Note: This page contains sample records for the topic sterile male sexual from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results. Last update: November 12, 2013.
Sexual maturation of Anastrepha fraterculus is a long process. Methoprene (a mimic of juvenile hormone) considerably reduces the time for sexual maturation in males. However, in other Anastrepha species, this effect depends on protein intake at the adult stage. Here, we evaluated the mating competitiveness of sterile laboratory males and females that were treated with methoprene (either the pupal or adult stage) and were kept under different regimes of adult food, which varied in the protein source and the sugar:protein ratio. Experiments were carried out under semi-natural conditions, where laboratory flies competed over copulations with sexually mature wild flies. Sterile, methoprene-treated males that reached sexual maturity earlier (six days old), displayed the same lekking behaviour, attractiveness to females and mating competitiveness as mature wild males. This effect depended on protein intake. Diets containing sugar and hydrolyzed yeast allowed sterilemales to compete with wild males (even at a low concentration of protein), while brewer´s yeast failed to do so even at a higher concentration. Sugar only fed males were unable to achieve significant numbers of copulations. Methoprene did not increase the readiness to mate of six-day-old sterile females. Long pre-copulatory periods create an additional cost to the management of fruit fly pests through the sterile insect technique (SIT). Our findings suggest that methoprene treatment will increase SIT effectiveness against A. fraterculus when coupled with a diet fortified with protein. Additionally, methoprene acts as a physiological sexing method, allowing the release of mature males and immature females and hence increasing SIT efficiency. PMID:22929968
Liendo, M C; Devescovi, F; Bachmann, G E; Utgés, M E; Abraham, S; Vera, M T; Lanzavecchia, S B; Bouvet, J P; Gómez-Cendra, P; Hendrichs, J; Teal, P E A; Cladera, J L; Segura, D F
The occurrence of genetic malesterility and development of highly sterile lines have been reported. The malesterility was not accompanied by any visible chromosomal aberration. It behaved as recessive and was governed by multiple factors. It was hypothesised that three major genes with additive effect were operating to produce highly sterile forms while less sterile forms would be dependent
The sterile insect technique (SIT) is a method of biological control whereby millions of factory reared sterilemale insects are released into the field. This technique is commonly used to combat the Mediterranean fruit fly (Ceratitis capitata, Diptera: Tephritidae). Sterile medfly males are less competent in attracting and mating with wild females, a property commonly linked to the irradiation process
Sexual maturation of Anastrepha fraterculus is a long process. Methoprene (a mimic of juvenile hormone) considerably reduces the time for sexual maturation in males. However, in other Anastrepha species, this effect depends on protein intake at the adult stage. Here, we evaluated the mating competit...
The malesterile plants that segregated in a BC5F2 of `C. sericeus × C. cajan var. TT-5' population were maintained by sib mating. The malesterile plants were crossed with ICPL-85012.Approximately 50%\\u000a of the F1 plants were sterile. F2 plants derived from the fertile F1 plants did not segregate for malesterility. The reciprocal hybrid i.e. ICPL-85012 × Fertile derivatives
K. B. Wanjari; A. N. Patil; M. C. Patel; J. G. Manjaya
The sterile insect technique is gaining an increasing role in the control of Mediter- ranean fruit fly, Ceratitis capitata (Wiedemann), populations. In the current study, we examine how post-teneral nutrition during the first 48 d after adult emergence affects performance and copu- latory success in leks of mass-reared sterile (TSL strain) males. We found that protein and sugar fed males
The increasing popularity of sterilization underscores the need for knowledge about couples choosing male and female procedures. This research delineates four sets of variables that may be important for the decision and examines their relationship with the choice of male or female procedure among a sample of married couples. (Author)
Genetic modifications causing germ cell death during meiotic prophase in the mouse frequently have sexually dimorphic phenotypes where oocytes reach more advanced stages than spermatocytes. To determine to what extent these dimorphisms are due to differences in male versus female meiotic prophase development, we compared meiotic chromosome events in the two sexes in both wild-type and mutant mice. We report
Nadine K. Kolas; Edyta Marcon; Michael A. Crackower; Christer Höög; Josef M. Penninger; Barbara Spyropoulos; Peter B. Moens
Couples who are considering elective sterilization should compare the risks and costs of male and female sterilization procedures as part of the decision process. Morbidity, mortality, failure rates, and short-term costs associated with male and female st...
The olive tree is usually hermaphrodite but self-incompatible. In the Western Mediterranean some cultivars are totally male-sterile.\\u000a Three different male-sterile phenotypes have been recognised. To infer the genetic basis of malesterility we studied its\\u000a inheritance and cytoplasmic diversity in wild (oleaster) and cultivated Mediterranean olive. In the cross Olivière×Arbequina, the male-sterile trait was maternally inherited and affected all progenies.
A natural malesterile mutant was recovered from the normal population of chilli cv. CA 452-1. The malesterility in the mutant was governed by a single recessive gene ms. The excessive vegetative growth provided easy identification of malesterile plants in the seedling stage. The plant was found to be promising for hybrid seed production.
Mitochondrial DNA was isolated from fertile and cytoplasmic malesterile lines of rice. Restriction analysis showed specific modifications in the malesterile cytoplasm. In addition to the major mitochondrial DNA, three small plasmid-like DNA molecules were detected by agarose gel electrophoresis in both cytoplasms. An additional molecule was specifically found in the sterile cytoplasm. These mitochondrial DNA modifications support the
The circumstances and characteristics of sexual assaults against adult males presenting to a crisis unit in a large metropolitan area were examined. Twenty-nine men, ranging in age from 18 to 65, who were victims of sexual assaults or attempted sexual assaults, were seen over a 16-month period. Information extracted from the unit database included client demographics and personal history, assault
LANA STERMAC; PETER M. SHERIDAN; ALISON DAVIDSON; SHEILA DUNN
Cytoplasmic malesterility (CMS) in plants is a classical example of genomic conflict, opposing maternally-inherited cytoplasmic genes (mitochondrial genes in most cases), which induce malesterility, and nuclear genes, which restore male fertility. In natural populations, this type of sex control leads to gynodioecy, that is, the co-occurrence of female and hermaphroditic individuals within a population. According to theoretical models,
Rice is one of the most important model crop plants whose heterosis has been well-exploited in commercial hybrid seed production via a variety of types of male-sterile lines. Hybrid rice cultivation area is steadily expanding around the world, especially in Southern Asia. Characterization of genes and proteins related to malesterility aims to understand how and why the malesterility occurs, and which proteins are the key players for microspores abortion. Recently, a series of genes and proteins related to cytoplasmic malesterility (CMS), photoperiod-sensitive malesterility, self-incompatibility, and other types of microspores deterioration have been characterized through genetics or proteomics. Especially the latter, offers us a powerful and high throughput approach to discern the novel proteins involving in male-sterile pathways which may help us to breed artificial male-sterile system. This represents an alternative tool to meet the critical challenge of further development of hybrid rice. In this paper, we reviewed the recent developments in our understanding of malesterility in rice hybrid production across gene, protein, and integrated network levels, and also, present a perspective on the engineering of male-sterile lines for hybrid rice production.
Malesterility genes isolated in four inbred lines of pearl millet were found allelic. The differences between male fertile and malesterile phenotypes is mainly due to a single gene. Presence of a dominant gene (Ms) resulted in male fertility and double recessiveness (ms ms) in malesterility. However, genic malesterility (GMS) in Pennisetum is not a simply inherited
The use of the D1/D2 dopamine receptor agonist apomorphine for the treatment of erectile dysfunction provides strong support in favor of a participation of the dopaminergic system in the control of sexual function. However, the exact involvement of dopamine in the control of sexual motivation and genital arousal in males is unknown. Experimental data in male rats suggested an implication
Gynodioecy, the coexistence of hermaphrodites and females (i.e. male-sterile plants) in natural plant populations, most often results from polymorphism at genetic loci involved in a particular interaction between the nuclear and cytoplasmic genetic compartments (cytonuclear epistasis): cytoplasmic malesterility (CMS). Although CMS clearly contributes to the coevolution of involved nuclear loci and cytoplasmic genomes in gynodioecious species, the occurrence of CMS genetic factors in the absence of sexual polymorphism (cryptic CMS) is not easily detected and rarely taken in consideration. We found cryptic CMS in the model plant Arabidopsis thaliana after crossing distantly related accessions, Sha and Mr-0. Malesterility resulted from an interaction between the Sha cytoplasm and two Mr-0 genomic regions located on chromosome 1 and chromosome 3. Additional accessions with either nuclear sterility maintainers or sterilizing cytoplasms were identified from crosses with either Sha or Mr-0. By comparing two very closely related cytoplasms with different male-sterility inducing abilities, we identified a novel mitochondrial ORF, named orf117Sha, that is most likely the sterilizing factor of the Sha cytoplasm. The presence of orf117Sha was investigated in worldwide natural accessions. It was found mainly associated with a single chlorotype in accessions belonging to a clade predominantly originating from Central Asia. More than one-third of accessions from this clade carried orf117Sha, indicating that the sterilizing-inducing cytoplasm had spread in this lineage. We also report the coexistence of the sterilizing cytoplasm with a non-sterilizing cytoplasm at a small, local scale in a natural population; in addition a correlation between cytotype and nuclear haplotype was detected in this population. Our results suggest that this CMS system induced sexual polymorphism in A. thaliana populations, at the time when the species was mainly outcrossing. PMID:23658632
Fertility restoration of Petersons cytoplasmic male-sterility in pepper ( Capsicum annuum L.) is quantitative and environment-dependent. QTL analysis of fertility restoration was performed based on the test-cross progeny of 77013A (a strict cytoplasmic-genetic malesterile line) and a doubled haploid population of 114 lines obtained from an F 1 hybrid between Yolo wonder (a sterility maintainer line) and Perennial (a
L. H. Wang; B. X. Zhang; V. Lefebvre; S. W. Huang; A. M. Daubèze; A. Palloix
Sex has always been a taboo subject in Asian society. However, over the past few years, awareness in the field of men's sexual health has improved, and interest in sexual health research has recently increased. The epidemiology and prevalence of erectile dysfunction, hypogonadism and premature ejaculation in Asia are similar in the West. However, several issues are specific to Asian males, including culture and beliefs, awareness, compliance and the availability of traditional/complementary medicine. In Asia, sexual medicine is still in its infancy, and a concerted effort from the government, relevant societies, physicians and the media is required to propel sexual medicine to the forefront of health care.
A male-sterile, female-sterile soybean mutant (w4-m sterile) was identified among progeny of germinal revertants of a gene-tagging study. Our objectives were to determine the genetics (inheritance, allelism, and linkage) and the cytology (micro- sporogenesis and microgametogenesis) of the w4-m sterile. The mutant was in- herited as a single recessive nuclear gene and was nonallelic to known male-sterile, female-sterile mutants st2
We identified Arabidopsis thaliana sterility mutants by screening T-DNA and EMS-mutagenized lines and characterized several male-sterile mutants with defects\\u000a specific for different anther processes. Approximately 44 and 855 sterile mutants were uncovered from the T-DNA and EMS screens,\\u000a respectively. Several mutants were studied in detail with defects that included the establishment of anther morphology, microspore\\u000a production, pollen differentiation, and anther
Paul M. Sanders; Anhthu Q. Bui; Koen Weterings; Katherine N. McIntire; Yung-Chao Hsu; Pei Yun Lee; Mai Thy Truong; T. P. Beals; R. B. Goldberg
The suppressive effects of trapping adult sea lampreys, Petromyzon marinus Linnaeus, and releasing sterilemales (SMRT) or females (SFRT) into a closed system were expressed in deterministic models. Suppression was modeled as a function of the proportion of the population removed by trapping, the number of sterile animals released, the reproductive rate and sex ratio of the population, and (for the SFRT) the rate of polygyny. Releasing sterilemales reduced populations more quickly than did the release of sterile females. For a population in which 30% are trapped, sterile animals are initially released at ratio of 10 sterile to 1 fertile animal, 5 adult progeny are produced per fertile mating, 60% are male, and males mate with an average of 1.65 females, the initial population is reduced 87% by SMRT and 68% by SFRT in one generation. The extent of suppression achieved is most sensitive to changes in the initial sterile release ratio. Given the current status of sea lamprey populations and trapping operations in the Great Lakes, the sterile-male-release technique has the best chance for success on a lake-wide basis if implemented in Lake Michigan. The effectiveness of the sterile-female-release technique should be investigated in a controlled study. Advancing trapping technology should be a high priority in the near term, and artificial rearing of sea lampreys to the adult stage should be a high priority in the long term. The diligent pursuit of sea lamprey suppression over a period of several decades can be expected to yield great benefits.
Klassen, Waldemar; Adams, Jean V.; Twohey, Michael B.
A `two-line system' using photoperiod-sensitivecytoplasmic malesterility (PCMS) caused by Aegilops crassa cytoplasm has been proposed as a newmeans of producing hybrid wheat. The PCMS line ismaintained by self-pollination under short-dayconditions (?14.5 h light period), and F1 seedscan be produced by outcrossing of the PCMS line witha pollinator under long-day conditions (?15 h lightperiod). As the levels of malesterility
\\u000a The management of malesexual dysfunction and specifically erectile dysfunction (ED) has seen major changes in each decade\\u000a since the 1970s thanks to the discovery that a papaverine injection could produce erection, the NIH Consensus Statement which\\u000a defined ED in 1992, advances in minimally invasive diagnostics, and the development of orally effective erectogenic class\\u000a of drugs, the phosphodiesterase type-5 inhibitors
A genic malesterile Chinese cabbage, Brassica campestris L. ssp. chinensis Makino, was examined using cytological and cytochemical methods to characterize the process of pollen abortion in this plant.\\u000a Thick sections of both fertile and sterile anthers at different developmental stages were stained using Toluidine Blue O,\\u000a Periodic Acid-Schiffs (PAS) reaction and Sudan Black B to detect cytochemical changes that
Summary. A study of malesterility over a period of three consecutive years on a conifer species endemic to Taiwan, Taiwania cryptomerioides Hayata (Taxodiaceae), was done for this article. With the aids of fluorescence and electron microscopic observations, the\\u000a ontogenic processes in the fertile and sterile microsporangia are compared, using samples collected from Chitou Experimental\\u000a Forest and Yeou-Shoei-Keng Clonal Orchard of
The current research explores how ethnicity influences sexual identity development. Among 139 sexual-minority male youths, measures of sexual identity development assessed the timing and sequencing of developmental milestones, disclosure of sexual identity to others, internalized homophobia, and same- and opposite-sex relationship histories. Findings demonstrated that participants, regardless of ethnicity, experienced most identity milestones at developmentally appropriate ages, had moderately low
... sexual dysfunction can be caused by physical or psychological problems. The June 23/30, 2004, issue of JAMA includes an article about the various types of malesexual dysfunction and treatments for them. ...
In this article, we provide a concise review of the past and current literature on the neglected influence of progesterone on malesexual behavior. Although there has been increased interest in all aspects of malesexual function, and the importance of androgens in the regulation of male copulatory behavior has long been well documented, knowledge of the role of progesterone
The history of sterilization dates back to the time of Hippocrates, when female sterilization was recommended for preventing hereditary mental diseases. James Blundell introduced surgical sterilization in 1823 for the prevention of high risk pregnancies. Vasectomy was first performed in the US at the end of the 19th century, mainly to prevent hereditary disorders. Malesterilization was a means of genocide during Nazi rule in Germany. Religious beliefs have the most powerful impact on the practice or nonpractice of family planning. In the teachings of Islam, Christianity, and Judaism, only sporadic references explicitly prohibit contraception, yet various religious edicts have interpreted these references too broadly by advocating prohibition of most contraceptive methods. Recently, the world community endorsed the basic right of couples to decide the number of children they want and the right to family planning with free informed choice. An integral part of a successful family planning program is voluntarism. In Europe and North America sterilization is legal, except in Italy, France, and Turkey. In Latin America sterilization is illegal in a number of countries; in Burma and Vietnam restrictions are in place; and in Africa fertility regulation is illegal in one-third of the countries. Informed consent before sterilization during counseling by a skilled, unbiased counselor is indispensable. All family planning services should be part of the national health care system including the voluntary contraception services. Incentives may compromise voluntarism. Most programs require a minimum age and a minimum number of children, marital status, and spousal consent. For sterilization, a waiting period of 1-30 days has been recommended. The exclusion of childless and single individuals has been challenged as a violation of human rights. For mentally retarded people parents or guardians provide consent. Major ethical issues in the future could emerge concerning novel fertility techniques: cryopreservation of sperm and intracytoplasmic sperm injection. PMID:8535748
Strong indication was found for the existence of a chromosal monogenic dominant malesterility-gene in chenese cabbage. This source of malesterility can be of practical use for the production of hybrid varieties. A pronounced drawback is the required removal, in the breeding and seed production stage, of the approximately 50% male fertile plants from each offspring of malesterile
The present study was aimed at characterizing cytoplasmic malesterility (CMS) and identifying the fertility restorer gene for CMS ( Diplotaxis catholica) Brassica juncea derived through sexual hybridization. The fertility restorer gene was identified by crossing the CMS line with progeny plants derived from somatic hybrids of B. juncea and D. cathoilca. The CMS line is comparable to the nuclear
A. Pathania; S. R. Bhat; V. Dinesh Kumar; Ashutosh; P. B. Kirti; S. Prakash; V. L. Chopra
Comparative genetic mapping provides insights into the evolution of the reproductive barriers that separate closely related species. This approach has been used to document the accumulation of reproductive incompatibilities over time, but has only been applied to a few taxa. House mice offer a powerful system to reconstruct the evolution of reproductive isolation between multiple subspecies pairs. However, studies of the primary reproductive barrier in house micehybrid malesterilityhave been restricted to a single subspecies pair: Mus musculus musculus and Mus musculus domesticus. To provide a more complete characterization of reproductive isolation in house mice, we conducted an F2 intercross between wild-derived inbred strains from Mus musculus castaneus and M. m. domesticus. We identified autosomal and X-linked QTL associated with a range of hybrid malesterility phenotypes, including testis weight, sperm density, and sperm morphology. The pseudoautosomal region (PAR) was strongly associated with hybrid sterility phenotypes when heterozygous. We compared QTL found in this cross with QTL identified in a previous F2 intercross between M. m. musculus and M. m. domesticus and found three shared autosomal QTL. Most QTL were not shared, demonstrating that the genetic basis of hybrid malesterility largely differs between these closely related subspecies pairs. These results lay the groundwork for identifying genes responsible for the early stages of speciation in house mice.
White, Michael A.; Stubbings, Maria; Dumont, Beth L.; Payseur, Bret A.
BACKGROUND: The novel chimeric open reading frame (orf) resulting from the rearrangement of a mitochondrial genome is generally thought to be a causal factor in the occurrence of cytoplasmic malesterility (CMS). Both positive and negative correlations have been found between CMS-associated orfs and the occurrence of CMS when CMS-associated orfs were expressed and targeted at mitochondria. Some orfs cause
The sterile insect technique (SIT) has been proposed as an area-wide method to control the South American fruit fly, Anastrepha fraterculus (Wiedemann). This technique requires sterilization, a procedure that affects, along with other factors, the ability of males to modulate female sexual receptivity after copulation. Numerous pre-release treatments have been proposed to counteract the detrimental effects of irradiation, rearing and handling and increase SIT effectiveness. These include treating newly emerged males with a juvenile hormone mimic (methoprene) or supplying protein to the male's diet to accelerate sexual maturation prior to release. Here, we examine how male irradiation, methoprene treatment and protein intake affect remating behavior and the amount of sperm stored in inseminated females. In field cage experiments, we found that irradiated laboratory males were equally able to modulate female remating behavior as fertile wild males. However, females mated with 6-day-old, methoprene-treated males remated more and sooner than females mated with naturally matured males, either sterile or wild. Protein intake by males was not sufficient to overcome reduced ability of methoprene-treated males to induce refractory periods in females as lengthy as those induced by wild and naturally matured males. The amount of sperm stored by females was not affected by male irradiation, methoprene treatment or protein intake. This finding revealed that factors in addition to sperm volume intervene in regulating female receptivity after copulation. Implications for SIT are discussed. PMID:23340454
Abraham, S; Liendo, M C; Devescovi, F; Peralta, P A; Yusef, V; Ruiz, J; Cladera, J L; Vera, M T; Segura, D F
Obesity concerns more than 200 million people in the world, with an increasing prevalence in western countries. It is closely related to multiple medical conditions, such as diabetes and hypertension. It was recently shown that testosterone deficiency syndrome and erectile dysfunction (ED) are also linked to male obesity. In this group of patients, ED may be due to defects in corpus cavernosum relaxation, endocrine modifications and nerve signal alterations. Weight loss and increased physical activities can improve erectile function in 30% of obese patients. Additional medical treatments of ED enhance erectile function in more than 80% of patients. Self image improvement associated with appropriate erectile dysfunction medical treatment allow better sexual life and potentially increased motivation for weight loss. PMID:23330231
Lucca, Ilaria; Paduch, Darius A; Pralong, François; Vaucher, Laurent
Under-reporting by male victims is more pronounced than for females victims, and so male victims remain a rarity for most sexual assault aftercare service providers. In this chapter, I present a review of forensic medical and psycho-social literature on male-on-male rape and sexual assault. Where appropriate, comparison is made with female victims, as that is the context with which most aftercare service providers are familiar. The following aspects are covered: prevalence; definitions; social perceptions of perpetrators and victims of sexual assault on males; characteristics of victims and assaults; physiological and psychological responses; and implications for forensic medical investigation. PMID:22951768
Malesexual problems are common and offer exceptional opportunities for clinicians to not only relieve distress but enhance individual and relationship satisfaction. However, limited clinical focus on sex behaviors alone often overlook this opportunity. With more comprehensive approaches, clinicians are able to both facilitate improved sexual function and to promote positive, realistic principles for healthy and satisfying male and couple
This article critically reviews the literature about adolescent males sexuality in order to describe the state of the science and to identify promising concepts and research designs that have the potential to guide the next generation of research. A critique was conducted on 94 peer-reviewed studies of sexual behaviors that included a sample of adolescent males; 11 scholarly texts and
Laureen H. Smith; Barbara J. Guthrie; Deborah J. Oakley
Blanchards (J Nerv Ment Dis 177:616623, 1989) theory of autogynephilia suggests that male-to-female transsexuals can be\\u000a categorized into different types based on their sexuality. Little previous research has compared the sexuality of male-to-female\\u000a transsexuals to biological females. The present study examined 15 aspects of sexuality among a non-clinical sample of 234\\u000a transsexuals and 127 biological females, using either an online
Known in over 150 species, cytoplasmic malesterility is encoded by aberrant mitochondrial genes that prevent pollen development. The RNA- or protein-level expression of most of the mitochondrial genes encoding cytoplasmic malesterility is altered in the presence of one or more nuclear genes called restorers of fertility that suppress the male-sterile phenotype. Cytoplasmic malesterility\\/restorer systems have been proven
Stéphane Bentolila; Antonio A. Alfonso; Maureen R. Hanson
Nucleocytoplasmic determination of malesterility in Thymus vulgaris L. has been assumed in all papers attempting to explain the remarkably high frequencies of malesteriles found in natural populations of this species. This paper provides strong evidence that both nuclear and cytoplasmic genes are involved in the determination of malesterility of this species, giving a complex inheritance. Interpopulation and
E. Belhassen; B. Dommée; A. Atlan; P. H. Gouyon; D. Pomente; M. W. Assouad; D. Couvet
Wild abortive cytoplasmic malesterility has been extensively used in hybrid seed production in the tropics. Using protoplast fusion between cytoplasmic malesterile and fertile maintainer lines; we report here, transfer of wild abortive cytoplasmic malesterility to the nuclear background of RCPL1-2C, an advance breeding line which also served as maintainer of this cytoplasm. In total, 27 putative cybrids
Bijoya Bhattacharjee; Aniruddha P. Sane; Hari S. Gupta
Seeds of homozygous ''Tift 23DBâ'' pearl millet (Pennisetum americanum (L.) K. Schum), maintainer for cytoplasmic malesterile (cms) ''Tift 23DAâ,'' were soaked in deionized water solutions of 250 and 1000 ppM of ethidium bromide (EB) at 5Â°C for 40 hours. Treated seeds were rinsed in tap water for 30 min, surface-dried, and planted in replicated two-row plots in the field
Laboratory?reared virgin females of 3 species of Tephritidae oviposited significantly fewer eggs than similar previously mated females. Melon flies, Dacus cucurbitae Coquillett, were most affected (3.0X more eggs for mated females), and Mediterranean fruit flies, Ceratitis capitata (Wiedemann), were least affected; oriental fruit flies, D. dorsalis Hendel, were in between. Numbers of eggs laid by females mated with males treated
Irving Keiser; Mohammad Ashraf; Ernest J. Harris; James A. Silva
Soybean (Glycine max [L.] Merr.) germplasm, isogenic except for loci controlling male-sterility (ms1) and nodulation (rj1) was utilized to investigate the effects of reproductive tissue development and nitrogen source on the initiation of monocarpic senescence. The experimental genotypes (Ms1Rj1, Ms1rj1, ms1Rj1, and ms1rj1, were selected from a cross between N69-2774 and N59-5259, and were inbred to the F5 generation. Green-house-grown plants were collected during the period of flowering (77 days after transplanting) until maturity (147 days after transplanting). Leaf tissues from the respective genotypes were analyzed at the various harvest dates for RNA, phenolic, and chlorophyll concentrations; acid protease activity; polypeptide banding patterns of chloroplast thylakoids; and chloroplastic ultrastructure. Regardless of nitrogen source, total chlorophyll concentrations declined between 77 and 119 days after transplanting, resulting in a 40% loss of chlorophyll per square centimeter in all genotypes. Leaf chlorophyll levels continued to decline at a constant rate in male-fertile genotypes, but remained at a constant level (26 micrograms chlorophyll per square centimeter) in male-sterile genotypes, for the remainder of the study. With increased leaf age, a gradual disruption of thylakoid structures was observed, particularly in chloroplasts from the male-fertile genotypes. Chloroplasts from the male-sterile genotypes appeared to lose starch grains but increased their number of chloroplastic lipid bodies with leaf aging. These data suggest that monocarpic senescence in soybeans was initiated at or before flowering. Although reproductive tissue development probably augmented the process, the response attributed to seed formation was not apparent until the mid-pod fill stage (119 days after transplanting). All genotypes had similar changes in other cellular components that are recognized as indicators of plant senescence regardless of whether the plants produced seed. Images Fig. 6 Fig. 7
Burke, John J.; Kalt-Torres, Willy; Swafford, James R.; Burton, Joseph W.; Wilson, Richard F.
Stroke represents the third leading cause of death, ranking behind heart disease and cancer and it is the major cause of worldwide long-term disability after the age of 65. Stroke has an important psychological and emotional impact on the patient and his environment. Some trials show the substantial lowering of libido, of the frequency of sexual intercourse, the presence of erectile dysfunction and reduced sexual satisfaction. After stroke it is important to evaluate the relational and sexual aspects of the patient and his sexual partner. A specialized consultation should be proposed when necessary to optimise the patient's post-stroke rehabilitation. PMID:17503716
Bianchi-Demicheli, F; Sekoranja, L; Temperli, P; Lövblad, K O; Ortigue, S; Sztajzel, R
Sterility in the universally exploited PET1-CMS system of sunflower is associated with the expression of orfH522, a novel mitochondrial gene. Definitive evidence that ORFH522 is directly responsible for malesterility is lacking.\\u000a To test the hypothesis that ORFH522 is sufficient to induce malesterility, a set of chimeric constructs were developed. The\\u000a cDNA of orfH522 was cloned in-frame with yeast
Forty-eight adult male volunteers attempted to suppress sexual arousal while viewing a sexually explicit videotape and generate an arousal response while viewing a neutral videotape. Attendance to the stimuli was assured by requiring subjects to provide an ongoing verbal description of the videotape they were viewing. While significant effects in controlling arousal were obtained, the degree of subject success varied
Our research concerns the basic mechanisms of cytoplasmic malesterility (CMS) and fertility restoration in maize. The molecular determination of CMS is in the DNA of the mitochondria (mtDNA) but specific nuclear restorer-of-fertility (Rf) genes can overrule the male-sterile effect of the cytoplasm. Our approach to the study of the Rf genes is threefold. We are attempting to tag the cms-S Rf genes and the cms-T Rf2 gene with controlling elements (CEs). Since we have identified a number of spontaneous Rf genes for cms-S and have demonstrated that they are themselves transposable, we are also searching for cases in which an Rf gene is inserted into a wild-type gene. The other aspect of our research involves the nuclear control over the organization of the mitochondrial genome. We found that the changes in mtDNA organization upon cytoplasmic reversion to fertility were characteristic of the nuclear background in which the reversion event occurred. We have investigated whether these differences are a reflection of differences in the organization of the mtDNA genome before reversion.
The effects of anabolic steroid use on malesexual behavior were assessed using a structured clinical interview administered to male body builders currently using steroids, and to two comparison groups (body builders with a past but not current history of steroid use, and a group of natural body builders who had never used steroids). Current anabolic steroid users had a
Most images of sexual abuse in contemporarysociety involve adult male perpetrators and femalevictims. In this paper, we consider the effects of childsexual abuse on the adult male gender roles of boyhood survivors of abuse. Specifically, we examinethe effects of coerced male-on-male (CM), coercedfemale-on-male (CF), and non-coerced female-on-male (NF)sexual contact on attitudes toward and behavior in adult heterosexual relationships. Usinglongitudinal data
In Sweden, approximately 1,500 men and 7,000 women are sterilized yearly. The frequency varies considerably between regions. The reasons for these differences are not fully known. More women than men are sterilized in Sweden, but a higher proportion of sterilized men undergo refertilization. The object of the study was to analyze counselling routines prior to sterilization, presterilization waiting time, the
With the progressive increase in the proportion of older people, there is an increasing interest in characterizing the modifications of sexual health and the effect of its perturbations as a function of the aging process. The aim of this review is to summarize the available evidence regarding the age-dependent modifications of malesexual function and their interaction with general health and age-dependent modification of endocrine function. Elderly patients are often affected by multiple organic diseases which can interfere with sexual function. Despite this evidence, several studies have indicated that, with advancing age, normal erections are not an absolute prerequisite to remain sexually active. Good physical health, the availability of a partner, and a regular and stable pattern of sexual activity earlier in life predict the maintenance of sexual activity in old age. Conversely, there are no convincing data that hormonal changes, associated with aging, have a primary role in underlying changes in sexual function in healthy aging men. Nonetheless, sexual dysfunctions especially in elderly people are poor investigated. Asking about sexual health remains difficult or embarrassing for many primary care physicians. In addition, many patients find it difficult to raise sexual issues with their doctor. This situation often results in sexual issues not being adequately addressed thus resulting in depression, social withdrawal and delayed diagnosis of underlying medical conditions often resulting in forthcoming cardiovascular events. Education and permission from a health care professional may help to alter such misconceptions. Information from physicians regarding normal age-related changes in sexuality and encouragement, together with advice on how to continue meaningful sexual relations, may play a key role in altering such negative attitudes. PMID:24054932
Corona, Giovanni; Rastrelli, Giulia; Maseroli, Elisa; Forti, Gianni; Maggi, Mario
Cytoplasmic male-sterile lines CMS89 and CMSBaso of sunflower (Helianthus annuus) differ from the fertile lines HA89 and Baso in a mitochondrial DNA sequence in the vicinity of theatpA gene. In addition, the transcriptional pattern of theatpA gene is changed in male-sterile lines compared to fertile ones. Besides one main transcript in the fertile lines, the male-sterile lines additionally show larger
For commercial development of hybrids the four pre-requisites are; availability of perfect male-sterility system, efficient\\u000a mass pollen transfer mechanism, hybrid vigor, and the large scale seed production of hybrids for commercialization. The type\\u000a of male-sterility governs the acceptance of hybrids by farmers. Genetic male-sterility (GMS) system was not accepted by farmers\\u000a due to the economics of large scale seed production.
Efforts were made to study microsporogenesis and genetics of fertility restoration of A4 cytoplasmic-nuclear male- sterility (CMS) system in pigeonpea. The process of microsporogenesis in the male-sterile (ICPA 2039) and its maintainer (ICPB 2039) plants was normal up to the tetrad formation stage. The tapetal cells in the male-sterile anthers degenerated soon after tetrad formation, resulting in shriveled and degenerated
VIJAY A. DALVI; K UL B. SAXENA; I. A. Madrap; VIJAY K. RAVIKOTI
We examined the relationships among sexual self?identity, sexual and drug use behaviors, and human immunodeficiency virus (HIV) infection among a sample of 224 male street prostitutes. Structured interviews were administered, and blood samples were collected and tested for HIV, syphilis, and hepatitis B. The sample included 17.9% homosexual, 46.4% heterosexual, and 35.7% bisexually identified men. Congruence between the prostitutes non?paid
Sterility is common in hybrids between divergent populations, such as the indica and japonica subspecies of Asian cultivated rice (Oryza sativa). Although multiple loci for plant hybrid sterility have been identified, it remains unknown how alleles of the loci interact at the molecular level. Here we show that a locus for indica-japonica hybrid malesterility, Sa, comprises two adjacent genes,
Blanchard's (J Nerv Ment Dis 177:616-623, 1989) theory of autogynephilia suggests that male-to-female transsexuals can be categorized into different types based on their sexuality. Little previous research has compared the sexuality of male-to-female transsexuals to biological females. The present study examined 15 aspects of sexuality among a non-clinical sample of 234 transsexuals and 127 biological females, using either an online or a paper questionnaire. The results showed that, overall, transsexuals tended to place more importance on partner's physical attractiveness and reported higher scores on Blanchard's Core Autogynephilia Scale than biological females. In addition, transsexuals classified as autogynephilic scored significantly higher on Attraction to Feminine Males, Core Autogynephilia, Autogynephilic Interpersonal Fantasy, Fetishism, Preference for Younger Partners, Interest in Uncommitted Sex, Importance of Partner Physical Attractiveness, and Attraction to Transgender Fiction than other transsexuals and biological females. In accordance with Blanchard's theory, autogynephilia measures were positively correlated to Sexual Attraction to Females among transsexuals. In contrast to Blanchard's theory, however, those transsexuals classified as autogynephilic scored higher on average on Sexual Attraction to Males than those classified as non-autogynephilic, and no transsexuals classified as autogynephilic reported asexuality. PMID:18299976
This study compares sexually victimized and nonsexually victimized male adolescent sexual abusers on a number of variables. Self-report measures were administered to 325 malesexually abusive youth (average age 16) in six residential facilities in the Midwest, 55% of whom reported sexual victimization. The results indicate that the sexually victimized sexual abusers have more severe developmental antecedents (trauma, family characteristics,
David L. Burton; Kerry Jo Duty; George S. Leibowitz
Two different forces are thought to contribute to the rapid accumulation of hybrid malesterility that has been observed in\\u000a many inter-specific crosses, namely the faster male and the dominance theories. For male heterogametic taxa, both faster male\\u000a and dominance would work in the same direction to cause the rapid evolution of malesterility; however, for taxa lacking differentiated\\u000a sex
Christopher S. Willett; PM Punta Morro; AB Abalone Cove; SC Santa Cruz; PES Pescadero; PLA Playa Altamira
Male fertility was restored to genetically engineered malesterile oilseed rape plants. Malesterile plants that express a chimaeric ribonuclease gene in the anther tapetal cell layer were crossed with male fertile plants that were transformed with a chimaeric tapetal-cell-specific ribonuclease-inhibitor gene. F1 progeny expressing both genes are restored to male fertility by the suppression of cytotoxic ribonuclease activity in
Celestina Mariani; Veronique Gossele; Marc De Beuckeleer; Marc De Block; Robert B. Goldberg; Willy De Greef; Jan Leemans
Male spawning-run sea lampreys Petromyzon marinus were exposed to various doses of cobalt-60 or cesium-137 radiation in an attempt to sterilize them for use in a program for controlling sea lampreys through the release of sterilemales. Males captured and irradiated during the early part of the upstream migration were not effectively sterilized at the doses tested. After irradiation, the sea lampreys were more susceptible to fungal infections by Saprolegnia sp., and many died without attempting to spawn. Males captured and irradiated during the middle and late parts of the spawning migration were effectively sterilized at a dose of 2,000 rads. However, some radiation-induced mortality was observed in males captured and irradiated during the middle part of the spawning migration. Radiation is not as effective as the chemosterilant bisazir for sterilizingmale sea lampreys.
The aim of this study was to evaluate the sexual functions and quality of life of women who have undergone tubal sterilization after tubal surgery. In all, 90 active premenopausal women, who had undergone tubal sterilization at least 1 year ago and been admitted to four different hospitals, were included in the study group. A total of 100 women at
This paper notes the lack of attention given to the sexuality of people with intellectual disabilities in both the literature and service delivery (in Australia). It discusses sterilization issues (such as authority to give consent and the "best interest" concept) and recommends approaches less intrusive on individual rights than sterilization.
Sixteen adult males participated in a repeated measures design in which they served as their own control to determine the effects of various amounts of alcohol on: (1) their sexual arousal elicited by erotic motion-pictures, as measured by a penile transducer, (2) the ability to voluntarily inhibit their arousal to those same films in accordance with instructions, and (3) the
Malesexual behavior is increasingly the focus of genetic study in a variety of animals. Genetic analysis in the soil roundworm Caenorhabditis elegans and the fruit fly Drosophila melanogaster has lead to identification of genes and circuits that govern behaviors ranging from motivation and mate-searching to court- ship and copulation. Some worm and fly genes have counterparts with related functions
Malesexual dysfunction (MSD) is a common disorder associated with a wide range of physical and psychological conditions. Erectile dysfunction, the most commonly studied aspect of MSD, is common and increases with age and with certain comorbid conditions. The pathophysiology of ED and other forms of MSD can be traced to a variety of etiologies, including vascular, hormonal, psychiatric, iatrogenic
Hybrid rice breeding in the US has depended largely upon male-sterile lines originating in China or from other Asian sources. By contrast, the program in Arkansas has developed all of its male-sterile lines at Stuttgart,AR using germplasm accessions available in the USDA Rice Germplasm Collection st...
In the period 19801984 about 70000 selfed seeds of the petunia cultivar Blue Bedder were treated with the chemical mutagens ethidium bromide (EB) and ethylnitroso urea (ENU) with the intention to induce (new sources of) cytoplasmic malesterility (CMS). This work resulted in 27 stable malesterile MS-plants, all derived from the ENU-treatments.
A. M. VAN HARTEN; D. W. VAN DER SPEK; E. C. J. Bal
Chimaeric ribonuclease genes that are expressed in the anthers of transformed tobacco and oilseed rape plants were constructed. Chimaeric ribonuclease gene expression within the anther selectively destroys the tapetal cell layer that surrounds the pollen sac, prevents pollen formation, and leads to malesterility. These nuclear malesterility genes should facilitate the production of hybrid seed in various crop plants.
Celestina Mariani; Marc De Beuckeleer; Jessie Truettner; Jan Leemans; Robert B. Goldberg
Fifteen sunflower (Helianthus annuus L.) cytoplasmic male-sterile, and a single male-fertile, cytotypes were studied by both mtDNA (mitochondrial DNA) restriction fragment length polymorphism (RFLP) and genetical analysis of male-fertility restoration patterns. It was found by multivariate analysis that the two methods of identification of cytoplasmic malesterility (CMS) should be of use in sunflower breeding programs. The RFLP study distinguished
D. Crouzillat; L. De La Canal; F. Vear; H. Serieys; G. Ledoigt
In most taxa with male dimorphisms, some males are large in body size with exaggerated secondary sexual characters (exaggerated morph), whereas other males in the same population are small and have reduced secondary sexual characters (reduced morph). What selective pressures cause male dimorphisms? Reduced morphologies may result when a) some males develop a morphology that, in the absence of sexual
We studied the effects of early sexual experience on the adult sexual performance of male dairy goats. Seven postpubertal males were exposed to an estrous female on four occasions during their 1st yr of life. These males were housed with six additional males (controls) that received no early sexual ex- perience. As yearlings, the 13 males were individually exposed to
Background and Aims Expression of the mitochondrial gene orf138 causes Ogura cytoplasmic malesterility (CMS) in Raphanus sativus, but little is known about the mechanism by which CMS takes place. A preliminary microarray experiment revealed that several nuclear genes concerned with flavonoid biosynthesis were inhibited in the male-sterile phenotype. In particular, a gene for one of the key enzymes for flavonoid biosynthesis, chalcone synthase (CHS), was strongly inhibited. A few reports have suggested that the inhibition of CHS causes nuclear-dependent malesterile expression; however, there do not appear to be any reports elucidating the effect of CHS on CMS expression. In this study, the expression patterns of the early genes in the flavonoid biosynthesis pathway, including CHS, were investigated in normal and male-sterile lines. Methods In order to determine the aberrant stage for CMS expression, the characteristics of male-sterile anthers are observed using light and transmission electron microscopy for several stages of flower buds. The expression of CHS and the other flavonoid biosynthetic genes in the anthers were compared between normal and male-sterile types using real time RT-PCR. Key Results Among the flavonoid biosynthetic genes analysed, the expression of CHS was strongly inhibited in the later stages of anther development in sterility cytoplasm; accumulation of putative naringenin derivatives was also inhibited. Conclusions These results show that flavonoids play an important role in the development of functional pollen, not only in nuclear-dependent malesterility, but also in CMS.
|A study of 359 men who sought sexual dysfunction treatment found that childhood sexual abuse did not predict sexual dysfunction in the men. Unemployment was the only significant predictor of malesexual dysfunction. Differences between the sexual abuse experiences of the male victims compared to female victims (n=73) are discussed. (Author/CR)|
|This study compares sexually victimized and nonsexually victimized male adolescent sexual abusers on a number of variables. Self-report measures were administered to 325 malesexually abusive youth (average age 16) in six residential facilities in the Midwest, 55% of whom reported sexual victimization. The results indicate that the sexually
Burton, David L.; Duty, Kerry Jo; Leibowitz, George S.
This study compares sexually victimized and nonsexually victimized male adolescent sexual abusers on a number of variables. Self-report measures were administered to 325 malesexually abusive youth (average age 16) in six residential facilities in the Midwest, 55% of whom reported sexual victimization. The results indicate that the sexually
Burton, David L.; Duty, Kerry Jo; Leibowitz, George S.
This paper discusses research on men's reproductive health and sexuality in Oaxaca, Mexico, and specifically why some men there choose to be sterilized. Men who opt for vasectomies do so after considering numerous cultural, historical, physiological, commercial, and other concerns. Men and women in Oaxaca negotiate certain cultural folk beliefs about supposed malesexual desires and practices before arriving at the decision to get the operation. Vasectomy as a method of birth control is chosen despite folk beliefs that take the form of a totemic illusion which treats malesexuality as naturalized, something fixed, and as entirely distinct from female sexuality. Among its many consequences, this totemic illusion serves to conceal inequalities in the sphere of reproductive health and sexuality in relation to contraception. PMID:16108204
Background Photoperiod-sensitive genic malesterile (PGMS) rice, Nongken 58S, was discovered in 1973. It has been widely used for the production of hybrid rice, and great achievements have been made in improving rice yields. However, the mechanism of the malesterility transition in PGMS rice remains to be determined. Results To investigate the transcriptome during the malesterility transition in PGMS rice, the transcriptome of Nongken 58S under short-day (SD) and long-day (LD) at the glume primordium differentiation and pistil/stamen primordium forming stages was compared. Seventy-three and 128 differentially expressed genes (DEGs) were identified at the glume primordium differentiation and pistil/stamen primordium forming stages, respectively. Five and 22 genes were markedly up-regulated (? 5-fold), and two and five genes were considerably down-regulated (? 5-fold) under SD during the malesterility transition. Gene ontology annotation and pathway analysis revealed that four biological processes and the circadian rhythms and the flowering pathways coordinately regulated the malesterility transition. Further quantitative PCR analysis demonstrated that the circadian rhythms of OsPRR1, OsPRR37, OsGI, Hd1, OsLHY and OsDof in leaves were obviously different between Nongken 58S and Nongken 58 under LD conditions. Moreover, both OsPRR37 and Hd1 in the inflorescence displayed differences between Nongken 58S and Nongken 58 under both LD and SD conditions. Conclusion The results presented here indicate that the transcriptome in Nongken 58S was significantly suppressed under LD conditions. Among these DEGs, the circadian rhythm and the flowering pathway were involved in the malesterility transition. Furthermore, these pathways were coordinately involved in the malesterility transition in PGMS rice.
Gynodioecy, the coexistence of female and hermaphrodite plants within a species, is often under nuclearcytoplasmic sex determination, involving cytoplasmic malesterility (CMS) genes and nuclear restorers. A good knowledge of CMS and restorer polymorphism is essential for understanding the evolution and maintenance of gynodioecy, but reciprocal crossing studies remain scarce. Although mitochondrial diversity has been studied in a few gynodioecious species, the relationship between mitotype diversity and CMS status is poorly known. From a French sample of Silene nutans, a gynodioecious species whose sex determination remains unknown, we chose the four most divergent mitotypes that we had sampled at the cytochrome b gene and tested by reciprocal crosses whether they carry distinct CMS genes. We show that gynodioecy in S. nutans is under nuclearcytoplasmic control, with at least two different CMSs and up to four restorers with epistatic interactions. Female occurrence and frequency were highly dependent on the mitotype, suggesting that the level of restoration varies greatly among CMSs. Two of the mitotypes, which have broad geographic distributions, represent different CMSs and are very unequally restored. We discuss the dynamics of gynodioecy at the large-scale meta-population level.
Garraud, C; Brachi, B; Dufay, M; Touzet, P; Shykoff, J A
Hybrid sterility in the heterogametic sex is a common feature of speciation in animals. In house mice, the contribution of the Mus musculus musculus X chromosome to hybrid malesterility is large. It is not known, however, whether F1 malesterility is caused by X-Y or X-autosome incompatibilities or a combination of both. We investigated the contribution of the M. musculus domesticus Y chromosome to hybrid malesterility in a cross between wild-derived strains in which males with a M. m. musculus X chromosome and M. m. domesticus Y chromosome are partially sterile, while males from the reciprocal cross are reproductively normal. We used eight X introgression lines to combine different X chromosome genotypes with different Y chromosomes on an F1 autosomal background, and we measured a suite of male reproductive traits. Reproductive deficits were observed in most F1 males, regardless of Y chromosome genotype. Nonetheless, we found evidence for a negative interaction between the M. m. domesticus Y and an interval on the M. m. musculus X that resulted in abnormal sperm morphology. Therefore, although F1 malesterility appears to be caused mainly by X-autosome incompatibilities, X-Y incompatibilities contribute to some aspects of sterility. PMID:22595240
Campbell, Polly; Good, Jeffrey M; Dean, Matthew D; Tucker, Priscilla K; Nachman, Michael W
Hybrid sterility in the heterogametic sex is a common feature of speciation in animals. In house mice, the contribution of the Mus musculus musculus X chromosome to hybrid malesterility is large. It is not known, however, whether F1 malesterility is caused by XY or X-autosome incompatibilities or a combination of both. We investigated the contribution of the M. musculus domesticus Y chromosome to hybrid malesterility in a cross between wild-derived strains in which males with a M. m. musculus X chromosome and M. m. domesticus Y chromosome are partially sterile, while males from the reciprocal cross are reproductively normal. We used eight X introgression lines to combine different X chromosome genotypes with different Y chromosomes on an F1 autosomal background, and we measured a suite of male reproductive traits. Reproductive deficits were observed in most F1 males, regardless of Y chromosome genotype. Nonetheless, we found evidence for a negative interaction between the M. m. domesticus Y and an interval on the M. m. musculus X that resulted in abnormal sperm morphology. Therefore, although F1 malesterility appears to be caused mainly by X-autosome incompatibilities, XY incompatibilities contribute to some aspects of sterility.
Campbell, Polly; Good, Jeffrey M.; Dean, Matthew D.; Tucker, Priscilla K.; Nachman, Michael W.
Three cytoplasmic male-sterile Nicotiana cultivars together with corresponding male-fertile progenitors and restored lines were investigated in order to find possible correlations between respiratory characteristics and malesterility. Oxygen consumption measurements were performed on cells from suspension cultures as well as on mitochondria isolated from green leaves. Inhibitors, which have been reported to specifically block either the cytochrome (KCN) or the alternative (propyl gallate and sali-cylhydroxamic acid [SHAM] respiratory pathways, were used in order to measure the capacity and activity of the two pathways. One of the inhibitors, SHAM, was found unsuitable to measure the activity of the alternative pathway due to the lack of specificity of SHAM for this pathway. A great difference in the capacity of the alternative pathway was detected between the two types of cell materials tested. Mitochondria isolated from green leaves showed a capacity of the alternative pathway of 5 to 20% of total mitochondrial repiration, while the capacity of cells from suspension cultures generally ranged from 50 to 80%. In addition to this, in organello synthesis of mitochondrial proteins revealed differences between mitochondria isolated from green leaves and from cell suspensions. No correlation, however, could be found between respiratory characteristics and malesterility. Images Figure 1 Figure 2
Hakansson, Gunilla; Glimelius, Kristina; Bonnett, Howard T.
Male hybrids between Anopheles gambiae and An. arabiensis suffer from hybrid sterility, and inviability effects are sometimes present as well. We examined the genetic basis of these reproductive barriers between the two species, using 21 microsatellite markers. Generally, recessive inviability effects were found on the X chromosome of gambiae that are incompatible with at least one factor on each arabiensis autosome. Inviability is complete when the gambiae and arabiensis inviability factors are hemi- or homozygous. Using a QTL mapping approach, regions that contribute to male hybrid sterility were also identified. The X chromosome has a disproportionately large effect on male hybrid sterility. Additionally, several moderate-to-large autosomal QTL were found in both species. The effect of these autosomal QTL is contingent upon the presence of an X chromosome from the other species. Substantial regions of the autosomes do not contribute markedly to male hybrid sterility. Finally, no evidence for epistatic interactions between conspecific sterility loci was found.
The effects of childhood circumcision on malesexual function have been debated. However, there are no studies, to our knowledge, that assess the possible effects of childhood circumcision age on malesexual function. In an attempt to answer this question, we performed a prospective study to determine the possible relationship between circumcision age and malesexual function, using a validated
The aim of this study is to provide evidence on the aphrodisiac property ofEurycoma longifolia Jack. An electric grid was used as an obstruction in the electrical copulation cage in order to determine how much an aversive\\u000a stimulus the sexually naive male rat for both the treated withE. longifolia Jack and control groups were willing to overcome to reach the
The mass-reared colony of Anastrepha ludens (Loew) currently used in Mexico for suppression of the Mexican fruit fly has been in use for over 10 years. Sterile flies are released into a wide range of environmental conditions as part of an integrated area-wide approach to suppress diverse populations of this pest in the Mexican Republic. This paper assesses the performance of the sterile flies interacting with wild populations from the different environments. We investigated the sexual compatibility and competitiveness of the sterile flies when competing with wild populations from 6 representatives Mexican states: Nuevo Leon, Tamaulipas, Sinaloa, Nayarit, Michoacan, and Chiapas. Results show that the males of the wild populations differed in the time to the onset and peak of sexual activity. Nevertheless, the index of sexual isolation (ISI) reflected sexual compatibility between the populations and the mass-reared strain, indicating that the sterile individuals mate satisfactorily with the wild populations from the 6 states. The male relative performance index (MRPI) showed that the sterilemale is as effective in copulating as the wild males. The female relative performance index (FRPI) reflected a general tendency for wild females to copulate in greater proportion than the sterile females, except for the strains from Tamaulipas and Chiapas. In general, the lower participation of the sterile females in copulation increases the possibilities of sterilemales to mate with wild females. The relative sterility index (RSI) showed that the acceptance by wild females of the sterilemales (25-55%) was similar to that of wild males. Females of the Chiapas strain showed the lowest acceptance of sterilemales. Finally, the results obtained in the Fried test (which measures induced sterility in eggs) showed a competitiveness coefficient ranging from 0.2 to 0.5. This suggests that sterilemales successfully compete and are compatible with flies from different geographic origins. (author) [Spanish] La colonia actualmente usada para controlar la mosca mexicana de la fruta, Anastrepha ludens (Loew), en Mexico tiene mas de 10 anos en cria masiva. Los insectos esteriles son liberados en una gran variedad de condiciones ambientales como parte de un control integrado para suprimir diversas poblaciones de esta plaga dentro de la Republica Mexicana. El objetivo de este documento esta dirigido a revisar el desempeno de las moscas esteriles frente a poblaciones silvestres procedentes de diferentes ambientes y para esto se realizaron comparaciones de compatibilidad y competitividad sexual de las moscas esteriles contra poblaciones silvestres de seis estados representativos de la Republica Mexicana: Nuevo Leon, Tamaulipas, Sinaloa, Nayarit, Michoacan y Chiapas. Los resultados obtenidos manifiestan diferencias en el horario de inicio de llamado y mayor actividad sexual del macho entre las moscas provenientes de cada estado. Sin embargo el indice de aislamiento (ISI) reflejo compatibilidad sexual entre la cepa de laboratorio y todas las poblaciones analizadas, indicando que los individuos esteriles pueden aparearse satisfactoriamente con las poblaciones silvestres de los seis estados. El indice de efectividad de apareamiento del macho (MRPI) reflejo de manera global que los machos esteriles son tan efectivos para copular como los silvestres. El indice de efectividad de apareamiento de la hembra (FRPI) reflejo que en la mayoria de los estados las hembras silvestres copularon en mayor proporcion que las hembras esteriles, excepto para las poblaciones de Tamaulipas y Chiapas. En general, la baja participacion de las hembras esteriles en el campo permitio al macho esteril ampliar su probabilidad de apareamiento con las hembras silvestres. En cuanto al indice de esterilidad relativa (RSI), observamos que la aceptacion de las hembras silvestres al macho esteril (25-55%) fue similar a la de los machos silvestres. Las hembras de la poblacion de Chiapas registro la menor aceptacion. Finalmente, los resultados obtenidos en la prueba de Fried, la cual determi
Orozco-Davila, D.; Hernandez, R.; Meza, S.; Dominguez, J. [Programa Moscamed Moscafrut-Desarrollo de Metodos, Central Poniente No. 14 altos-Esq. 2a Avenida Sur. CP 30700 Tapachula, Chiapas (Mexico)
Triticum aestivum cv. Norin 26 with Aegilops crassa, Ae. juvenalis or Ae. vavilovii cytoplasm (all D2 type) has been studied relative to its photoperiodic response of malesterility and fertility restoration patterns. Alloplasmic lines of Norin 26 with a D2 type cytoplasm showed almost complete malesterility under long-day conditions (=15 h), but high male fertility under short-day conditions (=14.5
In crosses between evolutionarily diverged populations, genomic incompatibilities may result in sterile hybrids, indicating evolution of reproductive isolation. In several plant families, crosses within a population can also lead to malesterile progeny because of conflict between the maternally and biparentally inherited genomes. We examined hybrid fertility between subspecies of the perennial outcrossing self-incompatible Lyrate rockcress (Arabidopsis lyrata) in large reciprocal F2 progenies and three generations of backcrosses. In one of the reciprocal F2 progenies, almost one-fourth of the plants were male-sterile. Correspondingly, almost one-half of the plants in one of the four reciprocal backcross progenies expressed malesterility. In an additional four independent F2 and backcross families, three segregated malesterility. The observed asymmetrical hybrid incompatibility is attributable to malesterility factors in one cytoplasm, for which the other population lacks effective fertility restorers. Genotyping of 96 molecular markers and quantitative trait locus mapping revealed that only 60% of the plants having the malesterile cytoplasm and lacking the corresponding restorers were phenotypically male-sterile. Genotyping data showed that there is only one restorer locus, which mapped to a 600-kb interval at the top of chromosome 2 in a region containing a cluster of pentatricopeptide repeat genes. Male fertility showed no trade-off with seed production. We discuss the role of cytoplasm and genomic conflict in incipient speciation and conclude that cytoplasmic malesterility-lowering hybrid fitness is a transient effect with limited potential to form permanent reproductive barriers between diverged populations of hermaphrodite self-incompatible species. PMID:23935000
Aalto, Esa A; Koelewijn, Hans-Peter; Savolainen, Outi
In crosses between evolutionarily diverged populations, genomic incompatibilities may result in sterile hybrids, indicating evolution of reproductive isolation. In several plant families, crosses within a population can also lead to malesterile progeny because of conflict between the maternally and biparentally inherited genomes. We examined hybrid fertility between subspecies of the perennial outcrossing self-incompatible Lyrate rockcress (Arabidopsis lyrata) in large reciprocal F2 progenies and three generations of backcrosses. In one of the reciprocal F2 progenies, almost one-fourth of the plants were male-sterile. Correspondingly, almost one-half of the plants in one of the four reciprocal backcross progenies expressed malesterility. In an additional four independent F2 and backcross families, three segregated malesterility. The observed asymmetrical hybrid incompatibility is attributable to malesterility factors in one cytoplasm, for which the other population lacks effective fertility restorers. Genotyping of 96 molecular markers and quantitative trait locus mapping revealed that only 60% of the plants having the malesterile cytoplasm and lacking the corresponding restorers were phenotypically male-sterile. Genotyping data showed that there is only one restorer locus, which mapped to a 600-kb interval at the top of chromosome 2 in a region containing a cluster of pentatricopeptide repeat genes. Male fertility showed no trade-off with seed production. We discuss the role of cytoplasm and genomic conflict in incipient speciation and conclude that cytoplasmic malesterilitylowering hybrid fitness is a transient effect with limited potential to form permanent reproductive barriers between diverged populations of hermaphrodite self-incompatible species.
Aalto, Esa A.; Koelewijn, Hans-Peter; Savolainen, Outi
Capturing the process of speciation early enough to determine the initial genetic causes of reproductive isolation remains a major challenge in evolutionary biology. We have found, to our knowledge, the first example of substantial intraspecific polymorphism for genetic factors contributing to hybrid malesterility. Specifically, we show that the occurrence of hybrid malesterility in crosses between Drosophila mojavensis and its sister species, Drosophila arizonae, is controlled by factors present at different frequencies in different populations of D. mojavensis. In addition, we show that hybrid malesterility is a complex phenotype; some hybrid males with motile sperm still cannot sire offspring. Because malesterility factors in hybrids between these species are not yet fixed within D. mojavensis, this system provides an invaluable opportunity to characterize the genetics of reproductive isolation at an early stage. PMID:15184657
Malesexual responses are reflexes mediated by the spinal cord and modulated by neural circuitries involving both the peripheral and central nervous system. While the brain interact with the reflexes to allow perception of sexual sensations and to exert excitatory or inhibitory influences, penile reflexes can occur despite complete transections of the spinal cord, as demonstrated by the reviewed animal studies on spinalization and human studies on spinal cord injury. Neurophysiological and neuropharmacological substrates of the malesexual responses will be discussed in this review, starting with the spinal mediation of erection and its underlying mechanism with nitric oxide (NO), followed by the description of the ejaculation process, its neural mediation and its coordination by the spinal generator of ejaculation (SGE), followed by the occurrence of climax as a multisegmental sympathetic reflex discharge. Brain modulation of these reflexes will be discussed through neurophysiological evidence involving structures such as the medial preoptic area of hypothalamus (MPOA), the paraventricular nucleus (PVN), the periaqueductal gray (PAG), and the nucleus para-gigantocellularis (nPGI), and through neuropharmacological evidence involving neurotransmitters such as serotonin (5-HT), dopamine and oxytocin. The pharmacological developments based on these mechanisms to treat malesexual dysfunctions will complete this review, including phosphodiesterase (PDE-5) inhibitors and intracavernous injections (ICI) for the treatment of erectile dysfunctions (ED), selective serotonin reuptake inhibitor (SSRI) for the treatment of premature ejaculation, and cholinesterase inhibitors as well as alpha adrenergic drugs for the treatment of anejaculation and retrograde ejaculation. Evidence from spinal cord injured studies will be highlighted upon each step. PMID:23360268
Courtois, Frédérique; Carrier, Serge; Charvier, Kathleen; Guertin, Pierre A; Journel, Nicolas Morel
A new improved method for hybrid seed production was successfully tested. This method is based on using a cytoplasmic malesterile line possessing a lethal gene with action that can be easily inhibited and a female sterile pollenizer. The lethal gene ensures 100% purity of the F1 crop. The female sterile pollenizer provides a permanent abundant flowering with excess of
We have analyzed the sterility associated with introgressions of the distal one-fourth of the X chrc- mosome from either Drosophila mauritiana or Drosophila sechellia into the genome of Drosophila simu- lans using a series of visible and DNA markers. Because in Drosophila hybrids, malesterility is usually complete and is often tightly linked with each of several markers used in
Eric L. Cabot; Andrew W. Davis; Norman A. Johnson; Chung-I Wu
Examined relationships between perceptions of marital communication and the choice of male or female sterilization in 313 couples. The wife's perception of marital communication was negatively related to the tendency for the couple to choose female sterilization, conditional on female labor force participation. Communication questions are
Fluctuating asymmetry (FA), a measure of developmental stability, may be important in human sexual selection, that is in mate choice and male-male competition. It is shown that in males (but not in females) resting metabolic rate (RMR) is positively related to FA. This is explained in terms of the balanced energy equation of males. Sexual selection for large body size
This article reviews available literature on male inmate sexual assault and discusses the legal, moral, and practical reasons why correctional personnel should work to prevent instances of sexual assault and sexual pressure from occurring in prisons and jails. Typical offender characteristics and motivations are presented. Victim characteristics and common psychological reactions to prison sexual assaults are highlighted also. Lastly, specific
Thomas J. Fagan; Deborah Wennerstrom; Jeanne Miller
Several researchers have suggested that orgasm plays a minimal role in female subjective sexual satisfaction. No data exist on this issue for males and the data for females are based on very global indices of sexual satisfaction. The purposes of this study were to investigate (a) the relationships between orgasm consistency and sexual enjoyment in both males and females, (b)
Pavlovian conditioning of the human malesexual response may be involved in the ontogenetic development of sexual interests and may be responsible for individual differences. We attempted to demonstrate Pavlovian conditioning of sexual interests in a nonclinical sample of adult males. Ten participants were exposed to 11 pairings of a slide of a moderately attractive, partially nude female adult (TARGET)
F1 hybrid seeds are produced by controlled hybridization of homozygous inbred lines. Malesterility avoids tedious emasculation\\u000a procedures of female parental plants but must be reversible easily in order to propagate and maintain the male-sterile lines.\\u000a Doubled haploid plants provide complete homozygosity and therefore may be used as parental lines to breed F1 hybrids. An environment-friendly F1 hybrid breeding technology
A. Ribarits; A. N. K. Mamun; S. Li; T. Resch; M. Fiers; E. Heberle-Bors; C.-M. Liu; A. Touraev
In previous experiments on the induction of translocations in the mouse tests were usually confined to the sons of treated animals. In the present experiment daughters of irradiated males were studied, with a view to finding the frequency of X-linked translocations and of autosomal aberrations causing malesterility. The treated males were given 600 rad X-rays to the hind part
The aim of this study is to provide evidence on the aphrodisiac property of Eurycoma longifolia Jack. An electric grid was used as an obstruction in the electrical copulation cage in order to determine how much an aversive stimulus the sexually naive male rat for both the treated with E. longifolia Jack and control groups were willing to overcome to reach the estrous receptive female in the goal cage. The intensity of the grid current was maintained at 0.12 mA and this was the intensity in which the male rats in the control group failed to crossover to reach the goal cage. Results showed that E. longifolia Jack continued to enhance and also maintain a high level of both the total number of successful crossovers, mountings, intromissions and ejaculations during the 9-12th week observation period. In conclusion, these results further enhanced and strengthened the aphrodisiac property of E. longifolia Jack. PMID:9868556
Malesterility of wheat-breeding line 337S (Triticum aestivum L.) is sensitive to both short day-length\\/low temperature and long day-length\\/high temperature. 337S was crossed with the\\u000a common wheat variety, Huamai No. 8 and the F1 was highly fertile. The F2 population segregated in a 15:1 ratio for fertility\\/sterility in 243 individuals under long day-length\\/high-temperature.\\u000a The two thermophotoperiod-responsive malesterile genes were
R. X. Guo; D. F. Sun; Z. B. Tan; D. F. Rong; C. D. Li
The pilot field studies here presented are part of a long-term research program aimed to develop a cost-effective sterile insect technique (SIT) methodology to suppress Aedes albopictus (Skuse) populations. Aedes albopictus is a mosquito species mainly developing in man-made containers and with an island-like urban and suburban distribution. These two features make the application of the sterile insect technique a possible control strategy. Five trials have been performed in three small towns from 2005 to 2009 (Emilia-Romagna region, northern Italy). Reared male pupae, sexed by a sieving technique allowing the recovery of approximately 26-29% of males, were exposed to gamma rays and immediately released in the field. Adult population density was estimated based on a weekly monitoring of egg density in the ovitraps, whereas induced sterility was estimated by measuring the hatching percentage of weekly collected eggs in SIT and control areas. Results showed that sterilemales released at the rate of 896-1,590 males/ha/wk induced a significant sterility level in the local population. In addition, when the sterility level achieved values in the range of 70-80%, a similar reduction also was found for the egg density in the ovitraps. We could estimate that the minimum egg sterility value of 81% should be maintained to obtain suppression of the local population. Immigration of mated females was not a main issue in the small villages where trials have been run. PMID:23540120
Bellini, R; Medici, A; Puggioli, A; Balestrino, F; Carrieri, M
Sexual behavior is variable between individuals, ranging from celibacy to sexual addictions. Within normal populations of individual men, ranging from young to middle aged, testosterone levels do not correlate with libido. To study the genetic mechanisms that contribute to individual differences in malesexual behavior, we used hybrid B6D2F1 male mice, which are a cross between two common inbred strains (C57BL/6J and DBA/2J). Unlike most laboratory rodent species in which malesexual behavior is highly dependent upon gonadal steroids, sexual behavior in a large proportion of these hybrid male mice after castration is independent of gonadal steroid hormones and their receptors; thus, we have the ability to discover novel genes involved in this behavior. Gene expression arrays, validation of gene candidates, and transgenic mice that overexpress one of the genes of interest were used to reveal genes involved in maintenance of malesexual behavior. Several genes related to neuroprotection and neurodegeneration were differentially expressed in the hypothalamus of males that continued to mate after castration. Male mice overexpressing the human form of one of these candidate genes, amyloid beta precursor protein (APP), displayed enhanced sexual behavior before castration and maintained sexual activity for a longer duration after castration compared with controls. Our results reveal a novel and unexpected relationship between APP and malesexual behavior. We speculate that declining APP during normal aging in males may contribute to the loss of sexual function. PMID:20668181
Park, Jin Ho; Bonthius, Paul J; Tsai, Houng-Wei; Bekiranov, Stefan; Rissman, Emilie F
This article examines four issues that need to be explored by the therapist as possible causes of stress for a male couple: stereotypic male roles, stereotypic sexual roles, homophobia, which includes the coming out process, and sexual dysfunctions. These issues can cause anxiety and stress, which may in turn cause relationship problems for a male couple. The role of the
|This study examined victim and assault characteristics and the nature and extent of coercion, violence, and physical injuries among adult male victims of sexual assaults. Client records of three groups presenting to a sexual assault care center were included: males assaulted by a stranger (n = 64), males assaulted by an acquaintance (n = 81), and
Many gay male couples make agreements about whether or not to permit sex with outside partners, yet little is known about the development and maintenance of these agreements, their impact on relationships, and whether they are an effective HIV prevention strategy. Using semi-structured, qualitative interviews, 39 gay male couples were asked about their sexual agreements and about other relationship dynamics that might affect their agreements. Analysis revealed a wide range of agreement types, all of which are presented along a continuum rather than as discrete categories. For couples with open agreements, most placed rules or conditions limiting when, where, how often, and with whom outside sex was permitted. Although motivations for having agreements varied, HIV prevention did not rank as a primary factor for any couple. Most couples had congruous agreements; however, a small number reported discrepancies which may increase HIV transmission risk. How couples handled breaks in their agreements also varied, depending on what condition was broken, whether it was disclosed, and the partner's reaction. Additional results include differences in agreement type and motivations for having an agreement based on couple serostatus. Overall, agreements benefited couples by providing boundaries for the relationship, supporting a non-heteronormative identity, and fulfilling the sexual needs of the couple. Future prevention efforts involving gay couples must address the range of agreement types and the meanings couples ascribe to them, in addition to tempering safety messages with the relationship issues that are important to and faced by gay couples.
In male rats, whether sexually experienced or sexually naive, the intraperitoneal administration of l-arginine (the natural substrate for nitric oxide synthase) (10, 25, 50 mg\\/kg) both increased the percentage of copulating in sexually naive rats and improved the indexes of sexual performance in sexually experienced rats, whereas the intraperitoneal administration of NG-nitro-l-arginine methyl ester (L-NAME) (a potent inhibitor of nitric
Augusta Benelli; Alfio Bertolini; Rosanna Poggioli; Elena Cavazzuti; Laura Calzà; Luciana Giardino; Rossana Arletti
OBJECTIVE:To determine if interval tubal sterilization leads to a change in female sexual interest or pleasure and to identify predictors of a positive or negative effect.METHODS:Our study population comprised 4576 women enrolled in a prospective, multicenter cohort study between 1978 and 1983. Potential demographic, clinical, and surgical predictors of sexual outcome were tested for significant variation from the overall pattern
Caroline Costello; Susan D Hillis; Polly A Marchbanks; Denise J Jamieson; Herbert B Peterson
Twelve Japanese rice cultivars were converted to CMS by asymmetric protoplast fusion with MTC-5A, the cytoplasm of which was derived from an indica rice, Chinsurah Boro II. With the exception of the cybrids that had a nucleus from Hoshiyutaka, most of these cybrid plants were sterile. The unique sequence downstream from the mitochondrial atp6 of MTC-5A was specifically amplified in
H. Akagi; A. Nakamura; R. Sawada; M. Oka; T. Fujimura
Explaining the evolution of male care has proved difficult. Recent theory predicts that female promiscuity and sexual selection on males inherently disfavour male care. In sharp contrast to these expectations, male-only care is often found in species with high extra-pair paternity and striking variation in mating success, where current theory predicts female-only care. Using a model that examines the coevolution of male care, female care and female choice; I show that inter-sexual selection can drive the evolution of male care when females are able to bias mating or paternity towards parental males. Surprisingly, female choice for parental males allows male care to evolve despite low relatedness between the male and the offspring in his care. These results imply that predicting how sexual selection affects parental care evolution will require further understanding of why females, in many species, either do not prefer or cannot favour males that provide care.
Male-sterile plants were identified in the wild H. annuus L. accessions PI 413178 and PI 413180, and maintained by backcrossing with the inbred line HA 89. Male-fertile progenies from crosses between cms plants of the two PIs and 12 USDA inbred lines indicated the presence of fertility restoration g...
The project was intended to make practical the use of nuclear malesterile (ms) genes in hybrid seed production by linking a marker gene to the male fertile allele of the ms gene and selecting for the segregating ms seed by discarding segregants showing t...
In male mammals, the X and Y chromosomes are transcriptionally silenced in primary spermatocytes by meiotic sex chromosome inactivation (MSCI) and remain repressed for the duration of spermatogenesis. Here, we test the longstanding hypothesis that disrupted MSCI might contribute to the preferential sterility of heterogametic hybrid males. We studied a cross between wild-derived inbred strains of Mus musculus musculus and M. m. domesticus in which sterility is asymmetric: F1 males with a M. m. musculus mother are sterile or nearly so while F1 males with a M. m. domesticus mother are normal. In previous work, we discovered widespread overexpression of X-linked genes in the testes of sterile but not fertile F1 males. Here, we ask whether this overexpression is specifically a result of disrupted MSCI. To do this, we isolated cells from different stages of spermatogenesis and measured the expression of several genes using quantitative PCR. We found that X overexpression in sterile F1 primary spermatocytes is coincident with the onset of MSCI and persists in postmeiotic spermatids. Using a series of recombinant X genotypes, we then asked whether X overexpression in hybrids is controlled by cis-acting loci across the X chromosome. We found that it is not. Instead, one large interval in the proximal portion of the M. m. musculus X chromosome is associated with both overexpression and the severity of sterility phenotypes in hybrids. These results demonstrate a strong association between X-linked hybrid malesterility and disruption of MSCI and suggest that trans-acting loci on the X are important for the transcriptional regulation of the X chromosome during spermatogenesis. PMID:23307891
Campbell, Polly; Good, Jeffrey M; Nachman, Michael W
Myths, stereotypes, and unfounded beliefs about malesexuality, in particular male homosexuality, are widespread in legal and medical communities, as well as among agencies providing services to sexual assault victims. These include perceptions that men in noninstitutionalized settings are rarely sexually assaulted, that male victims are responsible for their assaults, that malesexual assault victims are less traumatized by the experience than their female counterparts, and that ejaculation is an indicator of a positive erotic experience. As a result of the prevalence of such beliefs, there is an underreporting of sexual assaults by male victims; a lack of appropriate services for male victims; and, effectively, no legal redress for malesexual assault victims. By comparison, malesexual assault victims have fewer resources and greater stigma than do female sexual assault victims. Many male victims, either because of physiological effects of anal rape or direct stimulation by their assailants, have an erection, ejaculate, or both during the assault. This is incorrectly understood by assailant, victim, the justice system, and the medical community as signifying consent by the victim. Studies of malesexual physiology suggest that involuntary erections or ejaculations can occur in the context of nonconsensual, receptive anal sex. Erections and ejaculations are only partially under voluntary control and are known to occur during times of extreme duress in the absence of sexual pleasure. Particularly within the criminal justice system, this misconception, in addition to other unfounded beliefs, has made the courts unwilling to provide legal remedy to male victims of sexual assault, especially when the victim experienced an erection or an ejaculation during the assault. Attorneys and forensic psychiatrists must be better informed about the physiology of these phenomena to formulate evidence-based opinions. PMID:21653264
We evaluated the in£uence of pre- and post-copulatory sexual selection upon male reproductive traits in a naturally promiscuous species, Drosophila melanogaster. Sexual selection was removed in two replicate populations through enforced monogamous mating with random mate assignment or retained in polyandrous controls. Monogamous mating eliminates all opportunities for mate competition, mate discrimination, sperm competition, cryptic female choice and, hence, sexual
Scott Pitnick; Gary T. Miller; Jennifer Reagan; Brett Holland
According to the immunocompetence handicap hypothesis, males with attractive sexual ornamentation are more handicapped than their less ornamented rivals because of the immunosuppressive androgens required for the production of secondary sexual characters. Here we studied the predictions of the hypothesis in a wild cyprinid fish, the roach (Rutilus rutilus). We assayed (1) sexual ornamentation (breeding tubercles), (2) circulating androgens (11-ketotestosterone
Raine Kortet; Anssi Vainikka; Markus J. Rantala; Ilmari Jokinen; Jouni Taskinen
To explore sexual health knowledge among Latino immigrants in a Southern U.S. city, we conducted 20 qualitative interviews, (10 Women and 10 Men). We explored knowledge and factors associated with sexual health among male and female Latino immigrants in a Southern U.S. city experiencing a major growth of Latino immigrants in the past 10 years. Both genders demonstrated limited knowledge of Human Papillomavirus (HPV) and risks of sexually transmitted infection (STI) acquisition. Neither gender perceived that they could have an asymptomatic STI, including HPV. Gender differences exist in sexual behaviors and perceptions of STI risk. Females indicated that female Latinas tend to have older sexual initiation age, fewer lifetime sexual partners and more pro-active sexual health than did Latinos when referring to Latino males. Consequently, male and female Latino immigrants could benefit from culturally relevant programs to alleviate STI disparities. PMID:22273804
Seal, Paula S; Garcés-Palacio, Isabel C; Halanych, Jewell H; Scarinci, Isabel C
Current literature suggests that the causes of sexual aggression toward women lie in the fabric of a patriarchal society. The acceptance by males of negative, stereotypical and harmful myths about women, traditional sex-role stereotypes, the acceptance of interpersonal violence and the objectification of women foster an environment where sexual aggression can flourish. This paper explores several factors associated with male
The purpose of this study was to conduct a longitudinal examination of predictors of sexual aggression among male juvenile offenders. Four hundred and four adolescent males between the ages of 14 and 17 years were recruited from juvenile probation offices to take part in a prospective study of substance use and sexual risk. At baseline,
Yeater, Elizabeth A.; Lenberg, Kathryn L.; Bryan, Angela D.
Structured interviews were conducted with all male residents (n = 116) of a Veterans Affairs Nursing Home to gather information on sexual interest, preference, activity levels, satisfaction, and distress. We excluded males with severe cognitive impairment, leaving a sample of 61. Of these, 30 had partners. Sexual interest was significantly higher among those with partners (p = 0.014), although those
In Thymus vulgaris L., sex determination involves both the nuclear and the cytoplasmic genomes: the cytoplasm is responsible for malesterility (the female phenotype) whereas specific nuclear genes may restore male fertility (the hermaphrodite phenotype). The evolutionary dynamics of cytoplasmic male-sterility genes and nuclear restorer genes represents a coevolutionary conflict. Here we draw a parallel between this conflict and the
The fertility segregations of F1, F2, BCF1 descended from crosses between PSGMR and japonica varieties, and F1's anther cultured homozygous diploid pollen plant populations (H2) were studied to reveal the genetic mechanism of photoperiod sensitive genic malesterility in PSGMR under natural daylight\\u000a length at Shanghai. Rate of bagged seed-setting was used as an indicator of fertility. Fifteen F1 showed
Male reproductive output, pollen in plants and sperm in animals has been shown to constitute a substantial cost for many organisms. In parthenogenetic hermaphrodites, selection is therefore expected to reduce the allocation of resources to male reproductive output. However, sustained production of pollen or sperm has been observed in numerous asexual hermaphrodites. We studied the widespread production of pollen by
Soybean [Glycine max (L.) Merr.] is self-pollinated. To produce large quantities of hybrid seed, insect-mediated cross-pollination is necessary. An efficient nuclear male-sterile system for hybrid seed production would benefit from molecular and/or phenotypic markers linked to male fertility/sterility loci to facilitate early identification of phenotypes. Nuclear male-sterile, female-fertile ms3 mutant is a single recessive gene and displays high outcrossed seed set with pollinators. Our objective was to map the ms3 locus. A segregating population of 150 F(2) plants from Minsoy (PI 27890) x T284H, Ms3ms3 (A00-68), was screened with 231 simple sequence repeat markers. The ms3 locus mapped to molecular linkage group (MLG) D1b (Gm02) and is flanked by markers Satt157 and Satt542, with a distance of 3.7 and 12.3 cM, respectively. Female-partial sterile-1 (Fsp1) and the Midwest Oilseed male-sterile (msMOS) mutants previously were located on MLG D1b. msMOS and Fsp1 are independent genes located very close to each other. All 3 genes are located in close proximity of Satt157. We believe that this is the first report of clustering of fertility-related genes in plants. Characterization of these closely linked genes may help in understanding the evolutionary relationship among them. PMID:19617521
Cervantes-Martinez, Innan; Sandhu, Devinder; Xu, Min; Ortiz-Pérez, Evelyn; Kato, Kiyoaki K; Horner, Harry T; Palmer, Reid G
This paper reviews published literature on snakes to test the hypothesis that large male size, relative to female size, evolves because of the advantage it confers in male combat. Analysis of the data reveals a high correlation between the occurrence of male combat, and sexual dimorphism in which the male is the larger sex. This correlation holds (i) within the
Information about male customers of male prostitutes, including sociodemographic and life-style characteristics, sexual and drug use behaviors, and knowledge about HIV infection were collected from a convenience sample of 211 male street prostitutes and a convenience sample of 15 male customers as part of a feasibility study. Data from these two groups indicate that despite knowledge of HIV infection and
Edward V. Morse; Patricia M. Simon; Paul M. Balson; Howard J. Osofsky
Veneziano, Veneziano and LeGrand (2000) found support for the victim to victimizer hypothesis of sexual aggression with 74 sexually abusive youth. This project, a further step in examining this theory (Burton, 2000, Burton, Miller, & Shill, 2002) builds on their ideas with data from 179 adolescent sexual abusers, and supports their findings. In an examination of relationships, gender, modus operandi,
Understanding the genetic basis of reproductive isolation between recently diverged species is a central problem in evolutionary genetics. Here, I present analyses of the genetic architecture underlying hybrid malesterility and segregation distortion between the Bogota and USA subspecies of Drosophila pseudoobscura. Previously, a single gene, Overdrive (Ovd), was shown to be necessary but not sufficient for both malesterility and segregation distortion in F1 hybrids between these subspecies, requiring several interacting partner loci for full manifestation of hybrid phenomena. I map these partner loci separately on the Bogota X chromosome and USA autosomes using a combination of different mapping strategies. I find that hybrid sterility involves a single hybrid incompatibility of at least seven interacting partner genes that includes three large-effect loci. Segregation distortion involves three loci on the Bogota X chromosome and one locus on the autosomes. The genetic bases of hybrid sterility and segregation distortion are at least partiallybut not completelyoverlapping. My results lay the foundation for fine-mapping experiments to identify the complete set of genes that interact with Overdrive. While individual genes that cause hybrid sterility or inviability have been identified in a few cases, my analysis provides a comprehensive look at the genetic architecture of all components of a hybrid incompatibility underlying F1 hybrid sterility. Such an analysis would likely be unfeasible for most species pairs due to their divergence time and emphasizes the importance of young species pairs such as the D. pseudoobscura subspecies studied here.
Partial restoration of male fertility limits the use of C-type cytoplasmic malesterility (C-CMS) for the production of hybrid\\u000a seeds in maize. Nevertheless, the genetic basis of the trait is still unknown. Therefore, the aim to this study was to identify\\u000a genomic regions that govern partial restoration by means of a QTL analysis carried out in an F2 population (n = 180).
The purpose of this study was to conduct a longitudinal examination of predictors of sexual aggression among male juvenile offenders. Four hundred and four adolescent males between the ages of 14 and 17 years were recruited from juvenile probation offices to take part in a prospective study of substance use and sexual risk. At baseline, participants completed a series of questionnaires that assessed putative risk factors for sexual aggression. They then completed a measure of sexual aggression at the 6-month follow-up period. Correlational analyses revealed that participants who reported hard drug use, more frequent alcohol and marijuana use, and less severe offenses reported engaging in more severe sexual aggression. In addition, participants who reported higher impulsivity, sensation seeking, and externalizing behaviors also reported participating in more severe sexual aggression. When these variables were included in a regression analysis, only externalizing behaviors and severity of offense uniquely predicted severity of sexual aggression at the 6-month follow-up. PMID:22080583
Yeater, Elizabeth A; Lenberg, Kathryn L; Bryan, Angela D
Recently, sodium nitroprusside (SNP), a potent nitric oxide (NO) donor and a clinically used antihypertensive, has been introduced as a penile self-injection medical therapy for erectile dysfunction. However, it is known that many antihypertensives impairs sexual competence; NO regulates sexual competence and NO is cytostatic and cytotoxic for human sperm. Thus, a possibility exists that SNP may impair male reproductive competence. Testing this aspect is the aim of this study. This was assessed in male rats (using three i.p. doses: 60, 30 or 20 microg/kg) using noncompetitive copulation tests. The results show that the highest dose of SNP was toxic and caused rapid mortality of treated rats (within 30 min). The mid and low doses of SNP reversibly impaired several parameters of sexual competence in a dose-related fashion: sexual arousability, libido and sexual vigour. Some parameters of sexual behaviour remained unaltered: sexual motivation and intromission ratio, whilst one parameter was improved: sexual performance. In complete contrast, the ejaculatory competence and fertility remained unchanged. The SNP-induced impairments in sexual competence may be attributable to lowered testosterone levels and sedation mediated via its specific action and/or side effect. Further, this impairment of sexual function was not due to general toxicity, inhibition of penile sensitivity, penile erection or analgesic activity. It is concluded that SNP impairs malesexual competence, at least, in rats although it promotes penile erection. PMID:15171569
Ratnasooriya, W D; Jayakody, J R A C; Dharmasiri, M G
Rapid and divergent evolution of male genital morphology is a conspicuous and general pattern across internally fertilizing animals. Rapid genital evolution is thought to be the result of sexual selection, and the role of natural selection in genital evolution remains controversial. However, natural and sexual selection are believed to act antagonistically on male genital form. We conducted an experimental evolution study to investigate the combined effects of natural and sexual selection on the genital-arch lobes of male Drosophila simulans. Replicate populations were forced to evolve under lifetime monogamy (relaxed sexual selection) or lifetime polyandry (elevated sexual selection) and two temperature regimes, 25°C (relaxed natural selection) or 27°C (elevated natural selection) in a fully factorial design. We found that natural and sexual selection plus their interaction caused genital evolution. Natural selection caused some aspects of genital form to evolve away from their sexually selected shape, whereas natural and sexual selection operated in the same direction for other shape components. Additionally, sexual and natural selection tended to favour larger genitals. Thus we find that the underlying selection driving genital evolution is complex, does not only involve sexual selection, and that natural selection and sexual selection do not always act antagonistically.
Hodgson, Dave J.; Wedell, Nina; Sharma, Manmohan D.; Hunt, John; Hosken, David J.
This study compares sexually victimized and nonsexually victimized male adolescent sexual abusers on a number of variables. Self-report measures were administered to 325 malesexually abusive youth (average age 16) in six residential facilities in the Midwest, 55% of whom reported sexual victimization. The results indicate that the sexually victimized sexual abusers have more severe developmental antecedents (trauma, family characteristics, early exposure to pornography and personality) and recent behavioral difficulties (characteristics of sexual aggression, sexual arousal, use of pornography, and nonsexual criminal behavior) than the nonsexually victimized group. Results are contrasted with recent typological research, which found no relationship between sexual victimization and subtype membership. Treatment, research, and theoretical implications are discussed. PMID:21259148
Burton, David L; Duty, Kerry Jo; Leibowitz, George S
Juvenile hormone levels and adult diet have important effects on the attractiveness and competitiveness of male Anastrepha suspensa (Loew) (Caribbean fruit fly). Because the success of the sterile insect technique requires the release of males that can compete in the wild, these effects are of crucial importance. Laboratory and field cage experiments were conducted to compare malesexual performance on a lifetime basis and daily basis when submitted to four different treatments: (M+P+) application of the juvenile hormone analog, methoprene (M) and sugar and hydrolyzed yeast as adult food; (M+P-) application of M and sugar as adult food; (M-P+) no application of M and sugar and hydrolyzed yeast as adult food; and (M-P-) no application of M and sugar as adult food. On a daily basis, M+P+ males always performed better sexually, and 10% of these individuals were able to mate three consecutive times in the same day. However, the copula duration decreased with the increased number of matings on same day. In addition, M caused earlier maturation. On a lifetime basis, M+P+ males had significantly greater sexual success than other flies. The substantial improvement in malesexual performance because of the hormone application, protein supply, and interaction of hormone and protein has the potential of producing more efficacious sterilemales. PMID:20214366
In this article, the author examines the campaign leading up to the passage of the SexualSterilization Act in Alberta in 1928. The author asserts that the passage of this Act was the result of the influence of a few elite individuals, particularly those involved with the United Farm Women of Alberta social reform movement, and may not have been reflective of widespread favourable public sentiment. While there were serious misgivings regarding the passage of the SexualSterilization Act, the legislation was ultimately successful because of the pressing problems of inadequate mental facilities and budgetary constraints. The author discusses the legislation's eventual repeal in 1972 due to public denunciation of eugenic measures, concerns about liability, and the threat posed to individual liberties. This article was the winner of the William Morrow Essay Contest in 1999. PMID:12465643
For the sake of screening novel genes related to the malesterility in chili pepper for studying the molecular mechanism of plant malesterility, the gene differential expression analysis was performed by cDNA-amplified fragment length polymorphism (cDNA-AFLP) in the genic malesterile-fertile line 114AB of Capsicum annum L., and a variety of differentially expressed cDNA fragments were detected in fertile or sterility material. Camf1, a transcript-derived fragment (TDF) accumulated in fertile line flower buds was further investigated. The Camf1 has 1,854 bp in length with no introns containing a 1,707-bp open reading frame (ORF). The deduced amino acid sequence of Camf1 shares higher similarity to some members from a glyoxal oxidase-related protein family, and has a glyoxal oxidase conserved domain at the N-terminus and a domain of unknown function (DUF1929) at C-terminal end. Expression analysis showed that Camf1 expressed only in stage 3-7 flower buds of male fertile of C. annum L. 114AB, and no detection in all organs of malesterility. The peak of expression level of Camf1 appeared at stage 4 flower buds of fertile line. Furthermore, expression analysis of different organs revealed that Camf1 expressed only in anthers of male fertile material and there were no expression in sepals, petals, pistils, roots, stems, leaves and open flowers. These results suggested that Camf1 was an anther-specific gene and might be essential for the fertility of C. annum L. PMID:21559833
Empirical studies of sexual selection typically focus on one of the two mechanisms of sexual selection without integrating these into a description of total sexual selection, or study total sexual selection without quantifying the contributions of all of the mechanisms of sexual selection. However, this can provide an incomplete or misleading view of how sexually selected traits evolve if the mechanisms of sexual selection are opposing or differ in form. Here, we take a two-fold approach to advocate a direction for future studies of sexual selection. We first show how a quantitative partitioning and examination of sexual selection mechanisms can inform by identifying illustrative studies that describe both male-male competition and female mate choice acting on the same trait. In our sample, the most common trait where this occurred was body size, and selection was typically linear. We found that male-male competition and female mate choice can be reinforcing or opposing, although the former is most common in the literature. The mechanisms of sexual selection can occur simultaneously or sequentially, and we found they were more likely to be opposing when the mechanisms operated sequentially. The degree and timing that these mechanisms interact have important implications for the operation of sexual selection and needs to be considered in designing studies. Our examples highlight where empirical data are needed. We especially lack standardized measures of the form and strength of selection imposed by each mechanism of sexual selection and how they combine to determine total sexual selection. Secondly, using quantitative genetic principles, we outline how the selection imposed by individual mechanisms can be measured and combined to estimate the total strength and form of sexual selection. We discuss the evolutionary consequences of combining the mechanisms of sexual selection and interpreting total sexual selection. We suggest how this approach may result in empirical progress in the field of sexual selection. PMID:19120810
Hunt, John; Breuker, Casper J; Sadowski, Jennifer A; Moore, Allen J
Nuclear-mitochondrial gene interactions governing cytoplasmic malesterility (CMS) in angiosperms have been found to be unique to each system. Fertility restoration of three diverse alloplasmic CMS lines of Brassica juncea by a line carrying the fertility-restorer gene introgressed from Moricandia arvensis prompted this investigation to examine the molecular basis of CMS in these lines. Since previous studies had found altered atpA transcription associated with CMS in these lines, the atpA genes and transcripts of CMS, fertility-restored, and euplasmic lines were cloned and compared. atpA coding and downstream sequences were conserved among CMS and euplasmic lines but major differences were found in the 5' flanking sequences of atpA. A unique open reading frame (ORF), orf108, co-transcribed with atpA, was found in malesterile flowers of CMS lines carrying mitochondrial genomes of Diplotaxis berthautii, D. catholica, or D. erucoides. In presence of the restorer gene, the bicistronic orf108-atpA transcript was cleaved within orf108 to yield a monocistronic atpA transcript. Transgenic expression of orf108 with anther-specific Atprx18 promoter in Arabidopsis thaliana gave 50% pollen sterility, indicating that Orf108 is lethal at the gametophytic stage. Further, lack of transmission of orf108 to the progeny showed for the first time that mitochondrial ORFs could also cause female sterility. orf108 was found to be widely distributed among wild relatives of Brassica, indicating its ancient origin. This is the first report that shows that CMS lines of different origin and morphology could share common molecular basis. The gametic lethality of Orf108 offers a novel opportunity for transgene containment. PMID:22371076
Kumar, Pankaj; Vasupalli, Naresh; Srinivasan, R; Bhat, Shripad R
The aims of this prospective study were to compare sexual functioning between women with male partners who have erectile dysfunction (ED) and women without partners with ED and also to investigate the effect of the treatment of male ED on female partner's sexual function. The study included 87 women and their male partners. We divided the women into two groups:
SELAH?TT?N ÇAYAN; MURAT BOZLU; BÜLENT CANPOLAT; ERDEM AKBAY
Cytoplasmic malesterility (CMS) in Nicotiana is located on mitochondrial DNA (mtDNA) on which no selectable mutation has been isolated. The possibility of co-transfer of CMS and a selectable chloroplast trait, streptomycin resistance, was investigated by marker rescue from irradiated protoplasts, a method described from this laboratory (Menczel et al. 1982). As the source of the CMS factor, the Nicotiana
László Menczel; Ferenc Nagy; Gabriella Lázár; Pál Maliga
Beginning in late August, 2004, we began a program to release sterilemale oriental fruit flies, Bactrocera dorsalis, in a citrus orchard in central Oahu, Hawaii. This program follows the encouraging results obtained with the melon fly genetic sexing strain on the islands of Hawaii, Maui, and Oahu. ...
A syndrome of associated aberrant traits is described in Drosophila mel- anogaster. Six of these traits, mutation, sterility, male recombination, trans- mission ratio distortion, chromosomal aberrations and local increases in female recombination, have previously been reported. A seventh trait, nondisjunc- tion, is described for the first time. All of the traits we have examined are found nonreciprocally in F, hybrids.
MARGARET G. KIDWELL; JAMES F. KIDWELL; JOHN A. SVED
Mitochondrial (mt) and chloroplast (ct) DNAs from sugar beet carrying normal fertile and different cytoplasmic malesterile (cms) cytoplasms were compared by restriction analysis and for the occurrence of minicircles. One of the cms materials had the Owen cms cytoplasm currently used for hybrid production in sugar beet; the other three cms materials were derived from wild Beta beets. The
Meiotic studies have been carried out in a series of 1100 infertile and sterilemales. Of these, 599 cases have been studies in testicular biopsy, and 501, in semen samples. This is the largest meiotic series published so far. The incidence of meiotic anomalies was 4.3%. The most frequent chromosome abnormality was desynapsis (3.7%). However, the number of cases with
J. Egozcue; C. Templado; F. Vidal; J. Navarro; F. Morer-Fargas; S. Marina
Soybean [Glycine max (L.) Merr.] is a self-pollinated plant. Manual cross-pollination is used to produce limited quantities of hybrid seed. To produce large quantities of hybrid seed, insect-mediated cross-pollination is necessary. An efficient nuclear male-sterile system for hybrid seed producti...
A new cytoplasmic malesterile sunflower, CMS3 , was characterised in relation to the Petiolaris (PET1) cytoplasmic male-sterile sunflower, CMS89 . Southern blot analysis showed that the mitochondrial genome of CMS3 contains unique rearrangements in at least five loci (atp6, atp9, atpA, nad1+5 and coxIII) compared to the PET1 sterile and the fertile cytoplasms. Transcripts of two (coxIII and atp6)
Mariana Spassova; Françoise Moneger; Christopher J. Leaver; Peter Petrov; Atanas Atanassov; H. John J. Nijkamp; Jacques Hille
The purpose of this study was to examine the relationship between college men's sexual victimization experiences, engagement in a number of health risk behaviors, and sexual functioning. The study also examined sexual victimization by assault severity categories and utilized a multiitem, behaviorally specific, gender-neutral measure. Three hundred and two male college students were recruited for the current study from a
Effects of positive and negative musical mood induction on subjective and objective sexual arousal were examined in a group of sexually functional males (N = 24). Subjects evidenced significantly greater objective and subjective sexual response in the positive mood induction condition relative to both baseline and a neutral control condition. In contrast, the negative mood induction condition yielded significantly less
William B. Mitchell; Patricia Marten Dibartolo; Timothy A. Brown; David H. Barlow
The purpose of this study was to determine whether sexual orientation differences in gambling exist that parallel those for sexa question motivated by the idea that male homosexuality arises from prenatal brain feminization and that female homosexuality arises from prenatal brain masculinization. For gambling frequency, we hypothesized that male homosexuals would be more similar to female heterosexuals than male heterosexuals,
The mitochondrial genomes of petunia somatic hybrid plants, which were derived from the fusion of male fertile P. hybrida protoplasts with cytoplasmic malesterile P. parodii protoplasts, were analyzed by endonuclease restriction and Southern blot hybridization analyses. We studied sterile and fertile somatic hybrids to address two main questions. First, is there any correlation between the mitochondrial DNA restriction banding
Maury L. Boeshore; Irit Lifshitz; Maureen R. Hanson; Shamay Izhar
There are two known sources of cytoplasmic-genic malesterility (CMS) used to produce hybrid onion (Allium cepa L.) seed, S and T cytoplasms. Male-sterility has been observed in numerous other onion populations, indicating that additional sources of CMS may exist. A potentially new source of CMS w...
Perinatal period and adolescence are critical for brain development, which is the biological basis of an individual's sexual orientation and sexual behavior. In this study, animals were divided into two groups and their sexual orientations were observed: one group experienced drug treatments during the perinatal period, and the other group was castrated at puberty. The results showed that estradiol treatment had no effect on mature male offspring's sexual orientations, but 9 days and 14 days of clomiphene citrate treatment significantly increased the chance of homosexuality and effeminized behavior. In addition, the sexual orientation of mature normal male offspring, which were castrated when they were 21 days old,was not significant different from the control animals. These findings suggest that the inhibition of perinatal estrogen activities could suppress individual male-typical responses, enhance female-typical responses and induce homosexual orientations. Moreover, the masculinizing effects of estrogen were more obvious during perinatal period than adolescence. PMID:24115661
Most researchers who have investigated attributions of blame toward victims in sexual-assault depictions have considered only female victims of male perpetrators. Few researchers have investigated the effects of perpetrator gender or victim sexual orientation on blame attributions toward male victims. The present authors investigated those two variables. Participants were 161 undergraduates at a British university in social science courses, each
The present study investigated self-reported sexual interest following alcohol consumption in 48 male social drinkers ([Xbar] age = 19.7 years). A sexual interest questionnaire and Wilson's Psychological Conservatism Scale were administered in a pretest-posttest design. The results indicated that while self-reported sexual interest appeared to increase with alcohol doses, beliefs regarding the alcohol content of the drink may mediate this
Research examining how sexual minorities characterize love within same-sex relationships is scarce. In this study, the authors examined the validity of Sternberg's triangular theory of love in a sample of sexual minority male youth (N = 447). To test the adequacy of the theory for our population, the authors examined the psychometric properties of the Triadic Love Scale (TLS) and
JosÉ A. Bauermeister; Michelle M. Johns; Emily Pingel; Anna Eisenberg; Matt Leslie Santana; Marc Zimmerman
Background The genetic basis of postzygotic isolation is a central puzzle in evolutionary biology. Evolutionary forces causing hybrid sterility or inviability act on the responsible genes while they still are polymorphic, thus we have to study these traits as they arise, before isolation is complete. Methodology/Principal Findings Isofemale strains of D. mojavensis vary significantly in their production of sterile F1 sons when females are crossed to D. arizonae males. We took advantage of the intraspecific polymorphism, in a novel design, to perform quantitative trait locus (QTL) mapping analyses directly on F1 hybrid malesterility itself. We found that the genetic architecture of the polymorphism for hybrid malesterility (HMS) in the F1 is complex, involving multiple QTL, epistasis, and cytoplasmic effects. Conclusions/Significance The role of extensive intraspecific polymorphism, multiple QTL, and epistatic interactions in HMS in this young species pair shows that HMS is arising as a complex trait in this system. Directional selection alone would be unlikely to maintain polymorphism at multiple loci, thus we hypothesize that directional selection is unlikely to be the only evolutionary force influencing postzygotic isolation.
Reed, Laura K.; LaFlamme, Brooke A.; Markow, Therese A.
|A study compared 216 adolescent sexually victimized sexual offenders and 93 adolescent sexually victimized nonsexual offending delinquents. Sexually offending delinquents had closer relationships with their perpetrators, a higher chance of having a male perpetrator, a longer duration of sexual victimization, more forceful sexual victimization,
Burton, David L.; Miller, Diane Lynn; Shill, Chien Tai
The organisation of mtDNA was investigated for 28 sources of cytoplasmic malesterility (CMS) and a fertile line (normal cytoplasm) of Helianthus annuus by Southern hybridisation. In addition to nine known mitochondrial genes ( atp6, atp9, cob, coxI, coxII, coxIII, 18S, 5S and nd5) three probes for the open reading frames in the rearranged area of PET1, orfH522, orfH708 and orfH873, were used. Genetic similarities of the investigat-ed cytoplasms varied between 0.3 and 1. Cluster analyses using the UPGMA method allowed the distinction of ten mitochondrial (mt) types between the 29 investigated cytoplasms. Most mitochondrial types comprise two or more CMS sources, which could not be further separated, like the PET1-like CMS sources (with the exception of ANO1 and PRR1), or ANN1/ANN2/ANN3, ANN4/ ANN5, ARG3/RIG1, BOL1/EXI1/PEF1/PEP1 and GIG1/ PET2. ANL1, ANL2 and the fertile cytoplasms are also regarded as one mitochondrial type. Unique banding patterns were only observed for ANT1 ( atp6), MAX1 ( atp6, orfH522 and orfH708) and PRR1 ( coxII). However, four of the mitochondrial types showed unique hybridisation signals: ANN4/ANN5 had characteristic bands for atp6 and orfH708, PEF1/PEP1/EXI1/BOL1 for atp6and coxII, and PET2/GIG1 for atp9. The PET1-like cytoplasms all shared the same patterns for orfH522, orfH708and cob (except ANO1). It could be demonstrated that CMS sources, like, e.g., PET2 and PEF1, are different from PET1 in mtDNA organisation and the CMS mechanism. Therefore, these CMS sources represent interesting candidates for the development of new hybrid breeding systems based on new CMS mechanisms. PMID:12582659
Malesexual harassment of females is common across sexually reproducing species and can result in fitness costs to females. We hypothesized that females can reduce unwanted male attention by constructing a social niche where their female associates are more sexually attractive than themselves, thus influencing the decision-making of males to their advantage. We tested this hypothesis in the Trinidadian guppy (Poecilia reticulata), a species with high levels of malesexual harassment. First, we confirmed that non-receptive females were harassed less when they were paired with a more sexually attractive (receptive) female than with another non-receptive female. We then found that, indeed, females exploit this as a strategy to reduce sexual harassment; non-receptive females actively preferred to associate with receptive over non-receptive females. Importantly, when given access only to chemosensory cues, non-receptive females still showed this preference, suggesting that they use information from chemical cues to assess the sexual attractiveness of potential female partners. Receptive females in contrast showed no such preferences. Our results demonstrate that females can decrease male harassment by associating with females that are more sexually attractive than themselves and that they perform active partner choices based on this relative attractiveness. We propose that this strategy is likely to represent an important pathway by which females can construct social niches that influence the decision-making of others to their advantage; in this case, to reduce the sexual harassment they experience.
Brask, Josefine B.; Croft, Darren P.; Thompson, Katharine; Dabelsteen, Torben; Darden, Safi K.
Malesexual harassment of females is common across sexually reproducing species and can result in fitness costs to females. We hypothesized that females can reduce unwanted male attention by constructing a social niche where their female associates are more sexually attractive than themselves, thus influencing the decision-making of males to their advantage. We tested this hypothesis in the Trinidadian guppy (Poecilia reticulata), a species with high levels of malesexual harassment. First, we confirmed that non-receptive females were harassed less when they were paired with a more sexually attractive (receptive) female than with another non-receptive female. We then found that, indeed, females exploit this as a strategy to reduce sexual harassment; non-receptive females actively preferred to associate with receptive over non-receptive females. Importantly, when given access only to chemosensory cues, non-receptive females still showed this preference, suggesting that they use information from chemical cues to assess the sexual attractiveness of potential female partners. Receptive females in contrast showed no such preferences. Our results demonstrate that females can decrease male harassment by associating with females that are more sexually attractive than themselves and that they perform active partner choices based on this relative attractiveness. We propose that this strategy is likely to represent an important pathway by which females can construct social niches that influence the decision-making of others to their advantage; in this case, to reduce the sexual harassment they experience. PMID:22158959
Brask, Josefine B; Croft, Darren P; Thompson, Katharine; Dabelsteen, Torben; Darden, Safi K
In male rats, whether sexually experienced or sexually naive, the intraperitoneal administration of L-arginine (the natural substrate for nitric oxide synthase) (10, 25, 50 mg/kg) both increased the percentage of copulating in sexually naive rats and improved the indexes of sexual performance in sexually experienced rats, whereas the intraperitoneal administration of N(G)-nitro-L-arginine methyl ester (L-NAME) (a potent inhibitor of nitric oxide synthase) (10, 25, 50 mg/kg) had opposite effects. In contrast, after intracerebroventricular administration, L-arginine (25, 50, 100 microg/rat) had no effect - whether in naive or in experienced rats - whereas L-NAME completely prevented ejaculation in naive rats, at the dose of 100 microg/rat, but had no effect at all in experienced rats, up to the dose of 300 microg/rat. Finally, a direct relationship seems to exist between male copulatory performance and nitric oxide synthase activity in a discrete and defined brain area, the paraventricular nucleus of the hypothalamus: indeed, nitric oxide synthase mRNA expression in this nucleus in sexually potent rats is about twice that in sexually impotent rats. It is concluded that nitric oxide synthase is involved in the expression of malesexual activity, in spite of some inconsistencies that are hard to interpret. PMID:8750712
A careful examination of young men's sexuality by health professionals in pediatrics, primary care and reproductive health is foundational to adolescent malesexual health and healthy development. Through a review of existing literature, this article provides background and a developmental framework for sexual health services for adolescent boys. The article first defines and provides an overview of adolescent boys sexual health, and then discusses developmentally focused research on the following topics: (1) early romantic relationships and the evolution of power and influence within these relationships; (2) developmental readiness for sex and curiosity; (3) boys need for closeness and intimacy; (4) adopting codes of masculinity; (5) boys communicating about sex; and (6) contextual influences from peers, families, and providers. This article concludes by examining the implications of these data for sexual health promotion efforts for adolescent males, including HPV vaccination.
. Poor sperm motility characterized by a distinct aberration in flagellar waveform known as ``curlicue'' is a hallmark of t haplotype (t) homozygous malesterility. Previous studies have localized ``curlicue'' and a flagellar developmental defect, ``whipless'',\\u000a to the Hybrid Sterility 6 locus (Hst6), between the markers Pim1 and Crya1. More recent heterospecific breeding experiments between Mus spretus (Spretus) and Mus
John Fossella; Sadhana A. Samant; Lee M. Silver; Stephen M. King; Kevin T. Vaughan; Patricia Olds-Clarke; Karl A. Johnson; Atsushi Mikami; Richard B. Vallee; Stephen H. Pilder
A male-sterile (MS) radish (Raphanus sativus L.) was found in an accession collected from Uzbekistan. Unlike Ogura MS radishes in which no pollen grain is typically visible during anthesis, a small number of pollen grains stuck together in the dehiscing anthers was observed in the newly identified MS radish. Fluorescein diacetate tests and scanning electron micrographs showed that pollen grains in the new MS radish were severely deformed and non-viable. Cytological examination of pollen development stages showed a clear difference in the defective stage from that seen in Ogura male-sterility. Reciprocal cross-pollination with diverse male-fertile lines indicated that pollen grains of the new MS radish were completely sterile, and the female organs were fully fertile. When the new MS radish and Ogura MS lines were cross-pollinated with a set of eight breeding lines, all F1 progeny originating from crosses with the new MS radish were male-sterile. In contrast, most of the F1 progeny resulting from crosses with Ogura MS lines were male-fertile. These results demonstrated that factors associated with induction of the newly identified male-sterility are different from those of Ogura male-sterility. The lack of restorer lines for the newly identified male-sterility led us to predict that it might be a complete cytoplasmic male-sterility without restorer-of-fertility genes in nuclear genomes. However, cross-pollination with more diverse radish germplasm identified one accession introduced from Russia that could completely restore fertility, proving the existence of restorer-of-fertility gene(s) for the new male-sterility. Meanwhile, the PCR amplification profile of molecular markers for the classification of radish mitochondrial genome types revealed that the new MS radish contained a novel mitotype. PMID:18597066
Lee, Young-Pyo; Park, Suhyung; Lim, Chaewan; Kim, Hyojung; Lim, Heerae; Ahn, Youngsoon; Sung, Soon-Kee; Yoon, Moo-Kyoung; Kim, Sunggil
Research examining how sexual minorities characterize love within same-sex relationships is scarce. In this study, we examined the validity of Sternberg's Triangular Theory of Love in a sample of sexual minority male youth (N = 447). To test the adequacy of the theory for our population, we examined the psychometric properties of the Triadic Love Scale (TLS) and tested whether the three underlying constructs of the theory (Intimacy, Passion, and Commitment) emerged when participants were asked to consider their ideal relationship with another man. Using confirmatory factor analysis (CFA), we found support for the three-factor solution to characterize sexual minority male youths ideal romantic relationship, after minimizing item cross-loadings and adapting the content of the Passion subscale. We discuss the implications of our findings regarding the measurement of the TLS among sexual minority male youth and propose ways to enhance its measurement in future research.
Bauermeister, Jose A.; Johns, Michelle M.; Pingel, Emily; Eisenberg, Anna; Santana, Matt Leslie; Zimmerman, Marc
At its inception, psychoanalytic psychology heavily emphasized sexuality. Freud's ideas about the centrality of sexuality in development and in the etiology of psychopathology were accepted for many years by organized psychoanalysis and psychiatry. Modern psychoanalytic theory has replaced sexuality as an organizing concept with diverse paradigms and the field has fragmented as a result. Of the many theories that Freud posed about the role of sexuality in psychological functioning perhaps his most influential were those pertaining to the Oedipus complex. In this, the first article of a series on the psychodynamic aspects of human sexuality, Oedipal aggression in males is considered from a biopsychosocial perspective. Knowledge about sexual differentiation of the brain and sex differences in behavior resulting from research carried out after Freud's death suggests the need to revise Freud's ideas about the Oedipus complex. PMID:17480192
Copris ochus (Coleoptera: Scarabaeidae), an endangered species, is the largest dung beetle in Japan. In C. ochus, males have a long head horn, while females lack this long horn (sexual dimorphism). Very large males of C. ochus have disproportionately longer head horns than small males, suggesting male horn dimorphism, although the dimorphism has not been investigated quantitatively. To clarify sexual and male horn dimorphism in C. ochus quantitatively, we examined the scaling relationship between body size (prothorax width) and head horn length in 94 females and 76 males. These beetles were captured during July 1978 from a natural population on Mt. Aso in southwestern Japan using a light trap. Although the horn length of the females and males scaled with prothorax width, the scaling relationship differed between the sexes, i.e., the relationship was linear in females and nonlinear in males. Statistical tests for dimorphism in male horn length showed a significant discontinuous relationship, thus indicating distinct sexual and male dimorphism in head horns. Long- and short-horned C. ochus males may have different reproductive behaviors, as described in other horned dung beetles. PMID:18348608
This study sought to determine whether religious beliefs could distinguish between older adolescent males of differing sexual experience and to determine whether such beliefs could distinguish between older adolescent males differing in frequency of contraceptive use. Results are discussed and implications for health educators are set forth. (MT)
This paper presents a conceptual formulation, derived from developmental object relations theory and ego psychology, of the passage in male adolescence that culminates with the achievement of a masculine heterosexual identity. Themes of psychosexuality, male gender attributes, masculinity and object preference, and sexual orientation are discussed with reference to the adolescent stage. Finally, the critical tasks, core conflicts, and internalizations
APPETITIVE BEHAVIOR AND COPULATORY RESPONSES WHICH CHARACTERIZE THE MATING BEHAVIOR OF MALE BEAGLES WERE STUDIED IN DETAIL. 4 DIFFERENT SEXUAL REFLEXES EXHIBITED BY SPINAL MALE BEAGLES WERE COMPARED TO RELEVANT ASPECTS OF THE MATING BEHAVIOR. IT IS CONCLUDED THAT SOME ASPECTS OF MATING BEHAVIOR, PARTICULARLY THE INTENSE EJACULATORY REACTION (IER) AND THE COPULATORY LOCK, ARE PROBABLY COMPLETELY MEDIATED AT THE
We explored the balance of genetic and environmental factors on sexual dysfunctions during first intercourse experience in young men. Gender role conflict theory predicts that young males should show high levels of such dysfunctions coupled with mixed affective reactions. Three thousand one hundred eighty six male twins and their siblings (M = 26.17 years, SD = 4.77) completed items on
Pekka Santtila; N. Kenneth Sandnabba; Patrick Jern
The plant mitochondrial genome is characterized by a complex, multipartite structure. In cytoplasmic male-sterile (CMS) common bean, the sterility-inducing mitochondrial configuration maps as three autonomous DNA molecules, one containing the sterility-associated sequence pvs-orf239. We constructed a physical map of the mitochondrial ge- nome from the direct progenitors to the CMS cytoplasm and have shown that it maps as a single,
Hanna Janska; Rodrigo Sarria; Magdalena Woloszynska; Maria Arrieta-Montiel; Sally A. Mackenzie
Blind sterile 2 (bs2) is a spontaneous autosomal recessive mouse mutation exhibiting cataracts and malesterility. Detailed clinical and histological evaluation revealed that bs2 mice have cataracts resulting from severely disrupted lens fiber cells. Analysis of bs2 testes revealed the absence of mature sperm and the presence of large multinucleate cells within the lumens of seminiferous tubules. Linkage analysis mapped the bs2 locus to mouse chromosome 2, approximately 45cM distal from the centromere. Fine mapping established a 3.1Mb bs2 critical region containing 19 candidate genes. Sequence analysis of alkylglycerone-phosphate synthase (Agps), a gene within the bs2 critical region, revealed a G to A substitution at the +5 position of intron 14. This mutation results in two abundantly expressed aberrantly spliced Agps transcripts: Agps?exon14 lacking exon 14 or Agpsexon?1314 lacking both exons 13 and 14 as well as full-length Agps transcript. Agps is a peroxisomal enzyme which catalyzes the formation of the ether bond during the synthesis of ether lipids. Both aberrantly spliced Agps?exon14 and Agpsexon?1314 transcripts led to frame shift, premature stop and putative proteins lacking the enzymatic FAD domain. We present evidence that bs2 mice have significantly decreased levels of ether lipids. Human mutations in Agps result in rhizomelic chondrodysplasia punctata type 3 (RCDP3), a disease for which bs2 is the only genetic model. Thus, bs2 is a hypomorphic mutation in Agps, and represents a useful model for investigation of the tissue specificity of ether lipid requirements which will be particularly valuable for elucidating the mechanism of disease phenotypes resulting from ether lipid depletion.
The definite and persistent phenomenon of sexual assault upon males is virtually ignored in the literature, although incidence data reported here suggest the greater scope of the problem. The avoidance of the subject of sexual assault on males creates a negative environment for victims. While the motivation of assailants is briefly discussed, the article focuses on the psychological aftermath for sexual assault victims. A paradigm is offered, consisting of "Set-up," "Attack," and "Aftermath" phases. Male victims suffer "Rape Trauma Syndrome" as described for females, as well as various forms of stigmatization and secondary trauma. Differences and similarities between male and female victims are identified. Victim responses are discussed as they proceed through several stages, with implications for appropriate interventions on both the clinical and community levels. The article concludes with an extensive bibliography. PMID:7050240
Background Reproductive isolation is a defining characteristic of populations that represent unique biological species, yet we know very little about the gene expression basis for reproductive isolation. The advent of powerful molecular biology tools provides the ability to identify genes involved in reproductive isolation and focuses attention on the molecular mechanisms that separate biological species. Herein we quantify the sterility pattern of hybrid males in African Clawed Frogs (Xenopus) and apply microarray analysis of the expression pattern found in testes to identify genes that are misexpressed in hybrid males relative to their two parental species (Xenopus laevis and X. muelleri). Methodology/Principal Findings Phenotypic characteristics of spermatogenesis in sterilemale hybrids (X. laevis x X. muelleri) were examined using a novel sperm assay that allowed quantification of live, dead, and undifferentiated sperm cells, the number of motile vs. immotile sperm, and sperm morphology. Hybrids exhibited a dramatically lower abundance of mature sperm relative to the parental species. Hybrid spermatozoa were larger in size and accompanied by numerous undifferentiated sperm cells. Microarray analysis of gene expression in testes was combined with a correction for sequence divergence derived from genomic hybridizations to identify candidate genes involved in the sterility phenotype. Analysis of the transcriptome revealed a striking asymmetric pattern of misexpression. There were only about 140 genes misexpressed in hybrids compared to X. laevis but nearly 4,000 genes misexpressed in hybrids compared to X. muelleri. Conclusions/Significance Our results provide an important correlation between phenotypic characteristics of sperm and gene expression in sterile hybrid males. The broad pattern of gene misexpression suggests intriguing mechanisms creating the dominance pattern of the X. laevis genome in hybrids. These findings significantly contribute to growing evidence for allelic dominance in hybrids and have implications for the mechanism of species differentiation at the transcriptome level.
Malone, John H.; Chrzanowski, Thomas H.; Michalak, Pawel
The mitochondria of chive plants with normal N or male-sterile S cytoplasms have been examined by restriction fragment analysis and Southern hybridizations of mitochondrial DNA (mtDNA) and in organello protein biosynthesis. Restriction fragment patterns of the mtDNA differed extensively between N-and S-cytoplasms. The percentage of fragments with different mobility varied between 4448% depending on the restriction enzyme used. In contrast
Mitochondrial DNA from 1 fertile and 6 cytoplasmic malesterile (CMS) sunflower genotypes was studied. The CMS genotypes had been obtained either by specific crosses between different Helianthus species or by mutagenesis. CMS-associated restriction fragment length polymorphisms (RFLPs) were found in the vicinity of the atpA locus, generated by various restriction enzymes. The organization of the mitochondrial genes 26S rRNA,
Mariana Spassova; Michail Christov; Natasha Bohorova; Peter Petrov; Kalin Dudov; Atanas Atanassov; H. John J. Nijkamp; Jaques Hille
The present study describes a novel thermo-sensitive genic malesterile (TGMS) line, Qiong68ms. To analyse the mode of fertility inheritance and tag the TGMS gene, a set of F2, BC1 and F2:3 populations derived from a cross between Qiong68ms and K12 were evaluated for a period of 2 years. Classical genetic analyses and QTL mapping using the mean restoration percentage of
J. H. Tang; Z. Y. Fu; Y. M. Hu; J. S. Li; L. L. Sun; H. Q. Ji
To elucidate reactive oxygen species (ROS) metabolism of cotton cytoplasmic malesterility and the effects of restorer gene\\u000a on the metabolism of ROS, the metabolism changes in the production and scavenging of ROS and gene expression related to ROS-scavenging\\u000a enzymes were investigated in the anther mitochondria of CMS line, maintainer line and hybrid F1. During the abortion preliminary stage (sporogenous
Chloroplast DNAs of six isonuclear malesterile tobacco lines and their respective parental species were analysed with the restriction endonuclease, EcoR1. Four of the lines had the same fragmentation pattern as their respective maternal species. Two lines had a pattern which was different to either parental species. The results show that nucleotide changes can occur in chloroplast DNA of isonuclear male-sterile
Rafael Frankel; William R. Scowcroft; Paul R. Whitfeld
Asymmetric cell-fusion of the japonica cultivar ofOryza sativa (rice) with cytoplasmic-male-sterile (CMS) plants bearing cytoplasm derived from Chinsurah Boro II, resulted in two classes of cytoplasmic hybrids (cybrids), fertile and CMS. Southern-blot analysis of the mitochondrial DNA (mtDNA) indicates recombination events around a number of genes; however, the appearance of the CMS character is tightly correlated to reorganization around theatp6
60Co-irradiated protoplasts of the cytoplasmic male-sterile line A-58 CMS (Oryza saliva L.) were electrofused with iodoacetamide (IOA)-treated protoplasts of the fertile (normal) rice cultivar Fujiminori. Seven of the colonies that formed were identified as cytoplasmic hybrids (cybrids): they all had the peroxidase isozymes of the fertile Fujiminori parent, but contained four plasmid-like DNAs (Bl, B2, B3 and B4) from the
A novel cytoplasmic male-sterility (CMS) radish (Raphanus sativus L.) and its associated mitotype (DCGMS) were previously identified; however, no mtDNA fragments flanking the atp6 gene were found in the DCGMS mitotype. Unlike three other mitotypes in this study, a unique mtDNA organization, atp6nad3rps12, was found to be the major mtDNA structure associated with this mitotype. This organization may have arisen
Males complaining of erectile and ejaculatory dysfunctions were treated in a structured therapy program. Twenty-one males of heterosexual, homosexual, or bisexual orientation were divided into five groups, with two male therapists for each group. Patients were those usually considered difficult to treat in that 16 had a primary sexual dysfunction with an average duration of 6 years. Extensive evaluations were
Walter Everaerd; Joost Dekker; Johan Dronkers; Kees van der Rhee; Joel Staffeleu; Guus Wiselius
Maternally inherited mutations, such as cytoplasmic malesterility, provide useful systems in which to study the function of plant mitochondrial genomes and also their interaction with nuclear genes. We have studied the organization and expression of the organelle genomes of the male-sterile cytoplasm of Ogura radish and compared them with those of normal radish to identify alterations that might be involved in cytoplasmic malesterility. The chloroplast DNAs of Ogura and normal radish are virtually indistinguishable, whereas their mitochondrial DNAs are highly rearranged. Alignment of a restriction map constructed for the 257-kilobase Ogura mitochondrial genome with that published for the 242-kilobase genome of normal radish reveals that the two mitochondrial DNAs differ in arrangement by at least 10 inversions. The transcriptional patterns of several known mitochondrial genes and of rearranged mitochondrial sequences were examined in three nuclear backgrounds. Altered transcripts were observed for three mitochondrial genes, atpA, atp6, and coxI. Rearrangements map near each of these genes and therefore may be responsible for their transcriptional alterations. Radish nuclear genes that restore fertility to the Ogura cytoplasm have no effect on the atp6 and coxI transcripts, but do influence the atpA transcriptional pattern. Images
The release of genetically-modified or sterilemale mosquitoes offers a promising form of mosquito-transmitted pathogen control, but the insights derived from our understanding of male mosquito behaviour have not fully been incorporated into the design of such genetic control or sterile-male release methods. The importance of aspects of male life history and mating behaviour for sterile-male release programmes were investigated by projecting a stage-structured matrix model over time. An elasticity analysis of transient dynamics during sterile-male releases was performed to provide insight on which vector control methods are likely to be most synergistic. The results suggest that high mating competitiveness and mortality costs of released males are required before the sterile-release method becomes ineffective. Additionally, if released males suffer a mortality cost, older males should be released due to their increased mating capacity. If released males are of a homogenous size and size-assortative mating occurs in nature, this can lead to an increase in the abundance of large females and reduce the efficacy of the population-suppression effort. At a high level of size-assortative mating, the disease transmission potential of the vector population increases due to male releases, arguing for the release of a heterogeneously-sized male population. The female population was most sensitive to perturbations of density-dependent components of larval mortality and female survivorship and fecundity. These findings suggest source reduction might be a particularly effective complement to mosquito control based on the sterile insect technique (SIT). In order for SIT to realize its potential as a key component of an integrated vector-management strategy to control mosquito-transmitted pathogens, programme design of sterile-male release programmes must account for the ecology, behaviour and life history of mosquitoes. The model used here takes a step in this direction and can easily be modified to investigate additional aspects of mosquito behaviour or species-specific ecology.
A study was made of the restoration of fertility in cytoplasmic malesterile petunia. The fertility expression of plants with restorer genes in sterilizing cytoplasm proved quite dependent upon environmental conditions, especially temperature. In experiments with clones at a series of constant temperatures in the phytotron fertility appeared to follow an optimum curve, the position of the optimum and the
Photoperiod-sensitive genic malesterile (PSGMS) rice has a number of desirable characteristics for hybrid rice production. In this study we made use of a published rice genetic linkage map to determine the locations of PSGMS genes and we have characterized the effects of these genes on sterility by using molecular markers. A two-step approach was designed for mapping the genes:
Qifa Zhang; B. Z. Shen; X. K. Dai; M. H. Mei; M. A. Saghai Maroof; Z. B. Li
Genetic analysis of hybrid sterility and inviability has recently become a successful experimental approach to pursue the problem of speciation. In the present study, classical genetic analyses and high resolution two-dimensional gel electrophoresis (2DE) have been used to investigate the genetic basis of hybrid malesterility in three sibling species of the Drosophila melanogaster species subgroup. The genetic basis of
Objectives We compared the malesexual partners of teen girls, age 15 - 19 years-old, currently infected with a sexually transmitted infection (STI) versus the male partners of adult women, age 20 - 41 years-old, with an STI to determine risk factors in these high-risk sexual dyads related to the male partner. Study Design Interview of 514 men who were partnered with 152 teen girls and 362 adult women, enrolled in Project Sexual Awareness for Everyone (SAFE), a randomized controlled trial of behavioral intervention to reduce recurrent STIs. Results Compared to the male partners of adult women, male partners of teen girls were significantly more likely (p < 0.05) to be infected with any STI at intake. Men partnered with teens were younger and had significantly more sexual partners per year sexually active, shorter relationship length, and shorter length of monogamy with the index girls. They were more likely to report that it was really important for the teen to have their baby (p = 0.04) and were slightly more likely to be the father of her children (p = 0.17). Young age independently predicted STI infection in men. Conclusions Although all women had an STI at intake, important differences were noted among the male partners of teens versus adults. Clinicians with similar populations may use this data to understand the characteristics of male partners of teens with STIs, in order to more effectively counsel adult and teen women on partner notification, treatment and STI prevention.
THURMAN, Andrea Ries; HOLDEN, Alan E C; SHAIN, Rochelle N; PERDUE, Sondra T.
Despite the benefits of resistance, susceptibility to infectious disease is commonplace. Although specific susceptibility may be considered an inevitable consequence of the co-evolutionary arms race between parasite and host, a more general constraint may arise from the cost of an immune response. This cost hypothesis predicts a tradeoff between immune defense and other components of fitness. In particular, a tradeoff between immunity and sexually selected male behavior has been proposed. Here we provide experimental support for the direct phenotypic tradeoff between sexual activity and immunity by studying the antibacterial immune response in Drosophila melanogaster. Males exposed to more females showed a reduced ability to clear a bacterial infection, an effect that we experimentally link to changes in sexual activity. Our results suggest immunosuppression is an important cost of reproduction and that immune function and levels of disease susceptibility will be influenced by sexual selection.
Erectile dysfunction (ED) is a highly prevalent disorder in males that increases markedly with aging. Diagnostic and treatment approaches for the disorder have proliferated in the past decade, along with increased understanding of the underlying physiology of male erection. Two specific themes have emerged in the recent literature on the topic: 1.(a) erectile dysfunction is a socially legitimate, medically treatable
The most important characteristics for females judging the attractiveness of males, and for males judging females, were eyes, body build and facial complexion. Previously, females tended to place less importance on physical components of attraction for both themselves and men. Possible interpretations are: (1) women have become more egalitarian
Male pelvic pain, often referred to as chronic prostatitis or chronic pelvic pain syndrome (CP\\/CPPS), is a common yet poorly understood problem, associated with significant sexual dysfunction. A critical review of the literature is presented, with specific attention to co-morbid sexual dysfunction. Recommendations for future multidisciplinary research and clinical work are also made.
Seth N. P. Davis; Yitzchak M. Binik; Serge Carrier
In many research studies and findings from federal statistics, one of the few areas wherein African Americans are less overrepresented in incarcerated settings is for male juvenile sexual assault. In this study, using a large sample the authors hypothesized that perhaps this was due to less deviant sexual interest among these youth (as reported in prior studies) after controlling for
Being deeply understood relies on the ability of the social work clinician to have authentic and genuine empathy for their\\u000a client. This phenomenological study sought to understand the lived experience of men sexually abused as boys in their childhood,\\u000a and what life is like for them as sexual abuse survivors in adulthood. Analyses of fourteen male survivors narratives into\\u000a the
This article reports on a study of representations and narratives of sexual abstinence among adolescent males in rural Nigeria\\u000a that showed that abstinence occupied a variable position in the lives and minds of these youth: Beliefs about sexual abstinence\\u000a being moral and healthy and signifying decency, propriety, and decorum existed alongside narratives depicting it both as dangerous\\u000a and unhealthy and
Prevention of recombination is needed to preserve both phenotypic differentiation between species and sexual phenotypic differentiation within species. For species differentiation (speciation), isolating barriers preventing recombination may be pre-zygotic (gamete transfer barriers), or post-zygotic (either a developmental barrier resulting in hybrid inviability, or a chromosomal-pairing barrier resulting in hybrid sterility). The sterility barrier is usually the first to appear and,
Several synthetic juvenile hormones were applied topically and by injection to adult male Blattella germanica. These compounds included the Law synthetic juvenile hormone, the synthetic Roeller compound and farnesyl O-methyl ether. Mortalities were low up...
Secondary sexual characters in animals are exaggerated ornaments or weapons for intrasexual competition. Unexpectedly, we found that a male secondary sexual character in sea lamprey (Petromyzon marinus) is a thermogenic adipose tissue that instantly increases its heat production during sexual encounters. This secondary sexual character, developed in front of the anterior dorsal fin of mature males, is a swollen dorsal ridge known as the 'rope' tissue. It contains nerve bundles, multivacuolar adipocytes and interstitial cells packed with small lipid droplets and mitochondria with dense and highly organized cristae. The fatty acid composition of the rope tissue is rich in unsaturated fatty acids. The cytochrome c oxidase activity is high but the ATP concentration is very low in the mitochondria of the rope tissue compared with those of the gill and muscle tissues. The rope tissue temperature immediately rose up to 0.3°C when the male encountered a conspecific. Mature males generated more heat in the rope and muscle tissues when presented with a mature female than when presented with a male (paired t-test, P<0.05). On average, the rope generated 0.027±0.013 W cm(-3) more heat than the muscle in 10 min. Transcriptome analyses revealed that genes involved in fat cell differentiation are upregulated whereas those involved in oxidative-phosphorylation-coupled ATP synthesis are downregulated in the rope tissue compared with the gill and muscle tissues. Sexually mature male sea lamprey possess the only known thermogenic secondary sexual character that shows differential heat generation toward individual conspecifics. PMID:23804672
Chung-Davidson, Yu-Wen; Priess, M Cody; Yeh, Chu-Yin; Brant, Cory O; Johnson, Nicholas S; Li, Ke; Nanlohy, Kaben G; Bryan, Mara B; Brown, C Titus; Choi, Jongeun; Li, Weiming
Transcripts of the maize mitochondrial genes atp6, urf13-T and ORF25 were examined by Northern analysis from five normal (N), Texas malesterile (T), and T malesterile cytoplasm lines restored to fertility. A 5 kb DNA region containing the atp6 promoter is duplicated 5' to urf13-T and ORF25 in T cytoplasm. DNA sequence differences in the 5 kb repeat detected
The orfB locus of the normal (fertile) and Ogura (male-sterile) radish mitochondrial genomes has been characterized in order to determine if this region, which has previously been correlated with cytoplasmic malesterility (CMS) in Brassica napus cybrids (Bonhomme et al. 1991; Temple et al. 1992), could also be involved in radish CMS. In normal radish, orfB is expressed as a
The mitochondrial DNA of plants containing the malesterility-causing Ogura cytoplasm of radish contain a novel gene, orf138, that is transcribed as part of a bicistronic mRNA. Genetic studies have previously linked malesterility with the orf138 locus. To determine if orf138 is expressed at the protein level, and investigate the effect of fertility restoration on ORF138 levels, we have
In the adult sexually experienced male rat, the intracerebroventricular (i.c.v.) injection of pinacidil, a KATP channel opener, at the dose of 100-150-300 micrograms/rat worsened the copulatory performance in the presence of a receptive female, whereas the administration of glibenclamide, a KATP channel blocker, at the dose of 0.5 and 3 mg/kg intraperitoneally (i.p.) had an improving effect. These data indicate that KATP channels in target neurons may play an important role in the physiology of malesexual behavior. PMID:9010481
Benelli, A; Arletti, R; Poggioli, R; Cavazzuti, E; Mameli, M; Bertolini, A
The present work was aimed at developing vector construct(s) suitable for restoring fertility in transgenic malesterile tobacco\\u000a plants expressing male-sterility-inducing ORFH522 in tapetal cell layer (Nizampatnam et al. Planta 229:9871001, 2009). PTGS vectors that could produce either intron spliced hairpin RNA against the orfH522 or induce silencing of orfH522 by heterologous 3?UTR region were developed using the selected 316 bp
Mitochondrial DNA in the T male-sterile cytoplasm (cms-T) of maize contains an open reading frame (ORF 13) associated with the T type of sterility. Antibodies raised to a chemically synthesized oligopeptide corresponding to ORF 13 were used to establish the expression of a 13-kDa protein from this reading frame. The 13-kDa polypeptide is synthesized uniquely in cms-T maize and purifies with the membrane fraction of T mitochondria. We assign the symbol urf13-T to designate this mitochondrial gene. Presence of the nuclear restorer gene Rf1 in cms-T plants results in a decrease in abundance of 13-kDa protein and alteration in the transcripts of urf13-T. Images
Despite the widespread incidence of childhood sexual abuse, there is insufficient investigation into the childhood sexual history of perpetrators. In addition, there is little published on the specific similarities between childhood and adult sexual histories. The present study investigates the incidence of childhood sexual abuse in a carefully characterized sample of male pedophiles compared with a demographically similar control group. Concordance between and cognitive distortions about characteristics of childhood abuse and pedophilic behavior are also studied. Twenty men with pedophilia, heterosexual type were compared with 24 demographically similar, healthy male control subjects on a questionnaire specifically designed to assess childhood sexual history in pedophiles. Sixty percent of pedophiles compared with 4% of control subjects reported adult sexual advances as a child. Seventy-five percent of pedophiles and 22% of control subjects reported a first sexual encounter before age 14 years. About 60% concordance was found between acts experienced as a child and perpetrated as an adult. Finally, numerous inconsistencies throughout the questionnaire add preliminary support for the role of cognitive distortions with regard to childhood and adult sexual history. The present findings replicate the elevated rate of childhood sexual abuse found among pedophiles and are consistent with the notion of a causative relationship between early childhood abuse and later pedophilic behavior. PMID:12436016
Cohen, Lisa J; McGeoch, Pamela G; Gans, Sniezyna Watras; Nikiforov, Konstantin; Cullen, Ken; Galynker, Igor I
Cytoplasm has substantial genetic effects on progeny and is important for yield improvement in rice breeding. Studies on the cytoplasmic effects of cytoplasmic malesterility (CMS) show that most types of CMS have negative effects on yield-related traits and that these negative effects vary among CMS. Some types of genic malesterility (GMS), including photo-thermo sensitive malesterility (PTMS), have been widely used in rice breeding, but the cytoplasmic effects of GMS remain unknown. Here, we identified a GMS mutant line, h2s, which exhibited small, white anthers and failed to produce mature pollen. Unlike CMS, the h2s had significant positive cytoplasmic effects on the seed set rate, weight per panicle, yield, and general combining ability (GCA) for plant height, seed set rate, weight per panicle, and yield. These effects indicated that h2s cytoplasm may show promise for the improvement of rice yield. Genetic analysis suggested that the phenotype of h2s was controlled by a single recessive locus. We mapped h2s to a 152 kb region on chromosome 6, where 22 candidate genes were predicted. None of the 22 genes had previously been reported to be responsible for the phenotypes of h2s. Sequencing analysis showed a 12 bp deletion in the sixth exon of Loc_Os06g40550 in h2s in comparison to wild type, suggesting that Loc_Os06g40550 is the best candidate gene. These results lay a strong foundation for cloning of the H2S gene to elucidate the molecular mechanism of male reproduction.
Cytoplasm has substantial genetic effects on progeny and is important for yield improvement in rice breeding. Studies on the cytoplasmic effects of cytoplasmic malesterility (CMS) show that most types of CMS have negative effects on yield-related traits and that these negative effects vary among CMS. Some types of genic malesterility (GMS), including photo-thermo sensitive malesterility (PTMS), have been widely used in rice breeding, but the cytoplasmic effects of GMS remain unknown. Here, we identified a GMS mutant line, h2s, which exhibited small, white anthers and failed to produce mature pollen. Unlike CMS, the h2s had significant positive cytoplasmic effects on the seed set rate, weight per panicle, yield, and general combining ability (GCA) for plant height, seed set rate, weight per panicle, and yield. These effects indicated that h2s cytoplasm may show promise for the improvement of rice yield. Genetic analysis suggested that the phenotype of h2s was controlled by a single recessive locus. We mapped h2s to a 152 kb region on chromosome 6, where 22 candidate genes were predicted. None of the 22 genes had previously been reported to be responsible for the phenotypes of h2s. Sequencing analysis showed a 12 bp deletion in the sixth exon of Loc_Os06g40550 in h2s in comparison to wild type, suggesting that Loc_Os06g40550 is the best candidate gene. These results lay a strong foundation for cloning of the H2S gene to elucidate the molecular mechanism of male reproduction. PMID:23613915
A chemical malesterility system based on anther-localized conversion of the inactive D-enantiomer of the herbicide, glufosinate (2-amino-4-(methylphosphinyl)-butanoate) to the phytotoxic L is described. Highly pure D-glufosinate was isolated in >98% enantiomeric excess from the racemate via fermentation with a strain of Escherichia coli expressing the PAT (L-glufosinate N-acetyl transferase) gene and purification of the unreacted D-enantiomer from the broth by ion exchange. A modified (F58K, M213S) form of the D-amino acid oxidase (DAAO) (EC 22.214.171.124) from Rhodosporidium toruloides was designed, tested in vitro and found to efficiently oxidize D-glufosinate to its 2-oxo derivative [2-oxo-4-(methylphosphinyl)-butanoic acid]. Tobacco (Nicotiana tabacum) plants were transformed to express this modified oxidase under control of the TAP1 tapetum-specific promoter. A number of the resultant transgenic lines exhibited complete malesterility that persisted for two or more weeks immediately following foliar treatment with 75 or 200 g/ha of D-glufosinate without exhibiting obvious phytotoxic symptoms or any measurable decline in female fertility. Similarly, plants containing the same construct and, additionally, a PAT gene expressed from a plastocyanin promoter exhibited significantly reduced male fertility and no reduction in female fertility following foliar application of racemic glufosinate. Thus, foliar application of d-glufosinate either purified or as the commercial herbicide, combined with anther expression of a modified DAAO promises to provide a cost-effective conditional chemical malesterility system with the characteristics necessary for practical F? hybrid seed production. PMID:20678098
The role of male-male courtship in parasitic Hymenoptera is poorly known. A laboratory study was conducted to assess if Psyttalia concolor (Szépligeti) (Hymenoptera: Braconidae) male courtship can be affected by a previous experience in courting young conspecifics of both sexes. Two experiments were performed to evaluate the effect of experience in courting young wasps on both male courtship and male-male competition behavior. Results showed that a courting experience on both sexes can modify some sexual traits in a P. concolor male, without affecting its success in mating. When approaching virgin females, a P. concolor male that had a previous courtship experience with young wasps of either sex showed shorter latency times, more wing fanning, and longer courtship durations with respect to the control male. The hypothesis that a previous courting experience may allow a P. concolor male to refine its courtship behavior and to enhance courtship intensity in subsequent encounters with females was discussed.
The role of male-male courtship in parasitic Hymenoptera is poorly known. A laboratory study was conducted to assess if Psyttalia concolor (Szépligeti) (Hymenoptera: Braconidae) male courtship can be affected by a previous experience in courting young conspecifics of both sexes. Two experiments were performed to evaluate the effect of experience in courting young wasps on both male courtship and male-male competition behavior. Results showed that a courting experience on both sexes can modify some sexual traits in a P. concolor male, without affecting its success in mating. When approaching virgin females, a P. concolor male that had a previous courtship experience with young wasps of either sex showed shorter latency times, more wing fanning, and longer courtship durations with respect to the control male. The hypothesis that a previous courting experience may allow a P. concolor male to refine its courtship behavior and to enhance courtship intensity in subsequent encounters with females was discussed. PMID:23895402
The current report examined HIV-related high risk sexual behaviors among a small sample of gay and bisexual male methamphetamine abusers in Los Angeles. Participants were 16 methamphetamine-abusing or -dependent gay or bisexual males who participated in a treatment demonstration project between 1989 and 1993. All participants completed the NIDA\\/WAVE survey, a detailed inventory of HIV-related risk behaviors. Findings indicate a
Dominick Frosch; Steven Shoptaw; Alice Huber; Richard A. Rawson; Walter Ling
Demographic parameters including operational sex ratio (OSR) and population density may influence the opportunity for, and strength of sexual selection. Traditionally, male-biased OSRs and high population densities have been thought to increase the opportunity for sexual selection on malesexual traits due to increased male competition for mates. Recent experimental evidence, however, suggests that male-biased OSRs might reduce the opportunity
A novel cytoplasmic male-sterility (CMS) radish (Raphanus sativus L.) and its associated mitotype (DCGMS) were previously identified; however, no mtDNA fragments flanking the atp6 gene were found in the DCGMS mitotype. Unlike three other mitotypes in this study, a unique mtDNA organization, atp6-nad3-rps12, was found to be the major mtDNA structure associated with this mitotype. This organization may have arisen from short repeat sequence-mediated recombination events. The short repeat clusters involved in the mtDNA rearrangement around the atp6 gene also exist as repetitive sequences in the complete mitochondrial genomes of other members of the Brassicaceae family, including rapeseed and Arabidopsis. These sequences do not exist as repetitive elements in the mtDNA of tobacco, sugar beet, or rice. While studying the regions flanking atp6, we identified a truncated atp6 mtDNA fragment which consists of the 5' part of the atp6 gene linked to an unidentified sequence. This mtDNA structure was present in all mitotypes; however, a single nucleotide insertion mutation leading to a frame-shift was identified only in the DCGMS mitotype. Although this truncated atp6 organization was transcribed, there was no significantly different expression between male-sterile and fertile segregating individuals from the BC(1)F(1) population originating from a cross between male-sterile and restorer parents. Comprehensive survey of the single base-pair insertion showed that it was maternally inherited and unique to the DCGMS mitotype. Therefore, this single nucleotide polymorphism (SNP) in the coding sequence of the mtDNA will be a useful molecular marker for the detection of the DCGMS mitotype. PMID:19034407
Lee, Young-Pyo; Kim, Sunggil; Lim, Heerae; Ahn, Youngsoon; Sung, Soon-Kee
Background Among invertebrates, specific pheromones elicit inherent (fixed) behavioural responses to coordinate social behaviours such as sexual recognition and attraction. By contrast, the much more complex social odours of mammals provide a broad range of information about the individual owner and stimulate individual-specific responses that are modulated by learning. How do mammals use such odours to coordinate important social interactions such as sexual attraction while allowing for individual-specific choice? We hypothesized that male mouse urine contains a specific pheromonal component that invokes inherent sexual attraction to the scent and which also stimulates female memory and conditions sexual attraction to the airborne odours of an individual scent owner associated with this pheromone. Results Using wild-stock house mice to ensure natural responses that generalize across individual genomes, we identify a single atypical male-specific major urinary protein (MUP) of mass 18893Da that invokes a female's inherent sexual attraction to male compared to female urinary scent. Attraction to this protein pheromone, which we named darcin, was as strong as the attraction to intact male urine. Importantly, contact with darcin also stimulated a strong learned attraction to the associated airborne urinary odour of an individual male, such that, subsequently, females were attracted to the airborne scent of that specific individual but not to that of other males. Conclusions This involatile protein is a mammalian male sex pheromone that stimulates a flexible response to individual-specific odours through associative learning and memory, allowing female sexual attraction to be inherent but selective towards particular males. This 'darcin effect' offers a new system to investigate the neural basis of individual-specific memories in the brain and give new insights into the regulation of behaviour in complex social mammals. See associated Commentary http://www.biomedcentral.com/1741-7007/8/71
Conducted unstructured interviews with 18 male street prostitutes between the ages of 13 and 22 to determine the extent of accurate knowledge they possessed concerning four common sexually transmitted diseases. Found that subjects possessed more factual information on gonorrhea and syphilis than on herpes and Acquired Immune Deficiency Syndrome.
|Examines the relationship between sexual aggression and the variables of sex role stereotyping, fraternity affiliation, participation in athletics, hostility toward women, aggressive driving, aggressive attitudes, alcohol use, and masculinity. Findings from 86 male undergraduates reveal physical aggression, sex role stereotyping, and fraternity
Three samples of male Navy recruits (Total N = 7,850) were surveyed to determine whether a history of childhood physical abuse (CPA) and/or sexual abuse (CSA) was predictive of premilitary female rape, and whether these relationships were mediated by alco...
L. L. Merrill C. J. Thomsen S. R. Gold J. S. Miller
The effect of photoperiodic conditions on sexual behavior was investigated in male Syrian hamsters that were either gonadally intact, or castrated and treated with low doses of testosterone throughout the experiment. Hamsters were exposed to long (LD 16:8) or short (LD 8:16) days for 7 weeks; for the next 8 weeks, either they were exposed to an intermediate daylength (LD
J. B. Powers; E. A. Steel; J. B. Hutchison; M. H. Hastings; J. Herbert; A. P. Walker
Examines the relationship between sexual aggression and the variables of sex role stereotyping, fraternity affiliation, participation in athletics, hostility toward women, aggressive driving, aggressive attitudes, alcohol use, and masculinity. Findings from 86 male undergraduates reveal physical aggression, sex role stereotyping, and fraternity
Theoretical analysis of own and literature investigations of sexual motivation with the use of the partition test [Kudryavtseva, 1987, 1994] in male mice was carried out. It has been shown that appearance of a receptive female in the neighboring compartment of common cage separated by perforated transparent partition produces the enhancement of testosterone level in blood and stimulates the behavioral
Speciation, the evolution of reproductive isolation between populations, serves as the driving force for generating biodiversity. Postzygotic barriers to gene flow, such as F(1) hybrid sterility and inviability, play important roles in the establishment and maintenance of biological species. F(1) hybrid incompatibilities in taxa that obey Haldane's rule, the observation that the heterogametic sex suffers greater hybrid fitness problems than the homogametic sex, are thought to often result from interactions between recessive-acting X-linked loci and dominant-acting autosomal loci. Because they play such prominent roles in producing hybrid incompatibilities, we examine the dominance and nature of epistasis between alleles derived from Drosophila persimilis that confer hybrid malesterility in the genetic background of its sister species, D. pseudoobscura bogotana. We show that epistasis elevates the apparent dominance of individually recessive-acting QTL such that they can contribute to F(1) hybrid sterility. These results have important implications for assumptions underlying theoretical models of hybrid incompatibilities and may offer a possible explanation for why, to date, identification of dominant-acting autosomal "speciation genes" has been challenging. PMID:19686263
Introduction Male circumcision is being promoted for HIV prevention in high-risk heterosexual populations. However, there is a concern that circumcision may impair sexual function. Aim To assess adult male circumcisions effect on mens sexual function and pleasure. Methods Participants in a controlled trial of circumcision to reduce HIV incidence in Kisumu, Kenya were uncircumcised, HIV negative, sexually active men, aged 1824 years, with a hemoglobin ?9.0 mmol/L. Exclusion criteria included foreskin covering less than half the glans, a condition that might unduly increase surgical risks, or a medical indication for circumcision. Participants were randomized 1:1 to either immediate circumcision or delayed circumcision after 2 years (control group). Detailed evaluations occurred at 1, 3, 6, 12, 18, and 24 months. Main Outcome Measures (i) Sexual function between circumcised and uncircumcised men; and (ii) sexual satisfaction and pleasure over time following circumcision. Results Between February 2002 and September 2005, 2,784 participants were randomized, including the 100 excluded from this analysis because they crossed over, were not circumcised within 30 days of randomization, did not complete baseline interviews, or were outside the age range. For the circumcision and control groups, respectively, rates of any reported sexual dysfunction decreased from 23.6% and 25.9% at baseline to 6.2% and 5.8% at month 24. Changes over time were not associated with circumcision status. Compared to before they were circumcised, 64.0% of circumcised men reported their penis was much more sensitive, and 54.5% rated their ease of reaching orgasm as much more at month 24. Conclusions Adult male circumcision was not associated with sexual dysfunction. Circumcised men reported increased penile sensitivity and enhanced ease of reaching orgasm. These data indicate that integration of male circumcision into programs to reduce HIV risk is unlikely to adversely effect malesexual function.
Krieger, John N.; Mehta, Supriya D.; Bailey, Robert C.; Agot, Kawango; Ndinya-Achola, Jeckoniah O.; Parker, Corette; Moses, Stephen
Male harassment of females to gain mating opportunities is a consequence of an evolutionary conflict of interest between the sexes over reproduction and is common among sexually reproducing species. Male Trinidadian guppies Poecilia reticulata spend a large proportion of their time harassing females for copulations and their presence in female social groups has been shown to disrupt female-female social networks and the propensity for females to develop social recognition based on familiarity. In this study, we investigate the behavioural mechanisms that may lead to this disruption of female sociality. Using two experiments, we test the hypothesis that male presence will directly affect social behaviours expressed by females towards other females in the population. In experiment one, we tested for an effect of male presence on female shoaling behaviour and found that, in the presence of a free-swimming male guppy, females spent shorter amounts of time with other females than when in the presence of a free-swimming female guppy. In experiment two, we tested for an effect of male presence on the incidence of aggressive behaviour among female guppies. When males were present in a shoal, females exhibited increased levels of overall aggression towards other females compared with female only shoals. Our work provides direct evidence that the presence of sexually harassing males alters female-female social behaviour, an effect that we expect will be recurrent across taxonomic groups. PMID:21976624
Male harassment of females to gain mating opportunities is a consequence of an evolutionary conflict of interest between the sexes over reproduction and is common among sexually reproducing species. Male Trinidadian guppies Poecilia reticulata spend a large proportion of their time harassing females for copulations and their presence in female social groups has been shown to disrupt femalefemale social networks and the propensity for females to develop social recognition based on familiarity. In this study, we investigate the behavioural mechanisms that may lead to this disruption of female sociality. Using two experiments, we test the hypothesis that male presence will directly affect social behaviours expressed by females towards other females in the population. In experiment one, we tested for an effect of male presence on female shoaling behaviour and found that, in the presence of a free-swimming male guppy, females spent shorter amounts of time with other females than when in the presence of a free-swimming female guppy. In experiment two, we tested for an effect of male presence on the incidence of aggressive behaviour among female guppies. When males were present in a shoal, females exhibited increased levels of overall aggression towards other females compared with female only shoals. Our work provides direct evidence that the presence of sexually harassing males alters femalefemale social behaviour, an effect that we expect will be recurrent across taxonomic groups.
Grafting desirable scion on stress-tolerant rootstocks provides an opportunity to improve the cryotolerance of scion. Genic malesterile (GMS) lines of plant could be used as sterile line and maintainer in breeding, and they have the conspicuous characteristics that the fertility of which is easy to regain but hard to maintain by sexual reproduction. In order to maintain the fertility of GMS cotton by means of its perennial growth on the basis of frostless winters in Nanning, Guangxi autonomous region, GMS line A4 was grafted onto 7 cryotolerant rootstocks (F118, F697, F098, F112, F113, P098 and P113), and the cryotolerance and the overwintering survivorship of scions were investigated. In consequence, when compared with control (self-grafted A4), the relative conductivity of the grafted plants in shoot bark was reduced (8.80%), the content of soluble sugar, soluble protein and free proline were higher, 25.00, 1.55, 3.46%, respectively; the overwintering survival rate and the height of regeneration bud under field condition of grafted plants were higher, 10.44, 15.75%, respectively; the order of the grafted plants based on the average subordinate function value of overwintering survivorship was A4/F113>A4/F118>A4/F098>A4/F697>A4/F112>A4/P098>A4/P113>A4/A4(CK); the correlation analyses indicated that the physiological parameters of cryotolerance could be used for forecasting the overwintering survivorship, and the relative conductivity could be chosen as the first physiological parameter for forecasting cryotolerance or overwintering survivorship. The results indicate that the cryotolerance and the overwintering survivorship of GMS cotton could be improved by grafting, and F113 appeared to be a valuable rootstock. PMID:23667634
Grafting desirable scion on stress-tolerant rootstocks provides an opportunity to improve the cryotolerance of scion. Genic malesterile (GMS) lines of plant could be used as sterile line and maintainer in breeding, and they have the conspicuous characteristics that the fertility of which is easy to regain but hard to maintain by sexual reproduction. In order to maintain the fertility of GMS cotton by means of its perennial growth on the basis of frostless winters in Nanning, Guangxi autonomous region, GMS line A4 was grafted onto 7 cryotolerant rootstocks (F118, F697, F098, F112, F113, P098 and P113), and the cryotolerance and the overwintering survivorship of scions were investigated. In consequence, when compared with control (self-grafted A4), the relative conductivity of the grafted plants in shoot bark was reduced (8.80%), the content of soluble sugar, soluble protein and free proline were higher, 25.00, 1.55, 3.46%, respectively; the overwintering survival rate and the height of regeneration bud under field condition of grafted plants were higher, 10.44, 15.75%, respectively; the order of the grafted plants based on the average subordinate function value of overwintering survivorship was A4/F113>A4/F118>A4/F098>A4/F697>A4/F112>A4/P098>A4/P113>A4/A4(CK); the correlation analyses indicated that the physiological parameters of cryotolerance could be used for forecasting the overwintering survivorship, and the relative conductivity could be chosen as the first physiological parameter for forecasting cryotolerance or overwintering survivorship. The results indicate that the cryotolerance and the overwintering survivorship of GMS cotton could be improved by grafting, and F113 appeared to be a valuable rootstock.
This phenomenological study explores the experience of eight monogamous, heterosexual women whose husbands have been diagnosed as HIV positive as a result of male-to-malesexual contact. The women were not aware of the sexual orientation of their husbands nor that they had engaged in extramarital relations. The ramifications of the revelations of both the sexual orientation and the HIV status
Utilization of a two-line breeding system via photoperiod-thermo sensitive malesterility has a great potential for hybrid production in wheat (Triticum aestivum L.). 337S is a novel wheat malesterile line sensitive to both short daylength/low temperature and long daylength/high temperature. Five F2 populations derived from the crosses between 337S and five common wheat varieties were developed for genetic analysis. All F1s were highly fertile while segregation occurred in the F2 populations with a ratio of 3 fertile:1 sterile under short daylength/low temperature. It is shown that malesterility in 337S was controlled by a single recessive gene, temporarily designated as wptms3. Bulked segregant analysis (BSA) coupled with simple sequence repeat (SSR) markers was applied to map the sterile gene using one mapping population. The wptms3 gene was mapped to chromosome arm 1BS and flanked by Xgwm413 and Xgwm182 at a genetic distance of 3.2 and 23.5 cM, respectively. The accuracy and efficiency of marker-assisted selection were evaluated and proved essential for identifying homozygous recessive malesterile genotypes of the wptms3 gene in F2 generation.
People in Nepal generally hold fairly traditional views about sex and sexual health, whilst Western tourists often have a more liberal approach towards sex and relationships. There is evidence that significant sexual interaction occurs between male trekking guides and female travellers and\\/or local female sex workers in Nepal. This qualitative study explored trekking guides' sexual health knowledge, sexual relationships and
Padam Simkhada; Edwin R. van Teijlingen; Pramod R. Regmi; Prakash Bhatta
The current study examined and compared the psychometric properties of the Sexual Compulsivity Scale and the Compulsive Sexual Behavior Inventory in male college students. Participants included 334 male undergraduate students enrolled in Introductory Psychology courses. Zero-order correlation analyses were conducted and statistically compared to identify sexual behaviors and constructs significantly and differentially related to scores on the CSBI and SCS.
Tayla T. C. Lee; Kristin A. Ritchey; Johnathan D. Forbey; George A. Gaither
The effect of photoperiodic conditions on sexual behavior was investigated in male Syrian hamsters that were either gonadally intact, or castrated and treated with low doses of testosterone throughout the experiment. Hamsters were exposed to long (LD 16:8) or short (LD 8:16) days for 7 weeks; for the next 8 weeks, either they were exposed to an intermediate daylength (LD 12:12), or daylength conditions remained unchanged. Sexual behavior was affected by photoperiod conditions in both gonadally intact animals and testosterone-treated castrates, but to different degrees. Intact males exposed to short days for 15 weeks exhibited gonadal regression, and their copulatory performance was impaired. The percentage of animals that intromitted or ejaculated was significantly reduced. Additional measures of sexual performance among the copulating males were also affected. In contrast, among the castrates with testosterone clamped at low but stable levels, the proportion of males that mounted, intromitted, or ejaculated was not affected by photoperiod. However, among the males that continued to copulate, sexual performance changes were present in the short-day castrates that resembled those displayed by the intact males. We infer that these behavioral effects in both hormonal conditions reflect primarily a difficulty in the attainment of intromission. Gonadal regression alone cannot easily account for the behavioral deficits of the intact males, because circulating testosterone levels at the end of the experiment were not significantly different between the gonadally intact hamsters and the castrated, testosterone-treated hamsters exposed continuously to short days. Males transferred from either long or short days to the intermediate-daylength condition responded behaviorally to this photoperiod as if it were a short day, that is, their ejaculatory frequency declined. We conclude that male hamsters exposed to photoinhibitory daylengths exhibit deficits in their sexual behavior, not only because endogenous levels of testosterone decrease, but also because the substrates on which this hormone acts become less responsive. We hypothesize that under physiological conditions, the episodic secretion of testosterone imposes constraints on the maintenance or restoration of copulation, and that the potent behavioral effects achieved by constant-release implants of testosterone may mask the presence of photoperiodically induced alterations in the hamster's sensitivity to this gonadal hormone. PMID:2519581
Powers, J B; Steel, E A; Hutchison, J B; Hastings, M H; Herbert, J; Walker, A P
The purpose of this paper is to describe pertinent non-medical circumstances around male-on-malesexual assault, and supplements the earlier article in this journal regarding forensic medical aspects of this population. As services (medical, policing and judicial) see more males they will need to adapt themselves to their needs as well as those of their female clients. St. Mary's Sexual Assault Referral Centre (Greater Manchester, UK) opened in October 1986. Up to May 2003 it had seen 376 male (370 individual clients) and 7,789 female cases (7,403 clients). Of these, significantly fewer males reported to the police than females, although this difference has disappeared in recent years. There were also significant differences between the sexes regarding relationship, number of assailants, and assault location. There were no statistically significant differences between the sexes for age of the client, and presence in the assault of weapons or additional violence. PMID:16117283
In soybean [Glycine max (L.) Merr.], manual cross-pollination to produce large quantities of hybrid seed is difficult and time consuming. Identification of an environmentally stable male-sterility system could make hybrid seed production commercially valuable. In soybean, 2 environmentally sensitive male-sterile, female-fertile mutants (ms8 and msp) have been identified. Inheritance studies showed that sterility in both mutants is inherited as a single gene. The objectives of this study were to 1) confirm that msp and ms8 are independent genes; 2) identify the soybean chromosomes that contain the msp and the ms8 genes using bulked segregant analyses (BSAs); and 3) make a genetic linkage map of the regions containing these genes. Mapping populations consisting of 176 F(2) plants for ms8 and 134 F(2) plants for msp were generated. BSA revealed that Sat_389 and Satt172 are closely associated markers with ms8 and msp, respectively. Map location of Sat_389 suggested that the ms8 gene is located on chromosome 7; molecular linkage group (MLG) M. Map location of Satt172 indicated that the msp gene is located on chromosome 2 (MLG Dlb). Genetic linkage maps developed using F(2) populations revealed that ms8 is flanked by a telomere and Sat_389 and msp is flanked by Sat_069 and GMES4176. The region between the telomere and Sat_389 is physically 160 Kb. Soybean sequence information revealed that there are 13 genes present in that region. Protein BLASTP analyses revealed that homologs of 3 of the 13 genes are known to a play role in cell division, suggesting putative candidates for ms8. PMID:20864624
Frasch, Ryan M; Weigand, Courtney; Perez, Paola T; Palmer, Reid G; Sandhu, Devinder
Background Pelargonium is one of the most popular garden plants in the world. Moreover, it has a considerable economic importance in the ornamental plant market. Conventional cross-breeding strategies have generated a range of cultivars with excellent traits. However, gene transfer via Agrobacterium tumefaciens could be a helpful tool to further improve Pelargonium by enabling the introduction of new genes/traits. We report a simple and reliable protocol for the genetic transformation of Pelargonium spp. and the production of engineered long-life and malesterile Pelargonium zonale plants, using the pSAG12::ipt and PsEND1::barnase chimaeric genes respectively. Results The pSAG12::ipt transgenic plants showed delayed leaf senescence, increased branching and reduced internodal length, as compared to control plants. Leaves and flowers of the pSAG12::ipt plants were reduced in size and displayed a more intense coloration. In the transgenic lines carrying the PsEND1::barnase construct no pollen grains were observed in the modified anther structures, which developed instead of normal anthers. The locules of sterile anthers collapsed 34?days prior to floral anthesis and, in most cases, the undeveloped anther tissues underwent necrosis. Conclusion The chimaeric construct pSAG12::ipt can be useful in Pelargonium spp. to delay the senescence process and to modify plant architecture. In addition, the use of engineered malesterile plants would be especially useful to produce environmentally friendly transgenic plants carrying new traits by preventing gene flow between the genetically modified ornamentals and related plant species. These characteristics could be of interest, from a commercial point of view, both for pelargonium producers and consumers.
Purpose: Knowledge of sexual problems after pre- or postoperative radiotherapy (RT) with 50 Gy for rectal cancer is limited. In this study, we aimed to compare self-rated sexual functioning in irradiated (RT+) and nonirradiated (RT-) male patients at least 2 years after surgery for rectal cancer. Methods and Materials: Patients diagnosed with rectal cancer from 1993 to 2003 were identified from the Norwegian Rectal Cancer Registry. Male patients without recurrence at the time of the study. The International Index of Erectile Function, a self-rated instrument, was used to assess sexual functioning, and serum levels of serum testosterone were measured. Results: Questionnaires were returned from 241 patients a median of 4.5 years after surgery. The median age was 67 years at survey. RT+ patients (n = 108) had significantly poorer scores for erectile function, orgasmic function, intercourse satisfaction, and overall satisfaction with sex life compared with RT- patients (n = 133). In multiple age-adjusted analysis, the odds ratio for moderate-severe erectile dysfunction in RT+ patients was 7.3 compared with RT- patients (p <0.001). Furthermore, erectile dysfunction of this degree was associated with low serum testosterone (p = 0.01). Conclusion: RT for rectal cancer is associated with significant long-term effects on sexual function in males.
Bruheim, Kjersti, E-mail: Kjersti.firstname.lastname@example.org [Oslo University Hospital, Ulleval Cancer Centre, Oslo (Norway); Guren, Marianne G. [Oslo University Hospital, Ulleval Cancer Centre, Oslo (Norway); Dahl, Alv A. [Oslo University Hospital, Department of Clinical Cancer Research, the Norwegian Radium Hospital, Oslo (Norway); Faculty of Medicine, University of Oslo, Oslo (Norway); Skovlund, Eva [School of Pharmacy, University of Oslo, Oslo (Norway); Balteskard, Lise [University Hospital of Northern Norway, Tromso (Norway); Carlsen, Erik [Oslo University Hospital, Department of Gastrointestinal Surgery, Ulleval, Oslo (Norway); Fossa, Sophie D. [Oslo University Hospital, Department of Clinical Cancer Research, the Norwegian Radium Hospital, Oslo (Norway); Faculty of Medicine, University of Oslo, Oslo (Norway); Tveit, Kjell Magne [Oslo University Hospital, Ulleval Cancer Centre, Oslo (Norway); Faculty of Medicine, University of Oslo, Oslo (Norway)
Sexual violence against women is a major concern to researchers and policy makers, as well as to the general public. This study uses a sample of more than 2,000 college students to investigate the extent to which exposure to harsh parenting practices and sexually explicit materials contributes to perpetration and victimization. Findings indicate that frequent corporal punishment in the family of origin combined with consumption of pornographic materials increased the probability that males reported engaging in coercive sexual practices. For females, both frequent corporal punishment and exposure to paternal hostility combined with consumption of pornographic materials were associated with higher levels of reported sexual victimization. These results provide increased understanding of the impact of pornography use among a nonclinical sample, as well as the consequences of experiencing harsh corporal punishment in one's family of origin, on the sexual victimization of females. PMID:22852438
Simons, Leslie Gordon; Simons, Ronald L; Lei, Man-Kit; Sutton, Tara E
Shaham, Y., J. Puddicombe and J. Stewart. Sexually arousing events and relapse to heroin-seeking in sexually experienced male rats. Physiol Behav 61(2) 337341, 1997.We have shown previously, using a reinstatement procedure, that both priming injections of heroin and exposure to footshock stress reinstate heroin-taking behavior following prolonged drug-free periods. In the present study, we examined the effects of another highly
Sexual selection has driven the evolution and elaboration of a wide variety of displays and ornaments in male nonhuman primates,\\u000a including capes, cheek flanges, and sexual coloration. Among the most sexually dimorphic of all primates is the drill (Mandrillus leucophaeus), the males of which can be 3 times the mass of females, possess large canines, and exhibit extremely bright sexual
Jill S. Marty; James P. Higham; Elizabeth L. Gadsby; Caroline Ross
Our research concerns the basic mechanisms of cytoplasmic malesterility (CMS) and fertility restoration in maize. The molecular determination of CMS is in the DNA of the mitochondria (mtDNA) but specific nuclear restorer-of-fertility (Rf) genes can overrule the male-sterile effect of the cytoplasm. Our approach to the study of the Rf genes is threefold. We are attempting to tag the cms-S Rf genes and the cms-T Rf2 gene with controlling elements (CEs). Since we have identified a number of spontaneous Rf genes for cms-S and have demonstrated that they are themselves transposable, we are also searching for cases in which an Rf gene is inserted into a wild-type gene. The other aspect of our research involves the nuclear control over the organization of the mitochondrial genome. We found that the changes in mtDNA organization upon cytoplasmic reversion to fertility were characteristic of the nuclear background in which the reversion event occurred. We have investigated whether these differences are a reflection of differences in the organization of the mtDNA genome before reversion.
The hypothesis of the association between an increase in cytokinin activity and restoration of anther fertility in msm1 cytoplasm was tested. The following barley lines with Hordeum vulgare cv. Adorra nuclear gene background were studied: Adorra cytoplasm without nuclear restorer gene (fertile), Adorra cytoplasm homozygous for nuclear Rfm1a gene (fertile), msm1 cytoplasm without restorer gene (malesterile), msm1 cytoplasm homozygous for nuclear Rfm1a gene (fertile). Ethanolic extracts of root exudate were fractionated and bioassayed for cytokinins. Both the biological activity and the total quantity of cytokinins appeared lowest in the unrestored malesterile line. The total biological activities of cytokinins in the three fertile lines were similar, but the quantities in the restorer gene carriers appeared lower. On the other hand, the restorer gene carriers, independent of the cytoplasm, showed 8-9 times more of a bound cytokinin. Because the bound form is evidently underestimated by the bioassay, the increase in the bound cytokinin fraction may mean even a higher total content in the Rfm1a gene carriers than in Adorra without the gene. The bound cytokinin may be translocated more readily to distal organs (e.g., the anthers) compared with unbound cytokinins. Because cytokinins are associated with various ecophysiological processes, the rise in a particular form may explain the heterogeneous distribution of the restorer gene in wild barley populations in different regions of Israel.
We have sequenced five distinct mitochondrial genomes in maize: two fertile cytotypes (NA and the previously reported NB) and three cytoplasmic-male-sterile cytotypes (CMS-C, CMS-S, and CMS-T). Their genome sizes range from 535,825 bp in CMS-T to 739,719 bp in CMS-C. Large duplications (0.5120 kb) account for most of the size increases. Plastid DNA accounts for 2.34.6% of each mitochondrial genome. The genomes share a minimum set of 51 genes for 33 conserved proteins, three ribosomal RNAs, and 15 transfer RNAs. Numbers of duplicate genes and plastid-derived tRNAs vary among cytotypes. A high level of sequence conservation exists both within and outside of genes (1.657.04 substitutions/10 kb in pairwise comparisons). However, sequence losses and gains are common: integrated plastid and plasmid sequences, as well as noncoding native mitochondrial sequences, can be lost with no phenotypic consequence. The organization of the different maize mitochondrial genomes varies dramatically; even between the two fertile cytotypes, there are 16 rearrangements. Comparing the finished shotgun sequences of multiple mitochondrial genomes from the same species suggests which genes and open reading frames are potentially functional, including which chimeric ORFs are candidate genes for cytoplasmic malesterility. This method identified the known CMS-associated ORFs in CMS-S and CMS-T, but not in CMS-C.
Allen, James O.; Fauron, Christiane M.; Minx, Patrick; Roark, Leah; Oddiraju, Swetha; Lin, Guan Ning; Meyer, Louis; Sun, Hui; Kim, Kyung; Wang, Chunyan; Du, Feiyu; Xu, Dong; Gibson, Michael; Cifrese, Jill; Clifton, Sandra W.; Newton, Kathleen J.
Restoration of male fertility was achieved by fusing protoplasts from malesterile (CMS) Nicotiana sylvestris plants with X-irradiated protoplasts derived from fertile N. tabacum plants. The CMS N. sylvestris plants were derived from a previous somatic hybridization experiment and contained alien (Line 92) cytoplasm. About one quarter of the regenerated plants were found to be cybrids. i.e. they consisted of
To study the genetic differences responsible for the sterility of their male hybrids, we introgressed small segments of an X chromosome from Drosophila simulans into a pure Drosophila mauritiana genetic background, then assessed the fertility of males carrying heterospecific introgressions of varying size. Although this analysis examined less than 20% of the X chromosome (roughly 5% of the euchromatic portion
Jasmonic acid (JA) and its precursor 12-oxophytodienoic acid (OPDA) act as plant growth regulators and mediate responses to environmental cues. To investigate the role of these oxylipins in anther and pollen development, we characterized a T-DNA-tagged, male-sterile mutant of Arabidopsis, opr3. The opr3 mutant plants are sterile but can be rendered fertile by exogenous JA but not by OPDA. Cloning
The Polima cytoplasmic malesterility (CMS) system has been successfully used in three\\/two-line hybrid production in rapeseed\\u000a (Brassica napus L.). However, the sterility of the Polima (pol) CMS lines is sensitive to temperature fluctuations. Also, traces of pollen\\u000a can cause self-pollination within the CMS lines, which results in reduced levels of F1 hybrid seed purity and leads to a significant
Previous research has explored whether criminological theories can account for the apparently specialized behaviors of sexual offenders. One perspective proposes that criminals are versatile, engaging in an array of antisocial behaviors. The alternative perspective, more common in sexual offending research, is that sexual offenders (especially child molesters) engage in sexual offenses exclusively or predominantly. This study examined 374 malesexual
Danielle A. Harris; Paul Mazerolle; Raymond A. Knight
Cytoplasmic malesterility in plants is associated with mitochondrial dysfunction. We have proposed that a nuclear-encoded chimeric peptide formed by mitochondrial sequences when imported into the mitochondria may impair organelle function and induce malesterility in plants. A model developed to test this hypothesis is reported here. Assuming that the editing process in higher plant mitochondria reflects a requirement for producing active proteins, we have used edited and unedited coding sequences of wheat ATP synthase subunit 9 (atp9) fused to the coding sequence of a yeast coxIV transit peptide. Transgenic plants containing unedited atp9 exhibited either fertile, semifertile, or male-sterile phenotypes; controls containing edited atp9 or only the selectable marker gave fertile plants. Pollen fertility ranged from 31% to 75% in fertile plants, 10% to 20% in semifertile plants, and < 2% in male-sterile plants. Genetic and molecular data showed that the chimeric plasmid containing the transgene is inherited as a Mendelian trait. The transgenic protein is imported into the mitochondria. The production and frequency of semifertile or male-sterile transgenic plants conform to the proposed hypothesis. Images Fig. 2 Fig. 3 Fig. 4
Hernould, M; Suharsono, S; Litvak, S; Araya, A; Mouras, A
Incidence of sex chromosome aneuploidy in men is as high as 1:500. The predominant conditions are an additional Y chromosome (47,XYY) or an additional X chromosome (47,XXY). Behavioral studies using animal models of these conditions are rare. To assess the role of sex chromosome aneuploidy on sexual behavior, we used mice with a spontaneous mutation on the Y chromosome in which the testis-determining gene Sry is deleted (referred to as Y?) and insertion of a Sry transgene on an autosome. Dams were aneuploid (XXY?) and the sires had an inserted Sry transgene (XYSry). Litters contained six male genotypes, XY, XYY?, XXSry, XXY?Sry, XYSry and XYY?Sry. In order to eliminate possible differences in levels of testosterone, all of the subjects were castrated and received testosterone implants prior to tests for male sex behavior. Mice with an additional copy of the Y? chromosome (XYY?) had shorter latencies to intromit and achieve ejaculations than XY males. In a comparison of the four genotypes bearing the Sry transgene, males with two copies of the X chromosome (XXSry and XXY?Sry) had longer latencies to mount and thrust than males with only one copy of the X chromosome (XYSry and XYY?Sry) and decreased frequencies of mounts and intromissions as compared with XYSry males. The results implicate novel roles for sex chromosome genes in sexual behaviors.
Park, J. H.; Burns-Cusato, M.; Dominguez-Salazar, E.; Riggan, A.; Shetty, S.; Arnold, A. P.; Rissman, E. F.
Gonad function and sexual activity were evaluated in 44 young male adults who received a kidney shortly before or during adolescence. All patients were growth-retarded (-2.2 SD). Volume of the testes was decreased less than 12 ml, i.e, less than 10th centile) in 47% of patients, whereas hormone levels (testosterone, FSH, LH, and prolactin) were within the normal range. Oligospermia or azoospermia was found in 10 of 11 tested patients. Testicular function and sperm count were negatively correlated with renal function. Age at first ejaculation was increased and 57% of patients had never had sexual intercourse, although all patients reported normal sexual drive and normal erections. PMID:1929106
Although estimates of the incidence of reported child sexual maltreatment vary greatly, most authors agree there is a predominance of female to male victims. Yet studies of sexual offenders suggest afar greater proportion of male victims than is reported. This study compared circumstances surrounding the abuse for boy and girl victims. A total of 81 reported cases of malesexual
Edward D. Farber; Jacy Showers; Charles F. Johnson; Jack A. Joseph; Linda Oshins
Utilizing a 2 (lyrics: present or absent) × 2 (images: present or absent) design, this study examined the unique effects of sexually degrading music videos and music lyrics on males aggressive behavior toward women, as well as males endorsement of rape myths and sexual stereotypes. Under the guise of a media memory study, 187 male undergraduate students were randomly assigned
Eric L. Sprankle; Christian M. End; Miranda N. Bretz
In many species, successful mating requires the initial step of actively searching for and locating a female. The overall health or condition of a male is likely to affect their ability to do this, making search effort a potentially important component of sexual fitness that may have important consequences for population mean fitness. We investigated the potential population genetic consequences of search effort using 10 populations of Drosophila melanogaster, each fixed for a different recessive mutation with a visible phenotypic effect. Mate choice trials were conducted in arenas of varying size, requiring different levels of search ability. Sexual selection against mutant males was stronger when increased search effort was included than when it was excluded. Varying abilities to find mates can substantially increase the strength of selection against deleterious alleles.
MacLellan, Kelsie; Whitlock, Michael C.; Rundle, Howard D.
This study evaluated the effectiveness of an individual treatment program for five adult males who experienced childhood sexual abuse. A treatment manual focusing on abuse-related self-blame, anger, and anxiety was developed. Daily self-blame, anger, and anxiety self-ratings were completed before and throughout treatment. A multiple-baseline approach was used to evaluate treatment effects. Overall findings indicated that most participants experienced significant
Sexual differentiation in male marsupials has many similarities with that of eutherians. Marsupials have an XX-XY sex determining mechanism, and have a homologue of the testis-determining SRY gene on their Y-chromosome. However, the development pattern of SRY gene expression is different from the mouse in that it is expressed for a much longer period. SRY is expressed in a range
In the adult sexually experienced male rat, the intracerebroventricular (i.c.v.) injection of pinacidil, a KATP channel opener, at the dose of 100150300 ?\\/rat worsened the copulatory performance in the presence of a receptive female, whereas the administration of glibenclamide, a KATP channel blocker, at the dose of 0.5 and 3 mgkg intraperitoneally (i.p.) had an improving effect. These data indicate
A. Benelli; R. Arletti; R. Poggioli; E. Cavazzuti; M. Mameli; A. Bertolini
Prevention of recombination is needed to preserve both phenotypic differentiation between species and sexual phenotypic differentiation within species. For species differentiation (speciation), isolating barriers preventing recombination may be pre-zygotic (gamete transfer barriers), or post-zygotic (either a developmental barrier resulting in hybrid inviability, or a chromosomal-pairing barrier resulting in hybrid sterility). The sterility barrier is usually the first to appear and, although often initially only manifest in the heterogametic sex (Haldane's rule), is finally manifest in both sexes. For sexual differentiation, the first and only barrier is chromosomal-pairing, and always applies to the heterogametic sex. For regions of sex chromosomes affecting sexual differentiation there must be something analogous to the process generating the hybrid sterility seen when allied species cross. Explanations for Haldane's rule have generally assumed that the chromosomal-pairing barrier initiating evolutionary divergence into species is due to incompatibilities between gene products ("genic), or sets of gene products ("polygenic), rather than between chromosomes per se ("chromosomal"). However, if chromosomal incompatibilities promoting incipient sexual differentiation could also contribute to the process of incipient speciation, then a step towards speciation would have been taken in the heterogametic sex. Thus, incipient speciation, manifest as hybrid sterility when "varieties" are crossed, would appear at the earliest stage in the heterogametic sex, even in genera with homomorphic sex chromosomes (Haldane's rule for hybrid sterility). In contrast, it has been proposed that Haldane's rule for hybrid inviability needs differences in dosage compensation, so could not apply to genera with homomorphic sex chromosomes. PMID:10816367
Male-on-male rapes and sexual assaults comprise fewer than 10% of such assaults reported to the police, and so many physicians seldom encounter them. This paper provides an overview of the nature of sexual assault encountered by males, ensuing injuries, and comparisons with male-on-female assault cases. The retrospective epidemiological study was on two cohorts seen at St. Mary's Sexual Assault Referral Centre, Manchester. The participants were Centre clients seen between October 1986 and mid-May 2003; 376 male eases (370 individual clients) and 7,789 female cases (7,403 individual clients). The main outcome measure was the presence of injury (abrasion, laceration, or bruise) to defined body areas. The results showed that 66% of male cases (when assault type was known) had been raped, significantly fewer than in female cases, (p 0.00, a 0.05, O.R. 0.474, 95% C.I. 0.357 to 0.63). Eighteen per cent of male cases that had a forensic medical examination presented with an anal injury, significantly more than in females (p 0.00, a 0.05, O.R. 6.101, 95% C.I. 4.216 to 8.829). Significantly fewer males than females sustained injuries to other body areas. The conclusion was that males were significantly more likely (six times) than females to receive at least one injury to the anal area. Even so, males are five times more likely to have no anal injury. PMID:15176630
Cytoplasmic malesterility (CMS) in common bean is associated with the presence of a 3-kb unique mitochondrial sequence designated pvs. The pvs sequence encodes at least two open reading frames (297 and 720 bp in length) with portions derived from the chloroplast genome. Fertility restoration by the nuclear restorer gene Fr results in the loss of this transcriptionally active unique region. We examined the effect of CMS (pvs present) and fertility restoration by Fr (pvs absent) on the pattern of pollen development in bean. In the CMS line, pollen aborted in the tetrad stage late in microgametogenesis. Microspores maintained cytoplasmic connections throughout pollen development, indicating aberrant or incomplete cytokinesis. Pollen-specific events associated with pollen abortion and fertility restoration imply that a gametophytic factor or event may be involved in CMS. In situ hybridization experiments suggested that significant reduction or complete loss of the mitochondrial sterility-associated sequence occurred in fertile pollen of F2 populations segregating for fertility. These observations support a model of fertility restoration by the loss of a mitochondrial DNA sequence prior to or during microsporogenesis/gametogenesis.
We studied the efficiency of maintaining and restoring cytoplasmic malesterility (CMS) systems in pepper (Capsicum annuum L.). An Rf-linked molecular marker was employed to analyze the interaction between 6 CMS lines (A), 5 maintainers (B), and 6 restorers (C). Sterility was maintained in the matings of lines 201A x 200B, 203A x 200B, 206A x 200B, 200A x 201B, 206A x 201B, 200A x 202B, 200A x 203B, 200A x 206B, and 201A x 206B. All 6 restorers restored the fertility of lines 200A, 202A, 203A, and 204A, except that 213C could not restore the fertility of lines 200A and 204A. However, the 6 restorers had diverse restoring abilities in individual CMS lines. The Rf-linked molecular marker was amplified by PCR in lines 207C, 208C, and 213C. This DNA marker was only found in the F1 hybrids M39, M14, M19, M25, M13, M20, and M22. We conclude that the restorers 208C and 207C can transmit the Rf gene or the Rf-linked marker to F1 hybrids. PMID:23315867
Ma, Y; Huang, W; Ji, J-J; Gong, Z-H; Yin, C-C; Ahmed, S S; Zhao, Z-L
This study examined differences in male-perpetrated adult sexual assault experiences among women of various sexual orientations using a large urban convenience sample (N = 1,022). Results showed many similarities in disclosure to others, perceived helpfulness, and attributions of blame, but there were also differences by sexual orientation. Heterosexual women were more likely to experience completed sexual assault than lesbian or bisexual women. Lesbians were more likely to be assaulted by relatives than bisexual or heterosexual women. Finally, bisexual women disclosed the assault to the greatest number of formal support sources, were most likely to tell a romantic partner about the assault, received the fewest positive social reactions overall, and had higher posttraumatic stress disorder (PTSD) symptomatology. PMID:18225383
Long, Susan M; Ullman, Sarah E; Long, LaDonna M; Mason, Gillian E; Starzynski, Laura L
CONTEXT: Effects of zinc on malesexual competence are poorly understood. AIM: To study the effects of different doses of zinc on the sexual competence of males using a rat model. MATERIALS AND METHODS: Three subsets (eight in each subset) of sexually experienced adult male rats were supplemented with three different oral doses of zinc sulphate (a daily dose of 1 mg, 5 mg and 10 mg respectively) for two weeks. A subset of eight animals without zinc supplementation was used as the control group Sexual behavior was observed by placing them individually in cages with receptive females. STATISTICAL ANALYSIS: Data analysis was done using SPSS v10 for windows computer software. RESULTS: Supplementation of 5 mg of zinc/day for two weeks led to a prolongation of ejaculatory latency; 711.6 sec. (SEM 85.47) vs. 489.50 sec. (SEM 67.66), P < 0.05 and an increase in number of penile thrusting; 52.80 (SEM 11.28) vs. 26.50 (SEM 6.17), P < 0.05, compared to controls. The same group had elevated prolactin (PRL) and testosterone (T) levels compared to controls at the end of treatment period; PRL- 7.22 ng/dl (SEM 3.68) vs. 2.90 ng/dl (SEM 0.34) and T- 8.21 ng/ml (SEM 6.09) vs. 2.39 ng/ml (SEM 1.79), P < 0.05. In contrast, reduction of libido was evident in the same group, but this effect was not statistically significant (P > 0.05). However, partner preference index was positive and 5 mg zinc supplementation did not exert a significant adverse effect on the muscle strength and co-ordination. The subset of rats supplemented with 1 mg/day did not show a difference from the control group while supplementation with 10 mg/day led to a reduction of the libido index, number of mounts and intromissions. CONCLUSIONS: Zinc therapy improves sexual competence of male rats; the effect is dose dependent. Increase in the T levels is beneficial in this regard. However, increase in PRL is responsible for the reduced libido index. Further studies on pigs and monkeys are needed to evaluate the therapeutic use of zinc in sexual dysfunction.
Dissanayake, DMAB; Wijesinghe, PS; Ratnasooriya, WD; Wimalasena, S
Context: Effects of zinc on malesexual competence are poorly understood. Aim: To study the effects of different doses of zinc on the sexual competence of males using a rat model. Materials and Methods: Three subsets (eight in each subset) of sexually experienced adult male rats were supplemented with three different oral doses of zinc sulphate (a daily dose of 1 mg, 5 mg and 10 mg respectively) for two weeks. A subset of eight animals without zinc supplementation was used as the control group Sexual behavior was observed by placing them individually in cages with receptive females. Statistical Analysis : Data analysis was done using SPSS v10 for windows computer software. Results: Supplementation of 5 mg of zinc/day for two weeks led to a prolongation of ejaculatory latency; 711.6 sec. (SEM 85.47) vs. 489.50 sec. (SEM 67.66), P < 0.05 and an increase in number of penile thrusting; 52.80 (SEM 11.28) vs. 26.50 (SEM 6.17), P < 0.05, compared to controls. The same group had elevated prolactin (PRL) and testosterone (T) levels compared to controls at the end of treatment period; PRL- 7.22 ng/dl (SEM 3.68) vs. 2.90 ng/dl (SEM 0.34) and T- 8.21 ng/ml (SEM 6.09) vs. 2.39 ng/ml (SEM 1.79), P < 0.05. In contrast, reduction of libido was evident in the same group, but this effect was not statistically significant ( P > 0.05). However, partner preference index was positive and 5 mg zinc supplementation did not exert a significant adverse effect on the muscle strength and co-ordination. The subset of rats supplemented with 1 mg/day did not show a difference from the control group while supplementation with 10 mg/day led to a reduction of the libido index, number of mounts and intromissions. Conclusions : Zinc therapy improves sexual competence of male rats; the effect is dose dependent. Increase in the T levels is beneficial in this regard. However, increase in PRL is responsible for the reduced libido index. Further studies on pigs and monkeys are needed to evaluate the therapeutic use of zinc in sexual dysfunction. PMID:19881149
Dissanayake, Dmab; Wijesinghe, P S; Ratnasooriya, W D; Wimalasena, S
A hybrid gene was made by fusing the 2.2-kilobase 5' promoter region of a mouse group 1 major urinary protein (Mup) gene to the coding region of the herpes simplex virus type 1 thymidine kinase gene (HSV tk) and introduced into the genomes of mice by microinjection. Transgenic G0 males were sterile, or when fertile did not transmit the foreign gene, and the transgenic male descendants of G0 females were also sterile. Seven "lines" were established by breeding from G0 females and their transgenic female descendants. Six lines expressed HSV thymidine kinase activity in the liver, and activity correlated perfectly with the presence of HSV tk RNA. In three of four lines examined, expression was lower in female than in male liver, and in these lines the same sex difference was observed in the rate of run-on transcription of the foreign genes in liver nuclei. When females of one of the sexually dimorphic lines were treated with testosterone, the levels of HSV tk RNA and thymidine kinase activity were increased, although not to male levels. In these aspects of liver expression, and also in a lack of expression in seven other tissues, the hybrid gene exhibits many of the characteristics of an endogenous group 1 Mup gene. However, the gene was also expressed (at high levels) in the preputial gland and testis, two tissues in which Mup genes are not expressed. The gene, when introduced into five of the seven lines, carried a copy of the Escherichia coli supF gene attached beyond the 3' end of the HSV tk gene, but this did not affect the overall expression pattern. All of the lines were malesterile and expressed HSV thymidine kinase in the testis, but one line showed no activity in the liver, and another showed none in the preputial gland. Testicular expression is therefore the likely cause of sterility. Data are described which suggest that the causes of misexpression in the preputial gland and testis are different. Since expression in each tissue occurred in several lines, the structure of the hybrid gene must be responsible in each case. Five intensively studied lines showed at least four consistently different patterns of relative expression in preputial gland, testis, male liver, and female liver. These differences do not correlate in any way with the copy number of the foreign gene in the different lines and must be due to some other aspect of line specific integration. Images
Al-Shawi, R; Burke, J; Jones, C T; Simons, J P; Bishop, J O
Background Dengue is the most important mosquito-borne viral disease. In the absence of specific drugs or vaccines, control focuses on suppressing the principal mosquito vector, Aedes aegypti, yet current methods have not proven adequate to control the disease. New methods are therefore urgently needed, for example genetics-based sterile-male-release methods. However, this requires that lab-reared, modified mosquitoes be able to survive and disperse adequately in the field. Methodology/Principal Findings Adult male mosquitoes were released into an uninhabited forested area of Pahang, Malaysia. Their survival and dispersal was assessed by use of a network of traps. Two strains were used, an engineered genetically sterile (OX513A) and a wild-type laboratory strain, to give both absolute and relative data about the performance of the modified mosquitoes. The two strains had similar maximum dispersal distances (220 m), but mean distance travelled of the OX513A strain was lower (52 vs. 100 m). Life expectancy was similar (2.0 vs. 2.2 days). Recapture rates were high for both strains, possibly because of the uninhabited nature of the site. Conclusions/Significance After extensive contained studies and regulatory scrutiny, a field release of engineered mosquitoes was safely and successfully conducted in Malaysia. The engineered strain showed similar field longevity to an unmodified counterpart, though in this setting dispersal was reduced relative to the unmodified strain. These data are encouraging for the future testing and implementation of genetic control strategies and will help guide future field use of this and other engineered strains.
Our objective was to investigate the genitourinary defects and fertility of the male lysyl oxidase-like 1 gene (Loxl1) knockout (Loxl1(-/-)) mouse, with particular attention to fecundity and testicular, epididymal, gubernacular, and penile histopathology, which may lead us to a better understanding of the role of the elastin-homeostasis gene, LOXL1, in malesexual development. Genital morphometric evaluation of 6- to 9-month-old male Loxl1(-/-) mice (n = 26) was compared with C57Bl/6 controls (n = 24). Measurements included: body weight, scrotal development, evidence of feminization (nipples or vaginal pouch), penile malformations, anogenital distance, and absence/presence and size of perineal bulge. Sperm production was estimated using a standardized technique. A breeding program was conducted to determine how much of the infertility observed in Loxl1(-/-) pairs was due to the male factor. Finally, we performed histopathologic comparison of the genitourinary organs of Loxl1(-/-) and control mice. Loxl1(-/-) mice weighed less than their age-matched C57Bl/6 counterparts (P < .001). Size-adjusted perineal bulge was larger (P < .001), and resting location of the gonads was higher intra-abdominally (P = .048) in the Loxl1(-/-) mice. Estimates of daily sperm counts revealed that the Loxl1(-/-) mice had lower sperm production (P = .048). Loxl1(-/-) males bred with control females demonstrated relative fecundity values intermediate between Loxl1(-/-) pairs (lowest fecundity) and control pairs (highest fecundity), suggesting a component of male-factor infertility. No histologic differences were noted using hematoxylin-eosin or specialized elastin staining of the gonads, gubernaculum, and penis. Although further studies are warranted, these findings suggest a subtle and likely multifactorial role of the LOXL1 protein in malesexual development and fertility. PMID:19201700
Wood, Hadley M; Lee, Una J; Vurbic, Drina; Sabanegh, Edmund; Ross, Jonathan H; Li, Tiansen; Damaser, Margot S
A cytoplasm malesterile pepper (Capsicum annum L.) was examined using cytochemical method to study its pollen abortion. Thick sections of both anthers of malesterility line 8214A and its maintainer 8214B at different stages were stained using Periodic Acid-Schiff's (PAS) reaction to detect starch distribution. Anther structure and starch distribution in both anthers of malesterility and maintainer line were similar before the meiosis of microspore mother cells. After meiosis, the size of tapetal cells of fertile anthers of maintainer line increased and became high vacuolation. Abundant small starches appeared in the connective cells from tetrad stage to early stage of microspore development. At the late stage of microspore, the tapetal cells began to degenerate and the starches in the connective cells became large. Bi-cellular pollen synthesized starches after the large vacuole of vegetative cell disappeared, and abundant starches were stored in the mature pollen. In the anthers of malesterile line, meiosis of microspore mother could occurred and the tetrads could be formed in the locule, but the tetrads were extruded together because the locule could not enlarge its space. Finally, the tetrad microspores degenerated. The development of vascular tissue of the sterile anthers was normal and abundant starches were stored in the connective cells, which suggested that the function of plant transporting polysaccharide into anther was normal but tapetum could not transport the polysaccharide into locule. According to our result, the pollen abortion occurred in the tetrad stage and the abnormal development of tapetal cells might be the reason which induced tetrad microspore abortion in this malesterile pepper. PMID:18959002
This study was performed with male rats categorized as sexually naive (SN), sexually active (SA), or sexually inactive (SI). In a first experiment the effects of dopamine (DA) D2 agonist SND 919 (0.05, 1, and 10 mg/kg) on the copulatory behavior of SN, SA and SI rats were assessed. In a second experiment the DA D2 agonist B-HT 920 (0.2 mg/kg) was used, and examination was limited to SN and SA rats. The effects exerted on stretching-yawning, penile erection, and sedation by the same compounds at the same doses in these three rat categories were also investigated. The main findings were that SND 919 and B-HT 920 facilitated ejaculation in SA rats, and that the rats that were different as regards level of sexual activity exhibited different behavioral responses to the two DA agonists. PMID:8864270
Early puberty may increase lifetime reproductive success, but may also entail diverse costs. In male European ground squirrels (Spermophilus citellus), age at sexual maturity varies among individuals. We compared sexually active and inactive yearling males under standardized conditions in outdoor enclosures. Non-reproductive yearling males hibernated significantly longer than mature males and emerged when the mating period had already started. Testosterone
Anna Strauss; Elvira Mascher; Rupert Palme; Eva Millesi
To gather data on sexuality, specifically in male veterans, and to test the hypothesis that aged males remain interested in sexual intercourse yet suffer from erectile failure, veterans age 30 to 99 were surveyed. The mailed survey had 88 questions and was pretested on young potent males and aged impotent males. From 1031 randomly selected subjects, there were 806 replies:
Only high-quality males can bear the costs of an extreme sexual display. As a consequence, such males are not only more attractive, but they often live longer than average. Recent theory predicts, however, that high-quality males should sometimes invest so heavily in sexual displays that they die sooner than lower quality males. We manipulated the phenotypic quality of field crickets,
John Hunt; Robert Brooks; Michael D. Jennions; Michael J. Smith; Caroline L. Bentsen; Luc F. Bussière
Both intra- and inter-sexual selection may crucially determine a male's fitness. Their interplay, which has rarely been experimentally investigated, deter- mines a male's optimal reproductive strategy and thus is of fundamental importance to the understanding of a male's behaviour. Here we investigated the relative importance of intra- and inter-sexual selection for male fitness in the common lizard. We investigated which
P. S. FITZE; J. COTE; J. P. MARTÍNEZ-RICA; J. CLOBERT
Partial restoration of male fertility limits the use of C-type cytoplasmic malesterility (C-CMS) for the production of hybrid seeds in maize. Nevertheless, the genetic basis of the trait is still unknown. Therefore, the aim to this study was to identify genomic regions that govern partial restoration by means of a QTL analysis carried out in an F(2) population (n = 180). This population was derived from the Corn Belt inbred lines B37C and K55. F(2)BC(1) progenies were phenotyped at three locations in Switzerland. Male fertility was rated according to the quality and number of anthers as well as the anthesis-silking interval. A weak effect of environment on the expression of partial restoration was reflected by high heritabilities of all fertility-related traits. Partial restoration was inherited like an oligogenic trait. Three major QTL regions were found consistently across environments in the chromosomal bins 2.09, 3.06 and 7.03. Therefore, a marker-assisted counter-selection of partial restoration is promising. Minor QTL regions were found on chromosomes 3, 4, 5, 6 and 8. A combination of partial restorer alleles at different QTL can lead to full restoration of fertility. The maternal parent was clearly involved in the partial restoration, because the restorer alleles at QTL in bins 2.09, 6.04 and 7.03 originated from B37. The three major QTL regions collocated with other restorer genes of maize, a phenomenon, which seems to be typical for restorer genes. Therefore, a study of the clusters of restorer genes in maize could lead to a better understanding of their evolution and function. In this respect, the long arm of chromosome 2 is particularly interesting, because it harbors restorer genes for the three major CMS systems (C, T and S) of maize. PMID:21479555
This paper shows new evidence of a steady long-term decline in age of malesexual maturity since at least the mid-eighteenth century. A method for measuring the timing of male maturity is developed based on the age at which male young adult mortality accelerates. The method is applied to mortality data from Sweden, Denmark, Norway, the United Kingdom, and Italy. The secular trend toward earlier malesexual maturity parallels the trend toward earlier menarche for females, suggesting that common environmental cues influence the speed of both males' and females' sexual maturation.
The purpose of this study was to provide data addressing Diamond's (this issue) 4 problem areas in sexual orientation research by comparing gay, bisexual, and questioning male youth who report attempting suicide with those who do not. Secondary analyses were conducted with 2 datasets, 1 with a gay support group (n = 51) and the other with online youth (n = 681). Reported suicide attempts ranged from 39% among support-group youth, to 25% among Internet gay support group youth, to 9% among Internet non-support group youth. Sexual orientation, behavior, and identity did not predict suicidal attempt status, but suicide attempters experienced higher levels of both generic life stressors (low self-esteem, substance use, victimization) and gay-related stressors, particularly those directly related to visible (femininity) and behavioral (gay sex) aspects of their sexual identity. Support-group attendance was related to higher levels of suicidality and life stressors, as well as certain resiliency factors. Results suggest that there exists a minority of sexual-minority youth who are at risk but that it would be inappropriate to characterize the entire population as such. PMID:14710459
Summary This study examines the knowledge of sexually transmitted diseases (STDs) among male youths in Malaysia. A self-administered survey was carried out on a sample of 952 never-married males aged 15-24 years. The respondents were asked about their knowledge of STDs, how these diseases get transmitted and their sexual behaviours. The data showed that 92% of the respondents knew of at least one STD (syphilis, gonorrhoea, chlamydia, herpes, genital warts, yeast infection, trichomoniasis or HIV/AIDS). About 95% of them knew of at least one method of STD transmission. Urban and tertiary-educated male youths showed a substantially higher proportion of awareness of STDs and transmission methods compared with their rural and less-educated counterparts. The data also indicated that 10% of the study sample admitted to having had sexual experiences. There were still a large proportion of the respondents who were not aware of STDs other than syphilis and HIV/AIDS and the means of transmission, such as multiple sex partners, including those who claimed to be sexually active. Thus there is a need for more concerted efforts to disseminate information on STDs and transmission methods to a wider audience in Malaysia, especially youths in rural areas. PMID:23480474
Awang, Halimah; Wong, Li Ping; Jani, Rohana; Low, Wah Yun
Demographic parameters including operational sex ratio (OSR) and population density may influence the opportunity for, and strength of sexual selection. Traditionally, male-biased OSRs and high population densities have been thought to increase the opportunity for sexual selection on malesexual traits due to increased male competition for mates. Recent experimental evidence, however, suggests that male-biased OSRs might reduce the opportunity for sexual selection due to increased sexual coercion experienced by females. How OSR, density, and any resultant changes in the opportunity for sexual selection actually affect selection on malesexual traits is unclear. In this study, we independently manipulated OSR and density in the guppy (Poecilia reticulata) without altering the number of males present. We recorded male and female behavior and used DNA microsatellite data to assign paternity to offspring and estimate male reproductive success. We then used linear selection analyses to examine the effects of OSR and density on directional sexual selection on male behavioral and morphological traits. We found that females were pursued more by males in male-biased treatments, despite no change in individual male behavior. There were no differences in sexual behavior experienced by females or performed by males in relation to density. Neither OSR nor density significantly altered the opportunity for sexual selection. Also, Although there was significant multivariate linear selection operating on males, neither OSR nor density altered the pattern of sexual selection on male traits. Our results suggest that differences in either OSR or density (independent of the number of males present) are unlikely to alter directional evolutionary change in malesexual traits. PMID:18067568
To identify DNA markers linked to a fertility restorer (Rf) genefor Ogura cytoplasmic malesterility in radish (Raphanus sativus L.),a non-radioactive, amplified fragment length polymorphism (AFLP) analysiswas performed on bulked DNA samples from male-sterile and male-fertileradishes. Ten male-fertile and 10 male-sterile plants selected arbitrarilyfrom an F2 population made by selfing of F1 plant from a crossbetween a male-sterile (`MS-Gensuke') plant
|Examined family factors influencing sexual behavior among black and Hispanic adolescent males from San Bernardino County, California's 1996 Youth Survey. Family structure, parent sexual behaviors, and peer sexual norms closely associated with adolescent sexual attitudes and behaviors. Having a sibling who was a teen parent significantly
Rucibwa, Naphtal Kaberege; Modeste, Naomi; Montgomery, Susan; Fox, Curtis A.
Group home caregivers of 24 institutionalized, male, high-functioning adolescents and young adults with Autism Spectrum Disorder, were interviewed with the Interview Sexuality Autism. Most subjects were reported to express sexual interest and to display some kind of sexual behavior. Knowledge of socio-sexual skills existed, but practical use was
The effects of dopaminergic and opioidergic drugs on sexual incentive motivation were evaluated in sexually inexperienced male rats subjected to a choice procedure. Various parameters of ambulatory activity were recorded as well. Two drugs stimulating dopaminergic neurotransmission, amphetamine and apomorphine, failed to affect sexual incentive motivation, although ambulatory activity was enhanced by amphetamine. The dopamine antagonist cis(Z)-flupenthixol reduced sexual incentive
Presents research on the relationship of parenting processes to adolescent sexual behavior. An interaction effect was observed between parental communication about sexual issues and perceived parental support for males. For females, parental psychological control increased the odds that a sexually active daughter would take more sexual risks.
There is a wide body of literature to suggest that sexual experience may influence androgen secretion in various species, in turn, androgens may also influence anxiety. We hypothesized that sexual experience may alter anxiety behavior and secretion of endogenous androgens. Experiment 1: anxiety behavior of rats with a history of sexual experience was compared to that of sexually-inexperienced, naïve male
Anonymous data provided by 417 female and 179 malesexually active heterosexual respondents showed that in long term sexual relationships, sexual satisfaction was positively correlated with two different intimacy variables, the respondent's orgasm likelihood, and negatively correlated with conflict in the relationship. Multiple linear regression permitted us to measure the effect sizes of these variables as predictors of sexual satisfaction.
R. Vernon Haning; Stephen L. OKeefe; Elizabeth J. Randall; Martin J. Kommor; Elaine Baker; Robert Wilson
This paper presents interview data and media analysis on the gay male community in the USA. It describes how sexual objectification is more than the outcome of racism in the gay male community. Sexual objectification of gay men of colour in the USA produces a white sexual community. Ideologies of inclusivity and non?discrimination blind white gay men to the harmful
Aim of the studyThe root of Eurycoma longifolia Jack, native to South East Asia, has long been used as a male aphrodisiac remedy to treat sexual disorders.In the study we evaluated the influence of Eurycoma longifolia Jack on sexual behavior (including both motivation and copulatory performance) of sexually sluggish and impotent male rats.
Much attention has been devoted to understanding the evolution of elaborate male ornaments and how they may signal male quality. However, the evolution of multicomponent sexual signals remains poorly understood, and past research on this type of signaling has been largely theoretical. Satin bowerbirds, Ptilonorhynchus violaceus, are polygynous, are sexually dichromatic, and construct sexually selected display structures (bowers): a model
The purpose of this article is to demonstrate the traumatic impact that sexual abuse can have on a young male's development by addressing mediating dispositions that can render a child vulnerable to the effects of sexual abuse. Consideration is given to three different theoretical perspectives that are not exclusive to male victims but shed light on the impact that sexual
Terry Diamanduros; Clare E. Cosentino; P. Dawn Tysinger; Jeffrey A. Tysinger
Using the restriction endonucleases SaII, SmaI, BgII and KpnI, physical maps of chloroplast DNA isolated from normal and cytoplasmic malesterile (radish cytoplasm) lines of B. napus were constructed and compared. In this study, a rapid and simple procedure was developed for the isolation of chloroplast DNA restriction fragments from low gelling temperature agarose gels.
The inheritance of fertility restoration of six mitomycin C and streptomycin induced cytoplasmic male-sterile (cms) mutants and one cms line derived from Native American cultivar PI 432513 was evaluated. These cms sources were also compared with the commercially used cms PET1 (Helianthus petiolaris ...
Most of the alloplasmic cytoplasmic malesterility (CMS) systems are known to be associated with a number of floral abnormalities that result from nuclear-cytoplasmic incompatibilities. One such system, tour, which is derived from Brassica tournefortii, induces additional floral abnormalities and causes chlorosis in Brassica spp. While the restorer for this CMS has been reported to be present in B. napus,
N. Arumugam; A. Mukhopadhyay; V. Gupta; D. Pental; A. K. Pradhan
Fertility restoration of sorghum lines carrying the IS1112C (A3 group) sorghum male-sterile cytoplasm in the line A3Tx398 has been documented as a two-gene gametophytic mechanism involving complementary action of restoring alleles designated Rf3 and Rf4, as derived from IS1112C. Fertility restorat...
In selections of some more or less commonly grown onion varieties in the Netherlands the frequencies of genetical factors governing malesterility were determined. In the leading Dutch variety Rijnsburger the chromosomal factor ms was found to occur in a frequency of over 0.95 and the cytoplasmic factor S in a frequency of less than 0.01.
Defects in the human mitochondrial genetic system result in some diseases. These disorders are the result of rearrangements or point mutations in mitochondrial genes. In higher plants mutations and rearrangements in the mitochondrial DNA are believed to cause cytoplasmic malesterility (CMS), a mitochondrially inherited inability to produce viable pollen. In sorghum, formation of CMS is strongly correlated with anther-specific
The normal type (N) and cytoplasmic malesterile type T (cmsT) maize mitochondrial genomes are 570 kb and 540 kb in length respectively. Detailed hybridization studies have been undertaken to compare the sequence complexity and variation between the two genomes (genotype B37). They have approximately 500 kb of common sequences but there is considerable variation in sequence organization which can
Five accessions of members of the C group of malesterile maize cytoplasms (BB, C, ES, PR, and RB) in two nuclear backgrounds (A619 and A632) were examined to elucidate the nature of mitochondrial genome diversity within a related group of cytoplasms. Cosmid and plasmid clones carrying single copy and recombinationally active sequences from N and S cytoplasms of maize
D. R. Pring; D. M. Lonsdale; V. E. Gracen; A. G. Smith
Photoperiod-sensitive genic male-sterile rice has a number of desirable characteristics for hybrid rice production. Previous studies identified pms1, located on chromosome 7, as a major locus for photoperiod-sensitive genic malesterility. The objective of this study was to localize the pms1 locus to a specific DNA fragment by genetic and physical mapping. Using 240 highly sterile individuals and a random
N. Liu; Y. Shan; F. Wang; C. Xu; K. Peng; X. Li; Qifa Zhang
While numerous efforts have been made to understand the impact of child sexual abuse, little has been done to examine the childhood experiences of those who abuse children. Child sexual abusers have been studied from quantitative perspectives using behavioral checklists, parental-bonding surveys, and sexual history questionnaires. The purpose of this study was to explore incarcerated child sexual abusers' recollections of their childhood experiences using the descriptive existential lens of phenomenology. Eight incarcerated male child sexual abusers described their childhood from existential perspectives of lived space, lived other, lived body, and lived time via face-to-face semi-structured interviews. Analysis was accomplished through the qualitative, descriptive method of Max van Manen. Rich descriptions of the participants' insights into their daily childhood life experiences that shaped their self-concepts and contributed to their adult behaviors were gathered. Four major themes were identified: (1) failure to root, (2) what you see is what you learn, (3) stupid is as stupid does, and (4) life's moments. Data from this study suggest that the experiences of childhood significantly contribute to an adult self-concept that can be distorted by the lack of a secure home space, maladaptive relationships, internalization of inappropriate behavior, and a lack of significant family development. This study explores the psychosocial and behavioral consequences of early childhood experiences. The findings support the need for family and psychological mental health nurse practitioners to be more aware of early home environments; improve their assessment of children's developing self-concept and the potential for abusive relationships. PMID:20854041
To identify regions of the mitochondrial genome potentially involved in the expression of alloplasmic 'Tournefortii-Stiewe' cytoplasmic malesterility (CMS) in Brassica napus, transcripts of 25 mitochondrial genes were analysed in fertile and near isogenic male-sterile plants (BC 8 generation). Differences were detected in the transcription of genes for subunit 9 of ATP synthase ( atp9), cytochrome b ( cob) and
Sperm competition affects sexual selection intensity on males, but models suggest it cannot affect the relative intensity of sexual selection on males compared to females. However, if sperm competition depresses the payoff for male multiple mating, it could affect the relative intensity of sexual selection and even cause sexual selection to be more intense on females than males (reversal of
Mitochondrial DNA fragments of two nearly isogenic lines of sugar beet (Beta vulgaris L.) were amplified by RAPD analysis. A number of fragments, most of them unique to either the male-sterile or the male-fertile\\u000a cytoplasm, were selected for cloning and sequencing. One fragment was present in the PCR fingerprint pattern of both cytoplasms,\\u000a whereas five of the selected fragments were
In the leek moth, Acrolepiopsis assectella, the male, stimulated by a calling female, produces a sexual pheromone that is active on the female. The male-produced pheromone blend contains eight alkanes previously isolated from the male hair-pencils. We used EAG techniques to study the effect of the pheromone on females reared on leek or on artificial diet and on males reared
Reproductive behavior in male rodents is made up of anticipatory and consummatory elements which are regulated in the brain by sensory systems, reward circuits and hormone signaling. Gonadal steroids play a key role in the regulation of malesexual behavior via steroid receptors in the hypothalamus and preoptic area. Typical patterns of male reproductive behavior have been characterized, however these are not fixed but are modulated by adult experience. We assessed the effects of repeated sexual experience on male reproductive behavior of C57BL/6 mice; including measures of olfactory investigation of females, mounting, intromission and ejaculation. The effects of sexual experience on the number of cells expressing either androgen receptor (AR) or estrogen receptor alpha (ER?) in the primary brain nuclei regulating malesexual behavior was also measured. Sexually experienced male mice engaged in less sniffing of females before initiating sexual behavior and exhibited shorter latencies to mount and intromit, increased frequency of intromission, and increased duration of intromission relative to mounting. No changes in numbers of ER?-positive cells were observed, however sexually experienced males had increased numbers of AR-positive cells in the medial preoptic area (MPOA); the primary regulatory nucleus for malesexual behavior. These results indicate that sexual experience results in a qualitative change in male reproductive behavior in mice that is associated with increased testosterone sensitivity in the MPOA and that this nucleus may play a key integrative role in mediating the effects of sexual experience on male behavior.
Swaney, William T.; Dubose, Brittany N.; Curley, James P.; Champagne, Frances A.
The sexual health of young men is often neglected by health care systems that assume healthy developmental trajectories. Clinical morbidities and sexual concerns are not uncommon among sexually emerging young men. Sexually-transmitted infections, transient sexual dysfunction and lack of screening for genitourinary abnormalities contribute to this morbidity. This article discusses common sexual issues and concerns of adolescents and young adult
Interspecific F1 hybrid males of the Drosophila bipectinata species complex are sterile, while females are fertile, following Haldane's rule. A backcross scheme involving a single recessive visible marker on the X chromosome has been used to assess the putative roles of X-autosome and X-Y interactions in hybrid malesterility in the D. bipectinata species complex. The results suggest that X-Y interactions are playing the major role in hybrid malesterility in the crosses D. bipectinata x D. parabipectinata and D. bipectinata x D. pseudoananassae, while X-autosome interactions are largely involved in hybrid malesterility in the crosses D. malerkotliana x D. bipectinata and D. malerkotliana x D. parabipectinata. However, by using this single marker it is not possible to rule out the involvement of autosome-autosome interactions in hybrid malesterility. These findings also lend further support to the phylogenetic relationships among 4 species of the D. bipectinata complex. PMID:17893743
Gene expression differences between the sexes account for the majority of sexually dimorphic phenotypes, and the study of sex-biased gene expression is important for understanding the genetic basis of complex sexual dimorphisms. However, it has been difficult to test the nature of this relationship due to the fact that sexual dimorphism has traditionally been conceptualized as a dichotomy between males and females, rather than an axis with individuals distributed at intermediate points. The wild turkey (Meleagris gallopavo) exhibits just this sort of continuum, with dominant and subordinate males forming a gradient in male secondary sexual characteristics. This makes it possible for the first time to test the correlation between sex-biased gene expression and sexually dimorphic phenotypes, a relationship crucial to molecular studies of sexual selection and sexual conflict. Here, we show that subordinate male transcriptomes show striking multiple concordances with their relative phenotypic sexual dimorphism. Subordinate males were clearly male rather than intersex, and when compared to dominant males, their transcriptomes were simultaneously demasculinized for male-biased genes and feminized for female-biased genes across the majority of the transcriptome. These results provide the first evidence linking sexually dimorphic transcription and sexually dimorphic phenotypes. More importantly, they indicate that evolutionary changes in sexual dimorphism can be achieved by varying the magnitude of sex-bias in expression across a large proportion of the coding content of a genome.
Pointer, Marie A.; Harrison, Peter W.; Wright, Alison E.; Mank, Judith E.
Both natural selection and sexual selection may act on nest-building. We tested experimentally how different regimes of egg-predation and male-male competition influence nest-building before mating, using the marine fish sand goby, Pomatoschistus minutus. Males with sneaker males present built the smallest nest-openings, smaller than males held alone or with Pomatoschistus microps males (which may predate eggs and compete over nest-sites
There is evidence that risks for HIV and sexually transmitted infections among adolescent females are higher for those with\\u000a older malesexual partners. Yet, little empirical research has been conducted with male adolescents who engage in sexual activity\\u000a with older men. In this article, we summarize in a number of ways the range of sexual activity reported by an ethnically
Douglas BruceGary; Gary W. Harper; M. Isabel Fernández; Omar B. Jamil
In recent years there has been a steady increase in the amount of literature on perceptions of male victim of sexual assault. Much of this research focuses around the concept of victim blame. This paper reviews the research on perceptions of male victims of sexual assault, with particular reference to victim blame for male rape. The paper considers the conceptual
Conducted 7 experiments with Wistar rats, who were observed in a mating area equipped with a water spout, that revealed the emergence of displacement drinking and hindlimb scratching in noncopulating castrated males and in males with medial preoptic (MPO) lesions exposed to sexually attractive stimulus females. By contrast, sexually quiescent males in the postejaculatory refractory period showed no evidence of
Lifetime and current sexual and substance use behaviors were examined among 131 predominantly Hispanic and Black gay and bisexual adolescent males in New York City. Many youths engaged in anal sex with males (80%), and 22% bartered sex for money or drugs. Condom use with male partners typically was initiated one year after a youth became sexually active, was more
Margaret Rosario; Cheryl Koopman; Steven C. Dopkins; Mark Davies
We investigated how male Japanese quail (Coturnix coturnix japonica) learn through extensive social and sexual experience to discriminate between male and female conspecifics. Opportunity for heterosexual copulation was important for this learning, but even extensive copulatory opportunity was not sufficient to produce a sexual discrimination; subjects also required exposure to other males. Exposure to females after copulatory opportunity did not
Summary Transgenic mice are vital tools in both basic and applied research. Unfortunately, the transgenesis process as well as many other assisted reproductive techniques involving embryo transfer rely on vasectomized males to induce pseudopregnancy in surrogate mothers. Vasectomy is a surgical procedure associated with moderate pain and must be carried out under full anaesthesia by qualified personnel. Eliminating the need for vasectomy would be beneficial from the economic and animal welfare point of view. Our aim was to develop a transgene-based alternative to the surgical vasectomy procedure. We generated several transgenic mouse lines expressing a Protamine-1 (Prm1) EGFP fusion protein under the transcriptional and translational regulatory control of Prm1. Male mice from lines showing moderate transgene expression were fully fertile whereas strong overexpression of the Prm1-EGFP fusion protein resulted in complete and dominant malesterility without affecting the ability to mate and to produce copulatory plugs. Sterility was due to impaired spermatid maturation affecting sperm viability and motility. Furthermore, sperm having high Prm1-EGFP levels failed to support preimplantation embryonic development following Intracytoplasmic Sperm Injection (ICSI). The genetic vasectomy system was further improved by genetically linking the dominant malesterility to ubiquitous EGFP expression in the soma as an easy phenotypic marker enabling rapid genotyping of transgenic males and females. This double transgenic approach represents a reliable and cost-effective genetic vasectomy procedure making the conventional surgical vasectomy methodology obsolete.
MATEO, J. M., W. G. HOLMES, A. M. BELL AND M. TURNER. Sexual maturation in male prairie voles: Effects of the social environment. PHYSIOL BEHAV 56(2) 299-304, 1994.--The effects of various social contexts on sexual maturation in captive male prairie voles were investigated. Sexual maturity was assessed as the ability of a young male to produce urine capable of activating
J. M. MATEO; W. G. HOLMES; ANGELA M. BELL; MARJUT TURNER
Cytoplasmic malesterility (CMS) in commercial sunflower hybrids is thought to be derived from a related wild species, Helianthus petiolaris, yet CMS lines are known to carry the chloroplast DNA genotype of H. annuus. To clarify the origin of sunflower CMS, we developed a polymerase chain reaction-based strategy for detecting CMS in sunflower and surveyed more than 1,200 plants representing 55 accessions of H. annuus and 26 accessions of H. petiolaris. We also tested 160 progeny from three crosses for strict maternal inheritance of organelle DNAs to determine if the apparent discrepancy in the species donor of the mitochondrial DNA and chloroplast DNA genotypes in CMS lines might result from low-frequency maternal or biparental inheritance of either organelle. No CMS cytotypes were observed in natural populations of either H. annuus or H. petiolaris, and strict maternal inheritance of organelle DNA was observed. These data provide little insight, therefore, into the origin and population genetics of CMS in natural populations of sunflower, except that the evidence for strict maternal inheritance of organelles in sunflower makes it unlikely that the mtDNA and cpDNA genotypes in CMS lines were derived from different species. Nonetheless, the primers developed for assaying organelle DNA variation in sunflower may be useful tools for plant breeding programs, cytotype identification, and systematic and evolutionary studies in the domesticated sunflower and its relatives. PMID:8014465
Rieseberg, L H; Van Fossen, C; Arias, D; Carter, R L
The Arabidopsis thaliana MALESTERILITY1 (MS1) gene is critical for viable pollen formation and has homology to the PHD-finger class of transcription factors; however, its role in pollen development has not been fully defined. We show that MS1 transcription appears to be autoregulated by the wild-type MS1 transcript or protein. Using a functional green fluorescent protein (GFP) fusion to analyze the temporal and spatial expression of MS1, we demonstrate that the MS1:GFP protein is nuclear localized within the tapetum and is expressed in a developmentally regulated manner between late tetraspore and microspore release, then rapidly breaks down, probably by ubiquitin-dependent proteolysis. Absence of MS1 expression results in changes in tapetal secretion and exine structure. Microarray analysis has shown that 260 (228 downregulated and 32 upreglated) genes have altered expression in young ms1 buds. These genes are primarily associated with pollen wall and coat formation; however, a number of transcription factors and Cys proteases have also been identified as the putative primary regulatory targets of MS1. Ectopic expression of MS1 alters transcriptional regulation of vegetative gene expression, resulting in stunted plants with increased levels of branching, partially fertile flowers and an apparent increase in wall material on mature pollen. MS1 therefore plays a critical role in the induction of pollen wall and pollen coat materials in the tapetum and, ultimately, the production of viable pollen.
Yang, Caiyun; Vizcay-Barrena, Gema; Conner, Katie; Wilson, Zoe A.
Cytoplasmic malesterility (CMS) is a phenomenon widely observed in various plant species characterized with disrupted anther development caused by mitochondrial mutation. CMS is becoming a model system for the investigations of nucleus-cytoplasmic interaction. To reveal the possible effects of CMS genes on plant growth in adverse environment, plant development and biochemical characters of mitochondria from Honglian (HL)-CMS line Yuetai A and maintainer Yuetai B treated with H(2)O(2) were analyzed. Results showed that 40-60mM H(2)O(2) significantly inhibits rice seedling development and growth. When treated with H(2)O(2), ATP content and mitochondrial membrane potential in Yuetai A decreased significantly faster than those of Yuetai B. These biochemical changes were accompanied by the severe nuclear DNA fragmentation and the release of mitochondrial cytochrome c in the leaf cells of Yuetai A. In addition, the antioxidative enzyme activities and mitochondrial electron transfer chain complexes were significantly down-regulated. Disturbance of the biochemical indexes indicate that HL-CMS line is more susceptible to H(2)O(2) stress than the maintainer line, the deleterious effects caused by the CMS-related ORFH79 peptide compromises the adaptability of HL-CMS line to the adverse environment. PMID:22921008
S-type cytoplasmic malesterility (CMS-S) in maize is associated with high levels of a 1.6-kb RNA in mitochondria. This RNA contains two chimeric open reading frames (ORFs), orf355 and orf77. The previously described nuclear restorer-of-fertility allele Rf3 causes the processing of all transcripts that contain these chimeric ORFs. The Lancaster Surecrop-derived inbred line A619 carries a restorer that is distinct from Rf3 in that it selectively reduces only the CMS-S-specific 1.6-kb RNA. We have found that 10 additional Lancaster lines carry a single restoring allele traceable to either of two inbred lines, C103 and Oh40B. The C103 and Oh40B restorers are allelic to each other, but not to Rf3. Thus, this restoring allele, designated Rf9, represents a second naturally occurring CMS-S restorer in maize. Rf9 is a less effective restorer of fertility than is Rf3; its expression is influenced by both inbred nuclear background and temperature. Rf9 acts to reduce the amounts of orf355/orf77-containing linear mitochondrial subgenomes, which are generated by recombination of circular subgenomes with CMS-S-specific linear plasmids. The 1.6-kb RNA, which is transcribed only from linear ends, is correspondingly reduced.
The nna1 gene mutation is associated with spontaneous degeneration of cerebellar Purkinje cells and germ cells in Ataxia and MaleSterility (AMS) mouse. Since nna1 is also expressed in hippocampal neurons, we investigated their vulnerability to hypoperfusion in AMS mouse. Eight-week-old male wild type (WT) and AMS mice were subjected to bilateral common carotid artery occlusion (BCCAO) for 10 min and sacrificed 1, 3, 7 and 28 days after BCCAO. Nissl staining revealed the neuronal cell loss and pyknotic change in the CA1 of AMS mice. TUNEL(+) apoptotic cells were found in the area at 7 days in AMS mice. Bcl-2 mRNA and protein in WT hippocampus were increased, while they were not increased in AMS. Bax mRNA was increased in AMS. Moreover, Bax activation was immunohistochemically demonstrated only in AMS at 3 and 7 days after BCCAO. An oxidative DNA damage marker, 8-hydroxydeoxyguanosine-positive cells were increased in both strains at 1 day; decreased in WT at 3 days but remained high in AMS. BCCAO increased glutathione, an antioxidant, in WT, but not in AMS at 3 days. The mRNA level of mitochondrial uncoupling protein 2, a regulator of oxidative stress, was increased only in WT at 1 day. Nna1 mRNA was similarly expressed in WT and AMS, but the protein was undetectable in AMS. Thus, our results indicate the increased vulnerability of hippocampal CA1 neurons of AMS mice to cerebral hypoperfusion could be due to an imbalance between oxidative stress and antioxidative defense system. PMID:23219973
Data from cDNA-AFLP analysis based on the genome-wide transcriptional profiling on the flower buds of the male meiotic cytokinesis (mmc) mutant and its wild-type of Brassica campestris L. ssp. chinensis Makino, syn. B. rapa L. ssp. chinensis, indicated that mutation of the MMC gene resulted in changes in expression of a variety of genes. A transcript-derived fragment specifically accumulated in the wild-type flower buds was isolated, and the corresponding full-length cDNA and DNA was subsequently amplified. Bioinformatical analyses of this gene named BcMF15 (GenBank accession number EF600901) showed that it encoded a protein with 103 amino acids. The BcMF15 had a 88% nucleotide similarity to a lipid transfer protein-like gene. Moreover, sequence prediction indicated that BcMF15 might encode a membrane protein with a signal peptide at the N-terminus. Meanwhile, six domains were predicted in the deduced BcMF15 protein, such as the AAI domain existing in some crucial proteins of pollen development-preferential, signal peptide, transmembrane domain, vWF domain, ZnF_C4 domain, and Tryp_alpha_amyl domain. Spatial and temporal expression patterns analysis by RT-PCR indicated that BcMF15 was exclusively expressed in the fertile line, which indicated this gene is malesterile related. Phylogenetic analysis in Cruciferae revealed that the BcMF15 was relative conservative in evolution. We suppose BcMF15 may be a critical molecule in the transmembrane transportation and signal transduction during microspore development. PMID:18034318
Tian, Aimei; Cao, Jiashu; Huang, Li; Yu, Xiaolin; Ye, Wanzhi
Background: The genetic basis of postzygotic isolation is a central puzzle in evolutionary biology. Evolutionary forces causing hybrid sterility or inviability act on the responsible genes while they still are polymorphic, thus we have to study these traits as they arise, before isolation is complete. Methodology\\/Principal Findings: Isofemale strains of D. mojavensis vary significantly in their production of sterile F1
Laura K. Reed; Brooke A. LaFlamme; Therese A. Markow
We have previously shown that the expression of an unedited atp9 chimeric gene correlated with male-sterile phenotype in transgenic tobacco plant. To study the relationship between the expression of chimeric gene and the male-sterile trait, hemizygous and homozygous transgenic tobacco lines expressing the antisense atp9 RNA were constructed. The antisense producing plants were crossed with a homozygous male-sterile line, and the F1 progeny was analyzed. The offspring from crosses between homozygous lines produced only male-fertile plants, suggesting that the expression antisense atp9 RNA abolishes the effect of the unedited chimeric gene. In fact, the plants restored to male fertility showed a dramatic reduction of the unedited atp9 transcript levels, resulting in normal flower development and seed production. These results support our previous observation that the expression of unedited atp9 gene can induce malesterility. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4
Zabaleta, E; Mouras, A; Hernould, M; Suharsono; Araya, A
This study was designed to control plant fertility by cell lethal gene Barnase expressing at specific developmental stage and in specific tissue of male organ under the control of Cre/loxP system, for heterosis breeding, producing hybrid seed of eggplant. The Barnase-coding region was flanked by loxP recognition sites for Cre-recombinase. The eggplant inbred/pure line (E-38') was transformed with Cre gene and the inbred/pure line (E-8') was transformed with the Barnase gene situated between loxp. The experiments were done separately, by means of Agrobacterium co-culture. Four T0 -plants with the Barnase gene were obtained, all proved to be male-sterile and incapable of producing viable pollen. Flowers stamens were shorter, but the vegetative phenotype was similar to wild-type. Five T 0 -plants with the Cre gene developed well, blossomed out and set fruit normally. The crossing of male-sterile Barnase-plants with Cre expression transgenic eggplants resulted in site-specific excision with the male-sterile plants producing normal fruits. With the Barnase was excised, pollen fertility was fully restored in the hybrids. The phenotype of these restored plants was the same as that of the wild-type. Thus, the Barnase and Cre genes were capable of stable inheritance and expression in progenies of transgenic plants.
The mitochondrial genome of the S-type male-sterile cytoplasm of maize contains two linear episomes, S1 (6397 base pairs) and S2 (5453 base pairs). The S2 episome contains two large unidentified open reading frames, URF1 (3512 base pairs) and URF2 (1017 base pairs). We have demonstrated that a polypeptide with an apparent molecular mass of 130 kDa is the gene product of URF1. This polypeptide was first detected in Coomassie blue-stained protein gels of cms-S (where cms = cytoplasmic malesterile) but not in those of cms-T, cms-C, or normal mitochondrial proteins. The protein product of a translational fusion containing the 5? end of Escherichia coli lacZ and an internal segment from URF1 of S2 was recognized by antisera raised against the 130-kDa variant polypeptide. The mitochondria of fertile F1 hybrids of cms-S × Ky21 (the male parent carrying nuclear fertility restoration genes) contain as much of the 130-kDa protein as is found in cms-S mitochondria of sterile plants. Spontaneous fertile cytoplasmic revertants from cms-S in a WF9 nuclear background also synthesized the 130-kDa polypeptide. Therefore, the mere presence or absence of the URF1 gene product of S2 does not determine the fertility status of maize plants, because malesterile and male fertile (nuclear restored and revertant) plants can contain equivalent amounts of the 130-kDa polypeptide. Images
A two-line system using photoperiod-sensitive cytoplasmic malesterility (PCMS) caused by Aegilops crassa cytoplasm under long-day photoperiods (?15 h) has been proposed as a means of producing hybrid varieties in common wheat\\u000a (Triticum aestivum). The PCMS line is maintained by self-pollination under short-day conditions, and hybrid seeds can be produced through outcrossing\\u000a of the PCMS line with a pollinator line under
Summary 1. In animals, male reproduction is commonly a function of sexual attractiveness, based on the expression of sexually dimorphic traits that advertise genuinely the male's quality. Male performance may decline with age because physiological functions underlying sexual attractiveness may be affected by senescence. 2. Here we show that a sexual signal (foot colour) declines with age, due probably to
Maize mitochondrial (mt) tRNA genes were localized on the mt master circles of two fertile lines (WF9-N and B37-N) and of one cytoplasmic malesterile line (B37-cmsT) of maize. The three genomes contain 16 tRNA genes with 14 different anticodons which correspond to 13 amino acids. Out of these 16 tRNA genes, 6 show a high degree of homology with the corresponding chloroplast (cp) tRNA genes and were shown to originate from cp DNA insertions and to be expressed in the mitochondria. The organization of the mt tRNA genes in both fertile lines is similar. The same genes are found, in the same environment, as judged from the restriction maps, in fertile and malesterile lines that have the same nuclear background, but the relative organization of the mt tRNA genes on the master circle is completely different. PMID:1701208
Sangaré, A; Weil, J H; Grienenberger, J M; Fauron, C; Lonsdale, D
We have shown previously, using a reinstatement procedure, that both priming injections of heroin and exposure to footshock stress reinstate heroin-taking behavior following prolonged drug-free periods. In the present study, we examined the effect of another highly arousing event, exposure to a sexually active female, on reinstatement of heroin-seeking. Male rats were first given sexual experience, being allowed to copulate on 4 occasions with sexually active females and were then trained to self-administer heroin (100 micrograms/kg per infusion, IV) for 4 3-h sessions/day for 5-6 days and 1 6-h session/day for an additional 6 days. Extinction sessions were then given for 4 days, 6-h/day, during which saline was substituted for heroin. On tests for reinstatement, males were presented with: 1. The wire-mesh side of an empty cage (baseline condition), 2. the sight, odor, and smell of a sexually inactive female, 3. the sight, odor, and smell of a female in heat, 4. a female in heat, and allowed to copulate, 5. intermittent footshock (15 min, 0.5 mA, 0.5 s on, mean off period of 40 s), or 6. a priming injection of heroin (0.25 mg/kg, SC). Reinstatement of heroin-taking behavior was observed after exposure to the priming injection of heroin and to footshock stress. Reinstatement of heroin-taking behavior was not induced by exposure to the females in any of the conditions. Thus, motivational arousal, as such, does not appear to be a sufficient stimulus for relapse to heroin-taking. PMID:9035267
Results are given of genetic studies of malesterility using plants from two natural populations from Sussex, England. Both populations have substantial frequencies of females, z0.25 in population 1 and 0.60 in population 3. As in the few other gynodioecious populations studied in detail, many genetic factors are present. In population 1, there are at least two, and more likely
Background Plant mitochondria, semiautonomous organelles that function as manufacturers of cellular ATP, have their own genome that has\\u000a a slow rate of evolution and rapid rearrangement. Cytoplasmic malesterility (CMS), a common phenotype in higher plants, is\\u000a closely associated with rearrangements in mitochondrial DNA (mtDNA), and is widely used to produce F1 hybrid seeds in a variety\\u000a of valuable crop species.
Summary The primary goal of this study was to establish callus cultures of selected plant taxa containing both normal (N) and cytoplasmic\\u000a male-sterile (CMS) lines. A secondary goal was to attempt to differentiate the calli into whole flowering plants. Undifferentiated\\u000a and organ differentiated calli were produced in specific lines of N and CMS sorghum, pepper, sunflower, and tobacco. Calli\\u000a from both
Mitochondrial (mt) DNA from eight cytoplasmic male-sterile (cms) lines of sugar beet from different breeding stations was investigated by restriction fragment analysis and Southern hybridization. All cms lines showed similar but not identical restriction and hybridization signal patterns, readily distinguishable from those of fertile (N) cytoplasm. Digestion of the mtDNA with BamHI, EcoRI, SalI, and XhoI revealed distinct differences between
A. Weihe; N. A. Dudareva; S. G. Veprev; S. I. Maletsky; R. Melzer; R. I. Salganik; Th. Börner
Plants carrying Texas male-sterile (Tms) cytoplasm are normally sensitive to Drechslera maydis T-toxin. Tissue cultures were initiated from immature embryos of maize carrying Tms-cytoplasm, and plants were regenerated after selection for resistance to T-toxin. Fertile, T-toxin resistant plants were obtained from the unselected control cultures as well as from the selected material. In addition, one regenerant from an unselected culture
A male-sterile (MS) radish (Raphanus sativus L.) was found in an accession collected from Uzbekistan. Unlike Ogura MS radishes in which no pollen grain is typically visible\\u000a during anthesis, a small number of pollen grains stuck together in the dehiscing anthers was observed in the newly identified\\u000a MS radish. Fluorescein diacetate tests and scanning electron micrographs showed that pollen grains
Maize mitochondrial (mt) tRNA genes were localized on the mt master circles of two fertile lines (WF9-N and B37-N) and of one cytoplasmic malesterile line (B37-cmsT) of maize. The three genomes contain 16 tRNA genes with 14 different anticodons which correspond to 13 amino acids. Out of these 16 tRNA genes, 6 show a high degree of homology with
Abdourahamane Sangaré; Jacques-Henry Weil; Jean-Michel Grienenberger; Christiane Fauron; David Lonsdale
High resolution gel electrophoresis has allowed the assignment of fragment number and molecular weight to EcoRI, Sal1 and PstI restriction fragments of mitochondrial DNA from B37 normal (N) and B37 T, C and S malesterile cytoplasmic types of maize. A minimum complexity of 450-475 kb has been established. Hybridization of cloned EcoRI fragments to restriction digests of total mitochondrial
Despite considerable interest in the sexual behavior of nondisclosing men who have sex with men and women (MSMW), little is known about where they meet their male and female partners and whether their sexual risk behavior differs with partners met in different sexual venues (e.g., bars, Internet, parks). These issues were examined among 46 non-gay-identified MSMW who had not disclosed
Eric W. Schrimshaw; Karolynn Siegel; Martin J. Downing Jr
Study Objective Sexual reference display on a social networking web site (SNS) is associated with self-reported sexual intention; females are more likely to display sexually explicit content on SNSs. The purpose of this study was to investigate male college students' views towards sexual references displayed on publicly available SNSs by females. Design Focus groups Setting One large state university Participants Male college students age 1823 Interventions All tape recorded data was fully transcribed, then discussed to determine thematic consensus. Main Outcome Measures A trained male facilitator asked participants about views on sexual references displayed on SNSs by female peers and showed examples of sexual references from female's SNS profiles to facilitate discussion. Results A total of 28 heterosexual male participants participated in 7 focus groups. Nearly all participants reported using Facebook to evaluate potential female partners. Three themes emerged from our data. First, participants reported that displays of sexual references on social networking web sites increased sexual expectations. Second, sexual reference display decreased interest in pursuing a dating relationship. Third, SNS data was acknowledged as imperfect but valuable. Conclusion Females who display sexual references on publicly available SNS profiles may be influencing potential partners' sexual expectations and dating intentions. Future research should examine females' motivations and beliefs about displaying such references, and educate women about the potential impact of these sexual displays.
Moreno, Megan A.; Swanson, Michael J.; Royer, Heather; Roberts, Linda J.
Sexual size dimorphism may evolve as a result of both natural and sexual selection. In polygynous mammals, the main factor resulting in the evolution of large body size in males is the advantage conferred during competition for mates. In this study, we examined whether sexual selection acts on body size in mature fallow bucks (Dama dama) by examining how the
Alan G. McElligott; Martin P. Gammell; Hilda C. Harty; Dean R. Paini; Desmond T. Murphy; James T. Walsh; Thomas J. Hayden
This book links research on two topics--sexual assault on North American college and university campuses and the role played by male peer support in such assaults. Disputing the notion that college campuses are safe havens from crime, the first chapter defines sexual assault, notes the incidence and prevalence of campus sexual assault, and
This study examined the prevalence of and risk factors for sexual abuse of boys in South Korea by asking a national sample of 1,043 adult males whether they had experienced sexual abuse during childhood. The results indicate that 13.5% experienced at least one of the nine types of child sexual abuse assessed. In addition, the majority of the
Han, In Young; Lee, Yongwoo; Yoo, Seo Koo; Hong, Jun Sung
It is well documented that childhood sexual abuse is associated with deleterious outcomes in the areas of anxiety, depression, and sexual functioning. However, very little research has been conducted to specifically investigate childhood sexual abuse's relationship to adult social anxiety in both males and females. Participants included 250
This paper presents data from a series of prelimary neuropsychiatric studies, including neuropsychological, personality, sexual history, plethysmographic and neuroimaging investigations, on a sample of 22 male, heterosexual, nonexclusive pedophiles and 24 demographically similar healthy controls. A psychobiological model of pedophilia is proposed, positing that early childhood sexual abuse leads to neurodevelopmental abnormalities in the temporal regions mediating sexual arousal and
Lisa J. Cohen; Konstantin Nikiforov; Sniezyna Gans; Olga Poznansky; Pamela McGeoch; Carrie Weaver; Enid Gertmanian King; Ken Cullen; Igor Galynker
|This book links research on two topics--sexual assault on North American college and university campuses and the role played by male peer support in such assaults. Disputing the notion that college campuses are safe havens from crime, the first chapter defines sexual assault, notes the incidence and prevalence of campus sexual assault, and
An unusual pollination strategy is pollination by sexual deception in which orchids sexually attract male insects as pollinators. One gap in knowledge concerns the pattern and extent of pollinator movement among these sexually deceptive flowers and how this translates to pollen and gene flow. Our aim was to use mark and recapture techniques to investigate the behavior and movement of
Spontaneous reversion to pollen fertility and fertility restoration by the nuclear gene Fr in cytoplasmic malesterile common bean (Phaseolus vulgaris L.) are associated with the loss of a large portion of the mitochondrial genome. To understand better the molecular events responsible for this DNA loss, we have constructed a physical map of the mitochondrial genome of a stable fertile revertant line, WPR-3, and the cytoplasmic malesterile line (CMS-Sprite) from which it was derived. This involved a cosmid clone walking strategy with comparative DNA gel blot hybridizations. Mapping data suggested that the simplest model for the structure of the CMS-Sprite genome consists of three autonomous chromosomes differing only in short, unique regions. The unique region contained on one of these chromosomes is the malesterility-associated 3-kb sequence designated pvs. Based on genomic environments surrounding repeated sequences, we predict that chromosomes can undergo intra- and intermolecular recombination. The mitochondrial genome of the revertant line appeared to contain only two of the three chromosomes; the region containing the pvs sequence was absent. Therefore, the process of spontaneous cytoplasmic reversion to fertility likely involves the disappearance of an entire mitochondrial chromosome. This model is supported by the fact that we detected no evidence of recombination, excision or deletion events within the revertant genome that could account for the loss of a large segment of mitochondrial DNA.
The hybrid pigeonpea (Cajanus cajan) breeding technology based on cytoplasmic malesterility (CMS) is currently unique among legumes and displays major potential for yield increase. CMS is defined as a condition in which a plant is unable to produce functional pollen grains. The novel chimeric open reading frames (ORFs) produced as a results of mitochondrial genome rearrangements are considered to be the main cause of CMS. To identify these CMS-related ORFs in pigeonpea, we sequenced the mitochondrial genomes of three C. cajan lines (the male-sterile line ICPA 2039, the maintainer line ICPB 2039, and the hybrid line ICPH 2433) and of the wild relative (Cajanus cajanifolius ICPW 29). A single, circular-mapping molecule of length 545.7 kb was assembled and annotated for the ICPA 2039 line. Sequence annotation predicted 51 genes, including 34 protein-coding and 17 RNA genes. Comparison of the mitochondrial genomes from different Cajanus genotypes identified 31 ORFs, which differ between lines within which CMS is present or absent. Among these chimeric ORFs, 13 were identified by comparison of the related male-sterile and maintainer lines. These ORFs display features that are known to trigger CMS in other plant species and to represent the most promising candidates for CMS-related mitochondrial rearrangements in pigeonpea.
Tuteja, Reetu; Saxena, Rachit K.; Davila, Jaime; Shah, Trushar; Chen, Wenbin; Xiao, Yong-Li; Fan, Guangyi; Saxena, K. B.; Alverson, Andrew J.; Spillane, Charles; Town, Christopher; Varshney, Rajeev K.
The hybrid pigeonpea (Cajanus cajan) breeding technology based on cytoplasmic malesterility (CMS) is currently unique among legumes and displays major potential for yield increase. CMS is defined as a condition in which a plant is unable to produce functional pollen grains. The novel chimeric open reading frames (ORFs) produced as a results of mitochondrial genome rearrangements are considered to be the main cause of CMS. To identify these CMS-related ORFs in pigeonpea, we sequenced the mitochondrial genomes of three C. cajan lines (the male-sterile line ICPA 2039, the maintainer line ICPB 2039, and the hybrid line ICPH 2433) and of the wild relative (Cajanus cajanifolius ICPW 29). A single, circular-mapping molecule of length 545.7 kb was assembled and annotated for the ICPA 2039 line. Sequence annotation predicted 51 genes, including 34 protein-coding and 17 RNA genes. Comparison of the mitochondrial genomes from different Cajanus genotypes identified 31 ORFs, which differ between lines within which CMS is present or absent. Among these chimeric ORFs, 13 were identified by comparison of the related male-sterile and maintainer lines. These ORFs display features that are known to trigger CMS in other plant species and to represent the most promising candidates for CMS-related mitochondrial rearrangements in pigeonpea. PMID:23792890
Tuteja, Reetu; Saxena, Rachit K; Davila, Jaime; Shah, Trushar; Chen, Wenbin; Xiao, Yong-Li; Fan, Guangyi; Saxena, K B; Alverson, Andrew J; Spillane, Charles; Town, Christopher; Varshney, Rajeev K
The relevance of the social contact test Wall for evaluation of sexual motivation of male mice was tested and confirmed. Motivation of C57BL\\/6J male mice with alternative social experience (winners and victims in 10 and 20 daily male-male confrontations) was evaluated. Elevated primary sexual interest was detected in aggressive animals after 10 confrontations, while in submissive animals this interest was
Sexual selection can act through female choice and malemale competition. Although both processes can act simultaneously,\\u000a they are typically studied independently. Here, we adopt a more integrated approach to studying sexual selection by incorporating\\u000a measures of both processes using the western rainbowfish Melanotaenia australis, a freshwater fish endemic to northwestern Australia. We assessed malemale competition and female choice separately while
Michael J. Young; Leigh W. Simmons; Jonathan P. Evans
Objectives To assess differences in sexual health behaviors, outcomes, and potential sociocultural determinants among male college students in the United States and the Netherlands. Methods Survey data were collected from random samples of students from both national cultures. Results American men were more likely to report inadequate contraception, HIV/STD infection, and unintended pregnancy than were Dutch men. Religiosity and sexuality education were able to explain national differences in these sexual health outcomes. Conclusions Findings suggest that sexuality education seems to decrease, rather than increase, sexual risk in heterosexually active male college students.
Dodge, Brian; Sandfort, Theo G. M.; Yarber, William L.; de Wit, John
About 10 years ago, a sexually differentiated nucleus was identified in the preoptic area (POA) of the Japanese quail in the course of studies analyzing the dimorphic mechanisms involved in the activation of sexual behavior. In this species, males exposed to testosterone copulate while females never show this masculine behavior. The present paper reviews anatomical, neurochemical, and functional data that
Gian Carlo Panzica; Carla Viglietti-Panzica; Jacques Balthazart
|Male college students (N = 395) completed anonymous surveys to report personal attitudes supporting sexual aggression and estimated the attitudes of their peers. Participants also indicated their willingness to intervene against a peer if they witnessed sexual aggression. Although both personal and peer attitudes were correlated with willingness
Male college students (N = 395) completed anonymous surveys to report personal attitudes supporting sexual aggression and estimated the attitudes of their peers. Participants also indicated their willingness to intervene against a peer if they witnessed sexual aggression. Although both personal and peer attitudes were correlated with willingness
This research draws on in-depth, one-on-one interviews with a racially and ethnically diverse sample of 17 adolescent males,\\u000a both virgins and non-virgins, to explore how they use talk to construct their sexual selves and present themselves as sexual\\u000a decision-makers. The emphasis here is how some of the boys (n = 8) drew upon a particular discourse in their self-productions and implicated male
Dominant genic malesterility (DGMS) is an important approach to utilize the heterosis of Brassica napus, but the molecular mechanism of DGMS is not well understood. As an initial step towards understanding this event, some pilot studies were performed. Using suppression subtractive hybridization (SSH) and cDNA microarray, about 1200 significantly differentially expressed clones were isolated between the fertile and sterile
Genetic analysis of hybrid sterility and inviability has recently become a successful experimental approach to pursue the problem of speciation. In the present study, classical genetic analyses and high resolution two-dimensional gel electrophoresis (2DE) have been used to investigate the genetic basis of hybrid malesterility in three sibling species of the Drosophila melanogaster species subgroup. The genetic basis of
Haldane's rule (i.e., the preferential hybrid sterility and inviability of heterogametic sex) has been known for 70 years, but its genetic basis, which is crucial to the understanding of the process of species formation, remains unclear. In the present study, we have investigated the genetic basis of hybrid malesterility using Drosophila simulans, Drosophila mauritiana and Drosophila sechellia. An introgression
The topic of same-sex sexual initiation has generally remained understudied in the literature on sexual identity formation among sexual minority youth. This article analyzes the narratives of same-sex sexual initiation provided by 76 gay and bisexual Mexican immigrant men who participated in interviews for the Trayectos Study, an ethnographic study of sexuality and HIV risk. These participants were raised in a variety of locations throughout Mexico, where they also realized their same-sex attraction and initiated their sexual lives with men. We argue that Mexican male same-sex sexuality is characterized by three distinct patterns of sexual initiation--one heavily-based on gender roles, one based on homosociality, and one based on object choice--which inform the men's interpretations regarding sexual roles, partner preferences, and sexual behaviors. We analyzed the social factors and forms of cultural/sexual socialization that lead sexual minority youth specifically to each of these three patterns of sexual initiation. Our findings confirm the importance of studying same-sex sexual initiation as a topic in its own right, particularly as a tool to gain a greater understanding of the diversity of same-sex sexual experiences and sexual identities within and among ethnic/cultural groups. PMID:20838869
The topic of same-sex sexual initiation has generally remained understudied in the literature on sexual identity formation among sexual minority youth. This article analyzed the narratives of same-sex sexual initiation provided by 76 gay and bisexual Mexican immigrant men who participated in interviews for the Trayectos Study, an ethnographic study of sexuality and HIV risk. These participants were raised in a variety of locations throughout Mexico, where they also realized their same-sex attraction and initiated their sexual lives with men. We argue that Mexican male same-sex sexuality is characterized by three distinct patterns of sexual initiation-- one heavily-based on gender roles, one based on homosociality, and one based on object choice-- which inform the mens interpretations regarding sexual roles, partner preferences, and sexual behaviors. We analyzed the social factors and forms of cultural/sexual socialization that lead sexual minority youth specifically to each of these three patterns of sexual initiation. Our findings confirm the importance of studying same-sex sexual initiation as a topic in its own right, particularly as a tool to gain a greater understanding of the diversity of same-sex sexual experiences and sexual identities within and among ethnic/cultural groups.
|This study examines sexuality and HIV/AIDS prevention knowledge among minority ethnic male youth of Bangladesh. A cross-sectional survey was conducted through a self-administered questionnaire on 800 young males aged 15-24 years in the Chittagong Hill Tracts region in 2009. Of the respondents, almost one-third were sexually active and of them
|The authors used qualitative research methods to explore the context and sexual risk behavior associated with sexual intercourse involving multiple males and one female, commonly called "running a train." Participants were 20 adolescent males aged 14 to 22 years who were either perpetrators of dating violence or perceived by teachers to be at
Rothman, Emily F.; Decker, Michele R.; Reed, Elizabeth; Raj, Anita; Silverman, Jay G.; Miller, Elizabeth
This exploratory investigation examined the relationship between childhood sexual abuse (CSA) and related psychosocial characteristics and sexual behaviors among 46 gay\\/bisexual male escorts who advertise via the Internet. More than a quarter of men (28.3%) reported some history of CSA. Men reporting CSA were more likely to be from an ethnic minority group, identify as bisexual, have a primary male
Jeffrey T. Parsons; David S. Bimbi; Juline A. Koken; Perry N. Halkitis
In some species, female condition correlates positively with preferences for male secondary sexual traits. Women's preferences for sexually dimorphic characteristics in male faces (facial masculinity) have recently been reported to covary with self-reported attractiveness. As women's attractiveness has been proposed to signal reproductive condition, the findings in human (Homo sapiens) and other species may reflect similar processes. The current study
I. S. Penton-Voak; A. C. Little; B. C. Jones; D. M. Burt; B. P. Tiddeman; D. I. Perrett
This study examines sexuality and HIV/AIDS prevention knowledge among minority ethnic male youth of Bangladesh. A cross-sectional survey was conducted through a self-administered questionnaire on 800 young males aged 15-24 years in the Chittagong Hill Tracts region in 2009. Of the respondents, almost one-third were sexually active and of them
In a laboratory study, we monitored the lifetime sexual signalling (advertisement) of wild male Mediterranean fruit flies, and we tested the hypothesis that high lifetime intensity of sexual signalling indicates high survival probabilities. Almost all males exhibited signalling and individual signalling rates were highly variable from the beginning of the adults maturity and throughout their life span (average life span
Nikos T. Papadopoulos; Byron I. Katsoyannos; Nikos A. Kouloussis; James R. Carey; Hans-Georg Müller; Ying Zhang
Summary We analysed sexual size dimorphism for 21 populations of microtine rodents. Female to male size ratio varied considerably among populations from females significantly larger than males (ratio=1.18) to males larger than females (ratio=0.78). In a multiple regression analysis female to male home range size ratio explained 94% of the total variation in body size dimorphism and was the only
Group home caregivers of 24 institutionalized, male, high-functioning adolescents and young adults with Autism Spectrum Disorder,\\u000a were interviewed with the Interview Sexuality Autism. Most subjects were reported to express sexual interest and to display\\u000a some kind of sexual behavior. Knowledge of socio-sexual skills existed, but practical use was moderate. Masturbation was common.\\u000a Many subjects were seeking physical contact with others.
Hans Hellemans; Kathy Colson; Christine Verbraeken; Robert Vermeiren; Dirk Deboutte
Sexually potent and sexually sluggish\\/impotent male rats were treated orally with different amounts of Turnera diffusa and Pfaffia paniculata fluid extracts (0.25, 0.50, 1.0?ml\\/kg). While having no effect on the copulatory behavior of sexually potent rats, both plant\\u000a extracts singly or in combination improved the copulatory performance of sexually sluggish\\/impotent rats. The highest\\u000a dose of either extract (1?ml\\/kg)
R. Arletti; A. Benelli; E. Cavazzuti; G. Scarpetta; A. Bertolini
Despite their presumed high risk for AIDS, there are almost no sexual behavior data available which are sufficient for the development and assessment of intervention programs for male prostitutes. This study was designed to obtain such data. Fifty 1427?year?old male prostitutes in Manhattan were interviewed using structured instruments to assess sexual orientation, sexual behavior, knowledge of AIDS, and substance abuse.
We investigated how male Japanese quail (Coturnix coturnix japonica) learn through extensive social and sexual experience to discriminate between male and female conspecifics. Opportunity for heterosexual copulation was important for this learning, but even extensive copulatory opportunity was not sufficient to produce a sexual discrimination; subjects also required exposure to other males. Exposure to females after copulatory opportunity did not produce a sexual discrimination but facilitated its acquisition. Time or exposure to only the visual features of male birds (provided by taxidermic models) after copulatory opportunity did not result in differential responding to male and female conspecifics. Finally, presenting stimulus birds one at a time proved to be a more sensitive test of sexual-discrimination learning than presenting two stimulus birds at the same time. The results indicate that sexual-discrimination learning is similar to conventional associative learning. PMID:2598621
Closely related pathogens and parasites often have distinctly different strategies for transmission. In some cases, presence of one potential mode of transmission reduces the rate of or forbids another. In these cases, one can ask what the conditions are that favor the use of one mode of transmission over the other. We constructed a mathematical model to examine this issue for the case of maternally inherited endosymbionts of insects. Here, killing males (to enhance transmission through the female line by reducing sibling competition) and retaining live males as a vehicle for sexual transmission are mutually exclusive strategies. Our model indicates that sexual transmission of a maternally inherited parasite can exclude a male-killing strain, provided that a sexually transmitted infection can take over an infection by a male-killing strain either following exposure or when male killing is incomplete and sexual transmission is efficient. The presence of sexual transmission may also explain why secondary symbionts do not degrade toward the evolution of male killing but remain as "beneficial partners" to both male and female hosts. This stabilization may be fundamental to the evolution toward obligate mutualism, and thus it is important in the ecology and evolution of many arthropod groups. PMID:19272014
A cross sectional descriptive study was conducted from February 2008 to December 2009 at the largest Highway Terminal, Yangon, Myanmar to determine the prevalence of curable STIs (syphilis, gonorrhea, chlamydial infections, and trichomoniasis), to find out the associated factors for STIs, and to determine the antibiotic susceptibility pattern of gonococcal infection among highway drivers. Urine and blood specimens were collected from 601 male highway coach drivers after an interview about their behavior. Standard laboratory tests were carried out to detect STIs. Multivariate analysis was used to ascertain potential risk factors for STIs. The prevalence rates of syphilis, gonorrhea, chlamydial infections, and trichomoniasis were 4.8, 4.3, 5.7, and 9.8%, respectively. One hundred and two (17.0%) were infected with at least one of the tested four STIs, and 34 (5.7%) had STI co-infections (2STIs). Those who had multiple sexual contacts were likely to be infected with at least one STI, and those who had a history of inconsistent condom use within past two weeks and multiple sexual contacts were more likely to have STI co-infections (p < 0.05). Antimicrobial susceptibility of 21 Neisseria gonorrhoeae isolates showed that 85.7% were susceptible to azithromycin, 80.9% to spectinomycin, 66.7% to cefixime, 61.9% to ceftriaxone, and 38.1% to ciprofloxacin. The high prevalence of STIs in this study and the decreased susceptibility of Neisseria gonorrhoeae to cephalosporin and fluoroquinolone highlighted the role of periodic screening in early diagnosis and effective treatment of STIs among high-risk populations. PMID:24050075
People in Nepal generally hold fairly traditional views about sex and sexual health, whilst Western tourists often have a more liberal approach towards sex and relationships. There is evidence that significant sexual interaction occurs between male trekking guides and female travellers and/or local female sex workers in Nepal. This qualitative study explored trekking guides' sexual health knowledge, sexual relationships and condom use with female trekkers and local female sex workers. A total of 21 in-depth interviews were conducted with male trekking guides. Most reported having had sexual relationships with female trekkers and local female sex workers. Explanations for intercourse with female trekkers included: financial support; getting future trekkers through word-of-mouth advertising from the women they have had sex with; and opportunities for emigration. Interestingly, sexual intercourse is reported as more likely to be initiated by female trekkers than by guides, and more so by older women. In contrast, the main reasons for having sex with local female sex workers included: romantic love or sexual excitement and novelty. Awareness regarding sexual health was high among guides, but several factors discouraged the regular use of condoms. Further research with female tourists would help understand the motivations and reasons for their sexual behaviour. PMID:19813118
The dominant malesterility gene Ms-cd1 is identified in Brassica oleracea. Electron microscopical observations revealed that abortion of pollen development starts after tetrad formation. This important\\u000a malesterility phenotype is characterized by lack of degradation of the primary pollen mother cell (PMC) wall and delayed\\u000a degradation of callose surrounding the tetrads and thus arrest of microspore release. Gene expression of
Jungen Kang; Guoyu Zhang; Guusje Bonnema; Zhiyuan Fang; Xiaowu Wang
Twenty-one cold-tolerant, malesterile Brassica napus somatic hybrids were produced by protoplast fusion. The fusion partners were a coldsensitive, Ogura cytoplasmic malesterile cauliflower inbred (B. oleracea var. botrytis inbred NY7642A) and a cold-tolerant, fertile canola-type B. rapa cv. Candle. Hybridity was confirmed by morphology, isozyme expression, flow cytometry, and DNA hybridization. Organellar analyses revealed a very strong bias for
Male college students ( N = 395) completed anonymous surveys to report personal attitudes supporting sexual aggression and estimated the attitudes of their peers. Participants also indicated their willingness to intervene against a peer if they witnessed sexual aggression. Although both personal and peer attitudes were correlated with willingness to intervene, in regression analyses only perceived peer attitudes emerged as a significant predictor of willingness to intervene. Results suggest that personal attitudes supporting sexual aggression are not as relevant to men's willingness to intervene against sexual aggression as are perceived peer norms regarding sexual aggression. Findings are relevant to sexual assault prevention education with men, suggesting that attempts to encourage bystander intervention may be best presented in the context of challenging perceived norms. PMID:19401602
The aims of this study were to investigate whether sexual harassment is related to mental and physical health of both men and women, and to explore the possible moderating effects of gender on the relation between sexual harassment and health. In addition, we investigated whether women were more often bothered by sexual harassment than men, and whether victims who report
BACKGROUND: In Nepal, as in other Asian countries, the issue of sexuality still remains a taboo. Despite this fact, an increasing number of sexual activities is being reported by Nepalese students. This trend warrants serious and timely attention. Due to the sensitivity of the topic of premarital sexuality, youth receive inadequate education, guidance and services on reproductive health. The main
|A study of sexual behavior in migrant men was conducted in construction sites, markets, and factories in Shanghai, the largest city in China. An anonymous, self-administered questionnaire was completed by the migrants. Among 986 sexually active men, 14% had had more than one sexual partner in their lifetime, 31% premarital sex, 3.3% oral sex, and
Benign prostatic hyperplasia (BPH) is the leading cause of lower urinary tract symptoms among the aging male population. Epidemiological, pathophysiological and clinical studies indicate that many of these men also suffer from declining sexual function, especially those undergoing treatment for their BPH-related urinary symptoms. Although urinary symptoms and quality of life may improve with BPH therapy, the resulting effects on sexual function vary by medical, surgical and minimally invasive approaches and have not been consistently reported. As comprehensive, validated instruments to measure malesexual function are now available for routine use in the clinical setting, urologists and primary care providers caring for patients with BPH have the opportunity to monitor both urinary and sexual function before, during and after BPH therapy. Herein, we describe the relationship between BPH and its treatments on malesexual function, the role of new measures for sexual functioning and opportunities for future work to improve the care of men suffering from both maladies.
Sexual selection is generally caused by female choice and male--male competition. In female choice process, female preference is favored indirectly and\\/or directly by sexual selection. In indirect selection, females expressing the preference might gain indirect genetic benefits. In direct selection, females expressing the preference might gain direct benefits or avoid male-imposed costs. The white-tailed zygaenid moth Elcysma westwoodii is monandrous,
Male sex workers serve multiple groups (i.e., gay-identified men, heterosexually-identified men, and their own sexual partners), making them a unique source to test theories of gender, masculinity, and sexuality. To date, most scholarship on this topic has been qualitative. I assembled a dataset from the largest online male sex worker website to conduct the first quantitative analysis of male escorts
Background Arctium lappa L. root has traditionally been recommended as an aphrodisiac agent. It is used to treat impotence and sterility in China, and Native Americans included the root in herbal preparations for women in labor. However, its use has not been scientifically validated. The present study therefore investigated the effects of aqueous extract of Arctium lappa L. roots on sexual behavior in normal male rats. Methods Seventy-five albino male rats were randomly divided into five groups of 15 rats each. Rats in group 1 (control) were administered 10 mL?kg body weight distilled water (vehicle), group 2 received 60 mg/kg body weight sildenafil citrate (Viagra), while those in groups 3, 4, and 5 were given 300, 600, and 1,200 mg/kg body weight, respectively, of aqueous extract of Arctium lappa L. roots in the same volume. Female albino rats were made receptive by hormonal treatment. Sexual behavior parameters in male rats were monitored on days 3, 7 and 15 by pairing with receptive females (1:3). Male serum testosterone concentrations and potency were also determined. Results Oral administration of Arctium lappa L. roots extract at 600 and 1,200 mg/kg body weight significantly increased the frequencies of mount, intromission, and ejaculation frequency (p < 0.05). The latencies of mount and intromission were significantly reduced and ejaculation latency was prolonged. Administration of the extract also reduced the post-ejaculatory interval. The standard drug (Viagra) was more effective than the extract. The extract significantly increased the frequencies of all components of penile reflexes as well as serum testosterone levels, compared with the distilled water controls. Conclusions The results of this study demonstrate that aqueous extract of Arctium lappa L. roots enhances sexual behavior in male rats. The aphrodisiac effects of the plant extract may be related to the presence of flavonoids, saponins, lignans and alkaloids, acting via a multitude of central and peripheral mechanisms. These results thus support the traditional use of Arctium lappa L. root extract for treating impotence and sterility.
The Mediterranean fruit fly (medfly), Ceratitis capitata (Wied.), like many other polifagous tephritids (Diptera: Tephritidae), adopts a lek as mating system. The sterile insect technique (SIT) requires the release of sterilemales able to survive on the field, to compete with wild males, and attrac...
Group home caregivers of 24 institutionalized, male, high-functioning adolescents and young adults with Autism Spectrum Disorder, were interviewed with the Interview Sexuality Autism. Most subjects were reported to express sexual interest and to display some kind of sexual behavior. Knowledge of socio-sexual skills existed, but practical use was moderate. Masturbation was common. Many subjects were seeking physical contact with others. Half of the sample had experienced a relationship, while three were reported to have had sexual intercourse. The number of bisexual orientations appeared high. Ritual-sexual use of objects and sensory fascination with a sexual connotation were sometimes present. A paraphilia was present in two subjects. About one third of the group needed intervention regarding sexual development or behavior. PMID:16868848
Background Many extant male animals exhibit exaggerated body parts for display, defense or offence in sexual selection, such as male birds of paradise showing off colorful and elegant feathers and male moose and reindeers bearing large structured antlers. For insects, male rhinoceros and stag beetles have huge horn-like structure for fighting and competition and some male Leptopanorpa scorpionflies have very long abdominal terminal segments for sexual display and competition. Fossil records of insects having exaggerated body parts for sexual display are fairly rare. One example is two male holcorpids with elongate abdominal segments from sixth (A6) to eighth (A8) and enlarged male genitalia from Eocene, suggesting evolution of these characters occurred fairly late. Principal Findings We document two mecopterans with exaggerated male body parts from the late Middle Jurassic Jiulongshan Formation in northeastern China. Both have extremely extended abdominal segments from A6 to A8 and enlarged genitalia, which might have been used for sexual display and, to less extent, for fighting with other males in the competition for mates. Although Fortiholcorpa paradoxa gen. et sp. nov. and Miriholcorpa forcipata gen. et sp. nov. seem to have affinities with Holcorpidae, we deem both as Family Incertae sedis mainly due to significant differences in branching pattern of Media (M) veins and relative length of A8 for F. paradoxa, and indiscernible preservation of 5-branched M veins in hind wing for M. forcipata. Conclusions/Significance These two new taxa have extended the records of exaggerated male body parts of mecopterans for sexual display and/or selection from the Early Eocene to the late Middle Jurassic. The similar character present in some Leptopanorpa of Panorpidae suggests that the sexual display and/or sexual selection due to extremely elongated male abdominal and sexual organs outweigh the negative impact of bulky body and poor mobility in the evolutionary process.
Some plants without pods but with gynophores were observed in two F4 progenies of two crosses of goundnut (Arachis hypogaea L.). The flowers on these plants had translucent white anthers with no or a few sterile pollen grains. Three such plants in the succeeding generation were hand pollinated with pollen from a short-duration Indian cv. JL 24. The resulting F1
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 com- petition,
M. REICHARD; J. BRYJA; M. ONDRACKOVA; M. DAVIDOVA; P. KANIEWSKA; C. SMITH
Womens magazines are a popular site for analysis of socio-cultural messages about gender, sex, and sexuality. We analyzed six consecutive issues of Cosmopolitan and Cleo to identify the ways in which they construct and represent male and female sexuality. Overall, malesexuality was prioritised, real heterosex was depicted as penetrative, and orgasm was given precedence. Two main accounts of male
Purpose Male adolescents experience adverse sexual/reproductive health (SRH) outcomes, yet few providers deliver male SRH care. Given the lack of evidence base for male SRH care, the purpose of this study was to examine perceived importance in delivering SRH care to male adolescents among clinicians focused on male health. Methods Seventeen primary care clinicians focused on male health, representing pediatricians, family physicians, internists, and nurse practitioners, were individually queried about male adolescents SRH needs and perceived importance to screen/assess for 13 male SRH services using a case-scenario approach varying by visit type and allotted time. Results Participants were highly consistent in identifying a scope of 10 SRH services to deliver to male adolescents during a longer annual visit and a core set of 6 SRH services during a shorter annual visit including 1) counseling on sexually transmitted infection/human immunodeficiency (STI/HIV) risk reduction including testing/treatment; and assessing for 2) pubertal growth/development; 3) substance abuse/mental health; 4) non-STI/HIV genital abnormalities; 5) physical/sexual abuse; and 6) male pregnancy prevention methods. Participants did not agree whether SRH care should be delivered during non-annual acute visits. Conclusions Despite lack of data for male SRH care, clinicians focused on male health strongly agreed upon male SRH care to deliver during annual visits that varied by visit type and allotted time. Study findings provide a foundation for much needed clinical guidelines for male adolescents SRH care and have implications for education and training health professionals at all levels and the organization and delivery of male SRH services.
Little is known about risk\\/protective factors for sexually coercive behavior in general population youth. We used a Swedish\\u000a school-based population survey of sexual attitudes and experiences (response rate 77%) and investigated literature-based variables\\u000a across sexually coercive (SEX), non-sexual conduct problem (CP), and normal control (NC) participants to identify general\\u000a and specific risk\\/protective factors for sexual coercion. Among 1,933 male youth,
Cecilia Kjellgren; Gisela Priebe; Carl Göran Svedin; Niklas Långström
Little is known about risk/protective factors for sexually coercive behavior in general population youth. We used a Swedish school-based population survey of sexual attitudes and experiences (response rate 77%) and investigated literature-based variables across sexually coercive (SEX), non-sexual conduct problem (CP), and normal control (NC) participants to identify general and specific risk/protective factors for sexual coercion. Among 1,933 male youth, 101 (5.2%) reported sexual coercion (ever talked or forced somebody into genital, oral, or anal sex) (SEX), 132 (6.8%) were classified as CP, and the remaining 1,700 (87.9%) as NC. Of 29 tested variables, 25 were more common in both SEX and CP compared to NC youth, including minority ethnicity, separated parents, vocational study program, risk-taking, aggressiveness, depressive symptoms, substance abuse, sexual victimization, extensive sexual experiences, and sexual preoccupation. When compared to CP youth only, SEX youth more often followed academic study programs, used less drugs and were less risk-taking. Further, SEX more frequently than CP youth reported gender stereotypic and pro-rape attitudes, sexual preoccupation, prostitution, and friends using violent porn. Finally, in a multivariate logistic regression, academic study program, pro-rape attitudes, sexual preoccupation, and less risk-taking independently remained more strongly associated with SEX compared to CP offending. In conclusion, several sociodemographic, family, and individual risk/protective factors were common to non-sexual and sexually coercive antisocial behavior in late adolescence. However, pro-rape cognitions, and sexual preoccupation, were sexuality-related, specific risk factors. The findings could inform preventive efforts and the assessment and treatment of sexually coercive male youth. PMID:19888644
Kjellgren, Cecilia; Priebe, Gisela; Svedin, Carl Göran; Långström, Niklas
Numerous models have attempted to explain the evolution of extravagant male ornaments found in many species. Inter-sexual indicator models postulate that male ornaments evolved as signals of quality, and that females use these signals to select the highest quality males. These models involve three traits--male quality, male signals and female preferences--and have specific expectations about the relative strengths of the phenotypic relationships between these traits. Using data from anuran species, we assessed the relative strengths of the phenotypic relationships using meta-analysis. The relative strengths of these phenotypic correlations were as expected by indicator models, providing support for indicator models of inter-sexual selection. We also found much variation in our data, suggesting that additional, untested factors may mediate inter-sexual interactions in this taxon, such as differences in the importance of quality signalling between species. These factors require investigation, in order to improve our understanding of inter-sexual selection. PMID:22591267
BS366 is a thermo-sensitive malesterile line of wheat (Triticum aestivum L.) for two-line hybrid breeding, which exhibits aberrant meiotic cytokinesis under low temperature. Through transcriptome analysis, a possible regulatory role for plant actin cytoskeleton was suggested. However, the organization of actin cytoskeleton in meiosis has been poorly understood so far. Here, fixed microsporocytes during meiosis were labeled with tetramethylrhodamine isothiocyanate-phalloidin and 4',6-diamidino-2-phenylindole. Quantities of fluorescent micrographs were captured using a confocal microscope, including the transient state from metaphase to telophase. We observed that actin filaments were abundant in typical kariokinetic spindle, central spindle (parallel microtubules or actin fibers between two separated chromosomes in anaphase), and phragmoplast. Interestingly, we identified the Chinese lantern-shaped actin phragmoplast in wheat meiosis for the first time. Under low temperature, phragmoplast actin filaments were chaotic and normal cell plate failed to form. These data provide new insights into the organization of actin filaments during male meiosis of plant and support a role of actin cytoskeleton in bringing about thermo-sensitive malesterility in wheat. PMID:22350736
The purpose of this study was to compare sexual function between women of infertile couples (AR) and women seeking tubal ligation (TL). Women who attended Setor de Infertilidade do Serviço de Ginecologia e Obstetrícia do Hospital de Clinicas de Porto Alegre (HCPA) or the Serviço de Orientação e Planejamento Familiar (SERPLAN) completed the Female Sexual Function Index, a questionnaire about
Heitor Hentschel; Daniele Lima Alberton; Robert John Sawdy; Edison Capp; José Roberto Goldim; Eduardo Pandolfi Passos
In studies of sexual selection, larger size is often argued to increase male fitness, and relatively smaller males are explained by genetic and ?or environmental variation. We demonstrate that a size-development life-history trade-off could underlie the maintenance of a broad, unimodal distribution of size in male redback spiders (Latrodectus hasselti). Larger males are superior in direct competition, but redback males
|In a recent paper published in the "Journal of Child Sexual Abuse," we assessed the differences between sexually victimized and nonsexually victimized male adolescent sexual abusers (Burton, Duty, & Leibowitz, 2011). We found that the sexually victimized group had more severe developmental antecedents (e.g., trauma and early exposure to
Leibowitz, George S.; Burton, David L.; Howard, Alan
In a recent paper published in the "Journal of Child Sexual Abuse," we assessed the differences between sexually victimized and nonsexually victimized male adolescent sexual abusers (Burton, Duty, & Leibowitz, 2011). We found that the sexually victimized group had more severe developmental antecedents (e.g., trauma and early exposure to
Leibowitz, George S.; Burton, David L.; Howard, Alan
The aim of this study was to assess the impact of spinal cord injury on men's sexual motivation, through the sexual desire self-assessment, and the sexual arousal and orgasm physiological responses. This research consisted of a descriptive, nonprobabilistic and comparative study, designed to outline the target population characteristics to compare the studied variables. Forty spinal cord injured male patients and a control group composed of 50 able-bodied male individuals filled in a questionnaire that assessed sexual behaviour, functioning and satisfaction. Comparing the control group with the injured group in the postinjury period, there was no significant difference in the sexual desire; however, in relation to sexual arousal and the orgasm intensity, there was a significant difference. The same results were found when comparing the injured participants' preinjury and postinjury period reports. It was clear that the injury significantly reduced sexual arousal among quadriplegic participants and orgasm intensity among both quadriplegic and paraplegic men. The spinal cord injury had a significant impact on sexual arousal and orgasm physiological response, although the sexual desire perception was not significantly altered, indicating that spinal cord injury affects these men's sexual behaviour in terms of sexual performance and body sensitivity. PMID:19011580
Cardoso, Fernando Luiz; Savall, Ana Carolina R; Mendes, Aline K
Sexual motivation and copulation in male rats are associated with dopamine release in the nucleus accumbens. Demasculinized copulatory behavior has been demonstrated in prenatally stressed adult male rats. We have previously reported that approximately 80% of prenatally stressed male rats do not exhibit copulation and that no significant changes in nucleus accumbens dopamine release are seen during exposure to estrous
Under sexual conflict, males evolve traits to increase their mating and reproductive success that impose costs on females. Females evolve counter-adaptations to resist males and reduce those costs. Female resistance may instead serve as a mechanism for mate choice if the male-imposed costs are outwe...
Summary Background: Why do males and females behave differ- ently? Sexually dimorphic behaviors could arise from sex-specific neurons or by the modification of circuits present in both sexes. C. elegans males exhibit different behaviors than hermaphrodites. Although there is a sin- gle class of sex-specific sensory neurons in the head of males, most of their neurons are part of a
Jamie Q. White; Thomas J. Nicholas; Jeff Gritton; Long Truong; Eliott R. Davidson; Erik M. Jorgensen
Using data from a Canadian national representative sample survey of male university and college students, this study tested three hypotheses from a theoretical model which attempts to explain the relationship between male peer group dynamics and sexual assault in dating relationships. Consistent with previous research conducted in the United States, the findings reported here show that male peer support is
Objective Several studies have reported that Clomipramine has the ability to suppress male rat sexual behavior. Literature indicates that the activation of brain D2 receptors causes facilitation of penile erection, and a number of reports have indicated dopamines involvement in sexual function. Hence this study was undertaken to investigate the effect of Amantadine, a dopamine agonists on the Clomipramine induced sexual dysfunction. Methods The study subjects involved a total of 48 males and 48 females, 4 months old Sprague-Dawley albino rats, all housed in a group of six males and females separately in plexi glass cages in an acclimatized colony room (25±0.50C) maintained on a 12/12 hr light/dark cycle. The male rats were randomly divided into four groups of 12 male rats each. Group I served as controls. Group II, III, and IV were treated with Amantadine (9 mg/kg body weight, p.o) 30 min, prior to the treatment with 13.5 mg/kg, 27 mg/Kg and 54 mg/Kg bodyweight p.o of Clomipramine respectively for 60 days. The control group received vehicle 1 ml / kg p.o. The sexual behavior of the male rats was observed to determine the following parameters: mount latency, intromission latency, ejaculation latency, post ejaculatory pause, and intromission frequency. As well as the sexual behavior; serum testosterone and histopathology of the testes were also investigated in this study. Results The results indicate that Amantadine in all aspects failed to antagonize Clomipramine induced sexual dysfunction in male rats. Even the sexual competence of male rats treated with ½ therapeutic dose (TD) of Clomipramine failed to regain their sexual competence in the presence of Amantadine. Testicular damage and decline in testosterone levels continued in the presence of Amantadine. Conclusion Overall, the results suggest that Amantadine could not be a safe antidote to antagonize Clomipramine induced sexual dysfunction.
In rodents, sexual behavior depends on the adequate detection of sexually relevant stimuli. The olfactory bulb (OB) is a region of the adult mammalian brain undergoing constant cell renewal by continuous integration of new granular and periglomerular neurons in the accessory (AOB) and main (MOB) olfactory bulbs. The proliferation, migration, survival, maturation, and integration of these new cells to the OB depend on the stimulus that the subjects received. We have previously shown that 15 days after females control (paced) the sexual interaction an increase in the number of cells is observed in the AOB. No changes are observed in the number of cells when females are not allowed to control the sexual interaction. In the present study we investigated if in male rats sexual behavior increases the number of new cells in the OB. Male rats were divided in five groups: (1) males that did not receive any sexual stimulation, (2) males that were exposed to female odors, (3) males that mated for 1 h and could not pace their sexual interaction, (4) males that paced their sexual interaction and ejaculated one time and (5) males that paced their sexual interaction and ejaculated three times. All males received three injections of the DNA synthesis marker bromodeoxyuridine at 1h intervals, starting 1 h before the beginning of the behavioral test. Fifteen days later, males were sacrificed and the brains were processed to identify new cells and to evaluate if they differentiated into neurons. The number of newborn cells increased in the granular cell layer (GrCL; also known as the internal cell layer) of the AOB in males that ejaculated one or three times controlling (paced) the rate of the sexual interaction. Some of these new cells were identified as neurons. In contrast, no significant differences were found in the mitral cell layer (also known as the external cell layer) and glomerular cell layer (GlCL) of the AOB. In addition, no significant differences were found between groups in the MOB in any of the layers analyzed. Our results indicate that sexual behavior in male rats increases neurogenesis in the GrCL of the AOB when they control the rate of the sexual interaction. PMID:22783170
Portillo, Wendy; Unda, Nancy; Camacho, Francisco J; Sánchez, María; Corona, Rebeca; Arzate, Dulce Ma; Díaz, Néstor F; Paredes, Raúl G
Males will alter their mating behavior to cope with the presence of their competitors. Even exposure to odors from potential competitors can greatly increase male ejaculate expenditure in a variety of animals including insects, fishes, birds and rodents. Major efforts have been made to examine males' plastic responses to sperm competition and its fitness benefits. However, the effects of competitor absence on male's sexual motivation and behaviors remain unclear, which has been proposed to be one of the causes for the poor sexual performance of some captive mammals. This study revealed that sexual motivation can be greatly enhanced in captive male giant pandas (Ailuropoda melanoleuca) by exposure to chemosensory cues from either one or three conspecifics males. It had been shown that potential rivals' odors increased males' chemosensory investigation behavior, as well as their observing, following and sniffing behaviors towards estrous females. Behaviors changed regardless of the number of rivals (one or three). Our results demonstrate the effects of potential competition on male giant pandas' sexual motivation and behavioral coping strategy. We anticipate that our research will provide a fresh insight into the mechanisms underlying poor sexual performance in male captive mammals, and valuable information for the practical management and ex situ conservation of endangered species. PMID:23940532
The sterility of bybrids between various mouse species follows Haldane's rule by affecting only the males. Hitberto, five bybrid sterility (Hst) loci have been identified in the mouse genome. Haldane's rule bolds also for chromosomal sterility in all studied mammalian species, including man. The males heterozygous for various male-sterile chromosomal rearrangements show the same meiotic phenotype: partially asynaptic, rearranged autosomes
Strong child support enforcement requires fathers to take financial responsibility for their children and may also encourage more responsible sexual behavior. Using the 1997-2001 waves of the 1997 National Longitudinal Survey of Youth (N = 4,272), this article examines the association between child support enforcement and the sexual activity of
|Strong child support enforcement requires fathers to take financial responsibility for their children and may also encourage more responsible sexual behavior. Using the 1997-2001 waves of the 1997 National Longitudinal Survey of Youth (N = 4,272), this article examines the association between child support enforcement and the sexual activity of
Many commonly used antihypertensive drugs such as diuretics and beta-blockers can interfere with sexual function in both sexes, causing loss of libido, impairment of erectile function and ejaculation in men, and delay or prevent orgasm in women. Newly developed antihypertensive drugs should ideally not interfere with the patients quality of life including sexual function. This study examined the effects of
Paul Chan; Ju-Chi Liu; Yat-Ching Tong; Yi-Jen Chen; Chia-Chen Wang; Brian Tomlinson; Juei-Tang Cheng
The quality of functional outcome has become increasingly important in view of improvement in prognosis with colorectal cancer patients. Sexual dysfunction remains a common problem after colorectal cancer treatment, despite the good oncologic outcomes achieved by expert surgeons. Although radiotherapy and chemotherapy contribute, surgical nerve damage is the main cause of sexual dysfunction. The autonomic nerves are in close contact with the visceral pelvic fascia that surrounds the mesorectum. The concept of total mesorectal excision (TME) in rectal cancer treatment has led to a substantial improvement of autonomic nerve preservation. In addition, use of laparoscopy has allowed favorable results with regards to sexual function. The present paper describes the anatomy and pathophysiology of autonomic pelvic nerves, prevalence of sexual dysfunction, and the surgical technique of nerve preservation in order to maintain sexual function. PMID:23716030
In sexually dimorphic ungulates, sexual selection favoring rapid horn growth in males may be counterbalanced by a decrease in longevity if horns are costly to produce and maintain. Alternatively, if early horn growth varied with individual quality, it may be positively correlated with longevity. We studied Alpine ibex Capra ibex in the Gran Paradiso National Park, Italy, to test these
P. Bergeron; M. Festa-Bianchet; A. von Hardenberg; B. Bassano
Male mosquitofish allocate a large proportion of their time budget to attempting to inseminate unreceptive females. Because females invest considerable time and energy in avoiding unwanted copulations, sexual harassment is expected to conflict with other activities such as foraging. We found that sexual harassment more than halved the foraging efficiency of the female in a task requiring the retrieval of
|The goal of this investigation was to examine gender differences in experiences of sexual harassment during military service and the negative mental health symptoms associated with these experiences. Female (n = 2,319) and male (n = 1,627) former reservists were surveyed about sexual harassment during their military service and current mental
|Alcohol use and sexual assault on college campuses are highly prevalent and the focus of numerous prevention and intervention efforts. Our goals were to gain a greater understanding of the relationship between coercive sexual experiences, utilization of protective behavioral strategies and alcohol expectancies and consumption among male and
Palmer, Rebekka S.; McMahon, Thomas J.; Rounsaville, Bruce J.; Ball, Samuel A.
The goal of this investigation was to examine gender differences in experiences of sexual harassment during military service and the negative mental health symptoms associated with these experiences. Female (n = 2,319) and male (n = 1,627) former reservists were surveyed about sexual harassment during their military service and current mental health symptoms. As expected, women reported a higher frequency
We examined associations among parasite infections, secondary sexual traits and testosterone in male red-winged blackbirds sampled at the start of the breeding season. Parasites quantified included ectoparasitic lice and mites and endoparasitic blood protozoans, nematodes, trematodes and cestodes. Secondary sexual traits that we quantified included body size, epaulet size and color, song repertoire size and song switching rate, and behavioral
Patrick J. Weatherhead; Karen J. Metz; Gordon F. Bennett; Rebecca E. Irwin
|This exploratory investigation examined the relationship between childhood sexual abuse (CSA) and related psychosocial characteristics and sexual behaviors among 46 gay/bisexual male escorts who advertise via the Internet. More than a quarter of men (28.3%) reported some history of CSA. Men reporting CSA were more likely to be from an ethnic
Parsons, Jeffrey T.; Bimbi, David S.; Koken, Juline A.; Halkitis, Perry N.
|Data from male participants in the National Longitudinal Study of Adolescent Health are used to examine childhood predictors of late adolescent and early adulthood sexually coercive behavior and adolescent mediators of these relationships. A path analysis shows that experiencing sexual abuse as a child has a direct effect on perpetrating
Casey, Erin A.; Beadnell, Blair; Lindhorst, Taryn P.
The authors examined the relationship between self- monitoring and pluralistic ignorance and self-reported sexually aggressive behaviors by freshman and sophomore male college students. Results indicated that self-monitoring style and level of pluralistic ignorance were correlated positively with sexual aggression. The authors review relevant
This study compares the moral reasoning abilities of juvenile sexual and nonsexual offenders using a novel methodology that explores responses to questions addressing morality in a variety of offending contexts. Seven sexual and nine nonsexual adolescent male offenders from a maximum security detention facility in New South Wales, Australia, are presented with and asked to discuss a variety of hypothetical
The goal of this investigation was to examine psychiatric symptoms as predictors of the frequency and severity of sexually aggressive behaviors that had been perpetrated by college-aged men in the past year. Over 400 undergraduate males completed an assessment of sexual aggression, athletic involvement, fraternity affiliation, alcohol and drug use, mistrust of women, depression, and social anxiety. More than 40%
Esther J. Calzada; Elissa J. Brown; Megan E. Doyle
Alcohol use and sexual assault on college campuses are highly prevalent and the focus of numerous prevention and intervention efforts. Our goals were to gain a greater understanding of the relationship between coercive sexual experiences, utilization of protective behavioral strategies and alcohol expectancies and consumption among male and female college students. We surveyed 370 college students regarding their past year
Rebekka S. Palmer; Thomas J. McMahon; Bruce J. Rounsaville; Samuel A. Ball
The present research uniquely compared male control theory (MCT) versus female control theory (FCT) to illuminate motives for the sexual double standard (SDS), whereby men gain status from engaging in casual sex or having many sexual partners, but women are stigmatized for it. Consistent with MCT, men were more likely than women to endorse the SDS and to give sexual advice in ways that reinforce it-gender differences that were mediated by hostile sexism (HS) and endorsing the SDS, respectively. The data did not support FCT's argument that women are motivated by sexual economics to restrict female sexuality (Baumeister & Twenge, 2002). Both genders discouraged women from having casual sex to protect women from social stigma and rape myths that justify violence against sexual women. In concert, the findings support MCT more than FCT and suggest that sexism, stigma, and rape myths are primary obstacles to sexual equality. PMID:23386660
Rudman, Laurie A; Fetterolf, Janell C; Sanchez, Diana T
Sexual dimorphisms in the brain underlie behavioral sex differences, but the function of individual sexually dimorphic neuronal populations is poorly understood. Neuronal sexual dimorphisms typically represent quantitative differences in cell number, gene expression, or other features, and it is unknown whether these dimorphisms control sex-typical behavior exclusively in one sex or in both sexes. The progesterone receptor (PR) controls female sexual behavior, and we find many sex differences in number, distribution, or projections of PR-expressing neurons in the adult mouse brain. Using a genetic strategy we developed, we have ablated one such dimorphic PR-expressing neuronal population located in the ventromedial hypothalamus (VMH). Ablation of these neurons in females greatly diminishes sexual receptivity. Strikingly, the corresponding ablation in males reduces mating and aggression. Our findings reveal the functions of a molecularly defined, sexually dimorphic neuronal population in the brain. Moreover, we show that sexually dimorphic neurons can control distinct sex-typical behaviors in both sexes. PMID:23663785
Yang, Cindy F; Chiang, Michael C; Gray, Daniel C; Prabhakaran, Mahalakshmi; Alvarado, Maricruz; Juntti, Scott A; Unger, Elizabeth K; Wells, James A; Shah, Nirao M
Sexual conflict drives the coevolution of sexually antagonistic traits, such that an adaptation in one sex selects an opposing coevolutionary response from the other. Although many adaptations and counteradaptations have been identified in sexual conflict over mating interactions, few are known for sexual conflict over parental investment. Here we investigate a possible coevolutionary sequence triggered by mate desertion in the burying beetle Nicrophorus vespilloides, where males commonly leave before their offspring reach independence. Rather than suffer fitness costs as a consequence, our data suggest that females rely on the male's absence to recoup some of the costs of larval care, presumably because they are then free to feed themselves on the carcass employed for breeding. Consequently, forcing males to stay until the larvae disperse reduces components of female fitness to a greater extent than caring for young singlehandedly. Therefore we suggest that females may have co-evolved to anticipate desertion by their partners so that they now benefit from the male's absence.
A male patient with homosexual obsession in obsessive compulsive disorder shows a better outcome following a combination of pharmacotherapy and psychotherapy. This case report emphasizes the importance of combination therapy in obsessive compulsive disorder with abnormal sexual impulses and behavior.
Raguraman, Janakiraman; Priyadharshini, Kothai R.; Chandrasekaran, R.; Vijaysagar, John
Previous laboratory studies have demonstrated that estrogenic and antiandrogenic chemicals can alter several sexual characteristics in male poeciliid fishes. Whether similar disturbances occur under field conditions remains to be confirmed. Lake Apopka, Florida, is contaminated w...
Proper regulation of anther differentiation is crucial for producing functional pollen, and defects in or absence of any anther cell type result in malesterility. To deepen understanding of processes required to establish premeiotic cell fate and differentiation of somatic support cell layers a cytological screen of maize male-sterile mutants has been conducted which yielded 42 new mutants including 22 mutants with premeiotic cytological defects (increasing this class fivefold), 7 mutants with postmeiotic defects, and 13 mutants with irregular meiosis. Allelism tests with known and new mutants confirmed new alleles of four premeiotic developmental mutants, including two novel alleles of msca1 and single new alleles of ms32, ms8, and ocl4, and two alleles of the postmeiotic ms45. An allelic pair of newly described mutants was found. Premeiotic mutants are now classified into four categories: anther identity defects, abnormal anther structure, locular wall defects and premature degradation of cell layers, and/or microsporocyte collapse. The range of mutant phenotypic classes is discussed in comparison with developmental genetic investigation of anther development in rice and Arabidopsis to highlight similarities and differences between grasses and eudicots and within the grasses.
Timofejeva, Ljudmilla; Skibbe, David S.; Lee, Sidae; Golubovskaya, Inna; Wang, Rachel; Harper, Lisa; Walbot, Virginia; Cande, William Zacheus
The protein T-URF13 (URF13) is specific to mitochondria of maize (Zea mays L.) with Texas (T) male-sterile cytoplasm and has been implicated in causing malesterility and susceptibility to T-cytoplasm-specific fungal diseases. T-URF13 was purified from isolated mitochondria from maize (line B73) with T cytoplasm by gel filtration and a quasi two-dimensional polyacrylamide gel electrophoresis system. Antibodies to the purified and denatured protein were produced in rabbits. Anti-T-URF13 antiserum was used to show that T-URF13 is in the inner membrane of mitochondria and behaves as an integral membrane protein when mitochondria are fractionated with sodium carbonate or Triton X-114. The antiserum and protein A tagged with 20-nanometer-gold particles were used to localize T-URF13 in T mitochondria by electron microscopy of sections of isolated mitochondria from etiolated shoots and sections of roots and of tapetal cells at pre-and post-degeneration stages of microsporogenesis. The microscopic study confirms that T-URF13 is specifically localized in the mitochondrial membranes of all of the T mitochondria tested, notably those in the tapetum from the meiocyte stage to the late-microspore stage. No change in the amount of labeled T-URF13 protein in the mitochondria of aging tapetal cells was detected. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6
Hack, Ethan; Lin, Chentao; Yang, Hongyun; Horner, Harry T.
The results of an investigation of the synaptonemal complexes (SCs) of spermatocytes of sterilemales of the house mouse from the progeny of parents subjected to the action of a mutagen are presented in this study. A nonreciprocal translocation was readily identified by the configuration of the SCs. The translocation was observed at pachytene in 100% of cells; at diakinesis-metaphase I, in 58% of cells. A different pattern of association of the X chromosome with the rearrangement region was found in pachytene spermatocytes. Computer analysis of the relative lengths of the synaptonemal complex during the pachytene stage permitted the determination that the translocation took place from the 4th autosome to the 16th. The translocated segment was 66-75% of chromosome 4. In chromosome 16 the point of rupture is close to the distal end, and it was not possible to find the broken-off telomeric fragment of this chromosome in the male under study.
The effect of releases of bisexual (males and female) and unisexual (male only) sterilized medflies was compared in three large field evaluations over a 3-year period (1995 - 1997) in southwestern Guatemala. The two strains tested were a genetic sexing strain, Vienna-4/Tol-94, carrying the temperatu...
Many animals use chemical signals in sexual selection, but it is not clear how these sexual traits might have evolved to signal\\u000a honestly male condition. It is possible that there is a trade-off between maintaining the immune system and the elaboration\\u000a of ornaments. We experimentally challenged the immune system of male Iberian wall lizards, Podarcis hispanica, with a bacterial antigen
The effects ofEurycoma longifolia Jack were studied on the sexual behaviour of male rats. Sexually normal male rats were treated twice daily with 500 mg kg?1 of different fractions ofE. longifolia Jack for 10 days prior to test and were then observed for their copulatory behaviour with a receptive female in a copulation\\u000a cage. Results showed that was a significant
Emission rates of an androgen-sensitive male courtship vocalization were positively correlated with the volume of only the left hypothalamic sexually dimorphic area, pars compacta (SDApc) nucleus in sexually active male Mongolian gerbils. The asymmetric relationship between brain nucleus and vocal behavior was confirmed in testosterone (T)-treated castrated adult males but was eliminated by castration of males and did not exist
Summary An animal mating system characterized by male-male competition and active searching for sexually receptive females was modelled to study how varying sex ratio and spatiotemporal distribution of receptive females can affect the variance in male mating success (i. e. potential for sexual selection) in males. The temporal distribution of female receptivity periods appeared to be the variable that had
The mitochondrial genomes of maize plants exhibiting S-type cytoplasmic malesterility (cms-S) contain a repeated DNA region designated R. This region was found to be rearranged in the mitochondria of all cms-S cytoplasmically revertant fertile plants in all nuclear backgrounds analyzed. A 1.6-kb mRNA transcribed from the R region in mitochondria of sterile plants was absent from all cytoplasmic revertants
The genetic relationship among three cytoplasmic malesterility (CMS) systems, consisting of WA, Dissi, and Gambiaca, was\\u000a studied. The results showed that the maintainers of one CMS system can also maintain sterility in other cytoplasmic backgrounds.\\u000a The F1 plants derived from crosses involving A and R lines of the respective cytoplasm and their cross-combination with other CMS\\u000a systems showed similar
Majid Sattari; Arumugam Kathiresan; Glenn B. Gregorio; Sant S. Virmani
Somatic Brassica napus (+) Arabidopsis thaliana hybrids with a cytoplasmic malesterility (CMS)-inducing cytoplasm were screened for fertility-restored plants. One line was selected and recurrently backcrossed with the maintainer line, B. napus, resulting in fertile\\/sterile segregating populations. Restriction fragment length polymorphism mapping showed the co-segregation of A. thaliana chromosome (chr) III markers with the fertility trait. As it was not possible
The cultivated potato, Solanum tuberosum L. (2n=4x=48), has a very large number of related wild and cultivated tuber-bearing species widely distributed in the Americas. These species, grouped in 16 taxonomic series, range from the diploid to the hexaploid level. Polyploid species are either disomic or polysomic, and sexual polyploidization via genetically controlled 2 n gametes has played a major role in their evolution. Species are separated in nature by geographical and ecological barriers. However, there are several examples of sympatric species that share the same niches but do not readily cross (i.e., the diploids S. commersonii and S. chacoense in certain areas of Argentina). External barriers alone are, therefore, not sufficient to explain species integrity. In addition, there is no strong evidence indicating that genome differentiation is important in the group. In this review we present evidence supporting the assertion that interspecific pollen-pistil incompatibility, nuclear-cytoplasmic malesterility, and the endosperm are major forces that strengthen the external hybridization barriers allowing, at the same time and under specific circumstances, a certain amount of gene exchange without jeopardizing the integrity of the species. PMID:15278199
Among the fertile sugar beet lines with nuclear sterility maintenance genes, rf, in a homozygous recessive state, sublines capable of reverting spontaneously at a high rate to sterility were identified. Of 24 related fertile sublines studied, 6 were found to spontaneously revert to sterility with a frequency of about 19%. Genetic analysis confirmed the cytoplasmic nature of spontaneously arising sterility.
N. A. Dudareva; S. G. Veprev; A. V. Popovsky; S. I. Maletsky; I. P. Gileva; R. I. Salganik
Two subtypes of estrogen receptors (ER), ER? and ER?, have been identified in humans and numerous vertebrates, including the Japanese quail. We investigated in this species the specific role(s) of each receptor in the activation of malesexual behavior and the underlying estrogen-dependent neural plasticity. Castrated male Japanese quail received empty (CX) or testosterone-filled (T) implants or were daily injected
Aurore L. Seredynski; Gregory F. Ball; Jacques Balthazart; Thierry D. Charlier; Bruce Cushing