous butterfly Pieris rapae. We found that the virgin bursa exhibits extremely high levels of proteolytic activity. Furthermore, in virgin females, bursal proteolytic capacity increases with time since eclosion and ambient temperature, but is not sensitive to the pre-mating social environment. Post copulation, bursal proteolytic activity decreases rapidly before rebounding toward the end of a mating cycle, suggesting active female regulation of proteolysis and/or potential quenching of proteolysis by male ejaculate constituents. Using transcriptomic and proteomic approaches, we report identities for nine proteases actively transcribed by bursal tissue and/or expressed in the bursal lumen that may contribute to observed bursal proteolysis. We discuss how these dynamic physiological characteristics may function as female adaptations resulting from sexual conflict over female remating rate in this polyandrous butterfly. PMID:25994634
Bisphenol-A and Female Infertility: A Possible Role of Gene-Environment Interactions
Huo, Xiaona; Chen, Dan; He, Yonghua; Zhu, Wenting; Zhou, Wei; Zhang, Jun
2015-01-01
Background: Bisphenol-A (BPA) is widely used and ubiquitous in the environment. Animal studies indicate that BPA affects reproduction, however, the gene-environment interaction mechanism(s) involved in this association remains unclear. We performed a literature review to summarize the evidence on this topic. Methods: A comprehensive search was conducted in PubMed using as keywords BPA, gene, infertility and female reproduction. Full-text articles in both human and animals published in English prior to December 2014 were selected. Results: Evidence shows that BPA can interfere with endocrine function of hypothalamic-pituitary axis, such as by changing gonadotropin-releasing hormones (GnRH) secretion in hypothalamus and promoting pituitary proliferation. Such actions affect puberty, ovulation and may even result in infertility. Ovary, uterus and other reproductive organs are also targets of BPA. BPA exposure impairs the structure and functions of female reproductive system in different times of life cycle and may contribute to infertility. Both epidemiological and experimental evidences demonstrate that BPA affects reproduction-related gene expression and epigenetic modification that are closely associated with infertility. The detrimental effects on reproduction may be lifelong and transgenerational. Conclusions: Evidence on gene-environment interactions, especially from human studies, is still limited. Further research on this topic is warranted. PMID:26371021
EFFECTS OF METAM SODIUM ON REPRODUCTIVE FUNCTION IN THE FEMALE RAT
Metam sodium (MS) is a soil fumigant and Category III pesticide with a relatively low toxicity in mammals. But, there is some indication that it can impair rodent reproductive function. In ovariectomized, estradiol-primed rats, a single ip injection was reported to block the lute...
Pocar, Paola; Fiandanese, Nadia; Berrini, Anna; Secchi, Camillo; Borromeo, Vitaliano
2017-05-01
Endocrine disruptors (EDs) are compounds known to promote transgenerational inheritance of adult-onset disease in subsequent generations after maternal exposure during fetal gonadal development. This study was designed to establish whether gestational and lactational exposure to the plasticizer di(2-ethylhexyl)phthalate (DEHP) at environmental doses promotes transgenerational effects on reproductive health in female offspring, as adults, over three generations in the mouse. Gestating F0 mouse dams were exposed to 0, 0.05, 5mg/kg/day DEHP in the diet from gestational day 0.5 until the end of lactation. The incidence of adult-onset disease in reproductive function was recorded in F1, F2 and F3 female offspring. In adult F1 females, DEHP exposure induced reproductive adverse effects with: i) altered ovarian follicular dynamics with reduced primordial follicular reserve and a larger growing pre-antral follicle population, suggesting accelerated follicular recruitment; ii) reduced oocyte quality and embryonic developmental competence; iii) dysregulation of the expression profile of a panel of selected ovarian and pre-implantation embryonic genes. F2 and F3 female offspring displayed the same altered reproductive morphological phenotype and gene expression profiles as F1, thus showing transgenerational transmission of reproductive adverse effects along the female lineage. These findings indicate that in mice exposure to DEHP at doses relevant to human exposure during gonadal sex determination significantly perturbs the reproductive indices of female adult offspring and subsequent generations. Evidence of transgenerational transmission has important implications for the reproductive health and fertility of animals and humans, significantly increasing the potential biohazards of this toxicant. Copyright © 2017 Elsevier Inc. All rights reserved.
Female bonobos use copulation calls as social signals
Clay, Zanna; Pika, Simone; Gruber, Thibaud; Zuberbühler, Klaus
2011-01-01
During mating events, females of many primate species produce loud and distinct vocalizations known as ‘copulation calls’. The adaptive significance of these signals is considered to be in promoting the caller's direct reproductive success. Here, we investigated copulation calling in bonobos (Pan paniscus), a species in which females produce these vocalizations during sexual interactions with partners of both sexes. Females were more likely to call when mating with males than with females. We also observed a positive relationship between the likelihood of calling and partner rank, regardless of partner sex. Sexual activity generally increased with swelling size (an indicator of reproductive state) and, during their peak swelling, females called more with male than with female partners. Female bonobos are unusual among the non-human primates in terms of their heightened socio-sexuality. Our results suggest that in this species, copulation calls have undergone an evolutionary transition from a purely reproductive to a more general social function, reflecting the intrinsic evolutionary links between vocal behaviour and social cognition. PMID:21325305
Farnesoid X receptor immunolocalization in reproductive tissues of adult female rabbits.
Anaya-Hernández, Arely; Méndez-Tepepa, Maribel; Hernández-Aragón, Laura G; Pacheco, Pablo; Martínez-Gómez, Margarita; Castelán, Francisco; Cuevas, Estela
2014-07-01
Farnesoid X receptor (FXR) has been involved in lipid metabolism, cell proliferation, apoptosis, and aromatase expression, as well as in the steroid synthesis and signaling. Considering that these events occur in reproductive tissues in females, the aim of the present study was to determine the immunolocalization of FXR in the ovary, oviduct, uterus, and vagina of rabbits. Rabbits were sacrificed and their reproductive tissues were excised and histologically processed. Immunohistochemistry for FXR was done and reproductive tissues were photographed. FXR immunoreactivity was found in all types of ovarian follicles, ovarian stroma, and corpus luteum of virgin and pregnant rabbits. Also, oviductal and vaginal epithelium of virgins, as well as the oviductal smooth muscle, showed anti-FXR immunoreactivity. The uterine epithelium and musculature of virgins had scarce anti-FXR immunoreactivity. Although the role of FXR in female reproductive tissues is still not known, it is possible to consider various functions related to the reproductive tissue. Copyright © 2014 Elsevier GmbH. All rights reserved.
Laghezza Masci, Valentina; Di Luca, Marco; Gambellini, Gabriella; Taddei, Anna Rita; Belardinelli, Maria Cristina; Guerra, Laura; Mazzini, Massimo; Fausto, Anna Maria
2015-07-01
The morphology and ultrastructure of female accessory reproductive glands of Anopheles maculipennis s.s., Anopheles labranchiae and Anopheles stephensi were investigated by light and electron microscopy. The reproductive system in these species is characterized by two ovaries, two lateral oviducts, a single spermatheca and a single accessory gland. The gland is globular and has a thin duct which empties into the vagina, near the opening of the spermathecal duct. Significant growth of the accessory reproductive gland is observed immediately after blood meal, but not at subsequent digestion steps. At ultrastructural level, the gland consists of functional glandular units belonging to type 3 ectodermal glands. The secretory cells are elongated and goblet shaped, with most of their cytoplasm and large nucleus in the basal part, close to the basement lamella. Finely fibrous electron-transparent material occupies the secretory cavity that is in contact with the end of a short efferent duct (ductule) emerging from the gland duct. The present study is the first detailed description of female accessory gland ultrastructure in Anophelinae and provides insights into the gland's functional role in the reproductive biology of these insects. Copyright © 2015 Elsevier Ltd. All rights reserved.
Montesinos, D; Villar-Salvador, P; García-Fayos, P; Verdú, M
2012-02-01
• Differences in reproductive investment can trigger asymmetric, context-dependent, functional strategies between genders in dioecious species. However, little is known about the gender responses of dioecious species to nutrient availability. • We experimentally fertirrigated a set of male and female Juniperus thurifera trees monthly for 2 yr. Water potential, photosynthesis rate and stomatal conductance were measured monthly for 2 yr, while shoot nitrogen (N) concentration, carbon isotopic composition (δ(13) C), branch growth, trunk radial growth and reproductive investment per branch were measured yearly. • Control males had lower gas exchange rates and radial growth but greater reproductive investment and higher water use efficiency (WUE; as inferred from more positive δ(13) C values) than females. Fertirrigation did not affect water potential or WUE but genders responded differently to increased nutrient availability. The two genders similarly increased shoot N concentration when fertilized. The increase in shoot N was associated with increased photosynthesis in males but not in females, which presented consistently high photosynthetic rates across treatments. • Our results suggest that genders invest N surplus in different functions, with females presenting a long-term strategy by increasing N storage to compensate for massive reproductive masting events, while males seem to be more reactive to current nutrient availability, promoting gas-exchange capacity. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.
Ganmaa, Davaasambuu; Qin, Li-Qiang; Wang, Pei-Yu; Tezuka, Hideo; Teramoto, Shoji; Sato, Akio
2004-10-01
To examine whether the considerable quantities of increased female sex hormone levels found in modern milk as a result of modern dairy farming practices are safe for human consumption. Males and females of the P generation were maintained on a diet containing milk for 10 weeks before mating. Exposure to milk was continued up to the end of weaning of the F2b offspring. Two-generation reproduction study. Male and female Wistar Galas rats. P- and F1-generation rats were mated. Fertility, fecundity, and morphology and function of reproductive organs. Although milk had growth-promoting effects in both parents and offspring, it caused no impairments in fertility, fecundity, or reproductive organ development in either generation. However, a whole litter from a dam of the P generation was born dead, three litters in total had a pup with skeletal abnormalities, and the AGD of F2a female pups was reduced. These events occurred only in the milk-treated rats. It is unknown whether these issues had any relevance to milk or only happened by chance. Further study is required to determine whether milk from pregnant cows is completely free from adverse effects on reproductive health.
ESPÍRITO‐SANTO, M. M.; MADEIRA, B. G.; NEVES, F. S.; FARIA, M. L.; FAGUNDES, M.; FERNANDES, G. WILSON
2003-01-01
Patterns of phenological variation and reproductive investment were studied in the dioecious shrub Baccharis dracunculifolia DC (Asteraceae), and possible consequences on survivorship were evaluated. The sex ratio was determined in a natural field population (n = 921) of B. dracunculifolia in Belo Horizonte, Brazil. Fifty‐two males and 56 females were sampled at random from this population. During the reproductive season of 1999, inflorescence production, shoot growth and mortality, and xylem water potential were recorded for each individual. The population sex ratio was male‐biased (1·27 : 1, P < 0·05), and was associated with a higher mortality of female shoots (38·4 vs. 23·1 %, P < 0·05), and individuals (17·8 vs. 11·5 %, P < 0·1), despite lower water stress in female plants. Flowering phenology also differed between the sexes, with males producing more inflorescences, and earlier, than females. Owing to fruit maturation, the number of inflorescences supported by females was higher than that supported by males later in the reproductive season. This occurred during the dry season, and drought stress may have been responsible for the greater female mortality. Thus, the male‐biased sex ratio in this population of B. dracunculifolia is probably due to different reproductive functions of males and females. Intersexual differences in reproductive phenology had consequences for plant demography. PMID:12495915
A Physiological Signature of the Cost of Reproduction Associated with Parental Care.
Fowler, Melinda A; Williams, Tony D
2017-12-01
Costs of reproduction are an integral and long-standing component of life-history theory, but we still know relatively little about the specific physiological mechanisms underlying these trade-offs. We experimentally manipulated workload during parental care in female European starlings (Sturnus vulgaris) using attachment of radios and/or wing clipping and assessed measures of workload, current breeding productivity, future fecundity, and survival (local return rate) in relation to treatment. Females with wing clipping and radio attachment paid a clear cost of reproduction compared with all other treatment groups: they had lower future fecundity and lower return rates despite having lower current breeding productivity. We then measured 13 physiological traits, including measures of aerobic/metabolic capacity, oxidative stress and muscle damage, intermediary metabolism and energy supply, and immune function. Our results show that the cost of reproduction in females with wing clipping and radio attachment was associated with lower oxygen-carrying capacity (lower hematocrit and hemoglobin levels), lower energy reserves (plasma nonesterified fatty acid and triglyceride levels), decreased immune function (lower haptoglobin levels), and elevated levels of oxidative stress (higher levels of dROMs [reactive oxygen metabolites] and lower levels of the endogenous antioxidant uric acid). Our study provides evidence that costs of reproduction involve a widespread decline in physiological function across multiple physiological systems consistent with long-standing ideas of cumulative "wear and tear" and allostatic load.
Age-dependent trade-offs between immunity and male, but not female, reproduction.
McNamara, Kathryn B; van Lieshout, Emile; Jones, Therésa M; Simmons, Leigh W
2013-01-01
Immune function is costly and must be traded off against other life-history traits, such as gamete production. Studies of immune trade-offs typically focus on adult individuals, yet the juvenile stage can be a highly protracted period when reproductive resources are acquired and immune challenges are ubiquitous. Trade-offs during development are likely to be important, yet no studies have considered changes in adult responses to immune challenges imposed at different stages of juvenile development. By manipulating the timing of a bacterial immune challenge to the larvae of the cotton bollworm moth, we examined potential trade-offs between investment into immunity at different stages of juvenile development (early or late) and subsequent adult reproductive investment into sperm or egg production. Our data reveal an age-dependent trade-off between juvenile immune function and adult male reproductive investment. Activation of the immune response during late development resulted in a reduced allocation of resources to eupyrene (fertilizing) sperm production. Immune activation from the injection procedure itself (irrespective of whether individuals were injected with an immune elicitor or a control solution) also caused reproductive trade-offs; males injected early in development produced fewer apyrene (nonfertilizing) sperm. Contrary to many other studies, our study demonstrates these immune trade-offs under ad libitum nutritional conditions. No trade-offs were observed between female immune activation and adult reproductive investment. We suggest the differences in trade-offs observed between male sperm types and the absence of reproductive trade-offs in females may be the result of ontogenetic differences in gamete production in this species. Our data reveal developmental windows when trade-offs between immune function and gametic investment are made, and highlight the importance of considering multiple developmental periods when making inferences regarding the fundamental trade-offs expected between immune function and reproduction. © 2012 The Authors. Journal of Animal Ecology © 2012 British Ecological Society.
Metzger, Monika L.; Meacham, Lillian R.; Patterson, Briana; Casillas, Jacqueline S.; Constine, Louis S.; Hijiya, Nobuko; Kenney, Lisa B.; Leonard, Marcia; Lockart, Barbara A.; Likes, Wendy; Green, Daniel M.
2013-01-01
Purpose As more young female patients with cancer survive their primary disease, concerns about reproductive health related to primary therapy gain relevance. Cancer therapy can often affect reproductive organs, leading to impaired pubertal development, hormonal regulation, fertility, and sexual function, affecting quality of life. Methods The Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancer (COG-LTFU Guidelines) are evidence-based recommendations for screening and management of late effects of therapeutic exposures. The guidelines are updated every 2 years by a multidisciplinary panel based on current literature review and expert consensus. Results This review summarizes the current task force recommendations for the assessment and management of female reproductive complications after treatment for childhood, adolescent, and young adult cancers. Experimental pretreatment as well as post-treatment fertility preservation strategies, including barriers and ethical considerations, which are not included in the COG-LTFU Guidelines, are also discussed. Conclusion Ongoing research will continue to inform COG-LTFU Guideline recommendations for follow-up care of female survivors of childhood cancer to improve their health and quality of life. PMID:23382474
El-Kassaby, Yousry A; Funda, Tomas; Lai, Ben S K
2010-01-01
The impact of female reproductive success on the mating system, gene flow, and genetic diversity of the filial generation was studied using a random sample of 801 bulk seed from a 49-clone Pseudotsuga menziesii seed orchard. We used microsatellite DNA fingerprinting and pedigree reconstruction to assign each seed's maternal and paternal parents and directly estimated clonal reproductive success, selfing rate, and the proportion of seed sired by outside pollen sources. Unlike most family array mating system and gene flow studies conducted on natural and experimental populations, which used an equal number of seeds per maternal genotype and thus generating unbiased inferences only on male reproductive success, the random sample we used was a representative of the entire seed crop; therefore, provided a unique opportunity to draw unbiased inferences on both female and male reproductive success variation. Selfing rate and the number of seed sired by outside pollen sources were found to be a function of female fertility variation. This variation also substantially and negatively affected female effective population size. Additionally, the results provided convincing evidence that the use of clone size as a proxy to fertility is questionable and requires further consideration.
Al-Wathiqui, Nooria; Fallon, Timothy R; South, Adam; Weng, Jing-Ke; Lewis, Sara M
2016-12-22
Postcopulatory sexual selection is recognized as a key driver of reproductive trait evolution, including the machinery required to produce endogenous nuptial gifts. Despite the importance of such gifts, the molecular composition of the non-gametic components of male ejaculates and their interactions with female reproductive tracts remain poorly understood. During mating, male Photinus fireflies transfer to females a spermatophore gift manufactured by multiple reproductive glands. Here we combined transcriptomics of both male and female reproductive glands with proteomics and metabolomics to better understand the synthesis, composition and fate of the spermatophore in the common Eastern firefly, Photinus pyralis. Our transcriptome of male glands revealed up-regulation of proteases that may enhance male fertilization success and activate female immune response. Using bottom-up proteomics we identified 208 functionally annotated proteins that males transfer to the female in their spermatophore. Targeted metabolomic analysis also provided the first evidence that Photinus nuptial gifts contain lucibufagin, a firefly defensive toxin. The reproductive tracts of female fireflies showed increased gene expression for several proteases that may be involved in egg production. This study offers new insights into the molecular composition of male spermatophores, and extends our understanding of how nuptial gifts may mediate postcopulatory interactions between the sexes.
Scsukova, Sona; Rollerova, Eva; Bujnakova Mlynarcikova, Alzbeta
2016-12-01
A growing body of evidence suggests that exposure to chemical substances designated as endocrine disrupting chemicals (EDCs) due to their ability to disturb endocrine (hormonal) activity in humans and animals, may contribute to problems with fertility, pregnancy, and other aspects of reproduction. The presence of EDCs has already been associated with reproductive malfunction in wildlife species, but it remains difficult to prove causal relationships between the presence of EDCs and specific reproductive problems in vivo, especially in females. On the other hand, the increasing number of experiments with laboratory animals and in vitro research indicate the ability of different EDCs to influence the normal function of female reproductive system, and even their association with cancer development or progression. Research shows that EDCs may pose the greatest risk during prenatal and early postnatal development when organ and neural systems are forming. In this review article, we aim to point out a possible contribution of EDCs to the onset and development of female reproductive disorders and endocrine-related cancers with regard to the period of exposure to EDCs and affected endpoints (organs or processes). Copyright © 2016. Published by Elsevier Urban & Partner Sp. z o.o.
EFFECTS OF 3 WEEK EXPOSURES TO METAM SODIUM ON REPRODUCTIVE FUNCTION IN THE FEMALE RAT
Metam sodium (MS) is a soil fumigant and Category III pesticide with a relatively low toxicity in mammals. But, there is some indication that it can impair rodent reproductive function. In ovariectomized, estradiol-primed rats, a single ip injection was reported to block the lute...
EFFECTS OF 3 WEEK EXPOSURES ON REPRODUCTIVE FUNCTION IN THE FEMALE RAT TO METAM SODIUM
Metam sodium (MS) is a soil fumigant and Category III pesticide with a relatively low toxicity in mammals. But, there is some indication that it can impair rodent reproductive function. In ovariectomized, estradiol-primed rats, a single ip injection was reported to block the lute...
NASA Astrophysics Data System (ADS)
Tang, Jing-Yu; Ren, Ming-Xun
2011-09-01
Intra-inflorescence variation in floral traits is important to understand the pollination function of an inflorescence and the real reproductive outputs of a plant. Ruta graveolens (Rutaceae) produce both quaternary (four petals and eight stamens) and quinary (five petals and ten stamens) flowers on the same cymes, while their pollination roles and the effects on the reproductive success remained unexplored. We experimentally examined the biomass of female versus male organs and pollen viability and stigma receptivity to explore the sex allocation patterns between the flowers. The breeding systems and reproductive outputs through either female function (seed set) or male function (pollen dispersal) were also studied for quinary and quaternary flowers to determine whether there was functional bias. The results showed that R. graveolens was protandrous, with a mixed mating system. Its stamens could slowly move one by one and only dehisce when positioning at the flower center, which could greatly enhance pollen dispersal. The first-opened quinary flower allocated significantly higher resources (dry biomass) in female organs while quaternary flowers allocated more resource in male organs. The quaternary flowers experienced higher pollen limitation in seed production but were more successful in pollen dispersal and the quinary flowers reproduced both through female and male functions. Our data suggested that quinary and quaternary flower on same inflorescence in R. graveolens functioned mainly as the sex role that most resources were allocated, which probably reflect an adaptation for floral phenology and pollination process in this plant.
Townsend, Andrea K.; Clark, Anne B.; McGowan, Kevin J.; Lovette, Irby J.
2009-01-01
Understanding the benefits of cooperative breeding for group members of different social and demographic classes requires knowledge of their reproductive partitioning and genetic relatedness. From 2004-2007, we examined parentage as a function of relatedness and social interactions among members of 21 American crow (Corvus brachyrhynchos) family groups. Paired female breeders monopolized maternity of all offspring in their broods, whereas paired male breeders sired 82.7% of offspring, within-group auxiliary males sired 6.9% of offspring, and extragroup males sired 10.4% of offspring. Although adult females had fewer opportunities for direct reproduction as auxiliaries than males, they appeared to have earlier opportunities for independent breeding. These different opportunities for direct reproduction probably contributed to the male biased adult auxiliary sex ratio. Patterns of reproductive partitioning and conflict among males were most consistent with a synthetic reproductive skew model, in which auxiliaries struggled with breeders for a limited reproductive share, beyond which breeders could evict them. Counter to a frequent assumption of reproductive skew models, female breeders appeared to influence paternity, although their interests might have agreed with the interests of their paired males. Unusual among cooperative breeders, close inbreeding and incest occurred in this population. Incest avoidance between potential breeders did not significantly affect reproductive skew. PMID:20126287
Nazıroğlu, Mustafa; Yüksel, Murat; Köse, Seyit Ali; Özkaya, Mehmet Okan
2013-12-01
Environmental exposure to electromagnetic radiation (EMR) has been increasing with the increasing demand for communication devices. The aim of the study was to discuss the mechanisms and risk factors of EMR changes on reproductive functions and membrane oxidative biology in females and males. It was reported that even chronic exposure to EMR did not increase the risk of reproductive functions such as increased levels of neoantigens abort. However, the results of some studies indicate that EMR induced endometriosis and inflammation and decreased the number of follicles in the ovarium or uterus of rats. In studies with male rats, exposure caused degeneration in the seminiferous tubules, reduction in the number of Leydig cells and testosterone production as well as increases in luteinizing hormone levels and apoptotic cells. In some cases of male and female infertility, increased levels of oxidative stress and lipid peroxidation and decreased values of antioxidants such as melatonin, vitamin E and glutathione peroxidase were reported in animals exposed to EMR. In conclusion, the results of current studies indicate that oxidative stress from exposure to Wi-Fi and mobile phone-induced EMR is a significant mechanism affecting female and male reproductive systems. However, there is no evidence to this date to support an increased risk of female and male infertility related to EMR exposure.
Fetal programming of sexual development and reproductive function.
Zambrano, Elena; Guzmán, Carolina; Rodríguez-González, Guadalupe L; Durand-Carbajal, Marta; Nathanielsz, Peter W
2014-01-25
The recent growth of interest in developmental programming of physiological systems has generally focused on the cardiovascular system (especially hypertension) and predisposition to metabolic dysfunction (mainly obesity and diabetes). However, it is now clear that the full range of altered offspring phenotypes includes impaired reproductive function. In rats, sheep and nonhuman primates, reproductive capacity is altered by challenges experienced during critical periods of development. This review will examine available experimental evidence across commonly studied experimental species for developmental programming of female and male reproductive function throughout an individual's life-course. It is necessary to consider events that occur during fetal development, early neonatal life and prior to and during puberty, during active reproductive life and aging as reproductive performance declines. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
Lysophosphatidic Acid (LPA) Signaling in Human and Ruminant Reproductive Tract
Wocławek-Potocka, Izabela; Rawińska, Paulina; Kowalczyk-Zieba, Ilona; Boruszewska, Dorota; Sinderewicz, Emilia; Waśniewski, Tomasz; Skarzynski, Dariusz Jan
2014-01-01
Lysophosphatidic acid (LPA) through activating its G protein-coupled receptors (LPAR 1–6) exerts diverse cellular effects that in turn influence several physiological processes including reproductive function of the female. Studies in various species of animals and also in humans have identified important roles for the receptor-mediated LPA signaling in multiple aspects of human and animal reproductive tract function. These aspects range from ovarian and uterine function, estrous cycle regulation, early embryo development, embryo implantation, decidualization to pregnancy maintenance and parturition. LPA signaling can also have pathological consequences, influencing aspects of endometriosis and reproductive tissue associated tumors. The review describes recent progress in LPA signaling research relevant to human and ruminant reproduction, pointing at the cow as a relevant model to study LPA influence on the human reproductive performance. PMID:24744506
The effects of oxidative stress on female reproduction: a review
2012-01-01
Oxidative stress (OS), a state characterized by an imbalance between pro-oxidant molecules including reactive oxygen and nitrogen species, and antioxidant defenses, has been identified to play a key role in the pathogenesis of subfertility in both males and females. The adverse effects of OS on sperm quality and functions have been well documented. In females, on the other hand, the impact of OS on oocytes and reproductive functions remains unclear. This imbalance between pro-oxidants and antioxidants can lead to a number of reproductive diseases such as endometriosis, polycystic ovary syndrome (PCOS), and unexplained infertility. Pregnancy complications such as spontaneous abortion, recurrent pregnancy loss, and preeclampsia, can also develop in response to OS. Studies have shown that extremes of body weight and lifestyle factors such as cigarette smoking, alcohol use, and recreational drug use can promote excess free radical production, which could affect fertility. Exposures to environmental pollutants are of increasing concern, as they too have been found to trigger oxidative states, possibly contributing to female infertility. This article will review the currently available literature on the roles of reactive species and OS in both normal and abnormal reproductive physiological processes. Antioxidant supplementation may be effective in controlling the production of ROS and continues to be explored as a potential strategy to overcome reproductive disorders associated with infertility. However, investigations conducted to date have been through animal or in vitro studies, which have produced largely conflicting results. The impact of OS on assisted reproductive techniques (ART) will be addressed, in addition to the possible benefits of antioxidant supplementation of ART culture media to increase the likelihood for ART success. Future randomized controlled clinical trials on humans are necessary to elucidate the precise mechanisms through which OS affects female reproductive abilities, and will facilitate further explorations of the possible benefits of antioxidants to treat infertility. PMID:22748101
Mastronardi, Claudio; Smiley, Gregory G; Raber, Jacob; Kusakabe, Takashi; Kawaguchi, Akio; Matagne, Valerie; Dietzel, Anja; Heger, Sabine; Mungenast, Alison E; Cabrera, Ricardo; Kimura, Shioko; Ojeda, Sergio R
2006-12-20
Thyroid transcription factor 1 (TTF1) [also known as Nkx2.1 (related to the NK-2 class of homeobox genes) and T/ebp (thyroid-specific enhancer-binding protein)], a homeodomain gene required for basal forebrain morphogenesis, remains expressed in the hypothalamus after birth, suggesting a role in neuroendocrine function. Here, we show an involvement of TTF1 in the control of mammalian puberty and adult reproductive function. Gene expression profiling of the nonhuman primate hypothalamus revealed that TTF1 expression increases at puberty. Mice in which the Ttf1 gene was ablated from differentiated neurons grew normally and had normal basal ganglia/hypothalamic morphology but exhibited delayed puberty, reduced reproductive capacity, and a short reproductive span. These defects were associated with reduced hypothalamic expression of genes required for sexual development and deregulation of a gene involved in restraining puberty. No extrapyramidal impairments associated with basal ganglia dysfunction were apparent. Thus, although TTF1 appears to fulfill only a morphogenic function in the ventral telencephalon, once this function is satisfied in the hypothalamus, TTF1 remains active as part of the transcriptional machinery controlling female sexual development.
Gratao, Ana A; Dahlhoff, Maik; Sinowatz, Fred; Wolf, Eckhard; Schneider, Marlon R
2008-01-01
The epidermal growth factor receptor (EGFR) and its ligands are emerging as key molecules in regulating female reproduction. Here, we used a transgenic mouse model to evaluate whether and at which level of the reproduction cascade higher-than-normal levels of the EGFR ligand betacellulin (BTC) in the reproductive organs affect fertility. Western blots and immunohistochemistry revealed increased BTC levels in uterus and ovaries from transgenic females, particularly evident in granulosa cells of antral follicles. Onset of puberty, estrous cyclicity, and the anatomy and histology of reproductive organs at puberty were not altered as compared to control females. Fertility tests revealed a reduction (~50%) in litter size as the major reproductive deficit of transgenic females. Embryo implantation was delayed in transgenic females, but this was not the reason for the reduced litter size. Transgenic females produced a normal number of oocytes after natural ovulation. The in vivo fertilization rate was significantly reduced in untreated transgenic females but returned to normal levels after superovulation. Impaired oocyte fertilization in the absence of superovulation treatment was associated with MAPK3/MAPK1 hyperactivation in BTC transgenic ovaries, whereas similar levels of MAPK3/MAPK1 activation were detected in transgenic and control ovaries after superovulation treatment. Thus, tight regulation of MAPK3/MAPK1 activity appears to be essential for appropriate granulosa cell function during oocyte maturation. Our study identified hitherto unknown effects of BTC overabundance in reproduction and suggests BTC as a novel candidate protein for the modulation of fertility.
Thyroid hormones and female reproduction.
Silva, Juneo F; Ocarino, Natália M; Serakides, Rogéria
2018-05-14
Thyroid hormones are vital for the proper functioning of the female reproductive system, since they modulate the metabolism and development of ovarian, uterine and placental tissues. Therefore, hypo- and hyperthyroidism may result in subfertility or infertility in both women and animals. Other well-documented sequelae of maternal thyroid dysfunctions include menstrual/estral irregularity, anovulation, abortion, preterm delivery, preeclampsia, intrauterine growth restriction, postpartum thyroiditis, and mental retardation in children. Several studies have been carried out involving prospective and retrospective studies of women with thyroid dysfunction, as well as in vivo and in vitro assays of hypo- and hyperthyroidism using experimental animal models and/or ovarian, uterine and placental cell culture. These studies have sought to elucidate the mechanisms by which thyroid hormones influence reproduction to better understand the physiology of the reproductive system and to provide better therapeutic tools for reproductive dysfunctions that originate from thyroid dysfunctions. Therefore, this review aims to summarize and update the available information related to the role of thyroid hormones in the morphophysiology of the ovary, uterus and placenta in women and animals and the effects of hypo- and hyperthyroidism on the female reproductive system.
Obesity and reproductive function: a review of the evidence.
Klenov, Violet E; Jungheim, Emily S
2014-12-01
Over the last decade, the evidence linking obesity to impaired reproductive function has grown. In this article, we review this evidence and discuss the underlying pathophysiology. Obese women are less likely than normal-weight women to achieve pregnancy. Female obesity adversely affects reproductive function through alterations in the hypothalamic-pituitary-ovarian axis, oocyte quality, and endometrial receptivity. It is unclear which mechanism contributes the most to subfecundity, and it is likely a cumulative process. Emerging data highlight the contribution of male obesity to impaired reproductive function and that couple obesity has synergistic adverse effects. Once pregnant, obese women are at higher risk for adverse pregnancy outcomes. Weight loss improves reproductive potential in obese patients. As obese women surpass 35 years of age, age may be more important than body mass index in determining reproductive potential. Obstetrician gynecologists need to be aware of the negative impact of obesity on reproductive function so that they appropriately counsel their patients. Further work is needed to clarify the underlying pathophysiology responsible for adverse effects of obesity on reproduction so that novel treatment approaches may be developed.
Reproductive investment is connected to innate immunity in a long-lived animal.
Neggazi, Sara A; Noreikiene, Kristina; Öst, Markus; Jaatinen, Kim
2016-10-01
Life-history theory predicts that organisms optimize their resource allocation strategy to maximize lifetime reproductive success. Individuals can flexibly reallocate resources depending on their life-history stage, and environmental and physiological factors, which lead to variable life-history strategies even within species. Physiological trade-offs between immunity and reproduction are particularly relevant for long-lived species that need to balance current reproduction against future survival and reproduction, but their underlying mechanisms are poorly understood. A major unresolved issue is whether the first-line innate immune function is suppressed by reproductive investment. In this paper, we tested if reproductive investment is associated with the suppression of innate immunity, and how this potential trade-off is resolved depending on physiological state and residual reproductive value. We used long-lived capital-breeding female eiders (Somateria mollissima) as a model. We showed that the innate immune response, measured by plasma bacteria-killing capacity (BKC), was negatively associated with increasing reproductive investment, i.e., with increasing clutch size and advancing incubation stage. Females in a better physiological state, as indexed by low heterophil-to-lymphocyte (H/L) ratios, showed higher BKC during early incubation, but this capacity decreased as incubation progressed, whereas females in poorer state showed low BKC capacity throughout incubation. Although plasma BKC generally declined with increasing H/L ratios, this decrease was most pronounced in young females. Our results demonstrate that reproductive investment can suppress constitutive first-line immune defence in a long-lived bird, but the degree of immunosuppression depends on physiological state and age.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pocar, Paola, E-mail: paola.pocar@unimi.it; Fianda
Endocrine disruptors (EDs) are compounds known to promote transgenerational inheritance of adult-onset disease in subsequent generations after maternal exposure during fetal gonadal development. This study was designed to establish whether gestational and lactational exposure to the plasticizer di(2-ethylhexyl)phthalate (DEHP) at environmental doses promotes transgenerational effects on reproductive health in female offspring, as adults, over three generations in the mouse. Gestating F0 mouse dams were exposed to 0, 0.05, 5 mg/kg/day DEHP in the diet from gestational day 0.5 until the end of lactation. The incidence of adult-onset disease in reproductive function was recorded in F1, F2 and F3 female offspring.more » In adult F1 females, DEHP exposure induced reproductive adverse effects with: i) altered ovarian follicular dynamics with reduced primordial follicular reserve and a larger growing pre-antral follicle population, suggesting accelerated follicular recruitment; ii) reduced oocyte quality and embryonic developmental competence; iii) dysregulation of the expression profile of a panel of selected ovarian and pre-implantation embryonic genes. F2 and F3 female offspring displayed the same altered reproductive morphological phenotype and gene expression profiles as F1, thus showing transgenerational transmission of reproductive adverse effects along the female lineage. These findings indicate that in mice exposure to DEHP at doses relevant to human exposure during gonadal sex determination significantly perturbs the reproductive indices of female adult offspring and subsequent generations. Evidence of transgenerational transmission has important implications for the reproductive health and fertility of animals and humans, significantly increasing the potential biohazards of this toxicant. - Highlights: • Maternal exposure to DEHP transgenerationally affects female reproductive health. • DEHP reduced ovarian follicular reserve up to the third generation. • DEHP reduced oocyte and blastocyst developmental competence up to F3. • DEHP altered expression levels for key genes in ovary and blastocysts up to F4. • DEHP's adverse effects were observed at doses relevant for human exposure.« less
USDA-ARS?s Scientific Manuscript database
Male ejaculate proteins, including both sperm and seminal fluid proteins, play an important role in mediating reproductive biology. The function of ejaculate proteins can include enabling sperm-egg interactions, enhancing sperm storage, mediating female attractiveness, and even regulating female lif...
Emery Thompson, Melissa; Wilson, Michael L; Gobbo, Grace; Muller, Martin N; Pusey, Anne E
2008-11-01
Chimpanzees in Gombe National Park consume fruits of Vitex fischeri during a short annual fruiting season. This fruit species is a member of a genus widely studied for phytoestrogen composition and varied physiological effects. One particularly well-studied species, V. agnus-castus, is noted for its documented effects on female reproductive function, evidenced in increased progesterone levels and consequent regulation of luteal function. We examined reproductive hormone levels in both male and female chimpanzees during a 6-week period of intense V. fischeri consumption. V. fischeri consumption was associated with an abrupt and dramatic increase in urinary progesterone levels of female chimpanzees to levels far exceeding the normal range of variation. Female estrogen levels were not significantly impacted, nor were male testosterone levels. These are some of the first data indicating that phytochemicals in the natural diet of a primate can have significant impacts on the endocrine system, though the fluctuating nature of chimpanzee diet and reproductive function does not allow us to determine whether the effects observed during this short period had a broader positive or negative impact on female fertility. Given the widespread use of various Vitex species by African primates and the as-yet-undescribed phytochemical properties of these species, we predict that our observations may be indicative of a broader phenomenon. Copyright 2008 Wiley-Liss, Inc.
Maturation and sexual ontogeny in the spangled emperor Lethrinus nebulosus.
Marriott, R J; Jarvis, N D C; Adams, D J; Gallash, A E; Norriss, J; Newman, S J
2010-04-01
The reproductive development and sexual ontogeny of spangled emperor Lethrinus nebulosus populations in the Ningaloo Marine Park (NMP) were investigated to obtain an improved understanding of its evolved reproductive strategy and data for fisheries management. Evidence derived from (1) analyses of histological data and sampled sex ratios with size and age, (2) the identification of residual previtellogenic oocytes in immature and mature testes sampled during the spawning season and (3) observed changes in testis internal structure with increasing fish size and age, demonstrated a non-functional protogynous hermaphroditic strategy (or functional gonochorism). All the smallest and youngest fish sampled were female until they either changed sex to male at a mean 277.5 mm total length (L(T)) and 2.3 years old or remained female and matured at a larger mean L(T) (392.1 mm) and older age (3.5 years). Gonad masses were similar for males and females over the size range sampled and throughout long reproductive lives (up to a maximum estimated age of c. 31 years), which was another correlate of functional gonochorism. That the mean L(T) at sex change and female maturity were below the current minimum legal size (MLS) limit (410 mm) demonstrated that the current MLS limit is effective for preventing recreational fishers in the NMP retaining at least half of the juvenile males and females in their landed catches.
Mating-Induced Transcriptome Changes in the Reproductive Tract of Female Aedes aegypti
Degner, Ethan C.; Avila, Frank W.; Villarreal, Susan M.; Pleiss, Jeffrey A.; Wolfner, Mariana F.; Harrington, Laura C.
2016-01-01
The Aedes aegypti mosquito is a significant public health threat, as it is the main vector of dengue and chikungunya viruses. Disease control efforts could be enhanced through reproductive manipulation of these vectors. Previous work has revealed a relationship between male seminal fluid proteins transferred to females during mating and female post-mating physiology and behavior. To better understand this interplay, we used short-read RNA sequencing to identify gene expression changes in the lower reproductive tract of females in response to mating. We characterized mRNA expression in virgin and mated females at 0, 6 and 24 hours post-mating (hpm) and identified 364 differentially abundant transcripts between mating status groups. Surprisingly, 60 transcripts were more abundant at 0hpm compared to virgin females, suggesting transfer from males. Twenty of these encode known Ae. aegypti seminal fluid proteins. Transfer and detection of male accessory gland-derived mRNA in females at 0hpm was confirmed by measurement of eGFP mRNA in females mated to eGFP-expressing males. In addition, 150 transcripts were up-regulated at 6hpm and 24hpm, while 130 transcripts were down-regulated at 6hpm and 24hpm. Gene Ontology (GO) enrichment analysis revealed that proteases, a protein class broadly known to play important roles in reproduction, were among the most enriched protein classes. RNAs associated with immune system and antimicrobial function were also up-regulated at 24hpm. Collectively, our results suggest that copulation initiates broad transcriptome changes across the mosquito female reproductive tract, “priming” her for important subsequent processes of blood feeding, egg development and immune defense. Our transcriptome analysis provides a vital foundation for future studies of the consequences of mating on female biology and will aid studies seeking to identify specific gene families, molecules and pathways that support key reproductive processes in the female mosquito. PMID:26901677
Husak, Jerry F; Roy, Jordan C; Lovern, Matthew B
2017-04-15
Acquired energetic resources allocated to a particular trait cannot then be re-allocated to a different trait. This often results in a trade-off between survival and reproduction for the adults of many species, but such a trade-off may be manifested differently in juveniles not yet capable of reproduction. Whereas adults may allocate resources to current and/or future reproduction, juveniles can only allocate to future reproduction. Thus, juveniles should allocate resources toward traits that increase survival and their chances of future reproductive success. We manipulated allocation of resources to performance, via endurance exercise training, to examine trade-offs among endurance capacity, immune function and growth in juvenile green anole lizards. We trained male and female captive anoles on a treadmill for 8 weeks, with increasing intensity, and compared traits with those of untrained individuals. Our results show that training enhanced endurance capacity equally in both sexes, but immune function was suppressed only in females. Training had no effect on growth, but males had higher growth rates than females. Previous work showed that trained adults have enhanced growth, so juvenile growth is either insensitive to stimulation with exercise, or they are already growing at maximal rates. Our results add to a growing body of literature indicating that locomotor performance is an important part of life-history trade-offs that are sex and age specific. © 2017. Published by The Company of Biologists Ltd.
Postmating sexual conflict and female control over fertilization during gamete interaction.
Firman, Renée C
2018-06-01
Males and females rarely have identical evolutionary interests over reproduction, and when the fitness of both sexes is dependent upon paternity outcomes, sexual conflict over fertilization is inevitable. In internal fertilizers, the female tract is a formidable selective force on the number and integrity of sperm that reach the egg. Selection on sperm quality is intensified when females mate multiply and rival males are forced to compete for fertilizations. While male adaptations to sperm competition have been well documented (e.g., increased sperm fertilizing capacity), much less attention has been given to the evolutionary consequences of postmating sexual conflict for egg form and function. Specifically, increased sperm competitiveness can be detrimental by giving rise to an elevation in reproductive failure resulting from polyspermy. Spanning literature on both internal and external fertilizers, in this review I discuss how females respond to sperm competition via fertilization barriers that mediate sperm entry. These findings, which align directly with sexual conflict theory, indicate that females have greater control over fertilization than has previously been appreciated. I then consider the implications of gametic sexual conflict in relation to the development of reproductive isolation and speculate on potential mechanisms accounting for "egg defensiveness." Finally, I discuss the functional significance of egg defensiveness for both the sexes, and sperm selection for females. © 2018 New York Academy of Sciences.
Mutations and polymorphisms in FSH receptor: functional implications in human reproduction.
Desai, Swapna S; Roy, Binita Sur; Mahale, Smita D
2013-12-01
FSH brings about its physiological actions by activating a specific receptor located on target cells. Normal functioning of the FSH receptor (FSHR) is crucial for follicular development and estradiol production in females and for the regulation of Sertoli cell function and spermatogenesis in males. In the last two decades, the number of inactivating and activating mutations, single nucleotide polymorphisms, and spliced variants of FSHR gene has been identified in selected infertile cases. Information on genotype-phenotype correlation and in vitro functional characterization of the mutants has helped in understanding the possible genetic cause for female infertility in affected individuals. The information is also being used to dissect various extracellular and intracellular events involved in hormone-receptor interaction by studying the differences in the properties of the mutant receptor when compared with WT receptor. Studies on polymorphisms in the FSHR gene have shown variability in clinical outcome among women treated with FSH. These observations are being explored to develop molecular markers to predict the optimum dose of FSH required for controlled ovarian hyperstimulation. Pharmacogenetics is an emerging field in this area that aims at designing individual treatment protocols for reproductive abnormalities based on FSHR gene polymorphisms. The present review discusses the current knowledge of various genetic alterations in FSHR and their impact on receptor function in the female reproductive system.
Sugar‐coated sperm: Unraveling the functions of the mammalian sperm glycocalyx
Tecle, Eillen
2015-01-01
SUMMARY Mammalian spermatozoa are coated with a thick glycocalyx that is assembled during sperm development, maturation, and upon contact with seminal fluid. The sperm glycocalyx is critical for sperm survival in the female reproductive tract and is modified during capacitation. The complex interplay among the various glycoconjugates generates numerous signaling motifs that may regulate sperm function and, as a result, fertility. Nascent spermatozoa assemble their own glycans while the cells still possess a functional endoplasmic reticulum and Golgi in the seminiferous tubule, but once spermatogenesis is complete, they lose the capacity to produce glycoconjugates de novo. Sperm glycans continue to be modified, during epididymal transit by extracellular glycosidases and glycosyltransferases. Furthermore, epididymal cells secrete glycoconjugates (glycophosphatidylinositol‐anchored glycoproteins and glycolipids) and glycan‐rich microvesicles that can fuse with the maturing sperm membrane. The sperm glycocalyx mediates numerous functions in the female reproductive tract, including the following: inhibition of premature capacitation; passage through the cervical mucus; protection from innate and adaptive female immunity; formation of the sperm reservoir; and masking sperm proteins involved in fertilization. The immense diversity in sperm‐associated glycans within and between species forms a remarkable challenge to our understanding of essential sperm glycan functions. Mol. Reprod. Dev. 82: 635–650, 2015. © 2015 The Authors. Molecular Reproduction and Development published by Wiley Periodicals, Inc. PMID:26061344
Reinhardt, Klaus; Naylor, Richard A.; Siva-Jothy, Michael T.
2009-01-01
Increased female reproductive rates usually result in accelerated senescence. This correlation provides a link between the evolutionary conflict of the sexes and aging when ejaculate components elevate female reproductive rates at the cost of future reproduction. It is not clear whether this female cost is manifest as shorter lifespan or an earlier onset or a steeper rate of reproductive senescence. It also is unclear whether beneficial ejaculates release females from reproductive trade-offs and, if so, which senescence parameters are affected. We examined these issues in the bedbug, Cimex lectularius, a long-lived insect that shows reduced female lifespan as well as female reproductive senescence at the male-determined mating frequency. We demonstrate experimentally that, independently of the mating frequency, females receiving more ejaculate show increased reproductive rates and enter reproductive senescence later than females receiving less ejaculate. The rate of reproductive senescence did not differ between treatments, and reproductive rates did not predict mortality. The ejaculate effects were consistent in inter- and intra-population crosses, suggesting they have not evolved recently and are not caused by inbreeding. Our results suggest that ejaculate components compensate for the costs of elevated female reproductive rates in bedbugs by delaying the onset of reproductive senescence. Ejaculate components that are beneficial to polyandrous females could have arisen because male traits that protect the ejaculate have positive pleiotropic effects and/or because female counteradaptations to antagonistic male traits exceed the neutralization of those traits. That males influence female reproductive senescence has important consequences for trade-offs between reproduction and longevity and for studies of somatic senescence. PMID:19996174
Varga, S; Kytöviita, M-M
2014-03-01
In several gynodioecious species, intermediate sex between female and hermaphrodite has been reported, but few studies have investigated fitness parameters of this intermediate phenotype. Here, we examined the interactions between plant sex and arbuscular mycorrhizal (AM) fungal species affecting the reproductive output of Geranium sylvaticum, a sexually polymorphic plant species with frequent intermediate sexes between females and hermaphrodites, using a common garden experiment. Flowering phenology, AM colonisation levels and several plant vegetative and reproductive parameters, including seed and pollen production, were measured. Differences among sexes were detected in flowering, fruit set, pollen production and floral size. The two AM species used in the present work had different effects on plant fitness parameters. One AM species increased female fitness through increasing seed number and seed mass, while the other species reduced seed mass in all sexes investigated. AM fungi did not affect intermediate and hermaphrodite pollen content in anthers. The three sexes in G. sylvaticum did not differ in their reproductive output in terms of total seed production, but hermaphrodites had potentially larger fathering ability than intermediates due to higher anther number. The ultimate female function--seed production--did not differ among the sexes, but one of the AM fungi used potentially decreased host plant fitness. In addition, in the intermediate sex, mycorrhizal symbiosis functioned similarly in females as in hermaphrodites. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.
NASA Technical Reports Server (NTRS)
Flynn, Katherine M.; Miller, Shelly A.; Sower, Stacia A.; Schreibman, Martin P.
2002-01-01
The N-methyl-D-aspartate glutamate receptor (NMDAR) is found in hypothalamic nuclei involved in the regulation of reproduction in several species of mammals and fishes. NMDAR is believed to affect reproductive development and function by regulating gonadotropin releasing hormone (GnRH)-producing cells. These pathways are likely to be sexually dimorphic, as are several other neurotransmitter systems involved in reproductive function. In this report, male and female platyfish received intraperitoneal injections of 0, 5, 10, 20, 40 or 60 microg/g body wt. of the non-competitive NMDAR antagonist MK-801. Injections began at 6 weeks of age and continued thrice weekly until control animals reached puberty, as evidenced by anal fin maturation. The percent of pubescent animals was significantly affected by sex and treatment, with fewer MK-801-injected females in puberty than control females at each dose (P<0.001), and fewer pubescent females than males at 10, 20 and 40 microg/g (P<0.05). There were no MK-801-related effects in males. Histological analyses revealed typical immature gonads and pituitary glands in treated females, and typical mature morphology in control females and all males. Immunocytochemical distribution of the R1 subunit of the NMDAR within the brain-pituitary-gonad (BPG) axis was limited to GnRH-containing brain cells in all animals; however, NMDAR1 distribution was in an immature pattern in treated females and a mature pattern in all others. Neural concentrations of GnRH were unaffected by MK-801 treatment in both sexes. These data suggest that in the platyfish, NMDAR influence on reproductive development is sexually dimorphic and occurs at, or above, the level of GnRH-containing cells of the BPG axis.
Wu, Chen; Crowhurst, Ross N; Dennis, Alice B; Twort, Victoria G; Liu, Shanlin; Newcomb, Richard D; Ross, Howard A; Buckley, Thomas R
2016-01-01
Phasmatodea, more commonly known as stick insects, have been poorly studied at the molecular level for several key traits, such as components of the sensory system and regulators of reproduction and development, impeding a deeper understanding of their functional biology. Here, we employ de novo transcriptome analysis to identify genes with primary functions related to female odour reception, digestion, and male sexual traits in the New Zealand common stick insect Clitarchus hookeri (White). The female olfactory gene repertoire revealed ten odorant binding proteins with three recently duplicated, 12 chemosensory proteins, 16 odorant receptors, and 17 ionotropic receptors. The majority of these olfactory genes were over-expressed in female antennae and have the inferred function of odorant reception. Others that were predominantly expressed in male terminalia (n = 3) and female midgut (n = 1) suggest they have a role in sexual reproduction and digestion, respectively. Over-represented transcripts in the midgut were enriched with digestive enzyme gene families. Clitarchus hookeri is likely to harbour nine members of an endogenous cellulase family (glycoside hydrolase family 9), two of which appear to be specific to the C. hookeri lineage. All of these cellulase sequences fall into four main phasmid clades and show gene duplication events occurred early in the diversification of Phasmatodea. In addition, C. hookeri genome is likely to express γ-proteobacteria pectinase transcripts that have recently been shown to be the result of horizontal transfer. We also predicted 711 male terminalia-enriched transcripts that are candidate accessory gland proteins, 28 of which were annotated to have molecular functions of peptidase activity and peptidase inhibitor activity, two groups being widely reported to regulate female reproduction through proteolytic cascades. Our study has yielded new insights into the genetic basis of odour detection, nutrient digestion, and male sexual traits in stick insects. The C. hookeri reference transcriptome, together with identified gene families, provides a comprehensive resource for studying the evolution of sensory perception, digestive systems, and reproductive success in phasmids.
GENE-ENVIRONMENT INTERACTIONS: A REVIEW OF EFFECTS ON REPRODUCTION AND DEVELOPMENT
Polymorphisms in genes can lead to differences in the level of susceptibility of individuals to potentially adverse effects of environmental influences, such as chemical exposure, on prenatal development or male or female reproductive function. We have reviewed the literature in ...
Kin discrimination and female mate choice in the naked mole-rat Heterocephalus glaber.
Clarke, F M; Faulkes, C G
1999-10-07
Naked mole-rats are fossorial, eusocial rodents that naturally exhibit high levels of inbreeding. Persistent inbreeding in animals often results in a substantial decline in fitness and, thus, dispersal and avoidance of kin as mates are two common inbreeding avoidance mechanisms. In the naked mole-rat evidence for the former has recently been found. Here we address the latter mechanism by investigating kin recognition and female mate choice using a series of choice tests in which the odour, social and mate preferences of females were determined. Discrimination by females appears to be dependent on their reproductive status. Reproductively active females prefer to associate with unfamiliar males, whereas reproductively inactive females do not discriminate. Females do not discriminate between kin and non-kin suggesting that the criterion for recognition is familiarity, not detection of genetic similarity per se. In the wild, naked mole-rats occupy discrete burrow systems and dispersal and mixing with non-kin is thought to be comparatively rare. Thus, recognition by familiarity may function as a highly efficient kin recognition mechanism in the naked mole-rat. A preference by reproductively active females for unfamiliar males is interpreted as inbreeding avoidance. These findings suggest that, despite an evolutionary history of close inbreeding, naked mole-rats may not be exempt from the effects of inbreeding depression and will attempt to outbreed should the opportunity arise.
Wierman, Margaret E; Xu, Mei; Pierce, A; Bliesner, B; Bliss, S P; Roberson, M S
2012-01-01
Selective deletion of extracellular signal-regulated kinase (ERK) 1 and ERK2 in the pituitary gonadotrope and ovarian granulosa cells disrupts female reproductive axis function. Thus, we asked if ERK1 and ERK2 are critical for GnRH neuron ontogeny or the central control of female reproductive function. GnRH-Cre-recombinase (Cre+) expressing mice were crossed with mice with a global deletion of ERK1 and a floxed ERK2 allele (Erk1-/Erk2fl/fl) to selectively delete ERK2 in GnRH neurons. Cre-recombinase mRNA was selectively expressed in the brain of Cre+ mice. GnRH neuron number and location were determined during embryogenesis and in the adult. GnRH neuron counts at E15 did not differ between experimental and control groups (1,198 ± 65 and 1,160 ± 80 respectively, p = NS). In adults, numbers of GnRH neurons in the GnRHCre+Erk1-/Erk2- mice (741 ± 157) were similar to those in controls (756 ± 7), without alteration in their distribution across the forebrain. ERK1 and 2 deficiency did not alter the timing of vaginal opening, age at first estrus, or estrous cyclicity. Although ERK1 and 2 are components of a dominant signaling pathway in GnRH neuronal cells that modulates survival and control of GnRH gene expression, other signaling pathways compensate for their deletion in vivo to allow GnRH neuron survival and targeting and normal onset of female sexual maturation and reproductive function. In contrast to effects at the pituitary and the ovary, ERK1 and ERK2 are dispensable at the level of the GnRH neuron. Copyright © 2011 S. Karger AG, Basel.
Shechter, Asaf; Aflalo, Eliahu D; Davis, Claytus; Sagi, Amir
2005-07-01
In oviparous females, the synthesis of the yolk precursor vitellogenin is an important step in ovarian maturation and oocyte development. In decapod Crustacea, including the red-claw crayfish (Cherax quadricarinatus), this reproductive process is regulated by inhibitory neurohormones secreted by the endocrine X-organ-sinus gland (XO-SG) complex. In males, the C. quadricarinatus vitellogenin gene (CqVg), although present, is not expressed under normal conditions. We show here that endocrine manipulation by removal of the XO-SG complex from male animals induced CqVg transcription. The CqVg gene was expressed differentially during the molt cycle in these induced males: no expression was seen in the intermolt stages, but expression was occasionally detected in the premolt stages and always detected in the early postmolt stages. Relative quantitation with a real-time reverse transcriptase-polymerase chain reaction showed that expression of CqVg in induced early postmolt males was an order of magnitude lower than that in reproductive females, a finding that was consistent with RNA in situ hybridization results. The SDS-PAGE of high-density lipoproteins from the hemolymph of endocrinologically induced early postmolt males did not show the typical vitellogenin-related polypeptide profile found in reproductive females. On the other hand, removal of the XO-SG complex from intersex individuals, which are chromosomally female but functionally male and possess an arrested female reproductive system, induced the expression, translation, and release of CqVg products into the hemolymph, as was the case for vitellogenic females. The expression of CqVg in endocrinologically manipulated molting males and intersex animals provides an inducible model for the investigation and understanding of the endocrine regulation of CqVg expression and translation in Crustacea as well as the relationship between the endocrine axes regulating molt and reproduction.
Predictors of Stress Fracture Susceptibility in Young Female Recruits
2004-09-02
fracture as women who ran 4 or more times a week (OR = 2.17; 95% CI, 1.0-4.5). Among measures of reproductive history and birth control pill use, only...the analyses on menstrual function. No significant associations were found for birth control pill use. After adjusting for age and other potential...and Odds Ratios by Measures of Self-Reported Reproductive History, and Birth Control Use, Female Marine Corps Recruits, Parris Island, March 1995 to
Fetal and postnatal nutritional programming of reproductive performance in ruminants
USDA-ARS?s Scientific Manuscript database
The influence of nutrition on reproductive function in females has been studied for decades. In cows, early studies focused on the influence of nutritional status on the hypothalamic-pituitary-ovarian axis, demonstrating that in circumstances of extreme negative energy balance estrous cycles cease....
Successful reproduction depends upon the precise orchestration of many physiological processes. With respect to male reproductive performance, normal copulatory behavior and ejaculatory function are required to insure that semen is deposited in the female tract. Then, a suffici...
Angiogenesis in the female reproductive organs: pathological implications
Reynolds, Lawrence P; Grazul-Bilska, Anna T; Redmer, Dale A
2002-01-01
The female reproductive organs (ovary, uterus, and placenta) are some of the few adult tissues that exhibit regular intervals of rapid growth. They also are highly vascular and have high rates of blood flow. Angiogenesis, or vascular growth, is therefore an important component of the growth and function of these tissues. As with many other tissues, vascular endothelial growth factors (VEGFs) and fibroblast growth factors (FGFs) appear to be major angiogenic factors in the female reproductive organs. A variety of pathologies of the female reproductive organs are associated with disturbances of the angiogenic process, including dysfunctional uterine bleeding, endometrial hyperplasia and carcinoma, endometriosis, failed implantation and subnormal foetal growth, myometrial fibroids (uterine leiomyomas) and adenomyosis, ovarian hyperstimulation syndrome, ovarian carcinoma, and polycystic ovary syndrome. These pathologies are also associated with altered expression of VEGFs and/or FGFs. In the near future, angiogenic or antiangiogenic compounds may prove to be effective therapeutic agents for treating these pathologies. In addition, monitoring of angiogenesis or angiogenic factor expression may provide a means of assessing the efficacy of these therapies. PMID:12485460
Sociality, individual fitness and population dynamics of yellow-bellied marmots.
Armitage, Kenneth B
2012-02-01
Social behaviour was proposed as a density-dependent intrinsic mechanism that could regulate an animal population by affecting reproduction and dispersal. Populations of the polygynous yellow-bellied marmot (Marmota flaviventris) fluctuate widely from year to year primarily driven by the number of weaned young. The temporal variation in projected population growth rate was driven mainly by changes in the age of first reproduction and fertility, which are affected by reproductive suppression. Dispersal is unrelated to population density, or the presence of the father; hence, neither of these limits population growth or acts as an intrinsic mechanism of population regulation; overall, intrinsic regulation seems unlikely. Sociality affects the likelihood of reproduction in that the annual probability of reproducing and the lifetime number of offspring are decreased by the number of older females and by the number of same-aged females present, but are increased by the number of younger adult females present. Recruitment of a yearling female is most likely when her mother is present; recruitment of philopatric females is much more important than immigration for increasing the number of adult female residents. Predation and overwinter mortality are the major factors limiting the number of resident adults. Social behaviour is not directed towards population regulation, but is best interpreted as functioning to maximize direct fitness. © 2011 Blackwell Publishing Ltd.
Mowry, Annelise V; Kavazis, Andreas N; Sirman, Aubrey E; Potts, Wayne K; Hood, Wendy R
2016-01-01
Reproduction is thought to come at a cost to longevity. Based on the assumption that increased energy expenditure during reproduction is associated with increased free-radical production by mitochondria, oxidative damage has been suggested to drive this trade-off. We examined the impact of reproduction on liver mitochondrial function by utilizing post-reproductive and non-reproductive house mice (Mus musculus) living under semi-natural conditions. The age-matched post-reproductive and non-reproductive groups were compared after the reproductive females returned to a non-reproductive state, so that both groups were in the same physiological state at the time the liver was collected. Despite increased oxidative damage (p = 0.05) and elevated CuZnSOD (p = 0.002) and catalase (p = 0.04) protein levels, reproduction had no negative impacts on the respiratory function of liver mitochondria. Specifically, in a post-reproductive, maintenance state the mitochondrial coupling (i.e., respiratory control ratio) of mouse livers show no negative impacts of reproduction. In fact, there was a trend (p = 0.059) to suggest increased maximal oxygen consumption by liver mitochondria during the ADP stimulated state (i.e., state 3) in post-reproduction. These findings suggest that oxidative damage may not impair mitochondrial respiratory function and question the role of mitochondria in the trade-off between reproduction and longevity. In addition, the findings highlight the importance of quantifying the respiratory function of mitochondria in addition to measuring oxidative damage.
Shimizu, Takashi; Hoshino, Yumi; Miyazaki, Hitoshi; Sato, Eimei
2012-01-01
The female reproductive organs such as ovary, uterus, and placenta are some of the few adult tissues that exhibit regular intervals of rapid growth, and are highly vascularized and have high rates of blood flow. Angiogenesis is a process of vascular growth that is mainly limited to the reproductive system in healthy adult animals. The development of new blood vessels in the ovary and uterus is essential to guarantee the necessary supply of nutrients and hormones. The genetic and molecular mechanisms that control the development of capillary blood vessels in the reproductive organs are beginning to be elucidated. Reproductive organs contain and produce angiogenic factors which may act alone or in concert to regulate the process of vasculature. Vascular endothelial growth factors (VEGFs) and fibroblast growth factor (FGFs) are key factors for vascular system in the reproductive organs. Recent numerous studies reported several roles of VEGFs and FGFs on ovarian and uterine functions. In this review, we focus on the involvement of VEGFs and FGFs as angiogenic factors on reproductive organs and vascular therapy for diseases of reproductive organs using anti-angiogenic agents.
Experimental elevation of testosterone lowers fitness in female dark-eyed juncos.
Gerlach, Nicole M; Ketterson, Ellen D
2013-05-01
Testosterone (T) is often referred to as the "male hormone," but it can influence aggression, parental behavior, and immune function in both males and females. By experimentally relating hormone-induced changes in phenotype to fitness, it is possible to ask whether existing phenotypes perform better or worse than alternative phenotypes, and hence to predict how selection might act on a novel or rare phenotype. In a songbird, the dark-eyed junco (Junco hyemalis), we have examined the effects of experimentally elevated T in females on fitness-related behaviors such as parental care. In this study, we implanted female juncos with exogenous T and examined its effect on fitness (survival, reproduction, and extra-pair mating) to assess whether T-altered phenotypes would prove to be adaptive or deleterious for females. Experimental elevation of T decreased the likelihood that a female would breed successfully, and T-implanted females had lower total reproductive success at every stage of the reproductive cycle. They did not, however, differ from control females in fledgling quality, extra-pair offspring production, survival, or reproduction in the following year. Previous work in this system has shown that experimental elevation of T in males alters behavior and physiology and decreases survival but increases the production of extra-pair offspring, leading to higher net fitness relative to control animals. Our results suggest that increased T has divergent effects on male and female fitness in this species, and that prevailing levels in females may be adaptive for them. These findings are consistent with sexual conflict. Copyright © 2013 Elsevier Inc. All rights reserved.
Rubenstein, Dustin R.; Botero, Carlos A.; Lacey, Eileen A.
2016-01-01
Animal societies are typically divided into those in which reproduction within a group is monopolized by a single female versus those in which it is shared among multiple females. It remains controversial, however, whether these two forms of social structure represent distinct evolutionary outcomes or endpoints along a continuum of reproductive options. To address this issue and to determine whether vertebrates and insects exhibit the same patterns of variation in social structure, we examined the demographic and reproductive structures of 293 species of wasps, ants, birds and mammals. Using phylogenetically informed comparative analyses, we found strong evidence indicating that not all reproductive arrangements within social groups are viable in nature and that in societies with multiple reproductives, selection favours instead taxon-specific patterns of decrease in the proportion of breeders as a function of group size. These outcomes suggest that the selective routes to sociality differ depending upon whether monopolization of reproduction by one individual is possible and that variation within and among taxonomic groups may lead to the false perception of a continuum of social structures. Thus, the occurrence of very large societies may require either complete reproductive monopolization (monogyny/singular breeding) or the maintenance of a taxon-specific range of values for the proportional decrease in the number of breeders within a group (polygyny/plural breeding), both of which may reduce reproductive conflict among females. PMID:27293796
Rubenstein, Dustin R; Botero, Carlos A; Lacey, Eileen A
2016-05-01
Animal societies are typically divided into those in which reproduction within a group is monopolized by a single female versus those in which it is shared among multiple females. It remains controversial, however, whether these two forms of social structure represent distinct evolutionary outcomes or endpoints along a continuum of reproductive options. To address this issue and to determine whether vertebrates and insects exhibit the same patterns of variation in social structure, we examined the demographic and reproductive structures of 293 species of wasps, ants, birds and mammals. Using phylogenetically informed comparative analyses, we found strong evidence indicating that not all reproductive arrangements within social groups are viable in nature and that in societies with multiple reproductives, selection favours instead taxon-specific patterns of decrease in the proportion of breeders as a function of group size. These outcomes suggest that the selective routes to sociality differ depending upon whether monopolization of reproduction by one individual is possible and that variation within and among taxonomic groups may lead to the false perception of a continuum of social structures. Thus, the occurrence of very large societies may require either complete reproductive monopolization (monogyny/singular breeding) or the maintenance of a taxon-specific range of values for the proportional decrease in the number of breeders within a group (polygyny/plural breeding), both of which may reduce reproductive conflict among females.
Freeman, Elizabeth W.; Meyer, Jordana M.; Putman, Sarah B.; Schulte, Bruce A.; Brown, Janine L.
2013-01-01
Free-ranging African elephants live in a fission–fusion society, at the centre of which is the matriarch. Matriarchs are generally older females that guide their families to resources and co-ordinate group defense. While much is known about elephant society, knowledge is generally lacking about how age affects the physiology of wild elephants. Investigation of the ovarian activity of free-ranging elephants could provide insight into the reproductive ageing process, with implications for population management. Faecal samples were collected from 46 individuals ranging in age from 14 to 60 years for a 2-year period, and progestagen metabolite analyses were used to examine relationships between social status, age, season, and ovarian activity in female elephants in Addo Elephant National Park, South Africa. Social status was the strongest predictor of faecal progestagen metabolite concentrations in non-pregnant elephants, with grand matriarchs (n = 6) having the lowest values compared with matriarchs (n = 21) and non-matriarch females (n = 19). Likewise, social status and age were the strongest predictors of faecal progestagen metabolite concentrations in pregnant elephants (n = 27). The number of years since a non-pregnant female gave birth to her last calf (post-partum duration) was longer for older females with a higher social status, as well as during the dry season. Our results indicate that social standing and age of elephants are related to reproductive function, and that older females exhibit reductions in ovarian capacity. These results expand our understanding of reproduction and fertility throughout an elephant's lifespan, and the factors that impact gonadal function in free-ranging females. Given that possible over-abundance of elephants in areas such as Addo Elephant National Park is fuelling the debate over how best to manage these populations, knowledge about the reproductive potential of high-ranking females can provide managers with biological data to identify the best candidates for controlling growth through translocation or contraception. PMID:27293609
Freeman, Elizabeth W; Meyer, Jordana M; Putman, Sarah B; Schulte, Bruce A; Brown, Janine L
2013-01-01
Free-ranging African elephants live in a fission-fusion society, at the centre of which is the matriarch. Matriarchs are generally older females that guide their families to resources and co-ordinate group defense. While much is known about elephant society, knowledge is generally lacking about how age affects the physiology of wild elephants. Investigation of the ovarian activity of free-ranging elephants could provide insight into the reproductive ageing process, with implications for population management. Faecal samples were collected from 46 individuals ranging in age from 14 to 60 years for a 2-year period, and progestagen metabolite analyses were used to examine relationships between social status, age, season, and ovarian activity in female elephants in Addo Elephant National Park, South Africa. Social status was the strongest predictor of faecal progestagen metabolite concentrations in non-pregnant elephants, with grand matriarchs (n = 6) having the lowest values compared with matriarchs (n = 21) and non-matriarch females (n = 19). Likewise, social status and age were the strongest predictors of faecal progestagen metabolite concentrations in pregnant elephants (n = 27). The number of years since a non-pregnant female gave birth to her last calf (post-partum duration) was longer for older females with a higher social status, as well as during the dry season. Our results indicate that social standing and age of elephants are related to reproductive function, and that older females exhibit reductions in ovarian capacity. These results expand our understanding of reproduction and fertility throughout an elephant's lifespan, and the factors that impact gonadal function in free-ranging females. Given that possible over-abundance of elephants in areas such as Addo Elephant National Park is fuelling the debate over how best to manage these populations, knowledge about the reproductive potential of high-ranking females can provide managers with biological data to identify the best candidates for controlling growth through translocation or contraception.
Yarbrough, Victoria L; Winkle, Sean; Herbst-Kralovetz, Melissa M
2015-01-01
At the interface of the external environment and the mucosal surface of the female reproductive tract (FRT) lies a first-line defense against pathogen invasion that includes antimicrobial peptides (AMP). Comprised of a unique class of multifunctional, amphipathic molecules, AMP employ a wide range of functions to limit microbial invasion and replication within host cells as well as independently modulate the immune system, dampen inflammation and maintain tissue homeostasis. The role of AMP in barrier defense at the level of the skin and gut has received much attention as of late. Given the far reaching implications for women's health, maternal and fetal morbidity and mortality, and sexually transmissible and polymicrobial diseases, we herein review the distribution and function of key AMP throughout the female reproductive mucosa and assess their role as an essential immunological barrier to microbial invasion throughout the reproductive cycle of a woman's lifetime. A comprehensive search in PubMed/Medline was conducted related to AMP general structure, function, signaling, expression, distribution and barrier function of AMP in the FRT, hormone regulation of AMP, the microbiome of the FRT, and AMP in relation to implantation, pregnancy, fertility, pelvic inflammatory disease, complications of pregnancy and assisted reproductive technology. AMP are amphipathic peptides that target microbes for destruction and have been conserved throughout all living organisms. In the FRT, several major classes of AMP are expressed constitutively and others are inducible at the mucosal epithelium and by immune cells. AMP expression is also under the influence of sex hormones, varying throughout the menstrual cycle, and dependent on the vaginal microbiome. AMP can prevent infection with sexually transmissible and opportunistic pathogens of the female reproductive tissues, although emerging understanding of vaginal dysbiosis suggests induction of a unique AMP profile with increased susceptibility to these pathogens. During pregnancy, AMP are key immune effectors of the fetal membranes and placenta and are dysregulated in states of intrauterine infection and other complications of pregnancy. At the level of the FRT, AMP serve to inhibit infection by sexually and vertically transmissible as well as by opportunistic bacteria, fungi, viruses, and protozoa and must do so throughout the hormone flux of menses and pregnancy. Guarding the exclusive site of reproduction, AMP modulate the vaginal microbiome of the lower FRT to aid in preventing ascending microbes into the upper FRT. Evolving in parallel with, and in response to, pathogenic insults, AMP are relatively immune to the resistance mechanisms employed by rapidly evolving pathogens and play a key role in barrier function and host defense throughout the FRT. © The Author 2014. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Cyclooxygenase (COX) inhibition is of concern in fish because COX inhibitors (e.g., ibuprofen) are ubiquitous in aquatic systems/fish tissues, and can disrupt synthesis of prostaglandins that modulate a variety of essential biological functions including reproduction. High conten...
Normal Female Reproductive Anatomy
... hyphen, e.g. -historical Searches are case-insensitive Reproductive System, Female, Anatomy Add to My Pictures View /Download : ... 1500x1575 View Download Large: 3000x3150 View Download Title: Reproductive System, Female, Anatomy Description: Anatomy of the female reproductive ...
Sperm-storage defects and live birth in Drosophila females lacking spermathecal secretory cells.
Schnakenberg, Sandra L; Matias, Wilfredo R; Siegal, Mark L
2011-11-01
Male Drosophila flies secrete seminal-fluid proteins that mediate proper sperm storage and fertilization, and that induce changes in female behavior. Females also produce reproductive-tract secretions, yet their contributions to postmating physiology are poorly understood. Large secretory cells line the female's spermathecae, a pair of sperm-storage organs. We identified the regulatory regions controlling transcription of two genes exclusively expressed in these spermathecal secretory cells (SSC): Spermathecal endopeptidase 1 (Send1), which is expressed in both unmated and mated females, and Spermathecal endopeptidase 2 (Send2), which is induced by mating. We used these regulatory sequences to perform precise genetic ablations of the SSC at distinct time points relative to mating. We show that the SSC are required for recruiting sperm to the spermathecae, but not for retaining sperm there. The SSC also act at a distance in the reproductive tract, in that their ablation: (1) reduces sperm motility in the female's other sperm-storage organ, the seminal receptacle; and (2) causes ovoviviparity--the retention and internal development of fertilized eggs. These results establish the reproductive functions of the SSC, shed light on the evolution of live birth, and open new avenues for studying and manipulating female fertility in insects.
The ecology and evolutionary endocrinology of reproduction in the human female.
Vitzthum, Virginia J
2009-01-01
Human reproductive ecology (HRE) is the study of the mechanisms that link variation in reproductive traits with variation in local habitats. Empirical and theoretical contributions from biological anthropology, physiology, and demography have established the foundation necessary for developing a comprehensive understanding, grounded in life history theory (LHT), of temporal, individual, and populational variation in women's reproductive functioning. LHT posits that natural selection leads to the evolution of mechanisms that tend to allocate resources to the competing demands of growth, reproduction, and survival such that fitness is locally maximized. (That is, among alternative allocation patterns exhibited in a population, those having the highest inclusive fitness will become more common over generational time.) Hence, strategic modulation of reproductive effort is potentially adaptive because investment in a new conception may risk one's own survival, future reproductive opportunities, and/or current offspring survival. The hypothalamic-pituitary-ovarian (HPO) axis is the principal neuroendocrine pathway by which the human female modulates reproductive functioning according to the changing conditions in her habitat. Adjustments of reproductive investment in a potential conception are manifested in temporal and individual variation in ovarian cycle length, ovulation, hormone levels, and the probability of conception. Understanding the extent and causes of adaptive and non-adaptive variation in ovarian functioning is fundamental to ascertaining the proximate and remote determinants of human reproductive patterns. In this review I consider what is known and what still needs to be learned of the ecology of women's reproductive biology, beginning with a discussion of the principal explanatory frameworks in HRE and the biometry of ovarian functioning. Turning next to empirical studies, it is evident that marked variation between cycles, women, and populations is the norm rather than an aberration. Other than woman's age, the determinants of these differences are not well characterized, although developmental conditions, dietary practices, genetic variation, and epigenetic mechanisms have all been hypothesized to play some role. It is also evident that the reproductive functioning of women born and living in arduous conditions is not analogous to that of athletes, dieters, or even the lower end of the "normal range" of HPO functioning in wealthier populations. Contrary to the presumption that humans have low fecundity and an inefficient reproductive system, both theory and present evidence suggest that we may actually have very high fecundity and a reproductive system that has evolved to be flexible, ruthlessly efficient and, most importantly, strategic. Copyright 2009 Wiley-Liss, Inc.
Burkholder, Tanya H.; Colenda, Lyn; Tuschong, Laura M.; Starost, Matthew F.; Bauer, Thomas R.; Hickstein, Dennis D.
2006-01-01
Nonmyeloablative conditioning regimens are increasingly replacing myeolablative conditioning prior to allogeneic hematopoietic stem cell transplantation (SCT). The recent advent of these conditioning regimens has limited the assessment of the long-term effects of this treatment, including analysis of reproductive function. To address the question of reproductive function after nonmyeloablative transplantation, we analyzed a cohort of young dogs with the genetic disease canine leukocyte adhesion deficiency that were treated with a nonmyeloablative dose of 200 cGy total body irradiation followed by matched-littermate SCT. Five males and 5 females entered puberty; all 5 males and 4 females subsequently sired or delivered litters following transplantation. We demonstrate that fertility is intact and dogs have uncomplicated parturitions following nonmyeloablative conditioning for SCT. These results are encouraging for children and adults of childbearing age who receive similar conditioning regimens prior to allogeneic transplantation. PMID:16645166
Neuroendocrine control of reproductive aging: roles of GnRH neurons.
Yin, Weiling; Gore, Andrea C
2006-03-01
The process of reproductive senescence in many female mammals, including humans, is characterized by a gradual transition from regular reproductive cycles to irregular cycles to eventual acyclicity, and ultimately a loss of fertility. In the present review, the role of the hypothalamic gonadotropin-releasing hormone (GnRH) neurons is considered in this context. GnRH neurons provide the primary driving force upon the other levels of the reproductive axis. With respect to aging, GnRH cells undergo changes in biosynthesis, processing and release of the GnRH decapeptide. GnRH neurons also exhibit morphologic and ultrastructural alterations that appear to underlie these biosynthetic properties. Thus, functional and morphologic changes in the GnRH neurosecretory system may play causal roles in the transition to acyclicity. In addition, GnRH neurons are regulated by numerous inputs from neurotransmitters, neuromodulators and glia. The relationship among GnRH cells and their inputs at the cell body (thereby affecting GnRH biosynthesis) and the neuroterminal (thereby affecting GnRH neurosecretion) is crucial to the function of the GnRH system, with age-related changes in these relationships contributing to the reproductive senescent process. Therefore, the aging hypothalamus is characterized by changes intrinsic to the GnRH cell, as well as its regulatory inputs, which summate to contribute to a loss of reproductive competence in aging females.
NASA Astrophysics Data System (ADS)
Vázquez, M. Guadalupe; Bas, Claudia C.; Spivak, Eduardo D.
2013-12-01
The magnitude of variations in reproductive traits of Palaemon macrodactylus females throughout a breeding season was studied in a non-native population at Mar del Plata harbor, Argentina. Fecundity, egg size, reproductive output, weight and elemental composition of eggs, and larvae were analyzed in females collected at the beginning, in the mid point, and near the end of a reproductive season and designated as early, middle season, and late females. The highest reproductive output was observed in early females, while the highest fecundity and egg volume occurred in middle season females. Eggs and larvae showed larger body mass in early than in late females. Embryos from early females contained and consumed more carbon during development than embryos from late females, and they also used part of the available nitrogen. Differences in reproduction were observed among the three groups of females. On the one hand, late females matured early but had a poor first reproduction, with few embryos and high egg loss; however, they had longer reproductive life and an enhanced reproductive output in the following season when they became early females. On the other hand, females collected at the midpoint in the reproductive season matured later and had the highest fecundity and egg volume. In addition, larvae with different characteristics resulted from each type of female and were presumably well adapted to the conditions prevailing at the moment they hatched. The extended reproductive period and the diversity of embryos and larvae produced may favor the invading ability of the species.
Maggi, Adriana; Della Torre, Sara
2018-02-27
Epidemiological and clinical studies have largely demonstrated major differences in the prevalence of metabolic disorders in males and females, but the biological cause of these dissimilarities remain to be elucidated. Mammals are characterized by a major change in reproductive strategies and it is conceivable that these changes subjected females to a significant evolutionary pressure that perfected the coupling between energy metabolism and reproduction. This review will address the plausibility that female liver functions diverged significantly from males given the role of liver in the control of metabolism. Indeed, it is well known that the liver is sexually dimorphic, and this might be relevant to explain the lower susceptibility to hepatic diseases and liver-derived metabolic disturbances (such as the cardiovascular diseases) characteristic of females during their fertile period. Furthermore, estrogens and the hepatic ERα play a significant role in liver sexual-specific functions and in the control of metabolic functions. A better grasp of the role of male and female sex steroids in the liver of the two sexes may therefore represent an important element to conceive novel treatments aimed at preventing metabolic diseases particularly in ageing women or limiting undesired side effect in the treatment of gender dysphoria. Copyright © 2018. Published by Elsevier GmbH.
Alexander, Marcalee S; New, Peter W; Biering-Sørensen, Fin; Courtois, Frederique; Popolo, Giulio Del; Elliott, Stacy; Kiekens, Carlotte; Vogel, Lawrence; Previnaire, Jean G
2017-01-01
Data set review and modification. To describe modifications in the International Spinal Cord Injury (SCI) Male Sexual Function Basic Data Set Version 2.0 and the International SCI Female Sexual and Reproductive Function Basic Data Set Version 2.0. International expert work group using on line communication. An international team of experts was compiled to review and revise the International SCI Male Sexual Function and Female Sexual and Reproductive Function Basic Data Sets Version 1.0. The group adapted Version 1.0 based upon review of published research, suggestions from concerned individuals and on line work group consensus. The revised data sets were then posted on the International Spinal Cord Society (ISCoS) and American Spinal Injury Association (ASIA) websites for 2 months for review. Subsequently, the data sets were approved by the ISCoS Scientific and Executive Committees and ASIA board of directors. The data sets were modified to a self-report format. They were reviewed for appropriateness for the pediatric age group and adapted to include a new variable to address the issue of sexual orientation. A clarification of the difference between the data sets and the autonomic standards was also developed. Sexuality is a continuously evolving topic. Modifications were needed to address this topic in a comprehensive fashion. It is recommended that Version 2.0 of these data sets are used for ongoing documentation of sexual status in the medical record and for documentation of sexual concerns during on-going research.
Rodriguez, Karina F.; Ungewitter, Erica K.; Crespo-Mejias, Yasmin; Liu, Chang; Nicol, Barbara; Kissling, Grace E.; Yao, Humphrey Hung-Chang
2015-01-01
Background Mice exposed to high levels of arsenic in utero have increased susceptibility to tumors such as hepatic and pulmonary carcinomas when they reach adulthood. However, the effects of in utero arsenic exposure on general physiological functions such as reproduction and metabolism remain unclear. Objectives We evaluated the effects of in utero exposure to inorganic arsenic at the U.S. Environmental Protection Agency (EPA) drinking water standard (10 ppb) and at tumor-inducing levels (42.5 ppm) on reproductive end points and metabolic parameters when the exposed females reached adulthood. Methods Pregnant CD-1 mice were exposed to sodium arsenite [none (control), 10 ppb, or 42.5 ppm] in drinking water from gestational day 10 to birth, the window of organ formation. At birth, exposed offspring were fostered to unexposed dams. We examined reproductive end points (age at vaginal opening, reproductive hormone levels, estrous cyclicity, and fertility) and metabolic parameters (body weight changes, hormone levels, body fat content, and glucose tolerance) in the exposed females when they reached adulthood. Results Arsenic-exposed females (10 ppb and 42.5 ppm) exhibited early onset of vaginal opening. Fertility was not affected when females were exposed to the 10-ppb dose. However, the number of litters per female was decreased in females exposed to 42.5 ppm of arsenic in utero. In both 10-ppb and 42.5-ppm groups, arsenic-exposed females had significantly greater body weight gain, body fat content, and glucose intolerance. Conclusion Our findings revealed unexpected effects of in utero exposure to arsenic: exposure to both a human-relevant low dose and a tumor-inducing level led to early onset of vaginal opening and to obesity in female CD-1 mice. Citation Rodriguez KF, Ungewitter EK, Crespo-Mejias Y, Liu C, Nicol B, Kissling GE, Yao HH. 2016. Effects of in utero exposure to arsenic during the second half of gestation on reproductive end points and metabolic parameters in female CD-1 mice. Environ Health Perspect 124:336–343; http://dx.doi.org/10.1289/ehp.1509703 PMID:26295903
Chemical Communication and Reproduction Partitioning in Social Wasps.
Dani, Francesca Romana; Turillazzi, Stefano
2018-05-22
Social wasps encompass species displaying diverse social organization regarding colony cycle, nest foundation, caste differences (from none to significant dimorphism) and number of reproductive queens. Current phylogenetic data suggests that sociality occured independently in the subfamily Stenogastrinae and in the Polistinae+Vespinae clade. In most species, including those with the simplest social organization, colony reproduction is monopolised by a single or few females. Since their nest mates can also develop ovaries and lay eggs, dominant females must somehow inhibit them from reproducing. Physical interactions in the form of open aggression or, usually, ritualised dominance by the fertile females contribute to fertility inhibition in several species, but it is unlikely to function in large colonies. In the latter case, reproduction within the colony is likely to be regulated through pheromones. Relatively little is known about these semiochemicals. Studies on all the three social wasp subfamilies, revealed that cuticular hydrocarbon components differ in abundance between egg-laying and not egg-laying females and that their composition depends on fertility status. In several species, females have been reported to manifestly react towards females with activated ovaries, but there is little evidence to support the hypothesis that fertile individuals are either recognized through their CHC composition, or that over-represented CHC constituents can inhibit fertility. Moreover, very little information exists on the possibility that exocrine glands release fertility signals or chemicals inhibiting fertility.
Intake of Erythrocytes Required for Reproductive Development of Female Schistosoma japonicum.
Wang, Jipeng; Wang, Shuqi; Liu, Xiufeng; Xu, Bin; Chai, Riyi; Zhou, Pan; Ju, Chuan; Sun, Jun; Brindley, Paul J; Hu, Wei
2015-01-01
The reproductive development and maturation of female schistosomes are crucial since their released eggs are responsible for the host immunopathology and transmission of schistosomiasis. However, little is known about the nutrients required by female Schistosoma japonicum during its sexual maturation. We evaluated the promoting effect of several nutrients (calf serum, red blood cells (RBCs), ATP and hypoxanthine) on the reproductive development of pre-adult females at 18 days post infection (dpi) from mixed infections and at 50 dpi from unisexual infections of laboratory mice in basic medium RPMI-1640. We found RBCs, rather than other nutrients, promoted the female sexual maturation and egg production with significant morphological changes. In 27% of females (18 dpi) from mixed infections that paired with males in vitro on day 14, vitelline glands could be positively stained by Fast Blue B; and in 35% of females (50 dpi) from unisexual infections on day 21, mature vitelline cells were observed. Infertile eggs were detected among both groups. To analyze which component of mouse RBCs possesses the stimulating effect, RBCs were fractionated and included in media. However, the RBC fractions failed to stimulate development of the female reproductive organs. In addition, bovine hemoglobin hydrolysate, digested by neutral protease, was found to exhibit the promoting activity instead of untreated bovine hemoglobin. The other protein hydrolysate, lactalbumin hydrolysate, exhibited a similar effect with bovine hemoglobin hydrolysate. Using quantitative RT-PCR, we found the expression levels of four reproduction-related genes were significantly stimulated by RBCs. These data indicate that RBCs provide essential nutrients for the sexual maturation of female S. japonicum and that the protein component of RBCs appeared to constitute the key nutrient. These findings would improve laboratory culture of pre-adult schistosomes to adult worms in medium with well-defined components, which is important to investigate the function of genes related to female sexual maturation.
Intake of Erythrocytes Required for Reproductive Development of Female Schistosoma japonicum
Wang, Jipeng; Wang, Shuqi; Liu, Xiufeng; Xu, Bin; Chai, Riyi; Zhou, Pan; Ju, Chuan; Sun, Jun; Brindley, Paul J.; Hu, Wei
2015-01-01
The reproductive development and maturation of female schistosomes are crucial since their released eggs are responsible for the host immunopathology and transmission of schistosomiasis. However, little is known about the nutrients required by female Schistosoma japonicum during its sexual maturation. We evaluated the promoting effect of several nutrients (calf serum, red blood cells (RBCs), ATP and hypoxanthine) on the reproductive development of pre-adult females at 18 days post infection (dpi) from mixed infections and at 50 dpi from unisexual infections of laboratory mice in basic medium RPMI-1640. We found RBCs, rather than other nutrients, promoted the female sexual maturation and egg production with significant morphological changes. In 27% of females (18 dpi) from mixed infections that paired with males in vitro on day 14, vitelline glands could be positively stained by Fast Blue B; and in 35% of females (50 dpi) from unisexual infections on day 21, mature vitelline cells were observed. Infertile eggs were detected among both groups. To analyze which component of mouse RBCs possesses the stimulating effect, RBCs were fractionated and included in media. However, the RBC fractions failed to stimulate development of the female reproductive organs. In addition, bovine hemoglobin hydrolysate, digested by neutral protease, was found to exhibit the promoting activity instead of untreated bovine hemoglobin. The other protein hydrolysate, lactalbumin hydrolysate, exhibited a similar effect with bovine hemoglobin hydrolysate. Using quantitative RT-PCR, we found the expression levels of four reproduction-related genes were significantly stimulated by RBCs. These data indicate that RBCs provide essential nutrients for the sexual maturation of female S. japonicum and that the protein component of RBCs appeared to constitute the key nutrient. These findings would improve laboratory culture of pre-adult schistosomes to adult worms in medium with well-defined components, which is important to investigate the function of genes related to female sexual maturation. PMID:25978643
Oli, Madan K; Armitage, Kenneth B
2003-08-01
Theoretical and empirical studies suggest that the age of first reproduction (the age at which reproduction begins) can have a substantial influence on population dynamics and individual fitness. Using complete survival and reproductive histories of 428 female yellow-bellied marmots (Marmota flaviventris) from a 40-year study (1962-2001), we investigated causes and fitness consequences of delayed maturity. Most females (86%) died without reproducing. The age of first reproduction of females that survived to reproduce at least once (n=60) ranged from 2 to 6 years. Females maturing later did not have a larger lifetime number of successful reproductive events or offspring production, nor did they experience improved survival. Females reproducing earlier had a higher fitness than those that delayed maturity. These results suggest that the net cost of early maturity was less than fitness benefits associated with early onset of reproduction, and that age of first reproduction in our study population is under substantial directional selection favoring early maturity. We conclude that female yellow-bellied marmots delay onset of reproduction not because of fitness benefits of foregoing reproduction at an earlier age, but due to the social suppression of reproduction by older, reproductive females, which enhances their own fitness to the detriment of the fitness of young females. Our results indicate that female yellow-bellied marmots that survive to reproduce may act to increase their own direct fitness, and that social suppression of reproduction of young females is a part of that strategy.
Sickness-induced changes in physiology do not affect fecundity or same-sex behavior.
Sylvia, Kristyn E; Báez Ramos, Patricia; Demas, Gregory E
2018-02-01
Previous work in our lab has shown that early-life infection affects female reproductive physiology and function (i.e., smaller ovaries, abnormal estrous cycles) and alters investigation and aggression towards male conspecifics in a reproductive context. Although many studies have investigated the effects of postnatal immune challenge on physiological and behavioral development, fewer studies have examined whether these changes have ultimate effects on reproduction. In the current study, we paired Siberian hamsters (Phodopus sungorus) and simulated a bacterial infection in early life by administering lipopolysaccharide (LPS) to male and female pups on pnd3 and pnd5. In adulthood, hamsters were paired with novel individuals of the same sex, and we scored an array of social behaviors (e.g., investigation, aggression). We then paired animals with individuals of the opposite sex for 5 consecutive nights, providing them with the opportunity to mate. We found that females exhibited impaired reproductive physiology and function in adulthood (i.e., smaller ovaries and abnormal estrous cycles), similar to our previous work. However, both LPS-treated males and females exhibited similar same-sex social behavior when compared with saline-treated controls, they successfully mated, and there were no significant changes in fecundity. These data suggest that the physiological changes in response to neonatal immune challenge may not have long-term effects on reproductive success in a controlled environment. Collectively, the results of this study are particularly important when investigating the relationships between physiology and behavior within an ultimate context. Animals exposed to early-life stress may in fact be capable of compensating for changes in physiology in order to survive and reproduce in some contexts. Copyright © 2017 Elsevier Inc. All rights reserved.
A role for tachykinins in female mouse and rat reproductive function.
Pintado, C Oscar; Pinto, Francisco M; Pennefather, Jocelyn N; Hidalgo, Agustin; Baamonde, Ana; Sanchez, Teresa; Candenas, M Luz
2003-09-01
Tachykinins may be involved in reproduction. A reverse transcription-polymerase chain reaction assay was used to analyze the expression of tachykinins and tachykinin receptors in different types of reproductive cells from mice. The preprotachykinin (PPT) genes, PPT-A, PPT-B and PPT-C, that encode substance P/neurokinin A, neurokinin B, and hemokinin-1, respectively, and the genes that encode the tachykinin NK1, NK2, and NK3 receptors were all expressed, at different levels, in the uterus of superovulated, unfertilized mice. The mRNA of neprilysin (NEP), the main enzyme involved in tachykinin metabolism, was also expressed in the uterus. Isolated cumulus granulosa cells expressed PPT-A, PPT-B, PPT-C, and NEP and low levels of the tachykinin NK1 and NK2 receptors. Mouse oocytes expressed PPT-A and -B mRNA transcripts. A low expression of the three tachykinin receptors was observed but PPT-C and NEP were undetectable. Two- and 8- to 16-cell mouse embryos expressed only a low-abundance transcript corresponding to the NK1 receptor. However, the mRNAs of PPT-B, PPT-C and NEP appeared in blastocyst-stage embryos. A low-abundance transcript corresponding to the NK2 receptor was the only target gene detected in mice sperm. Female mice or rats treated neonatally with capsaicin showed a reduced fertility. A reduction in litter size was observed in female rats treated in vivo with the tachykinin NK3 receptor antagonist SR 142801. These data show that tachykinins of both neuronal and nonneuronal origin are differentially expressed in various types of reproductive cells and may play a role in female reproductive function.
Haldar, Chandana; Yadav, Rajesh; Alipreeta
2006-08-01
We studied the annual correlation of ovarian activity and pineal gland in relation with seasonal variation and gestation of a tropical zone short-nosed fruit bat Cynopterus sphinx. Female bats showed bimodal polyestry (February/March and September/October) in their reproductive cycle. Plasma estradiol concentration ran parallel with ovarian activity and had an inverse relation with pineal mass and peripheral melatonin concentration. Due to the delayed embryonic development in the uterus (October-March) of female bats, interestingly, the uterine activity did not show a parallel relation with ovarian activity and estradiol level. Further, compared with normal non-pregnant females, melatonin level was high during gestation and delayed embryonic development phase. This suggests that the reproductive synchrony and annual variation in ovarian activity of this nocturnal flying mammal differ from other common tropical mammals. The delayed embryonic development in bats might be an adaptive strategy for the unfavorable conditions of the seasons and might be regulated by high peripheral estradiol and melatonin concentration.
Reproductive maturation and senescence in the female brown bear
Schwartz, Charles C.; Keating, Kim A.; Reynolds III, Harry V.; Barnes, Victor G.; Sellers, Richard A.; Swenson, J.E.; Miller, Sterling D.; McLellan, B.N.; Keay, Jeffrey A.; McCann, Robert; Gibeau, Michael; Wakkinen, Wayne F.; Mace, Richard D.; Kasworm, Wayne; Smith, Rodger; Herrero, Steven
2003-01-01
Changes in age-specific reproductive rates can have important implications for managing populations, but the number of female brown (grizzly) bears (Ursus arctos) observed in any one study is usually inadequate to quantify such patterns, especially for older females and in hunted areas. We examined patterns of reproductive maturation and senescence in female brown bears by combining data from 20 study areas from Sweden, Alaska, Canada, and the continental United States. We assessed reproductive performance based on 4,726 radiocollared years for free-ranging female brown bears (age 3); 482 of these were for bears 20 years of age. We modeled age-specific probability of litter production using extreme value distributions to describe probabilities for young- and old-age classes, and a power distribution function to describe probabilities for prime-aged animals. We then fit 4 models to pooled observations from our 20 study areas. We used Akaike’s Information Criterion (AIC) to select the best model. Inflection points suggest that major shifts in litter production occur at 4–5 and 28–29 years of age. The estimated model asymptote (0.332, 95% CI ¼ 0.319–0.344) was consistent with the expected reproductive cycle of a cub litter every 3 years (0.333). We discuss assumptions and biases in data collection relative to the shape of the model curve. Our results conform to senescence theory and suggest that female age structure in contemporary brown bear populations is considerably younger than would be expected in the absence of modern man. This implies that selective pressures today differ from those that influenced brown bear evolution.
Reproductive parameters of the Pacific angel shark Squatina californica (Selachii: Squatinidae).
Romero-Caicedo, A F; Galván-Magaña, F; Hernández-Herrera, A; Carrera-Fernández, M
2016-04-01
Reproductive characteristics of the Pacific angel shark, Squatina californica, were evaluated from 420 specimens obtained from the artisanal fishery in La Paz Bay, Gulf of California, Mexico. Females (99 cm, 6000 g) were larger than males (95 cm, 5000 g) in terms of both total length (L(T)) and body mass (M(T)). The overall sex ratio was significantly different from the expected 1:1, suggesting sexual segregation of mature individuals in La Paz Bay. Males had developed reproductive organs and calcified claspers from 72 cm L(T); the median size at maturity (LT50 ) was 75.6 cm. In females, only the left ovary was functional and mature ovarian follicles were present from 77 cm L(T); the estimated LT50 was 77.7 cm. For the 10 gravid females sampled, uterine fecundity was between two and 10 embryos. Mature, non-gravid females with small and large ovarian follicles appeared simultaneously with gravid females with follicles that did not exceed 1.9 cm diameter. © 2016 The Fisheries Society of the British Isles.
Mayor, P; López-Béjar, M; Jori, F; Fenech, M; López-Gatius, F
2003-07-15
In the present study, we examined certain features of the functional anatomy of the female genital tract of the wild brush-tailed porcupine (Atherurus africanus) to obtain data on the reproductive biology of this African forest rodent. Two consecutive experiments were performed. The aim of the first was to establish macroscopic and microscopic features of the genital organs, and to explore correlations between predominant ovarian structures and vaginal contents in 20 wild, mature females. In the second experiment, we inspected the external genitalia and vaginal smears of a further 10 females in captivity on a daily basis for 90 days. The uterus of the brush-tailed porcupine is bicornuate and composed of two separated uterine horns, a uterine body and cervix. The genital tract does not present a vaginal vestibule. Thus, there is no portion common to genital and urinary tracts. Females in the follicular phase of the oestrous cycle showed increased cornification of the vaginal epithelium and a high density of eosinophilic cells in vaginal smears. The vulva and vaginal opening were open, reddish and tumefacted. In luteal phase or in pregnancy, epithelial cornification and eosinophilic features were notably reduced and the vagina presented a pale, non-tumefacted vulva and a vaginal closure membrane. Females in captivity showed spontaneous cycles, a polyoestrous reproduction pattern and, based on features of the external genitalia and vaginal smears, their oestrous cycle length was 27.1+/-6.4 days (n=12).
MIPs are ancestral ligands for the sex peptide receptor.
Kim, Young-Joon; Bartalska, Katarina; Audsley, Neil; Yamanaka, Naoki; Yapici, Nilay; Lee, Ju-Youn; Kim, Yong-Chul; Markovic, Milica; Isaac, Elwyn; Tanaka, Yoshiaki; Dickson, Barry J
2010-04-06
Upon mating, females of many animal species undergo dramatic changes in their behavior. In Drosophila melanogaster, postmating behaviors are triggered by sex peptide (SP), which is produced in the male seminal fluid and transferred to female during copulation. SP modulates female behaviors via sex peptide receptor (SPR) located in a small subset of internal sensory neurons that innervate the female uterus and project to the CNS. Although required for postmating responses only in these female sensory neurons, SPR is expressed broadly in the CNS of both sexes. Moreover, SPR is also encoded in the genomes of insects that lack obvious SP orthologs. These observations suggest that SPR may have additional ligands and functions. Here, we identify myoinhibitory peptides (MIPs) as a second family of SPR ligands that is conserved across a wide range of invertebrate species. MIPs are potent agonists for Drosophila, Aedes, and Aplysia SPRs in vitro, yet are unable to trigger postmating responses in vivo. In contrast to SP, MIPs are not produced in male reproductive organs, and are not required for postmating behaviors in Drosophila females. We conclude that MIPs are evolutionarily conserved ligands for SPR, which are likely to mediate functions other than the regulation of female reproductive behaviors.
Melin, Anna; Tornberg, Asa B; Skouby, Sven; Faber, Jens; Ritz, Christian; Sjödin, Anders; Sundgot-Borgen, Jorunn
2014-04-01
Low energy availability (EA) in female athletes with or without an eating disorder (ED) increases the risk of oligomenorrhoea/functional hypothalamic amenorrhoea and impaired bone health, a syndrome called the female athlete triad (Triad). There are validated psychometric instruments developed to detect disordered eating behaviour (DE), but no validated screening tool to detect persistent low EA and Triad conditions, with or without DE/ED, is available. The aim of this observational study was to develop and test a screening tool designed to identify female athletes at risk for the Triad. Female athletes (n=84) with 18-39 years of age and training ≥5 times/week filled out the Low Energy Availability in Females Questionnaire (LEAF-Q), which comprised questions regarding injuries and gastrointestinal and reproductive function. Reliability and internal consistency were evaluated in a subsample of female dancers and endurance athletes (n=37). Discriminant as well as concurrent validity was evaluated by testing self-reported data against measured current EA, menstrual function and bone health in endurance athletes from sports such as long distance running and triathlon (n=45). The 25-item LEAF-Q produced an acceptable sensitivity (78%) and specificity (90%) in order to correctly classify current EA and/or reproductive function and/or bone health. The LEAF-Q is brief and easy to administer, and relevant as a complement to existing validated DE screening instruments, when screening female athletes at risk for the Triad, in order to enable early detection and intervention.
Sexual function in infertile women with polycystic ovary syndrome and unexplained infertility.
Diamond, Michael P; Legro, Richard S; Coutifaris, Christos; Alvero, Ruben; Robinson, Randal D; Casson, Peter A; Christman, Gregory M; Huang, Hao; Hansen, Karl R; Baker, Valerie; Usadi, Rebecca; Seungdamrong, Aimee; Bates, G Wright; Rosen, R Mitchell; Schlaff, William; Haisenleder, Daniel; Krawetz, Stephen A; Barnhart, Kurt; Trussell, J C; Santoro, Nanette; Eisenberg, Esther; Zhang, Heping
2017-08-01
While female sexual dysfunction is a frequent occurrence, characteristics in infertile women are not well delineated. Furthermore, the impact of infertility etiology on the characteristics in women with differing androgen levels observed in women with polycystic ovary syndrome and unexplained infertility has not been assessed. The objective of the study was to determine the characteristics of sexual dysfunction in women with polycystic ovary syndrome and unexplained infertility. A secondary data analysis was performed on 2 of Eunice Kennedy Shriver National Institute of Child Health and Human Development Cooperative Reproductive Medicine Networks clinical trials: Pregnancy in Polycystic Ovary Syndrome Study II and Assessment of Multiple Intrauterine Gestations From Ovarian Stimulation. Both protocols assessed female sexual function using the Female Sexual Function Inventory and the Female Sexual Distress Scale. Women with polycystic ovary syndrome had higher weight and body mass index than women with unexplained infertility (each P < .001), greater phenotypic (Ferriman-Gallwey hirsutism score, sebum score, and acne score; each P < .001), and hormonal (testosterone, free testosterone, and dehydroepiandrosterone; each P < .001) evidence of androgen excess. Sexual function scores, as assessed by the Female Sexual Function Inventory, were nearly identical. The Female Sexual Distress Scale total score was higher in women with polycystic ovary syndrome. The mean Female Sexual Function Inventory total score increased slightly as the free androgen index increased, mainly as a result of the desire subscore. This association was more pronounced in the women with unexplained infertility. Reproductive-age women with infertility associated with polycystic ovary syndrome and unexplained infertility, despite phenotypic and biochemical differences in androgenic manifestations, do not manifest clinically significant differences in sexual function. Copyright © 2017 Elsevier Inc. All rights reserved.
Neuromedin s as novel putative regulator of luteinizing hormone secretion.
Vigo, E; Roa, J; López, M; Castellano, J M; Fernandez-Fernandez, R; Navarro, V M; Pineda, R; Aguilar, E; Diéguez, C; Pinilla, L; Tena-Sempere, M
2007-02-01
Neuromedin S (NMS), a 36 amino acid peptide structurally related to neuromedin U, was recently identified in rat brain as ligand for the G protein-coupled receptor FM4/TGR-1, also termed neuromedin U receptor type-2 (NMU2R). Central expression of NMS appears restricted to the suprachiasmatic nucleus, and NMS has been involved in the regulation of dark-light rhythms and suppression of food intake. Reproduction is known to be tightly regulated by metabolic and photoperiodic cues. Yet the potential contribution of NMS to the control of reproductive axis remains unexplored. We report herein analyses of hypothalamic expression of NMS and NMU2R genes, as well as LH responses to NMS, in different developmental and functional states of the female rat. Expression of NMS and NMU2R genes was detected at the hypothalamus along postnatal development, with significant fluctuations of their relative levels (maximum at prepubertal stage and adulthood). In adult females, hypothalamic expression of NMS (which was confined to suprachiasmatic nucleus) and NMU2R significantly varied during the estrous cycle (maximum at proestrus) and was lowered after ovariectomy and enhanced after progesterone supplementation. Central administration of NMS evoked modest LH secretory responses in pubertal and cyclic females at diestrus, whereas exaggerated LH secretory bursts were elicited by NMS at estrus and after short-term fasting. Conversely, NMS significantly decreased elevated LH concentrations of ovariectomized rats. In summary, we provide herein novel evidence for the ability of NMS to modulate LH secretion in the female rat. Moreover, hypothalamic expression of NMS and NMU2R genes appeared dependent on the functional state of the female reproductive axis. Our data are the first to disclose the potential implication of NMS in the regulation of gonadotropic axis, a function that may contribute to the integration of circadian rhythms, energy balance, and reproduction.
Faber-Hammond, Joshua; Samanta, Manoj P; Whitchurch, Elizabeth A; Manning, Dustin; Sisneros, Joseph A; Coffin, Allison B
2015-01-01
Acoustic communication is essential for the reproductive success of the plainfin midshipman fish (Porichthys notatus). During the breeding season, type I males use acoustic cues to advertise nest location to potential mates, creating an audible signal that attracts reproductive females. Type II (sneaker) males also likely use this social acoustic signal to find breeding pairs from which to steal fertilizations. Estrogen-induced changes in the auditory system of breeding females are thought to enhance neural encoding of the advertisement call, and recent anatomical data suggest the saccule (the main auditory end organ) as one possible target for this seasonal modulation. Here we describe saccular transcriptomes from all three sexual phenotypes (females, type I and II males) collected during the breeding season as a first step in understanding the mechanisms underlying sexual phenotype-specific and seasonal differences in auditory function. We used RNA-Seq on the Ion Torrent platform to create a combined transcriptome dataset containing over 79,000 assembled transcripts representing almost 9,000 unique annotated genes. These identified genes include several with known inner ear function and multiple steroid hormone receptors. Transcripts most closely matched to published genomes of nile tilapia and large yellow croaker, inconsistent with the phylogenetic relationship between these species but consistent with the importance of acoustic communication in their life-history strategies. We then compared the RNA-Seq results from the saccules of reproductive females with a separate transcriptome from the non-reproductive female phenotype and found over 700 differentially expressed transcripts, including members of the Wnt and Notch signaling pathways that mediate cell proliferation and hair cell addition in the inner ear. These data constitute a valuable resource for furthering our understanding of the molecular basis for peripheral auditory function as well as a range of future midshipman and cross-species comparative studies of the auditory periphery.
Redundancy in Kiss1 Expression Safeguards Reproduction in the Mouse
Popa, Simina M.; Moriyama, Ryutaro M.; Caligioni, Claudia S.; Yang, Jasmine J.; Cho, Caroline M.; Concepcion, Tessa L.; Oakley, Amy E.; Lee, In Hae; Sanz, Elisenda; Amieux, Paul S.; Caraty, Alain; Palmiter, Richard D.; Navarro, Victor M.; Chan, Yee-Ming; Seminara, Stephanie B.; Clifton, Donald K.
2013-01-01
Kisspeptin (Kiss1) signaling to GnRH neurons is widely acknowledged to be a prerequisite for puberty and reproduction. Animals lacking functional genes for either kisspeptin or its receptor exhibit low gonadotropin secretion and infertility. Paradoxically, a recent study reported that genetic ablation of nearly all Kiss1-expressing neurons (Kiss1 neurons) does not impair reproduction, arguing that neither Kiss1 neurons nor their products are essential for sexual maturation. We posited that only minute quantities of kisspeptin are sufficient to support reproduction. If this were the case, animals having dramatically reduced Kiss1 expression might retain fertility, testifying to the redundancy of Kiss1 neurons and their products. To test this hypothesis and to determine whether males and females differ in the required amount of kisspeptin needed for reproduction, we used a mouse (Kiss1-CreGFP) that has a severe reduction in Kiss1 expression. Mice that are heterozygous and homozygous for this allele (Kiss1Cre/+ and Kiss1Cre/Cre) have ∼50% and 95% reductions in Kiss1 transcript, respectively. We found that although male Kiss1Cre/Cre mice sire normal-sized litters, female Kiss1Cre/Cre mice exhibit significantly impaired fertility and ovulation. These observations suggest that males require only 5% of normal Kiss1 expression to be reproductively competent, whereas females require higher levels for reproductive success. PMID:23736293
Is bigger better? The relationship between size and reproduction in female Asian elephants.
Crawley, J A H; Mumby, H S; Chapman, S N; Lahdenperä, M; Mar, K U; Htut, W; Thura Soe, A; Aung, H H; Lummaa, V
2017-10-01
The limited availability of resources is predicted to impose trade-offs between growth, reproduction and self-maintenance in animals. However, although some studies have shown that early reproduction suppresses growth, reproduction positively correlates with size in others. We use detailed records from a large population of semi-captive elephants in Myanmar to assess the relationships between size (height and weight), reproduction and survival in female Asian elephants, a species characterized by slow, costly life history. Although female height gain during the growth period overlapped little with reproductive onset in the population, there was large variation in age at first reproduction and only 81% of final weight had been reached by peak age of reproduction at the population level (19 years). Those females beginning reproduction early tended to be taller and lighter later in life, although these trends were not significant. We found that taller females were more likely to have reproduced by a given age, but such effects diminished with age, suggesting there may be a size threshold to reproduction which is especially important in young females. Because size was not linked with female survival during reproductive ages, the diminishing effect of height on reproduction with age is unlikely to be due to biased survival of larger females. We conclude that although reproduction may not always impose significant costs on growth, height may be a limiting factor to reproduction in young female Asian elephants, which could have important implications considering their birth rates are low and peak reproduction is young - 19 years in this population. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.
The Role of Hox Genes in Female Reproductive Tract Development, Adult Function, and Fertility.
Du, Hongling; Taylor, Hugh S
2015-11-09
HOX genes convey positional identity that leads to the proper partitioning and adult identity of the female reproductive track. Abnormalities in reproductive tract development can be caused by HOX gene mutations or altered HOX gene expression. Diethylstilbestrol (DES) and other endocrine disruptors cause Müllerian defects by changing HOX gene expression. HOX genes are also essential regulators of adult endometrial development. Regulated HOXA10 and HOXA11 expression is necessary for endometrial receptivity; decreased HOXA10 or HOXA11 expression leads to decreased implantation rates. Alternation of HOXA10 and HOXA11 expression has been identified as a mechanism of the decreased implantation associated with endometriosis, polycystic ovarian syndrome, leiomyoma, polyps, adenomyosis, and hydrosalpinx. Alteration of HOX gene expression causes both uterine developmental abnormalities and impaired adult endometrial development that prevent implantation and lead to female infertility. Copyright © 2016 Cold Spring Harbor Laboratory Press; all rights reserved.
Telocytes in female reproductive system (human and animal).
Aleksandrovych, Veronika; Walocha, Jerzy A; Gil, Krzysztof
2016-06-01
Telocytes (TCs) are a newly discovered type of cell with numerous functions. They have been found in a large variety of organs: heart (endo-, myo-, epi- and pericardium, myocardial sleeves, heart valves); digestive tract and annex glands (oesophagus, stomach, duodenum, jejunum, liver, gallbladder, salivary gland, exocrine pancreas); respiratory system (trachea and lungs); urinary system (kidney, renal pelvis, ureters, bladder, urethra); female reproductive system (uterus, Fallopian tube, placenta, mammary gland); vasculature (blood vessels, thoracic duct); serous membranes (mesentery and pleura); and other organs (skeletal muscle, meninges and choroid plexus, neuromuscular spindles, fascia lata, skin, eye, prostate, bone marrow). Likewise, TCs are widely distributed in vertebrates (fish, reptiles, birds, mammals, including human). This review summarizes particular features of TCs in the female reproductive system, emphasizing their involvement in physiological and pathophysiological processes. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.
RNA-Binding Proteins in Female Reproductive Pathologies.
Khalaj, Kasra; Miller, Jessica E; Fenn, Christian R; Ahn, SooHyun; Luna, Rayana L; Symons, Lindsey; Monsanto, Stephany P; Koti, Madhuri; Tayade, Chandrakant
2017-06-01
RNA-binding proteins are key regulatory molecules involved primarily in post-transcriptional gene regulation of RNAs. Post-transcriptional gene regulation is critical for adequate cellular growth and survival. Recent reports have shown key interactions between these RNA-binding proteins and other regulatory elements, such as miRNAs and long noncoding RNAs, either enhancing or diminishing their response to RNA stabilization. Many RNA-binding proteins have been reported to play a functional role in mediation of cytokines involved in inflammation and immune dysfunction, and some have been classified as global post-transcriptional regulators of inflammation. The ubiquitous expression of RNA-binding proteins in a wide variety of cell types and their unique mechanisms of degradative action provide evidence that they are involved in reproductive tract pathologies. Aberrant inflammation and immune dysfunction are major contributors to the pathogenesis and disease pathophysiology of many reproductive pathologies, including ovarian and endometrial cancers in the female reproductive tract. Herein, we discuss various RNA-binding proteins and their unique contributions to female reproductive pathologies with a focus on those mediated by aberrant inflammation and immune dysfunction. Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.
Male-biased hermaphrodites in a gynodioecious shrub, Daphne jezoensis.
Sinclair, J P; Kameyama, Y; Shibata, A; Kudo, G
2016-09-01
Gynodioecy, a state where female and hermaphrodite plants coexist in populations, has been widely proposed an intermediate stage in the evolutionary pathway from hermaphroditism to dioecy. In the gynodioecy-dioecy pathway, hermaphrodites may gain most of their fitness through male function once females invade populations. To test this prediction, comprehensive studies on sex ratio variation across populations and reproductive characteristics of hermaphrodite and female phenotypes are necessary. This study examined the variation in sex ratio, sex expression, flower and fruit production and sexual dimorphism of morphological traits in a gynodioecious shrub, Daphne jezoensis, over multiple populations and years. Population sex ratio (hermaphrodite:female) was close to 1:1 or slightly hermaphrodite-biased. Sex type of individual plants was largely fixed, but 15% of plants changed their sex during a 6-year census. Hermaphrodite plants produced larger flowers and invested 2.5 times more resources in flower production than female plants, but they exhibited remarkably low fruit set (proportion of flowers setting fruits). Female plants produced six times more fruits than hermaphrodite plants. Low fruiting ability of hermaphrodite plants was retained even when hand-pollination was performed. Fruit production of female plants was restricted by pollen limitation under natural conditions, irrespective of high potential fecundity, and this minimised the difference in resources allocated to reproduction between the sexes. Negative effects of previous flower and fruit production on current reproduction were not apparent in both sexes. This study suggests that gynodioecy in this species is functionally close to a dioecious mating system: smaller flower production with larger fruiting ability in female plants, and larger flower production with little fruiting ability in hermaphrodite plants. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.
Emelumadu, Obiageli Fidelia; Igwegbe, Anthony Osita; Monago, Ifeoma Nwamaka; Ilika, Amobi Linus
2017-01-01
Background This was a prospective study designed to evaluate the impact of thyroid function abnormalities on reproductive hormones during menstrual cycle in HIV infected females at Nnamdi Azikiwe University Teaching Hospital Nnewi, South-East Nigeria. Methods The study randomly recruited 35 Symptomatic HIV infected females and 35 Symptomatic HIV infected females on antiretroviral therapy (HAART) for not less than six weeks from an HIV clinic and 40 apparently heathy control females among the hospital staff of NAUTH Nnewi. They were all premenopausal females with regular menstrual cycle and aged between 15–45 years. Blood samples were collected at follicular and luteal phases of their menstrual cycle for assay of Thyroid indices (FT3, FT4 and TSH) and Reproductive indices (FSH, LH, Estrogen, Progesterone, Prolactin and Testosterone) using ELISA method. Results The result showed significantly higher FSH and LH but significantly lower progesterone (prog) and estrogen (E2) in the test females compared to control females at both phases of menstrual cycle (P<0.05). There was significantly lower FT3 but significantly higher TSH value in Symptomatic HIV females (P<0.05). FSH, LH and TSH values were significantly lowered while prog and FT3 were significantly higher in Symptomatic HIV on ART compared to Symptomatic HIV females (P<0.05). FT3, FT4, Prog and E2 were inversely correlated while FSH and LH were positively correlated with duration of HIV infection in HIV females (P<0.05 respectively). There was a direct correlation between CD4+ count and FT3 while inverse correlation was found between CD4+ count and TSH levels (P<0.05). Discussion The present study demonstrated hypothyroidism with a significant degree of primary hypogonadism in Symptomatic HIV infected females at both follicular and luteal phases of menstrual cycle which tends to normalize on treatments. PMID:28723963
NASA Astrophysics Data System (ADS)
Rini Saraswati, Tyas; Yuniwarti, Enny Yusuf W.; Tana, Silvan
2018-03-01
Otus angelinae is included as a protected animal because of its endangered existence. Whereas, it has many values such as for mice pest control. Therefore, this research aims to optimize the reproductive function of Otus angelinae by administering turmeric powder mixed in its feed. This study was held on a laboratory scale with two male and two female Otus angelinae three months of age. Each subject is divided into two groups: a control group and a treatment group which is treated with turmeric powder 108 mg/owl/day mixed in 30 g catfish/day for a month. The parameter observed were the development of hierarchy follicles and the ovarium weight of female Otus angelinae, whereas the testis organs and testes weight were observed for the male. Both the female’s and male’s body weight, liver weight and the length of ductus reproduction were also observed. The data was analyzed descriptively. The results showed that the administration of turmeric powder can induce the development of ovarian follicles hierarchy and the length of ductus reproduction of female Otus angelinae and also induce the development of the testes and the length of ductus reproduction of male Otus angelinae. The addition of turmeric powder increased the liver weight of the female Otus angelinae, however it does not affect the body weight.
Discrete two-sex models of population dynamics: On modelling the mating function
NASA Astrophysics Data System (ADS)
Bessa-Gomes, Carmen; Legendre, Stéphane; Clobert, Jean
2010-09-01
Although sexual reproduction has long been a central subject of theoretical ecology, until recently its consequences for population dynamics were largely overlooked. This is now changing, and many studies have addressed this issue, showing that when the mating system is taken into account, the population dynamics depends on the relative abundance of males and females, and is non-linear. Moreover, sexual reproduction increases the extinction risk, namely due to the Allee effect. Nevertheless, different studies have identified diverse potential consequences, depending on the choice of mating function. In this study, we investigate the consequences of three alternative mating functions that are frequently used in discrete population models: the minimum; the harmonic mean; and the modified harmonic mean. We consider their consequences at three levels: on the probability that females will breed; on the presence and intensity of the Allee effect; and on the extinction risk. When we consider the harmonic mean, the number of times the individuals of the least abundant sex mate exceeds their mating potential, which implies that with variable sex-ratios the potential reproductive rate is no longer under the modeller's control. Consequently, the female breeding probability exceeds 1 whenever the sex-ratio is male-biased, which constitutes an obvious problem. The use of the harmonic mean is thus only justified if we think that this parameter should be re-defined in order to represent the females' breeding rate and the fact that females may reproduce more than once per breeding season. This phenomenon buffers the Allee effect, and reduces the extinction risk. However, when we consider birth-pulse populations, such a phenomenon is implausible because the number of times females can reproduce per birth season is limited. In general, the minimum or modified harmonic mean mating functions seem to be more suitable for assessing the impact of mating systems on population dynamics.
Mayor, P; Bodmer, R E; Lopez-Bejar, M
2011-02-01
This study examined anatomical and histological characteristics of genital organs of 38 black agouti females in the wild in different reproductive stages, collected by rural hunters in the North-eastern Peruvian Amazon. Females in the follicular phase of the estrous cycle had greater antral follicle sizes than other females, the largest antral follicle measuring 2.34mm. Antral follicles in pregnant females and females in luteal phase of the estrous cycle had an average maximum diameter smaller than 1mm. In black agouti females in follicular phase, some antral follicles are selected to continue to growth, reaching a pre-ovulatory diameter of 2mm. Mean ovulation rate was 2.5 follicles and litter size was 2.1 embryos or fetuses per pregnant female, resulting in a rate of ovum mortality of 20.8%. Many follicles from which ovulation did not occur of 1-mm maximum diameter luteinize forming accessory CL. The constituent active luteal tissues of the ovary are functional and accessory CL. Although all females had accessory CL, transformation of follicles into accessory CL occurred especially in pregnant females, resulting in a contribution from 9% to 23% of the total luteal volume as pregnancy advances. The persistence of functional CL throughout pregnancy might reflect the importance for the maintenance of gestation and may be essential for the continuous hormonal production. The duplex uterus of the agouti female is composed by two completely independent uterine horns with correspondent separate cervices opening into the vagina. In pregnant females, most remarkable observed uterine adaptations were induced by the progressive enlargement caused by the normal pregnancy evolution. The wild black agouti showed different vaginal epithelium features in accordance with the reproductive state of the female. Copyright © 2011 Elsevier B.V. All rights reserved.
Harris, Breanna N.; Saltzman, Wendy
2013-01-01
Previous studies indicate that reproductive condition can alter the stress response and glucocorticoid release. Although the functional significance of hypothalamic-pituitary-adrenal (HPA) axis modulation by breeding condition is not fully understood, one possible explanation is the behavior hypothesis, which states that an animal’s need to express parental behavior may be driving modulation of the HPA axis. This possibility is consistent with findings of blunted activity and reactivity of the HPA axis in lactating female mammals; however, effects of reproductive status on HPA function have not been well characterized in male mammals that express parental behavior. Therefore, we tested this hypothesis in the monogamous and biparental California mouse. Several aspects of HPA activity were compared in males from three reproductive conditions: virgin males (housed with another male), non-breeding males (housed with a tubally ligated female), and first-time fathers (housed with a female and their first litter of pups). In light of the behavior hypothesis we predicted that new fathers would differ from virgin and non-breeding males in several aspects of HPA function and corticosterone (CORT) output: decreased amplitude of the diurnal rhythm in CORT, a blunted CORT increase following predator-odor stress, increased sensitivity to glucocorticoid negative feedback, and/or a blunted CORT response to pharmacological stimulation. In addition, we predicted that first-time fathers would be more resistant to CORT-induced suppression of testosterone secretion, as testosterone is important for paternal behavior in this species. We found that virgin males, non-breeding males and first-time fathers did not display any CORT differences in diurnal rhythm, response to a predator-odor stressor, or response to pharmacological suppression or stimulation. Additionally, there were no differences in circulating testosterone concentrations. Adrenal mass was, however, significantly lower in new fathers than in virgin or non-breeding males. These results suggest that the behavior hypothesis does not explain HPA function across reproductive conditions in male California mice. PMID:23474132
Function and regulation of MTA1 and MTA3 in malignancies of the female reproductive system.
Brüning, Ansgar; Blankenstein, Thomas; Jückstock, Julia; Mylonas, Ioannis
2014-12-01
The family of metastasis-associated (MTA) genes is a small group of transcriptional co-regulators which are involved in various physiological functions, ranging from lymphopoietic cell differentiation to the development and maintenance of epithelial cell adhesions. By recruiting histone-modifying enzymes to specific promoter sequences, MTA proteins can function both as transcriptional repressors and activators of a number of cancer-relevant proteins, including Snail, E-cadherin, signal transducer and activator of transcriptions (STATs), and the estrogen receptor. Their involvement in the epithelial-mesenchymal transition process and regulatory interactions with estrogen receptor activity has made MTA proteins highly interesting research candidates, especially in the field of hormone-sensitive breast cancer and malignancies of the female reproductive tract. This review focuses on the current knowledge about the function and regulation of MTA1 and MTA3 proteins in gynecological cancer, including ovarian, endometrial, and cervical tumors.
Goldberg, Jay K; Wallace, Alisa K; Weiss, Stacey L
2017-09-14
Sex pheromones can perform a variety of functions ranging from revealing the location of suitable mates to being honest signals of mate quality, and they are used in the mate selection process by many species of reptile. In this study, we determined whether the skin lipids of female striped plateau lizards (Sceloporus virgatus) can predict the reproductive quality of females, thereby having the potential to serve as pheromones. Using gas chromatography/mass spectrometry, we identified 17 compounds present in skin lipids of female lizards. Using principal component analysis to compare the skin lipid profile of receptive and non-receptive females, we determined that an uncharacterized compound may allow for chemical identification of receptive mates. We also compared extracted principal components to measures of female fitness and reproductive qualities and found that the level of two 18 carbon fatty acids present in a female's skin lipids may indicate her clutch size. Finally, we compared the information content of the skin lipids to that of female-specific color ornaments to assess whether chemical and visual cues transmit different information or not. We found that the chroma of a female's orange throat patch is also related to her clutch size, suggesting that chemical signals may reinforce the information communicated by visual ornamentation in this species which would support the "backup signals" hypothesis for multiple signals.
NASA Astrophysics Data System (ADS)
Goldberg, Jay K.; Wallace, Alisa K.; Weiss, Stacey L.
2017-10-01
Sex pheromones can perform a variety of functions ranging from revealing the location of suitable mates to being honest signals of mate quality, and they are used in the mate selection process by many species of reptile. In this study, we determined whether the skin lipids of female striped plateau lizards ( Sceloporus virgatus) can predict the reproductive quality of females, thereby having the potential to serve as pheromones. Using gas chromatography/mass spectrometry, we identified 17 compounds present in skin lipids of female lizards. Using principal component analysis to compare the skin lipid profile of receptive and non-receptive females, we determined that an uncharacterized compound may allow for chemical identification of receptive mates. We also compared extracted principal components to measures of female fitness and reproductive qualities and found that the level of two 18 carbon fatty acids present in a female's skin lipids may indicate her clutch size. Finally, we compared the information content of the skin lipids to that of female-specific color ornaments to assess whether chemical and visual cues transmit different information or not. We found that the chroma of a female's orange throat patch is also related to her clutch size, suggesting that chemical signals may reinforce the information communicated by visual ornamentation in this species which would support the "backup signals" hypothesis for multiple signals.
Caloric restriction: Impact upon pituitary function and reproduction
Martin, Bronwen; Golden, Erin; Carlson, Olga D.; Egan, Josephine M.; Mattson, Mark P.; Maudsley, Stuart
2008-01-01
Reduced energy intake, or caloric restriction (CR), is known to extend life span and to retard age-related health decline in a number of different species, including worms, flies, fish, mice and rats. CR has been shown to reduce oxidative stress, improve insulin sensitivity, and alter neuroendocrine responses and central nervous system (CNS) function in animals. CR has particularly profound and complex actions upon reproductive health. At the reductionist level the most crucial physiological function of any organism is its capacity to reproduce. For a successful species to thrive, the balance between available energy (food) and the energy expenditure required for reproduction must be tightly linked. An ability to coordinate energy balance and fecundity involves complex interactions of hormones from both the periphery and the CNS and primarily centers upon the master endocrine gland, the anterior pituitary. In this review article we review the effects of CR on pituitary gonadotrope function and on the male and female reproductive axes. A better understanding of how dietary energy intake affects reproductive axis function and endocrine pulsatility could provide novel strategies for the prevention and management of reproductive dysfunction and its associated comorbidities. PMID:18329344
The effects of in utero bisphenol A exposure on reproductive capacity in several generations of mice
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ziv-Gal, Ayelet, E-mail: zivgal1@illinois.edu; Wang, Wei, E-mail: weiwang2@illinois.edu; Zhou, Changqing, E-mail: czhou27@illinois.edu
In utero bisphenol A (BPA) exposure affects reproductive function in the first generation (F1) of mice; however, not many studies have examined the reproductive effects of BPA exposure on subsequent generations. In this study, pregnant mice (F0) were orally dosed with vehicle, BPA (0.5, 20, and 50 μg/kg/day) or diethylstilbestrol (DES; 0.05 μg/kg/day) daily from gestation day 11 until birth. F1 females were used to generate the F2 generation, and F2 females were used to generate the F3 generation. Breeding studies at the ages of 3, 6, and 9 months were conducted to evaluate reproductive capacity over time. Further, studiesmore » were conducted to evaluate pubertal onset, litter size, and percentage of dead pups; and to calculate pregnancy rate, and mating, fertility, and gestational indices. The results indicate that BPA exposure (0.5 and 50 μg/kg/day) significantly delayed the age at vaginal opening in the F3 generation compared to vehicle control. Both DES (0.05 μg/kg/day) and BPA (50 μg/kg/day) significantly delayed the age at first estrus in the F3 generation compared to vehicle control. BPA exposure reduced gestational index in the F1 and F2 generations compared to control. Further, BPA exposure (0.5 μg/kg/day) compromised the fertility index in the F3 generation compared to control. Finally, in utero BPA exposure reduced the ability of female mice to maintain pregnancies as they aged. Collectively, these data suggest that BPA exposure affects reproductive function in female mice and that some effects may be transgenerational in nature. - Highlights: • In utero BPA delayed vaginal opening in the F3 generation compared to control. • In utero BPA delayed estrus in the F3 generation compared to control. • In utero BPA reduced the ability of F1 and F2 female mice to maintain pregnancies. • In utero BPA compromised the ability of F3 female mice to become pregnant. • Some effects of in utero BPA may be transgenerational in nature.« less
Ovarian and Uterine Functions in Female Survivors of Childhood Cancers.
Oktem, Ozgur; Kim, Samuel S; Selek, Ugur; Schatmann, Glenn; Urman, Bulent
2018-02-01
Adult survivors of childhood cancers are more prone to developing poor reproductive and obstetrical outcomes than their siblings and the general population as a result of previous exposure to chemotherapy and radiation during childhood. Chemotherapy drugs exert cytotoxic effects systemically and therefore can damage the ovaries, leading to infertility, premature ovarian failure, and, to a lesser extent, spontaneous abortions. They have very limited or no deleterious effects on the uterus that can be recognized clinically. By contrast, radiation is detrimental to both the ovaries and the uterus, thereby causing a greater magnitude of adverse effects on the female reproductive function. These include infertility, premature ovarian failure, miscarriage, fetal growth restrictions, perinatal deaths, preterm births, delivery of small-for-gestational-age infants, preeclampsia, and abnormal placentation. Regrettably, the majority of these adverse outcomes arise from radiation-induced uterine injury and are reported at higher incidence in the adult survivors of childhood cancers who were exposed to uterine radiation during childhood in the form of pelvic, spinal, or total-body irradiation. Recent findings of long-term follow-up studies evaluating reproductive performance of female survivors provided some reassurance to female cancer survivors by documenting that pregnancy and live birth rates were not significantly compromised in survivors, including those who had been treated with alkylating agents and had not received pelvic, cranial, and total-body irradiation. We aimed in this narrative review article to provide an update on the impact of chemotherapy and radiation on the ovarian and uterine function in female survivors of childhood cancer. Adult survivors of childhood cancers are more prone to developing a number of poor reproductive and obstetrical outcomes than their siblings and the general population as a result of previous exposure to chemotherapy and radiation during childhood. The impact of radiation therapy on the female genital system is greater than chemotherapy regimens because radiation is detrimental to both the uterus and the ovaries, whereas toxic effects of chemotherapy drugs are confined to the ovaries. Therefore, radiation-induced uterine damage accounts for most poor obstetrical outcomes in the survivors. These include infertility, miscarriages, stillbirths, fetal growth restrictions, preeclampsia, and preterm deliveries. © AlphaMed Press 2017.
Siefferman, Lynn; Hill, Geoffrey E
2005-08-01
Although the function of ornamental traits in males has been the focus of intensive research for decades, expression of such traits in females has received much less study. Eastern bluebirds (Sialia sialis) display structurally based ultraviolet/blue and melanin-based chestnut plumage, and in males this plumage coloration is related to both reproductive success and competitive ability. Compared to males, female bluebirds show a subdued expression of blue and chestnut ornamental coloration, and we used a combination of an aviary nutritional-stress experiment and four years of field data to test the hypothesis that coloration functions as a signal of female quality. First, we tested the effect of food intake on expression of structural and melanin coloration in female eastern bluebirds to determine whether structural or melanin coloration are condition-dependent traits. Females that were given ad libitum access to food displayed more ornamented structural coloration than females on a food-restricted diet, but there was no effect of the experiment on melanin ornamentation. Second, we used field data to assess whether female ornamentation correlated with measures of mate quality and parental effort. The structural coloration of females predicted first egg date, maternal provisioning rates, and measures of reproductive success. These data indicate that structural coloration is dependent on nutritional condition and suggest that sexual selection is acting on structurally based plumage coloration in female eastern bluebirds.
Liver ERα regulates AgRP neuronal activity in the arcuate nucleus of female mice.
Benedusi, Valeria; Della Torre, Sara; Mitro, Nico; Caruso, Donatella; Oberto, Alessandra; Tronel, Claire; Meda, Clara; Maggi, Adriana
2017-04-26
Recent work revealed the major role played by liver Estrogen Receptor α (ERα) in the regulation of metabolic and reproductive functions. By using mutant mice with liver-specific ablation of Erα, we here demonstrate that the hepatic ERα is essential for the modulation of the activity of Agouti Related Protein (AgRP) neurons in relation to the reproductive cycle and diet. Our results suggest that the alterations of hepatic lipid metabolism due to the lack of liver ERα activity are responsible for a neuroinflammatory status that induces refractoriness of AgRP neurons to reproductive and dietary stimuli. The study therefore points to the liver ERα as a necessary sensor for the coordination of systemic energy metabolism and reproductive functions.
Jak2 is Necessary for Neuroendocrine Control of Female Reproduction
Wu, Sheng; Divall, Sara; Hoffman, Gloria E.; Le, Wei Wei; Wagner, Kay-Uwe; Wolfe, Andrew
2011-01-01
GnRH neurons represent the final common output of signals from the brain that regulates reproductive function. A wide range of environmental factors impact GnRH neuron activity including disease, stress, nutrition, and seasonal cues, as well as gonadal steroid hormones. The CNS response is thought to be mediated, at least in part, through intermediate signaling molecules that affect GnRH neuronal activity. In vitro, GnRH neuronal cell lines respond to a variety of ligands which activate the Jak/STAT intracellular signaling pathway. In order to determine its biological function in reproduction, we used Cre/LoxP technology to generate GnRH neuron specific Jak2 conditional knockout (Jak2 G−/−) mice. GnRH mRNA levels were reduced in Jak2 G−/− mice when compared to controls, while the number of GnRH neurons was equivalent, indicating a reduction in GnRH gene expression. Secretion of GnRH is also reduced as basal serum LH levels were significantly lower in female Jak2 G−/− mice while the pituitary responded normally to exogenous GnRH. Preovulatory LH surge levels were blunted in Jak2 G−/− mice, which was correlated with reduced GnRH neuronal activation as assessed by c-Fos. However the activation of GnRH neurons following release from estrogen negative feedback is retained. Female Jak2 G−/− mice exhibited significantly delayed puberty and first estrus, abnormal estrous cyclicity and impaired fertility. These results demonstrate an essential role for Jak2 signaling in GnRH neurons for normal reproductive development and fertility in female mice. PMID:21209203
Histological characterization of peppermint shrimp ( Lysmata wurdemanni) androgenic gland
NASA Astrophysics Data System (ADS)
Liu, Xin; Zhang, Dong; Lin, Tingting
2017-12-01
The androgenic gland (AG) is an important endocrine gland for male reproductive function in crustaceans. In the present study, we investigated the histological characteristics of the androgenic gland of peppermint shrimp, Lysmata wurdemanni. The peppermint shrimp matures as male first, then some individuals may become euhermaphrodite after several moltings (transitional phase). Euhermaphrodite-phase shrimp acts as male at intermolts. However, it can be fertilized as a female immediately after molting. Considering the male reproductive function acts in its lifespan except for at larval stages, and female reproductive system starts to develop at transitional phase, we hypothesized that AG activity might be reduced to allow and promote vitellogenesis onset in early transitional phase and the following euhermaphrodite phase. So AG cell structure might be different in three phases in L. wurdemanni. The results showed that AG exists in the male in transitional and euhermaphrodite phases. The gland cell clusters surrounding the ejaculatory ducts locate at the roots of the fifth pereopods. The nucleus diameters are similar in the three phases while the nucleus- to-cell ratio is the lowest in euhermaphrodite phase. Our results indicated that for the individuals that will become euhermaphrodite, the cellular structure of AG changes since transitional phase. Male reproductive function which is still available in euhermaphrodite-phase shrimp should be due to the existence of the gland.
Seasonal Reproductive Biology of Drosophila suzukii (Diptera: Drosophilidae) in Temperate Climates.
Grassi, Alberto; Gottardello, Angela; Dalton, Daniel T; Tait, Gabriella; Rendon, Dalila; Ioriatti, Claudio; Gibeaut, David; Rossi Stacconi, M Valerio; Walton, Vaughn M
2018-02-08
Drosophila suzukii (Matsumura; Diptera: Drosophilidae) is a key pest of sweet cherry and small fruits worldwide. The present studies were designed to describe the reproductive physiology in both sexes, through dissections of their reproductive organs. We extensively dissected female D. suzukii throughout the season from 2013 to 2016 and classified the reproductive status flies based on five recognizable ovarian maturation stages: 1) no ovaries; 2) unripe ovaries 3) ripening eggs in ovarioles; 4) mature eggs in ovarioles; and 5) mature eggs in the abdomen. Development was examined as a function of calendar days as well as degree-days (DD). Results obtained from winter collections revealed that females collected from November to March contained a lower percentage of mature eggs than females collected from April to September. These data suggest that environmental conditions during the dormant period induce reproductive diapause. Oogenesis likely increased with an increase in mean monthly temperatures and DD. The first overwintered females with mature eggs were dissected as early as 21 February 2014 in Trento (7 DD). Additionally, we found that a low proportion of males (less than 50%) had sperm in their testes between January and March, yet during the same period females already have sperm stored in their spermathecal. Ivy berries was an alternative but unfavorable non-crop host during the late dormant period, as evidenced by emergence of smaller adults when compared to individuals emerging from cherry fruits. This study showed that D. suzukii females have great potential for oviposition early in the season, posing a risk to early season maturing crop hosts. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Aprison, Erin Z.; Ruvinsky, Ilya
2015-01-01
Pheromones are secreted molecules that mediate animal communications. These olfactory signals can have substantial effects on physiology and likely play important roles in organismal survival in natural habitats. Here we show that a blend of two ascaroside pheromones produced by C. elegans males primes the female reproductive system in part by improving sperm guidance toward oocytes. Worms have different physiological responses to different ratios of the same two molecules, revealing an efficient mechanism for increasing coding potential of a limited repertoire of molecular signals. The endogenous function of the male sex pheromones has an important side benefit. It substantially ameliorates the detrimental effects of prolonged heat stress on hermaphrodite reproduction because it increases the effectiveness with which surviving gametes are used following stress. Hermaphroditic species are expected to lose female-specific traits in the course of evolution. Our results suggest that some of these traits could have serendipitous utility due to their ability to counter the effects of stress. We propose that this is a general mechanism by which some mating-related functions could be retained in hermaphroditic species, despite their expected decay. PMID:26645097
Valdez, Diego J.; Vera Cortez, Marilina; Della Costa, Natalia S.; Lèche, Alvina; Hansen, Cristian; Navarro, Joaquín L.; Martella, Mónica B.
2014-01-01
Seasonal rhythm in sex hormones has been extensively studied in birds, as well as its relationship with the type of mating system. The Greater Rhea (Rhea americana), a South American ratite species, reproduces seasonally and has a complex mating system: female-defense polygyny and sequential polyandry. The present study aimed at analyzing the endocrine basis of reproduction in this species and its relationship with its mating system. We used HPLC and electrochemiluminescence techniques to identify and measure plasma testosterone and estradiol levels. Annual oscillations in sex hormones, testosterone and estradiol, in adult males and females were observed. Lower levels of these hormones were exhibited during the non reproductive season (February to July), whereas their maximum values were reached in September for males and November-December for females. These fluctuations reflect the seasonal changes in gonadal function. By contrast, no significant sex hormones oscillations were observed in juvenile males and females (negative control of seasonal changes). Greater rheas maintain high testosterone and estradiol levels throughout the reproductive period. The high testosterone levels during incubation and chick rearing did not inhibit parental behavior in males, which appears not to conform to the “Challenge Hypothesis”. In females, the high estradiol levels throughout the reproductive season would be needed to sustain their long egg-laying period. PMID:24837464
Reduced resistance to oxidative stress during reproduction as a cost of early-life stress.
Zimmer, Cédric; Spencer, Karen A
2015-05-01
Stress exposure during early-life development can have long-term consequences for a variety of biological functions including oxidative stress. The link between early-life stress and oxidative balance is beginning to be explored and previous studies have focused on this link in adult non-breeding or immature individuals. However, as oxidative stress is considered as the main physiological mechanism underlying the trade-off between self-maintenance and investment in reproduction, it is necessary to look at the consequences of early-life stress on oxidative status during reproduction. Here, we investigated the effects of exposure to pre- and/or post-natal stress on oxidative balance during reproduction under benign or stressful environmental conditions in an avian model species, the Japanese quail. We determined total antioxidant status (TAS), total oxidant status (TOS) and resistance to a free-radical attack in individual exposed to pre-natal stress, post-natal stress or both and in control individuals exposed to none of the stressors. TAS levels decreased over time in all females that reproduced under stressful conditions. TOS decreased between the beginning and the end of reproductive period in pre-natal control females. In all females, resistance to a free-radical attack decreased over the reproductive event but this decrease was more pronounced in females from a pre-natal stress development. Our results suggest that pre-natal stress may be associated with a higher cost of reproduction in terms of oxidative stress. These results also confirm that early-life stress can be associated with both benefits and costs depending of the life-history stage or environmental context. Copyright © 2014 Elsevier Inc. All rights reserved.
Mechanisms linking energy balance and reproduction: impact of prenatal environment.
Rhinehart, Erin M
2016-01-01
The burgeoning field of metabolic reproduction regulation has been gaining momentum due to highly frequent discoveries of new neuroendocrine factors regulating both energy balance and reproduction. Universally throughout the animal kingdom, energy deficits inhibit the reproductive axis, which demonstrates that reproduction is acutely sensitive to fuel availability. Entrainment of reproductive efforts with energy availability is especially critical for females because they expend large amounts of energy on gestation and lactation. Research has identified an assortment of both central and peripheral factors involved in the metabolic regulation of reproduction. From an evolutionary perspective, these mechanisms likely evolved to optimize reproductive fitness in an environment with an unpredictable food supply and regular bouts of famine. To be effective, however, the mechanisms responsible for the metabolic regulation of reproduction must also retain developmental plasticity to allow organisms to adapt their reproductive strategies to their particular niche. In particular, the prenatal environment has emerged as a critical developmental window for programming the mechanisms responsible for the metabolic control of reproduction. This review will discuss the current knowledge about hormonal and molecular mechanisms that entrain reproduction with prevailing energy availability. In addition, it will provide an evolutionary, human life-history framework to assist in the interpretation of findings on gestational programming of the female reproductive function, with a focus on pubertal timing as an example. Future research should aim to shed light on mechanisms underlying the prenatal modulation of the adaptation to an environment with unstable resources in a way that optimizes reproductive fitness.
Aging and fertility patterns in wild chimpanzees provide insights into the evolution of menopause
Thompson, Melissa Emery; Jones, James H.; Pusey, Anne E.; Brewer-Marsden, Stella; Goodall, Jane; Marsden, David; Matsuzawa, Tetsuro; Nishida, Toshisada; Reynolds, Vernon; Sugiyama, Yukimaru; Wrangham, Richard W.
2008-01-01
Summary Human menopause is remarkable in that reproductive senescence is markedly accelerated relative to somatic aging, leaving an extended post-reproductive period for a large proportion of women [1, 2]. Functional explanations for this are debated [4-11], in part because comparative data from closely-related species are inadequate. Existing studies of chimpanzees are based on very small samples and have not provided clear conclusions about the reproductive function of aging females [12-19]. These studies have not examined whether reproductive senescence in chimpanzees exceeds the pace of general aging, as in humans, or occurs in parallel with declines in overall health, as in many other animals [20, 21]. In order to remedy these problems, we examined fertility and mortality patterns in 6 free-living chimpanzee populations. Chimpanzee and human birth rates show similar patterns of decline beginning in the 4th decade, suggesting that the physiology of reproductive senescence was relatively conserved in human evolution. However, in contrast to humans, chimpanzee fertility declines are consistent with declines in survivorship, and healthy females maintain high birth rates late into life. Thus, in contrast to recent claims [16], we find no evidence that menopause is a typical characteristic of chimpanzee life histories. PMID:18083515
Narbona, Eduardo; Dirzo, Rodolfo
2010-08-01
Monoecious plants have the capacity to allocate resources separately to male and female functions more easily than hermaphrodites. This can be advantageous against environmental stresses such as leaf herbivory. However, studies showing effects of herbivory on male and female functions and on the interaction with the plant's pollinators are limited, particularly in tropical plants. Here, the effects of experimental defoliation were examined in the monoecious shrub Croton suberosus (Euphorbiaceae), a wasp-pollinated species from a Mexican tropical dry forest. Three defoliation treatments were applied: 0 % (control), 25 % (low) or 75 % (high) of plant leaf area removed. Vegetative (production of new leaves) and reproductive (pistillate and staminate flower production, pollen viability, nectar production, fruit set, and seed set) performance variables, and the abundance and activity of floral visitors were examined. Defoliated plants overcompensated for tissue loss by producing more new leaves than control plants. Production of staminate flowers gradually decreased with increasing defoliation and the floral sex ratio (staminate : pistillate flowers) was drastically reduced in high-defoliation plants. In contrast, female reproductive performance (pistillate flower production, fruit set and seed set) and pollinator visitation and abundance were not impacted by defoliation. The asymmetrical effects of defoliation on male and female traits of C. suberosus may be due to the temporal and spatial flexibility in the allocation of resources deployed by monoecious plants. We posit that this helps to maintain the plant's pollination success in the face of leaf herbivory stress.
Lietze, Verena-Ulrike; Geden, Christopher J.; Blackburn, Patrick; Boucias, Drion G.
2007-01-01
Pathological studies demonstrated that the salivary gland hypertrophy virus of houseflies (MdSGHV) shuts down reproduction in infected females. The mechanism that underlay the disruption of reproduction functioned on several levels. Females infected at the previtellogenic stage did not produce eggs, reflecting a block in the gonadotropic cycle. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analysis of hemolymph samples demonstrated that MdSGHV infection reduced the levels of both the female-specific hexamerin and egg yolk proteins. Furthermore, reverse transcriptase quantitative real-time PCR data demonstrated that infection blocked hexamerin and yolk protein gene transcription. When females were allowed to develop eggs prior to infection (postvitellogenic stage), the outcome of mating attempts depended upon when mating took place. If egg-containing, virus-infected females were mated within 24 h of infection, they copulated and deposited a single batch of fertilized eggs. However, if mating was delayed for a longer period, the egg-containing females refused to copulate with healthy males. Both of these results suggested that a virus-induced signal influenced the central nervous system, shutting down female receptivity and egg production. All experiments demonstrated that MdSGHV-infected males did not display azoospermia and were fertile. Both healthy females mated with infected males, and the resulting F1 progeny were free of salivary gland hypertrophy symptoms, which suggests that the virus is not sexually or vertically transmitted. PMID:17827327
Tarín, J J; Pérez-Albalá, S; Pertusa, J F; Cano, A
2002-03-15
This study aims to ascertain whether oral administration of pharmacological doses of Vitamins C and E has any detrimental effect on reproductive fitness of female mice. We fed hybrid female mice from the first day of weaning a standard diet supplemented or not supplemented with pharmacological doses of Vitamins C and E. At the age of 28 weeks, we individually caged females with a male for the rest of their reproductive life. We performed a series of mating experiments to ascertain the number of oocytes ovulated and the potential for embryo development in vitro to the blastocyst stage and in vivo to Day 12 of gestation. The antioxidant diet decreased the frequency of litters, litter size, total number of offspring born and survival of male pups to weaning. This effect was associated with lower number of corpora lutea in the left ovary, decreased percentage of viable fetuses, and higher number of fetal resorptions in the left uterine horn when compared to the control group. The strategy of supplementing the diet with antioxidant vitamins to prevent the age associated decrease in reproductive potential should not be implemented in human beings until a safe and efficient diet is designed.
Masting promotes individual- and population-level reproduction by increasing pollination efficiency.
Moreira, Xoaquín; Abdala-Roberts, Luis; Linhart, Yan B; Mooney, Kailen A
2014-04-01
Masting is a reproductive strategy defined as the intermittent and synchronized production of large seed crops by a plant population. The pollination efficiency hypothesis proposes that masting increases pollination success in plants. Despite its general appeal, no previous studies have used long-term data together with population- and individual-level analyses to assess pollination efficiency between mast and non-mast events. Here we rigorously tested the pollination efficiency hypothesis in ponderosa pine (Pinus ponderosa), a long-lived monoecious, wind-pollinated species, using a data set on 217 trees monitored annually for 20 years. Relative investment in male and female function by individual trees did not vary between mast and non-mast years. At both the population and individual level, the rate of production of mature female cones relative to male strobili production was higher in mast than non-mast years, consistent with the predicted benefit of reproductive synchrony on reproductive success. In addition, at the individual level we found a higher conversion of unfertilized female conelets into mature female cones during a mast year compared to a non-mast year. Collectively, parallel results at the population and individual tree level provide robust evidence for the ecological, and potentially also evolutionary, benefits of masting through increased pollination efficiency.
Role of oxidative stress in female reproduction
Agarwal, Ashok; Gupta, Sajal; Sharma, Rakesh K
2005-01-01
In a healthy body, ROS (reactive oxygen species) and antioxidants remain in balance. When the balance is disrupted towards an overabundance of ROS, oxidative stress (OS) occurs. OS influences the entire reproductive lifespan of a woman and even thereafter (i.e. menopause). OS results from an imbalance between prooxidants (free radical species) and the body's scavenging ability (antioxidants). ROS are a double-edged sword – they serve as key signal molecules in physiological processes but also have a role in pathological processes involving the female reproductive tract. ROS affect multiple physiological processes from oocyte maturation to fertilization, embryo development and pregnancy. It has been suggested that OS modulates the age-related decline in fertility. It plays a role during pregnancy and normal parturition and in initiation of preterm labor. Most ovarian cancers appear in the surface epithelium, and repetitive ovulation has been thought to be a causative factor. Ovulation-induced oxidative base damage and damage to DNA of the ovarian epithelium can be prevented by antioxidants. There is growing literature on the effects of OS in female reproduction with involvement in the pathophsiology of preeclampsia, hydatidiform mole, free radical-induced birth defects and other situations such as abortions. Numerous studies have shown that OS plays a role in the pathoysiology of infertility and assisted fertility. There is some evidence of its role in endometriosis, tubal and peritoneal factor infertility and unexplained infertility. This article reviews the role OS plays in normal cycling ovaries, follicular development and cyclical endometrial changes. It also discusses OS-related female infertility and how it influences the outcomes of assisted reproductive techniques. The review comprehensively explores the literature for evidence of the role of oxidative stress in conditions such as abortions, preeclampsia, hydatidiform mole, fetal embryopathies, preterm labour and preeclampsia and gestational diabetes. The review also addresses the growing literature on the role of nitric oxide species in female reproduction. The involvement of nitric oxide species in regulation of endometrial and ovarian function, etiopathogenesis of endometriosis, and maintenance of uterine quiescence, initiation of labour and ripening of cervix at parturition is discussed. Complex interplay between cytokines and oxidative stress in the etiology of female reproductive disorders is discussed. Oxidant status of the cell modulates angiogenesis, which is critical for follicular growth, corpus luteum formation endometrial differentiation and embryonic growth is also highlighted in the review. Strategies to overcome oxidative stress and enhance fertility, both natural and assisted are delineated. Early interventions being investigated for prevention of preeclampsia are enumerated. Trials investigating combination intervention strategy of vitamin E and vitamin C supplementation in preventing preeclampsia are highlighted. Antioxidants are powerful and there are few trials investigating antioxidant supplementation in female reproduction. However, before clinicians recommend antioxidants, randomized controlled trials with sufficient power are necessary to prove the efficacy of antioxidant supplementation in disorders of female reproduction. Serial measurement of oxidative stress biomarkers in longitudinal studies may help delineate the etiology of some of the diosorders in female reproduction such as preeclampsia. PMID:16018814
Identification of a pheromone regulating caste differentiation in termites.
Matsuura, Kenji; Himuro, Chihiro; Yokoi, Tomoyuki; Yamamoto, Yuuka; Vargo, Edward L; Keller, Laurent
2010-07-20
The hallmark of social insects is their caste system: reproduction is primarily monopolized by queens, whereas workers specialize in the other tasks required for colony growth and survival. Pheromones produced by reigning queens have long been believed to be the prime factor inhibiting the differentiation of new reproductive individuals. However, there has been very little progress in the chemical identification of such inhibitory pheromones. Here we report the identification of a volatile inhibitory pheromone produced by female neotenics (secondary queens) that acts directly on target individuals to suppress the differentiation of new female neotenics and identify n-butyl-n-butyrate and 2-methyl-1-butanol as the active components of the inhibitory pheromone. An artificial pheromone blend consisting of these two compounds had a strong inhibitory effect similar to live neotenics. Surprisingly, the same two volatiles are also emitted by eggs, playing a role both as an attractant to workers and an inhibitor of reproductive differentiation. This dual production of an inhibitory pheromone by female reproductives and eggs probably reflects the recruitment of an attractant pheromone as an inhibitory pheromone and may provide a mechanism ensuring honest signaling of reproductive status with a tight coupling between fertility and inhibitory power. Identification of a volatile pheromone regulating caste differentiation in a termite provides insights into the functioning of social insect colonies and opens important avenues for elucidating the developmental pathways leading to reproductive and nonreproductive castes.
Identification of a pheromone regulating caste differentiation in termites
Matsuura, Kenji; Himuro, Chihiro; Yokoi, Tomoyuki; Yamamoto, Yuuka; Vargo, Edward L.; Keller, Laurent
2010-01-01
The hallmark of social insects is their caste system: reproduction is primarily monopolized by queens, whereas workers specialize in the other tasks required for colony growth and survival. Pheromones produced by reining queens have long been believed to be the prime factor inhibiting the differentiation of new reproductive individuals. However, there has been very little progress in the chemical identification of such inhibitory pheromones. Here we report the identification of a volatile inhibitory pheromone produced by female neotenics (secondary queens) that acts directly on target individuals to suppress the differentiation of new female neotenics and identify n-butyl-n-butyrate and 2-methyl-1-butanol as the active components of the inhibitory pheromone. An artificial pheromone blend consisting of these two compounds had a strong inhibitory effect similar to live neotenics. Surprisingly, the same two volatiles are also emitted by eggs, playing a role both as an attractant to workers and an inhibitor of reproductive differentiation. This dual production of an inhibitory pheromone by female reproductives and eggs probably reflects the recruitment of an attractant pheromone as an inhibitory pheromone and may provide a mechanism ensuring honest signaling of reproductive status with a tight coupling between fertility and inhibitory power. Identification of a volatile pheromone regulating caste differentiation in a termite provides insights into the functioning of social insect colonies and opens important avenues for elucidating the developmental pathways leading to reproductive and nonreproductive castes. PMID:20615972
Cerda-Molina, Ana Lilia; Hernández-López, Leonor; Chavira, Roberto; Cárdenas, Mario; Paez-Ponce, Denisse; Cervantes-De la Luz, Harry; Mondragón-Ceballos, Ricardo
2006-01-01
In mammalian species, social chemosignals are important in modulating endocrine reproductive functions. In nonhuman primates, previous studies have described a high frequency of mounting behavior by females in the follicular and periovulatory phases of the menstrual cycle. Stumptailed macaque females do not signal receptivity by means of sexual swellings, as do others macaques, therefore providing a good model in which to study chemical signaling of reproductive status. We exposed anesthetized stumptailed males to vaginal secretions of either late follicular or menses phase or to saline solution to determine the endocrine changes promoting male sexual behavior. In males exposed to follicular secretions, plasma testosterone concentrations were sustained up to 120 min after exposure. Such an effect was not observed in animals exposed to menses or saline odor sources. A luteinizing hormone surge, occurring 30 minutes after exposure to late follicular phase secretion swabs, preceded this sustained testosterone effect. The fact that late follicular scents induce sustained testosterone concentrations provides support to the idea that stumptailed males draw information concerning female reproductive status from the female's vaginal odor.
Reproduction in shark-attacked sea turtles is supported by stress-reduction mechanisms.
Jessop, Tim; Sumner, Joanna; Lance, Val; Limpus, Col
2004-01-01
Vertebrates exhibit varied behavioural and physiological tactics to promote reproductive success. We examined mechanisms that could enable female loggerhead turtles to undertake nesting activities and maintain seasonal reproduction despite recent shark injuries of varying severity. We proposed that endocrinal mechanisms that regulate both a turtle's stress response and reproductive ability are modified to promote successful and continued reproduction. Irrespective of the degree of injury, females did not exhibit increased levels of the stress hormone corticosterone, nor decreased levels of the reproductive steroid testosterone; hormone responses consistent with stress. When exposed to a capture stressor, females with shark injury did not exhibit any greater corticosterone response than controls. In addition, breeding females showed a reduced corticosterone stress response compared to non-breeding females. Reduced endocrinal responses following shark injury, and during breeding in general may, in part, enable females to maintain behavioural and physiological commitment to reproduction. PMID:15101429
Rodriguez, Amanda; Tripurani, Swamy K.; Burton, Jason C.; Clementi, Caterina; Larina, Irina; Pangas, Stephanie A.
2016-01-01
Pregnancy is a complex physiological process tightly controlled by the interplay among hormones, morphogens, transcription factors, and signaling pathways. Although recent studies using genetically engineered mouse models have revealed that ligands and receptors of transforming growth factor beta (TGFbeta) and bone morphogenetic protein (BMP) signaling pathways are essential for multiple reproductive events during pregnancy, the functional role of SMAD transcription factors, which serve as the canonical signaling platform for the TGFbeta/BMP pathways, in the oviduct and uterus is undefined. Here, we used a mouse model containing triple conditional deletion of the BMP receptor signaling Smads (Smad1 and Smad5) and Smad4, the central mediator of both TGFbeta and BMP signaling, to investigate the role of the SMADs in reproductive tract structure and function in cells from the Amhr2 lineage. Unlike the respective single- or double-knockouts, female Smad1flox/flox Smad5flox/flox Smad4flox/flox Amhr2cre/+conditional knockout (i.e., Smad1/5/4-Amhr2-cre KO) mice are sterile. We discovered that Smad1/5/4-Amhr2-cre KO females have malformed oviducts that subsequently develop oviductal diverticuli. These oviducts showed dysregulation of multiple genes essential for oviduct and smooth muscle development. In addition, uteri from Smad1/5/4-Amhr2-cre KO females exhibit multiple defects in stroma, epithelium, and smooth muscle layers and fail to assemble a closed uterine lumen upon embryo implantation, with defective uterine decidualization that led to pregnancy loss at early to mid-gestation. Taken together, our study uncovers a new role for the SMAD transcription factors in maintaining the structural and functional integrity of oviduct and uterus, required for establishment and maintenance of pregnancy. PMID:27335065
Immunology of the Uterine and Vaginal Mucosae.
Zhou, Jordan Z; Way, Sing Sing; Chen, Kang
2018-04-01
Along with the maintenance of symbiotic mutualism with commensal microbes and protection against invasive infections common to all mucosal barrier tissues, female reproductive tissues have additional, unique tasks that include dynamic cyclic cellular turnover in menstruation and immunological tolerance to genetically foreign fetal antigens in pregnancy. Here we review current knowledge on distinct features of the immune cells in female reproductive tissue with regard to antimicrobial host defense and adaptations to accommodate the fetus during pregnancy. Outstanding areas for future research to obtain new functional insights on this enigmatic mucosal barrier are also highlighted. Copyright © 2018 Elsevier Ltd. All rights reserved.
Protection of the female reproductive system from natural and artificial insults
Tilly, Jonathan L.; Kolesnick, Richard N.
2010-12-14
Described are methods for protecting the female reproductive system against natural and artificial insults by administering to women a composition comprising an agent that antagonizes one or more acid sphingomyelinase (ASMase) gene products. Specifically, methods disclosed herein serve to protect women's germline from damage resulting from cancer therapy regimens including chemotherapy or radiotherapy. In one aspect, the method preserves, enhances, or revives ovarian function in women, by administering to women a composition containing sphingosine-1-phosphate, or an analog thereof. Also disclosed are methods to prevent or ameliorate menopausal syndromes and to improve in vitro fertilization techniques.
NASA Astrophysics Data System (ADS)
Sal Moyano, M. P.; Gavio, M. A.; Cuartas, E. I.
2010-09-01
Morphology and function of the male reproductive tract, female spermatheca and patterns of sperm storage were assessed in the crab Libinia spinosa using histological methods. Testes are characterized by the presence of peripheral spermatogonia and different sequences of sperm maturity. Spermatophores begin to be packed in the last portion. The vas deferens consists of three sections: anterior, with undeveloped spermatophores and free sperm; median, with well-developed spermatophores; and posterior with granular secretions. Female spermathecae are of the ventral type, with a velum separating dorsal and ventral chambers. Live individuals were kept in the laboratory and arranged in pairs. An experiment was conducted toward the end of the reproductive season, in which males with the right gonopod excised were placed with receptive females. After mating, females were killed and the spermathecae dissected for histological study and observation of the pattern of sperm storage. Spermatozoa were found forming discrete sperm packages. New ejaculates can fill the entire spermatheca or be restricted to the ventral chamber; sperm are rounded, with a distinguishable acrosomal core. Old ejaculates are restricted to the dorsal chamber and are of irregular shape and larger size; an acrosomal core was not distinguishable. The secretions produced by the glandular epithelium of the dorsal chamber of the spermathecae are likely to have a role in the removal of dead sperm.
[Osteopontin and male reproduction].
Liu, Qian; Xie, Qing-Zhen
2012-05-01
Osteopontin (OPN) is an extracellular matrix protein with multifunctions, expressed in various tissues and body fluids, involved in various physiological and pathological processes. It is also detected in the reproductive tract of both males and females, and participates in the implantation, development and differentiation of embryos. Recent studies have indicated that OPN is closely related with male fertility and may affect sperm quality and fertilization. An insight into the functions of OPN may help to explain the mechanisms of male infertility and improve the success rate of assisted reproductive technology.
Explaining sex differences in lifespan in terms of optimal energy allocation in the baboon.
King, Annette M; Kirkwood, Thomas B L; Shanley, Daryl P
2017-10-01
We provide a quantitative test of the hypothesis that sex role specialization may account for sex differences in lifespan in baboons if such specialization causes the dependency of fitness upon longevity, and consequently the optimal resolution to an energetic trade-off between somatic maintenance and other physiological functions, to differ between males and females. We present a model in which females provide all offspring care and males compete for access to reproductive females and in which the partitioning of available energy between the competing fitness-enhancing functions of growth, maintenance, and reproduction is modeled as a dynamic behavioral game, with the optimal decision for each individual depending upon his/her state and the behavior of other members of the population. Our model replicates the sexual dimorphism in body size and sex differences in longevity and reproductive scheduling seen in natural populations of baboons. We show that this outcome is generally robust to perturbations in model parameters, an important finding given that the same behavior is seen across multiple populations and species in the wild. This supports the idea that sex differences in longevity result from differences in the value of somatic maintenance relative to other fitness-enhancing functions in keeping with the disposable soma theory. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.
Chang, Chawnshang; Lee, Soo Ok; Wang, Ruey-Sheng; Yeh, Shuyuan; Chang, Ta-Min
2013-01-01
ABSTRACT Androgens/androgen receptor (AR) signaling is involved primarily in the development of male-specific phenotypes during embryogenesis, spermatogenesis, sexual behavior, and fertility during adult life. However, this signaling has also been shown to play an important role in development of female reproductive organs and their functions, such as ovarian folliculogenesis, embryonic implantation, and uterine and breast development. The establishment of the testicular feminization (Tfm) mouse model exploiting the X-linked Tfm mutation in mice has been a good in vivo tool for studying the human complete androgen insensitivity syndrome, but this mouse may not be the perfect in vivo model. Mouse models with various cell-specific AR knockout (ARKO) might allow us to study AR roles in individual types of cells in these male and female reproductive systems, although discrepancies are found in results between labs, probably due to using various Cre mice and/or knocking out AR in different AR domains. Nevertheless, no doubt exists that the continuous development of these ARKO mouse models and careful studies will provide information useful for understanding AR roles in reproductive systems of humans and may help us to develop more effective and more specific therapeutic approaches for reproductive system-related diseases. PMID:23782840
Zheng, Huiyong; Avis, Nancy E.; Greendale, Gail A.; Harlow, Siobán D.
2015-01-01
Objective: To determine whether reproductive hormones are related to sexual function during the menopausal transition. Design: The Study of Women's Health Across the Nation (SWAN) is a multiethnic cohort study of the menopausal transition located at seven US sites. At baseline, the 3302 community-based participants, aged 42–52, had an intact uterus and at least one ovary and were not using exogenous hormones. Participants self-identified as White, Black, Hispanic, Chinese, or Japanese. At baseline and at each of the 10 follow-up visits, sexual function was assessed by self-administered questionnaires, and blood was drawn to assay serum levels of T, estradiol, FSH, SHBG, and dehydroepiandrosterone sulfate. Main Outcome Measures: Self-reported frequency of masturbation, sexual desire, sexual arousal, orgasm, and pain during intercourse. Results: Masturbation, sexual desire, and arousal were positively associated with T. Masturbation, arousal, and orgasm were negatively associated with FSH. Associations were modest. Estradiol was not related to any measured sexual function domain. Pain with intercourse was not associated with any hormone. Conclusions: Reproductive hormones were associated with sexual function in midlife women. T was positively associated, supporting the role of androgens in female sexual function. FSH was negatively associated, supporting the role of menopausal status in female sexual function. The modest associations in this large study suggest that the relationships are subtle and may be of limited clinical significance. PMID:25412335
Randolph, John F; Zheng, Huiyong; Avis, Nancy E; Greendale, Gail A; Harlow, Siobán D
2015-01-01
To determine whether reproductive hormones are related to sexual function during the menopausal transition. The Study of Women's Health Across the Nation (SWAN) is a multiethnic cohort study of the menopausal transition located at seven US sites. At baseline, the 3302 community-based participants, aged 42-52, had an intact uterus and at least one ovary and were not using exogenous hormones. Participants self-identified as White, Black, Hispanic, Chinese, or Japanese. At baseline and at each of the 10 follow-up visits, sexual function was assessed by self-administered questionnaires, and blood was drawn to assay serum levels of T, estradiol, FSH, SHBG, and dehydroepiandrosterone sulfate. Self-reported frequency of masturbation, sexual desire, sexual arousal, orgasm, and pain during intercourse. Masturbation, sexual desire, and arousal were positively associated with T. Masturbation, arousal, and orgasm were negatively associated with FSH. Associations were modest. Estradiol was not related to any measured sexual function domain. Pain with intercourse was not associated with any hormone. Reproductive hormones were associated with sexual function in midlife women. T was positively associated, supporting the role of androgens in female sexual function. FSH was negatively associated, supporting the role of menopausal status in female sexual function. The modest associations in this large study suggest that the relationships are subtle and may be of limited clinical significance.
In mammals, the secretion of gonadotropin-releasing hormone (GnRH) from the brain hypothalamic median eminence constitutes the final common path to the pituitary that results in the ovulatory surge of luteinizing hormone (LH). In rodent test species, a growing number of environme...
Early-life nutritional effects on the female reproductive system.
Chan, K A; Tsoulis, M W; Sloboda, D M
2015-02-01
There is now considerable epidemiological and experimental evidence indicating that early-life environmental conditions, including nutrition, affect subsequent development in later life. These conditions induce highly integrated responses in endocrine-related homeostasis, resulting in persistent changes in the developmental trajectory producing an altered adult phenotype. Early-life events trigger processes that prepare the individual for particular circumstances that are anticipated in the postnatal environment. However, where the intrauterine and postnatal environments differ markedly, such modifications to the developmental trajectory may prove maladaptive in later life. Reproductive maturation and function are similarly influenced by early-life events. This should not be surprising, because the primordial follicle pool is established early in life and is thus vulnerable to early-life events. Results of clinical and experimental studies have indicated that early-life adversity is associated with a decline in ovarian follicular reserve, changes in ovulation rates, and altered age at onset of puberty. However, the underlying mechanisms regulating the relationship between the early-life developmental environment and postnatal reproductive development and function are unclear. This review examines the evidence linking early-life nutrition and effects on the female reproductive system, bringing together clinical observations in humans and experimental data from targeted animal models. © 2015 Society for Endocrinology.
Asaba, Akari; Osakada, Takuya; Touhara, Kazushige; Kato, Masahiro; Mogi, Kazutaka; Kikusui, Takefumi
2017-08-01
Vocal communication in animals is important for ensuring reproductive success. Male mice emit song-like "ultrasonic vocalizations (USVs)" when they encounter female mice, and females show approach to the USVs. However, it is unclear whether USVs of male mice trigger female behavioral and endocrine responses in reproduction. In this study, we first investigated the relationship between the number of deliveries in breeding pairs for 4months and USVs syllables emitted from those paired males during 3min of sexual encounter with unfamiliar female mice. There was a positive correlation between these two indices, which suggests that breeding pairs in which males could emit USVs more frequently had more offspring. Further, we examined the effect of USVs of male mice on female sexual behavior. Female mice showed more approach behavior towards vocalizing males than devocalized males. Finally, to determine whether USVs of male mice could activate the neural system governing reproductive function in female mice, the activation of kisspeptin neurons, key neurons to drive gonadotropin-releasing hormone neurons in the hypothalamus, was examined using dual-label immunocytochemistry with cAMP response element-binding protein phosphorylation (pCREB). In the arcuate nucleus (Arc), the number of kisspeptin neurons expressing pCREB significantly increased after exposure to USVs of male as compared with noise exposure group. In conclusion, our results suggest that USVs of male mice promote fertility in female mice by activating both their approaching behavior and central kisspeptin neurons. Copyright © 2017 Elsevier Inc. All rights reserved.
[Influencing factors for reproductive health of female workers in petrochemical industry].
Kou, Z X; Wang, S L; Chen, Z L; He, Y H; Yu, W L; Mei, L Y; Zhang, H D
2018-02-20
Objective: To investigate the reproductive health status of female workers in petrochemical industry, and to provide a reference for improving reproductive health status and developing preventive and control measures for female workers in petrochemical industry. Methods: A face-to-face questionnaire survey was performed from January to October, 2016. The Questionnaire on Women's Reproductive Health was used to investigate the reproductive health of female workers in petrochemical industry. The multivariate logistic regression model was used to identify the influencing factors for reproductive health of female workers in petrochemical industry. Results: Among the 7485 female workers, 1 268 (40.9%) had abnormal menstrual period, 1 437 (46.4%) had abnormal menstrual volume, 177 (28.5%) had hyperplasia of mammary glands, and 1 807 (24.6%) had gynecological inflammation. The reproductive system diseases in female workers in petrochemical industry were associated with the factors including age, marital status, education level, unhealthy living habits, abortion, overtime work, work shift, workload, video operation, occupational exposure, positive events, and negative events, and among these factors, negative events (odds ratio[ OR ]= 1.856) , unhealthy living habits ( OR =1.542) , and positive events ( OR =1.516) had greater impact on reproductive system diseases. Conclusion: Many chemical substances in the occupational environment of petrochemical industry can cause damage to the reproductive system, which not only affects the health of the female workers, but also poses potential threats to the health of their offspring. Occupational exposure, unhealthy living habits, overtime work, and work shift have great influence on reproductive system diseases in female workers.
Campbell, Christina J
2004-06-01
Reports on the behavior of spider monkeys (genus Ateles) describe a suite of 5-6 behaviors that are indicative of an estrous female. This study presents hormonal data as an independent measure of reproductive state to determine if these behaviors are associated with any particular reproductive state or stage of the ovarian cycle. Fecal samples collected from 6 free-ranging female black-handed spider monkeys (Ateles geoffroyi) over the course of 11 months were assayed for estrogen (E1C) and progesterone (PdG) metabolites, using an enzyme immunoassay. Behavioral data collected from the same females were analyzed for patterns associated with different reproductive states. A more detailed analysis of behavioral data associated with reproductively cycling periods determined whether each behavior clustered with copulations or a particular phase in the ovarian cycle. Observations of place-sniffing were more frequent for 4 of 5 females when reproductively cycling. Of all copulations observed, 80% occurred when the female participant was reproductively cycling. In addition, the rates of self-clitoral hold and self-clitoral rub behaviors were significantly higher for 2 of 4 and 4 of 5 of females, respectively, when reproductively cycling. No behavior consistently occurred in association with copulations or with any particular phase in the ovarian cycle. Results from this study suggest that the behaviors tested in this paper can provide some information regarding female spider monkey reproductive state (whether or not she is reproductively cycling), but that they are not indicators of estrus in female spider monkeys. Copyright 2003 Wiley-Liss, Inc.
Automatic attention towards face or body as a function of mating motivation.
Lu, Hui Jing; Chang, Lei
2012-03-22
Because women's faces and bodies carry different cues of reproductive value, men may attend to different perceptual cues as functions of their long-term versus short-term mating motivations. We tested this hypothesis in three experiments on 135 male and 132 female participants. When influenced by short-term rather than long-term mating motivations, men's attention was captured by (Study 1), was shifted to (Study 2), and was distracted by (Study 3) the waist/hip area rather than the face on photographs of attractive women. Similar effects were not found among the female participants in response to photographs of attractive men. These results support the evolutionary view that, similar to the attentional selectivity found in other domains of life, male perceptual attention has evolved to selectively capture and hold reproductive information about the opposite sex as a function of short-term versus long-term mating goals.
Diamanti-Kandarakis, Evanthia; Papalou, Olga; Kandaraki, Eleni A; Kassi, Georgia
2017-02-01
Nutrition can generate oxidative stress and trigger a cascade of molecular events that can disrupt oxidative and hormonal balance. Nutrient ingestion promotes a major inflammatory and oxidative response at the cellular level in the postprandial state, altering the metabolic state of tissues. A domino of unfavorable metabolic changes is orchestrated in the main metabolic organs, including adipose tissue, skeletal muscle, liver and pancreas, where subclinical inflammation, endothelial dysfunction, mitochondrial deregulation and impaired insulin response and secretion take place. Simultaneously, in reproductive tissues, nutrition-induced oxidative stress can potentially violate delicate oxidative balance that is mandatory to secure normal reproductive function. Taken all the above into account, nutrition and its accompanying postprandial oxidative stress, in the unique context of female hormonal background, can potentially compromise normal metabolic and reproductive functions in women and may act as an active mediator of various metabolic and reproductive disorders. © 2017 European Society of Endocrinology.
Sanderson, J L; Nichols, H J; Marshall, H H; Vitikainen, E I K; Thompson, F J; Walker, S L; Cant, M A; Young, A J
2015-10-01
Dominant females in social species have been hypothesized to reduce the reproductive success of their subordinates by inducing elevated circulating glucocorticoid (GC) concentrations. However, this 'stress-related suppression' hypothesis has received little support in cooperatively breeding species, despite evident reproductive skews among females. We tested this hypothesis in the banded mongoose (Mungos mungo), a cooperative mammal in which multiple females conceive and carry to term in each communal breeding attempt. As predicted, lower ranked females had lower reproductive success, even among females that carried to term. While there were no rank-related differences in faecal glucocorticoid (fGC) concentrations prior to gestation or in the first trimester, lower ranked females had significantly higher fGC concentrations than higher ranked females in the second and third trimesters. Finally, females with higher fGC concentrations during the third trimester lost a greater proportion of their gestated young prior to their emergence from the burrow. Together, our results are consistent with a role for rank-related maternal stress in generating reproductive skew among females in this cooperative breeder. While studies of reproductive skew frequently consider the possibility that rank-related stress reduces the conception rates of subordinates, our findings highlight the possibility of detrimental effects on reproductive outcomes even after pregnancies have become established. © 2015 The Authors.
Functional morphology of the genital organs in the wild paca (Cuniculus paca) female.
Mayor, P; Guimarães, D A; López, C
2013-08-01
Functional morphology of the genital organs is a key knowledge component for enhanced understanding of physiological patterns and for the determination of the reproductive performance in wild species. This study examines the morphology of genital organs of 133 paca females in the wild. Estimated conceptions and parturitions were mostly (83.7% and 75.5%, respectively) localized in the wet season. The pregnancy rate between 57.1% and 61.4% suggests an estimated yearly production of 1.37-1.48 parturitions and a long estimated farrowing interval of 247-266 days. Although large antral follicles were observed in all females, pregnant females had a greater number of antral follicles than females in the luteal phase. The average litter size was 1.03 foetuses per pregnant female, and mean ovulation rate was 1.33 follicles, resulting in a rate of reproductive wastage of 28.7%. The constituent active luteal tissues of the ovary were oestrous cyclic, pregnancy and accessory CL. The 50% of pregnant females in the late pregnancy stage lacked pregnancy CL, suggesting that placenta may become the mean source of progesterone during late stages of pregnancy. Results of the present study suggest that the observation of the vaginal closure membrane should not be an accurate tool for diagnosing oestrus in the paca female. Copyright © 2013 Elsevier B.V. All rights reserved.
Daikoku, Takiko; Yoshie, Mikihiro; Xie, Huirong; Sun, Xiaofei; Cha, Jeeyeon; Ellenson, Lora Hedrick; Dey, Sudhansu K.
2013-01-01
Heightened mammalian target of rapamycin complex 1 (mTORC1) activity by genetic deletion of its direct inhibitor, Tsc1, is associated with aberrant development and dysfunction of the female reproductive tract in mice. Here, we compared the phenotypes of mice with conditional deletion of Tsc1 in the female reproductive tract by either progesterone receptor (PR)-Cre (Tsc1PR(d/d)), which inactivates Tsc1 in all major cell types in the uterus (epithelium, stroma and myometrium), or anti-Mullerian hormone type 2 receptor (Amhr2)-Cre (Tsc1Amhr2(d/d)), which inactivates stromal and myometrial Tsc1. Tsc1PR(d/d) and Tsc1Amhr2(d/d) females are infertile resulting from oviductal hyperplasia, retention of embryos in the oviduct and implantation failure. In contrast to the appropriate embryonic development after fertilization seen in Tsc1Amhr2(d/d) females, embryo development was disrupted in Tsc1PR(d/d) females. In addition, uteri in Tsc1PR(d/d) and Tsc1Amhr2(d/d) females showed epithelial hyperplasia but not endometrial cancer. In conclusion, Tsc1PR(d/d) and Tsc1Amhr2(d/d) have overlapping yet distinct phenotypes in the context of compartment-specific deletion of Tsc1. PMID:23475984
Matsuwaki, Takashi; Nishihara, Masugi; Sato, Tsuyoshi; Yoda, Tetsuya; Iwakura, Yoichiro; Chida, Dai
2010-11-01
Exposure to chronic stressors results in dysregulation of the hypothalamic-pituitary-adrenal axis and a disruption in reproduction. CRH, the principal regulator of the hypothalamic-pituitary-adrenal axis induces the secretion of ACTH from the pituitary, which stimulates adrenal steroidogenesis via the specific cell-surface melanocortin 2 receptor (MC2R). Previously, we demonstrated that MC2R(-/-) mice had undetectable levels of corticosterone despite high ACTH levels. Here, we evaluated the reproductive functions of female MC2R(-/-) mice and analyzed the mechanism of the disrupted cyclicity of these mice. The expression of CRH in the paraventricular nucleus was significantly increased in MC2R(-/-) mice under nonstressed conditions. Although MC2R(-/-) females were fertile, they showed a prolonged estrous cycle. After hormonal stimulation, MC2R(-/-) females produced nearly-normal numbers of eggs, but slightly less than MC2R(+/-) females, and showed near-normal ovarian histology. During diestrus, the number of GnRH-positive cells in the medial preoptic area was significantly reduced in MC2R(-/-) females. CRH type 1 receptor antagonist restored estrous cyclicity in MC2R(-/-) females. Kisspeptin-positive areas in the arcuate nucleus were comparable, whereas kisspeptin-positive areas in the anteroventral periventricular nucleus in MC2R(-/-) females were significantly reduced compared with MC2R(+/-) females, suggesting that arcuate nucleus kisspeptin is not involved, but anteroventral periventricular nucleus kisspeptin may be involved, in the maintenance of estrous cyclicity. Our findings show that high levels of hypothalamic CRH disturb estrous cyclicity in the female animals and that the MC2R(-/-) female is a unique animal model of functional hypothalamic amenorrhea.
Female reproductive disorders: the roles of endocrine-disrupting compounds and developmental timing
Crain, D. Andrew; Janssen, Sarah J.; Edwards, Thea M.; Heindel, Jerrold; Ho, Shuk-mei; Hunt, Patricia; Iguchi, Taisen; Juul, Anders; McLachlan, John A.; Schwartz, Jackie; Skakkebaek, Niels; Soto, Ana M.; Swan, Shanna; Walker, Cheryl; Woodruff, Teresa K.; Woodruff, Tracey J.; Giudice, Linda C.; Guillette, Louis J.
2014-01-01
Objective To evaluate the possible role of endocrine-disrupting compounds (EDCs) on female reproductive disorders emphasizing developmental plasticity and the complexity of endocrine-dependent ontogeny of reproductive organs. Declining conception rates and the high incidence of female reproductive disruptions warrant evaluation of the impact of EDCs on female reproductive health. Design Publications related to the contribution of EDCs to disorders of the ovary (aneuploidy, polycystic ovary syndrome, and altered cyclicity), uterus (endometriosis, uterine fibroids, fetal growth restriction, and pregnancy loss), breast (breast cancer, reduced duration of lactation), and pubertal timing were identified, reviewed, and summarized at a workshop. Conclusion(s) The data reviewed illustrate that EDCs contribute to numerous human female reproductive disorders and emphasize the sensitivity of early life-stage exposures. Many research gaps are identified that limit full understanding of the contribution of EDCs to female reproductive problems. Moreover, there is an urgent need to reduce the incidence of these reproductive disorders, which can be addressed by correlative studies on early life exposure and adult reproductive dysfunction together with tools to assess the specific exposures and methods to block their effects. This review of the EDC literature as it relates to female health provides an important platform on which women’s health can be improved. PMID:18929049
Laidlaw, Clinton T; Condon, Jacob M; Belk, Mark C
2014-01-01
The cost of reproduction hypothesis suggests that current reproduction has inherent tradeoffs with future reproduction. These tradeoffs can be both in the form of energy allocated to current offspring as opposed to somatic maintenance and future reproduction (allocation costs), or as an increase in mortality as a result of morphological or physiological changes related to reproduction (viability costs). Individuals may be able to decrease viability costs by altering behavior. Female western mosquitofish, Gambusia affinis experience a reduction in swimming ability as a consequence of pregnancy. We test for a viability cost of reproduction, and for behavioral compensation in pregnant female G. affinis by measuring survival of females in early and later stages of pregnancy when exposed to predation. Late-stage pregnant females experience a 70% greater probability of mortality compared to early-stage pregnant females. The presence of a refuge roughly doubled the odds of survival of both early and late-stage pregnant females. However, there was no interaction between refuge availability and stage of pregnancy. These data do not provide evidence for behavioral compensation by female G. affinis for elevated viability costs incurred during later stages of pregnancy. Behavioral compensation may be constrained by other aspects of the cost of reproduction.
Stephens, Shannon B Z; Rouse, Melvin L; Tolson, Kristen P; Liaw, Reanna B; Parra, Ruby A; Chahal, Navi; Kauffman, Alexander S
2017-01-01
The neuropeptide kisspeptin, encoded by Kiss1 , regulates reproduction by stimulating GnRH secretion. Kiss1- syntheizing neurons reside primarily in the hypothalamic anteroventral periventricular (AVPV/PeN) and arcuate (ARC) nuclei. AVPV/PeN Kiss1 neurons are sexually dimorphic, with females expressing more Kiss1 than males, and participate in estradiol (E 2 )-induced positive feedback control of GnRH secretion. In mice, most AVPV/PeN Kiss1 cells coexpress tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine synthesis (in this case, dopamine). Dopamine treatment can inhibit GnRH neurons, but the function of dopamine signaling arising specifically from AVPV/PeN Kiss1 cells is unknown. We generated a novel TH flox mouse and used Cre-Lox technology to selectively ablate TH specifically from Kiss1 cells. We then examined the effects of selective TH knock-out on puberty and reproduction in both sexes. In control mice, 90% of AVPV/PeN Kiss1 neurons coexpressed TH , whereas in mice lacking TH exclusively in Kiss1 cells (termed Kiss THKOs), TH was successfully absent from virtually all Kiss1 cells. Despite this absence of TH , both female and male Kiss THKOs displayed normal body weights, puberty onset, and basal gonadotropin levels in adulthood, although testosterone (T) was significantly elevated in adult male Kiss THKOs. The E 2 -induced LH surge was unaffected in Kiss THKO females, and neuronal activation status of kisspeptin and GnRH cells was also normal. Supporting this, fertility and fecundity were normal in Kiss THKOs of both sexes. Thus, despite high colocalization of TH and Kiss1 in the AVPV/PeN, dopamine produced in these cells is not required for puberty or reproduction, and its function remains unknown.
Sexually antagonistic polymorphism in simultaneous hermaphrodites
Jordan, Crispin Y.; Connallon, Tim
2015-01-01
In hermaphrodites, pleiotropic genetic tradeoffs between female and male reproductive functions can lead to sexually antagonistic (SA) selection, where individual alleles have conflicting fitness effects on each sex function. While an extensive theory of SA selection exists for dioecious species, these results have not been generalized to hermaphrodites. We develop population genetic models of SA selection in simultaneous hermaphrodites, and evaluate effects of dominance, selection on each sex function, self-fertilization, and population size, on the maintenance of polymorphism. Under obligate outcrossing, hermaphrodite model predictions converge exactly with those of dioecious populations. Self-fertilization in hermaphrodites generates three points of divergence with dioecious theory. First, opportunities for stable polymorphism decline sharply and become less sensitive to dominance with increased selfing. Second, selfing introduces an asymmetry in the relative importance of selection through male versus female reproductive functions, expands the parameter space favorable for the evolutionary invasion of female-beneficial alleles, and restricts invasion criteria for male-beneficial alleles. Finally, contrary to models of unconditionally beneficial alleles, selfing decreases genetic hitchhiking effects of invading SA alleles, and should therefore decrease these population genetic signals of SA polymorphisms. We discuss implications of SA selection in hermaphrodites, including its potential role in the evolution of “selfing syndromes”. PMID:25311368
Veiga-Lopez, Almudena; Lee, James S; Padmanabhan, Vasantha
2010-08-01
Prenatal testosterone (T) excess causes reproductive and metabolic disruptions including insulin resistance, attributes of women with polycystic ovary syndrome. This study tested the hypothesis that insulin resistance contributes toward severity of reproductive disruptions in prenatally T-treated females. Pregnant sheep were injected im with 100 mg of T-propionate semiweekly from d 30-90 of gestation. Immediately after the first breeding season, a subset of controls and prenatal T-treated (TR) sheep were administered an insulin sensitizer (rosiglitazone; 8 mg/d) orally for 8 months. Untreated control and prenatal T-treated females (T group) were studied in parallel. Biochemical analyses revealed rosiglitazone to be safe for use in sheep. Glucose tolerance tests performed before and after the insulin sensitizer treatment found that insulin sensitizer decreased cumulative insulin, cumulative insulin/glucose ratio, and insulin area under the curve by about 50% and increased the insulin sensitivity index by about 70% in the TR compared with the T group. Twenty percent of TR females showed a reduced number of cycles in the second relative to first breeding season as opposed to 80% of T group females showing such deterioration. Insulin sensitizer treatment also decreased the number of aberrant cycles (>/=18 d) during the second breeding season in the TR group relative to the first as opposed to the T group females showing an increase in the second breeding season relative to the first. These findings provide evidence that insulin sensitizer treatment prevents further deterioration of the reproductive axis in prenatal T-treated sheep, a finding of translational relevance to women with polycystic ovary syndrome.
Liu, Wei; Li, Shi-Zhu; Li, Zhi; Wang, Yang; Li, Xi-Yin; Zhong, Jian-Xiang; Zhang, Xiao-Juan; Zhang, Jun; Zhou, Li; Gui, Jian-Fang
2015-11-18
Gynogenesis is one of unisexual reproduction modes in vertebrates, and produces all-female individuals with identical genetic background. In sexual reproduction vertebrates, the roles of primordial germ cells on sexual dimorphism and gonadal differentiation have been largely studied, and two distinct functional models have been proposed. However, the role of primordial germ cells remains unknown in unisexual animals, and it is also unclear whether the functional models in sexual reproduction animals are common in unisexual animals. To solve these puzzles, we attempt to utilize the gynogenetic superiority of polyploid Carassius gibelio to create a complete germ cell-depleted gonad model by a similar morpholino-mediated knockdown approach used in other examined sexual reproduction fishes. Through the germ cell-depleted gonad model, we have performed comprehensive and comparative transcriptome analysis, and revealed a complete alteration of sex-biased gene expression. Moreover, the expression alteration leads to up-regulation of testis-biased genes and down-regulation of ovary-biased genes, and results in the occurrence of sterile all-males with testis-like gonads and secondary sex characteristics in the germ cell-depleted gynogenetic Carassius gibelio. Our current results have demonstrated that unisexual gynogenetic embryos remain keeping male sex determination information in the genome, and the complete depletion of primordial germ cells in the all-female fish leads to sex-biased gene expression alteration and sterile all-male occurrence.
Mitochondrial functionality in female reproduction.
Gąsior, Łukasz; Daszkiewicz, Regina; Ogórek, Mateusz; Polański, Zbigniew
2017-01-04
In most animal species female germ cells are the source of mitochondrial genome for the whole body of individuals. As a source of mitochondrial DNA for future generations the mitochondria in the female germ line undergo dynamic quantitative and qualitative changes. In addition to maintaining the intact template of mitochondrial genome from one generation to another, mitochondrial role in oocytes is much more complex and pleiotropic. The quality of mitochondria determines the ability of meiotic divisions, fertilization ability, and activation after fertilization or sustaining development of a new embryo. The presence of normal number of functional mitochondria is also crucial for proper implantation and pregnancy maintaining. This article addresses issues of mitochondrial role and function in mammalian oocyte and presents new approaches in studies of mitochondrial function in female germ cells.
Idris, N; Carothers Carraway, C A; Carraway, K L
2001-11-01
ErbB2 has been implicated in numerous functions, including normal and aberrant development of a variety of tissues. Although no soluble ligand has been identified for ErbB2, we have recently shown that ASGP-2, the transmembrane subunit of the cell surface glycoprotein Muc4 (also called sialomucin complex, SMC), can act as an intramembrane ligand for ErbB2 and modulate its activity. Muc4/SMC is abundantly expressed at the apical surface of most epithelia of the rat female reproductive tract. Since Muc4/SMC can interact with ErbB2 when they are expressed in the same cell and membrane, we investigated whether these two proteins are co-expressed and co-localized in tissues of the female reproductive tract. Using an anti-ErbB2 antibody from Dako, we found moderate staining at the basolateral surface of the oviduct and also around the cell membrane of the most superficial and medial layers of the stratified epithelia of the vagina. In contrast, Neomarkers neu Ab1 antibody intensely stained the apical surface of the epithelium of the oviduct and the medial and basal layers of the stratified epithelia of the vagina, substantially overlapping the distribution of Muc4/SMC. Furthermore, Muc4/SMC and ErbB2 association in different tissues of the female reproductive tract was demonstrated by co-immunoprecipitation analysis. Interestingly, phosphorylated ErbB2 detected by anti-phospho-ErbB2 is primarily present at the apical surface of the oviduct. Thus, our results show that differentially localized forms of ErbB2 are recognized by different antibodies and raise interesting questions about the nature of the different forms of ErbB2, the mechanism for differential localization, and possible functions of ErbB2 in the female reproductive tract. They also raise a cautionary note about the use of different ErbB2 antibodies for expression and localization studies. Copyright 2001 Wiley-Liss, Inc.
Hämäläinen, Anni; Dammhahn, Melanie; Aujard, Fabienne; Kraus, Cornelia
2015-01-01
Muscle strength reflects physical functioning, declines at old age and predicts health and survival in humans and laboratory animals. Age-associated muscle deterioration causes loss of strength and may impair fitness of wild animals. However, the effects of age and life-history characteristics on muscle strength in wild animals are unknown. We investigated environment- and sex-specific patterns of physical functioning by measuring grip strength in wild and captive gray mouse lemurs. We expected more pronounced strength senescence in captivity due to condition-dependent, extrinsic mortality found in nature. Males were predicted to be stronger but potentially experience more severe senescence than females as predicted by life history theory. We found similar senescent declines in captive males and females as well as wild females, whereas wild males showed little decline, presumably due to their early mortality. Captive animals were generally weaker and showed earlier declines than wild animals. Unexpectedly, females tended to be stronger than males, especially in the reproductive season. Universal intrinsic mechanisms (e.g. sarcopenia) likely cause the similar patterns of strength loss across settings. The female advantage in muscle strength merits further study; it may follow higher reproductive investment by males, or be an adaptation associated with female social dominance. Copyright © 2014 Elsevier Inc. All rights reserved.
Studies of lead exposure on reproductive system: a review of work in China.
Xuezhi, J; Youxin, L; Yilan, W
1992-09-01
This paper, based on a review of a series studies conducted in China from 1978 through 1991, describes the possible links between low level lead exposure and the adverse effects on reproductive system. Effects on menstrual status and pregnancy outcome manifested mainly as higher prevalences of menstrual disturbance, spontaneous abortion and threatened abortion in exposed females. Transfer of lead via placenta and human milk was shown by higher lead levels in milk and blood of infant. Impairment of male reproductive function was observed as decreased volume of ejaculation, prolonged latency of semen melting, reduced total sperm count and alive spermatozoa, retarded sperm activity as well as lowered density of semen fluid in exposed male workers with Pb-B over 40 micrograms.dl-1. In addition, poorer performance of WISC-R test was revealed in children with Pb-B level over 30 micrograms.dl-1, and retarded physical development was observed in children with Pb-B over 20 micrograms.dl-1. Therefore, health surveillance including the assessment of adverse effects on reproductive system of both female and male lead exposed workers should not be ignored. Furthermore, safety exposure limit of work place, particularly for female workers of child-bearing age, should be developed.
Manire, C A; Rasmussen, L E; Gross, T S
1999-10-01
Previous studies in the placental viviparous bonnethead shark, Sphyrna tiburo, have correlated 17 beta-estradiol, progesterone, testosterone, and dihydrotestosterone with reproductive events in both males and females. However, several key reproductive events, including implantation, maintenance of pregnancy, and parturition, did not correlate with these four steroid hormones. Therefore, the present study investigated three steroid hormones, 11-ketotestosterone, 11-ketoandrostenedione, and dihydroprogesterone, which have demonstrably important roles in the reproductive cycles of teleosts. It was hypothesized that one or more of these three hormones would correlate with specific reproductive events in S. tiburo. Concurrently, developmental (growth and/or maturation) analyses of these three steroids plus 17 beta-estradiol, progesterone, testosterone, and dihydrotestosterone were investigated in juvenile bonnethead sharks. Serum dihydroprogesterone concentrations were highest in mature females and 11-ketotestosterone concentrations were highest in mature males. In mature females, 11-ketoandrostenedione levels were elevated from the time of mating, through six months of sperm storage and another four months of gestation. At parturition concentrations became significantly lower and remained lower until mating occurred again in another two to three months. Serum 11-ketotestosterone concentrations were the highest at implantation though not significant. In mature males, significantly elevated serum levels of dihydroprogesterone occurred in April and May, near the start of annual testicular development. During growth in males, testosterone and dihydrotestosterone increased progressively and in females, testosterone increased progressively. At maturity in males, significant increases occurred in testosterone and 11-ketotestosterone concentrations while, in females, dihydroprogesterone, 11-ketotestosterone, 17 beta-estradiol, progesterone, testosterone, and dihydrotestosterone concentrations increased. This study shows that although testosterone may be the primary androgen in the bonnethead shark, other derived androgens may have important functions in growth, maturation, and reproduction. J. Exp. Zool. 284:595-603, 1999. Copyright 1999 Wiley-Liss, Inc.
Saucedo, Lucia; Sobarzo, Cristian; Brukman, Nicolás; Guidobaldi, Hector Alejandro; Lustig, Livia; Giojalas, Laura Cecilia; Buffone, Mariano Gabriel; Vazquez-Levin, Monica Hebe; Marín-Briggiler, Clara
2018-06-04
Fibroblast Growth Factor 2 (FGF2) and its receptors (FGFRs) have been described in several tissues, where they regulate cellular proliferation, differentiation, motility and apoptosis. Although FGF2/FGFRs expression in the male reproductive tract has been reported, there is scarce evidence on their presence in the female reproductive tract and their involvement in the modulation of sperm function. Therefore, the objective of this study was to determine the expression of FGF2 in the female reproductive tract and to assess the role of the FGF2/FGFRs system in the regulation of sperm physiology using the murine model. FGF2 was detected in uterus and oviduct protein extracts, and it was immunolocalized in epithelial cells of the uterus, isthmus and ampulla, as well as in the cumulus oophorus-oocyte complex. The receptors FGFR1, FGFR2, FGFR3 and FGFR4 were immunodetected in the flagellum and acrosomal region of sperm recovered from the cauda epididymis. Analysis of testis sections showed the expression of FGFRs in germ cells at different stages of the spermatogenesis, suggesting the testicular origin of the sperm FGFRs. Sperm incubation with recombinant FGF2 (rFGF2) led to increased sperm motility and velocity, and to enhanced intracellular Ca2+ levels and acrosomal loss compared to the control. In conclusion, this study shows that FGF2 is expressed in tissues of the female reproductive tract. Also, the fact that functional FGFRs are present in mouse sperm and that rFGF2 affects sperm motility and acrosomal exocytosis, suggests the involvement of this system in the in vivo regulation of sperm function.
Molecular etiopathology of naturally occurring reproductive diseases in female goats
Beena, V.; Pawaiya, R. V. S.; Gururaj, K.; Singh, D. D.; Mishra, A. K.; Gangwar, N. K.; Gupta, V. K.; Singh, R.; Sharma, A. K.; Karikalan, M.; Kumar, Ashok
2017-01-01
Aim: The aim of the present study was to investigate the molecular etiopathology of occurrence of reproductive diseases in female goats. Reproductive diseases in goats account for major economic losses to goat farmers in terms of valuable loss of offspring and animal productivity. Materials and Methods: A total of 660 female genitalia were examined for pathological conditions (macroscopic and microscopic lesions). The etiopathological study was carried out for the presence of pathogenic organisms such as Brucella, Chlamydia, and Campylobacter in the uterus and ovary. Based on the microscopic lesions, suspected samples were subjected to diagnostic polymerase chain reaction (PCR) for various etiological agents employing 16srRNA genus specific primers for Campylobacter and Chlamydophila and OMP31 gene-based PCR for Brucella melitensis and nested PCR using ITS-1 gene primers for Toxoplasma gondii. For Brucella suspected samples, immunohistochemistry (IHC) was also performed. Results: In studied female genitalia, 108 (16.30%) showed gross abnormalities with overall 23.32% occurrence of pathological conditions (macroscopic and microscopic lesions). Pathological involvement of the uterus was the highest 68 (62.96%), followed by the ovaries 27 (25%) and other organs. Major uterine condition observed was endometritis (5.60%). In uterine infections, 35 (5.30%) samples were found positive for Campylobacter spp., 12 (1.81%) samples for B. melitensis, and 3 (0.45%) samples were positive for Chlamydophila spp. Among the samples positive for B. melitensis by PCR, 3 were found positive by IHC also. Corynebacterium ovis was detected by PCR using specific primers in a case of hydrosalpinx. It was concluded that many pathological lesions in female genitalia of functional significance play a major role in infertility in goats. Conclusion: The present study concluded that many pathological lesions in female genitalia of functional significance play a major role in infertility in goats. PMID:28919691
Farias, Nahuel E; Spivak, Eduardo D; Luppi, Tomas A
2017-07-01
We studied the functional morphology of the female reproductive system of the purple stone crab Danielethus crenulatus. The most remarkable feature is the relative storage capacity and extensibility of the seminal receptacles. These receptacles are a pair of simple sacs that lack internal structures dividing the internal lumen. Differences in seminal receptacle size and contents are accompanied by conspicuous changes in receptacle lining at a tissue level. Full seminal receptacles contain discrete sperm masses formed by hardened fluid and densely packed spermatophores. Different sperm masses are likely from different mates and their stratified disposition within the seminal receptacles is compatible with rival sperm displacement and last sperm precedence. Additionally, the anatomical structure of the vulva and vagina suggest active female control over copula. We discuss our results in the general context of sperm storage in brachyurans and the implications for the mating system of this species. © 2017 Wiley Periodicals, Inc.
Tartu, Sabrina; Angelier, Frédéric; Herzke, Dorte; Moe, Børge; Bech, Claus; Gabrielsen, Geir W; Bustnes, Jan Ove; Chastel, Olivier
2014-04-01
High levels of environmental pollutants such as persistent organic pollutants (POPs) including PCB and DDT have been found in the Arctic and many of those pollutants may impair reproduction through endocrine disruption. Nevertheless, their effects on stress hormones remain poorly understood, especially in free-ranging birds. Corticosterone, the principal glucocorticoid in birds, can indirectly impair reproduction. The aim of the present study was to examine the relationships between POPs and reproduction through their potential consequences on different reproductive traits (breeding decision, egg-laying date, breeding success) and corticosterone secretion (baseline and stress-induced levels). We addressed those questions in an Arctic population of female black-legged kittiwakes during the pre-breeding stage and measured several legacy POPs (PCBs and pesticides: HCB, p,p'-DDE, CHL) in whole blood. POP levels were not related to breeding decision neither to breeding success, whereas females with high levels of pesticides laid their eggs earlier in the season. We found a negative relationship between POP levels and body condition index in non-breeding females. Black-legged kittiwakes with higher levels of PCB showed stronger adrenocortical response when subjected to a capture-handling stress protocol. We suggest that PCBs may disrupt corticosterone secretion whereas the positive relationship between pesticides and egg-laying date could either originate from a direct effect of pesticides or may be related to other confounding factors such as age or individual's quality. Although no direct negative reproduction output of POPs was found in this study, it is possible that the most contaminated individuals would be more sensitive to environmental stress and would be less able to maintain parental investment than less polluted individuals. Copyright © 2014 Elsevier B.V. All rights reserved.
Thomas, Peter
2012-01-01
Using cDNA cloning strategies commonly employed for G protein-coupled receptors (GPCR), GPCR-30 (GPR30), was isolated from mammalian cells before knowledge of its cognate ligand. GPR30 is evolutionarily conserved throughout the vertebrates. A broad literature suggests that GPR30 is a Gs-coupled heptahelical transmembrane receptor that promotes specific binding of naturally occurring and man-made estrogens but not cortisol, progesterone, or testosterone. Its “pregenomic” signaling actions are manifested by plasma membrane-associated actions familiar to GPCR, namely, stimulation of adenylyl cyclase and Gβγ-subunit protein-dependent release of membrane-tethered heparan bound epidermal growth factor. These facts regarding its mechanism of action have led to the formal renaming of this receptor to its current functional designate, G protein-coupled estrogen receptor (ER) (GPER)-1. Further insight regarding its biochemical action and physiological functions in vertebrates is derived from receptor knockdown studies and the use of selective agonists/antagonists that discriminate GPER-1 from the nuclear steroid hormone receptors, ERα and ERβ. GPER-1-selective agents have linked GPER-1 to physiological and pathological events regulated by estrogen action, including, but not limited to, the central nervous, immune, renal, reproductive, and cardiovascular systems. Moreover, immunohistochemical studies have shown a positive association between GPER-1 expression and progression of female reproductive cancer, a relationship that is diametrically opposed from ER. Unlike ER knockout mice, GPER-1 knockout mice are fertile and show no overt reproductive anomalies. However, they do exhibit thymic atrophy, impaired glucose tolerance, and altered bone growth. Here, we discuss the role of GPER-1 in female reproductive cancers as well as renal and vascular physiology. PMID:22495674
Filardo, Edward J; Thomas, Peter
2012-07-01
Using cDNA cloning strategies commonly employed for G protein-coupled receptors (GPCR), GPCR-30 (GPR30), was isolated from mammalian cells before knowledge of its cognate ligand. GPR30 is evolutionarily conserved throughout the vertebrates. A broad literature suggests that GPR30 is a Gs-coupled heptahelical transmembrane receptor that promotes specific binding of naturally occurring and man-made estrogens but not cortisol, progesterone, or testosterone. Its "pregenomic" signaling actions are manifested by plasma membrane-associated actions familiar to GPCR, namely, stimulation of adenylyl cyclase and Gβγ-subunit protein-dependent release of membrane-tethered heparan bound epidermal growth factor. These facts regarding its mechanism of action have led to the formal renaming of this receptor to its current functional designate, G protein-coupled estrogen receptor (ER) (GPER)-1. Further insight regarding its biochemical action and physiological functions in vertebrates is derived from receptor knockdown studies and the use of selective agonists/antagonists that discriminate GPER-1 from the nuclear steroid hormone receptors, ERα and ERβ. GPER-1-selective agents have linked GPER-1 to physiological and pathological events regulated by estrogen action, including, but not limited to, the central nervous, immune, renal, reproductive, and cardiovascular systems. Moreover, immunohistochemical studies have shown a positive association between GPER-1 expression and progression of female reproductive cancer, a relationship that is diametrically opposed from ER. Unlike ER knockout mice, GPER-1 knockout mice are fertile and show no overt reproductive anomalies. However, they do exhibit thymic atrophy, impaired glucose tolerance, and altered bone growth. Here, we discuss the role of GPER-1 in female reproductive cancers as well as renal and vascular physiology.
Young, Andrew J; Bennett, Nigel C
2013-01-01
In cooperatively breeding mammals and birds, intra-sexual reproductive competition among females may often render variance in reproductive success higher among females than males, leading to the prediction that intra-sexual selection in such species may have yielded the differential exaggeration of competitive traits among females. However, evidence to date suggests that female-biased reproductive variance in such species is rarely accompanied by female-biased sexual dimorphisms. We illustrate the problem with data from wild Damaraland mole-rat, Fukomys damarensis, societies: the variance in lifetime reproductive success among females appears to be higher than that among males, yet males grow faster, are much heavier as adults and sport larger skulls and incisors (the weapons used for fighting) for their body lengths than females, suggesting that intra-sexual selection has nevertheless acted more strongly on the competitive traits of males. We then consider potentially general mechanisms that could explain these disparities by tempering the relative intensity of selection for competitive trait exaggeration among females in cooperative breeders. Key among these may be interactions with kin selection that could nevertheless render the variance in inclusive fitness lower among females than males, and fundamental aspects of the reproductive biology of females that may leave reproductive conflict among females more readily resolved without overt physical contests.
Brain Sex Matters: estrogen in cognition and Alzheimer’s disease
Li, Rena; Cui, Jie; Shen, Yong
2014-01-01
Estrogens are the primary female sex hormones and play important roles in both reproductive and non-reproductive systems. Estrogens can be synthesized in non-reproductive tissues such as liver, heart, muscle, bone and the brain. During the past decade, increasing evidence suggests that brain estrogen can not only be synthesized by neurons, but also by astrocytes. Brain estrogen also works locally at the site of synthesis in paracrine and/or intracrine fashion to maintain important tissue-specific functions. Here, we will focus on the biology of brain estrogen and its impact on cognitive function and Alzheimer’s disease. This comprehensive review provides new insights into brain estrogens by presenting a better understanding of the tissue-specific estrogen effects and their roles in healthy ageing and cognitive function. PMID:24418360
True, Cadence; Nasrin Alam, Sayeda; Cox, Kimberly; Chan, Yee-Ming; Seminara, Stephanie B
2015-04-01
Humans carrying mutations in neurokinin B (NKB) or the NKB receptor fail to undergo puberty due to decreased secretion of GnRH. Despite this pubertal delay, many of these patients go on to achieve activation of their hypothalamic-pituitary-gonadal axis in adulthood, a phenomenon termed reversal, indicating that NKB signaling may play a more critical role for the timing of pubertal development than adult reproductive function. NKB receptor-deficient mice are hypogonadotropic but have no defects in the timing of sexual maturation. The current study has performed the first phenotypic evaluation of mice bearing mutations in Tac2, the gene encoding the NKB ligand, to determine whether they have impaired sexual development similar to their human counterparts. Male Tac2-/- mice showed no difference in the timing of sexual maturation or fertility compared with wild-type littermates and were fertile. In contrast, Tac2-/- females had profound delays in sexual maturation, with time to vaginal opening and first estrus occurring significantly later than controls, and initial abnormalities in estrous cycles. However, cycling recovered in adulthood and Tac2-/- females were fertile, although they produced fewer pups per litter. Thus, female Tac2-/- mice parallel humans harboring NKB pathway mutations, with delayed sexual maturation and activation of the reproductive cascade later in life. Moreover, direct comparison of NKB ligand and receptor-deficient females confirmed that only NKB ligand-deficient animals have delayed sexual maturation, suggesting that in the absence of the NKB receptor, NKB may regulate the timing of sexual maturation through other tachykinin receptors.
Melatonin and female reproduction.
Tamura, Hiroshi; Takasaki, Akihisa; Taketani, Toshiaki; Tanabe, Manabu; Lee, Lifa; Tamura, Isao; Maekawa, Ryo; Aasada, Hiromi; Yamagata, Yoshiaki; Sugino, Norihiro
2014-01-01
Melatonin (N-acetyl-5-methoxytryptamine) is secreted during the dark hours at night by the pineal gland. After entering the circulation, melatonin acts as an endocrine factor and a chemical messenger of light and darkness. It regulates a variety of important central and peripheral actions related to circadian rhythms and reproduction. It also affects the brain, immune, gastrointestinal, cardiovascular, renal, bone and endocrine functions and acts as an oncostatic and anti-aging molecule. Many of melatonin's actions are mediated through interactions with specific membrane-bound receptors expressed not only in the central nervous system, but also in peripheral tissues. Melatonin also acts through non-receptor-mediated mechanisms, for example serving as a scavenger for reactive oxygen species and reactive nitrogen species. At both physiological and pharmacological concentrations, melatonin attenuates and counteracts oxidative stress and regulates cellular metabolism. Growing scientific evidence of reproductive physiology supports the role of melatonin in human reproduction. This review was conducted to investigate the effects of melatonin on female reproduction and to summarize our findings in this field. © 2013 The Authors. Journal of Obstetrics and Gynaecology Research © 2013 Japan Society of Obstetrics and Gynecology.
O'Malley, Robert C; Stanton, Margaret A; Gilby, Ian C; Lonsdorf, Elizabeth V; Pusey, Anne; Markham, A Catherine; Murray, Carson M
2016-01-01
An increase in faunivory is a consistent component of human evolutionary models. Animal matter is energy- and nutrient-dense and can provide macronutrients, minerals, and vitamins that are limited or absent in plant foods. For female humans and other omnivorous primates, faunivory may be of particular importance during the costly periods of pregnancy and early lactation. Yet, because animal prey is often monopolizable, access to fauna among group-living primates may be mediated by social factors such as rank. Wild chimpanzees (Pan troglodytes) across Africa habitually consume insects and/or vertebrates. However, no published studies have examined patterns of female chimpanzee faunivory during pregnancy and early lactation relative to non-reproductive periods, or by females of different rank. In this study, we assessed the influence of reproductive state and dominance rank on the consumption of fauna (meat and insects) by female chimpanzees of Gombe National Park, Tanzania. Using observational data collected over 38 years, we tested (a) whether faunivory varied by reproductive state, and (b) if high-ranking females spent more time consuming fauna than lower-ranking females. In single-factor models, pregnant females consumed more meat than lactating and baseline (meaning not pregnant and not in early lactation) females, and high-ranking females consumed more meat than lower-ranking females. A two-factor analysis of a subset of well-sampled females identified an interaction between rank and reproductive state: lower-ranking females consumed more meat during pregnancy than lower-ranking lactating and baseline females did. High-ranking females did not significantly differ in meat consumption between reproductive states. We found no relationships between rank or reproductive state with insectivory. We conclude that, unlike insectivory, meat consumption by female chimpanzees is mediated by both reproductive state and social rank. We outline possible mechanisms for these patterns, relate our findings to meat-eating patterns in women from well-studied hunter-gatherer societies, and discuss potential avenues for future research. Copyright © 2015 Elsevier Ltd. All rights reserved.
Stanton, Margaret A.; Gilby, Ian C.; Lonsdorf, Elizabeth V.; Pusey, Anne; Markham, A. Catherine; Murray, Carson M.
2015-01-01
An increase in faunivory is a consistent component of human evolutionary models. Animal matter is energy- and nutrient-dense and can provide macronutrients, minerals, and vitamins that are limited or absent in plant foods. For female humans and other omnivorous primates, faunivory may be of particular importance during the costly periods of pregnancy and early lactation. Yet, because animal prey is often monopolizable, access to fauna among group-living primates may be mediated by social factors such as rank. Wild chimpanzees (Pan troglodytes) across Africa habitually consume insects and/or vertebrates. However, no published studies have examined patterns of female chimpanzee faunivory during pregnancy and early lactation relative to non-reproductive periods, or by females of different rank. In this study, we assessed the influence of reproductive state and dominance rank on the consumption of fauna (meat and insects) by female chimpanzees of Gombe National Park, Tanzania. Using observational data collected over 38 years, we tested (a) whether faunivory varied by reproductive state, and (b) if high-ranking females spent more time consuming fauna than lower-ranking females. In single-factor models, pregnant females consumed more meat than lactating and baseline (meaning not pregnant and not in early lactation) females, and high-ranking females consumed more meat than lower-ranking females. A two-factor analysis of a subset of well-sampled females identified an interaction between rank and reproductive state: lower-ranking females consumed more meat during pregnancy than lower-ranking lactating and baseline females did. High-ranking females did not significantly differ in meat consumption between reproductive states. We found no relationships between rank or reproductive state with insectivory. We conclude that, unlike insectivory, meat consumption by female chimpanzees is mediated by both reproductive state and social rank. We outline several possible mechanisms for these patterns, relate our findings to meat-eating patterns in women from well-studied hunter-gatherer societies, and discuss potential avenues for future research. PMID:26767956
Schmidt, Christina M.; Blount, Jonathan D.; Bennett, Nigel C.
2014-01-01
Oxidative stress has been implicated as both a physiological cost of reproduction and a driving force on an animal's lifespan. Since increased reproductive effort is generally linked with a reduction in survival, it has been proposed that oxidative stress may influence this relationship. Support for this hypothesis is inconsistent, but this may, in part, be due to the type of tissues that have been analyzed. In Damaraland mole-rats the sole reproducing female in the colony is also the longest lived. Therefore, if oxidative stress does impact the trade-off between reproduction and survival in general, this species may possess some form of enhanced defense. We assessed this relationship by comparing markers of oxidative damage (malondialdehyde, MDA; protein carbonyls, PC) and antioxidants (total antioxidant capacity, TAC; superoxide dismutase, SOD) in various tissues including plasma, erythrocytes, heart, liver, kidney and skeletal muscle between wild-caught reproductive and non-reproductive female Damaraland mole-rats. Reproductive females exhibited significantly lower levels of PC across all tissues, and lower levels of MDA in heart, kidney and liver relative to non-reproductive females. Levels of TAC and SOD did not differ significantly according to reproductive state. The reduction in oxidative damage in breeding females may be attributable to the unusual social structure of this species, as similar relationships have been observed between reproductive and non-reproductive eusocial insects. PMID:25068591
Patterns of cetacean vaginal folds yield insights into functionality
Orbach, Dara N.; Marshall, Christopher D.; Mesnick, Sarah L.; Würsig, Bernd
2017-01-01
Complex foldings of the vaginal wall are unique to some cetaceans and artiodactyls and are of unknown function(s). The patterns of vaginal length and cumulative vaginal fold length were assessed in relation to body length and to each other in a phylogenetic context to derive insights into functionality. The reproductive tracts of 59 female cetaceans (20 species, 6 families) were dissected. Phylogenetically-controlled reduced major axis regressions were used to establish a scaling trend for the female genitalia of cetaceans. An unparalleled level of vaginal diversity within a mammalian order was found. Vaginal folds varied in number and size across species, and vaginal fold length was positively allometric with body length. Vaginal length was not a significant predictor of vaginal fold length. Functional hypotheses regarding the role of vaginal folds and the potential selection pressures that could lead to evolution of these structures are discussed. Vaginal folds may present physical barriers, which obscure the pathway of seawater and/or sperm travelling through the vagina. This study contributes broad insights to the evolution of reproductive morphology and aquatic adaptations and lays the foundation for future functional morphology analyses. PMID:28362830
Rubinstein, C Dustin; Wolfner, Mariana F
2014-01-01
Seminal proteins are critical for reproductive success in all animals that have been studied. Although seminal proteins have been identified in many taxa, and female reproductive responses to receipt of these proteins have been documented in several, little is understood about the mechanisms by which seminal proteins affect female reproductive physiology. To explore this topic, we investigated how a Drosophila seminal protein, ovulin, increases ovulation rate in mated females. Ovulation is a relatively simple physiological process, with known female regulators: previous studies have shown that ovulation rate is promoted by the neuromodulator octopamine (OA) in D. melanogaster and other insects. We found that ovulin stimulates ovulation by increasing OA signaling in the female. This finding supports a model in which a male seminal protein acts through "hacking" a well-conserved, regulatory system females use to adjust reproductive output, rather than acting downstream of female mechanisms of control or in parallel pathways altogether. We also discuss similarities between 2 forms of intersexual control of behavior through chemical communication: seminal proteins and pheromones.
Survival of female Lesser Scaup: Effects of body size, age, and reproductive effort
Rotella, J.J.; Clark, R.G.; Afton, A.D.
2003-01-01
In birds, larger females generally have greater breeding propensity, reproductive investment, and success than do smaller females. However, optimal female body size also depends on how natural selection acts during other parts of the life cycle. Larger female Lesser Scaup (Aythya affinis) produce larger eggs than do smaller females, and ducklings from larger eggs survive better than those hatching from smaller eggs. Accordingly, we examined patterns of apparent annual survival for female scaup and tested whether natural selection on female body size primarily was stabilizing, a frequent assumption in studies of sexually dimorphic species in which males are the larger sex, or was directional, counter-acting reproductive advantages of large size. We estimated survival using mark-recapture methods for individually marked females from two study sites in Canada (Erickson, Manitoba; St. Denis, Saskatchewan). Structurally larger (adults) and heavier (ducklings) females had lower survival than did smaller individuals in Manitoba; no relationship was detected in adults from Saskatchewan. Survival of adult females declined with indices of increasing reproductive effort at both sites; consequently, the cost of reproduction could explain age-related patterns of breeding propensity in scaup. Furthermore, if larger females are more likely to breed than are smaller females, then cost of reproduction also may help explain why survival was lower for larger females. Overall, we found that advantages of large body size of female scaup during breeding or as young ducklings apparently were counteracted by natural selection favoring lightweight juveniles and structurally smaller adult females through higher annual survival.
Reproductive toxicologic evaluations of Bulbine natalensis Baker stem extract in albino rats.
Yakubu, M T; Afolayan, A J
2009-08-01
The effects of oral administration of aqueous extract of Bulbine natalensis Baker stem at daily doses of 25, 50, and 100mg/kg body weight on the reproductive function of Wistar rats were evaluated. The indices of mating and fertility success as well as quantal frequency increased after 7 days of treatment in all the dose groups except the 100mg/kg body weight group. The number of litters was not statistically different (P>0.05) from the control. Whereas the absolute weights of the epididymis, seminal vesicle, and prostate were not affected, that of the testes was significantly increased. The epididymal sperm count, motility, morphology, and viscosity were not different from the control after 7 days of treatment. The male rat serum testosterone, progesterone, luteinizing hormone, and follicle-stimulating hormone significantly increased in the 25 and 50mg/kg body weight groups, whereas the estradiol concentration decreased significantly at all the doses. The extract dose of 100mg/kg body weight decreased the serum testosterone and progesterone levels in male rats. The prolactin concentration was not affected by all the doses. All the indices of reproduction, maternal, embryo/fetotoxic, teratogenic, and reproductive hormones in the female rats were not statistically different from that of their control except the resorption index, which increased at the dose of 100mg/kg body weight of the extract. Histologic examination of the cross section of rat testes that received the extract at all the doses investigated revealed well-preserved seminiferous tubules with normal amount of stroma, normal population of spermatogenic and supporting cells, as well as normal spermatocytes within the lumen. The results revealed that the aqueous extract of Bulbine natalensis stem at doses of 25 and 50mg/kg body weight enhanced the success rate of mating and fertility due to increased libido as well as the levels of reproductive hormones in male rats. The absence of alterations in the reproductive parameters of female rats at doses of 25 and 50mg/kg body weight of Bulbine natalensis stem extract suggest that the extract is "safe" for use at these doses by females during the organogenic period of pregnancy, whereas the extract dose of 100mg/kg body weight portends a negative effect on some reproductive functions of male and female rats.
Zhang, Wenya; Guo, Rui; Ai, Shiwei; Yang, Ying; Ding, Jian; Zhang, Yingmei
2018-09-15
Environment contamination is known to affect the growth, reproduction, and even mortality of anuran species, and hence modulate their life history traits. Although knowledge of the ability of amphibians to cope with harsh environments has gained ongoing research, the reproductive strategy of free-living amphibians subjected to long-term heavy metal pollution is largely unknown. This study aimed to explore the variation in the life history traits, including age structure, maturation age, reproductive investment, and reproduction trade-off, in female Bufo raddei, a widespread anuran in Baiyin (BY) in northwest of China, subjected to sublethal heavy metal pollution. B. raddei collected from Liujiaxia (LJX), a relatively unpolluted area, were used as control. Skeletochronological analysis revealed variation in the average breeding age of females: more than 70% of females from BY began to breed 1 year before the toads collected from LJX. Females from BY tended to prioritize reproduction over survival and invested more in their first reproductive event. Further, females in BY with a high fluctuating asymmetry index showed a relatively lower reproductive investment. For trade-off in offspring number and size, BY population optimize larger clutch sizes with smaller egg size compared with population in LJX. Changes in female reproductive investment caused by heavy metal pollution might ultimately alter the structural stability of amphibian population. Copyright © 2018 Elsevier Inc. All rights reserved.
In vitro differentiation of primordial germ cells and oocyte-like cells from stem cells.
Costa, José J N; Souza, Glaucinete B; Soares, Maria A A; Ribeiro, Regislane P; van den Hurk, Robert; Silva, José R V
2018-02-01
Infertility is the result of failure due to an organic disorder of the reproductive organs, especially their gametes. Recently, much progress has been made on generating germ cells, including oocytes, from various types of stem cells. This review focuses on advances in female germ cell differentiation from different kinds of stem cells, with emphasis on embryonic stem cells, adult stem cells, and induced pluripotent stem cells. The advantages and disadvantages of the derivation of female germ cells from several types of stem cells are also highlighted, as well as the ability of stem cells to generate mature and functional female gametes. This review shows that stem cell therapies have opened new frontiers in medicine, especially in the reproductive area, with the possibility of regenerating fertility.
Roles of Female and Male Genotype in Post-Mating Responses in Drosophila melanogaster.
Delbare, Sofie Y N; Chow, Clement Y; Wolfner, Mariana F; Clark, Andrew G
2017-10-30
Mating induces a multitude of changes in female behavior, physiology, and gene expression. Interactions between female and male genotype lead to variation in post-mating phenotypes and reproductive success. So far, few female molecules responsible for these interactions have been identified. Here, we used Drosophila melanogaster from 5 geographically dispersed populations to investigate such female × male genotypic interactions at the female transcriptomic and phenotypic levels. Females from each line were singly-mated to males from the same 5 lines, for a total of 25 combinations. Reproductive output and refractoriness to re-mating were assayed in females from the 25 mating combinations. Female × male genotypic interactions resulted in significant differences in these post-mating phenotypes. To assess whether female × male genotypic interactions affect the female post-mating transcriptome, next-generation RNA sequencing was performed on virgin and mated females at 5 to 6 h post-mating. Seventy-seven genes showed strong variation in mating-induced expression changes in a female × male genotype-dependent manner. These genes were enriched for immune response and odorant-binding functions, and for expression exclusively in the head. Strikingly, variation in post-mating transcript levels of a gene encoding a spermathecal endopeptidase was correlated with short-term egg production. The transcriptional variation found in specific functional classes of genes might be a read-out of female × male compatibility at a molecular level. Understanding the roles these genes play in the female post-mating response will be crucial to better understand the evolution of post-mating responses and related conflicts between the sexes. © The American Genetic Association 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fokidis, H.B., T.S. Risch and T.C. Glenn
Factors underlying the evolution of female-biased sexual size dimorphism in mammals are poorly understood. In an effort to better understand these factors we tested whether larger female southern flying squirrels, Glaucomys volans, gained reproductive advantages (larger litters or more male mates) and direct resource benefits, such as larger home ranges or access to more food (i.e. mast-producing trees). As dimorphism can vary with age in precocial breeding species, we compared females during their first reproduction and during a subsequent breeding attempt. Females were not significantly larger or heavier than males at first reproduction, but became about 7% heavier and 22%more » larger than males at subsequent breeding. Larger females produced larger litters and had home ranges containing a greater proportion of upland hardwood trees. Female body size was not associated with either multiple male mating or home range size, but females with larger home ranges had higher indexes of body condition. Females in precocial breeding flying squirrels initiate reproduction before sexual size dimorphism is evident, and thus, may be allocating resources to both reproduction and growth simultaneously, or delaying growth entirely. Larger females produce more pups and have access to more food resources. Thus, selection for increased female size may partly explain how female-biased sexual size dimorphism is maintained in this species.« less
Preston, B T; Stevenson, I R; Pemberton, J M; Coltman, D W; Wilson, K
2003-03-22
Male contests for access to receptive females are thought to have selected for the larger male body size and conspicuous weaponry frequently observed in mammalian species. However, when females copulate with multiple males within an oestrus, male reproductive success is a function of both pre- and postcopulatory strategies. The relative importance of these overt and covert forms of sexual competition has rarely been assessed in wild populations. The Soay sheep mating system is characterized by male contests for mating opportunities and high female promiscuity. We find that greater horn length, body size and good condition each independently influence a male's ability to monopolize receptive females. For males with large horns at least, this behavioural success translates into greater siring success. Consistent with sperm-competition theory, we also find that larger testes are independently associated with both higher copulation rates and increased siring success. This advantage of larger testes emerges, and strengthens, as the number of oestrous females increases, as dominant males can no longer control access to them all. Our results thus provide direct quantitative evidence that male reproductive success in wild populations of mammals is dependent upon the relative magnitude of both overt contest competition and covert sperm competition.
Brown, Megan E; Converse, Sarah J.; Chandler, Jane N.; Shafer, Charles; Brown, Janine L; Keefer, Carol L; Songsasen, Nucharin
2016-01-01
Reproductive success of endangered whooping cranes (Grus americana) maintained ex situ is poor. As part of an effort to identify potential causes of poor reproductive success in a captive colony, we used non-invasive endocrine monitoring to assess gonadal and adrenal steroids of bird pairs with various reproductive outcomes and evaluated the relationships of hormones and behaviors to reproductive performance. Overall, reproductively successful (i.e., egg laying) females had significantly higher mean estrogen levels but lower mean progestogen concentrations than did unsuccessful females. Other hormones, including glucocorticoids and androgens, were not significantly different between successful and unsuccessful individuals. Observations of specific behaviors such as unison calling, marching, and the number of copulation attempts, along with overall time spent performing reproductive behaviors, were significantly higher in successful pairs. Our findings indicate that overall reproductive performance of whooping crane pairs is linked to female gonadal hormone excretion and reproductive behaviors, but not to altered adrenal hormone production.
Brown, Megan E; Converse, Sarah J; Chandler, Jane N; Shafer, Charles; Brown, Janine L; Keefer, Carol L; Songsasen, Nucharin
2016-05-01
Reproductive success of endangered whooping cranes (Grus americana) maintained ex situ is poor. As part of an effort to identify potential causes of poor reproductive success in a captive colony, we used non-invasive endocrine monitoring to assess gonadal and adrenal steroids of bird pairs with various reproductive outcomes and evaluated the relationships of hormones and behaviors to reproductive performance. Overall, reproductively successful (i.e., egg laying) females had significantly higher mean estrogen levels but lower mean progestogen concentrations than did unsuccessful females. Other hormones, including glucocorticoids and androgens, were not significantly different between successful and unsuccessful individuals. Observations of specific behaviors such as unison calling, marching, and the number of copulation attempts, along with overall time spent performing reproductive behaviors, were significantly higher in successful pairs. Our findings indicate that overall reproductive performance of whooping crane pairs is linked to female gonadal hormone excretion and reproductive behaviors, but not to altered adrenal hormone production. Published by Elsevier Inc.
Dougherty, Liam R; van Lieshout, Emile; McNamara, Kathryn B; Moschilla, Joe A; Arnqvist, Göran; Simmons, Leigh W
2017-05-31
Traumatic mating (or copulatory wounding) is an extreme form of sexual conflict whereby male genitalia physically harm females during mating. In such species females are expected to evolve counter-adaptations to reduce male-induced harm. Importantly, female counter-adaptations may include both genital and non-genital traits. In this study, we examine evolutionary associations between harmful male genital morphology and female reproductive tract morphology and immune function across 13 populations of the seed beetle Callosobruchus maculatus We detected positive correlated evolution between the injuriousness of male genitalia and putative female resistance adaptations across populations. Moreover, we found evidence for a negative relationship between female immunity and population productivity, which suggests that investment in female resistance may be costly due to the resource trade-offs that are predicted between immunity and reproduction. Finally, the degree of female tract scarring (harm to females) was greater in those populations with both longer aedeagal spines and a thinner female tract lining. Our results are thus consistent with a sexual arms race, which is only apparent when both male and female traits are taken into account. Importantly, our study provides rare evidence for sexually antagonistic coevolution of male and female traits at the within-species level. © 2017 The Author(s).
van Lieshout, Emile; Moschilla, Joe A.; Arnqvist, Göran
2017-01-01
Traumatic mating (or copulatory wounding) is an extreme form of sexual conflict whereby male genitalia physically harm females during mating. In such species females are expected to evolve counter-adaptations to reduce male-induced harm. Importantly, female counter-adaptations may include both genital and non-genital traits. In this study, we examine evolutionary associations between harmful male genital morphology and female reproductive tract morphology and immune function across 13 populations of the seed beetle Callosobruchus maculatus. We detected positive correlated evolution between the injuriousness of male genitalia and putative female resistance adaptations across populations. Moreover, we found evidence for a negative relationship between female immunity and population productivity, which suggests that investment in female resistance may be costly due to the resource trade-offs that are predicted between immunity and reproduction. Finally, the degree of female tract scarring (harm to females) was greater in those populations with both longer aedeagal spines and a thinner female tract lining. Our results are thus consistent with a sexual arms race, which is only apparent when both male and female traits are taken into account. Importantly, our study provides rare evidence for sexually antagonistic coevolution of male and female traits at the within-species level. PMID:28539510
Dietary Deficiency of Essential Amino Acids Rapidly Induces Cessation of the Rat Estrous Cycle
Bannai, Makoto; Ichimaru, Toru; Nakano, Sayako; Murata, Takuya; Higuchi, Takashi; Takahashi, Michio
2011-01-01
Reproductive functions are regulated by the sophisticated coordination between the neuronal and endocrine systems and are sustained by a proper nutritional environment. Female reproductive function is vulnerable to effects from dietary restrictions, suggesting a transient adaptation that prioritizes individual survival over reproduction until a possible future opportunity for satiation. This adaptation could also partially explain the existence of amenorrhea in women with anorexia nervosa. Because amino acid nutritional conditions other than caloric restriction uniquely alters amino acid metabolism and affect the hormonal levels of organisms, we hypothesized that the supply of essential amino acids in the diet plays a pivotal role in the maintenance of the female reproductive system. To test this hypothesis, we examined ovulatory cyclicity in female rats under diets that were deficient in threonine, lysine, tryptophan, methionine or valine. Ovulatory cyclicity was monitored by daily cytological evaluations of vaginal smears. After continuous feeding of the deficient diet, a persistent diestrus or anovulatory state was induced most quickly by the valine-deficient diet and most slowly by the lysine-deficient diet. A decline in the systemic insulin-like growth factor 1 level was associated with a dietary amino acid deficiency. Furthermore, a paired group of rats that were fed an isocaloric diet with balanced amino acids maintained normal estrous cyclicity. These disturbances of the estrous cycle by amino acid deficiency were quickly reversed by the consumption of a normal diet. The continuous anovulatory state in this study is not attributable to a decrease in caloric intake but to an imbalance in the dietary amino acid composition. With a shortage of well-balanced amino acid sources, reproduction becomes risky for both the mother and the fetus. It could be viewed as an adaptation to the diet, diverting resources away from reproduction and reallocating them to survival until well-balanced amino acid sources are found. PMID:22132231
Johnson, L W
1989-03-01
The reproductive anatomy, physiology, and breeding behavior of the llama is unique enough to make familiarity with it imperative. Female puberty averages 12 months, while many males are not reproductively functional until after 3 years. Proper management of a breeding pair or herd is necessary to maintain maximum reproductive performance. Proof of pregnancy is suggested by rejection of the male and may/should be confirmed by progesterone assay, rectal palpation, or ultrasound techniques. The postpartum female is notable for breeding back rapidly, with high pregnancy rates resulting. Both male and female factors enter into llama infertility, with each gender having significant incidence of reproductive anatomical abnormalities. Management as well as acquired infertility problems (heat factors, trauma, infection, neoplasia, and hormonal imbalances) contribute to the bulk of infertility cases investigated. Techniques used to diagnose infertility in llamas are quite comparable to the equine species; however, female body size and semen analysis in the male present significant challenges. The approach to therapy has been quite empirical to date, owing to lack of consistent problems and numbers to afford conclusive trials. Alterations of pregnancy include resorption, abortions, and stillbirths. Resorption between 30 to 60 days of gestation is reported regularly. Abortions caused by stress occur regularly. Infection abortions caused by leptospirosis, toxoplasmosis, and chlamydiosis are to be expected. Ponderosa pine-related abortions are suspected. In summary, I find use for a broad background in large animal theriogenology to apply to llama infertility. There no doubt are additional diagnostic techniques and therapeutic regimens that have application, and it is up to us all to keep good records and share the information.
2016-11-02
Anxiety Disorder; Cervical Cancer; Endometrial Cancer; Female Reproductive Cancer; Gestational Trophoblastic Tumor; Ovarian Epithelial Cancer; Ovarian Germ Cell Tumor; Sexual Dysfunction; Uterine Sarcoma; Vaginal Cancer; Vulvar Cancer
Sociality, mating system and reproductive skew in marmots: evidence and hypotheses.
Allainé
2000-10-05
Marmot species exhibit a great diversity of social structure, mating systems and reproductive skew. In particular, among the social species (i.e. all except Marmota monax), the yellow-bellied marmot appears quite different from the others. The yellow-bellied marmot is primarily polygynous with an intermediate level of sociality and low reproductive skew among females. In contrast, all other social marmot species are mainly monogamous, highly social and with marked reproductive skew among females. To understand the evolution of this difference in reproductive skew, I examined four possible explanations identified from reproductive skew theory. From the literature, I then reviewed evidence to investigate if marmot species differ in: (1) the ability of dominants to control the reproduction of subordinates; (2) the degree of relatedness between group members; (3) the benefit for subordinates of remaining in the social group; and (4) the benefit for dominants of retaining subordinates. I found that the optimal skew hypothesis may apply for both sets of species. I suggest that yellow-bellied marmot females may benefit from retaining subordinate females and in return have to concede them reproduction. On the contrary, monogamous marmot species may gain by suppressing the reproduction of subordinate females to maximise the efficiency of social thermoregulation, even at the risk of departure of subordinate females from the family group. Finally, I discuss scenarios for the simultaneous evolution of sociality, monogamy and reproductive skew in marmots.
Bodkin, James L.; Mulcahy, Daniel M.; Lensink, Calvin J.
1993-01-01
We estimated age at sexual maturity and age-specific reproductive rates by examining carcasses and reproductive tracts from 177 female sea otters (Enhydra lutris). Carcasses were recovered from south-central Alaska, Primarily from western Prince William Sound, as a result of the T/V Exxon Valdez oil spill in 1989. We found 65% of our sample to be sexually mature. Sexual maturity was first attained at age 2. The proportion of sexually mature animals increased from 30% at age 2 to 100% at age 5. Annual reproductive rates increased from 22% at age 2 to 78% at age 5 and remained relatively stable (75-88%) through to age 15. the sex ratio (female:male) of 49 fetal sea otters was 18:37 and differed significantly from parity. Females younger than 8 tended to produce more female fetuses, while older mothers did not. Our estimates of the reproductive characteristics of female sea otters obtained by examination of reproductive tracts were similiar to those reported in the literature based on in situ observations of marked individuals.
Sirot, Laura K.; Poulson, Rebecca L.; McKenna, M. Caitlin; Girnary, Hussein; Wolfner, Mariana F.; Harrington, Laura C.
2009-01-01
Male reproductive gland proteins (mRGPs) impact the physiology and/or behavior of mated females in a broad range of organisms. We sought to identify mRGPs of the yellow fever mosquito, Aedes aegypti, the primary vector of dengue and yellow fever viruses. Earlier studies with Ae. aegypti demonstrated that “matrone” (a partially purified male reproductive accessory gland substance) or male accessory gland fluid injected into virgin female Ae. aegypti affect female sexual refractoriness, blood feeding and digestion, flight, ovarian development, and oviposition. Using bioinformatic comparisons to Drosophila melanogaster accessory gland proteins and mass spectrometry of proteins from Ae. aegypti male accessory glands and ejaculatory ducts (AG/ED) and female reproductive tracts, we identified 63 new putative Ae. aegypti mRGPs. Twenty-one of these proteins were found in the reproductive tract of mated females, but not of virgin females, suggesting that they are transferred from males to females during mating. Most of the putative mRGPs fall into the same protein classes as mRGPs in other organisms, although some appear to be evolving rapidly and lack identifiable homologs in Culex pipiens, Anopheles gambiae, and D. melanogaster. Our results identify candidate male-derived molecules that may have an important influence on behavior, survival and reproduction of female mosquitoes. PMID:18207079
Hormone levels predict individual differences in reproductive success in a passerine bird.
Ouyang, Jenny Q; Sharp, Peter J; Dawson, Alistair; Quetting, Michael; Hau, Michaela
2011-08-22
Hormones mediate major physiological and behavioural components of the reproductive phenotype of individuals. To understand basic evolutionary processes in the hormonal regulation of reproductive traits, we need to know whether, and during which reproductive phases, individual variation in hormone concentrations relates to fitness in natural populations. We related circulating concentrations of prolactin and corticosterone to parental behaviour and reproductive success during both the pre-breeding and the chick-rearing stages in both individuals of pairs of free-living house sparrows, Passer domesticus. Prolactin and baseline corticosterone concentrations in pre-breeding females, and prolactin concentrations in pre-breeding males, predicted total number of fledglings. When the strong effect of lay date on total fledgling number was corrected for, only pre-breeding baseline corticosterone, but not prolactin, was negatively correlated with the reproductive success of females. During the breeding season, nestling provisioning rates of both sexes were negatively correlated with stress-induced corticosterone levels. Lastly, individuals of both sexes with low baseline corticosterone before and high baseline corticosterone during breeding raised the most offspring, suggesting that either the plasticity of this trait contributes to reproductive success or that high parental effort leads to increased hormone concentrations. Thus hormone concentrations both before and during breeding, as well as their seasonal dynamics, predict reproductive success, suggesting that individual variation in absolute concentrations and in plasticity is functionally significant, and, if heritable, may be a target of selection.
Roa, J; Vigo, E; Castellano, J M; Navarro, V M; Fernández-Fernández, R; Casanueva, F F; Dieguez, C; Aguilar, E; Pinilla, L; Tena-Sempere, M
2006-06-01
Kisspeptins, products of the KiSS-1 gene with ability to bind G protein-coupled receptor 54 (GPR54), have been recently identified as major gatekeepers of reproductive function with ability to potently activate the GnRH/LH axis. Yet, despite the diversity of functional states of the female gonadotropic axis, pharmacological characterization of this effect has been mostly conducted in pubertal animals or adult male rodents, whereas similar studies have not been thoroughly conducted in the adult female. In this work, we evaluated maximal LH and FSH secretory responses to kisspeptin-10, as well as changes in sensitivity and hypothalamic expression of KiSS-1 and GPR54 genes, in different physiological and experimental models in the adult female rat. Kisspeptin-10 (1 nmol, intracerebroventricular) was able to elicit robust LH bursts at all phases of the estrous cycle, with maximal responses at estrus; yet, in diestrus LH, responses to kisspeptin were detected at doses as low as 0.1 pmol. In contrast, high doses of kisspeptin only stimulated FSH secretion at diestrus. Removal of ovarian sex steroids did not blunt the ability of kisspeptin to further elicit stimulated LH and FSH secretion, but restoration of maximal responses required replacement with estradiol and progesterone. Finally, despite suppressed basal levels, LH and FSH secretory responses to kisspeptin were preserved in pregnant and lactating females, although the magnitude of LH bursts and the sensitivity to kisspeptin were much higher in pregnant dams. Interestingly, hypothalamic KiSS-1 gene expression significantly increased during pregnancy, whereas GPR54 mRNA levels remained unaltered. In summary, our current data document for the first time the changes in hypothalamic expression of KiSS-1 system and the gonadotropic effects (maximal responses and sensitivity) of kisspeptin in different functional states of the female reproductive axis. The present data may pose interesting implications in light of the potential therapeutic use of kisspeptin analogs in the pharmacological manipulation of the gonadotropic axis in the female.
Sex differences in the drivers of reproductive skew in a cooperative breeder.
Nelson-Flower, Martha J; Flower, Tom P; Ridley, Amanda R
2018-04-16
Many cooperatively breeding societies are characterized by high reproductive skew, such that some socially dominant individuals breed, while socially subordinate individuals provide help. Inbreeding avoidance serves as a source of reproductive skew in many high-skew societies, but few empirical studies have examined sources of skew operating alongside inbreeding avoidance or compared individual attempts to reproduce (reproductive competition) with individual reproductive success. Here, we use long-term genetic and observational data to examine factors affecting reproductive skew in the high-skew cooperatively breeding southern pied babbler (Turdoides bicolor). When subordinates can breed, skew remains high, suggesting factors additional to inbreeding avoidance drive skew. Subordinate females are more likely to compete to breed when older or when ecological constraints on dispersal are high, but heavy subordinate females are more likely to successfully breed. Subordinate males are more likely to compete when they are older, during high ecological constraints, or when they are related to the dominant male, but only the presence of within-group unrelated subordinate females predicts subordinate male breeding success. Reproductive skew is not driven by reproductive effort, but by forces such as intrinsic physical limitations and intrasexual conflict (for females) or female mate choice, male mate-guarding and potentially reproductive restraint (for males). Ecological conditions or "outside options" affect the occurrence of reproductive conflict, supporting predictions of recent synthetic skew models. Inbreeding avoidance together with competition for access to reproduction may generate high skew in animal societies, and disparate processes may be operating to maintain male vs. female reproductive skew in the same species. © 2018 John Wiley & Sons Ltd.
Lu, Kai; Chen, Xia; Li, Wenru; Li, Yue; Zhang, Zhichao; Zhou, Qiang
2018-01-10
Insulin-like peptides (ILPs) sense and transduce nutritional information and are linked to female reproduction in many insect species. Our previous studies have shown that "Target of rapamycin" (TOR) pathway functions through juvenile hormone (JH) to regulate amino acids-mediated vitellogenesis in the brown planthopper, Nilaparvata lugens, one of the most destructive rice pests in Asia. Recent reports have demonstrated that DNA methyltransferases (Dnmts) are also involved in female reproduction of N. lugens. However, the roles of ILPs and Dnmts in the nutritional regulation of female reproduction have not been fully elucidated. ILPs and Dnmts are highly expressed in the adult females after a supplement of amino acids, indicating nutrition-stimulated expression patterns of these genes. RNA interference-mediated depletion of NlILP2 or NlILP4 dramatically decreased the expression levels of NlDnmt1 and NlDnmt2 (tRNA methyltransferase), and resulted in severely impaired ovary growth as well as the substantial reduction of fecundity. Notably, NlILP2 or NlILP4 knockdown led to reduced mRNA accumulation of S6 kinase (S6K), a downstream target of the nutritional TOR pathway, and decreased vitellogenin content in the fat body. Silencing NlDnmt1 or NlDnmt2 effectively suppressed ovary development and decreased female fecundity. However, NlDnmt1 or NlDnmt2 knockdown did not influence the expression of NlILP2 and NlILP4. We infer that amino acids act on ILPs and Dnmts to regulate vitellogenesis and oocyte maturation in N. lugens. Copyright © 2017 Elsevier B.V. All rights reserved.
Bolund, Elisabeth; Lummaa, Virpi; Smith, Ken R.; Hanson, Heidi A.; Maklakov, Alexei A.
2016-01-01
The causes underlying sex differences in lifespan are strongly debated. While females commonly outlive males in humans, this is generally less pronounced in societies before the demographic transition to low mortality and fertility rates. Life-history theory suggests that reduced reproduction should benefit female lifespan when females pay higher costs of reproduction than males. Using unique longitudinal demographic records on 140,600 reproducing individuals from the Utah Population Database, we demonstrate a shift from male-biased to female-biased adult lifespans in individuals born before versus during the demographic transition. Only women paid a cost of reproduction in terms of shortened post-reproductive lifespan at high parities. Therefore, as fertility decreased over time, female lifespan increased, while male lifespan remained largely stable, supporting the theory that differential costs of reproduction in the two sexes result in the shifting patterns of sex differences in lifespan across human populations. Further, our results have important implications for demographic forecasts in human populations and advance our understanding of lifespan evolution. PMID:27087670
Paukku, Satu; Kotiaho, Janne S
2005-11-01
One of the most studied life-history trade-offs is that resulting from the cost of reproduction: a trade-off arises when reproduction diverts limited resources from other life-history traits. We examine the cost of reproduction in male, and the effect of male mating status on female Callosobruchus maculatus seed beetles. Cost of reproduction for male C. maculatus was manifested as reduced longevity. There was also a positive relationship between male body size and male longevity. Females mated to males that had already copulated twice did not live as long as females mated to males that had copulated once or not at all. The third copulation of males also lasted longer than the two previous ones. We conclude that even though the cost of reproduction for males has been studied much less than that in females, there is growing evidence that male reproductive effort is more complex than has traditionally been thought.
Reproductive strategies in snakes.
Shine, Richard
2003-01-01
Snakes of both sexes display remarkable flexibility and diversity in their reproductive tactics. Many features of reproduction in female snakes (such as reproductive mode and frequency, seasonality and multiple mating) allow flexible maternal control. For example, females can manipulate not only the genotypes of their offspring (through mate choice or enhanced sperm competition) but also the phenotypes of their offspring (through allocation 'decisions', behavioural and physiological thermoregulation, and nest-site selection). Reliance on stored energy ('capital') to fuel breeding results in low frequencies of female reproduction and, in extreme cases, semelparity. A sophisticated vomeronasal system not only allows male snakes to locate reproductive females by following scent trails, but also facilitates pheromonally mediated mate choice by males. Male-male rivalry takes diverse forms, including female mimicry and mate guarding; combat bouts impose strong selection for large body size in males of some species. Intraspecific (geographical) variation and phenotypic plasticity in a wide array of reproductive traits (offspring size and number; reproductive frequency; incidence of multiple mating; male tactics such as mate guarding and combat; mate choice criteria) provide exceptional opportunities for future studies. PMID:12803888
Reproductive strategies in snakes.
Shine, Richard
2003-05-22
Snakes of both sexes display remarkable flexibility and diversity in their reproductive tactics. Many features of reproduction in female snakes (such as reproductive mode and frequency, seasonality and multiple mating) allow flexible maternal control. For example, females can manipulate not only the genotypes of their offspring (through mate choice or enhanced sperm competition) but also the phenotypes of their offspring (through allocation 'decisions', behavioural and physiological thermoregulation, and nest-site selection). Reliance on stored energy ('capital') to fuel breeding results in low frequencies of female reproduction and, in extreme cases, semelparity. A sophisticated vomeronasal system not only allows male snakes to locate reproductive females by following scent trails, but also facilitates pheromonally mediated mate choice by males. Male-male rivalry takes diverse forms, including female mimicry and mate guarding; combat bouts impose strong selection for large body size in males of some species. Intraspecific (geographical) variation and phenotypic plasticity in a wide array of reproductive traits (offspring size and number; reproductive frequency; incidence of multiple mating; male tactics such as mate guarding and combat; mate choice criteria) provide exceptional opportunities for future studies.
Garnier, Alexandre; Gaillard, Jean-Michel; Gauthier, Dominique; Besnard, Aurélien
2016-01-01
The fitness costs of reproduction can be masked by individual differences, and may only become apparent during adverse environmental conditions. Individual differences, however, are usually assessed by reproductive success, so how fitness costs are influenced by the interplay between the environmental context and overall individual differences requires further investigation. Here, we evaluated fitness costs of reproduction based on 15 yr of monitoring of individual Alpine ibex (Capra ibex) during a period when the population was affected by a severe disease outbreak (pneumonia). We quantified fitness costs using a novel multi-event capture-mark-recapture (CMR) modeling approach that accounted for uncertainty in reproductive status to estimate the survival and reproductive success of female ibex while also accounting for overall individual heterogeneity using mixture models. Our results show that the ability of females to reproduce was highly heterogeneous. In particular, one group including 76% of females had a much higher probability of giving birth annually (between 0.66 and 0.77, depending on the previous reproductive status) than females of the second group (24% of females, between 0 and 0.05 probability of giving birth annually). Low reproductive costs in terms of future reproduction occurred and were independent of the pneumonia outbreak. There was no survival cost of reproduction either before or after the epizootic, but the cost was high during the epizootic. Our findings indicate that adverse environmental conditions, such as disease outbreaks, may lead to survival costs of reproduction in long-lived species and select against females that have a high reproductive effort. Thereby, the occurrence of adverse conditions increases the diversity of reproductive tactics within a population.
Balaban-Feld, Jesse; Valone, Thomas J
2017-09-01
Work on the repeatability of reproductive behaviour has mainly focused on the consistency of female preferences. We characterised the consistency of individual male Drosophila melanogaster reproductive behaviour in two experiments. In the first experiment, we allowed males to interact with a pair of live females that differed in body size. We then controlled female behaviour in a second experiment by examining the courtship behaviour of individual males interacting with a pair of decapitated females that varied in body size. In both experiments, we examined the consistency of individual male reproductive behaviour across two repeated trials on the same day. Males did not exhibit a courtship preference for the larger female in either experiment, but, in experiment 1, males did exhibit post-copulatory choice by copulating for longer durations with the large female, and males that mated with the same type of female in both trials exhibited repeatable behaviour. In general, we found weak evidence of consistent male courtship behaviour in the presence of behaving females. However, when female behaviour was controlled in experiment 2, we found that male courtship behaviour was highly repeatable. These results indicate that individual male D. melanogaster exhibit consistent reproductive behaviour and demonstrate the importance of controlling female behaviour when attempting to characterise the repeatability of male reproductive behaviour. Copyright © 2017 Elsevier B.V. All rights reserved.
"S.P.E.R.M." (seminal proteins (are) essential reproductive modulators): the view from Drosophila.
Wolfner, M F
2007-01-01
The seminal fluid that females receive from their mates contains a suite of proteins that have important effects on sperm, as well as on reproduction in general. Seminal proteins are vital for the fertility of mating animals in several diverse taxonomic groups. For example, in Drosophila melanogaster, the approximately 70-106 accessory gland proteins (Acps) that are a major part of the seminal fluid are essential for the storage and utilization of sperm, as well as for increasing egg production and laying by the female. In addition, Acps have been implicated in modifying the female's eating behaviour, her receptivity to re-mating and her longevity. This review will first summarise the molecular nature and reproductive function of Drosophila Acps in general, as elucidated by genetic/ transgenesis, biochemical, and physiological experiments. The article will then focus on Acps that affect, or interact with, sperm. Sperm storage is a stepwise process in Drosophila and Acps facilitate at least some of these steps. For example, Acps promote sperm entry into storage, apparently by modulating muscle contractions in the female's reproductive tract. One Acp is known to be essential for the entry of sperm into storage. This Acp, which is cleaved after entering females, binds to sperm and enters the sperm-storage organs. Egg production, which is also modulated by Acps, can affect the transition between the steps in sperm storage, although not the rate of release of sperm from storage. Results on additional roles of Acp-sperm interaction in Drosophila will be reviewed.
Kisspeptin modulates fertilization capacity of mouse spermatozoa.
Hsu, Meng-Chieh; Wang, Jyun-Yuan; Lee, Yue-Jia; Jong, De-Shien; Tsui, Kuan-Hao; Chiu, Chih-Hsien
2014-06-01
Kisspeptin acts as an upstream regulator of the hypothalamus-pituitary-gonad axis, which is one of the main regulatory systems for mammalian reproduction. Kiss1 and its receptor Kiss1r (also known as G protein-coupled receptor 54 (Gpr54)) are expressed in various organs, but their functions are not well understood. The purpose of this study was to investigate the expression profiles and functions of kisspeptin and KISS1R in the reproductive tissues of imprinting control region mice. To identify the expression pattern and location of kisspeptin and KISS1R in gonads, testes and ovarian tissues were examined by immunohistochemical or immunofluorescent staining. Kisspeptin and KISS1R were expressed primarily in Leydig cells and seminiferous tubules respectively. KISS1R was specifically localized in the acrosomal region of spermatids and mature spermatozoa. Kisspeptin, but not KISS1R, was expressed in the cumulus-oocyte complex and oviductal epithelium of ovarian and oviductal tissues. The sperm intracellular calcium concentrations significantly increased in response to treatment with kisspeptin 10 in Fluo-4-loaded sperm. The IVF rates decreased after treatment of sperm with the kisspeptin antagonist peptide 234. These results suggest that kisspeptin and KISS1R might be involved in the fertilization process in the female reproductive tract. In summary, this study indicates that kisspeptin and KISS1R are expressed in female and male gametes, respectively, and in mouse reproductive tissues. These data strongly suggest that the kisspeptin system could regulate mammalian fertilization and reproduction. © 2014 Society for Reproduction and Fertility.
Reproduction Symposium: developmental programming of reproductive and metabolic health.
Padmanabhan, V; Veiga-Lopez, A
2014-08-01
Inappropriate programming of the reproductive system by developmental exposure to excess steroid hormones is of concern. Sheep are well suited for investigating developmental origin of reproductive and metabolic disorders. The developmental time line of female sheep (approximately 5 mo gestation and approximately 7 mo to puberty) is ideal for conducting sequential studies of the progression of metabolic and/or reproductive disruption from the developmental insult to manifestation of adult consequences. Major benefits of using sheep include knowledge of established critical periods to target adult defects, a rich understanding of reproductive neuroendocrine regulation, availability of noninvasive approaches to monitor follicular dynamics, established surgical approaches to obtain hypophyseal portal blood for measurement of hypothalamic hormones, and the ability to perform studies in natural setting thereby keeping behavioral interactions intact. Of importance is the ability to chronically instrument fetus and mother for determining early endocrine perturbations. Prenatal exposure of the female to excess testosterone (T) leads to an array of adult reproductive disorders that include LH excess, functional hyperandrogenism, neuroendocrine defects, multifollicular ovarian morphology, and corpus luteum dysfunction culminating in early reproductive failure. At the neuroendocrine level, all 3 feedback systems are compromised. At the pituitary level, gonadotrope (LH secretion) sensitivity to GnRH is increased. Multifollicular ovarian morphology stems from persistence of follicles as well as enhanced follicular recruitment. These defects culminate in progressive loss of cyclicity and reduced fecundity. Prenatal T excess also leads to fetal growth retardation, an early marker of adult reproductive and metabolic diseases, insulin resistance, hypertension, and behavioral deficits. Collectively, the reproductive and metabolic deficits of prenatal T-treated sheep provide proof of concept for the developmental origin of fertility and metabolic disorders. Studies with the environmental endocrine disruptor bisphenol A (BPA) show that reproductive disruptions found in prenatal BPA-treated sheep are similar to those seen in prenatal T-treated sheep. The ubiquitous exposure to endocrine disrupting compounds with steroidogenic potential via the environment and food sources calls for studies addressing the impact of developmental exposure to environmental steroid mimics on reproductive function.
The effect of sexual transmission on Zika virus dynamics.
Saad-Roy, C M; Ma, Junling; van den Driessche, P
2018-04-25
Zika virus is a human disease that may lead to neurological disorders in affected individuals, and may be transmitted vectorially (by mosquitoes) or sexually. A mathematical model of Zika virus transmission is formulated, taking into account mosquitoes, sexually active males and females, inactive individuals, and considering both vector transmission and sexual transmission from infectious males to susceptible females. Basic reproduction numbers are computed, and disease control strategies are evaluated. The effect of the incidence function used to model sexual transmission from infectious males to susceptible females is investigated. It is proved that for such functions that are sublinear, if the basic reproduction [Formula: see text], then the disease dies out and [Formula: see text] is a sharp threshold. Moreover, under certain conditions on model parameters and assuming mass action incidence for sexual transmission, it is proved that if [Formula: see text], there exists a unique endemic equilibrium that is globally asymptotically stable. However, under nonlinear incidence, it is shown that for certain functions backward bifurcation and Hopf bifurcation may occur, giving rise to subthreshold equilibria and periodic solutions, respectively. Numerical simulations for various parameter values are displayed to illustrate these behaviours.
Chuei, Jason Y; Asa, Cheryl S; Hall-Woods, Monica; Ballou, Jonathon; Traylor-Holzer, Kathy
2007-07-01
The need for contraception in the successful management of captive wild animals is becoming increasingly apparent. Because concerns exist regarding the reversibility of the contraceptive implant melengestrol acetate (MGA), reproductive data for 94 female Amur (Panthera tigris altaica) and Sumatran tigers (Panthera tigris sumatrae) were analyzed using survival analyses to evaluate return to reproductive status after implant removal or assumed expiration. Females placed in potential breeding situations after MGA implants were surgically removed showed a 62% return to reproduction by 5.25 years, whereas females with implants that were assumed to have expired showed only a 30% return to reproduction by 6 years. Implanted females did not reproduce as successfully as non-implanted control females, which showed an 85% probability of reproducing after placement in a new breeding situation by 2.66 years. Parturition increased the probability of reproducing in non-implanted females, but not in implanted females. Litter size, stillbirths, and offspring survival were not significantly different between non-implanted, implant-removed and implant-expired female tigers. Ten female tigers reproduced both before and after implant placement, and the differences in litter size, stillbirths, and offspring survival were not significant, nor were they significantly different from non-implanted females. Prior parturition, age when implant was removed, and duration of implantation did not affect the probability of reproducing for females after implant removal. These results show substantial reversibility of MGA implants, leading to 62% successful reproduction after implant removal. The reasons for lower successful reproduction in animals previously treated with the contraceptive compared to non-implanted females are not known, but a greater delay in reversibility was seen when implants were left in place and only presumed expired. Zoo Biol 26:275-288, 2007. (c) 2007 Wiley-Liss, Inc.
COX, SAM; SMITH, LEE; BOGANI, DEBORA; CHEESEMAN, MICHAEL; SIGGERS, PAM; GREENFIELD, ANDY
2007-01-01
In developing male embryos, the female reproductive tract primordia (Müllerian ducts) regress due to the production of testicular anti-Müllerian hormone (AMH). Because of the association between secreted frizzled-related proteins (SFRPs) and apoptosis, their reported developmental expression patterns and the role of WNT signaling in female reproductive tract development, we examined expression of Sfrp2 and Sfrp5 during development of the Müllerian duct in male (XY) and female (XX) mouse embryos. We show that expression of both Sfrp2 and Sfrp5 is dynamic and sexually dimorphic. In addition, the male-specific expression observed for both genes prior to the onset of regression is absent in mutant male embryos that fail to undergo Müllerian duct regression. We identified ENU-induced point mutations in Sfrp5 and Sfrp2 that are predicted to severely disrupt the function of these genes. Male embryos and adults homozygous for these mutations, both individually and in combination, are viable and apparently fertile with no overt abnormalities of reproductive tract development. PMID:16700072
Mondet, Fanny; Rau, Andrea; Klopp, Christophe; Rohmer, Marine; Severac, Dany; Le Conte, Yves; Alaux, Cedric
2018-05-04
The parasite Varroa destructor represents a significant threat to honeybee colonies. Indeed, development of Varroa infestation within colonies, if left untreated, often leads to the death of the colony. Although its impact on bees has been extensively studied, less is known about its biology and the functional processes governing its adult life cycle and adaptation to its host. We therefore developed a full life cycle transcriptomic catalogue in adult Varroa females and included pairwise comparisons with males, artificially-reared and non-reproducing females (10 life cycle stages and conditions in total). Extensive remodeling of the Varroa transcriptome was observed, with an upregulation of energetic and chitin metabolic processes during the initial and final phases of the life cycle (e.g. phoretic and post-oviposition stages), whereas during reproductive stages in brood cells genes showing functions related to transcriptional regulation were overexpressed. Several neurotransmitter and neuropeptide receptors involved in behavioural regulation, as well as active compounds of salivary glands, were also expressed at a higher level outside the reproductive stages. No difference was detected between artificially-reared phoretic females and their counterparts in colonies, or between females who failed to reproduce and females who successfully reproduced, indicating that phoretic individuals can be reared outside host colonies without impacting their physiology and that mechanisms underlying reproductive failure occur before oogenesis. We discuss how these new findings reveal the remarkable adaptation of Varroa to its host biology and notably to the switch from living on adults to reproducing in sealed brood cells. By spanning the entire adult life cycle, our work captures the dynamic changes in the parasite gene expression and serves as a unique resource for deciphering Varroa biology and identifying new targets for mite control.
Choi, Young Jae; Kim, Na Na; Shin, Hyun Suk; Choi, Cheol Young
2014-01-01
Leptin plays an important role in energy homeostasis and reproductive function in fish, especially in reproduction. Migrating fish, such as salmonoids, are affected by external environmental factors, and salinity changes are a particularly important influence on spawning migrations. The aim of this study was to test whether changes in salinity affect the expression of leptin, estrogen receptors (ERs), and vitellogenin (VTG) in chum salmon (Oncorhynchus keta). The expression and activity of leptin, the expression of ERs and VTG, and the levels of estradiol-17β and cortisol increased after the fish were transferred to FW, demonstrating that changes in salinity stimulate the HPG axis in migrating female chum salmon. These findings reveal details about the role of elevated leptin levels and sex steroid hormones in stimulating sexual maturation and reproduction in response to salinity changes in chum salmon. PMID:25049977
Sex steroid hormone determination of the maternal brain: effects beyond reproduction.
Kinsley, C H; Meyer, E; Rafferty, K A
2012-10-01
Herein we discuss the effects of hormones on reproduction, but with a focus on the ripples that emanate from the main effects. That is, the role of hormones in reproductive events is both well-known and well accepted; less studied and understood are effects that appear to be ancillary to the primary objectives of the hormonal effects, which support, complement and extend their primary effects. We present evidence for how the hormonal stimulation of pregnancy constructs the maternal brain; makes it more efficient; enhances cognition; regulates stress responsiveness; modifies sensory systems (we discuss mainly olfaction); neurogenesis; and learning. Thus, steroid and other hormones and neuropeptides restructure the nervous system, particularly of females, to produce and regulate maternal behavior as well as behaviors and physiological systems that contribute to and support what is arguably the primary function of the hormones: survival and effective nurturance of the female's metabolic and genetic investment.
Response of round gobies, Neogobius melanostomus, to conspecific sounds
NASA Astrophysics Data System (ADS)
Isabella-Valenzi, Lisa
A useful model group to examine reproductive plasticity in acoustic responsiveness is the family Gobiidae. Male round gobies
What's in the Gift? Towards a Molecular Dissection of Nuptial Feeding in a Cricket.
Pauchet, Yannick; Wielsch, Natalie; Wilkinson, Paul A; Sakaluk, Scott K; Svatoš, Aleš; ffrench-Constant, Richard H; Hunt, John; Heckel, David G
2015-01-01
Nuptial gifts produced by males and transferred to females during copulation are common in insects. Yet, their precise composition and subsequent physiological effects on the female recipient remain unresolved. Male decorated crickets Gryllodes sigillatus transfer a spermatophore to the female during copulation that is composed of an edible gift, the spermatophylax, and the ampulla that contains the ejaculate. After transfer of the spermatophore, the female detaches the spermatophylax and starts to eat it while sperm from the ampulla are evacuated into the female reproductive tract. When the female has finished consuming the spermatophylax, she detaches the ampulla and terminates sperm transfer. Hence, one simple function of the spermatophylax is to ensure complete sperm transfer by distracting the female from prematurely removing the ampulla. However, the majority of orally active components of the spermatophylax itself and their subsequent effects on female behavior have not been identified. Here, we report the first analysis of the proteome of the G. sigillatus spermatophylax and the transcriptome of the male accessory glands that make these proteins. The accessory gland transcriptome was assembled into 17,691 transcripts whilst about 30 proteins were detected within the mature spermatophylax itself. Of these 30 proteins, 18 were encoded by accessory gland encoded messages. Most spermatophylax proteins show no similarity to proteins with known biological functions and are therefore largely novel. A spermatophylax protein shows similarity to protease inhibitors suggesting that it may protect the biologically active components from digestion within the gut of the female recipient. Another protein shares similarity with previously characterized insect polypeptide growth factors suggesting that it may play a role in altering female reproductive physiology concurrent with fertilization. Characterization of the spermatophylax proteome provides the first step in identifying the genes encoding these proteins in males and in understanding their biological functions in the female recipient.
What’s in the Gift? Towards a Molecular Dissection of Nuptial Feeding in a Cricket
Pauchet, Yannick; Wielsch, Natalie; Wilkinson, Paul A.; Sakaluk, Scott K.; Svatoš, Aleš
2015-01-01
Nuptial gifts produced by males and transferred to females during copulation are common in insects. Yet, their precise composition and subsequent physiological effects on the female recipient remain unresolved. Male decorated crickets Gryllodes sigillatus transfer a spermatophore to the female during copulation that is composed of an edible gift, the spermatophylax, and the ampulla that contains the ejaculate. After transfer of the spermatophore, the female detaches the spermatophylax and starts to eat it while sperm from the ampulla are evacuated into the female reproductive tract. When the female has finished consuming the spermatophylax, she detaches the ampulla and terminates sperm transfer. Hence, one simple function of the spermatophylax is to ensure complete sperm transfer by distracting the female from prematurely removing the ampulla. However, the majority of orally active components of the spermatophylax itself and their subsequent effects on female behavior have not been identified. Here, we report the first analysis of the proteome of the G. sigillatus spermatophylax and the transcriptome of the male accessory glands that make these proteins. The accessory gland transcriptome was assembled into 17,691 transcripts whilst about 30 proteins were detected within the mature spermatophylax itself. Of these 30 proteins, 18 were encoded by accessory gland encoded messages. Most spermatophylax proteins show no similarity to proteins with known biological functions and are therefore largely novel. A spermatophylax protein shows similarity to protease inhibitors suggesting that it may protect the biologically active components from digestion within the gut of the female recipient. Another protein shares similarity with previously characterized insect polypeptide growth factors suggesting that it may play a role in altering female reproductive physiology concurrent with fertilization. Characterization of the spermatophylax proteome provides the first step in identifying the genes encoding these proteins in males and in understanding their biological functions in the female recipient. PMID:26439494
2017-01-01
Semen liquefaction changes semen from a gel-like to watery consistency and is required for sperm to gain mobility and swim to the fertilization site in the Fallopian tubes. Kallikrein-related peptidases 3 (KLK3) and other kallikrein-related peptidases from male prostate glands are responsible for semen liquefaction by cleaving gel-forming proteins (semenogelin and collagen). In a physiological context, the liquefaction process occurs within the female reproductive tract. How seminal proteins interact with the female reproductive environment is still largely unexplored. We previously reported that conditional genetic ablation of Esr1 (estrogen receptor α) in the epithelial cells of the female reproductive tract (Wnt7aCre/+;Esr1f/f) causes female infertility, partly due to a drastic reduction in the number of motile sperm entering the oviduct. In this study, we found that post-ejaculated semen from fertile wild-type males was solidified and the sperm were entrapped in Wnt7aCre/+;Esr1f/f uteri, compared to the watery semen (liquefied) found in Esr1f/f controls. In addition, semenogelin and collagen were not degraded in Wnt7aCre/+;Esr1f/f uteri. Amongst multiple gene families aberrantly expressed in the absence of epithelial ESR1, we have identified that a lack of Klks in the uterus is a potential cause for the liquefaction defect. Pharmacological inhibition of KLKs in the uterus replicated the phenotype observed in Wnt7aCre/+;Esr1f/f uteri, suggesting that loss of uterine and seminal KLK function causes this liquefaction defect. In human cervical cell culture, expression of several KLKs and their inhibitors (SPINKs) was regulated by estrogen in an ESR1-dependent manner. Our study demonstrates that estrogen/ESR1 signaling in the female reproductive tract plays an indispensable role in normal semen liquefaction, providing fundamental evidence that exposure of post-ejaculated semen to the suboptimal microenvironment in the female reproductive tract leads to faulty liquefaction and subsequently causes a fertility defect. PMID:28414719
Jennings, Kimberly J; Chasles, Manon; Cho, Hweyryoung; Mikkelsen, Jens; Bentley, George; Keller, Matthieu; Kriegsfeld, Lance J
2017-11-01
Males of many species rely on chemosensory information for social communication. In male Syrian hamsters (Mesocricetus auratus), as in many species, female chemosignals potently stimulate sexual behavior and a concurrent, rapid increase in circulating luteinizing hormone (LH) and testosterone (T). However, under winter-like, short-day (SD) photoperiods, when Syrian hamsters are reproductively quiescent, these same female chemosignals fail to elicit behavioral or hormonal responses, even after T replacement. It is currently unknown where in the brain chemosensory processing is gated in a seasonally dependent manner such that reproductive responses are only displayed during the appropriate breeding season. The goal of the present study was to determine where this gating occurred by identifying neural loci that respond differentially to female chemosignals across photoperiods, independent of circulating T concentrations. Adult male Syrian hamsters were housed under either long-day (LD) (reproductively active) or SD (reproductively inactive) photoperiods with half of the SD animals receiving T replacement. Animals were exposed to either female hamster vaginal secretions (FHVSs) diluted in mineral oil or to vehicle, and the activational state of chemosensory processing centers and elements of the neuroendocrine reproductive axis were examined. Components of the chemosensory pathway upstream of hypothalamic centers increased expression of FOS, an indirect marker of neuronal activation, similarly across photoperiods. In contrast, the preoptic area (POA) of the hypothalamus responded to FHVS only in LD animals, consistent with its role in promoting expression of male sexual behavior. Within the neuroendocrine axis, the RF-amide related peptide (RFRP), but not the kisspeptin neuronal system responded to FHVS only in LD animals. Neither response within the POA or the RFRP neuronal system was rescued by T replacement in SD animals, mirroring photoperiodic regulation of reproductive responses. Considering the POA and the RFRP neuronal system promote reproductive behavior and function in male Syrian hamsters, differential activation of these systems represents a potential means by which photoperiod limits expression of reproduction to the appropriate environmental context. © The Author 2017. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.
Estradiol Membrane-Initiated Signaling in the Brain Mediates Reproduction.
Micevych, Paul E; Mermelstein, Paul G; Sinchak, Kevin
2017-11-01
Over the past few years our understanding of estrogen signaling in the brain has expanded rapidly. Estrogens are synthesized in the periphery and in the brain, acting on multiple receptors to regulate gene transcription, neural function, and behavior. Various estrogen-sensitive signaling pathways often operate in concert within the same cell, increasing the complexity of the system. In females, estrogen concentrations fluctuate over the estrous/menstrual cycle, dynamically modulating estrogen receptor (ER) expression, activity, and trafficking. These dynamic changes influence multiple behaviors but are particularly important for reproduction. Using the female rodent model, we review our current understanding of estradiol signaling in the regulation of sexual receptivity. Copyright © 2017 Elsevier Ltd. All rights reserved.
Arabinogalactan proteins and pectin distribution during female gametogenesis in Quercus suber L.
Lopes, Ana Lúcia; Costa, Mário Luís; Sobral, Rómulo; Costa, Maria Manuela; Amorim, Maria Isabel; Coimbra, Sílvia
2016-01-01
Background and Aims Quercus suber L. (cork oak) is one of the most important monoecious tree species in semi-arid regions of Southern Europe, with a high ecological value and economic potential. However, as a result of its long reproductive cycle, complex reproductive biology and recalcitrant seeds, conventional breeding is demanding. In its complex reproductive biology, little is known about the most important changes that occur during female gametogenesis. Arabinogalactan proteins (AGPs) and pectins are the main components of plant cell walls and have been reported to perform common functions in cell differentiation and organogenesis of reproductive plant structures. AGPs have been shown to serve as important molecules in several steps of the reproductive process in plants, working as signalling molecules, associated with the sporophyte–gametophyte transition, and pectins have been implicated in pollen–pistil interactions before double fertilization. In this study, the distribution of AGP and pectin epitopes was assessed during female gametogenesis. Methods Immunofluorescence labelling of female flower cells was performed with a set of monoclonal antibodies (mAbs) directed to the carbohydrate moiety of AGPs (JIM8 and JIM13) and pectic homogalacturonans (HGs) (mAbs JIM5 and JIM7). Key Results The selective labelling obtained with AGP and pectin mAbs JIM8, JIM13, JIM5 and JIM7 during Q. suber female gametogenesis shows that AGPs and pectic HG can work as markers for mapping gametophytic cell differentiation in this species. Pectic HG showed different distribution patterns, depending on their levels of methyl esterification. Methyl-esterified HGs showed a uniform distribution in the overall female flower cells before fertilization and a more specific pattern after fertilization. A low methyl-ester pectin distribution pattern during the different developmental stages appears to be related to the pathway that pollen tubes follow to reach the embryo sac. AGPs showed a more sparse distribution in early stages of development, but specific labelling is shown in the synergids and their filiform apparatus. Conclusions The labelling obtained with anti-AGP and anti-pectin mAbs in Q. suber female flower cells showed a dynamic distribution of AGPs and pectic HGs, which may render these molecules useful molecular markers during female gametogenesis. Changes occurring during development will be determined in order to help describe cork oak ovule structural properties before and after fertilization, providing new insight to better understand Q. suber female gametogenesis. PMID:26994101
Conserved Insulin Signaling in the Regulation of Oocyte Growth, Development, and Maturation
DAS, DEBABRATA; ARUR, SWATHI
2017-01-01
Insulin signaling regulates various aspects of physiology, such as glucose homeostasis and aging, and is a key determinant of female reproduction in metazoans. That insulin signaling is crucial for female reproductive health is clear from clinical data linking hyperinsulinemic and hypoinsulinemic condition with certain types of ovarian dysfunction, such as altered steroidogenesis, polycystic ovary syndrome, and infertility. Thus, understanding the signaling mechanisms that underlie the control of insulin-mediated ovarian development is important for the accurate diagnosis of and intervention for female infertility. Studies of invertebrate and vertebrate model systems have revealed the molecular determinants that transduce insulin signaling as well as which biological processes are regulated by the insulin-signaling pathway. The molecular determinants of the insulin-signaling pathway, from the insulin receptor to its downstream signaling components, are structurally and functionally conserved across evolution, from worms to mammals – yet, physiological differences in signaling still exist. Insulin signaling acts cooperatively with gonadotropins in mammals and lower vertebrates to mediate various aspects of ovarian development, mainly owing to evolution of the endocrine system in vertebrates. In contrast, insulin signaling in Drosophila and Caenorhabditis elegans directly regulates oocyte growth and maturation. In this review, we compare and contrast insulin-mediated regulation of ovarian functions in mammals, lower vertebrates, C. elegans, and Drosophila, and highlight conserved signaling pathways and regulatory mechanisms in general while illustrating insulin’s unique role in specific reproductive processes. PMID:28379636
A Few Meters Matter: Local Habitats Drive Reproductive Cycles in a Tropical Lizard.
Otero, Luisa M; Huey, Raymond B; Gorman, George C
2015-09-01
Reproductive phenology often varies geographically within species, driven by environmental gradients that alter growth and reproduction. However, environments can differ between adjacent habitats at single localities. In lowland Puerto Rico, both open (sunny, warm) and forested (shady, cool) habitats may be only meters apart. The lizard Anolis cristatellus lives in both habitats: it thermoregulates carefully in the open but is a thermoconformer in the forest. To determine whether reproduction differs between habitats, we compared reproductive cycles of females in open versus forest habitats at two localities for over 2 years. Open females were more likely than forest females to be reproductive throughout the year, probably because open females were able to bask and thereby achieve warmer body temperatures. These between-habitat differences in reproduction were especially marked in cool months and are equivalent in magnitude to those between populations separated by elevation. Thus, environmental differences (even on a microlandscape scale) matter to reproduction and probably to demography.
Meslin, Camille; Plakke, Melissa S.; Deutsch, Aaron B.; Small, Brandon S.; Morehouse, Nathan I.; Clark, Nathan L.
2015-01-01
Persistent adaptive challenges are often met with the evolution of novel physiological traits. Although there are specific examples of single genes providing new physiological functions, studies on the origin of complex organ functions are lacking. One such derived set of complex functions is found in the Lepidopteran bursa copulatrix, an organ within the female reproductive tract that digests nutrients from the male ejaculate or spermatophore. Here, we characterized bursa physiology and the evolutionary mechanisms by which it was equipped with digestive and absorptive functionality. By studying the transcriptome of the bursa and eight other tissues, we revealed a suite of highly expressed and secreted gene products providing the bursa with a combination of stomach-like traits for mechanical and enzymatic digestion of the male spermatophore. By subsequently placing these bursa genes in an evolutionary framework, we found that the vast majority of their novel digestive functions were co-opted by borrowing genes that continue to be expressed in nonreproductive tissues. However, a number of bursa-specific genes have also arisen, some of which represent unique gene families restricted to Lepidoptera and may provide novel bursa-specific functions. This pattern of promiscuous gene borrowing and relatively infrequent evolution of tissue-specific duplicates stands in contrast to studies of the evolution of novelty via single gene co-option. Our results suggest that the evolution of complex organ-level phenotypes may often be enabled (and subsequently constrained) by changes in tissue specificity that allow expression of existing genes in novel contexts, such as reproduction. The extent to which the selective pressures encountered in these novel roles require resolution via duplication and sub/neofunctionalization is likely to be determined by the need for specialized reproductive functionality. Thus, complex physiological phenotypes such as that found in the bursa offer important opportunities for understanding the relative role of pleiotropy and specialization in adaptive evolution. PMID:25725432
Fujii, Junichi; Iuchi, Yoshihito; Okada, Futoshi
2005-09-02
Controlled oxidation, such as disulfide bond formation in sperm nuclei and during ovulation, plays a fundamental role in mammalian reproduction. Excess oxidation, however, causes oxidative stress, resulting in the dysfunction of the reproductive process. Antioxidation reactions that reduce the levels of reactive oxygen species are of prime importance in reproductive systems in maintaining the quality of gametes and support reproduction. While anti-oxidative enzymes, such as superoxide dismutase and peroxidase, play a central role in eliminating oxidative stress, reduction-oxidation (redox) systems, comprised of mainly glutathione and thioredoxin, function to reduce the levels of oxidized molecules. Aldo-keto reductase, using NADPH as an electron donor, detoxifies carbonyl compounds resulting from the oxidation of lipids and proteins. Thus, many antioxidative and redox enzyme genes are expressed and aggressively protect gametes and embryos in reproductive systems.
A Role for the Chemokine Receptor CCR6 in Mammalian Sperm Motility and Chemotaxis
Caballero-Campo, Pedro; Buffone, Mariano G.; Benencia, Fabian; Conejo-García, José R.; Rinaudo, Paolo F.; Gerton, George L.
2013-01-01
Although recent evidence indicates that several chemokines and defensins, well-known as inflammatory mediators, are expressed in the male and female reproductive tracts, the location and functional significance of chemokine networks in sperm physiology and sperm reproductive tract interactions are poorly understood. To address this deficiency in our knowledge, we examined the expression and function in sperm of CCR6, a receptor common to several chemoattractant peptides, and screened several reproductive tract fluids for the presence of specific ligands. CCR6 protein is present in mouse and human sperm and mainly localized in the sperm tail with other minor patterns in sperm from mice (neck and acrosomal region) and men (neck and midpiece regions). As expected from the protein immunoblotting and immunofluorescence results, mouse Ccr6 mRNA is expressed in the testis. Furthermore, the Defb29 mRNA encoding the CCR6 ligand, β-defensin DEFB29, is expressed at high levels in the epididymis. As determined by protein chip analysis, several chemokines (including some that act through CCR6, such as CCL20/MIP-3α (formerly Macrophage Inflammatory Protein 3α) and protein hormones were present in human follicular fluid, endometrial secretions, and seminal plasma. In functional chemotaxis assays, capacitated human sperm exhibited a directional movement towards CCL20, and displayed modifications in motility parameters. Our data indicate that chemokine ligand/receptor interactions in the male and female genital tracts promote sperm motility and chemotaxis under non-inflammatory conditions. Therefore, some of the physiological reactions mediated by CCR6 ligands in male reproduction extend beyond a pro-inflammatory response and might find application in clinical reproduction and/or contraception. PMID:23765988
Reproductive Conflict and the Evolution of Menopause in Killer Whales.
Croft, Darren P; Johnstone, Rufus A; Ellis, Samuel; Nattrass, Stuart; Franks, Daniel W; Brent, Lauren J N; Mazzi, Sonia; Balcomb, Kenneth C; Ford, John K B; Cant, Michael A
2017-01-23
Why females of some species cease ovulation prior to the end of their natural lifespan is a long-standing evolutionary puzzle [1-4]. The fitness benefits of post-reproductive helping could in principle select for menopause [1, 2, 5], but the magnitude of these benefits appears insufficient to explain the timing of menopause [6-8]. Recent theory suggests that the cost of inter-generational reproductive conflict between younger and older females of the same social unit is a critical missing term in classical inclusive fitness calculations (the "reproductive conflict hypothesis" [6, 9]). Using a unique long-term dataset on wild resident killer whales, where females can live decades after their final parturition, we provide the first test of this hypothesis in a non-human animal. First, we confirm previous theoretical predictions that local relatedness increases with female age up to the end of reproduction. Second, we construct a new evolutionary model and show that given these kinship dynamics, selection will favor younger females that invest more in competition, and thus have greater reproductive success, than older females (their mothers) when breeding at the same time. Third, we test this prediction using 43 years of individual-based demographic data in resident killer whales and show that when mothers and daughters co-breed, the mortality hazard of calves from older-generation females is 1.7 times that of calves from younger-generation females. Intergenerational conflict combined with the known benefits conveyed to kin by post-reproductive females can explain why killer whales have evolved the longest post-reproductive lifespan of all non-human animals. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.
Dental senescence in a long-lived primate links infant survival to rainfall
King, Stephen J.; Arrigo-Nelson, Summer J.; Pochron, Sharon T.; Semprebon, Gina M.; Godfrey, Laurie R.; Wright, Patricia C.; Jernvall, Jukka
2005-01-01
Primates tend to be long-lived, and, except for humans, most primate females are able to reproduce into old age. Although aging in most mammals is accompanied by dental senescence due to advanced wear, primates have low-crowned teeth that wear down before old age. Because tooth wear alters crown features gradually, testing whether early dental senescence causes reproductive senescence has been difficult. To identify whether and when low-crowned teeth compromise reproductive success, we used a 20-year field study of Propithecus edwardsi, a rainforest lemur from Madagascar with a maximum lifespan of >27 years. We analyzed tooth wear in three dimensions with dental topographic analysis by using Geographical Information Systems (GIS) technology. We report that tooth wear exposes compensatory shearing blades that maintain dental function for 18 years. Beyond this age, female fertility remains high; however infants survive only if lactation seasons have elevated rainfall. Therefore, low-crowned teeth accommodate wear to a point, after which reproductive success closely tracks environmental fluctuations. These results suggest a tooth wear-determined, but rainfall-mediated, onset of reproductive senescence. Additionally, our study indicates that even subtle changes in climate may affect reproductive success of rainforest species. PMID:16260727
Gee, G.F.; Russman, S.E.; Ellis, David H.; Gee, George F.; Mirande, Claire M.
1996-01-01
Conclusions: Although the general pattern of avian physiology applies to cranes, we have identified many physiological mechanisms (e.g., effects of disturbance) that need further study. Studies with cranes are expensive compared to those done with domestic fowl because of the crane's larger size, low reproductive rate, and delayed sexual maturity. To summarize, the crane reproductive system is composed of physiological and anatomical elements whose function is controlled by an integrated neural-endocrine system. Males generally produce semen at a younger age than when females lay eggs. Eggs are laid in clutches of two (1 to 3), and females will lay additional clutches if the preceding clutches are removed. Both sexes build nests and incubate the eggs. Molt begins during incubation and body molt may be completed annually in breeding pairs. However, remiges are replaced sequentially over 2 to 3 years, or abruptly every 2 to 3 years in other species. Most immature birds replace their juvenal remiges over a 2 to 3 year period. Stress interferes with reproduction in cranes by reducing egg production or terminating the reproductive effort. In other birds, stress elevates corticosterone levels and decreases LHRH release. We know little about the physiological response of cranes to stress.
Effect of subacute exposure to lead and estrogen on immature pre-weaning rat leukocytes
DOE Office of Scientific and Technical Information (OSTI.GOV)
Villagra, R.; Tchernitchin, N.N.; Tchernitchin, A.N.
1997-02-01
Lead is an environmental pollutant known to cause damage to human health, affecting specially the central nervous system, reproductive organs, the immune system and kidney. From the perspective or reproduction, lead affects both men and women. Reported effects in women include infertility, miscarriage, pre-eclampsia, pregnancy hypertension and premature delivery. In experimental animals, lead affects female reproductive organs through different mechanisms. The heavy metal may interact at the enzyme level. It may interfere with the action of reproductive hormones at the target organ, modifying the activity of estrogen receptors in the pregnant uterus and inhibiting responses where estrogens play a role.more » Lead may induce imprinting mechanism, causing persistent changes in uterine estrogen receptors and ovary LH receptors following perinatal exposure. Finally, it may interfere at the level of hypothalamus-pituitary, decreasing pituitary response to growth hormone releasing factor, affecting levels of FSH and LH and increasing blood levels of glucocorticoids, which modify the action of estrogens in the uterus. This study examines the mechanisms of lead-induced interference with female reproductive and immune functions. 33 refs., 2 figs., 2 tabs.« less
Corticosterone mediated costs of reproduction link current to future breeding.
Crossin, Glenn T; Phillips, Richard A; Lattin, Christine R; Romero, L Michael; Williams, Tony D
2013-11-01
Life-history theory predicts that costs are associated with reproduction. One possible mediator of costs involves the secretion of glucocorticoid hormones, which in birds can be measured in feathers grown during the breeding period. Glucocorticoids mediate physiological responses to unpredictable environmental or other stressors, but they can also function as metabolic regulators during more predictable events such as reproduction. Here we show that corticosterone ("Cort") in feathers grown during the breeding season reflects reproductive effort in two Antarctic seabird species (giant petrels, Macronectes spp.). In females of both species, but not males, feather Cort ("fCort") was nearly 1.5-fold higher in successful than failed breeders (those that lost their eggs/chicks), suggesting a cost of successful reproduction, i.e., high fCort levels in females reflect the elevated plasma Cort levels required to support high metabolic demands of chick-rearing. Successful breeding also led to delayed moult prior to winter migration. The fCort levels and pre-migration moult score that we measured at the end of current breeding were predictive of subsequent reproductive effort in the following year. Birds with high fCort and a delayed initiation of moult were much more likely to defer breeding in the following year. Cort levels and the timing of moult thus provide a potential mechanism for the tradeoff between current and future reproduction. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.
Patil, Chetan N; Racusen, Lorraine C; Reckelhoff, Jane F
2017-11-01
Polycystic ovary syndrome (PCOS) is the most common endocrine and reproductive disorder in premenopausal women, characterized by hyperandrogenemia, metabolic syndrome, and inflammation. Women who had PCOS during their reproductive years remain hyperandrogenemic after menopause. The consequence of chronic hyperandrogenemia with advanced aging has not been studied to our knowledge. We have characterized a model of hyperandrogenemia in female rats and have aged them to 22-25 months to mimic advanced aging in hyperandrogenemic women, and tested the hypothesis that chronic exposure to hyperandrogenemia with aging has a deleterious effect on renal function. Female rats were chronically implanted with dihydrotestosterone pellets (DHT 7.5 mg/90 days) that were changed every 85 days or placebo pellets, and renal function was measured by clearance methods. Aging DHT-treated females had a threefold higher level of DHT with significantly higher body weight, mean arterial pressure, left kidney weight, proteinuria, and kidney injury molecule-1 (KIM-1), than did age-matched controls. In addition, DHT-treated-old females had a 60% reduction in glomerular filtration rate, 40% reduction in renal plasma flow, and significant reduction in urinary nitrate and nitrite excretion (UNOxV), an index of nitric oxide production. Morphological examination of kidneys showed that old DHT-treated females had significant focal segmental glomerulosclerosis, global sclerosis, and interstitial fibrosis compared to controls. Thus chronic hyperandrogenemia that persists into old age in females is associated with renal injury. These data suggest that women with chronic hyperandrogenemia such as in PCOS may be at increased risk for development of chronic kidney disease with advanced age. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.
English, Sinead; Huchard, Elise; Nielsen, Johanna F; Clutton-Brock, Tim H
2013-01-01
In polygynous species, variance in reproductive success is higher in males than females. There is consequently stronger selection for competitive traits in males and early growth can have a greater influence on later fitness in males than in females. As yet, little is known about sex differences in the effect of early growth on subsequent breeding success in species where variance in reproductive success is higher in females than males, and competitive traits are under stronger selection in females. Greater variance in reproductive success has been documented in several singular cooperative breeders. Here, we investigated consequences of early growth for later reproductive success in wild meerkats. We found that, despite the absence of dimorphism, females who exhibited faster growth until nutritional independence were more likely to become dominant, whereas early growth did not affect dominance acquisition in males. Among those individuals who attained dominance, there was no further influence of early growth on dominance tenure or lifetime reproductive success in males or females. These findings suggest that early growth effects on competitive abilities and fitness may reflect the intensity of intrasexual competition even in sexually monomorphic species. PMID:24340181
Clark, Rebecca M; Zera, Anthony J; Behmer, Spencer T
2015-01-15
Although life-history trade-offs result from the differential acquisition and allocation of nutritional resources to competing physiological functions, many aspects of this topic remain poorly understood. Wing-polymorphic insects, which possess alternative morphs that trade off allocation to flight capability versus early reproduction, provide a good model system for exploring this topic. In this study, we used the wing-polymorphic cricket Gryllus firmus to test how expression of the flight capability versus reproduction trade-off was modified across a heterogeneous protein-carbohydrate nutritional landscape. Newly molted adult female long- and short-winged crickets were given one of 13 diets with different concentrations and ratios of protein and digestible carbohydrate; for each cricket, we measured consumption patterns, growth and allocation to reproduction (ovary mass) versus flight muscle maintenance (flight muscle mass and somatic lipid stores). Feeding responses in both morphs were influenced more by total macronutrient concentration than by protein-carbohydrate ratio, except at high-macronutrient concentration, where protein-carbohydrate balance was important. Mass gain tended to be greatest on protein-biased diets for both morphs, but was consistently lower across all diets for long-winged females. When long-winged females were fed high-carbohydrate foods, they accumulated greater somatic lipid stores; on high-protein foods, they accumulated greater somatic protein stores. Food protein-carbohydrate content also affected short-winged females (selected for early reproductive onset), which showed dramatic increases in ovary size, including ovarian stores of lipid and protein, on protein-biased foods. This is the first study to show how the concentration and ratio of dietary protein and carbohydrate affects consumption and allocation to key physiological features associated with the reproduction-dispersal life-history trade-off. © 2015. Published by The Company of Biologists Ltd.
Microcystin-LR impairs zebrafish reproduction by affecting oogenesis and endocrine system.
Zhao, Yanyan; Xie, Liqiang; Yan, Yunjun
2015-02-01
Previous studies have shown that microcystins (MCs) are able to exert negative effects on the reproductive system of fish. However, few data are actually available on the effects of MC-LR on the reproductive system of female fish. In the present study, female zebrafish were exposed to 2, 10, and 50 μg L(-1) of MC-LR for 21 d, and its effects on oogenesis, sex hormones, transcription of genes on the hypothalamic-pituitary-gonad (HPG) axis, and reproduction were investigated for the first time. It was observed that egg production significantly declined at ⩾ 10 μg L(-1) MC-LR. MC-LR exposure to zebrafish increased the concentrations of 17β-estradiol (E2) and vitellogenin (VTG) at 10 μg L(-1) level, whereas concentrations of E2, VTG and testosterone declined at 50 μg L(-1) MC-LR. The transcriptions of steroidogenic pathway gene (cyp19a, cyp19b, 17βhsd, cyp17 and hmgra) changed as well after the exposure and corresponded well with the alterations of hormone levels. A number of intra- and extra-ovarian factors, such as gnrh3, gnrhr1, fshβ, fshr, lhr, bmp15, mrpβ, ptgs2 and vtg1 which regulate oogenesis, were significantly changed with a different dose-related effect. Moreover, MC-LR exposure to female zebrafish resulted in decreased fertilization and hatching rates, and may suggest the possibility of trans-generational effects of MC-LR exposure. The results demonstrate that MC-LR could modulate endocrine function and oogenesis, eventually leading to disruption of reproductive performance in female zebrafish. These data suggest there is a risk for aquatic population living in MC polluted areas. Copyright © 2014 Elsevier Ltd. All rights reserved.
Reproductive Failure in UK Harbour Porpoises Phocoena phocoena: Legacy of Pollutant Exposure?
Murphy, Sinéad; Barber, Jonathan L; Learmonth, Jennifer A.; Read, Fiona L.; Deaville, Robert; Perkins, Matthew W.; Brownlow, Andrew; Davison, Nick; Penrose, Rod; Pierce, Graham J.; Law, Robin J.; Jepson, Paul D.
2015-01-01
Reproductive failure in mammals due to exposure to polychlorinated biphenyls (PCBs) can occur either through endocrine disrupting effects or via immunosuppression and increased disease risk. To investigate further, full necropsies and determination of summed 25 polychlorinated biphenyls congeners (∑PCBs lipid weight) in blubber were undertaken on 329 UK-stranded female harbour porpoises (1990-2012). In sexually mature females, 25/127 (19.7%) showed direct evidence of reproductive failure (foetal death, aborting, dystocia or stillbirth). A further 21/127 (16.5%) had infections of the reproductive tract or tumours of reproductive tract tissues that could contribute to reproductive failure. Resting mature females (non-lactating or non-pregnant) had significantly higher mean ∑PCBs (18.5 mg/kg) than both lactating (7.5 mg/kg) and pregnant females (6 mg/kg), though not significantly different to sexually immature females (14.0 mg/kg). Using multinomial logistic regression models ΣPCBs was found to be a significant predictor of mature female reproductive status, adjusting for the effects of confounding variables. Resting females were more likely to have a higher PCB burden. Health status (proxied by “trauma” or “infectious disease” causes of death) was also a significant predictor, with lactating females (i.e. who successfully reproduced) more likely to be in good health status compared to other individuals. Based on contaminant profiles (>11 mg/kg lipid), at least 29/60 (48%) of resting females had not offloaded their pollutant burden via gestation and primarily lactation. Where data were available, these non-offloading females were previously gravid, which suggests foetal or newborn mortality. Furthermore, a lower pregnancy rate of 50% was estimated for “healthy” females that died of traumatic causes of death, compared to other populations. Whether or not PCBs are part of an underlying mechanism, we used individual PCB burdens to show further evidence of reproductive failure in the North-east Atlantic harbour porpoise population, results that should inform conservation management. PMID:26200456
High basal metabolic rate does not elevate oxidative stress during reproduction in laboratory mice.
Brzęk, Paweł; Książek, Aneta; Ołdakowski, Łukasz; Konarzewski, Marek
2014-05-01
Increased oxidative stress (OS) has been suggested as a physiological cost of reproduction. However, previous studies reported ambiguous results, with some even showing a reduction of oxidative damage during reproduction. We tested whether the link between reproduction and OS is mediated by basal metabolic rate (BMR), which has been hypothesized to affect both the rate of radical oxygen species production and antioxidative capacity. We studied the effect of reproduction on OS in females of laboratory mice divergently selected for high (H-BMR) and low (L-BMR) BMR, previously shown to differ with respect to parental investment. Non-reproducing L-BMR females showed higher oxidative damage to lipids (quantified as the level of malondialdehyde in internal organ tissues) and DNA (quantified as the level of 8-oxodG in blood serum) than H-BMR females. Reproduction did not affect oxidative damage to lipids in either line; however, it reduced damage to DNA in L-BMR females. Reproduction increased catalase activity in liver (significantly stronger in L-BMR females) and decreased it in kidneys. We conclude that the effect of reproduction on OS depends on the initial variation in BMR and varies between studied internal organs and markers of OS.
Developmental programming of reproductive and metabolic health1,2
Padmanabhan, V.; Veiga-Lopez, A.
2014-01-01
The inappropriate programming of the reproductive system by developmental exposure to excess steroid hormones is of concern. Sheep are well suited for investigating developmental origin of reproductive and metabolic disorders. The developmental time line of female sheep (~5 mo gestation and ~7 mo to puberty) is ideal for conducting sequential studies of the progression of metabolic and (or) reproductive disruption from the developmental insult to manifestation of adult consequences. Major benefits of using sheep include knowledge of established critical periods to target adult defects, a rich understanding of reproductive neuroendocrine regulation, availability of non-invasive approaches to monitor follicular dynamics, established surgical approaches to obtain hypophyseal portal blood for measurement of hypothalamic hormones, and the ability to perform studies in natural setting keeping behavioral interactions intact. Of importance is the ability to chronically instrument fetus and mother for determining early endocrine perturbations. Prenatal exposure of the female to excess testosterone (T) leads to an array of adult reproductive disorders that include LH excess, functional hyperandrogenism, neuroendocrine defects, multifollicular ovarian morphology, and corpus luteum dysfunction culminating in early reproductive failure. At the neuroendocrine level all three feedback systems are compromised. At the pituitary level, gonadotrope (LH secretion) sensitivity to GnRH is increased. Multifollicular ovarian morphology stems from persistence of follicles, as well as enhanced follicular recruitment. These defects culminate in progressive loss of cyclicity and reduced fecundity. Prenatal T excess also leads to fetal growth retardation, an early marker of adult reproductive/metabolic diseases, insulin resistance, hypertension and behavioral deficits. Collectively, the reproductive and metabolic deficits of prenatal T-treated sheep provide proof of concept for the developmental origin of fertility and metabolic disorders. Studies with the environmental endocrine disruptor, bisphenol-A (BPA), show that reproductive disruptions found in prenatal BPA-treated sheep are similar to those seen in prenatal T-treated sheep. The ubiquitous exposure to endocrine disrupting compounds (EDC) with steroidogenic potential via the environment and food sources, calls for studies addressing the impact of developmental exposure to environmental steroid mimics on reproductive function. PMID:25074449
ERK Signaling in the Pituitary Is Required for Female But Not Male Fertility
Bliss, Stuart P.; Miller, Andrew; Navratil, Amy M.; Xie, JianJun; McDonough, Sean P.; Fisher, Patricia J.; Landreth, Gary E.; Roberson, Mark S.
2009-01-01
Males and females require different patterns of pituitary gonadotropin secretion for fertility. The mechanisms underlying these gender-specific profiles of pituitary hormone production are unknown; however, they are fundamental to understanding the sexually dimorphic control of reproductive function at the molecular level. Several studies suggest that ERK1 and -2 are essential modulators of hypothalamic GnRH-mediated regulation of pituitary gonadotropin production and fertility. To test this hypothesis, we generated mice with a pituitary-specific depletion of ERK1 and 2 and examined a range of physiological parameters including fertility. We find that ERK signaling is required in females for ovulation and fertility, whereas male reproductive function is unaffected by this signaling deficiency. The effects of ERK pathway ablation on LH biosynthesis underlie this gender-specific phenotype, and the molecular mechanism involves a requirement for ERK-dependent up-regulation of the transcription factor Egr1, which is necessary for LHβ expression. Together, these findings represent a significant advance in elucidating the molecular basis of gender-specific regulation of the hypothalamic-pituitary-gonadal axis and sexually dimorphic control of fertility. PMID:19372235
Reproductive skew drives patterns of sexual dimorphism in sponge-dwelling snapping shrimps
Chak, Solomon Tin Chi; Duffy, J. Emmett; Rubenstein, Dustin R.
2015-01-01
Sexual dimorphism is typically a result of strong sexual selection on male traits used in male–male competition and subsequent female choice. However, in social species where reproduction is monopolized by one or a few individuals in a group, selection on secondary sexual characteristics may be strong in both sexes. Indeed, sexual dimorphism is reduced in many cooperatively breeding vertebrates and eusocial insects with totipotent workers, presumably because of increased selection on female traits. Here, we examined the relationship between sexual dimorphism and sociality in eight species of Synalpheus snapping shrimps that vary in social structure and degree of reproductive skew. In species where reproduction was shared more equitably, most members of both sexes were physiologically capable of breeding. However, in species where reproduction was monopolized by a single individual, a large proportion of females—but not males—were reproductively inactive, suggesting stronger reproductive suppression and conflict among females. Moreover, as skew increased across species, proportional size of the major chela—the primary antagonistic weapon in snapping shrimps—increased among females and sexual dimorphism in major chela size declined. Thus, as reproductive skew increases among Synalpheus, female–female competition over reproduction appears to increase, resulting in decreased sexual dimorphism in weapon size. PMID:26041357
Place, Ned J.; Cruickshank, Jenifer
2009-01-01
Short day (SD) lengths delay puberty, suppress ovulation, inhibit sexual behavior, and decelerate reproductive aging in female Siberian hamsters (Phodopus sungorus). To date, the modulation of the age-associated decline in reproductive outcomes has only been demonstrated in female hamsters experiencing different day lengths during development. To determine if developmental delay is necessary for photo-inhibition to decelerate reproductive aging, hamsters raised in LD were transferred to SD as young adults and remained there for 6 months. Females that demonstrated the most immediate and sustained photo-inhibition were found to have greater numbers of ovarian primordial follicles at advanced ages (9 and 12 months) than did females held in LD, nonresponders to SD, and females with a marginal SD-response. Similarly, for females raised in SD from conception to 6 months of age, prolonged developmental delay was associated with greater numbers of primordial follicles at later ages as compared to hamsters that became refractory to SD. A robust response to SD in juvenile and adult hamsters is associated with decelerated reproductive aging, which may result in greater reproductive success in older females as compared to age-matched individuals demonstrating a more modest response to SD. PMID:19470367
Stoops, M A; MacKinnon, K M; Roth, T L
2012-12-01
The objective was to identify suitable enzyme immunoassays to monitor gonadal and placental function in the female polar bear. Immunoreactive progesterone, progesterone metabolite (PdG), estrogen, and androgen metabolite (T) concentrations were measured in fecal samples collected over 24 mo from captive female bears (N = 20). Whereas fecal extracts produced displacement curves parallel to the standard curve for each respective steroid, T and PdG more accurately reflected reproductive events. Concentrations of fecal T increased (P < 0.05) during the breeding season, and brief spikes were associated with estrus and mating. A postovulatory increase in PdG was not always detected, but sustained baseline T after mating appeared consistent with ovulation. Parturient bears excreted higher PdG concentrations (P < 0.05) during expected time of embryo implantation in Fall, and a late gestational rise in fecal T occurred 30 days prepartum. Many nonparturient bears also had a PdG rise in the Fall, suggesting they experienced either pregnancy loss or a pseudopregnancy. Differentiating pregnant and pseudopregnant states was not achieved using fecal PdG alone, but when combined with fecal T, comprehensive diagnoses could be made. Nonparturient bears demonstrated elevated (P < 0.05) fecal T during summer months, whereas parturient bears did not. In summary, noninvasive hormone monitoring techniques were established for the female polar bear. Although this study was directed at facilitating management and breeding efforts of captive polar bears, the methods could be applied to studies of reproductive function in wild populations. Copyright © 2012 Elsevier Inc. All rights reserved.
Behavioral evidence for a role of chemoreception during reproduction in lake trout
Buchinger, Tyler J.; Li, Weiming; Johnson, Nicholas
2015-01-01
Chemoreception is hypothesized to influence spawning site selection, mate search, and synchronization of gamete release in chars (Salvelinus spp.), but behavioral evidence is generally lacking. Here, we provide a survey of the behavioral responses of reproductive male and female lake trout (Salvelinus namaycush) to natural conspecific chemosensory stimuli. A flow-through laboratory assay with side-by-side artificial spawning reefs was used to evaluate behavioral preferences of spawning-phase males and females for chemosensory stimuli from juveniles and from spawning-phase males and females. Males and females preferred male and juvenile stimuli over no stimuli, but only had weak preferences for female stimuli. Only females had a preference for male over juvenile stimuli when given a direct choice between the two. The unexpected observation of male attraction to male stimuli, even when offered female stimuli, indicates a fundamental difference from the existing models of chemical communication in fishes. We discuss our results from the perspectives of prespawning aggregation, mate evaluation, and spawning synchronization. Identification of specific components of the stimuli will allow confirmation of the function and may have management implications for native and invasive populations of lake trout that are ecologically and economically important.
Sex steroids effects in normal endocrine pancreatic function and diabetes.
Morimoto, Sumiko; Jiménez-Trejo, Francisco; Cerbón, Marco
2011-01-01
Traditionally the role of sexual steroid hormones was focused primarily on reproductive organs: the breast, female reproductive tract (uterus, mammary gland, and ovary), and male reproductive tract (testes, epididymis and prostate), however our current understanding of tissue-specific effects of sex steroids has elucidated new aspects in its functionality. Recent data have shown that many other tissues are targets of those hormones in addition to classical reproductive organs. The pancreas (which performs both endocrine and exocrine functions), has proven to be an extragonadal target of sexual steroid hormone action. The endocrine pancreas has a pivotal role on carbohydrate homeostasis and deterioration in function produces diabetes. Diabetes is a metabolic disorder that has high prevalence worldwide, particularly in developing countries. It has been shown that steroid hormones have an important role in susceptibility and development of diabetes in animal models, in humans its role is less clear, however the most evident effect is on the perimenopausal women, in this stage the decrease in gonadal steroids produces an increase on susceptibility to develop diabetes mellitus; in men, hypoandrogenism is associated with an increased prevalence of insulin resistance. This review focused on the effects of sexual steroids on pancreatic function and diabetes.
Modeling adverse environmental impacts on the reproductive system.
Sussman, N B; Mazumdar, S; Mattison, D R
1999-03-01
When priority topics are being established for the study of women's health, it is generally agreed that one important area on which to focus research is reproduction. For example, increasing attention has been directed to environmental exposures that disrupt the endocrine system and alter reproduction. These concerns also suggest the need to give greater attention to the use of animal toxicologic testing to draw inferences about human reproductive risks. Successful reproduction requires multiple simultaneous and sequential processes in both the male and female, and the effect of toxicity on reproduction-related processes is time dependent. Currently, however, the risk assessment approach does not allow for the use of multiple processes or for considering the reproductive process response as a function of time. We discuss several issues in modeling exposure effects on reproductive function for risk assessment and present an overview of approaches for reproductive risk assessment. Recommendations are provided for an effective animal study design for determining reproductive risk that addresses optimization of the duration of dosing, observation of the effects of exposure on validated biomarkers, analysis of several biomarkers for complete characterization of the exposure on the underlying biologic processes, the need for longitudinally observed exposure effects, and a procedure for estimating human reproductive risk from the animal findings. An approach to characterizing reproductive toxicity to estimate the increased fertility risks in a dibromochloropropane (DBCP)-exposed human population is illustrated, using several reproductive biomarkers simultaneously from a longitudinal rabbit inhalation study of DBCP and an interspecies extrapolation method.
Differential resource allocation in deer mice exposed to sin nombre virus.
Lehmer, Erin M; Clay, Christine A; Wilson, Eric; St Jeor, Stephen; Dearing, M Denise
2007-01-01
The resource allocation hypothesis predicts that reproductive activity suppresses immunocompetence; however, this has never been tested in an endemic disease system with free-ranging mammals. We tested the resource allocation hypothesis in wild deer mice (Peromyscus maniculatus) with natural exposure to Sin Nombre Virus (SNV). Immunocompetence was estimated from the extent of swelling elicited after deer mice were injected with phytohemagglutinin (PHA); swelling is positively correlated with immunocompetence. After livetrapping deer mice, we determined their reproductive state and SNV infection status. Males were more likely to be seropositive for SNV than females (37% vs. 25%) and exhibited 10% less swelling after PHA injection. The swelling response of females differed with both infection status and reproductive condition. There was also a significant infection status by reproductive condition interaction: non-reproductive, seropositive females experienced the least amount of swelling, whereas females in all other categories experienced significantly greater swelling. The swelling response of males differed with both SNV infection status and reproductive condition, but there was no significant infection status by reproductive condition interaction. Seronegative males elicited greater swelling than seropositive males regardless of reproductive status. In contrast to the resource allocation hypothesis, these results do not indicate that reproductive activity suppresses immunocompetence of deer mice but rather suggest that chronic SNV infection reduces immunocompetence. Sex-based differences in swelling indicate that SNV modulates the immune system of female deer mice differently than it does that of males, particularly during reproduction. We propose that differences in resource allocation between males and females could result from inherent sex-based differences in parental investment.
Berger, David; Olofsson, Martin; Friberg, Magne; Karlsson, Bengt; Wiklund, Christer; Gotthard, Karl
2012-11-01
1. A high rate of reproduction may be costly if ecological factors limit immediate reproductive output as a fast metabolism compromises own future survival. Individuals with more reserves need more time and opportunity to realize their reproductive potential. Theory therefore predicts that the reproductive rate, defined as the investment in early reproduction in proportion to total potential, should decrease with body size within species. 2. However, metabolic constraints on body size- and temperature-dependent biological rates may impede biophysical adaptation. Furthermore, the sequential manner resources that are allocated to somatic vs. reproductive tissue during ontogeny may, when juveniles develop in unpredictable environments, further contribute to non-adaptive variation in adult reproductive rates. 3. With a model on female egg laying in insects, we demonstrate how variation in body reserves is predicted to affect reproductive rate under different ecological scenarios. Small females always have higher reproductive rates but shorter lifespans. However, incorporation of female host selectivity leads to more similar reproductive rates among female size classes, and oviposition behaviour is predicted to co-evolve with reproductive rate, resulting in small females being more selective in their choice and gaining relatively more from it. 4. We fed simulations with data on the butterfly Pararge aegeria to compare model predictions with reproductive rates of wild butterflies. However, simulated reproductive allometry was a poor predictor of that observed. Instead, reproductive rates were better explained as a product of metabolic constraints on rates of egg maturation, and an empirically derived positive allometry between reproductive potential and size. However, fitness is insensitive to moderate deviations in reproductive rate when oviposition behaviour is allowed to co-evolve in the simulations, suggesting that behavioural compensation may mitigate putative metabolic and developmental constraints. 5. More work is needed to understand how physiology and development together with compensatory behaviours interact in shaping reproductive allometry. Empirical studies should evaluate adaptive hypotheses against proper null hypotheses, including prediction from metabolic theory, preferentially by studying reproductive physiology in combination with behaviour. Conversely, inferences of constraint explanations on reproductive rates must take into consideration that adaptive scenarios may predict similar allometric exponents. © 2012 The Authors. Journal of Animal Ecology © 2012 British Ecological Society.
González-Medina, Erick; Castillo-Guerrero, José Alfredo; Herzka, Sharon Zinah; Fernández, Guillermo
2018-01-01
Understanding the role of diet in the physiological condition of adults during reproduction and hence its effect on reproductive performance is fundamental to understand reproductive strategies in long-lived animals. In birds, little is known about the influence of the quality of food consumed at the beginning of the reproductive period and its short-term effects on reproductive performance. To assess the role of diet in the physiological condition of female blue-footed booby, Sula nebouxii (BFBO), during reproduction we evaluated whether individual differences in diet (assessed by using δ13C and δ15N values of whole blood from female birds and muscle tissue of the principal prey species) prior to egg laying and during incubation influenced their lipid metabolic profile (measured as triglyceride levels and C:N ratio) and their reproductive performance (defined by laying date, clutch size and hatching success). Females with higher δ15N values in their blood during the courtship and incubation periods had a higher lipid metabolic profile, earlier laying date, greater clutch size (2-3 eggs) and higher hatching success. Females that laid earlier and more eggs (2-3 eggs) consumed more Pacific anchoveta (Cetengraulis mysticetus) and Pacific thread herring (Opisthonema libertate) than did other females. These two prey species also had high amounts of lipids (C:N ratio) and caloric content (Kcal/g fresh weight). The quality of food consumed by females at the beginning of reproduction affected their physiological condition, as well as their short-term reproductive performance. Our work emphasizes the importance of determining the influence of food quality during reproduction to understand the reproductive decisions and consequences in long-lived animals.
González-Medina, Erick; Castillo-Guerrero, José Alfredo; Herzka, Sharon Zinah
2018-01-01
Understanding the role of diet in the physiological condition of adults during reproduction and hence its effect on reproductive performance is fundamental to understand reproductive strategies in long-lived animals. In birds, little is known about the influence of the quality of food consumed at the beginning of the reproductive period and its short-term effects on reproductive performance. To assess the role of diet in the physiological condition of female blue-footed booby, Sula nebouxii (BFBO), during reproduction we evaluated whether individual differences in diet (assessed by using δ13C and δ15N values of whole blood from female birds and muscle tissue of the principal prey species) prior to egg laying and during incubation influenced their lipid metabolic profile (measured as triglyceride levels and C:N ratio) and their reproductive performance (defined by laying date, clutch size and hatching success). Females with higher δ15N values in their blood during the courtship and incubation periods had a higher lipid metabolic profile, earlier laying date, greater clutch size (2–3 eggs) and higher hatching success. Females that laid earlier and more eggs (2–3 eggs) consumed more Pacific anchoveta (Cetengraulis mysticetus) and Pacific thread herring (Opisthonema libertate) than did other females. These two prey species also had high amounts of lipids (C:N ratio) and caloric content (Kcal/g fresh weight). The quality of food consumed by females at the beginning of reproduction affected their physiological condition, as well as their short-term reproductive performance. Our work emphasizes the importance of determining the influence of food quality during reproduction to understand the reproductive decisions and consequences in long-lived animals. PMID:29462199
O'Connor, Constance M; Nannini, Michael; Wahl, David H; Wilson, Samantha M; Gilmour, Kathleen M; Cooke, Steven J
2013-01-01
Experimental implants were used to investigate the effect of elevated cortisol (the primary stress hormone in teleost fish) on energetic and physiological condition prior to reproduction in male and female largemouth bass (Micropterus salmoides). Fish were wild-caught from lakes in Illinois, and held in experimental ponds for the duration of the study. Between 9 and 13 days after cortisol treatment, and immediately prior to the start of the reproductive period, treated and control animals were sampled. Females exhibited lower muscle lipid content, lower liver glycogen content, and higher hepatosomatic indices than males, regardless of treatment. Also, cortisol-treated females had higher hepatosomatic indices and lower final mass than control females, whereas males showed no differences between treatment groups. Finally, cortisol-treated females had higher gonadal cortisol concentrations than control females. In general, we found evidence of reduced energetic stores in female fish relative to male fish, likely due to timing differences in the allocation of resources during reproduction between males and females. Perhaps driven by the difference in energetic reserves, our data further suggest that females are more sensitive than males to elevated cortisol during the period immediately prior to reproduction. Copyright © 2012 Wiley Periodicals, Inc.
Tantibhedhyangkul, Julierut; Copland, Susannah D; Haqq, Andrea M; Price, Thomas M
2008-11-01
To present a case of unrecognized female epispadias. Case report. University-based reproductive endocrinology and fertility clinic. A 16-year-old girl with epispadias, history of mild urinary incontinence, auditory neuropathy, and functional hyperandrogenism. None. Peripheral blood array-based comparative genomic hybridization. The patient was referred for evaluation of excessive weight gain, secondary amenorrhea, and abnormal external genitalia. Examination under anesthesia revealed bilateral labia minora hypertrophy, bifid clitoris, and a patulous urethra, consistent with female epispadias. Hormonal evaluation showed functional hyperandrogenism, and peripheral blood array-based comparative genomic hybridization showed no chromosomal deletions or duplications. Female epispadias is a rare abnormality, not commonly recognized by most practitioners. The diagnosis is supported by a history of urinary incontinence and physical findings of bifid clitoris and patulous urethra. The condition can have serious physical and psychological consequences leading to a gross disruption of social function.
Putman, Sarah B.; Brown, Janine L.; Franklin, Ashley D.; Schneider, Emily C.; Boisseau, Nicole P.; Asa, Cheryl S.; Pukazhenthi, Budhan S.
2015-01-01
Because of poor reproduction after the lifting of an 8-year breeding moratorium, a biomedical survey of female lions in U.S. zoos was initiated in 2007. Fecal estrogen (FEM), progestagen (FPM) and glucocorticoid (FGM) metabolites were analyzed in samples collected 3–4 times per wk from 28 lions at 17 facilities (0.9–13.8 yr of age) for 4 mo—3.5 yr and body weights were obtained ~monthly from 17 animals at eight facilities (0.0–3.0 yr of age). Based on FEM, estrous cycle length averaged 17.5 ± 0.4 d in duration, with estrus lasting 4.4 ± 0.2 d. All but one female exhibited waves of estrogenic activity indicative of follicular activity; however, not all females expressed estrous behaviors (73%), suggesting silent estrus was common. Female lions experienced puberty earlier than expected; waves of estrogenic activity were observed as young as 1.1 yr of age, which may be related to a faster growth rate of captive vs. wild lions. Mean gestation length was 109.5 ± 1.0 d, whereas the non-pregnant luteal phase was less than half (46.0 ± 1.2 d). Non-mating induced increases in FPM were observed in 33% of females housed without a male, consistent with spontaneous ovulation. A number of study animals had been contracepted, and the return to cyclicity after treatment withdrawal, while variable, was ~4.0 yr and longer than the 1-yr expected efficacy, especially for those implanted with Suprelorin. For FGM, there were no differences in overall, baseline or peak mean concentrations among the age groups or across seasons, nor were there any relationships between reproductive parameters and FGM concentrations. Overall, results suggest that poor reproduction in lions after the breeding moratorium was not related to altered adrenal or ovarian steroid activity, but for some females may have been a consequence of individual institutions’ management decisions. PMID:26460849
Putman, Sarah B; Brown, Janine L; Franklin, Ashley D; Schneider, Emily C; Boisseau, Nicole P; Asa, Cheryl S; Pukazhenthi, Budhan S
2015-01-01
Because of poor reproduction after the lifting of an 8-year breeding moratorium, a biomedical survey of female lions in U.S. zoos was initiated in 2007. Fecal estrogen (FEM), progestagen (FPM) and glucocorticoid (FGM) metabolites were analyzed in samples collected 3-4 times per wk from 28 lions at 17 facilities (0.9-13.8 yr of age) for 4 mo-3.5 yr and body weights were obtained ~monthly from 17 animals at eight facilities (0.0-3.0 yr of age). Based on FEM, estrous cycle length averaged 17.5 ± 0.4 d in duration, with estrus lasting 4.4 ± 0.2 d. All but one female exhibited waves of estrogenic activity indicative of follicular activity; however, not all females expressed estrous behaviors (73%), suggesting silent estrus was common. Female lions experienced puberty earlier than expected; waves of estrogenic activity were observed as young as 1.1 yr of age, which may be related to a faster growth rate of captive vs. wild lions. Mean gestation length was 109.5 ± 1.0 d, whereas the non-pregnant luteal phase was less than half (46.0 ± 1.2 d). Non-mating induced increases in FPM were observed in 33% of females housed without a male, consistent with spontaneous ovulation. A number of study animals had been contracepted, and the return to cyclicity after treatment withdrawal, while variable, was ~4.0 yr and longer than the 1-yr expected efficacy, especially for those implanted with Suprelorin. For FGM, there were no differences in overall, baseline or peak mean concentrations among the age groups or across seasons, nor were there any relationships between reproductive parameters and FGM concentrations. Overall, results suggest that poor reproduction in lions after the breeding moratorium was not related to altered adrenal or ovarian steroid activity, but for some females may have been a consequence of individual institutions' management decisions.
Plasticity in body composition in breeding birds: what drives the metabolic costs of egg production?
Vézina, François; Williams, Tony D
2003-01-01
Body composition in vertebrates is known to show phenotypic plasticity, and changes in organ masses are usually rapid and reversible. One of the most rapid and reversible changes is the transformation of the female avian reproductive organs before breeding. This provides an excellent system to investigate the effects of plasticity in organ size on basal metabolic rate (BMR) through relationships between organ masses and BMR. We compared body composition of female European starlings (Sturnus vulgaris) during various reproductive stages over 3 yr and investigated the pattern of changes in reproductive and nonreproductive organ mass during follicular development and ovulation. Furthermore, we analyzed the relationship between organ mass and resting metabolic rate (RMR) in nonbreeding, laying, and chick-rearing females. Our analysis revealed marked variation in organ masses between breeding stages but no consistent pattern among years except for kidney and pectoralis muscle. Furthermore, changes in nonreproductive organs did not parallel the cycle of growth and regression of the reproductive organs. The oviduct gained 62% of its 22-fold increase in mass in only 3 d, and oviduct regression was just as rapid and began even before the final egg of the clutch was laid, with 42% of the oviduct mass lost before laying of the final egg. In laying females, 18% of variation in mass-corrected RMR was explained by the mass of the oviduct (r2=0.18, n=80, P<0.0005), while pectoralis muscle mass in nonbreeding individuals and liver and gizzard mass in chick-rearing females were the only organs significantly related to RMR (r2=0.31-0.44). We suggest that the nonreproductive organs are affected more by changes in local ecological conditions than the reproductive state itself and that the activity and maintenance cost of the oviduct is high enough that selection has led to a very tight size-function relationship for this organ.
Divergent roles of growth factors in the GnRH regulation of puberty in mice
DiVall, Sara A.; Williams, Tameeka R.; Carver, Sarah E.; Koch, Linda; Brüning, Jens C.; Kahn, C. Ronald; Wondisford, Fredric; Radovick, Sally; Wolfe, Andrew
2010-01-01
Pubertal onset, initiated by pulsatile gonadotropin-releasing hormone (GnRH), only occurs in a favorable, anabolic hormonal milieu. Anabolic factors that may signal nutritional status to the hypothalamus include the growth factors insulin and IGF-1. It is unclear which hypothalamic neuronal subpopulation these factors affect to ultimately regulate GnRH neuron function in puberty and reproduction. We examined the direct role of the GnRH neuron in growth factor regulation of reproduction using the Cre/lox system. Mice with the IR or IGF-1R deleted specifically in GnRH neurons were generated. Male and female mice with the IR deleted in GnRH neurons displayed normal pubertal timing and fertility, but male and female mice with the IGF-1R deleted in GnRH neurons experienced delayed pubertal development with normal fertility. With IGF-1 administration, puberty was advanced in control females, but not in females with the IGF-1R deleted in GnRH neurons, in control males, or in knockout males. These mice exhibited developmental differences in GnRH neuronal morphology but normal number and distribution of neurons. These studies define the role of IGF-1R signaling in the coordination of somatic development with reproductive maturation and provide insight into the mechanisms regulating pubertal timing in anabolic states. PMID:20628204
Summer habitat selection by Dall’s sheep in Wrangell-St. Elias National Park and Preserve, Alaska
Roffler, Gretchen H.; Adams, Layne G.; Hebblewhite, Mark
2017-01-01
Sexual segregation occurs frequently in sexually dimorphic species, and it may be influenced by differential habitat requirements between sexes or by social or evolutionary mechanisms that maintain separation of sexes regardless of habitat selection. Understanding the degree of sex-specific habitat specialization is important for management of wildlife populations and the design of monitoring and research programs. Using mid-summer aerial survey data for Dall’s sheep (Ovis dalli dalli) in southern Alaska during 1983–2011, we assessed differences in summer habitat selection by sex and reproductive status at the landscape scale in Wrangell-St. Elias National Park and Preserve (WRST). Males and females were highly segregated socially, as were females with and without young. Resource selection function (RSF) models containing rugged terrain, intermediate values of the normalized difference vegetation index (NDVI), and open landcover types best explained resource selection by each sex, female reproductive classes, and all sheep combined. For male and all female models, most coefficients were similar, suggesting little difference in summer habitat selection between sexes at the landscape scale. A combined RSF model therefore may be used to predict the relative probability of resource selection by Dall’s sheep in WRST regardless of sex or reproductive status.
Quantifying inbreeding avoidance through extra-pair reproduction.
Reid, Jane M; Arcese, Peter; Keller, Lukas F; Germain, Ryan R; Duthie, A Bradley; Losdat, Sylvain; Wolak, Matthew E; Nietlisbach, Pirmin
2015-01-01
Extra-pair reproduction is widely hypothesized to allow females to avoid inbreeding with related socially paired males. Consequently, numerous field studies have tested the key predictions that extra-pair offspring are less inbred than females' alternative within-pair offspring, and that the probability of extra-pair reproduction increases with a female's relatedness to her socially paired male. However, such studies rarely measure inbreeding or relatedness sufficiently precisely to detect subtle effects, or consider biases stemming from failure to observe inbred offspring that die during early development. Analyses of multigenerational song sparrow (Melospiza melodia) pedigree data showed that most females had opportunity to increase or decrease the coefficient of inbreeding of their offspring through extra-pair reproduction with neighboring males. In practice, observed extra-pair offspring had lower inbreeding coefficients than females' within-pair offspring on average, while the probability of extra-pair reproduction increased substantially with the coefficient of kinship between a female and her socially paired male. However, simulations showed that such effects could simply reflect bias stemming from inbreeding depression in early offspring survival. The null hypothesis that extra-pair reproduction is random with respect to kinship therefore cannot be definitively rejected in song sparrows, and existing general evidence that females avoid inbreeding through extra-pair reproduction requires reevaluation given such biases. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.
Osadchuk, L V; Salomacheva, I N; Osadchuk, A V
2010-01-01
The study was designed to investigate genetic differences in reproductive consequences of social hierarchy using inbred mice strains BALB/cLac, PT and CBA/Lac. Two adult males of different genotypes were housed together for 5 days. Hierarchical status of both partners was determined by asymmetry in agonistic behavior. The number of epididymal sperm and a proportion of abnormal sperm, weights of reproductive organs, serum concentration and testicular content of testosterone, and the testosterone response to introduction of a receptive female were determined. The testosterone measures were significantly decreased in the PT strain, the epididymal sperm number was significantly decreased in the BALB/cLac strain and a proportion of abnormal sperm heads was significantly increase in the CBA/Lac (in both dominants and subordinates) as compared to control mice. The testicular testosterone response to a receptive female and precopulatory behavior was unchanged in dominants and suppressed in subordinates of the BALB/cLac strain. The results indicate that in laboratory mice the pattern of reproductive response to social hierarchy is determined by genetic background.
Apomixis in hawkweed: Mendel's experimental nemesis.
Koltunow, Anna M G; Johnson, Susan D; Okada, Takashi
2011-03-01
Mendel used hawkweeds and other plants to verify the laws of inheritance he discovered using Pisum. Trait segregation was not evident in hawkweeds because many form seeds asexually by apomixis. Meiosis does not occur during female gametophyte formation and the mitotically formed embryo sacs do not require fertilization for seed development. The resulting progeny retain a maternal genotype. Hawkweeds in Hieracium subgenus Pilosella form mitotic embryo sacs by apospory. The initiation of sexual reproduction is required to stimulate apospory in ovules and to promote the function of the dominant locus, LOSS OF APOMEIOSIS, which stimulates the differentiation of somatic aposporous initial (AI) cells near sexually programmed cells. As AI cells undergo nuclear mitosis the sexual pathway terminates. The function of the dominant locus LOSS OF PARTHENOGENESIS in aposporous embryo sacs enables fertilization-independent embryo and endosperm development. Deletion of either locus results in partial reversion to sexual reproduction, and loss of function in both loci results in reversion to sexual development. In these apomicts, sexual reproduction is therefore the default reproductive mode upon which apomixis is superimposed. These loci are unlikely to encode factors critical for sexual reproduction but might recruit the sexual pathway to enable apomixis. Incomplete functional penetrance of these dominant loci is likely to lead to the generation of rare sexual progeny also derived from these facultative apomicts.
Kawatsu, Kazutaka
2013-01-01
Sexual reproduction involves many costs. Therefore, females acquiring a capacity for parthenogenetic (or asexual) reproduction will gain a reproductive advantage over obligately sexual females. In contrast, for males, any trait coercing parthenogens into sexual reproduction (male coercion) increases their fitness and should be under positive selection because parthenogenesis deprives them of their genetic contribution to future generations. Surprisingly, although such sexual conflict is a possible outcome whenever reproductive isolation is incomplete between parthenogens and the sexual ancestors, it has not been given much attention in the studies of the maintenance of sex. Using two mathematical models, I show here that the evolution of male coercion substantially favours the maintenance of sex even though a female barrier against the coercion can evolve. First, the model based on adaptive-dynamics theory demonstrates that the resultant antagonistic coevolution between male coercion and a female barrier fundamentally ends in either the prevalence of sex or the co-occurrence of two reproductive modes. This is because the coevolution between the two traits additionally involves sex-ratio selection, that is, an increase in parthenogenetic reproduction leads to a female-biased population sex ratio, which will enhance reproductive success of more coercive males and directly promotes the evolution of the coercion among males. Therefore, as shown by the individual-based model, the establishment of obligate parthenogenesis in the population requires the simultaneous evolution of strong reproductive isolation between males and parthenogens. These findings should shed light on the interspecific diversity of reproductive modes as well as help to explain the prevalence of sexual reproduction.
Kawatsu, Kazutaka
2013-01-01
Sexual reproduction involves many costs. Therefore, females acquiring a capacity for parthenogenetic (or asexual) reproduction will gain a reproductive advantage over obligately sexual females. In contrast, for males, any trait coercing parthenogens into sexual reproduction (male coercion) increases their fitness and should be under positive selection because parthenogenesis deprives them of their genetic contribution to future generations. Surprisingly, although such sexual conflict is a possible outcome whenever reproductive isolation is incomplete between parthenogens and the sexual ancestors, it has not been given much attention in the studies of the maintenance of sex. Using two mathematical models, I show here that the evolution of male coercion substantially favours the maintenance of sex even though a female barrier against the coercion can evolve. First, the model based on adaptive-dynamics theory demonstrates that the resultant antagonistic coevolution between male coercion and a female barrier fundamentally ends in either the prevalence of sex or the co-occurrence of two reproductive modes. This is because the coevolution between the two traits additionally involves sex-ratio selection, that is, an increase in parthenogenetic reproduction leads to a female-biased population sex ratio, which will enhance reproductive success of more coercive males and directly promotes the evolution of the coercion among males. Therefore, as shown by the individual-based model, the establishment of obligate parthenogenesis in the population requires the simultaneous evolution of strong reproductive isolation between males and parthenogens. These findings should shed light on the interspecific diversity of reproductive modes as well as help to explain the prevalence of sexual reproduction. PMID:23469150
Influence of body condition on reproductive output in the guinea pig.
Michel, Catherine Louise; Bonnet, Xavier
2012-01-01
Reproduction is expensive. Substantial body reserves (i.e. high body condition) are usually required for females to undertake offspring production. In many vertebrates, maternal body condition positively influences reproductive output, and emaciated individuals skip reproduction. However, the impact of extremely high body condition, more specifically obesity, on animal reproductive performance remains poorly understood and research has generated contradictory results. For instance, obesity negatively affects fertility in women, but does not influence reproductive capacity or reproductive output in laboratory rodents. We examined the influence of high body condition on reproductive status and reproductive output in the guinea pig. In captivity, when fed ad libitum, guinea pigs store large amounts of fat tissues and exhibit a tendency for obesity. Our results show that obesity negatively affected reproduction in this species: both the proportion of fertile females and litter size were lower in the fattest females. Therefore, guinea pigs may represent suitable organisms to better understand the negative effect of obesity on reproduction. Copyright © 2011 Wiley Periodicals, Inc., A Wiley Company.
Nozu, Ryo; Murakumo, Kiyomi; Yano, Nagisa; Furuyama, Rina; Matsumoto, Rui; Yanagisawa, Makio; Sato, Keiichi
2018-03-03
Captive breeding in aquaria is a useful means for ex situ preservation of threatened elasmobranch species. To promote captive breeding, it is important to determine the female reproductive status. However, information regarding reproductive status in female elasmobranchs is limited. Here, we used zebra sharks, Stegostoma fasciatum, as a model for elasmobranch reproduction in captivity. We investigated the relationships among changes in the sex steroid hormone levels, follicle size, and egg-laying period to develop indicators for the female reproductive status. We confirmed that mature female zebra sharks undergo an annual reproductive cycle. Additionally, we showed that the variations in sex steroid hormone levels correlated with reproductive status in mature female zebra sharks. Plasma estradiol-17ß (E2) concentrations increased two months before ovarian follicle development and decreased along with follicle regression. Interestingly, E2 levels were inversely correlated with water temperature (R = -0.901). Moreover, high levels of testosterone (T) correlated well with the laying period. These results strongly suggest that E2 is an indicator for ovarian follicle development, and that T is a useful indicator for both the onset and end of the egg-laying period in captive zebra sharks. Copyright © 2018 Elsevier Inc. All rights reserved.
Sisneros, Joseph A
2009-08-01
The plainfin midshipman fish, Porichthys notatus, is a seasonally breeding species of marine teleost fish that generates acoustic signals for intraspecific social and reproductive-related communication. Female midshipman use the inner ear saccule as the main acoustic endorgan for hearing to detect and locate vocalizing males that produce multiharmonic advertisement calls during the breeding season. Previous work showed that the frequency sensitivity of midshipman auditory saccular afferents changed seasonally with female reproductive state such that summer reproductive females became better suited than winter nonreproductive females to encode the dominant higher harmonics of the male advertisement calls. The focus of this study was to test the hypothesis that seasonal reproductive-dependent changes in saccular afferent tuning is paralleled by similar changes in saccular sensitivity at the level of the hair-cell receptor. Here, I examined the evoked response properties of midshipman saccular hair cells from winter nonreproductive and summer reproductive females to determine if reproductive state affects the frequency response and threshold of the saccule to behaviorally relevant single tone stimuli. Saccular potentials were recorded from populations of hair cells in vivo while sound was presented by an underwater speaker. Results indicate that saccular hair cells from reproductive females had thresholds that were approximately 8 to 13 dB lower than nonreproductive females across a broad range of frequencies that included the dominant higher harmonic components and the fundamental frequency of the male's advertisement call. These seasonal-reproductive-dependent changes in thresholds varied differentially across the three (rostral, middle, and caudal) regions of the saccule. Such reproductive-dependent changes in saccule sensitivity may represent an adaptive plasticity of the midshipman auditory sense to enhance mate detection, recognition, and localization during the breeding season.
Prunskaite-Hyyryläinen, Renata; Skovorodkin, Ilya; Xu, Qi; Miinalainen, Ilkka; Shan, Jingdong; Vainio, Seppo J.
2016-01-01
The Müllerian duct (MD) is the anlage of the oviduct, uterus and upper part of the vagina, the main parts of the female reproductive tract. Several wingless-type mouse mammary tumor virus (MMTV) integration site family member (Wnt) genes, including Wnt4, Wnt5a and Wnt7a, are involved in the development of MD and its derivatives, with Wnt4 particularly critical, since the MD fails to develop in its absence. We use, here, Wnt4EGFPCre-based fate mapping to demonstrate that the MD tip cells and the subsequent MD cells are derived from Wnt4+ lineage cells. Moreover, Wnt4 is required for the initiation of MD-forming cell migration. Application of anti-Wnt4 function-blocking antibodies after the initiation of MD elongation indicated that Wnt4 is necessary for the elongation as well, and consistent with this, cell culture wound-healing assays with NIH3T3 cells overexpressing Wnt4 promoted cell migration by comparison with controls. In contrast to the Wnt4 null embryos, some Wnt4monomeric cherry/monomeric cherry (Wnt4mCh/mCh) hypomorphic mice survived to adulthood and formed MD in ∼45% of cases. Nevertheless, the MD of the Wnt4mCh/mCh females had altered cell polarization and basement membrane deposition relative to the controls. Examination of the reproductive tract of the Wnt4mCh/mCh females indicated a poorly coiled oviduct, absence of the endometrial glands and an undifferentiated myometrium, and these mice were prone to develop a hydro-uterus. In conclusion, the results suggest that the Wnt4 gene encodes signals that are important for various aspects of female reproductive tract development. PMID:26721931
Genome-Wide Responses of Female Fruit Flies Subjected to Divergent Mating Regimes
Gerrard, Dave T.; Fricke, Claudia; Edward, Dominic A.; Edwards, Dylan R.; Chapman, Tracey
2013-01-01
Elevated rates of mating and reproduction cause decreased female survival and lifetime reproductive success across a wide range of taxa from flies to humans. These costs are fundamentally important to the evolution of life histories. Here we investigate the potential mechanistic basis of this classic life history component. We conducted 4 independent replicated experiments in which female Drosophila melanogaster were subjected to ‘high’ and ‘low’ mating regimes, resulting in highly significant differences in lifespan. We sampled females for transcriptomic analysis at day 10 of life, before the visible onset of ageing, and used Tiling expression arrays to detect differential gene expression in two body parts (abdomen versus head+thorax). The divergent mating regimes were associated with significant differential expression in a network of genes showing evidence for interactions with ecdysone receptor. Preliminary experimental manipulation of two genes in that network with roles in post-transcriptional modification (CG11486, eyegone) tended to enhance sensitivity to mating costs. However, the subtle nature of those effects suggests substantial functional redundancy or parallelism in this gene network, which could buffer females against excessive responses. There was also evidence for differential expression in genes involved in germline maintenance, cell proliferation and in gustation / odorant reception. Interestingly, we detected differential expression in three specific genes (EcR, keap1, lbk1) and one class of genes (gustation / odorant receptors) with previously reported roles in determining lifespan. Our results suggest that high and low mating regimes that lead to divergence in lifespan are associated with changes in the expression of genes such as reproductive hormones, that influence resource allocation to the germ line, and that may modify post-translational gene expression. This predicts that the correct signalling of nutrient levels to the reproductive system is important for maintaining organismal integrity. PMID:23826372
Normal development of the female reproductive system
The embryonic development of the female reproductive system involves a progression of events that is conserved across vertebrate species. The early gonad progresses from a form that is undifferentiated in both genotypic males and females. Rudimentary male (Wolffian) and female (M...
Marijuana, the Endocannabinoid System and the Female Reproductive System.
Brents, Lisa K
2016-06-01
Marijuana use among women is highly prevalent, but the societal conversation on marijuana rarely focuses on how marijuana affects female reproduction and endocrinology. This article reviews the current scientific literature regarding marijuana use and hypothalamic-pituitary-ovarian (HPO) axis regulation, ovarian hormone production, the menstrual cycle, and fertility. Evidence suggests that marijuana can reduce female fertility by disrupting hypothalamic release of gonadotropin releasing hormone (GnRH), leading to reduced estrogen and progesterone production and anovulatory menstrual cycles. Tolerance to these effects has been shown in rhesus monkeys, but the effects of chronic marijuana use on human female reproduction are largely unknown. Marijuana-induced analgesia, drug reinforcement properties, tolerance, and dependence are influenced by ovarian hormones, with estrogen generally increasing and progesterone decreasing sensitivity to marijuana. Carefully controlled regulation of the Endocannabinoid System (ECS) is required for successful reproduction, and the exogenous cannabinoids in marijuana may disrupt the delicate balance of the ECS in the female reproductive system.
Early social learning triggers neurogenomic expression changes in a swordtail fish.
Cui, Rongfeng; Delclos, Pablo J; Schumer, Molly; Rosenthal, Gil G
2017-05-17
Mate choice can play a pivotal role in the nature and extent of reproductive isolation between species. Mating preferences are often dependent on an individual's social experience with adult phenotypes throughout development. We show that olfactory preference in a swordtail fish ( Xiphophorus malinche ) is affected by previous experience with adult olfactory signals. We compare transcriptome-wide gene expression levels of pooled sensory and brain tissues between three treatment groups that differ by social experience: females with no adult exposure, females exposed to conspecifics and females exposed to heterospecifics. We identify potential functionally relevant genes and biological pathways differentially expressed not only between control and exposure groups, but also between groups exposed to conspecifics and heterospecifics. Based on our results, we speculate that vomeronasal receptor type 2 paralogs may detect species-specific pheromone components and thus play an important role in reproductive isolation between species. © 2017 The Author(s).
Characterization of gonadal transcriptomes from the turbot (Scophthalmus maximus).
Hu, Yulong; Huang, Meng; Wang, Weiji; Guan, Jiantao; Kong, Jie
2016-01-01
The mechanisms underlying sexual reproduction and sex ratio determination remains unclear in turbot, a flatfish of great commercial value. And there is limited information in the turbot database regarding genes related to the reproductive system. Here, we conducted high-throughput transcriptome profiling of turbot gonad tissues to better understand their reproductive functions and to supply essential gene sequence information for marker-assisted selection programs in the turbot industry. In this study, two gonad libraries representing sex differences in Scophthalmus maximus yielded 453 818 high-quality reads that were assembled into 24 611 contigs and 33 713 singletons by using 454 pyrosequencing, 13 936 contigs and singletons (CS) of which were annotated using BLASTx. GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analyses revealed that various biological functions and processes were associated with many of the annotated CS. Expression analyses showed that 510 genes were differentially expressed in males versus females; 80% of these genes were annotated. In addition, 6484 and 6036 single nucleotide polymorphisms (SNPs) were identified in male and female libraries, respectively. This transcriptome resource will serve as the foundation for cDNA or SNP microarray construction, gene expression characterization, and sex-specific linkage mapping in turbot.
Male Reproductive System (For Teens)
... genes come from the father's sperm and the mother's egg, which are produced by the male and female reproductive systems. What Is the Male Reproductive System? Most species have two sexes: male and female. Each sex has its own ...
Evaluation of reproductive status in Atlantic Tripletail by traditional and nonlethal approaches
Parr, R. T.; Jennings, Cecil A.; Denslow, N. D.; Kroll, K.J.; Bringolf, R.B.
2016-01-01
Reproductive biology information is an important tool for fishery management actions such as the identification of spawning areas and the development of protective size limits, bag limits, and seasons. Such information for the management of Atlantic TripletailLobotes surinamensis is currently limited, particularly in the western Atlantic Ocean, as information regarding the reproductive biology of this species is sparse in the published literature. To this end, we determined the reproductive status of tripletail and compared the results of a nonlethal sampling method, plasma vitellogenin (VTG) analysis, with those of two traditional (lethal) methods, gonadosomatic index (GSI) and gonad histology. A total of 223 (122 male and 101 female) tripletail were sampled over 2 years near Jekyll Island, Georgia. Gonad histology indicated that 107 (94%) of the male tripletail were in the spawning-capable reproductive phase. Female tripletail were found in all reproductive phases, but only nine (8.9%) were in the spawning-capable phase. Plasma VTG was strongly related to GSI in females (R2 = 0.832, n = 77), and female GSI differed significantly among reproductive phases (p < 0.0001). The estimated length at which 50% (L50) of female tripletail reached maturity was 463 mm; however, the L50 for male tripletail could not be determined because of the lack of immature fish within the study sample. Our study provides valuable information for the management of tripletail and indicates that a nonlethal approach (plasma VTG) may be useful for differentiating developing and spawning-capable females from males and from females in other reproductive phases.
Influence of climate variability on anchovy reproductive timing off northern Chile
NASA Astrophysics Data System (ADS)
Contreras-Reyes, Javier E.; Canales, T. Mariella; Rojas, Pablo M.
2016-12-01
We investigated the relationship between environmental variables and the Gonadosomatic Monthly Mean (GMM) index of anchovy (Engraulis ringens) to understand how the environment affects the dynamics of anchovy reproductive timing. The data examined corresponds to biological information collected from samples of the landings off northern Chile (18°21‧S, 24°00‧S) during the period 1990-2010. We used the Humboldt Current Index (HCI) and the Multivariate ENSO Index (MEI), which combine several physical-oceanographic factors in the Tropical and South Pacific regions. Using the GMM index, we studied the dynamics of anchovy reproductive timing at different intervals of length, specifically females with a length between 11.5 and 14 cm (medium class) and longer than 14 cm (large class). Seasonal Autoregressive Integrated Mobile Average (SARIMA) was used to predict missing observations. The trends of the environment and reproductive indexes were explored via the Breaks For Additive Season and Trend (BFAST) statistical technique and the relationship between these indexes via cross-correlation functions (CCF) analysis. Our results showed that the habitat of anchovy switched from cool to warm condition, which also influenced gonad development. This was revealed by two and three significant changes (breaks) in the trend of the HCI and MEI indexes, and two significant breaks in the GMM of each time series of anchovy females (medium and large). Negative cross-correlation between the MEI index and GMM of medium and large class females was found, indicating that as the environment gets warmer (positive value of MEI) a decrease in the reproductive activity of anchovy can be expected. Correlation between the MEI index and larger females was stronger than with medium females. Additionally, our results indicate that the GMM index of anchovy for both length classes reaches two maximums per year; the first from August to September and the second from December to January. The intensity (maximum GMM values at rise point) of reproductive activity was not equal though, with the August-September peak being the highest. We also discuss how the synchronicity between environment and reproductive timing, the negative correlation found between MEI and GMM indexes, and the two increases per year of anchovy GMM relate to previous studies. Based on these findings we propose ways to advance in the understanding of how anchovy synchronize gonad development with the environment.
Mechanical signaling in reproductive tissues: mechanisms and importance.
Jorge, Soledad; Chang, Sydney; Barzilai, Joshua J; Leppert, Phyllis; Segars, James H
2014-09-01
The organs of the female reproductive system are among the most dynamic tissues in the human body, undergoing repeated cycles of growth and involution from puberty through menopause. To achieve such impressive plasticity, reproductive tissues must respond not only to soluble signals (hormones, growth factors, and cytokines) but also to physical cues (mechanical forces and osmotic stress) as well. Here, we review the mechanisms underlying the process of mechanotransduction-how signals are conveyed from the extracellular matrix that surrounds the cells of reproductive tissues to the downstream molecules and signaling pathways that coordinate the cellular adaptive response to external forces. Our objective was to examine how mechanical forces contribute significantly to physiological functions and pathogenesis in reproductive tissues. We highlight how widespread diseases of the reproductive tract, from preterm labor to tumors of the uterus and breast, result from an impairment in mechanical signaling. © The Author(s) 2014.
Ding, Tianbo; Chi, Hsin; Gökçe, Ayhan; Gao, Yulin; Zhang, Bin
2018-02-20
Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) is a serious pest that is capable of bisexual and arrhenotokous reproduction. In arrhenotokous reproduction, virgin females initially produce male offspring; later, when their sons are sexually mature, the mothers begin bisexual reproduction by carrying out oedipal mating with their sons. Because a virgin female produces many male offspring before oedipal mating occurs, multiple oedipal mating is common. In this study, we investigated the effect of multiple oedipal mating on the population growth of F. occidentalis by using the age-stage, two-sex life table theory. In the arrhenotokous cohorts, all unfertilized eggs developed into males. In the bisexual cohorts, the offspring sex ratio was significantly female biased with the mean number of female offspring and male offspring being 72.68 and 29.00, respectively. These were the same as the net reproductive rate of female offspring and male offspring. In arrhenotokous cohorts, the number of males available for oedipal mating significantly affected the production of female offspring. The number of female offspring increased as the number of sons available for oedipal mating increased. Correctly characterizing this unique type of reproduction will provide important information for predicting the timing of future outbreaks of F. occidentalis, as well as aiding in formulating successful management strategies against the species.
Horsley, Kimberly; Stark, Lloyd R; McLetchie, D Nicholas
2011-05-01
Expected life history trade-offs associated with sex differences in reproductive investment are often undetected in seed plants, with the difficulty arising from logistical issues of conducting controlled experiments. By controlling genotype, age and resource status of individuals, a bryophyte was assessed for sex-specific and location-specific patterns of vegetative, asexual and sexual growth/reproduction across a regional scale. Twelve genotypes (six male, six female) of the dioecious bryophyte Bryum argenteum were subcultured to remove environmental effects, regenerated asexually to replicate each genotype 16 times, and grown over a period of 92 d. Plants were assessed for growth rates, asexual and sexual reproductive traits, and allocation to above- and below-ground regenerative biomass. The degree of sexual versus asexual reproductive investment appears to be under genetic control, with three distinct ecotypes found in this study. Protonemal growth rate was positively correlated with asexual reproduction and sexual reproduction, whereas asexual reproduction was negatively correlated (appeared to trade-off) with vegetative growth (shoot production). No sex-specific trade-offs were detected. Female sex-expressing shoots were longer than males, but the sexes did not differ in growth traits, asexual traits, sexual induction times, or above- and below-ground biomass. Males, however, had much higher rates of inflorescence production than females, which translated into a significantly higher (24x) prezygotic investment for males relative to females. Evidence for three distinct ecotypes is presented for a bryophyte based on regeneration traits. Prior to zygote production, the sexes of this bryophyte did not differ in vegetative growth traits but significantly differed in reproductive investment, with the latter differences potentially implicated in the strongly biased female sex ratio. The disparity between males and females for prezygotic reproductive investment is the highest known for bryophytes.
Santillo, Alessandra; Falvo, Sara; Di Fiore, Maria Maddalena; Chieffi Baccari, Gabriella
2017-05-15
The brain of amphibians contains all the key enzymes of steroidogenesis and has a high steroidogenic activity. In seasonally-breeding amphibian species brain steroid levels fluctuate synchronously with the reproductive cycle. Here we report a study of gene expression of StAR protein, key steroidogenic enzymes and sex hormone receptors in the telencephalon (T) and diencephalon-mesencephalon (D-M) of male and female reproductive and post-reproductive Pelophylax esculentus, a seasonally breeding anuran amphibian. Significant differences in gene expression were observed between (a) the reproductive and post-reproductive phase, (b) the two brain regions and (c) male and female frogs. During the reproductive phase, star gene expression increased in the male (both T and D-M) but not in the female brain. Seasonal fluctuations in expression levels of hsd3b1, hsd17b1, srd5a1 and cyp19a1 genes for neurosteroidogenic enzymes occurred in D-M region of both sexes, with the higher levels in reproductive period. Moreover, the D-M region generally showed higher levels of gene expression than the T region in both sexes. Gene expression was higher in females than males for most genes, suggesting higher neurosteroid production in female brain. Seasonal and sex-linked changes were also observed in gene expression for androgen (ar) and estrogen (esr1, esr2) receptors, with the males showing the highest ar levels in reproductive phase and the highest esr1 and esr2 levels in post-reproductive phase; in contrast, females showed the maximum expression for all three genes in reproductive phase. The results are the first evidence for seasonal changes and sexual dimorphism of gene expression of the neurosteroidogenic pathway in amphibians. Copyright © 2016 Elsevier Inc. All rights reserved.
Edwards, Katie L; Shultz, Susanne; Pilgrim, Mark; Walker, Susan L
2015-04-01
Ex situ populations of endangered species such as the black rhinoceros play an important role in global conservation strategies. However, the European captive population of eastern black rhinoceros is performing sub-optimally, with growth rates and genetic viability limited by low birth rates and high reproductive skew. We investigated several intrinsic differences between parous and nulliparous females that may underlie differences in reproductive success, including ovarian cyclicity, adrenal activity, behaviour and body condition. Faecal samples were collected from 39 females (17 parous, 15 nulliparous and 7 pre-reproductive) at 11 zoological institutions, every other day for between 4months and 6years. Progestagen metabolite concentration indicated that although all non-pregnant females exhibited ovarian activity, irregular cyclicity was common. Longer cycles (>40days) were more common in nulliparous females and periods of acyclicity observed more often in females that had not bred for at least 7years. Even when endocrine data indicated clear ovarian activity, overt behavioural signs of oestrus were not always apparent, particularly among nulliparous females. Faecal glucocorticoids did not differ between parous and nulliparous females, although did differ according to individual temperament. More unpredictable temperaments were associated with higher glucocorticoids, and nulliparous females tended to be rated as more unpredictable. Finally, nulliparous females had higher body condition scores than parous females. This is the first comprehensive survey of the reproductive physiology of this European captive population, and highlights a number of intrinsic differences related to parity, which may underlie differences in reproductive success among captive female black rhinoceros. Copyright © 2014 Elsevier Inc. All rights reserved.
Klaper, Rebecca; Rees, Christopher B.; Drevnick, Paul; Weber, Daniel; Sandheinrich, Mark; Carvan, Michael J.
2006-01-01
Background Methylmercury (MeHg) is a known neurotoxic agent, but the mechanisms by which MeHg may act on reproductive pathways are relatively unknown. Several studies have indicated potential changes in hormone levels as well as declines in vertebrates with increasing dietary MeHg exposure. Objectives The purpose of this study was to identify alterations in gene expression associated with MeHg exposure, specifically those associated with previously observed changes in reproduction and reproductive biomarkers. Fathead minnows, Pimephales promelas, were fed one of three diets that were similar to documented concentrations of MeHg in the diets of wild invertivorous and piscivorous fish. We used a commercial macroarray in conjunction with quantitative polymerase chain reaction to examine gene expression in fish in relation to exposure to these environmentally relevant doses of MeHg. Results Expression of genes commonly associated with endocrine disruption was altered with Hg exposure. Specifically, we observed a marked up-regulation in vitellogenin mRNA in individual Hg-exposed males and a significant decline in vitellogenin gene expression in female fish with increasing Hg concentrations. Other genes identified by the macroarray experiment included those associated with egg fertilization and development, sugar metabolism, apoptosis, and electron transport. We also observed differences in expression patterns between male and female fish not related to genes specifically associated with reproduction, indicating a potential physiological difference in the reaction of males and females to MeHg. Conclusion Gene expression data may provide insight into the mechanisms by which MeHg affects reproduction in fish and indicate how MeHg differs in its effect from other heavy metals and endocrine-disrupting compounds. PMID:16966085
Boric Acid Is Reproductively Toxic to Adult Xenopus laevis, but Not Endocrine Active.
Fort, Douglas J; Fort, Troy D; Mathis, Michael B; Ball, R Wayne
2016-11-01
The potential reproductive and endocrine toxicity of boric acid (BA) in the African clawed frog, Xenopus laevis, was evaluated using a 30-day exposure of adult frogs. Adult female and male frogs established as breeders were exposed to a culture water control and 4 target (nominal) test concentrations [5.0, 7.5, 10.0, and 15 mg boron (B)/L, equivalent to 28.5, 42.8, 57.0, and 85.5 mg BA/L] using flow-through diluter exposure system. The primary endpoints measured were adult survival, growth (weight and snout-vent length [SVL]), necropsy data, reproductive fecundity, and development of progeny (F1) from the exposed frogs. Necropsy endpoints included gonad weight, gonado-somatic index (GSI), ovary profile (oocyte normalcy and stage distribution), sperm count, and dysmorphology. Endocrine endpoints included plasma estradiol (E2), testosterone (T), dihydrotestosteone (DHT), gonadal CYP 19 (aromatase), and gonadal 5α-reductase (5-AR). BA exposure to adult female X. laevis increased the proportion of immature oocytes (< stage II) in the ovaries of females, reduced sperm counts and increased sperm cell dysmorphology frequency in male frogs exposed to 15 mg B/L. No effects on the other general, developmental (F1), or endocrine endpoints were observed. Based on the results of the present study, the no observed adverse effects concentration (NOAEC) for the reproductive endpoints was 10 mg B/L; and 15 mg B/L for reproductive fecundity, F1 embryo larval development, and endocrine function. These results confirmed that although BA is capable of inducing reproductive toxicity at high concentrations, it is not an endocrine disrupting agent. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
Innate immunity is not related to the sex of adult Tree Swallows during the nestling period
Houdek, Bradley J.; Lombardo, Michael P.; Thorpe, Patrick A.; Hahn, D. Caldwell
2011-01-01
Evolutionary theory predicts that exposure to more diverse pathogens will result in the evolution of a more robust immune response. We predicted that during the breeding season the innate immune function of female Tree Swallows (Tachycineta bicolor) should be more effective than that of males because (1) the transmission of sexually transmitted microbes during copulation puts females at greater risk because ejaculates move from males to females, (2) females copulate with multiple males, exposing them to the potentially pathogenic microbes in semen, and (3) females spend more time in the nest than do males so may be more exposed to nest microbes and ectoparasites that can be vectors of bacterial and viral pathogens. In addition, elevated testosterone in males may suppress immune function. We tested our prediction during the 2009 breeding season with microbicidal assays in vitro to assess the ability of the innate immune system to kill Escherichia coli. The sexes did not differ in the ability of their whole blood to kill E. coli. We also found no significant relationships between the ability of whole blood to kill E. coli and the reproductive performance or the physical condition of males or females. These results indicate that during the nestling period there are no sexual differences in this component of the innate immune system. In addition, they suggest that there is little association between this component of innate immunity and the reproductive performance and physical condition during the nestling period of adult Tree Swallows.
Reproductive competition between females in the matrilineal Mosuo of southwestern China
Ji, Ting; Wu, Jia-Jia; He, Qiao-Qiao; Xu, Jing-Jing; Mace, Ruth; Tao, Yi
2013-01-01
The matrilineal Mosuo of southwestern China live in communal households where brothers and sisters of three generations live together (duolocal residence), and men visit their wives, who reside elsewhere, only at night in ‘visiting’ marriages. Here we show that these communally breeding sisters are in reproductive conflict, in the sense that they share the resources needed to reproduce. We analyse determinants of reproductive success in females and males, and show that co-resident female kin are in competition; the more female kin reside in the household, the more reproductive success is reduced. Male reproductive success, however, is not determined by the kin in his natal household; duolocal males are not in reproductive conflict with their siblings. Competition with female cousins can be worse than that between sisters. We also find that female work on the farm (which is the main communal resource) is not equal. We use a ‘tug-of-war’ model of reproductive skew generated by incomplete control, to model the patterns of effort put into competition between sisters and cousins. The model predicts that more dominant (older) sisters will put less effort into reproductive conflict than will less dominant (younger) sisters; but younger sisters will also have lower reproductive success because they are less efficient at gaining access to the shared resource. Both predictions are consistent with our data. Younger sisters work less in the fields than do older sisters, which may represent a form of conflict or may be because their average relatedness to the household is lower than that of their more fertile older sisters. PMID:24167311
Hurd, Hilary; Ardin, Richard
2003-01-01
During copulation, male insects pass accessory gland components to the female with the spermatophore. These gifts can affect female reproductive behaviour, ovulation and oviposition. Here, we show that female mealworm beetles, Tenebrio molitor, mated with males infected with metacestodes of the rat tapeworm, Hymenolepis diminuta, produced significantly more offspring than those mated with uninfected males. There is a significant positive relationship between parasite intensity in the male and reproductive output in the female. Infection results in a significant increase in bean-shaped accessory gland (BAG) size. We suggest that infected males pass superior nuptial gifts to females and discuss the confounding effects of infection in male and female beetles upon overall fitness costs of infection for the host and the likelihood that the parasite is manipulating host investment in reproduction. PMID:14667373
Bennell, K L; Brukner, P D; Malcolm, S A
1996-09-01
It is apparent that bone density in male athletes can be reduced without a concomitant decrease in testosterone, suggesting that bone density and testosterone concentrations in the normal range are not closely related in male athletes. Further research is necessary to monitor concurrent changes in bone density and testosterone over a period of time in exercising males. In any case, the effect of exercise on the male reproductive system does not appear as extreme as that which can occur in female athletes, and any impact on bone density is not nearly as evident. These results imply that factors apart from testosterone concentrations must be responsible for the observed osteopenia in some male athletes. Many factors have the potential to adversely affect bone density, independently of alterations in reproductive function. These include low calcium intake, energy deficit, weight loss, psychological stress, and low body fat, all of which may be associated with intense endurance training. Future research investigating skeletal health in male athletes should include a thorough assessment of reproductive function in addition to these other factors.
NASA Astrophysics Data System (ADS)
Grabowski, Raphael Cezar; Negreiros-Fransozo, Maria Lucia; Castilho, Antonio Leão
2016-01-01
The predictability of certain environmental factors that affect the life cycle of the seabob shrimp Xiphopenaeus kroyeri (Heller, 1862) was evaluated in a study of its reproductive biology in an area adjacent to Babitonga Bay, State of Santa Catarina, Brazil. Monthly sampling was conducted from July 2010 through June 2011 at depths of 5, 8, 11, 14, and 17 m. 76 004 individuals were obtained, with a pronounced peak in absolute abundance in austral autumn (34 208), coinciding with the annual closed season from March to May. Grain size composition of the sediment showed the closest relationship to the distribution of individuals (multiple linear regression, P <0.05), related to their burying habit. The observed correlations between the abundance of reproductive males (bearing spermatophores) and females with spent gonads (cross-correlation, P <0.05), and between reproductive males and reproductive females (with a 1-month lag) suggest that the peak of reproductive males preceded the peak of female ones. This result agrees with the pattern expected for females, which copulate in post-ecdysis (spent gonads). Spawning seemed to take place at greater depths, as evidenced by the concentration of reproductive females in these areas. The reproductive activities observed here confirm that this species follows a tropical/subtropical reproductive pattern, spawning continuously throughout the year, with the highest peaks in spring and autumn. The data indicate that the juvenile recruitment period observed in August-September resulted from the reproductive output noted in April-May. Additionally, the reproductive period recorded in November led to the juvenile peak observed in March-May.
Chinn, Sarah S; Miller, Melissa A.; Tinker, M. Tim; Staedler, Michelle M.; Batac, Francesca I.; Dodd, Erin M.; Henkel, Laird A.
2016-01-01
Sea otters (Enhydra lutris) have exceptionally high energetic requirements, which nearly double during lactation and pup care. Thus, females are extremely vulnerable to caloric insufficiency. Despite a number of compensatory strategies, the metabolic challenge of reproduction culminates in numerous maternal deaths annually. Massive depletion of energy reserves results in a case presentation that we define as end-lactation syndrome (ELS), characterized by moderate to severe emaciation not attributable to a concurrent, independent disease process in females dying during late pup care or postweaning. We compiled detailed data for 108 adult female southern sea otters (Enhydra lutris nereis) examined postmortem that stranded in California, US, 2005–12, and assessed pathology, reproductive status, and the location and timing of stranding. We introduce simple, grossly apparent, standardized physical criteria to assess reproductive stage for female sea otters. We also describe ELS, examine associated risk factors, and highlight female life history strategies that likely optimize reproduction and survival. Our data suggest that females can reset both the timing and energetic demands of reproduction through fetal loss, pup abandonment, or early weaning as part of specific physiologic checkpoints during each reproductive cycle. Females appear to preload nutritionally during delayed implantation and gestation to increase fitness and reproductive success. We found that ELS was a major cause of death, affecting 56% of enrolled adult females. Peak ELS prevalence occurred in late spring, possibly reflecting the population trend toward fall/winter pupping. Increasing age and number of pregnancies were associated with a higher risk of ELS. Although the proportion of ELS females was highest in areas with dense sea otter populations, cases were recovered throughout the range, suggesting that death from ELS is associated with, but not solely caused by, population resource limitation.
Animal models of physiologic markers of male reproduction: genetically defined infertile mice
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chubb, C.
The present report focuses on novel animal models of male infertility: genetically defined mice bearing single-gene mutations that induce infertility. The primary goal of the investigations was to identify the reproductive defects in these mutant mice. The phenotypic effects of the gene mutations were deciphered by comparing the mutant mice to their normal siblings. Initially testicular steroidogenesis and spermatogenesis were investigated. The physiologic markers for testicular steroidogenesis were steroid secretion by testes perifused in vitro, seminal vesicle weight, and Leydig cell histology. Spermatogenesis was evaluated by the enumeration of homogenization-resistant sperm/spermatids in testes and by morphometric analyses of germ cellsmore » in the seminiferous epithelium. If testicular function appeared normal, the authors investigated the sexual behavior of the mice. The parameters of male sexual behavior that were quantified included mount patency, mount frequency, intromission latency, thrusts per intromission, ejaculation latency, and ejaculation duration. Females of pairs breeding under normal circumstances were monitored for the presence of vaginal plugs and pregnancies. The patency of the ejaculatory process was determined by quantifying sperm in the female reproductive tract after sexual behavior tests. Sperm function was studied by quantitatively determining sperm motility during videomicroscopic observation. Also, the ability of epididymal sperm to function within the uterine environment was analyzed by determining sperm capacity to initiate pregnancy after artificial insemination. Together, the experimental results permitted the grouping of the gene mutations into three general categories. They propose that the same biological markers used in the reported studies can be implemented in the assessment of the impact that environmental toxins may have on male reproduction.« less
Cartledge, Victoria A; Gartrell, Brett; Jones, Susan M
2005-05-01
This study investigates the relationships between plasma corticosterone concentrations and white cell counts in captive females of the viviparous lizard Egernia whitii during two phases of the reproductive cycle. Gestating and postpartum females were captured in the field and held in the laboratory for 4 weeks. Plasma corticosterone and progesterone concentrations and white blood cell counts were examined in blood samples taken at capture and after 24 h, 1 week, and 4 weeks in captivity. At 24 h after capture, plasma corticosterone concentrations in both groups had increased significantly compared with initial values but then returned to initial concentrations after 1 week in captivity and remained low in the 4 week samples. Plasma progesterone concentrations remained elevated in the gestating females until the week 4 sample, just prior to parturition. The hormone data suggest that capture and captivity did not represent a significant long-term stressor to these animals. The increase in plasma corticosterone concentration was associated with heterophilia in the differential leucocyte count in both groups of females. Lymphocyte numbers decreased only in gestating females, suggesting that reproductive status may influence the interaction between adrenal activity and immune function.
Living on the wedge: female control of paternity in a cooperatively polyandrous cichlid
Kohda, Masanori; Heg, Dik; Makino, Yoshimi; Takeyama, Tomohiro; Shibata, Jun-ya; Watanabe, Katsutoshi; Munehara, Hiroyuki; Hori, Michio; Awata, Satoshi
2009-01-01
Theories suggest that, in cooperatively breeding species, female control over paternity and reproductive output may affect male reproductive skew and group stability. Female paternity control may come about through cryptic female choice or female reproductive behaviour, but experimental studies are scarce. Here, we show a new form of female paternity control in a cooperatively polyandrous cichlid fish (Julidochromis transcriptus), in which females prefer wedge-shaped nesting sites. Wedge-shaped sites allowed females to manipulate the siring success of the group member males by spawning the clutch at the spot where the large males were just able to enter and fertilize the outer part of the clutch. Small males fertilized the inner part of the clutch, protected from the large aggressive males, leading to low male reproductive skew. Small males provided more brood care than large males. Multiple paternity induced both males to provide brood care and reduced female brood care accordingly. This is, to our knowledge, the first documented case in a species with external fertilization showing female mating behaviour leading to multiple male paternity and increased male brood care as a result. PMID:19726479
Tissue Trace Elements and Lipid Peroxidation in Breeding Female Bank Voles Myodes glareolus.
Bonda-Ostaszewska, Elżbieta; Włostowski, Tadeusz; Łaszkiewicz-Tiszczenko, Barbara
2018-04-27
Recent studies have demonstrated that reproduction reduces oxidative damage in various tissues of small mammal females. The present work was designed to determine whether the reduction of oxidative stress in reproductive bank vole females was associated with changes in tissue trace elements (iron, copper, zinc) that play an essential role in the production of reactive oxygen species. Lipid peroxidation (a marker of oxidative stress) and iron concentration in liver, kidneys, and skeletal muscles of reproducing bank vole females that weaned one litter were significantly lower than in non-reproducing females; linear regression analysis confirmed a positive relation between the tissue iron and lipid peroxidation. The concentrations of copper were significantly lower only in skeletal muscles of reproductive females and correlated positively with lipid peroxidation. No changes in tissue zinc were found in breeding females when compared with non-breeding animals. These data indicate that decreases in tissue iron and copper concentrations may be responsible for the reduction of oxidative stress in reproductive bank vole females.
Socioecological predictors of immune defences in wild spotted hyenas
Flies, Andrew S.; Mansfield, Linda S.; Flies, Emily J.; Grant, Chris K.; Holekamp, Kay E.
2016-01-01
Summary Social rank can profoundly affect many aspects of mammalian reproduction and stress physiology, but little is known about how immune function is affected by rank and other socio-ecological factors in free-living animals.In this study we examine the effects of sex, social rank, and reproductive status on immune function in long-lived carnivores that are routinely exposed to a plethora of pathogens, yet rarely show signs of disease.Here we show that two types of immune defenses, complement-mediated bacterial killing capacity (BKC) and total IgM, are positively correlated with social rank in wild hyenas, but that a third type, total IgG, does not vary with rank.Female spotted hyenas, which are socially dominant to males in this species, have higher BKC, and higher IgG and IgM concentrations, than do males.Immune defenses are lower in lactating than pregnant females, suggesting the immune defenses may be energetically costly.Serum cortisol and testosterone concentrations are not reliable predictors of basic immune defenses in wild female spotted hyenas.These results suggest that immune defenses are costly and multiple socioecological variables are important determinants of basic immune defenses among wild hyenas. Effects of these variables should be accounted for when attempting to understand disease ecology and immune function. PMID:27833242
Savabieasfahani, Mozhgan; Lee, James S; Herkimer, Carol; Sharma, Tejinder P; Foster, Douglas L; Padmanabhan, Vasantha
2005-01-01
Prenatal exposure of the female sheep to excess testosterone (T) leads to hypergonadotropism, multifollicular ovaries, and progressive loss of reproductive cycles. We have determined that prenatal T treatment delays the latency of the estradiol (E2)-induced LH surge. To extend this finding into a natural physiological context, the present study was conducted to determine if the malprogrammed surge mechanism alters the reproductive cycle. Specifically, we wished to determine if prenatal T treatment 1) delays the onset of the preovulatory gonadotropin surge during the natural follicular phase rise in E2, 2) alters pulsatile LH secretion and the dynamics of the secondary FSH surge, and 3) compromises the ensuing luteal function. Females prenatally T-treated from Day 60 to Day 90 of gestation (147 days is term) and control females were studied when they were approximately 2.5 yr of age. Reproductive cycles of control and prenatally T-treated females were synchronized with PGF2alpha, and peripheral blood samples were collected every 2 h for 120 h to characterize cyclic changes in E2, LH, and FSH and then daily for 14 days to monitor changes in luteal progesterone. To assess LH pulse patterns, blood samples were also collected frequently (each 5 min for 6 h) during the follicular and luteal phases of the cycle. The results revealed that, in prenatally T-treated females, 1) the preovulatory increase in E2 was normal; 2) the latencies between the preovulatory increase in E2 and the peaks of the primary LH and FSH surges were longer, but the magnitudes similar; 3) follicular-phase LH pulse frequency was increased; 4) the interval between the primary and secondary FSH surges was reduced but there was a tendency for an increase in duration of the secondary FSH surge; but 5) luteal progesterone patterns were in general unaltered. Thus, exposure of the female to excess T before birth produces perturbances and maltiming in periovulatory gonadotropin secretory dynamics, but these do not produce apparent defects in cycle regularity or luteal function. To reveal the pathologies that lead to the eventual subfertility arising from excess T exposure during midgestation, studies at older ages must be conducted to assess if there is progressive disruption of neuroendocrine and ovarian function.
Park, Sun-Ji; Kim, Tae-Shin; Kim, Jin-Man; Chang, Kyu-Tae; Lee, Hyun-Shik; Lee, Dong-Seok
2015-12-01
Superovulation induced by exogenous gonadotropin treatment (PMSG/hCG) increases the number of available oocytes in humans and animals. However, Superovulatory PMSG/hCG treatment is known to affect maternal environment, and these effects may result from PMSG/hCG treatment-induced oxidative stress. 2-Cys peroxiredoxins (2-Cys Prxs) act as antioxidant enzymes that protect cells from oxidative stress induced by various exogenous stimuli. Therefore, the objective of this study was to test the hypothesis that repeated PMSG/hCG treatment induces 2-Cys Prx expression and overoxidation in the reproductive tracts of female mice. Immunohistochemistry and western blotting analyses further demonstrated that, after PMSG/hCG treatment, the protein expression levels of 2-Cys Prxs increased most significantly in the ovaries, while that of Prx1 was most affected by PMSG/hCG stimulation in all tissues of the female reproductive tract. Repeated PMSG/hCG treatment eventually leads to 2-Cys Prxs overoxidation in all reproductive organs of female mice, and the abundance of the 2-Cys Prxs-SO2/3 proteins reported here supports the hypothesis that repeated superovulation induces strong oxidative stress and damage to the female reproductive tract. Our data suggest that excessive oxidative stress caused by repeated PMSG/hCG stimulation increases 2-Cys Prxs expression and overoxidation in the female reproductive organs. Intracellular 2-Cys Prx therefore plays an important role in maintaining the reproductive organ environment of female mice upon exogenous gonadotropin treatment.
Oktem, Ozgur; Guzel, Yılmaz; Aksoy, Senai; Aydin, Elvin; Urman, Bulent
2015-03-01
Systemic lupus erythematosus (SLE) is a chronic autoimmune systemic disease that mainly affects women of reproductive age. Emerging data from recent molecular studies show us that estrogen hormone plays a central role in the development of this disease. By acting via its cognate receptors ERα and ERβ expressed on immune cells, estrogen can modulate immune function in both the innate and adaptive immune responses. Interestingly, estrogen may also evoke autoimmune responses after binding to B lymphocytes leading to the generation of high-affinity autoantibodies and proinflammatory cytokines (so-called estrogen-induced autoimmunity). Unfortunately, reproductive function of young female patients with this disease is commonly compromised by different pathophysiologic processes. First, ovarian reserve is diminished even in the presence of mild disease suggesting a direct impact of the disease itself on ovarian function possibly due to ovarian involvement in the form of autoimmune oophoritis. Second, SLE patients with severe manifestations of the disease are treated with alkylating chemotherapy agent cyclophosphamide. Cyclophosphamide and other drugs of alkylating category have the highest gonadotoxicity. Therefore, SLE patients exposed to cyclophosphamide have a much higher risk of developing infertility and premature ovarian failure than do the counterparts who are treated with other less toxic treatments. Third, the functions of the hypothalamic pituitary ovarian axis are perturbed by chronic inflammatory state. And finally adverse pregnancy outcomes are more commonly observed in SLE patients such as fetal loss, preterm birth, intrauterine fetal growth restriction, preeclampsia-eclampsia, and fetal congenital heart block. We aimed in this review article to provide the readers an update on how estrogen hormone closely interacts with and induces lupus-prone changes in the immune system. We also discuss ovarian function and other reproductive outcomes in SLE patients and the current strategies to preserve their fertility in the light of the most recent evidence-based findings of the clinical trials and molecular studies.
To feed or to breed: morphological constraints of mouthbrooding in coral reef cardinalfishes
Hoey, Andrew S.; Bellwood, David R.; Barnett, Adam
2012-01-01
Functionally coupled biomechanical systems are widespread in nature and are viewed as major constraints on evolutionary diversification, yet there have been few attempts to explore the implications of performing multiple functions within a single anatomical structure. Paternally mouthbrooding cardinalfishes present an ideal system to investigate the constraints of functional coupling as the oral jaws of male fishes are directly responsible for both feeding and reproductive functions. To test the effects of (i) mouthbrooding on feeding and (ii) feeding on reproductive potential we compared the feeding apparatus between sexes of nine species of cardinalfish and compared brood characteristics among species from different trophic groups, respectively. Mouthbrooding was strongly associated with the morphology of the feeding apparatus in males. Male cardinalfishes possessed longer heads, snouts and jaws than female conspecifics irrespective of body size, trophic group or evolutionary history. Conversely, reproductive potential also appeared to be related to trophic morphology. Piscivorous cardinalfishes produced larger, but fewer eggs, and had smaller brood volumes than species from the two invertebrate feeding groups. These interrelationships suggest that feeding and reproduction in the mouth of cardinalfishes may be tightly coupled. If so this may, in part, have contributed to the limited morphological diversification exhibited by cardinalfishes. PMID:22319124
To feed or to breed: morphological constraints of mouthbrooding in coral reef cardinalfishes.
Hoey, Andrew S; Bellwood, David R; Barnett, Adam
2012-06-22
Functionally coupled biomechanical systems are widespread in nature and are viewed as major constraints on evolutionary diversification, yet there have been few attempts to explore the implications of performing multiple functions within a single anatomical structure. Paternally mouthbrooding cardinalfishes present an ideal system to investigate the constraints of functional coupling as the oral jaws of male fishes are directly responsible for both feeding and reproductive functions. To test the effects of (i) mouthbrooding on feeding and (ii) feeding on reproductive potential we compared the feeding apparatus between sexes of nine species of cardinalfish and compared brood characteristics among species from different trophic groups, respectively. Mouthbrooding was strongly associated with the morphology of the feeding apparatus in males. Male cardinalfishes possessed longer heads, snouts and jaws than female conspecifics irrespective of body size, trophic group or evolutionary history. Conversely, reproductive potential also appeared to be related to trophic morphology. Piscivorous cardinalfishes produced larger, but fewer eggs, and had smaller brood volumes than species from the two invertebrate feeding groups. These interrelationships suggest that feeding and reproduction in the mouth of cardinalfishes may be tightly coupled. If so this may, in part, have contributed to the limited morphological diversification exhibited by cardinalfishes.
Post-copulatory sexual selection and female fitness in Scathophaga stercoraria.
Martin, Oliver Y; Hosken, David J; Ward, Paul I
2004-02-22
Whether sexual selection increases or decreases female fitness is determined by the occurrence and relative importance of sexual-conflict processes and the ability of females to choose high-quality males. Experimentally enforced polyandry and monogamy have previously been shown to cause rapid evolution in the yellow dung fly Scathophaga stercoraria. Flies from polyandrous lines invested more in reproductive tissue, and this investment influenced paternity in sperm competition, but came at a cost to immune function. While some fitness consequences of enforced polyandry or monogamy have been examined when flies mate multiply, the consequences for female fitness when singly copulated remain unexplored. Under a good-genes scenario females from polyandrous lines should be of higher general quality and should outperform females from monogamous lines even with a single copulation. Under sexual conflict, costly adaptations will afford no advantages when females are allowed to mate only once. We investigate the lifetime reproductive success and longevity of females evolving under enforced monogamy or polyandry when mating once with males from these selection regimes. Females from polyandrous lines were found to have lower fitness than their monogamous counterparts when mating once. They died earlier and produced significantly fewer eggs and offspring. These results suggest that sexual conflict probably drove evolution under enforced polyandry as female fitness did not increase overall as expected with purely good-genes effects.
Austen, Emily J; Weis, Arthur E
2014-07-01
Adaptive explanations for variation in sex allocation centre on variation in resource status and variation in the mating environment. The latter can occur when dichogamy causes siring opportunity to vary across the flowering season. In this study, it is hypothesized that the widespread tendency towards declining fruit-set from first to last flowers on plants can similarly lead to a varying mating environment by causing a temporal shift in the quality (not quantity) of siring opportunities. A numerical model was developed to examine the effects of declining fruit-set on the expected male versus female reproductive success (functional gender) of first and last flowers on plants, and of early- and late-flowering plants. Within- and among-plant temporal variation in pollen production, ovule production and fruit-set in 70 Brassica rapa plants was then characterized to determine if trends in male and female investment mirror expected trends in functional gender. Under a wide range of model conditions, functional femaleness decreased sharply in the last flowers on plants, and increased from early- to late-flowering plants in the population. In B. rapa, pollen production decreased more rapidly than ovule production from first to last flowers, leading to a within-plant increase in phenotypic femaleness. Among plants, ovule production decreased from early- to late-flowering plants, causing a temporal decrease in phenotypic femaleness. The numerical model confirmed that declining fruit-set can drive temporal variation in functional gender, especially among plants. The discrepancy between observed trends in phenotypic gender in B. rapa and expected functional gender predicted by the numerical model does not rule out the possibility that male reproductive success decreases with later flowering onset. If so, plants may experience selection for early flowering through male fitness. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Overbeek, Annelies; van den Berg, Marleen H; Kremer, Leontien C M; van den Heuvel-Eibrink, Marry M; Tissing, Wim J E; Loonen, Jacqueline J; Versluys, Birgitta; Bresters, Dorine; Kaspers, Gertjan J L; Lambalk, Cornelis B; van Leeuwen, Flora E; van Dulmen-den Broeder, Eline
2012-08-23
Advances in childhood cancer treatment over the past decades have significantly improved survival, resulting in a rapidly growing group of survivors. However, both chemo- and radiotherapy may adversely affect reproductive function. This paper describes the design and encountered methodological challenges of a nationwide study in the Netherlands investigating the effects of treatment on reproductive function, ovarian reserve, premature menopause and pregnancy outcomes in female childhood cancer survivors (CCS), the DCOG LATER-VEVO study. The study is a retrospective cohort study consisting of two parts: a questionnaire assessing medical, menstrual, and obstetric history, and a clinical assessment evaluating ovarian and uterine function by hormonal analyses and transvaginal ultrasound measurements. The eligible study population consists of adult female 5-year survivors of childhood cancer treated in the Netherlands, whereas the control group consists of age-matched sisters of the participating CCS. To date, study invitations have been sent to 1611 CCS and 429 sister controls, of which 1215 (75%) and 333 (78%) have responded so far. Of these responders, the majority consented to participate in both parts of the study (53% vs. 65% for CCS and sister controls respectively). Several challenges were encountered involving the study population: dealing with bias due to the differences in characteristics of several types of (non-) participants and finding an adequately sized and well-matched control group. Moreover, the challenges related to the data collection process included: differences in response rates between web-based and paper-based questionnaires, validity of self-reported outcomes, interpretation of clinical measurements of women using hormonal contraceptives, and inter- and intra-observer variation of the ultrasound measurements. The DCOG LATER-VEVO study will provide valuable information about the reproductive potential of paediatric cancer patients as well as long-term survivors of childhood cancer. Other investigators planning to conduct large cohort studies on late effects may encounter similar challenges as those encountered during this study. The solutions to these challenges described in this paper may be useful to these investigators. NTR2922; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2922
Laron, Zvi
2006-01-01
Laron syndrome (LS) or primary GH insensitivity is a unique human model to study the effects of congenital IGF-I deficiency. Within our cohort of 63 patients with LS, 15 female patients were regularly followed since birth or infancy, throughout puberty. We observed that they were short at birth, with small genitalia and gonads -- during puberty, developed delayed puberty but eventually reached between 16 and 19 1/2 years full sexual development. Reproduction is unaffected at a young adult age. It is concluded that IGF-I in concert with the sex hormones has a modulatory but not essential function on female sexual development and maturation.
Environmental factors, epigenetics, and developmental origin of reproductive disorders.
Ho, Shuk-Mei; Cheong, Ana; Adgent, Margaret A; Veevers, Jennifer; Suen, Alisa A; Tam, Neville N C; Leung, Yuet-Kin; Jefferson, Wendy N; Williams, Carmen J
2017-03-01
Sex-specific differentiation, development, and function of the reproductive system are largely dependent on steroid hormones. For this reason, developmental exposure to estrogenic and anti-androgenic endocrine disrupting chemicals (EDCs) is associated with reproductive dysfunction in adulthood. Human data in support of "Developmental Origins of Health and Disease" (DOHaD) comes from multigenerational studies on offspring of diethylstilbestrol-exposed mothers/grandmothers. Animal data indicate that ovarian reserve, female cycling, adult uterine abnormalities, sperm quality, prostate disease, and mating behavior are susceptible to DOHaD effects induced by EDCs such as bisphenol A, genistein, diethylstilbestrol, p,p'-dichlorodiphenyl-dichloroethylene, phthalates, and polyaromatic hydrocarbons. Mechanisms underlying these EDC effects include direct mimicry of sex steroids or morphogens and interference with epigenomic sculpting during cell and tissue differentiation. Exposure to EDCs is associated with abnormal DNA methylation and other epigenetic modifications, as well as altered expression of genes important for development and function of reproductive tissues. Here we review the literature exploring the connections between developmental exposure to EDCs and adult reproductive dysfunction, and the mechanisms underlying these effects. Copyright © 2016 Elsevier Inc. All rights reserved.
Environmental Factors, Epigenetics, and Developmental Origin of Reproductive Disorders
Ho, Shuk-Mei; Cheong, Ana; Adgent, Margaret A.; Veevers, Jennifer; Suen, Alisa A.; Tam, Neville N.C.; Leung, Yuet-Kin; Jefferson, Wendy N.; Williams, Carmen J.
2016-01-01
Sex-specific differentiation, development, and function of the reproductive system are largely dependent on steroid hormones. For this reason, developmental exposure to estrogenic and anti-androgenic endocrine disrupting chemicals (EDCs) is associated with reproductive dysfunction in adulthood. Human data in support of “Developmental Origins of Health and Disease” (DOHaD) comes from multigenerational studies on offspring of diethylstilbestrol-exposed mothers/grandmothers. Animal data indicate that ovarian reserve, female cycling, adult uterine abnormalities, sperm quality, prostate disease, and mating behavior are susceptible to DOHaD effects induced by EDCs such as bisphenol A, genistein, diethylstilbestrol, p,p′-dichlorodiphenyl-dichloroethylene, phthalates, and polyaromatic hydrocarbons. Mechanisms underlying these EDC effects include direct mimicry of sex steroids or morphogens and interference with epigenomic sculpting during cell and tissue differentiation. Exposure to EDCs is associated with abnormal DNA methylation and other epigenetic modifications, as well as altered expression of genes important for development and function of reproductive tissues. Here we review the literature exploring the connections between developmental exposure to EDCs and adult reproductive dysfunction, and the mechanisms underlying these effects. PMID:27421580
Maffucci, Jacqueline A.; Gore, Andrea C.
2009-01-01
The hypothalamic-pituitary-gonadal (HPG) axis undergoes a number of changes throughout the reproductive life cycle that are responsible for the development, puberty, adulthood, and senescence of reproductive systems. This natural progression is dictated by the neural network controlling the hypothalamus including the cells that synthesize and release gonadotropin-releasing hormone (GnRH) and their regulatory neurotransmitters. Glutamate and GABA are the primary excitatory and inhibitory neurotransmitters in the central nervous system, and as such contribute a great deal to modulating this axis throughout the lifetime via their actions on receptors in the hypothalamus, both directly on GnRH neurons as well as indirectly though other hypothalamic neural networks. Interactions among GnRH neurons, glutamate, and GABA, including the regulation of GnRH gene and protein expression, hormone release, and modulation by estrogen, are critical to age-appropriate changes in reproductive function. Here, we present evidence for the modulation of GnRH neurosecretory cells by the balance of glutamate and GABA in the hypothalamus, and the functional consequences of these interactions on reproductive physiology across the life cycle. PMID:19349036
Tissue distribution and functional analysis of vitellogenin-6 of Toxocara canis.
Zhu, Hong-Hong; Ma, Guang-Xu; Luo, Yong-Fang; Luo, Yong-Li; Yin, Sha-Sha; Xiong, Yi; Zhou, Rong-Qiong
2017-06-01
Toxocara canis is an common intestinal nematode of canids and the principal causative agent of human toxocariasis. Vitellogenin (Vg), a source of amino acids and lipids in the eggs, are considered to play an important role in embryo development of a wide range of organisms. In the present study, the transcriptional levels of Tc-vit-6 gene in male and female adult T. canis were determined by quantitative real-time PCR, which indicated high transcription of Tc-vit-6 in the intestine, reproductive tract and body wall of male and female adult T. canis. The fragment of Tc-vit-6 encoding a vWD domain, was cloned and expressed to produce a rabbit anti-TcvWD polyclonal antibody. Tissue distribution of TcVg6 was detected by immunohistochemical assays, which showed predominant distribution of TcVg6 in the tissues of intestine, as well as reproductive tract (including some of the germ cells) and musculature of male and female adult worms. Collectively, these results indicated multiple biological roles of TcVg6 apart from that in the reproduction of T. canis. Copyright © 2017 Elsevier Inc. All rights reserved.
Luo, Yong-Li; Ma, Guang-Xu; Luo, Yong-Fang; Kuang, Ce-Yan; Jiang, Ai-Yun; Li, Guo-Qing; Zhou, Rong-Qiong
2018-03-01
Toxocara canis is a zoonotic parasite with worldwide distribution. ATP-binding cassette (ABC) transporters are integral membrane proteins which involve in a range of biological processes in various organisms. In present study, the full-length coding sequence of abcg-5 gene of T. canis (Tc-abcg-5) was cloned and characterized. A 633 aa polypeptide containing two conserved Walker A and Walker B motifs was predicted from a continuous 1902 nt open reading frame. Quantitative real-time PCR was employed to determine the transcriptional levels of Tc-abcg-5 gene in adult male and female worms, which indicated high mRNA level of Tc-abcg-5 in the reproductive tract of adult female T. canis. Tc-abcg-5 was expressed to produce rabbit polyclonal antiserum against recombinant TcABCG5. Indirect-fluorescence immunohistochemical assays were carried out to detect the tissue distribution of TcABCG5, which showed predominant distribution of TcABCG5 in the uterus (especially in the germ cells) of adult female T. canis. Tissue transcription and expression pattern of Tc-abcg-5 indicated that Tc-abcg-5 might play essential roles in the reproduction of this parasitic nematode.
Advances in human reproductive ecology.
Ellison, P T
1994-01-01
Human reproductive ecology pertains to reproduction biology and changes due to environmental influences. The research literature relies on clinical, epidemiological, and demographic analysis. The emphasis is on normal, nonpathological states and a broad range of ecological conditions. This review focused on the importance of age and energetic stress from ecological conditions rather than dieting or self-directed exercise in changing female fecundity. The literature on male reproductive ecology is still small but growing. J.W. Wood provided a comprehensive overview of the field. Natural fertility, as defined by Henry, is the lack of parity-specific fertility limitation. There is evidence that fertility can vary widely in natural fertility populations. There are consistent age patterns among different natural fertility populations. Doring found that there was higher frequency of anovulatory and luteal insufficiency in cycles during perimenarche and perimenopausal periods. Infertility studies have shown declines in pregnancy rates in women over the age of 30 years. Ovum donation evaluations have found both uterine age and ovarian and oocyte age to be related to the probability of a successful pregnancy. Basal follicle stimulating hormone and the endometrial thickness are important predictors of ovarian capacity and related to age and declining fecundity. Much of the literature on fecundity is derived from women with impaired reproductive physiology. In Lipson and Ellison's study of healthy women, average follicular and average luteal estradiol values declined with increasing subject age. Low follicular levels were correlated with smaller follicular size, low oocyte fertilizability, reduced endometrial thickness, and low pregnancy rates. Comparisons across populations have shown that populations experience declines in luteal function with age, but levels of luteal functions varied widely. Chronic conditions which slow growth and delay reproductive maturation may impact on lower ovarian function throughout adult life. There is a range of ovarian function along a continuum due to energetic stress. Evidence from the Lese in Zaire, the Tamang of Nepal, and Polish farm women outside Crakow suggest that workload affects ovarian function. Luteal function and ovulatory frequency is lower when women are losing weight. Among the Tamang losing weight between seasons there was evidence of lower ovarian function during the monsoon season. Polish farm women who work very hard in summer had lower ovarian function. The effect of lactation on amenorrhea appears to be due to the energetic stress on the mother in the intensity and duration of suckling. Women in poorer nutritional status may require more intense suckling. Seasonality of energy balance may be related to seasonality of female fecundity and conceptions.
Reproduction reduces photosynthetic capacity in females of the subdioecious Honckenya peploides
NASA Astrophysics Data System (ADS)
Sánchez-Vilas, Julia; Retuerto, Rubén
2011-03-01
As a consequence of the different reproductive functions performed by the sexes, sexually dimorphic/polymorphic plants may exhibit gender-related variations in the energy and resources allocated to reproduction, and in the physiological processes that underlie these differences. This study investigated whether the sexes of the subdioecious plant Honckenya peploides differ in ecophysiological traits related to photosynthetic capacity and whether possible differences depend on reproductive status and on the plant's position (edge or centre) in the population. We registered in three sites in NW Spain, the sex and density of shoots of two segregated clumps of plants. These clumps represent an extreme case of sex-ratio variation across space, with separated single-sex clumps of plants. In two of these sites we measured photosynthetic efficiencies, chlorophyll content, and specific leaf areas. In females, reproduction reduced photochemical efficiency, chlorophyll content and increased the specific leaf area, which is a key leaf trait related to photosynthetic capacity. In males, no differences due to reproduction were detected. The position within the clump affected the specific leaf area of the shoots, with shoots growing at the edge having the lowest values, regardless of the sex. Finally, the effects of position in photosynthetic efficiency and chlorophyll content where highly variable among clumps. We conclude that the differential effects of reproduction on sexes may entail different costs that could be crucial in the outcome of interactions between them, contributing to their spatial segregation.
Effects of plant sex on range distributions and allocation to reproduction.
Johnson, Marc T J; Smith, Stacey D; Rausher, Mark D
2010-05-01
Despite an abundance of theory, few empirical studies have explored the ecological and evolutionary consequences of sex. We used a comparative phylogenetic approach to examine whether transitions between sexual and asexual reproduction are associated with changes in the size and distribution of species' geographical ranges, and their investment in reproduction. Here, we reconstructed the phylogeny of the genus Oenothera sections Oenothera and Calylophus (Onagraceae), which contain 35 sexual and 30 functionally asexual species. From each species, we collected data on the geographical distribution and variation in plant traits related to reproduction. Functionally asexual species occurred at higher latitudes, but did not differ in range size, compared with sexual species. Transitions to asexuality were associated with decreased investment in floral structures, including the length of petals, floral tubes and styles. Decreased anther size and increased seed size within asexual species also suggest altered allocation to male and female fitness. The observed range shifts are consistent with superior colonization of environments by asexual species following glaciation, and the observed changes in reproductive allocation support predictions made by models relating to the evolution of selfing. Our results suggest that the evolutionary consequences of asexual reproduction might be less restrictive than previously thought.
2012-01-01
Background Sexual reproduction is common in eukaryotic microorganisms, with few species reproducing exclusively asexually. However, in some organisms, such as fungi, asexual reproduction alternates with episodic sexual reproduction events. Fungi are thus appropriate organisms for studies of the reasons for the selection of sexuality or clonality and of the mechanisms underlying this selection. Magnaporthe oryzae, an Ascomycete causing blast disease on rice, reproduces mostly asexually in natura. Sexual reproduction is possible in vitro and requires (i) two strains of opposite mating types including (ii) at least one female-fertile strain (i.e. a strain able to produce perithecia, the female organs in which meiosis occurs). Female-fertile strains are found only in limited areas of Asia, in which evidence for contemporary recombination has recently been obtained. We induced the forced evolution of four Chinese female-fertile strains in vitro by the weekly transfer of asexual spores (conidia) between Petri dishes. We aimed to determine whether female fertility was rapidly lost in the absence of sexual reproduction and whether this loss was controlled genetically or epigenetically. Results All the strains became female-sterile after 10 to 19 rounds of selection under asexual conditions. As no single-spore isolation was carried out, the observed decrease in the production of perithecia reflected the emergence and the invasion of female-sterile mutants. The female-sterile phenotype segregated in the offspring of crosses between female-sterile evolved strains and female-fertile wild-type strains. This segregation was maintained in the second generation in backcrosses. Female-sterile evolved strains were subjected to several stresses, but none induced the restoration of female fertility. This loss of fertility was therefore probably due to genetic rather than epigenetic mechanisms. In competition experiments, female-sterile mutants produced similar numbers of viable conidia to wild-type strains, but released them more efficiently. This advantage may account for the invasion of our populations by female-sterile mutants. Conclusions We show for the first time that, in the absence of sexual reproduction, female-sterile mutants of M. oryzae rice strains can arise and increase in abundance in asexual generations. This change in phenotype was frequent and probably caused by mutation. These results suggest that female fertility may have been lost rapidly during the dispersion of the fungus from Asia to the rest of the world. PMID:22458778
Gobush, K S; Mutayoba, B M; Wasser, S K
2008-12-01
Widespread poaching prior to the 1989 ivory ban greatly altered the demographic structure of matrilineal African elephant (Loxodonta africana) family groups in many populations by decreasing the number of old, adult females. We assessed the long-term impacts of poaching by investigating genetic, physiological, and reproductive correlates of a disturbed social structure resulting from heavy poaching of an African elephant population in Mikumi National Park, Tanzania, prior to 1989. We examined fecal glucocorticoid levels and reproductive output among 218 adult female elephants from 109 groups differing in size, age structure, and average genetic relatedness over 25 months from 2003 to 2005. The distribution in group size has changed little since 1989, but the number of families with tusked old matriarchs has increased by 14.2%. Females from groups that lacked an old matriarch, first-order adult relatives, and strong social bonds had significantly higher fecal glucocorticoid values than those from groups with these features (all females R(2)= 0.31; females in multiadult groups R(2)= 0.46). Females that frequented isolated areas with historically high poaching risk had higher fecal glucocorticoid values than those in low poaching risk areas. Females with weak bonds and low group relatedness had significantly lower reproductive output (R(2)[U]=0.21). Females from disrupted groups, defined as having observed average group relatedness 1 SD below the expected mean for a simulated unpoached family, had significantly lower reproductive output than females from intact groups, despite many being in their reproductive prime. These results suggest that long-term negative impacts from poaching of old, related matriarchs have persisted among adult female elephants 1.5 decades after the 1989 ivory ban was implemented.
The function of multiple ejaculations in bitterling.
Smith, C; Warren, M; Rouchet, R; Reichard, M
2014-09-01
In some taxa, males perform multiple ejaculations, which may function in sperm competition or in maintaining a baseline density of spermatozoa in the female reproductive tract to ensure fertilization, a process that has been termed 'topping up'. We investigated the function of multiple ejaculations in two species of bitterling, the European bitterling (Rhodeus amarus) and Chinese rose bitterling (Rhodeus ocellatus). Bitterling oviposit in living freshwater mussels, with fertilization taking place within the mussel gill cavity. Thus, although fertilization is external, the mussel is analogous to the female reproductive tract in an internally fertilizing species. We measured the frequency of ejaculations and mussel inspections by individual males of two bitterling species in 28 replicated mesocosms and examined focal male responses to rival ejaculations and the presence of females in spawning condition. We used a model of ejaculatory behaviour to simulate the temporal abundance of spermatozoa in mussels. Male R. amarus exhibited high rates of ejaculation and inspection of the siphons of mussels and increased their ejaculation rate in response to the presence of females in spawning condition. Rhodeus ocellatus showed lower overall rates of ejaculation, but significantly elevated ejaculation rate in response to rival ejaculations. The ejaculatory strategy of R. amarus is one that maintains a minimum level of spermatozoa in mussels, which is elevated when the probability of oviposition increases. In contrast, R. ocellatus engages more directly in sperm competition with rivals. We discuss these results in the context of the function of multiple ejaculations and male mating tactics. © 2014 The Authors. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.
Govindaraj, Vijayakumar; Shridharan, Radhika Nagamangalam; Rao, Addicam Jagannadha
2018-05-16
Although neonatal exposure to estrogen or estrogenic compounds results in irreversible changes in the brain function and reproductive abnormalities during adulthood but the underlying mechanisms are still largely unknown. The present study has attempted to compare the protein profiles of sexually dimorphic brain regions of adult female rats which were exposed to estradiol- 17β during neonatal period. The total proteins extracted from pre-optic area (POA), hypothalamus, hippocampus and pituitary of control and neonatally E2 treated female rats was subjected to 2D-SDS-PAGE and differentially expressed proteins were identified by MALDI TOF/TOF-MS. Our results revealed that a total of 21 protein spots which were identified as differentially expressed in all the four regions analyzed; the differential expression was further validated by RT-PCR and western blotting. The differentially expressed proteins such as 14-3-3 zeta/delta (POA), LMNA (hippocampus), Axin2 (hypothalamus), Syntaxin-7 (hippocampus), prolactin and somatotropin (pituitary) which have very important functions in the process of neuronal differentiation, migration, axon outgrowth, formation of dendritic spine density and synaptic plasticity and memory have not been previously reported in association with neonatal estrogen exposure. The affected brain functions are very important for the establishment of sex specific brain morphology and behavior. Our results suggest that the differentially expressed proteins may play an important role in irreversible changes in the brain function as well as reproductive abnormalities observed in the female rats during adulthood. Copyright © 2018 Elsevier Inc. All rights reserved.
The impact of female reproductive function on outcomes after traumatic brain injury.
Ripley, David L; Harrison-Felix, Cindy; Sendroy-Terrill, Melissa; Cusick, Christopher P; Dannels-McClure, Amy; Morey, Clare
2008-06-01
To determine the impact of traumatic brain injury (TBI) on female menstrual and reproductive functioning and to examine the relationships between severity of injury, duration of amenorrhea, and TBI outcomes. Retrospective cohort survey. Telephone interview. Women (N=30; age range, 18-45y), between 1 and 3 years postinjury, who had completed inpatient rehabilitation for TBI. Not applicable. Data collected included menstrual and reproductive functioning pre- and postinjury, demographic, and injury characteristics. Outcome measures included the Glasgow Outcome Scale-Extended (GOS-E), the Mayo-Portland Adaptability Inventory-4 (MPAI-4), and the Medical Outcome Study 12-Item Short-Form Health Survey, Version 2 (SF-12v2). The median duration of amenorrhea was 61 days (range, 20-344d). Many subjects' menstrual function changed after TBI, reporting a significant increase in skipped menses postinjury (P<.001) and a trend toward more painful menses (P=.061). More severe TBI, as measured by the duration of posttraumatic amnesia, was significantly predictive of a longer duration of amenorrhea (P=.004). Subjects with a shorter duration of amenorrhea scored significantly better on the SF-12 physical component subscale (P=.004), the GOS-E (P=.05), and the MPAI-4 participation subscale (P=.05) after controlling for age, injury severity, and time postinjury. The severity of TBI was predictive of duration of amenorrhea and a shorter duration of amenorrhea was predictive of better ratings of global outcome, community participation, and health-related quality of life postinjury.
The long-term effects of the Holocaust on the reproductive function of female survivors.
Pasternak, Alfred; Brooks, Philip G
2007-01-01
The aim of this study was to evaluate the effect of internment in the German concentration camps during World War II on menstrual function; future fertility; and, ultimately, on gynecologic diseases or future surgery needs. Five hundred eighty Hungarian female survivors of concentration camps. Menstrual and reproductive histories of the women were obtained and analyzed, comparing histories and events from pre-internment, internment, and post-internment periods of time. The mean age of the survivors at the time of internment was 23.4 +/- 8.0 years (95% CI 22.7-24.1). Amenorrhea occurred in 94.8% of the women during encampment (95% CI 92.7%-96.5%), with 82.4% experiencing cessation of menses immediately after internment (95% CI 76.9%-85.6%). Only 0.6% of women (95% CI 0.12%-1.63%) menstruated longer than 4 months after internment. After liberation, all but 8.9% of the women resumed menstruation within the first year (95% CI 88.4%-93.3%). Fecundity subsequent to liberation was not significantly affected by the imprisonment nor was there a significant increase in spontaneous abortion, ectopic pregnancies, stillbirths, or other pregnancy complications. Additionally, there was no evidence of impact on the subsequent frequency of gynecologic diseases or surgical procedures. Imprisonment in German concentration camps during the Holocaust resulted in enormous emotional and psychological changes in the survivors. In addition, this study reveals abrupt changes in short-term menstrual function but little long-term physical damage to reproductive function.
Disrupted kisspeptin signaling in GnRH neurons leads to hypogonadotrophic hypogonadism.
Novaira, Horacio J; Sonko, Momodou L; Hoffman, Gloria; Koo, Yongbum; Ko, Chemyong; Wolfe, Andrew; Radovick, Sally
2014-02-01
Landmark studies have shown that mutations in kisspeptin and the kisspeptin receptor (Kiss1r) result in reproductive dysfunction in humans and genetically altered mouse models. However, because kisspeptin and its receptor are present in target cells of the central and peripheral reproductive axis, the precise location(s) for the pathogenic signal is unknown. The study described herein shows that the kisspeptin-Kiss1r signaling pathway in the GnRH neuron is singularly critical for both the onset of puberty as well as the attainment of normal reproductive function. In this study, we directly test the hypothesis that kisspeptin neurons regulate GnRH secretion through the activation of Kiss1r on the plasma membrane of GnRH neurons. A GnRH neuron-specific Kiss1r knockout mouse model (GKirKO) was generated, and reproductive development and phenotype were assessed. Both female and male GKirKO mice were infertile, having low serum LH and FSH levels. External abnormalities such as microphallus and decreased anogenital distance associated with failure of preputial gland separation were present in GKirKO males. A delay in pubertal onset and abnormal estrous cyclicity were observed in female GKirKO mice. Taken together, these data provide in vivo evidence that Kiss1r in GnRH neurons is critical for reproductive development and fertility.
Sodium fluoride adversely affects ovarian development and reproduction in Drosophila melanogaster.
Khatun, Salma; Rajak, Prem; Dutta, Moumita; Roy, Sumedha
2017-11-01
The study demonstrates the effects of chronic sub-lethal exposure of sodium fluoride (NaF) on reproductive structure and function of female Drosophila melanogaster. As a part of treatment, flies were maintained in food supplemented with sub-lethal concentrations of NaF (10-100 μg/mL). Fecundity, ovarian morphology, presence and profusion of viable cells from ovary and fat body were taken into consideration for evaluating changes in reproductive homeostasis. Wing length (a factor demonstrating body size and reproductive fitness) was also monitored after NaF exposure. Significant reduction in fecundity, alteration in ovarian morphology along with an increase in apoptosis was observed in treated females. Simultaneous decline in viable cell number and larval weight validates the result of MTT assay. Furthermore, altered ovarian Glucose-6-phosphate dehydrogenase and catalase activities together with increased rate of lipid peroxidation after 20 and 40 μg/mL NaF exposure confirmed the changes in reproduction related metabolism. Enhanced lipid peroxidation known for ROS generation might have induced genotoxicity which is confirmed through Comet assay. The enzyme activities were not dose dependent, rather manifested a bimodal response, which suggests a well-knit interaction among the players inducing stress and the ones that help establish physiological homeostasis. Copyright © 2017 Elsevier Ltd. All rights reserved.
Lourdais, Olivier; Lorioux, Sophie; DeNardo, Dale F
2013-01-01
Females often manage the high energy demands associated with reproduction by accumulating and storing energy in the form of fat before initiating their reproductive effort. However, fat stores cannot satisfy all reproductive resource demands, which include considerable investment of amino acids (e.g., for the production of yolk proteins or gluconeogenesis). Because capital breeders generally do not eat during reproduction, these amino acids must come from internal resources, typically muscle proteins. Although the energetic costs of reproduction have been fairly well studied, there are limited data on structural and performance costs associated with the muscle degradation required to meet amino acid demands. Thus, we examined structural changes (epaxial muscle width) and performance costs (constriction and strength) over the course of reproduction in a pure capital breeder, the children's python (Antaresia childreni). We found that both egg production (i.e., direct resource allocation) and maternal care (egg brooding) induce muscle catabolism and affect performance of the female. Although epaxial muscle loss was minimal in nonreproductive females, it reached up to 22% (in females after oviposition) and 34% (in females after brooding) of initial muscle width. Interestingly, we found that individuals with higher initial muscular condition allocated more of their muscle into reproduction. The amount of muscle loss was significantly linked to clutch mass, underscoring the role of structural protein in egg production. Egg brooding significantly increased proteolysis and epaxial loss despite no direct allocation to the offspring. Muscle loss was linked to a significant reduction in performance in postreproductive females. Overall, these results demonstrate that capital-breeding females experience dramatic costs that consume structural resources and jeopardize performance.
Sifakis, Stavros; Androutsopoulos, Vasilis P; Tsatsakis, Aristeidis M; Spandidos, Demetrios A
2017-04-01
Endocrine disrupting chemicals (EDCs) comprise a group of chemical compounds that have been examined extensively due to the potential harmful effects in the health of human populations. During the past decades, particular focus has been given to the harmful effects of EDCs to the reproductive system. The estimation of human exposure to EDCs can be broadly categorized into occupational and environmental exposure, and has been a major challenge due to the structural diversity of the chemicals that are derived by many different sources at doses below the limit of detection used by conventional methodologies. Animal and in vitro studies have supported the conclusion that endocrine disrupting chemicals affect the hormone dependent pathways responsible for male and female gonadal development, either through direct interaction with hormone receptors or via epigenetic and cell-cycle regulatory modes of action. In human populations, the majority of the studies point towards an association between exposure to EDCs and male and/or female reproduction system disorders, such as infertility, endometriosis, breast cancer, testicular cancer, poor sperm quality and/or function. Despite promising discoveries, a causal relationship between the reproductive disorders and exposure to specific toxicants is yet to be established, due to the complexity of the clinical protocols used, the degree of occupational or environmental exposure, the determination of the variables measured and the sample size of the subjects examined. Future studies should focus on a uniform system of examining human populations with regard to the exposure to specific EDCs and the direct effect on the reproductive system. Copyright © 2017 Elsevier B.V. All rights reserved.
Reproductive alterations in hyperinsulinemic but normoandrogenic MSG obese female rats.
Gaspar, Renato Simões; Benevides, Renata Ohana Alves; Fontelles, João Lucas de Lima; Vale, Caroline Castro; França, Lucas Martins; Barros, Paulo de Tarso Silva; Paes, Antonio Marcus de Andrade
2016-05-01
Obesity and metabolic syndrome are the common causes of reproductive and fertility disorders in women. In particular, polycystic ovary syndrome, which is clinically characterized by hyperandrogenism, oligo/anovulation, and polycystic ovarian morphology, has been increasingly associated with metabolic disorders. However, given the broad interplay between metabolic and reproductive functions, this remains a field of intense research. In this study, we investigated the effect of monosodium l-glutamate (MSG)-induced obesity on reproductive biology of female rats. Newborn female rats were subcutaneously injected with MSG (4g/kg/day) or equiosmolar saline (CTR) each 2 days up to postnatal day (pnd) 10. On pnd 60, estrous cycle was evaluated using vaginal smears twice a day for 15 days, which showed MSG rats to be oligocyclic. Thereafter, animals were killed on estrous phase for blood and tissue collection. MSG rats had increased body mass, accumulation of retroperitoneal and visceral fat pads, and visceral adipocyte hypertrophy compared with CTR rats. MSG rats were also dyslipidemic and hyperinsulinemic but were normoglycemic and normoandrogenic. Ovarian morphology analysis showed that MSG rats had a two-fold decrease in oocyte count but a six-fold increase on ovarian follicular cysts, along with a higher number of total primordial and atretic follicles. Moreover, MSG rats had a four-fold increase in anti-Müllerian hormone immunohistochemical staining on antral follicles. Taken together, data presented here characterize MSG obesity as a unique model to study the metabolic pathways underlying reproductive disorders in the absence of overactivated hypothalamic-pituitary-gonadal axis. © 2016 Society for Endocrinology.
The impact of sex ratio and economic status on local birth rates.
Chipman, A; Morrison, E
2013-04-23
Human mating and reproductive behaviour can vary depending on various mechanisms, including the local sex ratio. Previous research shows that as sex ratios become female-biased, women from economically deprived areas are less likely to delay reproductive opportunities to wait for a high-investing mate but instead begin their reproductive careers sooner. Here, we show that the local sex ratio also has an impact on female fertility schedules. At young ages, a female-biased ratio is associated with higher birth rates in the poorest areas, whereas the opposite is true for the richest areas. At older ages, a female-biased ratio is associated with higher birth rates in the richest, but not the poorest areas. These patterns suggest that female-female competition encourages poorer women to adopt a fast life-history strategy and give birth early, and richer women to adopt a slow life-history strategy and delay reproduction.
de Resende, F C; Nascimento, L B
2015-06-01
Data on reproductive activity of fossorial species are limited because the specimens are difficult to be observed and captured. Here in, we present the reproductive cycle of female Atractus pantostictus, a fossorial neotropical species, and the sexual maturity of males and females in south-eastern Brazil. The female reproductive cycle of A. pantostictus is seasonal, with vitellogenic follicles being found from September to April and eggs in November, February, March and April with the number varying between two and four. Spermatozoa were found in the lumen of the glandular and non-glandular uterus in females collected during the rainy season. Sperm storage tubules were found in the posterior infundibulum of the females, where the storage of sperm occurs for a short time. The storage may occur because mating and ovulation are dissociated. © 2014 Blackwell Verlag GmbH.
Hinck, Jo Ellen; Papoulias, Diana M.; Annis, Mandy L.; Tillitt, Donald E.; Marr, Carrie; Denslow, Nancy D.; Kroll, Kevin J.; Nachtmann, Jason
2011-01-01
Population declines of the endangered razorback sucker Xyrauchen texanus in the Colorado River basin have been attributed to predation by and competition with nonnative fishes, habitat alteration, and dam construction. The reproductive health and seasonal variation of the reproductive end points of razorback sucker populations are currently unknown. Using nonlethal methods, we characterized the plasma hormonal fluctuations of reproductively mature female and male razorback suckers over a 12-month period in a hatchery by measuring their vitellogenin (VTG) and three sex hormones: 17β-estradiol (E2), testosterone (T), and 11-ketotestosterone (KT). Fish were identified as reproductive or nonreproductive based on their body weight, VTG, and sex hormone profiles. In reproductive females, the E2 concentration increased in the fall and winter, and increases in T and VTG concentrations were generally associated with the spawning period. Mean T concentrations were consistently greater in reproductive females than in nonreproductive females, but this pattern was even more pronounced during the spawning period (spring). Consistently low T concentrations (<3 ng/mL) in adult females during the spawning period may indicate reproductive impairment. In reproductive males, spring increases in KT and T concentrations were associated with spawning; concentrations of E2 (<0.48 ng/mL) and VTG (<0.001 mg/mL) were low in males throughout the study. In addition, the E2 : KT ratio and T were the best metrics by which to distinguish female from male adult razorback suckers throughout the year. These metrics of reproductive health and condition may be particularly important to recovery efforts of razorback suckers given that the few remaining wild populations are located in a river where water quality and quantity issues are well documented. In addition to the size, age, and recruitment information currently considered in the recovery goals of this endangered species, reproductive end points could be included as recovery metrics with which to monitor seasonal trends and determine whether repatriated populations are cycling naturally.
Zanchi-Silva, Djan; Borges-Nojosa, Diva M; Galdino, Conrado A B
2014-09-01
The reproductive ecology of Ameivula ocellifera was studied from September 2009 to August 2010 in a coastal area of the state of Ceará, Brazil. Females reproduced continuously throughout the year, with a peak at the end of the rainy season. Even though there was a predominance of pre-reproductive individuals in the sample, gonadal activity of males peaked synchronously to female reproduction. Mean clutch size was 1.98 ± 0.56 and positively associated with female body size, while mean egg volume was 510.54 ± 84.29 mm3 and unrelated to female body size. We did not find any association between clutch size and average egg volume.
A new role for bicarbonate secretion in cervico-uterine mucus release.
Muchekehu, Ruth W; Quinton, Paul M
2010-07-01
Cervical mucus thinning and release during the female reproductive cycle is thought to rely mainly on fluid secretion. However, we now find that mucus released from the murine reproductive tract critically depends upon concurrent bicarbonate (HCO(3)(-)) secretion. Prostaglandin E(2) (PGE(2))- and carbachol-stimulated mucus release was severely inhibited in the absence of serosal HCO(3)(-), HCO(3)(-) transport, or functional cystic fibrosis transmembrane conductance regulator (CFTR). In contrast to mucus release, PGE(2)- and carbachol-stimulated fluid secretion was not dependent on bicarbonate or on CFTR, but was completely blocked by niflumic acid. We found stimulated mucus release was severely impaired in the cystic fibrosis F508 reproductive tract, even though stimulated fluid secretion was preserved. Thus, CFTR mutations and/or poor bicarbonate secretion may be associated with reduced female fertility associated with abnormal mucus and specifically, may account for the increased viscosity and lack of cyclical changes in cervical mucus long noted in women with cystic fibrosis.
A new role for bicarbonate secretion in cervico-uterine mucus release
Muchekehu, Ruth W; Quinton, Paul M
2010-01-01
Cervical mucus thinning and release during the female reproductive cycle is thought to rely mainly on fluid secretion. However, we now find that mucus released from the murine reproductive tract critically depends upon concurrent bicarbonate (HCO3−) secretion. Prostaglandin E2 (PGE2)- and carbachol-stimulated mucus release was severely inhibited in the absence of serosal HCO3−, HCO3− transport, or functional cystic fibrosis transmembrane conductance regulator (CFTR). In contrast to mucus release, PGE2- and carbachol-stimulated fluid secretion was not dependent on bicarbonate or on CFTR, but was completely blocked by niflumic acid. We found stimulated mucus release was severely impaired in the cystic fibrosis ΔF508 reproductive tract, even though stimulated fluid secretion was preserved. Thus, CFTR mutations and/or poor bicarbonate secretion may be associated with reduced female fertility associated with abnormal mucus and specifically, may account for the increased viscosity and lack of cyclical changes in cervical mucus long noted in women with cystic fibrosis. PMID:20478977
Molecular Imaging Provides Novel Insights on Estrogen Receptor Activity in Mouse Brain
Stell, Alessia; Belcredito, Silvia; Ciana, Paolo; Maggi, Adriana
2009-01-01
Estrogen receptors have long been known to be expressed in several brain areas in addition to those directly involved in the control of reproductive functions. Investigations in humans and in animal models suggest a strong influence of estrogens on limbic and motor functions, yet the complexity and heterogeneity of neural tissue have limited our approaches to the full understanding of estrogen activity in the central nervous system. The aim of this study was to examine the transcriptional activity of estrogen receptors in the brain of male and female mice. Exploiting the ERE-Luc reporter mouse, we set up a novel, bioluminescence-based technique to study brain estrogen receptor transcriptional activity. Here we show, for the first time, that estrogen receptors are similarly active in male and female brains and that the estrous cycle affects estrogen receptor activity in regions of the central nervous system not known to be associated with reproductive functions. Because of its reproducibility and sensitivity, this novel bioluminescence application candidates as an innovative methodology for the study and development of drugs targeting brain estrogen receptors. PMID:19123998
Molecular imaging provides novel insights on estrogen receptor activity in mouse brain.
Stell, Alessia; Belcredito, Silvia; Ciana, Paolo; Maggi, Adriana
2008-01-01
Estrogen receptors have long been known to be expressed in several brain areas in addition to those directly involved in the control of reproductive functions. Investigations in humans and in animal models suggest a strong influence of estrogens on limbic and motor functions, yet the complexity and heterogeneity of neural tissue have limited our approaches to the full understanding of estrogen activity in the central nervous system. The aim of this study was to examine the transcriptional activity of estrogen receptors in the brain of male and female mice. Exploiting the ERE-Luc reporter mouse, we set up a novel, bioluminescence-based technique to study brain estrogen receptor transcriptional activity. Here we show, for the first time, that estrogen receptors are similarly active in male and female brains and that the estrous cycle affects estrogen receptor activity in regions of the central nervous system not known to be associated with reproductive functions. Because of its reproducibility and sensitivity, this novel bioluminescence application stands as a candidate as an innovative methodology for the study and development of drugs targeting brain estrogen receptors.
Bazarganipour, Fatemeh; Foroozanfard, Fatemeh; Taghavi, Seyed Abdolvahab; Hekmatzadeh, Fatemeh; Sarviye, Malihe; Hosseini, Nazafarin
2013-06-01
To evaluate reproductive health education which is essential to the prevention of sexual risk behavior and its associated adverse outcomes of unwanted pregnancy, AIDS and other sexually transmitted disease in adolescents. Little is known about youth educational needs about reproductive health in Iran. The aim of this study is evaluation of female youth educational needs about reproductive health in non-medical universities in the city of Qom, north central of Iran. The study was descriptive-analytical type conducted in nine non-medical universities (400 students). A questionnaire was constructed to meet the purpose of the study based on similar studies of knowledge and attitude in different countries, yet it was modified according to Iranian culture and social norms. The findings showed that a majority of participants have moderate knowledge about all components of reproductive health. Approximately, one - third of the participants reported difficulties to discuss about sexual health with mothers. The most of the participants believed insufficient female youth reproductive health services and low knowledge about reproductive health were the main barriers for female youth reproductive health aims. The participants in this study are representatives of an important subgroup in Iran in order to evaluate female youth reproductive health educational needs. The study identified many misconception and negative attitude that need to be addressed. A health education program through parents, peers, mass media campaign and more comprehensive family planning curriculum in universities are recommended to overcome misconception and spread awareness.
Ma, G X; Zhou, R Q; Hu, L; Luo, Y L; Luo, Y F; Zhu, H H
2018-03-01
Toxocara canis is an important but neglected zoonotic parasite, and is the causative agent of human toxocariasis. Chondroitin proteoglycans are biological macromolecules, widely distributed in extracellular matrices, with a great diversity of functions in mammals. However, there is limited information regarding chondroitin proteoglycans in nematode parasites. In the present study, a female-enriched chondroitin proteoglycan 2 gene of T. canis (Tc-cpg-2) was cloned and characterized. Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to measure the transcription levels of Tc-cpg-2 among tissues of male and female adult worms. A 485-amino-acid (aa) polypeptide was predicted from a continuous 1458-nuleotide open reading frame and designated as TcCPG2, which contains a 21-aa signal peptide. Conserved domain searching indicated three chitin-binding peritrophin-A (CBM_14) domains in the amino acid sequence of TcCPG2. Multiple alignment with the inferred amino acid sequences of Caenorhabditis elegans and Ascaris suum showed that CBM_14 domains were well conserved among these species. Phylogenetic analysis suggested that TcCPG2 was closely related to the sequence of chondroitin proteoglycan 2 of A. suum. Interestingly, a high level of Tc-cpg-2 was detected in female germline tissues, particularly in the oviduct, suggesting potential roles of this gene in reproduction (e.g. oogenesis and embryogenesis) of adult T. canis. The functional roles of Tc-cpg-2 in reproduction and development in this parasite and related parasitic nematodes warrant further functional studies.
Genetics and genomics of reproductive performance in dairy and beef cattle.
Berry, D P; Wall, E; Pryce, J E
2014-05-01
Excellent reproductive performance in both males and females is fundamental to profitable dairy and beef production systems. In this review we undertook a meta-analysis of genetic parameters for female reproductive performance across 55 dairy studies or populations and 12 beef studies or populations as well as across 28 different studies or populations for male reproductive performance. A plethora of reproductive phenotypes exist in dairy and beef cattle and a meta-analysis of the literature suggests that most of the female reproductive traits in dairy and beef cattle tend to be lowly heritable (0.02 to 0.04). Reproductive-related phenotypes in male animals (e.g. semen quality) tend to be more heritable than female reproductive phenotypes with mean heritability estimates of between 0.05 and 0.22 for semen-related traits with the exception of scrotal circumference (0.42) and field non-return rate (0.001). The low heritability of reproductive traits, in females in particular, does not however imply that genetic selection cannot alter phenotypic performance as evidenced by the decline until recently in dairy cow reproductive performance attributable in part to aggressive selection for increased milk production. Moreover, the antagonistic genetic correlations among reproductive traits and both milk (dairy cattle) and meat (beef cattle) yield is not unity thereby implying that simultaneous genetic selection for both increased (milk and meat) yield and reproductive performance is indeed possible. The required emphasis on reproductive traits within a breeding goal to halt deterioration will vary based on the underlying assumptions and is discussed using examples for Ireland, the United Kingdom and Australia as well as quantifying the impact on genetic gain for milk production. Advancements in genomic technologies can aid in increasing the accuracy of selection for especially reproductive traits and thus genetic gain. Elucidation of the underlying genomic mechanisms for reproduction could also aid in resolving genetic antagonisms. Past breeding programmes have contributed to the deterioration in reproductive performance of dairy and beef cattle. The tools now exist, however, to reverse the genetic trends in reproductive performance underlying the observed phenotypic trends.
Cryptic reproductive isolation in the Drosophila simulans species complex.
Price, C S; Kim, C H; Gronlund, C J; Coyne, J A
2001-01-01
Forms of reproductive isolation that act after copulation but before fertilization are potentially important components of speciation, but are studied only infrequently. We examined postmating, prezygotic reproductive isolation in three hybridizations within the Drosophila simulans species complex. We allowed females to mate only once, observed and timed all copulations, dissected a subset of the females to track the storage and retention of sperm, examined the number and hatchability of eggs laid after insemination, counted all progeny produced, and measured the longevity of mated females. Each of the three hybridizations is characterized by a different set of cryptic barriers to heterospecific fertilization. When D. simulans females mate with D. sechellia males, few heterospecific sperm are transferred, even during long copulations. In contrast, copulations of D. simulans females with D. mauritiana males are often too short to allow sperm transfer. Those that are long enough to allow insemination, however, involve the transfer of many sperm, but only a fraction of these heterospecific sperm are stored by females, who also lay fewer eggs than do D. simulans females mated with conspecific males. Finally, when D. mauritiana females mate with D. simulans males, sperm are transferred and stored in abundance, but are lost rapidly from the reproductive tract and are therefore used inefficiently. These results add considerably to the list of reproductive isolating mechanisms in this well-studied clade and possibly to the list of evolutionary processes that could contribute to their reproductive isolation.
Liu, Yun; Zhong, Zhang-cheng; Wang, Xiao-xue; Xie, Jun; Yang, Wen-ying
2011-03-01
A field research was conducted on the photosynthesis and transpiration characteristics of dioecious Trichosanthes kirilowii individuals at four key development stages. At vegetative growth stage, the photosynthesis rate, transpiration rate, stomatal conductance, and water use efficiency of male individuals were higher than those of female individuals, and hence, male individuals entered into reproductive growth stage 22 days earlier than female individuals. After entering into reproductive growth stage, male individuals had higher photosynthesis rate, transpiration rate, and stomatal conductance, but slightly lower water use efficiency than female individuals. As the female individuals started to reproductive growth, their photosynthesis rate and water use efficiency were significantly lower, while the transpiration rate and stomatal conductance were higher than those of the male individuals. The effects of climate factors on the growth and development of T. kirilowii mainly occurred at its vegetative growth and early reproductive growth stages, and weakened at later reproductive growth stages. Higher temperature and lower relative humidity benefited the growth and development of T. kirilowii, and illumination could enhance the photosynthesis rate of T. kirilowii, especially its male individuals. After entering into reproductive growth stage, the photosynthesis rate of male individuals increased significantly with increasing illumination, but that of female individuals only had a slight increase, and the transpiration rate of male individuals as well as the photosynthesis rate of female individuals all increased significantly with increasing temperature.
Mehl, N S; Srisuwatanasagul, S; Swangchan-Uthai, T; Sirivaidyapong, S; Khalid, M
2017-01-01
Effect of a GnRH-agonist (deslorelin) was studied on reproductive function and ovarian luteinizing hormone receptor (LHR) and follicle stimulating hormone receptor (FSHR) expression in prepubertal female cats that were either implanted with 4.7-mg deslorelin (implanted: n = 6) or not (controls: n = 18) or ovariohysterectomized at prepubertal age (prepubertal OVH: n = 6). Body weights, fecal estradiol, and sexual behavior of implanted and control cats were monitored for 48 weeks followed by collection of ovaries and uteri. Ovaries and uteri were collected from control cats at follicular, luteal, and inactive stage (n = 6/group) and from prepubertal OVH cats at prepubertal age. Ovaries and uteri were analyzed for anatomical/histological characteristics. Ovaries were also analyzed for LHR and FSHR expression. Statistical analysis showed higher (P ≤ 0.05) body weight in control than implanted cats only during 22nd to 26th weeks of the study. Estrus was observed in control cats only. Deslorelin reduced (P ≤ 0.05) ovarian weight and number of antral follicles but did not affect endometrial thickness and gland diameter. However, myometrial thickness of implanted cats was significantly lower than control cats at follicular and luteal stage. Ovarian LHR mRNA expression was lower (P ≤ 0.05) in implanted cats than control cats at follicular stage. FSHR mRNA and LHR protein expression did not differ among the three groups. FSHR protein expression was lower (P ≤ 0.05) in prepubertal OVH cats and was not affected by deslorelin. In conclusion, deslorelin suppresses reproductive function in prepubertal female cats for at least 48 weeks possibly through a change in the ovarian mRNA expression of LHR. Copyright © 2016 Elsevier Inc. All rights reserved.
Henry, MaLinda D.; Hankerson, Sarah J.; Siani, Jennifer M.; French, Jeffrey A.; Dietz, James M.
2013-01-01
Across taxa, cooperative breeding has been associated with high reproductive skew. Cooperatively breeding golden lion tamarins (Leontopithecus rosalia) were long thought to have a monogynous mating system in which reproduction was limited to a single dominant female. Subordinates with few reproductive opportunities delayed dispersal and remained in the natal group to provide alloparental care to siblings, thus allowing dominant reproductive females to meet the energetic needs associated with high rates of reproduction and successful infant rearing. The goal of this study was to re-assess monogyny in wild golden lion tamarin groups based upon pregnancy diagnoses that used non-invasive enzyme immunoassay for progesterone and cortisol, combined with weekly data on individual weight gain, bi-annual physical examinations noting pregnancy and lactation status and daily behavioral observations. We established quantitative and qualitative criteria to detect and determine the timing of pregnancies that did not result in the birth of infants. Pregnancy polygyny occurred in 83% of golden lion tamarin groups studied. The loss of 64% of subordinate pregnancies compared to only 15% by dominant females limited reproductive success mainly to dominant females, thus maintaining high reproductive skew in female golden lion tamarins. Pregnancy loss by subordinate adults did not appear to result from dominant interference in subordinate hormonal mechanisms, but more likely resulted from subordinate abandonment of newborn infants to mitigate dominant aggression. PMID:23454002
Marijuana, the Endocannabinoid System and the Female Reproductive System
Brents, Lisa K.
2016-01-01
Marijuana use among women is highly prevalent, but the societal conversation on marijuana rarely focuses on how marijuana affects female reproduction and endocrinology. This article reviews the current scientific literature regarding marijuana use and hypothalamic-pituitary-ovarian (HPO) axis regulation, ovarian hormone production, the menstrual cycle, and fertility. Evidence suggests that marijuana can reduce female fertility by disrupting hypothalamic release of gonadotropin releasing hormone (GnRH), leading to reduced estrogen and progesterone production and anovulatory menstrual cycles. Tolerance to these effects has been shown in rhesus monkeys, but the effects of chronic marijuana use on human female reproduction are largely unknown. Marijuana-induced analgesia, drug reinforcement properties, tolerance, and dependence are influenced by ovarian hormones, with estrogen generally increasing and progesterone decreasing sensitivity to marijuana. Carefully controlled regulation of the Endocannabinoid System (ECS) is required for successful reproduction, and the exogenous cannabinoids in marijuana may disrupt the delicate balance of the ECS in the female reproductive system. PMID:27354844
Lourdais, Olivier; Dupoué, Andréaz; Guillon, Michaël; Guiller, Gaëtan; Michaud, Bruno; DeNardo, Dale F
Water constraints can mediate evolutionary conflict either among individuals (e.g., parent-offspring conflict, sexual conflict) or within an individual (e.g., cost of reproduction). During pregnancy, water is of particular importance because the female provides all water needed for embryonic development and experiences important maternal shifts in behavior and physiology that, together, can compromise female water balance if water availability is limited. We examined the effect of pregnancy on evaporative water loss and microhabitat selection in a viviparous snake, the aspic viper. We found that both physiological (increased metabolism and body temperature) and morphological (body distension) changes contribute to an increased evaporative water loss in pregnant females. We also found that pregnant females in the wild select warmer and moister basking locations than nonreproductive females, likely to mitigate the conflict between thermal needs and water loss. Water resources likely induce significant reproductive constraints across diverse taxa and thus warrant further consideration in ecological research. From an evolutionary perspective, water constraints during reproduction may contribute to shaping reproductive effort.
Reproductive success and foraging of the crab spider Misumena vatia.
Fritz, Robert S; Morse, Douglass H
1985-01-01
Reproductive success and growth rate data were collected for individually marked crab spiders Misumena vatia (Clerck) in 1980, 1981, and 1982. All measures of reproductive success were found to be quite variable between individuals within years, but did not differ between years. Reproductive effort (mass of clutch/prereproductive mass of female) was the least variable measurement and was not correlated with female weight at reproduction. Clutch weight and number of eggs per clutch were highly correlated with female reproductive weight. Egg weight was not correlated with the number of eggs per clutch. Hatching success did not vary with clutch size and averaged 94.5%. Growth rates of spiders were highly variable, indicating large variation in feeding rate. In 1981 and 1982, approximately 20% of female spiders were unable to capture enough prey to grow and reproduce. Primary prey species differed in weight and in their contribution to spider egg production. Spiders attacked a larger percentage of bumblebees but captured a larger percentage of honeybees. There was no simple relationship between diet choice and reproductive success. Spiders which selected suboptimal umbels to forage on some or all of the time, however, had significantly lower reproductive success than spiders choosing the best umbels.
Abedi, Parvin; Jorfi, Maryam; Afshari, Poorandokht; Fakhri, Ahmad
2017-08-01
This study aimed to evaluate the relation between health-promoting lifestyle and sexual function among women of reproductive age. In this cross-sectional study, 1200 women were recruited randomly from 10 public health centers in Ahvaz, Iran. A demographic questionnaire, Health Promoting Lifestyle Profile 2 (HPLP2), and Female Sexual Function Index (FSFI) were used for data collection. The inclusion criteria were as follows: women aged 15-45 years, married, monogamous, and having basic literacy. Data were analyzed using Kruskal-Wallis test, chi-square test, Spearman correlation coefficient, and logistic regression. All aspects of sexual function showed a significant relationship with different dimensions of HPLP2, except for pain and physical activity ( p < 0.001). Women who had better self-actualization were more likely to have better sexual function than other women (OR = 1.10, 95% CI: 1.06-1.14, p < 0.001). Other variables like responsibility, interpersonal relations and stress management also showed a significant correlation with sexual function. Results of this study showed that health-promoting lifestyle dimensions are significantly related to all aspects of sexual function in women of reproductive age. Health policy makers should take lifestyle-related factors of reproductive-aged women into account when seeking to improve the sexual wellbeing of this population. Further attention should also be given to assessing the direction of causality.
Johnson, Joseph S; Lacki, Michael J
2013-07-01
Many small mammals are heterothermic endotherms capable of maintaining an elevated core body temperature or reducing their thermoregulatory set point to enter a state of torpor. Torpor can confer substantial energy savings, but also incurs ecological costs, such as hindering allocation of energy towards reproduction. We placed temperature-sensitive radio transmitters on 44 adult Rafinesque's big-eared bats (Corynorhinus rafinesquii) and deployed microclimate dataloggers inside 34 day roosts to compare the use of torpor by different sex and reproductive classes of bats during the summer. We collected 324 bat-days of skin-temperature data from 36 females and 4 males. Reproductive females employed fewer torpor bouts per day than non-reproductive females and males (P < 0.0001), and pregnant and lactating females had higher average (P < 0.0001) and minimum (P < 0.0001) skin temperatures than non-reproductive females. Pregnant females spent less time torpid (P < 0.0001) than non-reproductive females, but lactating females used relatively deep, long torpor bouts. Microclimates varied inside tree species with different configurations of entrances to the roost cavity (P < 0.0001). Bats spent more time torpid when roosting in water tupelo (Nyssa aquatica) trees possessing only a basal entrance to the cavity (P = 0.001). Of the tree species used as roosts, water tupelo cavities exhibited the least variable daytime and nighttime temperatures. These data demonstrate that use of summer torpor is not uniform among sex and reproductive classes in Rafinesque's big-eared bat, and variation in microclimate among tree roosts due to species and structural characteristics facilitates the use of different thermoregulatory strategies in these bats.
Lind, Craig M; Husak, Jerry F; Eikenaar, Cas; Moore, Ignacio T; Taylor, Emily N
2010-05-01
We describe the reproductive cycle of Northern Pacific rattlesnakes (Crotalus oreganus) by quantifying steroid hormone concentrations and observing reproductive behaviors in free-ranging individuals. Additionally, we examined reproductive tissues from museum specimens. Plasma steroid hormone concentrations were quantified for both male and female snakes throughout the active season (March-October). We measured testosterone (T), 5alpha-dihydrotestosterone (DHT), and corticosterone (B) concentrations in both sexes and 17beta-estradiol (E2) and progesterone (P) in females only. We observed reproductive behaviors (e.g., consortship, courtship, and copulation) in the field and measured testis and follicle size in male and female snakes from museum collections to relate steroid hormone concentrations to the timing of reproductive events. Our study revealed that C. oreganus in central California exhibits a bimodal pattern of breeding, with most mating behavior occurring in the spring and some incidences of mating behavior observed in late summer/fall. Each breeding period corresponded with elevated androgen (T or DHT) levels in males. Testes were regressed in the spring when the majority of reproductive behavior was observed in this population, and they reached peak volume in August and September during spermatogenesis. Although we did not detect seasonal variation in female hormone concentrations, some females had high E2 in the spring and fall, coincident with mating and with increased follicle size (indicating vitellogenesis) in museum specimens. Females with high E2 concentrations also had high T and DHT concentrations. Corticosterone concentrations in males and females were not related either to time of year or to concentrations of any other hormones quantified. Progesterone concentrations in females also did not vary seasonally, but this likely reflected sampling bias as females tended to be underground, and thus unobtainable, in summer months when P would be expected to be elevated during gestation. In females, P was positively correlated with T and DHT, and E2 was positively correlated with T. Published by Elsevier Inc.
Family feuds: social competition and sexual conflict in complex societies.
Rubenstein, Dustin R
2012-08-19
Darwin was initially puzzled by the processes that led to ornamentation in males-what he termed sexual selection-and those that led to extreme cooperation and altruism in complex animal societies-what was later termed kin selection. Here, I explore the relationships between sexual and kin selection theory by examining how social competition for reproductive opportunities-particularly in females-and sexual conflict over mating partners are inherent and critical parts of complex altruistic societies. I argue that (i) patterns of reproductive sharing within complex societies can drive levels of social competition and reproductive conflict not only in males but also in females living in social groups, and ultimately the evolution of female traits such as ornaments and armaments; (ii) mating conflict over female choice of sexual partners can influence kin structure within groups and drive the evolution of complex societies; and (iii) patterns of reproductive sharing and conflict among females may also drive the evolution of complex societies by influencing kin structure within groups. Ultimately, complex societies exhibiting altruistic behaviour appear to have only arisen in taxa where social competition over reproductive opportunities and sexual conflict over mating partners were low. Once such societies evolved, there were important selective feedbacks on traits used to regulate and mediate intra-sexual competition over reproductive opportunities, particularly in females.
Reproduction elevates the corticosterone stress response in common fruit bats.
Klose, Stefan M; Smith, Carolynn L; Denzel, Andrea J; Kalko, Elisabeth K V
2006-04-01
Changes in reproductive state or the environment may affect the sensitivity of the hypothalamic-pituitary-andrenal (HPA) axis. However, little is known about the dynamics of the resulting corticosteroid stress response, in particular in tropical mammals. In this study, we address the modulation of corticosterone release in response to different reproductive conditions and seasonality in 326 free-living common fruit-eating bats (Artibeus jamaicensis) on Barro Colorado Island in Panama during dry and wet seasons. We present strong evidence that stress sensitivity is primarily modulated by reproductive condition. In reproductively active females, corticosterone increases were more rapid and reached higher levels, but also decreased significantly faster than in inactive females. The corticosterone response was weaker in reproducing males than in females and delayed compared to non-reproductive males. Testes volume in reproductively active males was negatively correlated with corticosterone concentrations. Our findings suggest differentiated dynamics in the corticosterone stress response between sexes, potentially reflecting conflicting ecological demands. In females, a strong acute corticosterone response may represent high stress- and risk-sensitivity that facilitates escape and thus helps to protect reproduction. In males, suppression during reproductive activity could reflect lowered stress sensitivity to avoid chronically elevated corticosterone levels in times of frequent aggressive and therefore costly inter-male encounters.
2008-01-01
Background Exaggerated male ornaments and displays often evolve in species where males only provide females with ejaculates during reproduction. Although "good genes" arguments are typically invoked to explain this phenomenon, a simpler alternative is possible if variation in male reproductive quality (e.g. sperm number, ejaculate content, mating rate) is an important determinant of female reproductive success. The "phenotype-linked fertility hypothesis" states that female preference for male ornaments or displays has been selected to ensure higher levels of fertility and has driven the evolution of exaggerated male traits. Females of the stalk-eyed fly Teleopsis dalmanni must mate frequently to maintain high levels of fertility and prefer to mate with males exhibiting large eyespan, a condition-dependent sexual ornament. If eyespan indicates male reproductive quality, females could directly increase their reproductive success by mating with males with large eyespan. Here we investigate whether male eyespan indicates accessory gland and testis length, and then ask whether mating with large eyespan males affects female fertility. Results Male eyespan was a better predictor of two key male reproductive traits – accessory gland and testis length – than was body size alone. This positive relationship held true over three levels of increasing environmental stress during the maturation of the adult accessory glands and testes. Furthermore, females housed with a large eyespan male exhibited higher levels of fertility than those with small eyespan males. Conclusion Male eyespan in stalk-eyed flies is subject to strong directional mate preference and is a reliable indicator of male reproductive quality – both because males with larger eyespan have bigger accessory glands and testes, and also as they confer higher fertility on females. Fertility enhancement may have arisen because males with larger eyespan mated more often and/or because they transferred more sperm or other substances per ejaculate. The need to ensure high levels of fertility could thus have been an important selective force in the coevolution of female preference and male eyespan in stalk-eyed flies. Our results support the phenotype-linked fertility hypothesis and suggest that it might be of general importance in explaining the evolution of exaggerated male ornaments and displays in species where males only provide females with ejaculates during reproduction. PMID:18710553
Rogers, David W; Denniff, Matthew; Chapman, Tracey; Fowler, Kevin; Pomiankowski, Andrew
2008-08-18
Exaggerated male ornaments and displays often evolve in species where males only provide females with ejaculates during reproduction. Although "good genes" arguments are typically invoked to explain this phenomenon, a simpler alternative is possible if variation in male reproductive quality (e.g. sperm number, ejaculate content, mating rate) is an important determinant of female reproductive success. The "phenotype-linked fertility hypothesis" states that female preference for male ornaments or displays has been selected to ensure higher levels of fertility and has driven the evolution of exaggerated male traits. Females of the stalk-eyed fly Teleopsis dalmanni must mate frequently to maintain high levels of fertility and prefer to mate with males exhibiting large eyespan, a condition-dependent sexual ornament. If eyespan indicates male reproductive quality, females could directly increase their reproductive success by mating with males with large eyespan. Here we investigate whether male eyespan indicates accessory gland and testis length, and then ask whether mating with large eyespan males affects female fertility. Male eyespan was a better predictor of two key male reproductive traits--accessory gland and testis length--than was body size alone. This positive relationship held true over three levels of increasing environmental stress during the maturation of the adult accessory glands and testes. Furthermore, females housed with a large eyespan male exhibited higher levels of fertility than those with small eyespan males. Male eyespan in stalk-eyed flies is subject to strong directional mate preference and is a reliable indicator of male reproductive quality--both because males with larger eyespan have bigger accessory glands and testes, and also as they confer higher fertility on females. Fertility enhancement may have arisen because males with larger eyespan mated more often and/or because they transferred more sperm or other substances per ejaculate. The need to ensure high levels of fertility could thus have been an important selective force in the coevolution of female preference and male eyespan in stalk-eyed flies. Our results support the phenotype-linked fertility hypothesis and suggest that it might be of general importance in explaining the evolution of exaggerated male ornaments and displays in species where males only provide females with ejaculates during reproduction.
Quantifying inbreeding avoidance through extra-pair reproduction
Reid, Jane M; Arcese, Peter; Keller, Lukas F; Germain, Ryan R; Duthie, A Bradley; Losdat, Sylvain; Wolak, Matthew E; Nietlisbach, Pirmin
2015-01-01
Extra-pair reproduction is widely hypothesized to allow females to avoid inbreeding with related socially paired males. Consequently, numerous field studies have tested the key predictions that extra-pair offspring are less inbred than females’ alternative within-pair offspring, and that the probability of extra-pair reproduction increases with a female's relatedness to her socially paired male. However, such studies rarely measure inbreeding or relatedness sufficiently precisely to detect subtle effects, or consider biases stemming from failure to observe inbred offspring that die during early development. Analyses of multigenerational song sparrow (Melospiza melodia) pedigree data showed that most females had opportunity to increase or decrease the coefficient of inbreeding of their offspring through extra-pair reproduction with neighboring males. In practice, observed extra-pair offspring had lower inbreeding coefficients than females’ within-pair offspring on average, while the probability of extra-pair reproduction increased substantially with the coefficient of kinship between a female and her socially paired male. However, simulations showed that such effects could simply reflect bias stemming from inbreeding depression in early offspring survival. The null hypothesis that extra-pair reproduction is random with respect to kinship therefore cannot be definitively rejected in song sparrows, and existing general evidence that females avoid inbreeding through extra-pair reproduction requires reevaluation given such biases. PMID:25346331
Gou, Bin; Liu, Ying; Guntur, Ananya R.; Stern, Ulrich; Yang, Chung-Hui
2014-01-01
Selecting a suitable site to deposit their eggs is an important reproductive need of Drosophila females. While their choosiness towards egg-laying sites is well documented, the specific neural mechanism that activates females’ search for attractive egg-laying sites is not known. Here we show that distention/contraction of females’ internal reproductive tract triggered by egg-delivery through the tract plays a critical role in activating such search. We found that females start to exhibit acetic acid attraction prior to depositing each egg but no attraction when they are not laying eggs. Artificially distending the reproductive tract triggers acetic acid attraction in non-egg-laying females whereas silencing the mechanosensitive neurons we identified that can sense the contractile status of the tract eliminates such attraction. Our work uncovers the circuit basis of an important reproductive need of Drosophila females and provides a simple model to dissect the neural mechanism that underlies a reproductive need-induced behavioral modification. PMID:25373900
Zhou, Changqing; Gao, Liying; Flaws, Jodi A
2017-06-01
Phthalates are used in consumer products and are known endocrine-disrupting chemicals. However, limited information is available on the effects of phthalate mixtures on female reproduction. Previously, we developed a phthalate mixture made of 35% diethyl phthalate, 21% di(2-ethylhexyl) phthalate, 15% dibutyl phthalate, 15% di-isononyl phthalate, 8% di-isobutyl phthalate, and 5% benzylbutyl phthalate that mimics human exposure. We tested the effects of prenatal exposure to this mixture on reproductive outcomes in first-filial-generation (F1) female mice and found that it impaired reproductive outcomes. However, the impact of this exposure on second-filial-generation (F2) and third-filial-generation (F3) females was unknown. Thus, we hypothesized that prenatal exposure to the phthalate mixture induces multigenerational and transgenerational effects on female reproduction. Pregnant CD-1 dams were orally dosed with vehicle (tocopherol-stripped corn oil) or a phthalate mixture (20 and 200 µg/kg/d, 200 and 500 mg/kg/d) daily from gestational day 10 to birth. Adult F1 females born to these dams were used to generate the F2 generation and adult F2 females born to F1 females were used to generate the F3 generation. F2 and F3 females were subjected to tissue collections and fertility tests. Prenatal phthalate mixture exposure increased uterine weight, anogenital distance, and body weight; induced cystic ovaries; and caused fertility complications in the F2 generation. It also increased uterine weight, decreased anogenital distance, and caused fertility complications in the F3 generation. These data suggest that prenatal exposure to the phthalate mixture induces multigenerational and transgenerational effects on female reproduction. Copyright © 2017 Endocrine Society.
Zhou, Changqing; Gao, Liying
2017-01-01
Phthalates are used in consumer products and are known endocrine-disrupting chemicals. However, limited information is available on the effects of phthalate mixtures on female reproduction. Previously, we developed a phthalate mixture made of 35% diethyl phthalate, 21% di(2-ethylhexyl) phthalate, 15% dibutyl phthalate, 15% di-isononyl phthalate, 8% di-isobutyl phthalate, and 5% benzylbutyl phthalate that mimics human exposure. We tested the effects of prenatal exposure to this mixture on reproductive outcomes in first-filial-generation (F1) female mice and found that it impaired reproductive outcomes. However, the impact of this exposure on second-filial-generation (F2) and third-filial-generation (F3) females was unknown. Thus, we hypothesized that prenatal exposure to the phthalate mixture induces multigenerational and transgenerational effects on female reproduction. Pregnant CD-1 dams were orally dosed with vehicle (tocopherol-stripped corn oil) or a phthalate mixture (20 and 200 µg/kg/d, 200 and 500 mg/kg/d) daily from gestational day 10 to birth. Adult F1 females born to these dams were used to generate the F2 generation and adult F2 females born to F1 females were used to generate the F3 generation. F2 and F3 females were subjected to tissue collections and fertility tests. Prenatal phthalate mixture exposure increased uterine weight, anogenital distance, and body weight; induced cystic ovaries; and caused fertility complications in the F2 generation. It also increased uterine weight, decreased anogenital distance, and caused fertility complications in the F3 generation. These data suggest that prenatal exposure to the phthalate mixture induces multigenerational and transgenerational effects on female reproduction. PMID:28368545
Park, Sun-Ji; Kim, Tae-Shin; Kim, Jin-Man; Chang, Kyu-Tae; Lee, Hyun-Shik; Lee, Dong-Seok
2015-01-01
Superovulation induced by exogenous gonadotropin treatment (PMSG/hCG) increases the number of available oocytes in humans and animals. However, Superovulatory PMSG/hCG treatment is known to affect maternal environment, and these effects may result from PMSG/hCG treatment-induced oxidative stress. 2-Cys peroxiredoxins (2-Cys Prxs) act as antioxidant enzymes that protect cells from oxidative stress induced by various exogenous stimuli. Therefore, the objective of this study was to test the hypothesis that repeated PMSG/hCG treatment induces 2-Cys Prx expression and overoxidation in the reproductive tracts of female mice. Immunohistochemistry and western blotting analyses further demonstrated that, after PMSG/hCG treatment, the protein expression levels of 2-Cys Prxs increased most significantly in the ovaries, while that of Prx1 was most affected by PMSG/hCG stimulation in all tissues of the female reproductive tract. Repeated PMSG/hCG treatment eventually leads to 2-Cys Prxs overoxidation in all reproductive organs of female mice, and the abundance of the 2-Cys Prxs-SO2/3 proteins reported here supports the hypothesis that repeated superovulation induces strong oxidative stress and damage to the female reproductive tract. Our data suggest that excessive oxidative stress caused by repeated PMSG/hCG stimulation increases 2-Cys Prxs expression and overoxidation in the female reproductive organs. Intracellular 2-Cys Prx therefore plays an important role in maintaining the reproductive organ environment of female mice upon exogenous gonadotropin treatment. PMID:26486164
The MMP-9/TIMP-1 System is Involved in Fluoride-Induced Reproductive Dysfunctions in Female Mice.
Wang, Hong-Wei; Zhao, Wen-Peng; Tan, Pan-Pan; Liu, Jing; Zhao, Jing; Zhou, Bian-Hua
2017-08-01
A total of 84 healthy female mice were kept with various concentrations of sodium fluoride (F) (0, 50, 100, 150 mg F - /L in drinking water for 90 days) and were then mated with healthy male mice for 1 week to study the effect of excessive fluoride on female reproductive function, particularly in embryo implantation. The rate of pregnancy, litter size, and the birth weight of female mice were evaluated. Ultrastructural changes of uteri tissues were observed by transmission electron microscopy (TEM). The mRNA expression levels of MMP-9 and TIMP-1 were determined by quantitative real-time PCR. The protein expression levels of MMP-9 and TIMP-1 were analyzed by western blotting. Results showed a significant decrease of litter size in mice exposed to fluoride. TEM images of uteri tissue of mice that underwent a 150 mg/L F - treatment for 90 days showed a vague nucleus, reduced microvilli, increased lysosomes, a dilated endoplasmic reticulum, and a vacuolization mitochondrion when compared with the control group. Following the damage of the structure, the expression levels of MMP-9 and TIMP-1 in uteri tissues were significantly unregulated in the F 150 group. These results show that MMP-9/TIMP-1 system disturbance and changes of histological structure in uteri tissue are involved in fluoride-induced reproductive dysfunctions.
Szykman, Micaela; Engh, Anne L.; Van Horn, Russell C.; Boydston, Erin E.; Scribner, Kim T.; Holekamp, Kay E.
2003-01-01
Spotted hyenas (Crocuta crocuta) are gregarious carnivores. The females are socially dominant to males, and adult males rarely direct aggression toward adult females. This study analyzed all cases in which adult immigrant males behaved aggressively toward adult females in a large population of free-living hyenas in Kenya, observed for 11 years. Our goals were to describe the conditions under which male attacks on females occur, and address possible adaptive functions. Most aggression directed by adult immigrant males against females occurred when coalitions of two or more males attacked a single adult female, who typically responded by defending herself and fighting back. Male aggression against females frequently occurred at sites of ungulate kills, but males never behaved aggressively toward females over food, and all male attacks on females were unprovoked. Although no mounting or other copulatory behaviors ever occurred during or immediately after an attack, the number of male attacks on females peaked around the time of conception. Daily rates at which males attacked females did not vary with female social rank. However, daily attack rates did vary significantly with female reproductive state, and the highest rates of male attack on females were observed during the two stages of the reproductive cycle during which females were most likely to conceive litters. The adaptive significance of male aggression against females in this species remains unknown, but a tight association between male attacks on females and a female's time of conception provides strong evidence of some role for male aggression in hyena sexual behavior. In particular, our data are consistent with hypotheses suggesting that male aggression toward females in this species either serves to inform females about male fitness or represents sexual harassment.
Debeffe, Lucie; Poissant, Jocelyn; McLoughlin, Philip D
2017-08-01
Costs associated with reproduction are widely known to play a role in the evolution of reproductive tactics with consequences to population and eco-evolutionary dynamics. Evaluating these costs as they pertain to species in the wild remains an important goal of evolutionary ecology. Individual heterogeneity, including differences in individual quality (i.e., among-individual differences in traits associated with survival and reproduction) or state, and variation in environmental and social conditions can modulate the costs of reproduction; however, few studies have considered effects of these factors simultaneously. Taking advantage of a detailed, long-term dataset for a population of feral horses (Sable Island, Nova Scotia, Canada), we address the question of how intrinsic (quality, age), environmental (winter severity, location), and social conditions (group size, composition, sex ratio, density) influence the costs of reproduction on subsequent reproduction. Individual quality was measured using a multivariate analysis on a combination of four static and dynamic traits expected to depict heterogeneity in individual performance. Female quality and age interacted with reproductive status of the previous year to determine current reproductive effort, while no effect of social or environmental covariates was found. High-quality females showed higher probabilities of giving birth and weaning their foal regardless of their reproductive status the previous year, while those of lower quality showed lower probabilities of producing foals in successive years. Middle-aged (prime) females had the highest probability of giving birth when they had not reproduced the year before, but no such relationship with age was found among females that had reproduced the previous year, indicating that prime-aged females bear higher costs of reproduction. We show that individual quality and age were key factors modulating the costs of reproduction in a capital breeder but that environmental or social conditions were not, highlighting the importance of considering multiple factors when studying costs of reproduction.
Bowman, Elizabeth; Tatar, Marc
2016-10-27
BACKGROUND: The ratio of protein to carbohydrate (P:C) consumed influences reproduction and lifespan, outcomes that are often maximized by different P:C intake. OBJECTIVE: Determine if reproduction in female Drosophila drives elevated P:C intake. Distinguish whether such a preference is driven by egg production or from male-derived sex peptides in seminal fluid. METHODS: Intake of protein and carbohydrate was measured in a diet-choice assay. Macronutrient intake was calculated for mated and unmated fertile females, mated and unmated sterile females, and both types of female when mated to wildtype males and to males lacking sex peptide. RESULTS: Mated females have high P:C intake relative to unmated females and mated, sterile females. Fertile females mated to wildtype males and to males lacking sex peptide have high P:C intake, but sterile females have similar, low P:C intake when unmated and when mated to males lacking sex peptide. CONCLUSIONS: The metabolic demands of egg production and sex peptides are individually sufficient to drive elevated P:C intake in adult female Drosophila. Reproductive state can thus modulate how animals consume macronutrients, which in turn can impact their health and aging.
Bowman, Elizabeth; Tatar, Marc
2016-01-01
BACKGROUND: The ratio of protein to carbohydrate (P:C) consumed influences reproduction and lifespan, outcomes that are often maximized by different P:C intake. OBJECTIVE: Determine if reproduction in female Drosophila drives elevated P:C intake. Distinguish whether such a preference is driven by egg production or from male-derived sex peptides in seminal fluid. METHODS: Intake of protein and carbohydrate was measured in a diet-choice assay. Macronutrient intake was calculated for mated and unmated fertile females, mated and unmated sterile females, and both types of female when mated to wildtype males and to males lacking sex peptide. RESULTS: Mated females have high P:C intake relative to unmated females and mated, sterile females. Fertile females mated to wildtype males and to males lacking sex peptide have high P:C intake, but sterile females have similar, low P:C intake when unmated and when mated to males lacking sex peptide. CONCLUSIONS: The metabolic demands of egg production and sex peptides are individually sufficient to drive elevated P:C intake in adult female Drosophila. Reproductive state can thus modulate how animals consume macronutrients, which in turn can impact their health and aging. PMID:28035342
USDA-ARS?s Scientific Manuscript database
Previous research demonstrated a favorable relationship between the number of follicles detectable in the bovine ovary by ultrasonography and fertility, and bovine females with diminished numbers of antral follicles had smaller reproductive tracts. Therefore, we hypothesized that uterine function w...
Sources of variation in survival of breeding female wood ducks
Hartke, Kevin M.; Grand, J.B.; Hepp, G.R.; Folk, T.H.
2006-01-01
In waterfowl, reproduction is physiologically demanding and females are exposed to varying risks of mortality at different periods of the breeding cycle. Moreover, differences among females may influence survival within breeding periods. We captured and fitted female Wood Ducks (Aix sponsa) with radio-transmitters before nest initiation during two breeding seasons to estimate survival and investigate sources of variation in survival. We partitioned the breeding season into three periods (preincubation, incubation, postnesting) according to breeding status of individual females, and used information-theoretic methods to compare models in which daily survival varied among periods, between successful and failed nesting females, and with parameters describing individual heterogeneity. Our analysis suggested that daily survival was best modeled as a function of breeding period, differences between successful and failed nesting females during postnesting, and early incubation body condition of successful females during post-nesting. Model-averaged daily survival was 0.9988 (95% CL: 0.9963-0.9996) during preincubation and 1.0 during incubation. Postnesting daily survival was 1.0 for failed nesting females and 0.9948 (0.9773-0.9988) for successful females, suggesting a trade-off between current reproduction and survival. Female age, body condition at capture, nest initiation date, and brood size generally were not useful for explaining variation in survival. Only early incubation body condition was important for modeling survival of successful females during postnesting; however, weight of evidence was limited and the effect on survival was weak. Mortality was greatest for females during preincubation and for females that nested successfully. Results support the hypothesis that brood care is costly for females. ?? The Cooper Ornithological Society 2006.
Gastric Bypass Surgery but Not Caloric Restriction Improves Reproductive Function in Obese Mice
Frank, Aaron P.; Zechner, Juliet F.; Clegg, Deborah J
2015-01-01
In women, obesity is associated with decrements in reproductive health that are improved with weight loss. Due to the difficulty of maintaining weight loss through lifestyle interventions, surgical interventions have become popular treatments for obesity. We examined how weight loss induced by Roux-en Y gastric bypass surgery (RYGB) or calorie restriction impacted expression of hypothalamic genes related to energy intake and reproduction. RYGB and calorie restriction induced equivalent weight loss; however, expression of the anorexigenic melanocortin pathway decreased only in calorie restricted mice. Serum estradiol concentrations were lower in calorie restricted mice relative to RYGB during proestrous, suggesting that RYGB maintained normal estrous cycling. Thus, effects of RYGB for female mice, and possibly humans, extend beyond weight loss to include enhanced reproductive health. PMID:26667161
Female freshwater crayfish adjust egg and clutch size in relation to multiple male traits
Galeotti, Paolo; Rubolini, Diego; Fea, Gianluca; Ghia, Daniela; Nardi, Pietro A; Gherardi, Francesca; Fasola, Mauro
2006-01-01
Females may invest more in reproduction if they acquire mates of high phenotypic quality, because offspring sired by preferred partners may be fitter than offspring sired by non-preferred ones. In this study, we tested the differential maternal allocation hypothesis in the freshwater crayfish, Austropotamobius italicus, by means of a pairing experiment aimed at evaluating the effects of specific male traits (body size, chelae size and chelae asymmetry) on female primary reproductive effort. Our results showed that females laid larger but fewer eggs for relatively small-sized, large-clawed males, and smaller but more numerous eggs for relatively large-sized, small-clawed males. Chelae asymmetry had no effects on female reproductive investment. While the ultimate consequences of this pattern of female allocation remain unclear, females were nevertheless able to adjust their primary reproductive effort in relation to mate characteristics in a species where inter-male competition and sexual coercion may mask or obscure their sexual preferences. In addition, our results suggest that female allocation may differentially affect male characters, thus promoting a trade-off between the expression of different male traits. PMID:16600888
Female urinary incontinence and sexuality
Mota, Renato Lains
2017-01-01
ABSTRACT Urinary incontinence is a common problem among women and it is estimated that between 15 and 55% of them complain of lower urinary symptoms. The most prevalent form of urinary incontinence is associated with stress, followed by mixed urinary incontinence and urge urinary incontinence. It is a symptom with several effects on quality of life of women mainly in their social, familiar and sexual domains. Female reproductive and urinary systems share anatomical structures, which promotes that urinary problems interfere with sexual function in females. This article is a review of both the concepts of female urinary incontinence and its impact on global and sexual quality of life. Nowadays, it is assumed that urinary incontinence, especially urge urinary incontinence, promotes anxiety and several self-esteem damages in women. The odour and the fear of incontinence during sexual intercourse affect female sexual function and this is related with the unpredictability and the chronicity of incontinence, namely urge urinary incontinence. Female urinary incontinence management involves conservative (pelvic floor muscle training), surgical and pharmacological treatment. Both conservative and surgical treatments have been studied about its benefit in urinary incontinence and also the impact among female sexual function. Unfortunately, there are sparse articles that evaluate the benefits of female sexual function with drug management of incontinence. PMID:28124522
Roy, Subhrajyoti; Chaudhuri, Tapas Kumar
2017-04-01
Diplazium esculentum, a commonly consumed seasonal vegetable, has been reported to have some pathological effects in some animals. But, its effect on the male reproductive function has not yet been studied. To investigate the effects of boiled D. esculentum (BDE), the form which human consumes, on male reproductive functions of Swiss albino mice. Male (120 in no.) and female (80 in no.) Swiss albino mice (6-8 weeks of age) were fed orally with 80, 160 and 320 mg/kg bw of BDE within a span of 180 d. After the treatment, body weight, absolute- and relative-testis weight, relative-weight of other organs, their biochemical parameters, hypo-osmotic swelling test (HOST) of spermatozoa, testis histology and fertility and fecundity tests were performed to justify the toxic effects of D. esculentum on male reproductive functions. Significant dose- and time-dependent decreases were observed in body weight, absolute- and relative-testis weight, relative-weights of other organs and their biochemical parameters, percentage of live spermatozoa and percentage of fertility and fecundity in BDE fed mice. Significant decreases were observed in diameter, perimeter and area of the seminiferous tubules of mice treated for 180 d. The percentage of empty seminiferous tubules was increased significantly in BDE treated mice when compared to the controls. These results suggest that the intake of D. esculentum, even after cooking, may induce infertility by altering the male reproductive function, and therefore, should be evaluated further as a potential antifertility agent.
Mondal, Mukti; Sarkar, Kaushik; Nath, Partha Pratim; Paul, Goutam
2018-02-01
The aim of the present study was to examine the effect of monosodium glutamate (MSG) on the functions of ovary and uterus in rat. Virgin female rats of Charles Foster strain (120 gms approximately) were administrated MSG by oral gavage at a dose level of 0.8, 1.6, 2.4 gm/kgBW/day, respectively for 30 and 40 days duration. We observed a significant decrease in the duration of proestrus, estrus and metestrus phases, and increase in the duration of diestrus phase and diestrus index compared to control. We found significant increase in the levels of serum LH, FSH and estradiol in test groups of rat. We also observed significant increase in the number of primary and primordial follicles, increase in the size of graafian follicle, and decrease in the size of corpus luteum. Further, we have seen significant increase in the activities SOD, CAT and GST, decrease in the activities GR and GPx, and decrease MDA level in MSG exposed groups. These results suggest that MSG impairs the functions of the ovary probably by augmenting the release of FSH, LH and estradiol; promoting the follicular maturation and improving the biochemical mechanism for antioxidant defense. We also observed significant potentiation of the force of contraction of uterus in estrus, metestrus and diestrus phases. This result suggests that MSG potentiates the contraction of uterus probably by stimulating the estradiol sensitivity to oxytocin. From the results it is concluded that MSG suppresses the female reproductive function in rat probably by impairing the functions of ovary and uterus. © 2017 Wiley Periodicals, Inc.
NASA Astrophysics Data System (ADS)
Lefebvre, Lyndsey S.; Payne, Amber M.; Field, John C.
2016-01-01
Female Pacific sanddab were collected from the Monterey Bay, California to describe their reproductive strategy and annual reproductive cycle, as well as to estimate length at maturity, fecundity, spawning fraction (SF), and spawning interval (SI). Captive females were held to examine degradation of spawning markers and confirmed the biological spawning capabilities of the species. The reproductive season extended from May through January, as determined through macroscopic and histological examination of ovaries. Oocyte development was asynchronous, and an indeterminate fecundity pattern was displayed. Absolute and relative batch fecundity values were variable (means = 6663 eggs and 54 eggs g- 1 somatic weight, respectively) and significantly related to maternal length. During the period of highest reproductive activity, SF ranged from 0.42 to 0.98, suggesting some females were spawning on a daily basis. Monthly SF and SI were related to length, with smaller females having a truncated season and lower SF compared to larger females. Lengths at 50% (119 mm) and 95% (149 mm) maturity showed a downward shift relative to the 1940s, though the magnitude and cause of this shift remain unknown. This study highlights the importance of considering demographic shifts and size-related dynamics when modeling a stock's reproductive potential.
Kapheim, Karen M; Johnson, Makenna M
2017-10-15
Eusocial insect colonies are defined by extreme variation in reproductive activity among castes, but the ancestral conditions from which this variation arose are unknown. Investigating the factors that contribute to variation in reproductive physiology among solitary insects that are closely related to social species can help to fill this gap. We experimentally tested the role of nutrition, juvenile hormone (JH) and social cues on reproductive maturation in solitary alkali bees (Halictidae: Nomia melanderi ). We found that alkali bee females emerge from overwintering with small Dufour's glands and small ovaries, containing oocytes in the early stages of development. Oocyte maturation occurs rapidly, and is staggered between the two ovaries. Lab-reared females reached reproductive maturity without access to mates or nesting opportunities, and many had resorbed oocytes. Initial activation of these reproductive structures does not depend on pollen consumption, though dietary protein or lipids may be necessary for long-term reproductive activity. JH is likely to be a limiting factor in alkali bee reproductive activation, as females treated with JH were more likely to develop mature oocytes and Dufour's glands. Unlike for related social bees, the effects of JH were not suppressed by the presence of older, reproductive females. These results provide valuable insight into the factors that influence reproductive activity in an important native pollinator, and those that may have been particularly influential in the evolution of reproductive castes. © 2017. Published by The Company of Biologists Ltd.
Membrane progesterone receptors in reproduction and cancer.
Valadez-Cosmes, Paulina; Vázquez-Martínez, Edgar Ricardo; Cerbón, Marco; Camacho-Arroyo, Ignacio
2016-10-15
Progesterone is a sexual steroid hormone that has a critical role in reproductive processes in males and females of several species, including humans. Furthermore, progesterone has been associated with pathological diseases such as breast, gynecological and brain cancer, regulating cell proliferation, apoptosis, and metastasis. In the past, progesterone actions were thought to be only mediated by its intracellular receptor (PR). However, recent evidence has demonstrated that membrane progesterone receptors (mPRs) mediate most of the non-classical progesterone actions. The role of the different mPRs subtypes in progesterone effects in reproduction and cancer is an emerging and exciting research area. Here we review studies to date regarding mPRs role in reproduction and cancer and discuss their functions and clinical relevance, suggesting mPRs as putative pharmacological targets and disease markers in cancer and diseases associated with reproduction. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Schenk, Sven; Krauditsch, Christian; Frühauf, Peter; Gerner, Christopher; Raible, Florian
2016-11-29
Animals require molecular signals to determine when to divert resources from somatic functions to reproduction. This decision is vital in animals that reproduce in an all-or-nothing mode, such as bristle worms: females committed to reproduction spend roughly half their body mass for yolk and egg production; following mass spawning, the parents die. An enigmatic brain hormone activity suppresses reproduction. We now identify this hormone as the sesquiterpenoid methylfarnesoate. Methylfarnesoate suppresses transcript levels of the yolk precursor Vitellogenin both in cell culture and in vivo , directly inhibiting a central energy-costly step of reproductive maturation. We reveal that contrary to common assumptions, sesquiterpenoids are ancient animal hormones present in marine and terrestrial lophotrochozoans. In turn, insecticides targeting this pathway suppress vitellogenesis in cultured worm cells. These findings challenge current views of animal hormone evolution, and indicate that non-target species and marine ecosystems are susceptible to commonly used insect larvicides.
Horsley, Kimberly; Stark, Lloyd R.; McLetchie, D. Nicholas
2011-01-01
Background and Aims Expected life history trade-offs associated with sex differences in reproductive investment are often undetected in seed plants, with the difficulty arising from logistical issues of conducting controlled experiments. By controlling genotype, age and resource status of individuals, a bryophyte was assessed for sex-specific and location-specific patterns of vegetative, asexual and sexual growth/reproduction across a regional scale. Methods Twelve genotypes (six male, six female) of the dioecious bryophyte Bryum argenteum were subcultured to remove environmental effects, regenerated asexually to replicate each genotype 16 times, and grown over a period of 92 d. Plants were assessed for growth rates, asexual and sexual reproductive traits, and allocation to above- and below-ground regenerative biomass. Key Results The degree of sexual versus asexual reproductive investment appears to be under genetic control, with three distinct ecotypes found in this study. Protonemal growth rate was positively correlated with asexual reproduction and sexual reproduction, whereas asexual reproduction was negatively correlated (appeared to trade-off) with vegetative growth (shoot production). No sex-specific trade-offs were detected. Female sex-expressing shoots were longer than males, but the sexes did not differ in growth traits, asexual traits, sexual induction times, or above- and below-ground biomass. Males, however, had much higher rates of inflorescence production than females, which translated into a significantly higher (24x) prezygotic investment for males relative to females. Conclusions Evidence for three distinct ecotypes is presented for a bryophyte based on regeneration traits. Prior to zygote production, the sexes of this bryophyte did not differ in vegetative growth traits but significantly differed in reproductive investment, with the latter differences potentially implicated in the strongly biased female sex ratio. The disparity between males and females for prezygotic reproductive investment is the highest known for bryophytes. PMID:21320878
Challenging cell phone impact on reproduction: a review.
Merhi, Zaher O
2012-04-01
The radiofrequency electromagnetic radiation (RF-EMR) produced by cell phones can enhance the excitability of the brain and has recently been classified as carcinogenic. The suggested use of hands-free kits lowers the exposure to the brain, but it might theoretically increase exposure to the reproductive organs. This report summarizes the potential effects of RF-EMR on reproductive potentials in both males and females. A critical review of the literature pertaining to the impact of cell phone RF-EMR on reproduction in male and female animals and humans was performed, with a focus on gonad metabolism, apoptosis of reproductive cells, fertility status, and serum reproductive hormones. While some animal and human studies revealed alterations in reproductive physiology in both males and females, others did not report any association. The in vitro and in vivo studies to date are highly diverse, very inconsistent in conduct and, in many cases, report different primary outcomes. The increasing use of cell phone warrants well-designed studies to ascertain the effect of their RF-EMR on reproduction.
Selvamani, Amutha; Sohrabji, Farida
2009-01-01
While human observational studies and animal studies report a neuroprotective role for estrogen therapy in stroke, the multicenter placebo-controlled Women's Health Initiative (WHI) study concluded that hormone therapy increased the risk for stroke in postmenopausal women. The present study therefore tested the hypothesis that estrogen replacement would increase the severity of a stroke-like injury in females when this replacement occurs after a prolonged hypoestrogenic period, such as the menopause or reproductive senescence, but not when given to females that were normally cycling immediately prior to the hormone replacement. Two groups of female rats were used: multiparous females with normal but lengthened estrus cycles (mature adults), and older multiparous females currently in a persistent acyclic state (reproductive senescent). Animals were either used intact, or were bilaterally ovariectomized and immediately replaced with a 17β-estradiol pellet or control pellet. Animals were subject to a forelimb placing test (a test for sensorimotor deficit) and thereafter to middle cerebral artery occlusion (MCAo) by stereotaxic injection of the vasoconstrictive peptide endothelin-1, adjacent to the MCA. One week after stroke, behavioral tests were performed again. Cortical and striatal infarct volume, measured from brain slices, was significantly greater in intact reproductive senescent females as compared to intact mature adults. Furthermore, estrogen treatment to ovariectomized mature adult females significantly reduced the cortical infarct volume. Paradoxically, estrogen treatment to ovariectomized reproductive senescent females significantly increased cortical and striatal infarct volumes as compared to control pellet replaced senescent females. Significant post-stroke behavioral deficit was observed in all groups on the side contralateral to the lesion, while senescent females also exhibited deficits on the ipsilateral side, in the cross-midline forelimb placement test. Using an animal model that approximates the natural ovarian aging process, these findings strongly support the hypothesis that the effectiveness of estrogen therapy in protecting brain health may depend critically on the time of initiation with respect to a female's reproductive status. PMID:18829137
Arnau-Bonachera, A; Cervera, C; Blas, E; Larsen, T; Martínez-Paredes, E; Ródenas, L; Pascual, J J
2017-12-11
To achieve functional but also productive females, we hypothesised that it is possible to modulate acquisition and allocation of animals from different genetic types by varying the main energy source of the diet. To test this hypothesis, we used 203 rabbit females belonging to three genetic types: H (n=66), a maternal line characterised by hyper-prolificacy; LP (n=67), a maternal line characterised by functional hyper-longevity; R (n=79), a paternal line characterised by growth rate. Females were fed with two isoenergetic and isoprotein diets differing in energy source: animal fat (AF) enhancing milk yield; cereal starch (CS) promoting body reserves recovery. Feed intake, weight, perirenal fat thickness (PFT), milk yield and blood traits were controlled during five consecutive reproductive cycles (RCs). Females fed with CS presented higher PFT (+0.2 mm, P0.05), particularly for those fed with AF. Moreover, LP females fed with AF progressively increased PFT across the RC, whereas those fed with CS increased PFT during early lactation (+7.3%; P<0.05), but partially mobilised it during late lactation (-2.8%; P<0.05). Independently of the diet offered, LP females reached weaning with similar PFT. H females fed with either of the two diets followed a similar trajectory throughout the RC. For milk yield, the effect of energy source was almost constant during the whole experiment, except for the first RC of females from the maternal lines (H and LP). These females yielded +34.1% (P<0.05) when fed with CS during this period. Results from this work indicate that the resource acquisition capacity and allocation pattern of rabbit females is different for each genetic type. Moreover, it seems that by varying the main energy source of the diet it is possible to modulate acquisition and allocation of resources of the different genetic types. However, the response of each one depends on its priorities over time.
USDA-ARS?s Scientific Manuscript database
Reproductive efficiency is of economic importance in commercial beef cattle production, as failure to achieve pregnancy reduces the number of calves marketed. Identification of genetic markers with predictive merit for reproductive success would facilitate early selection of females and avoid ineff...
Mangold, Alexandra; Trenkwalder, Katharina; Ringler, Max; Hödl, Walter; Ringler, Eva
2015-09-03
Reproductive skew, the uneven distribution of reproductive success among individuals, is a common feature of many animal populations. Several scenarios have been proposed to favour either high or low levels of reproductive skew. Particularly a male-biased operational sex ratio and the asynchronous arrival of females is expected to cause high variation in reproductive success among males. Recently it has been suggested that the type of benefits provided by males (fixed vs. dilutable) could also strongly impact individual mating patterns, and thereby affecting reproductive skew. We tested this hypothesis in Hyalinobatrachium valerioi, a Neotropical glass frog with prolonged breeding and paternal care. We monitored and genetically sampled a natural population in southwestern Costa Rica during the breeding season in 2012 and performed parentage analysis of adult frogs and tadpoles to investigate individual mating frequencies, possible mating preferences, and estimate reproductive skew in males and females. We identified a polygamous mating system, where high proportions of males (69 %) and females (94 %) reproduced successfully. The variance in male mating success could largely be attributed to differences in time spent calling at the reproductive site, but not to body size or relatedness. Female H. valerioi were not choosy and mated indiscriminately with available males. Our findings support the hypothesis that dilutable male benefits - such as parental care - can favour female polyandry and maintain low levels of reproductive skew among males within a population, even in the presence of direct male-male competition and a highly male-biased operational sex ratio. We hypothesize that low male reproductive skew might be a general characteristic in prolonged breeders with paternal care.
Generation of ER{alpha}-floxed and knockout mice using the Cre/LoxP system
DOE Office of Scientific and Technical Information (OSTI.GOV)
Antonson, P., E-mail: per.antonson@ki.se; Omoto, Y.; Humire, P.
2012-08-10
Highlights: Black-Right-Pointing-Pointer ER{alpha} floxed and knockout mice were generated. Black-Right-Pointing-Pointer Disruption of the ER{alpha} gene results in sterility in both male and female mice. Black-Right-Pointing-Pointer ER{alpha}{sup -/-} mice have ovaries with hemorrhagic follicles and hypoplastic uterus. Black-Right-Pointing-Pointer Female ER{alpha}{sup -/-} mice develop obesity. -- Abstract: Estrogen receptor alpha (ER{alpha}) is a nuclear receptor that regulates a range of physiological processes in response to estrogens. In order to study its biological role, we generated a floxed ER{alpha} mouse line that can be used to knock out ER{alpha} in selected tissues by using the Cre/LoxP system. In this study, we established amore » new ER{alpha} knockout mouse line by crossing the floxed ER{alpha} mice with Cre deleter mice. Here we show that genetic disruption of the ER{alpha} gene in all tissues results in sterility in both male and female mice. Histological examination of uterus and ovaries revealed a dramatically atrophic uterus and hemorrhagic cysts in the ovary. These results suggest that infertility in female mice is the result of functional defects of the reproductive tract. Moreover, female knockout mice are hyperglycemic, develop obesity and at the age of 4 months the body weight of these mice was more than 20% higher compared to wild type littermates and this difference increased over time. Our results demonstrate that ER{alpha} is necessary for reproductive tract development and has important functions as a regulator of metabolism in females.« less
On sexual behavior and sex-role reversal.
Schuiling, Gerard A
2005-09-01
Sex is not about reproduction; sex is about (re-)combination of DNA. Sex, not reproduction, always involves physical contact between two individuals; to achieve this, strategies of sexual behavior evolved. Sexual behavior, therefore, did not evolve as part of a reproductive strategy, but evolved to enable exchange of genetic material. In multicellular organisms the situation is more complicated than in unicellular organisms, as it is impossible for each cell within a multicellular body to have sex with another cell. Hence, evolution selected a system in which the possibility to have sex was limited to only one cell-line: the germ cells. As a result, sex adopted the character of fertilization, and sex and reproduction became inseparably linked. Still, in some species, including humans, sexual behavior still exhibits features of its evolutionary past: in humans (like in bonobo's) most sexual activity and many sexual behavioral patterns have nothing to do with reproduction (masturbation, homosexual behavior, for example); in humans, sexual behavior also became associated with other strategic objectives, such as intensifying the pair bond, expression of love or power. Different genders - male and female - evolved, and each gender evolved typical gender-related sexual and reproductive strategies as well. In most multicellular species, these strategies became inextricably mixed, and sexual behavior increasingly more - and in most species even exclusively - 'served' the interests of reproduction: sexual behavior became more or less synonymous with reproductive behavior. In most species, the 'mix' of sexual and reproductive strategies evolved into typical gender-related patterns of behavior, that is, in typical 'sex-roles'. Often, males are bigger and more 'beautiful' (= more intensely ornamented) than females; males compete with each other for access to females; males court females, while females choose males ('female choice'). However, ecological circumstances may cause a reversal of sex-roles, resulting in a situation in which females are bigger and more intensely ornamented than males, females compete for access to males, females court males and only males invest in care for the young, provided they are relatively certain of their paternity. Also, as in the case of the spotted hyena, females may be highly virilized and be socially dominant. This 'sex-role reversal' is seen, e.g., when males are relatively rare due to high predation pressure, or when the process of reproduction is very risky for the same reason: then it is 'better' that males, with their plenty of sperm, are wasted, than females with their few, precious eggs. It can be argued, with women being the fair sex, exhibiting competitive behavior and with an actively displaying courtship, and with men investing heavily in their offspring, meanwhile taking all (cultural) kinds of measures to guarantee their paternity, that humans, too, exhibit some degree of sex-role reversal.
NASA Astrophysics Data System (ADS)
Martínez, Gastón; Defeo, Omar
2006-12-01
A full analysis of the reproductive biology of the isopod Excirolana braziliensis Richardson 1912 was conducted in a sandy beach of Uruguay, located at the southernmost edge of its distributional range in the Atlantic Ocean. Reproductive and recruitment periods of E. braziliensis were concentrated in austral summer. Females with oostegites appeared in November, whereas total biomass, individual sizes and fecundity of ovigerous females peaked between December and January. These concurrent traits were responsible for the significant peak of juveniles in January. The size at maturity was 9.88 mm. Four embryonic developmental stages were described and identified: mean length linearly increased from stages I to III, whereas dry weight exponentially decreased from stages I to IV. The high reproductive output (0.41-0.58), reported for the first time in this isopod, exceeds the rates documented for other isopods. Reproduction of E. braziliensis at the southern edge of its range is semelparous: females produce one brood during the reproductive season, exhaust their energy reserves during incubation, and probably die at the end of the reproductive season. A macroscale comparison suggests that E. braziliensis at the southern edge of its range counteracts its narrow reproductive period by a short incubation period with larger individual mature female and embryo sizes, higher fecundity and a higher percentage of ovigerous females than in subtropical and tropical populations. These extreme reproductive indicators could be attributed to the internal retention of embryos that assures offspring survival, coupled with a high adaptation capability to environmental variations across its range.
Mura, Maria Elena; Ruiu, Luca
2018-06-21
The main objective of this study was to investigate the effects of the insecticidal compound spinosad on the survival, reproduction, and immune functions of the Mediterranean fruit fly. The lethal and sub-lethal effects were determined on Ceratitis capitata Wied. (Diptera: Tephritidae) challenged with different concentrations of spinosad. A median lethal concentration of 0.28 ppm was observed on flies feeding for 5 days on a treated diet. A significant and concentration-dependent decrease in fecundity, egg hatch rate, and lifespan was also detected in treated compared with control flies. Gene expression analyses conducted on treated insects by RT-qPCR revealed an immunomodulatory action of sub-lethal concentrations of spinosad. Target transcripts included several genes involved in medfly immunity and male or female reproductive functions. While a significant upregulation was detected in treated males a short time after spinosad ingestion, most target genes were downregulated in treated females. Our study confirmed the high toxicity of spinosad to C. capitata , highlighting an indirect effect on insect lifespan and reproductive performance at sub-lethal doses. In addition to defining the acute and sub-lethal toxicity of spinosad against the fly, this study provides new insights on the interaction of this compound with insect physiology.
Molecular regulation and role of angiogenesis in reproduction.
Rizov, Momchil; Andreeva, Petya; Dimova, Ivanka
2017-04-01
Angiogenesis is an essential process for proper functioning of the female reproductive system and for successful pregnancy realization. The multitude of factors required for physiological angiogenesis and the complexity of regulation of their temporal-spatial activities contribute to aberrations in human fertilization and pregnancy outcomes. In this study, we reviewed the current knowledge of the temporal expression patterns, functions, and regulatory mechanisms of angiogenic factors during foliculogenesis, early implantation/placentation and embryo development, as well as recurrent spontaneous abortions. Angiogenic factors including vascular endothelial growth factors and angiopoietins have documented roles in the development of primordial follicles into mature antral follicles. They also participate in decidualization, which is accompanied by the creation of an extensive network of vessels in the stromal bed that support the growth of the embryo and the placenta, and maintain early pregnancy. During placentation angiogenic and angiomodulatory cytokines, T and B lymphocytes and macrophages affect angiogenesis in a context-dependent manner. Defects in angiogenesis at the maternal-fetal interface contribute to miscarriage in humans. The establishment of more polymorphisms in the genes involved in angiogenesis/vasculogenesis, and their pathological phenotype and expression could give opportunities for prediction, creating a therapeutic strategy, and treatment of diseases related to female reproductive health and problematic conception. Copyright © 2017. Published by Elsevier B.V.
Effect of 17β-trenbolone on male and female reproduction in Japanese quail (Coturnix japonica)
Henry, Paula F.P.; Akuffo, Valorie G.; Chen, Yu; Karouna-Renier, Natalie K.; Sprague, Daniel T.; Bakst, Murray R.
2012-01-01
The anabolic steroid 17β trenbolone (17β-TB), a known endocrine disrupting chemical, may influence reproductive functions in avian wildlife. We evaluated the effects of dietary exposure to 17β-TB at 5 and 20 ppm on reproductive functional endpoints in Japanese quail during and after sexual maturation. In the male, 5 and 20 ppm treatments revealed no differences in body and testes weight, testes histology, plasma testosterone concentrations, or size and weight of the foam glands. However, the onset of foam production was significantly earlier (days of age) in the 20 ppm males. In females, dietary 17β-TB at 20 ppm caused a reduction in the number of maturing yellow yolk follicles and overall egg production. Plasma testosterone concentrations were reduced compared to controls. Histology of the oviductal sperm storage tubules was normal in all treatments. The number of sperm holes, sites on the perivitelline layer (PVL) where sperm bound and hydrolyzed a path through the PVL, was significantly greater in the 10th egg laid compared to the 1st egg laid in the 20 ppm treatment. Potential effects, albeit transient, on endpoints associated with male maturation warrant further investigation into the sensitivity of these measures in the event of embryonic and/or trans-generational exposure to 17β-TB.
2010-01-01
Background Sexual selection theory predicts that females, being the limiting sex, invest less in courtship signals than males. However, when chemical signals are involved it is often the female that initiates mating by producing stimuli that inform about sex and/or receptivity. This apparent contradiction has been discussed in the literature as 'the female pheromone fallacy'. Because the release of chemical stimuli may not have evolved to elicit the male's courtship response, whether these female stimuli represent signals remains an open question. Using techniques to visualise and block release of urine, we studied the role of urine signals during fighting and mating interactions of crayfish (Pacifastacus leniusculus). Test individuals were blindfolded to exclude visual disturbance from dye release and artificial urine introduction. Results Staged female-male pairings during the reproductive season often resulted in male mating attempts. Blocking female urine release in such pairings prevented any male courtship behaviour. Artificial introduction of female urine re-established male mating attempts. Urine visualisation showed that female urine release coincides with aggressive behaviours but not with female submissive behaviour in reproductive interactions as well as in intersexual and intrasexual fights. In reproductive interactions, females predominately released urine during precopulatory aggression; males subsequently released significantly less urine during mating than in fights. Conclusions Urine-blocking experiments demonstrate that female urine contains sex-specific components that elicit male mating behaviour. The coincidence of chemical signalling and aggressive behaviour in both females and males suggests that urine release has evolved as an aggressive signal in both sexes of crayfish. By limiting urine release to aggressive behaviours in reproductive interactions females challenge their potential mating partners at the same time as they trigger a sexual response. These double messages should favour stronger males that are able to overcome the resistance of the female. We conclude that the difference between the sexes in disclosing urine-borne information reflects their conflicting interests in reproduction. Males discontinue aggressive urine signalling in order to increase their chances of mating. Females resume urine signalling in connection with aggressive behaviour, potentially repelling low quality or sexually inactive males while favouring reproduction with high quality males. PMID:20353555
Hernandez-Jimenez, Armando; Rios-Cardenas, Oscar
2017-12-06
There is extensive morphological variation of male genitalia across animals with internal fertilization, even among closely related species. Most studies attempting to explain this extraordinary diversity have focused on processes that occur post-copula (e.g. sperm competition, cryptic female choice). Only a few studies have focused on the pre-copula process of female preference. In addition, the extent to which this variation could be associated with the use of different reproductive tactics has yet to be explored. Here, we show that female preference for male genitalia length in two livebearing fishes depends on the type of reproductive tactic of the males being evaluated as well as the body condition of the female. In a species where all males coax females to acquire matings (courters), females preferred males with short genitalia. In a species with genetically influenced alternative reproductive tactics (courter males that only court and produce courter sons, sneaker males that use the coercive tactic of sneak chase and produce sneaker sons), female preference depended on an interaction between male tactic and female condition: females in good condition preferred courter males with short genitalia, and sneaker males with long genitalia. Our results suggest that female preference for male traits favourable to their sons may be an important factor contributing to the diversification of male genitalia. Despite the contrasting selection for genitalia length that our female preference tests suggest, we found no significant differences in genitalia length between coaxing (courters) and coercive (sneakers) males. Our study represents a starting point to more clearly understand the role of alternative reproductive tactics and variation in female mate preference in the evolution of male genitalia. © 2017 The Author(s).
Hostetler, Jeffrey A; Onorato, David P; Bolker, Benjamin M; Johnson, Warren E; O'Brien, Stephen J; Jansen, Deborah; Oli, Madan K
2012-01-01
Genetic introgression has been suggested as a management tool for mitigating detrimental effects of inbreeding depression, but the role of introgression in species conservation has been controversial, partly because population-level impacts of genetic introgressions are not well understood. Concerns about potential inbreeding depression in the endangered Florida panther (Puma concolor coryi) led to the release of eight female Texas pumas (P. c. stanleyana) into the Florida panther population in 1995. We used long-term reproductive data (1995-2008) collected from 61 female Florida panthers to estimate and model reproduction probability (probability of producing a litter) and litter size, and to investigate the influence of intentional genetic introgression on these parameters. Overall, 6-month probability of reproduction (±1SE) was 0.232 ± 0.021 and average litter size was 2.60 ± 0.09. Although F(1) admixed females had a lower reproduction probability than females with other ancestries, this was most likely because kittens born to F(1) females survive better; consequently, these females are unavailable for breeding until kittens are independent. There was no evidence for the effect of ancestry on litter size or of heterozygosity on probability of reproduction or litter size. In contrast, earlier studies have shown that genetic introgression positively affected Florida panther survival. Our results, along with those of earlier studies, clearly suggest that genetic introgression can have differential effects on components of fitness and highlight the importance of examining multiple demographic parameters when evaluating the effects of management actions.
Reproductive strategies in males of the world's southernmost lizards.
Fernández, Jimena B; Medina, Marlin; Kubisch, Erika L; Scolaro, José A; Ibargüengoytía, Nora R
2017-03-01
Reproductive and life history patterns in reptiles are tightly related to the environmental conditions, so male reproductive cycles have been historically characterized as continuous, for tropical lizards, or seasonal, for temperate lizards. However, males of Liolaemus and Phymaturus lizards (Liolaemidae), from cold temperate climates of high altitudes or latitudes in Argentina and Chile, have developed a variety of reproductive cycles to coordinate with the short female reproductive season and to deal with the low frequency of reproductive females in the population. Using gonadal histology and morphological analysis, we describe the male reproductive biology, fat storage and sexual dimorphism of the viviparous lizards Liolaemus sarmientoi and Liolaemus magellanicus that inhabit an austral grass steppe at 51°S, in the southern limit of the American continent. Males of L. sarmientoi and L. magellanicus are reproductively available during the entire activity season of approximately 5 months. In addition, males of both species exhibit greater body sizes than females in morphological variables relevant in sexual selection. Meanwhile, females of both species exhibit larger inter-limb length than conspecific males, which suggests fecundity selection to increase space for a larger litter size. The continuous sperm production throughout the activity season allows these liolaemids to mate at any time when females ovulate, representing a selective advantage to deal with the short activity season and the adversities of the cold environment they inhabit. © 2016 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.
Jayaweera, Anuradhi; Barry, Katherine L.
2015-01-01
Strategic ejaculation is a behavioural strategy shown by many animals as a response to sperm competition and/or as a potential mechanism of cryptic male choice. Males invest more mating resources when the risk of sperm competition increases or they invest more in high quality females to maximize their reproductive output. We tested this hypothesis in the false garden mantid Pseudomantis albofimbriata, where females are capable of multiply mating and body condition is an indicator of potential reproductive fitness. We predicted male mantids would ejaculate strategically by allocating more sperm to high quality females. To determine if and how males alter their ejaculate in response to mate quality, we manipulated female food quantity so that females were either in good condition with many eggs (i.e. high quality) or poor condition with few eggs (i.e. low quality). Half of the females from each treatment were used in mating trials in which transferred sperm was counted before fertilisation occurred and the other half of females were used in mating trials where fertilisation occurred and ootheca mass and total eggs in the ootheca were recorded. Opposed to our predictions, the total number of sperm and the proportion of viable sperm transferred did not vary significantly between female treatments. Male reproductive success was entirely dependent on female quality/fecundity, rather than on the number of sperm transferred. These results suggest that female quality is not a major factor influencing postcopulatory male mating strategies in P. albofimbriata, and that sperm number has little effect on male reproductive success in a single mating scenario. PMID:25970459
Role of GnRH-II and its receptor in testicular function
USDA-ARS?s Scientific Manuscript database
The highly conserved, second mammalian isoform of gonadotropin-releasing hormone (GnRH-II) regulates the interaction between energy balance and reproductive behavior in females, as well as exhibits anti-proliferative effects on cancer cells. Furthermore, GnRH-II is an inefficient modulator of gonado...
Aladashvili-Chikvaidze, Nutsa; Kristesashvili, Jenara; Gegechkori, Manana
2015-01-01
Background: Higher risks of reproductive problems have been found in underweight and overweight women with rapid weight gain or loss but evidence is inconsistent especially in relation to the effect of age of body weight changes. Objective: The aim of our study was to detect the peculiarities of menstrual function, prevalence of different types of reproductive disorders and correlations of respective hormonal changes with body mass index (BMI) in young female patients with thinness or obesity since childhood. Materials and Methods: In this prospective cross-sectional study 48 underweight and 55 overweight/obese young women with different reproductive problems underwent complete clinical and hormonal analyses. All 103 patients had weight problems since childhood. Results: Polycystic ovarian syndrome and metabolic syndrome was the most frequent in overweight and obese women, whilst non-classical congenital adrenal hyperplasia and ovarian dysfunction prevailed in underweight women (p˂0.001). No difference was determined according to the age of menarche (p=0.885) and types of menstrual disturbances (p=0.34) between the study groups. Hypogonadotropic hypogonadism was not found in young women who were lean since childhood. Follicle-stimulating hormone (FSH) (p=0.013) and sex hormone binging globulin (SHBG) (p˂0.001) levels were higher in women with low BMI, whilst free testosterone (FT) (p=0.019) and total testosterone (TT) (p=0.003) levels were higher in high BMI participants. BMI negatively correlated with FSH (p=0.009) and SHBG (p=0.001); and positively correlated with FT (p=0.001) and TT (p=0.002). Conclusion: Peculiarities of menstrual function and hormonal changes in young women with thinness or obesity since childhood are related to the types of reproductive disorders and their childhood BMI. PMID:26000003
Poley, Jordan D; Sutherland, Ben J G; Jones, Simon R M; Koop, Ben F; Fast, Mark D
2016-07-04
Salmon lice, Lepeophtheirus salmonis (Copepoda: Caligidae), are highly important ectoparasites of farmed and wild salmonids, and cause multi-million dollar losses to the salmon aquaculture industry annually. Salmon lice display extensive sexual dimorphism in ontogeny, morphology, physiology, behavior, and more. Therefore, the identification of transcripts with differential expression between males and females (sex-biased transcripts) may help elucidate the relationship between sexual selection and sexually dimorphic characteristics. Sex-biased transcripts were identified from transcriptome analyses of three L. salmonis populations, including both Atlantic and Pacific subspecies. A total of 35-43 % of all quality-filtered transcripts were sex-biased in L. salmonis, with male-biased transcripts exhibiting higher fold change than female-biased transcripts. For Gene Ontology and functional analyses, a consensus-based approach was used to identify concordantly differentially expressed sex-biased transcripts across the three populations. A total of 127 male-specific transcripts (i.e. those without detectable expression in any female) were identified, and were enriched with reproductive functions (e.g. seminal fluid and male accessory gland proteins). Other sex-biased transcripts involved in morphogenesis, feeding, energy generation, and sensory and immune system development and function were also identified. Interestingly, as observed in model systems, male-biased L. salmonis transcripts were more frequently without annotation compared to female-biased or unbiased transcripts, suggesting higher rates of sequence divergence in male-biased transcripts. Transcriptome differences between male and female L. salmonis described here provide key insights into the molecular mechanisms controlling sexual dimorphism in L. salmonis. This analysis offers targets for parasite control and provides a foundation for further analyses exploring critical topics such as the interaction between sex and drug resistance, sex-specific factors in host-parasite relationships, and reproductive roles within L. salmonis.
The GnRH analogue triptorelin confers ovarian radio-protection to adult female rats.
Camats, N; García, F; Parrilla, J J; Calaf, J; Martín-Mateo, M; Caldés, M Garcia
2009-10-02
There is a controversy regarding the effects of the analogues of the gonadotrophin-releasing hormone (GnRH) in radiotherapy. This has led us to study the possible radio-protection of the ovarian function of a GnRH agonist analogue (GnRHa), triptorelin, in adult, female rats (Rattus norvegicus sp.). The effects of the X-irradiation on the oocytes of ovarian primordial follicles, with and without GnRHa treatment, were compared, directly in the female rats (F(0)) with reproductive parameters, and in the somatic cells of the resulting foetuses (F(1)) with cytogenetical parameters. In order to do this, the ovaries and uteri from 82 females were extracted for the reproductive analysis and 236 foetuses were obtained for cytogenetical analysis. The cytogenetical study was based on the data from 22,151 metaphases analysed. The cytogenetical parameters analysed to assess the existence of chromosomal instability were the number of aberrant metaphases (2234) and the number (2854) and type of structural chromosomal aberrations, including gaps and breaks. Concerning the reproductive analysis of the ovaries and the uteri, the parameters analysed were the number of corpora lutea, implantations, implantation losses and foetuses. Triptorelin confers radio-protection of the ovaries in front of chromosomal instability, which is different, with respect to the single and fractioned dose. The cytogenetical analysis shows a general decrease in most of the parameters of the triptorelin-treated groups, with respect to their controls, and some of these differences were considered to be statistically significant. The reproductive analysis indicates that there is also radio-protection by the agonist, although minor to the cytogenetical one. Only some of the analysed parameters show a statistically significant decrease in the triptorelin-treated groups.
Peng, Jia; Monsivais, Diana; You, Ran; Zhong, Hua; Pangas, Stephanie A.; Matzuk, Martin M.
2015-01-01
Members of the transforming growth factor β (TGF-β) superfamily are key regulators in most developmental and physiological processes. However, the in vivo roles of TGF-β signaling in female reproduction remain uncertain. Activin receptor-like kinase 5 (ALK5) is the major type 1 receptor for the TGF-β subfamily. Absence of ALK5 leads to early embryonic lethality because of severe defects in vascular development. In this study, we conditionally ablated uterine ALK5 using progesterone receptor-cre mice to define the physiological roles of ALK5 in female reproduction. Despite normal ovarian functions and artificial decidualization in conditional knockout (cKO) mice, absence of uterine ALK5 resulted in substantially reduced female reproduction due to abnormalities observed at different stages of pregnancy, including implantation defects, disorganization of trophoblast cells, fewer uterine natural killer (uNK) cells, and impairment of spiral artery remodeling. In our microarray analysis, genes encoding proteins involved in cytokine–cytokine receptor interactions and NK cell-mediated cytotoxicity were down-regulated in cKO decidua compared with control decidua. Flow cytometry confirmed a 10-fold decrease in uNK cells in cKO versus control decidua. According to these data, we hypothesize that TGF-β acts on decidual cells via ALK5 to induce expression of other growth factors and cytokines, which are key regulators in luminal epithelium proliferation, trophoblast development, and uNK maturation during pregnancy. Our findings not only generate a mouse model to study TGF-β signaling in female reproduction but also shed light on the pathogenesis of many pregnancy complications in human, such as recurrent spontaneous abortion, preeclampsia, and intrauterine growth restriction. PMID:26305969
Smith, Lauren N; Rotstein, David S; Ball, Ray L; Gerlach, Trevor J; Kinsel, Michael; Rodriguez, Maya; de Wit, Martine
2015-12-01
Few reports of neoplastic diseases in manatees exist in the veterinary literature. This case series presents reproductive neoplasia noted in eight wild and long-term captive female Florida manatees (Trichechus manatus latirostris) obtained through carcass recovery and animal rehabilitation programs between April 2009 and May 2014. All cases were evaluated histologically, and diagnoses of uterine carcinoma (n = 1), granulosa cell tumor (n = 2), ovarian adnexal tumor (n = 1), and leiomyoma (n = 5) were made. The underlying cause of tumor development and effects on reproductive success is currently unknown, but possible asymmetric reproductive aging and/or a correlation between obesity and reproductive disorder in long-term nonreproductive female manatees are of interest and warrant further investigation.
Colonello, J H; Cortés, F; Belleggia, M; Massa, A M
2016-05-01
The objective of this study was to estimate reproductive and population parameters of the spiny dogfish Squalus acanthias for the south-western Atlantic Ocean. In total, 2714 specimens (1616 males and 1098 females) were collected from surveys carried out using research vessels. Males ranged from 225 to 861 mm total length (LT ) and females from 235 to 925 mm LT . The size at maturity of females (651 mm) was significantly greater than that of males (565 mm). The maximum proportion of mature individuals (Pmax ) of the gestation ogive was <1, which indicates that a proportion of mature females was not in gestation. This inactivity may be explained by the occurrence of resting periods between cycles or by the asynchrony of the reproductive cycle. The estimated Pmax for the maternity ogive suggested that about one third of mature females were in the maternity stage (i.e. with embryos >156 mm). The temporal and spatial co-occurrence of non-gravid adult females at different stages of ovarian development, as well as gravid females at all embryonic development stages would indicate that the female reproductive cycle in the south-western Atlantic Ocean is asynchronous. The results indicate that S. acanthias is susceptible to fishing pressure on account of its length at maturity, extended reproductive cycles and low fecundity. © 2016 The Fisheries Society of the British Isles.
Liu, Zong-Yu; Jiang, Yi-Ping; Li, Lei; You, Lin-Lin; Wu, You; Xu, Bin; Ge, Lin-Quan; Wu, Jin-Cai
2016-03-01
The brown plant hopper (BPH), Nilaparvata lugens Stål (Hemiptera: Delphacidae), is a major pest affecting rice in Asia, and outbreaks of this pest are closely linked to pesticide-induced stimulation of reproduction. Therefore, the BPH is a classic example of a resurgent pest. However, the effects of different genes on the regulation of pesticide-induced reproductive stimulation in the BPH are unclear. In this study, the regulatory effects of acyl-coenzyme A oxidase (ACO) on the reproduction and biochemistry of the BPH were investigated with gene silencing. The number of eggs laid per female by triazophos (TZP)+dsACO BPH females was significantly lower than those of TZP-treated (without ACO silencing) or TZP+GFP females (negative control), with the number of eggs decreasing by 30.8% (from 529.5 to 366.3) and 32.0% (from 540.5 to 366.3), respectively. The preoviposition period, oviposition period, and longevity of the TZP-treated females were also influenced by dsACO treatment. Additionally, the amounts of crude fat, protein, and some fatty acids (oleic acid, palmitic acid, linoleic acid, stearic acid, and myristoleic acid) in TZP+dsACO females were significantly lower than in TZP-treated females. Thus, ACO is one of the key genes regulating the TZP-induced stimulation of reproduction in BPH females. Copyright © 2015 Elsevier Inc. All rights reserved.
Oxidative stress and its implications in female infertility - a clinician's perspective.
Agarwal, Ashok; Gupta, Sajal; Sharma, Rakesh
2005-11-01
Reactive oxygen species (ROS) have a role in the modulation of gamete quality and gamete interaction. Generation of ROS is inherent in spermatozoa and contaminating leukocytes. ROS influence spermatozoa, oocytes, embryos and their environment. Oxidative stress (OS) mediates peroxidative damage to the sperm membrane and induces nuclear DNA damage. ROS can modulate the fertilizing capabilities of the spermatozoa. There is extensive literature on OS and its role in male infertility and sperm DNA damage and its effects on assisted reproductive techniques. Evidence is accumulating on the role of ROS in female reproduction. Many animal and human studies have elucidated a role for ROS in oocyte development, maturation, follicular atresia, corpus luteum function and luteolysis. OS-mediated precipitation of pathologies in the female reproductive tract is similar to those involved in male infertility. OS influences the oocyte and embryo quality and thus the fertilization rates. ROS appears to play a significant role in the modulation of gamete interaction and also for successful fertilization to take place. ROS in culture media may impact post-fertilization development, i.e. cleavage rate, blastocyst yield and quality (indicators of assisted reproduction outcomes). OS is reported to affect both natural and assisted fertility. Antioxidant strategies should be able to intercept both extracellular and intracellular ROS. This review discusses the sources of ROS in media used in IVF-embryo transfer and strategies to overcome OS in oocyte in-vitro maturation, in-vitro culture and sperm preparation techniques.
Developmental effects of Arochlor 1242 in American kestrels and associated hormone concentrations
French, J.B.; Henry, P.F.P.; Rattner, B.A.
1996-01-01
Recently, diverse field and experimental studies have been brought together to suggest that abnormal sexual and reproductive development in wildlife might be caused by the endocrine-like activity of pollutants acting on embryos. For example, hormonal and gonadal anomalies in juvenile alligators from Florida are associated with exposure to DDT and dicofol, experimental work on laboratory rodents has identified estrogenic and androgenic properties of several pollutants, including polychlorinated biphenyls, and injection of gull eggs with metabolites of DDT produces intersex gonads in the male hatchlings. Very little evidence is available for birds that demonstrates a deficit in reproductive capability by this mechanism. Our breeding and egg-injection studies are investigating the potential of Aroclor 1242 and hydroxylated PCB congener 30, both with known estrogenic activity, to alter the course of embryonic development of reproductive structures and to affect later reproductive function in American kestrels. Findings from young birds whose parents were exposed indicated that gonadal morphology appeared consistent with the genetic sex of exposed birds; testes of exposed birds showed no difference in size or symmetry when compared to controls. Histological preparations showed very little intersexuality of male testes; females had ovaries that were indistinguishable from controls. Female hatchlings tended to show increased androgen and decreased estrogen in their serum with greater dose of Aroclor; females hatchlings that resulted from injected eggs showed an opposite trend. Analyses in progress include LHRH and catecholamine concentrations in the brain.
Male reproductive strategy explains spatiotemporal segregation in brown bears
Steyaert, Sam MJG; Kindberg, Jonas; Swenson, Jon E; Zedrosser, Andreas
2013-01-01
1. Spatiotemporal segregation is often explained by the risk for offspring predation or by differences in physiology, predation risk vulnerability or competitive abilities related to size dimorphism. 2. Most large carnivores are size dimorphic and offspring predation is often intraspecific and related to nonparental infanticide (NPI). NPI can be a foraging strategy, a strategy to reduce competition, or a male reproductive strategy. Spatiotemporal segregation is widespread among large carnivores, but its nature remains poorly understood. 3. We evaluated three hypotheses to explain spatiotemporal segregation in the brown bear, a size-dimorphic large carnivore in which NPI is common; the ‘NPI – foraging/competition hypothesis', i.e. NPI as a foraging strategy or a strategy to reduce competition, the ‘NPI – sexual selection hypothesis’, i.e. infanticide as a male reproductive strategy and the ‘body size hypothesis’, i.e. body-size-related differences in physiology, predation risk vulnerability or competitive ability causes spatiotemporal segregation. To test these hypotheses, we quantified spatiotemporal segregation among adult males, lone adult females and females with cubs-of-the-year, based on GPS-relocation data (2006–2010) and resource selection functions in a Scandinavian population. 4. We found that spatiotemporal segregation was strongest between females with cubs-of-the-year and adult males during the mating season. During the mating season, females with cubs-of-the-year selected their resources, in contrast to adult males, in less rugged landscapes in relative close proximity to certain human-related variables, and in more open habitat types. After the mating season, females with cubs-of-the-year markedly shifted their resource selection towards a pattern more similar to that of their conspecifics. No strong spatiotemporal segregation was apparent between females with cubs-of-the-year and conspecifics during the mating and the postmating season. 5. The ‘NPI – sexual selection hypothesis’ best explained spatiotemporal segregation in our study system. We suggest that females with cubs-of-the-year alter their resource selection to avoid infanticidal males. In species exhibiting NPI as a male reproductive strategy, female avoidance of infanticidal males is probably more common than observed or reported, and may come with a fitness cost if females trade safety for optimal resources. PMID:23461483
The impact of sex ratio and economic status on local birth rates
Chipman, A.; Morrison, E.
2013-01-01
Human mating and reproductive behaviour can vary depending on various mechanisms, including the local sex ratio. Previous research shows that as sex ratios become female-biased, women from economically deprived areas are less likely to delay reproductive opportunities to wait for a high-investing mate but instead begin their reproductive careers sooner. Here, we show that the local sex ratio also has an impact on female fertility schedules. At young ages, a female-biased ratio is associated with higher birth rates in the poorest areas, whereas the opposite is true for the richest areas. At older ages, a female-biased ratio is associated with higher birth rates in the richest, but not the poorest areas. These patterns suggest that female–female competition encourages poorer women to adopt a fast life-history strategy and give birth early, and richer women to adopt a slow life-history strategy and delay reproduction. PMID:23407502
Evolution of male and female genitalia following release from sexual selection.
Cayetano, Luis; Maklakov, Alexei A; Brooks, Robert C; Bonduriansky, Russell
2011-08-01
Despite the key functions of the genitalia in sexual interactions and fertilization, the role of sexual selection and conflict in shaping genital traits remains poorly understood. Seed beetle (Callosobruchus maculatus) males possess spines on the intromittent organ, and females possess a thickened reproductive tract wall that also bears spines. We investigated the role of sexual selection and conflict by imposing monogamous mating on eight replicate populations of this naturally polygamous insect, while maintaining eight other populations under polygamy. To establish whether responses to mating system manipulation were robust to ecological context, we simultaneously manipulated life-history selection (early/late reproduction). Over 18-21 generations, male genital spines evolved relatively reduced length in large males (i.e., shallower static allometry) in monogamous populations. Two nonintromittent male genital appendages also evolved in response to the interaction of mating system and ecology. In contrast, no detectable evolution occurred in female genitalia, consistent with the expectation of a delayed response in defensive traits. Our results support a sexually antagonistic role for the male genital spines, and demonstrate the evolution of static allometry in response to variation in sexual selection opportunity. We argue that further advances in the study of genital coevolution will require a much more detailed understanding of the functions of male and female genital traits. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.
Spatiotemporal variation in reproductive parameters of yellow-bellied marmots.
Ozgul, Arpat; Oli, Madan K; Olson, Lucretia E; Blumstein, Daniel T; Armitage, Kenneth B
2007-11-01
Spatiotemporal variation in reproductive rates is a common phenomenon in many wildlife populations, but the population dynamic consequences of spatial and temporal variability in different components of reproduction remain poorly understood. We used 43 years (1962-2004) of data from 17 locations and a capture-mark-recapture (CMR) modeling framework to investigate the spatiotemporal variation in reproductive parameters of yellow-bellied marmots (Marmota flaviventris), and its influence on the realized population growth rate. Specifically, we estimated and modeled breeding probabilities of two-year-old females (earliest age of first reproduction), >2-year-old females that have not reproduced before (subadults), and >2-year-old females that have reproduced before (adults), as well as the litter sizes of two-year old and >2-year-old females. Most reproductive parameters exhibited spatial and/or temporal variation. However, reproductive parameters differed with respect to their relative influence on the realized population growth rate (lambda). Litter size had a stronger influence than did breeding probabilities on both spatial and temporal variations in lambda. Our analysis indicated that lambda was proportionately more sensitive to survival than recruitment. However, the annual fluctuation in litter size, abetted by the breeding probabilities, accounted for most of the temporal variation in lambda.
Beani, L; Marchini, D; Cappa, F; Petrocelli, I; Gottardo, M; Manfredini, F; Giusti, F; Dallai, R
2017-08-01
Parasitic castration is an adaptive strategy where parasites usurp the hosts' reproductive physiology to complete their life cycle. The alterations in the host traits vary in their magnitude, from subtle changes in the host morpho-physiology and behaviour to the production of complex aberrant phenotypes, which often depend on the host gender. The strepsipteran macroparasite Xenos vesparum induces dramatic behavioural and physiological changes in its female host, the paper wasp Polistes dominula, while its effect on the male phenotype is largely unknown. In this study we investigated how a single X. vesparum parasite influences the functional morphology of P. dominula male reproductive apparatus. We performed morphometry and ultrastructure characterization of corpora allata, testes, seminal vesicles and accessory glands in parasitized and unparasitized males, and also in young and old males to control for the effect of age on the natural deterioration of these organs. Our results show that age significantly affects the development of male reproductive apparatus. A low parasite load - one parasite per host is the common prevalence in the field - has only a marginal impact on the reproductive morphology of P. dominula males, affecting quantitatively but not qualitatively the protein content of male accessory glands. Thus, in male P. dominula wasps, X. vesparum appears to behave as a true "parasite", in clear opposition to the role of "parasitoid" that it takes in female hosts where castration causes the reproductive death. Copyright © 2017 Elsevier Ltd. All rights reserved.
McNamara, K B; Simmons, L W
2017-09-01
Group living can select for increased immunity, given the heightened risk of parasite transmission. Yet, it also may select for increased male reproductive investment, given the elevated risk of female multiple mating. Trade-offs between immunity and reproduction are well documented. Phenotypically, population density mediates both reproductive investment and immune function in the Indian meal moth, Plodia interpunctella. However, the evolutionary response of populations to these traits is unknown. We created two replicated populations of P. interpunctella, reared and mated for 14 generations under high or low population densities. These population densities cause plastic responses in immunity and reproduction: at higher numbers, both sexes invest more in one index of immunity [phenoloxidase (PO) activity] and males invest more in sperm. Interestingly, our data revealed divergence in PO and reproduction in a different direction to previously reported phenotypic responses. Males evolving at low population densities transferred more sperm, and both males and females displayed higher PO than individuals at high population densities. These positively correlated responses to selection suggest no apparent evolutionary trade-off between immunity and reproduction. We speculate that the reduced PO activity and sperm investment when evolving under high population density may be due to the reduced population fitness predicted under increased sexual conflict and/or to trade-offs between pre- and post-copulatory traits. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.
Reid, Jane M; Arcese, Peter; Keller, Lukas F; Losdat, Sylvain
2014-01-01
Ongoing evolution of polyandry, and consequent extra-pair reproduction in socially monogamous systems, is hypothesized to be facilitated by indirect selection stemming from cross-sex genetic covariances with components of male fitness. Specifically, polyandry is hypothesized to create positive genetic covariance with male paternity success due to inevitable assortative reproduction, driving ongoing coevolution. However, it remains unclear whether such covariances could or do emerge within complex polyandrous systems. First, we illustrate that genetic covariances between female extra-pair reproduction and male within-pair paternity success might be constrained in socially monogamous systems where female and male additive genetic effects can have opposing impacts on the paternity of jointly reared offspring. Second, we demonstrate nonzero additive genetic variance in female liability for extra-pair reproduction and male liability for within-pair paternity success, modeled as direct and associative genetic effects on offspring paternity, respectively, in free-living song sparrows (Melospiza melodia). The posterior mean additive genetic covariance between these liabilities was slightly positive, but the credible interval was wide and overlapped zero. Therefore, although substantial total additive genetic variance exists, the hypothesis that ongoing evolution of female extra-pair reproduction is facilitated by genetic covariance with male within-pair paternity success cannot yet be definitively supported or rejected either conceptually or empirically. PMID:24724612
Pretty Good or Pretty Bad? The Ovary and Chemicals in Personal Care Products.
Craig, Zelieann R; Ziv-Gal, Ayelet
2018-04-01
Personal care products (PCP) contain a myriad of chemicals generally formulated to provide a safe and beneficial use. Nonetheless, an increasing amount of laboratory animal and human studies indicate that some chemicals in PCP are associated with decreased hormone production, diminished ovarian reserve, ovarian cancer, and early pregnancy loss. The ovary is key to female fertility by providing the eggs and sex steroid hormones for fertilization and maintenance of reproductive function, respectively. Thus, understanding how chemicals in PCP affect the ovary will shed some light on their potential effects on female fertility. In this review, we provide an overview of: (1) ovarian function as a determinant of fertility in females, (2) the status of knowledge regarding the effects of seven common chemicals in PCP on the ovary, and (3) significant gaps in the literature along with opportunities to eliminate some of the gaps. Findings from the limited existing data suggest that chemicals in PCP such as dibutyl phthalate can reach the ovary in humans and impact its function in animal models. Unfortunately, it is still difficult to assess how relevant findings of experimental studies are to women because of lack of human exposure data for most of these chemicals and the lack of studies that mimic real-life exposures. In contrast to chemicals such as bisphenol A and dioxin, the investigation of the effects of chemicals in PCP on reproductive function is still limited and warrants further investigation to fill existing data gaps.
Setchell, Joanna M; Smith, Tessa; Wickings, E Jean; Knapp, Leslie A
2008-11-01
Subordinate female cercopithecine primates often experience decreased reproductive success in comparison with high-ranking females, with a later age at sexual maturity and first reproduction and/or longer interbirth intervals. One explanation that has traditionally been advanced to explain this is high levels of chronic social stress in subordinates, resulting from agonistic and aggressive interactions and leading to higher basal levels of glucocorticoids. We assessed the relationships among fecal cortisol levels and reproductive condition, dominance rank, degree of social support, and fertility in female mandrills (Mandrillus sphinx) living in a semi-free-ranging colony in Franceville, Gabon. Lower-ranking females in this colony have a reproductive disadvantage relative to higher-ranking females, and we were interested in determining whether this relationship between dominance rank and reproductive success is mediated through stress hormones. We analyzed 340 fecal samples from 19 females, collected over a 14-month period. We found that pregnant females experienced higher fecal cortisol levels than cycling or lactating females. This is similar to results for other primate species and is likely owing to increased metabolic demands and interactions between the hypothalamus-pituitary-adrenal axis, estrogen, and placental production of corticotrophin releasing hormones during pregnancy. There was no influence of dominance rank on fecal cortisol levels, suggesting that subordinate females do not suffer chronic stress. This may be because female mandrills have a stable social hierarchy, with low levels of aggression and high social support. However, we found no relationship between matriline size, as a measure of social support, and fecal cortisol levels. Subordinates may be able to avoid aggression from dominants in the large enclosure or may react only transiently to specific aggressive events, rather than continuously expecting them. Finally, we found no relationship between fecal cortisol levels and fertility. There was no difference in fecal cortisol levels between conceptive and nonconceptive cycles, and no significant relationship between fecal cortisol level and either the length of postpartum amenorrhea or the number of cycles before conception. This suggests that the influence of dominance rank on female reproductive success in this population is not mediated through chronic stress in subordinate females, and that alternative explanations of the relationship between social rank and reproduction should be sought. Copyright 2008 Wiley-Liss, Inc.
Rosen, M. J.; Levin, E. C.; Hoy, R. R.
2009-01-01
In the obligatory reproductive dependence of a parasite on its host, the parasite must trade the benefit of ‘outsourcing’ functions like reproduction for the risk of assuming hazards associated with the host. In the present study, we report behavioral adaptations of a parasitic fly, Ormia ochracea, that resemble those of its cricket hosts. Ormia females home in on the male cricket's songs and deposit larvae, which burrow into the cricket, feed and emerge to pupate. Because male crickets call at night, gravid female Ormia in search of hosts are subject to bat predation, in much the same way as female crickets are when responding to male song. We show that Ormia has evolved the same evasive behavior as have crickets: an acoustic startle response to bat-like ultrasound that manifests clearly only during flight. Furthermore, like crickets, Ormia has a sharp response boundary between the frequencies of song and bat cries, resembling categorical perception first described in the context of human speech. PMID:19946084
Rosen, M J; Levin, E C; Hoy, R R
2009-12-01
In the obligatory reproductive dependence of a parasite on its host, the parasite must trade the benefit of 'outsourcing' functions like reproduction for the risk of assuming hazards associated with the host. In the present study, we report behavioral adaptations of a parasitic fly, Ormia ochracea, that resemble those of its cricket hosts. Ormia females home in on the male cricket's songs and deposit larvae, which burrow into the cricket, feed and emerge to pupate. Because male crickets call at night, gravid female Ormia in search of hosts are subject to bat predation, in much the same way as female crickets are when responding to male song. We show that Ormia has evolved the same evasive behavior as have crickets: an acoustic startle response to bat-like ultrasound that manifests clearly only during flight. Furthermore, like crickets, Ormia has a sharp response boundary between the frequencies of song and bat cries, resembling categorical perception first described in the context of human speech.
Xu, Gaixia; Lin, Guimiao; Lin, Suxia; Wu, Na; Deng, Yueyue; Feng, Gang; Chen, Qiang; Qu, Junle; Chen, Danni; Chen, Siping; Niu, Hanben; Mei, Shujiang; Yong, Ken-Tye; Wang, Xiaomei
2016-01-01
Despite the usefulness of quantum dots (QDs) in biomedicine and optoelectronics, their toxicity risks remain a major obstacle for clinical usages. Hence, we studied the reproductive toxicity of CdSe/ZnS QDs on two aspects, (i) in vivo ovarian functions and (ii) in vitro fertilization process. The body weight, estrous cycles, biodistribution of QDs, and oocyte maturation are evaluated on female mice treated with QDs. The mRNA level of the follicle-stimulating hormone receptor (FSHr) and luteinizing hormone receptor (LHr) in ovaries are assayed. Then, the matured cumulus-oocyte-complexes are harvested to co-culture with in vitro capacitated sperms, and the in vitro fertilization is performed. The result revealed that QDs are found in the ovaries, but no changes are detected on the behavior and estrous cycle on the female mice. The mRNA downregulations of FSHr and LHr are observed and the number of matured oocytes has shown a significant decrease when the QDs dosage was above 1.0 pmol/day. Additionally, we found the presence of QDs has reduced the in vitro fertilization success rate. This study highly suggests that the exposure of CdSe/ZnS QDs to female mice can cause adverse effects to the ovary functions and such QDs may have limited applications in clinical usage. PMID:27876896
Xu, Gaixia; Lin, Guimiao; Lin, Suxia; Wu, Na; Deng, Yueyue; Feng, Gang; Chen, Qiang; Qu, Junle; Chen, Danni; Chen, Siping; Niu, Hanben; Mei, Shujiang; Yong, Ken-Tye; Wang, Xiaomei
2016-11-23
Despite the usefulness of quantum dots (QDs) in biomedicine and optoelectronics, their toxicity risks remain a major obstacle for clinical usages. Hence, we studied the reproductive toxicity of CdSe/ZnS QDs on two aspects, (i) in vivo ovarian functions and (ii) in vitro fertilization process. The body weight, estrous cycles, biodistribution of QDs, and oocyte maturation are evaluated on female mice treated with QDs. The mRNA level of the follicle-stimulating hormone receptor (FSHr) and luteinizing hormone receptor (LHr) in ovaries are assayed. Then, the matured cumulus-oocyte-complexes are harvested to co-culture with in vitro capacitated sperms, and the in vitro fertilization is performed. The result revealed that QDs are found in the ovaries, but no changes are detected on the behavior and estrous cycle on the female mice. The mRNA downregulations of FSHr and LHr are observed and the number of matured oocytes has shown a significant decrease when the QDs dosage was above 1.0 pmol/day. Additionally, we found the presence of QDs has reduced the in vitro fertilization success rate. This study highly suggests that the exposure of CdSe/ZnS QDs to female mice can cause adverse effects to the ovary functions and such QDs may have limited applications in clinical usage.
Reichard, M; Bryja, J; Ondracková, M; Dávidová, M; Kaniewska, P; Smith, C
2005-04-01
Sexual selection involves two main mechanisms: intrasexual competition for mates and intersexual mate choice. We experimentally separated intrasexual (male-male interference competition) and intersexual (female choice) components of sexual selection in a freshwater fish, the European bitterling (Rhodeus sericeus). We compared the roles of multiple morphological and behavioural traits in male success in both components of sexual competition, and their relation to male reproductive success, measured as paternity of offspring. Body size was important for both female choice and male-male competition, though females also preferred males that courted more vigorously. However, dominant males often monopolized females regardless of female preference. Subordinate males were not excluded from reproduction and sired some offspring, possibly through sneaked ejaculations. Male dominance and a greater intensity of carotenoid-based red colouration in their iris were the best predictors of male reproductive success. The extent of red iris colouration and parasite load did not have significant effects on female choice, male dominance or male reproductive success. No effect of parasite load on the expression of red eye colouration was detected, though this may have been due to low parasite prevalence in males overall. In conclusion, we showed that even though larger body size was favoured in both intersexual and intrasexual selection, male-male interference competition reduced opportunities for female choice. Females, despite being choosy, had limited control over the paternity of their offspring. Our study highlights the need for reliable measures of male reproductive success in studies of sexual selection.
Barrell, G K; Ridgway, M J; Wellby, M; Pereira, A; Henry, B A; Clarke, I J
2016-04-01
Red deer are seasonal with respect to reproduction and food intake, so we tested the hypothesis that their brains would show seasonal changes in numbers of cells containing hypothalamic neuropeptides that regulate these functions. We examined the brains of male and female deer in non-breeding and breeding seasons to quantify the production of kisspeptin, gonadotropin inhibitory hormone (GnIH), neuropeptide Y (NPY) and γ-melanocyte stimulating hormone (γ-MSH - an index of pro-opiomelanocortin production), using immunohistochemistry. These neuropeptides are likely to be involved in the regulation of reproductive function and appetite. During the annual breeding season there were more cells producing kisspeptin in the arcuate nucleus of the hypothalamus than during the non-breeding season in males and females whereas there was no seasonal difference in the expression of GnIH. There were more cells producing the appetite stimulating peptide, NPY, in the arcuate/median eminence regions of the hypothalamus of females during the non-breeding season whereas the levels of an appetite suppressing peptide, γ-MSH, were highest in the breeding season. Male deer brains exhibited the converse, with NPY cell numbers highest in the breeding season and γ-MSH levels highest in the non-breeding season. These results support a role for kisspeptin as an important stimulatory regulator of seasonal breeding in deer, as in other species, but suggest a lack of involvement of GnIH in the seasonality of reproduction in deer. In the case of appetite regulation, the pattern exhibited by females for NPY and γ-MSH was as expected for the breeding and non-breeding seasons, based on previous studies of these peptides in sheep and the seasonal cycle of appetite reported for various species of deer. An inverse result in male deer most probably reflects the response of appetite regulating cells to negative energy balance during the mating season. Differences between the sexes in the seasonal changes in appetite regulating peptide cells of the hypothalamus present an interesting model for future studies. Copyright © 2016 Elsevier Inc. All rights reserved.
Van den Berghe, F; Paris, D B B P; Van Soom, A; Rijsselaere, T; Van der Weyde, L; Bertschinger, H J; Paris, M C J
2012-07-01
The African wild dog (Lycaon pictus) is an endangered exotic canid with less than 5500 animals remaining in the wild. Despite numerous strategies to conserve this species, numbers of free-living animals are in decline. It is a highly social species with a complex pack structure: separate male and female dominant hierarchies with, typically, participation of subdominant adults in the rearing of the dominant breeding pairs' pups. Basic reproductive knowledge is largely missing in this species, with only limited information available on the profile of reproductive hormones, based on non-invasive endocrine monitoring. The dominant or alpha male and female are reproductively active and the subdominants are generally reproductively suppressed. However, the occasional production of litters by subdominant females and evidence of multiple paternity within litters suggests that fertility of subordinates is not completely inhibited. In this respect, there are still considerable gaps in our knowledge about the mechanisms governing reproduction and reproductive suppression in African wild dogs, particularly the influence of dominance and pack structure on both male and female fertility. Given concerns over the long-term survival of this species, further research in this area is essential to provide valuable information for their captive breeding and conservation. Reproductive information can also be applied to the development of Assisted Reproductive Techniques for this species; the utility of which in African wild dog conservation is also discussed. Copyright © 2012 Elsevier B.V. All rights reserved.
Khendek, A; Chakraborty, A; Roche, J; Ledoré, Y; Personne, A; Policar, T; Żarski, D; Mandiki, R; Kestemont, P; Milla, S; Fontaine, P
2018-02-08
Pikeperch (Sander lucioperca) is a highly valuable fish in Europe. However, development of aquaculture of pikeperch is highly limited due to seasonality of production. This can be overcome by the controlled reproduction of domesticated fish. The first steps of domestication process may induce changes at anatomical, physiological and molecular levels, thereby affecting a variety of biological functions. While there is abundant literature on their effects on stress and growth for example, these effects on reproduction received limited attention notably in pikeperch, a promising candidate for the development of aquaculture. To answer the question of this life-history effect on pikeperch's reproduction, we compared two groups (weight: 1 kg) originated from Czech Republic and with the same domestication level (F0). The first group was a recirculating aquatic system cultured one (2 years, previously fed with artificial diet, never exposed to natural changes in temperature/photoperiod conditions) and the second one was a pond cultured group (3 to 4 years, bred under natural feeding and temperature/photoperiod). The wild group successfully spawned, while the farmed one did not spawn at all. During the program, gonadosomatic indexes of both males and females were significantly higher for the wild fish, as well as the sexual steroids. Gene expression analysis revealed significantly lower LH transcript levels at the pituitary level for the farmed females and lower FSH transcript levels at the pituitary level for the males. In conclusion this study showed that the previous rearing conditions (e.g. culture system, age, diet, etc.) alter the further progress of gametogenesis and the reproductive performances in response to controlled photothermal program for both sexes in pikeperch.
ERIC Educational Resources Information Center
Huxley, Virginia H.
2007-01-01
The ability to recognize and appreciate from a reproductive standpoint that males and females possess different attributes has been long standing. Only more recently have we begun to look more deeply into both the similarities and differences between men and women, as well as between boys and girls, with respect to the structure and function of…
Figueira, Marília I; Cardoso, Henrique J; Correia, Sara; Maia, Cláudio J; Socorro, Sílvia
2017-10-01
The tyrosine kinase receptor c-KIT and its ligand, the stem cell factor (SCF) are expressed in several tissues of male and female reproductive tract, playing an important role in the regulation of basic biological processes. The activation of c-KIT by SCF controls, cell survival and death, cell differentiation and migration. Also, the SCF/c-KIT system has been implicated in carcinogenesis of reproductive tissues due to its altered expression pattern or overactivation in consequence of gain-of-functions mutations. Over the years, it has also been shown that hormones, the primary regulators of reproductive function and causative agents in the case of hormone-dependent cancers, are also able to control the SCF/c-KIT tissue levels. Therefore, it is liable to suppose that disturbed SCF/c-KIT expression driven by (de)regulated hormone actions can be a relevant step towards carcinogenesis. The present review describes the SCF and c-KIT expression in cancers of reproductive tissues, discussing the implications of the hormonal regulation of the SCF/c-KIT system in cancer development. Understanding the relationship between hormonal imbalance and the SCF/c-KIT expression and activity would be relevant in the context of novel therapeutic approaches in reproductive cancers. Copyright © 2017 Elsevier B.V. All rights reserved.
Interactions between prolactin and kisspeptin to control reproduction.
Donato, Jose; Frazão, Renata
2016-01-01
Prolactin is best known for its effects of stimulating mammary gland development and lactogenesis. However, prolactin is a pleiotropic hormone that is able to affect several physiological functions, including fertility. Prolactin receptors (PRLRs) are widely expressed in several tissues, including several brain regions and reproductive tract organs. Upon activation, PRLRs may exert prolactin's functions through several signaling pathways, although the recruitment of the signal transducer and activator of transcription 5 causes most of the known effects of prolactin. Pathological hyperprolactinemia is mainly due to the presence of a prolactinoma or pharmacological effects induced by drugs that interact with the dopamine system. Notably, hyperprolactinemia is a frequent cause of reproductive dysfunction and may lead to infertility in males and females. Recently, several studies have indicated that prolactin may modulate the reproductive axis by acting on specific populations of hypothalamic neurons that express the Kiss1 gene. The Kiss1 gene encodes neuropeptides known as kisspeptins, which are powerful activators of gonadotropin-releasing hormone neurons. In the present review, we will summarize the current knowledge about prolactin's actions on reproduction. Among other aspects, we will discuss whether the interaction between prolactin and the Kiss1-expressing neurons can affect reproduction and how kisspeptins may become a novel therapeutic approach to treat prolactin-induced infertility.
Bowers, E Keith; Smith, Rebecca A; Hodges, Christine J; Zimmerman, Laura M; Thompson, Charles F; Sakaluk, Scott K
2012-07-22
The reproductive costs associated with the upregulation of immunity have been well-documented and constitute a fundamental trade-off between reproduction and self-maintenance. However, recent experimental work suggests that parents may increase their reproductive effort following immunostimulation as a form of terminal parental investment as prospects for future reproduction decline. We tested the trade-off and terminal investment hypotheses in a wild population of house wrens (Troglodytes aedon) by challenging the immune system of breeding females with lipopolysaccharide, a potent but non-lethal antigen. Immunized females showed no evidence of reproductive costs; instead, they produced offspring of higher phenotypic quality, but in a sex-specific manner. Relative to control offspring, sons of immunized females had increased body mass and their sisters exhibited higher cutaneous immune responsiveness to phytohaemagglutinin injection, constituting an adaptive strategy of sex-biased allocation by immune-challenged females to enhance the reproductive value of their offspring. Thus, our results are consistent with the terminal investment hypothesis, and suggest that maternal immunization can induce pronounced transgenerational effects on offspring phenotypes.
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Epigenetic effects of endocrine-disrupting chemicals on female reproduction: An ovarian perspective
Zama, Aparna Mahakali; Uzumcu, Mehmet
2010-01-01
The link between in utero and neonatal exposure to environmental toxicants, such as endocrine-disrupting chemicals (EDCs) and adult female reproductive disorders is well established in both epidemiological and animal studies. Recent studies examining the epigenetic mechanisms involved in mediating the effects of EDCs on female reproduction are gathering momentum. In this review, we describe the developmental processes that are susceptible to EDC exposures in female reproductive system, with a special emphasis on the ovary. We discuss studies with select EDCs that have been shown to have physiological and correlated epigenetic effects in the ovary, neuroendocrine system, and uterus. Importantly, EDCs that can directly target the ovary can alter epigenetic mechanisms in the oocyte, leading to transgenerational epigenetic effects. The potential mechanisms involved in such effects are also discussed. PMID:20609371
Abrams, Elizabeth T; Miller, Elizabeth M
2011-01-01
Life history theory posits that, as long as survival is assured, finite resources are available for reproduction, maintenance, and growth/storage. To maximize lifetime reproductive success, resources are subject to trade-offs both within individuals and between current and future investment. For women, reproducing is costly and time-consuming; the bulk of available resources must be allocated to reproduction at the expense of more flexible systems like immune function. When reproducing women contract infectious diseases, the resources required for immune activation can fundamentally shift the patterns of resource allocation. Adding to the complexity of the reproductive-immune trade-offs in women are the pleiotropic effects of many immune factors, which were modified to serve key roles in mammalian reproduction. In this review, we explore the complex intersections between immune function and female reproduction to situate proximate immunological processes within a life history framework. After a brief overview of the immune system, we discuss some important physiological roles of immune factors in women's reproduction and the conflicts that may arise when these factors must play dual roles. We then discuss the influence of reproductive-immune trade-offs on the patterning of lifetime reproductive success: (1) the effect of immune activation/infectious disease on the timing of life history events; (2) the role of the immune system, immune activation, and infectious disease on resource allocation within individual reproductive events, particularly pregnancy; and (3) the role of the immune system in shaping the offspring's patterns of future life history trade-offs. We close with a discussion of future directions in reproductive immunology for anthropologists. Copyright © 2011 Wiley Periodicals, Inc.
Removal of mouse ovary fat pad affects sex hormones, folliculogenesis and fertility.
Wang, Hong-Hui; Cui, Qian; Zhang, Teng; Guo, Lei; Dong, Ming-Zhe; Hou, Yi; Wang, Zhen-Bo; Shen, Wei; Ma, Jun-Yu; Sun, Qing-Yuan
2017-02-01
As a fat storage organ, adipose tissue is distributed widely all over the body and is important for energy supply, body temperature maintenance, organ protection, immune regulation and so on. In humans, both underweight and overweight women find it hard to become pregnant, which suggests that appropriate fat storage can guarantee the female reproductive capacity. In fact, a large mass of adipose tissue distributes around the reproductive system both in the male and female. However, the functions of ovary fat pad (the nearest adipose tissue to ovary) are not known. In our study, we found that the ovary fat pad-removed female mice showed decreased fertility and less ovulated mature eggs. We further identified that only a small proportion of follicles developed to antral follicle, and many follicles were blocked at the secondary follicle stage. The overall secretion levels of estrogen and FSH were lower in the whole estrus cycle (especially at proestrus); however, the LH level was higher in ovary fat pad-removed mice than that in control groups. Moreover, the estrus cycle of ovary fat pad-removed mice showed significant disorder. Besides, the expression of FSH receptor decreased, but the LH receptor increased in ovary fat pad-removed mice. These results suggest that ovary fat pad is important for mouse reproduction. © 2017 Society for Endocrinology.
Visual communication stimulates reproduction in Nile tilapia, Oreochromis niloticus (L.).
Castro, A L S; Gonçalves-de-Freitas, E; Volpato, G L; Oliveira, C
2009-04-01
Reproductive fish behavior is affected by male-female interactions that stimulate physiological responses such as hormonal release and gonad development. During male-female interactions, visual and chemical communication can modulate fish reproduction. The aim of the present study was to test the effect of visual and chemical male-female interaction on the gonad development and reproductive behavior of the cichlid fish Nile tilapia, Oreochromis niloticus (L.). Fifty-six pairs were studied after being maintained for 5 days under one of the four conditions (N = 14 for each condition): 1) visual contact (V); 2) chemical contact (Ch); 3) chemical and visual contact (Ch+V); 4) no sensory contact (Iso) - males and females isolated. We compared the reproductive behavior (nesting, courtship and spawning) and gonadosomatic index (GSI) of pairs of fish under all four conditions. Visual communication enhanced the frequency of courtship in males (mean +/- SEM; V: 24.79 +/- 3.30, Ch+V: 20.74 +/- 3.09, Ch: 0.1 +/- 0.07, Iso: 4.68 +/- 1.26 events/30 min; P < 0.05, two-way ANOVA with LSD post hoc test), induced spawning in females (3 spawning in V and also 3 in Ch+V condition), and increased GSI in males (mean +/- SEM; V: 1.39 +/- 0.08, Ch+V: 1.21 +/- 0.08, Ch: 1.04 +/- 0.07, Iso: 0.82 +/- 0.07%; P < 0.05, two-way ANOVA with LSD post hoc test). Chemical communication did not affect the reproductive behavior of pairs nor did it enhance the effects of visual contact. Therefore, male-female visual communication is an effective cue, which stimulates reproduction among pairs of Nile tilapia.
Current versus future reproduction and longevity: a re-evaluation of predictions and mechanisms.
Zhang, Yufeng; Hood, Wendy R
2016-10-15
Oxidative damage is predicted to be a mediator of trade-offs between current reproduction and future reproduction or survival, but most studies fail to support such predictions. We suggest that two factors underlie the equivocal nature of these findings: (1) investigators typically assume a negative linear relationship between current reproduction and future reproduction or survival, even though this is not consistently shown by empirical studies; and (2) studies often fail to target mechanisms that could link interactions between sequential life-history events. Here, we review common patterns of reproduction, focusing on the relationships between reproductive performance, survival and parity in females. Observations in a range of species show that performance between sequential reproductive events can decline, remain consistent or increase. We describe likely bioenergetic consequences of reproduction that could underlie these changes in fitness, including mechanisms that could be responsible for negative effects being ephemeral, persistent or delayed. Finally, we make recommendations for designing future studies. We encourage investigators to carefully consider additional or alternative measures of bioenergetic function in studies of life-history trade-offs. Such measures include reactive oxygen species production, oxidative repair, mitochondrial biogenesis, cell proliferation, mitochondrial DNA mutation and replication error and, importantly, a measure of the respiratory function to determine whether measured differences in bioenergetic state are associated with a change in the energetic capacity of tissues that could feasibly affect future reproduction or lifespan. More careful consideration of the life-history context and bioenergetic variables will improve our understanding of the mechanisms that underlie the life-history patterns of animals. © 2016. Published by The Company of Biologists Ltd.
Current versus future reproduction and longevity: a re-evaluation of predictions and mechanisms
Zhang, Yufeng
2016-01-01
ABSTRACT Oxidative damage is predicted to be a mediator of trade-offs between current reproduction and future reproduction or survival, but most studies fail to support such predictions. We suggest that two factors underlie the equivocal nature of these findings: (1) investigators typically assume a negative linear relationship between current reproduction and future reproduction or survival, even though this is not consistently shown by empirical studies; and (2) studies often fail to target mechanisms that could link interactions between sequential life-history events. Here, we review common patterns of reproduction, focusing on the relationships between reproductive performance, survival and parity in females. Observations in a range of species show that performance between sequential reproductive events can decline, remain consistent or increase. We describe likely bioenergetic consequences of reproduction that could underlie these changes in fitness, including mechanisms that could be responsible for negative effects being ephemeral, persistent or delayed. Finally, we make recommendations for designing future studies. We encourage investigators to carefully consider additional or alternative measures of bioenergetic function in studies of life-history trade-offs. Such measures include reactive oxygen species production, oxidative repair, mitochondrial biogenesis, cell proliferation, mitochondrial DNA mutation and replication error and, importantly, a measure of the respiratory function to determine whether measured differences in bioenergetic state are associated with a change in the energetic capacity of tissues that could feasibly affect future reproduction or lifespan. More careful consideration of the life-history context and bioenergetic variables will improve our understanding of the mechanisms that underlie the life-history patterns of animals. PMID:27802148
Naranjo Madrigal, Helven
2012-12-01
The lobster P. gracilis is important as a fishery resource and also contributes to food security of fishers in coastal communities in the North Pacific of Costa Rica. Due to the importance of updating knowledge related to the reproductive pattern of this species, we analyzed 357 specimens of female lobsters caught by the fishing methods of "hookah" and lung diving, from November 2007 to October 2008 in Playa Lagarto. Furthermore, we examined the size composition by depth; monthly pattern of reproductive activity (RAI) associated with the relative increase in sea surface temperature, and also the mean size at maturity using Generalized Linear Models. Four physiological states of sexual maturity showed that females with no signs of mating or sexual maturity have a minimum mean size of 62.3mm of cephalothorax length (CL). There are characteristics of functional maturity from very small sizes ranging from 30 to 50mm CL, being the smallest berried female reported for this specie of 35.8mm CL and the highest percentage of mature females between 70 and 80mm CL. Percentages of RAI remained above 50% during the year except October and January. In addition, it observed an increase in the RAI that started from April and continued until August associated with a relative increase in temperature on March, although the correlation was not significant (r2=0.49, p>0.05). It is possible that the low mean size at maturity (70.2mm LC) for P. gracilis in this region is related to the fishing activity. It recommends the establishment of a ban in the region of at least five months (April-August) in order to protect the reproductive seasonality of the species and to promote a recruitment increase in the fishing areas.
Gonadotrophin releasing hormone (GnRH) stimulates the release of pituitary luteinizing hormone (LH) and follicle stimulating hormone. These pituitary hormones are necessary for normal reproductive function in both males and females. It is well recognized that disruption of nor...
Endocrine disrupting chemicals (e.g., estrogens and androgens) are known to affect reproductive functions in fish. A synthetic estrogen used in birth control pills, 17á-ethynylestradiol (EE2), is discharged from wastewater treatment plants into water bodies throughout the United ...
Current knowledge and future challenges in camelid reproduction.
Tibary, A; Anouassi, A; Sghiri, A; Khatir, H
2007-01-01
Reproductive biology research on camelids offers some interesting peculiarities and challenges to scientists and animal production specialists. The objective of this paper is to review camelid reproduction, advances in reproductive physiology and reproductive biotechnologies in camelids and discuss some areas for further research. In the female, the focus has been on understanding follicular dynamics. This has allowed development of synchronization and superovulation strategies to support embryo transfer technologies which are now commonly used in camels. Some advances have been achieved in preservation of embryos by vitrification. Fertilization, early embryo development and embryo signaling for maternal recognition of pregnancy are still not fully understood. New information on the interaction of the developing embryo and the endometrium may shed some light on this signaling as well as the mechanism of prevention of luteolysis. The presence of a seminal ovulation-inducing factor (OIF) was confirmed in llamas and alpacas. Chronology of oocytes maturation has been described. In vitro production of embryos has been achieved resulting in successful pregnancies and births in the dromedary. These techniques offer a new tool for the production and study of interspecies/cross-species embryos and their effect on pregnancy. Male reproductive function remains poorly studied. Semen preservation and artificial insemination still present many challenges and are not used in production at the moment. The involvement of climatic and nutritional conditions as well as the role of leptin in the regulation of reproductive function need to be evaluated.
Stridulatory sound-production and its function in females of the cicada Subpsaltria yangi.
Luo, Changqing; Wei, Cong
2015-01-01
Acoustic behavior plays a crucial role in many aspects of cicada biology, such as reproduction and intrasexual competition. Although female sound production has been reported in some cicada species, acoustic behavior of female cicadas has received little attention. In cicada Subpsaltria yangi, the females possess a pair of unusually well-developed stridulatory organs. Here, sound production and its function in females of this remarkable cicada species were investigated. We revealed that the females could produce sounds by stridulatory mechanism during pair formation, and the sounds were able to elicit both acoustic and phonotactic responses from males. In addition, the forewings would strike the body during performing stridulatory sound-producing movements, which generated impact sounds. Acoustic playback experiments indicated that the impact sounds played no role in the behavioral context of pair formation. This study provides the first experimental evidence that females of a cicada species can generate sounds by stridulatory mechanism. We anticipate that our results will promote acoustic studies on females of other cicada species which also possess stridulatory system.
Polychlorinated biphenyls and reproductive hormones in female polar bears at Svalbard.
Haave, Marte; Ropstad, Erik; Derocher, Andrew E; Lie, Elisabeth; Dahl, Ellen; Wiig, Øystein; Skaare, Janneche U; Jenssen, Bjørn Munro
2003-04-01
High concentrations of polychlorinated biphenyls (PCBs) in polar bears from Svalbard have increased concern for that population's reproductive health. We examined whether there were associations between the plasma concentrations of PCBs and reproductive hormones [progesterone (P4)] and 17 beta-estradiol (E2)] in free-living female polar bears from Svalbard. Concentrations of P4 depended on reproductive status, and concentrations were lowest in females with offspring--females with cubs and females with yearlings. In these females, the P4 concentrations were positively correlated with plasma sigma PCBs (sum of all analyzed polychlorinated biphenyl congeners) concentrations. The sigma PCBs concentrations explained 27% of the variation in the P4 concentrations. There were no correlations between sigma PCBs and E2 and cortisol in any of the groups of polar bears, or between sigma PCBs and P4 in single polar bears. Although the sigma PCBs-P4 relationship in female polar bears with offspring is not evidence per se of a direct cause-effect association, the results indicate that PCBs may affect levels of P4 in polar bear females. There is a clear need to further assess the hormone balance and population health of polar bears at Svalbard.
Vittrup, Ida; Petersen, Gitte Lindved; Kamper-Jørgensen, Mads; Pinborg, Anja; Schmidt, Lone
2017-08-01
The objective was to assess the potential association between female and male alcohol consumption and probability of achieving a live birth after assisted reproductive treatment. From a nationwide Danish register-based cohort information on alcohol consumption at assisted reproductive treatment initiation was linked to information on births and abortions. From 1 January 2006 to 30 September 2010, 12,981 women and their partners went through 29,834 treatment cycles. Of these, 22.4% and 20.4% led to a live birth for female abstainers and heavy consumers (>7 drinks/week), respectively. Concerning men, 22.6% and 20.2% of cycles resulted in a live birth for abstainers and heavy consumers (>14 drinks/week), respectively. No statistically significant associations between alcohol consumption and live birth were observed. Adjusted odds ratios from trend analyses were 1.00 (95% confidence interval (CI) 0.99-1.01) and 0.99 (95% CI 0.97-1.01) for every one-unit increase in female and male weekly alcohol consumption at assisted reproductive treatment initiation, respectively. In conclusion, this study did not show significant associations between male or female alcohol consumption and odds of live birth after assisted reproductive treatment. Copyright © 2017 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.
Zedrosser, Andreas; Pelletier, Fanie; Bischof, Richard; Festa-Bianchet, Marco; Swenson, Jon E
2013-01-01
In iteroparous mammals, conditions experienced early in life may have long-lasting effects on lifetime reproductive success. Human-induced mortality is also an important demographic factor in many populations of large mammals and may influence lifetime reproductive success. Here, we explore the effects of early development, population density, and human hunting on survival and lifetime reproductive success in brown bear (Ursus arctos) females, using a 25-year database of individually marked bears in two populations in Sweden. Survival of yearlings to 2 years was not affected by population density or body mass. Yearlings that remained with their mother had higher survival than independent yearlings, partly because regulations prohibit the harvest of bears in family groups. Although mass as a yearling did not affect juvenile survival, it was positively associated with measures of lifetime reproductive success and individual fitness. The majority of adult female brown bear mortality (72%) in our study was due to human causes, mainly hunting, and many females were killed before they reproduced. Therefore, factors allowing females to survive several hunting seasons had a strong positive effect on lifetime reproductive success. We suggest that, in many hunted populations of large mammals, sport harvest is an important influence on both population dynamics and life histories.
Family feuds: social competition and sexual conflict in complex societies
Rubenstein, Dustin R.
2012-01-01
Darwin was initially puzzled by the processes that led to ornamentation in males—what he termed sexual selection—and those that led to extreme cooperation and altruism in complex animal societies—what was later termed kin selection. Here, I explore the relationships between sexual and kin selection theory by examining how social competition for reproductive opportunities—particularly in females—and sexual conflict over mating partners are inherent and critical parts of complex altruistic societies. I argue that (i) patterns of reproductive sharing within complex societies can drive levels of social competition and reproductive conflict not only in males but also in females living in social groups, and ultimately the evolution of female traits such as ornaments and armaments; (ii) mating conflict over female choice of sexual partners can influence kin structure within groups and drive the evolution of complex societies; and (iii) patterns of reproductive sharing and conflict among females may also drive the evolution of complex societies by influencing kin structure within groups. Ultimately, complex societies exhibiting altruistic behaviour appear to have only arisen in taxa where social competition over reproductive opportunities and sexual conflict over mating partners were low. Once such societies evolved, there were important selective feedbacks on traits used to regulate and mediate intra-sexual competition over reproductive opportunities, particularly in females. PMID:22777018
Review of hazards to female reproductive health in veterinary practice.
Scheftel, Joni M; Elchos, Brigid L; Rubin, Carol S; Decker, John A
2017-04-15
OBJECTIVE To review publications that address female reproductive health hazards in veterinary practice, summarize best practices to mitigate reproductive risks, and identify current knowledge gaps. DESIGN Systematized review. SAMPLE English-language articles describing chemical, biological, and physical hazards present in the veterinary workplace and associations with adverse reproductive outcomes or recommendations for minimizing risks to female reproductive health. PROCEDURES Searches of the CAB abstracts database were performed in July 2012 and in May 2015 with the following search terms: veterinarians AND occupational hazards and vets.id AND occupational hazards.sh. Searches of the PubMed database were conducted in November 2012 and in May 2015 with the following medical subject heading terms: occupational exposure AND veterinarians; anesthetics, inhalation/adverse effects AND veterinarians; risk factors AND pregnancy AND veterinarians; pregnancy outcome AND veterinarians; and animal technicians AND occupational exposure. Two additional PubMed searches were completed in January 2016 with the terms disinfectants/toxicity AND female AND fertility/drug effects and veterinarians/psychology AND stress, psychological. No date limits were applied to searches. RESULTS 4 sources supporting demographic trends in veterinary medicine and 118 resources reporting potential hazards to female reproductive health were identified. Reported hazards included exposure to anesthetic gases, radiation, antineoplastic drugs, and reproductive hormones; physically demanding work; prolonged standing; and zoonoses. CONCLUSIONS AND CLINICAL RELEVANCE Demographic information suggested that an increasing number of women of reproductive age will be exposed to chemical, biological, and physical hazards in veterinary practice. Information on reproductive health hazards and minimizing risk, with emphasis on developing a safety-focused work culture for all personnel, should be discussed starting in veterinary and veterinary technical schools and integrated into employee training.
Review of hazards to female reproductive health in veterinary practice
Scheftel, Joni M.; Elchos, Brigid L.; Rubin, Carol S.; Decker, John A.
2017-01-01
OBJECTIVE To review publications that address female reproductive health hazards in veterinary practice, summarize best practices to mitigate reproductive risks, and identify current knowledge gaps. DESIGN Systematized review. SAMPLE English-language articles describing chemical, biological, and physical hazards present in the veterinary workplace and associations with adverse reproductive outcomes or recommendations for minimizing risks to female reproductive health. PROCEDURES Searches of the CAB abstracts database were performed in July 2012 and in May 2015 with the following search terms: veterinarians AND occupational hazards and vets.id AND occupational hazards.sh. Searches of the PubMed database were conducted in November 2012 and in May 2015 with the following medical subject heading terms: occupational exposure AND veterinarians; anesthetics, inhalation/adverse effects AND veterinarians; risk factors AND pregnancy AND veterinarians; pregnancy outcome AND veterinarians; and animal technicians AND occupational exposure. Two additional PubMed searches were completed in January 2016 with the terms disinfectants/toxicity AND female AND fertility/drug effects and veterinarians/psychology AND stress, psychological. No date limits were applied to searches. RESULTS 4 sources supporting demographic trends in veterinary medicine and 118 resources reporting potential hazards to female reproductive health were identified. Reported hazards included exposure to anesthetic gases, radiation, antineoplastic drugs, and reproductive hormones; physically demanding work; prolonged standing; and zoonoses. CONCLUSIONS AND CLINICAL RELEVANCE Demographic information suggested that an increasing number of women of reproductive age will be exposed to chemical, biological, and physical hazards in veterinary practice. Information on reproductive health hazards and minimizing risk, with emphasis on developing a safety-focused work culture for all personnel, should be discussed starting in veterinary and veterinary technical schools and integrated into employee training. PMID:28358639
Ruiz-Ramoni, Damián; Ramoni-Perazzi, Paolo; Muñoz-Romo, Mariana
2017-03-01
Bimodal polyestry is the most common reproductive pattern in tropical bats, and it consists in producing one offspring per female twice a year. Reproductive patterns are closely related to rainfall regimes, frequently occurring twice a year in tropical regions. The goal of our study was to determine the reproductive pattern of the large fruit-eating bat, Artibeus amplus Handley, 1987 in a cave in the Venezuelan Andes inhabited by a large, stable colony. Thus, in this study we describe for the first time this important biological aspect of this unknown Neotropical bat species through the examination of external reproductive characteristics of males (inguinal or scrotal testes) and females (pregnant, lactating, post-lactating), based on 211 individuals (120 males and 91 females) captured between September 2008 and August 2009, in Cueva del Parque Las Escaleras, Estado Táchira, Venezuela. During this period of monthly sampling for a full year, most males displayed large scrotal testes, averaging 10 mm maximum length. The examination of females indicated that although pregnancy was first observed in November 2008, it reached a maximum during January and February 2009. Although adult males with scrotal testes throughout the year could imply that females have more than one pregnancy, our results suggested a seasonally monoestrous reproductive pattern for A. amplus. This study represents the first report of reproductive pattern for this poorly-known Neotropical frugivorous species. The observed monoestrous reproductive pattern supports the existence of synchronization between precipitation and reproduction. This synchronization has been frequently observed in most species of fruit bats. In this study, Artibeus amplus presumably adjust the parturition to anticipate the rainy season, as a strategy that allows maintenance of offspring during high availability of fruits.
Attardo, Geoffrey M.; Medlock, Jan; Aksoy, Serap
2014-01-01
Impact of reproductive processes upon female health has yielded conflicting results; particularly in relation to the role of reproduction-associated stress. We used the viviparous tsetse fly to determine if lactation, birth and involution lead to damage from oxidative stress (OS) that impairs subsequent reproductive cycles. Tsetse females carry an intrauterine larva to full term at each pregnancy cycle, and lactate to nourish them with milk secretions produced by the accessory gland ( = milk gland) organ. Unlike most K-strategists, tsetse females lack an apparent period of reproductive senescence allowing the production of 8–10 progeny over their entire life span. In a lactating female, over 47% of the maternal transcriptome is associated with the generation of milk proteins. The resulting single larval offspring weighs as much as the mother at birth. In studying this process we noted an increase in specific antioxidant enzyme (AOE) transcripts and enzymatic activity at critical times during lactation, birth and involution in the milk gland/fat body organ and the uterus. Suppression of superoxide dismutase (sod) decreased fecundity in subsequent reproductive cycles in young mothers and nearly abolished fecundity in geriatric females. Loss of fecundity was in part due to the inability of the mother to produce adequate milk to support larval growth. Longevity was also impaired after sod knockdown. Generation of OS in virgin females through exogenous treatment with hydrogen peroxide at times corresponding to pregnancy intervals reduced survival, which was exacerbated by sod knockdown. AOE expression may prevent oxidative damage associated with the generation of nutrients by the milk gland, parturition and milk gland breakdown. Our results indicate that prevention of OS is essential for females to meet the growing nutritional demands of juveniles during pregnancy and to repair the damage that occurs at birth. This process is particularly important for females to remain fecund during the latter portion of their lifetime. PMID:24763119
Involvement of galectin-1 in reproduction: past, present and future.
Barrientos, Gabriela; Freitag, Nancy; Tirado-González, Irene; Unverdorben, Laura; Jeschke, Udo; Thijssen, Victor L J L; Blois, Sandra M
2014-01-01
After recognition of its pivotal contribution to fetomaternal tolerance, the study of galectin-1 (gal-1) functions in the context of pregnancy became an attractive topic in reproductive medicine. Despite considerable advances in the understanding of the immuno- and growth-regulatory properties of gal-1 at the fetal-maternal interface, many functional aspects of this lectin in reproduction are only emerging. The published literature was searched using Pubmed focusing on gal-1 signalling and functional properties at the maternal-fetal interface, including data on its implication in pregnancy disorders and malignancies of the female reproductive system. Papers discussing animal and human studies were included. This review provides an overview of gal-1 functions during pregnancy, such as modulation of maternal immune responses and roles in embryo implantation and placentation. We also emphasize the role of gal-1 in key regulatory processes, including trophoblast migration, invasion, syncytium formation and expression of non-classical MHC class I molecules (HLA-G). In addition, we argue in favour of gal-1 pro-angiogenic properties, as observed in tumourigenesis and other pathological settings, and its implication in the angiogenesis process associated with early gestation. The involvement of gal-1 in the regulation of different processes during the establishment, development and maintenance of pregnancy could be described as unique. Gal-1 has emerged as an important lectin with major functions in pregnancy.
Influence of stimuli from populations of Peromyscus leucopus on maturation of young
Rogers, J.G.; Beauchamp, G.K.
1976-01-01
The effects of stimuli associated with conspecific laboratory populations on parameters of sexual maturation in Peromyscus leucopus were examined. Beginning at birth, experimental litters were exposed to the constant infusion of urine, feces, and other material from the populations through a metabolism funnel into their cages. As evidenced by age at first vaginal estrus, experimental females matured later than controls. They also had lighter weight reproductive organs. Testis weights were much greater in control than experimental males. These data suggest that stimuli from populations of P. leucopus can inhibit reproductive maturation of conspecifics. In view of the well-documented effects of chemical stimuli on reproductive maturation and function in other rodents, it is suggested that chemical stimuli in the feces, urine, or from other sources mediated the reproductive inhibition observed in this study.
Effect of electromagnetic waves on human reproduction.
Wdowiak, Artur; Mazurek, Paweł A; Wdowiak, Anita; Bojar, Iwona
2017-03-31
Electromagnetic radiation (EMR) emitting from the natural environment, as well as from the use of industrial and everyday appliances, constantly influence the human body. The effect of this type of energy on living tissues may exert various effects on their functioning, although the mechanisms conditioning this phenomenon have not been fully explained. It may be expected that the interactions between electromagnetic radiation and the living organism would depend on the amount and parameters of the transmitted energy and type of tissue exposed. Electromagnetic waves exert an influence on human reproduction by affecting the male and female reproductive systems, the developing embryo, and subsequently, the foetus. Knowledge concerning this problem is still being expanded; however, all the conditionings of human reproduction still remain unknown. The study presents the current state of knowledge concerning the problem, based on the latest scientific reports.
Sadahiro, Masato; Erickson, Connor; Lin, Wei-Jye; Shin, Andrew C; Razzoli, Maria; Jiang, Cheng; Fargali, Samira; Gurney, Allison; Kelley, Kevin A; Buettner, Christoph; Bartolomucci, Alessandro; Salton, Stephen R
2015-05-01
Targeted deletion of VGF, a secreted neuronal and endocrine peptide precursor, produces lean, hypermetabolic, and infertile mice that are resistant to diet-, lesion-, and genetically-induced obesity and diabetes. Previous studies suggest that VGF controls energy expenditure (EE), fat storage, and lipolysis, whereas VGF C-terminal peptides also regulate reproductive behavior and glucose homeostasis. To assess the functional equivalence of human VGF(1-615) (hVGF) and mouse VGF(1-617) (mVGF), and to elucidate the function of the VGF C-terminal region in the regulation of energy balance and susceptibility to obesity, we generated humanized VGF knockin mouse models expressing full-length hVGF or a C-terminally deleted human VGF(1-524) (hSNP), encoded by a single nucleotide polymorphism (rs35400704). We show that homozygous male and female hVGF and hSNP mice are fertile. hVGF female mice had significantly increased body weight compared with wild-type mice, whereas hSNP mice have reduced adiposity, increased activity- and nonactivity-related EE, and improved glucose tolerance, indicating that VGF C-terminal peptides are not required for reproductive function, but 1 or more specific VGF C-terminal peptides are likely to be critical regulators of EE. Taken together, our results suggest that human and mouse VGF proteins are largely functionally conserved but that species-specific differences in VGF peptide function, perhaps a result of known differences in receptor binding affinity, likely alter the metabolic phenotype of hVGF compared with mVGF mice, and in hSNP mice in which several C-terminal VGF peptides are ablated, result in significantly increased activity- and nonactivity-related EE.
Sadahiro, Masato; Erickson, Connor; Lin, Wei-Jye; Shin, Andrew C.; Razzoli, Maria; Jiang, Cheng; Fargali, Samira; Gurney, Allison; Kelley, Kevin A.; Buettner, Christoph
2015-01-01
Targeted deletion of VGF, a secreted neuronal and endocrine peptide precursor, produces lean, hypermetabolic, and infertile mice that are resistant to diet-, lesion-, and genetically-induced obesity and diabetes. Previous studies suggest that VGF controls energy expenditure (EE), fat storage, and lipolysis, whereas VGF C-terminal peptides also regulate reproductive behavior and glucose homeostasis. To assess the functional equivalence of human VGF1–615 (hVGF) and mouse VGF1–617 (mVGF), and to elucidate the function of the VGF C-terminal region in the regulation of energy balance and susceptibility to obesity, we generated humanized VGF knockin mouse models expressing full-length hVGF or a C-terminally deleted human VGF1–524 (hSNP), encoded by a single nucleotide polymorphism (rs35400704). We show that homozygous male and female hVGF and hSNP mice are fertile. hVGF female mice had significantly increased body weight compared with wild-type mice, whereas hSNP mice have reduced adiposity, increased activity- and nonactivity-related EE, and improved glucose tolerance, indicating that VGF C-terminal peptides are not required for reproductive function, but 1 or more specific VGF C-terminal peptides are likely to be critical regulators of EE. Taken together, our results suggest that human and mouse VGF proteins are largely functionally conserved but that species-specific differences in VGF peptide function, perhaps a result of known differences in receptor binding affinity, likely alter the metabolic phenotype of hVGF compared with mVGF mice, and in hSNP mice in which several C-terminal VGF peptides are ablated, result in significantly increased activity- and nonactivity-related EE. PMID:25675362
A Crucial New Direction for International Family Planning.
ERIC Educational Resources Information Center
Hosken, Fran P.
1984-01-01
Repressive attitudes toward female sexuality by Third World men and ignorance of the basic biology of the female reproductive system by Third World women have led to the failure of family planning efforts. Use of the "Universal Childbirth Picture Book," which illustrates the female reproductive system, is recommended. (IS)
Duplouy, Anne; Woestmann, Luisa; Gallego Zamorano, Juan; Saastamoinen, Marjo
2018-04-01
In butterflies, male reproductive success is highly related to the quality and the size of the spermatophore transferred to the female. The spermatophore is a capsule produced by the male during copulation, which in many species contains sperm in addition to a nuptial gift, and which is digested by the female after copulation. The nuptial gift may contribute to egg production and offspring quality, and in some cases also to female body maintenance. The production of the spermatophore, however, represents a cost for the male and, in polyandrous species, ejaculates are sometimes allocated adaptively across matings. Nonetheless, although the ecological factors affecting the reproductive success of female butterflies have been the topic of numerous studies, little information exists on the factors affecting males' contribution to reproduction, and the indirect impacts on female fecundity and fitness. We used the Glanville fritillary butterfly, Melitaea cinxia (Linnaeus, 1758) (Nymphalidae), in order to assess variation in male allocation to matings. In this species, smaller males produce smaller spermatophores, but variation in spermatophore size is not correlated with female reproductive success. We show that spermatophore size increases with male age at first mating, decreases with mating frequency and adult food-deprivation, and is not influenced by developmental food-limitation. The length of copulation period does not influence the spermatophore size nor influences the polyandrous mating behavior in this species. Male contribution to his spermatophore size is clearly influenced by his condition and adult-resource at the time of mating. Despite this variation, spermatophore size does not seem to have a direct impact on female reproductive output or mating behavior. © 2016 The Authors Insect Science published by Wiley Publishing Asia Pty Ltd on behalf of Institute of Zoology, Chinese Academy of Sciences.
Sex hormones and systemic inflammation are modulators of the obese-asthma phenotype.
Scott, H A; Gibson, P G; Garg, M L; Upham, J W; Wood, L G
2016-07-01
Both systemic inflammation and sex hormones have been proposed as potential mediators of the obese-asthma phenotype. The aim of this study was to examine the associations between sex hormones, oral contraceptive pill (OCP) use, systemic inflammation and airway inflammation in adults with asthma. Obese (n = 39) and nonobese (n = 42) females and obese (n = 24) and nonobese (n = 25) males with asthma were recruited. Females were further categorized as reproductive-aged (<50 years old; n = 36) or older (>50 years old; n = 45). Thirteen (36.1%) reproductive-aged females were using the OCP. Participants had induced sputum cell counts measured and blood analysed for sex hormones and inflammatory markers. Obese reproductive-aged females had higher sputum %neutrophils than nonobese reproductive-aged females (45.4 ± 24.3% vs 27.5 ± 17.5%, P = 0.016); however, there was no difference in sputum neutrophils in obese compared with nonobese males (P = 0.620) or older females (P = 0.087). Multiple linear regression analysis found testosterone and OCP use to be negative predictors of sputum %neutrophils, while C-reactive protein and IL-6 were positive predictors of sputum %neutrophils. BMI and age were not significant predictors in the multivariate model. Reproductive-aged females using the OCP had significantly lower sputum %neutrophils than those not using the OCP (23.2 ± 12.6% vs 42.1 ± 23.8%, P = 0.015). This study suggests that sex hormones and systemic inflammation may be mediating the obese-asthma phenotype. The observation that OCP use was associated with lower sputum %neutrophils in reproductive-aged females warrants further investigation. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Voordouw, Maarten J; Koella, Jacob C; Hurd, Hilary
2008-01-01
Background In female mosquitoes that transmit malaria, the benefits of being refractory to the Plasmodium parasite are balanced by the immunity costs in the absence of infection. Male mosquitoes, however, gain no advantage from being refractory to blood-transmitted parasites, so that any costs associated with an enhanced immune system in the males limit the evolution of female refractoriness and has practical implications for the release of transgenic males. Methods Aspects of the male cost of carrying Plasmodium-refractory genes were estimated by comparing the males' immune response and reproductive success among strains of Anopheles gambiae that had been selected for refractoriness or extreme susceptibility to the rodent malaria parasite, Plasmodium yoelii nigeriensis. The refractory males had a stronger melanization response than males from the susceptible line. Four traits were used as correlates of a male's reproductive success: the proportion of females that were inseminated by a fixed number of males in a cage within a fixed time frame, the proportion of females with motile sperm in their spermathecae, the proportion of ovipositing females, and the mean number of eggs per batch. Results Although there were significant differences among groups of males in sperm motility and oviposition success, these differences in male reproductive success were not associated with the refractory or susceptible male genotypes. Contrary to expectation, females mated to early emerging refractory males laid significantly more eggs per batch than females mated to later emerging susceptible males. Sperm motility and oviposition success were strongly correlated suggesting that variation in sperm motility influences female oviposition and ultimately male reproductive success. Conclusion An increased melanization response in male A. gambiae does not diminish male reproductive success under the experimental protocol used in this study. That refractory males induced ovipositing females to lay more eggs than susceptible males is an interesting result for any strategy considering the release of transgenic males. That sperm motility influences female oviposition is also important for the release of transgenic males. PMID:18534029
Fertility and sexual function in female Hodgkin lymphoma survivors of reproductive age.
Eeltink, Corien M; Incrocci, Luca; Witte, Birgit I; Meurs, Saskia; Visser, Otto; Huijgens, Peter; Verdonck-de Leeuw, Irma M
2013-12-01
To assess the perceived fertility status and to determine the association between perceived fertility status and sexual function, as reported by young female Hodgkin lymphoma survivors. Young female Hodgkin lymphoma survivors are at risk of infertility and impaired sexual function. However, little is known about their awareness of infertility and its association with sexual functioning. A descriptive questionnaire survey. In this cross-sectional study, a survey was completed by female Hodgkin lymphoma survivors (< 40 years). Outcome measures included self-reported fertility status and sexual problems and the internationally validated Female Sexual Function Index. In total, 36 survivors were included (mean age 32 years, SD 4). Eighteen women (50%) thought themselves fertile. Eight survivors (22%) who perceived themselves as being infertile were more often treated with alkylator-based chemotherapy, and 63% reported sexual dysfunction. Ten survivors (28%) were not aware as to whether they were fertile or not; seven of these would like to have children. The reported fertility status was related to age and chemotherapy regimen. Regarding sexuality, 14 (39%) of the female Hodgkin lymphoma survivors reported one or more sexual problem and none reported recovery. Female sexual dysfunction according to the Female Sexual Function Index was reported by 11 (31%) survivors. Almost 30% of Hodgkin lymphoma survivors do not know whether they are fertile or not. Overall sexual dysfunction is common in Hodgkin lymphoma survivors and comparable to the general population. However, a lack of desire was significantly more often reported in female Hodgkin lymphoma survivors. To prevent assumed infertility and unintended childlessness by postponing parenthood in young female survivors, awareness of fertility status is needed. There is also a need to routinely assess sexual function and provide adequate interventions to improve arousal and lubrication problems. © 2013 John Wiley & Sons Ltd.
Williams, N I; Caston-Balderrama, A L; Helmreich, D L; Parfitt, D B; Nosbisch, C; Cameron, J L
2001-06-01
Cross-sectional studies of exercise-induced reproductive dysfunction have documented a high proportion of menstrual cycle disturbances in women involved in strenuous exercise training. However, longitudinal studies have been needed to examine individual susceptibility to exercise-induced reproductive dysfunction and to elucidate the progression of changes in reproductive function that occur with strenuous exercise training. Using the female cynomolgus monkey (Macaca fascicularis), we documented changes in menstrual cyclicity and patterns of LH, FSH, estradiol, and progesterone secretion as the animals developed exercise-induced amenorrhea. As monkeys gradually increased running to 12.3 +/- 0.9 km/day, body weight did not change significantly although food intake remained constant. The time spent training until amenorrhea developed varied widely among animals (7-24 months; mean = 14.3 +/- 2.2 months) and was not correlated with initial body weight, training distance, or food intake. Consistent changes in function of the reproductive axis occurred abruptly, one to two menstrual cycles before the development of amenorrhea. These included significant declines in plasma reproductive hormone concentrations, an increase in follicular phase length, and a decrease in luteal phase progesterone secretion. These data document a high level of interindividual variability in the development of exercise-induced reproductive dysfunction, delineate the progression of changes in reproductive hormone secretion that occur with exercise training, and illustrate an abrupt transition from normal cyclicity to an amenorrheic state in exercising individuals, that is not necessarily associated with weight loss.
Hatch, Scott A.
1983-01-01
Sperm-storage glands were found in the uterovaginal (UV) region of the oviduct in Northern Fulmars (Fulmarus glacialis), Horned Puffins (Fratercula corniculata), and Leach's Storm-Petrels (Oceanodroma leucorhoa) collected before or shortly after egg laying. Previously described only in domestic Galliformes, UV sperm-storage glands may prove to be a common feature of the avian reproductive system. There is as yet no compelling explanation of their function in the Horned Puffin. In the Northern Fulmar, and probably in other petrels, however, sperm-storage glands allow the separation of the male and female over pelagic waters for several weeks immediately before egg laying. The likelihood of prolonged viability of sperm in the female reproductive tract should be considered in interpreting the sexual behavior of other wild birds.
Ősapay, György; Ősapay, Klára
2015-08-30
In Western countries, sperm quality and fertility of men significantly worsened. Female infertility does not show a better trend either. Subtle defects in the reproductive functions can not be explained by the current methods, and "unexplained infertility" is becoming a more common diagnosis. Every year 1 million couples seek expensive and time consuming fertility treatment in the world. Deeper understanding of an unhealthy lifestyle and the environmental damages may lead to personalized treatments to increase the chance of conception.The effects of various stressors on the male and female reproductive performance were scientifically substantiated by Selye and coworkers in 1976. Cognitive therapy methods can be applied against emotional stressors, supplementation by antioxidants against reactive oxygen compounds, and administration of vitamins and trace elements, especially when deficiency is found, may help before medical intervention on a rational and economical way in the fight against infertility.
de Oliveira, Marinez Moraes; Ribeiro, Tainá; Orlando, Tamira Maria; de Oliveira, Dênio Garcia Silva; Drumond, Mariana Martins; de Freitas, Rilke Tadeu Fonseca; Rosa, Priscila Vieira
2014-11-10
The goal of the present work was to study the reproductive performance of Nile Tilapia (Oreochromis niloticus) female broodstock fed diets containing different levels of crude protein (CP). Two hundred and forty Nile tilapia (O. niloticus) were used at an average age of 30 months, with 180 females and 60 males. The broodstock were lodged separately in masonry tanks with continuous water flow. The females were stocked in thirty tanks with dimensions of 8 m(3) in a completely randomized design consisting of five treatments and six replications. The treatments consisted of five diets with different levels of CP (32, 34, 36, 38 and 40%) and with digestible energy per gram of protein of 9.5 kg of feed. The crude protein (CP) levels positively influenced (p<0.05) reproductive parameters (female relative and absolute fecundity, egg diameter, fasting larvae survival capacity), the somatic indexes (gonadosomatic (GSI), hepatosomatic (HIS), viscerosomatic (VSI)), total plasma protein, albumin and triglycerides. There were no significant differences (p>0.05) observed with regard to spawning weight and female weight. The reproductive parameters studied in the present research indicate that diets formulated with 38% CP with digestible energy per gram of CP of 9.5 were the best diets for tilapia females during the reproductive period. Copyright © 2014 Elsevier B.V. All rights reserved.
Katz, Karen R; McDowell, Misti; Green, Mackenzie; Jahan, Shamim; Johnson, Laura; Chen, Mario
2015-12-01
Little is known about the sexual and reproductive health care needs of female sex workers in Dhaka, Bangladesh. Survey data were collected from 354 hotel-based and 323 street-based female sex workers using a venue-based stratified cluster sampling approach. In addition, in-depth interviews were conducted with 20 female sex workers recruited from drop-in centers. We calculated unmet need for family planning and examined fertility desires, use of condoms and other contraceptive methods, experiences with gender-based violence, sexual and reproductive health service needs, and preferences on where to receive services. The prevalence of unmet need was 25% among hotel-based female sex workers and 36% among street-based female sex workers. Almost all participants reported having used condoms in the past 30 days, and 44% of hotel-based sex workers and 30% of street-based sex workers reported dual method use during that period. Condom use was inconsistent, however, and condom breakage and nonuse for extra money were common. Many women reported experiencing gender-based violence. Sexual and reproductive health services had been obtained by 64% of hotel-based and 89% of street-based sex workers in the past six months; drop-in centers were their preferred site for receiving health services. Female sex workers in Dhaka need family planning and other sexual and reproductive health services and prefer receiving them from drop-in centers.