Lactulose promotes equol production and changes the microbial community during in vitro fermentation of daidzein by fecal inocula of sows.

PubMed

Zheng, Weijiang; Hou, Yanjun; Su, Yong; Yao, Wen

2014-02-01

Equol has higher biological effects than other isoflavones. However, only about 30-50% of humans possess a microbiota capable of producing equol from dietary daidzein. In recent years, interest has grown in dietary applications to improve equol production in human and other animals. In this study, lactulose was used as a potential equol-promoting prebiotic in vitro. The effect of lactulose on transformation of daidzein into equol by sows' fecal microbiota was investigated. Results showed that lactulose treatment improved bacteria growth parameters, changing the kinetics of fermentation in vitro. Lactulose significantly increased total gas production, T1/2, Tmax, and Rmax. Furthermore, lactulose altered the microflora composition, increased equol production associated with a reduction in the population of methanogen and increased the sulfate-reducing bacteria population during 24 h of incubation. Here, we report for the first time that in a certain condition (sealing or high pressure), via a dihydrodaidzein (DHD) pathway equol might be able to reform to daidzein by further metabolism using lactulose as a substrate. This study proposes that "hydrogen-producing prebiotic" might be a novel way to promote equol production in vivo or in vitro. Copyright © 2013 Elsevier Ltd. All rights reserved.

Bacterial metabolite S-equol modulates glucagon-like peptide-1 secretion from enteroendocrine L cell line GLUTag cells via actin polymerization.

PubMed

Harada, Kazuki; Sada, Shoko; Sakaguchi, Hidekazu; Takizawa, Mai; Ishida, Rika; Tsuboi, Takashi

2018-07-02

S-equol is one of gut bacterial metabolites produced from soybean isoflavone daizein. While S-equol is known to promote glucose-induced insulin secretion from pancreatic β cells, whether S-equol affects glucagon-like peptide-1 (GLP-1) secretion from enteroendoceine L cells remains unclear. Here we assessed the effect of S-equol on GLP-1 secretion from mouse enteroendocrine L cell line GLUTag cells. GLUTag cells expressed GPR30 and estrogen receptors, which are putative S-equol receptors. Application of S-equol induced an increase in intracellular Ca 2+ levels via GPR30. However, S-equol did not enhance GLP-1 exocytosis, and long-term treatment of S-equol suppressed GLP-1 secretion. Moreover, immunocytochemistry revealed that S-equol increased the density of cortical actin filaments via G 12/13 signaling under GPR30. These data suggest that S-equol prevents GLP-1 secretion as a result of competing regulation between Ca 2+ mobilization and actin reorganization. Copyright © 2018 Elsevier Inc. All rights reserved.

Isoflavone supplement composition and equol producer status affect gene expression in adipose tissue: a double-blind, randomized, placebo-controlled crossover trial in postmenopausal women.

PubMed

van der Velpen, Vera; Geelen, Anouk; Hollman, Peter C H; Schouten, Evert G; van 't Veer, Pieter; Afman, Lydia A

2014-11-01

Isoflavone supplements, consumed by women experiencing menopausal symptoms, are suggested to have positive effects on menopause-related adiposity and cardiovascular disease risk profile, but discussions about their safety are still ongoing. The objective was to study the effects of an 8-wk consumption of 2 different isoflavone supplements compared with placebo on whole-genome gene expression in the adipose tissue of postmenopausal women. This double-blind, randomized, placebo-controlled crossover intervention consisted of 2 substudies, one with a low-genistein (LG) supplement (56% daidzein + daidzin, 16% genistein + genistin, and 28% glycitein + glycitin) and the other with a high-genistein (HG) supplement (49% daidzein + daidzin, 41% genistein + genistin, and 10% glycitein + glycitin). Both supplements provided ∼ 100 mg isoflavones/d (aglycone equivalents). After the 8-wk isoflavone and placebo period, whole-genome arrays were performed in subcutaneous adipose tissue of postmenopausal women (n = 26 after LG, n = 31 after HG). Participants were randomized by equol-producing phenotype, and data analysis was performed per substudy for equol producers and nonproducers separately. Gene set enrichment analysis showed downregulation of expression of energy metabolism-related genes after LG supplementation (n = 24) in both equol-producing phenotypes and oppositely regulated expression for equol producers (down) and nonproducers (up) after HG supplementation (n = 31). Expression of inflammation-related genes was upregulated in equol producers but downregulated in nonproducers, independent of supplement type. Only 4.4-7.0% of the genes with significantly changed expression were estrogen responsive. Body weight, adipocyte size, and plasma lipid profile were not affected by isoflavone supplementation. Effects of isoflavones on adipose tissue gene expression were influenced by supplement composition and equol-producing phenotype, whereas estrogen-responsive effects were lacking. LG isoflavone supplementation resulted in a caloric restriction-like gene expression profile for both producer phenotypes and pointed toward a potential beneficial effect, whereas both supplements induced anti-inflammatory gene expression in equol producers. The study was registered at clinicaltrials.gov as NCT01556737. © 2014 American Society for Nutrition.

Impact of soy supplementation on sex steroids and vascular inflammation markers in postmenopausal women using tibolone: role of equol production capability.

PubMed

Törmälä, R; Appt, S; Clarkson, T B; Mueck, A O; Seeger, H; Mikkola, T S; Ylikorkala, O

2008-10-01

Tibolone is often taken concurrently with soy. Tibolone, soy and equol-producing capacity each affect vascular health, whereas their concomitant effects are unknown. We studied the effects of soy on sex steroids and vascular inflammation markers in long-term tibolone users. Postmenopausal women (n = 110) on tibolone were screened with a soy challenge to find 20 equol producers and 20 non-producers. All women were treated for 8 weeks in a cross-over trial with soy (52 g of soy protein containing 112 mg of isoflavones) or placebo. Serum estrone, 17beta-estradiol, testosterone, androstenedione, dehydroepiandrosterone sulfate (DHEAS), sex hormone binding globulin (SHBG), C-reactive protein (CRP), vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and platelet-selectin (P-selectin) were assessed. Soy decreased (7.1%) the estrone level, significantly (12.5%) only in equol producers (from 80.2 +/- 10.8 to 70.3 +/- 7.0 pmol/l; p = 0.04). Testosterone was reduced (15.5%; from 586 +/- 62.6 to 495 +/- 50.1 pmol/l, p = 0.02) during soy treatment, and more markedly in equol producers than non-producers (22.1% vs. 10.0%). No changes appeared in SHBG, CRP or ICAM-1, but VCAM-1 increased (9.2%) and P-selectin decreased (10.3%) during soy treatment. Soy modified the concentrations of estrone, testosterone and some endothelial markers. Equol production enforced these effects. Soy supplementation may be clinically significant in tibolone users.

The pharmacokinetic behavior of the soy isoflavone metabolite S-(-)equol and its diastereoisomer R-(+)equol in healthy adults determined by using stable-isotope-labeled tracers.

PubMed

Setchell, Kenneth Dr; Zhao, Xueheng; Jha, Pinky; Heubi, James E; Brown, Nadine M

2009-10-01

The nonsteroidal estrogen equol occurs as diastereoisomers, S-(-)equol and R-(+)equol, both of which have significant biological actions. S-(-)equol, the naturally occurring enantiomer produced by 20-30% of adults consuming soy foods, has selective affinity for estrogen receptor-beta, whereas both enantiomers modulate androgen action. Little is known about the pharmacokinetics of the diastereoisomers, despite current interest in developing equol as a nutraceutical or pharmaceutical agent. The objective was to compare the pharmacokinetics of S-(-)equol and R-(+)equol by using [13C] stable-isotope-labeled tracers to facilitate the optimization of clinical studies aimed at evaluating the potential of these diastereoisomers in the prevention and treatment of estrogen- and androgen-dependent conditions. A randomized, crossover, open-label study in 12 healthy adults (6 men and 6 women) compared the plasma and urinary pharmacokinetics of orally administered enantiomeric pure forms of S-(-)[2-13C]equol, R-(+)[2-13C]equol, and the racemic mixture. Plasma and urinary [13C]R-equol and [13C]S-equol concentrations were measured by tandem mass spectrometry. Plasma [13C]equol concentration appearance and disappearance curves showed that both enantiomers were rapidly absorbed, attained high circulating concentrations, and had a similar terminal elimination half-life of 7-8 h. The systemic bioavailability and fractional absorption of R-(+)[2-13C]equol were higher than those of S-(-)[2-13C]equol or the racemate. The pharmacokinetics of racemic (+/-)[2-13C]equol were different from those of the individual enantiomers: slower absorption, lower peak plasma concentrations, and lower systemic bioavailability. The high bioavailability of both diastereoisomers contrasts with previous findings for the soy isoflavones daidzein and genistein, both of which have relatively poor bioavailability, and suggests that low doses of equol taken twice daily may be sufficient to achieve biological effects.

Equol an isoflavonoid: potential for improved prostate health, in vitro and in vivo evidence

PubMed Central

2011-01-01

Background To determine: in vitro binding affinity of equol for 5alpha-dihydrotestosterone (5alpha-DHT), in vitro effects of equol treatment in human prostate cancer (LNCap) cells, and in vivo effects of equol on rat prostate weight and circulating levels of sex steroid hormones. Methods First, in vitro equol binding affinity for 5alpha-DHT was determined using 14C5alpha-DHT combined with cold 5alpha-DHT (3.0 nM in all samples). These steroids were incubated with increasing concentrations of equol (0-2,000 nM) and analyzed by Sephadex LH-20 column chromatography. 14C5alpha-DHT peak/profiles were determined by scintillation counting of column fractions. Using the 14C5alpha-DHT peak (0 nM equol) as a reference standard, a binding curve was generated by quantifying shifts in the 14C5alpha-DHT peaks as equol concentrations increased. Second, equol's in vitro effects on LNCap cells were determined by culturing cells (48 hours) in the presence of increasing concentrations of dimethyl sulfoxide (DMSO) (vehicle-control), 5alpha-DHT, equol or 5alpha-DHT+equol. Following culture, prostate specific antigen (PSA) levels were quantified via ELISA. Finally, the in vivo effects of equol were tested in sixteen male Long-Evans rats fed a low isoflavone diet. From 190-215 days, animals received 0.1cc s.c. injections of either DMSO-control vehicle (n = 8) or 1.0 mg/kg (body weight) of equol (in DMSO) (n = 8). At 215 days, body and prostate weights were recorded, trunk blood was collected and serum assayed for luteinizing hormone (LH), 5alpha-DHT, testosterone and 17beta-estradiol levels. Results Maximum and half maximal equol binding to 5alpha-DHT occurred at approximately 100 nM and 4.8 nM respectively. LNCap cells cultured in the presence of 5alpha-DHT significantly increased PSA levels. However, in the presence of 5alpha-DHT+equol, equol blocked the significant increases in PSA levels from LNCap cells. In vivo equol treatment significantly decreased rat prostate weights and serum 5alpha-DHT levels but did not alter LH, testosterone, and estradiol levels. Conclusions Equol administration appears to have potential beneficial effects for prostate health and other 5alpha-DHT mediated disorders. Equol administration: reduces PSA levels from LNCap cells under 5alpha-DHT stimulation, decreases rat prostate size, decreases serum 5alpha-DHT levels and androgen hormone action, while not altering other circulating sex steroids or LH levels. PMID:21232127

Equol status and blood lipid profile in hyperlipidemia after consumption of diets containing soy foods.

PubMed

Wong, Julia M W; Kendall, Cyril W C; Marchie, Augustine; Liu, Zhen; Vidgen, Ed; Holmes, Candice; Jackson, Chung-Ja; Josse, Robert G; Pencharz, Paul B; Rao, A Venketeshwer; Vuksan, Vladimir; Singer, William; Jenkins, David J A

2012-03-01

Recent analyses have challenged the effectiveness of soy foods as part of a cardiovascular risk reduction diet. The objective of the study was to show whether equol status determines the effectiveness of soy foods to lower LDL cholesterol and to raise HDL cholesterol. Eighty-five hypercholesterolemic men and postmenopausal women (42 men, 43 women) participated in 1 of 3 studies that represented a range of soy interventions and that followed the same general protocol at a Canadian university hospital research center. Soy foods were provided for 1 mo at doses of 30-52 g/d for the 3 studies as follows: 1) soy foods with either high-normal (73 mg/d) or low (10 mg/d) isoflavones, 2) soy foods with or without a prebiotic to enhance colonic fermentation (10 g polyfructans/d), or 3) soy foods with a low-carbohydrate diet (26% carbohydrate). Studies 1 and 2 were randomized controlled crossover trials, and study 3 was a parallel study. The separation of the group into equol producers (n = 30) and nonproducers (n = 55) showed similar reductions from baseline in LDL cholesterol (-9.3 ± 2.5% and -11.1 ± 1.6%, respectively; P = 0.834), with preservation of HDL cholesterol and apolipoprotein A-I only in equol producers compared with reductions in nonproducers (HDL cholesterol: +0.9 ± 2.7% compared with -4.3 ± 1.1%, P = 0.006; apolipoprotein A-I: -1.0 ± 1.1% compared with -4.7 ± 1.0%; P = 0.011). The amount of urinary equol excreted did not relate to the changes in blood lipids. Soy foods reduced serum LDL cholesterol equally in both equol producers and nonproducers. However, in equol producers, ~35% of our study population, soy consumption had the added cardiovascular benefit of maintaining higher HDL-cholesterol concentrations than those seen in equol nonproducers. This trial was registered at clinicaltrials.gov as NCT00877825 (study 1), NCT00516594 (study 2), and NCT00256516 (study 3).

S-equol, a potent ligand for estrogen receptor beta, is the exclusive enantiomeric form of the soy isoflavone metabolite produced by human intestinal bacterial flora.

PubMed

Setchell, Kenneth D R; Clerici, Carlo; Lephart, Edwin D; Cole, Sidney J; Heenan, Claire; Castellani, Danilo; Wolfe, Brian E; Nechemias-Zimmer, Linda; Brown, Nadine M; Lund, Trent D; Handa, Robert J; Heubi, James E

2005-05-01

The discovery of equol in human urine more than 2 decades ago and the finding that it is bacterially derived from daidzin, an isoflavone abundant in soy foods, led to the current nutritional interest in soy foods. Equol, unlike the soy isoflavones daidzein or genistein, has a chiral center and therefore can occur as 2 distinct diastereoisomers. Because it was unclear which enantiomer was present in humans, our objectives were to characterize the exact structure of equol, to examine whether the S- and R-equol enantiomers are bioavailable, and to ascertain whether the differences in their conformational structure translate to significant differences in affinity for estrogen receptors. With the use of chiral-phase HPLC and mass spectrometry, equol was isolated from human urine and plasma, and its enantiomeric structure was defined. Human fecal flora were cultured in vitro and incubated with daidzein to ascertain the stereospecificity of the bacterial production of equol. The pharmacokinetics of S- and R- equol were determined in 3 healthy adults after single-bolus oral administration of both enantiomers, and the affinity of each equol enantiomer for estrogen receptors was measured. Our studies definitively establish S-equol as the exclusive product of human intestinal bacterial synthesis from soy isoflavones and also show that both enantiomers are bioavailable. S-equol has a high affinity for estrogen receptor beta (K(i) = 0.73 nmol/L), whereas R-equol is relatively inactive. Humans have acquired an ability to exclusively synthesize S-equol from the precursor soy isoflavone daidzein, and it is significant that, unlike R-equol, this enantiomer has a relatively high affinity for estrogen receptor beta.

Equol inhibits growth, induces atresia, and inhibits steroidogenesis of mouse antral follicles in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahalingam, Sharada, E-mail: mahalin2@illinois.edu; Gao, Liying, E-mail: lgao@uiuc.edu; Gonnering, Marni, E-mail: mgonne2@illinois.edu

Equol is a non-steroidal estrogen metabolite produced by microbial conversion of daidzein, a major soy isoflavone, in the gut of some humans and many animal species. Isoflavones and their metabolites can affect endogenous estradiol production, action, and metabolism, potentially influencing ovarian follicle function. However, no studies have examined the effects of equol on intact ovarian antral follicles, which are responsible for sex steroid synthesis and further development into ovulatory follicles. Thus, the present study tested the hypothesis that equol inhibits antral follicle growth, increases follicle atresia, and inhibits steroidogenesis in the adult mouse ovary. To test this hypothesis, antral folliclesmore » isolated from adult CD-1 mice were cultured with vehicle control (dimethyl sulfoxide; DMSO) or equol (600 nM, 6 μM, 36 μM, and 100 μM) for 48 and 96 h. Every 24 h, follicle diameters were measured to monitor growth. At 48 and 96 h, the culture medium was subjected to measurement of hormone levels, and the cultured follicles were subjected to gene expression analysis. Additionally, follicles were histologically evaluated for signs of atresia after 96 h of culture. The results indicate that equol (100 μM) inhibited follicle growth, altered the mRNA levels of bcl2-associated X protein and B cell leukemia/lymphoma 2, and induced follicle atresia. Further, equol decreased the levels of estradiol, testosterone, androstenedione, and progesterone, and it decreased mRNA levels of cholesterol side-chain cleavage, steroid 17-α-hydroxalase, and aromatase. Collectively, these data indicate that equol inhibits growth, increases atresia, and inhibits steroidogenesis of cultured mouse antral follicles. - Highlights: • Equol exposure inhibits antral follicle growth. • Equol exposure increases follicle atresia. • Equol exposure inhibits sex steroid hormone levels. • Equol exposure inhibits mRNA levels of certain steroidogenic enzymes.« less

Impact of equol-producing capacity and soy-isoflavone profiles of supplements on bone calcium retention in postmenopausal women: a randomized crossover trial12

PubMed Central

Pawlowski, Jessica W; Martin, Berdine R; McCabe, George P; McCabe, Linda; Jackson, George S; Peacock, Munro; Barnes, Stephen; Weaver, Connie M

2015-01-01

Background: Postmenopausal estrogen depletion is a major contributing factor to bone loss. Soy isoflavones have variable effects on the prevention of postmenopausal bone loss, which is possibly related to the specific isoflavone content or the variable equol-producing capacity of individuals. Objective: We aimed to determine the effects of the content of isoflavones in a soy supplement and the equol-producing ability of the individual on postmenopausal bone calcium retention. Design: The study was a blinded, randomized, crossover intervention trial in 24 postmenopausal women who were prescreened for their ability to convert daidzein to equol. Women were equilibrated with 41Ca before the intervention. Interventions were 5 soy isoflavone oral supplements (2 doses of a genistein-rich soy supplement and 3 doses of mixed isoflavones in various proportions) and a bisphosphonate (risedronate). Each intervention was given sequentially for 50 d followed by a 50-d washout period. The percentage of bone calcium retention was determined from the change in urinary 41Ca:calcium. Results: Interventions that ranged from 52 to 220 mg total isoflavones/d increased bone calcium retention between 3.4% and 7.6% (P < 0.05), which was a moderate effect compared with that of risedronate at 15.3% (95% CI: 7.1%, 22.7%; P = 0.0014). The most-effective soy intervention delivered 105.23 mg total isoflavones/d as genistein, daidzein, and glycitein in their natural ratios and increased bone calcium retention by 7.6% (95% CI: 4.9%, 10.2%; P < 0.0001). Genistein, at 52.85 mg/d, increased bone calcium retention by 3.4% (95% CI: 0.5%, 6.2%; P = 0.029); but there was no benefit at higher amounts (113.52 mg/d). There was no difference (P = 0.5) in bone calcium retention between equol producers and nonproducers. Conclusion: Soy isoflavones, although not as potent as risedronate, are effective bone-preserving agents in postmenopausal women regardless of their equol-producing status, and mixed isoflavones in their natural ratios are more effective than enriched genistein. This trial was registered at clinicaltrials.gov as NCT00244907. PMID:26245807

Equol inhibits growth, induces atresia, and inhibits steroidogenesis of mouse antral follicles in vitro

PubMed Central

Mahalingam, Sharada; Gao, Liying; Gonnering, Marni; Helferich, William; Flaws, Jodi A.

2016-01-01

Equol is a non-steroidal estrogen metabolite produced by microbial conversion of daidzein, a major soy isoflavone, in the gut of some humans and many animal species. Isoflavones and their metabolites can affect endogenous estradiol production, action, and metabolism, potentially influencing ovarian follicle function. However, no studies have examined the effects of equol on intact ovarian antral follicles, which are responsible for sex steroid synthesis and further development into ovulatory follicles. Thus, the present study tested the hypothesis that equol inhibits antral follicle growth, increases follicle atresia, and inhibits steroidogenesis in the adult mouse ovary. To test this hypothesis, antral follicles isolated from adult CD-1 mice were cultured with vehicle control (dimethyl sulfoxide; DMSO) or equol (600 nM, 6 μM, 36 μM, 100 μM) for 48 and 96 h. Every 24 h, follicle diameters were measured to monitor growth. At 48 and 96 h, the culture medium was subjected to measurement of hormone levels, and the cultured follicles were subjected to gene expression analysis. Additionally, follicles were histologically evaluated for signs of atresia after 96 h of culture. The results indicate that equol (100 μM) inhibited follicle growth, altered the mRNA levels of bcl2-associated X protein and B cell leukemia/lymphoma 2, and induced follicle atresia. Further, equol decreased the levels of estradiol, testosterone, androstenedione, and progesterone, and it decreased mRNA levels of cholesterol side-chain cleavage, steroid 17-α-hydroxalase, and aromatase. Collectively, these data indicate that equol inhibits growth, increases atresia, and inhibits steroidogenesis of cultured mouse antral follicles. PMID:26876617

Phytoestrogens and Their Metabolites in Bulk-Tank Milk: Effects of Farm Management and Season

PubMed Central

Adler, Steffen A.; Purup, Stig; Hansen-Møller, Jens; Thuen, Erling; Steinshamn, Håvard

2015-01-01

Phytoestrogens have structures similar to endogenous steroids and may induce or inhibit the response of hormone receptors. The objectives of the present study were to compare the effects of long-term vs. short-term grassland management in organic and conventional dairy production systems, compare organic and conventional production systems and assess seasonal variation on phytoestrogen concentrations in bulk-tank milk. The concentrations of phytoestrogens were analyzed in bulk-tank milk sampled three times in two subsequent years from 28 dairy farms: Fourteen organic (ORG) dairy farms with either short-term or long-term grassland management were paired with 14 conventional (CON) farms with respect to grassland management. Grassland management varied in terms of time since establishment. Short-term grassland management (SG) was defined as establishment or reseeding every fourth year or more often, and long-term grassland management (LG) was defined as less frequent establishment or reseeding. The proportion of red clover (Trifolium pretense L.) in the herbage was positively correlated with milk concentrations of the mammalian isoflavone equol. Therefore, organically produced bulk-tank milk contained more equol than conventionally produced milk, and milk from ORG-SG farms had more equol than milk from ORG-LG farms. Milk produced during the indoor-feeding periods had more equol than milk produced during the outdoor feeding period, because pastures contained less red clover than fields intended for silage production. Organically produced milk had also higher concentrations of the mammalian lignan enterolactone, but in contrast to equol, concentrations increased in the outdoor-feeding periods compared to the indoor-feeding periods. There were no indications of fertility problems on ORG-SG farms who had the highest red clover proportions in the herbage. This study shows that production system, grassland management, and season affect milk concentrations of phytoestrogens. However, compared to soy products, milk concentrations of phytoestrogens are low and future studies are required to investigate if the intake of phytoestrogens from dairy products has physiological effects in humans. PMID:25996600

A Six-Month Randomized Controlled Trial of Whole Soy and Isoflavones Daidzein on Body Composition in Equol-Producing Postmenopausal Women with Prehypertension

PubMed Central

Liu, Zhao-min; Ho, Suzanne C.; Chen, Yu-ming; Woo, Jean

2013-01-01

Objectives. This paper reported the effects of commonly used whole soy foods (soy flour) and purified daidzein (one of the major isoflavones and the precursor of equol) on changes in anthropometric measurements and body composition in a 6-month double-blind, randomized, placebo-controlled trial among prehypertensive postmenopausal women who are also equol producers. Methods. 270 eligible women were randomized to either one of the three treatments: 40 g soy flour (whole soy group), 40 g low-fat milk powder + 63 mg daidzein (daidzein group), or 40 g low-fat milk powder (placebo group) daily each for 6 months. Anthropometric indicators and body composition were measured before and after intervention. Results. 253 subjects completed the study with good compliance. Urinary isoflavones levels suggested good compliance of subjects with supplementation. Whole soy and purified daidzein had no significant effect on body weight, body mass index (BMI), waist and hip circumferences, waist to hip ratio (WHR), body fat percentage, fat mass, and free fat mass. Conclusion. Six-month consumption of whole soy and purified daidzein at provided dosage had no improvement on body weight and composition compared with isocaloric milk placebo among prehypertensive equol-producing postmenopausal women. This trial is registered with ClinicalTrials.gov NCT01270737. PMID:23984051

Resveratrol, 4' Acetoxy Resveratrol, R-equol, Racemic Equol or S-equol as Cosmeceuticals to Improve Dermal Health.

PubMed

Lephart, Edwin D

2017-06-03

Phytochemicals are botanical compounds used in dermatology applications as cosmeceuticals to improve skin health. Resveratrol and equol are two of the best-known polyphenolic or phytoestrogens having similar chemical structures and some overlapping biological functions to 17β-estradiol. Human skin gene expression was reviewed for 28 different biomarkers when resveratrol, 4' acetoxy resveratrol (4AR), R -equol, racemic equol or S -equol were tested. Sirtuin 1 activator (SIRT 1) was stimulated by resveratrol and 4AR only. Resveratrol, R -equol and racemic equol were effective on the aging biomarkers proliferating cell nuclear factor (PCNA), nerve growth factor (NGF), 5α-reductase and the calcium binding proteins S100 A8 and A9. Racemic equol and 4AR displayed among the highest levels for the collagens, elastin and tissue inhibitor of the matrix metalloproteinase 1 (TIMP 1). S -equol displayed the lowest level of effectiveness compared to the other compounds. The 4AR analog was more effective compared to resveratrol by 1.6-fold. R -equol and racemic equol were almost equal in potency displaying greater inhibition vs. resveratrol or its 4' analog for the matrix metalloproteinases (MMPs), but among the inflammatory biomarkers, resveratrol, 4AR, R -equol and racemic equol displayed high inhibition. Thus, these cosmeceuticals display promise to improve dermal health; however, further study is warranted to understand how phytochemicals protect/enhance the skin.

Resveratrol, 4′ Acetoxy Resveratrol, R-equol, Racemic Equol or S-equol as Cosmeceuticals to Improve Dermal Health

PubMed Central

Lephart, Edwin D.

2017-01-01

Phytochemicals are botanical compounds used in dermatology applications as cosmeceuticals to improve skin health. Resveratrol and equol are two of the best-known polyphenolic or phytoestrogens having similar chemical structures and some overlapping biological functions to 17β-estradiol. Human skin gene expression was reviewed for 28 different biomarkers when resveratrol, 4′ acetoxy resveratrol (4AR), R-equol, racemic equol or S-equol were tested. Sirtuin 1 activator (SIRT 1) was stimulated by resveratrol and 4AR only. Resveratrol, R-equol and racemic equol were effective on the aging biomarkers proliferating cell nuclear factor (PCNA), nerve growth factor (NGF), 5α-reductase and the calcium binding proteins S100 A8 and A9. Racemic equol and 4AR displayed among the highest levels for the collagens, elastin and tissue inhibitor of the matrix metalloproteinase 1 (TIMP 1). S-equol displayed the lowest level of effectiveness compared to the other compounds. The 4AR analog was more effective compared to resveratrol by 1.6-fold. R-equol and racemic equol were almost equal in potency displaying greater inhibition vs. resveratrol or its 4′ analog for the matrix metalloproteinases (MMPs), but among the inflammatory biomarkers, resveratrol, 4AR, R-equol and racemic equol displayed high inhibition. Thus, these cosmeceuticals display promise to improve dermal health; however, further study is warranted to understand how phytochemicals protect/enhance the skin. PMID:28587197

The combined effects of soya isoflavones and resistant starch on equol production and trabecular bone loss in ovariectomised mice.

PubMed

Tousen, Yuko; Matsumoto, Yu; Matsumoto, Chiho; Nishide, Yoriko; Nagahata, Yuya; Kobayashi, Isao; Ishimi, Yoshiko

2016-07-01

Equol is a metabolite of the soya isoflavone (ISO) daidzein that is produced by intestinal microbiota. Equol has greater oestrogenic activity compared with other ISO, and it prevents bone loss in postmenopausal women. Resistant starch (RS), which has a prebiotic activity and is a dietary fibre, was reported to promote equol production. Conversely, the intestinal microbiota is reported to directly regulate bone health by reducing inflammatory cytokine levels and T-lymphocytes in bone. The present study evaluated the combined effects of diet supplemented with ISO and RS on intestinal microbiota, equol production, bone mineral density (BMD) and inflammatory gene expression in the bone marrow of ovariectomised (OVX) mice. Female ddY strain mice, aged 8 weeks, were either sham-operated (Sham, n 7) or OVX. OVX mice were randomly divided into the following four groups (seven per group): OVX control (OVX); OVX fed 0·05 % ISO diet (OVX+ISO); OVX fed 9 % RS diet (OVX+RS); and OVX fed 0·05 % ISO- and 9 % RS diet (OVX+ISO+RS). After 6 weeks, treatment with the combination of ISO and RS increased equol production, prevented the OVX-induced decline in trabecular BMD in the distal femur by modulating the enteric environment and altered OVX-induced inflammation-related gene expression in the bone marrow. However, there were no significant differences in bone parameters between the ISO+RS and ISO-alone groups in OVX mice. Our findings suggest that the combination of ISO and RS might alter intestinal microbiota and immune status in the bone marrow, resulting in attenuated bone resorption in OVX mice.

Soy proteins and isoflavones reduce interleukin-6 but not serum lipids in older women: a randomized controlled trial☆,☆☆

PubMed Central

Mangano, Kelsey M.; Hutchins-Wiese, Heather L.; Kenny, Anne M.; Walsh, Stephen J.; Abourizk, Robin H.; Bruno, Richard S.; Lipcius, Rosanne; Fall, Pamela; Kleppinger, Alison; Kenyon-Pesce, Lisa; Prestwood, Karen M.; Kerstetter, Jane E.

2015-01-01

Soy foods contain several components, notably, isoflavones and amino acids, that may improve cardiovascular health. We evaluated the long-term effect of soy protein and/or soy isoflavones supplementation on serum lipids and inflammatory markers using a 1-year randomized, double-blind, placebo-control, clinical trial in 131 healthy ambulatory women older than 60 years. We hypothesized that soy protein, in combination with isoflavones, would have the largest positive effect on coronary heart disease risk factors (serum lipids and inflammatory markers) compared with either intervention alone and that, within groups receiving isoflavones, equol producers would have more positive effects on coronary heart disease risk factors than nonequol producers. After a 1-month baseline period, participants were randomized into 1 of 4 intervention groups: soy protein (18 g/d) and isoflavone tablets (105 mg/d isoflavone aglycone equivalents), soy protein and placebo tablets, control protein and isoflavone tablets, or control protein and placebo tablets. T Tests were used to assess differences between equol and nonequol producers. Ninety-seven women completed the trial. Consumption of protein powder and isoflavone tablets did not differ among groups, and compliance with study powder and tablets was 79% and 90%, respectively. After 1 year, in the entire population, there were either no or little effects on serum lipids and inflammatory markers, regardless of treatment group. Equol producers, when analyzed separately, had significant improvements in total cholesterol/high-density lipoprotein and low-density lipoprotein/high-density lipoprotein ratios (−5.9%, P = .02; −7.2%, P = .04 respectively). Soy protein and isoflavone (either alone or together) did not impact serum lipids or inflammatory markers. Therefore, they should not be considered an effective intervention to prevent cardiovascular disease because of lipid modification in healthy late postmenopausal women lacking the ability to produce equol. PMID:24267042

Large inter-individual variation in isoflavone plasma concentration limits use of isoflavone intake data for risk assessment

PubMed Central

van der Velpen, V; Hollman, P C; van Nielen, M; Schouten, E G; Mensink, M; van't Veer, P; Geelen, A

2014-01-01

Background/objectives: Isoflavones are present in soy foods and soy-based supplements. Despite low plasma isoflavone concentrations in the general Western population, concentrations in supplement users exceed those suggested to be beneficial for health in Asian populations, raising concerns for adverse effects. To aid risk assessment, quantification of the relation between isoflavone intake and plasma concentrations is essential. Subjects/methods: Plasma samples were collected from postmenopausal women in three placebo-controlled crossover studies with 8-week periods for supplements (two studies, ~100 mg isoflavones/day, n=88) or 4-week periods for soy foods (one study, ~48 mg isoflavones/day, n=15). Plasma isoflavone concentrations (daidzein, equol, genistein and glycitein) were quantified using high-performance liquid chromatography and electrochemical detection. The association between plasma concentrations and isoflavone intake, equol producer status, intake–producer interaction and background dietary intake was assessed based on the assumption of a log-linear relation. Results: Median plasma total isoflavone concentrations after the soy food and supplement interventions were respectively 2.16 and 3.47 μmol/l for equol producers and 1.30 and 2.39 μmol/l for non-producers. Regression analysis showed that doubling isoflavone intake increased plasma concentrations by 55–62% (±s.e. 1–2%, R2>0.87) for daidzein, genistein, equol (only for producers) and total isoflavones; for glycitein the association was weaker (15±1%, R2=0.48). Adjustments for energy, carbohydrate and fat intake did not affect these estimates. Inter-individual variation, estimated based on repeated measures in one of the studies, was 30–96%. Conclusions: Although the relation between isoflavone intake and plasma concentrations was adequately quantified, the use of isoflavone intake data for risk assessment needs caution due to large inter-individual variation in plasma concentrations. PMID:24939433

Effect of whole soy and purified daidzein on ambulatory blood pressure and endothelial function--a 6-month double-blind, randomized controlled trial among Chinese postmenopausal women with prehypertension.

PubMed

Liu, Z-M; Ho, S C; Chen, Y-M; Tomlinson, B; Ho, S; To, K; Woo, J

2015-10-01

Although observational studies suggest that soy foods or isoflavones are cardio-protective, clinical trials on whole soy or isoflavone daidzein (one major isoflavone and the precursor of equol) on blood pressure (BP) and endothelial function (EF) are few and have not been specifically conducted among equol producers, a population most likely to benefit from soy treatment. We performed a 6-month double-blind, randomized, placebo-controlled trial to examine the effect of whole soy (soy flour) or purified daidzein on BP and EF in prehypertensive or untreated hypertensive postmenopausal women verified to be equol producers. A total of 270 eligible women were recruited and randomized to either one of the three treatment groups, 40 g soy flour (whole soy group), 40 g low-fat milk powder+63 mg daidzein (daidzein group) or 40 g low-fat milk powder (active control group) daily, each given as a solid beverage powder for 6 months. The primary outcome measures were 24 h ambulatory BP (ABP) and EF assessed by flow-mediated dilation using brachial artery ultrasound. A total of 253 subjects completed the study according to protocol. Urinary isoflavones indicated good compliance with the interventions. Intention to treat and per-protocol analysis indicated that there was no significant difference in the 6-month changes or % changes in parameters of ABP and brachial flow-mediated dilation among the three treatment groups. A further subgroup analysis among hypertensive women (n=138) did not alter the conclusions. Whole soy and purified daidzein had no significant effect on BP and vascular function among equol-producing postmenopausal women with prehypertension or untreated hypertension.

Urinary estrogen metabolites during a randomized soy trial

PubMed Central

Morimoto, Yukiko; Conroy, Shannon M.; Pagano, Ian S.; Isaki, Marissa; Franke, Adrian A.; Nordt, Frank J.; Maskarinec, Gertraud

2011-01-01

One of the hypothesized protective mechanisms of soy against breast cancer involves changes in estrogen metabolism to 2-hydroxy (OH) and 16α-OH estrogens. The current analysis examined the effect of soy foods on the 2:16α-OH E1 ratio among premenopausal women during a randomized, crossover intervention study; women were stratified by equol producer status, a characteristic thought to enhance the protective effects of soy isoflavones. The study consisted of a high-soy diet with 2 soy food servings/day and a low-soy diet with <3 servings of soy/week for 6 months each; estrogen metabolites were measured in 3 overnight urines (baseline and at the end of the low- and high-soy diet) using gas chromatography mass spectrometry for the 82 women who completed the study. Urinary isoflavonoids were assessed by liquid chromatography mass spectrometry. When applying mixed models, the 2:16α-OH E1 ratio increased (p=0.05) due to a non-significant decrease in 16α-OH E1 (p=0.21) at the end of high-soy diet. Similar non-significant increases in the 2:16α-OH E1 ratio were observed in equol producers (p=0.13) and non-producers (p=0.23). These findings suggest a beneficial influence of soy foods on estrogen metabolism regardless of equol producer status. PMID:22293063

Equol as a potent radiosensitizer in estrogen receptor-positive and -negative human breast cancer cell lines.

PubMed

Taghizadeh, Bita; Ghavami, Laleh; Nikoofar, Alireza; Goliaei, Bahram

2015-07-01

Breast cancer is the most common cause of cancer death among women worldwide, and diet plays an important role in its prevention and progression. Radiotherapy has a limited but important role in the management of nearly every stage of breast cancer. We studied whether equol, the major metabolite of the soybean isoflavone daidzein, could enhance radiosensitivity in two human breast cancer cell lines (T47D and MDA-MB-231). MTT assay was used to examine equol's effect on cell viability. Sensitivity of cells to equol, radiation and a combination of both was determined by colonogenic assays. Induction of apoptosis by equol, radiation and the combination of both was also determined by acridine orange/ethidium bromide double staining fluorescence microscopy. DNA strand breaks were assessed by Comet assay. MTT assay showed that equol (0.1-350 μM) inhibited MDA-MB-231 and T47D cell growth in a time- and dose-dependent manner. Treatment of cells with equol for 72 h (MDA-MB-231) and 24 h (T47D) was found to inhibit cell growth with IC50 values of 252 μM and 228 μM, respectively. Furthermore, pretreatment of cells with 50 μM equol for 72 h (MDA-MB-231) and 24 h (T47D) sensitized the cells to irradiation. Equol was also found to enhance radiation-induced apoptosis. Comet assay results showed that the radiosensitizing effect of equol was accompanied by increased radiation-induced DNA damages. These results suggest for the first time that equol can be considered as a radiosensitizing agent and its effects may be due to increasing cell death following irradiation, increasing the remaining radiation-induced DNA damage and thus reducing the surviving fraction of irradiated cells.

Equol is more active than soy isoflavone itself to compete for binding to thromboxane A(2) receptor in human platelets.

PubMed

Muñoz, Yenny; Garrido, Argelia; Valladares, Luis

2009-03-01

Several dietary intervention studies examining the health effect of soy isoflavones allude to the importance of equol in establishing the cardiovascular response to soy protein. Although, the specific mechanism by which this action occurs has not been established. The aim of this study was to investigate the inhibitory effect of soy-isoflavones and the metabolite of daidzein, equol, on agonist-induced platelet responses dependent on thromboxane A(2) (TxA(2)) receptor. Competitive radioligand binding assay was used to screen for affinity of these compounds to the TxA(2) receptor. The effect of equol on platelet activation, evaluate through of release of the ATP, by analogs of TxA(2) was analyzed. The effect of equol on platelet aggregation was investigated with ADP, U46619 (a TxA(2) mimic) and the calcium ionophore A23187. The data showed that aglycone isoflavones and equol bind to TxA(2) receptor in the micromol/L range, whereas their glucoside derivates had very low binding activity for this receptor. Under equilibrium conditions, the following order of the relative affinity in inhibiting [(3)H]-SQ29585 binding was: equol>genistein>daidzein>glycitein>genistin, daidzin, glycitin. Equol interaction was reversible and competitive for labeled-SQ29548 with not apparent decrease in the number of TxA(2) binding sites. In addition, from platelet activation studies, equol effectively inhibited ATP secretion elicited by the TxA(2) analog U46619. On the other hand, equol inhibited the platelet aggregation induced by U46619 and A23187, while it failed to inhibit that induced by ADP. The aglycone isoflavones from soy, and particularly equol, have been found to have biological effects attributable to thromboxane A(2) receptor antagonism. These findings may help elucidate how dietary isoflavone modulate platelet function and explain why soy-rich foods are claimed to have beneficial effects in the prevention of thrombotic events.

The effects of natural S-equol supplementation on skin aging in postmenopausal women: a pilot randomized placebo-controlled trial.

PubMed

Oyama, Ayuko; Ueno, Tomomi; Uchiyama, Shigeto; Aihara, Tomohiko; Miyake, Akira; Kondo, Sumio; Matsunaga, Kayoko

2012-02-01

The aim of this study was to investigate the effects of the natural S-equol supplement on skin aging in equol-nonproducing Japanese postmenopausal women. A randomized, double-blind, placebo-controlled trial examined the use of the natural S-equol supplement for 12 weeks in 101 postmenopausal Japanese women who were equol nonproducers. They were randomly assigned to one of three groups: placebo (n = 34), 10 mg S-equol/day (EQL10; n = 34), or 30 mg S-equol/day (EQL30; n = 33). Skin parameters of crow's-feet wrinkles (area and depth), hydration, transepidermal water loss, and elasticity were measured at baseline and at monthly intervals during treatment. Vaginal cytology, endometrial thickness, and mammography were performed before and after treatment. Serum hormone concentrations were measured at the same time as skin parameters. The EQL10 and EQL30 groups showed significant reductions in wrinkle area compared with the placebo group (P < 0.05). There was a significant difference in wrinkle depth between the placebo group and the EQL30 group (P < 0.05). Other skin parameters did not show significant differences after the treatment in any group. There were no abnormal results in hormone status or gynecological examinations. Our data suggest that natural S-equol supplementation (EQL10 and EQL30) may have a beneficial effect on crow's-feet wrinkles in postmenopausal women without serious adverse events.

Analysis of regulatory mechanisms of an insulin-inducible SHARP-2 gene by (S)-Equol.

PubMed

Haneishi, Ayumi; Takagi, Katsuhiro; Asano, Kosuke; Yamamoto, Taichi; Tanaka, Takashi; Nakamura, Soichiro; Noguchi, Tamio; Yamada, Kazuya

2012-09-01

Small compounds that activate the insulin-dependent signaling pathway have potential therapeutic applications in controlling type 2 diabetes mellitus. The rat enhancer of split- and hairy-related protein-2 (SHARP-2) is an insulin-inducible transcription factor that decreases expression of the phosphoenolpyruvate carboxykinase gene, a gluconeogenic enzyme gene. In this study, we screened for soybean isoflavones that can induce the rat SHARP-2 gene expression and analyzed their mechanism(s). Genistein and (S)-Equol, a metabolite of daidzein, induced rat SHARP-2 gene expression in H4IIE rat hepatoma cells. The (S)-Equol induction was mediated by both the phosphoinositide 3-kinase- and protein kinase C (PKC)-pathways. When a dominant negative form of atypical PKC lambda (aPKCλ) was expressed, the induction of SHARP-2 mRNA level by (S)-Equol was inhibited. In addition, Western blot analyses showed that (S)-Equol rapidly activated both aPKCλ and classical PKC alpha. Furthermore, the (S)-Equol induction was inhibited by treatment with a RNA polymerase inhibitor or a protein synthesis inhibitor. Finally, a reporter gene assay revealed that the transcriptional stimulation by (S)-Equol was mediated by nucleotide sequences located between -4687 and -4133 of the rat SHARP-2 gene. Thus, we conclude that (S)-Equol is an useful dietary supplement to control type 2 diabetes mellitus. Copyright © 2012 Elsevier Inc. All rights reserved.

Soya isoflavone consumption in relation to carotid intima-media thickness in Chinese equol excretors aged 40-65 years.

PubMed

Cai, Yun; Guo, Kaiping; Chen, Chaogang; Wang, Ping; Zhang, Bo; Zhou, Quan; Mei, Fang; Su, Yixiang

2012-11-14

Previous studies have suggested that the daidzein metabolite equol rather than daidzein itself contributes to the beneficial effect of soya foods in the prevention of CVD. The aim of the present study is to examine the proportion of equol excretion in Chinese adults and compare plasma lipids and carotid artery intima-media thickness (IMT) between equol excretors and non-excretors, and to evaluate the effect of soya isoflavone intakes on serum lipids and IMT in either equol excretors or non-excretors. Subjects (n 572; women n 362, men n 210) were recruited for the present study. An overnight urine sample was provided by each subject on their usual diet to quantify urinary concentrations of daidzein and equol. Far-wall IMT was determined by B-mode ultrasound in the right carotid at two sites, carotid bulb (CB-IMT) and common carotid artery (CCA-IMT), and fasting serum lipids were measured. Habitual dietary intakes were estimated with a FFQ, and soya isoflavone intake derived from the FFQ was assessed. Of the 572 subjects, the proportion of equol excretors on their usual diet was 25·0 % (n 143). Compared with non-excretors, equol excretors showed significantly lower serum TAG (-38·2 (95 % CI -70·4, -5·9) %, P = 0·012) and CCA-IMT (-4·9 (95 % CI -9·7, -0·3) %, P = 0·033). Equol excretors with higher daily isoflavone intakes (-5·4 mg/d) had significantly lower IMT (-16·2 %, P = 0·035) and tended to have higher HDL-cholesterol (P = 0·055) than did those with lower daily isoflavone intakes (1·5 mg/d), while no association was observed between soya isoflavone intakes and serum lipids or IMT in non-excretors. In conclusion, the benefits of soya isoflavones in preventing CVD may be apparent among equol excretors only.

Incomplete metabolism of phytoestrogens by gut microbiota from children under the age of three.

PubMed

Gaya, Pilar; Sánchez-Jiménez, Abel; Peirotén, Ángela; Medina, Margarita; Landete, José Maria

2018-05-01

Phytoestrogens are plant-derived polyphenols with structural and functional similarities to mammalian oestrogens. The aim of this work was to study the metabolism of phytoestrogens by children's intestinal microbiota and to compare it with previous results in adults. Faecal samples of 24 healthy children were subjected to phytoestrogen fermentation assay. Only one child produced equol, while O-desmethylangolensin was found in all. Urolithin production was detected in 14 children and enterolactone in 10. Further comparison with the metabolism of phytoestrogens by adult intestinal microbiota reflected that glycitein, dihydrogenistein, urolithins D and E, enterolactone, secoisolariciresinol and arctigenin were the most important metabolites differentiating between adult and child microbial gut metabolism. Although the child intestinal microbiota showed the ability to metabolise isoflavones, ellagitannins and lignans to a certain extent, it generally showed a reduced metabolism of phytoestrogens, with a lack of 5-hydroxy equol and enterodiol, and less urolithins and enterolactone producers.

Dietary seaweed modifies estrogen and phytoestrogen metabolism in healthy postmenopausal women.

PubMed

Teas, Jane; Hurley, Thomas G; Hebert, James R; Franke, Adrian A; Sepkovic, Daniel W; Kurzer, Mindy S

2009-05-01

Seaweed and soy foods are consumed daily in Japan, where breast cancer rates for postmenopausal women are significantly lower than in the West. Likely mechanisms include differences in diet, especially soy consumption, and estrogen metabolism. Fifteen healthy postmenopausal women participated in this double-blind trial of seaweed supplementation with soy challenge. Participants were randomized to 7 wk of either 5 g/d seaweed (Alaria) or placebo (maltodextrin). During wk 7, participants also consumed a daily soy protein isolate (2 mg isoflavones/kg body weight). After a 3-wk washout period, participants were crossed over to the alternate supplement schedule. There was an inverse correlation between seaweed dose (mg/kg body weight) and serum estradiol (E2) (seaweed-placebo = y = -2.29 x dose + 172.3; r = -0.70; P = 0.003), [corrected] which was linear across the range of weights. Soy supplementation increased urinary daidzein, glycitein, genistein, and O-desmethylangolensin (P = 0.0001) and decreased matairesinol and enterolactone (P < 0.05). Soy and seaweed plus soy (SeaSoy) increased urinary excretion of 2-hydroxyestrogen (2-OHE) (P = 0.0001) and the ratio of 2-OHE:16alpha-hydroxyestrone (16alphaOHE(1)) (P = 0.01). For the 5 equol excretors, soy increased urinary equol excretion (P = 0.0001); the combination of SeaSoy further increased equol excretion by 58% (P = 0.0001). Equol producers also had a 315% increase in 2:16 ratio (P = 0.001) with SeaSoy. Seaweed favorably alters estrogen and phytoestrogen metabolism and these changes likely include modulation of colonic bacteria.

Bioactivation of Phytoestrogens: Intestinal Bacteria and Health.

PubMed

Landete, J M; Arqués, J; Medina, M; Gaya, P; de Las Rivas, B; Muñoz, R

2016-08-17

Phytoestrogens are polyphenols similar to human estrogens found in plants or derived from plant precursors. Phytoestrogens are found in high concentration in soya, flaxseed and other seeds, fruits, vegetables, cereals, tea, chocolate, etc. They comprise several classes of chemical compounds (stilbenes, coumestans, isoflavones, ellagitannins, and lignans) which are structurally similar to endogenous estrogens but which can have both estrogenic and antiestrogenic effects. Although epidemiological and experimental evidence indicates that intake of phytoestrogens in foods may be protective against certain chronic diseases, discrepancies have been observed between in vivo and in vitro experiments. The microbial transformations have not been reported so far in stilbenes and coumestans. However, isoflavones, ellagitanins, and lignans are metabolized by intestinal bacteria to produce equol, urolithins, and enterolignans, respectively. Equol, urolithin, and enterolignans are more bioavailable, and have more estrogenic/antiestrogenic and antioxidant activity than their precursors. Moreover, equol, urolithins and enterolignans have anti-inflammatory effects and induce antiproliferative and apoptosis-inducing activities. The transformation of isoflavones, ellagitanins, and lignans by intestinal microbiota is essential to be protective against certain chronic diseases, as cancer, cardiovascular disease, osteoporosis, and menopausal symptoms. Bioavailability, bioactivity, and health effects of dietary phytoestrogens are strongly determined by the intestinal bacteria of each individual.

Increased probiotic yogurt or resistant starch intake does not affect isoflavone bioavailability in subjects consuming a high soy diet.

PubMed

Larkin, Theresa A; Price, William E; Astheimer, Lee B

2007-10-01

Probiotics and prebiotics that affect gut microflora balance and its associated enzyme activity may contribute to interindividual variation in isoflavone absorption after soy intake, possibly enhancing isoflavone bioavailability. This study examined the effects of the consumption of bioactive yogurt (a probiotic) or resistant starch (a known prebiotic) in combination with high soy intake on soy isoflavone bioavailability. Using a crossover design, chronic soy consumption was compared with soy plus probiotic yogurt or resistant starch in older male and postmenopausal females (n = 31). Isoflavone bioavailability was assessed at the beginning and end of each 5-wk dietary period by sampling plasma and urine after a standardized soy meal. Chronic soy intake did not significantly affect plasma or urinary isoflavones after the soy meal and there were no significant effects of probiotic or resistant starch treatment. However, there were trends for increased circulating plasma daidzein and genistein after the probiotic treatment and for increased plasma daidzein and genistein 24 h after soy intake with resistant starch treatment. Neither treatment induced or increased equol production, although there was a trend for increased plasma equol in "equol-positive" subjects (n = 12) after probiotic treatment. The weak or absence of effects of probiotic yogurt or resistant starch supplement to a chronic soy diet suggests that gut microflora were not modified in a manner that significantly affected isoflavone bioavailability or metabolism.

Xylitol affects the intestinal microbiota and metabolism of daidzein in adult male mice.

PubMed

Tamura, Motoi; Hoshi, Chigusa; Hori, Sachiko

2013-12-10

This study examined the effects of xylitol on mouse intestinal microbiota and urinary isoflavonoids. Xylitol is classified as a sugar alcohol and used as a food additive. The intestinal microbiota seems to play an important role in isoflavone metabolism. Xylitol feeding appears to affect the gut microbiota. We hypothesized that dietary xylitol changes intestinal microbiota and, therefore, the metabolism of isoflavonoids in mice. Male mice were randomly divided into two groups: those fed a 0.05% daidzein with 5% xylitol diet (XD group) and those fed a 0.05% daidzein-containing control diet (CD group) for 28 days. Plasma total cholesterol concentrations were significantly lower in the XD group than in the CD group (p < 0.05). Urinary amounts of equol were significantly higher in the XD group than in the CD group (p < 0.05). The fecal lipid contents (% dry weight) were significantly greater in the XD group than in the CD group (p < 0.01). The cecal microbiota differed between the two dietary groups. The occupation ratios of Bacteroides were significantly greater in the CD than in the XD group (p < 0.05). This study suggests that xylitol has the potential to affect the metabolism of daidzein by altering the metabolic activity of the intestinal microbiota and/or gut environment. Given that equol affects bone health, dietary xylitol plus isoflavonoids may exert a favorable effect on bone health.

Xylitol Affects the Intestinal Microbiota and Metabolism of Daidzein in Adult Male Mice

PubMed Central

Tamura, Motoi; Hoshi, Chigusa; Hori, Sachiko

2013-01-01

This study examined the effects of xylitol on mouse intestinal microbiota and urinary isoflavonoids. Xylitol is classified as a sugar alcohol and used as a food additive. The intestinal microbiota seems to play an important role in isoflavone metabolism. Xylitol feeding appears to affect the gut microbiota. We hypothesized that dietary xylitol changes intestinal microbiota and, therefore, the metabolism of isoflavonoids in mice. Male mice were randomly divided into two groups: those fed a 0.05% daidzein with 5% xylitol diet (XD group) and those fed a 0.05% daidzein-containing control diet (CD group) for 28 days. Plasma total cholesterol concentrations were significantly lower in the XD group than in the CD group (p < 0.05). Urinary amounts of equol were significantly higher in the XD group than in the CD group (p < 0.05). The fecal lipid contents (% dry weight) were significantly greater in the XD group than in the CD group (p < 0.01). The cecal microbiota differed between the two dietary groups. The occupation ratios of Bacteroides were significantly greater in the CD than in the XD group (p < 0.05). This study suggests that xylitol has the potential to affect the metabolism of daidzein by altering the metabolic activity of the intestinal microbiota and/or gut environment. Given that equol affects bone health, dietary xylitol plus isoflavonoids may exert a favorable effect on bone health. PMID:24336061

Equol and its relation to osteoporosis prevention using soy

USDA-ARS?s Scientific Manuscript database

Soy isoflavones are believed to have anti-osteoporotic properties, but the relationship to equol production status is unclear. To evaluate effects of soy isoflavones and metabolites on bone loss, 403 early postmenopausal women (54.0+/-4.0 y) were enrolled in an intent-to-treat, multi-site, 2-year, r...

Vascular function and atherosclerosis progression after 1 y of flavonoid intake in statin-treated postmenopausal women with type 2 diabetes: a double-blind randomized controlled trial.

PubMed

Curtis, Peter J; Potter, John; Kroon, Paul A; Wilson, Paddy; Dhatariya, Ketan; Sampson, Mike; Cassidy, Aedín

2013-05-01

In healthy participants, short-term flavan-3-ol and isoflavone intakes improve vascular function; however, the potential combined benefit of these compounds on atherosclerosis progression remains unclear for those at elevated risk of cardiovascular disease. The objective was to examine whether combined isoflavone and flavan-3-ol intake alters vascular function in postmenopausal women with type 2 diabetes mellitus (T2DM). A double-blind, parallel-design, placebo-controlled 1-y trial was conducted in postmenopausal T2DM patients randomly assigned to a split dose of 27 g flavonoid-enriched chocolate/d [850 mg flavan-3-ols (90 mg epicatechin) + 100 mg isoflavones (aglycone equivalents)/d] or matched placebo. Intima-media thickness of the common carotid artery (CCA-IMT), pulse wave velocity (PWV), augmentation index, blood pressure (BP), and vascular biomarkers were assessed. A total of 93 patients completed the trial. Overall, the flavonoid intervention did not significantly change CCA-IMT, augmentation index, or BP, but pulse pressure variability improved (flavonoid: -0.11 ± 0.07 mm Hg/min; placebo: 0.10 ± 0.11 mm Hg/min; P = 0.04). In a subgroup with PWV data, net improvements were observed [flavonoid (n = 18): -0.07 ± 0.38 m/s; placebo (n = 17): 0.68 ± 0.25 m/s; P = 0.01], which equated to a 10% CV risk reduction. Equol producers (n = 17) had larger reductions in diastolic BP, mean arterial pressure, and PWV (-2.24 ± 1.31 mm Hg, -1.24 ± 1.30 mm Hg, and -0.68 ± 0.40 m/s, respectively; P < 0.01) compared with non-equol producers (n = 30). Although the 1-y intervention did not change CCA-IMT or BP, clinically relevant improvements in arterial stiffness were observed; equol producers were particularly responsive. Flavonoids may augment existing therapeutic strategies to reduce cardiovascular disease risk in postmenopausal T2DM patients, and longer studies are needed to examine the effects on atherosclerosis progression. This trial was registered at clinicaltrials.gov as NCT00677599.

Effect of whole soy and purified isoflavone daidzein on renal function--a 6-month randomized controlled trial in equol-producing postmenopausal women with prehypertension.

PubMed

Liu, Zhao-min; Ho, Suzanne C; Chen, Yu-ming; Tang, Nelson; Woo, Jean

2014-09-01

The aim of the study was to examine the long-term effect of commonly used whole soy foods (soy flour) and purified daidzein (one major isoflavone and the precursor of equol) on renal function among prehypertensive postmenopausal women who are also equol producers, a population most likely to benefit from soy intervention. This was a 6-month double-blind, randomized, placebo-controlled trial. Two hundred seventy eligible Chinese women were randomized to either one of the three treatments: 40 g soy flour (whole soy group), 40 g low-fat milk powder + 63 mg daidzein (daidzein group) or 40 g low-fat milk powder (placebo group) daily each for 6 months. Fasting blood and 24-h urine samples were collected at the beginning and end of trial. Serum creatinine, cystatin C, urea, angiotensin-converting enzyme, minerals and 24-h urinary creatinine and minerals were analyzed. Estimated glomerular filtration rate (eGFR) was calculated with the Cockcroft-Gault and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations. Two hundred fifty-three subjects completed the study according to the protocol. Urinary isoflavones indicated good compliance of participants. No significant changes were observed in most of renal parameters, however, there was a less decrease in eGFRcockcroft in 6-month change (p=0.044) and %change (p=0.031) with whole soy intake relative to milk placebo. Subgroup analysis among women with lowered renal function suggested whole soy consumption tended to improve markers of renal function relative to control. Six-month consumption of whole soy tended to have a modest improvement of renal function in prehypertensive postmenopausal women with lowered renal function. Future trials in subjects with more declined renal function are necessary. The trial was registered in ClinicalTrials.gov with identifier of NCT01270737. (URL: http://clinicaltrials.gov/ct2/show/NCT01270737). Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Formononetin, a phyto-oestrogen, and its metabolites up-regulate interleukin-4 production in activated T cells via increased AP-1 DNA binding activity

PubMed Central

Park, Jin; Kim, Seung H; Cho, Daeho; Kim, Tae S

2005-01-01

Phyto-oestrogens are polyphenolic non-steroidal plant compounds with oestrogen-like biological activity. Phyto-oestrogens have many biological effects including oestrogen agonist/antagonist properties. However, the effect of phyto-oestrogens on allergic responses remains unclear. In this study we investigated whether formononetin, a phyto-oestrogen, and its metabolites, daidzein and equol, affect production of interleukin-4 (IL-4), a pro-inflammatory cytokine closely associated with allergic immune response, in primary CD4+ T cells and EL4 T lymphoma cells. Formononetin, daidzein and equol significantly enhanced IL-4 production from both CD4+ T cells and EL4 cells in a dose-dependent manner. Formononetin, daidzein and equol also enhanced IL-4 gene promoter activity in EL4 cells transiently transfected with IL-4 gene promoter constructs, but this effect was impaired in EL4 cells transfected with an IL-4 promoter construct deleted of P4 site carrying nuclear factor of activated T cells (NF-AT) and activator protein-1 (AP-1) binding sites. In addition, formononetin, daidzein and equol increased AP-1 DNA binding activities while did not affect NF-AT DNA binding activities. The enhancing effects on IL-4 production and AP-1 DNA binding activities were abrogated by specific inhibitors for phosphatidylinositol-3-kinase (PI3K), protein kinase C (PKC) and p38 mitogen-activated protein kinase (MAPK), indicating that formononetin, daidzein and equol might enhance IL-4 production by increased activation of AP-1 through the PI3-K/PKC/p38 MAPK signalling pathway. These results suggest that phyto-oestrogens and some of their metabolites may increase allergic responses via the enhancement of IL-4 production in T cells. PMID:16108819

Transport of steroid hormones, phytoestrogens, and estrogenic activity across a swine lagoon/sprayfield system.

PubMed

Yost, Erin E; Meyer, Michael T; Dietze, Julie E; Williams, C Michael; Worley-Davis, Lynn; Lee, Boknam; Kullman, Seth W

2014-10-07

The inflow, transformation, and attenuation of natural steroid hormones and phytoestrogens and estrogenic activity were assessed across the lagoon/sprayfield system of a prototypical commercial swine sow operation. Free and conjugated steroid hormones (estrogens, androgens, and progesterone) were detected in urine and feces of sows across reproductive stages, with progesterone being the most abundant steroid hormone. Excreta also contained phytoestrogens indicative of a soy-based diet, particularly, daidzein, genistein, and equol. During storage in barn pits and the anaerobic lagoon, conjugated hormones dissipated, and androgens and progesterone were attenuated. Estrone and equol persisted along the waste disposal route. Following application of lagoon slurry to agricultural soils, all analytes exhibited attenuation within 2 days. However, analytes including estrone, androstenedione, progesterone, and equol remained detectable in soil at 2 months postapplication. Estrogenic activity in the yeast estrogen screen and T47D-KBluc in vitro bioassays generally tracked well with analyte concentrations. Estrone was found to be the greatest contributor to estrogenic activity across all sample types. This investigation encompasses the most comprehensive suite of natural hormone and phytoestrogen analytes examined to date across a livestock lagoon/sprayfield and provides global insight into the fate of these analytes in this widely used waste management system.

Transport of Steroid Hormones, Phytoestrogens, and Estrogenic Activity across a Swine Lagoon/Sprayfield System

PubMed Central

Yost, Erin E.; Meyer, Michael T.; Dietze, Julie E.; Williams, C. Michael; Worley-Davis, Lynn; Lee, Boknam; Kullman, Seth W.

2017-01-01

The inflow, transformation, and attenuation of natural steroid hormones, phytoestrogens, and estrogenic activity was assessed across the lagoon/sprayfield system of a prototypical commercial swine sow operation. Free and conjugated steroid hormones (estrogens, androgens, and progesterone) were detected in urine and feces of sows across reproductive stages, with progesterone being the most abundant steroid hormone. Excreta also contained phytoestrogens indicative of a soy-based diet; particularly daidzein, genistein, and equol. During storage in barn pits and the anaerobic lagoon, conjugated hormones dissipated, and androgens and progesterone were attenuated. Estrone and equol persisted along the waste disposal route. Following application of lagoon slurry to agricultural soils, all analytes exhibited attenuation within 2 days. However, analytes including estrone, androstenedione, progesterone, and equol remained detectable in soil at two months post-application. Estrogenic activity in the yeast estrogen screen and T47D-KBluc in vitro bioassays generally tracked well with analyte concentrations. Estrone found to be the greatest contributor to estrogenic activity across all sample types. This investigation encompasses the most comprehensive suite of natural hormone and phytoestrogen analytes examined to date across a lagoon/sprayfield system, and provides global insight into the fate of these analytes in this widely used waste management system. PMID:25148584

Determination of in vitro isoflavone degradation in rumen fluid.

PubMed

Trnková, Andrea; Šancová, Kateřina; Zapletalová, Martina; Kašparovská, Jitka; Dadáková, Kateřina; Křížová, Ludmila; Lochman, Jan; Hadrová, Sylvie; Ihnatová, Ivana; Kašparovský, Tomáš

2018-06-01

The aim of this study was to determine the degradation of dietary isoflavones in rumen fluid under 2 feeding regimens. The experiments were performed in vitro using a rumen fluid buffer system. The rumen fluid was taken from cows fed either a hay diet or a concentrate-rich diet (the diet consisted of 34.6% maize silage, 17.6% haylage, 12.8% alfalfa hay, and 35.0% supplemental mixture on a dry matter basis). As a source of isoflavones, 40% soybean extract (Biomedica, Prague, Czech Republic) at levels of 5, 25, 50, and 75 mg per 40 mL of rumen fluid was used. Samples of soybean extract were incubated in triplicate at 39°C for 0, 3.0, 6.0, 12.0, and 24.0 h in incubation solution. The metabolism of daidzein and genistein was faster under concentrate-rich diet conditions. In general, production of equol started after 3 to 6 h of incubation and reached the highest rate after approximately 12 h of incubation regardless of the type of diet or concentration of extract. In most of the experiments, production of equol continued after 24 h of incubation. Generally, equol production was greater under the hay diet conditions. Furthermore, experiments with higher amounts of added soybean extract revealed possible inhibitory effects of high levels of isoflavones on the rumen microflora. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Growth performance, carcass characteristics and bioavailability of isoflavones in pigs fed soy bean based diets.

PubMed

Kuhn, Gerda; Hennig, U; Kalbe, Claudia; Rehfeldt, Charlotte; Ren, M Q; Moors, S; Degen, Gisela H

2004-08-01

A growth trial with 38 weaners (castrated male pigs) was designed to compare the growth performance and carcass quality of pigs fed diets containing either soy bean meal or soy protein concentrate in a pair-feeding design. Soy bean meal (SBM) and soy protein concentrate (SPC) differed in isoflavone (daidzein plus genistein) content (782 microg/g in SBM and 125 microg/g in SPC, respectively). During the experiment, all pigs were fed four-phases-diets characterized by decreasing protein concentrations with increasing age (weaner I, weaner II, grower, finisher diets). Rations of control and experimental groups were isoenergetic, isonitrogenous, and isoaminogen. The weanling pigs with an initial live weight of 8.4 +/- 1.1 kg were allotted to flat deck boxes. During the growing/finishing period (days 70-170 of age), the pigs were housed in single boxes. Both, the weaning and the grower/finishing performances (daily body weight gain, feed intake, feed conversion ratio) were similar in both groups. No differences were found between the groups in carcass composition (percentages of cuts, tissues, and protein/fat), and meat quality of pigs. Moreover, the IGF-1R mRNA expression in longissimus muscle was not influenced by the kind of soy product. However, circulating levels of isoflavones were clearly different between pigs fed SBM (genistein 239 +/- 44; daidzein 162 +/- 42; equol 12 +/- 4 ng/ml plasma) and animals fed SPC (genistein 22 +/- 9 and daidzein 8 +/- 3, and equol 10 +/- 3 ng/ml plasma). The results confirm the expected differences in the bioavailability of soy isoflavones, yet, there were no significant differences in performance of pigs fed either soy bean meal or soy protein concentrate.

Soy proteins and isoflavones affect bone mineral density in older women: a randomized controlled trial.

PubMed

Kenny, Anne M; Mangano, Kelsey M; Abourizk, Robin H; Bruno, Richard S; Anamani, Denise E; Kleppinger, Alison; Walsh, Stephen J; Prestwood, Karen M; Kerstetter, Jane E

2009-07-01

Soy foods contain several components (isoflavones and amino acids) that potentially affect bone. Few long-term, large clinical trials of soy as a means of improving bone mineral density (BMD) in late postmenopausal women have been conducted. Our goal was to evaluate the long-term effect of dietary soy protein and/or soy isoflavone consumption on skeletal health in late postmenopausal women. We conducted a randomized, double-blind, placebo-controlled clinical trial in 131 healthy ambulatory women aged >60 y. Ninety-seven women completed the trial. After a 1-mo baseline period, subjects were randomly assigned into 1 of 4 intervention groups: soy protein (18 g) + isoflavone tablets (105 mg isoflavone aglycone equivalents), soy protein + placebo tablets, control protein + isoflavone tablets, and control protein + placebo tablets. Consumption of protein powder and isoflavone pills did not differ between groups, and compliance with the study powder and pills was 80-90%. No significant differences in BMD were observed between groups from baseline to 1 y after the intervention or in BMD change between equol and non-equol producers. However, there were significant negative correlations between total dietary protein (per kg) and markers of bone turnover (P < 0.05). Because soy protein and isoflavones (either alone or together) did not affect BMD, they should not be considered as effective interventions for preserving skeletal health in older women. The negative correlation between dietary protein and bone turnover suggests that increasing protein intakes may suppress skeletal turnover. This trial was registered at ClinicalTrials.gov as NCT00668447.

Urinary Isoflavonoid Excretion is Similar after Consuming Soy Milk and Miso Soup in Japanese-American Women

PubMed Central

Maskarinec, Gertraud; Watts, Kirsten; Kagihara, Jamie; Hebshi, Sandra M.; Franke, Adrian A.

2009-01-01

Based on the hypothesis that isoflavones are absorbed more efficiently from fermented than from non-fermented soy foods, we compared the urinary isoflavonoid excretion (UIE) after intake of miso soup or soy milk. We recruited 21 women with Japanese ancestry who consumed standardized soy portions containing 48 mg isoflavones. On day 1, half the women consumed soy milk, the other half started with miso soup. On day 3, the subjects ate the other soy food and on day 5, they repeated the first food. Each participant collected a spot urine sample before and an overnight urine sample after soy food intake. All urine samples were analyzed for the daidzein, genistein, and equol using liquid chromatography-mass spectrometry and were expressed as nmol per mg creatinine. We applied mixed models to evaluate the difference in UIE by food while including the baseline values and covariates. Relative to baseline, both groups experienced significantly higher UIE after consuming any of the soy foods. We observed no significant difference in UIE when soy milk was compared to miso soup (p = 0.87) among all women or in the seven equol producers (p = 0.88). Repeated intake of the same food on different days showed high reproducibility within subjects. These preliminary results indicate similar UIEs after consuming a fermented soy food (miso) as compared to a non-fermented soy food (soy milk). Therefore, recommendations favoring fermented soy foods are not justified as long as the intestinal microflora is capable of hydrolyzing the isoflavone glucosides from non-fermented soy foods. PMID:18275624

Isoflavonoid-based bone-sparing treatments exert a low activity on reproductive organs and on hepatic metabolism of estradiol in ovariectomized rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Phrakonkham, Pascal; Chevalier, Joelle; Desmetz, Catherine

2007-10-15

The use of soy isoflavones is a potential alternative to hormone replacement therapy in post-menopausal bone-loss prevention. Nevertheless, phytoestrogens can target other organs and may disrupt cell proliferation, or could modify endogenous steroid hormone metabolism. These mechanisms could be linked to an increased risk of developing cancer. We therefore studied the possible side effects of such treatments in an experimental model of menopause. Forty adult female Wistar rats were ovariectomized and fed with a genistein-, daidzein- or equol-supplemented diet at bone-sparing levels (10 mg/kg BW/day) for 3 months. The estrogenic effects were assessed by histological and molecular analyses on reproductivemore » organs. The impact on the oxidative metabolism of estradiol and on associated cytochrome P450 (CYP) activities was evaluated in liver microsomes. The relative wet weights of both the uterus and the vagina were increased in the equol group, but no significant changes in proliferating cell nuclear antigen or hormone receptor mRNA expression were noticed. In contrast, genistein and daidzein did not induce uterotrophy but caused an overexpression of estrogen receptor {alpha} mRNA which could correspond to a long-lasting effect of physiological concentrations of estrogens. The hepatic metabolism of estradiol was influenced by daidzein which increased the synthesis of putative mutagenic derivatives. At the same time, genistein favored estrogen 2-hydroxylation, and equol decreased 4-hydroxyestrogen production. Surprisingly, no significant alteration in hepatic CYP activities was detected. Taken together, these results demonstrate that isoflavonoid-based bone-sparing treatments are able to cause side effects on other estrogen-sensitive target organs when given in the long-term.« less

Alterations in gut microflora populations and brush border functionality following intra-amniotic daidzein administration

USDA-ARS?s Scientific Manuscript database

Daidzein is an isoflavone found primarily in soybean and various soy-based products such as tofu. In the intestines, daidzein is reductively transformed to its constituent metabolites equol and O-desmethylangolensin. Although the ingestion of daidzein has been associated with marked physiological im...

Plasma isoflavones in Malaysian men according to vegetarianism and by age.

PubMed

Hod, Rafidah; Kouidhi, Wided; Ali Mohd, Mustafa; Husain, Ruby

2016-01-01

Epidemiological studies indicate lower prevalences of breast and prostate cancers and cardiovascular disease in Southeast Asia where vegetarianism is popular and diets are traditionally high in phytoestrogens. This study assessed plasma isoflavones in vegetarian and non-vegetarian Malaysian men according to age. Daidzein, genistein, equol (a daidzein metabolite), formononetin, biochanin A, estrone, estradiol and testosterone were measured by validated liquid chromatography tandem mass spectrometry (LCMSMS). Plasma isoflavone and sex hormone concentrations were measured in 225 subjects according to age (18-34, 35-44 and 45-67 years old). In all age groups, vegetarians had a higher concentration of circulating isoflavones compared with non-vegetarians especially in the 45-67 year age group where all isoflavones except equol, were significantly higher in vegetarians compared with omnivores. By contrast, the 18-34 year group had a significantly higher concentration of daidzein in vegetarians and significantly higher testosterone and estrone concentrations compared with non-vegetarians. In this age group there were weak correlations between estrone, estradiol and testosterone with some of the isoflavones. This human study provides the first Malaysian data for the phytoestrogen status of vegetarian and nonvegetarian men.

Bioconversion Using Lactic Acid Bacteria: Ginsenosides, GABA, and Phenolic Compounds.

PubMed

Lee, Na-Kyoung; Paik, Hyun-Dong

2017-05-28

Lactic acid bacteria (LAB) are used as fermentation starters in vegetable and dairy products and influence the pH and flavors of foods. For many centuries, LAB have been used to manufacture fermented foods; therefore, they are generally regarded as safe. LAB produce various substances, such as lactic acid, β-glucosidase, and β-galactosidase, making them useful as fermentation starters. Existing functional substances have been assessed as fermentation substrates for better component bioavailability or other functions. Representative materials that were bioconverted using LAB have been reported and include minor ginsenosides, γ-aminobutyric acid, equol, aglycones, bioactive isoflavones, genistein, and daidzein, among others. Fermentation mainly involves polyphenol and polysaccharide substrates and is conducted using bacterial strains such as Streptococcus thermophilus, Lactobacillus plantarum, and Bifidobacterium sp. In this review, we summarize recent studies of bioconversion using LAB and discuss future directions for this field.

A new method to evaluate anti-allergic effect of food component by measuring leukotriene B4 from a mouse mast cell line.

PubMed

Takasugi, Mikako; Muta, Emi; Yamada, Koji; Arai, Hirofumi

2018-02-01

Leukotrienes (LTs), chemical mediators produced by mast cells, play an important role in allergic symptoms such as food allergies and hay fever. We tried to construct an evaluation method for the anti-LTB 4 activity of chemical substances using a mast cell line, PB-3c. PB-3c pre-cultured with or without arachidonic acid (AA) was stimulated by calcium ionophore (A23187) for 20 min, and LTB 4 production by the cells was determined by HPLC with UV detection. LTB 4 was not detected when PB-3c was pre-cultured without AA. On the other hand, LTB 4 production by PB-3c pre-cultured with AA was detectable by HPLC, and the optimal conditions of PB-3c for LTB 4 detection were to utilize the cells pre-cultured with 50 µM AA for 48 h. MK-886 (5-lipoxygenase inhibitor) completely inhibited LTB 4 production, but AACOCF 3 (phospholipase A 2 inhibitor) slightly increased LTB 4 production, suggesting that LTB 4 was generated from exogenous free AA through 5-lipoxygenase pathway. We applied this technique to the evaluation of the anti-LTB 4 activity of food components. PB-3c pre-cultured with 50 µM AA for 48 h was stimulated with A23187 in the presence of 50 µM soybean isoflavones (daidzin, genistin, daidzein, and genistein), equol, quercetin, or kaempferol. Genistein, equol, quercetin, and kaempferol strongly inhibited LTB 4 production without cytotoxicity. These results suggest that a new assay system using PB-3c is convenient to evaluate LTB 4 inhibition activity by food components. This method could be utilized for elucidation of the mechanisms of LTB 4 release suppression by food components such as flavonoids and the structure-activity relationship.

SoyCaP: Soy and Prostate Cancer Prevention

DTIC Science & Technology

2006-11-01

2:16-hydroxyestrone ratio in postmenopausal women depends on equol production status but is not influenced by probiotic consumption. J Nutr 2005 Mar...their habitual diets, and received detailed instructions to exclude soy products in order to minimize isoflavone consumption from other sources...deparaffinized in AmeriClear (Scientific Products , Stockton, CA), rehydrated in graded alcohol, and transferred to phosphate buffered saline (PBS) (pH

Soy isoflavone metabolism in cats compared with other species: Urinary metabolite concentrations and glucuronidation by liver microsomes

PubMed Central

Redmon, Joanna M.; Shrestha, Binu; Cerundolo, Rosario; Court, Michael H.

2016-01-01

Soybean is a common source of protein in many pet foods. Slow glucuronidation of soy-derived isoflavones in cats has been hypothesized to result in accumulation with adverse health consequences. Here we evaluated species’ differences in soy isoflavone glucuronidation using urine samples from cats and dogs fed a soy-based diet and liver microsomes from cats compared with microsomes from 12 other species.Significant concentrations of conjugated (but not unconjugated) genistein, daidzein, and glycitein, and the gut microbiome metabolites, dihydrogenistein and dihydrodaidzein were found in cat and dog urine samples. Substantial amounts of conjugated equol were also found in cat urine but not in dog urine.β-glucuronidase treatment showed that all these compounds were significantly glucuronidated in dog urine while only daidzein (11%) and glycitein (37%) showed any glucuronidation in cat urine suggesting that alternate metabolic pathways including sulfation predominate in cats.Glucuronidation rates of genistein, daidzein, and equol by cat livers were consistently ranked within the lowest three out of 13 species’ livers evaluated. Ferret and mongoose livers were also ranked in the lowest four species.Our results demonstrate that glucuronidation is a minor pathway for soy isoflavone metabolism in cats compared with most other species. PMID:26366946

Soy isoflavone metabolism in cats compared with other species: urinary metabolite concentrations and glucuronidation by liver microsomes.

PubMed

Redmon, Joanna M; Shrestha, Binu; Cerundolo, Rosario; Court, Michael H

2016-01-01

1. Soybean is a common source of protein in many pet foods. Slow glucuronidation of soy-derived isoflavones in cats has been hypothesized to result in accumulation with adverse health consequences. Here, we evaluated species' differences in soy isoflavone glucuronidation using urine samples from cats and dogs fed a soy-based diet and liver microsomes from cats compared with microsomes from 12 other species. 2. Significant concentrations of conjugated (but not unconjugated) genistein, daidzein and glycitein, and the gut microbiome metabolites, dihydrogenistein and dihydrodaidzein, were found in cat and dog urine samples. Substantial amounts of conjugated equol were also found in cat urine but not in dog urine. 3. β-Glucuronidase treatment showed that all these compounds were significantly glucuronidated in dog urine while only daidzein (11%) and glycitein (37%) showed any glucuronidation in cat urine suggesting that alternate metabolic pathways including sulfation predominate in cats. 4. Glucuronidation rates of genistein, daidzein and equol by cat livers were consistently ranked within the lowest 3 out of 13 species' livers evaluated. Ferret and mongoose livers were also ranked in the lowest four species. 5. Our results demonstrate that glucuronidation is a minor pathway for soy isoflavone metabolism in cats compared with most other species.

Soy provides modest benefits on endothelial function without affecting inflammatory biomarkers in adults at cardiometabolic risk

PubMed Central

Reverri, Elizabeth J.; LaSalle, Colette D.; Franke, Adrian A.; Steinberg, Francene M.

2015-01-01

Scope Systemic inflammation, endothelial dysfunction, and oxidative stress are involved in the pathogenesis of the metabolic syndrome (MetS). Epidemiological evidence supports an association between whole soy food consumption and reduced risk of cardiovascular disease (CVD). The objective of this randomized, controlled, crossover study was to evaluate the effects of soy nut consumption on inflammatory biomarkers and endothelial function and to assess whether isoflavone metabolism to secondary products, equol and/or O-desmethylangolensin (ODMA), modifies these responses. Methods and Results n=17 adults at cardiometabolic risk were randomly assigned to the order of two snack interventions, soy nuts and macronutrient-matched control snack, for four weeks each, separated by a two week washout period. Outcome measures included biomarkers of inflammation, oxidative stress, and glycemic control (ELISA and clinical analyzers), endothelial function and arterial stiffness (peripheral arterial tonometry (PAT)), and isoflavone metabolites (LC-MS/MS). Results revealed that consuming soy nuts improved arterial stiffness as assessed by the augmentation index using PAT (P=0.03), despite lack of improvement in inflammatory biomarkers. Addition of equol and/ODMA production status as covariates did not significantly change these results. Conclusions Soy nuts when added to a usual diet for one month provide some benefit on arterial stiffness in adults at cardiometabolic risk. PMID:25351805

Factors affecting the bioavailability of soy isoflavones in humans after ingestion of physiologically relevant levels from different soy foods.

PubMed

Cassidy, Aedin; Brown, Jonathan E; Hawdon, Anne; Faughnan, Marian S; King, Laurence J; Millward, Joe; Zimmer-Nechemias, Linda; Wolfe, Brian; Setchell, Kenneth D R

2006-01-01

The precise role that isoflavones play in the health-related effects of soy foods, and their potential for adverse effects are controversial. This may be due in part to a lack of basic knowledge regarding their bioavailability and metabolism, particularly as it relates to the soy source. To date, there is little information concerning possible differences in the bioavailability of isoflavones derived from natural soy foods consumed at physiologically relevant intakes and whether age- or gender-related differences influence that bioavailability. In the current study of healthy adults [premenopausal (n = 21) and postmenopausal (n = 17) women and a group of men (n = 21)], we examined the effect of age, gender, and the food matrix on the bioavailability of isoflavones for both the aglycon and glucoside forms that are naturally present in 3 different soy foods, soy milk, textured vegetable protein, and tempeh. The study was designed as a random crossover trial so that all individuals received each of the 3 foods. The dose of isoflavones administered to each individual as a single bolus dose was 0.44 mg/kg body weight. Pharmacokinetic parameters were normalized to mg of each isoflavone ingested per kilogram body weight to account for differences in daidzein and genistein content between the diets. Serum isoflavone concentrations in all individuals and groups increased rapidly after the ingestion of each soy food; as expected, genistein concentrations exceeded daidzein concentrations in serum. In this small study, gender differences in peak concentrations of daidzein were observed, with higher levels attained in women. Consumption of tempeh (mainly isoflavone aglycon) resulted in higher serum peak levels of both daidzein (P < 0.001) and genistein (P < 0.01) and the associated area under the curve (P < 0.001 and P < 0.03, respectively) compared with textured vegetable protein (predominantly isoflavone glucosides). However, soy milk was absorbed faster and peak levels of isoflavones were attained earlier than with the other soy foods. Only 30% of the subjects were equol producers and no differences in equol production with age or gender were observed.

Anti-cancer Effects of Polyphenolic Compounds in Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor-resistant Non-small Cell Lung Cancer

PubMed Central

Jeong, Hyungmin; Phan, Ai N. H.; Choi, Jong-Whan

2017-01-01

Background: Polyphenolic phytochemicals are natural compounds, easily found in fruits and vegetables. Importantly, polyphenols have been intensively studied as excellent antioxidant activity which contributes to anticancer function of the natural compounds. Lung cancer has been reported to mainly account for cancer-related deaths in the world. Moreover, epidermal growth factor receptor tyrosine kinase inhibitor (TKI) resistance is one of the biggest issues in cancer treatment, especially in nonsmall cell lung cancer (NSCLC). Even though several studies both in preclinical and clinical trials have showed promising therapeutic effects of polyphenolic compounds in anticancer therapy, the function of the natural compounds in TKI-resistant (TKIR) lung cancer remains poorly studied. Objective: The aim of this study is to screen polyphenolic compounds as potential anticancer adjuvants which suppress TKIR lung cancer. Materials and Methods: Colony formation and thiazolyl blue tetrazolium blue assay were performed in the pair-matched TKI-sensitive (TKIS) versus TKIR tumor cell lines to investigate the therapeutic effect of polyphenolic compounds in TKIR NSCLC. Results: Our data show that equol, kaempferol, resveratrol, and ellagic acid exhibit strong anticancer effect in HCC827 panel. Moreover, the inhibitory effect of most of tested polyphenolic compounds was highly selective for TKIR lung cancer cell line H1993 while sparing the TKIS one H2073. Conclusion: This study provides an important screening of potential polyphenolic compounds for drug development to overcome TKI resistance in advanced lung cancer. SUMMARY The study provides an important screening of potential polyphenolic compounds for drug development to overcome tyrosine kinase inhibitor (TKI) resistance in advance lung cancerEquol, kaempferol, resveratrol, and ellagic acid show strong anticancer effect in HCC827 panel, including TKI-sensitive (TKIS) and TKI-resistant clonesThe inhibitory effect of polyphenolic compounds such as equol, kaempferol, resveratrol, ellagic acid, gallic acid, p-Coumaric, and hesperidin is highly selective for TKI-resistant lung cancer cell line H1993 while sparing the TKIS one H2073. Abbreviations used: EGFR: Epidermal growth factor receptor, EMT: Epithelial-to-mesenchymal transition, GTP: Green tea polyphenols, IGF1R: Insulin-like growth factor 1 receptor, MET: Met proto-oncogene, MTT: Thiazolyl blue tetrazolium blue, NSCLC: Non-small cell lung cancer, ROS: Reactive oxygen species, RTK: Receptor tyrosine kinase, STAT3: Signal transducer and activator of transcription 3, TKIR: TKI-resistant, TKIs: Tyrosine kinase inhibitors, TKIS: TKI-sensitive. PMID:29200719

Role of Protein Synthesis Initiation Factors in Dietary Soy Isoflavone-Mediated Effects on Breast Cancer Progression

DTIC Science & Technology

2013-03-01

and complemented with data from the present report (recently published in the Journal of Biological Chemistry ) (6), was that the described increase in...Biological Chemistry (6). To investigate if the increased protein expression in response to equol was due to an increase in gene expression, we... Chemistry . Volume 50, Number, 10. pp.41640-50. See Appendix 12    CONCLUSION: Results with highly metastatic cancer cell lines show that the effects of

In vitro and in vivo effects of phytoestrogens on protein turnover in rainbow trout (Oncorhynchus mykiss) white muscle.

PubMed

Cleveland, Beth M

2014-09-01

Soybeans and other legumes investigated as fishmeal replacements in aquafeeds contain phytoestrogens capable of binding to and activating estrogen receptors. Estradiol has catabolic effects in salmonid white muscle, partially through increases in protein turnover. The current study determines whether phytoestrogens promote similar effects. In rainbow trout (Oncorhynchus mykiss) primary myocyte cultures, the phytoestrogens genistein, daidzein, glycitein, and R- and S-equol reduced rates of protein synthesis and genistein, the phytoestrogen of greatest abundance in soy, also increased rates of protein degradation. Increased expression of the ubiquitin ligase fbxo32 and autophagy-related genes was observed with high concentrations of genistein (100 μM), and R- and S-equol (100 μM) also up-regulated autophagy-related genes. In contrast, low genistein concentrations in vitro (0.01-0.10 μM) and in vivo (5 μg/g body mass) decreased fbxo32 expression, suggesting a potential metabolic benefit for low levels of genistein exposure. Phytoestrogens reduced cell proliferation, indicating that effects of phytoestrogens extend from metabolic to mitogenic processes. Co-incubation of genistein with the estrogen receptor (ER) antagonist, ICI 182,780, ameliorated effects of genistein on protein degradation, but not protein synthesis or cell proliferation, indicating that effects of genistein are mediated through ER-dependent and ER-independent mechanisms. Collectively, these data warrant additional studies to determine the extent to which dietary phytoestrogens, especially genistein, affect physiological processes that impact growth and nutrient retention. Published by Elsevier Inc.

Interaction of soy isoflavones and their main metabolites with hOATP2B1 transporter.

PubMed

Navrátilová, Lucie; Applová, Lenka; Horký, Pavel; Mladěnka, Přemysl; Pávek, Petr; Trejtnar, František

2018-06-22

Membrane organic anion-transporting polypeptides (OATPs) are responsible for the drug transmembrane transport within the human body. The function of OATP2B1 transporter can be inhibited by various natural compounds. Despite increased research interest in soya as a part of human diet, the effect of its active components to interact with hOATP2B1 has not been elucidated in a complex extent. This in vitro study examined the inhibitory effect of main soy isoflavones (daidzin, daidzein, genistin, genistein, glycitin, glycitein, biochanin A, formononetin) and their metabolites formed in vivo (S-equol, O-desmethylangolensin) towards human OATP2B1 transporter. MDCKII cells overexpressing hOATP2B1 were employed to determine quantitative inhibitory parameters of the tested compounds and to analyze mechanism/s of the inhibitory interaction. The study showed that aglycones of soy isoflavones and the main biologically active metabolite S-equol were able to significantly inhibit hOATP2B1-mediated transport. The K i values for most of aglycones range from 1 to 20 μM. In contrast, glucosides did not exhibit significant inhibitory effect. The kinetic analysis did not indicate a uniform type of inhibition towards the hOATP2B1 although predominant mechanism of inhibition seemed to be competitive. These findings may suggest that tested soy isoflavones and their metabolites might affect transport of xenobiotics including drugs across tissue barriers via hOATP2B1.

Influence of 10 wk of soy consumption on plasma concentrations and excretion of isoflavonoids and on gut microflora metabolism in healthy adults.

PubMed

Wiseman, Helen; Casey, Karen; Bowey, Elizabeth A; Duffy, Rosanna; Davies, Margaret; Rowland, Ian R; Lloyd, Antony S; Murray, Alistair; Thompson, Richard; Clarke, Don B

2004-09-01

Little information is currently available on the role of the gut microflora in modulating isoflavone bioavailability or on sex differences in isoflavone metabolism and bioavailability. We sought to determine whether chronic soy consumption influences isoflavone bioavailability as judged by plasma isoflavone concentrations and modified gut microflora activities [beta-glucoside hydrolysis and equol and O-desmethylangolensin (O-DMA) production]. We also examined whether sex differences in isoflavone metabolism exist. A randomized, parallel, controlled study design was used to compare a high-soy diet (104 +/- 24 mg total isoflavones/d) with a low-soy diet (0.54 +/- 0.58 mg total isoflavones/d) in 76 healthy young adults for 10 wk. Concentrations of isoflavones and their gut microflora metabolites in the plasma, urine, and feces were significantly higher in the subjects who consumed the high-soy diet than in those who consumed the low-soy diet. Concentrations of O-DMA in plasma and urine were higher in the men than in the women. Fecal bacteria from subjects consuming both diets could convert daidzein to equol ex vivo. Fecal beta-glucosidase activity was significantly higher in the subjects who consumed the high-soy diet than in those who consumed the low-soy diet. Although interindividual variation in isoflavone metabolism was high, intraindividual variation was low. Only concentrations of O-DMA in plasma and urine appeared to be influenced by sex. Chronic soy consumption does not appear to induce many significant changes to the gut metabolism of isoflavones other than higher beta-glucosidase activity.

Probiotics: a proactive approach to health. A symposium report.

PubMed

Thomas, Linda V; Suzuki, Kaori; Zhao, Jia

2015-12-01

This report summarises talks given at the 8th International Yakult Symposium, held on 23-24 April 2015 in Berlin. Two presentations explored different aspects of probiotic intervention: the small intestine as a probiotic target and inclusion of probiotics into integrative approaches to gastroenterology. Probiotic recommendations in gastroenterology guidelines and current data on probiotic efficacy in paediatric patients were reviewed. Updates were given on probiotic and gut microbiota research in obesity and obesity-related diseases, the gut-brain axis and development of psychobiotics, and the protective effects of equol-producing strains for prostate cancer. Recent studies were presented on probiotic benefit for antibiotic-associated diarrhoea and people with HIV, as well as protection against the adverse effects of a short-term high-fat diet. Aspects of probiotic mechanisms of activity were discussed, including immunomodulatory mechanisms and metabolite effects, the anti-inflammatory properties of Faecalibacterium prausnitzii, the relationship between periodontitis, microbial production of butyrate in the oral cavity and ageing, and the pathogenic mechanisms of Campylobacter. Finally, an insight was given on a recent expert meeting, which re-examined the probiotic definition, advised on the appropriate use and scope of the term and outlined different probiotic categories and the prevalence of different mechanisms of activity.

Concentrations of isoflavones and their metabolites in the blood of pregnant and non-pregnant heifers fed soy bean.

PubMed

Woclawek-Potocka, Izabela; Piskula, Mariusz Krzysztof; Bah, Mamadou; Siemieniuch, Marta Jolanta; Korzekwa, Anna; Brzezicka, Edyta; Skarzynski, Dariusz Jan

2008-10-01

The present study compared the changes in isoflavones (daidzein and genistein) and their metabolite (equol and para-ethyl-phenol) concentrations in the blood plasma of cyclic and pregnant heifers after feeding with soy bean. Twelve healthy heifers were divided into three groups: cyclic heifers (days 8-12 of the estrous cycle; control group; n=4), an early pregnancy group (2 months pregnant; n=4) and a late pregnancy group (8 months pregnant; n=4). All heifers were fed a single dose of 2.5 kg of soy bean and then blood samples were taken from the jugular vein for 8 h at predetermined intervals. The concentrations of soy bean-derived isoflavones and their active metabolites were measured in the blood plasma on an HPLC system. In the blood plasma of the early- and late-pregnant heifers, we found lower concentrations and time-dependent decreases in daidzein and genistein in comparison to cyclic heifers (P<0.05). Moreover, we noticed significant increases of equol and para-ethyl-phenol in the blood plasma of the early-pregnant heifers (P<0.05). In contrast, in the blood plasma of the late-pregnant heifers, we did not find an increase in the isoflavone metabolite concentrations compared with the early-pregnant heifers (P>0.05). In conclusion, physiological status (cyclicity or pregnancy) of the females influenced the concentrations of isoflavone metabolites in the blood plasma of the heifers. The stage of pregnancy affects isoflavone absorption, biotransformation and metabolism differently and results in higher concentrations of active metabolites of isoflavones during early pregnancy in comparison to their lower concentrations during late pregnancy. Therefore, we surmise that cows are more sensitive to active isoflavone metabolite actions during early pregnancy than cyclic heifers and heifers in late pregnancy.

Experimentally induced mastitis and metritis modulate soy bean derived isoflavone biotransformation in diary cows.

PubMed

Kowalczyk-Zieba, I; Woclawek-Potocka, I; Piskula, M K; Piotrowska-Tomala, K K; Boruszewska, D; Bah, M M; Siemieniuch, M J; Skarzynski, D J

2011-12-01

The present study compared the changes in isoflavone (daidzein and genistein) and their metabolite (equol and para-ethyl-phenol) concentrations in the blood plasma of cows with induced mastitis and metritis after feeding with soy bean. Sixteen cows were divided into four groups: control for mastitis group, cows with induced mastitis group, control for metritis group, and cows with induced metritis group. All cows were fed a single dose of 2.5 kg of soy bean and then blood samples were taken from the jugular vein for 8 h at predetermined intervals. The concentrations of soy bean-derived isoflavones and their active metabolites were measured in the blood plasma on HPLC system. β-Glucuronidase activity in the blood plasma of cows was measured by fluorometric method. In the blood plasma of cows with induced mastitis and metritis, we found considerably higher concentrations and time-dependent increase in isoflavone metabolites (equol and para-ethyl-phenol) with reference to cyclic cows (P < 0.05). Moreover, we noticed significant decrease of genistein in the blood plasma of the cows with induced metritis compared with control cows (P < 0.05). In addition, in the blood plasma of the cows with induced metritis, we found an increase in β-glucuronidase activity compared with control cows (P < 0.05). In conclusion, health status of the females influenced the concentrations of isoflavone metabolites in the blood plasma of the cows. Experimentally induced mastitis and metritis increased isoflavone absorption, biotransformation and metabolism. Therefore, we suggest that cows with induced mastitis and metritis are more exposed to active isoflavone metabolite actions than healthy cows. Copyright © 2011. Published by Elsevier Inc.

Evaluation of a recombinant yeast cell estrogen screening assay.

PubMed Central

Coldham, N G; Dave, M; Sivapathasundaram, S; McDonnell, D P; Connor, C; Sauer, M J

1997-01-01

A wide range of chemicals with diverse structures derived from plant and environmental origins are reported to have hormonal activity. The potential for appreciable exposure of humans to such substances prompts the need to develop sensitive screening methods to quantitate and evaluate the risk to the public. Yeast cells transformed with plasmids encoding the human estrogen receptor and an estrogen responsive promoter linked to a reporter gene were evaluated for screening compounds for estrogenic activity. Relative sensitivity to estrogens was evaluated by reference to 17 beta-estradiol (E2) calibration curves derived using the recombinant yeast cells, MCF-7 human breast cancer cells, and a prepubertal mouse uterotrophic bioassay. The recombinant yeast cell bioassay (RCBA) was approximately two and five orders of magnitude more sensitive to E2 than MCF-7 cells and the uterotrophic assay, respectively. The estrogenic potency of 53 chemicals, including steroid hormones, synthetic estrogens, environmental pollutants, and phytoestrogens, was measured using the RCBA. Potency values produced with the RCBA relative to E2 (100) included estrone (9.6), diethylstilbestrol (74.3), tamoxifen (0.0047), alpha-zearalanol (1.3), equol (0.085), 4-nonylphenol (0.005), and butylbenzyl phathalate (0.0004), which were similar to literature values but generally higher than those produced by the uterotrophic assay. Exquisite sensitivity, absence of test compound biotransformation, ease of use, and the possibility of measuring antiestrogenic activity are important attributes that argue for the suitability of the RCBA in screening for potential xenoestrogens to evaluate risk to humans, wildlife, and the environment. Images Figure 1. Figure 2. Figure 3. Figure 4. PMID:9294720

Soy and phytoestrogens: possible side effects.

PubMed

Jargin, Sergei V

2014-01-01

Phytoestrogens are present in certain edible plants being most abundant in soy; they are structurally and functionally analogous to the estrogens. Phytoestrogens have been applied for compensation of hormone deficiency in the menopause. At the same time, soy products are used in infant food and other foodstuffs. Furthermore, soy is applied as animal fodder, so that residual phytoestrogens and their active metabolites such as equol can remain in meat and influence the hormonal balance of the consumers. There have been only singular reports on modified gender-related behavior or feminization in humans in consequence of soy consumption. In animals, the intake of phytoestrogens was reported to impact fertility, sexual development and behavior. Feminizing effects in humans can be subtle and identifiable only statistically in large populations.

Spermatozoa Production by Triploid Males in the New Zealand Freshwater Snail Potamopyrgus antipodarum

PubMed Central

Soper, D.M.; Neiman, M.; Savytskyy, O.P.; Zolan, M.E.; Lively, C.M.

2013-01-01

Asexual lineages derived from dioecious taxa are typically assumed to be all female. Even so, asexual females from a variety of animal taxa occasionally produce males. The existence of these males sets the stage for potential gene flow across asexual lineages as well as between sexual and asexual lineages. A recent study showed that asexual triploid female Potamopyrgus antipodarum, a New Zealand freshwater snail often used as a model to study sexual reproduction, occasionally produce triploid male offspring. Here, we show that these triploid male P. antipodarum 1) have testes that produce morphologically normal sperm, 2) make larger sperm cells that contain more nuclear DNA than the sperm produced by diploid sexual males, and 3) produce sperm that range in DNA content from haploid to diploid, and are often aneuploid. Analysis of meiotic chromosomes of triploid males showed that aberrant pairing during prophase I likely accounts for the high variation in DNA content among sperm. These results indicate that triploid male P. antipodarum produce sperm, but the extent to which these sperm are able to fertilize female ova remains unclear. Our results also suggest that the general assumption of sterility in triploid males should be more closely examined in other species in which such males are occasionally produced. PMID:24307744

Factors Affecting Pheromone Production by the Pepper Weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae) and Collection Efficiency

PubMed Central

Eller, Fred J.; Palmquist, Debra E.

2014-01-01

Several factors affecting pheromone production by male pepper weevils, Anthonomus eugenii Cano (Coleoptera: Curculionidae) as well as collection efficiency were investigated. Factors studied included: porous polymer adsorbents (Tenax versus Super Q), male age, time of day, male density, and male diet. Super Q was found to be a superior adsorbent for the male-produced alcohols and geranic acid as well as the plant-produced E-β-ocimene. Pheromone production increased with male age up to about age 15 days old and then tapered off. Male pepper weevils produced the highest amount of pheromone between noon and 2 pm (i.e., 4 to 6 h after “lights on”) and were producing ca. 800 ng/h during this period. Thereafter, pheromone production decreased and was extremely low during the scotophase (i.e., ca. 12 ng/h). Male pepper weevil density had a significant effect on both release rate and pheromone composition. Pheromone production on a per male basis was highest for individual males and the percentage of geranic acid in the blend was lowest for individual males. Male pepper weevils produced only extremely low amounts of pheromone when feeding on artificial diet; however, they produced very high amounts when on fresh peppers. Together, this information will be useful in designing better attractant lures for pepper weevils. PMID:26462948

Comparative metabolomics in vegans and omnivores reveal constraints on diet-dependent gut microbiota metabolite production

PubMed Central

Wu, Gary D; Compher, Charlene; Chen, Eric Z; Smith, Sarah A; Shah, Rachana D; Bittinger, Kyle; Chehoud, Christel; Albenberg, Lindsey G; Nessel, Lisa; Gilroy, Erin; Star, Julie; Weljie, Aalim M; Flint, Harry J; Metz, David C; Bennett, Michael J; Li, Hongzhe; Bushman, Frederic D; Lewis, James D

2015-01-01

Objective The consumption of an agrarian diet is associated with a reduced risk for many diseases associated with a ‘Westernised’ lifestyle. Studies suggest that diet affects the gut microbiota, which subsequently influences the metabolome, thereby connecting diet, microbiota and health. However, the degree to which diet influences the composition of the gut microbiota is controversial. Murine models and studies comparing the gut microbiota in humans residing in agrarian versus Western societies suggest that the influence is large. To separate global environmental influences from dietary influences, we characterised the gut microbiota and the host metabolome of individuals consuming an agrarian diet in Western society. Design and results Using 16S rRNA-tagged sequencing as well as plasma and urinary metabolomic platforms, we compared measures of dietary intake, gut microbiota composition and the plasma metabolome between healthy human vegans and omnivores, sampled in an urban USA environment. Plasma metabolome of vegans differed markedly from omnivores but the gut microbiota was surprisingly similar. Unlike prior studies of individuals living in agrarian societies, higher consumption of fermentable substrate in vegans was not associated with higher levels of faecal short chain fatty acids, a finding confirmed in a 10-day controlled feeding experiment. Similarly, the proportion of vegans capable of producing equol, a soy-based gut microbiota metabolite, was less than that was reported in Asian societies despite the high consumption of soy-based products. Conclusions Evidently, residence in globally distinct societies helps determine the composition of the gut microbiota that, in turn, influences the production of diet-dependent gut microbial metabolites. PMID:25431456

Changes in Attitudes towards Drug Educators as a Function of Communicator Sex and Role.

ERIC Educational Resources Information Center

Cotten-Huston, Annie L.; Baum, Carlene Stober

1980-01-01

Significant interactions between role and sex of communicator indicated that male ex-addicts produced more positive changes in evaluation than female ex-addicts, while female specialists produced more positive changes in evaluation than male specialists. Female specialists produced more positive changes in ratings of potency than male specialists.…

Puzzles in modern biology. I. Male sterility, failure reveals design

PubMed Central

Frank, Steven A.

2016-01-01

Many human males produce dysfunctional sperm. Various plants frequently abort pollen. Hybrid matings often produce sterile males. Widespread male sterility is puzzling. Natural selection prunes reproductive failure. Puzzling failure implies something that we do not understand about how organisms are designed. Solving the puzzle reveals the hidden processes of design. PMID:28004842

Multiple paternity in polyandrous barn owls (Tyto alba).

PubMed

Henry, Isabelle; Antoniazza, Sylvain; Dubey, Sylvain; Simon, Céline; Waldvogel, Céline; Burri, Reto; Roulin, Alexandre

2013-01-01

In polyandrous species females produce successive clutches with several males. Female barn owls (Tyto alba) often desert their offspring and mate to produce a 2(nd) annual brood with a second male. We tested whether copulating during chick rearing at the 1(st) annual brood increases the male's likelihood to obtain paternity at the 2(nd) annual breeding attempt of his female mate in case she deserts their brood to produce a second brood with a different male. Using molecular paternity analyses we found that 2 out of 26 (8%) second annual broods of deserting females contained in total 6 extra-pair young out of 15 nestlings. These young were all sired by the male with whom the female had produced the 1(st) annual brood. In contrast, none of the 49 1(st) annual breeding attempts (219 offspring) and of the 20 2(nd) annual breeding attempts (93 offspring) of non-deserting females contained extra-pair young. We suggest that female desertion can select male counter-strategies to increase paternity and hence individual fitness. Alternatively, females may copulate with the 1(st) male to derive genetic benefits, since he is usually of higher quality than the 2(nd) male which is commonly a yearling individual.

Male production in stingless bees: variable outcomes of queen-worker conflict.

PubMed

Tóth, Eva; Strassmann, Joan E; Nogueira-Neto, Paulo; Imperatriz-Fonseca, Vera L; Queller, David C

2002-12-01

The genetic structure of social insect colonies is predicted to affect the balance between cooperation and conflict. Stingless bees are of special interest in this respect because they are singly mated relatives of the multiply mated honeybees. Multiple mating is predicted to lead to workers policing each others' male production with the result that virtually all males are produced by the queen, and this prediction is borne out in honey bees. Single mating by the queen, as in stingless bees, causes workers to be more related to each others' sons than to the queen's sons, so they should not police each other. We used microsatellite markers to confirm single mating in eight species of stingless bees and then tested the prediction that workers would produce males. Using a likelihood method, we found some worker male production in six of the eight species, although queens produced some males in all of them. Thus the predicted contrast with honeybees is observed, but not perfectly, perhaps because workers either lack complete control or because of costs of conflict. The data are consistent with the view that there is ongoing conflict over male production. Our method of estimating worker male production appears to be more accurate than exclusion, which sometimes underestimates the proportion of males that are worker produced.

Reproductive ability of a cloned male detector dog and behavioral traits of its offspring

PubMed Central

Lee, Ji Hyun; Kim, Geon A; Kim, Rak Seung; Lee, Jong Su; Oh, Hyun Ju; Kim, Min Jung; Hong, Do Kyo

2016-01-01

In 2007, seven detector dogs were produced by somatic cell nuclear transfer using one nuclear donor dog, then trained and certified as excellent detector dogs, similar to their donor. In 2011, we crossed a cloned male and normal female by natural breeding and produced ten offspring. In this study, we investigated the puppies' temperaments, which we later compared with those of the cloned parent male. The results show that the cloned male had normal reproductive abilities and produced healthy offspring. All puppies completed narcotic detector dog training with a success rate for selection of 60%. Although the litter of cloned males was small in this study, a cloned male dog bred by natural mating produced puppies that later successfully completed the training course for drug detection. In conclusion, cloning an elite dog with superior genetic factors and breeding of the cloned dog was found to be a useful method to efficiently procure detector dogs. PMID:26435541

Reproductive ability of a cloned male detector dog and behavioral traits of its offspring.

PubMed

Lee, Ji Hyun; Kim, Geon A; Kim, Rak Seung; Lee, Jong Su; Oh, Hyun Ju; Kim, Min Jung; Hong, Do Kyo; Lee, Byeong Chun

2016-09-30

In 2007, seven detector dogs were produced by somatic cell nuclear transfer using one nuclear donor dog, then trained and certified as excellent detector dogs, similar to their donor. In 2011, we crossed a cloned male and normal female by natural breeding and produced ten offspring. In this study, we investigated the puppies' temperaments, which we later compared with those of the cloned parent male. The results show that the cloned male had normal reproductive abilities and produced healthy offspring. All puppies completed narcotic detector dog training with a success rate for selection of 60%. Although the litter of cloned males was small in this study, a cloned male dog bred by natural mating produced puppies that later successfully completed the training course for drug detection. In conclusion, cloning an elite dog with superior genetic factors and breeding of the cloned dog was found to be a useful method to efficiently procure detector dogs.

Heterosis Increases Fertility, Fecundity, and Survival of Laboratory-Produced F1 Hybrid Males of the Malaria Mosquito Anopheles coluzzii

PubMed Central

Ekechukwu, Nkiru E.; Baeshen, Rowida; Traorè, Sékou F.; Coulibaly, Mamadou; Diabate, Abdoulaye; Catteruccia, Flaminia; Tripet, Frédéric

2015-01-01

The success of vector control strategies aiming to decrease disease transmission via the release of sterile or genetically-modified male mosquitoes critically depends on mating between laboratory-reared males and wild females. Unfortunately, mosquito colonization, laboratory rearing, and genetic manipulations can all negatively affect male competitiveness. Heterosis is commonly used to produce domestic animals with enhanced vigor and homogenous genetic background and could therefore potentially improve the mating performance of mass-reared male mosquitoes. Here, we produced enhanced hybrid males of the malaria mosquito Anopheles coluzzii by crossing two strains colonized >35 and 8 years ago. We compared the amount of sperm and mating plug proteins they transferred to females, as well as their insemination rate, reproductive success and longevity under various experimental conditions. Across experiments, widespread adaptations to laboratory mating were detected in the older strain. In large-group mating experiments, no overall hybrid advantage in insemination rates and the amount of sperm and accessory gland proteins transferred to females was detected. Despite higher sperm activity, hybrid males did not appear more fecund. However, individual-male mating and laboratory-swarm experiments revealed that hybrid males, while inseminating fewer females than older inbred males, were significantly more fertile, producing larger mating plugs and drastically increasing female fecundity. Heterotic males also showed increased longevity. These results validate the use of heterosis for creating hybrid males with improved fitness from long-established inbred laboratory strains. Therefore, this simple approach could facilitate disease control strategies based on male mosquito releases with important ultimate benefits to human health. PMID:26497140

Probiotic Soy Product Supplemented with Isoflavones Improves the Lipid Profile of Moderately Hypercholesterolemic Men: A Randomized Controlled Trial.

PubMed

Cavallini, Daniela Cardoso Umbelino; Manzoni, Marla Simone Jovenasso; Bedani, Raquel; Roselino, Mariana Nougalli; Celiberto, Larissa Sbaglia; Vendramini, Regina Célia; de Valdez, Graciela Font; Abdalla, Dulcinéia Saes Parra; Pinto, Roseli Aparecida; Rosetto, Daniella; Valentini, Sandro Roberto; Rossi, Elizeu Antonio

2016-01-19

Cardiovascular disease is the leading cause of worldwide morbidity and mortality. Several studies have demonstrated that specific probiotics affect the host's metabolism and may influence the cardiovascular disease risk. The aim of this study was to investigate the influence of an isoflavone-supplemented soy product fermented with Enterococcus faecium CRL 183 and Lactobacillus helveticus 416 on cardiovascular risk markers in moderately hypercholesterolemic subjects. Randomized placebo-controlled double-blind trial Setting: São Paulo State University in Araraquara, SP, Brazil. 49 male healthy men with total cholesterol (TC) >5.17 mmol/L and <6.21 mmol/L Intervention: The volunteers have consumed 200 mL of the probiotic soy product (group SP-10(10) CFU/day), isoflavone-supplemented probiotic soy product (group ISP-probiotic plus 50 mg of total isoflavones/100 g) or unfermented soy product (group USP-placebo) for 42 days in a randomized, double-blind study. Lipid profile and additional cardiovascular biomarkers were analyzed on days 0, 30 and 42. Urine samples (24 h) were collected at baseline and at the end of the experiment so as to determine the isoflavones profile. After 42 days, the ISP consumption led to improved total cholesterol, non-HDL-C (LDL + IDL + VLDL cholesterol fractions) and electronegative LDL concentrations (reduction of 13.8%, 14.7% and 24.2%, respectively, p < 0.05). The ISP and SP have prevented the reduction of HDL-C level after 42 days. The C-reactive protein and fibrinogen levels were not improved. The equol production by the ISP group subjects was inversely correlated with electronegative LDL concentration. The results suggest that a regular consumption of this probiotic soy product, supplemented with isoflavones, could contribute to reducing the risk of cardiovascular diseases in moderately hypercholesterolemic men, through the an improvement in lipid profile and antioxidant properties.

Probiotic Soy Product Supplemented with Isoflavones Improves the Lipid Profile of Moderately Hypercholesterolemic Men: A Randomized Controlled Trial

PubMed Central

Cardoso Umbelino Cavallini, Daniela; Jovenasso Manzoni, Marla Simone; Bedani, Raquel; Roselino, Mariana Nougalli; Celiberto, Larissa Sbaglia; Vendramini, Regina Célia; de Valdez, Graciela Font; Saes Parra Abdalla, Dulcinéia; Aparecida Pinto, Roseli; Rosetto, Daniella; Roberto Valentini, Sandro; Antonio Rossi, Elizeu

2016-01-01

Background: Cardiovascular disease is the leading cause of worldwide morbidity and mortality. Several studies have demonstrated that specific probiotics affect the host’s metabolism and may influence the cardiovascular disease risk. Objectives: The aim of this study was to investigate the influence of an isoflavone-supplemented soy product fermented with Enterococcus faecium CRL 183 and Lactobacillus helveticus 416 on cardiovascular risk markers in moderately hypercholesterolemic subjects. Design: Randomized placebo-controlled double-blind trial Setting: São Paulo State University in Araraquara, SP, Brazil. Participants: 49 male healthy men with total cholesterol (TC) >5.17 mmol/L and <6.21 mmol/L Intervention: The volunteers have consumed 200 mL of the probiotic soy product (group SP-1010 CFU/day), isoflavone-supplemented probiotic soy product (group ISP–probiotic plus 50 mg of total isoflavones/100 g) or unfermented soy product (group USP-placebo) for 42 days in a randomized, double-blind study. Main outcome measures: Lipid profile and additional cardiovascular biomarkers were analyzed on days 0, 30 and 42. Urine samples (24 h) were collected at baseline and at the end of the experiment so as to determine the isoflavones profile. Results: After 42 days, the ISP consumption led to improved total cholesterol, non-HDL-C (LDL + IDL + VLDL cholesterol fractions) and electronegative LDL concentrations (reduction of 13.8%, 14.7% and 24.2%, respectively, p < 0.05). The ISP and SP have prevented the reduction of HDL-C level after 42 days. The C-reactive protein and fibrinogen levels were not improved. The equol production by the ISP group subjects was inversely correlated with electronegative LDL concentration. Conclusions: The results suggest that a regular consumption of this probiotic soy product, supplemented with isoflavones, could contribute to reducing the risk of cardiovascular diseases in moderately hypercholesterolemic men, through the an improvement in lipid profile and antioxidant properties. PMID:26797632

Urinary Estrogen Metabolites in 2 Soy Trials with Premenopausal Women

PubMed Central

Maskarinec, Gertraud; Morimoto, Yukiko; Heak, Sreang; Isaki, Marissa; Steinbrecher, Astrid; Custer, Laurie; Franke, Adrian A.

2012-01-01

Background Soy consumption may protect against breast cancer through modification of estrogen metabolism. Objective We examined the effect of soy foods on urinary estrogens and the 2-hydroxy (OH)/16α-OH estrone (E1) ratio in 2 dietary interventions with premenopausal women. Methods BEAN1 was a 2-year randomized trial and BEAN2 a 13-month randomized crossover study. In both interventions, study participants consumed a high-soy diet with 2 soy food servings/day and a low-soy diet with <3 servings of soy/week. Urine samples were collected at baseline and at the end of the diet periods, analyzed for 9 estrogen metabolites by liquid chromatography mass spectrometry, and adjusted for creatinine levels. For BEAN1, 2 samples for 188 participants and for BEAN2, 3 samples for 79 women were analyzed. We applied mixed-effects regression models with log-transformed values of estrogen metabolites and soy intake as the exposure variable. Results In BEAN1, no effect of the high-soy diet on individual estrogen metabolites or hydroxylation pathways was observed. The median 2-OH/16α-OH E1 ratio decreased non-significantly in the intervention group from 6.2 to 5.2 as compared to 6.8 and 7.2 in the control group (p=0.63). In BEAN2, only 4-OHE1 was significantly lower after the high-soy diet. Interaction terms of the high-soy diet with equol producer status, ethnicity, and weight status revealed no significant effect modification. Conclusions Contrary to our hypothesis and some previous reports, the results from 2 well controlled dietary interventions do not support an effect of a high-soy diet on a panel of urinary estrogen metabolites and the 2-OH/16α-OHE1 ratio. PMID:22713773

Effects of isoflavone-containing soya protein on ex vivo cholesterol efflux, vascular function and blood markers of CVD risk in adults with moderately elevated blood pressure: a dose-response randomised controlled trial.

PubMed

Richter, Chesney K; Skulas-Ray, Ann C; Fleming, Jennifer A; Link, Christina J; Mukherjea, Ratna; Krul, Elaine S; Kris-Etherton, Penny M

2017-05-01

Emerging CVD risk factors (e.g. HDL function and central haemodynamics) may account for residual CVD risk experienced by individuals who meet LDL-cholesterol and blood pressure (BP) targets. Recent evidence suggests that these emerging risk factors can be modified by polyphenol-rich interventions such as soya, but additional research is needed. This study was designed to investigate the effects of an isoflavone-containing soya protein isolate (delivering 25 and 50 g/d soya protein) on HDL function (i.e. ex vivo cholesterol efflux), macrovascular function and blood markers of CVD risk. Middle-aged adults (n 20; mean age=51·6 (sem 6·6) years) with moderately elevated brachial BP (mean systolic BP=129 (sem 9) mmHg; mean diastolic BP=82·5 (sem 8·4) mmHg) consumed 0 (control), 25 and 50 g/d soya protein in a randomised cross-over design. Soya and control powders were consumed for 6 weeks each with a 2-week compliance break between treatment periods. Blood samples and vascular function measures were obtained at baseline and following each supplementation period. Supplementation with 50 g/d soya protein significantly reduced brachial diastolic BP (-2·3 mmHg) compared with 25 g/d soya protein (Tukey-adjusted P=0·03) but not the control. Soya supplementation did not improve ex vivo cholesterol efflux, macrovascular function or other blood markers of CVD risk compared with the carbohydrate-matched control. Additional research is needed to clarify whether effects on these CVD risk factors depend on the relative health of participants and/or equol producing capacity.

Comparative metabolomics in vegans and omnivores reveal constraints on diet-dependent gut microbiota metabolite production.

PubMed

Wu, Gary D; Compher, Charlene; Chen, Eric Z; Smith, Sarah A; Shah, Rachana D; Bittinger, Kyle; Chehoud, Christel; Albenberg, Lindsey G; Nessel, Lisa; Gilroy, Erin; Star, Julie; Weljie, Aalim M; Flint, Harry J; Metz, David C; Bennett, Michael J; Li, Hongzhe; Bushman, Frederic D; Lewis, James D

2016-01-01

The consumption of an agrarian diet is associated with a reduced risk for many diseases associated with a 'Westernised' lifestyle. Studies suggest that diet affects the gut microbiota, which subsequently influences the metabolome, thereby connecting diet, microbiota and health. However, the degree to which diet influences the composition of the gut microbiota is controversial. Murine models and studies comparing the gut microbiota in humans residing in agrarian versus Western societies suggest that the influence is large. To separate global environmental influences from dietary influences, we characterised the gut microbiota and the host metabolome of individuals consuming an agrarian diet in Western society. Using 16S rRNA-tagged sequencing as well as plasma and urinary metabolomic platforms, we compared measures of dietary intake, gut microbiota composition and the plasma metabolome between healthy human vegans and omnivores, sampled in an urban USA environment. Plasma metabolome of vegans differed markedly from omnivores but the gut microbiota was surprisingly similar. Unlike prior studies of individuals living in agrarian societies, higher consumption of fermentable substrate in vegans was not associated with higher levels of faecal short chain fatty acids, a finding confirmed in a 10-day controlled feeding experiment. Similarly, the proportion of vegans capable of producing equol, a soy-based gut microbiota metabolite, was less than that was reported in Asian societies despite the high consumption of soy-based products. Evidently, residence in globally distinct societies helps determine the composition of the gut microbiota that, in turn, influences the production of diet-dependent gut microbial metabolites. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Vocal communication between male Xenopus laevis.

PubMed

Tobias, Martha L; Barnard, Candace; O'Hagan, Robert; Horng, Sam H; Rand, Masha; Kelley, Darcy B

2004-02-01

This study focuses on the role of male-male vocal communication in the reproductive repertoire of the South African clawed frog, Xenopus laevis . Six male and two female call types were recorded from native ponds in the environs of Cape Town, South Africa. These include all call types previously recorded in the laboratory as well as one previously unidentified male call: chirping. The amount of calling and the number of call types increased as the breeding season progressed. Laboratory recordings indicated that all six male call types were directed to males; three of these were directed to both sexes and three were directed exclusively to males. Both female call types were directed exclusively to males. The predominant call type, in both field and laboratory recordings, was the male advertisement call. Sexual state affected male vocal behaviour. Male pairs in which at least one male was sexually active (gonadotropin injected) produced all call types, whereas pairs of uninjected males rarely called. Some call types were strongly associated with a specific behaviour and others were not. Clasped males always growled and clasping males typically produced amplectant calls or chirps; males not engaged in clasping most frequently advertised. The amount of advertising produced by one male was profoundly affected by the presence of another male. Pairing two sexually active males resulted in suppression of advertisement calling in one; suppression was released when males were isolated after pairing. Vocal dominance was achieved even in the absence of physical contact (clasping). We suggest that X. laevis males gain a reproductive advantage by competing for advertisement privileges and by vocally suppressing neighbouring males.

Diverse Effects of Phytoestrogens on the Reproductive Performance: Cow as a Model

PubMed Central

Wocławek-Potocka, Izabela; Mannelli, Chiara; Boruszewska, Dorota; Kowalczyk-Zieba, Ilona; Waśniewski, Tomasz; Skarżyński, Dariusz J.

2013-01-01

Phytoestrogens, polyphenolic compounds derived from plants, are more and more common constituents of human and animal diets. In most of the cases, these chemicals are much less potent than endogenous estrogens but exert their biological effects via similar mechanisms of action. The most common source of phytoestrogen exposure to humans as well as ruminants is soybean-derived foods that are rich in the isoflavones genistein and daidzein being metabolized in the digestive tract to even more potent metabolites—para-ethyl-phenol and equol. Phytoestrogens have recently come into considerable interest due to the increasing information on their adverse effects in human and animal reproduction, increasing the number of people substituting animal proteins with plant-derived proteins. Finally, the soybean becomes the main source of protein in animal fodder because of an absolute prohibition of bone meal use for animal feeding in 1995 in Europe. The review describes how exposure of soybean-derived phytoestrogens can have adverse effects on reproductive performance in female adults. PMID:23710176

Multiple Paternity in Polyandrous Barn Owls (Tyto alba)

PubMed Central

Dubey, Sylvain; Simon, Céline; Waldvogel, Céline; Burri, Reto; Roulin, Alexandre

2013-01-01

In polyandrous species females produce successive clutches with several males. Female barn owls (Tyto alba) often desert their offspring and mate to produce a 2nd annual brood with a second male. We tested whether copulating during chick rearing at the 1st annual brood increases the male's likelihood to obtain paternity at the 2nd annual breeding attempt of his female mate in case she deserts their brood to produce a second brood with a different male. Using molecular paternity analyses we found that 2 out of 26 (8%) second annual broods of deserting females contained in total 6 extra-pair young out of 15 nestlings. These young were all sired by the male with whom the female had produced the 1st annual brood. In contrast, none of the 49 1st annual breeding attempts (219 offspring) and of the 20 2nd annual breeding attempts (93 offspring) of non-deserting females contained extra-pair young. We suggest that female desertion can select male counter-strategies to increase paternity and hence individual fitness. Alternatively, females may copulate with the 1st male to derive genetic benefits, since he is usually of higher quality than the 2nd male which is commonly a yearling individual. PMID:24244622

Postzygotic incompatibilities between the pupfishes, Cyprinodon elegans and Cyprinodon variegatus: hybrid male sterility and sex ratio bias.

PubMed

Tech, C

2006-11-01

I examined the intrinsic postzygotic incompatibilities between two pupfishes, Cyprinodon elegans and Cyprinodon variegatus. Laboratory hybridization experiments revealed evidence of strong postzygotic isolation. Male hybrids have very low fertility, and the survival of backcrosses into C. elegans was substantially reduced. In addition, several crosses produced female-biased sex ratios. Crosses involving C. elegans females and C. variegatus males produced only females, and in backcrosses involving hybrid females and C. elegans males, males made up approximately 25% of the offspring. All other crosses produced approximately 50% males. These sex ratios could be explained by genetic incompatibilities that occur, at least in part, on sex chromosomes. Thus, these results provide strong albeit indirect evidence that pupfish have XY chromosomal sex determination. The results of this study provide insight on the evolution of reproductive isolating mechanisms, particularly the role of Haldane's rule and the 'faster-male' theory in taxa lacking well-differentiated sex chromosomes.

Competitive pressures affect sexual signal complexity in Kurixalus odontotarsus: insights into the evolution of compound calls

PubMed Central

2017-01-01

ABSTRACT Male-male vocal competition in anuran species is critical for mating success; however, it is also energetically demanding and highly time-consuming. Thus, we hypothesized that males may change signal elaboration in response to competition in real time. Male serrate-legged small treefrogs (Kurixalus odontotarsus) produce compound calls that contain two kinds of notes, harmonic sounds called ‘A notes’ and short broadband sounds called ‘B notes’. Using male evoked vocal response experiments, we found that competition influences the temporal structure and complexity of vocal signals produced by males. Males produce calls with a higher ratio of notes:call, and more compound calls including more A notes but fewer B notes with contest escalation. In doing so, males minimize the energy costs and maximize the benefits of competition when the level of competition is high. This means that the evolution of sexual signal complexity in frogs may be susceptible to selection for plasticity related to adjusting performance to the pressures of competition, and supports the idea that more complex social contexts can lead to greater vocal complexity. PMID:29175862

Genetics Home Reference: Cushing disease

MedlinePlus

... unclear, Cushing disease affects females more often than males. Related Information What information about a genetic condition ... produce cortisol may also produce increased amounts of male sex hormones (androgens), leading to hirsutism in females. ...

Failed sperm development as a reproductive isolating barrier between species.

PubMed

Wünsch, Lisa K; Pfennig, Karin S

2013-01-01

Hybrid male sterility is a common reproductive isolating barrier between species. Yet, little is known about the actual developmental causes of this phenomenon, especially in naturally hybridizing species. We sought to evaluate the developmental causes of hybrid male sterility, using spadefoot toads as our study system. Plains spadefoot toads (Spea bombifrons) and Mexican spadefoot toads (S. multiplicata) hybridize where they co-occur in the southwestern USA. Hybrids are viable, but hybrid males suffer reduced fertility. We compared testes size and developmental stages of sperm cell maturation between hybrid males and males of each species. We found that testes of hybrid males did not differ in mean size from pure-species males. However, hybrids showed a greater range of within-individual variation in testes size than pure-species males. Moreover, although hybrids produced similar numbers of early stage sperm cells, hybrids produced significantly fewer mature spermatozoids than pure-species males. Interestingly, an introgressed individual produced numbers of live sperm comparable to pure-species males, but the majority of these sperm cells were abnormally shaped and non-motile. These results indicate that hybrid incompatibilities in late sperm development serve as a reproductive isolating barrier between species. The nature of this breakdown highlights the possibilities that hybrid males may vary in fertility and that fertility could possibly be recovered in introgressed males. © 2013 Wiley Periodicals, Inc.

Thelytokous parthenogenesis, male clonality and genetic caste determination in the little fire ant: new evidence and insights from the lab.

PubMed

Foucaud, J; Estoup, A; Loiseau, A; Rey, O; Orivel, J

2010-08-01

Previous studies indicate that some populations of the little fire ant, Wasmannia auropunctata, display an unusual reproduction system polymorphism. Although some populations have a classical haplodiploid reproduction system, in other populations queens are produced by thelytokous parthenogenesis, males are produced by a male clonality system and workers are produced sexually. An atypical genetic caste determination system was also suggested. However, these conclusions were indirectly inferred from genetic studies on field population samples. Here we set up experimental laboratory nests that allow the control of the parental relationships between individuals. The queens heading those nests originated from either putatively clonal or sexual populations. We characterized the male, queen and worker offspring they produced at 12 microsatellite loci. Our results unambiguously confirm the unique reproduction system polymorphism mentioned above and that male clonality is strictly associated with thelytokous parthenogenesis. We also observed direct evidence of the rare production of sexual gynes and arrhenotokous males in clonal populations. Finally, we obtained evidence of a genetic basis for caste determination. The evolutionary significance of the reproduction system polymorphism and genetic caste determination as well as future research opportunities are discussed.

Metabolomics reveals an involvement of pantothenate for male production responding to the short-day stimulus in the water flea, Daphnia pulex

PubMed Central

Toyota, Kenji; Gavin, Alex; Miyagawa, Shinichi; Viant, Mark R.; Iguchi, Taisen

2016-01-01

Under favorable conditions, the micro-crustacean Daphnia pulex produces female offspring by parthenogenesis, whereas under unfavorable conditions, they produce male offspring to induce sexual reproduction (environmental sex determination: ESD). We recently established a suitable system for ESD studies using D. pulex WTN6 strain, in which the sex of the offspring can be regulated by alterations in day-length; long-day and short-day conditions can induce female and male offspring, respectively. Taking advantage of this system, we have already demonstrated that methyl farnesoate (MF) synthesis is necessary for male offspring production, and identified ionotropic glutamate receptors as an upstream regulator of MF signaling. Despite these findings, the molecular mechanisms associated with MF signaling have not yet been well elucidated. In this study, we analyzed the whole metabolic profiles of mother daphnids reared under long-day (female-producing) and short-day (male-producing) conditions, and discovered that pantothenate (vitamin B5), a known precursor to coenzyme A, was significantly accumulated in response to the short-day condition. To confirm the innate role of pantothenate in D. pulex, this metabolite was administered to mother daphnids resulting in a significantly increased proportion of male offspring producing mothers. This study provides novel insights of the metabolic mechanisms of the ESD system in D. pulex. PMID:27113113

Males are here to stay: fertilization enhances viable egg production by clonal queens of the little fire ant ( Wasmannia auropunctata)

NASA Astrophysics Data System (ADS)

Miyakawa, Misato O.; Mikheyev, Alexander S.

2015-04-01

Evolution of reproduction strategies is affected by both phylogenetic and physiological constraints. Although clonality may benefit females, it may not be selected if a male contribution is necessary to start egg laying and embryo development. In little fire ant, Wasmannia auropunctata, sexual populations employ a typical Hymenopteran system of reproduction. In clonal populations, however, queens and males are produced with only maternal and paternal genomes, respectively, whereas sterile workers are produced sexually. Although this system requires both sexes for worker production, previous work has shown that workers may also be produced clonally by the queens. If so, why are males maintained in this species? Our data suggest that fertilization is necessary to increase the hatching rate of eggs. Although clonal queens can indeed produce both workers and queens without mating, the hatching rate is far below the level necessary to maintain functional colonies. On the other hand, virgin queens from populations exhibiting the original Hymenopteran reproduction system also show low hatching rates, but produce only haploid male eggs. Reasons for the existence of W. auropunctata males have been disputed. However, our data suggest that physiological constraints, such as the requirement for insemination, must be considered in regard to evolution of reproduction systems, in addition to ecological data and theoretical considerations of fitness.

Metabolomics reveals an involvement of pantothenate for male production responding to the short-day stimulus in the water flea, Daphnia pulex.

PubMed

Toyota, Kenji; Gavin, Alex; Miyagawa, Shinichi; Viant, Mark R; Iguchi, Taisen

2016-04-26

Under favorable conditions, the micro-crustacean Daphnia pulex produces female offspring by parthenogenesis, whereas under unfavorable conditions, they produce male offspring to induce sexual reproduction (environmental sex determination: ESD). We recently established a suitable system for ESD studies using D. pulex WTN6 strain, in which the sex of the offspring can be regulated by alterations in day-length; long-day and short-day conditions can induce female and male offspring, respectively. Taking advantage of this system, we have already demonstrated that methyl farnesoate (MF) synthesis is necessary for male offspring production, and identified ionotropic glutamate receptors as an upstream regulator of MF signaling. Despite these findings, the molecular mechanisms associated with MF signaling have not yet been well elucidated. In this study, we analyzed the whole metabolic profiles of mother daphnids reared under long-day (female-producing) and short-day (male-producing) conditions, and discovered that pantothenate (vitamin B5), a known precursor to coenzyme A, was significantly accumulated in response to the short-day condition. To confirm the innate role of pantothenate in D. pulex, this metabolite was administered to mother daphnids resulting in a significantly increased proportion of male offspring producing mothers. This study provides novel insights of the metabolic mechanisms of the ESD system in D. pulex.

The acoustic structure of male giant panda bleats varies according to intersexual context.

PubMed

Charlton, Benjamin D; Keating, Jennifer L; Rengui, Li; Huang, Yan; Swaisgood, Ronald R

2015-09-01

Although the acoustic structure of mammal vocal signals often varies according to the social context of emission, relatively few mammal studies have examined acoustic variation during intersexual advertisement. In the current study male giant panda bleats were recorded during the breeding season in three behavioural contexts: vocalising alone, during vocal interactions with females outside of peak oestrus, and during vocal interactions with peak-oestrous females. Male bleats produced during vocal interactions with peak-oestrous females were longer in duration and had higher mean fundamental frequency than those produced when males were either involved in a vocal interaction with a female outside of peak oestrus or vocalising alone. In addition, males produced bleats with higher rates of fundamental frequency modulation when they were vocalising alone than when they were interacting with females. These results show that acoustic features of male giant panda bleats have the potential to signal the caller's motivational state, and suggest that males increase the rate of fundamental frequency modulation in bleats when they are alone to maximally broadcast their quality and promote close-range contact with receptive females during the breeding season.

Reproductive traits in captive and free-ranging males of the critically endangered Iberian lynx (Lynx pardinus).

PubMed

Gañán, Natalia; Sestelo, Adrián; Garde, J Julián; Martínez, Fernando; Vargas, Astrid; Sánchez, Iñigo; Pérez-Aspa, María José; López-Bao, José Vicente; Palomares, Francisco; Gomendio, Montserrat; Roldan, Eduardo R S

2010-01-01

The Iberian lynx (Lynx pardinus) is the most endangered felid in the world. Adequate genetic management of in situ and ex situ populations, and linkage between both, require knowledge on male reproductive biology and factors influencing it. We examined the influence of age, free-ranging versus captive conditions and seasonality on phenotypic, endocrine and semen traits, and links between reproductive traits and male fertility. Males had relatively small testes, produced low sperm numbers, a low proportion of normal sperm, and a high proportion of motile sperm. Young (2-year-old) males had lower testosterone levels, fewer sperm, and a lower proportion of motile and normal sperm than > or =4-year-old males. No major differences were found in semen traits before and after the mating season or between free-ranging and captive males, although the latter had better sperm motility. Males with larger relative testes weight and more sperm copulated more frequently, whereas males that produced more sperm with higher motility produced more cubs per female. In conclusion, small relative testes size and low sperm quality could indicate either low levels of sperm competition or high levels of inbreeding. Young males are probably subfertile; there is a slight trend for males in the captive breeding programme to have better semen quality than wild males, and males with higher sperm production are sexually more active and more fertile. These findings have major implications for decisions regarding which males should breed, provide samples for the genetic resource bank, or participate in programmes involving the use of assisted reproductive techniques.

A specialized fungal parasite (Massospora cicadina) hijacks the sexual signals of periodical cicadas (Hemiptera: Cicadidae: Magicicada).

PubMed

Cooley, John R; Marshall, David C; Hill, Kathy B R

2018-01-23

Male periodical cicadas (Magicicada spp.) infected with conidiospore-producing ("Stage I") infections of the entomopathogenic fungus Massospora cicadina exhibit precisely timed wing-flick signaling behavior normally seen only in sexually receptive female cicadas. Male wing-flicks attract copulation attempts from conspecific males in the chorus; close contact apparently spreads the infective conidiospores. In contrast, males with "Stage II" infections that produce resting spores that wait for the next cicada generation do not produce female-specific signals. We propose that these complex fungus-induced behavioral changes, which resemble apparently independently derived changes in other cicada-Massospora systems, represent a fungus "extended phenotype" that hijacks cicadas, turning them into vehicles for fungus transmission at the expense of the cicadas' own interests.

The white gene of Drosophila melanogaster encodes a protein with a role in courtship behavior.

PubMed

Anaka, Matthew; MacDonald, C Danielle; Barkova, Eva; Simon, Karl; Rostom, Reem; Godoy, Ruth A; Haigh, Andrew J; Meinertzhagen, Ian A; Lloyd, Vett

2008-01-01

The white gene of Drosophila melanogaster has been extensively studied, yet it is still not understood how its ectopic overexpression induces male-male courtship. To investigate the cellular basis of this behavior, we examined the sexual behavior of several classes of mutants. We find that male-male courtship is seen not only in flies overexpressing the white gene, but also in mutants expected to have mislocalized White protein. This finding confirms that mislocalizing White transporter in the cells in which it is normally expressed will produce male-male courtship behaviors; the courtship behavior is not an indirect consequence of aberrant physiological changes elsewhere in the body. Male-male courtship is also seen in some mutants with altered monoamine metabolism and deficits in learning and memory, but can be distinguished from that produced by White mislocalization by its reduced intensity and locomotor activity. Double mutants overexpressing white and with mutations in genes for serotonergic neurons suggest that male-male courtship produced by mislocalizing White may not be mediated exclusively by serotonergic neurons. We also find decreased olfactory learning in white mutants and in individuals with mutations in the genes for White's binding partners, brown and scarlet. Finally, in cultured Drosophila and mammalian cells, the White transporter is found in the endosomal compartment. The additional genes identified here as being involved in male-male courtship increase the repertoire of mutations available to study sexual behavior in Drosophila.

The sperm of aging male bustards retards their offspring's development.

PubMed

Preston, Brian T; Saint Jalme, Michel; Hingrat, Yves; Lacroix, Frederic; Sorci, Gabriele

2015-02-03

Understanding whether the sperm of older males has a diminished capacity to produce successful offspring is a key challenge in evolutionary biology. We investigate this issue using 10 years of reproductive data on captive long-lived houbara bustards (Chlamydotis undulata), where the use of artificial insemination techniques means parents can only influence offspring quality via their gametes. Here we show that paternal aging reduces both the likelihood that eggs hatch and the rate at which chicks grow, with older males producing the lightest offspring after the first month. Surprisingly, this cost of paternal aging on offspring development is of a similar scale to that associated with maternal aging. Fitting with predictions on germline aging, the sperm of immature males produce the fastest growing offspring. Our findings thus indicate that any good genes benefit that might be offered by older 'proven' males will be eroded by aging of their germline DNA.

JH III production, titers and degradation in relation to reproduction in male and female Anthonomus grandis.

PubMed

Taub-Montemayor, Tina E; Min, Kyung-Jin; Chen, Zhaorigetu; Bartlett, Terri; Rankin, Mary Ann

2005-04-01

Juvenile hormone (JH) is necessary for the production of vitellogenin (Vg) in the boll weevil, Anthonomus grandis. Occurrence of Vg in this species is typically restricted to reproductively competent females, and is not detected in untreated males. However, the JH analog, methoprene stimulates Vg production in intact males and in the isolated abdomens of both male and female boll weevils (where in each case no Vg is detected without treatment), suggesting that males are competent to produce Vg but are normally not stimulated to do so. Preliminary work indicating that male boll weevil corpora allata (CA) produced little or no JH in vitro suggested that failure of males to produce Vg might be due to very low JH levels compared to females. This study re-examines the question of JH in male boll weevils by determining in vitro production of JH III by male CA during the first 10 days after adult emergence, determining hemolymph JH esterase activity during this same time period and hemolymph JH III titers in adults of both sexes. We also re-examine the ability of isolated male abdomens to produce Vg in response to hormonal stimulation, analyzing the effect of a wide range of methoprene and JH III dosages. Results indicate that male A. grandis have circulating JH titers and JH production similar to females. JH esterase activity is slightly but significantly higher in males than females. Vg production by isolated abdomens of both sexes after stimulation with methoprene or JH III was confirmed. Dose response studies indicated that high levels of methoprene were less effective than intermediate doses in stimulating Vg synthesis in both sexes. We conclude that the sexually dimorphic effect of JH on Vg synthesis is not due to differences in JH production or differences in JH titer between the sexes.

Effects of oxotremorine and physostigmine on the inhibitory avoidance impairment produced by amitriptyline in male and female mice.

PubMed

Monleón, Santiago; Urquiza, Adoración; Vinader-Caerols, Concepción; Parra, Andrés

2009-12-28

We have previously observed that amitriptyline and other antidepressants produce impairing effects on inhibitory avoidance (also called passive avoidance) in mice of both sexes. In the present study we investigated the involvement of the cholinergic system in the inhibitory avoidance impairment produced by acute amitriptyline in male and female CD1 mice. For this purpose, the effects on said task of acute i.p. administration of several doses of amitriptyline, either alone or in combination with the cholinergic agonists oxotremorine and physostigmine, were evaluated. Pre-training administration of 5, 7.5, 10 or 15 mg/kg of amitriptyline produced a significant impairment of inhibitory avoidance in both males and females. When oxotremorine (0.05 or 0.1 mg/kg) was co-administered with amitriptyline, the antidepressant's impairing effect was partially counteracted, although inhibitory avoidance learning was not significant. Physostigmine (0.15, 0.3 or 0.6 mg/kg) counteracted the impairment produced by amitriptyline, as mice treated with both drugs exhibited inhibitory avoidance learning. These results show that the inhibitory avoidance impairment produced by amitriptyline in male and female mice is mediated, at least partially, by the cholinergic system.

Mosaic male honey bees produced by queens inseminated with frozen spermatozoa.

PubMed

Harbo, J R

1980-01-01

Mosaic male honey bees were found as the progeny of queens that had been inseminated with spermatozoa stored in liquid nitrogen. The origins of these mosaics and the genotype of their gametes were determined by using mutant markers. The mosaics probably developed from an egg pronucleus and a sperm pronucleus that did not unite after the latter had entered the egg. Instead, both pronuclei produced haploid tissue independently. The three mosaics that were mated to queens all had mosaic testes. Therefore, these were situations in which a male honey bee produced two types of spermatozoa.

Male Reproductive System (For Teens)

MedlinePlus

... genes come from the father's sperm and the mother's egg, which are produced by the male and female reproductive systems. What Is the Male Reproductive System? Most species have two sexes: male and female. Each sex has its own ...

Impacts of inbreeding on bumblebee colony fitness under field conditions.

PubMed

Whitehorn, Penelope R; Tinsley, Matthew C; Brown, Mark J F; Darvill, Ben; Goulson, Dave

2009-07-02

Inbreeding and the loss of genetic diversity are known to be significant threats to small, isolated populations. Hymenoptera represent a special case regarding the impact of inbreeding. Haplodiploidy may permit purging of deleterious recessive alleles in haploid males, meaning inbreeding depression is reduced relative to diploid species. In contrast, the impact of inbreeding may be exacerbated in Hymenopteran species that have a single-locus complementary sex determination system, due to the production of sterile or inviable diploid males. We investigated the costs of brother-sister mating in the bumblebee Bombus terrestris. We compared inbred colonies that produced diploid males and inbred colonies that did not produce diploid males with outbred colonies. Mating, hibernation and colony founding took place in the laboratory. Once colonies had produced 15 offspring they were placed in the field and left to forage under natural conditions. The diploid male colonies had a significantly reduced fitness compared to regular inbred and outbred colonies; they had slower growth rates in the laboratory, survived for a shorter time period under field conditions and produced significantly fewer offspring overall. No differences in success were found between non-diploid male inbred colonies and outbred colonies. Our data illustrate that inbreeding exacts a considerable cost in Bombus terrestris through the production of diploid males. We suggest that diploid males may act as indicators of the genetic health of populations, and that their detection could be used as an informative tool in hymenopteran conservation. We conclude that whilst haplodiploids may suffer less inbreeding depression than diploid species, they are still highly vulnerable to population fragmentation and reduced genetic diversity due to the extreme costs imposed by the production of diploid males.

Allocation to Floral Structures in Thalictrum pubescens (Ranunculaceae), a Cryptically Dioecious Species

PubMed Central

DAVIS, SANDRA L.

2002-01-01

Females of Thalictrum pubescens produce stamens that contain sterile pollen, whereas males are both functionally and morphologically unisexual. This study examines the investment in stamen production by females of T. pubescens by comparing the female structures with those of their fully functional male counterparts. Stamens from females had the same biomass and contained the same amount of nitrogen and phosphorus as stamens from males. Anther size was the same in males and females, but filaments were longer in stamens from males. Females produced more pollen per anther than males, and pollen size was the same in both sexes. Within flowers, there was a positive correlation between the amount of pollen per anther and the length of anthers in males, but not in females. This would be expected if males growing in better environmental conditions or with greater vigour invested more resources in pollen production, thereby increasing fitness. Females, who receive no fitness benefits from increased pollen production, did not show this pattern. There was also evidence of a trade‐off within female flowers between the number of stamens and the number of pistils. This trade‐off was noted in conditions when variance among plants was reduced, namely in the field during a year when flower size was particularly small and in a previous glasshouse study. Therefore, it appears that when environmental variance is low, stamens are produced at the expense of producing more pistils, and hence seeds. In conclusion, stamen production does not appear to be inconsequential to females of Thalictrum pubescens. PMID:12125765

Comparative Developmental Staging of Female and Male Water Fleas Daphnia pulex and Daphnia magna During Embryogenesis.

PubMed

Toyota, Kenji; Hiruta, Chizue; Ogino, Yukiko; Miyagawa, Shinichi; Okamura, Tetsuro; Onishi, Yuta; Tatarazako, Norihisa; Iguchi, Taisen

2016-02-01

The freshwater crustacean genus Daphnia has been used extensively in ecological, developmental and ecotoxicological studies. Daphnids produce only female offspring by parthenogenesis under favorable conditions, but in response to various unfavorable conditions and external stimuli, they produce male offspring. Although we reported that exogenous exposure to juvenile hormones and their analogs can induce male offspring even under female-producing conditions, we recently established a male induction system in the Daphnia pulex WTN6 strain simply by changing day-length. This male and female induction system is suitable for understanding the innate mechanisms of sexual dimorphic development in daphnids. Embryogenesis has been described as a normal plate (developmental staging) in various daphnid species; however, all studies have mainly focused on female development. Here, we describe the developmental staging of both sexes during embryogenesis in two representative daphnids, D. pulex and D. magna, based on microscopic time-course observations. Our findings provide the first detailed insights into male embryogenesis in both species, and contribute to the elucidation of the mechanisms underlying sexual differentiation in daphnids.

Gastrointestinal microflora, food components and colon cancer prevention

PubMed Central

Davis, Cindy D.; Milner, John A.

2009-01-01

Evidence is emerging that the intestinal microbiota is intrinsically linked with overall health, including cancer risk. Moreover, its composition is not fixed, but can be influenced by several dietary components. Dietary modifiers, including the consumption of live bacteria (probiotics), nondigestible or limited digestible food constituents such as oligosaccharides (prebiotics) and polyphenols, or both (synbiotics), are recognized modifiers of the numbers and types of microbes and have been reported to reduce colon cancer risk experimentally. Microorganisms also have the ability to generate bioactive compounds from food components. Examples include equol from isoflavones, enterodiol and enterolactone from lignans, and urolithins from ellagic acid, which have also been demonstrated to retard experimentally induced cancers. The gastrointestinal microbiota can also influence both sides of the energy balance equation; namely, as a factor influencing energy utilization from the diet and as a factor that influences host genes that regulate energy expenditure and storage. Because of the link between obesity and cancer incidence and mortality, this complex relationship deserves greater attention. Thus, a complex interrelationship exists between the intestinal microbiota and colon cancer risk which can be modified by dietary components and eating behaviors. PMID:19716282

Clonal reproduction with androgenesis and somatic recombination: the case of the ant Cardiocondyla kagutsuchi

NASA Astrophysics Data System (ADS)

Okita, Ichiro; Tsuchida, Koji

2016-04-01

In haplodiploid insects such as ants, male sexuals develop from unfertilised haploid eggs, while female sexuals and workers develop from fertilized diploid eggs. However, some ant species do not exchange their gene pool between sexes; both male and female sexuals are clonally produced, while workers are sexually produced. To date, three ant species, Wasmannia auropunctata, Vollenhovia emeryi, and Paratrechina longicornis, have been reported to reproduce using such reproductive systems. In this study, we reveal that in one lineage of the ant Cardiocondyla kagutsuchi, male and female sexuals are also clonally produced. In contrast to the abovementioned three species, the workers were not only sexually produced but had recombinant sequences in their nuclear internal transcribed spacer regions, although the recombinant sequences were not detected in male or female sexuals. These results suggest that the lineage likely possesses a mechanism to compensate for the reduction in genetic variation due to clonal reproduction with somatic recombination that occurs within the workers.

Clonal reproduction with androgenesis and somatic recombination: the case of the ant Cardiocondyla kagutsuchi.

PubMed

Okita, Ichiro; Tsuchida, Koji

2016-04-01

In haplodiploid insects such as ants, male sexuals develop from unfertilised haploid eggs, while female sexuals and workers develop from fertilized diploid eggs. However, some ant species do not exchange their gene pool between sexes; both male and female sexuals are clonally produced, while workers are sexually produced. To date, three ant species, Wasmannia auropunctata, Vollenhovia emeryi, and Paratrechina longicornis, have been reported to reproduce using such reproductive systems. In this study, we reveal that in one lineage of the ant Cardiocondyla kagutsuchi, male and female sexuals are also clonally produced. In contrast to the abovementioned three species, the workers were not only sexually produced but had recombinant sequences in their nuclear internal transcribed spacer regions, although the recombinant sequences were not detected in male or female sexuals. These results suggest that the lineage likely possesses a mechanism to compensate for the reduction in genetic variation due to clonal reproduction with somatic recombination that occurs within the workers.

LUTEAR CELLS AND HEN-FEATHERING

PubMed Central

Boring, Alice M.; Morgan, T. H.

1918-01-01

The experimental evidence had made clear that some substance is produced in the testis of the male Sebright that suppresses in him the development of the secondary sexual plumage of the cock of his species. The detection in his testis of lutear cells like those in hens makes the conclusion highly probable that it is these cells that cause the suppression of cock-feathering in both the Sebright male and in hens of all fowls. Genetic work by Morgan had shown that one or two Mendelian factor-differences are responsible for hen-feathering in the Sebright. These factor-differences produce their effects through the testes. The presence of these genetic factors, we now see, causes the testes of the Sebright to produce a kind of secretory cell that is ordinarily only produced in the female, or possibly to a slight extent in young males (Boring), or in numbers insufficient to suppress the male plumage in the testes of some ordinary cock birds (Reeves). PMID:19871722

Is diversification in male reproductive traits driven by evolutionary trade-offs between weapons and nuptial gifts?

PubMed Central

Liu, Xingyue; Hayashi, Fumio; Lavine, Laura C.; Yang, Ding

2015-01-01

Many male animals have evolved exaggerated traits that they use in combat with rival males to gain access to females and secure their reproductive success. But some male animals invest in nuptial gifts that gains them access to females. Both these reproductive strategies are costly in that resources are needed to produce the weapon or nuptial gift. In closely related species where both weapons and nuptial gifts are present, little is known about the potential evolutionary trade-off faced by males that have these traits. In this study, we use dobsonflies (order Megaloptera, family Corydalidae, subfamily Corydalinae) to examine the presence and absence of enlarged male weapons versus nuptial gifts within and among species. Many dobsonfly species are sexually dimorphic, and males possess extremely enlarged mandibles that they use in battles, whereas in other species, males produce large nuptial gifts that increase female fecundity. In our study, we show that male accessory gland size strongly correlates with nuptial gift size and that when male weapons are large, nuptial gifts are small and vice versa. We mapped weapons and nuptial gifts onto a phylogeny we constructed of 57 species of dobsonflies. Our among-species comparison shows that large nuptial gift production evolved in many species of dobsonfly but is absent from those with exaggerated weapons. This pattern supports the potential explanation that the trade-off in resource allocation between weapons and nuptial gifts is important in driving the diversity of male mating strategies seen in the dobsonflies, whereas reduced male–male competition in the species producing large spermatophores could be an alternative explanation on their loss of male weapons. Our results shed new light on the evolutionary interplay of multiple sexually selected traits in animals. PMID:25925103

Presence of Putative Male-Produced Sex Pheromone in Lutzomyia cruciata (Diptera: Psychodidae), Vector of Leishmania mexicana.

PubMed

Serrano, A K; Rojas, J C; Cruz-López, L C; Malo, Edi A; Mikery, O F; Castillo, A

2016-11-01

Lutzomyia cruciata (Coquillet) is a vector of cutaneous leishmaniasis in Mexico and Central America. However, several aspects of its ecology and behavior are unknown, including whether a male pheromone partially mediates the sexual behavior of this sand fly. In this study, we evaluated the behavioral response of females to male abdominal extracts in a Y-tube olfactometer. The volatile compounds from male abdominal extracts were identified by gas chromatography-mass spectrometry and compared with those of female abdominal extracts. Finally, the disseminating structures of the putative sex pheromone were examined by scanning electron microscopy in the male abdomen. Females were more attracted to male abdominal extract than to the hexane control, suggesting the presence of male-produced sex pheromone. The male abdominal extracts were characterized by the presence of 12 sesquiterpene compounds. The major component, an unknown sesquiterpene with an abundance of 60%, had a mass spectrum with molecular ion of m/z 262. In contrast, the abdominal female extracts contained saturated fatty acids. Finally, we detected the presence of small "papules" with a mammiform morphology distributed on the abdominal surface of tergites IV-VII of male Lu. cruciata These structures are not present in females. We conclude that Lu. cruciata males likely produce a pheromone involved in attracting or courting females. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Sneaker "jack" males outcompete dominant "hooknose" males under sperm competition in Chinook salmon (Oncorhynchus tshawytscha).

PubMed

Young, Brent; Conti, David V; Dean, Matthew D

2013-12-01

In a variety of taxa, males deploy alternative reproductive tactics to secure fertilizations. In many species, small "sneaker" males attempt to steal fertilizations while avoiding encounters with larger, more aggressive, dominant males. Sneaker males usually face a number of disadvantages, including reduced access to females and the higher likelihood that upon ejaculation, their sperm face competition from other males. Nevertheless, sneaker males represent an evolutionarily stable strategy under a wide range of conditions. Game theory suggests that sneaker males compensate for these disadvantages by investing disproportionately in spermatogenesis, by producing more sperm per unit body mass (the "fair raffle") and/or by producing higher quality sperm (the "loaded raffle"). Here, we test these models by competing sperm from sneaker "jack" males against sperm from dominant "hooknose" males in Chinook salmon. Using two complementary approaches, we reject the fair raffle in favor of the loaded raffle and estimate that jack males were ∼1.35 times as likely as hooknose males to fertilize eggs under controlled competitive conditions. Interestingly, the direction and magnitude of this skew in paternity shifted according to individual female egg donors, suggesting cryptic female choice could moderate the outcomes of sperm competition in this externally fertilizing species.

Differences in carbachol dose, pain condition, and sex following lateral hypothalamic stimulation.

PubMed

Holden, J E; Wang, E; Moes, J R; Wagner, M; Maduko, A; Jeong, Y

2014-06-13

Lateral hypothalamic (LH) stimulation produces antinociception in female rats in acute, nociceptive pain. Whether this effect occurs in neuropathic pain or whether male-female sex differences exist is unknown. We examined the effect of LH stimulation in male and female rats using conditions of nociceptive and neuropathic pain. Neuropathic groups received chronic constriction injury (CCI) to induce thermal hyperalgesia, a sign of neuropathic pain. Nociceptive rats were naive for CCI, but received the same thermal stimulus following LH stimulation. To demonstrate that CCI ligation produced thermal hyperalgesia, males and females received either ligation or sham surgery for control. Both males and females demonstrated significant thermal hyperalgesia following CCI ligation (p<0.05), but male sham surgery rats also showed a significant left-right difference not present in female sham rats. In the second experiment, rats randomly assigned to CCI or nociceptive groups were given one of three doses of the cholinergic agonist carbachol (125, 250, or 500 nmol) or normal saline for control, microinjected into the left LH. Paw withdrawal from a thermal stimulus (paw withdrawal latency; PWL) was measured every 5 min for 45 min. Linear mixed models analysis showed that males and females in both pain conditions demonstrated significant antinociception, with the 500-nmol dose producing the greatest effect across groups compared with controls for the left paw (p<0.05). Female CCI rats showed equivalent responses to the three doses, while male CCI rats showed more variability for dose. However, nociceptive females responded only to the 500-nmol dose, while nociceptive males responded to all doses (p<0.05). For right PWL, only nociceptive males showed a significant carbachol dose response. These findings are suggestive that LH stimulation produces antinociception in male and female rats in both nociceptive and neuropathic pain, but dose response differences exist based on sex and pain condition. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Male-produced aggregation pheromone of Carpophilus sayi, a nitidulid vector of oak wilt disease, and pheromonal comparison with Carpophilus lugubris

Treesearch

Robert J. Bartelt; John F. Kyhl; Angie K. Ambourn; Jennifer Juzwik; Steven J. Seybold

2004-01-01

Carpophilus sayi, a nitidulid beetle vector of the oak wilt fungus, Ceratocystis fagacearum, was shown to have a male-produced aggregation pheromone. Six male-specific chemicals were identified from collections of volatiles. The two major compounds were (2E,4E,6E,8E)-3,5-dimethyl-7-ethyl-2,4,6,8- undecatetraene and (2E,4E,6E,8E...

Masculinization of nile tilapia (Oreochromis niloticus) using extract of bull testes

NASA Astrophysics Data System (ADS)

Yustiati, A.; Bangkit, I.; Zidni, I.

2018-03-01

Tilapia males grow faster to increase the production of the fish, there is a necessity to produce all males by using extract of bull testes. The research method used in this study was the experimental Completely Randomized Design (CRD) with five treatments and three replications. The treatments were A: without immersion and without oral treatment (control); B; immersion 600 μg·L-1 without oral treatment; C: immersion 600 μg·L-1 and oral at a dose of 30 mg·kg-1 feeds, D: immersion 600 μg·L-1 and oral at a dose of 40 mg·kg-1 feeds, E: immersion 600 μg·L-1 and oral at a dose of 50 mg·kg-1 feeds. Results showed that the use of bull testicle extract mixed to media at concentration of 3 ml L-1 produced red male nile of 69.07 %. In addition, the immersion of the extract at 500 μg·L-1 resulted the male of 86.71 %. Sex reversal by dipping at 600 μg·L-1 17α-methyltestosterone combined with oral administration at 40 mg·kg-1 produced the highest male of Nile Tilapia Java carp (86.67 %) compared with dipping, which produced 65.56 % of male. These results suggested that combination of dipping and oral is more effective for sex reversal.

Comparing the Reproductive Success of Yakima River Hatchery- and Wild-Origin Spring Chinook; Yakima/Klickitat Fisheries Project Monitoring and Evaluation, 2001-2002 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schroder, Steven L.; Knudsen, Curtis M.; Watson, Bruce D.

In 2001 hatchery- and wild-origin spring chinook were placed into an observation stream located at the Cle Elum Supplementation Research Facility to compare their reproductive success. Two groups containing both wild- and hatchery fish of both sexes were brought into the stream and allowed to spawn. Their longevity, spawning participation, and reproductive success were assessed. In addition, wild- and hatchery-origin precocious males were also introduced into one of the sections and allowed to spawn. We found that hatchery and wild males generally lived longer than females. In one group hatchery and wild females lived for similar periods of time whilemore » in the other wild females lived longer than hatchery fish. Wild females were also more successful at burying their eggs and the eggs they buried had higher survival rates. This result occurred in both groups of fish. Spawning participation in males was estimated by using two statistics referred to as percent gonad depletion (PGD) and percent testes retention (PRT). Both of these measures assumed that loss of testes weight in males would reflect their spawning participation and therefore could be used to estimate reproductive success. Hatchery and wild males had similar PGD and PRT values. One of these measures, PRT, was negatively associated with male reproductive success, confirming the idea that reduction in testes weight can be used as a surrogate measure of a male's ability to produce offspring Fry from the observation stream were collected throughout the emergence period that ran from January through May. Proportionate sub-samples of these fish were removed and microsatellite DNA was extracted from them. Pedigree analyses were performed to ascertain which adult fish had produced them. These analyses disclosed that wild males were more successful at producing progeny in one of the groups. No difference occurred in the other group. Precocial males and jacks fathered fewer progeny than did fish maturing at ages 4 and 5. In addition, male reproductive success was more than twice as variable as that seen in females. Some males apparently never spawned and others produced more than 7,000 offspring an amount that was more than double the quantity generated by the most successful female. Behavioral observations showed that a number of factors besides male origin influenced their reproductive success. One was relative body size; larger males tended to dominate smaller opponents and therefore had greater access to females. However, male dominance was not always related to relative size. The ability to attack and chase opponents was, however, positively related to reproductive success. We also discovered that the reproductive status of females and the social status of males were often reflected by their nuptial coloration. Territorial females typically had a single broad purple black stripe, light green or brown backs and white or gray ventral surfaces. Dominate males on the other hand, were generally a uniform dark brown or black color. The percentage of time that a male possessed a dark color pattern was positively linked to his reproductive success, as was the percentage of time he was observed courting or defending a female. The number of times a male was chased or attacked by a female also affected his reproductive success, in this situation the greater the frequency of such attacks the lower the reproductive success of the male. The pedigree analyses also disclosed that both hatchery and wild precocious males were able to fertilize eggs and produce offspring under natural spawning conditions. In conclusion we found differences in the reproductive competency of hatchery- and wild origin spring chinook. Wild females were better at depositing their eggs and having those eggs produce fry. In one study group wild males were more successful at producing offspring than hatchery males. Additional replications of such evaluations are being carried out to determine if the differences seen can be replicated. A repeat of the work done in 2001, for example, was performed in 2002 and additional studies will take place this coming year.« less

Male Responses to Female Aggression.

ERIC Educational Resources Information Center

Russell, Gordon W.; And Others

1988-01-01

Randomly assigned 60 male undergraduates to view film clip of professional lady wrestlers or of mud wrestling, or to no-film control. Both films produced negative changes in mood states, principally increase in aggression and decrease in social affection. Viewing films did not produce changes in men's acceptance of interpersonal violence against…

Aggregation Behavior and a Putative Aggregation Pheromone in Sugar Beet Root Maggot Flies (Diptera: Ulidiidae)

PubMed Central

Emmert, Susan Y.; Tindall, Kelly; Ding, Hongjian; Boetel, Mark A.; Rajabaskar, D.; Eigenbrode, Sanford D.

2017-01-01

Male-biased aggregations of sugar beet root maggot, Tetanops myopaeformis (Röder) (Diptera: Ulidiidae), flies were observed on utility poles near sugar beet (Beta vulgaris L. [Chenopodiaceae]) fields in southern Idaho; this contrasts with the approximately equal sex ratio typically observed within fields. Peak observation of mating pairs coincided with peak diurnal abundance of flies. Volatiles released by individual male and female flies were sampled from 08:00 to 24:00 hours in the laboratory using solid-phase microextraction and analyzed using gas chromatography/mass spectrometry (GC/MS). Eleven compounds were uniquely detected from males. Three of these compounds (2-undecanol, 2-decanol, and sec-nonyl acetate) were detected in greater quantities during 12:00–24:00 hours than during 08:00–12:00 hours. The remaining eight compounds uniquely detected from males did not exhibit temporal trends in release. Both sexes produced 2-nonanol, but males produced substantially higher (ca. 80-fold) concentrations of this compound than females, again peaking after 12:00 hours. The temporal synchrony among male aggregation behavior, peak mating rates, and release of certain volatile compounds by males suggest that T. myopaeformis flies exhibit lekking behavior and produce an associated pheromone. Field assays using synthetic blends of the putative aggregation pheromone showed evidence of attraction in both females and males. PMID:28423428

Selection by mating competitiveness improves the performance of Anastrepha ludens males of the genetic sexing strain Tapachula-7.

PubMed

Quintero-Fong, L; Toledo, J; Ruiz, L; Rendón, P; Orozco-Dávila, D; Cruz, L; Liedo, P

2016-10-01

The sexual performance of Anastrepha ludens males of the Tapachula-7 genetic sexing strain, produced via selection based on mating success, was compared with that of males produced without selection in competition with wild males. Mating competition, development time, survival, mass-rearing quality parameters and pheromone production were compared. The results showed that selection based on mating competitiveness significantly improved the sexual performance of offspring. Development time, survival of larvae, pupae and adults, and weights of larvae and pupae increased with each selection cycle. Differences in the relative quantity of the pheromone compounds (Z)-3-nonenol and anastrephin were observed when comparing the parental males with the F4 and wild males. The implications of this colony management method on the sterile insect technique are discussed.

Wolbachia-mediated parthenogenesis in the predatory thrips Franklinothrips vespiformis (Thysanoptera: Insecta).

PubMed Central

Arakaki, N.; Miyoshi, T.; Noda, H.

2001-01-01

Wolbachia are bacterial endosymbionts in arthropods and filarial nematodes. They cause thelytoky, which is a form of parthenogenesis in which females produce females without males, in hymenopteran insects. Infection of this parthenogenesis-inducing Wolbachia has been restricted to the order Hymenoptera, but was found in another insect order, Thysanoptera. A parthenogenetic colony of a predatory thrips Franklinothrips vespiformis (Aeolothripidae) possessed B-group Wolbachia. Male progeny were produced from this thrips by heat and tetracycline treatments. Males produced motile sperm, which were transferred to the female spermatheca by mating. However, the mating did not affect the sex ratios of the next generation, suggesting that the sperm do not fertilize the eggs. PMID:11375084

Regulatory Role of PBAN in Sex Pheromone Biosynthesis of Heliothine Moths

PubMed Central

Jurenka, Russell; Rafaeli, Ada

2011-01-01

Both males and females of heliothine moths utilize sex-pheromones during the mating process. Females produce and release a sex pheromone for the long–range attraction of males for mating. Production of sex pheromone in females is controlled by the peptide hormone (pheromone biosynthesis activating neuropeptide, PBAN). This review will highlight what is known about the role PBAN plays in controlling pheromone production in female moths. Male moths produce compounds associated with a hairpencil structure associated with the aedaegus that are used as short-range aphrodisiacs during the mating process. We will discuss the role that PBAN plays in regulating male production of hairpencil pheromones. PMID:22654810

Ultrasonic courtship song in the Asian corn borer moth, Ostrinia furnacalis

NASA Astrophysics Data System (ADS)

Nakano, Ryo; Ishikawa, Yukio; Tatsuki, Sadahiro; Surlykke, Annemarie; Skals, Niels; Takanashi, Takuma

2006-06-01

Although sex pheromone communication in the genus Ostrinia (Lepidoptera: Crambidae) has been studied intensively, acoustic communication in this genus has not been explored. In this study, we report that male-produced ultrasound serves as a courtship song in the Asian corn borer moth, O. furnacalis. Upon landing close to a pheromone-releasing female, a male showed a series of courtship behaviors involving emission of ultrasound. The sounds were produced when the wings were vibrated quickly in an upright position. The male song was composed of chirps, i.e., groups of pulses (duration of a chirp = 58.9 ms, 8.8 pulses/chirp), with a broadband frequency of 25-100 kHz. In flight tunnel experiments, deaf and hearing females showed a significant difference in the incidence of three behavioral responses to courting males, i.e., immediate acceptance, acceptance after walking, and rejection. Deaf females showed more ‘rejection’ and less ‘acceptance after walking’ than hearing females, indicating that the detection of male-produced ultrasound plays an important role in the acceptance of a male. The findings are discussed in the context of exploitation of receiver bias and mate choice.

Is diversification in male reproductive traits driven by evolutionary trade-offs between weapons and nuptial gifts?

PubMed

Liu, Xingyue; Hayashi, Fumio; Lavine, Laura C; Yang, Ding

2015-05-22

Many male animals have evolved exaggerated traits that they use in combat with rival males to gain access to females and secure their reproductive success. But some male animals invest in nuptial gifts that gains them access to females. Both these reproductive strategies are costly in that resources are needed to produce the weapon or nuptial gift. In closely related species where both weapons and nuptial gifts are present, little is known about the potential evolutionary trade-off faced by males that have these traits. In this study, we use dobsonflies (order Megaloptera, family Corydalidae, subfamily Corydalinae) to examine the presence and absence of enlarged male weapons versus nuptial gifts within and among species. Many dobsonfly species are sexually dimorphic, and males possess extremely enlarged mandibles that they use in battles, whereas in other species, males produce large nuptial gifts that increase female fecundity. In our study, we show that male accessory gland size strongly correlates with nuptial gift size and that when male weapons are large, nuptial gifts are small and vice versa. We mapped weapons and nuptial gifts onto a phylogeny we constructed of 57 species of dobsonflies. Our among-species comparison shows that large nuptial gift production evolved in many species of dobsonfly but is absent from those with exaggerated weapons. This pattern supports the potential explanation that the trade-off in resource allocation between weapons and nuptial gifts is important in driving the diversity of male mating strategies seen in the dobsonflies, whereas reduced male-male competition in the species producing large spermatophores could be an alternative explanation on their loss of male weapons. Our results shed new light on the evolutionary interplay of multiple sexually selected traits in animals. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Sneaker “jack” males outcompete dominant “hooknose” males under sperm competition in Chinook salmon (Oncorhynchus tshawytscha)

PubMed Central

Young, Brent; Conti, David V; Dean, Matthew D

2013-01-01

In a variety of taxa, males deploy alternative reproductive tactics to secure fertilizations. In many species, small “sneaker” males attempt to steal fertilizations while avoiding encounters with larger, more aggressive, dominant males. Sneaker males usually face a number of disadvantages, including reduced access to females and the higher likelihood that upon ejaculation, their sperm face competition from other males. Nevertheless, sneaker males represent an evolutionarily stable strategy under a wide range of conditions. Game theory suggests that sneaker males compensate for these disadvantages by investing disproportionately in spermatogenesis, by producing more sperm per unit body mass (the “fair raffle”) and/or by producing higher quality sperm (the “loaded raffle”). Here, we test these models by competing sperm from sneaker “jack” males against sperm from dominant “hooknose” males in Chinook salmon. Using two complementary approaches, we reject the fair raffle in favor of the loaded raffle and estimate that jack males were ∼1.35 times as likely as hooknose males to fertilize eggs under controlled competitive conditions. Interestingly, the direction and magnitude of this skew in paternity shifted according to individual female egg donors, suggesting cryptic female choice could moderate the outcomes of sperm competition in this externally fertilizing species. PMID:24455130

Effects of Cyclic Feeding and Starvation, Mating, and Sperm Condition on Egg Production and Fertility in the Common Bed Bug (Hemiptera: Cimicidae).

PubMed

Matos, Yvonne K; Osborne, Jason A; Schal, Coby

2017-11-07

Bed bugs (Cimex lectularius L.) are now endemic in most major cities, but information regarding their basic biology is still largely based on research done over four decades ago. We investigated the effects of starvation, mating, sperm storage, and female and male age on egg production and hatch. Egg production cycles varied with the number of bloodmeals that females received. Once-mated females fed every 5 d had constant egg production for ∼75 d followed by a monotonic decline to near zero. Percentage egg hatch was high and constant, but declined after ∼30 d to near zero. To determine whether the age of the female, male, or sperm affected these patterns, we mated newly eclosed females to 60-d-old virgin males, 60-d-old mated males, or newly eclosed males. Females produced the most eggs when mated to young males, followed by old mated males, and then old virgin males; percentage hatch followed a similar pattern, suggesting that sperm stored within males for long was deficient. To examine effects of sperm stored within females, we mated newly eclosed females, starved them for 30 or 60 d, then fed them every 5 d. The 60-d starved group produced fewer eggs than the 30-d starved group, and both produced fewer eggs than young females mated to old or young males. Longer periods of sperm storage within females caused lower corresponding percentage hatch. These findings indicate egg production and hatch are governed by complex interactions among female and male age, frequency of feeding and mating, and sperm condition. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Evidence that (+)-endo-Brevicomin is a male-produced component of the Southern Pine Beetle aggregation pheromone

Treesearch

Brian T. Sullivan; William P. Shepherd; Deepa S. Pureswarana; Takuya Tashiro; Kenji Mori

2007-01-01

Previous research indicated that the aggregation pheromone of the southern pine beetle, Dendroctonus frontalis, is produced only by females, the sex that initiates attacks. We provide evidence indicating that secondarily arriving males augment mass aggregation by releasing the attractive synergist (+)-endo-brevicomin. Healthy pines artificially...

INTERACTIVE EFFECTS OF VINCLOZOLIN AND TESTOSTERONE PROPIONATE ON PREGNANCY AND SEXUAL DIFFERENTIATION OF THE MALE AND FEMALE SD RAT

EPA Science Inventory

ABSTRACT
Sufficient levels of androgens during fetal sexual differentiation in the mammal produces the male phenotype, and the absence of androgens or the dysfunction of the androgen receptor can produce the female phenotype. In previous studies in our laboratory, adminis...

Food availability and offspring sex in a monogamous seabird: insights from an experimental approach

USGS Publications Warehouse

Merkling, Thomas; Leclaire, Sarah; Danchin, Etienne; Lhuillier, Emeline; Wagner, Richard H.; White, Joël; Hatch, Scott A.; Blanchard, Pierrick

2012-01-01

Sex allocation theory predicts that parents should favor offspring of the sex that provides the greatest fitness return. Despite growing evidence suggesting that vertebrates are able to overcome the constraint of chromosomal sex determination, the general pattern remains equivocal, indicating a need for experimental investigations. We used an experimental feeding design to study sex allocation during 3 years in black-legged kittiwakes (Rissa tridactyla). Intense male–male competition for securing a breeding site is common in this species in which males are heavier and larger than females. Hence, we hypothesized that parents producing fledglings in better than average condition, as supplementarily fed pairs do, would increase their fitness return by producing sons. Conversely, producing daughters would be a better tactic for Unfed parents. Hence, we predicted that Fed parents produce more sons than Unfed parents. This prediction is particularly expected if sexual dimorphism arises as early as during chick rearing, suggesting strong selective pressures for optimal male development. Our results showed that 1) males were heavier and larger than females prior to fledging and that 2) Fed parents produced relatively more male hatchlings than Unfed parents. We interpret this result in terms of a Trivers–Willard-type process. Furthermore, our data revealed that Unfed parents significantly overproduced female hatchlings, whereas offspring sex ratio was balanced among Fed parents. Because the 3 reproductive seasons we considered were particularly poor food years, Unfed parents may have overproduced daughters to avoid the apparent higher reproductive costs of raising sons.

Soy isoflavone phase II metabolism differs between rodents and humans: implications for the effect on breast cancer risk1234

PubMed Central

Brown, Nadine M; Zhao, Xueheng; Lindley, Stephanie L; Heubi, James E; King, Eileen C; Messina, Mark J

2011-01-01

Background: Human and animal studies have produced conflicting results with regard to the effect of soy isoflavones on breast cancer risk. This may be due to differences in isoflavone metabolism. Objective: The objective of this study was to determine whether soy isoflavone phase II metabolism differs between humans and rodents. Design: Circulating total and unconjugated isoflavone concentrations were determined by mass spectrometry in plasma samples from 7 separate studies: 1) in Sprague-Dawley rats and in 3 strains of mice fed commercial soy-containing diets; 2) in Sprague-Dawley rats gavaged with genistein; 3) in healthy adults who consumed single servings of soy nuts, soy milk, and tempeh; 4) in healthy adults subchronically given soy milk; 5) in healthy women orally administered 50 mg genistein; 6) in healthy women orally administered 20 mg pure S-(-)equol; and 7) in 6-mo-old infants fed soy infant formula and later, at age 3 y, a soy germ isoflavone supplement. Results: The proportion of unconjugated genistein in plasma from adults and infants who consumed different soy foods, pure genistein, or an isoflavone supplement was <1% in steady state and <2% at peak concentrations. By contrast, rodents fed soy-containing diets conjugate isoflavones less efficiently. The plasma percentages of unconjugated genistein concentrations in Sprague-Dawley rats and C57BL/6, nude, and transgenic AngptL4B6 mice were 4.0 ± 0.6%, 4.6 ± 0.6%, 11.6 ± 0%, and 30.1 ± 4.3%, respectively, which represent 20, 23, 58, and 150 times that in humans. Conclusion: The markedly higher circulating concentrations of biologically active (unconjugated) genistein in certain strains of mice cast doubt on the value of the use of these rodents for gaining insight into the effects of isoflavones in humans, especially with regard to the effects on breast tissue. PMID:21955647

Soy isoflavone phase II metabolism differs between rodents and humans: implications for the effect on breast cancer risk.

PubMed

Setchell, Kenneth D R; Brown, Nadine M; Zhao, Xueheng; Lindley, Stephanie L; Heubi, James E; King, Eileen C; Messina, Mark J

2011-11-01

Human and animal studies have produced conflicting results with regard to the effect of soy isoflavones on breast cancer risk. This may be due to differences in isoflavone metabolism. The objective of this study was to determine whether soy isoflavone phase II metabolism differs between humans and rodents. Circulating total and unconjugated isoflavone concentrations were determined by mass spectrometry in plasma samples from 7 separate studies: 1) in Sprague-Dawley rats and in 3 strains of mice fed commercial soy-containing diets; 2) in Sprague-Dawley rats gavaged with genistein; 3) in healthy adults who consumed single servings of soy nuts, soy milk, and tempeh; 4) in healthy adults subchronically given soy milk; 5) in healthy women orally administered 50 mg genistein; 6) in healthy women orally administered 20 mg pure S-(-)equol; and 7) in 6-mo-old infants fed soy infant formula and later, at age 3 y, a soy germ isoflavone supplement. The proportion of unconjugated genistein in plasma from adults and infants who consumed different soy foods, pure genistein, or an isoflavone supplement was <1% in steady state and <2% at peak concentrations. By contrast, rodents fed soy-containing diets conjugate isoflavones less efficiently. The plasma percentages of unconjugated genistein concentrations in Sprague-Dawley rats and C57BL/6, nude, and transgenic AngptL4B6 mice were 4.0 ± 0.6%, 4.6 ± 0.6%, 11.6 ± 0%, and 30.1 ± 4.3%, respectively, which represent 20, 23, 58, and 150 times that in humans. The markedly higher circulating concentrations of biologically active (unconjugated) genistein in certain strains of mice cast doubt on the value of the use of these rodents for gaining insight into the effects of isoflavones in humans, especially with regard to the effects on breast tissue.

Social Memory Formation Rapidly and Differentially Affects the Motivation and Performance of Vocal Communication Signals in the Bengalese Finch (Lonchura striata var. domestica).

PubMed

Toccalino, Danielle C; Sun, Herie; Sakata, Jon T

2016-01-01

Cognitive processes like the formation of social memories can shape the nature of social interactions between conspecifics. Male songbirds use vocal signals during courtship interactions with females, but the degree to which social memory and familiarity influences the likelihood and structure of male courtship song remains largely unknown. Using a habituation-dishabituation paradigm, we found that a single, brief (<30 s) exposure to a female led to the formation of a short-term memory for that female: adult male Bengalese finches were significantly less likely to produce courtship song to an individual female when re-exposed to her 5 min later (i.e., habituation). Familiarity also rapidly decreased the duration of courtship songs but did not affect other measures of song performance (e.g., song tempo and the stereotypy of syllable structure and sequencing). Consistent with a contribution of social memory to the decrease in courtship song with repeated exposures to the same female, the likelihood that male Bengalese finches produced courtship song increased when they were exposed to a different female (i.e., dishabituation). Three consecutive exposures to individual females also led to the formation of a longer-term memory that persisted over days. Specifically, when courtship song production was assessed 2 days after initial exposures to females, males produced fewer and shorter courtship songs to familiar females than to unfamiliar females. Measures of song performance, however, were not different between courtship songs produced to familiar and unfamiliar females. The formation of a longer-term memory for individual females seemed to require at least three exposures because males did not differentially produce courtship song to unfamiliar females and females that they had been exposed to only once or twice. Taken together, these data indicate that brief exposures to individual females led to the rapid formation and persistence of social memories and support the existence of distinct mechanisms underlying the motivation to produce and the performance of courtship song.

Haptic perception accuracy depending on self-produced movement.

PubMed

Park, Chulwook; Kim, Seonjin

2014-01-01

This study measured whether self-produced movement influences haptic perception ability (experiment 1) as well as the factors associated with levels of influence (experiment 2) in racket sports. For experiment 1, the haptic perception accuracy levels of five male table tennis experts and five male novices were examined under two different conditions (no movement vs. movement). For experiment 2, the haptic afferent subsystems of five male table tennis experts and five male novices were investigated in only the self-produced movement-coupled condition. Inferential statistics (ANOVA, t-test) and custom-made devices (shock & vibration sensor, Qualisys Track Manager) of the data were used to determine the haptic perception accuracy (experiment 1, experiment 2) and its association with expertise. The results of this research show that expert-level players acquire higher accuracy with less variability (racket vibration and angle) than novice-level players, especially in their self-produced movement coupled performances. The important finding from this result is that, in terms of accuracy, the skill-associated differences were enlarged during self-produced movement. To explain the origin of this difference between experts and novices, the functional variability of haptic afferent subsystems can serve as a reference. These two factors (self-produced accuracy and the variability of haptic features) as investigated in this study would be useful criteria for educators in racket sports and suggest a broader hypothesis for further research into the effects of the haptic accuracy related to variability.

Physiological Costs of Repetitive Courtship Displays in Cockroaches Handicap Locomotor Performance

PubMed Central

Mowles, Sophie L.; Jepson, Natalie M.

2015-01-01

Courtship displays are typically thought to have evolved via female choice, whereby females select mates based on the characteristics of a display that is expected to honestly reflect some aspect of the male’s quality. Honesty is typically enforced by mechanistic costs and constraints that limit the level at which a display can be performed. It is becoming increasingly apparent that these costs may be energetic costs involved in the production of dynamic, often repetitive displays. A female attending to such a display may thus be assessing the physical fitness of a male as an index of his quality. Such assessment would provide information on his current physical quality as well as his ability to carry out other demanding activities, qualities with which a choosy female should want to provision her offspring. In the current study we use courtship interactions in the Cuban burrowing cockroach, Byrsotria fumigata to directly test whether courtship is associated with a signaler’s performance capacity. Males that had produced courtship displays achieved significantly lower speeds and distances in locomotor trials than non-courting control males. We also found that females mated more readily with males that produced a more vigorous display. Thus, males of this species have developed a strategy where they produce a demanding courtship display, while females choose males based on their ability to produce this display. Courtship displays in many taxa often involve dynamic repetitive actions and as such, signals of stamina in courtship may be more widespread than previously thought. PMID:26606147

Male crickets adjust ejaculate quality with both risk and intensity of sperm competition.

PubMed

Simmons, Leigh W; Denholm, Amy; Jackson, Chantelle; Levy, Esther; Madon, Ewa

2007-10-22

Sperm competition theory predicts that males should increase their expenditure on the ejaculate with increasing risk of sperm competition, but decrease their expenditure with increasing intensity. There is accumulating evidence for sperm competition theory, based on examinations of testes size and/or the numbers of sperm ejaculated. However, recent studies suggest that ejaculate quality can also be subject to selection by sperm competition. We used experimental manipulations of the risk and intensity of sperm competition in the cricket, Teleogryllus oceanicus. We found that males produced ejaculates with a greater percentage of live sperm when they had encountered a rival male prior to mating. However, when mating with a female that presented a high intensity of sperm competition, males did not respond to risk, but produced ejaculates with a reduced percentage of live sperm. Our data suggest that males exhibit a fine-tuned hierarchy of responses to these cues of sperm competition.

Fluttering wing feathers produce the flight sounds of male streamertail hummingbirds.

PubMed

Clark, Christopher James

2008-08-23

Sounds produced continuously during flight potentially play important roles in avian communication, but the mechanisms underlying these sounds have received little attention. Adult male Red-billed Streamertail hummingbirds (Trochilus polytmus) bear elongated tail streamers and produce a distinctive 'whirring' flight sound, whereas subadult males and females do not. The production of this sound, which is a pulsed tone with a mean frequency of 858 Hz, has been attributed to these distinctive tail streamers. However, tail-less streamertails can still produce the flight sound. Three lines of evidence implicate the wings instead. First, it is pulsed in synchrony with the 29 Hz wingbeat frequency. Second, a high-speed video showed that primary feather eight (P8) bends during each downstroke, creating a gap between P8 and primary feather nine (P9). Manipulating either P8 or P9 reduced the production of the flight sound. Third, laboratory experiments indicated that both P8 and P9 can produce tones over a range of 700-900 Hz. The wings therefore produce the distinctive flight sound, enabled via subtle morphological changes to the structure of P8 and P9.

Phenotypic plasticity in sex pheromone production in Bicyclus anynana butterflies.

PubMed

Dion, Emilie; Monteiro, Antónia; Yew, Joanne Y

2016-12-14

Phenotypic plasticity refers to the environmental control of phenotypes. Cues experienced during development (developmental plasticity) or during adulthood (acclimatization) can both affect adult phenotypes. Phenotypic plasticity has been described in many traits but examples of developmental plasticity in physiological traits, in particular, remain scarce. We examined developmental plasticity and acclimatization in pheromone production in the butterfly Bicyclus anynana in response to rearing temperature. B. anynana lives in the African tropics where warm rearing temperatures of the wet season produce active males that court and females that choose, whereas cooler temperatures of the dry season lead to choosy less active males and courting females. We hypothesized that if male pheromone production is costly, it should be reduced in the dry season form. After describing the ultrastructure of pheromone producing cells, we showed that dry season males produced significantly less sex pheromones than wet season males, partly due to acclimatization and partly due to developmental plasticity. Variation in levels of one of the compounds is associated with differential regulation of a pheromone biosynthetic enzyme gene. This plasticity might be an adaptation to minimize pheromone production costs during the stressful dry season.

Female choice and the relatedness of mates in the guppy (Poecilia reticulata): mate choice and inbreeding depression.

PubMed

Pitcher, Trevor E; Rodd, F Helen; Rowe, Locke

2008-09-01

Several studies suggest that females may offset the costs of genetic incompatibility by exercising pre-copulatory or post-copulatory mate choice to bias paternity toward more compatible males. One source of genetic incompatibility is the degree of relatedness among mates; unrelated males are expected to be genetically more compatible with a female than her relatives. To address this idea, we investigated the potential for inbreeding depression and paternity biasing mechanisms (pre- and post-copulatory) of inbreeding avoidance in the guppy, Poecilia reticulata. Inbreeding resulted in a reduction in offspring number and quality. Females mated to siblings gave birth to significantly fewer offspring compared to females mated to non-siblings and inbred male offspring took longer to reach sexual maturity. There was no evidence of inbreeding avoidance in pre-copulatory behaviors of females or males. Sexual responsiveness of females to courting males and the number of sexual behaviors males directed at females did not decrease as a function of the relatedness of the two individuals. We also tested whether female guppies can use post-copulatory mechanisms to bias sperm usage toward unrelated males by comparing the number of offspring produced by females mated to two of their siblings (SS), two males unrelated to the female (NN), or to one unrelated male and a sibling male (NS). We found that NS females produced a number of offspring not significantly different than what would be expected if fertilization success were halfway between completely outbreeding (NN) and completely inbreeding (SS) females. This suggests that there is no significant improvement in the number of offspring produced by females mating to both related and unrelated males, relative to that which would be expected if sperm from both males were used equally. Our results suggest that female guppies do not discriminate against closely related males or their sperm.

Uptake of plant-derived specific alkaloids allows males of a butterfly to copulate.

PubMed

Honda, Keiichi; Matsumoto, Junya; Sasaki, Ken; Tsuruta, Yoshiaki; Honda, Yasuyuki

2018-04-03

Certain butterflies utilize plant-acquired alkaloids for their own chemical defense and/or for producing male sex pheromone; a trait known as pharmacophagy. Males of the danaine butterfly, Parantica sita, have been reported to ingest pyrrolizidine alkaloids (PAs) as adults to produce two PA-derived sex pheromone components, viz. danaidone (major) and 7R-hydroxydanaidal. We found, however, that not all PAs that can be precursors for the pheromone serve for mating success of males. Here we show that although the sex pheromone is regarded as a requisite for successful mating, uptake of specific PA(s) (lycopsamine-type PAs) is also imperative for the males to achieve copulation. The increase in the levels of two biogenic amines, octopamine and/or serotonin, in the brain and thoracic ganglia of males fed with specific PA(s) suggested that these alkaloids most likely enhance male mating activity. The results can present new evidence for the evolutionary provenance of pharmacophagous acquisition of PAs in PA-adapted insects.

Does egg colouration reflect male condition in birds?

NASA Astrophysics Data System (ADS)

Martínez-Padilla, Jesús; Dixon, Heather; Vergara, Pablo; Pérez-Rodríguez, Lorenzo; Fargallo, Juan A.

2010-05-01

How colouration provides information about individuals in birds has been a central issue in recent decades. Although much information has been derived, little is known about the adaptive significance of egg colouration in birds. A recent idea suggests that biliverdin- and porphyrin-pigmented eggs may act as a post-mating sexual signal for males to assess female quality. In birds, it is common for males to influence prelaying female condition by courtship feeding. Using Eurasian kestrels, a species that lays protoporphyrin-pigmented eggs, we descriptively assessed the influence of male feeding on egg pigmentation by considering female phenotype, condition, breeding parameters and male body condition. We found that older females and females with greyer tails (an index of individual quality) produce highly pigmented eggs. However, male body condition was the only variable that explained egg colouration when considered together with the female-related variables. Therefore, females that mated with males in better condition laid highly pigmented eggs. With the same species, we also explored the cost of producing protoporphyrin-pigmented eggs using a food-supply experiment before the laying period. Food supplementation did not increase egg pigmentation, but hatching success and egg mass were positively related to egg colouration only in food supplied pairs. We suggest that egg colouration might be costly to produce and probably suggests egg quality. However, this cost cannot be explained by female quality, but by male condition instead. In general, our results do not support the theory that egg colouration is a post-mating sexual signal in species where males determine female condition at the time of laying.

Sugar and Multivitamin Diet Effects on The Longevity and Mating Capacity of Laboratory-Reared Male Anopheline Mosquitoes.

PubMed

Phasomkusolsil, Siriporn; Pantuwatana, Kanchana; Tawong, Jaruwan; Khongtak, Weeraphan; Kertmanee, Yossasin; Monkanna, Nantaporn; Khaosanorh, Sakon; Wanja, Elizabeth W; Davidson, Silas A

2017-09-01

Successful mating by male mosquitoes is dependent on several factors, with sugar feeding being particularly important. The effect of ingested vitamins on adult male mosquitoes is poorly understood. This laboratory study used 3 anopheline species, Anopheles campestris, An. dirus, and An. sawadwongporni, to study the effect of sugar and vitamins on male longevity, copulation, and fecundity. Males were fed 1 of 5 diets containing different combinations of sugar and vitamins: 10% glucose, 10% sucrose, 10% multivitamin syrup, 10% multivitamin syrup + 10% glucose, and 10% multivitamin syrup + 10% sucrose. The longevity of males was measured for a period of 15 days. Forced mating was used to simulate copulation, and fecundity was measured by counting the number of eggs oviposited and the hatch rate of larvae. The longevity of An. campestris and An. dirus was greatest when fed a diet of 10% multivitamin syrup + 10% glucose, and the longevity of An. sawadwongporni was greatest when fed a diet of 10% multivitamin syrup + 10% sucrose. The 1st mating routinely produced the most viable eggs when males were mated with several females. The diet of 10% multivitamin syrup + 10% sucrose produced numerically greater egg production and larval emergence for all 3 species, although this was not always statistically significant due to variability and small sample size. These results indicate that the addition of multivitamin syrup to sucrose may produce healthier and more fit male anophelines. This has potential implications for increasing insectary operations and improving the fitness of laboratory-reared male mosquitoes that will be released for mosquito and disease-pathogen control studies.

Inter- and Intrapopulation Variation of the Pheromone, Ipsdienol Produced by Male Pine Engravers Ips pini (Say) (Coleoptera: Scolytidae)

Treesearch

D.R. Miller; J.H. Borden; K.N. Slessor

1989-01-01

We determined the chirality of ipsdienol in individual male pine engravers, Ips pini (Say), from New York, California, and two localities in British Columbia (BC). Both quantity and chirality of ipsdienol varied significantly between and within populations of I. pini . Beetles from California and southeastern BC produced...

CELLULAR AND MOLECULAR MECHANISMS OF ACTION OF LINURON: AN ANTIANDROGENIC HERBICIDE THAT PRODUCES REPRODUCTIVE MALFORMATIONS IN MALE RATS

EPA Science Inventory

Title: CELLULAR AND MOLECULAR MECHANISMS OF ACTION OF LINURON: AN ANTIANDROGENIC HERBICIDE THAT PRODUCES REPRODUCTIVE MALFORMATIONS IN MALE RATS. C Lambright1, J Ostby, K Bobseine, V Wilson, AK Hotchkiss2, PC Mann3 and LE Gray Jr1.

Antiandrogenic chemicals alter sex d...

Relationships between tree size, crown shape, gender segregation and sex allocation in Pinus halepensis, a Mediterranean pine tree.

PubMed

Ne'eman, Gidi; Goubitz, Shirrinka; Werger, Marinus J A; Shmida, Avi

2011-07-01

Sex allocation has been studied mainly in small herbaceous plants but much less in monoecious wind-pollinated trees. The aim of this study was to explore changes in gender segregation and sex allocation by Pinus halepensis, a Mediterranean lowland pine tree, within tree crowns and between trees differing in their size or crown shape. The production of new male and female cones and sex allocation of biomass, nitrogen and phosphorus were studied. The relationship between branch location, its reproductive status and proxies of branch vigour was also studied. Small trees produced only female cones, but, as trees grew, they produced both male and female cones. Female cones were produced mainly in the upper part of the crown, and male cones in its middle and lower parts. Lateral branch density was correlated with the number of male but not female cones; lateral branches were more dense in large than in small trees and even denser in hemispherical trees. Apical branches grew faster, were thicker and their phosphorus concentration was higher than in lateral shoots. Nitrogen concentration was higher in cone-bearing apical branches than in apical vegetative branches and in lateral branches with or without cones. Allocation to male relative to female function increased with tree size as predicted by sex allocation theory. The adaptive values of sex allocation and gender segregation patterns in P. halepensis, in relation to its unique life history, are demonstrated and discussed. Small trees produce only female cones that have a higher probability of being pollinated than the probability of male cones pollinating; the female-first strategy enhances population spread. Hemispherical old trees are loaded with serotinous cones that supply enough seeds for post-fire germination; thus, allocation to males is more beneficial than to females.

Protein and carbohydrate intake influence sperm number and fertility in male cockroaches, but not sperm viability.

PubMed

Bunning, Harriet; Rapkin, James; Belcher, Laurence; Archer, C Ruth; Jensen, Kim; Hunt, John

2015-03-07

It is commonly assumed that because males produce many, tiny sperm, they are cheap to produce. Recent work, however, suggests that sperm production is not cost-free. If sperm are costly to produce, sperm number and/or viability should be influenced by diet, and this has been documented in numerous species. Yet few studies have examined the exact nutrients responsible for mediating these effects. Here, we quantify the effects of protein (P) and carbohydrate (C) intake on sperm number and viability in the cockroach Nauphoeta cinerea, as well as the consequences for male fertility. We found the intake of P and C influenced sperm number, being maximized at a high intake of diets with a P : C ratio of 1 : 2, but not sperm viability. The nutritional landscapes for male fertility and sperm number were closely aligned, suggesting that sperm number is the major determinant of male fertility in N. cinerea. Under dietary choice, males regulate nutrient intake at a P : C ratio of 1 : 4.95, which is midway between the ratios needed to maximize sperm production and pre-copulatory attractiveness in this species. This raises the possibility that males regulate nutrient intake to balance the trade-off between pre- and post-copulatory traits in this species. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Female starlings adjust primary sex ratio in response to aromatic plants in the nest.

PubMed

Polo, Vicente; Veiga, José P; Cordero, Pedro J; Viñuela, Javier; Monaghan, Pat

2004-09-22

Adjustment of offspring sex ratios should be favoured by natural selection when parents are capable of facultatively altering brood sex ratios and of recognizing the circumstances that predict the probable fitness benefit of producing sons and daughters. Although experimental studies have shown that female birds may adjust offspring sex ratios in response to changes in their own condition and in the external appearance of their mate, and male attributes other than his external morphology are also thought to act as signals of male quality, it is not known whether females will respond to changes in such signals, in the absence of any change in the appearance of the male himself. Here, we experimentally manipulated a male courtship display, the green plants carried to the nest by male spotless starlings (Sturnus unicolor), without changing any physical attributes of the male himself, and examined whether this influenced female decisions on offspring sex ratio. We found that in an environment in which female starlings were producing more daughters than sons, experimental enhancement of the green nesting material caused females to significantly increase the number of male eggs produced and thereby removed the female bias. This effect was consistent in 2 years and at two localities. This demonstrates that the green material, whose function has long puzzled biologists, conveys important information to the female and that she facultatively adjusts offspring production accordingly.

Photoperiodism of Male Offspring Production in the Water Flea Daphnia pulex.

PubMed

Toyota, Kenji; Sato, Tomomi; Tatarazako, Norihisa; Iguchi, Taisen

2017-08-01

Photoperiodism is a biological seasonal timing system utilized to regulate development and reproduction in organisms. The freshwater micro-crustacean Daphnia pulex displays environmental sex determination, the precise physiological mechanisms of which are largely unknown due to the lack of an experimental system to induce female or male offspring production by alterations of the rearing environment. We recently found that D. pulex, WTN6 strain, produces female or male offspring in response to long-day or short-day conditions, respectively. Taking advantage of this system, here we report the photoperiodic response curve for male offspring production, showing 12 hours as natural critical daylength (50% incidence of male-producing mothers), and that male offspring inducibility is highly sensitive to photoperiodic alterations. By using monochromatic light emitting diode (LED) devices, we found that the effective wavelength is red-light (627 nm), which stably induces male offspring production. This suggests that the red-light photoreceptor may be decisive in the primary step of sex determination process in this strain. Our findings provide the first insights into photoperiodism and red-light as key factors in triggering male offspring production in daphnids.

Discovery and identification of a male-killing agent in the Japanese ladybird Propylea japonica (Coleoptera: Coccinellidae)

PubMed Central

2010-01-01

Background Endosymbionts that manipulate the reproduction of their hosts have been reported widely in invertebrates. One such group of endosymbionts is the male-killers. To date all male-killers reported are bacterial in nature, but comprise a diverse group. Ladybirds have been described as a model system for the study of male-killing, which has been reported in multiple species from widespread geographic locations. Whilst criteria of low egg hatch-rate and female-biased progenic sex ratio have been used to identify female hosts of male-killers, variation in vertical transmission efficiency and host genetic factors may result in variation in these phenotypic indicators of male-killer presence. Molecular identification of bacteria and screening for bacterial presence provide us with a more accurate method than breeding data alone to link the presence of the bacteria to the male-killing phenotype. In addition, by identifying the bacteria responsible we may find evidence for horizontal transfer between endosymbiont hosts and can gain insight into the evolutionary origins of male-killing. Phylogenetic placement of male-killing bacteria will allow us to address the question of whether male-killing is a potential strategy for only some, or all, maternally inherited bacteria. Together, phenotypic and molecular characterisation of male-killers will allow a deeper insight into the interactions between host and endosymbiont, which ultimately may lead to an understanding of how male-killers identify and kill male-hosts. Results A male-killer was detected in the Japanese coccinellid, Propylea japonica (Thunberg) a species not previously known to harbour male-killers. Families produced by female P. japonica showed significantly female-biased sex ratios. One female produced only daughters. This male-killer trait was maternally inherited and antibiotic treatment produced a full, heritable cure. Molecular analysis identified Rickettsia to be associated with the trait in this species of ladybird. Conclusion We conclude that P. japonica is host to a bacterial male-killer that is vertically inherited with variable transmission efficiency. Rickettsia presence correlates with the male-killing trait, but there is some variation in the phenotypic expression of the trait due to interaction with host factors. Phylogenetic analysis using the 16S rRNA and 17 kDa antigen genes suggests there may have been horizontal transfer of Rickettsial male-killers between different ladybird hosts. PMID:20149223

Male behaviors reveal multiple pherotypes within vine mealybug Planococcus ficus (Signoret) (Hemiptera; Pseudococcidae) populations

NASA Astrophysics Data System (ADS)

Kol-Maimon, Hofit; Levi-Zada, Anat; Franco, José Carlos; Dunkelblum, Ezra; Protasov, Alex; Eliyaho, Miriam; Mendel, Zvi

2010-12-01

The vine mealybug (VM) females collected in Israel produce two sex pheromone compounds: lavandulyl senecioate (LS) and ( S)-lavandulyl isovalerate (LI). The males display ambiguous behavior to LI: repulsion in the vineyard and attraction of laboratory-reared males. We addressed the question of individual male behavior, i.e., do males respond to both LS and LI, or might they display a distinct response to each of the two pheromone compounds. We compared male pherotype frequencies between wild-caught and laboratory-reared populations. Then, we examined the relationship between pherotype composition and male capture rates in pheromone traps. Finally, we addressed the heredity of the pherotypes. The Israeli VM populations contain nine different male pherotypes, as defined according to the male behavior to pheromone compounds. The studied Portuguese populations included five of the nine pherotypes; none of the Portuguese males were attracted to LI. It seems that the high frequency of males that were attracted to LI is related to dense VM populations. It is hypothesized that selection for the male pherotypes, I males, those that respond to LI, occur under high-density rearing conditions. This may result from shorter development times of males and females that produce more I male pherotypes. The lower relative frequency of trapping of males in LI-baited traps than expected from the percentage determined in a Petri dish arena suggests that males that respond solely to LS (S males) are better fliers. The results also suggest that the pherotype trait is inherited by both sexes of the VM.

Mating Plugs in Polyandrous Giants: Which Sex Produces Them, When, How and Why?

PubMed Central

Kuntner, Matjaž; Kralj-Fišer, Simona; Li, Daiqin

2012-01-01

Background Males usually produce mating plugs to reduce sperm competition. However, females can conceivably also produce mating plugs in order to prevent unwanted, superfluous and energetically costly matings. In spiders–appropriate models for testing plugging biology hypotheses–mating plugs may consist of male genital parts and/or of amorphous covers consisting of glandular or sperm secretions. In the giant wood spider Nephila pilipes, a highly sexually dimorphic and polygamous species, males are known to produce ineffective embolic plugs through genital damage, but nothing is known about the origin and function of additional conspicuous amorphous plugs (AP) covering female genitals. Methodology We tested alternative hypotheses of the nature and function of AP in N. pilipes by staging mating trials with varying degrees of polyandry. No APs were ever formed during mating trials, which rules out the possibility of male AP formation. Instead, those females that oviposited produced the AP from a liquid secreted during egg sac formation. Polyandrous females were more likely to lay eggs and to produce the AP, as were those that mated longer and with more total insertions. Our further tests revealed that, in spite of being a side product of egg sac production, AP, when hardened, prevented any subsequent copulation. Conclusions We conclude that in the giant wood spider (Nephila pilipes), the amorphous mating plugs are not produced by the males, that repeated copulations (most likely polyandrous) are necessary for egg fertilization and AP formation, and that the AP represents a female adaptation to sexual conflict through prevention of unwanted, excessive copulations. Considering the largely unknown origin of amorphous plugs in spiders, we predict that a similar pattern might be detected in other clades, which would help elucidate the evolutionary interplay of various selection pressures responsible for the origin and maintenance of mating plugs. PMID:22829900

Interspecific Cross-Mating Between Aedes aegypti and Aedes albopictus Laboratory Strains: Implication of Population Density on Mating Behaviors.

PubMed

Marcela, P; Hassan, A Abu; Hamdan, A; Dieng, H; Kumara, T K

2015-12-01

Mating behavior between Aedes aegypti and Ae. albopictus, established colony strains were examined under laboratory conditions (30-cm(3) screened cages) for 5 consecutive days. The effect of selected male densities (30, 20, 10) and female density (20) on the number of swarming, mating pairs, eggs produced, and inseminated females were evaluated. Male densities significantly increased swarming behavior, mating pairs, and egg production of heterospecific females, but female insemination was reduced. Aedes aegypti males mate more readily with heterospecific females than do Ae. albopictus males. The current study suggests that Ae. aegypti males were not species-specific in mating, and if released into the field as practiced in genetically modified mosquito techniques, they may mate with both Ae. aegypti and Ae. albopictus females, hence reducing populations of both species by producing infertile eggs.

Pheromone evolution and sexual behavior in Drosophila are shaped by male sensory exploitation of other males.

PubMed

Ng, Soon Hwee; Shankar, Shruti; Shikichi, Yasumasa; Akasaka, Kazuaki; Mori, Kenji; Yew, Joanne Y

2014-02-25

Animals exhibit a spectacular array of traits to attract mates. Understanding the evolutionary origins of sexual features and preferences is a fundamental problem in evolutionary biology, and the mechanisms remain highly controversial. In some species, females choose mates based on direct benefits conferred by the male to the female and her offspring. Thus, female preferences are thought to originate and coevolve with male traits. In contrast, sensory exploitation occurs when expression of a male trait takes advantage of preexisting sensory biases in females. Here, we document in Drosophila a previously unidentified example of sensory exploitation of males by other males through the use of the sex pheromone CH503. We use mass spectrometry, high-performance liquid chromatography, and behavioral analysis to demonstrate that an antiaphrodisiac produced by males of the melanogaster subgroup also is effective in distant Drosophila relatives that do not express the pheromone. We further show that species that produce the pheromone have become less sensitive to the compound, illustrating that sensory adaptation occurs after sensory exploitation. Our findings provide a mechanism for the origin of a sex pheromone and show that sensory exploitation changes male sexual behavior over evolutionary time.

Antinociceptive effects of JWH015 in female and male rats.

PubMed

Craft, Rebecca M; Greene, Nicholas Z; Wakley, Alexa A

2018-04-01

Despite greater chronic pain prevalence in females compared with males, and the analgesic potential of cannabinoid receptor type 2 (CB2) agonists, CB2 agonists have rarely been tested in females. The aim of the present study was to compare the antinociceptive effects of a CB2-preferring agonist, (2-methyl-1-propyl-1H-indol-3-yl)-1-naphthalenylmethanone (JWH015), in female and male rats against acute pain and persistent inflammatory pain. JWH015 (5-20 mg/kg, intraperitoneally) produced dose-dependent and time-dependent increases in latency to respond on the tail withdrawal and paw pressure tests that did not differ statistically between the sexes. JWH015 dose-dependently decreased locomotor activity in both sexes, but was more potent in females than males. JWH015 produced little catalepsy in either sex. In females, the antinociceptive effects of JWH015 against acute pain were blocked by rimonabant and SR144528, whereas locomotor suppression was antagonized by rimonabant. When administered 3 days after intraplantar injection of complete Freund's adjuvant, JWH015 produced a significantly greater antiallodynic effect in females at the highest dose tested (10 mg/kg, intraperitoneally). Antiallodynic effects of JWH015 were antagonized by rimonabant and SR144528 in both sexes. These studies indicate that systemically administered JWH015 produced antinociception that was both CB1 and CB2 receptor-mediated in both sexes. Unlike [INCREMENT]-9-tetrahydrocannabinol and other nonselective cannabinoid agonists, the CB2-preferring agonist JWH015 may produce more equivalent antinociception in females and males.

The Cultural Bind on the American Male

ERIC Educational Resources Information Center

Chenoweth, Gene

2012-01-01

In this article, the author talks about the cultural bind on the American male. The process starts with conception. If the spermatozoid that fertilizes the egg contains only X chromosomes a girl will be produced. If a single Y chromosome out of the 24 produced by the father is included, the baby will be a boy. From this point on the girls have a…

In utero treatment with the herbicide linuron produces male rat reproductive malformations similar to the phthalate esters but through a different mechanism of action.

EPA Science Inventory

Although linuron has been reported to act as an androgen receptor (AR) antagonist, the suite of malformations observed in male rat offspring after in utero exposure differs from that of other AR antagonists and more closely resembles that produced by phthalate esters (PE) such as...

The function of male sperm whale slow clicks in a high latitude habitat: communication, echolocation, or prey debilitation?

PubMed

Oliveira, Cláudia; Wahlberg, Magnus; Johnson, Mark; Miller, Patrick J O; Madsen, Peter T

2013-05-01

Sperm whales produce different click types for echolocation and communication. Usual clicks and buzzes appear to be used primarily in foraging while codas are thought to function in social communication. The function of slow clicks is less clear, but they appear to be produced by males at higher latitudes, where they primarily forage solitarily, and on the breeding grounds, where they roam between groups of females. Here the behavioral context in which these vocalizations are produced and the function they may serve was investigated. Ninety-nine hours of acoustic and diving data were analyzed from sound recording tags on six male sperm whales in Northern Norway. The 755 slow clicks detected were produced by tagged animals at the surface (52%), ascending from a dive (37%), and during the bottom phase (11%), but never during the descent. Slow clicks were not associated with the production of buzzes, other echolocation clicks, or fast maneuvering that would indicate foraging. Some slow clicks were emitted in seemingly repetitive temporal patterns supporting the hypothesis that the function for slow clicks on the feeding grounds is long range communication between males, possibly relaying information about individual identity or behavioral states.

Ejaculate of sneaker males is pheromonally inconspicuous in the black goby, Gobius niger (Teleostei, Gobiidae).

PubMed

Locatello, L; Mazzoldi, C; Rasotto, M B

2002-11-01

The black goby, Gobius niger, shows alternative male mating tactics, i.e., parental and sneaker males. Males release a sexual pheromone that attracts females and stimulates aggressive displays in males. This pheromone is produced by the mesorchial gland, a structure well developed in parental males but markedly undeveloped in sneakers. We measured the behavioral response of parental males to the ejaculates of males performing different reproductive tactics. Parental males reacted to the ejaculate of other parental males, with stereotypic aggressive behaviors, but not to the ejaculate of sneakers; consequently sneaker male ejaculate appears to be pheromonally inconspicuous. Copyright 2002 Wiley-Liss, Inc.

Transgression and the Situated Body: Gender, Sex, and the Gay Male Teacher.

ERIC Educational Resources Information Center

Rofes, Eric

This paper begins by examining representations of gay male school teachers in discourses produced by gay men, illustrating the ways gay men represent themselves in public discourse. The literature is reviewed for answers to questions about the role of the gay male teacher in education and the responsibility of the gay male teacher to gay…

Breeding periodicity for male sea turtles, operational sex ratios, and implications in the face of climate change.

PubMed

Hays, Graeme C; Fossette, Sabrina; Katselidis, Kostas A; Schofield, Gail; Gravenor, Mike B

2010-12-01

Species that have temperature-dependent sex determination (TSD) often produce highly skewed offspring sex ratios contrary to long-standing theoretical predictions. This ecological enigma has provoked concern that climate change may induce the production of single-sex generations and hence lead to population extirpation. All species of sea turtles exhibit TSD, many are already endangered, and most already produce sex ratios skewed to the sex produced at warmer temperatures (females). We tracked male loggerhead turtles (Caretta caretta) from Zakynthos, Greece, throughout the entire interval between successive breeding seasons and identified individuals on their breeding grounds, using photoidentification, to determine breeding periodicity and operational sex ratios. Males returned to breed at least twice as frequently as females. We estimated that the hatchling sex ratio of 70:30 female to male for this rookery will translate into an overall operational sex ratio (OSR) (i.e., ratio of total number of males vs females breeding each year) of close to 50:50 female to male. We followed three male turtles for between 10 and 12 months during which time they all traveled back to the breeding grounds. Flipper tagging revealed the proportion of females returning to nest after intervals of 1, 2, 3, and 4 years were 0.21, 0.38, 0.29, and 0.12, respectively (mean interval 2.3 years). A further nine male turtles were tracked for short periods to determine their departure date from the breeding grounds. These departure dates were combined with a photoidentification data set of 165 individuals identified on in-water transect surveys at the start of the breeding season to develop a statistical model of the population dynamics. This model produced a maximum likelihood estimate that males visit the breeding site 2.6 times more often than females (95%CI 2.1, 3.1), which was consistent with the data from satellite tracking and flipper tagging. Increased frequency of male breeding will help ameliorate female-biased hatchling sex ratios. Combined with the ability of males to fertilize the eggs of many females and for females to store sperm to fertilize many clutches, our results imply that effects of climate change on the viability of sea turtle populations are likely to be less acute than previously suspected. © 2010 Society for Conservation Biology.

Form and function of long-range vocalizations in a Neotropical fossorial rodent: the Anillaco Tuco-Tuco (Ctenomys sp.)

PubMed Central

Valentinuzzi, Veronica S.; Zufiaurre, Emmanuel

2016-01-01

The underground environment poses particular communication challenges for subterranean rodents. Some loud and low-pitched acoustic signals that can travel long distances are appropriate for long-range underground communication and have been suggested to be territorial signals. Long-range vocalizations (LRVs) are important in long-distance communication in Ctenomys tuco-tucos. We characterized the LRV of the Anillaco Tuco-Tuco (Ctenomys sp.) using recordings from free-living individuals and described the behavioral context in which this vocalization was produced during laboratory staged encounters between individuals of both sexes. Long-range calls of Anillaco tuco-tucos are low-frequency, broad-band, loud, and long sounds composed by the repetition of two syllable types: series (formed by notes and soft-notes) and individual notes. All vocalizations were initiated with series, but not all had individual notes. Males were heavier than females and gave significantly lower-pitched vocalizations, but acoustic features were independent of body mass in males. The pronounced variation among individuals in the arrangement and number of syllables and the existence of three types of series (dyads, triads, and tetrads), created a diverse collection of syntactic patterns in vocalizations that would provide the opportunity to encode multiple types of information. The existence of complex syntactic patterns and the description of soft-notes represent new aspects of the vocal communication of Ctenomys. Long-distance vocalizations by Anillaco Tuco-Tucos appear to be territorial signals used mostly in male-male interactions. First, emission of LRVs resulted in de-escalation or space-keeping in male-male and male-female encounters in laboratory experiments. Second, these vocalizations were produced most frequently (in the field and in the lab) by males in our study population. Third, males produced LRVs with greater frequency during male-male encounters compared to male-female encounters. Finally, males appear to have larger home ranges that were more spatially segregated than those of females, suggesting that males may have greater need for long-distance signals that advertise their presence. Due to their apparent rarity, the function and acoustic features of LRV in female tuco-tucos remain inadequately known. PMID:27761344

Sex differences in antinociceptive tolerance to delta-9-tetrahydrocannabinol in the rat

PubMed Central

Wakley, Alexa A.; Wiley, Jenny L.; Craft, Rebecca M.

2014-01-01

Background Sex differences in cannabinoid effects have been reported in rodents, with adult females typically being more sensitive than adult males. The present study compared the development of antinociceptive tolerance to delta-9-tetrahydrocannabinol (THC) in adult, gonadally intact female vs. male rats. Methods Cumulative dose-effect curves were obtained for THC (1.0–18 mg/kg i.p.) on warm water tail withdrawal and paw pressure tests. Vehicle or the sex-specific ED80 dose for THC was administered twice daily for 9 days; THC dose-effect curves were then re-determined. Results On the pre-chronic test day, THC was significantly more potent in females than males in producing antinociception on the tail withdrawal and paw pressure tests. After 9 days of twice-daily THC treatment (5.4 mg/kg/injection in females, 7.6 mg/kg/injection in males), THC potency on both tests decreased more in females than males. On the tail withdrawal test, chronic THC produced 4.2- vs. 2.8-fold increases in ED50 values in females vs. males, respectively. On the paw pressure test, chronic THC produced 4.4- vs. 2.9-fold increases in ED50 values in females vs. males, respectively. Chronic THC treatment did not significantly disrupt estrous cycling in females. Conclusions These results demonstrate that – even when sex differences in acute THC potency are controlled for – females develop more antinociceptive tolerance to THC than males. Given the importance of drug tolerance in the development of drug dependence, these results suggest that females may be more vulnerable than males to developing dependence after chronic cannabinoid exposure. PMID:25131716

Embryonic developmental plasticity in the long-snouted seahorse (Hippocampus reidi, Ginsburg 1933) in relation to parental preconception diet.

PubMed

Otero-Ferrer, Francisco; Izquierdo, Marisol; Fazeli, Alireza; Holt, William V

2016-06-01

The aim of the present study was to investigate the hypothesis that parental periconception nutrition in adult seahorses affects the development and growth of their offspring. We tested the hypothesis that because seahorse embryos develop inside the male's brood pouch, manipulation of the male's diet would affect offspring growth and development independently of the female's diet. Adult males and females were fed separately with either wild-caught crustaceans or commercial aquarium diet for 1 month before conception to influence the periconception environment. Approximately 10000 offspring were obtained from four different treatment groups (Male/Wild or Male/Commercial×Female/Wild or Female/Commercial). Weights, physical dimensions and fatty acid profiles of the newborns were determined. Offspring produced when the males receiving commercial diet were mated with wild-fed females were larger (P<0.05) than those produced by wild-fed males. When both males and females were fed with commercial diet, their offspring were significantly smaller than those from the other treatment groups. When commercial diet-fed females were mated with wild-fed males, the offspring showed distortion of the snout:head length ratio. These results support the view that the preconception diet received by males and females differentially affects embryonic development.

Persistent Females and Compliant Males Coordinate Alarm Calling in Diana Monkeys.

PubMed

Stephan, Claudia; Zuberbühler, Klaus

2016-11-07

Sexual dimorphisms in animal vocal behavior have been successfully explained by sexual selection theory (e.g., mammals [1-5]; birds [6, 7]; anurans [8, 9]), but this does not usually include alarm calls, which are thought to be the product of kin or individual selection (e.g., [10, 11]). Here, we present the results of playback experiments with wild Diana monkeys, a species with highly dimorphic predator-specific alarms, to investigate the communication strategies of males and females during predator encounters. First, we simulated predator presence by broadcasting vocalizations of their main predators, leopards or eagles. We found that males only produced predator-specific alarms after the females had produced theirs, in response to which the females ceased alarm calling. In a second experiment, we created congruent and incongruent situations, so that the calls of a predator were followed by playbacks of male or female alarms with a matching or mismatching referent. For congruent conditions, results were the same as in the first experiment. For incongruent conditions, however, the males always gave predator-specific alarms that referentially matched the females' calls, regardless of the previously displayed predator. In contrast, females always gave predator-specific alarms that matched the predator type, regardless of their own male's subsequent calls. Moreover, the females persistently continued to alarm call until their own male produced calls with the matching referent. Results show that males and females attend to the informational content of each other's alarm calls but prioritize them differently relative to an experienced external event, a likely reflection of different underlying selection pressures. Copyright © 2016 Elsevier Ltd. All rights reserved.

Parthenogenesis in Komodo dragons.

PubMed

Watts, Phillip C; Buley, Kevin R; Sanderson, Stephanie; Boardman, Wayne; Ciofi, Claudio; Gibson, Richard

2006-12-21

Parthenogenesis, the production of offspring without fertilization by a male, is rare in vertebrate species, which usually reproduce after fusion of male and female gametes. Here we use genetic fingerprinting to identify parthenogenetic offspring produced by two female Komodo dragons (Varanus komodoensis) that had been kept at separate institutions and isolated from males; one of these females subsequently produced additional offspring sexually. This reproductive plasticity indicates that female Komodo dragons may switch between asexual and sexual reproduction, depending on the availability of a mate--a finding that has implications for the breeding of this threatened species in captivity. Most zoos keep only females, with males being moved between zoos for mating, but perhaps they should be kept together to avoid triggering parthenogenesis and thereby decreasing genetic diversity.

Phenotypic plasticity in sex pheromone production in Bicyclus anynana butterflies

PubMed Central

Dion, Emilie; Monteiro, Antónia; Yew, Joanne Y.

2016-01-01

Phenotypic plasticity refers to the environmental control of phenotypes. Cues experienced during development (developmental plasticity) or during adulthood (acclimatization) can both affect adult phenotypes. Phenotypic plasticity has been described in many traits but examples of developmental plasticity in physiological traits, in particular, remain scarce. We examined developmental plasticity and acclimatization in pheromone production in the butterfly Bicyclus anynana in response to rearing temperature. B. anynana lives in the African tropics where warm rearing temperatures of the wet season produce active males that court and females that choose, whereas cooler temperatures of the dry season lead to choosy less active males and courting females. We hypothesized that if male pheromone production is costly, it should be reduced in the dry season form. After describing the ultrastructure of pheromone producing cells, we showed that dry season males produced significantly less sex pheromones than wet season males, partly due to acclimatization and partly due to developmental plasticity. Variation in levels of one of the compounds is associated with differential regulation of a pheromone biosynthetic enzyme gene. This plasticity might be an adaptation to minimize pheromone production costs during the stressful dry season. PMID:27966579

Sexual Cannibalism: High Incidence in a Natural Population with Benefits to Females

PubMed Central

Rabaneda-Bueno, Rubén; Rodríguez-Gironés, Miguel Á.; Aguado-de-la-Paz, Sara; Fernández-Montraveta, Carmen; De Mas, Eva; Wise, David H.; Moya-Laraño, Jordi

2008-01-01

Background Sexual cannibalism may be a form of extreme sexual conflict in which females benefit more from feeding on males than mating with them, and males avoid aggressive, cannibalistic females in order to increase net fitness. A thorough understanding of the adaptive significance of sexual cannibalism is hindered by our ignorance of its prevalence in nature. Furthermore, there are serious doubts about the food value of males, probably because most studies that attempt to document benefits of sexual cannibalism to the female have been conducted in the laboratory with non-natural alternative prey. Thus, to understand more fully the ecology and evolution of sexual cannibalism, field experiments are needed to document the prevalence of sexual cannibalism and its benefits to females. Methodology/Principal Findings We conducted field experiments with the Mediterranean tarantula (Lycosa tarantula), a burrowing wolf spider, to address these issues. At natural rates of encounter with males, approximately a third of L. tarantula females cannibalized the male. The rate of sexual cannibalism increased with male availability, and females were more likely to kill and consume an approaching male if they had previously mated with another male. We show that females benefit from feeding on a male by breeding earlier, producing 30% more offspring per egg sac, and producing progeny of higher body condition. Offspring of sexually cannibalistic females dispersed earlier and were larger later in the season than spiderlings of non-cannibalistic females. Conclusions/Significance In nature a substantial fraction of female L. tarantula kill and consume approaching males instead of mating with them. This behaviour is more likely to occur if the female has mated previously. Cannibalistic females have higher rates of reproduction, and produce higher-quality offspring, than non-cannibalistic females. Our findings further suggest that female L. tarantula are nutrient-limited in nature and that males are high-quality prey. The results of these field experiments support the hypothesis that sexual cannibalism is adaptive to females. PMID:18941517

Sexual cannibalism: high incidence in a natural population with benefits to females.

PubMed

Rabaneda-Bueno, Rubén; Rodríguez-Gironés, Miguel A; Aguado-de-la-Paz, Sara; Fernández-Montraveta, Carmen; De Mas, Eva; Wise, David H; Moya-Laraño, Jordi

2008-01-01

Sexual cannibalism may be a form of extreme sexual conflict in which females benefit more from feeding on males than mating with them, and males avoid aggressive, cannibalistic females in order to increase net fitness. A thorough understanding of the adaptive significance of sexual cannibalism is hindered by our ignorance of its prevalence in nature. Furthermore, there are serious doubts about the food value of males, probably because most studies that attempt to document benefits of sexual cannibalism to the female have been conducted in the laboratory with non-natural alternative prey. Thus, to understand more fully the ecology and evolution of sexual cannibalism, field experiments are needed to document the prevalence of sexual cannibalism and its benefits to females. We conducted field experiments with the Mediterranean tarantula (Lycosa tarantula), a burrowing wolf spider, to address these issues. At natural rates of encounter with males, approximately a third of L. tarantula females cannibalized the male. The rate of sexual cannibalism increased with male availability, and females were more likely to kill and consume an approaching male if they had previously mated with another male. We show that females benefit from feeding on a male by breeding earlier, producing 30% more offspring per egg sac, and producing progeny of higher body condition. Offspring of sexually cannibalistic females dispersed earlier and were larger later in the season than spiderlings of non-cannibalistic females. In nature a substantial fraction of female L. tarantula kill and consume approaching males instead of mating with them. This behaviour is more likely to occur if the female has mated previously. Cannibalistic females have higher rates of reproduction, and produce higher-quality offspring, than non-cannibalistic females. Our findings further suggest that female L. tarantula are nutrient-limited in nature and that males are high-quality prey. The results of these field experiments support the hypothesis that sexual cannibalism is adaptive to females.

Development of techniques for the analysis of isoflavones in soy foods and nutraceuticals.

PubMed

Dentith, Susan; Lockwood, Brian

2008-05-01

For over 20 years, soy isoflavones have been investigated for their ability to prevent a wide range of cancers and cardiovascular problems, and numerous other disease states. This research is underpinned by the ability of researchers to analyse isoflavones in various forms in a range of raw materials and biological fluids. This review summarizes the techniques recently used in their analysis. The speed of high performance liquid chromatography analysis has been improved, allowing analysis of more samples, and increasing the sensitivity of detection techniques allows quantification of isoflavones down to nanomoles per litre levels in biological fluids. The combination of high-performance liquid chromatography with immunoassay has allowed identification and estimation of low-level soy isoflavones. The use of soy isoflavone supplements has shown an increase in their circulating levels in plasma and urine, aiding investigation of their biological effects. The significance of the metabolite equol has spurned research into new areas, and recently the specific enantiomers have been studied. High-performance liquid chromatography, capillary electrophoresis and gas chromatography are widely used with a range of detection systems. Increasingly, immunoassay is being used because of its high sensitivity and low cost.

Extract of Punica granatum inhibits skin photoaging induced by UVB irradiation.

PubMed

Park, Hye Min; Moon, Eunjung; Kim, Ae-Jung; Kim, Mi Hyun; Lee, Sanghee; Lee, Jung Bok; Park, Yong Kon; Jung, Hyuk-Sang; Kim, Yoon-Bum; Kim, Sun Yeou

2010-03-01

Punica granatum (pomegranate) is kind of a fruit consumed fresh or in beverage. It has been widely used in traditional medicine in various parts of the world. In this study, we examined the efficacy of a Punica granatum (PG) extract in protecting skin against UVB-induced damage using cultured human skin fibroblasts. A Korean red PG sample was used, and its effects classified according to if the PG source originated from the rind, seed and fruit. The polyphenol content of PG, which is known to prevent other adverse cutaneous effects of UV irradiation, was measured by GC-MS. The protective effects of PG on UVB-induced skin photoaging were examined by determining the level of procollagen type I and MMP-1 after UVB irradiation. Based on the GC-MS quantitative analysis, catechin, quercetin, kaempferol, and equol were the predominant compounds detected in PG. In the changes of expression of procollagen type I and MMP-1 in UV irradiated human skin fibroblasts treated PG, especially extract prepared from rind, the synthesis of collagen was increased and the expression of MMP-1 was decreased. The major polyphenols in PG, particularly catechin, play a significant role in its photoprotective effects on UVB-induced skin damage.

Food fight: sexual conflict over free amino acids in the nuptial gifts of male decorated crickets.

PubMed

Gershman, S N; Hunt, J; Sakaluk, S K

2013-04-01

In decorated crickets, Gryllodes sigillatus, the spermatophore that a male transfers at mating includes a gelatinous spermatophylax that the female consumes, delaying her removal of the sperm-filled ampulla. Male fertilization success increases with the length of time females spend feeding on the spermatophylax, while females may benefit by prematurely discarding the spermatophylaxes of undesirable males. This sexual conflict should favour males that produce increasingly appealing spermatophylaxes, and females that resist this manipulation. To determine the genetic basis of female spermatophylax feeding behaviour, we fed spermatophylaxes to females of nine inbred lines and found that female genotype had a major influence on spermatophylax feeding duration. The amino acid composition of the spermatophylax was also significantly heritable. There was a positive genetic correlation between spermatophylax feeding duration and the gustatory appeal of the spermatophylax. This correlation suggests that genes expressed in males that produce more manipulative spermatophylaxes are positively linked to genes expressed in females that make them more vulnerable to manipulation. Outbred females spent less time feeding on spermatophylaxes than inbred females, and thus showed greater resistance to male manipulation. Further, in a nonspermatophylax producing cricket (Acheta domesticus), females were significantly more prone to feeding on spermatophylaxes than outbred female Gryllodes. Collectively, these results suggest a history of sexually antagonistic coevolution over the consumption of nuptial food gifts. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

Identification and biosynthesis of novel male specific esters in the wings of the tropical butterfly, Bicyclus martius sanaos.

PubMed

Wang, Hong-Lei; Brattström, Oskar; Brakefield, Paul M; Francke, Wittko; Löfstedt, Christer

2014-06-01

Representatives of the highly speciose tropical butterfly genus Bicyclus (Lepidoptera: Nymphalidae) are characterized by morphological differences in the male androconia, a set of scales and hair pencils located on the surface of the wings. These androconia are assumed to be associated with the release of courtship pheromones. In the present study, we report the identification and biosynthetic pathways of several novel esters from the wings of male B. martius sanaos. We found that the volatile compounds in this male butterfly were similar to female-produced moth sex pheromones. Components associated with the male wing androconial areas were identified as ethyl, isobutyl and 2-phenylethyl hexadecanoates and (11Z)-11-hexadecenoates, among which the latter are novel natural products. By topical application of deuterium-labelled fatty acid and amino acid precursors, we found these pheromone candidates to be produced in patches located on the forewings of the males. Deuterium labels from hexadecanoic acid were incorporated into (11Z)-11-hexadecenoic acid, providing experimental evidence of a Δ11-desaturase being active in butterflies. This unusual desaturase was found previously to be involved in the biosynthesis of female-produced sex pheromones of moths. In the male butterflies, both hexadecanoic acid and (11Z)-11-hexadecenoic acid were then enzymatically esterified to form the ethyl, isobutyl and 2-phenylethyl esters, incorporating ethanol, isobutanol, and 2-phenylethanol, derived from the corresponding amino acids L-alanine, L-valine, and L-phenylalanine.

"Wash leather scrotum" (scrotal dermatitis): a treatable cause of male infertility.

PubMed

Hendry, W F; Munro, D D

1990-02-01

A group of 16 male patients with infertility had dermatitis of the scrotum and groins giving lichenified oedematous skin; the resulting thickening and loss of rugosity produced a characteristic appearance that we have termed wash leather scrotum. Treatment of the dermatosis resulted in an improvement in sperm count and motility in most patients, and 5 couples produced one or more pregnancies.

PDF-1 neuropeptide signaling modulates a neural circuit for mate-searching behavior in C. elegans.

PubMed

Barrios, Arantza; Ghosh, Rajarshi; Fang, Chunhui; Emmons, Scott W; Barr, Maureen M

2012-12-01

Appetitive behaviors require complex decision making that involves the integration of environmental stimuli and physiological needs. C. elegans mate searching is a male-specific exploratory behavior regulated by two competing needs: food and reproductive appetite. We found that the pigment dispersing factor receptor (PDFR-1) modulates the circuit that encodes the male reproductive drive that promotes male exploration following mate deprivation. PDFR-1 and its ligand, PDF-1, stimulated mate searching in the male, but not in the hermaphrodite. pdf-1 was required in the gender-shared interneuron AIM, and the receptor acted in internal and external environment-sensing neurons of the shared nervous system (URY, PQR and PHA) to produce mate-searching behavior. Thus, the pdf-1 and pdfr-1 pathway functions in non-sex-specific neurons to produce a male-specific, goal-oriented exploratory behavior. Our results indicate that secretin neuropeptidergic signaling is involved in regulating motivational internal states.

HIGHER PARENTAL PERCEPTIONS OF WEALTH ASSOCIATED WITH THE BIRTH OF MORE SONS IN AN AUSTRALIAN POPULATION.

PubMed

Behie, A M; O'Donnell, M H

2017-09-20

Many industrialized nations are currently experiencing a decline in average secondary sex ratio (SSR) resulting in fewer boys being born relative to girls. While many potential factors may explain the decline in the birth of males relative to females, it seems most studies support the idea that male offspring are produced less often when environmental conditions are poor owing to males being more susceptible to loss in harsh environments. This study investigates the maternal factors that are associated with the sex of offspring in a cohort of the Australian population. It found that greater parental perceptions of wealth were significantly associated with an increase in the number of sons produced. These results suggest that male offspring are born at increased numbers to women with higher available resources, which may reflect the fact that male offspring are more vulnerable in poor environments.

Social Memory Formation Rapidly and Differentially Affects the Motivation and Performance of Vocal Communication Signals in the Bengalese Finch (Lonchura striata var. domestica)

PubMed Central

Toccalino, Danielle C.; Sun, Herie; Sakata, Jon T.

2016-01-01

Cognitive processes like the formation of social memories can shape the nature of social interactions between conspecifics. Male songbirds use vocal signals during courtship interactions with females, but the degree to which social memory and familiarity influences the likelihood and structure of male courtship song remains largely unknown. Using a habituation-dishabituation paradigm, we found that a single, brief (<30 s) exposure to a female led to the formation of a short-term memory for that female: adult male Bengalese finches were significantly less likely to produce courtship song to an individual female when re-exposed to her 5 min later (i.e., habituation). Familiarity also rapidly decreased the duration of courtship songs but did not affect other measures of song performance (e.g., song tempo and the stereotypy of syllable structure and sequencing). Consistent with a contribution of social memory to the decrease in courtship song with repeated exposures to the same female, the likelihood that male Bengalese finches produced courtship song increased when they were exposed to a different female (i.e., dishabituation). Three consecutive exposures to individual females also led to the formation of a longer-term memory that persisted over days. Specifically, when courtship song production was assessed 2 days after initial exposures to females, males produced fewer and shorter courtship songs to familiar females than to unfamiliar females. Measures of song performance, however, were not different between courtship songs produced to familiar and unfamiliar females. The formation of a longer-term memory for individual females seemed to require at least three exposures because males did not differentially produce courtship song to unfamiliar females and females that they had been exposed to only once or twice. Taken together, these data indicate that brief exposures to individual females led to the rapid formation and persistence of social memories and support the existence of distinct mechanisms underlying the motivation to produce and the performance of courtship song. PMID:27378868

Supplementation of Male Pheromone on Rock Substrates Attracts Female Rock Lizards to the Territories of Males: A Field Experiment

PubMed Central

Martín, José; López, Pilar

2012-01-01

Background Many animals produce elaborated sexual signals to attract mates, among them are common chemical sexual signals (pheromones) with an attracting function. Lizards produce chemical secretions for scent marking that may have a role in sexual selection. In the laboratory, female rock lizards (Iberolacerta cyreni) prefer the scent of males with more ergosterol in their femoral secretions. However, it is not known whether the scent-marks of male rock lizards may actually attract females to male territories in the field. Methodology/Principal Findings In the field, we added ergosterol to rocks inside the territories of male lizards, and found that this manipulation resulted in increased relative densities of females in these territories. Furthermore, a higher number of females were observed associated to males in manipulated plots, which probably increased mating opportunities for males in these areas. Conclusions/Significance These and previous laboratory results suggest that female rock lizards may select to settle in home ranges based on the characteristics of scent-marks from conspecific males. Therefore, male rock lizards might attract more females and obtain more matings by increasing the proportion of ergosterol when scent-marking their territories. However, previous studies suggest that the allocation of ergosterol to secretions may be costly and only high quality males could afford it, thus, allowing the evolution of scent-marks as an honest sexual display. PMID:22253895

Reciprocal Love: Mentoring Black and Latino Males through an Ethos of Care

ERIC Educational Resources Information Center

Jackson, Iesha; Sealey-Ruiz, Yolanda; Watson, Wanda

2014-01-01

Although mentoring programs can produce positive outcomes for youth, more research is needed that offers an account of how Black and Latino male mentors and mentees experience mentoring. This phenomenological study highlights the voices of a mentor and 14 Black and Latino males who are part of the Umoja Network for Young Men (UMOJA) an all-male,…

Attraction of spathius agrili yang (Hymenoptera: eulophidae) to male-produced "aggregation-sex pheromone:" differences between the sexes and mating status

USDA-ARS?s Scientific Manuscript database

Male and female Spathius agrili Yang were tested for attraction to the synthetic male pheromone. Lures consisting of a 3-component pheromone blend were placed in the center of a white filter paper target used to activate upwind flight in the wind tunnel. When virgin males and females were tested for...

Effects of environmentally relevant concentrations of atrazine on gonadal development of snapping turtles (Chelydra serpentina).

PubMed

de Solla, Shane R; Martin, Pamela A; Fernie, Kimberly J; Park, Brad J; Mayne, Gregory

2006-02-01

The herbicide atrazine has been suspected of affecting sexual development by inducing aromatase, resulting in the increased conversion of androgens to estrogens. We used snapping turtles (Chelydra serpentina), a species in which sex is dependent on the production of estrogen through aromatase activity in a temperature-dependent manner, to investigate if environmentally relevant exposures to atrazine affected gonadal development. Eggs were incubated in soil to which atrazine was applied at a typical field application rate (3.1 L/ha), 10-fold this rate (31 L/ha), and a control rate (no atrazine) for the duration of embryonic development. The incubation temperature (25 degrees C) was selected to produce only males. Although some males with testicular oocytes and females were produced in the atrazine-treated groups (3.3-3.7%) but not in the control group, no statistical differences were found among treatments. Furthermore, snapping turtle eggs collected from natural nests in a corn field were incubated at the pivotal temperature (27.5 degrees C) at which both males and females normally would be produced, and some males had oocytes in the testes (15.4%). The presence of low numbers of males with oocytes may be a natural phenomenon, and we have limited evidence to suggest that the presence of normal males with oocytes may represent a feminizing effect of atrazine. Histological examination of the thyroid gland revealed no effect on thyroid morphology.

A male-predominant cuticular hydrocarbon, 7-methyltricosane, is used as a contact pheromone in the western flower thrips Frankliniella occidentalis.

PubMed

Olaniran, Oladele A; Sudhakar, Akella V S; Drijfhout, Falko P; Dublon, Ian A N; Hall, David R; Hamilton, James G C; Kirk, William D J

2013-04-01

In a laboratory bioassay, adult female Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) spent more time near filter paper disks that had been exposed to adult males than near unexposed disks; this effect was not observed on disks exposed to adult females. The response could only partly be explained by the known male-produced aggregation pheromone, neryl (S)-2-methylbutanoate, suggesting the presence of an unknown male-produced compound. In gas chromatography/mass spectrometry analyses, 7-methyltricosane was detected on disks exposed to males, but not on disks exposed to females. Extracts of cuticular lipids also showed relatively large amounts of 7-methyltricosane on males, whereas only trace amounts were found on females and none on larvae. Bioassays of synthetic 7-methyltricosane showed that adults responded only after contact. The response to this compound was clearly different from that to n-tricosane or hexane-only controls. Females that contacted 7-methyltricosane on glass beads stayed in the vicinity and frequently raised the abdomen, a behavior that rejects mating attempts by males. Males stayed in the vicinity and wagged the abdomen sideways, a behavior used in fighting between males. This is the first identification of a contact pheromone in the order Thysanoptera.

A Subanalgesic Dose of Morphine Eliminates Nalbuphine Anti-analgesia in Postoperative Pain

PubMed Central

Gear, Robert W.; Gordon, Newton C.; Hossaini-Zadeh, Mehran; Lee, Janice S.; Miaskowski, Christine; Paul, Steven M.; Levine, Jon D.

2008-01-01

The agonist-antagonist kappa-opioid nalbuphine administered for postoperative pain produces greater analgesia in females than in males. In fact, males administered nalbuphine (5 mg) experience pain greater than those receiving placebo, suggesting the existence of an anti-analgesic effect. These sexually dimorphic effects on postoperative pain can be eliminated by co-administration of a fixed ratio of the prototypical opioid receptor antagonist naloxone with nalbuphine, implying a role for opioid receptors in the anti-analgesic as well as analgesic effects of nalbuphine. In the present study, we further evaluated the role of opioid receptors in the sex-specific effects on pain produced by nalbuphine by co-administering a dose of morphine low enough that it does not produce analgesia. Following extraction of bony impacted third molar teeth, nalbuphine (5 mg) was administered alone or in combination with either of two low doses of morphine (2 mg or 4 mg). Both doses of morphine reversed nalbuphine-induced anti-analgesia in males, but only the lower dose (2 mg) reached statistical significance. Neither dose affected nalbuphine-induced analgesia in females, and when administered alone in either males or females, morphine (2 mg) had no analgesic effect. Though not observed in females, the effect of morphine in males argues that, like naloxone, low dose morphine may act as an anti-analgesia opioid receptor antagonist. Perspective Previously we reported that the nalbuphine produces both analgesic and anti-analgesic effects, and that the opioid antagonist naloxone can enhance nalbuphine analgesia by selectively antagonizing the anti-analgesic effect. Here we show that morphine, given in a subanalgesic dose, reverses nalbuphine-induced anti-analgesia in males, perhaps by a similar mechanism. PMID:18201935

NMDA receptor activation upstream of methyl farnesoate signaling for short day-induced male offspring production in the water flea, Daphnia pulex.

PubMed

Toyota, Kenji; Miyakawa, Hitoshi; Yamaguchi, Katsushi; Shigenobu, Shuji; Ogino, Yukiko; Tatarazako, Norihisa; Miyagawa, Shinichi; Iguchi, Taisen

2015-03-14

The cladoceran crustacean Daphnia pulex produces female offspring by parthenogenesis under favorable conditions, but in response to various unfavorable external stimuli, it produces male offspring (environmental sex determination: ESD). We recently established an innovative system for ESD studies using D. pulex WTN6 strain, in which the sex of the offspring can be controlled simply by changes in the photoperiod: the long-day and short-day conditions can induce female and male offspring, respectively. Taking advantage of this system, we demonstrated that de novo methyl farnesoate (MF) synthesis is necessary for male offspring production. These results indicate the key role of innate MF signaling as a conductor between external environmental stimuli and the endogenous male developmental pathway. Despite these findings, the molecular mechanisms underlying up- and downstream signaling of MF have not yet been well elucidated in D. pulex. To elucidate up- and downstream events of MF signaling during sex determination processes, we compared the transcriptomes of daphnids reared under the long-day (female) condition with short-day (male) and MF-treated (male) conditions. We found that genes involved in ionotropic glutamate receptors, known to mediate the vast majority of excitatory neurotransmitting processes in various organisms, were significantly activated in daphnids by the short-day condition but not by MF treatment. Administration of specific agonists and antagonists, especially for the N-methyl-D-aspartic acid (NMDA) receptor, strongly increased or decreased, respectively, the proportion of male-producing mothers. Moreover, we also identified genes responsible for male production (e.g., protein kinase C pathway-related genes). Such genes were generally shared between the short-day reared and MF-treated daphnids. We identified several candidate genes regulating ESD which strongly suggests that these genes may be essential factors for male offspring production as an upstream regulator of MF signaling in D. pulex. This study provides new insight into the fundamental mechanisms underlying how living organisms alter their phenotypes in response to various external environments.

Condition-dependent female preference for male genitalia length is based on male reproductive tactics.

PubMed

Hernandez-Jimenez, Armando; Rios-Cardenas, Oscar

2017-12-06

There is extensive morphological variation of male genitalia across animals with internal fertilization, even among closely related species. Most studies attempting to explain this extraordinary diversity have focused on processes that occur post-copula (e.g. sperm competition, cryptic female choice). Only a few studies have focused on the pre-copula process of female preference. In addition, the extent to which this variation could be associated with the use of different reproductive tactics has yet to be explored. Here, we show that female preference for male genitalia length in two livebearing fishes depends on the type of reproductive tactic of the males being evaluated as well as the body condition of the female. In a species where all males coax females to acquire matings (courters), females preferred males with short genitalia. In a species with genetically influenced alternative reproductive tactics (courter males that only court and produce courter sons, sneaker males that use the coercive tactic of sneak chase and produce sneaker sons), female preference depended on an interaction between male tactic and female condition: females in good condition preferred courter males with short genitalia, and sneaker males with long genitalia. Our results suggest that female preference for male traits favourable to their sons may be an important factor contributing to the diversification of male genitalia. Despite the contrasting selection for genitalia length that our female preference tests suggest, we found no significant differences in genitalia length between coaxing (courters) and coercive (sneakers) males. Our study represents a starting point to more clearly understand the role of alternative reproductive tactics and variation in female mate preference in the evolution of male genitalia. © 2017 The Author(s).

Induction of taxol metabolism in the rat by dexamethasone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, C.D.; Gondi, K.N.; Walle, T.

1994-12-31

The antitumor drug taxol was metabolized to two major metabolites (RM1 and RM2) in adult male and female rat liver microsomes. The male rats produced RM1 2.6 fold faster than the females, and they produced RM2 3 fold faster than the females. This correlated well with the sex differences noticed in liver microsomal cytochrome P450 (CYP) 3A content (4.4 fold greater in male) and 6{beta}-hydroxylation of testosterone (2.4 fold greater in male). Taxol was metabolized to three major metabolites (RM1, RM2, and RM3) in adult male and female rat liver microsomes from rats pretreated with dexamethasone. Production of RM1 andmore » RM2 was increased in these rats (2.3 and 3.3 fold respectively in males; 6.5 and 8.7 fold respectively in females) as compared to the untreated rats. These results compared well with the induction of CYP 3A proteins (3.5 fold in male, 10 fold in female) and induction of 6{beta}-hydroxylation (1.9 fold in males, 3.8 fold in females). RM3, which was produced only by the rats pretreated with dexamethasone, had a retention time of 0.58 relative to taxol which corresponds to 6{alpha}- hydroxytaxol, the major human metabolite of taxol. This study indicates that taxol metabolism in the rat is likely due to CYP 3A enzymes. Although the evidence points toward CYP 3A1 as the major isoform involved, it does not rule out others. The findings also suggest that CYP 3A1 is responsible for the induced metabolite, RM3.« less

A general method for identifying major hybrid male sterility genes in Drosophila.

PubMed

Zeng, L W; Singh, R S

1995-10-01

The genes responsible for hybrid male sterility in species crosses are usually identified by introgressing chromosome segments, monitored by visible markers, between closely related species by continuous backcrosses. This commonly used method, however, suffers from two problems. First, it relies on the availability of markers to monitor the introgressed regions and so the portion of the genome examined is limited to the marked regions. Secondly, the introgressed regions are usually large and it is impossible to tell if the effects of the introgressed regions are the result of single (or few) major genes or many minor genes (polygenes). Here we introduce a simple and general method for identifying putative major hybrid male sterility genes which is free of these problems. In this method, the actual hybrid male sterility genes (rather than markers), or tightly linked gene complexes with large effects, are selectively introgressed from one species into the background of another species by repeated backcrosses. This is performed by selectively backcrossing heterozygous (for hybrid male sterility gene or genes) females producing fertile and sterile sons in roughly equal proportions to males of either parental species. As no marker gene is required for this procedure, this method can be used with any species pairs that produce unisexual sterility. With the application of this method, a small X chromosome region of Drosophila mauritiana which produces complete hybrid male sterility (aspermic testes) in the background of D. simulans was identified. Recombination analysis reveals that this region contains a second major hybrid male sterility gene linked to the forked locus located at either 62.7 +/- 0.66 map units or at the centromere region of the X chromosome of D. mauritiana.

Engaging Black Males on Their Own Terms: What Schools Can Learn from Black Males Who Produce Hip-Hop

ERIC Educational Resources Information Center

Irby, Decoteau J.; Petchauer, Emery; Kirkland, David

2013-01-01

Education scholars and practitioners have much to learn about engagement and motivation of Black males by directing their inquiries to more organic sites of hip-hop cultural production outside of schools. One such site is the hip-hop's informal labor economy where Black males engage in earning money through hip-hop cultural production. Labor…

Sexual Competitiveness, Field Survival, and Dispersal of Anastrepha obliqua (Diptera: Tephritidae) Fruit Flies Irradiated at Different Doses.

PubMed

Gallardo-Ortiz, Uriel; Pérez-Staples, Diana; Liedo, Pablo; Toledo, Jorge

2018-04-02

The sterile insect technique (SIT) is used in area-wide pest management programs for establishing low pest prevalence and/or areas free of fruit flies (Diptera: Tephritidae). The aim of this technique is to induce high levels of sterility in the wild population, for this the released insects must have a high sexual competitiveness and field dispersal. However, radiation decreases these biological attributes that do not allow it to compete successfully with wild insects. In this study the sexual competitiveness, field survival and dispersal of Anastrepha obliqua (Macquart; Diptera: Tephritidae) irradiated at 0, 40, 50, 60, 70, and 80 Gy were evaluated in laboratory. A dose of 60 Gy produced 98% sterility, whereas doses of 70 and 80 Gy produced 99% sterility. Sexual competitiveness was assessed in field cages, comparing males irradiated at 0, 50, 60, 70, and 80 Gy against wild males for mating with wild fertile females. Males irradiated at 50 and 60 Gy achieved more matings than those irradiated at 70 and 80 Gy. Wild males were more competitive than mass-reared males, even when these were not irradiated (0 Gy). There was no effect of irradiation on mating latency, yet wild males showed significantly shorter mating latency than mass-reared males. Female remating did not differ among those that mated with wild males and those that mated with males irradiated with different doses. The relative sterility index (RSI) increased from 0.25 at 80 Gy to 0.37 at 60 Gy. The Fried competitiveness index was 0.69 for males irradiated at 70 Gy and 0.57 for those irradiated at 80 Gy, which indicates that a 10 Gy reduction in the irradiation dose produces greater induction of sterility in the wild population. There were no significant differences in field survival and dispersal between flies irradiated at 70 or 80 Gy. Reducing the irradiation dose to 60 or 70 Gy could improve the performance of sterile males and the effectiveness of the SIT. Our results also distinguish between the effects of irradiation and mass-rearing on the performance of sterile males.

Does a parthenogenesis-inducing Wolbachia induce vestigial cytoplasmic incompatibility?

NASA Astrophysics Data System (ADS)

Kraaijeveld, Ken; Reumer, Barbara M.; Mouton, Laurence; Kremer, Natacha; Vavre, Fabrice; van Alphen, Jacques J. M.

2011-03-01

Wolbachia is a maternally inherited bacterium that manipulates the reproduction of its host. Recent studies have shown that male-killing strains can induce cytoplasmic incompatibility (CI) when introgressed into a resistant host. Phylogenetic studies suggest that transitions between CI and other Wolbachia phenotypes have also occurred frequently, raising the possibility that latent CI may be widespread among Wolbachia. Here, we investigate whether a parthenogenesis-inducing Wolbachia strain can also induce CI. Parthenogenetic females of the parasitoid wasp Asobara japonica regularly produce a small number of males that may be either infected or not. Uninfected males were further obtained through removal of the Wolbachia using antibiotics and from a naturally uninfected strain. Uninfected females that had mated with infected males produced a slightly, but significantly more male-biased sex ratio than uninfected females that had mated with uninfected males. This effect was strongest in females that mated with males that had a relatively high Wolbachia titer. Quantitative PCR indicated that infected males did not show higher ratios of nuclear versus mitochondrial DNA content. Wolbachia therefore does not cause diploidization of cells in infected males. While these results are consistent with CI, other alternatives such as production of abnormal sperm by infected males cannot be completely ruled out. Overall, the effect was very small (9%), suggesting that if CI is involved it may have degenerated through the accumulation of mutations.

Congenital adrenal hyperplasia

MedlinePlus

... body produces more androgen, a type of male sex hormone. This causes male characteristics to appear early (or inappropriately). Congenital adrenal hyperplasia can affect both boys and girls. About 1 in 10,000 to ...

Evidence for a male-produced pheromone in Tetropium fuscum (F.) and Tetropium cinnamopterum (Kirby) (Coleoptera: Cerambycidae)

NASA Astrophysics Data System (ADS)

Silk, Peter J.; Sweeney, Jon; Wu, Junping; Price, Jessica; Gutowski, Jerzy M.; Kettela, Edward G.

2007-08-01

( E)-6,10-dimethyl-5,9-undecadien-2-ol (geranyl acetol), termed here fuscol, was identified as a male-produced pheromone emitted by Tetropium fuscum (F.) and Tetropium cinnamopterum Kirby. In field experiments, traps baited with synthetic fuscol alone were not significantly attractive, but the combination of fuscol plus host volatiles (a synthetic blend of monoterpenes plus ethanol) attracted significantly more male and female T. fuscum and female T. cinnamopterum than did host volatiles alone. This is the first homoterpenoid alcohol to be described in the Cerambycidae, and the first pheromone reported from the sub-family Spondylidinae.

Evidence for volatile male-produced pheromone in banana weevilCosmopolites sordidus.

PubMed

Budenberg, W J; Ndiege, I O; Karago, F W

1993-09-01

Females of the banana weevil,Cosmopolites sordidus, were attracted to and made longer visits to live conspecific males, trapped volatiles from males, and dissected male hindguts in a still-air olfactometer. Male weevils were attracted to volatiles trapped from males and made longer visits to live males and volatiles from males. Live females, collected volatiles from females and female hindguts, elicited small or no behavioral responses from either sex. Electroantennogram (EAG) responses from both male and female antennae were elicited by collected volatiles from males and by dichloromethane extracts of male hindguts and bodies but not by surface washes of males. No significant EAG responses were given to equivalent material from females. It is therefore suggested that male banana weevils release an aggregation pheromone via their hindgut.

Inbreeding avoidance and female mate choice shape reproductive skew in capuchin monkeys (Cebus capucinus imitator).

PubMed

Wikberg, Eva C; Jack, Katharine M; Fedigan, Linda M; Campos, Fernando A; Yashima, Akiko S; Bergstrom, Mackenzie L; Hiwatashi, Tomohide; Kawamura, Shoji

2017-01-01

Reproductive skew in multimale groups may be determined by the need for alpha males to offer reproductive opportunities as staying incentives to subordinate males (concessions), by the relative fighting ability of the alpha male (tug-of-war) or by how easily females can be monopolized (priority-of-access). These models have rarely been investigated in species with exceptionally long male tenures, such as white-faced capuchins, where female mate choice for novel unrelated males may be important in shaping reproductive skew. We investigated reproductive skew in white-faced capuchins at Sector Santa Rosa, Costa Rica, using 20 years of demographic, behavioural and genetic data. Infant survival and alpha male reproductive success were highest in small multimale groups, which suggests that the presence of subordinate males can be beneficial to the alpha male, in line with the concession model's assumptions. None of the skew models predicted the observed degree of reproductive sharing, and the probability of an alpha male producing offspring was not affected by his relatedness to subordinate males, whether he resided with older subordinate males, whether he was prime aged, the number of males or females in the group or the number of infants conceived within the same month. Instead, the alpha male's probability of producing offspring decreased when he was the sire of the mother, was weak and lacked a well-established position and had a longer tenure. Because our data best supported the inbreeding avoidance hypothesis and female choice for strong novel mates, these hypotheses should be taken into account in future skew models. © 2016 John Wiley & Sons Ltd.

Sex-specific mating pheromones in the nematode Panagrellus redivivus.

PubMed

Choe, Andrea; Chuman, Tatsuji; von Reuss, Stephan H; Dossey, Aaron T; Yim, Joshua J; Ajredini, Ramadan; Kolawa, Adam A; Kaplan, Fatma; Alborn, Hans T; Teal, Peter E A; Schroeder, Frank C; Sternberg, Paul W; Edison, Arthur S

2012-12-18

Nematodes use an extensive chemical language based on glycosides of the dideoxysugar ascarylose for developmental regulation (dauer formation), male sex attraction, aggregation, and dispersal. However, no examples of a female- or hermaphrodite-specific sex attractant have been identified to date. In this study, we investigated the pheromone system of the gonochoristic sour paste nematode Panagrellus redivivus, which produces sex-specific attractants of the opposite sex. Activity-guided fractionation of the P. redivivus exometabolome revealed that males are strongly attracted to ascr#1 (also known as daumone), an ascaroside previously identified from Caenorhabditis elegans hermaphrodites. Female P. redivivus are repelled by high concentrations of ascr#1 but are specifically attracted to a previously unknown ascaroside that we named dhas#18, a dihydroxy derivative of the known ascr#18 and an ascaroside that features extensive functionalization of the lipid-derived side chain. Targeted profiling of the P. redivivus exometabolome revealed several additional ascarosides that did not induce strong chemotaxis. We show that P. redivivus females, but not males, produce the male-attracting ascr#1, whereas males, but not females, produce the female-attracting dhas#18. These results show that ascaroside biosynthesis in P. redivivus is highly sex-specific. Furthermore, the extensive side chain functionalization in dhas#18, which is reminiscent of polyketide-derived natural products, indicates unanticipated biosynthetic capabilities in nematodes.

A dwarf male reversal in bone-eating worms.

PubMed

Rouse, Greg W; Wilson, Nerida G; Worsaae, Katrine; Vrijenhoek, Robert C

2015-01-19

Darwin hypothesized that sexes in a species should be similar unless sexual selection, fecundity selection, or resource partitioning has driven them apart. Male dwarfism has evolved multiple times in a range of animals, raising questions about factors that drive such extreme size dimorphism. Ghiselin noted that dwarf males are more common among smaller marine animals, and especially among sedentary and sessile species living at low densities, where mates are difficult to find, or in deep-sea environments with limited energy sources. These benefits of male dwarfism apply well to Osedax (Annelida: Siboglinidae), bone-eating marine worms. Osedax males, notable for extreme sexual size dimorphism (SSD), are developmentally arrested larvae that produce sperm from yolk reserves. Harems of dwarf males reside in the lumen of the tube surrounding a female. Herein, we describe Osedax priapus n. sp., a species that deviates remarkably by producing males that anchor into, and feed on, bone via symbiont-containing "roots," just like female Osedax. Phylogenetic analyses revealed O. priapus n. sp. as a derived species, and the absence of dwarf males represents a character reversal for this genus. Some dwarf male features are retained due to functional and morphological constraints. Since O. priapus n. sp. males are anchored in bone, they possess an extensible trunk that allows them to roam across the bone to contact and inseminate females. Evolutionary and ecological implications of a loss of male dwarfism are discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

What is the latent structure of alcohol use disorders? A taxometric analysis of the Personality Assessment Inventory Alcohol Problems Scale in male and female prison inmates.

PubMed

Walters, Glenn D; Diamond, Pamela M; Magaletta, Philip R

2010-03-01

Three indicators derived from the Personality Assessment Inventory (PAI) Alcohol Problems scale (ALC)-tolerance/high consumption, loss of control, and negative social and psychological consequences-were subjected to taxometric analysis-mean above minus below a cut (MAMBAC), maximum covariance (MAXCOV), and latent mode factor analysis (L-Mode)-in 1,374 federal prison inmates (905 males, 469 females). Whereas the total sample yielded ambiguous results, the male subsample produced dimensional results, and the female subsample produced taxonic results. Interpreting these findings in light of previous taxometric research on alcohol abuse and dependence it is speculated that while alcohol use disorders may be taxonic in female offenders, they are probably both taxonic and dimensional in male offenders. Two models of male alcohol use disorder in males are considered, one in which the diagnostic features are categorical and the severity of symptomatology is dimensional, and one in which some diagnostic features (e.g., withdrawal) are taxonic and other features (e.g., social problems) are dimensional.

Survival rates and lifetime reproduction of breeding male Cooper’s Hawks in Wisconsin, 1980-2005

USGS Publications Warehouse

Rosenfield, Robert N.; Bielefeldt, John; Rosenfield, Laura J.; Booms, Travis L.; Bozek, Michael A.

2009-01-01

There are few published data on annual survival and no reports of lifetime reproduction for breeding Cooper's Hawks (Accipiter cooperii). Breeding males (n  =  105) in central and southeastern Wisconsin had an annual mortality rate of 19%, or a survival rate of 81% for birds ≤10 years of age. We did not detect significant differences in mortality rates between urban and rural habitats, nor between the earlier 13 years and later 13 years of this study. Male Cooper's Hawks produced from zero to 32 nestlings during their lifetimes. Body mass or size appeared unrelated to annual survivorship and lifetime reproduction, although lifetime reproduction was correlated strongly with longevity of breeding males. Fifteen of 66 males (23%) produced most (53%) of the nestlings. Our studies occurred in an area where breeding populations may be increasing with some of the highest reported productivity indices and nesting densities for this species. Habitat used for nesting on our Wisconsin study areas may be less important for survivorship and lifetime reproduction than acquisition of a nesting area in which a male will breed throughout his life.

CARCINOGENICITY OF BROMODICHLOROMETHANE ADMINISTERED IN DRINKING WATER TO THE MALE F344/N RAT AND B6C3F, MOUSE

EPA Science Inventory

CARCINOGENICITY OF BROMODICHLOROMETHANE ADMINISTERED IN DRINKING WATER TO THE MALE F344/N RAT AND B6C3F1 MOUSE.

Bromodichloromethane (BDCM) has been shown to produce kidney and large bowel tumors in both male and female F344/N rats, kidney tumors in male B6C3F 1 mice and ...

Efficacy of molecular markers jnurf13 and AcPms1 for prediction of genotypes at the nuclear Ms locus in North American open-pollinated populations of onion

USDA-ARS?s Scientific Manuscript database

Seed of hybrid onion (Allium cepa L.) is produced using cytoplasmic male sterility (CMS) and the for most widely used source of onion CMS, male sterility is conditioned by the interaction of male-sterile (S) cytoplasm and the homozygous recessive genotype at the nuclear male-fertility locus Ms. Due ...

Review on research of suppression male fertility and male contraceptive drug development by natural products.

PubMed

Bajaj, Vijay Kumar; Gupta, Radhey S

2013-08-01

Male contraceptive development in the present scenario is most viable aspect of research due to uncontrolled population growth in the world. In this respect investigators are busy to find out a safe male contraceptive drug. Researchers have started their finding for a suitable drug from natural sources because these are safe and easily acceptable for common man, most of natural sources are plants and their products. In this review 137 plants and their effects on reproduction and reproductive physiology are summarized. Some of them have intense effect on male reproductive system and do not produce any side effects. Reproductive toxicological studies are also important aspects of these kinds of researches, so it is important that drugs are safe and widely acceptable. An ideal male contraceptive can influence semen, testes, hormone level, accessory reproductive organs and general physiology of animals and produced some alterations. Many plants in this review are showing antifertility as well as antispermatogenic effects, so these may be used for further study for contraceptives development but it is important to find out the mechanism of reaction and further laboratory and clinical research on some plants are needed for final male contraceptive drug development. In conclusion this review will help for finding suitable plant products for male contraceptive clinical and laboratory studies.

Acoustic Characteristics of Long Calls Produced by Male Orang-Utans (Pongo pygmaeus wurmbii): Advertising Individual Identity, Context, and Travel Direction.

PubMed

Askew, James A; Morrogh-Bernard, Helen C

2016-01-01

Acoustic characteristics and context of the long-distance call of male orang-utans (Pongo pygmaeus wurmbii) were examined in a population of orang-utans from Central Kalimantan, Borneo. Male orang-utans produced long calls under different circumstances, including calls made spontaneously, in response to conspecifics, when accompanied by a snag crash and when travelling with a female. It was shown by acoustic analyses that there was individual discrimination between the male's calls, discrimination between the calls made under different contexts, and between calls from one individual from different years, which coincided with a change in his dominance status. We also confirm that flanged male orang-utans advertise their intended travel route, by long calling in the direction of their travel. If other orang-utans (males and females) within ear shot of the caller can identify the caller from their long call, and even obtain information about the context and status of the individual, they can then therefore choose whether to approach or avoid them. Thus, males seem to be using their long call to announce their presence, allowing them to orient themselves spatially to other orang-utans, and, potentially, to co-ordinate a network of loose associations between both males and females in the area. © 2016 S. Karger AG, Basel.

The effect of fig wall thickness in Ficus erecta var. beecheyana on parasitism

NASA Astrophysics Data System (ADS)

Tzeng, Hsy-Yu; Ou, Chern-Hsiung; Lu, Fu-Yuan; Bain, Anthony; Chou, Lien-Siang; Kjellberg, Finn

2014-05-01

Fig wasp communities constitute a model system to analyse determinants of community complexity and to investigate how biological interaction networks are maintained. It has been suggested for monoecious figs, that fig pollinating wasps avoid ovipositing in flowers located close to the fig wall because of strong parasitic pressure by wasps ovipositing through the fig wall. This behaviour could help explain why mainly seeds are produced in flowers located close to the fig wall, thus stabilizing the fig-pollinating wasp mutualism. In this contribution we explore, for dioecious figs, whether ovipositor length of parasitic species may really be limiting. In dioecious figs, functionally male figs produce pollinating wasps and pollen while female figs produce only seeds, facilitating selection of traits favouring pollinator reproduction in male figs. We show in Ficus erecta that fig walls are thicker in male figs than in female figs. Male figs presenting thick walls, thicker than the length of the parasites' ovipositors, went unparasitized while male figs presenting thinner walls were systematically parasitized. Hence, in F. erecta, ovipositor length of the parasites is limiting access to some figs. However, we also show that in another dioecious species, Ficus formosana, presenting thin walled male figs, no fig is protected against oviposition by its two parasites. Hence in dioecious as well as in monoecious figs, in some Ficus species, ovipositors of the parasites are limiting access to ovules, while in other Ficus species all ovules are exposed to parasitism.

Estrogens in Male Physiology.

PubMed

Cooke, Paul S; Nanjappa, Manjunatha K; Ko, CheMyong; Prins, Gail S; Hess, Rex A

2017-07-01

Estrogens have historically been associated with female reproduction, but work over the last two decades established that estrogens and their main nuclear receptors (ESR1 and ESR2) and G protein-coupled estrogen receptor (GPER) also regulate male reproductive and nonreproductive organs. 17β-Estradiol (E2) is measureable in blood of men and males of other species, but in rete testis fluids, E2 reaches concentrations normally found only in females and in some species nanomolar concentrations of estrone sulfate are found in semen. Aromatase, which converts androgens to estrogens, is expressed in Leydig cells, seminiferous epithelium, and other male organs. Early studies showed E2 binding in numerous male tissues, and ESR1 and ESR2 each show unique distributions and actions in males. Exogenous estrogen treatment produced male reproductive pathologies in laboratory animals and men, especially during development, and studies with transgenic mice with compromised estrogen signaling demonstrated an E2 role in normal male physiology. Efferent ductules and epididymal functions are dependent on estrogen signaling through ESR1, whose loss impaired ion transport and water reabsorption, resulting in abnormal sperm. Loss of ESR1 or aromatase also produces effects on nonreproductive targets such as brain, adipose, skeletal muscle, bone, cardiovascular, and immune tissues. Expression of GPER is extensive in male tracts, suggesting a possible role for E2 signaling through this receptor in male reproduction. Recent evidence also indicates that membrane ESR1 has critical roles in male reproduction. Thus estrogens are important physiological regulators in males, and future studies may reveal additional roles for estrogen signaling in various target tissues. Copyright © 2017 the American Physiological Society.

Increased pheromone signaling by small male sea lamprey has distinct effects on female mate search and courtship

USGS Publications Warehouse

Buchinger, Tyler J.; Bussy, Ugo; Buchinger, Ethan G.; Fissette, Skye D.; Li, Weiming; Johnson, Nicholas

2017-01-01

Male body size affects access to mates in many animals. Attributes of sexual signals often correlate with body size due to physiological constraints on signal production. Larger males generally produce larger signals, but costs of being large or compensation by small males can result in smaller males producing signals of equal or greater magnitude. Female choice following multiple male traits with different relationships to size might further complicate the effect of male body size on access to mates. We report the relationship between male body size and pheromone signaling, and the effects on female mate search and courtship in the sea lamprey (Petromyzon marinus). We predicted that pheromone production in the liver and the liver mass to body mass ratio would remain constant across sizes, resulting in similar mass-adjusted pheromone release rates across sizes but a positive relationship between absolute pheromone release and body mass. Our results confirmed positive relationships between body mass and liver mass, and liver mass and the magnitude of the pheromone signal. Surprisingly, decreasing body mass was correlated with higher pheromone concentrations in the liver, liver mass to body mass ratios, and mass-adjusted pheromone release rates. In a natural stream, females more often entered nests treated with small versus large male odors. However, close-proximity courtship behaviors were similar in nests treated with small or large male odors. We conclude that small males exhibit increased release of the main pheromone component, but female discrimination of male pheromones follows several axes of variation with different relationships to size.

Ejaculate traits in the Namibian cheetah (Acinonyx jubatus): influence of age, season and captivity.

PubMed

Crosier, Adrienne E; Marker, Laurie; Howard, JoGayle; Pukazhenthi, Budhan S; Henghali, Josephine N; Wildt, David E

2007-01-01

The objective was to examine the influence of animal age, season and captivity status on seminal quality in wild-born cheetahs (Acinonyx jubatus) in Namibia, Africa. Animals were divided into three age categories: juvenile (14-24 months; n = 16 males, 23 ejaculates); adult (25-120 months; n = 76 males, 172 ejaculates); and aged (>120 months; n = 5 males, 5 ejaculates). Seasons were categorised into hot-wet (January-April), cold-dry (May-August) and hot-dry (September-December). A comparison between freshly wild-caught (n = 29 males, 41 ejaculates) and captive-held cheetahs (n = 68 males, 159 ejaculates) was also conducted. Raw ejaculates contained 69.0 +/- 1.1% motile spermatozoa (mean +/- s.e.m.) with 73.6 +/- 1.5% of these cells containing an intact acrosome. Overall, 18.4 +/- 0.9% of spermatozoa were morphologically normal, with midpiece anomalies being the most prevalent (approximately 39%) defect. Juvenile cheetahs produced ejaculates with poorer sperm motility, forward progressive status, lower seminal volume and fewer total motile spermatozoa than adult and aged animals. Spermatogenesis continued unabated throughout the year and was minimally influenced by season. Proportions of sperm malformations were also not affected by season. Ejaculates from captive cheetahs had increased volume and intact acrosomes, but lower sperm density than wild-caught counterparts. In summary, Namibian cheetahs produce an extraordinarily high proportion of pleiomorphic spermatozoa regardless of age, season or living (captive versus free-ranging) status. Young males less than 2 years of age produce poorer ejaculate quality than adult and aged males. Because (1) all study animals were wild born and (2) there was little difference between freshly caught males and those maintained in captivity for protracted periods, our results affirm that teratospermia in the cheetah is mostly genetically derived. It also appears that an ex situ environment for the Namibian cheetah can ensure sperm quality comparable with that for free-living males.

Comparison of male chimeric mice generated from microinjection of JM8.N4 embryonic stem cells into C57BL/6J and C57BL/6NTac blastocysts.

PubMed

Fielder, Thomas J; Yi, Charles S; Masumi, Juliet; Waymire, Katrina G; Chen, Hsiao-Wen; Wang, Shuling; Shi, Kai-Xuan; Wallace, Douglas C; MacGregor, Grant R

2012-12-01

To identify ways to improve the efficiency of generating chimeric mice via microinjection of blastocysts with ES cells, we compared production and performance of ES-cell derived chimeric mice using blastocysts from two closely related and commonly used sub-strains of C57BL/6. Chimeras were produced by injection of the same JM8.N4 (C57BL/6NTac) derived ES cell line into blastocysts of mixed sex from either C57BL/6J (B6J) or C57BL/6NTac (B6NTac) mice. Similar efficiency of production and sex-conversion of chimeric animals was observed with each strain of blastocyst. However, B6J chimeric males had fewer developmental abnormalities involving urogenital and reproductive tissues (1/12, 8%) compared with B6NTac chimeric males (7/9, 78%). The low sample size did not permit determination of statistical significance for many parameters. However, in each category analyzed the B6J-derived chimeric males performed as well, or better, than their B6NTac counterparts. Twelve of 14 (86%) B6J male chimeras were fertile compared with 6 of 11 (55%) B6NTac male chimeras. Ten of 12 (83%) B6J chimeric males sired more than 1 litter compared with only 3 of 6 (50%) B6NTac chimeras. B6J male chimeras produced more litters per productive mating (3.42 ± 1.73, n = 12) compared to B6NTac chimeras (2.17 ± 1.33, n = 6). Finally, a greater ratio of germline transmitting chimeric males was obtained using B6J blastocysts (9/14; 64%) compared with chimeras produced using B6NTac blastocysts (4/11; 36%). Use of B6J host blastocysts for microinjection of ES cells may offer improvements over blastocysts from B6NTac and possibly other sub-strains of C57BL/6 mice.

Do Tetranychus urticae males avoid mating with familiar females?

PubMed

Yoshioka, T; Yano, S

2014-07-01

The two-spotted spider mite, Tetranychus urticae, usually lives in kin groups under common webs. Because only the first mating results in fertilisation in female T. urticae, adult males guard quiescent deutonymph females, those at the stage immediately before maturation, to ensure paternity. Therefore, the cost of precopulatory guarding time seems considerable for males. Moreover, the fitness indices of daughters from intra-population crosses were significantly lower than those of daughters from inter-population crosses, indicating that inbreeding depression exists in T. urticae. Therefore, we hypothesised that T. urticae males should be choosy in guarding familiar females to avoid inbreeding depression. Furthermore, webs should be a key element of the environment shared by familiar individuals. In this study, we demonstrated the inbreeding avoidance mechanism of T. urticae males in relation to webs produced by familiar females (known webs) or unfamiliar females (unknown webs). Regardless of surrounding webs (known or unknown), males preferred unfamiliar to familiar females. We further examined whether males detect unfamiliar females by their webs. When males had experienced a female's web without encountering that female, they subsequently preferred females that did not produce the surrounding webs in which the choice experiment was conducted. Results suggest that putative kin recognition for inbreeding avoidance in T. urticae males is based on the relationship between webs and females, and not on the discrimination of webs in shared environments. © 2014. Published by The Company of Biologists Ltd.

Growth and fatbody cycles in feral populations of the African clawed frog, Xenopus laevis (Pipidae), in California with comments on reproduction

USGS Publications Warehouse

McCoid, M.J.; Fritts, T.H.

1989-01-01

Feral populations of the African clawed frog (Xenopus laevis) exist in several areas of southern California. By following the first cohort of progeny produced by African clawed frogs at a recently colonized site, data on the growth rates and age at first maturity were obtained in field conditions. Females reached maturity at an earlier age than males, grew faster than males, and attained body lengths up to 25% larger than males. Larger females were capable of producing larger numbers of eggs than small females and, therefore, had greater reproductive potential. The relatively stable ambient temperatures of southern California contributed to the possibility of reproduction of clawed frogs during all but the coolest periods of the year. Cycles detected in the mass of fatbodies suggested that nutrients were mobilized from fat prior to and during ovulation. The amount of fat in females varied widely, but fat in males tended to accumulate as the males grew during the study period.

Growth and fat-body cycles in feral populations of the African clawed frog, Xenopus laevis (Pipidae), in California with comments on reproduction

USGS Publications Warehouse

McCoid, Michael J.; Fritts, Thomas H.

1989-01-01

Feral populations of the African clawed frog (Xenopus laevis) exist in several areas of southern California. By following the first cohort of progeny produced by African clawed frogs at a recently colonized site, data on the growth rates and age at first maturity were obtained in field conditions. Females reached maturity at an earlier age than males, grew faster than males, and attained body lengths up to 25% larger than males. Larger females were capable of producing larger numbers of eggs than small females and, therefore, had greater reproductive potential. The relatively stable ambient temperatures of southern California contributed to the possibility of reproduction of clawed frogs during all but the coolest periods of the year. Cycles detected in the mass of fatbodies suggested that nutrients were mobilized from fat prior to and during ovulation. The amount of fat in females varies widely, but fat in males tended to accumulate as the males grew during the study period.

Inbreeding affects sexual signalling in males but not females of Tenebrio molitor.

PubMed

Pölkki, Mari; Krams, Indrikis; Kangassalo, Katariina; Rantala, Markus J

2012-06-23

In many species of animals, individuals advertise their quality with sexual signals to obtain mates. Chemical signals such as volatile pheromones are species specific, and their primary purpose is to influence mate choice by carrying information about the phenotypic and genetic quality of the sender. The deleterious effects of consanguineous mating on individual quality are generally known, whereas the effect of inbreeding on sexual signalling is poorly understood. Here, we tested whether inbreeding reduces the attractiveness of sexual signalling in the mealworm beetle, Tenebrio molitor, by testing the preferences for odours of inbred and outbred (control) individuals of the opposite sex. Females were more attracted to the odours produced by outbred males than the odours produced by inbred males, suggesting that inbreeding reduces the attractiveness of male sexual signalling. However, we did not find any difference between the attractiveness of inbred and outbred female odours, which may indicate that the quality of females is either irrelevant for T. molitor males or quality is not revealed through female odours.

Inbreeding affects sexual signalling in males but not females of Tenebrio molitor

PubMed Central

Pölkki, Mari; Krams, Indrikis; Kangassalo, Katariina; Rantala, Markus J.

2012-01-01

In many species of animals, individuals advertise their quality with sexual signals to obtain mates. Chemical signals such as volatile pheromones are species specific, and their primary purpose is to influence mate choice by carrying information about the phenotypic and genetic quality of the sender. The deleterious effects of consanguineous mating on individual quality are generally known, whereas the effect of inbreeding on sexual signalling is poorly understood. Here, we tested whether inbreeding reduces the attractiveness of sexual signalling in the mealworm beetle, Tenebrio molitor, by testing the preferences for odours of inbred and outbred (control) individuals of the opposite sex. Females were more attracted to the odours produced by outbred males than the odours produced by inbred males, suggesting that inbreeding reduces the attractiveness of male sexual signalling. However, we did not find any difference between the attractiveness of inbred and outbred female odours, which may indicate that the quality of females is either irrelevant for T. molitor males or quality is not revealed through female odours. PMID:22237501

The clinical pharmacology and dynamics of marihuana cigarette smoking.

PubMed

Perez-Reyes, M; Owens, S M; Di Guiseppi, S

1981-01-01

We have studied the dynamics of marihuana smoking, the plasma concentration of delta 9-tetrahydrocannabinol (THC), and the pharmacologic effects produced by the sequential smoking of two 1% marihuana cigarettes at a 2-hour interval. Three males and three females, experienced marihuana smokers, participated in the study. The results indicate that each subject smoked his or her two cigarettes at a similar rate. The THC plasma concentrations produced by the smoking of the second cigarette were slightly lower than those produced by the first cigarette. The levels of the psychologic "high" caused by the two cigarettes were similar. However, the first cigarette accelerated the heart twice as much as the second cigarette. Between males and females there were marked differences in the rate at which the cigarettes were smoked. In particular, males took more puffs, took them more often, and consumed the cigarettes more rapidly than females. The plasma concentrations of THC, the self-reported psychologic effects, and the heart rate acceleration produced by the smoking of the two cigarettes were identical between the sexes.

The visible human male: a technical report.

PubMed Central

Spitzer, V; Ackerman, M J; Scherzinger, A L; Whitlock, D

1996-01-01

The National Library of Medicine's Visible Human Male data set consists of digital magnetic resonance (MR), computed tomography (CT), and anatomic images derived from a single male cadaver. The data set is 15 gigabytes in size and is available from the National Library of Medicine under a no-cost license agreement. The history of the Visible Human Male cadaver and the methods and technology to produce the data set are described. PMID:8653448

Termite queens close the sperm gates of eggs to switch from sexual to asexual reproduction.

PubMed

Yashiro, Toshihisa; Matsuura, Kenji

2014-12-02

Males and females are in conflict over genetic transmission in the evolution of parthenogenesis, because it enhances female reproductive output but deprives the males' genetic contribution. For males, any trait that coerces females into sexual reproduction should increase their fitness. However, in the termite Reticulitermes speratus, queens produce their replacements (neotenic queens) parthenogenetically while using normal sexual reproduction to produce other colony members. Here, we show that termite queens produce parthenogenetic offspring in the presence of kings by closing the micropyles (sperm gates; i.e., openings for sperm entry) of their eggs. Our field survey showed that termite eggs show large variation in numbers of micropyles, with some having none. Microsatellite analysis showed that embryos of micropyleless eggs develop parthenogenetically, whereas those of eggs with micropyles are fertilized and develop sexually. Surveys of eggs among queens of different age groups showed that queens begin to lay micropyleless eggs when they are older and thus, need to produce their replacements parthenogenetically. In addition, we found clear seasonality in new neotenic queen differentiation and micropyleless egg production. This micropyle-dependent parthenogenesis is the first identification, to our knowledge, of the mechanism through which females control egg fertilization over time in diploid animals, implying a novel route of the evolution of parthenogenesis in favor of female interests without interference from males.

Female Presence and Estrous State Influence Mouse Ultrasonic Courtship Vocalizations

PubMed Central

Hanson, Jessica L.; Hurley, Laura M.

2012-01-01

The laboratory mouse is an emerging model for context-dependent vocal signaling and reception. Mouse ultrasonic vocalizations are robustly produced in social contexts. In adults, male vocalization during courtship has become a model of interest for signal-receiver interactions. These vocalizations can be grouped into syllable types that are consistently produced by different subspecies and strains of mice. Vocalizations are unique to individuals, vary across development, and depend on social housing conditions. The behavioral significance of different syllable types, including the contexts in which different vocalizations are made and the responses listeners have to different types of vocalizations, is not well understood. We examined the effect of female presence and estrous state on male vocalizations by exploring the use of syllable types and the parameters of syllables during courtship. We also explored correlations between vocalizations and other behaviors. These experimental manipulations produced four main findings: 1) vocalizations varied among males, 2) the production of USVs and an increase in the use of a specific syllable type were temporally related to mounting behavior, 3) the frequency (kHz), bandwidth, and duration of syllables produced by males were influenced by the estrous phase of female partners, and 4) syllable types changed when females were removed. These findings show that mouse ultrasonic courtship vocalizations are sensitive to changes in female phase and presence, further demonstrating the context-sensitivity of these calls. PMID:22815817

An Unusual Role for doublesex in Sex Determination in the Dipteran Sciara.

PubMed

Ruiz, María Fernanda; Alvarez, Mercedes; Eirín-López, José M; Sarno, Francesca; Kremer, Leonor; Barbero, José L; Sánchez, Lucas

2015-08-01

The gene doublesex, which is placed at the bottom of the sex-determination gene cascade, plays the ultimate discriminatory role for sex determination in insects. In all insects where this gene has been characterized, the dsx premessenger RNA (pre-mRNA) follows a sex-specific splicing pattern, producing male- and female-specific mRNAs encoding the male-DSXM and female-DSXF proteins, which determine male and female development, respectively. This article reports the isolation and characterization of the gene doublesex of dipteran Sciara insects. The Sciara doublesex gene is constitutively transcribed during development and adult life of males and females. Sciara had no sex-specific doublesex mRNAs but the same transcripts, produced by alternative splicing of its primary transcript, were present in both sexes, although their relative abundance is sex specific. However, only the female DSXF protein, but not the male DSXM protein, was produced at similar amounts in both sexes. An analysis of the expression of female and male Sciara DSX proteins in Drosophila showed that these proteins conserved female and male function, respectively, on the control of Drosophila yolk-protein genes. The molecular evolution of gene doublesex of all insects where this gene has been characterized revealed that Sciara doublesex displays a considerable degree of divergence in its molecular organization and its splicing pattern with respect to the rest of dipterans as suggested by its basal position within the doublesex phylogeny. It is suggested that the doublesex gene is involved in Sciara sex determination although it appears not to play the discriminatory role performed in other insects. Copyright © 2015 by the Genetics Society of America.

ZENK expression following conspecific and heterospecific playback in the zebra finch auditory forebrain.

PubMed

Scully, Erin N; Hahn, Allison H; Campbell, Kimberley A; McMillan, Neil; Congdon, Jenna V; Sturdy, Christopher B

2017-07-28

Zebra finches (Taeniopygia guttata) are sexually dimorphic songbirds, not only in appearance but also in vocal production: while males produce both calls and songs, females only produce calls. This dimorphism provides a means to contrast the auditory perception of vocalizations produced by songbird species of varying degrees of relatedness in a dimorphic species to that of a monomorphic species, species in which both males and females produce calls and songs (e.g., black-capped chickadees, Poecile atricapillus). In the current study, we examined neuronal expression after playback of acoustically similar hetero- and conspecific calls produced by species of differing phylogenetic relatedness to our subject species, zebra finch. We measured the immediate early gene (IEG) ZENK in two auditory areas of the forebrain (caudomedial mesopallium, CMM, and caudomedial nidopallium, NCM). We found no significant differences in ZENK expression in either male or female zebra finches regardless of playback condition. We also discuss comparisons between our results and the results of a previous study conducted by Avey et al. [1] on black-capped chickadees that used similar stimulus types. These results are consistent with the previous study which also found no significant differences in expression following playback of calls produced by various heterospecific species and conspecifics [1]. Our results suggest that, similar to black-capped chickadees, IEG expression in zebra finch CMM and NCM is tied to the acoustic similarity of vocalizations and not the phylogenetic relatedness of the species producing the vocalizations. Copyright © 2017 Elsevier B.V. All rights reserved.

Restoring pollen fertility in transgenic male-sterile eggplant by Cre/loxp-mediated site-specific recombination system.

PubMed

Cao, Bihao; Huang, Zhiyin; Chen, Guoju; Lei, Jianjun

2010-04-01

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 T(0) -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.

Operating Without a Safety Net: Gay Male Adolescents and Emerging Adults’ Experiences of Marginalization and Migration, and Implications for Theory of Syndemic Production of Health Disparities

PubMed Central

Bruce, Douglas; Harper, Gary W.

2011-01-01

Health disparities among gay men (HIV, substance use, depression) have been described as a mutually occurring “syndemic” that is socially produced through two overarching dynamics: marginalization and migration. Although the syndemic theory proposes a developmental trajectory, it has been largely based on epidemiological studies of adult gay men and has not been examined using qualitative data from gay male adolescents and emerging adults describing their developmental experience. We conducted interviews with 54 HIV-positive gay and bisexual male adolescents and emerging adults at four sites in the United States. This study provides examples of developmental trajectories that help explain the early onset of socially produced health disparities among some gay male adolescents and emerging adults, but also the development of risk factors that may follow some gay men into adulthood. PMID:21398621

Male death resulting from hybridization between subspecies of the gypsy moth, Lymantria dispar

PubMed Central

Higashiura, Y; Yamaguchi, H; Ishihara, M; Ono, N; Tsukagoshi, H; Yokobori, S; Tokishita, S; Yamagata, H; Fukatsu, T

2011-01-01

We explored the origin of all-female broods resulting from male death in a Hokkaido population of Lymantria dispar through genetic crosses based on the earlier experiments done by Goldschmidt and by testing for the presence of endosymbionts that are known to cause male killing in some insect species. The mitochondrial DNA haplotypes of the all-female broods in Hokkaido were different from those of normal Hokkaido females and were the same as those widely distributed in Asia, including Tokyo (TK). Goldschmidt obtained all-female broods through backcrossing, that is, F1 females obtained by a cross between TK females (L. dispar japonica) and Hokkaido males (L. dispar praeterea) mated with Hokkaido males. He also obtained all-male broods by mating Hokkaido females with TK males. Goldschmidt inferred that female- and male-determining factors were weakest in the Hokkaido subspecies and stronger in the Honshu (TK) subspecies. According to his theory, the females of all-female broods mated with Honshu males should produce normal sex-ratio broods, whereas weaker Hokkaido sexes would be expected to disappear in F1 or F2 generations after crossing with the Honshu subspecies. We confirmed both of Goldschmidt's results: in the case of all-female broods mated with Honshu males, normal sex-ratio broods were produced, but we obtained only all-female broods in the Goldschmidt backcross and obtained an all-male brood in the F1 generation of a Hokkaido female crossed with a TK male. We found no endosymbionts in all-female broods by 4,′6-diamidino-2-phenylindole (DAPI) staining. Therefore, the all-female broods observed in L. dispar are caused by some incompatibilities between Honshu and Hokkaido subspecies. PMID:20628417

Acute and chronic dosing of Lepidium meyenii (Maca) on male rat sexual behavior.

PubMed

Lentz, Aaron; Gravitt, Karla; Carson, Culley C; Marson, Lesley

2007-03-01

The use of natural remedies for the treatment of sexual disorders is under current investigation. For generations people of the rural community in Peru have used Lepidium meyenii Walpers (Maca), because of their belief that it improves fertility and sexual desire. To determine the acute and chronic effects of Maca on male sexual behavior and to examine chronic administration of Maca on anxiety. Ejaculatory and mounting behavior and postejaculatory interval. Anxiety tests using an elevated plus maze, locomotion, and social interaction with another male. Maca (25 and 100 mg/kg) was orally administered to male rats for 30 days. Male sexual behavior was monitored after acute, 7 and 21 days of treatment. Anxiety behavior and locomotion were measured at 28-29 days using the elevated plus maze and social interaction tests. Maca treatment did not produce large changes in male sexual behavior. However, an increase in ejaculation latency and postejaculatory interval was observed after both acute and 7 days of treatment. After 21 days of treatment Maca had no effect on sexual behavior. Chronic administration of Maca did not increase locomotion or anxiety. Acute and short-term administration of Maca produced a small effect of rat male sexual behavior and long-term administration did not increase anxiety.

Stress hormone is implicated in satellite-caller associations and sexual selection in the Great Plains toad.

PubMed

Leary, Christopher J; Garcia, Apryl M; Knapp, Rosemary

2006-10-01

The effects of androgens on male-typical traits suggest that variation among males in circulating levels can play a major role in sexual selection. We examined whether variation in vocal attractiveness is attributable to differences in androgen levels among Great Plains toads (Bufo cognatus). We found that noncalling "satellite" males practicing an alternative mating tactic were more likely to associate with males producing long calls. However, callers with satellites did not have higher androgen levels than callers without satellites. Rather, callers with satellites had significantly lower corticosterone (CORT) levels than callers without satellites. A CORT manipulation experiment suggested that differences in calls for males with and without satellites were related to differences in CORT levels. Furthermore, there was a negative correlation between CORT level and call duration within most nights of chorus activity. However, the correlation was weak for the pooled data (across all nights), suggesting that local environmental and/or social factors also affect call duration. Last, we show that females preferred broadcast calls of longer duration, characteristic of males with satellites and low CORT. These results imply that satellites optimize their reproductive success by associating with males producing long calls. However, this association should negatively affect the fitness of attractive callers.

Predicted taxonomic patterns in pheromone production by longhorned beetles

NASA Astrophysics Data System (ADS)

Ray, Ann M.; Lacey, Emerson S.; Hanks, Lawrence M.

2006-11-01

Males of five species of three tribes in the longhorned beetle subfamily Cerambycinae produce volatile pheromones that share a structural motif (hydroxyl or carbonyl groups at carbons two and three in straight-chains of six, eight, or ten carbons). Pheromone gland pores are present on the prothoraces of males, but are absent in females, suggesting that male-specific gland pores could provide a convenient morphological indication that a species uses volatile pheromones. In this article, we assess the taxonomic distribution of gland pores within the Cerambycinae by examining males and females of 65 species in 24 tribes using scanning electron microscopy. Gland pores were present in males and absent in females of 49 species, but absent in both sexes of the remaining 16 species. Pores were confined to indentations in the cuticle. Among the species that had male-specific gland pores were four species already known to produce volatile compounds consistent with the structural motif. These findings support the initial assumption that gland pores are associated with the production of pheromones by males. There were apparently no taxonomic patterns in the presence of gland pores. These findings suggest that volatile pheromones play an important role in reproduction for many species of the Cerambycinae, and that the trait is evolutionarily labile.

Relaxation by urocortin of rat renal arteries: effects of diabetes in males and females.

PubMed

Sanz, Elena; Fernández, Nuria; Monge, Luis; Climent, Belén; Diéguez, Godofredo; García-Villalón, Angel Luis

2003-06-01

Urocortin is a peptide structurally related to corticotropin releasing factor (CRF), and the present study was performed to examine the effects of diabetes mellitus on the relaxation by urocortin of renal arteries from males and females. The response to urocortin was studied in isolated segments, 2 mm long, from renal arteries, from male and female, control (normoglycemic) and streptozotocin-induced diabetic rats. In the renal arterial segments precontracted with endothelin-1, urocortin produced concentration-dependent relaxation, that was not different between males and females. Diabetes reduced the relaxation in renal arteries from females but not in those from males. The potassium channel blocker charybdotoxin (10(-7) M) reduced the relaxation to urocortin of renal arteries from normoglycemic males and females. The cyclooxygenase inhibitor meclofenamate did not modify the relaxation to urocortin in renal arteries from normoglycemic males or females. The inhibitor of nitric oxide synthesis N(W)-nitro-L-arginine methyl ester (L-NAME, 10(-4) M) reduced the relaxation to urocortin in renal arteries from normoglycemic females, but not in renal arteries from normoglycemic males. Neither charybdotoxin, L-NAME or meclofenamate modified the relaxation to urocortin of renal arteries from diabetic females. These results suggest that urocortin produces a marked vasodilation of renal arteries, which may be mediated by nitric oxide in females and by activation of potassium channels in both genders, and is reduced by diabetes in renal arteries from females.

Testicular failure

MedlinePlus

... Testicular failure occurs when the testicles cannot produce sperm or male hormones, such as testosterone. Causes Testicular ... semen analysis to examine the number of healthy sperm you are producing. Sometimes, an ultrasound of the ...

Aquatic Plant Control Research Program. Use of the White Amur for Aquatic Plant Management.

DTIC Science & Technology

1984-08-01

These females are fed sex reversal Bisexual White Amur hormones prior to formation of sex organs. lairli 50,000 $0.08Fingrerlingl 1,000 0.50 This process...produces sex reversed females Fingerling 1,000 0.30 (males) carrying chromosomes capable of 4-7 1,000 1.75 producing only females . These "males" are...faster than other fish of per hectare), reduced growth rates have comparable sizes. In their native habitat, been reported by some workers . 9; I

Chronic metals ingestion by prairie voles produces sex-specific deficits in social behavior: an animal model of autism.

PubMed

Curtis, J Thomas; Hood, Amber N; Chen, Yue; Cobb, George P; Wallace, David R

2010-11-12

We examined the effects of chronic metals ingestion on social behavior in the normally highly social prairie vole to test the hypothesis that metals may interact with central dopamine systems to produce the social withdrawal characteristic of autism. Relative to water-treated controls, 10 weeks of chronic ingestion of either Hg(++) or Cd(++) via drinking water significantly reduced social contact by male voles when they were given a choice between isolation or contact with an unfamiliar same-sex conspecific. The effects of metals ingestion were specific to males: no effects of metals exposure were seen in females. Metals ingestion did not alter behavior of males allowed to choose between isolation or their familiar cage-mates, rather than strangers. We also examined the possibility that metals ingestion affects central dopamine functioning by testing the voles' locomotor responses to peripheral administration of amphetamine. As with the social behavior, we found a sex-specific effect of metals on amphetamine responses. Males that consumed Hg(++) did not increase their locomotor activity in response to amphetamine, whereas similarly treated females and males that ingested only water significantly increased their locomotor activities. Thus, an ecologically relevant stimulus, metals ingestion, produced two of the hallmark characteristics of autism - social avoidance and a male-oriented bias. These results suggest that metals exposure may contribute to the development of autism, possibly by interacting with central dopamine function, and support the use of prairie voles as a model organism in which to study autism. (c) 2010 Elsevier B.V. All rights reserved.

Males that drop a sexually selected weapon grow larger testes.

PubMed

Joseph, Paul N; Emberts, Zachary; Sasson, Daniel A; Miller, Christine W

2018-01-01

Costly sexually selected weapons are predicted to trade off with postcopulatory traits, such as testes. Although weapons can be important for achieving access to females, individuals of some species can permanently drop (i.e. autotomize) their weapons, without regeneration, to escape danger. We capitalized on this natural behavior to experimentally address whether the loss of a sexually selected weapon leads to increased testes investment in the leaf-footed cactus bug, Narnia femorata Stål (Hemiptera: Coreidae). In a second experiment, we measured offspring production for males that lost a weapon during development. As predicted, males that dropped a hind limb during development grew significantly larger testes than the control treatments. Hind-limb autotomy did not result in the enlargement of other nearby traits. Our results are the first to experimentally demonstrate that males compensate for natural weapon loss by investing more in testes. In a second experiment we found that females paired with males that lost a hind limb had 40% lower egg hatching success than females paired with intact males, perhaps because of lower mating receptivity to males with a lost limb. Importantly, in those cases where viable offspring were produced, males missing a hind limb produced 42% more offspring than males with intact limbs. These results suggest that the loss of a hind-limb weapon can, in some cases, lead to greater fertilization success. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

Size does matter: An assessment of reproductive potential in seahorses.

PubMed

Faleiro, Filipa; Almeida, Armando J; Ré, Pedro; Narciso, Luís

2016-07-01

In most animals, the mother plays the key role in reproduction, but male pregnancy in seahorses raises the question of whether the female still is the only determinant of offspring size or if she shares some responsibility with the male. This study evaluates the effects of both male and female size on the reproductive output of the long-snouted seahorse, Hippocampus guttulatus. Results demonstrated that, with regard to reproductive potential, the bigger the better. Seahorses preferred similar-sized or larger mates. Larger females produced bigger eggs with larger yolk reserves. Larger males had larger brood pouches, but did not produced larger broods. Male size was negatively correlated with embryo density and positively correlated with juvenile size. Both parents proved to play a decisive role in the reproductive output of this species. Newborn juveniles from the same parents were 15% bigger and 30% heavier when incubated in smaller and lower-density broods. This trade-off between the number and size of embryos inside the brood pouch clearly indicates a limited carrying capacity of the male, and demonstrates that the size of newborn seahorses can be, in part, paternally determined. Copyright © 2016 Elsevier B.V. All rights reserved.

Sex-Specific Differences in Agonistic Behaviour, Sound Production and Auditory Sensitivity in the Callichthyid Armoured Catfish Megalechis thoracata

PubMed Central

Hadjiaghai, Oliwia; Ladich, Friedrich

2015-01-01

Background Data on sex-specific differences in sound production, acoustic behaviour and hearing abilities in fishes are rare. Representatives of numerous catfish families are known to produce sounds in agonistic contexts (intraspecific aggression and interspecific disturbance situations) using their pectoral fins. The present study investigates differences in agonistic behaviour, sound production and hearing abilities in males and females of a callichthyid catfish. Methodology/Principal Findings Eight males and nine females of the armoured catfish Megalechis thoracata were investigated. Agonistic behaviour displayed during male-male and female-female dyadic contests and sounds emitted were recorded, sound characteristics analysed and hearing thresholds measured using the auditory evoked potential (AEP) recording technique. Male pectoral spines were on average 1.7-fold longer than those of same-sized females. Visual and acoustic threat displays differed between sexes. Males produced low-frequency harmonic barks at longer distances and thumps at close distances, whereas females emitted broad-band pulsed crackles when close to each other. Female aggressive sounds were significantly shorter than those of males (167 ms versus 219 to 240 ms) and of higher dominant frequency (562 Hz versus 132 to 403 Hz). Sound duration and sound level were positively correlated with body and pectoral spine length, but dominant frequency was inversely correlated only to spine length. Both sexes showed a similar U-shaped hearing curve with lowest thresholds between 0.2 and 1 kHz and a drop in sensitivity above 1 kHz. The main energies of sounds were located at the most sensitive frequencies. Conclusions/Significance Current data demonstrate that both male and female M. thoracata produce aggressive sounds, but the behavioural contexts and sound characteristics differ between sexes. Sexes do not differ in hearing, but it remains to be clarified if this is a general pattern among fish. This is the first study to describe sex-specific differences in agonistic behaviour in fishes. PMID:25775458

Methyl farnesoate synthesis is necessary for the environmental sex determination in the water flea Daphnia pulex.

PubMed

Toyota, Kenji; Miyakawa, Hitoshi; Hiruta, Chizue; Furuta, Kenjiro; Ogino, Yukiko; Shinoda, Tetsuro; Tatarazako, Norihisa; Miyagawa, Shinichi; Shaw, Joseph R; Iguchi, Taisen

2015-09-01

Sex-determination systems can be divided into two groups: genotypic sex determination (GSD) and environmental sex determination (ESD). ESD is an adaptive life-history strategy that allows control of sex in response to environmental cues in order to optimize fitness. However, the molecular basis of ESD remains largely unknown. The micro crustacean Daphnia pulex exhibits ESD in response to various external stimuli. Although methyl farnesoate (MF: putative juvenile hormone, JH, in daphnids) has been reported to induce male production in daphnids, the role of MF as a sex-determining factor remains elusive due to the lack of a suitable model system for its study. Here, we establish such a system for ESD studies in D. pulex. The WTN6 strain switches from producing females to producing males in response to the shortened day condition, while the MFP strain only produces females, irrespective of day-length. To clarify whether MF has a novel physiological role as a sex-determining factor in D. pulex, we demonstrate that a MF/JH biosynthesis inhibitor suppressed male production in WTN6 strain reared under the male-inducible condition, shortened day-length. Moreover, we show that juvenile hormone acid O-methyltransferase (JHAMT), a critical enzyme of MF/JH biosynthesis, displays MF-generating activity by catalyzing farnesoic acid. Expression of the JHAMT gene increased significantly just before the MF-sensitive period for male production in the WTN6 strain, but not in the MFP strain, when maintained under male-inducible conditions. These results suggest that MF synthesis regulated by JHAMT is necessary for male offspring production in D. pulex. Our findings provide novel insights into the genetic underpinnings of ESD and they begin to shed light on the physiological function of MF as a male-fate determiner in D. pulex. Copyright © 2015 Elsevier Ltd. All rights reserved.

Phytoestrogens and risk of prostate cancer: an updated meta-analysis of epidemiologic studies.

PubMed

Zhang, Qiang; Feng, Hongliang; Qluwakemi, Bakare; Wang, Jiaqi; Yao, Songpo; Cheng, Guangdong; Xu, Hui; Qiu, Hongbin; Zhu, Liling; Yuan, Mingxia

2017-02-01

This updated meta-analysis was performed to clarify the relationship between phytoestrogens and prostate cancer risk. Twenty one case-control and two cohort studies were finally selected for this meta-analysis, totaling 11,346 cases and 140,177 controls. Analytical results showed that daidzein (OR = 0.85; 95% CI: 0.75-0.96), genistein (OR = 0.87; 95% CI: 0.78-0.98), and glycitein (OR = 0.89; 95% CI: 0.81-0.98) were associated with a reduction of prostate cancer risk, but total isoflavones (OR = 0.93; 95% CI: 0.84-1.04), equol (OR = 0.86; 95% CI: 0.66-1.14), total lignans (OROgna.05; 95% CI: 0.54-2.04), secoisolariciresinol (OR = 1.02; 95% CI: 0.83-1.24), matairesinol (OR = 0.91; 95% CI: 0.75-1.11), enterolactone (OR = 0.94; 95% CI: 0.73-1.20), and coumestrol (OR = 0.89; 95% CI: 0.76-1.06) were not. Sensitivity and publication bias analyses demonstrated that the pooled estimates were stable and reliable. The results support the notion that some phytoestrogens may have a role in decreasing the risk of prostate cancer. Additional large and well-designed cohort studies are needed to confirm these relationships.

Inheritance of congenital cataracts and microphthalmia in the Miniature Schnauzer.

PubMed

Gelatt, K N; Samuelson, D A; Bauer, J E; Das, N D; Wolf, E D; Barrie, K P; Andresen, T L

1983-06-01

Congenital cataracts and microphthalmia in the Miniature Schnauzer were inherited as an autosomal recessive trait. Eighteen matings of affected X affected Miniature Schnauzers resulted in 87 offspring with congenital cataracts and microphthalmia (49 males/38 females). Two matings of congenital cataractous and microphthalmic Miniature Schnauzers (2 females) X a normal Miniature Schnauzer (1 male) yielded 11 clinically normal Miniature Schnauzers (7 males/4 females). Eighteen matings of congenital cataractous and microphthalmic Miniature Schnauzers (6 males) X carrier Miniature Schnauzers (9 females) produced 81 offspring; 39 exhibited congenital cataracts and microphthalmia (20 males/19 females) and 42 had clinically normal eyes (17 males/25 females).

Control of male sexual behavior and sexual orientation in Drosophila by the fruitless gene.

PubMed

Ryner, L C; Goodwin, S F; Castrillon, D H; Anand, A; Villella, A; Baker, B S; Hall, J C; Taylor, B J; Wasserman, S A

1996-12-13

Sexual orientation and courtship behavior in Drosophila are regulated by fruitless (fru), the first gene in a branch of the sex-determination hierarchy functioning specifically in the central nervous system (CNS). The phenotypes of new fru mutants encompass nearly all aspects of male sexual behavior. Alternative splicing of fru transcripts produces sex-specific proteins belonging to the BTB-ZF family of transcriptional regulators. The sex-specific fru products are produced in only about 500 of the 10(5) neurons that comprise the CNS. The properties of neurons expressing these fru products suggest that fru specifies the fates or activities of neurons that carry out higher order control functions to elicit and coordinate the activities comprising male courtship behavior.

Big brothers and little sisters? Sex selection and birth order.

PubMed

Salmon, Catherine

2007-09-01

Should you be allowed to choose the sex of your child? Even before the advent of modern reproductive technologies, people have expressed interest in producing a child of a specific sex, trying everything from herbal treatments to sexual positions that have been claimed to produce a male or female child. Modern technologies such as flow cytometry make this a realistic possibility but what might the consequences be? In India and China, a preference for male offspring has led (via abortion) to a significant sex-ratio imbalance in those populations. Do other countries express strong preferences for male or female offspring? This article will address the possible birth order implications. Will we live in a world of first-born boys and second-born girls?

Effect of electromagnetic irradiation produced by 3G mobile phone on male rat reproductive system in a simulated scenario.

PubMed

Kumar, Sanjay; Nirala, Jay Prakash; Behari, J; Paulraj, R

2014-09-01

Reports of declining male fertility have renewed interest in assessing the role of electromagnetic fields (EMFs). Testicular function is particularly susceptible to the radiation emitted by EMFs. Significant decrease in sperm count, increase in the lipid peroxidation damage in sperm cells, reduction in seminiferous tubules and testicular weight and DNA damage were observed following exposure to EMF in male albino rats. The results suggest that mobile phone exposure adversely affects male fertility.

Developmental Environment Effects on Sexual Selection in Male and Female Drosophila melanogaster

PubMed Central

Morimoto, Juliano; Pizzari, Tommaso; Wigby, Stuart

2016-01-01

The developmental environment can potentially alter the adult social environment and influence traits targeted by sexual selection such as body size. In this study, we manipulated larval density in male and female Drosophila melanogaster, which results in distinct adult size phenotypes–high (low) densities for small (large) adults–and measured sexual selection in experimental groups consisting of adult males and females from high, low, or a mixture of low and high larval densities. Overall, large adult females (those reared at low larval density) had more matings, more mates and produced more offspring than small females (those reared at high larval density). The number of offspring produced by females was positively associated with their number of mates (i.e. there was a positive female Bateman gradient) in social groups where female size was experimentally varied, likely due to the covariance between female productivity and mating rate. For males, we found evidence that the larval environment affected the relative importance of sexual selection via mate number (Bateman gradients), mate productivity, paternity share, and their covariances. Mate number and mate productivity were significantly reduced for small males in social environments where males were of mixed sizes, versus social environments where all males were small, suggesting that social heterogeneity altered selection on this subset of males. Males are commonly assumed to benefit from mating with large females, but in contrast to expectations we found that in groups where both the male and female size varied, males did not gain more offspring per mating with large females. Collectively, our results indicate sex-specific effects of the developmental environment on the operation of sexual selection, via both the phenotype of individuals, and the phenotype of their competitors and mates. PMID:27167120

Use of rhodamine B to mark the body and seminal fluid of male Aedes aegypti for mark-release-recapture experiments and estimating efficacy of sterile male releases

PubMed Central

Johnson, Brian J.; Mitchell, Sara N.; Paton, Christopher J.; Stevenson, Jessica; Staunton, Kyran M.; Snoad, Nigel; Beebe, Nigel; White, Bradley J.; Ritchie, Scott A.

2017-01-01

Background Recent interest in male-based sterile insect technique (SIT) and incompatible insect technique (IIT) to control Aedes aegypti and Aedes albopictus populations has revealed the need for an economical, rapid diagnostic tool for determining dispersion and mating success of sterilized males in the wild. Previous reports from other insects indicated rhodamine B, a thiol-reactive fluorescent dye, administered via sugar-feeding can be used to stain the body tissue and seminal fluid of insects. Here, we report on the adaptation of this technique for male Ae. aegypti to allow for rapid assessment of competitiveness (mating success) during field releases. Methodology/Principle findings Marking was achieved by feeding males on 0.1, 0.2, 0.4 or 0.8% rhodamine B (w/v) in 50% honey solutions during free flight. All concentrations produced >95% transfer to females and successful body marking after 4 days of feeding, with 0.4 and 0.8% solutions producing the longest-lasting body marking. Importantly, rhodamine B marking had no effect on male mating competitiveness and proof-of-principle field releases demonstrated successful transfer of marked seminal fluid to females under field conditions and recapture of marked males. Conclusions/Significance These results reveal rhodamine B to be a potentially useful evaluation method for male-based SIT/IIT control strategies as well as a viable body marking technique for male-based mark-release-recapture experiments without the negative side-effects of traditional marking methods. As a standalone method for use in mating competitiveness assays, rhodamine B marking is less expensive than PCR (e.g. paternity analysis) and stable isotope semen labelling methods and less time-consuming than female fertility assays used to assess competitiveness of sterilised males. PMID:28957318

Use of rhodamine B to mark the body and seminal fluid of male Aedes aegypti for mark-release-recapture experiments and estimating efficacy of sterile male releases.

PubMed

Johnson, Brian J; Mitchell, Sara N; Paton, Christopher J; Stevenson, Jessica; Staunton, Kyran M; Snoad, Nigel; Beebe, Nigel; White, Bradley J; Ritchie, Scott A

2017-09-01

Recent interest in male-based sterile insect technique (SIT) and incompatible insect technique (IIT) to control Aedes aegypti and Aedes albopictus populations has revealed the need for an economical, rapid diagnostic tool for determining dispersion and mating success of sterilized males in the wild. Previous reports from other insects indicated rhodamine B, a thiol-reactive fluorescent dye, administered via sugar-feeding can be used to stain the body tissue and seminal fluid of insects. Here, we report on the adaptation of this technique for male Ae. aegypti to allow for rapid assessment of competitiveness (mating success) during field releases. Marking was achieved by feeding males on 0.1, 0.2, 0.4 or 0.8% rhodamine B (w/v) in 50% honey solutions during free flight. All concentrations produced >95% transfer to females and successful body marking after 4 days of feeding, with 0.4 and 0.8% solutions producing the longest-lasting body marking. Importantly, rhodamine B marking had no effect on male mating competitiveness and proof-of-principle field releases demonstrated successful transfer of marked seminal fluid to females under field conditions and recapture of marked males. These results reveal rhodamine B to be a potentially useful evaluation method for male-based SIT/IIT control strategies as well as a viable body marking technique for male-based mark-release-recapture experiments without the negative side-effects of traditional marking methods. As a standalone method for use in mating competitiveness assays, rhodamine B marking is less expensive than PCR (e.g. paternity analysis) and stable isotope semen labelling methods and less time-consuming than female fertility assays used to assess competitiveness of sterilised males.

Polymorphism in hybrid male sterility in wild-derived Mus musculus musculus strains on proximal chromosome 17.

PubMed

Vyskocilová, Martina; Prazanová, Gabriela; Piálek, Jaroslav

2009-02-01

The hybrid sterility-1 (Hst1) locus at Chr 17 causes male sterility in crosses between the house mouse subspecies Mus musculus domesticus (Mmd) and M. m. musculus (Mmm). This locus has been defined by its polymorphic variants in two laboratory strains (Mmd genome) when mated to PWD/Ph mice (Mmm genome): C57BL/10 (carrying the sterile allele) and C3H (fertile allele). The occurrence of sterile and/or fertile (wild Mmm x C57BL)F1 males is evidence that polymorphism for this trait also exists in natural populations of Mmm; however, the nature of this polymorphism remains unclear. Therefore, we derived two wild-origin Mmm strains, STUS and STUF, that produce sterile and fertile males, respectively, in crosses with C57BL mice. To determine the genetic basis underlying male fertility, the (STUS x STUF)F1 females were mated to C57BL/10 J males. About one-third of resulting hybrid males (33.8%) had a significantly smaller epididymis and testes than parental animals and lacked spermatozoa due to meiotic arrest. A further one-fifth of males (20.3%) also had anomalous reproductive traits but produced some spermatozoa. The remaining fertile males (45.9%) displayed no deviation from values found in parental individuals. QTL analysis of the progeny revealed strong associations of male fitness components with the proximal end of Chr 17, and a significant effect of the central section of Chr X on testes mass. The data suggest that genetic incompatibilities associated with male sterility have evolved independently at the proximal end of Chr 17 and are polymorphic within both Mmd and Mmm genomes.

Evaluation of Quality Production Parameters and Mating Behavior of Novel Genetic Sexing Strains of the Mediterranean Fruit Fly Ceratitis capitata (Wiedemann) (Diptera: Tephritidae)

PubMed Central

Haq, Ihsan ul; Wornayporn, Viwat; Ahmad, Sohel; Sto Tomas, Ulysses; Dammalage, Thilakasiri; Gembinsky, Keke; Franz, Gerald; Cáceres, Carlos; Vreysen, Marc J. B.

2016-01-01

The Mediterranean fruit fly Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) is one of the most important pest of fruits and vegetables in tropical and subtropical countries. The sterile insect technique (SIT) as a component of area-wide integrated pest management (AW-IPM) approaches is being used for the successful management of this pest. VIENNA 8 is a genetic sexing strain (GSS) that has a white pupae (wp) and temperature sensitive lethal (tsl) mutation, the latter killing all female embryos when eggs are exposed to high temperatures (34°C). The use of this GSS permits production and the release of only males which has increased the cost effectiveness of the SIT several fold for this pest. An efficient method of identification of recaptured sterile males can further increase the cost effectiveness of the SIT for this pest. Therefore, VIENNA 8-Sergeant2 (Sr2) strain and the transgenic strain VIENNA 8–1260 having visible markers were constructed. All three strains were evaluated for egg production, egg hatch, and egg sterility parameters under semi mass-rearing conditions and mating competitiveness in field cages. VIENNA 8–1260 females produced significantly fewer eggs as compared with the two other strains, which produced similar numbers of eggs. However, egg hatch of all strains was similar. Egg hatch of eggs produced by untreated females that had mated with adult males that had been irradiated with 100 Gy as pupae 2 days before emergence, was different for the three strains, i.e., egg hatch of 0.63%, 0.77%, 0.89% for VIENNA 8, VIENNA 8–1260, and VIENNA 8-Sr2, respectively. Differences in male mating competitiveness of the three strains against wild-type males were gradually reduced with successive generations under semi mass-rearing conditions. However, VIENNA 8 males adapted faster to laboratory conditions as compared with VIENNA 8-Sr2 and VIENNA 8–1260 males with respect to mating competitiveness. VIENNA 8 males of the F10 generation were equally competitive with wild-type males, whereas the mating competitiveness of VIENNA 8-Sr2 and VIENNA 8–1260 males was similar but lower as compared with wild-type males. Males from all three strains copulated earlier than wild-type males. Results are discussed in relation with the potential benefits of incorporating novel strains for more effective SIT application. PMID:27336737

Male Reproductive System

MedlinePlus

... sexual intercourse. The male reproductive system also produces sex hormones, which help a boy develop into a sexually mature man during puberty . ... Understanding Early Sexual Development Questions and Answers About Sex Talking to Your ... Torsion For Boys: Trouble "Down There" Boys and Puberty All About ...

Zebra finch mates use their forebrain song system in unlearned call communication.

PubMed

Ter Maat, Andries; Trost, Lisa; Sagunsky, Hannes; Seltmann, Susanne; Gahr, Manfred

2014-01-01

Unlearned calls are produced by all birds whereas learned songs are only found in three avian taxa, most notably in songbirds. The neural basis for song learning and production is formed by interconnected song nuclei: the song control system. In addition to song, zebra finches produce large numbers of soft, unlearned calls, among which "stack" calls are uttered frequently. To determine unequivocally the calls produced by each member of a group, we mounted miniature wireless microphones on each zebra finch. We find that group living paired males and females communicate using bilateral stack calling. To investigate the role of the song control system in call-based male female communication, we recorded the electrical activity in a premotor nucleus of the song control system in freely behaving male birds. The unique combination of acoustic monitoring together with wireless brain recording of individual zebra finches in groups shows that the neuronal activity of the song system correlates with the production of unlearned stack calls. The results suggest that the song system evolved from a brain circuit controlling simple unlearned calls to a system capable of producing acoustically rich, learned vocalizations.

Zebra Finch Mates Use Their Forebrain Song System in Unlearned Call Communication

PubMed Central

Ter Maat, Andries; Trost, Lisa; Sagunsky, Hannes; Seltmann, Susanne; Gahr, Manfred

2014-01-01

Unlearned calls are produced by all birds whereas learned songs are only found in three avian taxa, most notably in songbirds. The neural basis for song learning and production is formed by interconnected song nuclei: the song control system. In addition to song, zebra finches produce large numbers of soft, unlearned calls, among which “stack” calls are uttered frequently. To determine unequivocally the calls produced by each member of a group, we mounted miniature wireless microphones on each zebra finch. We find that group living paired males and females communicate using bilateral stack calling. To investigate the role of the song control system in call-based male female communication, we recorded the electrical activity in a premotor nucleus of the song control system in freely behaving male birds. The unique combination of acoustic monitoring together with wireless brain recording of individual zebra finches in groups shows that the neuronal activity of the song system correlates with the production of unlearned stack calls. The results suggest that the song system evolved from a brain circuit controlling simple unlearned calls to a system capable of producing acoustically rich, learned vocalizations. PMID:25313846

Sound production during the spawning season in cavity-nesting darters of the subgenus Catonotus (Percidae: Etheostoma)

Treesearch

Carol E. Johnston; Dawn L. Johnson

2000-01-01

The cavity-nesting darters Etheostoma nigripinne, Etheostoma crossopterum, and their hybrid (E. nigripinne X E. crossopterum) were found to produce sounds associated with reproduction. Males produced sounds during aggessive encounters and courtship activities. All three taxa produced nonpulsed...

Spatiotemporal variability and sound characterization in silver croaker Plagioscion squamosissimus (Sciaenidae) in the Central Amazon.

PubMed

Borie, Alfredo; Mok, Hin-Kiu; Chao, Ning L; Fine, Michael L

2014-01-01

The fish family Sciaenidae has numerous species that produce sounds with superfast muscles that vibrate the swimbladder. These muscles form post embryonically and undergo seasonal hypertrophy-atrophy cycles. The family has been the focus of numerous passive acoustic studies to localize spatial and temporal occurrence of spawning aggregations. Fishes produce disturbance calls when hand-held, and males form aggregations in late afternoon and produce advertisement calls to attract females for mating. Previous studies on five continents have been confined to temperate species. Here we examine the calls of the silver croaker Plagioscion squamosissimus, a freshwater equatorial species, which experiences constant photoperiod, minimal temperature variation but seasonal changes in water depth and color, pH and conductivity. Dissections indicate that sonic muscles are present exclusively in males and that muscles are thicker and redder during the mating season. Disturbance calls were recorded in hand-held fish during the low-water mating season and high-water period outside of the mating season. Advertisement calls were recorded from wild fish that formed aggregations in both periods but only during the mating season from fish in large cages. Disturbance calls consist of a series of short individual pulses in mature males. Advertisement calls start with single and paired pulses followed by greater amplitude multi-pulse bursts with higher peak frequencies than in disturbance calls. Advertisement-like calls also occur in aggregations during the off season, but bursts are shorter with fewer pulses. Silver croaker produce complex advertisement calls that vary in amplitude, number of cycles per burst and burst duration of their calls. Unlike temperate sciaenids, which only call during the spawning season, silver croaker produce advertisement calls in both seasons. Sonic muscles are thinner, and bursts are shorter than at the spawning peak, but males still produce complex calls outside of the mating season.

Spatiotemporal Variability and Sound Characterization in Silver Croaker Plagioscion squamosissimus (Sciaenidae) in the Central Amazon

PubMed Central

Borie, Alfredo; Mok, Hin-Kiu; Chao, Ning L.; Fine, Michael L.

2014-01-01

Background The fish family Sciaenidae has numerous species that produce sounds with superfast muscles that vibrate the swimbladder. These muscles form post embryonically and undergo seasonal hypertrophy-atrophy cycles. The family has been the focus of numerous passive acoustic studies to localize spatial and temporal occurrence of spawning aggregations. Fishes produce disturbance calls when hand-held, and males form aggregations in late afternoon and produce advertisement calls to attract females for mating. Previous studies on five continents have been confined to temperate species. Here we examine the calls of the silver croaker Plagioscion squamosissimus, a freshwater equatorial species, which experiences constant photoperiod, minimal temperature variation but seasonal changes in water depth and color, pH and conductivity. Methods and Principal Findings Dissections indicate that sonic muscles are present exclusively in males and that muscles are thicker and redder during the mating season. Disturbance calls were recorded in hand-held fish during the low-water mating season and high-water period outside of the mating season. Advertisement calls were recorded from wild fish that formed aggregations in both periods but only during the mating season from fish in large cages. Disturbance calls consist of a series of short individual pulses in mature males. Advertisement calls start with single and paired pulses followed by greater amplitude multi-pulse bursts with higher peak frequencies than in disturbance calls. Advertisement-like calls also occur in aggregations during the off season, but bursts are shorter with fewer pulses. Conclusions and Significance Silver croaker produce complex advertisement calls that vary in amplitude, number of cycles per burst and burst duration of their calls. Unlike temperate sciaenids, which only call during the spawning season, silver croaker produce advertisement calls in both seasons. Sonic muscles are thinner, and bursts are shorter than at the spawning peak, but males still produce complex calls outside of the mating season. PMID:25098347

Effects of paclitaxel on mechanical sensitivity and morphine reward in male and female C57Bl6 mice

PubMed Central

Neelakantan, Harshini; Ward, Sara Jane; Walker, Ellen Ann

2016-01-01

This study evaluated the hypothesis that a paclitaxel treatment regimen sufficient to produce mechanical allodynia would alter sensitivities of male and female mice to the conditioned rewarding and reinforcing effects of morphine. Saline or paclitaxel were administered on days 1, 3, 5, and 7 in male and female C57Bl/6 mice to induce morphine-reversible mechanical allodynia as measured by the Von Frey filament test. Paclitaxel treatment did not change sensitivity to morphine conditioned place preference (CPP) relative to saline treatment in either male or female mice. Morphine produced peak self-administration under a fixed ratio-1 schedule of reinforcement for 0.03 mg/kg morphine per infusion in female mice and 0.1 mg/kg morphine per infusion in male mice. During the progressive ratio experiments, saline treatment in male mice decreased the number of morphine infusions for 12 days whereas the paclitaxel-treated male mice maintained responding for morphine similar to baseline levels during the same time period. However, paclitaxel did not have an overall effect on the reinforcing efficacy of morphine assessed over a limited dose range during the course of the repeated self-administration. These results suggest that the reward-related behavioral effects of morphine are overall not robustly altered by the presence of paclitaxel treatment under the current dosing regimen, with the exception of maintaining a small yet significant higher baseline than saline treatment during the development of allodynia in male mice. PMID:27929349

Degree-days as a tool for use in producing tilapia fry for sex inversion

USDA-ARS?s Scientific Manuscript database

Hormonal sex inversion of newly hatched tilapia fry continues to be an important method to produce monosex male tilapia fingerlings. Large numbers of tilapia fry suitable for sex inversion can be produced by periodic complete harvest of earthen reproduction ponds. Traditionally, harvest interval was...

Sex differences in coupled knee motions during the transition from non-weight bearing to weight bearing.

PubMed

Shultz, Sandra J; Beynnon, Bruce D; Schmitz, Randy J

2009-06-01

Knee ligament injuries frequently happen when the joint transitions from non-weight bearing (NWB) to weight bearing (WB). To gain insight into the mechanism that produces these injuries, physically active females (N = 41) and males (N = 39) underwent measurement of coupled tibiofemoral joint displacements [anterior tibial translation (ATT) and varus-valgus and internal-external rotations] and neuromuscular responses as the knee transitioned from NWB to WB in response to a 40% body weight load applied under the control of gravity. The transition from NWB to WB produced no difference in ATT between males and females; however, significant sex-based differences were noted for both transverse and frontal plane knee motions. With the knee NWB, females were in a greater absolute valgus compared to males (6.6 vs. 5.0 degrees), and moved through greater varus motion than males during the transition from NW to WB (2.3 vs. 1.4 degrees), resulting in similar valgus alignment for both sexes at peak WB (4.3 vs. 3.6 degrees). In the transverse plane, the knees of females were positioned in more external rotation compared to males when NWB (1.4 vs. -0.3 degrees), then females externally rotated their knees while males internally rotated their knees during the transition from NWB to WB. This resulted in a 3.4 degrees difference in transverse plane knee position at peak WB (2.3 vs. -1.1 degrees). Our findings suggest that the coupled knee motions produced during the transition from NWB to WB are sex dependent, and may provide insight into the knee motion patterns that place females at increased risk of knee ligament injury. Copyright 2008 Orthopaedic Research Society

Female voice communications in high levels of aircraft cockpit noises--Part I: spectra, levels, and microphones.

PubMed

Nixon, C W; Morris, L J; McCavitt, A R; McKinley, R L; Anderson, T R; McDaniel, M P; Yeager, D G

1998-07-01

Female produced speech, although more intelligible than male speech in some noise spectra, may be more vulnerable to degradation by high levels of some military aircraft cockpit noises. The acoustic features of female speech are higher in frequency, lower in power, and appear more susceptible than male speech to masking by some of these military noises. Current military aircraft voice communication systems were optimized for the male voice and may not adequately accommodate the female voice in these high level noises. This applied study investigated the intelligibility of female and male speech produced in the noise spectra of four military aircraft cockpits at levels ranging from 95 dB to 115 dB. The experimental subjects used standard flight helmets and headsets, noise-canceling microphones, and military aircraft voice communications systems during the measurements. The intelligibility of female speech was lower than that of male speech for all experimental conditions; however, differences were small and insignificant except at the highest levels of the cockpit noises. Intelligibility for both genders varied with aircraft noise spectrum and level. Speech intelligibility of both genders was acceptable during normal cruise noises of all four aircraft, but improvements are required in the higher levels of noise created during aircraft maximum operating conditions. The intelligibility of female speech was unacceptable at the highest measured noise level of 115 dB and may constitute a problem for other military aviators. The intelligibility degradation due to the noise can be neutralized by use of an available, improved noise-canceling microphone, by the application of current active noise reduction technology to the personal communication equipment, and by the development of a voice communications system to accommodate the speech produced by both female and male aviators.

Hybrid sterility and evolution in Hawaiian Drosophila: differential gene and allele-specific expression analysis of backcross males.

PubMed

Brill, E; Kang, L; Michalak, K; Michalak, P; Price, D K

2016-08-01

The Hawaiian Drosophila are an iconic example of sequential colonization, adaptive radiation and speciation on islands. Genetic and phenotypic analysis of closely related species pairs that exhibit incomplete reproductive isolation can provide insights into the mechanisms of speciation. Drosophila silvestris from Hawai'i Island and Drosophila planitibia from Maui are two closely related allopatric Hawaiian picture-winged Drosophila that produce sterile F1 males but fertile F1 females, a pattern consistent with Haldane's rule. Backcrossing F1 hybrid females between these two species to parental species gives rise to recombinant males with three distinct sperm phenotypes despite a similar genomic background: motile sperm, no sperm (sterile), and immotile sperm. We found that these three reproductive morphologies of backcross hybrid males produce divergent gene expression profiles in testes, as measured with RNA sequencing. There were a total of 71 genes significantly differentially expressed between backcross males with no sperm compared with those backcross males with motile sperm and immotile sperm, but no significant differential gene expression between backcross males with motile sperm and backcross males with immotile sperm. All of these genes were underexpressed in males with no sperm, including a number of genes with previously known activities in adult testis. An allele-specific expression analysis showed overwhelmingly more cis-divergent than trans-divergent genes, with no significant difference in the ratio of cis- and trans-divergent genes among the sperm phenotypes. Overall, the results indicate that the regulation of gene expression involved in sperm production likely diverged relatively rapidly between these two closely related species.

Role of P-450 aromatase in sex determination of the diamondback terrapin, Malaclemys terrapin.

PubMed

Jeyasuria, P; Roosenburg, W M; Place, A R

1994-09-15

Sex determination in the diamondback terrapin, Malaclemys terrapin, is temperature-dependent. Eggs incubated at 31 degrees C, and above, hatch in approximately 45 days as females. Eggs incubated below 27 degrees C hatch in about 60 days as males. Sex is not reversible after hatching. Nest temperatures in the wild can be as low as 20 degrees C and as high as 37 degrees C with as much as a 10 degrees C diel cycle. The shortest incubation time measured in nature was 56 days and the longest approaching 120 days. Nests in our study site produced predominantly (> 95%) male hatchlings. Treatment of developing embryos with estrogen produces females at male producing temperatures while treatment with fadrozole (a nonsteroidal aromatase inhibitor) induces partial male-like gonads. Treatment with a steroidal aromatase inhibitor (4-hydroxyandrostenedione, 4-OHA) had no effect on sex determination. Both fadrozole and 4-OHA are potent competitive inhibitors (Ki approximately 40-50 nM) for terrapin in vitro aromatase activity. These findings are consistent with aromatase expression being a key step in sex determination of terrapins. We have cloned a partial single copy P-450 aromatase from the terrapin using a cDNA library constructed from ovarian mRNA. This partial clone is highly homologous to other vertebrate aromatases.

Epigenetic Control of Gonadal Aromatase (cyp19a1) in Temperature-Dependent Sex Determination of Red-Eared Slider Turtles

PubMed Central

Matsumoto, Yuiko; Buemio, Alvin; Chu, Randy; Vafaee, Mozhgon; Crews, David

2013-01-01

In the red-eared slider turtle (Trachemys scripta), a species with temperature-dependent sex determination (TSD), the expression of the aromatase gene during gonad development is strictly limited to the female-producing temperature. The underlying mechanism remains unknown. In this study, we identified the upstream 5′-flanking region of the aromatase gene, gonad-specific promoter, and the temperature-dependent DNA methylation signatures during gonad development in the red-eared slider turtle. The 5′-flanking region of the slider aromatase exhibited sequence similarities to the aromatase genes of the American alligator, chicken, quail, and zebra finch. A putative TATA box was located 31 bp upstream of the gonad-specific transcription start site. DNA methylation at the CpG sites between the putative binding sites of the fork head domain factor (FOX) and vertebrate steroidogenic factor 1 (SF1) and adjacent TATA box in the promoter region were significantly lower in embryonic gonads at the female-producing temperature compared the male-producing temperature. A shift from male- to female-, but not from female- to male-, producing temperature changed the level of DNA methylation in gonads. Taken together these results indicate that the temperature, particularly female-producing temperature, allows demethylation at the specific CpG sites of the promoter region which leads the temperature-specific expression of aromatase during gonad development. PMID:23762231

Polyandry produces sexy sons at the cost of daughters in red flour beetles.

PubMed Central

Pai, Aditi; Yan, Guiyun

2002-01-01

Female mating with multiple males within a single fertile period is a common phenomenon in the animal kingdom. Female insects are particularly promiscuous. It is not clear why females mate with multiple partners despite several potential costs, such as expenditure of time and energy, reduced lifespan, risk of predation and contracting sexually transmitted diseases. Female red flour beetles (Tribolium castaneum) obtain sufficient sperm from a single insemination to retain fertility for several months. Nonetheless they copulate repeatedly within minutes with different males despite no direct fitness benefits from this behaviour. One hypothesis is that females mate with multiple partners to provide indirect benefits via enhanced offspring fitness. To test this hypothesis, we compared the relative fitness of F(1) offspring from females mated with single males and multiple males (2, 4, 8, or 16 partners), under the condition of relatively high intraspecific competition. We found that a female mating with 16 males enhanced the relative fitness of F(1) males (in two out of three trials) but reduced F(1) females' fitness (in two independent trials) in comparison with singly mated females. We also determined whether several important fitness correlates were affected by polyandry. We found that F(1) males from mothers with 16 partners inseminated more females than F(1) males from mothers with a single partner. The viability of the eggs sired or produced by F(1) males and females from highly polyandrous mothers was also increased under conditions of low intra-specific competition. Thus, the effects of polyandry on F(1) offspring fitness depend on environmental conditions. Our results demonstrated a fitness trade-off between male and female offspring from polyandrous mothers in a competitive environment. The mechanisms and biological significance of this unique phenomenon are discussed. PMID:11886623

Polyandry produces sexy sons at the cost of daughters in red flour beetles.

PubMed

Pai, Aditi; Yan, Guiyun

2002-02-22

Female mating with multiple males within a single fertile period is a common phenomenon in the animal kingdom. Female insects are particularly promiscuous. It is not clear why females mate with multiple partners despite several potential costs, such as expenditure of time and energy, reduced lifespan, risk of predation and contracting sexually transmitted diseases. Female red flour beetles (Tribolium castaneum) obtain sufficient sperm from a single insemination to retain fertility for several months. Nonetheless they copulate repeatedly within minutes with different males despite no direct fitness benefits from this behaviour. One hypothesis is that females mate with multiple partners to provide indirect benefits via enhanced offspring fitness. To test this hypothesis, we compared the relative fitness of F(1) offspring from females mated with single males and multiple males (2, 4, 8, or 16 partners), under the condition of relatively high intraspecific competition. We found that a female mating with 16 males enhanced the relative fitness of F(1) males (in two out of three trials) but reduced F(1) females' fitness (in two independent trials) in comparison with singly mated females. We also determined whether several important fitness correlates were affected by polyandry. We found that F(1) males from mothers with 16 partners inseminated more females than F(1) males from mothers with a single partner. The viability of the eggs sired or produced by F(1) males and females from highly polyandrous mothers was also increased under conditions of low intra-specific competition. Thus, the effects of polyandry on F(1) offspring fitness depend on environmental conditions. Our results demonstrated a fitness trade-off between male and female offspring from polyandrous mothers in a competitive environment. The mechanisms and biological significance of this unique phenomenon are discussed.

Antennally mediated negative feedback regulation of pheromone production in the pine engraver beetle, Ips pini

NASA Astrophysics Data System (ADS)

Ginzel, Matthew D.; Bearfield, Jeremy C.; Keeling, Christopher I.; McCormack, Colin C.; Blomquist, Gary J.; Tittiger, Claus

2007-01-01

Bark beetles use monoterpenoid aggregation pheromones to coordinate host colonization and mating. These chemical signals are produced de novo in midgut cells via the mevalonate pathway, and pheromone production may be regulated by a negative feedback system mediated through the antennae. In this study, we explored the effect of antennectomy on pheromone production and transcript levels of key mevalonate pathway genes in juvenile hormone III-treated male pine engraver beetles, Ips pini (Say). Antennectomized males produced significantly greater amounts of pheromone than podectomized males and those with intact antennae. Likewise, mRNA levels of three mevalonate pathway genes important in pheromone biosynthesis were measured by quantitative real-time PCR and found to be induced to a greater extent with antennectomy, suggesting a transcriptional regulation of pheromone production.

Occupational Segregation by Sex: Trends and Prospects.

ERIC Educational Resources Information Center

Blau, Francine D.; Hendricks, Wallace E.

1979-01-01

Investigates postwar trends in occupational segregation. Finds segregation increased slightly between 1950-60 as predominantly female clerical/professional jobs increased. Occupation mix changes (1960-70) were neutral in impact, but male inflow into female professions and female inflow into male sales/clerical jobs produced modest segregation…

Molecular mapping of two environmentally sensitive male-sterile mutants in soybean

USDA-ARS?s Scientific Manuscript database

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, two environmentally sensi...

Of mice and men (and mosquitofish): Antiandrogens and androgens in the environment

EPA Science Inventory

Androgens are hormones produced by the gonads and other endocrine organs of all vertebrates. Testosterone, along with its metabolite dihydrotestosterone, is critical for differentiation of the fetal male reproductive tract from an indifferent state, for the development of male tr...

Caenorhabditis elegans Male Copulation Circuitry Incorporates Sex-Shared Defecation Components To Promote Intromission and Sperm Transfer

PubMed Central

LeBoeuf, Brigitte; Garcia, L. Rene

2016-01-01

Sexual dimorphism can be achieved using a variety of mechanisms, including sex-specific circuits and sex-specific function of shared circuits, though how these work together to produce sexually dimorphic behaviors requires further investigation. Here, we explore how components of the sex-shared defecation circuitry are incorporated into the sex-specific male mating circuitry in Caenorhabditis elegans to produce successful copulation. Using behavioral studies, calcium imaging, and genetic manipulation, we show that aspects of the defecation system are coopted by the male copulatory circuitry to facilitate intromission and ejaculation. Similar to hermaphrodites, male defecation is initiated by an intestinal calcium wave, but circuit activity is coordinated differently during mating. In hermaphrodites, the tail neuron DVB promotes expulsion of gut contents through the release of the neurotransmitter GABA onto the anal depressor muscle. However, in the male, both neuron and muscle take on modified functions to promote successful copulation. Males require calcium-dependent activator protein for secretion (CAPS)/unc-31, a dense core vesicle exocytosis activator protein, in the DVB to regulate copulatory spicule insertion, while the anal depressor is remodeled to promote release of sperm into the hermaphrodite. This work shows how sex-shared circuitry is modified in multiple ways to contribute to sex-specific mating. PMID:28031243

Demographic analysis of arrhenotokous parthenogenesis and bisexual reproduction of Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae).

PubMed

Ding, Tianbo; Chi, Hsin; Gökçe, Ayhan; Gao, Yulin; Zhang, Bin

2018-02-20

Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) is a serious pest that is capable of bisexual and arrhenotokous reproduction. In arrhenotokous reproduction, virgin females initially produce male offspring; later, when their sons are sexually mature, the mothers begin bisexual reproduction by carrying out oedipal mating with their sons. Because a virgin female produces many male offspring before oedipal mating occurs, multiple oedipal mating is common. In this study, we investigated the effect of multiple oedipal mating on the population growth of F. occidentalis by using the age-stage, two-sex life table theory. In the arrhenotokous cohorts, all unfertilized eggs developed into males. In the bisexual cohorts, the offspring sex ratio was significantly female biased with the mean number of female offspring and male offspring being 72.68 and 29.00, respectively. These were the same as the net reproductive rate of female offspring and male offspring. In arrhenotokous cohorts, the number of males available for oedipal mating significantly affected the production of female offspring. The number of female offspring increased as the number of sons available for oedipal mating increased. Correctly characterizing this unique type of reproduction will provide important information for predicting the timing of future outbreaks of F. occidentalis, as well as aiding in formulating successful management strategies against the species.

Using plain language skills to create an educational brochure about sperm banking for adolescent and young adult males with cancer.

PubMed

Nagel, Kim; Wizowski, Lindsay; Duckworth, JoAnn; Cassano, Jane; Hahn, Shirley Ann; Neal, Michael

2008-01-01

Writing in plain language makes it easier for patients to read, understand, and make informed decisions about sperm banking. Greater attention to the issue and properly designed educational brochures for use by nurses in oncology and reproductive health is of evident importance but of unknown impact. A multidisciplinary clinical team followed an evidence-based, patient-centered approach to develop "plain language" patient education materials about sperm banking for adolescent and young adult (AYA) males with cancer. A patient education booklet was produced and implemented as part of the planned patient education for AYA male oncology patients at McMaster Children's Hospital, Hamilton Health Sciences, in Hamilton, Ontario, Canada. The patient education booklet for use by health professionals as a teaching tool to facilitate discussion with AYA males has been produced with the hope that it will contribute to better informed decision making regarding sperm banking and increased use of this technology for fertility preservation.

Moths behaving like butterflies. Evolutionary loss of long range attractant pheromones in castniid moths: a Paysandisia archon model.

PubMed

Sarto i Monteys, Víctor; Acín, Patricia; Rosell, Glòria; Quero, Carmen; Jiménez, Miquel A; Guerrero, Angel

2012-01-01

In the course of evolution butterflies and moths developed two different reproductive behaviors. Whereas butterflies rely on visual stimuli for mate location, moths use the 'female calling plus male seduction' system, in which females release long-range sex pheromones to attract conspecific males. There are few exceptions from this pattern but in all cases known female moths possess sex pheromone glands which apparently have been lost in female butterflies. In the day-flying moth family Castniidae ("butterfly-moths"), which includes some important crop pests, no pheromones have been found so far. Using a multidisciplinary approach we described the steps involved in the courtship of P. archon, showing that visual cues are the only ones used for mate location; showed that the morphology and fine structure of the antennae of this moth are strikingly similar to those of butterflies, with male sensilla apparently not suited to detect female-released long range pheromones; showed that its females lack pheromone-producing glands, and identified three compounds as putative male sex pheromone (MSP) components of P. archon, released from the proximal halves of male forewings and hindwings. This study provides evidence for the first time in Lepidoptera that females of a moth do not produce any pheromone to attract males, and that mate location is achieved only visually by patrolling males, which may release a pheromone at short distance, putatively a mixture of Z,E-farnesal, E,E-farnesal, and (E,Z)-2,13-octadecadienol. The outlined behavior, long thought to be unique to butterflies, is likely to be widespread in Castniidae implying a novel, unparalleled butterfly-like reproductive behavior in moths. This will also have practical implications in applied entomology since it signifies that the monitoring/control of castniid pests should not be based on the use of female-produced pheromones, as it is usually done in many moths.

Ultrasonic Songs of Male Mice

PubMed Central

Guo, Zhongsheng

2005-01-01

Previously it was shown that male mice, when they encounter female mice or their pheromones, emit ultrasonic vocalizations with frequencies ranging over 30–110 kHz. Here, we show that these vocalizations have the characteristics of song, consisting of several different syllable types, whose temporal sequencing includes the utterance of repeated phrases. Individual males produce songs with characteristic syllabic and temporal structure. This study provides a quantitative initial description of male mouse songs, and opens the possibility of studying song production and perception in an established genetic model organism. PMID:16248680

Female preferences drive the evolution of mimetic accuracy in male sexual displays.

PubMed

Coleman, Seth William; Patricelli, Gail Lisa; Coyle, Brian; Siani, Jennifer; Borgia, Gerald

2007-10-22

Males in many bird species mimic the vocalizations of other species during sexual displays, but the evolutionary and functional significance of interspecific vocal mimicry is unclear. Here we use spectrographic cross-correlation to compare mimetic calls produced by male satin bowerbirds (Ptilonorhynchus violaceus) in courtship with calls from several model species. We show that the accuracy of vocal mimicry and the number of model species mimicked are both independently related to male mating success. Multivariate analyses revealed that these mimetic traits were better predictors of male mating success than other male display traits previously shown to be important for male mating success. We suggest that preference-driven mimetic accuracy may be a widespread occurrence, and that mimetic accuracy may provide females with important information about male quality. Our findings support an alternative hypothesis to help explain a common element of male sexual displays.

Sex-role reversed nuptial feeding reduces male kleptoparasitism of females in Zeus bugs (Heteroptera; Veliidae)

PubMed Central

Arnqvist, Göran; Jones, Therésa M; Elgar, Mark A

2006-01-01

Males of a variety of taxa occasionally steal food secured by their mates. In some spiders and insects, males rely entirely on this form of intraspecific kleptoparasitism for their subsistence. However, this male strategy may be costly for females and a variety of different female counteradaptations have been proposed. In Zeus bugs (Phoreticovelia spp.), males ride on the back of their mates for extended periods and females produce a gland secretion that males feed on. By experimentally occluding the dorsal glands in females and varying food availability, we show that nuptial feeding by females reduces the extent to which the males kleptoparasitize their mates. We suggest that females have, at least in part, evolved this unique form of nuptial feeding as a counteradaptation to reduce the rate of kleptoparasitism by males. PMID:17148270

Maternal effects on male weaponry: female dung beetles produce major sons with longer horns when they perceive higher population density

PubMed Central

2012-01-01

Background Maternal effects are environmental influences on the phenotype of one individual that are due to the expression of genes in its mother, and are expected to evolve whenever females are better capable of assessing the environmental conditions that their offspring will experience than the offspring themselves. In the dung beetle Onthophagus taurus, conditional male dimorphism is associated with alternative reproductive tactics: majors fight and guard females whereas minors sneak copulations. Furthermore, variation in dung beetle population density has different fitness consequences for each male morph, and theory predicts that higher population density might select for a higher frequency of minors and/or greater expenditure on weaponry in majors. Because adult dung beetles provide offspring with all the nutritional resources for their development, maternal effects strongly influence male phenotype. Results Here we tested whether female O. taurus are capable of perceiving population density, and responding by changing the phenotype of their offspring. We found that mothers who were reared with other conspecifics in their pre-mating period produced major offspring that had longer horns across a wider range of body sizes than the major offspring of females that were reared in isolation in their pre-mating period. Moreover, our results indicate that this maternal effect on male weaponry does not operate through the amount of dung provided by females to their offspring, but is rather transmitted through egg or brood mass composition. Finally, although theory predicts that females experiencing higher density might produce more minor males, we found no support for this, rather the best fitting models were equivocal as to whether fewer or the same proportions of minors were produced. Conclusions Our study describes a new type of maternal effect in dung beetles, which probably allows females to respond to population density adaptively, preparing at least their major offspring for the sexual competition they will face in the future. This new type of maternal effect in dung beetles represents a novel transgenerational response of alternative reproductive tactics to population density. PMID:22823456

Maternal effects on male weaponry: female dung beetles produce major sons with longer horns when they perceive higher population density.

PubMed

Buzatto, Bruno A; Tomkins, Joseph L; Simmons, Leigh W

2012-07-23

Maternal effects are environmental influences on the phenotype of one individual that are due to the expression of genes in its mother, and are expected to evolve whenever females are better capable of assessing the environmental conditions that their offspring will experience than the offspring themselves. In the dung beetle Onthophagus taurus, conditional male dimorphism is associated with alternative reproductive tactics: majors fight and guard females whereas minors sneak copulations. Furthermore, variation in dung beetle population density has different fitness consequences for each male morph, and theory predicts that higher population density might select for a higher frequency of minors and/or greater expenditure on weaponry in majors. Because adult dung beetles provide offspring with all the nutritional resources for their development, maternal effects strongly influence male phenotype. Here we tested whether female O. taurus are capable of perceiving population density, and responding by changing the phenotype of their offspring. We found that mothers who were reared with other conspecifics in their pre-mating period produced major offspring that had longer horns across a wider range of body sizes than the major offspring of females that were reared in isolation in their pre-mating period. Moreover, our results indicate that this maternal effect on male weaponry does not operate through the amount of dung provided by females to their offspring, but is rather transmitted through egg or brood mass composition. Finally, although theory predicts that females experiencing higher density might produce more minor males, we found no support for this, rather the best fitting models were equivocal as to whether fewer or the same proportions of minors were produced. Our study describes a new type of maternal effect in dung beetles, which probably allows females to respond to population density adaptively, preparing at least their major offspring for the sexual competition they will face in the future. This new type of maternal effect in dung beetles represents a novel transgenerational response of alternative reproductive tactics to population density.

Sound-Triggered Production of Antiaggregation Pheromone Limits Overcrowding of Dendroctonus valens Attacking Pine Trees.

PubMed

Liu, Zhudong; Xin, Yucui; Xu, Bingbing; Raffa, Kenneth F; Sun, Jianghua

2017-01-01

For insects that aggregate on host plants, both attraction and antiaggregation among conspecifics can be important mechanisms for overcoming host resistance and avoiding overcrowding, respectively. These mechanisms can involve multiple sensory modalities, such as sound and pheromones. We explored how acoustic and chemical signals are integrated by the bark beetle Dendroctonus valens to limit aggregation in China. In its native North American range, this insect conducts nonlethal attacks on weakened trees at very low densities, but in its introduced zone in China, it uses mixtures of host tree compounds and the pheromone component frontalin to mass attack healthy trees. We found that exo-brevicomin was produced by both female and male D. valens, and that this pheromone functioned as an antiaggregating signal. Moreover, beetles feeding in pairs or in masses were more likely than were beetles feeding alone to produce exo-brevicomin, suggesting a potential role of sound by neighboring beetles in stimulating exo-brevicomin production. Sound playback showed that an agreement sound was produced by both sexes when exposed to the aggregation pheromone frontalin and attracts males, and an aggressive sound was produced only by males behaving territorially. These signals triggered the release of exo-brevicomin by both females and males, indicating an interplay of chemical and sonic communication. This study demonstrates that the bark beetle D. valens uses sounds to regulate the production of an antiaggregation pheromone, which may provide new approaches to pest management of this invasive species. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Sex-dependent components of the analgesia produced by athletic competition.

PubMed

Sternberg, W F; Bokat, C; Kass, L; Alboyadjian, A; Gracely, R H

2001-02-01

Competing in various athletic events (track meet, basketball game, or fencing match) can produce analgesia to cold pressor stimuli in male and female college athletes compared with baseline assessments. This competition-induced analgesia has been attributed to the stress associated with competition, which has components related to both physical exercise and the cognitive aspects of competing. This study evaluated the analgesic effect of exercise-related stress, and that caused by the cognitively stressful components of competing independent of exercise. Cold pressor pain ratings were assessed after competition in a track meet and after treadmill exercise or sedentary video game competition in both athletes and nonathletes. As expected, competing in athletics resulted in a decrease in cold pressor ratings in both male and female athletes. Independent of athletic status, treadmill running induced analgesia in women, but not in males, whereas sedentary video game competition produced analgesia in men, but not in women. These findings suggest that different components of the competitive athletic experience might be responsible for the analgesic effects in a sex-dependent manner.

A male-produced aggregation pheromone of Monochamus alternatus (Coleoptera: Cerambycidae), a major vector of pine wood nematode.

PubMed

Teale, Stephen A; Wickham, Jacob D; Zhang, Feiping; Su, Jun; Chen, Yi; Xiao, Wei; Hanks, Lawrence M; Millar, Jocelyn G

2011-10-01

The beetle Monochamus alternatus Hope (Coleoptera: Cerambycidae) is an efficient vector of pine wood nematode, the causal pathogen of pine wilt disease, that has resulted in devastating losses of pines in much of Asia. We assessed the response of adult M. alternatus to 2-(undecyloxy)-ethanol, the male-produced pheromone of the congeneric M. galloprovincialis Dejean, in field experiments in Fujian Province, People's Republic of China. Both sexes of M. alternatus were attracted to lures consisting of 2-(undecyloxy)-ethanol combined with the host plant volatiles alpha-pinene and ethanol. A follow-up experiment showed that 2-(undecyloxy)-ethanol was synergized by both ethanol and alpha-pinene. Coupled gas-chromatography mass-spectrometry analyses of volatiles sampled from field-collected beetles of both sexes revealed that 2-(undecyloxy)-ethanol was a sex-specific pheromone component produced only by males. The combination of 2- (undecyloxy) -ethanol with ethanol and/or alpha-pinene will provide a valuable and badly needed tool for quarantine detection, monitoring, and management of M. alternatus.

Identification of the sex pheromone of Lutzomyia longipalpis (Lutz & Neiva, 1912) (Diptera: Psychodidae) from Asunción, Paraguay.

PubMed

Brazil, Reginaldo P; Caballero, Norath Natalia; Hamilton, James Gordon C

2009-11-02

The sand fly Lutzomyia longipalpis is the main vector of Leishmania (L.) infantum (Nicolle), the causative agent of American visceral leishmaniasis (AVL) in the New World. Male Lu. longipalpis have secretory glands which produce sex pheromones in either abdominal tergites 4 or 3 and 4. These glands are sites of sex pheromone production and each pheromone type may represent true sibling species. In Latin America, apart from Lu. pseudolongipalpis Arrivillaga and Feliciangeli from Venezuela, populations of Lu. longipalpis s.l. can be identified by their male-produced sex pheromones: (S)-9-methylgermacrene-B, 3-methyl-alpha-himachalene and the two cembrenes, 1 and 2.In this study, we present the results of a coupled gas chromatography - mass spectrometry analysis of the pheromones of males Lu. longipalpis captured in an endemic area of visceral leishmaniasis in Asunción, Paraguay. Our results show that Lu. longipalpis from this site produce (S)-9-methylgermacrene-B which has also been found in Lu. longipalpis from different areas of Brazil, Colombia and Central America.

Sex-biased dispersal creates spatial genetic structure in a parthenogenetic ant with a dependent-lineage reproductive system.

PubMed

Kuhn, A; Bauman, D; Darras, H; Aron, S

2017-10-01

Reproduction and dispersal are key aspects of species life history that influence spatial genetic structure in populations. Several ant species in the genus Cataglyphis have evolved a unique breeding system in which new reproductives (that is, queens and males) are produced asexually by parthenogenesis; in contrast, non-reproductives (that is, workers) are produced via sexual reproduction by mates from distinct genetic lineages. We investigated how these two coexisting reproductive methods affect population-level spatial genetic structure using the ant Cataglyphis mauritanica as a model. We obtained genotypes for queens and their male mates from 338 colonies, and we found that the two lineages present in the study population occurred with equal frequency. Furthermore, analysis of spatial genetic structure revealed strong sex-biased dispersal. Because queens were produced by parthenogenesis and because they dispersed over short distances, there was an extreme level of spatial structuring: a mosaic of patches composed of clonal queens was formed. Males, on the other hand, dispersed over several hundred metres and, thus, across patches, ensuring successful interlineage mating.

Identification of the sex pheromone of Lutzomyia longipalpis (Lutz & Neiva, 1912) (Diptera: Psychodidae) from Asunción, Paraguay

PubMed Central

Brazil, Reginaldo P; Caballero, Norath Natalia; Hamilton, James Gordon C

2009-01-01

The sand fly Lutzomyia longipalpis is the main vector of Leishmania (L.) infantum (Nicolle), the causative agent of American visceral leishmaniasis (AVL) in the New World. Male Lu. longipalpis have secretory glands which produce sex pheromones in either abdominal tergites 4 or 3 and 4. These glands are sites of sex pheromone production and each pheromone type may represent true sibling species. In Latin America, apart from Lu. pseudolongipalpis Arrivillaga and Feliciangeli from Venezuela, populations of Lu. longipalpis s.l. can be identified by their male-produced sex pheromones: (S)-9-methylgermacrene-B, 3-methyl-α-himachalene and the two cembrenes, 1 and 2. In this study, we present the results of a coupled gas chromatography - mass spectrometry analysis of the pheromones of males Lu. longipalpis captured in an endemic area of visceral leishmaniasis in Asunción, Paraguay. Our results show that Lu. longipalpis from this site produce (S)-9-methylgermacrene-B which has also been found in Lu. longipalpis from different areas of Brazil, Colombia and Central America. PMID:19883505

Body size and symbiotic status influence gonad development in Aiptasia pallida anemones.

PubMed

Carlisle, Judith F; Murphy, Grant K; Roark, Alison M

2017-01-01

Pale anemones ( Aiptasia pallida ) coexist with dinoflagellates (primarily Symbiodinium minutum ) in a mutualistic relationship. The purpose of this study was to investigate the role of these symbionts in gonad development of anemone hosts. Symbiotic and aposymbiotic anemones were subjected to light cycles that induced gametogenesis. These anemones were then sampled weekly for nine weeks, and gonad development was analyzed histologically. Anemone size was measured as mean body column diameter, and oocytes or sperm follicles were counted for each anemone. Generalized linear models were used to evaluate the influence of body size and symbiotic status on whether gonads were present and on the number of oocytes or sperm follicles produced. Body size predicted whether gonads were present, with larger anemones being more likely than smaller anemones to develop gonads. Both body size and symbiotic status predicted gonad size, such that larger and symbiotic anemones produced more oocytes and sperm follicles than smaller and aposymbiotic anemones. Overall, only 22 % of aposymbiotic females produced oocytes, whereas 63 % of symbiotic females produced oocytes. Similarly, 6 % of aposymbiotic males produced sperm follicles, whereas 60 % of symbiotic males produced sperm follicles. Thus, while gonads were present in 62 % of symbiotic anemones, they were present in only 11 % of aposymbiotic anemones. These results indicate that dinoflagellate symbionts influence gonad development and thus sexual maturation in both female and male Aiptasia pallida anemones. This finding substantiates and expands our current understanding of the importance of symbionts in the development and physiology of cnidarian hosts.

Methylmercury chloride and selenomethionine interactions on health and reproduction in mallards

USGS Publications Warehouse

Heinz, G.H.; Hoffman, D.J.

1998-01-01

Adult mallards (Anas platyrhynchos) were fed a control diet or diets containing 10 ppm mercury as methylmercury chloride, 10 ppm selenium as seleno-DL-methionine, or 10 ppm mercury plus 10 ppm selenium. One of 12 adult males fed 10 ppm mercury died and 8 others suffered from paralysis of their legs by the time the study was terminated. However, when the diet contained 10 ppm selenium in addition to the 10 ppm mercury, none of 12 males became sick. In contrast to the protective effect of selenium against mercury poisoning in males, selenium plus mercury was worse than selenium or mercury alone for some measurements of reproductive success. Both selenium and mercury lowered duckling production through reductions in hatching success and survival of ducklings, but the combination of mercury plus selenium was worse than either mercury or selenium alone. Controls produced an average of 7.6 young per female, females fed 10 ppm selenium produced an average of 2.8 young, females fed 10 ppm mercury produced 1.1 young, and females fed both mercury and selenium produced 0.2 young. Teratogenic effects also were worse for the combined mercury plus selenium treatment; deformities were recorded in 6.1% of the embryos of controls, 16.4% for methylmercury chloride, 36.2% for selenomethionine, and 73.4% for the combination of methylmercury chloride and selenomethionine. The presence of methylmercury in the diet greatly enhanced the storage of selenium in tissues. The livers of males fed 10 ppm selenium contained a mean of 9.6 ppm selenium, whereas the livers of males fed 10 ppm selenium plus 10 ppm mercury contained a mean of 114 ppm selenium. However, selenium did not enhance the storage of mercury. The results show that mercury and selenium may be antagonistic to each other for adults and synergistic to young, even within the same experiment.

Auditory neural networks involved in attention modulation prefer biologically significant sounds and exhibit sexual dimorphism in anurans.

PubMed

Xue, Fei; Yue, Xizi; Fan, Yanzhu; Cui, Jianguo; Brauth, Steven E; Tang, Yezhong; Fang, Guangzhan

2018-03-09

Allocating attention to biologically relevant stimuli in a complex environment is critically important for survival and reproductive success. In humans, attention modulation is regulated by the frontal cortex, and is often reflected by changes in specific components of the event-related potential (ERP). Although brain networks for attention modulation have been widely studied in primates and avian species, little is known about attention modulation in amphibians. The present study aimed to investigate the attention modulation networks in an anuran species, the Emei music frog ( Babina daunchina ). Male music frogs produce advertisement calls from within underground nest burrows that modify the acoustic features of the calls, and both males and females prefer calls produced from inside burrows. We broadcast call stimuli to male and female music frogs while simultaneously recording electroencephalographic (EEG) signals from the telencephalon and mesencephalon. Granger causal connectivity analysis was used to elucidate functional brain networks within the time window of ERP components. The results show that calls produced from inside nests which are highly sexually attractive result in the strongest brain connections; both ascending and descending connections involving the left telencephalon were stronger in males while those in females were stronger with the right telencephalon. Our findings indicate that the frog brain allocates neural attention resources to highly attractive sounds within the window of early components of ERP, and that such processing is sexually dimorphic, presumably reflecting the different reproductive strategies of males and females. © 2018. Published by The Company of Biologists Ltd.

Motile Sperm Output by Male Cheetahs (Acinonyx jubatus) Managed Ex Situ Is Influenced by Public Exposure and Number of Care-Givers.

PubMed

Koester, Diana C; Freeman, Elizabeth W; Brown, Janine L; Wildt, David E; Terrell, Kimberly A; Franklin, Ashley D; Crosier, Adrienne E

2015-01-01

The collective cheetah (Acinonyx jubatus) population in zoological institutions has never been self-sustaining because of challenges in natural reproduction. A retrospective analysis of North American zoo-breeding records has revealed that >90% of litters produced since 2003 occurred in facilities 'off-display' from the public. We examined seminal, endocrine, and behavioral traits of 29 adult male cheetahs that were: 1) managed in public exhibit or off-display facilities; 2) maintained by different numbers of cheetah-specific care-givers; and 3) living adjacent to varying numbers of adult conspecifics. Cheetahs housed off-display produced more total motile sperm/ejaculate (P = 0.04) than on-exhibit males. This finding was mirrored in our laboratory's historical records where two-fold more total motile sperm (P < 0.01) were measured in ejaculates from individuals with no public exposure (n = 43) compared to on-exhibit (n = 116) counterparts. Males at institutions with ≤3 care-givers also produced more total motile sperm/ejaculate (P < 0.03) and spent more time behaviorally active (P < 0.01) than at facilities using >3 care-givers. Exposure to high numbers of conspecifics within the same institution did not impact (P > 0.05) seminal traits, and presence of the public, care-giver number, or animals/facility had no influence (P > 0.05) on androgen or glucocorticoid excretion or other behavioral metrics. Findings indicate that male cheetahs are sensitive to general public exposure and too many care-givers, resulting in compromised motile sperm output/ejaculate with mechanism of action unrelated to altered androgen or glucocorticoid excretion.

Paroxetine exposure skews litter sex ratios in mice suggesting a Trivers–Willard process

PubMed Central

Gaukler, Shannon Marie; Ruff, James Steven; Potts, Wayne K.

2016-01-01

While conducting a toxicity assessment of the antidepressant paroxetine (Paxil®), in wild-derived mice (Mus musculus), we observed that exposed dams (P0) produced female biased litters (32:68 M:F). Though numerous experimental manipulations have induced sex ratio bias in mice, none have assessed the fitness of the offspring from these litters relative to controls. Here, we retrospectively analyze experimentally derived fitness data gathered for the purpose of toxicological assessment in light of 2 leading hypothesis (Trivers–Willard hypothesis [TWH] and cost of reproduction hypothesis [CRH]), seeking to test if this facultative sex ratio adjustment fits into an adaptive framework. Control F1 males were heavier than F1 females, but no differences in mass were detected between exposed F1 males and females, suggesting that exposed dams did not save energy by producing fewer males, despite producing 29.2% lighter litters relative to controls. F1 offspring of both treatments were released into seminatural enclosures where fitness was quantified. In enclosures, the relative reproductive success of F1-exposed males (compared with controls) was reduced by ~20% compared with the relative reproductive success of F1-exposed females. Thus, exposed dams increased their fitness by adjusting litters toward females who were less negatively affected by the exposure than males. Collectively, these data provide less support that the observed sex ratio bias results in energetic savings (CRH), and more support for the TWH because fitness was increased by biasing litters toward female offspring. These mammalian data are unique in their ability to support the TWH through the use of relevant fitness data. PMID:27418753

Integrative omics analysis reveals differentially distributed proteins in dimorphic euspermatozoa of the squid, Loligo bleekeri.

PubMed

Yoshida, Masa-aki; Yamada, Lixy; Ochi, Hiroe; Iwata, Yoko; Tamura-Nakano, Miwa; Sawada, Hitoshi; Sauer, Warwick H H; Ogura, Atsushi; Hirohashi, Noritaka

2014-08-01

In the coastal squid Loligo bleekeri, each male produces one of two types of fertilization-competent spermatozoa (eusperm) that exhibit morphological and behavioral differences. Large "consort" males produce short-tailed spermatozoa that display free-swimming behavior when ejaculated into seawater. Small "sneaker" males, on the other hand, produce long-tailed spermatozoa that exhibit a self-swarming trait after ejaculation. To understand the molecular basis for adaptive traits employed by alternative male mating tactics, we performed the transcriptome deep sequencing (RNA-seq) and proteome analyses to search for differences in testicular mRNAs and sperm proteins, respectively. From mature male testes we identified a total of 236,455 contigs (FPKM ≧1) where 3789 and 2789 were preferentially (≧10-fold) expressed in consort and sneaker testes, respectively. A proteomic analysis detected 4302 proteins in the mature sperm as post-translational products. A strongly biased (≧10-fold) distribution occurred in 55 consort proteins and 61 sneaker proteins. There was no clear mRNA-protein correlation, making a ballpark estimate impossible for not only overall protein abundance but also the degree of biased sperm type expressed in the spermatozoa. A family encoding dynein heavy chain gene, however, was found to be biased towards sneakers, whereas many enzymes involving energy metabolism were heavily biased towards consort spermatozoa. The difference in flagellar length matched exactly the different amount of tubulins. From these results we hypothesize that discrete differential traits in dimorphic eusperm arose from a series of innovative alterations in the intracellular components of spermatozoa. Copyright © 2014 Elsevier Inc. All rights reserved.

Functional analysis of sex-determination genes by gene silencing with LNA-DNA gapmers in the silkworm, Bombyx mori.

PubMed

Sakai, Hiroki; Sakaguchi, Honami; Aoki, Fugaku; Suzuki, Masataka G

2015-08-01

The sexual fate of B. mori is determined genetically; ZW, female and ZZ, male. Recently, we successfully identified a strong candidate gene at the top of the sex determination cascade in B. mori. This gene was termed Feminizer (Fem) and revealed to be a source of Fem-piRNA. Further, we found that B. mori doublesex (Bmdsx) splicing was markedly altered to produce the male-type isoform when a Fem-piRNA inhibitor was injected into ZW embryos. Moreover, knockdown of Masculinizer (Masc), a Fem-piRNA target gene, altered to produce the female-type isoform of Bmdsx in male embryos. However, it remains unclear as to whether Masc directly regulates the sex-specific expression of Bmdsx. In previous studies, we determined that the male-specific isoform of the Bombyx homolog of IGF-II mRNA-binding protein (Imp(M)) was involved in the male-specific splicing of Bmdsx. In an attempt to clarify the genetic relationship between Fem, Masc, Imp(M), and Bmdsx, knockdown experiments were performed. Knockdown of Fem shifted into male-type Bmdsx, Imp(M) and Masc in female embryos. Knockdown of Masc led to the production of the female-type Bmdsx and a dramatic reduction in Imp(M) expression in male embryos. Knockdown of Imp(M) shifted Bmdsx splice mode from the male-type into the female-type. Our results suggest that: (1) Fem reduces Masc expression, (2) Masc dramatically induces Imp(M) expression, and (3) Imp(M) shifting Bmdsx splice mode from the female-type into the male-type. Based on these findings, we propose a possible genetic cascade regulating sex determination in B. mori. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Impact of male condition on his spermatophore and consequences for female reproductive performance in the Glanville fritillary butterfly.

PubMed

Duplouy, Anne; Woestmann, Luisa; Gallego Zamorano, Juan; Saastamoinen, Marjo

2018-04-01

In butterflies, male reproductive success is highly related to the quality and the size of the spermatophore transferred to the female. The spermatophore is a capsule produced by the male during copulation, which in many species contains sperm in addition to a nuptial gift, and which is digested by the female after copulation. The nuptial gift may contribute to egg production and offspring quality, and in some cases also to female body maintenance. The production of the spermatophore, however, represents a cost for the male and, in polyandrous species, ejaculates are sometimes allocated adaptively across matings. Nonetheless, although the ecological factors affecting the reproductive success of female butterflies have been the topic of numerous studies, little information exists on the factors affecting males' contribution to reproduction, and the indirect impacts on female fecundity and fitness. We used the Glanville fritillary butterfly, Melitaea cinxia (Linnaeus, 1758) (Nymphalidae), in order to assess variation in male allocation to matings. In this species, smaller males produce smaller spermatophores, but variation in spermatophore size is not correlated with female reproductive success. We show that spermatophore size increases with male age at first mating, decreases with mating frequency and adult food-deprivation, and is not influenced by developmental food-limitation. The length of copulation period does not influence the spermatophore size nor influences the polyandrous mating behavior in this species. Male contribution to his spermatophore size is clearly influenced by his condition and adult-resource at the time of mating. Despite this variation, spermatophore size does not seem to have a direct impact on female reproductive output or mating behavior. © 2016 The Authors Insect Science published by Wiley Publishing Asia Pty Ltd on behalf of Institute of Zoology, Chinese Academy of Sciences.

Haldane’s Rule Is Linked to Extraordinary Sex Ratios and Sperm Length in Stalk-Eyed Flies

PubMed Central

Wilkinson, Gerald S.; Christianson, Sarah J.; Brand, Cara L.; Ru, George; Shell, Wyatt

2014-01-01

We use three allopatric populations of the stalk-eyed fly Teleopsis dalmanni from Southeast Asia to test two predictions made by the sex chromosome drive hypothesis for Haldane’s rule. The first is that modifiers that suppress or enhance drive should evolve rapidly and independently in isolated populations. The second is that drive loci or modifiers should also cause sterility in hybrid males. We tested these predictions by assaying the fertility of 2066 males derived from backcross experiments involving two pairs of populations and found that the proportion of mated males that fail to produce any offspring ranged from 38 to 60% among crosses with some males producing strongly female-biased or male-biased sex ratios. After genotyping each male at 25–28 genetic markers we found quantitative trait loci (QTL) that jointly influence male sterility, sperm length, and biased progeny sex ratios in each pair of populations, but almost no shared QTL between population crosses. We also discovered that the extant XSR chromosome has no effect on sex ratio or sterility in these backcross males. Whether shared QTL are caused by linkage or pleiotropy requires additional study. Nevertheless, these results indicate the presence of a “cryptic” drive system that is currently masked by suppressing elements that are associated with sterility and sperm length within but not between populations and, therefore, must have evolved since the populations became isolated, i.e., in <100,000 years. We discuss how genes that influence sperm length may contribute to hybrid sterility. PMID:25164880

Sexual signalling in Propithecus verreauxi: male "chest badge" and female mate choice.

PubMed

Dall'Olio, Stefania; Norscia, Ivan; Antonacci, Daniela; Palagi, Elisabetta

2012-01-01

Communication, an essential prerequisite for sociality, involves the transmission of signals. A signal can be defined as any action or trait produced by one animal, the sender, that produces a change in the behaviour of another animal, the receiver. Secondary sexual signals are often used for mate choice because they may inform on a potential partner's quality. Verreaux's sifaka (Propithecus verreauxi) is characterized by the presence of two different morphs of males (bimorphism), which can show either a stained or clean chest. The chest becomes stained by secretions of the sternal gland during throat marking (rubbing throat and chest on a vertical substrate while smearing the scent deposition). The role of the chest staining in guiding female mate choice was previously hypothesized but never demonstrated probably due to the difficulty of observing sifaka copulations in the wild. Here we report that stained-chested males had a higher throat marking activity than clean-chested males during the mating season, but not during the birth season. We found that females copulated more frequently with stained-chested males than the clean-chested males. Finally, in agreement with the biological market theory, we found that clean-chested males, with a lower scent-releasing potential, offered more grooming to females. This "grooming for sex" tactic was not completely unsuccessful; in fact, half of the clean-chested males copulated with females, even though at low frequency. In conclusion, the chest stain, possibly correlated with different cues targeted by females, could be one of the parameters which help females in selecting mates.

The Goddard and Saturn Genes Are Essential for Drosophila Male Fertility and May Have Arisen De Novo

PubMed Central

Gubala, Anna M.; Schmitz, Jonathan F.; Kearns, Michael J.; Vinh, Tery T.; Bornberg-Bauer, Erich; Wolfner, Mariana F.

2017-01-01

New genes arise through a variety of mechanisms, including the duplication of existing genes and the de novo birth of genes from noncoding DNA sequences. While there are numerous examples of duplicated genes with important functional roles, the functions of de novo genes remain largely unexplored. Many newly evolved genes are expressed in the male reproductive tract, suggesting that these evolutionary innovations may provide advantages to males experiencing sexual selection. Using testis-specific RNA interference, we screened 11 putative de novo genes in Drosophila melanogaster for effects on male fertility and identified two, goddard and saturn, that are essential for spermatogenesis and sperm function. Goddard knockdown (KD) males fail to produce mature sperm, while saturn KD males produce few sperm, and these function inefficiently once transferred to females. Consistent with a de novo origin, both genes are identifiable only in Drosophila and are predicted to encode proteins with no sequence similarity to any annotated protein. However, since high levels of divergence prevented the unambiguous identification of the noncoding sequences from which each gene arose, we consider goddard and saturn to be putative de novo genes. Within Drosophila, both genes have been lost in certain lineages, but show conserved, male-specific patterns of expression in the species in which they are found. Goddard is consistently found in single-copy and evolves under purifying selection. In contrast, saturn has diversified through gene duplication and positive selection. These data suggest that de novo genes can acquire essential roles in male reproduction. PMID:28104747

Sex and age differences in the antidepressant-like effect of fluoxetine in the forced swim test.

PubMed

Fernández-Guasti, Alonso; Olivares-Nazario, Maribel; Reyes, Rebeca; Martínez-Mota, Lucía

2017-01-01

This study compared in males and females of three representative ages: young adults (3-5months old), middle-aged (12-15months old) and senescent (23-25months old) the antidepressant-like effect of fluoxetine (FLX, 5.0 and 10mg/kg) in the forced swim test (FST). Intact (non gonadectomized) rats were evaluated. Young adult females were chosen in proestrus/estrus or in metestrus/diestrus, while middle-aged and senescent females were selected in metestrus/diestrus. Locomotion and motor coordination were also recorded. Under basal conditions (without FLX), young adult and middle-aged females showed less immobility than males. This sex difference disappeared at senescence because males diminished their levels of immobility. Thus, senescent males showed lower immobility than middle-aged and young males. FLX (5 and 10mg/kg) produced similar actions in young females irrespective of their estrous cycle phase, therefore, these subgroups were pooled in a single one. Young adult and middle aged females clearly responded to 5 and 10mg/kg of FLX with a reduction in immobility, while young adult and middle-aged males only did to 10mg/kg. In senescent females 10mg/kg FLX reduced immobility. Remarkably, in senescent males this FLX dose did not produce an antidepressant-like effect. FLX marginally affected locomotion; however, at its highest dose (10mg/kg), and only in senescent males, interfered with motor coordination tested in the rotarod. These data show that sex and aging influence behavioral despair without treatment and after FLX. Copyright © 2016 Elsevier Inc. All rights reserved.

Sexual Signalling in Propithecus verreauxi: Male “Chest Badge” and Female Mate Choice

PubMed Central

Dall'Olio, Stefania; Norscia, Ivan; Antonacci, Daniela; Palagi, Elisabetta

2012-01-01

Communication, an essential prerequisite for sociality, involves the transmission of signals. A signal can be defined as any action or trait produced by one animal, the sender, that produces a change in the behaviour of another animal, the receiver. Secondary sexual signals are often used for mate choice because they may inform on a potential partner's quality. Verreaux's sifaka (Propithecus verreauxi) is characterized by the presence of two different morphs of males (bimorphism), which can show either a stained or clean chest. The chest becomes stained by secretions of the sternal gland during throat marking (rubbing throat and chest on a vertical substrate while smearing the scent deposition). The role of the chest staining in guiding female mate choice was previously hypothesized but never demonstrated probably due to the difficulty of observing sifaka copulations in the wild. Here we report that stained-chested males had a higher throat marking activity than clean-chested males during the mating season, but not during the birth season. We found that females copulated more frequently with stained-chested males than the clean-chested males. Finally, in agreement with the biological market theory, we found that clean-chested males, with a lower scent-releasing potential, offered more grooming to females. This “grooming for sex” tactic was not completely unsuccessful; in fact, half of the clean-chested males copulated with females, even though at low frequency. In conclusion, the chest stain, possibly correlated with different cues targeted by females, could be one of the parameters which help females in selecting mates. PMID:22615982

NITROBENZENE CARCINOGENICITY IN ANIMALS AND HUMAN HAZARD EVALUATION

EPA Science Inventory

Nitrobenzene (NB) human cancer studies have not been reported, but animals studies have. Three rodent strains inhaling NB produce cancer at eight sites. B6C3F1 mice respond with mammary gland malignant tumors and male lung and thyroid benign tumors, F344/N male rats respond with ...

IN UTERO EXPOSURE TO THE FUNGICIDE PROCYMIDONE AND DIBUTYL PHTHALATE PRODUCE DOSE ADDITIVE DISRUPTIONS OF MALE RAT SEXUAL DIFFERENTIATION

EPA Science Inventory

Procymidone (PRO) and dibutyl phthalate (DBP) alter male rat sexual differentiation by disrupting the androgen-signaling pathway via distinctly different cellular mechanisms of toxicity. DBP inhibits fetal Leydig cell androgen production whereas PRO binds AR and blocks androgen a...

Responses of Diaphorina citri (Hemiptera: Psyllidae) to conspecific vibrational signals and synthetic mimics

USDA-ARS?s Scientific Manuscript database

Mate-seeking in Diaphorina citri Kuwayama, a vector of the economically damaging huanglongbing citrus disease, typically includes male-female duetting behaviors. First, the male calls by beating its wings at ca. 170-250 Hz, producing vibrations that are transmitted along the host tree branches to th...

Morphological characterization of a new and easily recognizable nuclear male sterile mutant of sorghum (Sorghum bicolor).

USDA-ARS?s Scientific Manuscript database

All commercial sorghum (Sorghum bicolor L. Moench) hybrids are produced using A1 cytoplasmic male sterility (CMS) lines. However, this homogenous cytoplasm could predispose sorghum to devastating diseases. Furthermore, it is expensive to develop and maintain the CMS-based breeding system, because it...

Temporal and acoustic characteristics of Greek vowels produced by adults with cerebral palsy

NASA Astrophysics Data System (ADS)

Botinis, Antonis; Orfanidou, Ioanna; Fourakis, Marios; Fourakis, Marios

2005-09-01

The present investigation examined the temporal and spectral characteristics of Greek vowels as produced by speakers with intact (NO) versus cerebral palsy affected (CP) neuromuscular systems. Six NO and six CP native speakers of Greek produced the Greek vowels [i, e, a, o, u] in the first syllable of CVCV nonsense words in a short carrier phrase. Stress could be on either the first or second syllable. There were three female and three male speakers in each group. In terms of temporal characteristics, the results showed that: vowels produced by CP speakers were longer than vowels produced by NO speakers; stressed vowels were longer than unstressed vowels; vowels produced by female speakers were longer than vowels produced by male speakers. In terms of spectral characteristics the results showed that the vowel space of the CP speakers was smaller than that of the NO speakers. This is similar to the results recently reported by Liu et al. [J. Acoust. Soc. Am. 117, 3879-3889 (2005)] for CP speakers of Mandarin. There was also a reduction of the acoustic vowel space defined by unstressed vowels, but this reduction was much more pronounced in the vowel productions of CP speakers than NO speakers.

Vocal-fold collision mass as a differentiator between registers in the low-pitch range.

PubMed

Vilkman, E; Alku, P; Laukkanen, A M

1995-03-01

Register shift between the chest and falsetto register is generally studied in the higher-than-speaking pitch range. However, a similar difference can also be produced at speaking pitch level. The shift from breathy "falsetto" phonation to normal chest voice phonation was studied in normal female (pitch range 170-180 Hz) and male (pitch range 94-110 Hz) subjects. The phonations gliding from falsetto to normal chest voice were analyzed using iterative adaptive inverse filtering and electroglottography. Both trained and untrained, as well as female and male subjects, were able to produce an abrupt register shift from soft falsetto to soft chest register phonation. The differences between male and female speakers in the glottal flow waveforms were smaller than expected. The register shift is interpreted in terms of a "critical mass" concept of chest register phonation.

Behavioral and spermatogenic hybrid male breakdown in Nasonia.

PubMed

Clark, M E; O'Hara, F P; Chawla, A; Werren, J H

2010-03-01

Several reproductive barriers exist within the Nasonia species complex, including allopatry, premating behavioral isolation, postzygotic inviability and Wolbachia-induced cytoplasmic incompatibility. Here we show that hybrid males suffer two additional reproductive disadvantages, an inability to properly court females and decreased sperm production. Hybrid behavioral sterility, characterized by a reduced ability of hybrids to perform necessary courtship behaviors, occurs in hybrids between two species of Nasonia. Hybrid males produced in crosses between N. vitripennis and N. giraulti courted females at a reduced frequency (23-69%), compared with wild-type N. vitripennis and N. giraulti males (>93%). Reduced courtship frequency was not a simple function of inactivity among hybrids. A strong effect of cytoplasmic (mitochondrial) background was also found in N. vitripennis and N. giraulti crosses; F2 hybrids with giraulti cytoplasm showing reduced ability at most stages of courtship. Hybrids produced between a younger species pair, N. giraulti and N. longicornis, were behaviorally fertile. All males possessed motile sperm, but sperm production is greatly reduced in hybrids between the older species pair, N. vitripennis and N. giraulti. This effect on hybrid males, lowered sperm counts rather than nonfunctional sperm, is different from most described cases of hybrid male sterility, and may represent an earlier stage of hybrid sperm breakdown. The results add to previous studies of F2 hybrid inviability and behavioral sterility, and indicate that Wolbachia-induced hybrid incompatibility has arisen early in species divergence, relative to behavioral sterility and spermatogenic infertility.

Behavioural and spermatogenic hybrid male breakdown in Nasonia

PubMed Central

Clark, Michael E.; O’Hara, F. Patrick; Chawla, Ankur; Werren, John H.

2010-01-01

Several reproductive barriers exists within the Nasonia species complex, including allopatry, premating behavioural isolation, postzygotic inviability and Wolbachia-induced cytoplasmic incompatibility. Here we show that hybrid males suffer two additional reproductive disadvantages, an inability to properly court females and decreased sperm production. Hybrid behavioural sterility, characterized by a reduced ability of hybrids to perform necessary courtship behaviours, occurs in hybrids between two species of Nasonia. Hybrid males produced in crosses between N. vitripennis and N. giraulti courted females at a reduced frequency (23-69%), compared to wild-type N. vitripennis and N. giraulti males (>93%). Reduced courtship frequency was not a simple function of inactivity among hybrids. A strong effect of cytoplasmic (mitochondrial) background was also found in N. vitripennis and N. giraulti crosses; F2 hybrids with giraulti cytoplasm showing reduced ability at most stages of courtship. Hybrids produced between a younger species pair, N. giraulti and N. longicornis, were behaviourally fertile. All males possessed motile sperm, but sperm production is greatly reduced in hybrids between the older species pair, N. vitripennis and N. giraulti. This effect on hybrid males, lowered sperm counts rather than non-functional sperm, is different from most described cases of hybrid male sterility and may represent an earlier stage of hybrid sperm breakdown. The results add to previous studies of F2 hybrid inviability and behavioural sterility, and indicated that Wolbachia induced hybrid incompatibility has arisen early in species divergence, relative to behavioural sterility and spermatogenic infertility. PMID:20087395

Chronic wasting disease in white-tailed deer: Infection, mortality, and implications for heterogeneous transmission

USGS Publications Warehouse

Samuel, Michael D.; Storm, Daniel J.

2016-01-01

Chronic wasting disease (CWD) is a fatal neurodegenerative disease affecting free-ranging and captive cervids that now occurs in 24 U.S. states and two Canadian provinces. Despite the potential threat of CWD to deer populations, little is known about the rates of infection and mortality caused by this disease. We used epidemiological models to estimate the force of infection and disease-associated mortality for white-tailed deer in the Wisconsin and Illinois CWD outbreaks. Models were based on age-prevalence data corrected for bias in aging deer using the tooth wear and replacement method. Both male and female deer in the Illinois outbreak had higher corrected age-specific prevalence with slightly higher female infection than deer in the Wisconsin outbreak. Corrected ages produced more complex models with different infection and mortality parameters than those based on apparent prevalence. We found that adult male deer have a more than threefold higher risk of CWD infection than female deer. Males also had higher disease mortality than female deer. As a result, CWD prevalence was twofold higher in adult males than females. We also evaluated the potential impacts of alternative contact structures on transmission dynamics in Wisconsin deer. Results suggested that transmission of CWD among male deer during the nonbreeding season may be a potential mechanism for producing higher rates of infection and prevalence characteristically found in males. However, alternatives based on high environmental transmission and transmission from females to males during the breeding season may also play a role.

Male vocal competition is dynamic and strongly affected by social contexts in music frogs.

PubMed

Fang, Guangzhan; Jiang, Fan; Yang, Ping; Cui, Jianguo; Brauth, Steven E; Tang, Yezhong

2014-03-01

Male-male vocal competition in anuran species is critical for mating success; however, it is also highly time-consuming, energetically demanding and likely to increase predation risks. Thus, we hypothesized that changes in the social context would cause male vocal competition to change in real time in order to minimize the costs and maximize the benefits of competition. To test this hypothesis, we assessed the effect of repeating playbacks of either white noise (WN) or male advertisement calls on male call production in the Emei music frog (Babina daunchina), a species in which males build mud-retuse burrows and call from within these nests. Previous studies have shown that calls produced from inside burrows are highly sexually attractive (HSA) to females while those produced outside nests are of low sexual attractiveness (LSA). Results showed that most subjects called responsively after the end of WN playbacks but before the onset of conspecific call stimuli although call numbers were similar, indicating that while males adjusted competitive patterns according to the biological significance of signals, their competitive motivation did not change. Furthermore, these data indicate that the frogs had evolved the ability of interval timing. Moreover, when the inter-stimulus interval (ISI) between playbacks was varied, the subjects preferentially competed with HSA calls when the ISI was short (<4 s) but responded equally to HSA and LSA calls if the ISI was long (≥4 s), suggesting that males allocate competitive efforts depending on both the perceived sexual attractiveness of rivals and the time available for calling. Notably, approximately two-thirds of male calls occurred in response to HSA calls, a preference rate comparable to that previously found for females in phonotaxis experiments and consistent with the idea that the mechanisms underlying both the male's competitive responses to rivals and the female's preferences toward potential mates coevolved under the same selective pressure.

Evaluation of 9.5 PSIA as a suit pressure for prolonged extravehicular activity

NASA Technical Reports Server (NTRS)

Dixon, G. A.; Krutz, R.

1986-01-01

A study was undertaken to determine if a pressure of 9.5 psia would aid against the occurrence of decompression sickness in both males and females (without prebreathing or stage decompression requirements) during a typical simulated extravehicular activity scenario. Twenty percent of the male subjects produced grades 1 and 2 bubbles while females did not produce bubble signals at all. It is concluded that a pressure of 9.5 psia can protect the astronaut from both formation of severe bubbling and development of bends symptoms when exposed to these study conditions.

Dairy producer attitudes to pain in cattle in relation to disbudding calves.

PubMed

Wikman, I; Hokkanen, A-H; Pastell, M; Kauppinen, T; Valros, A; Hänninen, L

2013-01-01

Pain is an important indicator of poor welfare of livestock. Despite this, pain has largely gone unrecognized in farm animals due to attitudes of producers and veterinarians, although they play a key role in monitoring and managing the perception of animal pain. Producer attitudes toward animal welfare influence livestock management and production. The aim was to quantify dairy producer attitudes to the painfulness of various cattle diseases and disbudding, a painful routine procedure performed on farm to ensure safer handling of cattle. A questionnaire on disbudding-related opinions and practices was sent to 1,000 Finnish dairy producers (response rate: 45%). Attitudes toward disbudding were gauged using a 5-point Likert scale and attitudes to cattle pain scored on an 11-point numerical rating scale. Principal components analysis was used to assess the loadings, which were further tested for differences between producer gender and housing systems with Mann-Whitney U-tests, and between herd milk yield, herd size, and age and work experience of producers with a Kruskal-Wallis test. Four main factors were identified: factor I ("taking disbudding pain seriously"), factor II ("sensitivity to pain caused by cattle diseases"), factor III ("ready to medicate calves myself"), and factor IV ("pro horns"). Female producers took disbudding pain more seriously, were more sensitive to pain caused to cattle by diseases, and were more ready to medicate disbudded calves than male producers. Producers with tie-stalls favored horns over producers with freestalls. Male producers with tie-stalls were sensitive to cattle pain and preferred horns over male producers with freestalls. Female producers with freestalls were more ready to medicate calves, but did not prefer horns more than female producers with tie-stalls. Taking disbudding seriously correlated with sensitivity to pain caused by cattle diseases. Producers with low-milk-yielding herds were less willing to medicate calves and more willing to keep cattle with horns than producers with higher-yielding herds. Older producers were more sensitive to cattle pain than middle-aged and younger producers. No effect was established for taking disbudding pain seriously: the pro-horn factor was associated with work experience, age, and herd size. Women rated pain higher and were more positive toward pain medication for animals than men. Maintaining horns are more important for producers with tie-stalls than for those with freestalls. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Plasticity of signaling and mate choice in a trilling species of the Mecopoda complex (Orthoptera: Tettigoniidae).

PubMed

Krobath, I; Römer, H; Hartbauer, M

2017-01-01

Males of a trilling species in the Mecopoda complex produce conspicuous calling songs that consist of two motifs: an amplitude-modulated motif with alternating loud and soft segments (AM-motif) and a continuous, high-intensity trill. The function of these song motifs for female attraction and competition between males was investigated. We tested the hypothesis that males modify their signaling behavior depending on the social environment (presence/absence of females or rival males) when they compete for mates. Therefore, we analyzed acoustic signaling of males in three different situations: (1) solo singing, (2) acoustic interaction with another male, and (3) singing in the presence of a female. In addition, the preference of females for these song motifs and further song parameters was studied in two-choice experiments. As expected, females showed a preference for conspicuous and loud song elements, but nevertheless, males increased the proportion of the AM-motif in the presence of a female. In acoustic interactions, males reduced bout duration significantly compared to both other situations. However, song bouts in this situation still overlapped more than expected by chance, which indicates intentionally simultaneous singing. A multivariate statistical analysis revealed that the proportion of the AM-motif and the duration of loud segments within the AM-motif allow a reliable prediction of whether males sing in isolation, compete with another male, or sing in the presence of a female. These results indicate that the AM-motif plays a dominant role especially in close-range courtship and that males are challenged in finding a balance between attracting females and saving energy during repeated acoustic interactions. Males of acoustic insects often produce conspicuous calling songs that have a dual function in male-male competition and mate attraction. High signal amplitudes and signal rates are associated with high energetic costs for signal production. We would therefore predict that males adjust their signaling behavior according to their perception of the social context. Here we studied signal production and mate choice in a katydid, where males switch between loud and soft song segments in a dynamic way. Additionally, we examined the attractiveness of different song elements in female choice tests. Our results show how males of this katydid deal with the conflict of remaining attractive for females and competing with a costly signal with rivals.

Male adaptations to minimize sexual cannibalism during reproduction in the funnel-web spider Hololena curta.

PubMed

Xiao, Yong-Hong; Zunic-Kosi, Alenka; Zhang, Long-Wa; Prentice, Thomas R; McElfresh, J Steven; Chinta, Satya P; Zou, Yun-Fan; Millar, Jocelyn G

2015-12-01

Males of many spider species risk being attacked and cannibalized while searching for, courting, and mating with conspecific females. However, there are exceptions. We show that the funnel-web spider, Hololena curta, has 3 adaptations that minimize risk to males during courtship and mating, and enhance reproductive success. First, males detected chemical or tactile signals associated with webs of virgin females, and differentiated them from webs of mated females, enabling males to increase encounter rates with virgin females and avoid aggressive mated females. Second, males produced stereotyped vibrational signals during courting which induced female quiescence and suppressed female aggression. Third, when touched by males, sexually receptive females entered a cataleptic state, allowing males to safely approach and copulate. Because males can mate multiple times and the sex ratio in natural populations of H. curta is female biased, overall reproductive output is likely increased by males of this species avoiding sexual cannibalism. © 2015 Institute of Zoology, Chinese Academy of Sciences.

When not to copy: female fruit flies use sophisticated public information to avoid mated males

NASA Astrophysics Data System (ADS)

Loyau, Adeline; Blanchet, Simon; van Laere, Pauline; Clobert, Jean; Danchin, Etienne

2012-10-01

Semen limitation (lack of semen to fertilize all of a female's eggs) imposes high fitness costs to female partners. Females should therefore avoid mating with semen-limited males. This can be achieved by using public information extracted from watching individual males' previous copulating activities. This adaptive preference should be flexible given that semen limitation is temporary. We first demonstrate that the number of offspring produced by males Drosophila melanogaster gradually decreases over successive copulations. We then show that females avoid mating with males they just watched copulating and that visual public cues are sufficient to elicit this response. Finally, after males were given the time to replenish their sperm reserves, females did not avoid the males they previously saw copulating anymore. These results suggest that female fruit flies may have evolved sophisticated behavioural processes of resistance to semen-limited males, and demonstrate unsuspected adaptive context-dependent mate choice in an invertebrate.

Bilateral coordination and the motor basis of female preference for sexual signals in canary song

PubMed Central

Suthers, Roderick A.; Vallet, Eric; Kreutzer, Michel

2012-01-01

SUMMARY The preference of female songbirds for particular traits in the songs of courting males has received considerable attention, but the relationship of preferred traits to male quality is poorly understood. Female domestic canaries (Serinus canaria, Linnaeus) preferentially solicit copulation with males that sing special high repetition rate, wide-band, multi-note syllables, called ‘sexy’ or A-syllables. Syllables are separated by minibreaths but each note is produced by pulsatile expiration, allowing high repetition rates and long duration phrases. The wide bandwidth is achieved by including two notes produced sequentially on opposite sides of the syrinx, in which the left and right sides are specialized for low or high frequencies, respectively. The emphasis of low frequencies is facilitated by a positive relationship between syllable repetition rate and the bandwidth of the fundamental frequency of notes sung by the left syrinx, such that bandwidth increases with increasing syllable repetition rate. The temporal offset between notes prevents cheating by unilaterally singing a note on the left side with a low fundamental frequency and prominent higher harmonics. The syringeal and respiratory motor patterns by which sexy syllables are produced support the hypothesis that these syllables provide a sensitive vocal–auditory indicator of a male's performance limit for the rapid, precisely coordinated interhemispheric switching, which is essential for many sensory and motor processes involving specialized contributions from each cerebral hemisphere. PMID:22875764

Reproductive and resource benefits to large female body size in a mammal with female-biased sexual size dimorphism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fokidis, H.B., T.S. Risch and T.C. Glenn

Factors underlying the evolution of female-biased sexual size dimorphism in mammals are poorly understood. In an effort to better understand these factors we tested whether larger female southern flying squirrels, Glaucomys volans, gained reproductive advantages (larger litters or more male mates) and direct resource benefits, such as larger home ranges or access to more food (i.e. mast-producing trees). As dimorphism can vary with age in precocial breeding species, we compared females during their first reproduction and during a subsequent breeding attempt. Females were not significantly larger or heavier than males at first reproduction, but became about 7% heavier and 22%more » larger than males at subsequent breeding. Larger females produced larger litters and had home ranges containing a greater proportion of upland hardwood trees. Female body size was not associated with either multiple male mating or home range size, but females with larger home ranges had higher indexes of body condition. Females in precocial breeding flying squirrels initiate reproduction before sexual size dimorphism is evident, and thus, may be allocating resources to both reproduction and growth simultaneously, or delaying growth entirely. Larger females produce more pups and have access to more food resources. Thus, selection for increased female size may partly explain how female-biased sexual size dimorphism is maintained in this species.« less

Neonatal Handling Produces Sex Hormone-Dependent Resilience to Stress-Induced Muscle Hyperalgesia in Rats.

PubMed

Alvarez, Pedro; Green, Paul G; Levine, Jon D

2018-06-01

Neonatal handling (NH) of male rat pups strongly attenuates stress response and stress-induced persistent muscle hyperalgesia in adults. Because female sex is a well established risk factor for stress-induced chronic muscle pain, we explored whether NH provides resilience to stress-induced hyperalgesia in adult female rats. Rat pups underwent NH, or standard (control) care. Muscle mechanical nociceptive threshold was assessed before and after water avoidance (WA) stress, when they were adults. In contrast to male rats, NH produced only a modest protection against WA stress-induced muscle hyperalgesia in female rats. Gonadectomy completely abolished NH-induced resilience in male rats but produced only a small increase in this protective effect in female rats. The administration of the antiestrogen drug fulvestrant, in addition to gonadectomy, did not enhance the protective effect of NH in female rats. Finally, knockdown of the androgen receptor by intrathecal antisense treatment attenuated the protective effect of NH in intact male rats. Together, these data indicate that androgens play a key role in NH-induced resilience to WA stress-induced muscle hyperalgesia. NH induces androgen-dependent resilience to stress-induced muscle pain. Therefore, androgens may contribute to sex differences observed in chronic musculoskeletal pain and its enhancement by stress. Copyright © 2018 The American Pain Society. Published by Elsevier Inc. All rights reserved.

Use of Electroencephalography (EEG) to Assess CNS Changes Produced by Pesticides with different Modes of Action: Effects of Permethrin, Deltamethrin, Fipronil, Imidacloprid, Carbaryl, and Triadimefon

EPA Science Inventory

The electroencephalogram (EEG) is an apical measure, capable of detecting changes in brain neuronal activity produced by internal or external stimuli. We assessed whether pesticides with different modes of action produced different changes in the EEG of adult male Long-Evans rats...

Infection increases the value of nuptial gifts, and hence male reproductive success, in the Hymenolepis diminuta-Tenebrio molitor association.

PubMed Central

Hurd, Hilary; Ardin, Richard

2003-01-01

During copulation, male insects pass accessory gland components to the female with the spermatophore. These gifts can affect female reproductive behaviour, ovulation and oviposition. Here, we show that female mealworm beetles, Tenebrio molitor, mated with males infected with metacestodes of the rat tapeworm, Hymenolepis diminuta, produced significantly more offspring than those mated with uninfected males. There is a significant positive relationship between parasite intensity in the male and reproductive output in the female. Infection results in a significant increase in bean-shaped accessory gland (BAG) size. We suggest that infected males pass superior nuptial gifts to females and discuss the confounding effects of infection in male and female beetles upon overall fitness costs of infection for the host and the likelihood that the parasite is manipulating host investment in reproduction. PMID:14667373

Why can't a woman be more like a man? A renaissance perspective on the biological basis for female inferiority.

PubMed

Walton, M T; Fineman, R M; Walton, P J

1996-01-01

Western biomedical theory supported the idea of human female inferiority. The Aristotelian formulation was: Nature intends to produce the perfect male form with external genitalia; the female with internal genitalia is less than perfect and thus a defect of nature. In the Renaissance, peripubertal virilization in females was interpreted as further evidence that females were "defective" males capable of developing into the more perfect male form.

Prenatal stress and ethanol exposure produces inversion of sexual partner preference in mice.

PubMed

Popova, Nina K; Morozova, Maryana V; Amstislavskaya, Tamara G

2011-02-01

The presence of a sexually receptive female behind perforated transparent partition induced sexual arousal and specific behavior in male mice so they spent more time near partition in an attempt to make their way to the female. Three-chambered free-choice model was used to evaluate sexual partner preference. The main pattern of sexual preference was the time spent by a male mouse at the partition dividing female (F-partition time) versus a partition dividing male (M-partition time). Pregnant mice were given ethanol (11vol.%) for 1-21 gestational days, and were exposed to restraint stress (2h daily for 15-21 day of the gestation). Control pregnant mice had free access to water and food and were not stressed. Adult male offspring of ethanol and stress exposed dams (E+S) showed decreased F-partition time and increased M-partition time. Whereas F-partition time in all control mice prevailed over M-partition time, 78% E+S mice demonstrated prevailed M-partition time. E+S mice were more active in social interaction with juvenile male. No significant differences between E+S and control mice in the open field and novelty tests were revealed. Therefore, E+S exposure during dam gestation inverted sexual partner preference in male offspring, suggesting that stress and alcohol in pregnancy produces predisposition to homosexuality. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Big enough for an aromatase inhibitor? How adiposity affects male fertility.

PubMed

Stephens, Sahar M; Polotsky, Alex J

2013-07-01

Obesity is a pandemic and is associated with multiple medical problems including subfertility. Male obesity has been associated with altered semen parameters and reproductive hormonal levels, including a reduced testosterone:estradiol (T:E₂) ratio. Treatment methods employed for obesity-related male subfertility include gonadotropin administration, weight loss, and aromatase inhibitors. Letrozole is a highly effective nonsteroidal aromatase inhibitor that has been used to treat male subfertility in several case series with promising results. Adequately designed randomized controlled studies are needed to produce evidence-based data on the role of aromatase inhibitors in male subfertility management and evaluate the side-effect profile. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Winning the genetic lottery: biasing birth sex ratio results in more grandchildren.

PubMed

Thogerson, Collette M; Brady, Colleen M; Howard, Richard D; Mason, Georgia J; Pajor, Edmond A; Vicino, Greg A; Garner, Joseph P

2013-01-01

Population dynamics predicts that on average parents should invest equally in male and female offspring; similarly, the physiology of mammalian sex determination is supposedly stochastic, producing equal numbers of sons and daughters. However, a high quality parent can maximize fitness by biasing their birth sex ratio (SR) to the sex with the greatest potential to disproportionately outperform peers. All SR manipulation theories share a fundamental prediction: grandparents who bias birth SR should produce more grandoffspring via the favored sex. The celebrated examples of biased birth SRs in nature consistent with SR manipulation theories provide compelling circumstantial evidence. However, this prediction has never been directly tested in mammals, primarily because the complete three-generation pedigrees needed to test whether individual favored offspring produce more grandoffspring for the biasing grandparent are essentially impossible to obtain in nature. Three-generation pedigrees were constructed using 90 years of captive breeding records from 198 mammalian species. Male and female grandparents consistently biased their birth SR toward the sex that maximized second-generation success. The most strongly male-biased granddams and grandsires produced respectively 29% and 25% more grandoffspring than non-skewing conspecifics. The sons of the most male-biasing granddams were 2.7 times as fecund as those of granddams with a 50∶50 bias (similar results are seen in grandsires). Daughters of the strongest female-biasing granddams were 1.2 times as fecund as those of non-biasing females (this effect is not seen in grandsires). To our knowledge, these results are the first formal test of the hypothesis that birth SR manipulation is adaptive in mammals in terms of grandchildren produced, showing that SR manipulation can explain biased birth SR in general across mammalian species. These findings also have practical implications: parental control of birth SR has the potential to accelerate genetic loss and risk of extinction within captive populations of endangered species.

Attempting to Change Sex Role Attitudes in Adolescents: Explorations of Reverse Effects.

ERIC Educational Resources Information Center

Matteson, David R.

1991-01-01

Interventions designed to change sex role stereotypes have usually used presentations on women's roles and have been effective with females only, producing no effects or reverse effects with males. Conducted three experiments using media presentations focusing on men. Findings from 12 male and 28 female adolescents revealed that 2 presentations…

The Female-to-Male Transsexual Voice: Physiology vs. Performance in Production

ERIC Educational Resources Information Center

Papp, Viktoria

2011-01-01

Results of the three studies on the speech production of female-to-male transgender individuals (transmen) present phonetic evidence that speech produces the transmen by what I termed triple decoupling. Transmen successfully decouple gender from biological sex. The results of the longitudinal studies exemplified that speakers born and raised…

Are Attractive Men's Faces Masculine or Feminine? The Importance of Type of Facial Stimuli

ERIC Educational Resources Information Center

Rennels, Jennifer L.; Bronstad, P. Matthew; Langlois, Judith H.

2008-01-01

The authors investigated whether differences in facial stimuli could explain the inconsistencies in the facial attractiveness literature regarding whether adults prefer more masculine- or more feminine-looking male faces. Their results demonstrated that use of a female average to dimorphically transform a male facial average produced stimuli that…

Male Stereotypes in Radio Serials of the 1930s and 1940s.

ERIC Educational Resources Information Center

St John, Jacqueline

Because they tend to reflect dominant cultural values that are more obvious and taken for granted by historians, male stereotypes in radio serials, or "soap operas," have been ignored. They are prevalent, however, especially in the representative "Golden Age" productions of Anne and Frank Hummert. The Hummerts produced 46% of…

Why are there so many molecular markers tagging the Ms locus of onion

USDA-ARS?s Scientific Manuscript database

The primary source of male sterility used to produce hybrid-onion cultivars is conditioned by the interaction of the cytoplasm (N versus S) and alleles at one nuclear male-fertility restoration (Ms) locus Due to the biennial life cycle of onion and the necessity to score testcross progenies, the de...

Acoustic and Durational Properties of Indian English Vowels

ERIC Educational Resources Information Center

Maxwell, Olga; Fletcher, Janet

2009-01-01

This paper presents findings of an acoustic phonetic analysis of vowels produced by speakers of English as a second language from northern India. The monophthongal vowel productions of a group of male speakers of Hindi and male speakers of Punjabi were recorded, and acoustic phonetic analyses of vowel formant frequencies and vowel duration were…

Variable Variation: Annual and Seasonal Changes in Offspring Sex Ratio in a Bat

PubMed Central

Barclay, Robert M. R.

2012-01-01

Many organisms produce offspring with sex-ratios that deviate from equal numbers of males and females, and numerous adaptive explanations have been proposed. In some species, offspring sex-ratio varies across the reproductive season, again with several explanations as to why this might be adaptive. However, patterns for birds and mammals are inconsistent, and multiple factors are likely involved. Long-term studies on a variety of species may help untangle the complexity. I analyzed a long-term data set on the variation in offspring sex-ratio of the big brown bat, Eptesicus fuscus, a temperate-zone, insectivorous species. Sex ratio varied seasonally, but only in some years. Births early in the season were significantly female biased in years in which parturition occurred relatively early, but not in years with late parturition. Survival of female pups increased with earlier median birth date for the colony, and early-born females were more likely to survive and reproduce as one-year olds, compared to later-born pups. I argue that, due to the unusual timing of reproductive activities in male and female bats that hibernate, producing female offspring early in the year increases their probability of reproducing as one year olds, but this is not the case for male offspring. Thus, mothers that can give birth early in the year, benefit most by producing a female pup. The relative benefit of producing female or male offspring varies depending on the length of the growing season and thus the time available for female pups to reach sexual maturity. This suggests that not only does sex-ratio vary seasonally and among years, depending on the condition of the mother and the environment, but also likely varies geographically due to differences in season length. PMID:22570704

Logging affects fledgling sex ratios and baseline corticosterone in a forest songbird.

PubMed

Leshyk, Rhiannon; Nol, Erica; Burke, Dawn M; Burness, Gary

2012-01-01

Silviculture (logging) creates a disturbance to forested environments. The degree to which forests are modified depends on the logging prescription and forest stand characteristics. In this study we compared the effects of two methods of group-selection ("moderate" and "heavy") silviculture (GSS) and undisturbed reference stands on stress and offspring sex ratios of a forest interior species, the Ovenbird (Seiurus aurocapilla), in Algonquin Provincial Park, Canada. Blood samples were taken from nestlings for corticosterone and molecular sexing. We found that logging creates a disturbance that is stressful for nestling Ovenbirds, as illustrated by elevated baseline corticosterone in cut sites. Ovenbirds nesting in undisturbed reference forest produce fewer male offspring per brood (proportion male = 30%) while logging with progressively greater forest disturbance, shifted the offspring sex ratio towards males (proportion male: moderate = 50%, heavy = 70%). If Ovenbirds in undisturbed forests usually produce female-biased broods, then the production of males as a result of logging may disrupt population viability. We recommend a broad examination of nestling sex ratios in response to anthropogenic disturbance to determine the generality of our findings.

Phase-Specific Vocalizations of Male Mice at the Initial Encounter during the Courtship Sequence

PubMed Central

Matsumoto, Yui K.; Okanoya, Kazuo

2016-01-01

Mice produce ultrasonic vocalizations featuring a variety of syllables. Vocalizations are observed during social interactions. In particular, males produce numerous syllables during courtship. Previous studies have shown that vocalizations change according to sexual behavior, suggesting that males vary their vocalizations depending on the phase of the courtship sequence. To examine this process, we recorded large sets of mouse vocalizations during male–female interactions and acoustically categorized these sounds into 12 vocal types. We found that males emitted predominantly short syllables during the first minute of interaction, more long syllables in the later phases, and mainly harmonic sounds during mounting. These context- and time-dependent changes in vocalization indicate that vocal communication during courtship in mice consists of at least three stages and imply that each vocalization type has a specific role in a phase of the courtship sequence. Our findings suggest that recording for a sufficiently long time and taking the phase of courtship into consideration could provide more insights into the role of vocalization in mouse courtship behavior in future study. PMID:26841117

The evolution of adult light emission color in North American fireflies

PubMed Central

Hall, David W.; Sander, Sarah E.; Pallansch, Jennifer C.; Stanger-Hall, Kathrin F.

2016-01-01

Firefly species (Lampyridae) vary in the color of their adult bioluminescence. It has been hypothesized that color is selected to enhance detection by conspecifics. One mechanism to improve visibility of the signal is to increase contrast against ambient light. High contrast implies that fireflies active early in the evening will emit yellower luminescence to contrast against ambient light reflected from green vegetation, especially in habitats with high vegetation cover. Another mechanism to improve visibility is to use reflection off the background to enhance the light signal. Reflectance predicts that sedentary females will produce greener light to maximize reflection off the green vegetation on which they signal. To test these predictions, we recorded over 7500 light emission spectra and determined peak emission wavelength for 675 males, representing 24 species, at 57 field sites across the Eastern United States. We found support for both hypotheses: males active early in more vegetated habitats produced yellower flashes in comparison to later-active males with greener flashes. Further, in 2 of the 8 species with female data, female light emissions were significantly greener as compared to males. PMID:27412777

Sex-different effects of tributyltin on brain aromatase, estrogen receptor and retinoid X receptor gene expression in rockfish (Sebastiscus marmoratus).

PubMed

Zhang, Jiliang; Zuo, Zhenghong; Zhu, Wenwen; Sun, Ping; Wang, Chonggang

2013-09-01

Since the brain plays important roles in reproduction, the brain aromatase (Cyp19b), estrogen receptor (ER), retinoid X receptor (RXR) α and peroxisome proliferator-activated receptor γ were examined in rockfish after TBT exposure (1, 10, and 100 ng L(-1)). The results showed that the Cyp19b expression was elevated in the male rockfish, while no effect was produced in the females. Inconsistently, serum testosterone and 17β-estradiol showed no change in the males, while an increase of testosterone and a decrease of 17β-estradiol were observed in the females. TBT affected the ER expression in the males depending on the concentrations, however, no change was observed in the females. In addition, TBT elevated the RXRα expression in the males but produced an opposite effect in the females. In conclusion, TBT might have had sex-different effects on the brain Cyp19b, ER and RXR expression in rockfish, indicating a complex endocrine disrupting effect of TBT. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Male infertility and its causes in human.

PubMed

Miyamoto, Toshinobu; Tsujimura, Akira; Miyagawa, Yasushi; Koh, Eitetsu; Namiki, Mikio; Sengoku, Kazuo

2012-01-01

Infertility is one of the most serious social problems facing advanced nations. In general, approximate half of all cases of infertility are caused by factors related to the male partner. To date, various treatments have been developed for male infertility and are steadily producing results. However, there is no effective treatment for patients with nonobstructive azoospermia, in which there is an absence of mature sperm in the testes. Although evidence suggests that many patients with male infertility have a genetic predisposition to the condition, the cause has not been elucidated in the vast majority of cases. This paper discusses the environmental factors considered likely to be involved in male infertility and the genes that have been clearly shown to be involved in male infertility in humans, including our recent findings.

Pheromone trailing behavior of the brown tree snake, Boiga irregularis.

PubMed

Greene, M J; Stark, S L; Mason, R T

2001-11-01

The ability of snakes to follow pheromone trails has significant consequences for survival and reproduction. Of particular importance is the ability of snakes to locate conspecifics during the breeding season via the detection of pheromone trails. In this study, the ability of male brown tree snakes (Boiga irregularis), a tropical, rear-fanged colubrid, to follow pheromone trails produced by reproductively active conspecifics was tested in the laboratory by using a Y maze. Males displayed a trailing response to both female and male pheromone trails over blank controls. As males of this species display ritualized combat behavior, these responses likely represent both direct and indirect mechanisms, respectively, for the location of potential mates in the wild. Males did not, however, discriminate between male and female trails when given a choice on the Y maze.

Comprehensive assessment of hormones, phytoestrogens, and estrogenic activity in an anaerobic swine waste lagoon

USGS Publications Warehouse

Yost, Erin E.; Meyer, Michael T.; Dietze, Julie E.; Meissner, Benjamin M.; Williams, Mike; Worley-Davis, Lynn; Lee, Boknam; Kullman, Seth W.

2013-01-01

In this study, the distribution of steroid hormones, phytoestrogens, and estrogenic activity was thoroughly characterized within the anaerobic waste lagoon of a typical commercial swine sow operation. Three independent rounds of sampling were conducted in June 2009, April 2010, and February 2011. Thirty-seven analytes in lagoon slurry and sludge were assessed using LC/MS-MS, and yeast estrogen screen was used to determine estrogenic activity. Of the hormone analytes, steroidal estrogens were more abundant than androgens or progesterone, with estrone being the predominant estrogen species. Conjugated hormones were detected only at low levels. The isoflavone metabolite equol was by far the predominant phytoestrogen species, with daidzein, genistein, formononetin, and coumestrol present at lower levels. Phytoestrogens were often more abundant than steroidal estrogens, but contributed minimally towards total estrogenic activity. Analytes were significantly elevated in the solid phases of the lagoon; although low observed log KOC values suggest enhanced solubility in the aqueous phase, perhaps due to dissolved or colloidal organic carbon. The association with the solid phase, as well as recalcitrance of analytes to anaerobic degradation, results in a markedly elevated load of analytes and estrogenic activity within lagoon sludge. Overall, findings emphasize the importance of adsorption and transformation processes in governing the fate of these compounds in lagoon waste, which is ultimately used for broadcast application as a fertilizer.

Soy Isoflavones and Prostate Cancer: A Review of Molecular Mechanisms

PubMed Central

Mahmoud, Abeer M.; Yang, Wancai; Bosland, Maarten C.

2014-01-01

Soy isoflavones are dietary components for which an association has been demonstrated with reduced risk of prostate cancer (PCa) in Asian populations. However, the exact mechanism by which these isoflavones may prevent the development or progression of PCa is not completely understood. There are a growing number of animal and in vitro studies that have attempted to elucidate these mechanisms. The predominant and most biologically active isoflavones in soy products, genistein, daidzein, equol, and glycetin, inhibit prostate carcinogenesis in some animal models. Cell-based studies show that soy isoflavones regulate genes that control cell cycle and apoptosis. In this review, we discuss the literature relevant to the molecular events that may account for the benefit of soy isoflavones in PCa prevention or treatment. These reports show that although soy isoflavone-induced growth arrest and apoptosis of PCa cells are plausible mechanisms, other chemo protective mechanisms are also worthy of consideration. These possible mechanisms include antioxidant defense, DNA repair, inhibition of angiogenesis and metastasis, potentiation of radio- and chemotherapeutic agents, and antagonism of estrogen- and androgen-mediated signaling pathways. Moreover, other cells in the cancer milieu, such as the fibroblastic stromal cells, endothelial cells, and immune cells, may be targeted by soy isoflavones, which may contribute to soy-mediated prostate cancer prevention. In this review, these mechanisms are discussed along with considerations about the doses and the preclinical models that have been used. PMID:24373791

Gas chromatographic–mass spectrometric fragmentation study of phytoestrogens as their trimethylsilyl derivatives: Identification in soy milk and wastewater samples

USGS Publications Warehouse

Ferrar, Imma; Barber, Larry B.; Thurman, E. Michael

2009-01-01

An analytical method for the identification of eight plant phytoestrogens (biochanin A, coumestrol, daidzein, equol, formononetin, glycitein, genistein and prunetin) in soy products and wastewater samples was developed using gas chromatography coupled with ion trap mass spectrometry (GC/MS–MS). The phytoestrogens were derivatized as their trimethylsilyl ethers with trimethylchlorosilane (TMCS) and N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA). The phytoestrogens were isolated from all samples with liquid–liquid extraction using ethyl acetate. Daidzein-d4 and genistein-d4 labeled standards were used as internal standards before extraction and derivatization. The fragmentation patterns of the phytoestrogens were investigated by isolating and fragmenting the precursor ions in the ion-trap and a typical fragmentation involved the loss of a methyl and a carbonyl group. Two characteristic fragment ions for each analyte were chosen for identification and confirmation. The developed methodology was applied to the identification and confirmation of phytoestrogens in soy milk, in wastewater effluent from a soy-milk processing plant, and in wastewater (influent and effluent) from a treatment plant. Detected concentrations of genistein ranged from 50,000 μg/L and 2000 μg/L in soy milk and in wastewater from a soy-plant, respectively, to 20 μg/L and <1 μg/L for influent and effluent from a wastewater treatment plant, respectively.

Comprehensive Assessment of Hormones, Phytoestrogens, and Estrogenic Activity in an Anaerobic Swine Waste Lagoon

PubMed Central

2013-01-01

In this study, the distribution of steroid hormones, phytoestrogens, and estrogenic activity was thoroughly characterized within the anaerobic waste lagoon of a typical commercial swine sow operation. Three independent rounds of sampling were conducted in June 2009, April 2010, and February 2011. Thirty-seven analytes in lagoon slurry and sludge were assessed using LC/MS-MS, and yeast estrogen screen was used to determine estrogenic activity. Of the hormone analytes, steroidal estrogens were more abundant than androgens or progesterone, with estrone being the predominant estrogen species. Conjugated hormones were detected only at low levels. The isoflavone metabolite equol was by far the predominant phytoestrogen species, with daidzein, genistein, formononetin, and coumestrol present at lower levels. Phytoestrogens were often more abundant than steroidal estrogens, but contributed minimally toward total estrogenic activity. Analytes were significantly elevated in the solid phases of the lagoon; although low observed log KOC values suggest enhanced solubility in the aqueous phase, perhaps due to dissolved or colloidal organic carbon. The association with the solid phase, as well as recalcitrance of analytes to anaerobic degradation, results in a markedly elevated load of analytes and estrogenic activity within lagoon sludge. Overall, findings emphasize the importance of adsorption and transformation processes in governing the fate of these compounds in lagoon waste, which is ultimately used for broadcast application as a fertilizer. PMID:24144340

Education from a Gender Equality Perspective

ERIC Educational Resources Information Center

US Agency for International Development, 2008

2008-01-01

Education is universally acknowledged to benefit individuals and promote national development. Educating females and males produces similar increases in their subsequent earnings and expands future opportunities and choices for both boys and girls. However, educating girls produces many additional socio-economic gains that benefit entire…

The effect of female wings on male courtship behavior in the cricket Gryllus bimaculatus

NASA Astrophysics Data System (ADS)

Itoh, Masanori; Murakami, Shio

2002-03-01

Sexual dimorphism exists in the shape and the structure of the forewings of the cricket (Gryllus bimaculatus). However, the functional significance of the wings in the G. bimaculatus female has been unclear. In common blue butterflies (Polyommatus icarus), wings in females have been suggested as being important for attracting males. To test whether female crickets need wings for conspecific males to recognize them and initiate mating behavior, we removed all wings from females and observed the behavior of males towards them. Most males (87.5%) showed mating behavior towards the wingless females: they produced courtship song and transferred spermatophores to the wingless females. Similarly, 88.5% of the males showed mating behavior towards intact females. When males were placed with both a wingless female and an intact female, no significant difference was detected in male mate choice. The findings demonstrate that the wing of the G. bimaculatus female is not necessary for female recognition by conspecific males and the initiation of male mating behavior, and that it is not important in male mate choice.

The Potential Organ Involved in Cantharidin Biosynthesis in Epicauta chinensis Laporte (Coleoptera: Meloidae)

PubMed Central

Jiang, Ming; Lü, Shumin

2017-01-01

Cantharidin, a terpenoid defensive toxin mainly produced by blister beetles, is among the most widely known insect natural products in the world. However, little is known about the site of cantharidin biosynthesis in vivo. Our previous research showed that 3-hydroxy-3-methylglutary-CoA reductase (HMGR) is an essential enzyme in cantharidin biosynthesis. In this report, we further investigated cantharidin titer and HMGR mRNA expression levels in different tissues of male and female Epicauta chinensis, and performed a comparative analysis of HMGR transcript levels in male Tenebrio molitor, a Tenebrionidae beetle that cannot produce cantharidin. HMGR transcripts had a positive correlation with cantharidin production. Furthermore, the specifically high amounts of HMGR transcript and abundant cantharidin production in fat body of male E. chinensis indicated the process of cantharidin synthesis may occur in the fat body. PMID:28423415

Sex-reversed somatic cell cloning in the mouse.

PubMed

Inoue, Kimiko; Ogonuki, Narumi; Mekada, Kazuyuki; Yoshiki, Atsushi; Sado, Takashi; Ogura, Atsuo

2009-10-01

Somatic cell nuclear transfer has many potential applications in the fields of basic and applied sciences. However, it has a disadvantage that can never be overcome technically-the inflexibility of the sex of the offspring. Here, we report an accidental birth of a female mouse following nuclear transfer using an immature Sertoli cell. We produced a batch of 27 clones in a nuclear transfer experiment using Sertoli cells collected from neonatal male mice. Among them, one pup was female. This "male-derived female" clone grew into a normal adult and produced offspring by natural mating with a littermate. Chromosomal analysis revealed that the female clone had a 39,X karyotype, indicating that the Y chromosome had been deleted in the donor cell or at some early step during nuclear transfer. This finding suggests the possibility of resuming sexual reproduction after a single male is cloned, which should be especially useful for reviving extinct or endangered species.

Talker's voice and gender stereotype in human auditory sentence processing--evidence from event-related brain potentials.

PubMed

Lattner, Sonja; Friederici, Angela D

2003-03-27

The present study investigated the influence of implicit speaker information on the sentence interpretation. We auditorily presented sentences that comprised of either stereotypically male or stereotypically female self-referent utterances. In the congruent conditions, these utterances were produced by speakers whose gender matched the semantic content. In the incongruent condition, stereotypically male utterances were produced by female speakers and vice versa. The event-related brain potentials (ERP) of 32 listeners exhibited a late positivity (P600) for the incongruent condition. No significant differences were observed between male and female listeners. In the absence of any ERP effect in the earlier time range, it was concluded that the access of the semantic information as such is independent of the speaker's voice, but that speaker property, semantic content and stereotypical knowledge are integrated in a later processing stage.

Construction of a multicontrol sterility system for a maize male-sterile line and hybrid seed production based on the ZmMs7 gene encoding a PHD-finger transcription factor.

PubMed

Zhang, Danfeng; Wu, Suowei; An, Xueli; Xie, Ke; Dong, Zhenying; Zhou, Yan; Xu, Liwen; Fang, Wen; Liu, Shensi; Liu, Shuangshuang; Zhu, Taotao; Li, Jinping; Rao, Liqun; Zhao, Jiuran; Wan, Xiangyuan

2018-02-01

Although hundreds of genetic male sterility (GMS) mutants have been identified in maize, few are commercially used due to a lack of effective methods to produce large quantities of pure male-sterile seeds. Here, we develop a multicontrol sterility (MCS) system based on the maize male sterility 7 (ms7) mutant and its wild-type Zea mays Male sterility 7 (ZmMs7) gene via a transgenic strategy, leading to the utilization of GMS in hybrid seed production. ZmMs7 is isolated by a map-based cloning approach and encodes a PHD-finger transcription factor orthologous to rice PTC1 and Arabidopsis MS1. The MCS transgenic maintainer lines are developed based on the ms7-6007 mutant transformed with MCS constructs containing the (i) ZmMs7 gene to restore fertility, (ii) α-amylase gene ZmAA and/or (iii) DNA adenine methylase gene Dam to devitalize transgenic pollen, (iv) red fluorescence protein gene DsRed2 or mCherry to mark transgenic seeds and (v) herbicide-resistant gene Bar for transgenic seed selection. Self-pollination of the MCS transgenic maintainer line produces transgenic red fluorescent seeds and nontransgenic normal colour seeds at a 1:1 ratio. Among them, all the fluorescent seeds are male fertile, but the seeds with a normal colour are male sterile. Cross-pollination of the transgenic plants to male-sterile plants propagates male-sterile seeds with high purity. Moreover, the transgene transmission rate through pollen of transgenic plants harbouring two pollen-disrupted genes is lower than that containing one pollen-disrupted gene. The MCS system has great potential to enhance the efficiency of maize male-sterile line propagation and commercial hybrid seed production. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

The Male Sex Pheromone of the Butterfly Bicyclus anynana: Towards an Evolutionary Analysis

PubMed Central

Nieberding, Caroline M.; de Vos, Helene; Schneider, Maria V.; Lassance, Jean-Marc; Estramil, Natalia; Andersson, Jimmy; Bång, Joakim; Hedenström, Erik; Löfstedt, Christer; Brakefield, Paul M.

2008-01-01

Background Female sex pheromones attracting mating partners over long distances are a major determinant of reproductive isolation and speciation in Lepidoptera. Males can also produce sex pheromones but their study, particularly in butterflies, has received little attention. A detailed comparison of sex pheromones in male butterflies with those of female moths would reveal patterns of conservation versus novelty in the associated behaviours, biosynthetic pathways, compounds, scent-releasing structures and receiving systems. Here we assess whether the African butterfly Bicyclus anynana, for which genetic, genomic, phylogenetic, ecological and ethological tools are available, represents a relevant model to contribute to such comparative studies. Methodology/Principal Findings Using a multidisciplinary approach, we determined the chemical composition of the male sex pheromone (MSP) in the African butterfly B. anynana, and demonstrated its behavioural activity. First, we identified three compounds forming the presumptive MSP, namely (Z)-9-tetradecenol (Z9-14:OH), hexadecanal (16:Ald ) and 6,10,14-trimethylpentadecan-2-ol (6,10,14-trime-15-2-ol), and produced by the male secondary sexual structures, the androconia. Second, we described the male courtship sequence and found that males with artificially reduced amounts of MSP have a reduced mating success in semi-field conditions. Finally, we could restore the mating success of these males by perfuming them with the synthetic MSP. Conclusions/Significance This study provides one of the first integrative analyses of a MSP in butterflies. The toolkit it has developed will enable the investigation of the type of information about male quality that is conveyed by the MSP in intraspecific communication. Interestingly, the chemical structure of B. anynana MSP is similar to some sex pheromones of female moths making a direct comparison of pheromone biosynthesis between male butterflies and female moths relevant to future research. Such a comparison will in turn contribute to understanding the evolution of sex pheromone production and reception in butterflies. PMID:18648495

The Goddard and Saturn Genes Are Essential for Drosophila Male Fertility and May Have Arisen De Novo.

PubMed

Gubala, Anna M; Schmitz, Jonathan F; Kearns, Michael J; Vinh, Tery T; Bornberg-Bauer, Erich; Wolfner, Mariana F; Findlay, Geoffrey D

2017-05-01

New genes arise through a variety of mechanisms, including the duplication of existing genes and the de novo birth of genes from noncoding DNA sequences. While there are numerous examples of duplicated genes with important functional roles, the functions of de novo genes remain largely unexplored. Many newly evolved genes are expressed in the male reproductive tract, suggesting that these evolutionary innovations may provide advantages to males experiencing sexual selection. Using testis-specific RNA interference, we screened 11 putative de novo genes in Drosophila melanogaster for effects on male fertility and identified two, goddard and saturn, that are essential for spermatogenesis and sperm function. Goddard knockdown (KD) males fail to produce mature sperm, while saturn KD males produce few sperm, and these function inefficiently once transferred to females. Consistent with a de novo origin, both genes are identifiable only in Drosophila and are predicted to encode proteins with no sequence similarity to any annotated protein. However, since high levels of divergence prevented the unambiguous identification of the noncoding sequences from which each gene arose, we consider goddard and saturn to be putative de novo genes. Within Drosophila, both genes have been lost in certain lineages, but show conserved, male-specific patterns of expression in the species in which they are found. Goddard is consistently found in single-copy and evolves under purifying selection. In contrast, saturn has diversified through gene duplication and positive selection. These data suggest that de novo genes can acquire essential roles in male reproduction. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Sexual rest and post-meiotic sperm ageing in house mice.

PubMed

Firman, R C; Young, F J; Rowe, D C; Duong, H T; Gasparini, C

2015-07-01

Fertilization by aged sperm can result in adverse fitness consequences for both males and females. Sperm storage during male sexual rest could provide an environment for post-meiotic sperm senescence causing a deterioration in the quality of stored sperm, possibly impacting on both sperm performance (e.g. swimming ability) and DNA quality. Here, we compared the proportion of sperm with fragmented DNA, an indicator of structural damage of DNA within the sperm cell, among males that had been sexually rested for approximately 2 months, to that of males that had mated recently. We found no evidence of intra-epididymal sperm DNA damage or any impairment in sperm performance, and consequently no evidence of post-meiotic sperm senescence. Our results suggest that male house mice are likely to possess mechanisms that function to ensure that their sperm reserves remain stocked with 'young', viable sperm during periods of sexual inactivity. We also discuss the possibility that our experimental design leads to no difference in the age of sperm among males from the two mating treatments. Post-meiotic sperm senescence is especially relevant under sperm competition. Thus, we sourced mice from populations that differed in their levels of post-copulatory sexual selection, enabling us to gain insight into how selection for higher sperm production influences the rate of sperm ageing and levels of DNA fragmentation. We found that males from the population that produced the highest number of sperm also had the smallest proportion of DNA-fragmented sperm and discuss this outcome in relation to selection acting upon males to ensure that they produce ejaculates with high-quality sperm that are successful in achieving fertilizations under competitive conditions. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

Physiological and brain alterations produced by high-fat diet in male and female rats can be modulated by increased levels of estradiol during critical periods of development.

PubMed

Carrillo, Beatriz; Collado, Paloma; Díaz, Francisca; Chowen, Julie A; Pérez-Izquierdo, Mª Ángeles; Pinos, Helena

2017-07-11

Overnutrition due to a high-fat diet (HFD) can increase the vulnerability of the metabolic system to maladjustments. Estradiol has an inhibitory role on food intake and this hormone has demonstrated to be a crucial organizer during brain development. Our aim was to determine whether increased levels of estradiol in the early postnatal period modulate the alterations in metabolism and brain metabolic circuits produced by overnutrition. Twenty-four male and 24 female Wistar rats were submitted to a HFD (34.9% fat) or a control diet (5% fat) from gestational day 6. From postnatal (P) 6 to P13, both control and HFD groups were administered a s.c. injection of vehicle or estradiol benzoate (0.4 mg/kg), resulting in eight experimental groups (n = 6 in each group). Body weight, food intake and subcutaneous, visceral, and brown fat pads were measured. Agouti-related peptide, neuropeptide Y, orexin, and proopiomelanocortin (POMC) were analyzed by quantitative real-time polymerase chain reaction assay and plasma estradiol levels were measured by ELISA. Males fed a HFD showed an increase in body weight and the amount of visceral and subcutaneous fat, which was coincident with an increase in the number of kilocalories ingested. Neonatal estradiol treatment restored the body weight and subcutaneous fat of HFD males to control levels. Hypothalamic POMC mRNA levels in HFD females were increased with respect to control females. This increase was reverted with estradiol treatment during development. HFD and estradiol treatment have different effects on males and females. Overnutrition affects physiological parameters, such as body weight, visceral, and subcutaneous fat content, in males, while females present alterations in hypothalamic POMC mRNA levels. Hence, the increase in estradiol levels during a period that is critical for the programing of the feeding system can modulate some of the alterations produced by the continuous intake of high-fat content food.

Amygdalar activation of group I metabotropic glutamate receptors produces anti- and pro-conflict effects depending upon animal sex in a sexually dimorphic conditioned conflict-based anxiety model.

PubMed

De Jesús-Burgos, María I; González-García, Stephanie; Cruz-Santa, Yanira; Pérez-Acevedo, Nivia L

2016-04-01

Women are more susceptible than men to develop anxiety disorders, however, the mechanisms involved are still unclear. In this study, we investigated the role of group I metabotropic glutamate receptors (mGluRs), a target for anxiety disorders, and whether estradiol may modulate conflict-based anxiety in female rats by using the Vogel Conflict Test (VCT). We used ovariectomized female rats with high (OVX+EB) and low (OVX) estradiol levels and intact male rats to evaluate sex differences. Infusion of (S)-3,5-Dihydroxyphenylglycine (DHPG), a group I mGluR agonist, into the basolateral amygdala, a region involved in anxiety-responses, statistically increased the number of shocks in OVX, but not OVX+EB female rats at 0.1, nor at 1.0 μM. In contrast, DHPG statistically decreased the number of shocks in male rats at 1.0 μM only. DHPG (0.1 μM) increased the number of recoveries in OVX, but not OVX+EB or male rats. Sex differences were detected for the number of shocks, recoveries and punished licks, where female rats displayed more conflict than male rats. Western blot analyses showed that protein expression of mGluR1, but not mGluR5 was higher in OVX+EB>OVX>male rats in the amygdala, whereas no significant differences were detected in the hippocampus, olfactory bulb and/or the periaqueductal gray. Therefore, DHPG produced paradoxical effects that are sex dependent; producing anxiolytic-like effects in female rats, while anxiogenic-like effects in male rats according to the VCT. These results highlight the importance of including female experimental models to underpin the neural circuitry of anxiety according to sex and for the screening of novel anxiolytic compounds. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Management practices for male calves on Canadian dairy farms.

PubMed

Renaud, D L; Duffield, T F; LeBlanc, S J; Haley, D B; Kelton, D F

2017-08-01

Morbidity, mortality, and antimicrobial use and resistance are major concerns in the rearing of male dairy calves, so information to support disease prevention is important. The objective of this cross-sectional study was to describe management practices associated with the care of male calves during their first days of life on Canadian dairy farms. A survey was completed by dairy producers across Canada between March 1 and April 30, 2015. The survey included 192 questions covering producer background, farm characteristics, biosecurity practices, disease prevalence, calf health, animal welfare, lameness, milking hygiene, reproduction, and Internet and social media use. A total of 1,025 surveys were completed online, by telephone, or by mail, representing 9% of all dairy farms in Canada. Five percent of respondents (n = 49) answered that they had euthanized at least 1 male calf at birth in the previous year, and blunt force trauma was commonly used in these cases. The majority of respondents always fed colostrum to male calves; however, 9% (n = 80) did not always feed colostrum. Almost 40% (n = 418) of respondents reported always dipping the navels of male calves, 12% (n = 123) vaccinated male calves, and 17% (n = 180) did not provide the same quantity of feed to male calves as heifer calves. The care of male calves differed greatly depending on the geographical region of the respondents. However, some regional effects may be confounded by economic conditions and the logistics of marketing male dairy calves in different parts of the country. Herd size was another important variable in many aspects of the management of male calves on dairy farms. Larger herd sizes were more likely to use an appropriate method of euthanasia at birth but were less likely to always feed colostrum to their male calves or feed them the same as female calves. Familiarity with the Code of Practice for the Care and Handling of Dairy Cattle (National Farm Animal Care Council) by respondents was associated with better care of male calves on dairy farms. The results of this survey suggest that the treatment of male dairy calves on Canadian dairy farms varies and that there are opportunities to improve the health management of male calves on the farms of origin. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Motile Sperm Output by Male Cheetahs (Acinonyx jubatus) Managed Ex Situ Is Influenced by Public Exposure and Number of Care-Givers

PubMed Central

Koester, Diana C.; Freeman, Elizabeth W.; Brown, Janine L.; Wildt, David E.; Terrell, Kimberly A.; Franklin, Ashley D.; Crosier, Adrienne E.

2015-01-01

The collective cheetah (Acinonyx jubatus) population in zoological institutions has never been self-sustaining because of challenges in natural reproduction. A retrospective analysis of North American zoo-breeding records has revealed that >90% of litters produced since 2003 occurred in facilities ‘off-display’ from the public. We examined seminal, endocrine, and behavioral traits of 29 adult male cheetahs that were: 1) managed in public exhibit or off-display facilities; 2) maintained by different numbers of cheetah-specific care-givers; and 3) living adjacent to varying numbers of adult conspecifics. Cheetahs housed off-display produced more total motile sperm/ejaculate (P = 0.04) than on-exhibit males. This finding was mirrored in our laboratory’s historical records where two-fold more total motile sperm (P < 0.01) were measured in ejaculates from individuals with no public exposure (n = 43) compared to on-exhibit (n = 116) counterparts. Males at institutions with ≤3 care-givers also produced more total motile sperm/ejaculate (P < 0.03) and spent more time behaviorally active (P < 0.01) than at facilities using >3 care-givers. Exposure to high numbers of conspecifics within the same institution did not impact (P > 0.05) seminal traits, and presence of the public, care-giver number, or animals/facility had no influence (P > 0.05) on androgen or glucocorticoid excretion or other behavioral metrics. Findings indicate that male cheetahs are sensitive to general public exposure and too many care-givers, resulting in compromised motile sperm output/ejaculate with mechanism of action unrelated to altered androgen or glucocorticoid excretion. PMID:26332582

Disrupting Mating Behavior of Diaphorina citri (Liviidae).

PubMed

Lujo, S; Hartman, E; Norton, K; Pregmon, E A; Rohde, B B; Mankin, R W

2016-12-01

Severe economic damage from citrus greening disease, caused by 'Candidatus Liberibacter asiaticus' bacteria, has stimulated development of methods to reduce mating and reproduction in populations of its insect vector, Diaphorina citri (Hemiptera: Liviidae). Male D. citri find mating partners by walking on host plants, intermittently producing vibrational calls that stimulate duetting replies by receptive females. The replies provide orientational feedback, assisting the search process. To test a hypothesis that D. citri mating can be disrupted using vibrational signals that compete with and/or mask female replies, courtship bioassays were conducted in citrus trees with or without interference from female reply mimics produced by a vibrating buzzer. Statistically significant reductions occurred in the rates and proportions of mating when the buzzer produced reply mimics within 0.4 s after male courtship calls compared with undisturbed controls. Observations of courtship behaviors in the two bioassays revealed activity patterns that likely contributed to the reductions. In both disruption and control tests, males reciprocated frequently between structural bifurcations and other transition points where signal amplitudes changed. Males in the disruption bioassay had to select among vibrational signals combined from the buzzer and the female at each transition point. They often turned towards the buzzer instead of the female. There was a statistically significant reduction in the proportion of males mating if they contacted the buzzer, possibly due to its higher vibration amplitude and duration in comparison with female replies. Potential applications of D. citri mating disruption technology in citrus groves are discussed. Published by Oxford University Press on behalf of Entomological Society of America 2016. This work is written by US Government employees and is in the public domain in the US.

Retracted article: In vitro derivation of mammalian germ cells from stem cells and their potential therapeutic application.

PubMed

Saito, Shigeo; Lin, Ying-Chu; Murayama, Yoshinobu; Nakamura, Yukio; Eckner, Richard; Niemann, Heiner; Yokoyama, Kazunari K

2015-12-01

Pluripotent stem cells (PSCs) are a unique type of cells because they exhibit the characteristics of self-renewal and pluripotency. PSCs may be induced to differentiate into any cell type, even male and female germ cells, suggesting their potential as novel cell-based therapeutic treatment for infertility problems. Spermatogenesis is an intricate biological process that starts from self-renewal of spermatogonial stem cells (SSCs) and leads to differentiated haploid spermatozoa. Errors at any stage in spermatogenesis may result in male infertility. During the past decade, much progress has been made in the derivation of male germ cells from various types of progenitor stem cells. Currently, there are two main approaches for the derivation of functional germ cells from PSCs, either the induction of in vitro differentiation to produce haploid cell products, or combination of in vitro differentiation and in vivo transplantation. The production of mature and fertile spermatozoa from stem cells might provide an unlimited source of autologous gametes for treatment of male infertility. Here, we discuss the current state of the art regarding the differentiation potential of SSCs, embryonic stem cells, and induced pluripotent stem cells to produce functional male germ cells. We also discuss the possible use of livestock-derived PSCs as a novel option for animal reproduction and infertility treatment.

Egg Speckling Patterns Do Not Advertise Offspring Quality or Influence Male Provisioning in Great Tits

PubMed Central

Stoddard, Mary Caswell; Fayet, Annette L.; Kilner, Rebecca M.; Hinde, Camilla A.

2012-01-01

Many passerine birds lay white eggs with reddish brown speckles produced by protoporphyrin pigment. However, the function of these spots is contested. Recently, the sexually selected eggshell coloration (SSEC) hypothesis proposed that eggshell color is a sexually selected signal through which a female advertises her quality (and hence the potential quality of her future young) to her male partner, thereby encouraging him to contribute more to breeding attempts. We performed a test of the SSEC hypothesis in a common passerine, the great tit Parus major. We used a double cross-fostering design to determine whether males change their provisioning behavior based on eggshell patterns they observe at the nest. We also tested the assumption that egg patterning reflects female and/or offspring quality. Because birds differ from humans in their color and pattern perception, we used digital photography and models of bird vision to quantify egg patterns objectively. Neither male provisioning nor chick growth was related to the pattern of eggs males observed during incubation. Although heavy females laid paler, less speckled eggs, these eggs did not produce chicks that grew faster. Therefore, we conclude that the SSEC hypothesis is an unlikely explanation for the evolution of egg speckling in great tits. PMID:22815730

Production and evaluation of YY-male Brook Trout to eradicate nonnative wild brook trout populations

USGS Publications Warehouse

Kennedy, Patrick; Schill, Daniel J.; Meyer, Kevin A.; Campbell, Matthew R.; Vu, Ninh V.; Hansen, Michael J.

2017-01-01

Nonnative Brook Trout Salvelinus fontinalis were introduced throughout western North America in the early 1900s, resulting in widespread self-sustaining populations that are difficult to eradicate and often threaten native salmonid populations. A novel approach for their eradication involves use of YY male (MYY) Brook Trout (created in the hatchery by feminizing XY males and crossing them with normal XY males). If MYY Brook Trout survive after stocking, and reproduce successfully with wild females, in theory this could eventually drive the sex ratio of the wild population to 100% males, at which point the population would not be able to reproduce and would be eradicated. This study represents the first successful development of a FYY and MYY salmonid broodstock, which was produced in four years at relatively low cost. Field trials demonstrated that stocked hatchery MYY Brook Trout survived and produced viable MYY offspring in streams, although reproductive fitness appeared to have been lower than their wild conspecifics. Even if reduced fitness is the norm in both streams and alpine lakes, our population simulations suggest that eradication can be achieved in reasonable time periods under some MYY stocking scenarios, especially when wild Brook Trout are simultaneously suppressed in the population.

Sexual maturation and fertility of male Nigerian Dwarf goat (Capra hircus) clones produced by somatic cell nuclear transfer.

PubMed

Gauthier, M; Pierson, J; Drolet, M; Bhatia, B; Baldassarre, H; Keefer, C L

2001-01-01

Three, genetically identical, Nigerian Dwarf bucks produced by somatic cell nuclear transfer (NT) of fetal fibroblasts were monitored for sexual maturation and fertility. Starting at four months of age, these male clones were trained to serve an artificial vagina (AV). Average age of the NT-derived bucks at first semen collection was 20 weeks, which was not different from that of other young bucks of this breed (average age at first collection = 20 weeks). Average sperm production at 5 months of age for the NT-derived bucks was 5.0 x 10(8) spermatozoa, which was comparable to that of dwarf bucks of similar age (3.4 x 10(8) spermatozoa). At seven months of age, semen collected from two NT-derived bucks was used to artificially inseminate six females (three does per buck). Five does were confirmed pregnant by ultrasound at day 42. Nine healthy kids, four males and five females, were born in March and April 2000. Viable spermatozoa were collected from one of the F1 males at 28 weeks of age. These results demonstrated that NT-derived bucks and one of their male offspring developed sexually within the normal timeframe for their breed and that the clones were fertile.

C-X-C motif chemokine ligand 10 produced by mouse Sertoli cells in response to mumps virus infection induces male germ cell apoptosis

PubMed Central

Jiang, Qian; Wang, Fei; Shi, Lili; Zhao, Xiang; Gong, Maolei; Liu, Weihua; Song, Chengyi; Li, Qihan; Chen, Yongmei; Wu, Han; Han, Daishu

2017-01-01

Mumps virus (MuV) infection usually results in germ cell degeneration in the testis, which is an etiological factor for male infertility. However, the mechanisms by which MuV infection damages male germ cells remain unclear. The present study showed that C-X-C motif chemokine ligand 10 (CXCL10) is produced by mouse Sertoli cells in response to MuV infection, which induces germ cell apoptosis through the activation of caspase-3. CXC chemokine receptor 3 (CXCR3), a functional receptor of CXCL10, is constitutively expressed in male germ cells. Neutralizing antibodies against CXCR3 and an inhibitor of caspase-3 activation significantly inhibited CXCL10-induced male germ cell apoptosis. Furthermore, the tumor necrosis factor-α (TNF-α) upregulated CXCL10 production in Sertoli cells after MuV infection. The knockout of either CXCL10 or TNF-α reduced germ cell apoptosis in the co-cultures of germ cells and Sertoli cells in response to MuV infection. Local injection of MuV into the testes of mice confirmed the involvement of CXCL10 in germ cell apoptosis in vivo. These results provide novel insights into MuV-induced germ cell apoptosis in the testis. PMID:29072682

Gene expression changes in male accessory glands during ageing are accompanied by reproductive decline in Drosophila melanogaster.

PubMed

Koppik, Mareike; Fricke, Claudia

2017-12-01

Senescence is accompanied by loss of reproductive functions. Here, we studied reproductive ageing in Drosophila melanogaster males and asked whether the expected decline in male reproductive success is due to diminished functionality of the male accessory gland (AG). The male AG produces the majority of seminal fluid proteins (SFPs) transferred to the female at mating. SFPs induce female postmating changes and are key to male reproductive success. We measured age-dependent gene expression changes for five representative SFP genes in males from four different age groups ranging from 1 to 6 weeks after eclosion. Simultaneously, we also measured male reproductive success in postmating traits mediated by transfer of these five SFPs. We found a decreased in male SFP gene expression with advancing age and an accompanying decline in male postmating success. Hence, male reproductive senescence is associated with a decline in functionality of the male AG. While overall individual SFP genes decreased in expression, our results point towards the idea that the composition of an ejaculate might change with male age as the rate of change was variable for those five genes. © 2017 John Wiley & Sons Ltd.

Comparison of reproductive traits of regular and irradiated male desert locust Schistocerca gregaria (Orthoptera: Acrididae): Evidence of last-male sperm precedence

PubMed Central

Dushimirimana, Severin; Hance, Thierry; Damiens, David

2012-01-01

Summary The sterile insect technique (SIT) is increasingly used to control pest insect populations. The success of SIT control programs depends on the ability to release sterile males and on the capacity of sterile males to compete with wild males to inseminate wild females. In this study, we evaluated the mating performance of Schistocerca gregaria (Försk.) males irradiated with 4 Gray. We compared reproductive traits, such as duration of precopulation time, mating duration, quantity of sperm stored by females after copulation, number of females mated successively and postmating competition of irradiated males with non-irradiated males. Irradiated males were able to mate but the resulting number of offspring was dramatically reduced compared to the average number of offspring observed during a regular mating. During a single copulation, irradiated males transferred fewer sperm than regular males but, theoretically, this quantity is enough to fertilize all the eggs produced by a female during its reproductive life. Irradiated males also had the ability to remove sperm from a previous mating with unirraditated males. This new information on the mating strategies helps explain the post-copulation guarding behaviour of S. gregaria. PMID:23213413

Hybridogenesis through thelytokous parthenogenesis in two Cataglyphis desert ants.

PubMed

Eyer, P A; Leniaud, L; Darras, H; Aron, S

2013-02-01

Hybridogenesis is a sexual reproductive system, whereby parents from different genetic origin hybridize. Both the maternal and paternal genomes are expressed in somatic tissues, but the paternal genome is systematically excluded from the germ line, which is therefore purely maternal. Recently, a unique case of hybridogenesis at a social level was reported in the desert ant Cataglyphis hispanica. All workers are sexually produced hybridogens, whereas sexual forms (new queens and males) are produced by queens through parthenogenesis. Thus, only maternal genes are perpetuated across generations. Here, we show that such an unusual reproductive strategy also evolved in two other species of Cataglyphis belonging to the same phylogenetic group, Cataglyphis velox and Cataglyphis mauritanica. In both species, queens mate exclusively with males originating from a different genetic lineage than their own to produce hybrid workers, while they use parthenogenesis to produce the male and female reproductive castes. In contrast to single-queen colonies of C. hispanica, colonies of C. velox and C. mauritanica are headed by several queens. Most queens within colonies share the same multilocus genotype and never transmit their mates' alleles to the reproductive castes. Social hybridogenesis in the desert ants has direct consequences on the genetic variability of populations and on caste determination. We also discuss the maintenance of this reproductive strategy within the genus Cataglyphis. © 2012 Blackwell Publishing Ltd.

Male attitude towards masturbating: an impediment to infertility evaluation and sperm parameters.

PubMed

Pottinger, A M; Carroll, K; Mason, G

2016-09-01

Male attitude about masturbation may influence early diagnosis and treatment of infertility and may be of particular burden in developing countries. We sought to explore attitude about masturbating and examine comfort/discomfort with masturbating and sexual history, pregnancy history and sperm quality in men investigating fertility potential. The study consisted of 83 male volunteers, 23-61 years, attending a fertility management unit in Kingston, Jamaica. Comfort with masturbation was assessed by a self-administered questionnaire. Participants also completed the unit's standard intake form for infertility investigations and produced a semen sample. T-tests, Mann-Whitney U-test and chi-square were used to compare differences in comfort level with outcome variables. We found 59% were comfortable masturbating although requiring external stimulation to produce a sample (48%); 6% (n = 5) failed to produce a sample after repeated attempts. A higher percentage of men uncomfortable with masturbating reported sexual problems (P < 0.05) and spending a longer time trying to have a baby (P < 0.05). Semen quality was not associated with masturbating comfort. Producing a sample by masturbation is standard for many assisted conception treatments. As comfort with masturbating may influence delay in infertility investigations and fertility outcome, efforts to improve men's comfort level with semen production should be considered in pre-treatment fertility counselling. © 2015 Blackwell Verlag GmbH.

Pre-Release Consumption of Methyl Eugenol Increases the Mating Competitiveness of Sterile Males of the Oriental Fruit Fly, Bactrocera dorsalis, in Large Field Enclosures

PubMed Central

Shelly, Todd E.; Edu, James; McInnis, Donald

2010-01-01

The sterile insect technique may be implemented to control populations of the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), when environmental concerns preclude widespread use of chemical attractants or toxicants. The goal of the present study was to evaluate whether the mating competitiveness of sterile B. dorsalis males could be increased via pre-release feeding on methyl eugenol. Males of the oriental fruit fly are strongly attracted to this plant-borne compound, which they ingest and use in the synthesis of the sex pheromone. Previous studies conducted in the laboratory and small field-cages have shown that males given methyl eugenol produce a more attractive pheromone for females and have a higher mating success rate than males denied methyl eugenol. Here, levels of egg sterility were compared following the release of wild-like flies and either methyl eugenol-fed (treated) or methyl eugenol-deprived (control) sterile males in large field enclosures at four over flooding ratios ranging from 5:1 to 60:1 (sterile: wild-like males). Treated sterile males were fed methyl eugenol for 1–4 h (depending on the over flooding ratio tested) 3 d prior to release. Eggs were dissected from introduced fruits (apples), incubated in the laboratory, and scored for hatch rate. The effect of methyl eugenol was most pronounced at lower over flooding ratios. At the 5:1 and 10:1 over flooding ratios, the level of egg sterility observed for treated, sterile males was significantly greater than that observed for control, sterile males. In addition, the incidence of egg sterility reported for treated sterile males at these lower over flooding ratios was similar to that noted for treated or control sterile males at the 30:1 or 60:1 over flooding ratios. This latter result, in particular, suggests that pre-release feeding on methyl eugenol allows for a reduction in the number of sterile flies that are produced and released, thus increasing the cost-effectiveness of the sterile insect technique. PMID:20569140

Unusually high-pitched neonate distress calls of the open-habitat Mongolian gazelle ( Procapra gutturosa) and their anatomical and hormonal predictors

NASA Astrophysics Data System (ADS)

Volodin, Ilya A.; Volodina, Elena V.; Frey, Roland; Kirilyuk, Vadim E.; Naidenko, Sergey V.

2017-06-01

In neonate ruminants, the acoustic structure of vocalizations may depend on sex, vocal anatomy, hormonal profiles and body mass and on environmental factors. In neonate wild-living Mongolian gazelles Procapra gutturosa, hand-captured during biomedical monitoring in the Daurian steppes at the Russian-Mongolian border, we spectrographically analysed distress calls and measured body mass of 22 individuals (6 males, 16 females). For 20 (5 male, 15 female) of these individuals, serum testosterone levels were also analysed. In addition, we measured relevant dimensions of the vocal apparatus (larynx, vocal folds, vocal tract) in one stillborn male Mongolian gazelle specimen. Neonate distress calls of either sex were high in maximum fundamental frequency (800-900 Hz), but the beginning and minimum fundamental frequencies were significantly lower in males than in females. Body mass was larger in males than in females. The levels of serum testosterone were marginally higher in males. No correlations were found between either body mass or serum testosterone values and any acoustic variable for males and females analysed together or separately. We discuss that the high-frequency calls of neonate Mongolian gazelles are more typical for closed-habitat neonate ruminants, whereas other open-habitat neonate ruminants (goitred gazelle Gazella subgutturosa, saiga antelope Saiga tatarica and reindeer Rangifer tarandus) produce low-frequency (<200 Hz) distress calls. Proximate cause for the high fundamental frequency of distress calls of neonate Mongolian gazelles is their very short, atypical vocal folds (4 mm) compared to the 7-mm vocal folds of neonate goitred gazelles, producing distress calls as low as 120 Hz.

Effects of Tribulus terrestris on endocrine sensitive organs in male and female Wistar rats.

PubMed

Martino-Andrade, Anderson J; Morais, Rosana N; Spercoski, Katherinne M; Rossi, Stefani C; Vechi, Marina F; Golin, Munisa; Lombardi, Natália F; Greca, Cláudio S; Dalsenter, Paulo R

2010-01-08

Investigate the possible effects of Tribulus terrestris (TT) on endocrine sensitive organs in intact and castrated male rats as well as in a post-menopausal rat model using ovariectomized females. Three different dose levels of TT (11, 42 and 110 mg/kg/day) were administered to castrated males for 7 days and to intact males and castrated females for 28 days. In addition to TT treatment, all experiments also included a group of rats treated with dehydroepiandrosterone (DHEA). In experiments using castrated males and females we also used testosterone and 17 alpha-ethynylestradiol, respectively, as positive controls for androgenicity and estrogenicity. Neither DHEA nor TT was able to stimulate androgen sensitive tissues like the prostate and seminal vesicle in both intact and castrated male rats. In addition, administration of TT to intact male rats for 28 days did not change serum testosterone levels as well as did not produce any quantitative change in the fecal excretion of androgenic metabolites. However, a slight increase in the number of homogenization-resistant spermatids was observed in rats treated with 11 mg/kg/day of TT extract. In ovariectomized females, TT did not produce any stimulatory effects in uterine and vaginal epithelia. Tribulus terrestris was not able to stimulate endocrine sensitive tissues such as the prostate, seminal vesicle, uterus and vagina in Wistar rats, indicating lack of androgenic and estrogenic activity in vivo. We also showed a positive effect of TT administration on rat sperm production, associated with unchanged levels of circulating androgens. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

Gonadal Hormone Modulation of Mu, Kappa, and Delta Opioid Antinociception in Male and Female Rats

PubMed Central

Stoffel, Erin C.; Ulibarri, Catherine M.; Folk, John E.; Rice, Kenner C.

2005-01-01

Previous studies suggest that sex differences in morphine antinociception in rodents might be attributed to the activational effects of gonadal hormones. The present study determined whether hormonal modulation of opioid antinociception in adult rats extends to opioids other than the prototypic mu agonist morphine. Male and female rats were sham-gonadectomized (sham-GDX) or gonadectomized (GDX) and replaced with no hormone, estradiol (E2, females), progesterone (P4, females), E2+P4 (females), or testosterone (males). Approximately 28 days later, nociception was evaluated on the 50°C hot plate and warm water tail withdrawal tests before and after subcutaneous administration of hydromorphone, buprenorphine, U50,488, or SNC 80. In sham-GDX (gonadally intact) rats, the mu agonists and U50,488 were less effective in females than in males in at least one nociceptive test, and the delta agonist SNC 80 was less effective in males than in females. In males, gonadectomy tended to decrease, and testosterone tended to increase antinociception produced by 3 of the 4 agonists. In females, gonadectomy and hormone treatment had more variable effects, although E2 tended to decrease mu opioid antinociception. The present results suggest that activational effects of gonadal hormones are relatively modest and somewhat inconsistent on antinociception produced by various opioid agonists in the adult rat. Perspective: This study demonstrates that reproductive hormones such as testosterone in males and estradiol in females do not consistently modulate sensitivity to the analgesic effects of opioids in the adult organism. PMID:15820914

Acarbose, 17-α-estradiol, and nordihydroguaiaretic acid extend mouse lifespan preferentially in males

PubMed Central

Harrison, David E; Strong, Randy; Allison, David B; Ames, Bruce N; Astle, Clinton M; Atamna, Hani; Fernandez, Elizabeth; Flurkey, Kevin; Javors, Martin A; Nadon, Nancy L; Nelson, James F; Pletcher, Scott; Simpkins, James W; Smith, Daniel; Wilkinson, J Erby; Miller, Richard A

2014-01-01

Four agents — acarbose (ACA), 17-α-estradiol (EST), nordihydroguaiaretic acid (NDGA), and methylene blue (MB) — were evaluated for lifespan effects in genetically heterogeneous mice tested at three sites. Acarbose increased male median lifespan by 22% (P < 0.0001), but increased female median lifespan by only 5% (P = 0.01). This sexual dimorphism in ACA lifespan effect could not be explained by differences in effects on weight. Maximum lifespan (90th percentile) increased 11% (P < 0.001) in males and 9% (P = 0.001) in females. EST increased male median lifespan by 12% (P = 0.002), but did not lead to a significant effect on maximum lifespan. The benefits of EST were much stronger at one test site than at the other two and were not explained by effects on body weight. EST did not alter female lifespan. NDGA increased male median lifespan by 8–10% at three different doses, with P-values ranging from 0.04 to 0.005. Females did not show a lifespan benefit from NDGA, even at a dose that produced blood levels similar to those in males, which did show a strong lifespan benefit. MB did not alter median lifespan of males or females, but did produce a small, statistically significant (6%, P = 0.004) increase in female maximum lifespan. These results provide new pharmacological models for exploring processes that regulate the timing of aging and late-life diseases, and in particular for testing hypotheses about sexual dimorphism in aging and health. PMID:24245565

Acarbose, 17-α-estradiol, and nordihydroguaiaretic acid extend mouse lifespan preferentially in males.

PubMed

Harrison, David E; Strong, Randy; Allison, David B; Ames, Bruce N; Astle, Clinton M; Atamna, Hani; Fernandez, Elizabeth; Flurkey, Kevin; Javors, Martin A; Nadon, Nancy L; Nelson, James F; Pletcher, Scott; Simpkins, James W; Smith, Daniel; Wilkinson, J Erby; Miller, Richard A

2014-04-01

Four agents--acarbose (ACA), 17-α-estradiol (EST), nordihydroguaiaretic acid (NDGA), and methylene blue (MB)--were evaluated for lifespan effects in genetically heterogeneous mice tested at three sites. Acarbose increased male median lifespan by 22% (P < 0.0001), but increased female median lifespan by only 5% (P = 0.01). This sexual dimorphism in ACA lifespan effect could not be explained by differences in effects on weight. Maximum lifespan (90th percentile) increased 11% (P < 0.001) in males and 9% (P = 0.001) in females. EST increased male median lifespan by 12% (P = 0.002), but did not lead to a significant effect on maximum lifespan. The benefits of EST were much stronger at one test site than at the other two and were not explained by effects on body weight. EST did not alter female lifespan. NDGA increased male median lifespan by 8-10% at three different doses, with P-values ranging from 0.04 to 0.005. Females did not show a lifespan benefit from NDGA, even at a dose that produced blood levels similar to those in males, which did show a strong lifespan benefit. MB did not alter median lifespan of males or females, but did produce a small, statistically significant (6%, P = 0.004) increase in female maximum lifespan. These results provide new pharmacological models for exploring processes that regulate the timing of aging and late-life diseases, and in particular for testing hypotheses about sexual dimorphism in aging and health. © 2013 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

Paternal preconception alcohol exposure imparts intergenerational alcohol-related behaviors to male offspring on a pure C57BL/6J background.

PubMed

Rompala, Gregory R; Finegersh, Andrey; Slater, Michelle; Homanics, Gregg E

2017-05-01

While alcohol use disorder (AUD) is a highly heritable condition, the basis of AUD in families with a history of alcoholism is difficult to explain by genetic variation alone. Emerging evidence suggests that parental experience prior to conception can affect inheritance of complex behaviors in offspring via non-genomic (epigenetic) mechanisms. For instance, male C57BL/6J (B6) mice exposed to chronic intermittent vapor ethanol (CIE) prior to mating with Strain 129S1/SvImJ ethanol-naïve females produce male offspring with reduced ethanol-drinking preference, increased ethanol sensitivity, and increased brain-derived neurotrophic factor (BDNF) expression in the ventral tegmental area (VTA). In the present study, we tested the hypothesis that these intergenerational effects of paternal CIE are reproducible in male offspring on an inbred B6 background. To this end, B6 males were exposed to 6 weeks of CIE (or room air as a control) before mating with ethanol-naïve B6 females to produce ethanol (E)-sired and control (C)-sired male and female offspring. We observed a sex-specific effect, as E-sired males exhibited decreased two-bottle free-choice ethanol-drinking preference, increased sensitivity to the anxiolytic effects of ethanol, and increased VTA BDNF expression; no differences were observed in female offspring. These findings confirm and extend our previous results by demonstrating that the effects of paternal preconception ethanol are reproducible using genetically identical, inbred B6 animals. Copyright © 2016 Elsevier Inc. All rights reserved.

The transformer2 gene of the pumpkin fruit fly, Bactrocera tau (Walker), functions in sex determination, male fertility and testis development.

PubMed

Thongsaiklaing, Thanaset; Nipitwattanaphon, Mingkwan; Ngernsiri, Lertluk

2018-06-22

The insect transformer2 (tra2) gene has a prevalent role in cooperating with the sex determining gene transformer (tra) to direct female differentiation. Here, we report the identification and characterization of Btau-tra2, the tra2 ortholog of the pumpkin fruit fly, Bactrocera tau, an invasive agricultural pest. The Btau-tra2 gene produces three transcript variants. However, only two transcripts can be examined; one is present at all developmental stages in the soma and germline of both sexes and the other one is specific to embryo and the germline. Knocking down the function of Btau-tra2 produced a male biased sex ratio and some intersexes. Consistent with a role in sex determination, the obtained intersexual and male sterility phenotypes express a mix of male and female splice variants of the tra and doublesex (dsx) orthologs, indicating that Btau-tra2 has a conserved splicing regulatory function and acts together/upstream of tra and dsx. In addition, some males obtained from the knock down are fertile but their fertilities are extremely reduced. Moreover, almost all surviving RNAi males harbor testes having some defects in their external morphologies. Most notably, the body size of a few surviving RNAi flies was two to three folds increased with respect to the normal size. Our findings suggest that Btua-tra2 is involved in male fertility and may also have an unprecedented role in body size control besides its conserved role in sex determination. This article is protected by copyright. All rights reserved. © 2018 The Royal Entomological Society.

Birth order, estrogens and sex-ratio adaptation in African wild dogs (Lycaon pictus).

PubMed

Creel, S; Creel, N M; Monfort, S L

1998-10-01

Because the sex of mammals is chromosomally determined, populations generally produce a similar proportion of males and females. However, it has been recognized for more than century that individuals might increase their fitness by over-producing offspring of one sex, under certain conditions. Small biases in the secondary sex ratio are seen in many vertebrates. Here, we report that the sex ratio of primiparous African wild dogs (Lycaon pictus) is strongly biased in favor of sons (63%), while multiparous females produce an excess of daughters (64%). The direction of these biases is predicted by individual females' need for subordinate helpers. For humans, elevated estrogens have been hypothesized to bias the secondary sex ratio toward males. Consistent with this hypothesis, primiparous female wild dogs had basal estrogen levels double those of multiparous females.

Androgens and bone.

PubMed

De Oliveira, D H A; Fighera, T M; Bianchet, L C; Kulak, C A M; Kulak, J

2012-12-01

Testosterone is the major gonadal sex steroid produced by the testes in men. Androgens induce male sexual differentiation before birth and sexual maturation during puberty; in adult men, they maintain the function of the male genital system, including spermatogenesis. Testosterone is also produced in smaller amounts by the ovaries in women. The adrenal glands produce the weaker androgens dehydroepiandrosterone, dehydroepiandrosterone sulfate, and androstenedione. Because testosterone can be metabolized to estradiol by the aromatase enzyme, there has been controversy as to which gonadal sex steroid has the greater skeletal effect. In this respect, there is increasing evidence that at least part of the effects of androgens in men can be explained by their aromatization into estrogens. The current evidence suggests that estradiol plays a greater role in maintenance of skeletal health than testosterone, but that androgens also have direct beneficial effects on bone.

A post-processing algorithm for time domain pitch trackers

NASA Astrophysics Data System (ADS)

Specker, P.

1983-01-01

This paper describes a powerful post-processing algorithm for time-domain pitch trackers. On two successive passes, the post-processing algorithm eliminates errors produced during a first pass by a time-domain pitch tracker. During the second pass, incorrect pitch values are detected as outliers by computing the distribution of values over a sliding 80 msec window. During the third pass (based on artificial intelligence techniques), remaining pitch pulses are used as anchor points to reconstruct the pitch train from the original waveform. The algorithm produced a decrease in the error rate from 21% obtained with the original time domain pitch tracker to 2% for isolated words and sentences produced in an office environment by 3 male and 3 female talkers. In a noisy computer room errors decreased from 52% to 2.9% for the same stimuli produced by 2 male talkers. The algorithm is efficient, accurate, and resistant to noise. The fundamental frequency micro-structure is tracked sufficiently well to be used in extracting phonetic features in a feature-based recognition system.

Evolution of postmating reproductive isolation: measuring the fitness effects of chromosomal regions containing hybrid male sterility factors.

PubMed

Johnson, N A; Wu, C I

1993-08-01

At least six regions of the X chromosome can cause male sterility when introgressed from Drosophila mauritiana into Drosophila simulans. In this article, we present the results of the other fitness effects caused by two X-linked regions that contain hybrid male sterility factors. In both regions, females that are heterozygous for an introgression with such a sterility factor produce substantially-fewer offspring than females heterozygous for an introgression that lacks the sterility factor. Thus, the hybrid male sterility factors, or other genes nearby, have substantial effects on female productivity. In contrast, hybrid male sterility factors have little or no effect on the relative viabilities of either sex. The evolutionary implications of these findings are discussed.

Sexual cannibalism increases male material investment in offspring: quantifying terminal reproductive effort in a praying mantis

PubMed Central

Brown, William D.; Barry, Katherine L.

2016-01-01

Models of the evolution of sexual cannibalism argue that males may offset the cost of cannibalism if components of the male body are directly allocated to the eggs that they fertilize. We tested this idea in the praying mantid Tenodera sinensis. Males and females were fed differently radiolabelled crickets and allowed to mate. Half of the pairs progressed to sexual cannibalism and we prevented cannibalism in the other half. We assess the relative allocation of both male-derived somatic materials and ejaculate materials into the eggs and soma of the female. Our results show that male somatic investment contributes to production of offspring. The eggs and reproductive tissues of cannibalistic females contained significantly more male-derived amino acids than those of non-cannibalistic females, and there was an increase in the number of eggs produced subsequent to sexual cannibalism. Sexual cannibalism thus increases male material investment in offspring. We also show that males provide substantial investment via the ejaculate, with males passing about 25% of their radiolabelled amino acids to females via the ejaculate even in the absence of cannibalism. PMID:27358366

Manakins can produce iridescent and bright feather colours without melanosomes.

PubMed

Igic, Branislav; D'Alba, Liliana; Shawkey, Matthew D

2016-06-15

Males of many species often use colourful and conspicuous ornaments to attract females. Among these, male manakins (family: Pipridae) provide classic examples of sexual selection favouring the evolution of bright and colourful plumage coloration. The highly iridescent feather colours of birds are most commonly produced by the periodic arrangement of melanin-containing organelles (melanosomes) within barbules. Melanin increases the saturation of iridescent colours seen from optimal viewing angles by absorbing back-scattered light; however, this may reduce the wide-angle brightness of these signals, contributing to a dark background appearance. We examined the nanostructure of four manakin species (Lepidothrix isidorei, L. iris, L. nattereri and L. coeruleocapilla) to identify how they produce their bright plumage colours. Feather barbs of all four species were characterized by dense and fibrous internal spongy matrices that likely increase scattering of light within the barb. The iridescent, yet pale or whitish colours of L. iris and L. nattereri feathers were produced not by periodically arranged melanosomes within barbules, but by periodic matrices of air and β-keratin within barbs. Lepidothrix iris crown feathers were able to produce a dazzling display of colours with small shifts in viewing geometry, likely because of a periodic nanostructure, a flattened barb morphology and disorder at a microstructural level. We hypothesize that iridescent plumage ornaments of male L. iris and L. nattereri are under selection to increase brightness or luminance across wide viewing angles, which may potentially increase their detectability by females during dynamic and fast-paced courtship displays in dim light environments. © 2016. Published by The Company of Biologists Ltd.

The Development of a Greeting Signal in Wild Chimpanzees

ERIC Educational Resources Information Center

Laporte, Marion N. C.; Zuberbuhler, Klaus

2011-01-01

Adult chimpanzees produce a unique vocal signal, the pant-grunt, when encountering higher-ranking group members. The behaviour is typically directed to a specific receiver and has thus been interpreted as a "greeting" signal. The alpha male obtains a large share of these calls, followed by the other adult males of the group. In this study, we…

A Five Year Analysis of Female vs. Male College Students' Persistence to Graduation: One Case Study.

ERIC Educational Resources Information Center

Stoner, Kenneth L.; DeRidder, Janet Waller

1982-01-01

Recent literature indicates sex is related to retention with more men persisting to graduation. In this University of Tennessee (Knoxville) study, analysis according to sex classification produced results contrary to the latest research findings: rather than males, females tended to graduate earlier or on schedule proportionately more frequently…

Inter-Sentential Patterns of Code-Switching: A Gender-Based Investigation of Male and Female EFL Teachers

ERIC Educational Resources Information Center

Gulzar, Malik Ajmal; Farooq, Muhammad Umar; Umer, Muhammad

2013-01-01

This article has sought to contribute to discussions concerning the value of inter-sentential patterns of code-switching (henceforth ISPCS) particularly in the context of EFL classrooms. Through a detailed analysis of recorded data produced in that context, distinctive features in the discourse were discerned which were associated with males' and…

50 CFR 14.252 - What definitions do I need to know?

Code of Federal Regulations, 2014 CFR

2014-10-01

... wildlife species means a specimen of any of the following eight species: Lion (Panthera leo), tiger... from the breeding of any combination of any of these species, for example, a liger (a male lion and a female tiger) or a tiglon (a male tiger and a female lion), whether naturally or artificially produced...

50 CFR 14.252 - What definitions do I need to know?

Code of Federal Regulations, 2013 CFR

2013-10-01

... wildlife species means a specimen of any of the following eight species: Lion (Panthera leo), tiger... from the breeding of any combination of any of these species, for example, a liger (a male lion and a female tiger) or a tiglon (a male tiger and a female lion), whether naturally or artificially produced...

50 CFR 14.252 - What definitions do I need to know?

Code of Federal Regulations, 2012 CFR

2012-10-01

... wildlife species means a specimen of any of the following eight species: Lion (Panthera leo), tiger... from the breeding of any combination of any of these species, for example, a liger (a male lion and a female tiger) or a tiglon (a male tiger and a female lion), whether naturally or artificially produced...

The Effectiveness of Verbal Counseling VS. Social Interaction Counseling of College Males. Final Report.

ERIC Educational Resources Information Center

Stewart, Norman R.; Hay, Nancy M.

The purpose of this investigation was to assess the effectiveness of three different short-term treatment interventions with college males characterized by little or no dating behavior and fears about dating. The treatments were designed to produce evidence concerning the effectiveness of: (1) lay versus professional action interventions, (2)…

Men's Behavior toward Women after Viewing Sexually-Explicit Films: Degradation Makes a Difference.

ERIC Educational Resources Information Center

Mulac, Anthony; Jansma, Laura L.; Linz, Daniel G.

2002-01-01

Notes that short-term exposure to nonviolent sexual media stimuli can produce cognitive changes in men which can affect their behavior toward women. Explores differences among these behavioral effects in a group of male and female undergraduate students based upon sexual degradation in film content and male viewers' gender schematicity. Discusses…

Relative Effects of Juvenile and Adult Environmental Factors on Mate Attraction and Recognition in the Cricket, Allonemobius socius

PubMed Central

Olvido, Alexander E.; Fernandes, Pearl R.; Mousseau, Timothy A.

2010-01-01

Finding a mate is a fundamental aspect of sexual reproduction. To this end, specific-mate recognition systems (SMRS) have evolved that facilitate copulation between producers of the mating signal and their opposite-sex responders. Environmental variation, however, may compromise the efficiency with which SMRS operate. In this study, the degree to which seasonal climate experienced during juvenile and adult life-cycle stages affects the SMRS of a cricket, Allonemobius socius (Scudder) (Orthoptera: Gryllidae) was assessed. Results from two-choice behavioral trials suggest that adult ambient temperature, along with population and family origins, mediate variation in male mating call, and to a lesser extent directional response of females for those calls. Restricted maximum-likelihood estimates of heritability for male mating call components and for female response to mating call appeared statistically nonsignificant. However, appreciable “maternal genetic effects” suggest that maternal egg provisioning and other indirect maternal determinants of the embryonic environment significantly contributed to variation in male mating call and female response to mating calls. Thus, environmental factors can generate substantial variation in A. socius mating call, and, more importantly, their marginal effect on female responses to either fast-chirp or long-chirp mating calls suggest negative fitness consequences to males producing alternative types of calls. Future studies of sexual selection and SMRS evolution, particularly those focused on hybrid zone dynamics, should take explicit account of the loose concordance between signal producers and responders suggested by the current findings. PMID:20673114

"Mitochondrial Eve", "Y Chromosome Adam", testosterone, and human evolution.

PubMed

Howard, James Michael

2002-01-01

I suggest primate evolution began as a consequence of increased testosterone in males which increased aggression and sexuality, therefore, reproduction and success. With time, negative effects of excessive testosterone reduced spermatogenesis and started a decline of the group. Approximately 30-40 million years ago, the gene DAZ (Deleted in AZoospermia) appeared on the Y chromosome, increased spermatogenesis, and rescued the early primates from extinction. (Note: DAZ is considered by some to specifically, positively affect spermatogenesis; others suggest it has no effect on spermatogenesis.) Hominid evolution continued with increasing testosterone. The advent of increased testosterone in females of Homo erectus (or Homo ergaster) increased the female-to-male body size ratio, and eventually produced another era of excessive testosterone. Excessive testosterone caused a reduction in population size (bottleneck) that produced the "Mitochondrial Eve" (ME) mechanism. (Only certain females continued during the bottleneck to transmit their mitochondrial DNA.) That is, the ME mechanism culminated, again, in excessive testosterone and reduced spermatogenesis in the hominid line. Approximately 50,000 to 200,000 years ago, a "doubling" of the DAZ gene occurred on the Y chromosome in hominid males which rescued the hominid line with increased spermatogenesis in certain males. This produced the "Y Chromosome Adam" event. The doubling of DAZ allowed further increases in testosterone in hominids that resulted in the increased size and development of the brain. Modern humans periodically fluctuate between the positive and negative consequences of increased levels of testosterone, currently identifiable as the secular trend, increased infections, and reduced spermatogenesis.

First artificial hybrid of the eel species Anguilla australis and Anguilla anguilla.

PubMed

Burgerhout, Erik; Brittijn, Sebastiaan A; Kurwie, Tagried; Decker, Paul; Dirks, Ron P; Palstra, Arjan P; Spaink, Herman P; Van den Thillart, Guido E E J M

2011-03-13

Studies on artificial hybridization of different Anguilla species were conducted recently, i.e. female A. australis with male A. dieffenbachii, and female A. japonica with male A. anguilla. The existence of these artificial hybrids was however not demonstrated by independent genetic methods. Two species - A. anguilla and A. australis - that are phylogenetically close but have different sexual maturation times (12-25 weeks and 6-8 weeks, respectively), were expected to produce favourable hybrids for reproduction studies. A modification of the protocol for the reproduction of Anguilla japonica was used to produce eight-day Anguilla australis larvae, with a success rate of 71.4%. Thus ten out of 14 females produced eggs that could be fertilized, and three batches resulted in mass hatching. Hybrid larvae from female A. australis x male A. Anguilla survived for up to seven days post fertilization (dpf). The early development of the hybrid showed typical characteristics of A. anguilla tail pigmentation at 50 hours post fertilization (hpf), indicating expression of genes derived from the father. In this paper we describe the first production of hybrid larvae from male A. anguilla and female A. australis and their survival for up to 7 dpf. A species-specific nucleotide difference in the 18 S rDNA gene confirmed that genes from both A. australis and A. anguilla were present in the hybrids. The developmental stages of the hybrid eel embryos and larvae are described using high resolution images. Video footage also indicated a heart beat in 5-dpf larva.

The effects of sexual experience and estrus on male-seeking motivated behavior in the female rat

PubMed Central

Nofrey, Barbara; Rocha, Beatriz; Lopez, Hassan H.; Ettenberg, Aaron

2008-01-01

Ovariectomized (OVX) female rats were trained to traverse a straight alley and return to a goal box where they had previously encountered a male rat, a female rat or an empty goal box. The time required to run the alley was used as an index of the subjects’ motivation to re-engage the goal box target. Subjects were tested in both estrus and non-estrus, first sexually naïve and then again after sexual experience. Female rats ran most quickly for a male target, most slowly for an empty goal box, and at intermediate speeds for a female target. Sexual experience tended to slow run times for all but male targets. Estrus enhanced approach behavior for males and an empty goal box, but tended to slow the approach toward females, both before and after sexual experience. This latter finding was further investigated in a second experiment in which sexually naïve OVX females were tested during estrus and non-estrus in a locomotor activity apparatus, a runway with an empty goal box, and an open field. Estrus produced no changes in spontaneous locomotion either in the activity box or the open field, but decreased run times in the alley and increased the number of center-square entries in the open-field. Thus, estrus produces increases in sexual motivation that selectively enhance exploratory, presumably male-seeking behavior, but not simple spontaneous locomotion. PMID:18761024

Robotic crabs reveal that female fiddler crabs are sensitive to changes in male display rate.

PubMed

Mowles, Sophie L; Jennions, Michael D; Backwell, Patricia R Y

2018-01-01

Males often produce dynamic, repetitive courtship displays that can be demanding to perform and might advertise male quality to females. A key feature of demanding displays is that they can change in intensity: escalating as a male increases his signalling effort, but de-escalating as a signaller becomes fatigued. Here, we investigated whether female fiddler crabs, Uca mjoebergi , are sensitive to changes in male courtship wave rate. We performed playback experiments using robotic male crabs that had the same mean wave rate, but either escalated, de-escalated or remained constant. Females demonstrated a strong preference for escalating robots, but showed mixed responses to robots that de-escalated ('fast' to 'slow') compared to those that waved at a constant 'medium' rate. These findings demonstrate that females can discern changes in male display rate, and prefer males that escalate, but that females are also sensitive to past display rates indicative of prior vigour. © 2018 The Authors.

Heterosexual Male Carriers Could Explain Persistence of Homosexuality in Men: Individual-Based Simulations of an X-Linked Inheritance Model.

PubMed

Chaladze, Giorgi

2016-10-01

Homosexuality has been documented throughout history and is found in almost all human cultures. Twin studies suggest that homosexuality is to some extent heritable. However, from an evolutionary perspective, this poses a problem: Male homosexuals tend to have on average five times fewer children than heterosexual males, so how can a phenomenon associated with low reproductive success be maintained at relatively stable frequencies? Recent findings of increased maternal fecundity of male homosexuals suggest that the genes responsible for homosexuality in males increase fecundity in the females who carry them. Can an increase in maternal fecundity compensate for the fecundity reduction in homosexual men and produce a stable polymorphism? In the current study, this problem was addressed with an individual-based modeling (IBM) approach. IBM suggests that male homosexuality can be maintained in a population at low and stable frequencies if roughly more than half of the females and half of the males are carriers of genes that predispose the male to homosexuality.

Sex determination in beetles: Production of all male progeny by Parental RNAi knockdown of transformer

PubMed Central

Shukla, Jayendra Nath; Palli, Subba Reddy

2012-01-01

Sex in insects is determined by a cascade of regulators ultimately controlling sex-specific splicing of a transcription factor, Doublesex (Dsx). We recently identified homolog of dsx in the red flour beetle, Tribolium castaneum (Tcdsx). Here, we report on the identification and characterization of a regulator of Tcdsx splicing in T. castaneum. Two male-specific and one female-specific isoforms of T. castaneum transformer (Tctra) were identified. RNA interference-aided knockdown of Tctra in pupa or adults caused a change in sex from females to males by diverting the splicing of Tcdsx pre-mRNA to male-specific isoform. All the pupa and adults developed from Tctra dsRNA injected final instar larvae showed male-specific sexually dimorphic structures. Tctra parental RNAi caused an elimination of females from the progeny resulting in production of all male progeny. Transformer parental RNAi could be used to produce all male population for use in pest control though sterile male release methods. PMID:22924109

Expression of putative sex-determining genes during the thermosensitive period of gonad development in the snapping turtle, Chelydra serpentina.

PubMed

Rhen, T; Metzger, K; Schroeder, A; Woodward, R

2007-01-01

Modes of sex determination are quite variable in vertebrates. The developmental decision to form a testis or an ovary can be influenced by one gene, several genes, environmental variables, or a combination of these factors. Nevertheless, certain morphogenetic aspects of sex determination appear to be conserved in amniotes. Here we clone fragments of nine candidate sex-determining genes from the snapping turtle Chelydra serpentina, a species with temperature-dependent sex determination (TSD). We then analyze expression of these genes during the thermosensitive period of gonad development. In particular, we compare gene expression profiles in gonads from embryos incubated at a male-producing temperature to those from embryos at a female-producing temperature. Expression of Dmrt1 and Sox9 mRNA increased gradually at the male-producing temperature, but was suppressed at the female-producing temperature. This finding suggests that Dmrt1 and Sox9 play a role in testis development. In contrast, expression of aromatase, androgen receptor (Ar), and Foxl2 mRNA was constant at the male-producing temperature, but increased several-fold in embryos at the female-producing temperature. Aromatase, Ar, and Foxl2 may therefore play a role in ovary development. In addition, there was a small temperature effect on ER alpha expression with lower mRNA levels found in embryos at the female-producing temperature. Finally, Dax1, Fgf9, and SF-1 were not differentially expressed during the sex-determining period, suggesting these genes are not involved in sex determination in the snapping turtle. Comparison of gene expression profiles among amniotes indicates that Dmrt1 and Sox9 are part of a core testis-determining pathway and that Ar, aromatase, ER alpha, and Foxl2 are part of a core ovary-determining pathway. 2007 S. Karger AG, Basel

A Comparative Analysis of the Morphology and Evolution of Permanent Sperm Depletion in Spiders

PubMed Central

2011-01-01

Once thought to be energetically cheap and easy to produce, empirical work has shown that sperm is a costly and limited resource for males. In some spider species, there is behavioral evidence that sperm are permanently depleted after a single mating. This extreme degree of mating investment appears to co-occur with other reproductive strategies common to spiders, e.g. genital mutilation and sexual cannibalism. Here we corroborate that sperm depletion in the golden orb-web spider Nephila clavipes is permanent by uncovering its mechanistic basis using light and electron microscopy. In addition, we use a phylogeny-based statistical analysis to test the evolutionary relationships between permanent sperm depletion (PSD) and other reproductive strategies in spiders. Male testes do not produce sperm during adulthood, which is unusual in spiders. Instead, spermatogenesis is nearly synchronous and ends before the maturation molt. Testis size decreases as males approach their maturation molt and reaches its lowest point after sperm is transferred into the male copulatory organs (pedipalps). As a consequence, the amount of sperm available to males for mating is limited to the sperm contained in the pedipalps, and once it is used, males lose their ability to fertilize eggs. Our data suggest that PSD has evolved independently at least three times within web-building spiders and is significantly correlated with the evolution of other mating strategies that limit males to monogamy, including genital mutilation and sexual cannibalism. We conclude that PSD may be an energy-saving adaptation in species where males are limited to monogamy. This could be particularly important in web-building spiders where extreme sexual size dimorphism results in large, sedentary females and small, searching males who rarely feed as adults and are vulnerable to starvation. Future work will explore possible energetic benefits and the evolutionary lability of PSD relative to other mate-limiting reproductive behaviors. PMID:21264312

Pheromones in White Pine Cone Beetle, Conophthorus coniperdu (Schwarz) (Coleoptera: Scolytidae)

Treesearch

Goran Birgersson; Gary L. DeBarr; Peter de Groot; Mark J. Dalusky; Harold D. Pierce; John H. Borden; Holger Meyer; Wittko Francke; Karl E. Espelie; C. Wayne Berisford

1995-01-01

Female white pine cone beetles, Conophrhorus coniperda, attacking second-year cones of eastern white pine, Pinus strobus L., produced a sex-specific pheromone that attracted conspecific males in laboratory bioassays and to field traps. Beetle response was enhanced by host monoterpenes. The female-produced compound was identified in...

Characterization of an Aggregation Pheromone in Hylesinus pruinosus (Coleoptera: Curculionidae: Scolytinae)

Treesearch

William Shepherd; Brian Sullivan; Bradley Hoosier; JoAnne Barrett; Tessa Bauman

2010-01-01

We conducted laboratory and field bioassays to characterize the pheromone system of an ash bark beetle, Hylesinus pruinosus Eichhoff (Coleoptera: Curculionidae: Scolytinae). Solitary females in newly initiated galleries in ash logs produced (+)-exo-brevicomin, whereas male beetles paired with females produced (+)-endo-brevicomin, lesser quantities of...

Male rank affects reproductive success and offspring performance in bank voles.

PubMed

Kruczek, Małgorzata; Zatorska, Magdalena

2008-07-05

Laboratory studies reveal that in several rodent species the females prefer dominant males as mating partners. Here we investigate the correlation between males' social rank and their reproductive success. Similar numbers of females mating with relatively more dominant or relatively more subordinate males produced a litter, and parturition took place 19-21 days after mating. Relatively more dominant males tended to sire more pups than did relatively more subordinates, but the mean number of offspring per litter did not differ significantly between the two groups. Significantly more pups fathered by relatively more dominant males survived to weaning than those sired by relatively more subordinate fathers. Dominance had a long-term effect on the reproductive activity of the offspring: their rate of sexual maturation was increased. In pups sired by a relatively more dominant father, the uteruses of females, and the testes and accessory sex glands of males, were significantly heavier than those of offspring born to relatively more subordinate males. Our results suggest that social rank is an important determinant of the reproductive success of bank vole males.

Impact of inflammation on male fertility.

PubMed

Sarkar, Oli; Bahrainwala, Jamila; Chandrasekaran, Sambamurthy; Kothari, Shiva; Mathur, Premendu P; Agarwal, Ashok

2011-01-01

The male uro-genital tract is susceptible to gram-negative bacterial infections that produce a state of inflammation, particularly in the testis and epididymis. Development of germline stem cells into motile spermatozoa takes place in these organs and thus any impairment therein has a direct effect on male fertility. A number of factors are known to impair male fertility including environmental and chemical factors, lifestyle, and infections. The last is a little-known and poorly understood cause of male sub-/infertility. The presence of the pro-inflammatory cytokines like tumor necrosis factor-alpha (TNF- alpha), interleukin-1alpha (IL-1alpha) and interleukin-1beta (IL-1beta) in the male uro-genital tract following bacterial infections suggests that such infections could have cytokine-mediated anti-fertility effects. Furthermore, inflammation has been associated with elevated levels of reactive oxygen species and oxidative stress both of which affect male fertility. The present article summarizes the effects of inflammation on the testis, epididymis and spermatozoa. We review the correlations between inflammation and oxidative stress vis-à-vis spermatogenesis and discuss the implications of infections on male fertility/infertility and assisted reproductive technologies for the male.

Fast-growing willow shrub named `Canastota`

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abrahamson, Lawrence P; Kopp, Richard F; Smart, Lawrence B

A distinct male cultivar of Salix sachalinensis.times.S. miyabeana named `Canastota`, characterized by rapid stem growth producing greater than 2.7-fold more woody biomass than its female parent (Salix sachalinensis `SX61`), 28% greater woody biomass yield than its male parent (Salix miyabeana `SX64`), and 20% greater woody biomass yield than a standard production cultivar, Salix dasyclados `SV1` when grown in the same field for the same length of time (two growing seasons after coppice) in Tully, N.Y. `Canastota` can be planted from dormant stem cuttings, produces multiple stems after coppice, and the stem biomass can be harvested when the plant is dormant.more » In the spring following harvest, the plant will re-sprout very vigorously, producing new stems that can be harvested after two to four years of growth. This harvest cycle can be repeated several times. `Canastota` displays a low incidence of rust disease or damage by willow sawfly.« less

Fast-growing willow shrub named `Canastota`

DOEpatents

Abrahamson, Lawrence P.; Kopp, Richard F.; Smart, Lawrence B.; Volk, Timothy A.

2007-05-15

A distinct male cultivar of Salix sachalinensis.times.S. miyabeana named `Canastota`, characterized by rapid stem growth producing greater than 2.7-fold more woody biomass than its female parent (Salix sachalinensis `SX61`), 28% greater woody biomass yield than its male parent (Salix miyabeana `SX64`), and 20% greater woody biomass yield than a standard production cultivar, Salix dasyclados `SV1` when grown in the same field for the same length of time (two growing seasons after coppice) in Tully, N.Y. `Canastota` can be planted from dormant stem cuttings, produces multiple stems after coppice, and the stem biomass can be harvested when the plant is dormant. In the spring following harvest, the plant will re-sprout very vigorously, producing new stems that can be harvested after two to four years of growth. This harvest cycle can be repeated several times. `Canastota` displays a low incidence of rust disease or damage by willow sawfly.

Male Responses to Conspecific Advertisement Signals in the Field Cricket Gryllus rubens (Orthoptera: Gryllidae)

PubMed Central

Jang, Yikweon

2011-01-01

In many species males aggregate and produce long-range advertisement signals to attract conspecific females. The majority of the receivers of these signals are probably other males most of the time, and male responses to competitors' signals can structure the spatial and temporal organization of the breeding aggregation and affect male mating tactics. I quantified male responses to a conspecific advertisement stimulus repeatedly over three age classes in Gryllus rubens (Orthoptera: Gryllidae) in order to estimate the type and frequency of male responses to the broadcast stimulus and to determine the factors affecting them. Factors tested included body size, wing dimorphism, age, and intensity of the broadcast stimulus. Overall, males employed acoustic response more often than positive phonotactic response. As males aged, the frequency of positive phonotactic response decreased but that of the acoustic response increased. That is, males may use positive phonotaxis in the early stages of their adult lives, possibly to find suitable calling sites or parasitize calling males, and then later in life switch to acoustic responses in response to conspecific advertisement signals. Males with smaller body size more frequently exhibited acoustic responses. This study suggests that individual variation, more than any factors measured, is critical for age-dependent male responses to conspecific advertisement signals. PMID:21283758

Male responses to conspecific advertisement signals in the field cricket Gryllus rubens (Orthoptera: Gryllidae).

PubMed

Jang, Yikweon

2011-01-20

In many species males aggregate and produce long-range advertisement signals to attract conspecific females. The majority of the receivers of these signals are probably other males most of the time, and male responses to competitors' signals can structure the spatial and temporal organization of the breeding aggregation and affect male mating tactics. I quantified male responses to a conspecific advertisement stimulus repeatedly over three age classes in Gryllus rubens (Orthoptera: Gryllidae) in order to estimate the type and frequency of male responses to the broadcast stimulus and to determine the factors affecting them. Factors tested included body size, wing dimorphism, age, and intensity of the broadcast stimulus. Overall, males employed acoustic response more often than positive phonotactic response. As males aged, the frequency of positive phonotactic response decreased but that of the acoustic response increased. That is, males may use positive phonotaxis in the early stages of their adult lives, possibly to find suitable calling sites or parasitize calling males, and then later in life switch to acoustic responses in response to conspecific advertisement signals. Males with smaller body size more frequently exhibited acoustic responses. This study suggests that individual variation, more than any factors measured, is critical for age-dependent male responses to conspecific advertisement signals.

Sperm precedence in female apple maggots alternately mated to normal and irradiated males

DOE Office of Scientific and Technical Information (OSTI.GOV)

Myers, H.S.; Barry, B.D.; Burnside, J.A.

1976-01-15

A dose of irradiation (Cesium 137) of 3 krad was sufficient to sterilize both sexes of the apple maggot, Rhagoletis pomonella (Walsh). When the irradiated male (IM) mated with normal female (NF), egg production was not reduced compared with a normal mating, but the eggs were not viable. Also, two matings of 1 NF with either 2 IM or with 1 NM and 1 IM, produced fewer eggs than a single mating with 1 normal male. Sperm precedence exhibited for the 2nd of the 2 matings was not complete.

Stocker and feedlot performance of beef heifers sired by Braunvieh and Wagyu bulls from Angus-, Brahman-, Senepol- and Tuli-sired dams

USDA-ARS?s Scientific Manuscript database

Female beef calves not retained within the cow-calf enterprise are sold and moved through the same production phases as male calves to produce finished beef. Female beef calves can be purchased at a lower price and have more post-weaning marketing opportunities than male calves. The objective of thi...

The Impact of a Culturally Appropriate, STD/AIDS Education Intervention on Black Male Adolescents' Sexual and Condom Use Behavior.

ERIC Educational Resources Information Center

DeLamater, John; Wagstaff, David A.; Havens, Kayt Klein

A culturally appropriate, theoretically based videotape was developed in collaboration with local African American producers to promote condom use among 15-to-19-year-old black males seeking treatment at a municipal sexually transmitted disease (STD) clinic. The videotape's immediate, short-term (30-day), and long-term (6-month) impacts were…

Inferred Paternity and Male Reproductive Success in a Killer Whale (Orcinus orca) Population.

PubMed

Ford, Michael J; Hanson, M Bradley; Hempelmann, Jennifer A; Ayres, Katherine L; Emmons, Candice K; Schorr, Gregory S; Baird, Robin W; Balcomb, Kenneth C; Wasser, Samuel K; Parsons, Kim M; Balcomb-Bartok, Kelly

2011-01-01

We used data from 78 individuals at 26 microsatellite loci to infer parental and sibling relationships within a community of fish-eating ("resident") eastern North Pacific killer whales (Orcinus orca). Paternity analysis involving 15 mother/calf pairs and 8 potential fathers and whole-pedigree analysis of the entire sample produced consistent results. The variance in male reproductive success was greater than expected by chance and similar to that of other aquatic mammals. Although the number of confirmed paternities was small, reproductive success appeared to increase with male age and size. We found no evidence that males from outside this small population sired any of the sampled individuals. In contrast to previous results in a different population, many offspring were the result of matings within the same "pod" (long-term social group). Despite this pattern of breeding within social groups, we found no evidence of offspring produced by matings between close relatives, and the average internal relatedness of individuals was significantly less than expected if mating were random. The population's estimated effective size was <30 or about 1/3 of the current census size. Patterns of allele frequency variation were consistent with a population bottleneck.

Pterin pigments amplify iridescent ultraviolet signal in males of the orange sulphur butterfly, Colias eurytheme

PubMed Central

Rutowski, R.L; Macedonia, J.M; Morehouse, N; Taylor-Taft, L

2005-01-01

Animal colouration is typically the product of nanostructures that reflect or scatter light and pigments that absorb it. The interplay between these colour-producing mechanisms may influence the efficacy and potential information content of colour signals, but this notion has received little empirical attention. Wing scales in the male orange sulphur butterfly (Colias eurytheme) possess ridges with lamellae that produce a brilliant iridescent ultraviolet (UV) reflectance via thin-film interference. Curiously, these same scales contain pterin pigments that strongly absorb wavelengths below 550 nm. Given that male UV reflectance functions as a sexual signal in C. eurytheme, it is paradoxical that pigments in the wing scales are highly UV absorbing. We present spectrophotometric analyses of the wings before and after pterin removal that show that pterins both depress the amplitude of UV iridescence and suppress a diffuse UV reflectance that emanates from the scales. This latter effect enhances the directionality and spectral purity of the iridescence, and increases the signal's chromaticity and potential signal content. Our findings also suggest that pterins amplify the contrast between iridescent UV reflectance and scale background colour as a male's wings move during flight. PMID:16191648

Pterin pigments amplify iridescent ultraviolet signal in males of the orange sulphur butterfly, Colias eurytheme.

PubMed

Rutowski, R L; Macedonia, J M; Morehouse, N; Taylor-Taft, L

2005-11-07

Animal colouration is typically the product of nanostructures that reflect or scatter light and pigments that absorb it. The interplay between these colour-producing mechanisms may influence the efficacy and potential information content of colour signals, but this notion has received little empirical attention. Wing scales in the male orange sulphur butterfly (Colias eurytheme) possess ridges with lamellae that produce a brilliant iridescent ultraviolet (UV) reflectance via thin-film interference. Curiously, these same scales contain pterin pigments that strongly absorb wavelengths below 550 nm. Given that male UV reflectance functions as a sexual signal in C. eurytheme, it is paradoxical that pigments in the wing scales are highly UV absorbing. We present spectrophotometric analyses of the wings before and after pterin removal that show that pterins both depress the amplitude of UV iridescence and suppress a diffuse UV reflectance that emanates from the scales. This latter effect enhances the directionality and spectral purity of the iridescence, and increases the signal's chromaticity and potential signal content. Our findings also suggest that pterins amplify the contrast between iridescent UV reflectance and scale background colour as a male's wings move during flight.

The evolution of adult light emission color in North American fireflies.

PubMed

Hall, David W; Sander, Sarah E; Pallansch, Jennifer C; Stanger-Hall, Kathrin F

2016-09-01

Firefly species (Lampyridae) vary in the color of their adult bioluminescence. It has been hypothesized that color is selected to enhance detection by conspecifics. One mechanism to improve visibility of the signal is to increase contrast against ambient light. High contrast implies that fireflies active early in the evening will emit yellower luminescence to contrast against ambient light reflected from green vegetation, especially in habitats with high vegetation cover. Another mechanism to improve visibility is to use reflection off the background to enhance the light signal. Reflectance predicts that sedentary females will produce greener light to maximize reflection off the green vegetation on which they signal. To test these predictions, we recorded over 7500 light emission spectra and determined peak emission wavelength for 675 males, representing 24 species, at 57 field sites across the Eastern United States. We found support for both hypotheses: males active early in more vegetated habitats produced yellower flashes in comparison to later-active males with greener flashes. Further, in two of the eight species with female data, female light emissions were significantly greener as compared to males. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Physiologic and endocrinologic characterization of male sex-biased diabetes in C57BLKS/J mice congenic for the fat mutation at the carboxypeptidease E locus.

PubMed

Leiter, E H; Kintner, J; Flurkey, K; Beamer, W G; Naggert, J K

1999-02-01

The fat gene in mice represents a recessive mutation at the carboxypeptidase E (Cpe) locus. The mutant allele (Cpe(fat)) encodes a highly unstable enzyme and produces an obesity phenotype characterized by attenuated processing of prohormones such as proinsulin that require this exopeptidase for full maturation. This article presents a preliminary physiologic and endocrinologic characterization of the stock of C57BLKS/LtJ-Cpe(fat)/Cpe(fat) mice at the backcross generation (N10) currently distributed by The Jackson Laboratory. Although previously reported not to be diabetogenic at N5, an additional five backcrosses to the C57BLKS/J background resulted in a male-biased development of both obesity and diabetes. Major differences distinguishing this mutant stock from the phenotypes produced by either the diabetes (Lepr(db)) or obese (Lep(ob)) mutations on the same inbred strain background are lack of hyperphagia and hypercorticism, sensitivity of diabetic males to exogenous insulin, and a milder and male-biased diabetes syndrome that is not associated with widespread beta-cell necrosis and islet atrophy, and that often remits with age.

(R)-3-hydroxyhexan-2-one is a major pheromone component of Anelaphus inflaticollis (Coleoptera: Cerambycidae).

PubMed

Ray, A M; Swift, I P; Moreira, J A; Millar, J G; Hanks, L M

2009-10-01

We report the identification and field bioassays of a major component of the male-produced aggregation pheromone of Anelaphus inflaticollis Chemsak, an uncommon desert cerambycine beetle. Male A. inflaticollis produced a sex-specific blend of components that included (R)-3-hydroxyhexan-2-one, (S)-2-hydroxyhexan-3-one, 2,3-hexanedione, and (2R,3R)- and (2R,3S)-2,3-hexanediols. Field trials with baited bucket traps determined that the reconstructed synthetic pheromone blend and (R)-3-hydroxyhexan-2-one alone attracted adult A. inflaticollis of both sexes, with significantly more beetles being attracted to the blend. We conclude that (R)-3-hydroxyhexan-2-one is a major pheromone component of A. inflaticollis, and our results suggest that one or more of the minor components may further increase attraction of conspecifics. Scanning electron microscopy showed that male A. inflaticollis have pores on the prothorax that are consistent in structure with sex-specific pheromone gland pores in related species. Males also displayed stereotyped calling behavior similar to that observed in other cerambycine species. This study represents the first report of volatile pheromones for a cerambycine species in the tribe Elaphidiini.

Facultative adjustment of the offspring sex ratio and male attractiveness: a systematic review and meta-analysis.

PubMed

Booksmythe, Isobel; Mautz, Brian; Davis, Jacqueline; Nakagawa, Shinichi; Jennions, Michael D

2017-02-01

Females can benefit from mate choice for male traits (e.g. sexual ornaments or body condition) that reliably signal the effect that mating will have on mean offspring fitness. These male-derived benefits can be due to material and/or genetic effects. The latter include an increase in the attractiveness, hence likely mating success, of sons. Females can potentially enhance any sex-biased benefits of mating with certain males by adjusting the offspring sex ratio depending on their mate's phenotype. One hypothesis is that females should produce mainly sons when mating with more attractive or higher quality males. Here we perform a meta-analysis of the empirical literature that has accumulated to test this hypothesis. The mean effect size was small (r = 0.064-0.095; i.e. explaining <1% of variation in offspring sex ratios) but statistically significant in the predicted direction. It was, however, not robust to correction for an apparent publication bias towards significantly positive results. We also examined the strength of the relationship using different indices of male attractiveness/quality that have been invoked by researchers (ornaments, behavioural displays, female preference scores, body condition, male age, body size, and whether a male is a within-pair or extra-pair mate). Only ornamentation and body size significantly predicted the proportion of sons produced. We obtained similar results regardless of whether we ran a standard random-effects meta-analysis, or a multi-level, Bayesian model that included a correction for phylogenetic non-independence. A moderate proportion of the variance in effect sizes (51.6-56.2%) was due to variation that was not attributable to sampling error (i.e. sample size). Much of this non-sampling error variance was not attributable to phylogenetic effects or high repeatability of effect sizes among species. It was approximately equally attributable to differences (occurring for unknown reasons) in effect sizes among and within studies (25.3, 22.9% of the total variance). There were no significant effects of year of publication or two aspects of study design (experimental/observational or field/laboratory) on reported effect sizes. We discuss various practical reasons and theoretical arguments as to why small effect sizes should be expected, and why there might be relatively high variation among studies. Currently, there are no species where replicated, experimental studies show that mothers adjust the offspring sex ratio in response to a generally preferred male phenotype. Ultimately, we need more experimental studies that test directly whether females produce more sons when mated to relatively more attractive males, and that provide the requisite evidence that their sons have higher mean fitness than their daughters. © 2015 Cambridge Philosophical Society.

Rehousing periadolescent male guinea pigs (Cavia porcellus) apart from their mothers for 24 hours increases maternally directed sexual behavior and plasma testosterone.

PubMed

Maken, D S; Hennessy, M B

1999-12-01

Periadolescent male guinea pigs (Cavia porcellus) housed continuously with their mother displayed little or no sexual behavior when they were tested with her in a novel environment. However, if males were rehoused without their mother for 24 hr before testing, they frequently directed courtship and sexual behavior toward her. This effect occurred whether the mother was isolated or not during the rehousing period. In addition, rehousing without the mother produced a significant rise in the plasma testosterone levels of the males. It appears that continuous housing with the mother inhibits sexual and courtship behavior directed toward her, as well as gonadal activity, in periadolescent male guinea pigs. These effects may serve to prevent inbreeding.

Vinclozolin--the lack of a transgenerational effect after oral maternal exposure during organogenesis.

PubMed

Schneider, Steffen; Kaufmann, Wolfgang; Buesen, Roland; van Ravenzwaay, Bennard

2008-04-01

The purpose of the study was to investigate a possible transgenerational effect of the fungicide vinclozolin on the male reproductive system following oral exposure since this effect was reported by Anway et al. [Anway MD, Cupp AS, Uzumcu M, Skinner MK. Epigenetic transgenerational actions of endocrine disruptors and male fertility. Science 2005;308(5727 (June 3)):1466-9] after intraperitoneal administration. Pregnant Wistar rats were dosed by oral gavage with vinclozolin 0, 4 or 100mg/(kg bw day) on days 6-15 post coitum (p.c.). F1 male offspring was mated with untreated females to produce F2, which were then similarly mated to produce F3 offspring. F0 maternal treatment had no effect on mating and fertility indices or male offspring sexual development, mean sperm parameters, or histopathology of the sexual organs in F1, F2 or F3 males (at age 127-134 days). Apoptotic germ cell counts were statistically significantly lower in F1, F2 and F3 generations, however, control values showed a pronounced variance over time. Also, as anti-androgenic compounds are more likely to induce the opposite effect (increased apoptosis), this observation is not considered to be treatment related. Consequently, spermatogenesis was not affected by vinclozolin exposure in utero. As vinclozolin has been shown to induce clear anti-androgenic effects in offspring following treatment with 100mg/(kg bw day) during entire gestation, the lack of effects in this study indicates that the window of sensitivity for anti-androgenic effects is from days 16-20 p.c. No transgenerational effect on the male reproductive system was found. The NOAEL was >100mg/(kg bw day) for fertility and reproductive performance, for systemic parental and developmental toxicity in F1, F2 and F3 males.

TNFR1 signaling resistance associated with female stem cell cytokine production is independent of TNFR2-mediated pathways

PubMed Central

Markel, Troy A.; Crisostomo, Paul R.; Wang, Meijing; Wang, Yue; Lahm, Tim; Novotny, Nathan M.; Tan, Jiangning; Meldrum, Daniel R.

2008-01-01

End-organ ischemia is a common source of patient morbidity and mortality. Stem cell therapy represents a novel treatment modality for ischemic diseases and may aid injured tissues through the release of beneficial paracrine mediators. Female bone marrow mesenchymal stem cells (MSCs) have demonstrated a relative resistance to detrimental TNF receptor 1 (TNFR1) signaling and are thought to be superior to male stem cells in limiting inflammation. However, it is not known whether sex differences exist in TNF receptor 2 (TNFR2)-ablated MSCs. Therefore, we hypothesized that 1) sex differences would be observed in wild-type (WT) and TNFR2-ablated MSC cytokine signaling, and 2) the production of IL-6, VEGF, and IGF-1 in males, but not females, would be mediated through TNFR2. MSCs were harvested from male and female WT and TNFR2 knockout (TNFR2KO) mice and were subsequently exposed to TNF (50 ng/ml) or LPS (100 ng/ml). After 24 h, supernatants were collected and measured for cytokines. TNF and LPS stimulated WT stem cells to produce cytokines, but sex differences were only seen in IL-6 and IGF-1 after TNF stimulation. Ablation of TNFR2 increased VEGF and IGF-1 production in males compared with wild-type, but no difference was observed in females. Female MSCs from TNFR2KOs produced significantly lower levels of VEGF and IGF-1 compared with male TNFR2KOs. The absence of TNFR2 signaling appears to play a greater role in male MSC cytokine production. As a result, male, but not female stem cell cytokine production may be mediated through TNFR2 signaling cascades. PMID:18685063

Evidence of biphonation and source-filter interactions in the bugles of male North American wapiti (Cervus canadensis).

PubMed

Reby, D; Wyman, M T; Frey, R; Passilongo, D; Gilbert, J; Locatelli, Y; Charlton, B D

2016-04-15

With an average male body mass of 320 kg, the wapiti, ITALIC! Cervus canadensis, is the largest extant species of Old World deer (Cervinae). Despite this large body size, male wapiti produce whistle-like sexual calls called bugles characterised by an extremely high fundamental frequency. Investigations of the biometry and physiology of the male wapiti's relatively large larynx have so far failed to account for the production of such a high fundamental frequency. Our examination of spectrograms of male bugles suggested that the complex harmonic structure is best explained by a dual-source model (biphonation), with one source oscillating at a mean of 145 Hz (F0) and the other oscillating independently at an average of 1426 Hz (G0). A combination of anatomical investigations and acoustical modelling indicated that the F0 of male bugles is consistent with the vocal fold dimensions reported in this species, whereas the secondary, much higher source at G0 is more consistent with an aerodynamic whistle produced as air flows rapidly through a narrow supraglottic constriction. We also report a possible interaction between the higher frequency G0 and vocal tract resonances, as G0 transiently locks onto individual formants as the vocal tract is extended. We speculate that male wapiti have evolved such a dual-source phonation to advertise body size at close range (with a relatively low-frequency F0 providing a dense spectrum to highlight size-related information contained in formants) while simultaneously advertising their presence over greater distances using the very high-amplitude G0 whistle component. © 2016. Published by The Company of Biologists Ltd.

Advertisement-call modification, male competition and female preference in the bird-voiced treefrog Hyla avivoca

PubMed Central

Martínez-Rivera, Carlos César; Gerhardt, H. Carl

2009-01-01

Senders and receivers influence dynamic characteristics of the signals used for mate attraction over different time scales. On a moment-to-moment basis, interactions among senders competing for a mate influence dynamic characteristics, whereas the preferences of receivers of the opposite gender exert an influence over evolutionary time. We observed and recorded the calling patterns of the bird-voiced treefrog Hyla avivoca, to assess how the dynamic characters of calls vary during interactions among groups of males in a chorus. This question was also addressed using playback experiments with males. Playback experiments with females showed how changes in dynamic call properties are likely to affect male mating success. Frogs calling in pairs, groups, or in response to playbacks produced longer calls than did isolated males. During call overlap, males often increased the duration of the silent interval (gaps) between the pulses of their calls so that the pulses of the calls of two neighbors interdigitated. This change resulted in increased variability of pulse rate, a traditionally static acoustic property; however, males also produced high proportions of non-overlapped calls in which variability in pulse rate was low and had species-typical values. Females preferred long calls to short and average-duration calls, and non-overlapped calls to overlapped calls. Given a choice between pairs of overlapped calls, females preferred pairs in which the proportion of overlap was low and pairs in which the pulses of such calls interdigitated completely. The observed patterns of vocal competition thus reflect the preferences of conspecific females, which have influenced the evolution of the calling behavior of H. avivoca. PMID:19789730

Development of molecular method for sex identification in date palm (Phoenix dactylifera L.) plantlets using novel sex-linked microsatellite markers.

PubMed

Maryam; Jaskani, Muhammad Jafar; Awan, Faisal Saeed; Ahmad, Saeed; Khan, Iqrar A

2016-06-01

Microsatellite markers containing simple sequence repeats (SSRs) are a valuable tool for genetic analysis. Date palm is a dioecious and slow flowering and is very difficult to identify the gender of the trees until it reaches the reproductive age (5-10 years). A total of 12 microsatellite primers were used with 30 date palm samples, 14 parents (8 male + 6 females) and 16 progeny (developed from parents breeding) which showed that microsatellites were highly polymorphic, having a great number of alleles. A total of 124 alleles were characterized in 12 SSR loci. On average, there are 9.08 alleles per locus, with a range from 5 to 16 alleles, for primers mpdCIR15 and mpdCIR57, respectively. These primers produced 15 polymorphic loci specifically in male date palm samples and the seedlings harboring the unique fragments were further characterized as male plants. Increasingly, 38.46 % of these loci were scored as homozygous alleles while 61.53 % heterozygous allelic loci were determined. Primer mpdCIR48 produced a specific locus (250/250) in all male samples whereas the same locus was absent in female samples. Similarly, a locus of 300/310 bp reoccurred in 5 date palm male samples using marker DP-168 which indicated that these are the promising candidate marker to detect the sex in date palm seedlings at early stage. The data resulted from combination of 12 primers enabled the 16 seedling samples progeny (developed from parents breeding) of date palm cultivars to divide into two groups i.e., male and female regarding their sex expression comparative to the parents (male + female) using the principle coordinate analysis.

Sex Differences in Regional Brain Glucose Metabolism Following Opioid Withdrawal and Replacement.

PubMed

Santoro, Giovanni C; Carrion, Joseph; Patel, Krishna; Vilchez, Crystal; Veith, Jennifer; Brodie, Jonathan D; Dewey, Stephen L

2017-08-01

Methadone and buprenorphine are currently the most common pharmacological treatments for opioid dependence. Interestingly, the clinical response to these drugs appears to be sex specific. That is, females exhibit superior therapeutic efficacy, defined as extended periods of abstinence and longer time to relapse, compared with males. However, the underlying metabolic effects of opioid withdrawal and replacement have not been examined. Therefore, using 18 FDG and microPET, we measured differences in regional brain glucose metabolism in males and females following morphine withdrawal and subsequent methadone or buprenorphine replacement. In both males and females, spontaneous opioid withdrawal altered glucose metabolism in regions associated with reward and drug dependence. Specifically, metabolic increases in the thalamus, as well as metabolic decreases in insular cortex and the periaqueductal gray, were noted. However, compared with males, females exhibited increased metabolism in the preoptic area, primary motor cortex, and the amygdala, and decreased metabolism in the caudate/putamen and medial geniculate nucleus. Methadone and buprenorphine initially abolished these changes uniformly, but subsequently produced their own regional metabolic alterations that varied by treatment and sex. Compared with sex-matched control animals undergoing spontaneous opioid withdrawal, male animals treated with methadone exhibited increased caudate/putamen metabolism, whereas buprenorphine produced increased ventral striatum and motor cortex metabolism in females, and increased ventral striatum and somatosensory cortex metabolism in males. Notably, when treatment effects were compared between sexes, methadone-treated females showed increased cingulate cortex metabolism, whereas buprenorphine-treated females showed decreased metabolism in cingulate cortex and increased metabolism in the globus pallidus. Perhaps the initial similarities in males and females underlie early therapeutic efficacy, whereas these posttreatment sex differences contribute to clinical treatment failure more commonly experienced by the former.

[Epidemiologic and therapeutic study on gonococcal infections--clinical efficacy of cefetamet pivoxil].

PubMed

Nishimura, M; Kumamoto, Y; Hirose, T; Hayashi, K; Tsukamoto, T; Gohro, T; Ikegaki, S; Kamito, H; Inoke, T; Henmi, I

1990-07-01

We studied the epidemiology of 109 cases of gonococcal infections (105 males with urethritis and 4 females with cervicitis), together with the basic and clinical effects of cefetamet pivoxil in the cases. The peak of age distribution of the male patients was in the younger half of their twenties, and all of the 4 female cases were between 20 and 39 years old. The major source of infections in the males younger than 25 years old was their girl friends or so-called pick-up friends, and that of the males older than 25 years old workers serving at an amusement center, for example, bars and so-called special massage parlor, which accounted for about three fourths of the male cases between 35 and 44 years old. The distribution of the MIC (inoculum size; 10(6) CFU/ml) of Cefetamet against beta-lactamase non penicillinase producing Neisseria gonorrhoeae (non-PPNG) ranged from 0.025 to 0.1 microgram/ml and that against beta-lactamase producing Neisseria gonorrhoeae ranged from 0.025 to 0.05 microgram/ml. The isolation rate of PPNG was 10.2% (9/88). In male patients with gonococcal urethritis, the efficacy rate was 100% on days 3 and 7 for 1,000 mg single dose and 7-day treatment and 500 mg single dose treatment. One of the cases treated with 250 mg single dose therapy was unchanged at 3, but the efficacy rate of the remaining cases was 100% at day 7. Complicated urethritis with C. trachomatis was noticed in 25.7% (5/105) of the male urethritis and in 25.0% (1/4) of the female cervicitis cases. The only side effect was diarrhea observed in 1 of the 124 case (0.8%).

Sterilization of sea lampreys (Petromyzon marinus) by immersion in an aqueous solution of bisazir

USGS Publications Warehouse

Hanson, Lee H.

1981-01-01

Groups of sea lamprey (Petromyzon marinus) eggs fertilized by males previously immersed in an aqueous solution of p,p-bis(1-aziridinyl)-N-methylphosphinothioic amide (bisazir) at concentrations of 10–100 mg/L produced fewer normal, live prolarvae after 15–17 d of incubation than did groups of eggs fertilized by normal males. Mortality of embryos or prolarvae was nearly 100% in groups of eggs fertilized by males that had been immersed in a 50 mg/L solution of bisazir for 4 h or in a 100 mg/L solution for 2 h. The immersion technique appears to be an efficient method of sterilizing large numbers of male sea lampreys for use in a proposed sterile-male-release program.Key words: sea lamprey, Petromyzon marinus; pest control, fish control, sterile-male technique, sterilization, chemosterilants, bisazir, Great Lakes

Demand for male contraception.

PubMed

Dorman, Emily; Bishai, David

2012-10-01

The biological basis for male contraception was established decades ago, but despite promising breakthroughs and the financial burden men increasingly bear due to better enforcement of child support policies, no viable alternative to the condom has been brought to market. Men who wish to control their fertility must rely on female compliance with contraceptives, barrier methods, vasectomy or abstinence. Over the last 10 years, the pharmaceutical industry has abandoned most of its investment in the field, leaving only nonprofit organisations and public entities pursuing male contraception. Leading explanations are uncertain forecasts of market demand pitted against the need for critical investments to demonstrate the safety of existing candidate products. This paper explores the developments and challenges in male contraception research. We produce preliminary estimates of potential market size for a safe and effective male contraceptive based on available data to estimate the potential market for a novel male method.

The evolution of sex differences in mate searching when females benefit: new theory and a comparative test.

PubMed

McCartney, J; Kokko, H; Heller, K-G; Gwynne, D T

2012-03-22

Sexual selection is thought to have led to searching as a profitable, but risky way of males obtaining mates. While there is great variation in which sex searches, previous theory has not considered search evolution when both males and females benefit from multiple mating. We present new theory and link it with data to bridge this gap. Two different search protocols exist between species in the bush-cricket genus Poecilimon (Orthoptera): females search for calling males, or males search for calling females. Poecilimon males also transfer a costly nuptial food gift to their mates during mating. We relate variations in searching protocols to variation in nuptial gift size among 32 Poecilimon taxa. As predicted, taxa where females search produce significantly larger nuptial gifts than those where males search. Our model and results show that search roles can reverse when multiple mating brings about sufficiently strong material benefits to females.

Sex differences in frass production and weight change in Tenebrio molitor (Coleoptera) infected with cysticercoids of the tapeworm Hymenolepis diminuta (Cestoda)

PubMed Central

Shea, John F.

2005-01-01

In their intermediate host, parasites alter aspects of host physiology including waste production and body weight. Further, this alteration may differ between female and male hosts. To study this, a beetle (Tenebrio molitor)-tapeworm (Hymenolepis diminuta) system was used. Infected and uninfected male and female beetles were individually housed in vials without food. Each beetle's weight change and frass production were measured over 24 h periods at 3, 7, 12 and 16 days post-infection. Treatment (infection) had no effect on weight change, but males lost more weight than females. Further, infected females produced more frass than control females. Males on the day of infection had a higher food intake than females. These results suggest that males will be more exposed to infection than females and could explain why males had a higher median cysticercoid infection level. PMID:17119613

Sex differences in frass production and weight change in Tenebrio molitor (Coleoptera) infected with cysticercoids of the tapeworm Hymenolepis diminuta (Cestoda).

PubMed

Shea, John F

2005-11-11

In their intermediate host, parasites alter aspects of host physiology including waste production and body weight. Further, this alteration may differ between female and male hosts. To study this, a beetle (Tenebrio molitor)-tapeworm (Hymenolepis diminuta) system was used. Infected and uninfected male and female beetles were individually housed in vials without food. Each beetle's weight change and frass production were measured over 24 h periods at 3, 7, 12 and 16 days post-infection. Treatment (infection) had no effect on weight change, but males lost more weight than females. Further, infected females produced more frass than control females. Males on the day of infection had a higher food intake than females. These results suggest that males will be more exposed to infection than females and could explain why males had a higher median cysticercoid infection level.

Improving hybrid seed production in corn with glyphosate-mediated male sterility.

PubMed

Feng, Paul C C; Qi, Youlin; Chiu, Tommy; Stoecker, Martin A; Schuster, Christopher L; Johnson, Scott C; Fonseca, Augustine E; Huang, Jintai

2014-02-01

Hybrid corn varieties exhibit benefits associated with heterosis and account for most of the corn acreage in the USA. Hybrid seed corn is produced by crossing a female parent which is male-sterile and therefore incapable of self-pollination with a male parent as the pollen donor. The majority of hybrid seed corn is produced by mechanical detasseling which involves physically removing the tassel, a process that is laborious and costly. Glyphosate-resistant corn was developed via expression of a glyphosate insensitive 5-enolpyruvyl-shikimate 3-phosphate synthase enzyme (CP4-EPSPS). Experimentation with molecular expression elements resulted in selective reduction of CP4-EPSPS expression in male reproductive tissues. The resulting plant demonstrated sterile tassel following glyphosate application with little to no injury to the rest of the plant. Using (14)C-glyphosate as a marker, we also examined the translocation of glyphosate to the tassel via spray application in a track sprayer to simulate field application. The results allowed optimization of spray parameters such as dose, spray timing and target to maximize tassel delivery of glyphosate for efficient sterilization. The Roundup hybridization system (RHS) is a novel process for hybrid seed production based on glyphosate-mediated male sterility. RHS replaces mechanical detasseling with glyphosate spray and greatly simplifies the process of hybrid seed corn production. © 2013 Society of Chemical Industry.

Mate-sampling costs and sexy sons.

PubMed

Kokko, H; Booksmythe, I; Jennions, M D

2015-01-01

Costly female mating preferences for purely Fisherian male traits (i.e. sexual ornaments that are genetically uncorrelated with inherent viability) are not expected to persist at equilibrium. The indirect benefit of producing 'sexy sons' (Fisher process) disappears: in some models, the male trait becomes fixed; in others, a range of male trait values persist, but a larger trait confers no net fitness advantage because it lowers survival. Insufficient indirect selection to counter the direct cost of producing fewer offspring means that preferences are lost. The only well-cited exception assumes biased mutation on male traits. The above findings generally assume constant direct selection against female preferences (i.e. fixed costs). We show that if mate-sampling costs are instead derived based on an explicit account of how females acquire mates, an initially costly mating preference can coevolve with a male trait so that both persist in the presence or absence of biased mutation. Our models predict that empirically detecting selection at equilibrium will be difficult, even if selection was responsible for the location of the current equilibrium. In general, it appears useful to integrate mate sampling theory with models of genetic consequences of mating preferences: being explicit about the process by which individuals select mates can alter equilibria. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

Mother's prior intrauterine position affects the sex ratio of her offspring in house mice.

PubMed

Vandenbergh, J G; Huggett, C L

1994-11-08

Sex ratio alterations related to environmental factors occur in several mammals, but no mechanism has been identified to explain the adjustment. Intrauterine position (IUP) may provide the context in which such alterations occur. Previous studies on house mice and gerbils reveal that the position of a fetus in the uterus in relation to the sex of its neighbors influences its later anatomy, physiology, and behavior. The anogenital distance (AGD) of females located between two males (2M) is longer than that of females not between two males (OM). We have found that the IUP, as determined by cesarean section and by an index of the AGD, correlates with the sex ratio of the litters produced by female mice. The sex ratio of the first litter born to 2M females was 58% males, for 1M females was 51% males and for OM females was 42% males. The effect on sex ratio continues into the second litter. The number of pups produced by mothers of different IUPs in her first two litters did not differ, suggesting that the sex ratio adjustment occurs prior to parturition. These results provide a basis for the natural variability observed in sex ratios of litter-bearing mammals and suggest that one or more intrauterine mechanisms may be responsible for environmentally related sex ratio alterations.

Spontaneous polyploidy, gynogenesis and androgenesis in second generation (F2 ) koi Cyprinus carpio × goldfish Carassius auratus hybrids.

PubMed

Delomas, T A; Gomelsky, B; Anil, A; Schneider, K J; Warner, J L

2017-01-01

The objective of this study was to characterize the genetics of second generation (F 2 ) koi Cyprinus carpio × goldfish Carassius auratus hybrids. Spermatozoa produced by a novel, fertile F 1 male were found to be diploid by flow-cytometric analysis. Backcross (F 1 female × C. carpio male and C. carpio female × F 1 male) juveniles were triploid, confirming that female and male F 1 hybrids both produced diploid gametes. The vast majority of surviving F 2 juveniles was diploid and small proportions were aneuploid (2·1n-2·3n and 3·1n-3·9n), triploid (3n) and tetraploid (4n). Microsatellite genotyping showed that F 2 diploids repeated either the complete maternal or the complete paternal genotype. Fish with the maternal genotype were female and fish with the paternal genotype were male. This demonstrates that F 2 diploids were the result of spontaneous gynogenesis and spontaneous androgenesis. Analysis of microsatellite inheritance and the sex ratio in F 2 crosses showed that spontaneous gynogenesis and androgenesis did not always occur in equal proportions. One cross was found to have an approximate equal number of androgenetic and gynogenetic offspring while in several other crosses spontaneous androgenesis was found to occur more frequently than spontaneous gynogenesis. © 2016 The Fisheries Society of the British Isles.

Dietary exposure to aflatoxin in human male infertility in Benin City, Nigeria.

PubMed

Ibeh, I N; Uraih, N; Ogonar, J I

1994-01-01

To discover the relationship between aflatoxin levels, if any, in serum of infertile men in comparison with random controls from the community. In a parallel experiment, adult male rats were given an aflatoxin-contaminated diet. 100 adult males, yielding 50 semen samples, from men attending Infertility Clinics at a university teaching hospital and 50 normal men in the same community. The staple foods of the men were assayed for aflatoxin content. The rats were given the aflatoxin-rich diet, and their spermatozoa were examined and their ability to reproduce assessed. A random sampling of semen from 100 adult males comprising 50 samples drawn from infertile men and 50 drawn from normal individuals within the same community revealed the presence of aflatoxins in 20 semen samples from the infertile group (40.0%) and four samples from the fertile group (8.0%). The mean aflatoxin concentrations were 1.660 +/- 0.04 micrograms/mL (infertile men) and 1.041 +/- 0.01 micrograms/mL (fertile men). Infertile men with aflatoxin in their semen showed a higher percentage of spermatozoal abnormality (50.0%) than the fertile men (10.0-15.0%). Dietary exposure of adult male Albino rats to aflatoxin (8.5 micrograms AF1/g of Guinea growers feed for 14 days) produced deleterious effects on the spermatozoa of the affected rats, producing features that resemble those seen in semen of infertile men exposed to aflatoxin.

Measurements of humpback whale song sound levels received by a calf in association with a singer.

PubMed

Chen, Jessica; Pack, Adam A; Au, Whitlow W L; Stimpert, Alison K

2016-11-01

Male humpback whales produce loud "songs" on the wintering grounds and some sing while escorting mother-calf pairs, exposing them to near-continuous sounds at close proximity. An Acousonde acoustic and movement recording tag deployed on a calf off Maui, Hawaii captured sounds produced by a singing male escort. Root-mean-square received levels ranged from 126 to 158 dB re 1 μPa. These levels represent rare direct measurements of sound to which a newly born humpback calf may be naturally exposed by a conspecific, and may provide a basis for informed decisions regarding anthropogenic sound levels projected near calves.

(2E,6Z,9Z)-2,6,9-Pentadecatrienal as a Male-Produced Aggregation-Sex Pheromone of the Cerambycid Beetle Elaphidion mucronatum.

PubMed

Millar, Jocelyn G; Mitchell, Robert F; Meier, Linnea R; Johnson, Todd D; Mongold-Diers, Judith A; Hanks, Lawrence M

2017-12-01

An increasing body of evidence suggests that the volatile pheromones of cerambycid beetles are much more diverse in structure than previously hypothesized. Here, we describe the identification, synthesis, and field testing of (2E,6Z,9Z)-2,6,9-pentadecatrienal as a male-produced aggregation-sex pheromone of the cerambycid Elaphidion mucronatum (Say) (subfamily Cerambycinae, tribe Elaphidiini). This novel structure is unlike any previously described cerambycid pheromone, and in field bioassays attracted only this species. Males produced about 9 μg of pheromone per 24 h period, and, in field trials, lures loaded with 10, 25, and 100 mg of synthetic pheromone attracted beetles of both sexes, whereas lures loaded with 1 mg of pheromone or less were not significantly attractive. Other typical cerambycine pheromones such as 3-hydroxy-2-hexanone, syn-2,3-hexanediol, and anti-2,3-hexanediol were not attractive to E. mucronatum, and when combined with (2E,6Z,9Z)-2,6,9-pentadecatrienal, the former two compounds appeared to inhibit attraction. Unexpectedly, adults of the cerambycine Xylotrechus colonus (F.) were attracted in significant numbers to a blend of 3-hydroxyhexan-2-one and (2E,6Z,9Z)-2,6,9-pentadecatrienal, even though there is no evidence that this species produces the latter compound. From timed pheromone trap catches, adults of E. mucronatum were determined to be active from dusk until shortly after midnight.

Deforestation: risk of sex ratio distortion in hawksbill sea turtles.

PubMed

Kamel, Stephanie Jill; Mrosovsky, N

2006-06-01

Phenotypic sex in sea turtles is determined by nest incubation temperatures, with warmer temperatures producing females and cooler temperatures producing males. The common finding of highly skewed female-biased hatchling sex ratios in sea turtle populations could have serious repercussions for the long-term survival of these species and prompted us to examine the thermal profile of a relatively pristine hawksbill nesting beach in Guadeloupe, French West Indies. Data loggers placed at nest depth revealed that temperatures in the forested areas were significantly cooler than temperatures in the more open, deforested areas. Using these temperatures as a predictor of sex ratio, we were able to assess the relative contributions of the different beach zones to the primary sex ratio: significantly more males were likely to be produced in the forested areas. Coastal forests are therefore important male-producing areas for the hawksbill sea turtle, and this has urgent conservation implications. On Guadeloupe, as on many Caribbean islands, deforestation rates are high and show few signs of slowing, as there is continual pressure to develop beachfront areas. The destruction of coastal forest could have serious consequences both in terms of local nesting behavior and of regional demography through the effects on population sex ratios. Human alterations to nesting habitat in other reptile taxa have been shown to modify the thermal properties of nest sites in ways that can disrupt their ecology by allowing parasite transmission, increasing vulnerability to climate change, or rendering existing habitat unsuitable.

Evolutionary variation in the mechanics of fiddler crab claws

PubMed Central

2013-01-01

Background Fiddler crabs, genus Uca, are classic examples of how intense sexual selection can produce exaggerated male traits. Throughout the genus the enlarged “major” cheliped (claw) of the male fiddler crab is used both as a signal for attracting females and as a weapon for combat with other males. However, the morphology of the major claw is highly variable across the approximately 100 species within the genus. Here we address variation, scaling, and correlated evolution in the mechanics of the major claw by analyzing the morphology and mechanical properties of the claws of 21 species of fiddler crabs from the Pacific, Gulf and Atlantic coasts of the Americas. Results We find that the mechanics that produce claw closing forces, the sizes of claws and the mechanical strength of the cuticle of claws are all highly variable across the genus. Most variables scale isometrically with body size across species but claw force production scales allometrically with body size. Using phylogenetically independent contrasts, we find that the force that a claw can potentially produce is positively correlated with the strength of the cuticle on the claw where forces are delivered in a fight. There is also a negative correlation between the force that a claw can potentially produce and the size of the claw corrected for the mass of the claw. Conclusions These relationships suggest that there has been correlated evolution between force production and armoring, and that there is a tradeoff between claw mechanics for signaling and claw mechanics for fighting. PMID:23855770

Synergism between Enantiomers Creates Species-Specific Pheromone Blends and Minimizes Cross-Attraction for Two Species of Cerambycid Beetles.

PubMed

Meier, Linnea R; Zou, Yunfan; Millar, Jocelyn G; Mongold-Diers, Judith A; Hanks, Lawrence M

2016-11-01

Research over the last decade has revealed extensive parsimony among pheromones within the large insect family Cerambycidae, with males of many species producing the same, or very similar aggregation pheromones. Among some species in the subfamily Cerambycinae, interspecific attraction is minimized by temporal segregation, and/or by minor pheromone components that synergize attraction of conspecifics or inhibit attraction of heterospecifics. Less is known about pheromone-based mechanisms of reproductive isolation among species in the largest subfamily, the Lamiinae. Here, we present evidence that the pheromone systems of two sympatric lamiine species consist of synergistic blends of enantiomers of (E)-6,10-dimethyl-5,9-undecadien-2-ol (fuscumol) and the structurally related (E)-6,10-dimethyl-5,9-undecadien-2-yl acetate (fuscumol acetate), as a mechanism by which species-specific blends of pheromone components can minimize interspecific attraction. Male Astylidius parvus (LeConte) were found to produce (R)- and (S)-fuscumol + (R)-fuscumol acetate + geranylacetone, whereas males of Lepturges angulatus (LeConte) produced (R)- and (S)-fuscumol acetate + geranylacetone. Field experiments confirmed that adult beetles were attracted only by their species-specific blend of the enantiomers of fuscumol and fuscumol acetate, respectively, and not to the individual enantiomers. Because other lamiine species are known to produce single enantiomers or blends of enantiomers of fuscumol and/or fuscumol acetate, synergism between enantiomers, or inhibition by enantiomers, may be a widespread mechanism for forming species-specific pheromone blends in this subfamily.

2,3-Hexanediols as Sex Attractants and a Female-produced Sex Pheromone for Cerambycid Beetles in the Prionine Genus Tragosoma

PubMed Central

Barbour, James D.; McElfresh, J. Steven; Moreira, Jardel A.; Swift, Ian; Wright, Ian M.; Žunič, Alenka; Mitchell, Robert F.; Graham, Elizabeth E.; Alten, Ronald L.; Millar, Jocelyn G.; Hanks, Lawrence M.

2013-01-01

Recent work suggests that closely related cerambycid species often share pheromone components, or even produce pheromone blends of identical composition. However, little is known of the pheromones of species in the subfamily Prioninae. During field bioassays in California, males of three species in the prionine genus Tragosoma were attracted to 2,3-hexanediols, common components of male-produced aggregation pheromones of beetles in the subfamily Cerambycinae. We report here that the female-produced sex pheromone of Tragosoma depsarium “sp. nov. Laplante” is (2R,3R)-2,3-hex-anediol, and provide evidence from field bioassays and electro-antennography that the female-produced pheromone of both Tragosoma pilosicorne Casey and T depsarium “harrisi” LeConte may be (2S,3R)-2,3-hexanediol. Sexual dimorphism in the sculpting of the prothorax suggests that the pheromone glands are located in the prothorax of females. This is the second sex attractant pheromone structure identified from the subfamily Prioninae, and our results provide further evidence of pheromonal parsimony within the Cerambycidae, in this case extending across both subfamily and gender lines. PMID:22923142

Strategic Acoustic Control of a Hummingbird Courtship Dive.

PubMed

Clark, Christopher J; Mistick, Emily A

2018-04-23

Male hummingbirds court females with a high-speed dive in which they "sing" with their tail feathers. The male's choice of trajectory provides him strategic control over acoustic frequency and pressure levels heard by the female. Unlike related species, male Costa's hummingbirds (Calypte costae) choose to place their dives to the side of females. Here we show that this minimizes an audible Doppler curve in their dive sound, thereby depriving females of an acoustic indicator that would otherwise reveal male dive speed. Wind-tunnel experiments indicate that the sounds produced by their feathers are directional; thus, males should aim their tail toward females. High-speed video of dives reveal that males twist half of their tail vertically during the dive, which acoustic-camera video shows effectively aims this sound sideways, toward the female. Our results demonstrate that male animals can strategically modulate female perception of dynamic aspects of athletic motor displays, such as their speed. Copyright © 2018 Elsevier Ltd. All rights reserved.

Hormonal priming, induction of ovulation and in-vitro fertilization of the endangered Wyoming toad (Bufo baxteri)

PubMed Central

Browne, Robert K; Seratt, Jessica; Vance, Carrie; Kouba, Andrew

2006-01-01

The endangered Wyoming toad (Bufo baxteri) is the subject of an extensive captive breeding and reintroduction program. Wyoming toads in captivity rarely ovulate spontaneously and hormonal induction is used to ovulate females or to stimulate spermiation in males. With hormonal induction, ovulation is unreliable and egg numbers are low. The sequential administration of anovulatory doses of hormones (priming) has increased egg numbers and quality in both anurans and fish. Consequently, we tested the efficacy of a combination of human Chorionic Gonadotrophin (hCG) and Luteinizing Hormone Releasing Hormone analogue (LHRHa) administered as one dose, or two or three sequential doses to Bufo baxteri on egg numbers, fertilization and early embryo development. Spawning toads deposited eggs into Simplified Amphibian Ringers (SAR) solution to enable controlled in-vitro fertilization (IVF) with sperm from hormonally induced male toads. Unprimed females receiving a single mixed normally ovulatory dose of 500 IU hCG plus 4 micrograms of LHRHa produced no eggs. Whereas females primed with this dose and an anovulatory dose (100 IU hCG and 0.8 micrograms of LHRHa) of the same hormones, or primed only with an anovulatory dose, spawned after then receiving an ovulatory dose. Higher total egg numbers were produced with two primings than with one priming. Moreover, two primings produced significantly more eggs from each individual female than one priming. The cleavage rate of eggs was not found to differ between one or two primings. Nevertheless, embryo development with eggs from two primings gave a significantly greater percentage neurulation and swim-up than those from one priming. Of the male toads receiving a single dose of 300 IU hCG, 80% produced spermic urine with the greatest sperm concentration 7 hours post-administration (PA). However, peak sperm motility (95%) was achieved at 5 hours PA and remained relatively constant until declining 20 hours PA. In conclusion, Bufo baxteri egg numbers and quality benefited from sequential priming with LHRHa and hCG whereas spermic urine for IVF was produced from males with a single dose of hCG. The power of assisted reproduction technology in the conservation of endangered amphibians is shown by the release of nearly 2000 tadpoles produced by IVF during this study. PMID:16790071

Male-Biased Sexual Size Dimorphism, Resource Defense Polygyny, and Multiple Paternity in the Emei Moustache Toad (Leptobrachium boringii)

PubMed Central

Hudson, Cameron M.; Fu, Jinzhong

2013-01-01

We tested the hypotheses that the Emei moustache toad (Leptobrachium boringii) exhibits resource defense polygyny and that combat led to the evolution of male-biased sexual size dimorphism. Between February and March of 2011 and 2012, 26 female and 55 male L. boringii from Mount Emei UNESCO World Heritage Site, Sichuan, China, were observed throughout the breeding season. Prior to the breeding season, males grow 10–16 keratinized maxillary nuptial spines, which fall off once the season has ended. Throughout this time, males construct and defend aquatic nests where they produce advertisement calls to attract females. In a natural setting, we documented 14 cases involving a total of 22 males where males used their moustaches for aggressive interaction, and nest takeover was observed on seven occasions. Males were also observed to possess injuries resulting from combat. Genetic analysis using microsatellite DNA markers revealed several cases of multiple paternity, both within nest and within clutch. This observation indicated that some alternative male reproductive strategy, such as satellite behaviour, is occurring, which may have led to the multiple paternity. Larger males were observed to mate more frequently, and in multiple nests, suggesting that females are selecting for larger males, or that larger males are more capable of defending high quality territories. PMID:23840725

Sex Allocation and Reproductive Success in the Andromonoecious Perennial Solanum carolinense (Solanaceae). II. Paternity and Functional Gender.

PubMed

Elle, Elizabeth; Meagher, Thomas R

2000-12-01

According to Bateman's principle, male fitness in entomophilous plant species should be limited by mating opportunity, which is influenced by the size or number of flowers. We determined male-specific fitness consequences of floral phenotype in andromonoecious Solanum carolinense, examined the relationship between male and female reproductive success within plants, and evaluated the distribution of functional gender among plants. A maximum likelihood-based paternity analysis, based on multilocus allozyme phenotypes of parents and offspring from four experimental plots, was used to determine male reproductive success and its relationship to floral phenotype. Male success was enhanced by an increase in the proportion of male flowers produced but not by an increase in total flower number, even though all flowers contain male parts. Larger flower size increased male success in only one plot. Male and female reproductive success were negatively correlated, and plants varied in functional gender from completely female to completely male. This gender specialization may occur because hermaphroditic and male flowers differ in their ability to contribute to male and female success. Although sex allocation theory predicts a positive relationship between the size or number of plant parts and reproductive success, this study indicates that aspects of floral morphology that affect gender specialization should also be considered.

Treatment effects produced by the Twin-block appliance vs the Forsus Fatigue Resistant Device in growing Class II patients.

PubMed

Giuntini, Veronica; Vangelisti, Andrea; Masucci, Caterina; Defraia, Efisio; McNamara, James A; Franchi, Lorenzo

2015-09-01

To compare the dentoskeletal changes produced by the Twin-block appliance (TB) followed by fixed appliances vs the Forsus Fatigue Resistant Device (FRD) in combination with fixed appliances in growing patients having Class II division 1 malocclusion. Twenty-eight Class II patients (19 females and 9 males; mean age, 12.4 years) treated consecutively with the TB followed by fixed appliances were compared with a group of 36 patients (16 females and 20 males; mean age, 12.3 years) treated consecutively with the FRD in combination with fixed appliances and with a sample of 27 subjects having untreated Class II malocclusion (13 females and 14 males; mean age, 12.2 years). Mean observation interval was 2.3 years in all groups. Cephalometric changes were compared among the three groups by means of ANOVA and Tukey's post hoc tests. The FRD produced a significant restraint of the maxilla compared with the TB and control samples (SNA, -1.1° and -1.8°, respectively). The TB sample exhibited significantly greater mandibular advancement and greater increments in total mandibular length than either the FRD or control groups (SNB, 1.9° and 1.5°, respectively; and Co-Gn, 2.0 mm and 3.4 mm, respectively). The FRD produced a significantly greater amount of proclination of the mandibular incisors than what occurred with the TB or the control samples (2.9° and 5.6°, respectively). The TB appliance produced greater skeletal effects in terms of mandibular advancement and growth stimulation while the Forsus caused significant proclination of the mandibular incisors.

Consequences of Nosema apis infection for male honey bees and their fertility

PubMed Central

Peng, Yan; Baer-Imhoof, Barbara; Harvey Millar, A.; Baer, Boris

2015-01-01

The queens of eusocial bees, ants and wasps mate only during a very short period early in life and males therefore produce ejaculates consisting of large numbers of high quality sperm. Such extreme selection for high fecundity resulted in males investing minimally into their somatic survival, including their immune system. However, if susceptible males are unable to protect their reproductive tissue from infections, they compromise queen fitness if they transfer pathogens during mating. We used the honey bee Apis mellifera and investigated the course of infection of the sexually transmitted pathogen Nosema apis. We predicted that honey bee males are susceptible but protect their reproductive tissues from infections. We investigated the effects of N. apis infections on the midgut, the accessory glands and the accessory testes and quantified the consequences of infection on male survival and fecundity. We found that N. apis is able to infect males, and as infections progressed, it significantly impacted fertility and survival in older males. Even though we confirm males to be able to minimize N. apis infections of their reproductive tissues, the parasite is present in ejaculates of older males. Consequently N. apis evolved alternative routes to successfully infect ejaculates and get sexually transmitted. PMID:26123530

Consequences of Nosema apis infection for male honey bees and their fertility.

PubMed

Peng, Yan; Baer-Imhoof, Barbara; Millar, A Harvey; Baer, Boris

2015-06-30

The queens of eusocial bees, ants and wasps mate only during a very short period early in life and males therefore produce ejaculates consisting of large numbers of high quality sperm. Such extreme selection for high fecundity resulted in males investing minimally into their somatic survival, including their immune system. However, if susceptible males are unable to protect their reproductive tissue from infections, they compromise queen fitness if they transfer pathogens during mating. We used the honey bee Apis mellifera and investigated the course of infection of the sexually transmitted pathogen Nosema apis. We predicted that honey bee males are susceptible but protect their reproductive tissues from infections. We investigated the effects of N. apis infections on the midgut, the accessory glands and the accessory testes and quantified the consequences of infection on male survival and fecundity. We found that N. apis is able to infect males, and as infections progressed, it significantly impacted fertility and survival in older males. Even though we confirm males to be able to minimize N. apis infections of their reproductive tissues, the parasite is present in ejaculates of older males. Consequently N. apis evolved alternative routes to successfully infect ejaculates and get sexually transmitted.

Proteomic Analysis of Pachytene Spermatocytes of Sterile Hybrid Male Mice.

PubMed

Wang, Lu; Guo, Yueshuai; Liu, Wenjing; Zhao, Weidong; Song, Gendi; Zhou, Tao; Huang, Hefeng; Guo, Xuejiang; Sun, Fei

2016-09-01

Incompatibilities in interspecific hybrids, such as reduced hybrid fertility and lethality, are common features resulting from reproductive isolation that lead to speciation. Subspecies crosses of house mice produce offspring in which one sex is infertile or absent, yet the molecular mechanisms of hybrid sterility are poorly understood. In this study, we observed extensive asynapsis of chromosomes and disturbance of the sex body in pachytene spermatocytes of sterile F1 males (PWK/Ph female × C57BL/6J male). We report the high-confidence identification of 4005 proteins in the pachytene spermatocytes of fertile F1 males (PWK/Ph male × C57BL/6J female) and sterile F1 males (PWK/Ph female × C57BL/6J male), of which 215 were upregulated and 381 were downregulated. Bioinformatics analysis of the proteome led to the identification of 43 and 59 proteins known to be essential for male meiosis and spermatogenesis in mice, respectively. Characterization of the proteome of pachytene spermatocytes associated with hybrid male sterility provides an inventory of proteins that is useful for understanding meiosis and the mechanisms of hybrid male infertility. © 2016 by the Society for the Study of Reproduction, Inc.

Sexual cannibalism increases male material investment in offspring: quantifying terminal reproductive effort in a praying mantis.

PubMed

Brown, William D; Barry, Katherine L

2016-06-29

Models of the evolution of sexual cannibalism argue that males may offset the cost of cannibalism if components of the male body are directly allocated to the eggs that they fertilize. We tested this idea in the praying mantid Tenodera sinensis Males and females were fed differently radiolabelled crickets and allowed to mate. Half of the pairs progressed to sexual cannibalism and we prevented cannibalism in the other half. We assess the relative allocation of both male-derived somatic materials and ejaculate materials into the eggs and soma of the female. Our results show that male somatic investment contributes to production of offspring. The eggs and reproductive tissues of cannibalistic females contained significantly more male-derived amino acids than those of non-cannibalistic females, and there was an increase in the number of eggs produced subsequent to sexual cannibalism. Sexual cannibalism thus increases male material investment in offspring. We also show that males provide substantial investment via the ejaculate, with males passing about 25% of their radiolabelled amino acids to females via the ejaculate even in the absence of cannibalism. © 2016 The Author(s).

Gender differences in the effects of cathinone and the interaction with caffeine on temperature and locomotor activity in the rat.

PubMed

Alsufyani, Hadeel A; Docherty, James R

2017-08-15

We have investigated gender differences in the effects of cathinone and the interaction with caffeine on temperature and movement activity in Wistar rats. Telemetry probes were implanted in rats under isoflurane anaesthesia, and 7 days later, temperature and activity were recorded in conscious unrestrained animals. Caffeine (10mg/lkg) or vehicle, and 30min later, cathinone (5mg/kg) or vehicle, were injected subcutaneously. Cathinone produced significant and marked increases in activity, and the response to cathinone was significantly greater in female animals. The combination of caffeine and cathinone causes a short lived potentiation followed by a prolonged inhibition of the activity response to cathinone. Cathinone alone had minor effects on temperature. However, the combination of caffeine and cathinone produced a significant acute rise in temperature only in male rats in the 90min after cathinone injection. Hence, cathinone caused greater increases in activity in female than in male rats. Secondly, caffeine produced an initial potentiation followed by a prolonged inhibition of the activity response to cathinone. Thirdly, cathinone in combination with caffeine significantly raised temperature acutely in male but not female rats. These differences highlight the need to carry out gender studies of the actions of stimulants. Copyright © 2017 Elsevier B.V. All rights reserved.

Methyltestosterone alters sex determination in the American alligator (Alligator mississippiensis).

PubMed

Murray, Christopher M; Easter, Michael; Merchant, Mark; Rheubert, Justin L; Wilson, Kelly A; Cooper, Amos; Mendonça, Mary; Wibbels, Thane; Marin, Mahmood Sasa; Guyer, Craig

2016-09-15

Effects of xenobiotics can be organizational, permanently affecting anatomy during embryonic development, and/or activational, influencing transitory actions during adulthood. The organizational influence of endocrine-disrupting contaminants (EDC's) produces a wide variety of reproductive abnormalities among vertebrates that exhibit temperature-dependent sex determination (TSD). Typically, such influences result in subsequent activational malfunction, some of which are beneficial in aquaculture. For example, 17-αmethyltestosterone (MT), a synthetic androgen, is utilized in tilapia farming to bias sex ratio towards males because they are more profitable. A heavily male-biased hatchling sex ratio is reported from a crocodile population near one such tilapia operation in Guanacaste, Costa Rica. In this study we test the effects of MT on sexual differentiation in American alligators, which we used as a surrogate for all crocodilians. Experimentally, alligators were exposed to MT in ovo at standard ecotoxicological concentrations. Sexual differentiation was determined by examination of primary and secondary sex organs post hatching. We find that MT is capable of producing male embryos at temperatures known to produce females and demonstrate a dose-dependent gradient of masculinization. Embryonic exposure to MT results in hermaphroditic primary sex organs, delayed renal development and masculinization of the clitero-penis (CTP). Copyright © 2016. Published by Elsevier Inc.

Improvement of vitrification of in vitro produced buffalo embryos with special reference to sex ratio following vitrification

PubMed Central

Mahmoud, K. Gh. M; Scholkamy, T. H; Darwish, S. F

2015-01-01

Cryopreservation and sexing of embryos are integrated into commercial embryo transfer technologies. To improve the effectiveness of vitrification of in vitro produced buffalo embryos, two experiments were conducted. The first evaluated the effect of exposure time (2 and 3 min) and developmental stage (morula and blastocysts) on the viability and development of vitrified buffalo embryos. Morphologically normal embryos and survival rates (re-expansion) significantly increased when vitrified morulae were exposed for 2 min compared to 3 min (P<0.001). On the other hand, morphologically normal and survival rates of blastocysts significantly increased when exposed for 3 min compared to 2 min (P<0.001). However, there were no significant differences between the two developmental stages (morulae and blastocystes) in the percentages of morphologically normal embryos and re-expansion rates after a 24 h culture. The second experiment aimed to evaluate the effect of viability on the sex ratio of buffalo embryos after vitrification and whether male and female embryos survived vitrification differently. A total number of 61 blastocysts were vitrified for 3 min with the same cryoprotectant as experiment 1. Higher percentages of males were recorded for live as compared to dead embryos; however, this difference was not significant. In conclusion, the post-thaw survival and development of in vitro produced morulae and blastocysts were found to be affected by exposure time rather than developmental stage. Survivability had no significant effect on the sex ratio of vitrified blastocysts; nevertheless, the number of surviving males was higher than dead male embryos. PMID:27175197

Temperature-dependent sex determination modulates cardiovascular maturation in embryonic snapping turtles Chelydra serpentina.

PubMed

Alvine, Travis; Rhen, Turk; Crossley, Dane A

2013-03-01

We investigated sex differences in cardiovascular maturation in embryos of the snapping turtle Chelydra serpentina, a species with temperature-dependent sex determination. One group of eggs was incubated at 26.5°C to produce males. Another group of eggs was incubated at 26.5°C until embryos reached stage 17; eggs were then shifted to 31°C for 6 days to produce females, and returned to 26.5°C for the rest of embryogenesis. Thus, males and females were at the same temperature when autonomic tone was determined and for most of development. Cholinergic blockade increased resting blood pressure (P(m)) and heart rate (f(H)) in both sexes at 75% and 90% of incubation. However, the magnitude of the f(H) response was enhanced in males compared with females at 90% of incubation. β-adrenergic blockade increased P(m) at 75% of incubation in both sexes but had no effect at 90% of incubation. β-adrenergic blockade reduced f(H) at both time points but produced a stronger response at 90% versus 75% of incubation. We found that α-adrenergic blockade decreased P(m) in both sexes at 75% and 90% of incubation and decreased f(H) at 75% of incubation in both sexes. At 90% of incubation, f(H) decreased in females but not males. Although these data clearly demonstrate sexual dimorphism in the autonomic regulation of cardiovascular physiology in embryos, further studies are needed to test whether differences are caused by endocrine signals from gonads or by a hormone-independent temperature effect.

Sexual behavior and locomotion induced by sexual cues in male rats following lesion of Lobules VIa and VII of the cerebellar vermis.

PubMed

Ortiz-Pulido, Ricardo; Miquel, Marta; Garcia, Luis I; Perez, Cesar A; Aranda-Abreu, Gonzalo E; Toledo, Rebeca; Hernandez, Maria Elena; Manzo, Jorge

2011-06-01

The cerebellum is an important contributor to the neural basis of sexual behavior, but the specific cerebellar regions underlying different aspects of reproduction are still unknown. Here, we used experimental lesions of Lobules VIa and VII of the vermis to investigate their specific role, both in locomotion stimulated by sexual cues and the execution of sexual behavior. Sexually experienced male rats and receptive females were used, and experimental males received an electrolytic lesion of either lobule. Before and after the lesion, males were tested for sexual behavior, and for locomotion on a horizontal or ascending bar to reach an estrous female. The lesion of Lobule VIa produced impairments in intromission-related behaviors during copulation, and produced slippery footsteps that increased the time to cross the bars with a stronger effect on the ascending bar. The lesion of Lobule VII produced a dramatic arrest of respiration that precluded further behavioral tests. These results suggested that Lobule VIa is involved in the integration of sensory inputs coming from in-copula penile stimulation, implying the existence of a penis-cerebellum neural pathway for a proprioception-like process involved in the proper spatial orientation of the erected penis. Walking on bars showed an alteration of the stepping cycle that suggests the role of Lobule VIa in the fine tuning of locomotion spinal reflexes. The lesion of Lobule VII suggested its role in the physiology of respiration, a topic that deserves further research. Copyright © 2011 Elsevier Inc. All rights reserved.

Determination of the Relative and Absolute Configurations of the Female-produced Sex Pheromone of the Cerambycid Beetle Prionus californicus

PubMed Central

Rodstein, Joshua; Barbour, James D.; McElfresh, J. Steven; Wright, Ian M.; Barbour, Karen S.; Ray, Ann M.; Hanks, Lawrence M.

2010-01-01

We previously identified the basic structure of the female-produced sex attractant pheromone of the cerambycid beetle, Prionus californicus Motschulsky (Cerambycidae: Prioninae), as 3,5-dimethyldodecanoic acid. A synthesized mixture of the four stereoisomers of 3,5-dimethyldodecanoic acid was highly attractive to male beetles. Here, we describe stereoselective syntheses of three of the four possible stereoisomers, and the results of laboratory and field bioassays showing that male beetles are attracted specifically to (3R,5S)-3,5-dimethyldodecanoic acid, but not to its enantiomer, (3S,5R)-3,5-dimethyldodecanoic acid, indicating that the (3R,5S)-enantiomer is the active pheromone component. The diastereomeric (3R,5R)- and (3S,5S)-enantiomers were excluded from consideration because their gas chromatographic retention times were different from that of the insect-produced compound. The mixture of the four stereoisomers of 3,5-dimethyldodecanoic acid was as attractive to male P. californicus as the (3R,5S)-enantiomer, indicating that none of the other three stereoisomers inhibited responses to the active enantiomer. Beetles responded to as little as 10 ng and 10 μg of synthetic 3,5-dimethyldodecanoic acid in laboratory and field studies, respectively. Field studies indicated that capture rate did not increase with dosages of 3,5-dimethyldodecanoic acid greater than 100 μg. In field bioassays, males of a congeneric species, P. lecontei Lameere, were captured in southern California but not in Idaho. PMID:21127949

Kinematic control of male Allen's Hummingbird wing trill over a range of flight speeds.

PubMed

Clark, Christopher J; Mistick, Emily A

2018-05-18

Wing trills are pulsed sounds produced by modified wing feathers at one or more specific points in time during a wingbeat. Male Allen's Hummingbird ( Selasphorus sasin ) produce a sexually dimorphic 9 kHz wing trill in flight. Here we investigate the kinematic basis for trill production. The wingtip velocity hypothesis posits that trill production is modulated by the airspeed of the wingtip at some point during the wingbeat, whereas the wing rotation hypothesis posits that trill production is instead modulated by wing rotation kinematics. To test these hypotheses, we flew six male Allen's Hummingbirds in an open jet wind tunnel at flight speeds of 0, 3, 6, 9, 12 and 14 m s -1 , and recorded their flight with two 'acoustic cameras' placed below and behind, or below and lateral to the flying bird. The acoustic cameras are phased arrays of 40 microphones that used beamforming to spatially locate sound sources within a camera image. Trill Sound Pressure Level (SPL) exhibited a U-shaped relationship with flight speed in all three camera positions. SPL was greatest perpendicular to the stroke plane. Acoustic camera videos suggest that the trill is produced during supination. The trill was up to 20 dB louder during maneuvers than it was during steady state flight in the wind tunnel, across all airspeeds tested. These data provide partial support for the wing rotation hypothesis. Altered wing rotation kinematics could allow male Allen's Hummingbird to modulate trill production in social contexts such as courtship displays. © 2018. Published by The Company of Biologists Ltd.

An integral projection model with YY-males and application to evaluating grass carp control

USGS Publications Warehouse

Erickson, Richard A.; Eager, Eric A.; Brey, Marybeth; Hansen, Michael J.; Kocovsky, Patrick

2017-01-01

Invasive fish species disrupt ecosystems and cause economic damage. Several methods have been discussed to control populations of invasive fish including the release of YY-males. YY-males are fish that have 2 male chromosomes compared to a XY-male. When YY-males mate, they only produce male (XY) offspring. This decreases the female proportion of the population and can, in theory, eradicate local populations by biasing the sex-ratio. YY-males have been used as a population control tool for brook trout in montane streams and lakes in Idaho, USA. The YY-male control method has been discussed for grass carp in Lake Erie, North America. We developed and presented an integral projection model for grass carp to model the use of YY-males as a control method for populations in this lake. Using only the YY-male control method, we found that high levels of YY-males would need to be release annually to control the species. Specifically, these levels were the same order of magnitude as the baseline adult population (e.g., 1000 YY-males needed to be released annual for 20 years to control a baseline adult population of 2500 grass carp). These levels may not be reasonable or obtainable for fisheries managers given the impacts of YY-males on aquatic vegetation and other constraints of natural resource management.

Corticosteroid receptor expression in a teleost fish that displays alternative male reproductive tactics.

PubMed

Arterbery, Adam S; Deitcher, David L; Bass, Andrew H

2010-01-01

Corticosteroid signaling mechanisms mediate a wide range of adaptive physiological responses, including those essential to reproduction. Here, we investigated the presence and relative abundance of corticosteroid receptors during the breeding season in the plainfin midshipman fish (Porichthys notatus), a species that has two male reproductive morphs. Only type I "singing" males acoustically court females and aggressively defend a nest site, whereas type II "sneaker" males steal fertilizations from nesting type I males. Cloning and sequencing first identified glucocorticoid (GR) and mineralocorticoid (MR) receptors in midshipman that exhibited high sequence identity with other vertebrate GRs and MRs. Absolute-quantitative real-time PCR then revealed higher levels of GR in the central nervous system (CNS) of type II males than type I males and females, while GR levels in the sound-producing, vocal muscle and the liver were higher in type I males than type II males and females. MR expression was also greater in the CNS of type II males than type I males or females, but the differences were more modest in magnitude. Lastly, plasma levels of cortisol, the main glucocorticoid in teleosts, were 2- to 3-fold greater in type II males compared to type I males. Together, the results suggest a link between corticosteroid regulation and physiological and behavioral variation in a teleost fish that displays male alternative reproductive tactics.

Systemic functional expression of N-acetyltransferase polymorphism in the F344 Nat2 congenic rat

PubMed Central

Hein, David W.; Bendaly, Jean; Neale, Jason R.; Doll, Mark A.

2008-01-01

Rat lines congenic for the rat N-acetyltransferase 2 [(RAT)Nat2] gene were constructed and characterized. F344 (homozygous Nat2 rapid) males were mated to WKY (homozygous Nat2 slow) females to produce heterozygous F1. F1 females were then backcrossed to F344 males. Heterozygous acetylator female progeny from this and each successive backcross were identified by rat Nat2 genotyping and mated with F344 rapid acetylator males. Following ten generations of backcross mating, heterozygous acetylator brother/sister progeny were mated to produce the homozgygous rapid and slow acetylator Nat2 congenic rat lines. p-Aminobenzoic acid (selective for rat NAT2) and 4-aminobiphenyl N-acetyltransferase activities were expressed in all tissues examined (liver, lung, esophagus, stomach, small intestine, colon, pancreas, kidney, skin, leukocytes, and urinary bladder in male and female rats and in breast of female and prostate of male rats). NAT2 expression in rat extrahepatic tissues was much higher than in liver. In each tissue, activities were Nat2-genotype dependent, with highest levels in homozygous rapid acetylators, intermediate levels in heterozygous acetylators, and lowest in homozygous slow acetylators. Sulfamethazine (selective for rat NAT1) N-acetyltransferase activities were observed in all tissues examined in both male and female rats except for breast (females), bladder and leukocytes. In each tissue, the activity was Nat2-genotype independent, with similar levels in homozygous rapid, heterozygous, and homozygous slow acetylators. These congenic rat lines are useful to investigate the role of NAT2 genetic polymorphism in susceptibility to cancers related to arylamine carcinogen exposures. PMID:18799801

Haldane's rule and heterogametic female and male sterility in the mouse.

PubMed

Biddle, F G; Eales, B A; Dean, W L

1994-04-01

Failed genetic experiments or experiments designed for other purposes sometimes reveal novel genetic information. The interspecific cross between laboratory strain mice of the Mus musculus musculus/domesticus complex and the separate species M. spretus is known to produce fertile F1 females and sterile F1 males. Infertility of the interspecific F1 XY male is said to be an example of what has become known as Haldane's rule: "When in the F1 offspring of two different animal races one sex is absent, rare, or sterile, that sex is the heterozygous [heterogametic] sex." We attempted to use fertile single-X (or XO) female laboratory mice of the M. m. musculus/domesticus complex mated to M. spretus males to construct females with specific X chromosomes to study segregation distortion of X chromosome marker genes that we reported previously in crosses with the two species. We assumed that the interspecific F1 XO female would be fertile like the interspecific F1 XX female but, instead, we found that it is infertile. Haldane's rule is not specific to sex, but demonstration of this has required study of separate species pairs with heterogametic males or with heterogametic females. The fertile XO laboratory mouse is female, but it is also heterogametic, producing both X and nullo-X eggs. Infertility of both the interspecific and heterogametic F1 XO female and F1 XY male in the same cross between laboratory mice and M. spretus suggests that heterogamety is at the cause of the infertility.(ABSTRACT TRUNCATED AT 250 WORDS)

The evolution of parental care in the context of sexual selection: a critical reassessment of parental investment theory.

PubMed

Wade, Michael J; Shuster, Stephen M

2002-09-01

Males and females are often defined by differences in their energetic investment in gametes. In most sexual species, females produce few large ova, whereas males produce many tiny sperm. This difference in initial parental investment is presumed to exert a fundamental influence on sex differences in mating and parental behavior, resulting in a taxonomic bias toward parental care in females and away from parental care in males. In this article, we reexamine the logic of this argument as well as the evolutionarily stable strategy (ESS) theory often used to substantiate it. We show that the classic ESS model, which contrasts parental care with offspring desertion, violates the necessary relationship between mean male and female fitness. When the constraint of equal male and female mean fitness is correctly incorporated into the ESS model, its results are congruent with those of evolutionary genetic theory for the evolution of genes with direct and indirect effects. Male parental care evolves whenever half the magnitude of the indirect effect of paternal care on offspring viability exceeds the direct effect of additional mating success gained by desertion. When the converse is true, desertion invades and spreads. In the absence of a genetic correlation between the sexes, the evolution of paternal care is independent of maternal care. Theories based on sex differences in gametic investment make no such specific predictions. We discuss whether inferences about the evolution of sex differences in parental care can hold if the ESS theory on which they are based contains internal contradictions.

Vibrational duetting mimics to trap and disrupt mating of the devastating Asian citrus psyllid insect pest

USDA-ARS?s Scientific Manuscript database

The Asian citrus psyllid (ACP) is the primary vector of a bacterium that produces a devastating disease of citrus, huanglongbing. Efficient surveillance of ACP at low population densities is essential for timely pest management programs. ACP males search for mates on tree branches by producing vibra...

Gonadal expression of Sf1 and aromatase during sex determination in the red-eared slider turtle (Trachemys scripta), a reptile with temperature-dependent sex determination.

PubMed

Ramsey, Mary; Shoemaker, Christina; Crews, David

2007-12-01

Many egg-laying reptiles have temperature-dependent sex determination (TSD), where the offspring sex is determined by incubation temperature during a temperature-sensitive period (TSP) in the middle third of development. The underlying mechanism transducing a temperature cue into an ovary or testis is unknown, but it is known that steroid hormones play an important role. During the TSP, exogenous application of estrogen can override a temperature cue and produce females, while blocking the activity of aromatase (Cyp19a1), the enzyme that converts testosterone to estradiol, produces males from a female-biased temperature. The production of estrogen is a key step in ovarian differentiation for many vertebrates, including TSD reptiles, and temperature-based differences in aromatase expression during the TSP may be a critical step in ovarian determination. Steroidogenic factor-1 (Sf1) is a key gene in vertebrate sex determination and regulates many steroidogenic enzymes, including aromatase. We find that Sf1 and aromatase are differentially expressed during sex determination in the red-eared slider turtle, Trachemys scripta elegans. Sf1 is expressed at higher levels during testis development while aromatase expression increases during ovary determination. We also assayed Sf1 and aromatase response to sex-reversing treatments via temperature or the modulation of estrogen availability. Sf1 expression was redirected to low-level female-specific patterns with feminizing temperature shift or exogenous estradiol application and redirected to more intense male-specific patterns with male-producing temperature shift or inhibition of aromatase activity. Conversely, aromatase expression was redirected to more intense female-specific patterns with female-producing treatment and redirected toward diffuse low-level male-specific patterns with masculinizing sex reversal. Our data do not lend support to a role for Sf1 in the regulation of aromatase expression during slider turtle sex determination, but do support a critical role for estrogen in ovarian development.

Behavioral, Ultrastructural and Chemical Studies on the Honeydew and Waxy Secretions by Nymphs and Adults of the Asian Citrus Psyllid Diaphorina citri (Hemiptera: Psyllidae)

PubMed Central

Ammar, El-Desouky; Alessandro, Rocco; Shatters Jr, Robert G.; Hall, David G.

2013-01-01

The Asian citrus psyllid (ACP), Diaphorina citri (Hemiptera: Psyllidae) is the primary vector of the bacterium causing citrus huanglongbing (citrus greening), the most serious disease of citrus worldwide. Psyllids and other hemipterans produce large amounts of honeydew, which has been used previously as an indicator of phloem sap composition and insect feeding or metabolism. Behavioral, ultrastructural and chemical studies on ACP, its honeydew and waxy secretions showed important differences between nymphs, males and females, and suggested some mechanisms by which the psyllids, especially nymphs and adult females, can minimize their contamination with honeydew excretions. The anal opening in ACP, near the posterior end of the abdomen, is on the ventral side in nymphs and on the dorsal side in adult males and females. Video recordings showed that adult males produce clear sticky droplets of honeydew gently deposited behind their body on the leaf surface, whereas adult females produce whitish honeydew pellets powerfully propelled away from the female body, probably to get their excretions away from eggs and newly hatched nymphs. ACP nymphs produce long ribbons or tubes of honeydew that frequently stay attached to the exuviae after molting, or drop when feeding on the lower side of citrus leaves. Furthermore, honeydew excretions of both nymphs and adult females are covered with a thin layer of whitish waxy material ultrastructurally composed of a convoluted network of long fine filaments or ribbons. This material is extruded from intricate arrays of wax pores in the circumanal ring (around the anus) that is found in nymphs and females but not in males of ACP or other psyllid species. Infrared microscopy and mass spectroscopy revealed that, in addition to various sugars, honeydew excretions of ACP nymphs and females are covered with a thin layer of wax similar in profile to ester waxes. PMID:23762268

Raising the Level of Self-Concept, Attitudes, and Academic Achievement of Black Male Students, Ages 8-12, through Art and Cultural Heritage Materials.

ERIC Educational Resources Information Center

Rolle, Sandra

An experienced art teacher working with students in grades two through six implemented and evaluated a practicum intervention designed to improve the self-images of male black students, their academic accomplishments, and their feelings of pride in their school. Five actions were taken to attain the objective: (1) cultural materials produced by…

Hyperinfection with Strongyloides in a HIV-negative elderly male

PubMed Central

Girija, S; Kannan, Suresh; Jeyakumari, D; Gopal, R

2012-01-01

Strongyloides stercoralis is an intestinal nematode producing mild infection in the immunocompetent and fatal hyperinfection syndrome in the immunocompromised. An elderly HIV-negative male presented with symptoms of chronic respiratory disease and vague abdominal symptoms. Examination of sputum and stools showed larvae of S. stercoralis. Bacterial and fungal causes of respiratory infections were ruled out. The patient responded to oral ivermectin. PMID:23508878

Within-male melanin-based plumage and bill elaboration in male house sparrows.

PubMed

Václav, Radovan

2006-12-01

If there is a cost to producing a dark color patch, the size of a patch may not correspond with its pigment concentration. The plumage of male house sparrows represents a case of dark, melanin-based ornamentation, but also a case of neglecting the composite nature of dark signals in birds. Here, I investigated what kind of associations exist between the brightness, chroma, and hue of dark integumentary patches and the size of a secondary sexual trait, the bib, in male house sparrows. I found that males with a larger bib also had a darker bib and bill, and a more saturated bib, bill, epaulets, head crown, and breast than small-bibbed males. Male bib coloration in terms of brightness and chroma was more strongly related to bib size than the coloration of other integumentary patches. However, with respect to hue, only the hue of the bill and cheeks was related to bib size. My results indicate that size, brightness, and chroma of the bib, but also chroma of other deeply colored patches, convey redundant information about the signaler's quality in male house sparrows.

Determinants of immigration strategies in male crested macaques (Macaca nigra)

PubMed Central

Marty, Pascal R.; Hodges, Keith; Agil, Muhammad; Engelhardt, Antje

2016-01-01

Immigration into a new group can produce substantial costs due to resistance from residents, but also reproductive benefits. Whether or not individuals base their immigration strategy on prospective cost-benefit ratios remains unknown. We investigated individual immigration decisions in crested macaques, a primate species with a high reproductive skew in favour of high-ranking males. We found two different strategies. Males who achieved low rank in the new group usually immigrated after another male had immigrated within the previous 25 days and achieved high rank. They never got injured but also had low prospective reproductive success. We assume that these males benefitted from immigrating into a destabilized male hierarchy. Males who achieved high rank in the new group usually immigrated independent of previous immigrations. They recieved injuries more frequently and therefore bore immigration costs. They, however, also had higher reproductive success prospects. We conclude that male crested macaques base their immigration strategy on relative fighting ability and thus potential rank in the new group i.e. potential reproductive benefits, as well as potential costs of injury. PMID:27535622

Inbreeding avoidance in rhesus macaques: whose choice?

PubMed

Manson, J H; Perry, S E

1993-03-01

Whether nonhuman primates avoid copulating with close kin living in their social group is controversial. If sexual aversion to relatives occurs, it should be stronger in females than in males because of females' greater investment in each offspring and hence greater costs resulting from less viable offspring. Data presented here show that adult male rhesus macaques breeding in their natal groups at Cayo Santiago experienced high copulatory success, but copulated less with females of their own matrilineages than with females of other matrilineages. Adult females were never observed to copulate with males of their own matrilineage during their fertile periods. Although natal males sometimes courted their relatives, examination of two measures of female mate choice showed that females chose unrelated natal males over male kin. Female aversion to male kin was specific to the sexual context; during the birth season, females did not discriminate against their male relatives in distributing grooming. Evolved inbreeding avoidance mechanisms probably produce different outcomes at Cayo Santiago than in wild rhesus macaque populations. Gender differences in sexual aversion to relatives may be partly responsible for differences between studies in reported frequency of copulations by related pairs.

Frequency-dependent sexual selection.

PubMed

O'Donald, P; Majerus, M E

1988-07-06

Sexual selection by female choice is expected to give rise to a frequency-dependent sexual advantage in favour of preferred male phenotypes: the rarer the preferred phenotypes, the more often they are chosen as mates. This 'rare-male advantage' can maintain a polymorphism when two or more phenotypes are mated preferentially: each phenotype gains an advantage when it is rarer than the others; no preferred phenotype can then be lost from the population. Expression of preference may be complete or partial. In models of complete preference, females with a preference always mate preferentially. Models of partial preference are more realistic: in these models, the probability that a female mates preferentially depends on the frequency with which she encounters the males she prefers. Two different 'encounter models' of partial preference have been derived: the O'Donald model and the Charlesworth model. The encounter models contain the complete preference model as a limiting case. In this paper, the Charlesworth model is generalized to allow for female preference of more than one male phenotype. Levels of frequency dependence can then be compared in the O'Donald and Charlesworth models. The complete preference model and both encounter models are formulated in the same genetical terms of preferences for dominant and recessive male phenotypes. Polymorphic equilibria and conditions for stability are derived for each of the three models. The models are then fitted to data of frequencies of matings observed in experiments with the two-spot ladybird. The complete preference model gives as good a fit as the encounter models to the data of these and other experiments. The O'Donald and Charlesworth encounter models are shown to produce a very similar frequency-dependent relation. Generally, as females become less choosy, they express their preference with more dependence on male frequency, whereas the resulting selection of the males becomes less frequency dependent. More choosy females are more constant in expressing their preference, producing greater frequency dependence in the selection of the males.

Reproduction of Varroa destructor and offspring mortality in worker and drone brood cells of Africanized honey bees.

PubMed

Calderón, R A; Ureña, S; van Veen, J W

2012-04-01

Varroa destructor is known to be the most serious parasite of Apis mellifera worldwide. In order to reproduce varroa females enter worker or drone brood shortly before the cell is sealed. From March to December 2008, the reproductive rate and offspring mortality (mature and immature stages), focusing on male absence and male mortality of V. destructor, was investigated in naturally infested worker and drone brood of Africanized honey bees (AHB) in Costa Rica. Data were obtained from 388 to 403 single infested worker and drone brood cells, respectively. Mite fertility in worker and drone brood cells was 88.9 and 93.1%, respectively. There was no difference between the groups (X(2) = 3.6, P = 0.06). However, one of the most significant differences in mite reproduction was the higher percentage of mites producing viable offspring in drone cells (64.8%) compared to worker cells (37.6%) (X(2) = 57.2, P < 0.05). A greater proportion of mites in worker brood cells produced non-viable female offspring. Mite offspring mortality in both worker and drone cells was high in the protonymph stage (mobile and immobile). A significant finding was the high rate of male mortality. The worker and drone brood revealed that 23.9 and 6.9%, respectively, of the adult male offspring was found dead. If the absence (missing) of the male and adult male mortality are taken together the percentage of cells increased to 40.0 and 21.3% in worker and drone cells, respectively (X(2) = 28.8, P < 0.05). The absence of the male or male mortality in a considerable number of worker cells naturally infested with varroa is the major factor in our study which reduces the production of viable daughters in AHB colonies in Costa Rica.

Sexual dimorphism of sonic apparatus and extreme intersexual variation of sounds in Ophidion rochei (Ophidiidae): first evidence of a tight relationship between morphology and sound characteristics in Ophidiidae

PubMed Central

2012-01-01

Background Many Ophidiidae are active in dark environments and display complex sonic apparatus morphologies. However, sound recordings are scarce and little is known about acoustic communication in this family. This paper focuses on Ophidion rochei which is known to display an important sexual dimorphism in swimbladder and anterior skeleton. The aims of this study were to compare the sound producing morphology, and the resulting sounds in juveniles, females and males of O. rochei. Results Males, females, and juveniles possessed different morphotypes. Females and juveniles contrasted with males because they possessed dramatic differences in morphology of their sonic muscles, swimbladder, supraoccipital crest, and first vertebrae and associated ribs. Further, they lacked the ‘rocker bone’ typically found in males. Sounds from each morphotype were highly divergent. Males generally produced non harmonic, multiple-pulsed sounds that lasted for several seconds (3.5 ± 1.3 s) with a pulse period of ca. 100 ms. Juvenile and female sounds were recorded for the first time in ophidiids. Female sounds were harmonic, had shorter pulse period (±3.7 ms), and never exceeded a few dozen milliseconds (18 ± 11 ms). Moreover, unlike male sounds, female sounds did not have alternating long and short pulse periods. Juvenile sounds were weaker but appear to be similar to female sounds. Conclusions Although it is not possible to distinguish externally male from female in O. rochei, they show a sonic apparatus and sounds that are dramatically different. This difference is likely due to their nocturnal habits that may have favored the evolution of internal secondary sexual characters that help to distinguish males from females and that could facilitate mate choice by females. Moreover, the comparison of different morphotypes in this study shows that these morphological differences result from a peramorphosis that takes place during the development of the gonads. PMID:23217241

Communication calls produced by electrical stimulation of four structures in the guinea pig brain

PubMed Central

Green, David B.; Shackleton, Trevor M.; Grimsley, Jasmine M. S.; Zobay, Oliver; Palmer, Alan R.

2018-01-01

One of the main central processes affecting the cortical representation of conspecific vocalizations is the collateral output from the extended motor system for call generation. Before starting to study this interaction we sought to compare the characteristics of calls produced by stimulating four different parts of the brain in guinea pigs (Cavia porcellus). By using anaesthetised animals we were able to reposition electrodes without distressing the animals. Trains of 100 electrical pulses were used to stimulate the midbrain periaqueductal grey (PAG), hypothalamus, amygdala, and anterior cingulate cortex (ACC). Each structure produced a similar range of calls, but in significantly different proportions. Two of the spontaneous calls (chirrup and purr) were never produced by electrical stimulation and although we identified versions of chutter, durr and tooth chatter, they differed significantly from our natural call templates. However, we were routinely able to elicit seven other identifiable calls. All seven calls were produced both during the 1.6 s period of stimulation and subsequently in a period which could last for more than a minute. A single stimulation site could produce four or five different calls, but the amygdala was much less likely to produce a scream, whistle or rising whistle than any of the other structures. These three high-frequency calls were more likely to be produced by females than males. There were also differences in the timing of the call production with the amygdala primarily producing calls during the electrical stimulation and the hypothalamus mainly producing calls after the electrical stimulation. For all four structures a significantly higher stimulation current was required in males than females. We conclude that all four structures can be stimulated to produce fictive vocalizations that should be useful in studying the relationship between the vocal motor system and cortical sensory representation. PMID:29584746

Communication calls produced by electrical stimulation of four structures in the guinea pig brain.

PubMed

Green, David B; Shackleton, Trevor M; Grimsley, Jasmine M S; Zobay, Oliver; Palmer, Alan R; Wallace, Mark N

2018-01-01

One of the main central processes affecting the cortical representation of conspecific vocalizations is the collateral output from the extended motor system for call generation. Before starting to study this interaction we sought to compare the characteristics of calls produced by stimulating four different parts of the brain in guinea pigs (Cavia porcellus). By using anaesthetised animals we were able to reposition electrodes without distressing the animals. Trains of 100 electrical pulses were used to stimulate the midbrain periaqueductal grey (PAG), hypothalamus, amygdala, and anterior cingulate cortex (ACC). Each structure produced a similar range of calls, but in significantly different proportions. Two of the spontaneous calls (chirrup and purr) were never produced by electrical stimulation and although we identified versions of chutter, durr and tooth chatter, they differed significantly from our natural call templates. However, we were routinely able to elicit seven other identifiable calls. All seven calls were produced both during the 1.6 s period of stimulation and subsequently in a period which could last for more than a minute. A single stimulation site could produce four or five different calls, but the amygdala was much less likely to produce a scream, whistle or rising whistle than any of the other structures. These three high-frequency calls were more likely to be produced by females than males. There were also differences in the timing of the call production with the amygdala primarily producing calls during the electrical stimulation and the hypothalamus mainly producing calls after the electrical stimulation. For all four structures a significantly higher stimulation current was required in males than females. We conclude that all four structures can be stimulated to produce fictive vocalizations that should be useful in studying the relationship between the vocal motor system and cortical sensory representation.

Temporal and spectral properties of the songs of the southern green stink bug Nezara viridula (L.) from Slovenia.

PubMed

Cokl, A; Virant-Doberlet, M; Stritih, N

2000-01-01

Substrate born songs of the southern green stinkbug Nezara viridula (L.) from Slovenia were recorded and analysed. The male calling song is composed of narrow-band regularly repeated single pulses and of broad-band frequency modulated pulses grouped into pulse trains. The female calling song is characterised by broad-band pulsed and narrow-band non-pulsed pulse trains. A frequency modulated pre-pulse precedes the narrow-band pulse train. A frequency-modulated post-pulse usually follows the pulse train of the male courtship song. The male calling song triggers broad-band pulse trains of the female courtship song. The female also produces a repelling low-frequency vibration that inhibits male calling and courtship. The male rival song is characterised by prolonged pulses with a typical frequency modulation.

Older males signal more reliably.

PubMed Central

Proulx, Stephen R; Day, Troy; Rowe, Locke

2002-01-01

The hypothesis that females prefer older males because they have higher mean fitness than younger males has been the centre of recent controversy. These discussions have focused on the success of a female who prefers males of a particular age class when age cues, but not quality cues, are available. Thus, if the distribution of male quality changes with age, such that older males have on average genotypes with higher fitness than younger males, then a female who mates with older males has fitter offspring, which allows the female preference to spread through a genetic correlation. We develop a general model for male display in a species with multiple reproductive bouts that allows us to identify the conditions that promote reliable signalling within an age class. Because males have opportunities for future reproduction, they will reduce their levels of advertising compared with a semelparous species. In addition, because higher-quality males have more future reproduction, they will reduce their advertising more than low-quality males. Thus, the conditions for reliable signalling in a semelparous organism are generally not sufficient to produce reliable signalling in species with multiple reproductive bouts. This result is due to the possibility of future reproduction so that, as individuals age and the opportunities for future reproduction fade, signalling becomes more reliable. This provides a novel rationale for female preference for older mates; older males reveal more information in their sexual displays. PMID:12495495

Components of male aggregation pheromone of strawberry blossom weevil, Anthonomus rubi herbst. (Coleoptera:Curculionidae).

PubMed

Innocenzi, P J; Hall, D R; Cross, J V

2001-06-01

The strawberry blossom weevil, Anthonomus rubi, is a major pest of strawberries in the United Kingdom and continental Europe. As part of a project to develop noninsecticidal control methods, the pheromone system of this species was investigated. Comparison of volatiles produced by field-collected, overwintering individuals of each sex led to identification of three male-specific compounds--(Z)-2-(3,3-dimethylcyclohexylidene)ethanol, (cis)-1-methyl-2-(1-methylethenyl)cyclobutaneethanol, and 2-(1-methylethenyl)-5-methyl-4-hexen-1-ol (lavandulol)--in amounts of 6.1, 1.2, and 0.82 microg/day/ male. The first two compounds are components of the aggregation pheromone of the boll weevil, Anthonomus grandis, grandlure II and grandlure I, respectively. Grandlure I was the (1R,2S)-(+) enantiomer and lavandulol was a single enantiomer, although the absolute configuration was not determined. Trace amounts of the other two grandlure components (Z)-(3,3-dimethylcyclohexylidene)acetaldehyde (grandlure III) and (E)-(3,3-dimethylcyclohexylidene)acetaldehyde (grandlure IV) were also detected. (E,E)-1-(1-Methylethyl)-4-methylene-8-methyl-2,7-cyclo-decadiene (germacrene-D), a known volatile from strawberry plants, Fragaria ananassa, was collected in increased amounts in the presence of pheromone-producing weevils. Male weevils only produced pheromone on F. ananassa and not on scented mayweed, Matracaria recutita, or cow parsley, Anthriscus sylvestris, although these are known food sources. In field trials using various combinations of synthetic grandlures I, II, III, and IV and lavandulol, significantly more weevils were caught in traps baited with blends containing grandlure I and II and lavandulol than in those baited with blends without lavandulol or unbaited controls. Addition of grandlure III and IV had no significant effect on attractiveness. Horizontal sticky traps were found to be more effective than vertical sticky traps or standard boll weevil traps. In mid-season females predominated in the catches, but later more males than females were trapped.

Male dominance rank and reproductive success in chimpanzees, Pan troglodytes schweinfurthii.

PubMed

Wroblewski, Emily E; Murray, Carson M; Keele, Brandon F; Schumacher-Stankey, Joann C; Hahn, Beatrice H; Pusey, Anne E

2009-01-01

Competition for fertile females determines male reproductive success in many species. The priority of access model predicts that male dominance rank determines access to females, but this model has been difficult to test in wild populations, particularly in promiscuous mating systems. Tests of the model have produced variable results, probably because of the differing socioecological circumstances of individual species and populations. We tested the predictions of the priority of access model in the chimpanzees of Gombe National Park, Tanzania. Chimpanzees are an interesting species in which to test the model because of their fission-fusion grouping patterns, promiscuous mating system and alternative male mating strategies. We determined paternity for 34 offspring over a 22-year period and found that the priority of access model was generally predictive of male reproductive success. However, we found that younger males had higher success per male than older males, and low-ranking males sired more offspring than predicted. Low-ranking males sired offspring with younger, less desirable females and by engaging in consortships more often than high-ranking fathers. Although alpha males never sired offspring with related females, inbreeding avoidance of high-ranking male relatives did not completely explain the success of low-ranking males. While our work confirms that male rank typically predicts male chimpanzee reproductive success, other factors are also important; mate choice and alternative male strategies can give low-ranking males access to females more often than would be predicted by the model. Furthermore, the success of younger males suggests that they are more successful in sperm competition.

Free-Ranging Male Koalas Use Size-Related Variation in Formant Frequencies to Assess Rival Males

PubMed Central

Charlton, Benjamin D.; Whisson, Desley A.; Reby, David

2013-01-01

Although the use of formant frequencies in nonhuman animal vocal communication systems has received considerable recent interest, only a few studies have examined the importance of these acoustic cues to body size during intra-sexual competition between males. Here we used playback experiments to present free-ranging male koalas with re-synthesised bellow vocalisations in which the formants were shifted to simulate either a large or a small adult male. We found that male looking responses did not differ according to the size variant condition played back. In contrast, male koalas produced longer bellows and spent more time bellowing when they were presented with playbacks simulating larger rivals. In addition, males were significantly slower to respond to this class of playback stimuli than they were to bellows simulating small males. Our results indicate that male koalas invest more effort into their vocal responses when they are presented with bellows that have lower formants indicative of larger rivals, but also show that males are slower to engage in vocal exchanges with larger males that represent more dangerous rivals. By demonstrating that male koalas use formants to assess rivals during the breeding season we have provided evidence that male-male competition constitutes an important selection pressure for broadcasting and attending to size-related formant information in this species. Further empirical studies should investigate the extent to which the use of formants during intra-sexual competition is widespread throughout mammals. PMID:23922967

[Effect of bemithyl on sexual behavior and spermatogenesis in rats].

PubMed

Bugaeva, L I; Spasov, A A; Kuzubova, E A

2006-01-01

Bemithyl produced different influence on the sexual behavior (pairing motivation) and spermatogenesis in rats, depending on the dose and duration of drug administration. A three-day administration of bemithyl (20 and 200 mg/kg, p.o.) stimulated the sexual activity and spermatogenesis in male rats irrespective of the drug dose. The chronic administration of bemithyl over a period of 60 days led to a decrease in the male sexual activity and spermatogenesis index. This behavior can be related to the drug influence on the hypothalamus/pituitary structures responsible for the male rat generative function.

Vomeronasal organ removal before sexual experience impairs male hamster mating behavior.

PubMed

Meredith, M

1986-01-01

Removal of vomeronasal chemoreceptors before sexual experience in male hamsters resulted in complete failure to mate in some animals but removal of these receptors after sexual experience had no effect. Animals were tested for mating behavior with intact behaviorally receptive females and also with anesthetized males scented with vaginal fluid. The two tests produced essentially the same result. Histological analysis of the lesions and radioimmunoassay of androgen levels showed no group differences, other than vomeronasal organ removal, that could account for the results. The behavioral data suggest that the vomeronasal system may be concerned with the production of preprogrammed behavior.

Sexual selection leads to a tenfold difference in reproductive success of alternative reproductive tactics in male Atlantic salmon

NASA Astrophysics Data System (ADS)

Tentelier, Cédric; Lepais, Olivier; Larranaga, Nicolas; Manicki, Aurélie; Lange, Frédéric; Rives, Jacques

2016-06-01

The precocious maturation of some male Atlantic salmon ( Salmo salar L.) has become a textbook example of alternative mating tactics, but the only estimates of reproductive success available so far are either the collective contribution of precocious males to reproduction in the wild or individual reproductive success in oversimplified experimental conditions. Using genetic parentage analysis on anadromous and precocious potential spawners and their offspring, we quantified components of individual reproductive success of both tactics in a natural population. On average, precocious males produced 2.24 (variance 67.62) offspring, against 27.17 (3080) for anadromous males. For both tactics, most of the variance in reproductive success was due to mating success, with 83 % of precocious males having no mate, against 50 % for anadromous males. Body size increased reproductive success of anadromous males and tended to decrease precocious males' reproductive success. Although these results do not solve the coexistence of alternative reproductive tactics (ARTs) in Atlantic salmon, their inclusion in comprehensive models of lifetime reproductive success should shed light on the evolution of precocious maturation in Atlantic salmon and its effect on the selection of phenotypic traits.

Sexual selection leads to a tenfold difference in reproductive success of alternative reproductive tactics in male Atlantic salmon.

PubMed

Tentelier, Cédric; Lepais, Olivier; Larranaga, Nicolas; Manicki, Aurélie; Lange, Frédéric; Rives, Jacques

2016-06-01

The precocious maturation of some male Atlantic salmon (Salmo salar L.) has become a textbook example of alternative mating tactics, but the only estimates of reproductive success available so far are either the collective contribution of precocious males to reproduction in the wild or individual reproductive success in oversimplified experimental conditions. Using genetic parentage analysis on anadromous and precocious potential spawners and their offspring, we quantified components of individual reproductive success of both tactics in a natural population. On average, precocious males produced 2.24 (variance 67.62) offspring, against 27.17 (3080) for anadromous males. For both tactics, most of the variance in reproductive success was due to mating success, with 83% of precocious males having no mate, against 50% for anadromous males. Body size increased reproductive success of anadromous males and tended to decrease precocious males' reproductive success. Although these results do not solve the coexistence of alternative reproductive tactics (ARTs) in Atlantic salmon, their inclusion in comprehensive models of lifetime reproductive success should shed light on the evolution of precocious maturation in Atlantic salmon and its effect on the selection of phenotypic traits.

A 13-15/21 translocation chromosome in carrier father and mongol son.

PubMed

SERGOVICH, F R; SOLTAN, H C; CARR, D H

1962-10-20

Cytogenetic and dermatoglyphic features were studied in a family in which the mongoloid propositus inherited a 13-15/21 translocation chromosome from his father. Seven other healthy male carriers scattered throughout the pedigree produced nine chromosomally normal children and five carrier children in addition to the mongoloid propositus. These results show that carrier males do not necessarily produce an unusually large proportion of carrier children as previous reports would indicate. Dermatoglyphic studies showed that translocation carriers in this family have neither significantly more centralized nor less centralized palmar axial triradii than non-carrier relatives. No direct evidence was therefore found for the hypothesis that an allele is present on chromosome 21 which influences the height of the triradius.

Endocrine-disruptor molecular responses, occurrence of intersex and gonado-histopathological changes in tilapia species from a tropical freshwater dam (Awba Dam) in Ibadan, Nigeria.

PubMed

Adeogun, Aina O; Onibonoje, Kolawole; Ibor, Oju R; Omiwole, Roseline A; Chukwuka, Azubuike V; Ugwumba, Alex O; Ugwumba, Adiaha A A; Arukwe, Augustine

2016-05-01

In the present study, the occurrence of endocrine disruptive responses in Tilapia species from Awba Dam has been investigated, and compared to a reference site (Modete Dam). The Awba Dam is a recipient of effluents from University of Ibadan (Nigeria) and several other anthropogenic sources. A total of 132 Tilapia species (Sarotherodon malenotheron (n=57 and 32, males and females, respectively) and Tilapia guineensis (n=23 and 20, males and females, respectively)) were collected from June to September 2014. At the reference site, samples of adult male and female S. melanotheron (48 males and 47 females) and T. guineensis (84 males and 27 females) were collected. Gonads were morphologically and histologically examined and gonadosomatic index (GSI) was calculated. Hepatic mRNA transcriptions of vitellogenin (Vtg) and zona radiata protein (Zrp) genes were analyzed using validated RT-qPCR. Significant increase in Vtg and Zrp transcripts were observed in male tilapias from Awba Dam, compared to males from the reference site. In addition, male tilapias from Awba Dam produced significantly higher Vtg and Zrp mRNA, compared to females in June and July. However, at the natural peak spawning period in August and September, females produced, significantly higher Vtg and Zrp mRNA, compared to males. Fish gonads revealed varying incidence of intersex with a striking presence of two (2) pairs of testes and a pair of ovary in S. melanotheron from Awba Dam. The entire fish population examined at Awba Dam showed a high prevalence of intersex (34.8%), involving phenotypic males and females of both species. Analysis of sediment contaminant levels revealed that As, Cd, Pb, Hg and Ni (heavy metals), monobutyltin cation, 4-iso-nonyphenol and PCB congeners (138, 153 and 180) were significantly higher in Awba Dam, compared to the reference site. Principal component analysis (PCA) showed that fish variables were positively correlated with sediment contaminant burden at Awba Dam, indicating that the observed endocrine disruptive responses are associated with contaminant concentrations. Overall, the occurrence of intersex and elevated expressions of Vtg and Zrp in male fish, suggest that the measured contaminants were eliciting severe endocrine disruptive effects in Awba Dam biota, which is an important source of domestic water supply and fisheries for the University of Ibadan community. Copyright © 2016 Elsevier B.V. All rights reserved.

77 FR 41357 - Monsanto Co.; Availability of Petition for Determination of Nonregulated Status of Canola...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-13

... Produced Through Genetic Engineering Which Are Plant Pests or Which There Is Reason to Believe Are Plant... into the environment) of organisms and products altered or produced through genetic engineering that... CP4 EPSPS expression in male reproductive tissues (i.e., pollen). Enhanced CP4 EPSPS expression in the...

Relative effectiveness of carp pituitary extract, luteinizing hormone releasing hormone analog LHRHa injections and LHRHa implants for producing hybrid catfish fry

USDA-ARS?s Scientific Manuscript database

Adoption of the hybrid catfish (channel catfish, Ictalruus punctatus, female x blue catfish, I. furcatus, male) is increasing in the catfish industry. The most effective way to produce fry is hormone induced spawning of females coupled with hand stripping and in vitro fertilization. The success of...

A Target Region Amplified Polymorphism (TRAP) Marker for Fertility Restorer Gene Rf1 and Chromosomal Localization of Rf1 and Rf2 in Cotton

USDA-ARS?s Scientific Manuscript database

Cytoplasmic male sterility (CMS), a maternally inherited trait and characterized as an inability to produce functional pollen , is an important biological system for economically producing hybrid seed to enhance crop yield and studying cytoplasmic and nuclear gene interactions. In cultivated tetrapl...

Early flowering and seed production in a yellow birch progeny test

Treesearch

Knud E. Clausen

1976-01-01

Trees in a yellow birch progeny test began to bear seed when 7 years old and the proportion of fruiting trees increased in the following 2 years. Male catkins were produced at age 8 and the number of trees with males increased greatly the following years. Although there is much variation between and within families in earliness of flowering and in number of flowers and...

VINCLOZOLIN (V) TREATMENT INDUCES REPRODUCTIVE MALFORMATIONS AND INFERTILITY IN F1 MALE RATS WHEN ADMINISTERED DURING SEXUAL BUT NOT GONADAL DIFFERENTIATION. THE EFFECTS ARE NOT TRANSMITTED TO THE SUBSEQUENT GENERATIONS.

EPA Science Inventory

V produces adverse reproductive effects in male rats when administered during sexual differentiation by acting as an androgen-antagonist. It was recently reported that four generations of SD rats, derived from dams dosed via ip injection GD8-15 with 100 mg V/kg/day, displayed pro...

Low Testosterone Correlates with Delayed Development in Male Orangutans

PubMed Central

Emery Thompson, Melissa; Zhou, Amy; Knott, Cheryl D.

2012-01-01

Male orangutans (Pongo spp.) display an unusual characteristic for mammals in that some adult males advance quickly to full secondary sexual development while others can remain in an adolescent-like form for a decade or more past the age of sexual maturity. Remarkably little is understood about how and why differences in developmental timing occur. While fully-developed males are known to produce higher androgen levels than arrested males, the longer-term role of steroid hormones in male life history variation has not been examined. We examined variation in testosterone and cortisol production among 18 fully-developed (“flanged”) male orangutans in U.S. captive facilities. Our study revealed that while testosterone levels did not vary significantly according to current age, housing condition, and species origin, males that had undergone precocious development had higher testosterone levels than males that had experienced developmental arrest. While androgen variation had previously been viewed as a state-dependent characteristic of male developmental status, our study reveals that differences in the physiology of early and late developing males are detectable long past the developmental transition and may instead be trait-level characteristics associated with a male’s life history strategy. Further studies are needed to determine how early in life differences in testosterone levels emerge and what consequences this variation may have for male behavioral strategies. PMID:23077585

Toward responsible stock enhancement: broadcast spawning dynamics and adaptive genetic management in white seabass aquaculture.

PubMed

Gruenthal, Kristen M; Drawbridge, Mark A

2012-06-01

The evolutionary effects captive-bred individuals that can have on wild conspecifics are necessary considerations for stock enhancement programs, but breeding protocols are often developed without the knowledge of realized reproductive behavior. To help fill that gap, parentage was assigned to offspring produced by a freely mating group of 50 white seabass (Atractoscion nobilis), a representative broadcast spawning marine finfish cultured for conservation. Similar to the well-known and closely related red drum (Sciaenops ocellatus), A. nobilis exhibited large variation in reproductive success. More males contributed and contributed more equally than females within and among spawns in a mating system best described as lottery polygyny. Two females produced 27% of the seasonal offspring pool and female breeding effective size averaged 1.85 per spawn and 12.38 seasonally, whereas male breeding effective size was higher (6.42 and 20.87, respectively), with every male contributing 1-7% of offspring. Further, females batch spawned every 1-5 weeks, while males displayed continuous reproductive readiness. Sex-specific mating strategies resulted in multiple successful mate pairings and a breeding effective to census size ratio of ≥0.62. Understanding a depleted species' mating system allowed management to more effectively utilize parental genetic variability for culture, but the fitness consequences of long-term stocking can be difficult to address.

Cytoplasmic male sterility-associated chimeric open reading frames identified by mitochondrial genome sequencing of four Cajanus genotypes.

PubMed

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

2013-10-01

The hybrid pigeonpea (Cajanus cajan) breeding technology based on cytoplasmic male sterility (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.

Acoustic signals in the sand fly Lutzomyia (Nyssomyia) intermedia (Diptera: Psychodidae)

PubMed Central

2011-01-01

Background Acoustic signals are part of the courtship of many insects and they often act as species-specific signals that are important in the reproductive isolation of closely related species. Here we report the courtship songs of the sand fly Lutzomyia (Nyssomyia) intermedia, one of the main vectors of cutaneous leishmaniasis in Brazil. Findings Recordings were performed using insects from three localities from Eastern Brazil: Posse and Jacarepaguá in Rio de Janeiro State and Corte de Pedra in Bahia State. The three areas have remnants of the Brazilian Atlantic forest, they are endemic for cutaneous leishmaniasis and L. intermedia is the predominant sand fly species. We observed that during courtship L. intermedia males from all populations produced pulse songs consisting of short trains. No significant differences in song parameters were observed between the males of the three localities. Conclusions L. intermedia males produce acoustic signals as reported for some other sand flies such as the sibling species of the Lutzomyia longipalpis complex. The lack of differences between the males from the three localities is consistent with previous molecular studies of the period gene carried out in the same populations, reinforcing the idea that L. intermedia is not a species complex in the studied areas and that the three populations are likely to have similar vectorial capacities. PMID:21569534

Acoustic signals in the sand fly Lutzomyia (Nyssomyia) intermedia (Diptera: Psychodidae).

PubMed

Vigoder, Felipe M; Souza, Nataly A; Peixoto, Alexandre A

2011-05-13

Acoustic signals are part of the courtship of many insects and they often act as species-specific signals that are important in the reproductive isolation of closely related species. Here we report the courtship songs of the sand fly Lutzomyia (Nyssomyia) intermedia, one of the main vectors of cutaneous leishmaniasis in Brazil. Recordings were performed using insects from three localities from Eastern Brazil: Posse and Jacarepaguá in Rio de Janeiro State and Corte de Pedra in Bahia State. The three areas have remnants of the Brazilian Atlantic forest, they are endemic for cutaneous leishmaniasis and L. intermedia is the predominant sand fly species. We observed that during courtship L. intermedia males from all populations produced pulse songs consisting of short trains. No significant differences in song parameters were observed between the males of the three localities. L. intermedia males produce acoustic signals as reported for some other sand flies such as the sibling species of the Lutzomyia longipalpis complex. The lack of differences between the males from the three localities is consistent with previous molecular studies of the period gene carried out in the same populations, reinforcing the idea that L. intermedia is not a species complex in the studied areas and that the three populations are likely to have similar vectorial capacities.

How parasitoid females produce sexy sons: a causal link between oviposition preference, dietary lipids and mate choice in Nasonia

PubMed Central

Blaul, Birgit; Ruther, Joachim

2011-01-01

Sexual selection theory predicts that phenotypic traits used to choose a mate should reflect honestly the quality of the sender and thus, are often costly. Physiological costs arise if a signal depends on limited nutritional resources. Hence, the nutritional condition of an organism should determine both its quality as a potential mate and its ability to advertise this quality to the choosing sex. In insects, the quality of the offspring's nutrition is often determined by the ovipositing female. A causal connection, however, between the oviposition decisions of the mother and the mating chances of her offspring has never been shown. Here, we demonstrate that females of the parasitic wasp Nasonia vitripennis prefer those hosts for oviposition that have been experimentally enriched in linoleic acid (LA). We show by 13C-labelling that LA from the host diet is a precursor of the male sex pheromone. Consequently, males from LA-rich hosts produce and release higher amounts of the pheromone and attract more virgin females than males from LA-poor hosts. Finally, males from LA-rich hosts possess three times as many spermatozoa as those from LA-poor hosts. Hence, females making the right oviposition decisions may increase both the fertility and the sexual attractiveness of their sons. PMID:21429922

How parasitoid females produce sexy sons: a causal link between oviposition preference, dietary lipids and mate choice in Nasonia.

PubMed

Blaul, Birgit; Ruther, Joachim

2011-11-07

Sexual selection theory predicts that phenotypic traits used to choose a mate should reflect honestly the quality of the sender and thus, are often costly. Physiological costs arise if a signal depends on limited nutritional resources. Hence, the nutritional condition of an organism should determine both its quality as a potential mate and its ability to advertise this quality to the choosing sex. In insects, the quality of the offspring's nutrition is often determined by the ovipositing female. A causal connection, however, between the oviposition decisions of the mother and the mating chances of her offspring has never been shown. Here, we demonstrate that females of the parasitic wasp Nasonia vitripennis prefer those hosts for oviposition that have been experimentally enriched in linoleic acid (LA). We show by (13)C-labelling that LA from the host diet is a precursor of the male sex pheromone. Consequently, males from LA-rich hosts produce and release higher amounts of the pheromone and attract more virgin females than males from LA-poor hosts. Finally, males from LA-rich hosts possess three times as many spermatozoa as those from LA-poor hosts. Hence, females making the right oviposition decisions may increase both the fertility and the sexual attractiveness of their sons.

Adaptive Sex Determination and Population Dynamics in a Brackish-water Amphipod

NASA Astrophysics Data System (ADS)

Watt, Penelope J.; Adams, Jonathan

1993-09-01

Gammarus duebeni is a sexually dimorphic amphipod with an unusual and environmentally mediated sex determining system. In seasonal populations, environmental sex determination (ESD) is selectively advantageous and males and females are produced at different times of the year, but it has been predicted that where generations overlap or the breeding season is long, ESD should no longer have a selective advantage over genetic mechanisms of sex determination and males and females should be produced simultaneously. The dynamics of a supposedly bivoltine population at Totton Marsh on the south coast of England were investigated. The field study showed that the breeding season at Totton was not in fact bivoltine but long, extending through most of the year with a short break in early summer. Population sex ratio fluctuated seasonally: this pattern appears to be the product of differences in production of males and females rather than growth or mortality. Thus, contrary to expectations, ESD does occur in this population. Photoperiod is the cue for sex determination in the laboratory, but in the field this alone could not account for the observed pattern of male and female production at Totton Marsh. Another major variable must be involved and it is proposed that it also has an influence on other G. duebeni populations.

Cytoplasmic Male Sterility-Associated Chimeric Open Reading Frames Identified by Mitochondrial Genome Sequencing of Four Cajanus Genotypes

PubMed Central

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.

2013-01-01

The hybrid pigeonpea (Cajanus cajan) breeding technology based on cytoplasmic male sterility (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

Effect of azadirachtin of neemix-4.5 on SWR/J mice.

PubMed

Abou-Tarboush, F M; El-Ashmaoui, H M; Hussein, H I; Al-Rajhy, D; Al-Assiry, M

2009-10-01

Inbred normal SWR/J male and female mice, 8-10 weeks old and weighing 22.55-26.72 g, were used throughout the study. A total of 100 males and 100 females were used and were divided into 20 groups, 10 animals in each group. Azadirachtin of neemix-4.5, a commercial botanical pesticide derived from the neem tree, orally administered to male and female SWR/J mice at a dose level 9.0 mg/kg (1/10 LD50) for different treatment periods (2, 4, 6, 8 or 11.5 weeks) has produced signs of toxicity, mortality and changes in body and tissue weights of both sexes at almost all treated periods used in the present study. Moreover the oral administration of this dose level for 11.5 weeks has also resulted in some histopathological changes in the livers, kidneys and testes of treated animals compared with the control group, and the degree of these changes ranged from mild to severe in these organs of treated males. However, conflicting results have been reported concerning the toxicity of azadirachtin in mammalian species using different formulations of neem-based pesticides. It appears, therefore, that the toxicity produced by neemix-4.5 in the present study may be due to factors other than azadirachtin in this formulation.

Wake up and smell the conflict: odour signals in female competition

PubMed Central

Stockley, Paula; Bottell, Lisa; Hurst, Jane L.

2013-01-01

Odour signals used in competitive and aggressive interactions between males are well studied in the context of sexual selection. By contrast, relatively little is known about comparable signals used by females, despite current interest in the evolution of female ornaments and weaponry. Available evidence suggests that odour signals are important in competitive interactions between female mammals, with reductions or reversals of male-biased sexual dimorphism in signalling where female competition is intense. Scent marking is often associated with conflict between females over access to resources or reproductive opportunities. Female scent marks may therefore provide reliable signals of competitive ability that could be used both by competitors and potential mates. Consistent with this hypothesis, we report that aggressive behaviour of female house mice is correlated with the amount of major urinary protein (MUP) excreted in their urine, a polymorphic set of proteins that are used in scent mark signalling. Under semi-natural conditions, females with high MUP output are more likely to produce offspring sired by males that have high reproductive success, and less likely to produce offspring by multiple different sires, suggesting that females with strong MUP signals are monopolized by males of particularly high quality. We conclude that odour signals are worthy of more detailed investigation as mediators of female competition. PMID:24167312

Human food safety and environmental hazards associated with the use of methyltestosterone and other steroids in production of all-male tilapia.

PubMed

Mlalila, Nichrous; Mahika, Charles; Kalombo, Lonji; Swai, Hulda; Hilonga, Askwar

2015-04-01

In recent years, all-male cultures of Nile tilapia (Oreochromis niloticus) have been the most preferred mode of production in aquaculture industry. All-male individuals achieve higher somatic growth rate and shut high energy losses associated with gonadal development and reproduction. The economic advantages of culturing all-male tilapia have led to the development of procedures for producing unisex cultures, using 17α-methyltestosterone (MT). Despite widespread use of the MT in tilapia farming, the implications of hormone treatment in relation to human health and the environment have raised a number of concerns in the scientific community. In this review, the hormonal application processes, economic and ecological significance of MT, food safety and residual MT, comparative uses of steroids in aquaculture, animal husbandry, and medicine have been briefly reviewed for regulatory guidelines, and finally, future research perspectives have been addressed. The review can be used as policy-making guidelines in aquaculture framework development as can be emphasized in African continent, among others. The most important conclusion to draw is that the quantity of MT used in conventional practice is large compared to the actual dose required for sex reversal, fish produced are safe for human consumptions, and the environmental hazards should be further emphasized.

Analgesic Activity of Tramadol and Buprenorphine after Voluntary Ingestion by Rats (Rattus norvegicus)

PubMed Central

Taylor, Bryan F; Ramirez, Harvey E; Battles, August H; Andrutis, Karl A; Neubert, John K

2016-01-01

Effective pain management for rats and mice is crucial due to the continuing increase in the use of these species in biomedical research. Here we used a recently validated operant orofacial pain assay to determine dose–response curves for buprenorphine and tramadol when mixed in nut paste and administered to male and female rats. Statistically significant analgesic doses of tramadol in nut paste included doses of 20, 30, and 40 mg/kg for female rats but only 40 mg/kg for male rats. For male rats receiving buprenorphine mixed in nut paste, a significant analgesic response was observed at 0.5 and 0.6 mg/kg. None of the doses tested produced a significant analgesic response in female rats. Our results indicate that at the doses tested, tramadol and buprenorphine produced an analgesic response in male rats. In female rats, tramadol shows a higher analgesic effect than buprenorphine. The analgesic effects observed 60 min after administration of the statistically significant oral doses of both drugs were similar to the analgesic effects of 0.03 mg/kg subcutaneous buprenorphine 30 min after administration. The method of voluntary ingestion could be effective, is easy to use, and would minimize stress to the rats during the immediate postoperative period. PMID:26817983