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1

Synergistic Disruption of External Male Sex Organ Development by a Mixture of Four Antiandrogens  

PubMed Central

Background By disrupting the action of androgens during gestation, certain chemicals present in food, consumer products, and the environment can induce irreversible demasculinization and malformations of sex organs among male offspring. However, the consequences of simultaneous exposure to such chemicals are not well described, especially when they exert their actions by differing molecular mechanisms. Objectives To fill this gap, we investigated the effects of mixtures of a widely used plasticizer, di(2-ethylhexyl) phthalate (DEHP); two fungicides present in food, vinclozolin and prochloraz; and a pharmaceutical, finasteride, on landmarks of male sexual development in the rat, including changes in anogenital distance (AGD), retained nipples, sex organ weights, and malformations of genitalia. These chemicals were chosen because they disrupt androgen action with differing mechanisms of action. Results Strikingly, the effect of combined exposure to the selected chemicals on malformations of external sex organs was synergistic, and the observed responses were greater than would be predicted from the toxicities of the individual chemicals. In relation to other hallmarks of disrupted male sexual development, including changes in AGD, retained nipples, and sex organ weights, the combined effects were dose additive. When the four chemicals were combined at doses equal to no observed adverse effect levels estimated for nipple retention, significant reductions in AGD were observed in male offspring. Conclusions Because unhindered androgen action is essential for human male development in fetal life, these findings are highly relevant to human risk assessment. Evaluations that ignore the possibility of combination effects may lead to considerable underestimations of risks associated with exposures to chemicals that disrupt male sexual differentiation. PMID:20049201

Christiansen, Sofie; Scholze, Martin; Dalgaard, Majken; Vinggaard, Anne Marie; Axelstad, Marta; Kortenkamp, Andreas; Hass, Ulla

2009-01-01

2

No attitude, no standing around: the organization of social and sexual interaction at a gay male private sex party in New York city.  

PubMed

Following the onset of the AIDS epidemic, many jurisdictions have outlawed commercial sex-on-premise venues (bathhouses, adult theaters, sex clubs), greatly changing the culture of public or group sex. Today, in New York City (NYC), private sex parties are the main venues for group sex. Dozens of such events are held on a regular basis in the city, attracting sometimes a few hundred participants. Past research in group sex venues shows that different spaces allow for different kinds of sexual and social interaction. What are the norms of interaction of today's private sex parties? This article answers this question by using data collected ethnographically in one recurring gay male private sex party in NYC. The event was a small organization that brought all its participants together in one space at the same time, thus creating great physical intimacy and leading to convivial socialization and interpersonal bonding. This differs from the model of anonymous and impersonal sex that previous researchers have seen in public and commercial spaces. Private sex parties present risk for the transmission of HIV and other sexually-transmitted infections, but their organization and norms of interaction also present new avenues for prevention. Policy-makers should work to make these places safer rather than outlawing them. PMID:23979786

Meunier, Étienne

2014-05-01

3

Technology, normalisation and male sex work.  

PubMed

Technological change, particularly the growth of the Internet and smart phones, has increased the visibility of male escorts, expanded their client base and diversified the range of venues in which male sex work can take place. Specifically, the Internet has relocated some forms of male sex work away from the street and thereby increased market reach, visibility and access and the scope of sex work advertising. Using the online profiles of 257 male sex workers drawn from six of the largest websites advertising male sexual services in Australia, the role of the Internet in facilitating the normalisation of male sex work is discussed. Specifically we examine how engagement with the sex industry has been reconstituted in term of better informed consumer-seller decisions for both clients and sex workers. Rather than being seen as a 'deviant' activity, understood in terms of pathology or criminal activity, male sex work is increasingly presented as an everyday commodity in the market place. In this context, the management of risks associated with sex work has shifted from formalised social control to more informal practices conducted among online communities of clients and sex workers. We discuss the implications for health, legal and welfare responses within an empowerment paradigm. PMID:25215634

MacPhail, Catherine; Scott, John; Minichiello, Victor

2014-09-12

4

Sex mosaics in a male dimorphic ant Cardiocondyla kagutsuchi  

NASA Astrophysics Data System (ADS)

Gynandromorphy, or the development of organisms with a combination of male and female morphological features, is common in Hymenoptera. The underlying mechanism is likely associated with the sex-determination system, and studying this phenomenon should lead to a deeper understanding of both embryonic development and sex determination. The reproductive capabilities of gynandromorphs (hereafter, sex mosaics) remain unclear. We studied gynandromorphy in the Malaysian ant Cardiocondyla kagutsuchi, which has sex mosaics of queens (gynandromorphs; mosaic of queens and winged male) and workers (ergatandromorphs; mosaic of worker and wingless ergatoid male). These sex mosaics were classified into seven morphological categories. Most individuals had more male than female body areas. Behavioral observations revealed that sex mosaics behave more in accordance with the “sex” of their brain than that of the reproductive organs (gaster). Relative DNA quantities showed that both female and male regions contained haploid and diploid nuclei, irrespective of their phenotypic appearance, indicating that external appearance did not reflect internal tissues. Nearly one third of the adults were sex mosaics and they were not infected with Wolbachia. Our results suggest that the production of sex mosaics in this species does not pose a substantial cost to colonies and that the underlying causes are therefore not strongly selected against.

Yoshizawa, Juri; Mimori, Kohei; Yamauchi, Katsusuke; Tsuchida, Koji

2009-01-01

5

[Thr arteries of the male sex organs of Japanese quail (Coturnix coturnix japonica) and their development after hatching].  

PubMed

A total of 83 male Japanese quails of the following age groups were used for this study: 11, 18, 25, 32, 35, 37, 39, 41, 43 days, and 7, 9, 17 weeks after hatching. Neoprene-Latex, Tensol-Cement, and the china ink were injected via the aortic arch. In most of male Japanese quails, the testes are supplied by the A. testicularis originated from the Aorta descendens through a common trunk with the A. renalis cranialis. But in only 3 quails had this artery originated directly from the Aorta descendens on either side. In 9 quails had the A. testicularis accessoria originating independently from the Aorta descendens and running cranially or caudally in short distance to the normal A. testicularis. The arteries for the Ductus deferens were divided into 3 categories. The Rami ureterodeferentiales craniales were spread out from A. testicularis or Rami epididymales. The Rami ureterodeferentiales medii came from the A. renalis media and the A. renalis caudalis. The Rami ureterodeferentiales caudales originated from the A. caudae lateralis and A. pudenda. The Receptaculum ductus deferentis, the Corpus vasculare paracloacalis and the Phallus nonprotrudens in the Cloaca were supplied from the thick Ramus cloacalis of the A. pudenda. The Ramus bursalis of this artery supplied the Glandula proctodaealis and the Bursa cloacalis, and was also thick. The arteries to the genital organs were observed in the 11 day old male quail. The A. pudenda began developing at about 30 days after hatching when the quail's body matured. While the A. testicularis began developing at about 40 days after hatching when the male Japanese quail was full of the spermatogenic activity. PMID:1497141

Okamoto, T; Vollmerhaus, B; Roos, H; Waibl, H; König, H E

1992-06-01

6

Aromatase inhibitors in male sex  

PubMed Central

Aromatase inhibitors (AI) have been used in males in idiopathic short stature, constitutional delay of puberty, precocious puberty, gynecomastia, oligospermia, hypogonadism related to obesity and ageing. This retrospective study echoed the benefit of AI in Indian males in varied conditions. PMID:24251180

Singh, Santosh Kumar

2013-01-01

7

Effect of housing system, slaughter weight and slaughter strategy on carcass and meat quality, sex organ development and androstenone and skatole levels in Duroc finished entire male pigs.  

PubMed

This study aimed at evaluating the effect of housing system (HS), slaughter weight (SW) and strategy (SS) on carcass a nd meat quality, sexual organ development and boar taint in entire males. Twelve pens of 10 pigs were used (two trials). Half of male pens were allowed visual contact with females (MF) and half with males (MM). Half MM or MF were slaughtered at 105 or 130 kg in trial 1, or penwise or by split marketing in trial 2 at 120 kg. Housing system showed no significant effect on carcass or meat quality. MF presented significantly longer testicles and heavier bulbourethral glands compared to MM. The distribution of androstenone and skatole levels was affected by SW but not by HS or SS, samples with androstenone >1 ?g/g of the different groups falling within the range of 16 to 22%. All correlations between androstenone and sex organs were significant. Housing system and slaughter strategy did not reduce the risk of boar tainted carcasses. PMID:21641121

Fàbrega, E; Gispert, M; Tibau, J; Hortós, M; Oliver, M A; Furnols, M Font I

2011-12-01

8

Male sex determination: insights into molecular mechanisms  

Microsoft Academic Search

Disorders of sex development often arise from anomalies in the molecular or cellular networks that guide the differentiation of the embryonic gonad into either a testis or an ovary, two functionally distinct organs. The activation of the Y-linked gene Sry (sex-determining region Y) and its downstream target Sox9 (Sry box-containing gene 9) triggers testis differentiation by stimulating the differentiation of

Kathryn McClelland; Josephine Bowles; Peter Koopman

2012-01-01

9

New pleasures and old dangers: reinventing male sex work.  

PubMed

Understandings of male sex workers (MSWs) shift with technological, conceptual, and social changes. Research has historically constructed MSWs as psychologically unstable, desperate, or destitute victims and their clients as socially deviant perverts. These perceptions, however, are no longer supported by contemporary research and changing societal perceptions of the sex industry, challenging how we understand and describe "escorts." The changing understandings of sexuality and the increasing power of the Internet are both important forces behind recent changes in the structure and organization of MSWs. The growth in the visibility and reach of escorts has created opportunities to form an occupational account of MSWs that better accounts for the dynamic and diverse nature of the MSW experience in the early 21st century. Recent changes in the structure and organization of male sex work have provided visibility to the increasingly diverse geographical distribution of MSW, the commodification of race and racialized desire, new populations of heterosexual men and women as clients, and the successful dissemination of safer sexual messages to MSWs through online channels. This article provides a broad overview of the literature on MSWs, concentrating its focus on studies that have emerged over the past 20 years and identifying areas for future research. PMID:23480072

Minichiello, Victor; Scott, John; Callander, Denton

2013-01-01

10

Male work and sex ratio in social crab spiders  

Microsoft Academic Search

Summary: Biased sex ratios may alter the contribution that individuals of either sex make to group living. Such a possibility has not been examined in social spiders, in part as adult male spider anatomy and behaviour are focussed on mating. Subadult male behaviour was examined in two congener social crab spiders that have similar ecological niches, Diaea ergandros with an

T. A. Evans

2000-01-01

11

Variably male-biased sex ratio in a marine bird with females larger than males  

Microsoft Academic Search

When the costs of rearing males and females differ progeny sex ratios are expected to be biased toward the less expensive\\u000a sex. Blue-footed booby (Sula nebouxii) females are larger and roughly 32% heavier than males, thus presumably more costly to rear. We recorded hatching and fledging\\u000a sex ratios in 1989, and fledging sex ratios during the next 5?years. In 1989,

Roxana Torres; Hugh Drummond

1999-01-01

12

Family Support Tied to Safer Sex for Young Gay Males  

MedlinePLUS

... please enable JavaScript. Family Support Tied to Safer Sex for Young Gay Males: Study Closeness, open discussions ... Issues Gay, Lesbian, Bisexual and Transgender Health Teen Sexual Health WEDNESDAY, Oct. 15, 2014 (HealthDay News) -- Young gay ...

13

Male mutation rates and the cost of sex for females  

NASA Astrophysics Data System (ADS)

ALTHOUGH we do not know why sex evolved, the twofold cost of meiosis for females provides a standard against which postulated benefits of sex can be evaluated1. The most reliable benefit is sex's ability to reduce the impact of deleterious mutations2,3. But deleterious mutations may themselves generate a large and previously overlooked female-specific cost of sex. DNA sequence comparisons have confirmed Haldane's suggestion that most mutations arise in the male germ line4,5; recent estimates of ?, the ratio of male to female mutation rates, are ten, six and two in humans, primates and rodents, respectively6-8. Consequently, male gametes may give progeny more mutations than the associated sexual recombination eliminates. Here I describe computer simulations showing that the cost of male mutations can easily exceed the benefits of recombination, causing females to produce fitter progeny by parthenogenesis than by mating. The persistence of sexual reproduction by females thus becomes even more problematic.

Redfield, Rosemary J.

1994-05-01

14

A comparison of sex offenders against female and male minors  

Microsoft Academic Search

Male sex offenders against minors were grouped according to age and sex of victims, and according to whether they had offended against one or more than one minor. Cases of incest or courtship disorder were not included in the study. Among offenders against female children, the number of one-case offenders was substantially larger than that of multicase offenders. The opposite

Kurt Freund; Robin Watson; Doug Rienzo

1987-01-01

15

Condition dependence of male mortality drives the evolution of sex differences in longevity.  

PubMed

Males and females age at different rates and have different life expectancies across the animal kingdom, but what causes the longevity "gender gaps" remains one of the most fiercely debated puzzles among biologists and demographers. Classic theory predicts that the sex experiencing higher rate of extrinsic mortality evolves faster aging and reduced longevity. However, condition dependence of mortality can counter this effect by selecting against senescence in whole-organism performance. Contrary to the prevailing view but in line with an emerging new theory, we show that the evolution of sex difference in longevity depends on the factors that cause sex-specific mortality and cannot be predicted from the mortality rate alone. Experimental evolution in an obligately sexual roundworm, Caenorhabditis remanei, in which males live longer than females, reveals that sexual dimorphism in longevity erodes rapidly when the extrinsic mortality in males is increased at random. We thus experimentally demonstrate evolution of the sexual monomorphism in longevity in a sexually dimorphic organism. Strikingly, when extrinsic mortality is increased in a way that favors survival of fast-moving individuals, males evolve increased longevities, thereby widening the gender gap. Thus, sex-specific selection on whole-organism performance in males renders them less prone to the ravages of old age than females, despite higher rates of extrinsic mortality. Our results reconcile previous research with recent theoretical breakthroughs by showing that sexual dimorphism in longevity evolves rapidly and predictably as a result of the sex-specific interactions between environmental hazard and organism's condition. PMID:25308078

Chen, Hwei-yen; Maklakov, Alexei A

2014-10-20

16

Nocturnal male sex drive in Drosophila.  

PubMed

Many behaviors and physiological processes including locomotor activity, feeding, sleep, mating, and migration are dependent on daily or seasonally reoccurring, external stimuli. In D. melanogaster, one of the best-studied circadian behaviors is locomotion. The fruit fly is considered a diurnal (day active/night inactive) insect, based on locomotor-activity recordings of single, socially naive flies. We developed a new circadian paradigm that can simultaneously monitor two flies in simple social contexts. We find that heterosexual couples exhibit a drastically different locomotor-activity pattern than individual males, females, or homosexual couples. Specifically, male-female couples exhibit a brief rest phase around dusk but are highly active throughout the night and early morning. This distinct locomotor-activity rhythm is dependent on the clock genes and synchronized with close-proximity encounters, which reflect courtship, between the male and female. The close-proximity rhythm is dependent on the male and not the female and requires circadian oscillators in the brain and the antenna. Taken together, our data show that constant exposure to stimuli emanating from the female and received by the male olfactory and other sensory systems is responsible for the significant shift in intrinsic locomotor output of socially interacting flies. PMID:17276917

Fujii, Shinsuke; Krishnan, Parthasarathy; Hardin, Paul; Amrein, Hubert

2007-02-01

17

Neonatal sex steroids affect responses to Seoul virus infection in male but not female Norway rats  

Microsoft Academic Search

Previous studies illustrate that after inoculation with Seoul virus (i.e., the naturally occurring hantavirus found in Norway rats), adult male rats produce higher antibody responses, exhibit higher Th1 responses (i.e., IgG2a, IL-2, and IFN?), and shed virus longer than females, but these difference are not altered by manipulation of sex steroids in adulthood. To determine whether sex steroid hormones organize

Sabra L. Klein; Aimee L. Marson; Alan L. Scott; Gary Ketner; Gregory E. Glass

2002-01-01

18

Beyond the Bravado: Sex Roles and the Exploitive Male.  

ERIC Educational Resources Information Center

Examines the tendency of men to engage in domestic violence and sexual exploitation and presents male sex-role acquisition as a process of psychosocial violence against young boys, which creates a sense of shame, powerlessness, self-alienation, isolation from others, and retaliatory rage and inhibits capacities for intimacy and mutuality.…

Taubman, Stan

1986-01-01

19

The Male Sex Role: A Selected and Annotated Bibliography.  

ERIC Educational Resources Information Center

This bibliography, containing more than 250 entries, presents research and theoretical perspectives into the male sex role. Articles were chosen for their usefulness to researchers, with emphasis on scientific and data-based research literature. All the annotations use a standard format including subjects, method, findings and comments. Articles…

Grady, Kathleen E.; And Others

20

Regulation of male sex determination: genital ridge formation and Sry activation in mice.  

PubMed

Sex determination is essential for the sexual reproduction to generate the next generation by the formation of functional male or female gametes. In mammals, primary sex determination is commenced by the presence or absence of the Y chromosome, which controls the fate of the gonadal primordium. The somatic precursor of gonads, the genital ridge is formed at the mid-gestation stage and gives rise to one of two organs, a testis or an ovary. The fate of the genital ridge, which is governed by the differentiation of somatic cells into Sertoli cells in the testes or granulosa cells in the ovaries, further determines the sex of an individual and their germ cells. Mutation studies in human patients with disorders of sex development and mouse models have revealed factors that are involved in mammalian sex determination. In most of mammals, a single genetic trigger, the Y-linked gene Sry (sex determination region on Y chromosome), regulates testicular differentiation. Despite identification of Sry in 1990, precise mechanisms underlying the sex determination of bipotential genital ridges are still largely unknown. Here, we review the recent progress that has provided new insights into the mechanisms underlying genital ridge formation as well as the regulation of Sry expression and its functions in male sex determination of mice. PMID:25139092

Tanaka, Satomi S; Nishinakamura, Ryuichi

2014-12-01

21

Chemosterilization of male sea lampreys, (Petromyzon marinus), does not affect sex pheromone release  

USGS Publications Warehouse

Release of males sterilized by injection with bisazir is an important experimental technique in management of sea lamprey (Petromyzon marinus), an invasive, nuisance species in the Laurentian Great Lakes. Sea lampreys are semelparous and sterilization can theoretically eliminate a male's reproductive capacity and, if the ability to obtain mates is not affected, waste the sex products of females spawning with him. It has been demonstrated that spermiating males release a sex pheromone that attracts ovulating females. We demonstrated that sterilized, spermiating males also released the pheromone and attracted ovulating females. In a two-choice maze, ovulating females increased searching behavior and spent more time in the side of the maze containing chemical stimuli from sterilized, spermiating males. This attraction response was also observed in spawning stream experiments. Also, electro-olfactograms showed that female olfactory organs were equally sensitive to chemical stimuli from sterilized and nonsterilized, spermiating males. Finally, fast atom bombardment mass spectrometry showed that extracts from water conditioned with sterilized and nonsterilized, spermiating males contained the same pheromonal molecule at similar levels. We concluded that injection of bisazir did not affect the efficacy of sex pheromone in sterilized males.

Siefkes, Michael J.; Bergstedt, Roger A.; Twohey, Michael B.; Li, Weiming

2003-01-01

22

A sex-specific transcription factor controls male identity in a simultaneous hermaphrodite.  

PubMed

Evolutionary transitions between hermaphroditic and dioecious reproductive states are found in many groups of animals. To understand such transitions, it is important to characterize diverse modes of sex determination utilized by metazoans. Currently, little is known about how simultaneous hermaphrodites specify and maintain male and female organs in a single individual. Here we show that a sex-specific gene, Smed-dmd-1 encoding a predicted doublesex/male-abnormal-3 (DM) domain transcription factor, is required for specification of male germ cells in a simultaneous hermaphrodite, the planarian Schmidtea mediterranea. dmd-1 has a male-specific role in the maintenance and regeneration of the testes and male accessory reproductive organs. In addition, a homologue of dmd-1 exhibits male-specific expression in Schistosoma mansoni, a derived, dioecious flatworm. These results demonstrate conservation of the role of DM domain genes in sexual development in lophotrochozoans and suggest one means by which modulation of sex-specific pathways can drive the transition from hermaphroditism to dioecy. PMID:23652002

Chong, Tracy; Collins, James J; Brubacher, John L; Zarkower, David; Newmark, Phillip A

2013-01-01

23

The use of the Internet by gay and bisexual male escorts: sex workers as sex educators.  

PubMed

While prior studies have targeted street-based male sex workers as potential vectors of disease transmission, the number of men who work independently through Internet chat-rooms and other online endeavors has steadily increased. It is likely that these men differ substantially from their street-based counterparts in terms of sexual risk behaviors with their clients. The purpose of this study was to explore the ways in which the Internet has impacted the work of male escorts and their sexual practices with clients. Semi-structured qualitative interviews and quantitative surveys were administered to 46 such men. Less than half the men reported unprotected anal sex with clients. The qualitative data lend support to this finding, in that the majority talked about refusing any unsafe sex with clients, and many reported taking the extra step of educating their clients about the dangers of risky sex. Some of the escorts described the methods used to incorporate safer sex practices into sessions with their clients. Internet-based male escorts can play an important role as potential sex educators on the front lines of the fight against HIV and other sexually transmitted infections. PMID:15511734

Parsons, J T; Koken, J A; Bimbi, D S

2004-11-01

24

Effects of size and sex on the social organization of reef-associated hogfishes, Bodianus spp  

Microsoft Academic Search

Three species of wrasses (Labridae) were examined in the field to determine the relative importance of size and sex in structuring social organization. The Spanish hogfish, Bodianus rufus, was characterized by stable dominance hierarchies that were linearly organized according to sex and relative size. Males were the largest and most-dominant individuals within discrete social groups of females (harems) whose dominance

Steven G. Hoffman

1985-01-01

25

HIV behavioural risks and the role of work environment among Chinese male sex workers in Hong Kong.  

PubMed

Male sex workers are a highly marginalised group in Hong Kong and it is increasingly so with an influx of them travelling from mainland China to work as "freelance" sex workers. This study aimed to measure important work environment variables that might affect the likelihood of condom use among male sex workers working in Hong Kong. A cross-sectional survey of 161 participants recruited by snowball and convenience sampling methods through outreach workers of a local non-governmental organization was conducted in 2007-2008. Only 27.4%, 54.7% and 42.6% reported consistent condom use when engaging in oral, anal and vaginal sex, respectively. Logistic regression shows unsafe sex was nearly four times (OR=3.41; 95%CI 1.51-7.69) as common in institutionalised male sex workers as among their independent counterparts. Lack of condoms provided at workplaces was a major barrier in this socio-legal context and was strongly associated with condom non-use amongst institutionalised sex workers (OR= 10.86; 95%CI 2.94-40.17). The present study finds that when compared with independent Male sex workers (MSWs), institutionalised MSWs were older, less educated, earned a higher income but more likely to engage in unsafe sex with their clients and their partners. Public health physicians must work with law-enforcing authorities to provide clear guidelines to remove these HIV prevention barriers. PMID:22293067

Wong, William C W; Leung, Phil W S; Li, C W

2012-01-01

26

Sex behaviour of male Japanese tourists in Bangkok, Thailand.  

PubMed

This paper explores why Japanese men engage in potentially risky commercial sexual behaviours while on holiday in Thailand. Semi-structured, in-depth interviews were conducted with 30 heterosexual male Japanese tourists, aged 19-36, who paid for sex with Thai women. Study participants were recruited at guesthouses in Bangkok. Analysis revealed eight main factors that encourage participation in commercial sex: a sense of freedom and anonymity during "time-out" spent travelling in a foreign country; a sense that there are permissive norms governing commercial sex in Thailand; the perceived sexual desirability of Thai women, a sense of economic and racial superiority relative to Thai women; a sense of loneliness or feeling in need of companionship; peer influence; the widespread availability of inexpensive sexual services in Thailand; and sexual desire or need. Findings indicate that Japanese male sexual conduct reflects individual drives while on holiday, in the context of interactions among Japanese peers, shaped by Thailand's socio-cultural environment. PMID:16641061

Yokota, Fumihiko

2006-01-01

27

How to make a sexy snake: estrogen activation of female sex pheromone in male red-sided garter snakes.  

PubMed

Vertebrates indicate their genetic sex to conspecifics using secondary sexual signals, and signal expression is often activated by sex hormones. Among vertebrate signaling modalities, the least is known about how hormones influence chemical signaling. Our study species, the red-sided garter snake (Thamnophis sirtalis parietalis), is a model vertebrate for studying hormonal control of chemical signals because males completely rely on the female sex pheromone to identify potential mates among thousands of individuals. How sex hormones can influence the expression of this crucial sexual signal is largely unknown. We created two groups of experimental males for the first experiment: Sham (blank implants) and E2 (17?-estradiol implants). E2 males were vigorously courted by wild males in outdoor bioassays, and in a Y-maze E2 pheromone trails were chosen by wild males over those of small females and were indistinguishable from large female trails. Biochemically, the E2 pheromone blend was similar to that of large females, and it differed significantly from Shams. For the second experiment, we implanted males with 17?-estradiol in 2007 but removed the implants the following year (2008; Removal). That same year, we implanted a new group of males with estrogen implants (Implant). Removal males were courted by wild males in 2008 (implant intact) but not in 2009 (removed). Total pheromone quantity and quality increased following estrogen treatment, and estrogen removal re-established male-typical pheromone blends. Thus, we have shown that estrogen activates the production of female pheromone in adult red-sided garter snakes. This is the first known study to quantify both behavioral and biochemical responses in chemical signaling following sex steroid treatment of reptiles in the activation/organization context. We propose that the homogametic sex (ZZ, male) may possess the same targets for activation of sexual signal production, and the absence of the activator (17?-estradiol in this case) underlies expression of the male phenotype. PMID:22323194

Parker, M Rockwell; Mason, Robert T

2012-03-01

28

Development of Reproductive Anatomy I. Development of sex organs: overview  

E-print Network

organs mature & secondary sex characteristics appear Differences in hair growth, change in fat1 Development of Reproductive Anatomy I. Development of sex organs: overview II. All the same Development of sex organs: overview Sex determination occurs first in the gonads and is followed

Dever, Jennifer A.

29

Sex and the unspoken in male street prostitution.  

PubMed

Although the overwhelming majority of male prostitutes work through agencies or by placing their own ads, most studies of male prostitution focus upon young men who work on the street. Remarkably, these studies seldom identify the dynamics of poverty and street-level violence as important elements of their examination. Investigations of male sex work-few though they are-focus almost exclusively upon sexual aspects of "the life." Despite the importance of these networks in shaping the contours of street life, and often in enabling one's very survival, the primary research focus has remained on questions of sexual identity, sexual practices with clients, and sexual abuse as a causative factor. Meanwhile, studies that do examine the dynamics of male street life typically do not examine questions of prostitution or other issues related to sexuality. A dominant theme within this literature consists of specifying the social mores of the most aggressive and socially problematic participants within street society, particularly gang members and drug dealers. The dissimilar nature of these images relates directly to the political projects of the dominant culture, which, in a very general way, seeks to "rescue" (reintegrate) deviant white youth, while controlling and excluding deviant youth of color. The political aim of reintegrating runaways into middle-class trajectories has the effect of authorizing certain discourses regarding their behavior on the streets, while marginalizing or completely disallowing others. This article seeks to examine and challenge these trends of representation. PMID:18019069

Kaye, Kerwin

2007-01-01

30

ORIGINAL PAPER Signaling in multiple modalities in male rhesus macaques: sex  

E-print Network

. Sex skin luminance was signif- icantly correlated across different skin regions. Sex skin luminance to convey different information. Sex skin appearance was not related to androgen levels although we foundORIGINAL PAPER Signaling in multiple modalities in male rhesus macaques: sex skin coloration

Maestripieri, Dario

31

Male breast cancer, age and sex chromosome aneuploidy  

PubMed Central

Background: In cultured, dividing transformed T lymphocytes and in dividing bone marrow cells from normal men and those with a haematological malignancy, sex chromosome aneuploidy has been found to increase in prevalence and degree with age. This has rarely been investigated in non-dividing uncultured blood samples. The loss and gain of the X chromosome in dividing transformed lymphocytes in women with age is much more frequent than that of the Y chromosome in males. However, paradoxically X chromosome aneuploidy is rarely seen in the dividing cells of bone marrow of females. Methods: In blood samples from 565 men with breast cancer and 54 control men from the England and Wales general population, 80 cell nuclei per sample were scored for presence of X and Y chromosomes using fluorescent centromeric probes. Results: Sex chromosome aneuploidy, largely Y chromosome loss, was present in 63% of cases and 57% of controls, with the prevalence and degree of aneuploidy increasingly sharply and highly significantly with age. At ages 65–80 years, 71% of cases and 85% of controls showed aneuploidy and 15% and 25%, respectively, had ?10% of cells aneuploid. Allowing for age, aneuploidy was less prevalent (P=0.03) in cases than controls. Conclusion: Sex chromosome aneuploidy in non-dividing nuclei of peripheral blood cells is frequent in adult men, the prevalence and degree increasing sharply with age. The possible relation of sex chromosome aneuploidy to breast cancer risk in men, and to cancer risk generally, needs further investigation, ideally in cohort studies. PMID:23299533

Jacobs, P A; Maloney, V; Cooke, R; Crolla, J A; Ashworth, A; Swerdlow, A J

2013-01-01

32

Offspring sex ratio is unrelated to male attractiveness in dark-eyed juncos ( Junco hyemalis )  

Microsoft Academic Search

Sex allocation theory predicts that parents should bias investment toward the offspring sex that confers higher relative fitness on the parents. When variance in reproductive success is higher in males than females, and some males are more attractive to females than others, thereby achieving higher reproductive success, female parents mated to attractive males are expected to bias reproductive allocation toward

Jennifer L. Grindstaff; Alex C. Buerkle; Joseph M. Casto; Val Nolan Jr; Ellen D. Ketterson

2001-01-01

33

Male phenotypic quality influences offspring sex ratio in a polygynous ungulate  

Microsoft Academic Search

Evolutionary models of sex ratio adjustment applied to mammals have ignored that females may gain indirect genetic benefits from their mates. The differential allocation hypothesis (DAH) predicts that females bias the sex ratio of their offspring towards (more costly) males when breeding with an attractive male. We manipulated the number of available males during rut in a polygynous ungulate species,

Knut H. Røed; Øystein Holand; Atle Mysterud; Aage Tverdal; Jouko Kumpula; Mauri Nieminen

2007-01-01

34

Sex Role Orientations of Male and Female Collegiate Athletes from Selected Individual and Team Sports.  

ERIC Educational Resources Information Center

Uses the Bem Sex Role Inventory to compare the sex role orientations of male and female collegiate athletes. Results indicate no significant differences for team sports players, but higher femininity scores for females in individual sports. (FMW)

Wrisberg, Craig A.; And Others

1988-01-01

35

Attraction of Female and Male Bactrocera papayae to Conspecific Males Fed with Methyl Eugenol and Attraction of Females to Male Sex Pheromone Components  

Microsoft Academic Search

The attraction of female and male Bactrocera papayae to conspecific males fed with methyl eugenol (ME) and female attraction to male synthetic sex pheromone, trans-coniferyl alcohol (CF), were evaluated in a wind tunnel. Earlier and greater attraction were exhibited by both females and males to ME-fed than to non-ME-fed males as dusk approaches. Males increased their precopulatory behavior (i.e., wing

Alvin Kah-Wei Hee; Keng-Hong Tan

1998-01-01

36

Both male and female novel traits promote the correlated evolution of genitalia between the sexes in an arthropod.  

PubMed

The correlated evolution of genitalia between sexes has been demonstrated in many taxa. However, it remains unclear whether female rather than male genitalia can play a key role in the correlated evolution of male and female genitalia. We conducted an extensive cross-population analysis of the divergence patterns of genital structures, weights of whole genital organs, and the bodies of both sexes, and male genital length in a group of xystodesmid millipedes showing diverse genital morphologies. We demonstrate that the correlated evolution of male and female genitalia toward exaggerated states has occurred in the millipedes, which have evolved novel traits in both males (forceps-like gonopods) and females (retractable bellows). Enlargement and elongation of forceps-like gonopods may be advantageous in sperm competition, whereas enlargement and elongation of the bellows may facilitate acceptance/rejection of insemination for ensuring the female's fitness. These male and female genital parts have affected the correlated evolution in the opposite sex, resulting in diversification and exaggeration of genital morphology. Our study suggests that evolutionary novel traits in not only males but also in females could play an important role in the correlated evolution of genitalia between the sexes. PMID:24116383

Tanabe, Tsutomu; Sota, Teiji

2014-02-01

37

ORGAN DONATION BY SUICIDES: SEX AND ETHNICITY.  

PubMed

Summary.-An analysis of 2,034 actual organ donations by suicides for the years 2008-2010 indicated that women were more likely to be donors than were men and Blacks more likely to donate than were Whites. The sex difference was consistent with the responses of men and women to surveys of the general public about their willingness to become organ donors, but the ethnic difference was the reverse of the responses to surveys of the general public about their willingness to be organ donors. Future research should explore the role of the responses, positive vs negative toward organ donation, of the significant others of those dying from different causes of death, and the extent to which people have signed donor cards. PMID:25457096

Lester, David; Hathaway, Dominique

2014-12-01

38

Male sex work and HIV risk among young heroin users in Hanoi, Vietnam.  

PubMed

The present study describes complex drug and sexual risk in a group of male sex workers (n = 79) who were recruited in the context of a larger study of young heroin users in Hanoi, Vietnam (n = 1270). Male sex workers were significantly more likely than male non-sex workers to be migrants (P < 0.001) and to have unstable housing (P < 0.001), to have lifetime exposure to marijuana (P < 0.001), 3,4 methylenedioxymethamphetamine (MDMA, ecstasy) (P < 0.01), amphetamines (P < 0.05), cocaine (P < 0.01) and morphine (P < 0.001). Male sex workers are more likely to currently use MDMA (P < 0.05), amphetamines (P < 0.001), morphine (P < 0.05) and to 'smoke' as their most frequent mode of heroin administration (P < 0.01). Male sex workers are more likely to have both male and female concurrent sex partners (P < 0.001), to have a history of sexual victimisation (P < 0.001), to have had more than three different sex partners in the past 30 days (P < 0.001), and to have had partners who injected drugs before sex (P < 0.001) or who used drugs during sex (P < 0.01). In their last sexual encounter with a client partner, approximately one-third (31.1%) reported having had receptive anal sex. In nearly three-quarters of these exchanges (71.4%), no condom was used. Similarly, in their last sexual encounter with a client partner, 42.2% reported having had insertive anal sex and in nearly half (47.4%) of these encounters no condom was used. Consistent with recent data from elsewhere in the region, there is an urgent need for additional research on male sex work in South-east Asia in order to properly situate behavioural interventions for male sex workers in this region. PMID:18082070

Clatts, Michael C; Giang, Le M; Goldsamt, Lloyd A; Yi, Huso

2007-12-01

39

"Cut-bristles" : a sex-limited mutant phenotype of male orbital  

E-print Network

Note "Cut-bristles" : a sex-limited mutant phenotype of male orbital bristles of Ceratitis capitata of Ceratitis capitata, is charac- terised by the disappearance of the lancet-shape bristles, a male sex-linked and another autosomal gene. Mediterranean fruit fly / Ceratitis capitata / "cut-bristles" mutant Résumé

Paris-Sud XI, Université de

40

Personality, Sex-Role Orientation, and Psychological Health in Stereotypically Masculine Groups of Males.  

ERIC Educational Resources Information Center

Sex role identity and personality characteristics were examined in 104 male college football players and police cadets by means of the Bem Sex Role Inventory and the California Psychological Inventory. No significant differences were found between these stereotypically "masculine" groups and normative samples of males. (CMG)

Mills, Carol J.; Bohannon, Wayne E.

1983-01-01

41

The Relationship of Sex-Role Orientation to Death Anxiety in Middle-Aged Males.  

ERIC Educational Resources Information Center

Examined the relationship between sex-role orientation and death anxiety in 237 middle-aged men who completed the Bem Sex-Role Inventory and Boyar's Fear of Death Scale. Results indicated neither amount of contact with death nor traditional male sex-role orientation were related to death anxiety. (JAC)

Downey, Ann M.

1984-01-01

42

The Vomeronasal Organ of the Male Ferret  

Microsoft Academic Search

The vomeronasal organ (VNO) is known to play a major role in sexual behavior in many mammals. This study is the first report that the adult male ferret has a VNO, which is considerably smaller and morphologically different from the usually crescent- shaped epithelium in several mammalian species, particularly rodents. There were no differences in the size or structure of

Elke Weiler; Raimund Apfelbach; Albert I. Farbman

1999-01-01

43

Men's constructions of masculinity and male sexuality through talk of buying sex.  

PubMed

Commercial sex is an everyday occurrence across a range of contexts in South Africa. In this paper we turn our attention to the often-marginalised role of the buyers of sex by drawing on narrative interviews with male clients of female sex workers recruited through online advertisements in order to explore the ways in which heterosexual men construct, negotiate and perform their masculinity and sexuality through talking about their experiences of paying for sex. We highlight parallels between men's narratives of paying for sex and dominant discourses of gender and heterosexuality. We show how men draw on heteronormative sexual scripts in constructing and making sense of paid sexual encounters and how men are simultaneously able to construct and enact a particular idealised version of masculinity and male sexuality through their talk on paying for sex. Finally, we discuss how online resources could be used more extensively in future research with the male clients of sex workers. PMID:25287270

Huysamen, Monique; Boonzaier, Floretta

2014-10-01

44

Fertile male mice with three sex chromosomes: Evidence that infertility in XYY male mice is an effect of two Y chromosomes  

Microsoft Academic Search

In the mouse XYY males are sterile, presumably because pairing abnormalities resulting from the presence of three sex chromosomes lead to meiotic breakdown. We have produced male mice, designated XYY*X, that have three sex chromosome pairing regions but only one intact Y chromosome. Unexpectedly XYY*X males are fertile, although they are no more efficient in sex chromosome pairing than previously

Patricia A. Hunt; Eva M. Eicher

1991-01-01

45

Oleic acid is a precursor of linoleic acid and the male sex pheromone in Nasonia vitripennis.  

PubMed

Linoleic acid (C18:2(?9,12), LA) is crucial for many cell functions in organisms. It has long been a paradigm that animals are unable to synthesize LA from oleic acid (C18:1(?9), OA) because they were thought to miss ?(12)-desaturases for inserting a double bound at the ?(12)-position. Today it is clear that this is not true for all animals because some insects and other invertebrates have been demonstrated to synthesize LA. However, the ability to synthesize LA is known in only five insect orders and no examples have been reported so far in the Hymenoptera. LA plays a particular role in the parasitic wasp Nasonia vitripennis, because it is the precursor of the male sex pheromone consisting of (4R,5R)- and (4R,5S)-5-hydroxy-4-decanolides. Here we demonstrate by stable isotope labeling that N. vitripennis is able to incorporate externally applied fully (13)C-labeled OA into the male sex pheromone suggesting that they convert initially OA into LA. To verify this assumption, we produced fly hosts (Lucilia caesar) which were experimentally enriched in (13)C-labeled OA and reared male parasitoids on these hosts. Chemical analysis of transesterified lipid raw extracts from hosts and parasitoids revealed that N. vitripennis but not L. caesar contained (13)C-labeled LA methyl ester. Furthermore, male wasps from the manipulated hosts produced significant amounts of (13)C-labeled sex pheromone. These results suggest that N. vitripennis possesses a ?(12)-desaturase. The additional fitness relevant function as pheromone precursor might have favored the evolution of LA biosynthesis in N. vitripennis to make the wasps independent of the formerly essential nutrient. PMID:24874439

Blaul, Birgit; Steinbauer, Robert; Merkl, Philipp; Merkl, Rainer; Tschochner, Herbert; Ruther, Joachim

2014-08-01

46

The avian Z-linked gene DMRT1 is required for male sex determination in the chicken  

Microsoft Academic Search

Sex in birds is chromosomally based, as in mammals, but the sex chromosomes are different and the mechanism of avian sex determination has been a long-standing mystery. In the chicken and all other birds, the homogametic sex is male (ZZ) and the heterogametic sex is female (ZW). Two hypotheses have been proposed for the mechanism of avian sex determination. The

Craig A. Smith; Kelly N. Roeszler; Thomas Ohnesorg; David M. Cummins; Peter G. Farlie; Timothy J. Doran; Andrew H. Sinclair

2009-01-01

47

Male-male contests for mates, sexual size dimorphism, and sex ratio in a natural population of a solitary parasitoid.  

PubMed

Understanding how different behavioural and life history traits interact is fundamental to developing ethological theory. Here we study the interaction of male-male competition for mates and sexual size dimorphism in a solitary wasp, with implications for sex allocation. In Hymenoptera, females are normally larger than males suggesting that males do not benefit as much as females from larger size. However, in our focal species, a solitary Eurytoma wasp, males compete for mates by pairwise contests at female emergence sites, suggesting that male size may strongly affect fitness. In contests observed in the field, larger males were more likely to win fights, and males fighting at female emergence sites were much larger than average males. Males showed higher variance in body size than females, such that all the smallest individuals were males, a majority of medium-to-large individuals were female, but the majority of largest individuals were male. Our data suggest that sexual size dimorphism in this species has been affected by intra-sexual selection for male size, which may have implications for sex allocation. PMID:23872503

Macedo, Margarete V; Monteiro, Ricardo F; Silveira, Mariana P; Mayhew, Peter J

2013-11-01

48

From Client to Pimp: Male Violence against Female Sex Workers  

ERIC Educational Resources Information Center

The present study explores intimate partner violence (IPV) among female sex workers from the red-light area based in Mumbai, India. Using a grounded theory approach, in-depth interviews were conducted with ten sex workers to explore their experiences of IPV in the context of commercial sex work. Narratives were analyzed and themes constructed. A…

Karandikar, Sharvari; Prospero, Moises

2010-01-01

49

Fluorochemicals used in food packaging inhibit male sex hormone synthesis  

SciTech Connect

Polyfluoroalkyl phosphate surfactants (PAPS) are widely used in food contact materials (FCMs) of paper and board and have recently been detected in 57% of investigated materials. Human exposure occurs as PAPS have been measured in blood; however knowledge is lacking on the toxicology of PAPS. The aim of this study was to elucidate the effects of six fluorochemicals on sex hormone synthesis and androgen receptor (AR) activation in vitro. Four PAPS and two metabolites, perfluorooctanoic acid (PFOA) and 8:2 fluorotelomer alcohol (8:2 FTOH) were tested. Hormone profiles, including eight steroid hormones, generally showed that 8:2 diPAPS, 8:2 monoPAPS and 8:2 FTOH led to decreases in androgens (testosterone, dehydroepiandrosterone, and androstenedione) in the H295R steroidogenesis assay. Decreases were observed for progesterone and 17-OH-progesterone as well. These observations indicated that a step prior to progestagen and androgen synthesis had been affected. Gene expression analysis of StAR, Bzrp, CYP11A, CYP17, CYP21 and CYP19 mRNA showed a decrease in Bzrp mRNA levels for 8:2 monoPAPS and 8:2 FTOH indicating interference with cholesterol transport to the inner mitochondria. Cortisol, estrone and 17?-estradiol levels were in several cases increased with exposure. In accordance with these data CYP19 gene expression increased with 8:2 diPAPS, 8:2 monoPAPS and 8:2 FTOH exposures indicating that this is a contributing factor to the decreased androgen and the increased estrogen levels. Overall, these results demonstrate that fluorochemicals present in food packaging materials and their metabolites can affect steroidogenesis through decreased Bzrp and increased CYP19 gene expression leading to lower androgen and higher estrogen levels. -- Highlights: ? Fluorochemicals found in 57% of paper and board food packaging were tested. ? Collectively six fluorochemicals were tested for antiandrogenic potential in vitro. ? Three out of six tested fluorochemicals inhibited synthesis of male sex hormones. ? Generally, levels of estrogens and cortisol stayed unaffected or increased. ? The effect on steroid synthesis was specific on gene expression of Bzrp and CYP19.

Rosenmai, A.K., E-mail: akjro@food.dtu.dk [Division of Toxicology and Risk Assessment, National Food Institute, Technical University of Denmark, DK-2860 Søborg (Denmark); Nielsen, F.K. [Section of Toxicology, Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2100 Copenhagen (Denmark)] [Section of Toxicology, Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2100 Copenhagen (Denmark); Pedersen, M. [Division of Food Chemistry, National Food Institute, Technical University of Denmark, DK-2860 Søborg (Denmark)] [Division of Food Chemistry, National Food Institute, Technical University of Denmark, DK-2860 Søborg (Denmark); Hadrup, N. [Division of Toxicology and Risk Assessment, National Food Institute, Technical University of Denmark, DK-2860 Søborg (Denmark)] [Division of Toxicology and Risk Assessment, National Food Institute, Technical University of Denmark, DK-2860 Søborg (Denmark); Trier, X. [Division of Food Chemistry, National Food Institute, Technical University of Denmark, DK-2860 Søborg (Denmark)] [Division of Food Chemistry, National Food Institute, Technical University of Denmark, DK-2860 Søborg (Denmark); Christensen, J.H. [Department of Basic Sciences and Environment, Faculty of Life Sciences, University of Copenhagen, DK-1871 Frederiksberg C. (Denmark)] [Department of Basic Sciences and Environment, Faculty of Life Sciences, University of Copenhagen, DK-1871 Frederiksberg C. (Denmark); Vinggaard, A.M. [Division of Toxicology and Risk Assessment, National Food Institute, Technical University of Denmark, DK-2860 Søborg (Denmark)] [Division of Toxicology and Risk Assessment, National Food Institute, Technical University of Denmark, DK-2860 Søborg (Denmark)

2013-01-01

50

MMPI Profiles of Males with Abnormal Sex Chromosome Complements  

ERIC Educational Resources Information Center

Nine males with Klinefelter's syndrome (XXY) and seven XYY males, located primarily in prisons and psychiatric hospitals, were administered the Minnesota Multiphasic Personality Inventory. (Author/KW)

Rosen, M.; And Others

1971-01-01

51

Perceived stigma of purchasing sex among latino and non-latino male clients of female sex workers in tijuana, Mexico.  

PubMed

HIV prevention efforts must be comprehensive in their understanding of the factors involved in HIV risk. Male clients, who have received less research attention than female sex workers (FSWs), may experience stigma as a function of purchasing sex. Perceived stigma may be related to poor psychological outcomes, risky psychosexual characteristics, and higher drug and sexual risk behavior among male clients of FSWs. However, perceived stigma of purchasing sex may differ between clients of different ethnic groups. In the present study, we examine the correlates of perceived stigma of purchasing sex among Latino versus non-Latino male clients of FSWs in Tijuana, Mexico. Using time-location sampling, we recruited 375 male clients (323 Latino, 52 non-Latino) in Tijuana who completed a computerized survey on various measures. We measured perceived stigma of purchasing sex using three items we developed for this study. Using linear regression analyses we found that perceived stigma was associated with greater guilt, a greater feeling of escape from everyday life, and more negative condom attitudes among Latino clients. This was not found among non-Latino clients. Features of Latino culture, like machismo, and how they may relate to stigma of purchasing sex are discussed. PMID:23979714

Pitpitan, Eileen V; Strathdee, Steffanie A; Semple, Shirley J; Wagner, Karla D; Chavarin, Claudia V; Earnshaw, Valerie A; Patterson, Thomas L

2015-02-01

52

Anim. Behav., 1998, 55, 16311635 Sex recognition and mate choice by male western toads, Bufo boreas  

E-print Network

Anim. Behav., 1998, 55, 1631­1635 Sex recognition and mate choice by male western toads, Bufo and mate choice in male western toads, Bufo boreas. When given a simultaneous choice between a male & Cohen 1995). Frog and toad advertisement calls may be considered a form of long-range courtship (Rand

Blaustein, Andrew R.

53

Shadow of domestic violence and extramarital sex cohesive with spousal communication among males in Nepal  

PubMed Central

Background Public health and human right issues are challenging in low and middle income countries. The main objectives of this paper were to determine the prevalence and factors associated with domestic violence, extramarital sex, and spousal communication among male. Methods A cross-sectional study among 2466 married males in Kathmandu, Nepal was conducted using random sampling method. Adjusted odds ratios (AORs) and 95% confidence intervals (CI) of associated factors were estimated by stepwise backward likelihood ratio method. Results Prevalence of domestic violence was 63.14% (95% CI 61.20-65.05), extramarital sex was 32.12% (95% CI 30.27-34.00), and spousal communication was 48.87% (95% CI 46.85-50.90). Nearly one in five male (18.20%) had not used condom during extramarital sex. Interestingly, male who had more than three or equal children were less likely to have perpetrated domestic violence compared with those who had less children. Older male aged 25 and above were more likely (AORs?=?1.55, 95% CI 1.19-2.03) to have extramarital sex compared with male aged 24 or below. Those male who had studied secondary or higher level of education were less likely to have extramarital sex compared to those who had primary level or no education. Male who had higher income were more likely to have spousal communication compared to those who had less income. Surprisingly, those male who had extramarital sex were less likely to have spousal communication compared with those was not involved in extramarital sex. Conclusion Practice of domestic violence and extramarital sex is quite common among married male in Nepal, where spousal communication is sparse. These findings can be used to advocate for immediate attention and activities needs to be endorsed by policymakers and programmers. PMID:24924872

2014-01-01

54

The Weaker Sex? The Propensity for Male-Biased Piglet Mortality  

PubMed Central

For the most part solutions to farm animal welfare issues, such as piglet mortality, are likely to lie within the scientific disciplines of environmental design and genetic selection, however understanding the ecological basis of some of the complex dynamics observed between parent and offspring could make a valuable contribution. One interesting, and often discussed, aspect of mortality is the propensity for it to be sex-biased. This study investigated whether known physiological and behavioural indicators of piglet survival differed between the sexes and whether life history strategies (often reported in wild or feral populations) relating to parental investment were being displayed in a domestic population of pigs. Sex ratio (proportion of males (males/males+females)) at birth was 0.54 and sex allocation (maternal investment measured as piglet birth weight/litter weight) was statistically significantly male-biased at 0.55 (t35?=?2.51 P?=?0.017), suggesting that sows invested more in sons than daughters during gestation. Despite this investment in birth weight, a known survival indicator, total pre-weaning male mortality was statistically significantly higher than female mortality (12% vs. 7% respectively z?=?2.06 P?=?0.040). Males tended to suffer from crushing by the sow more than females and statistically significantly more males died from disease-related causes. Although males were born on average heavier, with higher body mass index and ponderal index, these differences were not sustained. In addition male piglets showed impaired thermoregulation compared to females. These results suggest male-biased mortality exists despite greater initial maternal investment, and therefore reflects the greater susceptibility of this sex to causal mortality factors. Life history strategies are being displayed by a domestic population of pigs with sows in this study displaying a form of parental optimism by allocating greater resources at birth to males and providing an over-supply of this more vulnerable sex in expectation of sex-biased mortality. PMID:22272334

Baxter, Emma M.; Jarvis, Susan; Palarea-Albaladejo, Javier; Edwards, Sandra A.

2012-01-01

55

Sex- and Gonad-Affecting Scent Compounds and 3 Male Pheromones in the Rat  

PubMed Central

This study was aimed at identifying sex pheromones of the rat (Rattus norvegicus). We characterized the volatiles and semivolatiles of rat preputial gland and voided urine by using gas chromatography–mass spectrometry (GC–MS) and quantified them by their GC areas (abundances) and percentage of GC areas (relative abundances). Although all the compounds other than 4-heptanone and phenol detected were shared by males and females, the quantities for some of these sex-common compounds exhibited sexual dimorphism and decreased with gonadectomy. Thus, these compounds might be sex pheromones. Among them, squalene from preputial glands and 2-heptanone and 4-ethyl phenol from urine were 3 major compounds. They were richer in males and could be suppressed by castration. Adding any of the 3 compounds (at a concentration higher than its physiological level in male urine) to castrated male urine (CMU) increased the attractiveness of CMU to sex-naive females. Adding the 3 together (at the levels in normal male urine) to CMU significantly increased the attractiveness of CMU to females. However, such combination did not fully restore females' preference for urine from intact males, suggesting that some other trace compounds such as 4-heptanone and phenol might also play some roles in sex attractiveness. Thus, squalene, 2-heptanone, and 4-ethyl phenol were indeed male pheromone molecules in rats. Our study also indicates that E,E-?-farnesene and E-?-farnesene, both richer in females than males, might be putative female pheromones. PMID:18515819

Sun, Lixing; Zhang, Jin-Hua; Feng, Zhi-Yong

2008-01-01

56

Cloning of Taiwan water buffalo male-specific DNA sequence for sexing  

Microsoft Academic Search

Random amplified polymorphic DNA (RAPD) fingerprinting was carried out to investigate the sex-specific DNA sequence for sexing in Taiwan water buffalos. One hundred and forty random primers were used for RAPD-PCR (polymerase chain reaction). One of these primers, OPC-16, produced a 321bp fragment found only in tested males. This male-specific fragment was isolated and constructed into plasmids for nucleotide sequencing,

Yan-Ming Horng; Yi-Ting Chen; Chean-Ping Wu; Yu-Shine Jea; Mu-Chiou Huang

2004-01-01

57

the DomeMales are lured byfood and sex into erotic contests and deadly brawls  

E-print Network

Dancing in the DomeMales are lured byfood and sex into erotic contests and deadly brawls by Paul J dome webs between low, leafless branches. Webs are usually four to six- teen inches wide space, where they annually' reenact a silent, ancient drama of sex and combat. My study site

Watson, Paul J.

58

Change of the heterogametic sex from male to female in the frog.  

PubMed Central

Two different types of sex chromosomes, XX/XY and ZZ/ZW, exist in the Japanese frog Rana rugosa. They are separated in two local forms that share a common origin in hybridization between the other two forms (West Japan and Kanto) with male heterogametic sex determination and homomorphic sex chromosomes. In this study, to find out how the different types of sex chromosomes differentiated, particularly the evolutionary reason for the heterogametic sex change from male to female, we performed artificial crossings between the West Japan and Kanto forms and mitochondrial 12S rRNA gene sequence analysis. The crossing results showed male bias using mother frogs with West Japan cytoplasm and female bias using those with Kanto cytoplasm. The mitochondrial genes of ZZ/ZW and XX/XY forms, respectively, were similar in sequence to those of the West Japan and Kanto forms. These results suggest that in the primary ZZ/ZW form, the West Japan strain was maternal and thus male bias was caused by the introgression of the Kanto strain while in the primary XX/XY form and vice versa. We therefore hypothesize that sex ratio bias according to the maternal origin of the hybrid population was a trigger for the sex chromosome differentiation and the change of heterogametic sex. PMID:12807781

Ogata, M; Ohtani, H; Igarashi, T; Hasegawa, Y; Ichikawa, Y; Miura, I

2003-01-01

59

HIV Risk and Social Networks Among Male-to-Female Transgender Sex Workers in Boston, Massachusetts  

PubMed Central

Male-to-female transgender individuals who engage in sex work constitute a group at high risk for HIV infection in the United States. This mixed-methods formative study examined sexual risk among preoperative transgender male-to-female sex workers (N = 11) in Boston. More than one third of the participants were HIV-infected and reported a history of sexually transmitted diseases. Participants had a mean of 36 (SD = 72) transactional male sex partners in the past 12 months, and a majority reported at least one episode of unprotected anal sex. Qualitative themes included (a) sexual risk, (b) motivations for engaging in sex work, (c) consequences of sex work, (d) social networks (i.e., “trans mothers,” who played a pivotal role in initiation into sex work), and (e) potential intervention strategies. Results suggest that interventions with transgender male-to-female sex workers must be at multiple levels and address the psychosocial and environmental contexts in which sexual risk behavior occurs. PMID:19732696

Reisner, Sari L.; Mimiaga, Matthew J.; Bland, Sean; Mayer, Kenneth H.; Perkovich, Brandon; Safren, Steven A.

2013-01-01

60

Prevalence and correlates of sexual risk among male and female sex workers in Tijuana, Mexico.  

PubMed

We investigated prevalence and correlates of sexual risk behaviours among male and female sex workers in Tijuana, Mexico, the busiest border crossing area on the US - Mexico border, analysing survey data from a purposive, cross-sectional sample of male and female sex workers who worked in a range of indoor and outdoor settings. Logistic regression was used to determine factors that were associated with sexual risk-taking, defined as failing to use a condom with last client. In bivariate regression models, gender, work setting (e.g., indoor vs. outdoor), poverty, engaging in survival sex, marital status and perceived drug addiction were correlated with sexual risk. When controlling for work location, housing insecurity, poverty, survival sex, marital status and perceived drug addiction, male sex workers were still 10 times more likely than female sex workers (FSW) to engage in sex without a condom during their last encounter with a client. And, although FSW were significantly more likely than males to have used a condom with a client, they were significantly less likely than males to have used a condom with their regular partner. Future research should further examine how gender shapes sexual risk activities in both commercial and non-commercial relationships. PMID:22304493

Katsulis, Yasmina; Durfee, Alesha

2012-01-01

61

Sex Chromosome  

NSDL National Science Digital Library

A sex chromosome is one of the two chromosomes that specify an organism's genetic sex. Humans have two kinds of sex chromosomes, one called X and the other Y. Normal females possess two X chromosomes and normal males one X and one Y.

Darryl Leja (National Human Genome Research Institute REV)

2005-04-14

62

The Molecular Basis Of Male Sex Determination During Temperature-Dependent Sex Determination.  

E-print Network

??The red-eared slider turtle (Trachemys scripta) possesses temperature-dependent sex determination (TSD) in which the incubation temperature of the developing embryo determines gonadal sex. Although a… (more)

Bieser, Kayla

2013-01-01

63

Functional development of sex accessory organs of the male rat. Use of oestradiol benzoate to identify the neonatal period as critical for development of normal protein-synthetic and secretory capabilities.  

PubMed Central

Functional development of the sex accessory tissues was studied in the male rat. Three potentially crucial developmental periods (neonatal, prepubertal and pubertal) were examined, and then the functional integrity of the accessory tissues was investigated in the adult, when the animals would have been expected to display normal function. Four accessory tissues (the seminal vesicles, ventral prostate and caput and cauda epididymides) were used because of their different embryological origins and responses to androgens in the adult. Synthesis and secretion of previously characterized tissue-specific androgen-dependent proteins were taken as indicators of normal function. Development was perturbed by using oestradiol benzoate, since this was known to affect gross development of the seminal vesicles and ventral prostate when given to neonatal rats. Treatment during the first 5 days after birth severely restricted development of the seminal vesicles and ventral prostate. Protein secreted by the former was only 1% of the normal amount, and in many cases several major secretory proteins were essentially missing. Prostatic protein secretion was less than 20% of normal, but all the major proteins were detectable. In both tissues overall protein synthesis per cell was quantitatively normal, but the proportion devoted to specific major secretory proteins was markedly depressed, i.e. the response is differential. In contrast, treatment during the prepubertal period was without noticeable effects. Development of the seminal vesicles and prostate was somewhat inhibited by treatment at puberty, but these changes were minor compared with those after neonatal exposure to oestradiol benzoate. No effects on epididymal protein synthesis or secretory proteins were observed, and epididymal weight and DNA content were only moderately decreased regardless of when oestradiol benzoate was administered during sexual maturation. Hence the neonatal period is not so critical for epididymal development. The substantial changes elicited by oestrogen treatment during neonatal life in seminal-vesicle and prostatic protein synthesis and secretion were compared with those evoked in sexually mature males by either oestrogen treatment or castration. Both these latter treatments resulted in a general decrease in seminal-vesicle protein synthesis and secretion, but the marked differential effects on major proteins after neonatal exposure were absent. Castration did, however, evoke a differential prostatic response, but this was not seen after oestrogen treatment of adults. Images Fig. 1. Fig. 2. PMID:7306031

Higgins, S J; Brooks, D E; Fuller, F M; Jackson, P J; Smith, S E

1981-01-01

64

The Profile and Treatment of Male Adolescent Sex Offenders.  

ERIC Educational Resources Information Center

Outlines characteristics of sex offenders, including family and school histories, sexual attitudes, social skills and relationships, delinquent behaviors, psychiatric diagnoses, and cognitive distortions based on mythical beliefs. Treatment requires correction of thinking errors and promotion of accountability, empathy, education, morality,…

Lakey, Joyce F.

1994-01-01

65

Identification of a sex pheromone from male yellow mealworm beetles, Tenebrio molitor.  

PubMed

The sex pheromone released by the adult female Tenebrio molitor, 4-methyl-1-nonanol, is well known. In addition, there is evidence that adult males release a pheromone that attracts females. The purpose of the present study was to isolate and identify male-released pheromone(s). Emissions from virgin adult males and females were collected on filter paper and extracted with pentane. Extracts were analyzed by gas chromatography-mass spectrometry. One male-specific compound was detected and identified as (Z)-3-dodecenyl acetate (Z3-12:Ac). In arena bioassays, E3-12:Ac was attractive to females only, at 1 and 10 microg doses. E3-12:Ac was also attractive to females at a 10-microg dose. The presence of both male and female pheromones, each attracting the opposite sex, may contribute to maintaining a high-density population of both sexes. PMID:16273437

Bryning, Gareth P; Chambers, John; Wakefield, Maureen E

2005-11-01

66

The Sicker Sex: Understanding Male Biases in Parasitic Infection, Resource Allocation and Fitness  

PubMed Central

The “sicker sex” idea summarizes our knowledge of sex biases in parasite burden and immune ability whereby males fare worse than females. The theoretical basis of this is that because males invest more on mating effort than females, the former pay the costs by having a weaker immune system and thus being more susceptible to parasites. Females, conversely, have a greater parental investment. Here we tested the following: a) whether both sexes differ in their ability to defend against parasites using a natural host-parasite system; b) the differences in resource allocation conflict between mating effort and parental investment traits between sexes; and, c) effect of parasitism on survival for both sexes. We used a number of insect damselfly species as study subjects. For (a), we quantified gregarine and mite parasites, and experimentally manipulated gregarine levels in both sexes during adult ontogeny. For (b), first, we manipulated food during adult ontogeny and recorded thoracic fat gain (a proxy of mating effort) and abdominal weight (a proxy of parental investment) in both sexes. Secondly for (b), we manipulated food and gregarine levels in both sexes when adults were about to become sexually mature, and recorded gregarine number. For (c), we infected male and female adults of different ages and measured their survival. Males consistently showed more parasites than females apparently due to an increased resource allocation to fat production in males. Conversely, females invested more on abdominal weight. These differences were independent of how much food/infecting parasites were provided. The cost of this was that males had more parasites and reduced survival than females. Our results provide a resource allocation mechanism for understanding sexual differences in parasite defense as well as survival consequences for each sex. PMID:24194830

Córdoba-Aguilar, Alex; Munguía-Steyer, Roberto

2013-01-01

67

Hepatic injury induces contrasting response in liver and kidney to chemicals that are metabolically activated: Role of male sex hormone  

SciTech Connect

Injury to liver, resulting in loss of its normal physiological/biochemical functions, may adversely affect a secondary organ. We examined the response of the liver and kidney to chemical substances that require metabolic activation for their toxicities in mice with a preceding liver injury. Carbon tetrachloride treatment 24 h prior to a challenging dose of carbon tetrachloride or acetaminophen decreased the resulting hepatotoxicity both in male and female mice as determined by histopathological examination and increases in serum enzyme activities. In contrast, the renal toxicity of the challenging toxicants was elevated markedly in male, but not in female mice. Partial hepatectomy also induced similar changes in the hepatotoxicity and nephrotoxicity of a challenging toxicant, suggesting that the contrasting response of male liver and kidney was associated with the reduction of the hepatic metabolizing capacity. Carbon tetrachloride pretreatment or partial hepatectomy decreased the hepatic xenobiotic-metabolizing enzyme activities in both sexes but elevated the renal p-nitrophenol hydroxylase, p-nitroanisole O-demethylase and aminopyrine N-demethylase activities significantly only in male mice. Increases in Cyp2e1 and Cyp2b expression were also evident in male kidney. Castration of males or testosterone administration to females diminished the sex-related differences in the renal response to an acute liver injury. The results indicate that reduction of the hepatic metabolizing capacity induced by liver injury may render secondary target organs susceptible to chemical substances activated in these organs. This effect may be sex-specific. It is also suggested that an integrated approach should be taken for proper assessment of chemical hazards.

Kim, Young C. [College of Pharmacy, Seoul National University, San 56-1 Shinrim-Dong, Kwanak-Ku, Seoul (Korea, Republic of)], E-mail: youckim@snu.ac.kr; Yim, Hye K.; Jung, Young S. [College of Pharmacy, Seoul National University, San 56-1 Shinrim-Dong, Kwanak-Ku, Seoul (Korea, Republic of); Park, Jae H. [College of Veterinary Medicine, Seoul National University, San 56-1 Shinrim-Dong, Kwanak-Ku, Seoul (Korea, Republic of); Kim, Sung Y. [College of Pharmacy, Wonkwang University, 344-2 Shinyong-Dong, Iksan (Korea, Republic of)

2007-08-15

68

Sexually dimorphic neurons in the ventromedial hypothalamus govern mating in both sexes and aggression in males  

PubMed Central

SUMMARY Sexual dimorphisms in the brain underlie behavioral sex differences, but the function of individual sexually dimorphic neuronal populations is poorly understood. Neuronal sexual dimorphisms typically represent quantitative differences in cell number, gene expression, or other features, and it is unknown if these dimorphisms control sex-typical behavior in one sex exclusively or in both sexes. The progesterone receptor (PR) controls female sexual behavior, and we find many sex differences in number, distribution, or projections of PR-expressing neurons in the adult mouse brain. We have ablated one such PR-expressing neuronal population located in the ventromedial hypothalamus (VMH) using a novel genetic strategy. Ablation of these neurons in females greatly diminishes sexual receptivity. Strikingly, the corresponding ablation in males reduces mating and aggression. Our findings reveal the functions of a molecularly-defined, sexually dimorphic neuronal population in the brain. Moreover we show that sexually dimorphic neurons can control distinct sex-typical behaviors in both sexes. PMID:23663785

Yang, Cindy F.; Chiang, Michael; Gray, Daniel C.; Prabhakaran, Mahalakshmi; Alvarado, Maricruz; Juntti, Scott A.; Unger, Elizabeth K.; Wells, James A.; Shah, Nirao M.

2013-01-01

69

Tribolium castaneum Transformer-2 regulates sex determination and development in both males and females  

PubMed Central

Tribolium castaneum Transformer (TcTra) is essential for female sex determination and maintenance through the regulation of sex-specific splicing of doublesex (dsx) pre-mRNA. In females, TcTra also regulates the sex-specific splicing of its own pre-mRNA to ensure continuous production of functional Tra protein. Transformer protein is absent in males and hence dsx pre-mRNA is spliced in a default mode. The mechanisms by which males inhibit the production of functional Tra protein are not known. Here, we report on functional characterization of transformer-2 (tra-2) gene (an ortholog of Drosophila transformer-2) in T. castaneum. RNA interference-mediated knockdown in the expression of gene coding for tra-2 in female pupae or adults resulted in the production of male-specific isoform of dsx and both female and male isoforms of tra suggesting that Tra-2 is essential for the female-specific splicing of tra and dsx pre-mRNAs. Interestingly, knockdown of tra-2 in males did not affect the splicing of dsx but resulted in the production of both female and male isoforms of tra suggesting that Tra-2 suppresses female-specific splicing of tra pre-mRNA in males. This dual regulation of sex-specific splicing of tra pre-mRNA ensures a tight regulation of sex determination and maintenance. These data suggest a critical role for Tra-2 in suppression of female sex determination cascade in males. In addition, RNAi studies showed that Tra-2 is also required for successful embryonic and larval development in both sexes. PMID:24056158

Shukla, Jayendra Nath; Palli, Subba Reddy

2014-01-01

70

Offspring sex ratio allocation in the parasitic jaeger: selection for pale females and melanic males?  

Microsoft Academic Search

The maintenance of plumage color polymorphism in the parasitic jaeger (Stercorarius parasiticus) is still not well understood. Earlier studies indicated that selection may favor pale females and melanic males. If so, females would maximize their fitness, producing pale female and melanic male offspring. We therefore predicted that females might bias their offspring sex ratio toward daughters in pale pairs and

Kirstin Janssen; Kjell Einar Erikstad; Staffan Bensch

2006-01-01

71

Offspring sex ratio allocation in the parasitic jaeger: selection for pale females and melanic males?  

Microsoft Academic Search

The maintenance of plumage color polymorphism in the parasitic jaeger (Stercorarius parasiticus) is still not well understood. Earlier studies indicated that selection may favor pale females and melanic males. If so, females would maximize their fitness, producing pale female and melanic male offspring. We therefore predicted that females might bias their offspring sex ratio toward daughters in pale pairs and

Kirstin Janssen; Kjell Einar Erikstad; Staffan Benschc

2005-01-01

72

Heterosexuals' Attitudes toward Lesbianism and Male Homosexuality: Their Affective Orientation toward Sexuality and Sex Guilt  

Microsoft Academic Search

This study sought to determine if there was a relationship between heterosexuals' attitudes toward lesbianism and male homosexuality and their affective orientation toward sexuality (erotophiliaerotophobia) and sex guilt. Subjects were 72 male and 57 female heterosexual college undergraduates. A self-report questionnaire was administered in a health education class and mailed to campus dormitories. The variables were measured by four scales:

William L. Yarber; Bernadette Yee

1983-01-01

73

The Tyranny of Surveillance: Male Teachers and the Policing of Masculinities in a Single Sex School  

ERIC Educational Resources Information Center

This paper draws on research into male teachers in one single sex high school in the Australian context to highlight how issues of masculinity impact on their pedagogical practices and relationships with boys. The study is situated within the broader international field of research on male teachers, masculinities and schooling in Australia, the UK…

Martino, Wayne; Frank, Blye

2006-01-01

74

Female-biased sex ratios and the proportion of cryptic male morphs of migrant juvenile Ruffs  

E-print Network

males made up ca. 1% of juvenile populations, similar to estimates from mixed- age populations elsewhere, their proportion among juveniles provides the first estimate of the morphs'proportional reproductive suc- cess. 1Female-biased sex ratios and the proportion of cryptic male morphs of migrant juvenile Ruffs

75

Male adolescent birth control behavior: The importance of developmental factors and sex differences  

Microsoft Academic Search

A survey of sex and birth control behavior of 51 male adolescents aged 15–17 was conducted utilizing a structured interview protocol. The purpose of the study was to describe male adolescent birth control behavior incorporating developmental issues, and to interpret the findings in light of what is known about female birth control behavior. Based on research with teenage females, three

Donald D. Cohen; Ryda D. Rose

1984-01-01

76

Mental Health and Sexual Identity in a Sample of Male Sex Workers in the Czech Republic  

PubMed Central

Background Previous qualitative research has examined male sex workers in the Czech Republic, but this mapping study is the first to investigate male sex work in a quantitative research design and focus on the mental health of these sex workers. This study also examines male sex workers’ mental health problems in relation to their sexual identity or orientation. Material/Methods A sample of Czech male sex workers (N=40) were examined on a range of sexual and psychological variables using a quantitative survey administered face-to-face. The study employed locally validated versions of Beck’s Depression Inventory and Zung’s Self-Report Anxiety Scale. Results The results indicate that for homosexuals, working as a male sex worker is not related to any serious mental health problems. However, those identifying as heterosexual and bisexual more frequently reported symptoms of depression and bisexuals showed significantly more anxiety. Conclusions These findings suggest sexual identity is an important issue to consider when addressing the mental health needs of this population. PMID:25239091

Bar-Johnson, Michael; Weiss, Petr

2014-01-01

77

The Male Sex Pheromone of the Butterfly Bicyclus anynana: Towards an Evolutionary Analysis  

PubMed Central

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

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

78

Persistent organic pollutants and male reproductive health  

PubMed Central

Environmental contaminants such as persistent organic pollutants (POPs) are man-made bioaccumulative compounds with long half-lives that are found throughout the world as a result of heavy use in a variety of consumer products during the twentieth century. Wildlife and animal studies have long suggested adverse effects of exposure to these compounds on human reproductive health, which, according to the endocrine disrupter hypothesis, are ascribed to the compounds’ potential to interfere with endocrine signaling, especially when exposure occurs during certain phases of fetal and childhood development. An extensive number of epidemiological studies have addressed the possible effects of exposure to POPs on male reproductive health, but the results are conflicting. Thus far, most studies have focused on investigating exposure and the different reproductive health outcomes during adulthood. Some studies have addressed the potential harmful effects of fetal exposure with respect to malformations at birth and/or reproductive development, whereas only a few studies have been able to evaluate whether intrauterine exposure to POPs has long-term consequences for male reproductive health with measurable effects on semen quality markers and reproductive hormone levels in adulthood. Humans are not exposed to a single compound at a time, but rather, to a variety of different substances with potential divergent hormonal effects. Hence, how to best analyze epidemiological data on combined exposures remains a significant challenge. This review on POPs will focus on current knowledge regarding the potential effects of exposure to POPs during fetal and childhood life and during adulthood on male reproductive health, including a critical revision of the endocrine disruption hypothesis, a comment on pubertal development as part of reproductive development and a comment on how to account for combined exposures in epidemiological research. PMID:24369135

Vested, Anne; Giwercman, Aleksander; Bonde, Jens Peter; Toft, Gunnar

2014-01-01

79

Identification of a Sex Pheromone From Male Yellow MealWorm Beetles, Tenebrio molitor  

Microsoft Academic Search

The sex pheromone released by the adult female Tenebrio molitor, 4-methyl-1-nonanol, is well known. In addition, there is evidence that adult males release a pheromone that attracts females. The purpose of the present study was to isolate and identify male-released pheromone(s). Emissions from virgin adult males and females were collected on filter paper and extracted with pentane. Extracts were analyzed

Gareth P. Bryning; John Chambers; Maureen E. Wakefield

2005-01-01

80

Observations on sex ratio and behavior of males in Xyleborinus saxesenii Ratzeburg (Scolytinae, Coleoptera)  

PubMed Central

Abstract Strongly female-biased sex ratios are typical for the fungalfeeding haplodiploid Xyleborini (Scolytinae, Coleoptera), and are a result of inbreeding and local mate competition (LMC). These ambrosia beetles are hardly ever found outside of trees, and thus male frequency and behavior have not been addressed in any empirical studies to date. In fact, for most species the males remain undescribed. Data on sex ratios and male behavior could, however, provide important insights into the Xyleborini’s mating system and the evolution of inbreeding and LMC in general. In this study, I used in vitro rearing methods to obtain the first observational data on sex ratio, male production, male and female dispersal, and mating behavior in a xyleborine ambrosia beetle. Females of Xyleborinus saxesenii Ratzeburg produced between 0 and 3 sons per brood, and the absence of males was relatively independent of the number of daughters to be fertilized and the maternal brood sex ratio. Both conformed to a strict LMC strategy with a relatively precise and constant number of males. If males were present they eclosed just before the first females dispersed, and stayed in the gallery until all female offspring had matured. They constantly wandered through the gallery system, presumably in search of unfertilized females, and attempted to mate with larvae, other males, and females of all ages. Copulations, however, only occurred with immature females. From galleries with males, nearly all females dispersed fertilized. Only a few left the natal gallery without being fertilized, and subsequently went on to produce large and solely male broods. If broods were male-less, dispersing females always failed to found new galleries. PMID:21594184

H.W. Biedermann, Peter

2010-01-01

81

Common Spontaneous Sex-Reversed XX males of the Medaka Oryzias latipes  

Microsoft Academic Search

In the medaka, a duplicated version of the dmrt1 gene, dmrt1bY, has been identified as a candidate for the master male sex-determining gene on the Y chromosome. By screening several strains of Northern and Southern medaka we identified a considerable number of males with normal phenotype and uncompro- mised fertility, but lacking dmrt1bY. The frequency of such males was 10%

Indrajit Nanda; Ute Hornung; Mariko Kondo; Michael Schmid; Manfred Schartl

82

Phf7 controls male sex determination in the Drosophila germline.  

PubMed

Establishment of germline sexual identity is critical for production of male and female germline stem cells, as well as sperm versus eggs. Here we identify PHD Finger Protein 7 (PHF7) as an important factor for male germline sexual identity in Drosophila. PHF7 exhibits male-specific expression in early germ cells, germline stem cells, and spermatogonia. It is important for germline stem cell maintenance and gametogenesis in males, whereas ectopic expression in female germ cells ablates the germline. Strikingly, expression of PHF7 promotes spermatogenesis in XX germ cells when they are present in a male soma. PHF7 homologs are also specifically expressed in the mammalian testis, and human PHF7 rescues Drosophila Phf7 mutants. PHF7 associates with chromatin, and both the human and fly proteins bind histone H3 N-terminal tails with a preference for dimethyl lysine 4 (H3K4me2). We propose that PHF7 acts as a conserved epigenetic "reader" that activates the male germline sexual program. PMID:22595675

Yang, Shu Yuan; Baxter, Ellen M; Van Doren, Mark

2012-05-15

83

Gadd45g is essential for primary sex determination, male fertility and testis development.  

PubMed

In humans and most mammals, differentiation of the embryonic gonad into ovaries or testes is controlled by the Y-linked gene SRY. Here we show a role for the Gadd45g protein in this primary sex differentiation. We characterized mice deficient in Gadd45a, Gadd45b and Gadd45g, as well as double-knockout mice for Gadd45ab, Gadd45ag and Gadd45bg, and found a specific role for Gadd45g in male fertility and testis development. Gadd45g-deficient XY mice on a mixed 129/C57BL/6 background showed varying degrees of disorders of sexual development (DSD), ranging from male infertility to an intersex phenotype or complete gonadal dysgenesis (CGD). On a pure C57BL/6 (B6) background, all Gadd45g(-/-) XY mice were born as completely sex-reversed XY-females, whereas lack of Gadd45a and/or Gadd45b did not affect primary sex determination or testis development. Gadd45g expression was similar in female and male embryonic gonads, and peaked around the time of sex differentiation at 11.5 days post-coitum (dpc). The molecular cause of the sex reversal was the failure of Gadd45g(-/-) XY gonads to achieve the SRY expression threshold necessary for testes differentiation, resulting in ovary and Müllerian duct development. These results identify Gadd45g as a candidate gene for male infertility and 46,XY sex reversal in humans. PMID:23516551

Johnen, Heiko; González-Silva, Laura; Carramolino, Laura; Flores, Juana Maria; Torres, Miguel; Salvador, Jesús M

2013-01-01

84

HIV, syphilis infection, and sexual practices among transgenders, male sex workers, and other men who have sex with men in Jakarta, Indonesia  

Microsoft Academic Search

Objectives: To establish the prevalence of HIV, syphilis, and sexual risk behaviour among three groups of men who have sex with men in Jakarta, Indonesia, and to investigate sexual links between these men and broader heterosexual populations.Methods: Anonymous, cross sectional surveys among community recruited transgender and male sex workers and self recognised men who have sex with men (MSM) were

E Pisani; P Girault; M Gultom; N Sukartini; J Kumalawati; S Jazan; E Donegan

2004-01-01

85

GADD45G functions in male sex determination by promoting p38 signaling and Sry expression.  

PubMed

Male sex determination in mammals is induced by Sry, a gene whose regulation is poorly understood. Here we show that mice mutant for the stress-response gene Gadd45g display complete male-to-female sex reversal. Gadd45g and Sry have a strikingly similar expression pattern in the genital ridge, and they are coexpressed in gonadal somatic cells. In Gadd45g mutants, Sry expression is delayed and reduced, and yet Sry seemed to remain poised for expression, because its promoter is demethylated on schedule and is occupied by active histone marks. Instead, p38 MAPK signaling is impaired in Gadd45g mutants. Moreover, the transcription factor GATA4, which is required for Sry expression, binds to the Sry promoter in vivo in a MAPK-dependent manner. The results suggest that a signaling cascade, involving GADD45G ? p38 MAPK ? GATA4 ? SRY, regulates male sex determination. PMID:23102581

Gierl, Mathias S; Gruhn, Wolfram H; von Seggern, Annika; Maltry, Nicole; Niehrs, Christof

2012-11-13

86

Sex determination in beetles: Production of all male progeny by Parental RNAi knockdown of transformer  

PubMed Central

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

Shukla, Jayendra Nath; Palli, Subba Reddy

2012-01-01

87

Sex differences in flea infections among rodent hosts: is there a male bias?  

PubMed

Recognizing patterns of parasite distribution among wildlife hosts is of major importance due to growing risk of transmission of zoonotic diseases to humans. Thus, sex-dependent parasite distribution in higher vertebrates is extensively studied, and males are often found more parasitized than females. Male-biased parasitism may be the result of weaker immunocompetence of male hosts owing to the immunosuppressive effect of androgens. Moreover, larger hosts (males) may demonstrate higher parasite infestation levels than smaller individuals (females), as they constitute a better nutritional resource for parasites and provide them with a greater variety of niches. In the present work, we investigated sex-dependent patterns of flea distribution among three common rodent species (Apodemus agrarius, Apodemus flavicollis, and Myodes glareolus). We hypothesized that males have a higher flea infestation than females. We confirm male-biased parasitism in A. agrarius and M. glareolus, but not in A. flavicollis. Additionally, flea infestation increased with body mass in A. agrarius, but not in A. flavicollis and M. glareolus. The detected differences in parasite distribution among sexes are probably the result of immunosuppressive effects of androgens and spatial behavior of males. PMID:25410932

Kowalski, Krzysztof; Bogdziewicz, Micha?; Eichert, Urszula; Rychlik, Leszek

2015-01-01

88

Sex Reassignment Surgery in the Female-to-Male Transsexual  

PubMed Central

In female-to-male transsexuals, the operative procedures are usually performed in different stages: first the subcutaneous mastectomy which is often combined with a hysterectomy-ovarectomy (endoscopically assisted). The next operative procedure consists of the genital transformation and includes a vaginectomy, a reconstruction of the horizontal part of the urethra, a scrotoplasty and a penile reconstruction usually with a radial forearm flap (or an alternative). After about one year, penile (erection) prosthesis and testicular prostheses can be implanted when sensation has returned to the tip of the penis. The authors provide a state-of-the-art overview of the different gender reassignment surgery procedures that can be performed in a female-to-male transsexual. PMID:22851915

Monstrey, Stan J.; Ceulemans, Peter; Hoebeke, Piet

2011-01-01

89

The trap of sex in social insects: from the female to the male perspective.  

PubMed

The phenotype of male Hymenoptera and the peculiar role of males has been neglected and greatly understudied, given the spectacular cooperative behavior of female social insects. In social insects there has been considerable progress in understanding the molecular mechanisms behind haplodiploid sex determination but, beyond that, very little is known concerning the neural, endocrine, and genetic correlates of sexual selection in males. An opportunity is being missed: the male phenotype in Hymenoptera is a natural experiment to compare the drives of natural versus sexual selection. In contrast to females, males do not work, they usually display far from the nest to gain mates, compete among rivals in nuptial flights or for a symbolic territory at leks, and engage in direct or ritualized conflicts. By comparing the available data on male paper wasps with studies on other social Hymenoptera, we summarize what we currently know about the physical, hormonal, neural and behavioral traits in a model system appropriate to examine current paradigms on sexual selection. Here we review male behavior in social Hymenoptera beyond sex stereotypes: the subtle role of "drones" in the colony, the lack of armaments and ornaments, the explosive mating crowds, the "endurance" race, the cognitive bases of the "choosy" male and his immune defense. Social insect males are not just simple-minded mating machines, they are shaped, constrained and perhaps trapped by sexual selection. PMID:25280909

Beani, Laura; Dessì-Fulgheri, Francesco; Cappa, Federico; Toth, Amy

2014-10-01

90

Identification of DNA markers linked to the male sex in dioecious hemp (Cannabis sativa L.)  

Microsoft Academic Search

A 400-bp RAPD marker generated by a primer of random decamer sequence has been found associated with the male sex phenotype\\u000a in 14 dioecious cultivars and accessions of hemp (Cannabis sativa L.). The primer OPA8 generates a set of bands, most of which polymorphic among all the individual plants tested, and 1 of\\u000a which, named OPA8400, present in all male

G. Mandolino; A. Carboni; S. Forapani; V. Faeti; P. Ranalli

1999-01-01

91

Bile Acid Secreted by Male Sea Lamprey That Acts as a Sex Pheromone  

Microsoft Academic Search

We show that reproductively mature male sea lampreys release a bile acid that acts as a potent sex pheromone, inducing preference and searching behavior in ovulated female lampreys. The secreted bile acid 7alpha,12alpha,24-trihydroxy-5alpha-cholan-3-one 24-sulfate was released in much higher amounts relative to known vertebrate steroid pheromones and may be secreted through the gills. Hence, the male of this fish species

Weiming Li; Alexander P. Scott; Michael J. Siefkes; Honggao Yan; Qin Liu; Sang-Seon Yun; Douglas A. Gage

2002-01-01

92

HIV prevention needs among street-based male sex workers in Providence, Rhode Island.  

PubMed

We examined data derived from a needs assessment of the personal and social characteristics and HIV risk behavior of street-based male sex workers, in Providence, Rhode Island, who engage in transactional sexual intercourse with other men. Substance use, injected drugs, needle sharing, and psychosocial distress were highly prevalent among the sample. History of physical, sexual, and emotional abuse was associated with increased risk of condomless anal sexual intercourse with paying male clients. PMID:25211761

Landers, Stewart; Closson, Elizabeth F; Oldenburg, Catherine E; Holcomb, Richard; Spurlock, Shannon; Mimiaga, Matthew J

2014-11-01

93

Strategies for Recruiting Steady Male Partners of Female Sex Workers for HIV Research.  

PubMed

Steady male partners of female sex workers (FSW) are a key population for HIV prevention, but researchers face challenges finding and recruiting this population. We conducted 40 in-depth interviews with FSW and steady male partners of FSW in Santo Domingo, Dominican Republic about how to engage steady male partners in HIV research. Participants cautioned that male partners might be unwilling to participate because of discomfort disclosing intimate information and cultural norms of masculinity. They recommended inviting male partners to research offices, instead of venue-based recruitment, because it was more private and trust-promoting. Most participants suggested that FSW could refer their partners or men could refer their friends who have FSW partners. Participants emphasized that referrals could break down trust-related barriers that prevent male partners from participating. Establishing an environment of respect and trust in the research setting can aid referral processes as individuals who participate communicate their positive experiences to their networks. PMID:25192901

Fleming, Paul J; Barrington, Clare; Perez, Martha; Donastorg, Yeycy; Kerrigan, Deanna

2014-09-01

94

Aggressive behavior of the male parent predicts brood sex ratio in a songbird  

NASA Astrophysics Data System (ADS)

Brood sex ratio is often affected by parental or environmental quality, presumably in an adaptive manner that is the sex that confers higher fitness benefits to the mother is overproduced. So far, studies on the role of parental quality have focused on parental morphology and attractiveness. However, another aspect, the partner's behavioral characteristics, may also be expected to play a role in brood sex ratio adjustment. To test this hypothesis, we investigated whether the proportion of sons in the brood is predicted by the level of territorial aggression displayed by the father, in the collared flycatcher ( Ficedula albicollis). The proportion of sons in the brood was higher in early broods and increased with paternal tarsus length. When controlling for breeding date and body size, we found a higher proportion of sons in the brood of less aggressive fathers. Male nestlings are more sensitive to the rearing environment, and the behavior of courting males may often be used by females to assess their future parental activity. Therefore, adjusting brood sex ratio to the level of male aggression could be adaptive. Our results indicate that the behavior of the partner could indeed be a significant determinant in brood sex ratio adjustment, which should not be overlooked in future studies.

Szász, Eszter; Garamszegi, László Zsolt; Hegyi, Gergely; Szöll?si, Eszter; Markó, Gábor; Török, János; Rosivall, Balázs

2014-08-01

95

Sex and pollen: the role of males in stabilising a plant-seed eater pollinating mutualism.  

PubMed

Some plants are exclusively pollinated by an insect whose larvae feed on their seeds. The net outcome of a single visit for the plant depends on the number of ovules fertilised by the visitor, the number of eggs laid, and the number of seeds eaten by each larva. Unlike other known plant-seed eater pollinating mutualisms, the globeflower-globeflower fly mutualism (Trollius europaeus-Chiastocheta spp.) is unique in that not only females but also males visit flowers, and both sexes are potential pollinators. I analysed the relative efficiency of Chiastocheta males versus females in transporting pollen and fertilising globeflower ovules. I show that there is no sex-specific morphological adaptation or behaviour to enhance pollen collection and transportation in Chiastocheta flies, and that males contribute to pollination. However, because of their smaller body size, males transport significantly less pollen than females. Less seeds are produced after a visit from a male than after a visit from a female. A single female visit contributes to about 12% of total seed production, and a single male visit to only 5.4%. Females tend to spend more time inside the flower than males, and the number of ovules fertilised is significantly correlated with the time insects spent inside the closed corolla. The lower efficiency of ovule fertilisation by a male's single visit is compensated for by the higher rate of flower visitation by males: a flower receives about twice as many visits from males as from females during a time unit. The contribution of males to pollination is of major importance with respect to understanding the evolutionary stability of the globeflower-globeflower fly mutualism, as males satiate pollen requirement of flowers, masking the antagonistic effect of ovipositing females. PMID:12647104

Després, Laurence

2003-03-01

96

MALE-BIASED SEX RATIOS IN LABORATORY REARINGS OF GYPSY MOTH PARASITOIDS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Male-biased sex ratios in populations of parasitic wasps used in biological control are undesirable, because a low ratio of females can prevent the establishment of introduced species or hinder commercial production of species used for augmentative control. This problem has arisen in the culture of...

97

Identification of a Sex Attractant Pheromone for Male Winterform Pear Psylla, Cacopsylla pyricola  

Technology Transfer Automated Retrieval System (TEKTRAN)

Pear psylla, Cacopsylla pyricola (Förster) (Hemiptera: Psyllidae), a major economic pest of pears, have been shown to use a female-produced sex attractant pheromone. We compared the chemical profiles obtained from cuticular extracts of diapausing and post-diapause winterform males and females, with...

98

OLFACTORY DISCRIMINATION OF SEX PHEROMONE STEREOISOMERS: CHIRALITY RECOGNITION BY PINK HIBISCUS MEALYBUG MALES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Our previous field studies suggested that the two chiral centers that existed in sex pheromone of pink hibiscus mealybug, Maconellicoccus hirsutus, could elicit different male attractive responses. The chiral center in the acidic moiety of the ester seemed to be more critical than the alcoholic por...

99

Assisted reproduction in a cohort of same-sex male couples and single men.  

PubMed

To date, there is limited published data on same-sex male couples and single men using assisted reproduction treatment to build their families. The objective of this retrospective study was to better understand treatment considerations and outcomes for this population when using assisted reproduction treatment. A total of 37 same-sex male couples and eight single men (seven homosexual and one heterosexual) who attended the CReATe Fertility Centre for assisted reproduction services were studied. There was a 21-fold increase in the number of same-sex male couples and single men undergoing assisted reproduction treatment since 2003. The mean age was 46years (24-58). Twenty-eight couples (76%) chose to use spermatozoa from both partners to fertilize their donated oocytes. Most men (32 same-sex male couples and seven single men; 87%) obtained oocytes from an anonymous donor, whereas five couples and one single man (13%) had a known donor. Anonymous donors who were open to be contacted by the child after the age of 18 were selected by 67% of patients. Of all 25 deliveries, eight (32%) were sets of twins. All of the twins were half genetic siblings. PMID:23768615

Grover, Stephanie A; Shmorgun, Ziva; Moskovtsev, Sergey I; Baratz, Ari; Librach, Clifford L

2013-08-01

100

HIV risk profile of male street youth involved in survival sex  

Microsoft Academic Search

Objectives: To compare HIV risk factors of male street youth involved in survival sex with those of their never involved peers and to describe the sexual activities of the involved youths.Methods: From 2001 to 2003, street youth aged 14–23 years were recruited from street youth agencies in Montreal, Canada. Information was collected on sociodemographic characteristics, substance use, and sexual behaviours.

N Haley; E Roy; P Leclerc; J-F Boudreau; J-F Boivin

2004-01-01

101

Male-biased sex ratio in litters of Alpine marmots supports the helper repayment hypothesis  

Microsoft Academic Search

In a French population of Alpine marmots (Marmota marmota), the sex ratio at weaning was biased in favor of males. This bias also seemed to exist at birth. Under Fisher's equal allocation principle, this means that daughters should be more costly to produce than sons. Because the Alpine marmot can be considered a cooperative breeding species, we investigated whether the

Dominique Allaine; Francine Brondex; Laurent Graziani; Jacques Coulon; Irene Till-Bottraudb

2000-01-01

102

Does Sex (Female versus Male) Influence the Impact of Class Attendance on Examination Performance?  

ERIC Educational Resources Information Center

The "conventional wisdom" is that grades are related to class attendance, i.e., students who attend classes more frequently obtain better grades and class attendance dramatically contributes to enhanced learning. However, the influence of sex (female vs. male) on this relationship is understudied. Furthermore, there have been several studies…

Cortright, Ronald N.; Lujan, Heidi L.; Cox, Julie H.; DiCarlo, Stephen E.

2011-01-01

103

Differences of Personality, Defensiveness, and Compliance between Admitting and Denying Male Sex Offenders.  

ERIC Educational Resources Information Center

Assessed predicted psychological differences between denying (n=30) and admitting (n=72) male sex offenders within the framework of Eysenck's theory on the personality of criminals. The Eysenck Personality Questionnaire (EPQ) and Gudjonsson's Compliance Questionnaire (CQ) were administered to consenting participants who were probationers in…

Birgisson, Gunnar Hrafn

1996-01-01

104

Sex differences in the functional organization of the brain for language  

Microsoft Academic Search

A much debated question is whether sex differences exist in the functional organization of the brain for language *RF 1-4*. A long-held hypothesis posits that language functions are more likely to be highly lateralized in males and to be represented in both cerebral hemispheres in females (5,6), but attempts to demonstrate this have been inconclusive (7- 17). Here we use

R. Todd Constable; Pawel Skudlarski; Robert K. Fulbright; Richard A. Bronen; Jack M. Fletcher; Donald P. Shankweiler; Leonard Katz; John C. Gore

1995-01-01

105

Adverse Childhood Experiences in the Lives of Male Sex Offenders: Implications for Trauma-Informed Care.  

PubMed

This study explored the prevalence of childhood trauma in a sample of male sexual offenders (N = 679) using the Adverse Childhood Experience (ACE) scale. Compared with males in the general population, sex offenders had more than 3 times the odds of child sexual abuse (CSA), nearly twice the odds of physical abuse, 13 times the odds of verbal abuse, and more than 4 times the odds of emotional neglect and coming from a broken home. Less than 16% endorsed zero ACEs and nearly half endorsed four or more. Multiple maltreatments often co-occurred with other types of household dysfunction, suggesting that many sex offenders were raised within a disordered social environment. Higher ACE scores were associated with higher risk scores. By enhancing our understanding of the frequency and correlates of early adverse experiences, we can better devise trauma-informed interventions that respond to the clinical needs of sex offender clients. PMID:24872347

Levenson, Jill S; Willis, Gwenda M; Prescott, David S

2014-05-28

106

Masculine epigenetic sex marks of the CYP19A1/aromatase promoter in genetically male chicken embryonic gonads are resistant to estrogen-induced phenotypic sex conversion.  

PubMed

Sex of birds is genetically determined through inheritance of the ZW sex chromosomes (ZZ males and ZW females). Although the mechanisms of avian sex determination remains unknown, the genetic sex is experimentally reversible by in ovo exposure to exogenous estrogens (ZZ-male feminization) or aromatase inhibitors (ZW-female masculinization). Expression of various testis- and ovary-specific marker genes during the normal and reversed gonadal sex differentiation in chicken embryos has been extensively studied, but the roles of sex-specific epigenetic marks in sex differentiation are unknown. In this study, we show that a 170-nt region in the promoter of CYP19A1/aromatase, a key gene required for ovarian estrogen biosynthesis and feminization of chicken embryonic gonads, contains highly quantitative, nucleotide base-level epigenetic marks that reflect phenotypic gonadal sex differentiation. We developed a protocol to feminize ZZ-male chicken embryonic gonads in a highly quantitative manner by direct injection of emulsified ethynylestradiol into yolk at various developmental stages. Taking advantage of this experimental sex reversal model, we show that the epigenetic sex marks in the CYP19A1/aromatase promoter involving DNA methylation and histone lysine methylation are feminized significantly but only partially in sex-converted gonads even when morphological and transcriptional marks of sex differentiation show complete feminization, being indistinguishable from gonads of normal ZW females. Our study suggests that the epigenetic sex of chicken embryonic gonads is more stable than the morphologically or transcriptionally characterized sex differentiation, suggesting the importance of the nucleotide base-level epigenetic sex in gonadal sex differentiation. PMID:22539680

Ellis, Haley L; Shioda, Keiko; Rosenthal, Noël F; Coser, Kathryn R; Shioda, Toshi

2012-07-01

107

Masculine Epigenetic Sex Marks of the CYP19A1/Aromatase Promoter in Genetically Male Chicken Embryonic Gonads Are Resistant to Estrogen-Induced Phenotypic Sex Conversion1  

PubMed Central

ABSTRACT Sex of birds is genetically determined through inheritance of the ZW sex chromosomes (ZZ males and ZW females). Although the mechanisms of avian sex determination remains unknown, the genetic sex is experimentally reversible by in ovo exposure to exogenous estrogens (ZZ-male feminization) or aromatase inhibitors (ZW-female masculinization). Expression of various testis- and ovary-specific marker genes during the normal and reversed gonadal sex differentiation in chicken embryos has been extensively studied, but the roles of sex-specific epigenetic marks in sex differentiation are unknown. In this study, we show that a 170-nt region in the promoter of CYP19A1/aromatase, a key gene required for ovarian estrogen biosynthesis and feminization of chicken embryonic gonads, contains highly quantitative, nucleotide base-level epigenetic marks that reflect phenotypic gonadal sex differentiation. We developed a protocol to feminize ZZ-male chicken embryonic gonads in a highly quantitative manner by direct injection of emulsified ethynylestradiol into yolk at various developmental stages. Taking advantage of this experimental sex reversal model, we show that the epigenetic sex marks in the CYP19A1/aromatase promoter involving DNA methylation and histone lysine methylation are feminized significantly but only partially in sex-converted gonads even when morphological and transcriptional marks of sex differentiation show complete feminization, being indistinguishable from gonads of normal ZW females. Our study suggests that the epigenetic sex of chicken embryonic gonads is more stable than the morphologically or transcriptionally characterized sex differentiation, suggesting the importance of the nucleotide base-level epigenetic sex in gonadal sex differentiation. PMID:22539680

Ellis, Haley L.; Shioda, Keiko; Rosenthal, Noël F.; Coser, Kathryn R.; Shioda, Toshi

2012-01-01

108

Stigma, social inequality, and HIV risk disclosure among Dominican male sex workers?  

PubMed Central

Some quantitative behavioral studies in the USA have concluded that bisexually behaving Latino men are less likely than White men to disclose to their female partners that they have engaged in same-sex risk behavior and/or are HIV-positive, presumably exposing female partners to elevated risk for HIV infection. Nevertheless, very little theoretical or empirical research has been conducted to understand the social factors that promote or inhibit sexual risk disclosure among Latino men who have sex with men (MSM), and much of the existing literature has neglected to contextualize disclosure patterns within broader experiences of stigma and social inequality. This paper examines decisions about disclosure of sex work, same-sex behavior, and sexual risk for HIV among male sex workers in two cities in the Dominican Republic. Data derive from long-term ethnography and qualitative in-depth interviews with 72 male sex workers were used to analyze the relationships among experiences of stigma, social inequality, and patterns of sexual risk disclosure. Thematic analysis of interviews and ethnographic evidence revealed a wide range of stigma management techniques utilized by sex workers to minimize the effects of marginality due to their engagement in homosexuality and sex work. These techniques imposed severe constraints on men’s sexual risk disclosure, and potentially elevated their own and their female partners’ vulnerability to HIV infection. Based on the study’s findings, we conclude that future studies of sexual risk disclosure among ethnic minority MSM should avoid analyzing disclosure as a decontextualized variable, and should seek to examine sexual risk communication as a dynamic social process constrained by hierarchical systems of power and inequality. PMID:18410986

Padilla, Mark; Castellanos, Daniel; Guilamo-Ramos, Vincent; Reyes, Armando Matiz; Sánchez Marte, Leonardo E.; Soriano, Martha Arredondo

2010-01-01

109

Functionally reproductive diploid and haploid males in an inbreeding hymenopteran with complementary sex determination  

PubMed Central

It has become a matter of orthodoxy that among wasps, ants, bees, and other insects in the order Hymenoptera, only uniparental haploid males that arise from unfertilized eggs are capable of reproduction. This idea is of interest because the best understood and perhaps most widespread sex determination system among these insects [known as single locus complementary sex determination (sl-CSD)] does not depend on ploidy alone and, paradoxically, consistently results in small numbers of diploid biparental males. To date, the reproductive potential of diploid males has been studied in 13 of the perhaps 200,000 hymenopterans world-wide; in each of these instances, the diploid males are genetic dead ends because they are inviable or sterile. The data from these species have resulted in a general conclusion that has been invoked for virtually all species with sl-CSD and has become the basis for assumptions regarding conservation biology, sex ratio analysis, and the evolution of social behavior. Here, we report that in the solitary vespid wasp Euodynerus foraminatus, both diploid and haploid males are fertile, which documents normal fertility in diploid males of a hymenopteran with sl-CSD. This wasp has high levels of inbreeding because of frequent brother–sister mating in nature; therefore, diploid males are more frequently produced and thus more likely exposed to selection favoring their fertility. Because inbreeding and diploid male production may be important features of the population biology of many hymenopterans, we sound a cautionary note regarding ideas about the evolutionary ecology of these insects. PMID:15232002

Cowan, David P.; Stahlhut, Julie K.

2004-01-01

110

Neonatal MeCP2 is important for the organization of sex differences in vasopressin expression  

PubMed Central

Several neurodevelopmental disorders are marked by atypical Methyl-CpG-binding protein 2 (MeCP2) expression or function; however, the role of MeCP2 is complex and not entirely clear. Interestingly, there are sex differences in some of these disorders, and it appears that MeCP2 has sex-specific roles during development. Specifically, recent data indicate that a transient reduction in MeCP2 within developing amygdala reduces juvenile social play behavior in males to female-typical levels. These data suggest that MeCP2 within the amygdala is involved in programming lasting sex differences in social behavior. In the present study, we infused MeCP2 or control siRNA into the amygdala of male and female rats during the first three days of postnatal life in order to assess the impact of a transient reduction in MeCP2 on arginine vasopressin (AVP), a neural marker that is expressed differentially between males and females and is linked to a number of social behaviors. The expression of AVP, as well as several other genes, was measured in two-week old and adult animals. Two-week old males expressed more AVP and galanin mRNA in the amygdala than females, and a transient reduction in MeCP2 eliminated this sex difference by reducing the expression of both gene products in males. A transient reduction in MeCP2 also decreased androgen receptor (AR) mRNA in two-week old males. In adulthood, control males had more AVP-immunoreactive (AVP-ir) cells than females in the centromedial amygdala (CMA), bed nucleus of the striaterminalis (BST) and in the fibers that project from these cells to the lateral septum (LS). A transient reduction in MeCP2 eliminated this sex difference. Interestingly, there were no lasting differences in galanin or AR levels in adulthood. Reducing MeCP2 levels during development did not alter estrogen receptor?, neurofilament or Foxg1. We conclude that a transient reduction in MeCP2 expression in the developing male amygdala has a transient impact on galanin and AR expression but a lasting impact on AVP expression, highlighting the importance of MeCP2 in organizing sex differences in the amygdala. PMID:22430799

Forbes-Lorman, Robin M; Rautio, Jared J; Kurian, Joseph R; Auger, Anthony P

2012-01-01

111

Reversed sex change by widowed males in polygynous and protogynous fishes: female removal experiments in the field  

NASA Astrophysics Data System (ADS)

Sex change, either protogyny (female to male) or protandry (male to female), is well known among fishes, but evidence of bidirectional sex change or reversed sex change in natural populations is still very limited. This is the first report on female removal experiments for polygnous and protogynous fish species to induce reversed sex change in the widowed males in the field. We removed all of the females and juveniles from the territories of dominant males in the cleaner wrasse Labroides dimidiatus (Labridae) and the rusty angelfish Centropyge ferrugata (Pomacanthidae) on the coral reefs of Okinawa. In both species, if new females or juveniles did not immigrate into the territories of the widowed males, some of them emigrated to form male-male pairs. When a male-male pair formed, the smaller, subordinate partner began to perform female sexual behaviours ( n = 4 in L. dimidiatus; n = 2 in C. ferrugata) and, finally, released eggs ( n = 1, respectively). Thus, the reversed sex change occurred in the widowed males according to the change of their social status. These results suggest that such female removal experiments will contribute to the discovery of reversed sex change in the field also in other polygnous and protogynous species.

Kuwamura, Tetsuo; Suzuki, Shohei; Kadota, Tatsuru

2011-12-01

112

Homeoproteins Six1 and Six4 regulate male sex determination and mouse gonadal development.  

PubMed

The Y-linked gene Sry regulates mammalian sex determination in bipotential embryonic gonads. Here, we report that the transcription factors Six1 and Six4 are required for male gonadal differentiation. Loss of Six1 and Six4 together, but neither alone, resulted in a male-to-female sex-reversal phenotype in XY mutant gonads accompanied by a failure in Sry activation. Decreased gonadal precursor cell formation at the onset of Sry expression and a gonadal size reduction in both sexes were also found in mutant embryos. Forced Sry transgene expression in XY mutant gonads rescued testicular development but not the initial disruption to precursor growth. Furthermore, we identified two downstream targets of Six1/Six4 in gonadal development, Fog2 (Zfpm2) and Nr5a1 (Ad4BP/Sf1). These two distinct Six1/Six4-regulated pathways are considered to be crucial for gonadal development. The regulation of Fog2 induces Sry expression in male sex determination, and the regulation of Nr5a1 in gonadal precursor formation determines gonadal size. PMID:23987514

Fujimoto, Yuka; Tanaka, Satomi S; Yamaguchi, Yasuka L; Kobayashi, Hiroki; Kuroki, Shunsuke; Tachibana, Makoto; Shinomura, Mai; Kanai, Yoshiakira; Morohashi, Ken-Ichirou; Kawakami, Kiyoshi; Nishinakamura, Ryuichi

2013-08-26

113

Hombre Seguro (Safe Men): a sexual risk reduction intervention for male clients of female sex workers  

PubMed Central

Background Male clients of female sex workers (FSWs) are at risk of HIV and other sexually transmitted infections (STIs). We conducted a two-arm randomized controlled trial to test the efficacy of a sexual risk reduction intervention for male clients of FSWs in Tijuana, Mexico. Methods/Design Male clients of FSWs who were at least 18, were HIV-negative at baseline, and reported recent unprotected sex with FSWs were randomized to the Hombre Seguro sexual risk reduction intervention, or a time-attention didactic control condition. Each condition lasted approximately one hour. Participants underwent interviewer-administered surveys and testing for HIV and other STIs at baseline, and at 4, 8, and 12 month follow-ups. Combined HIV/STI incidence and unprotected vaginal and anal sex acts with FSWs were the primary outcomes. Discussion A total of 400 participants were randomized to one of the two conditions. Analyses indicated that randomization was successful; there were no significant differences between the participants in the two conditions at baseline. Average follow-up was 84% across both conditions. This is the first study to test the efficacy of a sexual risk reduction intervention for male clients of FSWs using the rigor of a randomized controlled trial. Trial registration NCT01280838, Date of registration: January 19, 2011. PMID:24885949

2014-01-01

114

Environmental conditions affect sex expression in monoecious, but not in male and female plants of Urtica dioica  

Microsoft Academic Search

Urtica dioica is a sub-dioecious plant species, i.e. males and females coexist with monoecious individuals. Under standard conditions, seed sex ratio (SSR, fraction of males) was found to vary significantly among seed samples collected from female plants originating from the same population (0.05–0.76). As a first step, we investigated the extent to which SSR and sex expression of male, female,

Grit A. Glawe; Tom J. de Jong

2005-01-01

115

Characteristics of sex partners and sexual partnership correlates of inconsistent condom use among male injection drug users in India.  

PubMed

Previous studies have established the risky behaviors of IDUs in India, and that IDUs are sexually active; however, there is a need to better understand the nature of sexual partnerships of IDUs. A total of 783 (Delhi) and 766 (Imphal) male IDUs were recruited into the study through respondent-driven sampling. We examined characteristics of sex partners of male IDUs and individual and sexual partnership characteristics associated with unprotected sex in Delhi and Imphal. While 16.8% of sexual partnerships in Delhi were male-to-male, there were almost no male-to-male partnerships in Imphal. The majority of partners of male IDUs in Delhi (82.5%) and Imphal (92.3%) do not inject drugs, with the exception of male partners of male IDUs in Delhi. Commercial partners (females: 58.3%; males: 71.3%) were the most common type of sex partners of male IDUs in Delhi, while regular partners (65.2%) were the most common type of sex partners in Imphal. In Delhi, characteristics of sex partners significantly associated with unprotected sex were being male/transgender (AOR 2.2; 95% CI: 1.2-4.0), being a regular (AOR 5.1; 95% CI: 2.8-9.4) or non-regular partner (AOR 2.7; 95% CI: 1.7- 4.5), and sharing needles/syringes with the index IDU (AOR 2.8; 95% CI: 1.4-5.3). In Imphal, partner characteristics associated with unprotected sex were being a regular (AOR 10.1; 95% CI: 41-25.1) or non-regular partner (AOR 3.4; 95% CI: 1.5-7.6), and living outside of town or state (AOR 3.3; 95% CI: 1.2-9.6). Enhanced understanding of disassortative sexual mixing and context of unprotected sex within sexual partnerships may enhance sexual risk reduction interventions for IDUs. PMID:25427360

Tun, Waimar; Bhattacharya, Aruna; Apicella, Louis; Shasikumar Singh, Yumnam; Lewis, Dean

2014-07-01

116

Sex, symptom, and premorbid social functioning associated with perceptual organization dysfunction in schizophrenia  

PubMed Central

Impairments in visual perceptual organization abilities are a repeatedly observed cognitive deficit in schizophrenia. These impairments have been found to be most prominent among patients with histories of poor premorbid social functioning, disorganized symptoms, and poor clinical outcomes. Despite the demonstration of significant sex differences for these clinical factors in schizophrenia, the extent of sex differences for visual perceptual organization in schizophrenia is unknown. Therefore, we investigated the extent to which previously known correlates (premorbid social sexual functioning and disorganized symptoms) and a novel factor (participant sex) accounted for performance on two perceptual organization tasks (contour integration and Ebbinghaus illusion) that have previously demonstrated sensitivity to schizophrenia. We also determined the relative degree to which each of these factors predicted task scores over and above the others. Schizophrenia patients (N = 109, 43 females) from different levels of care were ascertained. Female patients demonstrated higher contour integration scores, but lower performance on the context sensitivity index of the Ebbinghaus illusion, compared to males. Contour integration performance was significantly associated with poorer premorbid adolescent social sexual functioning and higher levels of disorganized symptoms, supporting past results that indicate a relationship among poor premorbid social sexual functioning, disorganized symptoms, and visual perceptual abnormalities in schizophrenia. However, analyses of Ebbinghaus illusion performance suggests there is a complex relationship among patient sex, clinical factors and perceptual abilities with relatively intact bottom–up grouping processes in females, but greater problems, compared to males with more top–down mediated context sensitivity. Therefore, sex differences may be an important consideration for future studies of visual perceptual organization in schizophrenia. PMID:23986732

Joseph, Jamie; Bae, Grace; Silverstein, Steven M.

2013-01-01

117

Preventing HIV Transmission Among Partners of HIV-Positive Male Sex Workers in Mexico City: A Modeling Study.  

PubMed

Mexico has a concentrated HIV epidemic, with male sex workers constituting a key affected population. We estimated annual HIV cumulative incidence among male sex workers' partners, and then compared incidence under three hypothetical intervention scenarios: improving condom use; and scaling up HIV treatment as prevention, considering current viral suppression rates (CVS, 60.7 %) or full viral suppression among those treated (FVS, 100 %). Clinical and behavioral data to inform model parameterization were derived from a sample (n = 79) of male sex workers recruited from street locations and Clínica Condesa, an HIV clinic in Mexico City. We estimated annual HIV incidence among male sex workers' partners to be 8.0 % (95 % CI: 7.3-8.7). Simulation models demonstrated that increasing condom use by 10 %, and scaling up HIV treatment initiation by 50 % (from baseline values) would decrease the male sex workers-attributable annual incidence to 5.2, 4.4 % (CVS) and 3.2 % (FVS), respectively. Scaling up the number of male sex workers on ART and implementing interventions to ensure adherence is urgently required to decrease HIV incidence among male sex workers' partners in Mexico City. PMID:25307025

Monteiro, João Filipe G; Marshall, Brandon D L; Escudero, Daniel; Sosa-Rubí, Sandra G; González, Andrea; Flanigan, Timothy; Operario, Don; Mayer, Kenneth H; Lurie, Mark N; Galárraga, Omar

2014-10-12

118

Condom use among female commercial sex workers and male clients in Hong Kong.  

PubMed

The use of condoms is an aid to protection against human immunodeficiency virus (HIV) infection and other sexually transmitted diseases (STDs). In a one-and-a-half month period in mid-1993, 190 commercial female sex workers and 633 male clients of 8 Social Hygiene Clinics in Hong Kong were interviewed on their practice in condom usage. For both sex workers and clients, 18.5% and 22.8% never and 55.3% and 50.3% seldom used condoms during sexual contacts with paying partners and non-paying partners respectively. The majority (86%) of male clients claimed that they would use a condom if they knew it could reduce risk of contracting HIV and other STD. Condom promotion activities are necessary, particularly for those at higher risk of infection because of their sexual behaviour. PMID:7948161

Wong, K H; Lee, S S; Lo, Y C; Lo, K K

1994-01-01

119

Agency-Based Male Sex Work: A Descriptive Focus on Physical, Personal, and Social Space  

PubMed Central

Thirty male sex workers (MSWs) from a single agency participated in a qualitative interview about social and occupational aspects of their lives. MSWs established physical (defined areas where clients were not invited) and psychological (limitations of relationship with clients, other escorts, and the agency manager) boundaries to construct personal and professional space regarding sex work. Physical and psychological boundaries often were blended (e.g., bringing friends/family to the agency, utilizing the agency as a “drop-in community center”). The agency further mitigated negative aspects of sex work by providing job training, social support, stigma management, and dual-use space. Actors co-created a context wherein business could be conducted while meeting MSWs' psychosocial needs. PMID:19779572

Smith, Michael D.; Grov, Christian; Seal, David W.

2009-01-01

120

Male- and female-specific variants of doublesex gene products have different roles to play towards regulation of Sex combs reduced expression and sex comb morphogenesis in Drosophila.  

PubMed

Sexually dimorphic characters have two-fold complexities in pattern formation as they have to get input from both somatic sex determination as well as the positional determining regulators. Sex comb development in Drosophila requires functions of the somatic sex-determining gene doublesex and the homeotic gene Sex combs reduced. Attempts have not been made to decipher the role of dsx in imparting sexually dimorphic expression of SCR and the differential function of sex-specific variants of dsx products in sex comb development. Our results in this study indicate that male-like pattern of SCR expression is independent of dsx function, and dsx F must be responsible for bringing about dimorphism in SCR expression, whereas dsx M function is required with Scr for the morphogenesis of sex comb. PMID:23938378

Devi, Thangjam Ranjita; Shyamala, B V

2013-09-01

121

Sex-specific expression of an evolutionarily conserved male regulatory gene, DMRT1, in birds  

Microsoft Academic Search

Based on its Z-sex-chromosomal location and its structural homology to male sexual regulatory factors in humans (DMRT1 and DMRT2), Drosophila (Dsx), and Caenorhabditis elegans (Mab-3), chicken DMRT1 is an excellent candidate for a testis-determining factor in birds. The data we present provide further strong support for this hypothesis. By whole mount in situ hybridization chicken DMRT1 is expressed at higher

Z. Shan; I. Nanda; Y. Wang; M. Schmid; A. Vortkamp; T. Haaf

2000-01-01

122

Violence and HIV Sexual Risk Behaviors Among Female Sex Partners of Male Drug Users  

Microsoft Academic Search

Objective: Violence and HIV are emerging as interconnected public health hazards among drug users and their families. The purposes of this study are to (1) determine the prevalence of sexual and physical abuse of non-drug-using female sex partners of male drug users, and (2) ascertain the association between such violence and HIV-related risk behaviors. Methods: From 11\\/93 to 11\\/95, 208

Haiou He; H. Virginia McCoy; Sally J. Stevens; Michael J. Stark

1998-01-01

123

Weed Killer Deforms Sex Organs in Frogs, Study Finds  

NSDL National Science Digital Library

This Web site discusses current research findings surrounding the use of the weed killer, atrazine, and sex organ deformities in frogs exposed to it. The article from the New York Times summarizes the recent research report; free registration is required to view it. This site reports focus on the potential impact of atrazine on humans, but they do raise it as an important question.

Press., Associated

2002-01-01

124

Deconstructing the Erected Hierarchy: Sex and Power in Organizations.  

ERIC Educational Resources Information Center

Two characteristics that are commonly associated with organizational behavior, power and sex, are examined. Sexual behavior within the workplace and schools is discussed as are the effects of sexual stereotypes, sexually harassing and non-harassing sexual behavior, and office romances on the organization and its members. A conclusion is that these…

Shakeshaft, Charol

125

No evidence for increased extinction proneness with decreasing effective population size in a parasitoid with complementary sex determination and fertile diploid males  

Microsoft Academic Search

BACKGROUND: In species with single locus complementary sex determination (sl-CSD), the sex of individuals depends on their genotype at one single locus with multiple alleles. Haploid individuals are always males. Diploid individuals are females when heterozygous, but males when homozygous at the sex-determining locus. Diploid males are typically unviable or effectively sterile, hence imposing a genetic load on populations. Diploid

Jan Elias; Silvia Dorn; Dominique Mazzi

2010-01-01

126

The costs of risky male behaviour: sex differences in seasonal survival in a small sexually monomorphic primate  

PubMed Central

Male excess mortality is widespread among mammals and frequently interpreted as a cost of sexually selected traits that enhance male reproductive success. Sex differences in the propensity to engage in risky behaviours are often invoked to explain the sex gap in survival. Here, we aim to isolate and quantify the survival consequences of two potentially risky male behavioural strategies in a small sexually monomorphic primate, the grey mouse lemur Microcebus murinus: (i) most females hibernate during a large part of the austral winter, whereas most males remain active and (ii) during the brief annual mating season males roam widely in search of receptive females. Using a 10-year capture–mark–recapture dataset from a population of M. murinus in Kirindy Forest, western Madagascar, we statistically modelled sex-specific seasonal survival probabilities. Surprisingly, we did not find any evidence for direct survival benefits of hibernation—winter survival did not differ between males and females. By contrast, during the breeding season males survived less well than females (sex gap: 16%). Consistent with the ‘risky male behaviour’ hypothesis, the period for lowered male survival was restricted to the short mating season. Thus, sex differences in survival in a promiscuous mammal can be substantial even in the absence of sexual dimorphism. PMID:18426751

Kraus, Cornelia; Eberle, Manfred; Kappeler, Peter M

2008-01-01

127

Insights into the preservation of the homomorphic sex-determining chromosome of Aedes aegypti from the discovery of a male-biased gene tightly linked to the M-locus.  

PubMed

The preservation of a homomorphic sex-determining chromosome in some organisms without transformation into a heteromorphic sex chromosome is a long-standing enigma in evolutionary biology. A dominant sex-determining locus (or M-locus) in an undifferentiated homomorphic chromosome confers the male phenotype in the yellow fever mosquito Aedes aegypti. Genetic evidence suggests that the M-locus is in a nonrecombining region. However, the molecular nature of the M-locus has not been characterized. Using a recently developed approach based on Illumina sequencing of male and female genomic DNA, we identified a novel gene, myo-sex, that is present almost exclusively in the male genome but can sporadically be found in the female genome due to recombination. For simplicity, we define sequences that are primarily found in the male genome as male-biased. Fluorescence in situ hybridization (FISH) on A. aegypti chromosomes demonstrated that the myo-sex probe localized to region 1q21, the established location of the M-locus. Myo-sex is a duplicated myosin heavy chain gene that is highly expressed in the pupa and adult male. Myo-sex shares 83% nucleotide identity and 97% amino acid identity with its closest autosomal paralog, consistent with ancient duplication followed by strong purifying selection. Compared with males, myo-sex is expressed at very low levels in the females that acquired it, indicating that myo-sex may be sexually antagonistic. This study establishes a framework to discover male-biased sequences within a homomorphic sex-determining chromosome and offers new insights into the evolutionary forces that have impeded the expansion of the nonrecombining M-locus in A. aegypti. PMID:24398378

Hall, Andrew Brantley; Timoshevskiy, Vladimir A; Sharakhova, Maria V; Jiang, Xiaofang; Basu, Sanjay; Anderson, Michelle A E; Hu, Wanqi; Sharakhov, Igor V; Adelman, Zach N; Tu, Zhijian

2014-01-01

128

Insights into the Preservation of the Homomorphic Sex-Determining Chromosome of Aedes aegypti from the Discovery of a Male-Biased Gene Tightly Linked to the M-Locus  

PubMed Central

The preservation of a homomorphic sex-determining chromosome in some organisms without transformation into a heteromorphic sex chromosome is a long-standing enigma in evolutionary biology. A dominant sex-determining locus (or M-locus) in an undifferentiated homomorphic chromosome confers the male phenotype in the yellow fever mosquito Aedes aegypti. Genetic evidence suggests that the M-locus is in a nonrecombining region. However, the molecular nature of the M-locus has not been characterized. Using a recently developed approach based on Illumina sequencing of male and female genomic DNA, we identified a novel gene, myo-sex, that is present almost exclusively in the male genome but can sporadically be found in the female genome due to recombination. For simplicity, we define sequences that are primarily found in the male genome as male-biased. Fluorescence in situ hybridization (FISH) on A. aegypti chromosomes demonstrated that the myo-sex probe localized to region 1q21, the established location of the M-locus. Myo-sex is a duplicated myosin heavy chain gene that is highly expressed in the pupa and adult male. Myo-sex shares 83% nucleotide identity and 97% amino acid identity with its closest autosomal paralog, consistent with ancient duplication followed by strong purifying selection. Compared with males, myo-sex is expressed at very low levels in the females that acquired it, indicating that myo-sex may be sexually antagonistic. This study establishes a framework to discover male-biased sequences within a homomorphic sex-determining chromosome and offers new insights into the evolutionary forces that have impeded the expansion of the nonrecombining M-locus in A. aegypti. PMID:24398378

Hall, Andrew Brantley; Timoshevskiy, Vladimir A.; Sharakhova, Maria V.; Jiang, Xiaofang; Basu, Sanjay; Anderson, Michelle A.E.; Hu, Wanqi; Sharakhov, Igor V.; Adelman, Zach N.; Tu, Zhijian

2014-01-01

129

High-Resolution Sex-Specific Linkage Maps of the Mouse Reveal Polarized Distribution of Crossovers in Male Germline  

PubMed Central

Since the publication of the first comprehensive linkage map for the laboratory mouse, the architecture of recombination as a basic biological process has become amenable to investigation in mammalian model organisms. Here we take advantage of high-density genotyping and the unique pedigree structure of the incipient Collaborative Cross to investigate the roles of sex and genetic background in mammalian recombination. Our results confirm the observation that map length is longer when measured through female meiosis than through male meiosis, but we find that this difference is modified by genotype at loci on both the X chromosome and the autosomes. In addition, we report a striking concentration of crossovers in the distal ends of autosomes in male meiosis that is absent in female meiosis. The presence of this pattern in both single- and double-recombinant chromosomes, combined with the absence of a corresponding asymmetry in the distribution of double-strand breaks, indicates a regulated sequence of events specific to male meiosis that is anchored by chromosome ends. This pattern is consistent with the timing of chromosome pairing and evolutionary constraints on male recombination. Finally, we identify large regions of reduced crossover frequency that together encompass 5% of the genome. Many of these “cold regions” are enriched for segmental duplications, suggesting an inverse local correlation between recombination rate and mutation rate for large copy number variants. PMID:24578350

Liu, Eric Yi; Morgan, Andrew P.; Chesler, Elissa J.; Wang, Wei; Churchill, Gary A.; Pardo-Manuel de Villena, Fernando

2014-01-01

130

Sex chromosome pre-reduction in male meiosis of Lethocerus patruelis (Stål, 1854) (Heteroptera, Belostomatidae) with some notes on the distribution of the species  

PubMed Central

Abstract The karyotype and meiosis in males of giant water bug Lethocerus patruelis (Heteroptera: Belostomatidae: Lethocerinae) were studied using standard and fluorochrome (CMA3 and DAPI) staining of chromosomes. The species was shown to have 2n = 22A + 2m + XY where 2m are a pair of microchromosomes. NORs are located in X and Y chromosomes. Within Belostomatidae, Lethocerus patruelis is unique in showing sex chromosome pre-reduction in male meiosis, with the sex chromosomes undergoing reductional division at anaphase I and equational division at anaphase II. Cytogenetic data on the family Belostomatidae are summarized and compared. In addition, the structure of the male internal reproductive organs of Lethocerus patruelis is presented, the contemporary distribution of Lethocerus patruelis in Bulgaria and in the northern Aegean Islands is discussed, and the first information about the breeding and nymphal development of this species in Bulgaria is provided. PMID:24039515

Grozeva, Snejana; Kuznetsova, Valentina G.; Simov, Nikolay; Langourov, Mario; Dalakchieva, Svetla

2013-01-01

131

Male-biased sex ratios of fish embryos near a pulp mill: temporary recovery after a short-term shutdown.  

PubMed Central

In a previous study we showed that broods from the viviparous eelpout Zoarces viviparus were significantly male biased in 1998 in the vicinity of a large kraft pulp mill on the Swedish Baltic coast. One suggested hypothesis was that masculinizing compounds in the effluent were affecting gonadal differentiation of the embryos, resulting in skewed sex ratios. In this article, we present further evidence for a causal relationship between the exposure to the effluent and the male-biased sex ratios. Analyses of historical samples showed that the eelpout produced male-biased broods close to the mill in 1997 in addition to 1998. During 1999, the mill was shut down for 17 days, coinciding with the period when the gonads of the eelpout embryos differentiate. Subsequently, in the fall of 1999, the sex ratios were no longer male biased; however, the following year (2000), a significant male bias reappeared. Investigations at 13 sites for up to 4 years showed a relatively stable sex ratio around 50/50, with the exceptions by the mill and with few observations of deviating ratios at other sites. Several reports document endocrine disturbances in fish near pulp and paper mills, including the expression of male secondary sex characters in female fish. The repeatedly identified male bias at the investigated mill, the normalization after mill shutdown, and the reappearance the following year indicate that pulp mill effluents also can affect sex ratios of nearby fish. PMID:12153752

Larsson, D G Joakim; Förlin, Lars

2002-01-01

132

Accessory sex glands as a tool to measure the efficacy of immunocastration in male pigs.  

PubMed

The use of an anti-gonadotropin-releasing hormone vaccine for immunocastration of male pigs has been recently approved in the European Union. This technique is potentially useful for avoiding both castration-associated pain for the animal and boar taint in pork. However, some animals may escape immunocastration and be slaughtered as entire males, potentially exhibiting boar taint. Therefore, it is important to check the efficacy of immunocastration on the slaughter line. To achieve that, the currently proposed method, based on testis weight, is not fully reliable because there is some overlap in the distributions of testis weight between immunocastrates and entire males. On the basis of literature data on the effect of immunocastration on the development of accessory sex glands, this paper provides evidence that the weight of seminal vesicles might be a much better criterion for checking the efficacy of immunocastration, because their size decreases more rapidly, and to a greater extent, than that of the testis. PMID:22444264

Bonneau, M

2010-06-01

133

Same-sex sexual behaviors among male migrants in a context of male "marriage squeeze": results from an exploratory survey in urban Xi'an, China.  

PubMed

The male marriage squeeze in China may increase the prevalence of male same-sex sexual behaviors among unmarried male migrants who lack stable female sexual partners. The same-sex sexual behaviors among unmarried male migrants appear to be at high risk of transmission of human immunodeficiency virus (HIV) and sexually transmitted infections (STIs), mainly because of a lack of knowledge of these diseases. Using data from the "Survey on Reproductive Health and Family Life of Migrant Male Bachelors in Urban Areas" conducted in Xi'an City, Shaanxi Province, in December 2009 and January 2010, this study compares same-sex sexual behaviors of unmarried with that of married male migrants (including married but separated men who are migrating without their spouse or partner and cohabitating men who are migrating with their spouse or partner). It is reported that the prevalence of same-sex sexual behaviors among unmarried males reaches 11%, more than twice the 5.1% reported by married but separated men and thrice the 3.8% reported by cohabitating men. It also appears that the same-sex sexual behaviors is significantly associated with men's attitudes toward same-sex sexual behaviors (odds ratio = 1.59, p < .001), toward life-long bachelorhood (odds ratio = 1.35, p < .01), and with marital status (odds ratio = 0.37, p < .01). The frequency of condom use appears to be higher among unmarried men than among men who are married, whether or not they migrated with their wives, and is significantly associated with scores on knowledge about HIV/AIDS (estimated coefficient = .12, p < .001) and STIs (estimated coefficient = .22, p < .01). It is also associated with the likelihood of same-sex sexual behaviors (estimated coefficients = .83, p < .01) and marital status (estimated coefficients for married but separated = -.50, p < .05; estimated coefficients for cohabitating = -.77, p < .001). PMID:22782362

Yang, Xueyan; Attané, Isabelle; Li, Shuzhuo; Yang, Bo

2012-11-01

134

Rapid communication Male reproductive organs of Apis dorsata  

E-print Network

Rapid communication Male reproductive organs of Apis dorsata G Koeniger M Mardan F Ruttner 1 — Based on an examination of a large number of everted copulatory organs of Apis dor- sata drones. The result is of significance for classification within the genus Apis. Apis dorsata / Apis laboriosa

Paris-Sud XI, Université de

135

Evidence that meiotic sex chromosome inactivation is essential for male fertility.  

PubMed

The mammalian X and Y chromosomes share little homology and are largely unsynapsed during normal meiosis. This asynapsis triggers inactivation of X- and Y-linked genes, or meiotic sex chromosome inactivation (MSCI). Whether MSCI is essential for male meiosis is unclear. Pachytene arrest and apoptosis is observed in mouse mutants in which MSCI fails, e.g., Brca1(-/-), H2afx(-/-), Sycp1(-/-), and Msh5(-/-). However, these also harbor defects in synapsis and/or recombination and as such may activate a putative pachytene checkpoint. Here we present evidence that MSCI failure is sufficient to cause pachytene arrest. XYY males exhibit Y-Y synapsis and Y chromosomal escape from MSCI without accompanying synapsis/recombination defects. We find that XYY males, like synapsis/recombination mutants, display pachytene arrest and that this can be circumvented by preventing Y-Y synapsis and associated Y gene expression. Pachytene expression of individual Y genes inserted as transgenes on autosomes shows that expression of the Zfy 1/2 paralogs in XY males is sufficient to phenocopy the pachytene arrest phenotype; insertion of Zfy 1/2 on the X chromosome where they are subject to MSCI prevents this response. Our findings show that MSCI is essential for male meiosis and, as such, provide insight into the differential severity of meiotic mutations' effects on male and female meiosis. PMID:21093264

Royo, Hélène; Polikiewicz, Grzegorz; Mahadevaiah, Shantha K; Prosser, Haydn; Mitchell, Mike; Bradley, Allan; de Rooij, Dirk G; Burgoyne, Paul S; Turner, James M A

2010-12-01

136

Carotenoid-Based Ornaments of Female and Male American Goldfinches (Spinus tristis) Show Sex-Specific Correlations  

E-print Network

348 Carotenoid-Based Ornaments of Female and Male American Goldfinches (Spinus tristis) Show Sex of carotenoid-based bill and plumage ornamentation in Amer- ican goldfinches Spinus tristis, a species in which

Murphy, Troy G.

137

Sex Ratios of Black Crappies Harvested during Spring Fisheries on Two Minnesota Lakes: Are Males in the Majority?  

Microsoft Academic Search

Sex-selective fishing mortality can alter the demographics and life history patterns of fish populations, yet the extent of this mortality is rarely investigated in harvest-oriented recreational fisheries. Potential differences in habitat use between sexes and nest-guarding behavior suggest that male black crappies Pomoxis nigromaculatus could dominate angler harvest during spring fisheries. We examined the potential for male-dominated harvest in spring

Daniel A. Isermann; Douglas W. Schultz; Andrew J. Carlson

2010-01-01

138

Effects of sex steroids on aromatase mRNA expression in the male and female quail brain  

PubMed Central

Castrated male quail display intense male-typical copulatory behavior in response to exogenous testosterone but ovariectomized females do not. The behavior of males is largely mediated by the central aromatization of testosterone into estradiol. The lack of behavioral response in females could result from a lower rate of aromatization. This is probably not the case because although the enzymatic sex difference is clearly present in gonadally intact sexually mature birds, it is not reliably found in gonadectomized birds treated with testosterone, in which the behavioral sex difference is always observed. We previously discovered that the higher aromatase activity in sexually mature males as compared to females is not associated with major differences in aromatase mRNA density. A reverse sex difference (females > males) was even detected in the bed nucleus of the stria terminalis. We analyzed here by in situ hybridization histochemistry the density of aromatase mRNA in gonadectomized male and female quail that were or were not exposed to a steroid profile typical of their sex. Testosterone and ovarian steroids (presumably estradiol) increased aromatase mRNA concentration in males and females respectively but mRNA density was similar in both sexes. A reverse sex difference in aromatase mRNA density (females >males) was detected in the bed nucleus of subjects exposed to sex steroids. Together these data suggest that although the induction of aromatase activity by testosterone corresponds to an increased transcription of the enzyme, the sex difference in enzymatic activity results largely from post-transcriptional controls that remain to be identified. PMID:20951703

Voigt, Cornelia; Ball, Gregory F.; Balthazart, Jacques

2010-01-01

139

H2AX Is Required for Chromatin Remodeling and Inactivation of Sex Chromosomes in Male Mouse Meiosis  

Microsoft Academic Search

During meiotic prophase in male mammals, the X and Y chromosomes condense to form a macrochromatin body, termed the sex, or XY, body, within which X- and Y-linked genes are transcriptionally repressed. The molecular basis and biological function of both sex body formation and meiotic sex chromosome inactivation (MSCI) are unknown. A phosphorylated form of H2AX, a histone H2A variant

Oscar Fernandez-Capetillo; Shantha K. Mahadevaiah; Arkady Celeste; Peter J. Romanienko; R. Daniel Camerini-Otero; William M. Bonner; Katia Manova; Paul Burgoyne; André Nussenzweig

2003-01-01

140

Prevalence of Same-Sex Sexual Behavior and Associated Characteristics among Low-Income Urban Males in Peru  

Microsoft Academic Search

Background. Peru has a concentrated HIV epidemic in which men who have sex with men are particularly vulnerable. We describe the lifetime prevalence of same-sex sexual contact and associated risk behaviors of men in Peru's general population, regardless of their sexual identity. Methods and Results. A probability sample of males from low-income households in three Peruvian cities completed an epidemiologic

Jesse L. Clark; Carlos F. Caceres; Andres G. Lescano; Kelika A. Konda; Segundo R. Leon; Franca R. Jones; Susan M. Kegeles; Jeffrey D. Klausner; Thomas J. Coates

2007-01-01

141

Sex steroid hormones modulate responses to social challenge and opportunity in males of the monogamous convict cichlid, Amatitliana  

E-print Network

Sex steroid hormones modulate responses to social challenge and opportunity in males s t r a c t Steroid hormones play an important role in modulating behavioral responses to various social a repeated measure design to create behavioral profiles and explore how sex steroid hormones respond

Hofmann, Hans A.

142

Drug-using male clients of female sex workers who report being paid for sex: HIV/STI, demographic and drug use correlates  

PubMed Central

Background Research has focused on male clients of female sex workers (FSWs) and their risk for HIV/STIs. Yet, it is unclear whether the commercial sex behaviors of these men are limited to paying for sex, or whether they may also be paid for sex themselves. Methods We analyzed interview data and HIV/STI test results from 170 drug-using male clients of FSWs in Tijuana, Mexico, to determine the extent to which these men report being paid for sex and the association with positive HIV/STI results. Results Over one-quarter of men reported having been paid for sex in the past four months. In a multivariate logistic regression model, reporting having been paid for sex was significantly associated with testing positive for any HIV/STI (Adjusted Odds Ratio [AdjOR] 3.53, 95% C.I. 1.33–9.35), being bisexual (AdjOR 15.59, 95% C.I. 4.81–50.53), injection drug use in the past four months (AdjOR 2.65, 95% C.I. 1.16–6.03), and cocaine use in the past four months (AdjOR 2.93, 95% C.I. 1.22–7.01). Conclusions Findings suggest that drug-using male clients of FSWs may be characterized by unique risk profiles that require tailored HIV prevention interventions. PMID:23863514

Wagner, Karla D.; Pitpitan, Eileen V.; Chavarin, Claudia V.; Magis-Rodriguez, Carlos; Patterson, Thomas L.

2013-01-01

143

Sex differences in recovery from PTSD in male and female interpersonal assault survivors  

PubMed Central

Men and women differ in exposure to trauma and the development of posttraumatic stress disorder (PTSD); however, research regarding sex differences in recovery from PTSD has been sparse. This study evaluated the treatment response trajectory for 69 male and female interpersonal assault survivors, using a modified Cognitive Processing Therapy (CPT) protocol that allowed survivors to receive up to18 sessions of CPT, with treatment end determined by therapy progress. Few sex differences were observed in trauma history, baseline PTSD and depressive severity, Axis I comorbidity, anger, guilt and dissociation. Women did report more sexual assault in adulthood and elevated baseline guilt cognitions, whereas men reported more baseline anger directed inward. Attrition and total number of sessions did not differ by sex. Over the course of treatment and follow-up, men and women demonstrated similar rates of change in PTSD and depressive symptoms. However, medium effect sizes on both of these primary outcomes at the 3-month follow-up assessment favored women. Several differences in the slope of change emerged on secondary outcomes such that women evidenced more rapid gains on global guilt, guilt cognitions, anger/irritability, and dissociation. Results suggest that male survivors may warrant additional attention to address these important clinical correlates. PMID:23510841

Galovski, Tara E.; Blain, Leah M.; Chappuis, Courtney; Fletcher, Thomas

2013-01-01

144

Absence of the Candidate Male Sex-Determining Gene dmrt1b(Y) of Medaka from Other Fish Species  

Microsoft Academic Search

Although the sex-determining genes are known in mammals, Drosophila, and C. elegans, little is known in other animals. Fishes are an attractive group of organisms for studying the evolution of sex determination because they show an amazing variety of mechanisms, ranging from environmental sex determination and different forms of hermaphroditism to classical sex chromosomal XX\\/XY or WZ\\/ZZ systems and modifications

Mariko Kondo; Indrajit Nanda; Ute Hornung; Shuichi Asakawa; Nobuyoshi Shimizu; Hiroshi Mitani; Michael Schmid; Akihiro Shima; Manfred Schartl

2003-01-01

145

Sex Hormone Influence on Hepatitis in Young Male A/JCr Mice Infected with Helicobacter hepaticus? †  

PubMed Central

Hepatitis B virus (HBV), the leading cause of human hepatocellular carcinoma, is especially virulent in males infected at an early age. Likewise, the murine liver carcinogen Helicobacter hepaticus is most pathogenic in male mice infected before puberty. We used this model to investigate the influence of male sex hormone signaling on infectious hepatitis. Male A/JCr mice were infected with H. hepaticus or vehicle at 4 weeks and randomized into surgical and pharmacologic treatment groups. Interruption of androgen pathways was confirmed by hormone measurements, histopathology, and liver gene and Cyp4a protein expression. Castrated males and those receiving the competitive androgen receptor antagonist flutamide had significantly less severe hepatitis as determined by histologic activity index than intact controls at 4 months. Importantly, the powerful androgen receptor agonist dihydrotestosterone did not promote hepatitis. No effect on hepatitis was evident in males treated with the 5?-reductase inhibitor dutasteride, the peroxisome proliferator-activated receptor-? agonist bezafibrate, or the nonsteroidal anti-inflammatory drug flufenamic acid. Consistent with previous observations of hepatitis-associated liver-gender disruption, transcriptional alterations involved both feminine (cytochrome P450 4a14) and masculine (cytochrome P450 4a12 and trefoil factor 3) genes, as well gender-neutral (H19 fetal liver mRNA, lipocalin 2, and ubiquitin D) genes. Hepatitis was associated with increased unsaturated C18 long-chain fatty acids (oleic acid and linoleic acid) relative to saturated stearic acid. Our results indicate that certain forms of androgen interruption can inhibit H. hepaticus-induced hepatitis in young male mice, whereas androgen receptor agonism does not worsen disease. This raises the possibility of targeted hormonal therapy in young male patients with childhood-acquired HBV. PMID:18559427

Theve, Elizabeth J.; Feng, Yan; Taghizadeh, Koli; Cormier, Kathleen S.; Bell, David R.; Fox, James G.; Rogers, Arlin B.

2008-01-01

146

Sex-specific signaling in the blood-brain barrier is required for male courtship in Drosophila.  

PubMed

Soluble circulating proteins play an important role in the regulation of mating behavior in Drosophila melanogaster. However, how these factors signal through the blood-brain barrier (bbb) to interact with the sex-specific brain circuits that control courtship is unknown. Here we show that male identity of the blood-brain barrier is necessary and that male-specific factors in the bbb are physiologically required for normal male courtship behavior. Feminization of the bbb of adult males significantly reduces male courtship. We show that the bbb-specific G-protein coupled receptor moody and bbb-specific Go signaling in adult males are necessary for normal courtship. These data identify sex-specific factors and signaling processes in the bbb as important regulators of male mating behavior. PMID:23359644

Hoxha, Valbona; Lama, Chamala; Chang, Peter L; Saurabh, Sumit; Patel, Naiya; Olate, Nicole; Dauwalder, Brigitte

2013-01-01

147

Diversity of commercial sex among men and male-born trans people in three Peruvian cities  

PubMed Central

In Peru, commercial sex involving men and male-born travestis, transgenders and transsexuals (CSMT) is usually represented as a dangerous practice carried out on the streets by people experiencing economic hardship and social exclusion. However, in reality little is known about the complexities of this practice in Peru. This paper presents findings from an ethnographic study of the characteristics, patterns and socio-cultural aspects of CSMT in three Peruvian cities. The study included participant observation in sex work venues and interviews with 42 sex workers and 25 key informants. We found that CSMT in Peru takes many forms (some not previously described in the country) and is practised in different places by people from various socioeconomic levels. In many cases, the practice appears linked to ideals of social mobility, migratory experiences and other economic activities. In addition, the increasing use of the internet and mobile phones has changed patterns of sex work in Peru. We review the implications of these findings for future research and public health interventions. PMID:21936651

Zúñiga, Mario; Zunt, Joseph; Mejía, Carolina; Montano, Silvia; Sánchez, Jorge L.

2011-01-01

148

Induction of Female-to-Male Sex Change in Adult Zebrafish by Aromatase Inhibitor Treatment  

PubMed Central

This study investigated whether undifferentiated germ and/or somatic stem cells remain in the differentiated ovary of a species that does not undergo sex changes under natural conditions and retain their sexual plasticity. The effect of aromatase inhibitor (AI)-treatment on sexually mature female zebrafish was examined. A 5-month AI treatment caused retraction of the ovaries after which testes-like organs appeared, and cyst structures filled with spermatozoa-like cells were observed in sections of these tissues. Electron microscopic observations revealed that these cells appeared as large sperm heads without tails. Sperm formation was re-examined after changing the diet to an AI-free food. A large number of normal sperm were obtained after eight weeks, and no formation of ovarian tissue was observed. Artificial fertilization using sperm from the sex-changed females was successful. These results demonstrated that sex plasticity remains in the mature ovaries of this species. PMID:24292399

Takatsu, Kanae; Miyaoku, Kaori; Roy, Shimi Rani; Murono, Yuki; Sago, Tomohiro; Itagaki, Hideyuki; Nakamura, Masaru; Tokumoto, Toshinobu

2013-01-01

149

Induction of Female-to-Male Sex Change in Adult Zebrafish by Aromatase Inhibitor Treatment  

NASA Astrophysics Data System (ADS)

This study investigated whether undifferentiated germ and/or somatic stem cells remain in the differentiated ovary of a species that does not undergo sex changes under natural conditions and retain their sexual plasticity. The effect of aromatase inhibitor (AI)-treatment on sexually mature female zebrafish was examined. A 5-month AI treatment caused retraction of the ovaries after which testes-like organs appeared, and cyst structures filled with spermatozoa-like cells were observed in sections of these tissues. Electron microscopic observations revealed that these cells appeared as large sperm heads without tails. Sperm formation was re-examined after changing the diet to an AI-free food. A large number of normal sperm were obtained after eight weeks, and no formation of ovarian tissue was observed. Artificial fertilization using sperm from the sex-changed females was successful. These results demonstrated that sex plasticity remains in the mature ovaries of this species.

Takatsu, Kanae; Miyaoku, Kaori; Roy, Shimi Rani; Murono, Yuki; Sago, Tomohiro; Itagaki, Hideyuki; Nakamura, Masaru; Tokumoto, Toshinobu

2013-12-01

150

Relationship Characteristics and HIV Transmission Risk in Same-sex Male Couples in HIV Serodiscordant Relationships  

PubMed Central

Unprotected anal intercourse (UAI) remains a main risk factor for HIV among men who have sex with men (MSM) and this is of particular concern for partners of HIV serodiscordant status. However, HIV transmission risk has been demonstrated to vary by the sexual position adopted among partners. Guided by interdependence theory, this study examined how relational factors were differentially associated with risk taking (HIV-positive/insertive and HIV-negative/receptive) and strategic positioning (HIV-positive/receptive and HIV-negative/insertive) UAI withinserodiscordant same-sex male couples. HIV-positive men and their HIV-negative partners (ncouples=91; nindividuals=182) simultaneously but independently completed computerized questionnaires and HIV-positive men had blood drawn for viral load.A minority of couples (30%) engaged in risk taking and/or strategicpositioning unprotected anal sex. Results of multinomial logistic regressionindicated that HIV-negative partners’ levels of relationship commitment were positively associated with the odds of engaging in both risk taking and strategic positioning sexual behaviors. For HIV-negative partners, reports of relationship intimacy, autonomy, and sexual satisfaction were negatively associated with odds of reporting risk taking behavior. In contrast, HIV-positive partners’reported sexual satisfaction was positively associated with odds of engaging in risk taking behavior. Findings suggested that aspects of relational quality may be differentially associated with sexual decision making for same-sex male couples in serodiscordant relationships. Study findings lend support for the incorporation ofdiscussions of HIV risk reduction strategies, enhancing communication between partners, and support for general relationship functioning in HIV care. PMID:24243004

Starks, Tyrel J.; Gamarel, Kristi E.; Johnson, Mallory O.

2014-01-01

151

Plant odorants interfere with detection of sex pheromone signals by male Heliothis virescens  

PubMed Central

In many insects, mate finding relies on female-released sex pheromones, which have to be deciphered by the male olfactory system within an odorous background of plant volatiles present in the environment of a calling female. With respect to pheromone-mediated mate localization, plant odorants may be neutral, favorable, or disturbing. Here we examined the impact of plant odorants on detection and coding of the major sex pheromone component, (Z)-11-hexadecenal (Z11-16:Ald) in the noctuid moth Heliothis virescens. By in vivo imaging the activity in the male antennal lobe (AL), we monitored the interference at the level of olfactory sensory neurons (OSN) to illuminate mixture interactions. The results show that stimulating the male antenna with Z11-16:Ald and distinct plant-related odorants simultaneously suppressed pheromone-evoked activity in the region of the macroglomerular complex (MGC), where Z11-16:Ald-specific OSNs terminate. Based on our previous findings that antennal detection of Z11-16:Ald involves an interplay of the pheromone binding protein (PBP) HvirPBP2 and the pheromone receptor (PR) HR13, we asked if the plant odorants may interfere with any of the elements involved in pheromone detection. Using a competitive fluorescence binding assay, we found that the plant odorants neither bind to HvirPBP2 nor affect the binding of Z11-16:Ald to the protein. However, imaging experiments analyzing a cell line that expressed the receptor HR13 revealed that plant odorants significantly inhibited the Z11-16:Ald-evoked calcium responses. Together the results indicate that plant odorants can interfere with the signaling process of the major sex pheromone component at the receptor level. Consequently, it can be assumed that plant odorants in the environment may reduce the firing activity of pheromone-specific OSNs in H. virescens and thus affect mate localization. PMID:23060749

Pregitzer, Pablo; Schubert, Marco; Breer, Heinz; Hansson, Bill S.; Sachse, Silke; Krieger, Jürgen

2012-01-01

152

MULTIPLE-MATING OF MALE AND FEMALE CODLING MOTH (LEPIDOPTERA: TORTRICIDAE) IN APPLE ORCHARDS TREATED WITH SEX PHEROMONE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Studies were conducted with codling moth, Cydia pomonella (L.), to evaluate the mating status of male and female moths in apple, Malus domestica (Borkhausen), orchards treated with and without sex pheromone dispensers. Laboratory studies first examined the effect of multiple mating of male and femal...

153

Social Deficits in Male Children and Adolescents with Sex Chromosome Aneuploidy: A Comparison of XXY, XYY, and XXYY Syndromes  

ERIC Educational Resources Information Center

We compare social skills in three groups of males with sex chromosome aneuploidies (SCAs) using the Social Responsiveness Scale (SRS). Participants included males with XXY (N = 102, M = 10.08 years), XYY (N = 40, M = 9.93 years), and XXYY (N = 32, M = 11.57 years). XXY had lower (better) SRS scores compared to XYY and XXYY. Scores were not…

Cordeiro, Lisa; Tartaglia, Nicole; Roeltgen, David; Ross, Judith

2012-01-01

154

Removal of adult males from the rearing environment increases preference for same-sex partners in the zebra finch  

Microsoft Academic Search

The developmental processes producing preferences for opposite-sex mating partners are not well understood. Zebra finches, Taeniopygia guttata, are colonial and socially monogamous with biparental care. To determine whether the early social environment contributes to sexual partner preference, we removed adult males from breeding colonies when the oldest chicks were less than 1 week old (male-removal rearing) or left them in

Elizabeth Adkins-Regan; Alan Krakauer

2000-01-01

155

Identification and Validation of a New Male Sex-Specific ISSR Marker in Pointed Gourd (Trichosanthes dioica Roxb.)  

PubMed Central

The aim of the present study was to develop a genetic sex marker for the pointed gourd (Trichosanthes dioica Roxb.) to allow gender determination at any stage in the life cycle. Screening of genomic DNA with intersimple sequence repeat (ISSR) primers was used to discover sex-specific touch-down polymerase chain reaction (Td-PCR) amplification products. Using pooled DNA from male and female genotypes and 42 ISSR primers, a putative male specific marker (~550?bp) was identified. DNA marker specific to male is an indication of existence of nonepigenetic factors involved in gender development in pointed gourd. The ISSR technique has proved to be a reliable technique in gender determination of pointed gourd genotypes at the seedling phenophase. The sex marker developed here could also be used as a starting material towards sequence characterization of sex linked genes for better understanding the developmental as well as evolutionary pathways in sexual dimorphism. PMID:25538949

Adhikari, Sinchan; Saha, Soumen; Bandyopadhyay, Tapas Kumar

2014-01-01

156

Sex and Condom Use in a Large Jail Unit for Men Who Have Sex with Men (MSM) and Male-to-Female Transgenders  

PubMed Central

Few data are available on factors contributing to sexual activity and condom use in custody settings, particularly among self-identified sexual minority prisoners. To address this gap, we undertook a study of sexual behavior and condom use of 101 randomly-selected men who have sex with men (MSM) and male-to-female transgender inmates in a segregated Los Angeles jail unit that has weekly condom access. Most survey participants (53%) reported anal sex during custody. Although 65% of these reported using condoms, 75% also reported having sex without condoms. Qualitative interviews (n=17) indicate a wide range of reasons for participating in protected and unprotected sex during custody, the use of cues within the custody environment to assess potential partners’ HIV status, and support for increased condom availability. Findings also indicate that high-risk sex occurs frequently in this unit and that condom distribution likely prevents a substantial amount of related HIV/STD risk. PMID:20693745

Harawa, Nina T.; Sweat, Jeffery; George, Sheba; Sylla, Mary

2013-01-01

157

Differential Interactions of Sex Pheromone and Plant Odour in the Olfactory Pathway of a Male Moth  

PubMed Central

Most animals rely on olfaction to find sexual partners, food or a habitat. The olfactory system faces the challenge of extracting meaningful information from a noisy odorous environment. In most moth species, males respond to sex pheromone emitted by females in an environment with abundant plant volatiles. Plant odours could either facilitate the localization of females (females calling on host plants), mask the female pheromone or they could be neutral without any effect on the pheromone. Here we studied how mixtures of a behaviourally-attractive floral odour, heptanal, and the sex pheromone are encoded at different levels of the olfactory pathway in males of the noctuid moth Agrotis ipsilon. In addition, we asked how interactions between the two odorants change as a function of the males' mating status. We investigated mixture detection in both the pheromone-specific and in the general odorant pathway. We used a) recordings from individual sensilla to study responses of olfactory receptor neurons, b) in vivo calcium imaging with a bath-applied dye to characterize the global input response in the primary olfactory centre, the antennal lobe and c) intracellular recordings of antennal lobe output neurons, projection neurons, in virgin and newly-mated males. Our results show that heptanal reduces pheromone sensitivity at the peripheral and central olfactory level independently of the mating status. Contrarily, heptanal-responding olfactory receptor neurons are not influenced by pheromone in a mixture, although some post-mating modulation occurs at the input of the sexually isomorphic ordinary glomeruli, where general odours are processed within the antennal lobe. The results are discussed in the context of mate localization. PMID:22427979

Deisig, Nina; Kropf, Jan; Vitecek, Simon; Pevergne, Delphine; Rouyar, Angela; Sandoz, Jean-Christophe; Lucas, Philippe; Gadenne, Christophe

2012-01-01

158

Sex differences in impaling behaviour of Great Grey Shrike Lanius excubitor: do males have better impaling skills than females?  

PubMed

Prey impaling in shrikes Laniidae is considered to be a feeding adaptation to dismember and consume large prey and is unique among food-storing animals. However, other exaptations of this behaviour were recorded, including signals in mate choice, where cache size is a sign of male quality. Thus, due to a strong sexual selection, male and female birds might differ in their behavioural patterns of impaling behaviour. We examined sex differences in impaling behaviour of the Great Grey Shrike Lanius excubitor - one of the species where caches are known to be sexual signals. Data were collected in western Poland during breeding seasons in the years 2006-2010. In the studied population, we recorded several sex-specific differences in impaling behaviour. Males impaled prey, invertebrates as well as vertebrates, faster and with fewer attempts per impaling event than females. Sexes differed in the location of impaled prey; males selected more visible places, especially during the mating and courtship phase, whereas females impaled prey in concealed locations. Males also had slightly better impaling success compared to females. We suggest that sex differences in impaling behaviour may be due to different uses of impaled prey, and the better impaling skills of males may be the result of better experience in impaling which is forced by sexual selection in this species. We also discuss other factors which might trigger sex-specific differences in food caching by shrikes. PMID:22659619

Antczak, Marcin; Hromada, Martin; Tryjanowski, Piotr

2012-09-01

159

Male-biased brood sex ratio depresses average phenotypic quality of barn swallow nestlings under experimentally harsh conditions.  

PubMed

Sex allocation strategies are believed to evolve in response to variation in fitness costs and benefits arising from the production of either sex and can be influenced by the differential susceptibility of sons and daughters to environmental conditions. We tested the effects of manipulating brood size and the sex ratio of the nestmates and the effect of sex on the phenotypic quality of individual barn swallow (Hirundo rustica) nestlings. Brood enlargement, which results in harsh rearing conditions, negatively affected the morphology and immunity of the nestlings. However, the negative consequences of brood enlargement were more marked among male than female offspring. In enlarged but not reduced broods, high proportions of male nestmates resulted in lowered individual body mass, body condition and feather growth. Thus, the consequences of a harsh environment on individual nestlings differed between the sexes and depended on the sex ratio among the other nestlings in the brood. The evolution of sex allocation strategies may therefore depend on the sex of individual nestlings but also on an interaction between environment and progeny sex ratio. PMID:18270745

Saino, Nicola; de Ayala, Rosa Mary; Martinelli, Roberta; Boncoraglio, Giuseppe

2008-05-01

160

Production of all female progeny: evidence for the presence of the male sex determination factor on the Y chromosome.  

PubMed

The red flour beetle, Tribolium castaneum, follows an XX (female) and XY (male) sex determination system. Maternal supply of the protein Transformer (Tra) is required for XX insects to follow the female pathway. The nature and source of the signal that regulates male sex determination in XY beetles are not known. Parental RNAi-aided knockdown in expression of tra masculinizes genetic females (XX) that are fertile. The virgin females mated with these masculinized genetic females produced all female progeny. We present the genetic evidence to show that the factor responsible for male sex determination is present on the Y chromosome. These data also suggest that the Y chromosome in T. castaneum is not required for male fertility. PMID:24577442

Shukla, Jayendra Nath; Palli, Subba Reddy

2014-05-15

161

The Role of Clitoral Anatomy in Female to Male Sex Reassignment Surgery  

PubMed Central

Introduction. Controversies on clitoral anatomy and its role in female sexual function still make clitoral reconstructive surgery very challenging. We evaluated the role of clitoral anatomic features in female to male sex reassignment surgery. Material and Methods. The study included 97 female transsexuals, aged from 18 to 41 years, who underwent single stage metoidioplasty between March 2008 and January 2013. The operative technique involved vaginectomy, the release of clitoral ligaments and urethral plate, urethroplasty by combining buccal mucosa graft and genital flaps, and scrotoplasty with insertion of testicle prostheses. Postoperative questionnaire was used to evaluate aesthetic, functional, and sexual outcome. Results. The mean followup was 30 months. The mean length of the neophallus was 7?cm, compared to mean preoperative length of the hypertrophied clitoris of 3.3?cm. Complications occurred in 27.84% of all patients, related mostly to urethroplasty. Voiding while standing was achieved in all cases. None of the patients had problems in sexual arousal, masturbation, or orgasms. Conclusion. Accurate knowledge of the clitoral anatomy, physiology, and neurovascular supply is crucial for a successful outcome of female to male sex reassignment surgery. Our approach appears to ensure overall satisfaction and high quality of sexual life. PMID:24982953

2014-01-01

162

Plant volatiles enhance behavioral responses of grapevine moth males, Lobesia botrana to sex pheromone.  

PubMed

Plant volatiles play an important role in the lives of phytophagous insects, by guiding them to oviposition, feeding and mating sites. We tested the effects of different host-plant volatiles on attraction of Lobesia botrana males to the female-produced sex pheromone, in a wind tunnel. Addition of volatile emissions from grapevines or individual plant volatiles to pheromone increased the behavioral responses of L. botrana males over those to pheromone alone. At a low release rate (under-dosed) of pheromone, addition of (E)-?-caryophyllene, (Z)-3-hexenyl acetate, 1-hexanol, or 1-octen-3-ol increased all behavioral responses, from activation to pheromone source contact, while addition of (E)-4,8-dimethyl-1,3,7-nonatriene, (E)-?-farnesene, (Z)-3-hexenol, or methyl salicylate affected only the initial behavioral responses. Dose-response experiments suggested an optimal release ratio of 1:1000 (sex pheromone: host plant volatile). Our results highlight the role of plant volatiles in the sensory ecology of L. botrana. PMID:22323083

von Arx, Martin; Schmidt-Büsser, Daniela; Guerin, Patrick M

2012-02-01

163

HIV prevalence and risk behaviors among male clients of female sex workers in Yunnan, China  

PubMed Central

Objectives To assess the prevalence and risk factors of HIV among male clients of female sex workers in China. Methods Convenience sampling methods were used to recruit 315 clients using FSW-client and client-client networks. Subjects provided information on socio-demographic characteristics and sexual and drug behavior patterns. Blood samples were collected for HIV testing and urine samples for opiate testing. Results Overall HIV prevalence was 6.0%; among drug users it was 30.8%. 33.7% of respondents reported that they always use condoms in commercial sex and 63.5% that they used a condom in the last commercial sex episode. Drug use (OR: 6.1; 95% CI: 1.7–21.4) and lack of a regular sexual partner (OR: 6.3; 95% CI: 1.8–21.9) were significantly associated with HIV infection. Conclusions Clients of FSWs serve as potential bridges for HIV transmission from the high-risk FSWs to the low-risk general population, making them a key target for intervention. High HIV prevalence rates among clients in Kaiyuan is particularly alarming given their risk behavior patterns including high rates of partner exchange, low condom use rates, and drug using behaviors. Innovative interventions are needed to reduce the risk of HIV among clients and reduce the bridge of transmission to the general population. PMID:19730110

Jin, Xia; Smith, Kumi; Chen, Ray Y.; Ding, Guowei; Yao, Yan; Wang, Haibo; Qian, Han-Zhu; Chang, Dongfang; Wang, Guixiang; Wang, Ning

2009-01-01

164

Prevalence of Consensual Male–Male Sex and Sexual Violence, and Associations with HIV in South Africa: A Population-Based Cross-Sectional Study  

PubMed Central

Background In sub-Saharan Africa the population prevalence of men who have sex with men (MSM) is unknown, as is the population prevalence of male-on-male sexual violence, and whether male-on-male sexual violence may relate to HIV risk. This paper describes lifetime prevalence of consensual male–male sexual behavior and male-on-male sexual violence (victimization and perpetration) in two South African provinces, socio-demographic factors associated with these experiences, and associations with HIV serostatus. Methods and Findings In a cross-sectional study conducted in 2008, men aged 18–49 y from randomly selected households in the Eastern Cape and KwaZulu-Natal provinces provided anonymous survey data and dried blood spots for HIV serostatus assessment. Interviews were completed in 1,737 of 2,298 (75.6%) of enumerated and eligible households. From these households, 1,705 men (97.1%) provided data on lifetime history of same-sex experiences, and 1,220 (70.2%) also provided dried blood spots for HIV testing. 5.4% (n?=?92) of participants reported a lifetime history of any consensual sexual activity with another man; 9.6% (n?=?164) reported any sexual victimization by a man, and 3.0% (n?=?51) reported perpetrating sexual violence against another man. 85.0% (n?=?79) of men with a history of consensual sex with men reported having a current female partner, and 27.7% (n?=?26) reported having a current male partner. Of the latter, 80.6% (n?=?21/26) also reported having a female partner. Men reporting a history of consensual male–male sexual behavior are more likely to have been a victim of male-on-male sexual violence (adjusted odds ratio [aOR]?=?7.24; 95% CI 4.26–12.3), and to have perpetrated sexual violence against another man (aOR?=?3.10; 95% CI 1.22–7.90). Men reporting consensual oral/anal sex with a man were more likely to be HIV+ than men with no such history (aOR?=?3.11; 95% CI 1.24–7.80). Men who had raped a man were more likely to be HIV+ than non-perpetrators (aOR?=?3.58; 95% CI 1.17–10.9). Conclusions In this sample, one in 20 men (5.4%) reported lifetime consensual sexual contact with a man, while about one in ten (9.6%) reported experience of male-on-male sexual violence victimization. Men who reported having had sex with men were more likely to be HIV+, as were men who reported perpetrating sexual violence towards other men. Whilst there was no direct measure of male–female concurrency (having overlapping sexual relationships with men and women), the data suggest that this may have been common. These findings suggest that HIV prevention messages regarding male–male sex in South Africa should be mainstreamed with prevention messages for the general population, and sexual health interventions and HIV prevention interventions for South African men should explicitly address male-on-male sexual violence. Please see later in the article for the Editors' Summary PMID:23853554

Dunkle, Kristin L.; Jewkes, Rachel K.; Murdock, Daniel W.; Sikweyiya, Yandisa; Morrell, Robert

2013-01-01

165

Sex-Biased Gene Expression on the Avian Z Chromosome: Highly Expressed Genes Show Higher Male-Biased Expression  

PubMed Central

Dosage compensation, the process whereby expression of sex-linked genes remains similar between sexes (despite heterogamety) and balanced with autosomal expression, was long believed to be essential. However, recent research has shown that several lineages, including birds, butterflies, monotremes and sticklebacks, lack chromosome-wide dosage compensation mechanisms and do not completely balance the expression of sex-linked and autosomal genes. To obtain further understanding of avian sex-biased gene expression, we studied Z-linked gene expression in the brain of two songbirds of different genera (zebra finch, Taeniopygia guttata, and common whitethroat, Sylvia communis) using microarray technology. In both species, the male-bias in gene expression was significantly higher for Z than for autosomes, although the ratio of Z-linked to autosomal expression (Z:A) was relatively close to one in both sexes (range: 0.89–1.01). Interestingly, the Z-linked male-bias in gene expression increased with expression level, and genes with low expression showed the lowest degree of sex-bias. These results support the view that the heterogametic females have up-regulated their single Z-linked homologues to a high extent when the W-chromosome degraded and thereby managed to largely balance their Z:A expression with the exception of highly expressed genes. The male-bias in highly expressed genes points towards male-driven selection on Z-linked loci, and this and other possible hypotheses are discussed. PMID:23056488

Naurin, Sara; Hasselquist, Dennis; Bensch, Staffan; Hansson, Bengt

2012-01-01

166

Baseline sacroiliac joint magnetic resonance imaging abnormalities and male sex predict the development of radiographic sacroiliitis.  

PubMed

We evaluated the relationship between the baseline sacroiliac joint (SIJ) magnetic resonance imaging (MRI) findings and the development of radiographic sacroiliitis and tested their prognostic significance in cases of ankylosing spondylitis. Patients who had undergone an SIJ MRI at the rheumatology department were identified. Individuals for whom pelvic X-rays were available after at least 1 year of MRI were included in the analysis. All radiographs and MRI examinations were scored by two independent readers. Medical records of the patients were reviewed to obtain potentially relevant demographic and clinical data. We identified 1,069 SIJ MRIs, and 328 fulfilled our inclusion criteria. Reliability analysis revealed moderate to good inter- and intra-observer agreement. On presentation data, 14 cases were excluded because they had unequivocal radiographic sacroiliitis at baseline. After a mean of 34.8 months of follow-up, 24 patients developed radiographic sacroiliitis. The presence of active sacroiliitis (odds ratio (OR) 15.1) and structural lesions on MRI (OR 8.3), male sex (OR 4.7), fulfillment of Calin's inflammatory back pain criteria (P = 0.001), and total MRI activity score (P < 0.001) were found to be related to the development of radiographic sacroiliitis. By regression modeling, the presence of both active inflammatory and structural damage lesions on MRI and male sex were found to be predictive factors for the development of radiographic sacroiliitis. Our present results suggest that the occurrence of both active inflammatory and structural lesions in SIJs revealed by MRI is a significant risk factor for radiographic sacroiliitis, especially in male patients with early inflammatory back pain. PMID:23765093

Akar, Servet; Isik, Sibel; Birlik, Bilge; Solmaz, Dilek; Sari, Ismail; Onen, Fatos; Akkoc, Nurullah

2013-10-01

167

Partners met via sex parties present significantly greater odds for condomless anal sex among MSM: an event-level analysis of venues where male partners are met.  

PubMed

One hundred forty-seven men who have sex with men completed time-line follow-back interviews about the venues where they met their male partners (n = 1180 sexual events with first-time partners, <30 days). We ran multivariate models to determine the association between venues and condomless anal sex (CAS). After adjusting for known correlates of CAS, partners met at sex parties presented significantly greater odds for CAS compared with meeting a partner at a gay bar/club (adjusted odds ratio = 0.44), online (adjusted odds ratio = 0.42), bathhouse (adjusted odds ratio = 0.35), or via "other" venues (adjusted odds ratio = 0.35), all P < 0.01. These findings highlight the need to develop innovative HIV/sexually transmitted infection prevention initiatives for men who attend sex parties. PMID:25226209

Grov, Christian; Rendina, H J; Ventuneac, Ana; Parsons, Jeffrey T

2014-12-15

168

Useless Hearing in Male Emblemasoma auditrix (Diptera, Sarcophagidae) – A Case of Intralocus Sexual Conflict during Evolution of a Complex Sense Organ?  

PubMed Central

Sensory modalities typically are important for both sexes, although sex-specific functional adaptations may occur frequently. This is true for hearing as well. Consequently, distinct behavioural functions were identified for the different insect hearing systems. Here we describe a first case, where a trait of an evolutionary novelty and a highly specialized hearing organ is adaptive in only one sex. The main function of hearing of the parasitoid fly Emblemasoma auditrix is to locate the host, males of the cicada species Okanagana rimosa, by their calling song. This task is performed by female flies, which deposit larvae into the host. We show that male E. auditrix possess a hearing sense as well. The morphology of the tympanal organ of male E. auditrix is rather similar to the female ear, which is 8% broader than the male ear. In both sexes the physiological hearing threshold is tuned to 5 kHz. Behavioural tests show that males are able to orient towards the host calling song, although phonotaxis often is incomplete. However, despite extensive observations in the field and substantial knowledge of the biology of E. auditrix, no potentially adaptive function of the male auditory sense has been identified. This unique hearing system might represent an intralocus sexual conflict, as the complex sense organ and the behavioural relevant neuronal network is adaptive for only one sex. The correlated evolution of the sense organ in both sexes might impose substantial constraints on the sensory properties of the ear. Similar constraints, although hidden, might also apply to other sensory systems in which behavioural functions differ between sexes. PMID:24489872

Lakes-Harlan, Reinhard; deVries, Thomas; Stölting, Heiko; Stumpner, Andreas

2014-01-01

169

The Transcriptome of Lutzomyia longipalpis (Diptera: Psychodidae) Male Reproductive Organs  

PubMed Central

Background It has been suggested that genes involved in the reproductive biology of insect disease vectors are potential targets for future alternative methods of control. Little is known about the molecular biology of reproduction in phlebotomine sand flies and there is no information available concerning genes that are expressed in male reproductive organs of Lutzomyia longipalpis, the main vector of American visceral leishmaniasis and a species complex. Methods/Principal Findings We generated 2678 high quality ESTs (“Expressed Sequence Tags”) of L. longipalpis male reproductive organs that were grouped in 1391 non-redundant sequences (1136 singlets and 255 clusters). BLAST analysis revealed that only 57% of these sequences share similarity with a L. longipalpis female EST database. Although no more than 36% of the non-redundant sequences showed similarity to protein sequences deposited in databases, more than half of them presented the best-match hits with mosquito genes. Gene ontology analysis identified subsets of genes involved in biological processes such as protein biosynthesis and DNA replication, which are probably associated with spermatogenesis. A number of non-redundant sequences were also identified as putative male reproductive gland proteins (mRGPs), also known as male accessory gland protein genes (Acps). Conclusions The transcriptome analysis of L. longipalpis male reproductive organs is one step further in the study of the molecular basis of the reproductive biology of this important species complex. It has allowed the identification of genes potentially involved in spermatogenesis as well as putative mRGPs sequences, which have been studied in many insect species because of their effects on female post-mating behavior and physiology and their potential role in sexual selection and speciation. These data open a number of new avenues for further research in the molecular and evolutionary reproductive biology of sand flies. PMID:22496818

Bretãs, Jorge A. C.; Mazzoni, Camila J.; Souza, Nataly A.; Albano, Rodolpho M.; Wagner, Glauber; Davila, Alberto M. R.; Peixoto, Alexandre A.

2012-01-01

170

Behavioral treatment of deviant sex-role behaviors in a male child1  

PubMed Central

This study demonstrated reinforcement control over pronounced feminine behaviors in a male child who had been psychologically evaluated as manifesting “childhood cross-gender identity”. The clinical history of the subject paralleled the retrospective reports of adult transsexuals, including (a) cross-gender clothing preferences, (b) actual or imaginal use of cosmetic articles, (c) feminine behavior mannerisms, (d) aversion to masculine activities, coupled with preference for girl playmates and feminine activities, (e) preference for female role, (f) feminine voice inflection and predominantly feminine content in speech, and (g) verbal statements about the desire or preference to be a girl. The subject was treated sequentially in the clinic and home environments by his mother, trained to be his therapist. The mother was taught to reinforce masculine behaviors and to extinguish feminine behaviors, by using social reinforcement in the clinic and a token reinforcement procedure in the home. During this treatment, his feminine behaviors sharply decreased and masculine behavior increased. The treatment effects were found to be largely response-specific and stimulus-specific; consequently, it was necessary to strengthen more than one masculine behavior and weaken several feminine behaviors, in both clinic and home settings. A multiple-baseline intrasubject design was used to ensure both replication and identification of relevant treatment variables. Follow-up data three years after the treatment began suggests that the boy's sex-typed behaviors have become normalized. This study suggests a preliminary step toward correcting pathological sex-role development in boys, which may provide a basis for the primary prevention of adult transsexualism or similar adult sex-role deviation. PMID:4436165

Rekers, George A.; Lovaas, O. Ivar

1974-01-01

171

Sex peptide of Drosophila melanogaster males is a global regulator of reproductive processes in females  

PubMed Central

Seminal fluid proteins (Sfps) alter female behaviour and physiology and can mediate sexual conflict. In Drosophila melanogaster, a single Sfp, the sex peptide (SP), triggers remarkable post-mating responses in females, including altered fecundity, feeding, immunity and sexual receptivity. These effects can favour the evolutionary interests of males while generating costs in females. We tested the hypothesis that SP is an upstream master-regulator able to induce diverse phenotypes through efficient induction of widespread transcriptional changes in females. We profiled mRNA responses to SP in adult female abdomen (Abd) and head+thorax (HT) tissues using microarrays at 3 and 6 h following mating. SP elicited a rich, subtle signature of temporally and spatially controlled mRNAs. There were significant alterations to genes linked to egg development, early embryogenesis, immunity, nutrient sensing, behaviour and, unexpectedly, phototransduction. There was substantially more variation in the direction of differential expression across time points in the HT versus Abd. The results support the idea that SP is an important regulator of gene expression in females. The expression of many genes in one sex can therefore be under the influence of a regulator expressed in the other. This could influence the extent of sexual conflict both within and between loci. PMID:22977156

Gioti, A.; Wigby, S.; Wertheim, B.; Schuster, E.; Martinez, P.; Pennington, C. J.; Partridge, L.; Chapman, T.

2012-01-01

172

Behavioural evidence of male volatile pheromones in the sex-role reversed wolf spiders Allocosa brasiliensis and Allocosa alticeps  

NASA Astrophysics Data System (ADS)

The use of chemical signals in a sexual context is widespread in the animal kingdom. Most studies in spiders report the use of female pheromones that attract potential sexual partners. Allocosa brasiliensis and Allocosa alticeps are two burrowing wolf spiders that show sex-role reversal. Females locate male burrows and initiate courtship before males perform any detectable visual or vibratory signal. So, females of these species would be detecting chemical or mechanical cues left by males. Our objective was to explore the potential for male pheromones to play a role in mate detection in A. brasiliensis and A. alticeps. We designed two experiments. In Experiment 1, we tested the occurrence of male contact pheromones by evaluating female courtship when exposed to empty burrows constructed by males or females (control). In Experiment 2, we tested the existence of male volatile pheromones by evaluating female behaviour when exposed to artificial burrows connected to tubes containing males, females or empty tubes (control). Our results suggest the occurrence of male volatile pheromones that trigger female courtship in both Allocosa species. The sex-role reversal postulated for these wolf spiders could be driving the consequent reversal in typical pheromone-emitter and detector roles expected for spiders.

Aisenberg, Anita; Baruffaldi, Luciana; González, Macarena

2010-01-01

173

Mecp2 organizes juvenile social behavior in a sex-specific manner  

PubMed Central

Methyl-CpG-binding protein 2 (MeCP2) binds methylated DNA and recruits co-repressor proteins to modify chromatin and alter gene transcription. Mutations of the MECP2 gene can cause Rett syndrome (RTT), while subtle reductions of MeCP2 expression may be associated with male dominated social and neurodevelopmental disorders. We report that transiently decreased amygdala Mecp2 expression during a sensitive period of brain sexual differentiation disrupts the organization of sex differences in juvenile social play behavior. Interestingly, neonatal treatment with Mecp2 siRNA within the developing amygdala reduced juvenile social play behavior in males but not females. Reduced Mecp2 expression did not change juvenile sociability or anxiety-like behavior, suggesting this disruption is associated with subtle behavioral modification. This suggests Mecp2 may have an overlooked role in the organization of sexually dimorphic behaviors and that male juvenile behavior is particularly sensitive to Mecp2 disruption during this period of development. PMID:18614683

Kurian, Joseph R.; Bychowski, Meaghan E.; Forbes-Lorman, Robin M.; Auger, Catherine J.; Auger, Anthony P.

2008-01-01

174

Annual changes in plasma levels of cortisol and sex steroid hormones in male rainbow trout, Oncorhynchus mykiss  

Microsoft Academic Search

The profiles of cortisol, testosterone, 11-ketotestosterone and 17?, 20?-dihydroxy-4-pregnene-3-one in male rainbow trout\\u000a reared under constant water temperature and natural photoperiod were determined by radioimmunoassay. Gonads of male rainbow\\u000a trout reached maturity when the fish were two years old. Changes in the plasma levels of both sex steroid hormones and cortisol\\u000a were closely related to the GSI. Plasma levels of

Ya-Yi Hou; Xiao-Dong Han; Yuzuru Suzuki

2001-01-01

175

Sex Hormones, Gonadotropins and Prolactin in Male Epileptic Subjects in Remission: Role of the Epileptic Syndrome and of Antiepileptic Drugs  

Microsoft Academic Search

Sex steroid peripheral pattern, pulsatile luteinizing hormone (LH) secretion, gonadotropin and prolactin responses to LH-releasing hormone (LHRH) and thyrotropin-releasing hormone (TRH) were studied in 35 male epileptics treated with phenobarbital (PB), carbamazepine (CBZ), or phenytoin (PHT), and in age-matched healthy males. Idiopathic generalized epilepsy (IGE) was diagnosed in 12 cases and partial epilepsy (PE) in 23 cases. Patients were seizure-free

Giovanni Murialdo; Carlo Andrea Galimberti; Stefano Fonzi; Raffaele Manni; Patrizia Costelli; Cristina Parodi; Franco Torre; G. Piero Solinas; Alessandro Polleri; Amelia Tartara

1994-01-01

176

Green Light Synergistally Enhances Male Sweetpotato Weevil Response to Sex Pheromone  

PubMed Central

Sweetpotato, commercially grown in over 100 countries, is one of the ten most important staple crops in the world. Sweetpotato weevil is a major pest of sweetpotato in most areas of cultivation, the feeding of which induces production in the sweetpotato root of extremely bitter tasting and toxic sesquiterpenes which can render the sweetpotato unfit for consumption. A significant step towards improved management of this weevil species was the identification of a female-produced sex pheromone [(Z)-3-dodecenyl (E)-2-butenoate] to which males are highly attracted. Reported here are results of research that documents a nearly 5-fold increase in male sweetpotato weevil catch in traps baited with this pheromone and a green light provided by a solar-powered, light-emitting diode (LED). The combination of olfactory and night-visible visual cues significantly enhanced trap effectiveness for this nighttime-active insect species. These results provide promise for improved sweetpotato weevil detection and suppression in mass trapping programs. PMID:24675727

McQuate, Grant T.

2014-01-01

177

Facultative sex ratio adjustment in response to male tarsus length in the Varied Tit Parus varius  

Microsoft Academic Search

During the last decade, evidence from a number of studies has suggested systematic devi- ations from a 1 : 1 primary sex ratio in birds, in spite of the fact that birds have chromosomal sex determination systems; the mechanism of sex allocation is not fully understood. How- ever, it still remains uncertain whether adaptive manipulations of primary sex ratio occur,

Noriyuki Yamaguchi; Katsura K. Kawano; Kazuhiro Eguchi; Tetsukazu Yahara

2004-01-01

178

Stress and mental disorders in female military personnel: Comparisons between the sexes in a male dominated profession  

Microsoft Academic Search

The proportion of women in militaries is growing; however, many studies in the area of military mental health have been conducted with majority male samples. The present study examined sex differences in trauma exposure, work stress, and mental disorders in the Canadian Community Health Survey – Canadian Forces Supplement, a representative sample of 5155 regular force personnel and 3286 reservists

Natalie P. Mota; Maria Medved; JianLi Wang; Gordon J. G. Asmundson; Debbie Whitney; Jitender Sareen

179

Discriminating Males and Unpredictable Females: Males Differentiate Self-Similar Facial Cues More than Females in the Judgment of Opposite-Sex Attractiveness  

PubMed Central

Attractiveness judgment in the context of mate preferences is thought to reflect an assessment of mate quality in relation to an absolute scale of genetic fitness and a relative scale of self-similarity. In this study, subjects judged the attractiveness and trustworthiness of faces in composite images that were manipulated to produce self-similar (self-resemblance) and dissimilar (other-resemblance) images. Males differentiated between self- and other-resemblance as well as among different degrees of self-resemblance in their attractiveness ratings; females did not. Specifically, in Experiment 1, using a morphing technique, we created previously unseen face images possessing different degrees (0%, 30%, 40%, or 50%) of incorporation of the subject's images (different degrees of self-resemblance) and found that males preferred images that were closer to average (0%) rather than more self-similar, whereas females showed no preference for any degree of self-similarity. In Experiment 2, we added a pro-social question about trustworthiness. We replicated the Experiment 1 attractiveness rating results and further found that males differentiated between self- and other-resemblance for the same degree of composites; women did not. Both males and females showed a similar preference for self-resemblances when judging trustworthiness. In conclusion, only males factored self-resemblance into their attractiveness ratings of opposite-sex individuals in a manner consistent with cues of reproductive fitness, although both sexes favored self-resemblance when judging trustworthiness. PMID:24594644

Zhuang, Jin-Ying; Zhang, Sen; Xu, Jing; Hu, Die

2014-01-01

180

Age, Sex, and Telomere Dynamics in a Long-Lived Seabird with Male-Biased Parental Care  

PubMed Central

The examination of telomere dynamics is a recent technique in ecology for assessing physiological state and age-related traits from individuals of unknown age. Telomeres shorten with age in most species and are expected to reflect physiological state, reproductive investment, and chronological age. Loss of telomere length is used as an indicator of biological aging, as this detrimental deterioration is associated with lowered survival. Lifespan dimorphism and more rapid senescence in the larger, shorter-lived sex are predicted in species with sexual size dimorphism, however, little is known about the effects of behavioral dimorphism on senescence and life history traits in species with sexual monomorphism. Here we compare telomere dynamics of thick-billed murres (Urialomvia), a species with male-biased parental care, in two ways: 1) cross-sectionally in birds of known-age (0-28 years) from one colony and 2) longitudinally in birds from four colonies. Telomere dynamics are compared using three measures: the telomere restriction fragment (TRF), a lower window of TRF (TOE), and qPCR. All showed age-related shortening of telomeres, but the TRF measure also indicated that adult female murres have shorter telomere length than adult males, consistent with sex-specific patterns of ageing. Adult males had longer telomeres than adult females on all colonies examined, but chick telomere length did not differ by sex. Additionally, inter-annual telomere changes may be related to environmental conditions; birds from a potentially low quality colony lost telomeres, while those at more hospitable colonies maintained telomere length. We conclude that sex-specific patterns of telomere loss exist in the sexually monomorphic thick-billed murre but are likely to occur between fledging and recruitment. Longer telomeres in males may be related to their homogamous sex chromosomes (ZZ) or to selection for longer life in the care-giving sex. Environmental conditions appeared to be the primary drivers of annual changes in adult birds. PMID:24023967

Young, Rebecca C.; Kitaysky, Alexander S.; Haussmann, Mark F.; Descamps, Sebastien; Orben, Rachael A.; Elliott, Kyle H.; Gaston, Anthony J.

2013-01-01

181

Age, sex, and telomere dynamics in a long-lived seabird with male-biased parental care.  

PubMed

The examination of telomere dynamics is a recent technique in ecology for assessing physiological state and age-related traits from individuals of unknown age. Telomeres shorten with age in most species and are expected to reflect physiological state, reproductive investment, and chronological age. Loss of telomere length is used as an indicator of biological aging, as this detrimental deterioration is associated with lowered survival. Lifespan dimorphism and more rapid senescence in the larger, shorter-lived sex are predicted in species with sexual size dimorphism, however, little is known about the effects of behavioral dimorphism on senescence and life history traits in species with sexual monomorphism. Here we compare telomere dynamics of thick-billed murres (Urialomvia), a species with male-biased parental care, in two ways: 1) cross-sectionally in birds of known-age (0-28 years) from one colony and 2) longitudinally in birds from four colonies. Telomere dynamics are compared using three measures: the telomere restriction fragment (TRF), a lower window of TRF (TOE), and qPCR. All showed age-related shortening of telomeres, but the TRF measure also indicated that adult female murres have shorter telomere length than adult males, consistent with sex-specific patterns of ageing. Adult males had longer telomeres than adult females on all colonies examined, but chick telomere length did not differ by sex. Additionally, inter-annual telomere changes may be related to environmental conditions; birds from a potentially low quality colony lost telomeres, while those at more hospitable colonies maintained telomere length. We conclude that sex-specific patterns of telomere loss exist in the sexually monomorphic thick-billed murre but are likely to occur between fledging and recruitment. Longer telomeres in males may be related to their homogamous sex chromosomes (ZZ) or to selection for longer life in the care-giving sex. Environmental conditions appeared to be the primary drivers of annual changes in adult birds. PMID:24023967

Young, Rebecca C; Kitaysky, Alexander S; Haussmann, Mark F; Descamps, Sebastien; Orben, Rachael A; Elliott, Kyle H; Gaston, Anthony J

2013-01-01

182

Wolbachia is not all about sex: male-feminizing Wolbachia alters the leafhopper Zyginidia pullula transcriptome in a mainly sex-independent manner  

PubMed Central

Wolbachia causes the feminization of chromosomally male embryos in several species of crustaceans and insects, including the leafhopper Zyginidia pullula. In contrast to the relatively well-established ecological aspects of male feminization (e.g., sex ratio distortion and its consequences), the underlying molecular mechanisms remain understudied and unclear. We embarked on an exploratory study to investigate the extent and nature of Wolbachia's effect on gene expression pattern in Z. pullula. We sequenced whole transcriptomes from Wolbachia-infected and uninfected adults. 18147 loci were assembled de novo, including homologs of several Drosophila sex determination genes. A number of transcripts were flagged as candidate Wolbachia sequences. Despite the resemblance of Wolbachia-infected chromosomal males to uninfected and infected chromosomal females in terms of sexual morphology and behavior, principal component analysis revealed that gene expression patterns did not follow these sexual phenotype categories. The principal components generated by differentially expressed genes specified a strong sex-independent Wolbachia effect, followed by a weaker Wolbachia-sexual karyotype interaction effect. Approaches to further examine the molecular mechanism of Wolbachia-host interactions have been suggested based on the presented findings. PMID:25225494

Asgharian, Hosseinali; Chang, Peter L.; Mazzoglio, Peter J.; Negri, Ilaria

2014-01-01

183

Neonatal testosterone partially organizes sex differences in stress-induced emotionality in mice  

PubMed Central

Major depressive disorder (MDD) is a debilitating disorder of altered mood regulation. Despite well established sex differences in MDD prevalence, the mechanism underlying the increased female vulnerability remains unknown. Although evidence suggests an influence of adult circulating hormone levels on mood (i.e. activational effects of hormones), MDD prevalence is consistently higher in women across life stages (and therefore hormonal states), suggesting that additional underlying structural or biological differences place women at higher risk. Studies in human subjects and in rodent models suggest a developmental origin for mood disorders, and interestingly, a developmental process also establishes sex differences in the brain. Hence, based on these parallel developmental trajectories, we hypothesized that a proportion of the female higher vulnerability to MDD may originate from the differential organization of mood regulatory neural networks early in life (i.e. organizational effects of hormones). To test this hypothesis in a rodent system, we took advantage of a well-established technique used in the field of sexual differentiation (neonatal injection with testosterone) to masculinize sexually dimorphic brain regions in female mice. We then investigated adult behavioral consequences relating to emotionality by comparing neonatal testosterone-treated females to normal males and females. Under baseline/trait conditions, neonatal testosterone treatment of female mice did not influence adult emotionality, but masculinized adult locomotor activity, as revealed by the activational actions of hormones. Conversely, the increased vulnerability of female mice to develop high emotionality following unpredictable chronic mild stress (UCMS) was partially masculinized by neonatal testosterone exposure, with no effect on post-UCMS locomotion. The elevated female UCMS-induced vulnerability did not differ between adult hormone treated groups. These results demonstrate that sex differences in adult emotionality in mice are partially caused by the organizational effects of sex hormones during development, hence supporting a developmental hypothesis of the human adult female prevalence of MDD. PMID:22394611

Seney, Marianne L.; Walsh, Christopher; Stolakis, Ryan; Sibille, Etienne

2012-01-01

184

Changing seasonality and phenological responses of free-living male arctic ground squirrels: the importance of sex  

PubMed Central

Many studies have addressed the effects of climate change on species as a whole; however, few have examined the possibility of sex-specific differences. To understand better the impact that changing patterns of snow-cover have on an important resident Arctic mammal, we investigated the long-term (13 years) phenology of hibernating male arctic ground squirrels living at two nearby sites in northern Alaska that experience significantly different snow-cover regimes. Previously, we demonstrated that snow-cover influences the timing of phenological events in females. Our results here suggest that the end of heterothermy in males is influenced by soil temperature and an endogenous circannual clock, but timing of male emergence from hibernation is influenced by the timing of female emergence. Males at both sites, Atigun and Toolik, end heterothermy on the same date in spring, but remain in their burrows while undergoing reproductive maturation. However, at Atigun, where snowmelt and female emergence occur relatively early, males emerge 8 days earlier than those at Toolik, maintaining a 12-day period between male and female emergence found at each site, but reducing the pre-emergence euthermic period that is critical for reproductive maturation. This sensitivity in timing of male emergence to female emergence will need to be matched by phase shifts in the circannual clock and responsiveness to environmental factors that time the end of heterothermy, if synchrony in reproductive readiness between the sexes is to be preserved in a rapidly changing climate. PMID:23836786

Sheriff, Michael J.; Richter, Melanie M.; Buck, C. Loren; Barnes, Brian M.

2013-01-01

185

SEGMENTING THE MALE PELVIC ORGANS FROM LIMITED ANGLE IMAGES WITH APPLICATION TO ART  

E-print Network

SEGMENTING THE MALE PELVIC ORGANS FROM LIMITED ANGLE IMAGES WITH APPLICATION TO ART Charles Brandon: SEGMENTING THE MALE PELVIC ORGANS FROM LIMITED ANGLE IMAGES WITH APPLICATION TO ART. (Under the direction, requires that the male pelvic organs of interest be segmented and that correspondence be estab- lished

186

Sex hormones and pituitary function in male epileptic patients with altered or normal sexuality.  

PubMed

Male epileptic patients frequently complain of sexual dysfunction, particularly impotence and loss of libido. Epilepsy itself, antiepileptic drugs (AEDs), and psychosocial factors are believed to contribute to impaired sexuality. We studied luteinizing hormone (LH) pulsatile secretion, gonadotropin, and prolactin (PRL) responses to LH-releasing hormone (LHRH) and thyrotropin-releasing hormone (TRH) in 37 adult male epileptic patients receiving AED monotherapy who were seizure-free and had normal EEGs. Sexuality was assessed by psychological interview. Impotence was diagnosed in 8 patients (in 2 combined with loss of sexual desire). The occurrence of hyposexuality (approximately 20%) was independent of epilepsy syndrome or AED. No change in total testosterone (T) level was observed. Free T (fT) and dihydrotestosterone (DHT) levels were lower and sex hormone binding globulin (SHBG) levels were higher in epileptic subjects than in healthy controls, but a statistically significant difference was not observed between hypo- and normosexual patients. In impotent epileptic patients, estradiol (E2) levels were significantly increased as compared with those of patients with preserved sexuality and of healthy controls. The unbalanced relation between androgen and E2 levels was emphasized by decreased T/E2, fT/E2, and DHT/E2 ratios obtained in hyposexual epileptic patients. In this group, LHRH induced blunted LH peaks. No changes were noted in LH pulsatility features. These findings of higher E2 levels and of decreased LH response to LHRH administration in some epileptic patients with impaired sexuality, may suggest they have subclinical hypogonadotropic hypogonadism. PMID:7607114

Murialdo, G; Galimberti, C A; Fonzi, S; Manni, R; Costelli, P; Parodi, C; Solinas, G P; Amoretti, G; Tartara, A

1995-04-01

187

CHALLENGES IN BIODEGRADATION OF TRACE ORGANIC CONTAMINANTS-GASOLINE OXYGENATES AND SEX HORMONES  

EPA Science Inventory

Advances in analytical methods have led to the identification of several classes of organic chemicals that are associated with adverse environmental impacts. Two such classes of organic chemicals, gasoline oxygenates and sex hormones, are used to illustrate challenges associated ...

188

Effects of Vomeronasal Organ Removal on Olfactory Sex Discrimination and Odor Preferences of Female Ferrets  

Microsoft Academic Search

Previous research suggests that body odorants, including anal scents and urinary odors, contribute to sex discrimination and mate identification in European ferrets of both sexes. We assessed the possible role of the vomeronasal organ (VNO) in these functions by surgically removing the organ bilaterally in sexually experienced female ferrets. Lesioned (VNOx) and sham-oper- ated control (VNOi) females reliably discriminated between

S. K. Woodley; A. L. Cloe; P. Waters; M. J. Baum

2004-01-01

189

Attraction of male European tarnished plant bug, Lygus rugulipennis to components of the female sex pheromone in the field.  

PubMed

Previous work showed that females of the European tarnished plant bug, Lygus rugulipennis Poppius (Heteroptera: Miridae), produced three chemicals, hexyl butyrate, (E)-2-hexenyl butyrate, and (E)-4-oxo-2-hexenal, and that these were suspected to be components of the female sex pheromone. In field experiments, traps baited with blends of these chemicals dispensed from polyethylene vials and sachets failed to catch significant numbers of males. Here, we report more recent field experiments in which the chemicals were released from glass microcapillary tubes. A blend of hexyl butyrate and (E)-4-oxo-2-hexenal was significantly attractive to male L. rugulipennis. In addition, whereas the mixture of all three components attracted fewer L. rugulipennis males, this tertiary blend captured significantly greater numbers of males of the congeneric species Lygus pratensis than the binary mixture. The possible reasons for the success of the microcapillaries compared with other dispensers are discussed. PMID:16222779

Innocenzi, P J; Hall, D; Cross, J V; Hesketh, H

2005-06-01

190

A protective effect of circumcision among receptive male sex partners of Indian men who have sex with men.  

PubMed

The role of circumcision in the transmission of human immunodeficiency virus (HIV) among men who have sex with men (MSM) in resource restricted regions is poorly understood. This study explored the association of circumcision with HIV seroprevalence, in conjunction with other risk factors such as marriage and sex position, for a population of MSM in India. Participants (n = 387) were recruited from six drop-in centers in a large city in southern India. The overall HIV prevalence in this sample was high, at 18.6%. Bivariate and multivariable analyses revealed a concentration of risk among receptive only, married, and uncircumcised MSM, with HIV prevalence in this group reaching nearly 50%. The adjusted odds of HIV infection amongst circumcised men was less than one fifth that of uncircumcised men [adjusted odds ratio (AOR) 0.17; 95% CI 0.07-0.46; P < 0.001]. Within the group of receptive only MSM, infection was found to be lower among circumcised individuals (AOR, 0.30, 95% CI 0.12-0.76; P < 0.05) in the context of circumcised MSM engaging in more UAI, having a more recent same sex encounter and less lubricant use when compared to uncircumcised receptive men. To further explain these results, future studies should focus on epidemiologic analyses of risk, augmented by social and sexual network analyses of MSM mixing. PMID:21681562

Schneider, John A; Michaels, Stuart; Gandham, Sabitha R; McFadden, Rachel; Liao, Chuanhong; Yeldandi, Vijay V; Oruganti, Ganesh

2012-02-01

191

Short-term treatment of adult male zebrafish (Danio Rerio) with 17?-ethinyl estradiol affects the transcription of genes involved in development and male sex differentiation.  

PubMed

The synthetic estrogen 17?-ethinyl estradiol (EE2) disturbs reproduction and causes gonadal malformation in fish. Effects on the transcription of genes involved in gonad development and function that could serve as sensitive biomarkers of reproductive effects in the field is, however, not well known. We have studied mRNA expression in testes and liver of adult zebrafish (Danio rerio) males treated with 0, 5 or 25 ng/L EE2for 14 days. qPCR analysis showed that the mRNA expression of four genes linked to zebrafish male sex determination and differentiation, Anti-Mullerian Hormone, Double sex and mab-related protein, Sry-related HMG box-9a and Nuclear receptor subfamily 5 group number 1b were significantly decreased by 25 ng/L, but not 5 ng/L EE2 compared with the levels in untreated fish. The decreased transcription was correlated with a previously shown spawning failure in these males (Reyhanian et al., 2011. Aquat Toxicol 105, 41-48), suggesting that decreased mRNA expression of genes regulating male sexual function could be involved in the functional sterility. The mRNA level of Cytochrome P-45019a, involved in female reproductive development, was unaffected by hormone treatment. The transcription of the female-specific Vitellogenin was significantly induced in testes. While testicular Androgen Receptor and the Estrogen Receptor-alpha mRNA levels were unchanged, Estrogen receptor-beta was significantly decreased by 25 ng/L EE2. Hepatic Estrogen Receptor-alpha mRNA was significantly increased by both exposure concentrations, while Estrogen Receptor-beta transcription was unaltered. The decreased transcription of male-predominant genes supports a demasculinization of testes by EE2 and might reflect reproductive disturbances in the environment. PMID:24747828

Reyhanian Caspillo, Nasim; Volkova, Kristina; Hallgren, Stefan; Olsson, Per-Erik; Porsch-Hällström, Inger

2014-08-01

192

Male-specific, sex pheromone-selective projection neurons in the antennal lobes of the moth Manduca sexta  

Microsoft Academic Search

1.A subset of olfactory projection neurons in the brain of maleManduca sexta is described, and their role in sex pheromone information processing is examined.2.These neurons have extensive arborizations in the macroglomerular complex (MGC), a distinctive and sexually dimorphic area of neuropil in the antennal lobe (AL), to which the axons of two known classes of antennal pheromone receptors project. Each

Thomas A. Christensen; John G. Hildebrand

1987-01-01

193

The association between substance use and intimate partner violence within black male same-sex relationships.  

PubMed

Compared with the extant research on heterosexual intimate partner violence (IPV)-including the knowledge base on alcohol and illicit drug use as predictors of such IPV-there is a paucity of studies on IPV among men who have sex with men (MSM), especially Black MSM. This study investigates the prevalence of experiencing and perpetrating IPV among a sample of Black MSM couples and examines whether heavy drinking and/or illicit substance use is associated with IPV. We conducted a secondary analysis on a data set from 74 individuals (constituting 37 Black MSM couples) screened for inclusion in a couple-based HIV prevention pilot study targeting methamphetamine-involved couples. More than one third (n= 28, 38%) reported IPV at some point with the current partner: 24 both experiencing and perpetrating, 2 experiencing only, and 2 perpetrating only. IPV in the past 30 days was reported by 21 (28%) of the participants: 18 both experiencing and perpetrating, 1 experiencing only, and 2 perpetrating only. Heavy drinking and methamphetamine use each was associated significantly with experiencing and perpetrating IPV throughout the relationship as well as in the past 30 days. Rock/crack cocaine use was significantly associated with any history of experiencing and perpetrating IPV. Altogether, IPV rates in this sample of Black MSM couples equal or exceed those observed among women victimized by male partners as well as the general population of MSM. This exploratory study points to a critical need for further efforts to understand and address IPV among Black MSM. Similar to heterosexual IPV, results point to alcohol and illicit drug use treatment as important avenues to improve the health and social well-being of Black MSM. PMID:24919997

Wu, Elwin; El-Bassel, Nabila; McVinney, L Donald; Hess, Leona; Fopeano, Mark V; Hwang, Hyesung G; Charania, Mahnaz; Mansergh, Gordon

2015-03-01

194

New Sexing Strains for Mediterranean Fruit Fly Ceratitis capitata : Transforming Females into Males  

Microsoft Academic Search

Sex determination mechanisms, differing in their modality, are widely represented in all the various animal taxa, even at\\u000a the intraspecific level. Within the highly diversified class Insecta, Drosophila has been used to unravel the molecular and\\u000a genetic mechanistic interactions that are involved in sex determination. Indeed, the molecularly characterized genes of the\\u000a Drosophila sex determination hierarchy X:A > Sxl >

G. Saccone; A. Pane; A. DE SIMONE; M. Salvemini; A. Milano; L. Annunziata; U. Mauro; L. C. Polito

195

Religiosity and Determinants of Safe Sex in Iranian Non-Medical Male Students  

Microsoft Academic Search

This study evaluates the safe sex determinants in college students. In the qualitative section, premarital sex, sex with steady\\u000a girlfriend and religion’s impact were highlighted. In the quantitative part, the relations between the religiosity score and\\u000a past sexual activity, attitude, norms, and self-efficacy with regard to sexual abstinence were investigated. Students who\\u000a had a higher religious score were significantly more

Kambiz Karimzadeh Shirazi; Mohammad Ali Morowatisharifabad

2009-01-01

196

Do males hatch first and dominate sex ratios in White Stork Ciconia ciconia chicks?  

Microsoft Academic Search

Sex allocation has been a fertile topic in the development of evolutionary theory. The dominant models for vertebrates have\\u000a provided predictions of sex ratios based on asymmetry in breeding success between sexes and the relative effect of local competition.\\u000a In birds, empirical work has provided some support for these models, but has also generated apparently contradictory observations.\\u000a Recent models have

Piotr Tryjanowski; Tim H. Sparks; Marcin Bochenski; Miroslawa Dabert; Mariusz Kasprzak; Piotr Kaminski; Slawomir Mroczkowski; Ewa Wisniewska; Leszek Jerzak

2011-01-01

197

Offspring sex ratios reflect lack of repayment by auxiliary males in a cooperatively breeding passerine  

Microsoft Academic Search

The repayment hypothesis posits that primary sex ratios in cooperative species should be biased towards the helping sex because\\u000a these offspring “repay” a portion of their cost through helping behavior and therefore are less expensive to produce. However,\\u000a many cooperatively breeding birds and mammals do not show the predicted bias in the primary sex ratio. Recent theoretical\\u000a work has suggested

Claire W. Varian-Ramos; Jordan Karubian; Vanessa Talbott; Irma Tapia; Michael S. Webster

2010-01-01

198

Evolution of DMY, a Newly Emergent Male Sex-Determination Gene of Medaka Fish  

Microsoft Academic Search

The Japanese medaka fish Oryzias latipes has an XX\\/XY sex-determination system. The Y-linked sex-determi- nation gene DMY is a duplicate of the autosomal gene DMRT1, which encodes a DM-domain-containing transcriptional factor. DMY appears to have originated recently within Oryzias, allowing a detailed evolution- ary study of the initial steps that led to the new gene and new sex-determination system. Here

Jianzhi Zhang

2004-01-01

199

Increased reproductive effort results in male-biased offspring sex ratio: an experimental study in a species with reversed sexual size dimorphism.  

PubMed Central

Adaptive sex-ratio theory predicts that parents should overproduce the more beneficial offspring sex. Based on a recent experimental study of lesser black-backed gulls, we tested this hypothesis with the great skua, Catharacta skua, a bird species closely related to gulls but where females are the larger sex. When in poor body condition, the gulls overproduced daughters, the smaller and more viable sex under those circumstances. To discriminate between a mandatory physiological overproduction of female (i.e. non-male) eggs versus the overproduction of the smaller and presumably more viable sex, we conducted an egg-removal experiment with the great skua. Since the males are smaller, larger size and being male are separated. Through egg removal we induced females to increase egg production effort. Eggs were sexed using a DNA-based technique. Manipulated pairs produced a significant male bias at the end of the extended laying sequence, while the sex ratio in the control group did not differ from unity. Our results present an example of facultative sex-ratio manipulation and support the hypothesis that in sexually dimorphic birds parents overproduce the smaller sex under adverse conditions. PMID:11600083

Kalmbach, E.; Nager, R. G.; Griffiths, R.; Furness, R. W.

2001-01-01

200

Faced with inequality: chicken do not have a general dosage compensation of sex-linked genes  

Microsoft Academic Search

BACKGROUND: The contrasting dose of sex chromosomes in males and females potentially introduces a large-scale imbalance in levels of gene expression between sexes, and between sex chromosomes and autosomes. In many organisms, dosage compensation has thus evolved to equalize sex-linked gene expression in males and females. In mammals this is achieved by X chromosome inactivation and in flies and worms

Hans Ellegren; Lina Hultin-Rosenberg; Björn Brunström; Lennart Dencker; Kim Kultima; Birger Scholz

2007-01-01

201

Street Life and Drug Risk Behaviors Associated with Exchanging Sex Among Male Street Children in Lahore, Pakistan  

PubMed Central

Background Throughout the developing world, children living on urban streets is a byproduct of economic deprivation. In Lahore, Pakistan, there are an estimated 5,000–7,000 street children. Purpose The study examined HIV risk behaviors and factors associated with exchanging sex among male street children in Lahore, Pakistan. Methods The survey was conducted from August 2003 to March 2004 among 565 registrants, ages 5–19, of Project Smile, a program that aimed to enhance the lives of street children in Lahore. We analyzed the frequency of and correlates of recent (past three months) sex exchange for money, drugs, or goods. Multivariate log-binomial regression was used to evaluate the independent effect of covariates on exchange sex. Results Approximately 40% of participants reported having exchanged sex during the past three months. In multivariate analysis, the factors associated with exchanging sex were living on the street for longer than 48 months (Prevalence Ratio [PR]=1.36, 95% Confidence Interval [CI]: 0.99–1.85), reporting ever having used drugs (PR=1.87, 1.10–3.16), cutting one’s self (PR=1.66, 95% CI: 1.26–2.19), and having heard of HIV/AIDS (PR=1.36, 95% CI: 1.03–1.80) after adjusting for demographic and street life variables. Conclusions We found high rates of sex exchange among a sample of street children in Lahore, Pakistan. The finding that children who have heard about HIV/AIDS are more likely to exchange sex suggests that children at HIV risk talk about HIV, but accuracy of their conversations is unclear. Street children in Pakistan are in great need of HIV education and safe alternatives for generating income. PMID:19237107

Towe, Vivian L.; Hasan, Salman ul; Zafar, S. Tariq; Sherman, Susan G.

2009-01-01

202

Tricks of the trade: sexual health behaviors, the context of HIV risk, and potential prevention intervention strategies for male sex workers.  

PubMed

Sex work is a significant risk for HIV and sexually transmitted infection (STI) among men who have sex with men (MSM); however, there is a dearth of knowledge about how to reduce risk in this group. MSM sex workers (N = 32) completed a semistructured qualitative interview and a close-ended quantitative assessment. Analyses focused on themes relevant to intervention development. Participants reported an average of 46 male sex partners in the prior 12 months; 31% of participants were HIV-infected. Male sex workers frequently used substances during sex and had elevated levels of psychological distress. Qualitative findings suggest that trauma-informed mental health and substance abuse treatment, ready access to HIV/STI testing and treatment and condoms/informational materials, support groups to address isolation/loneliness, skill-building for risk reduction with sex partners, and paid incentives as add-ons to effective behavior change interventions may be valuable intervention components. Targeting consumers of paid/exchanged sex may assist with changing community norms regarding the practice of transactional sex. Multipronged interventions to decrease sexual risk taking among male sex workers would also benefit from addressing the unique socioeconomic and legal needs of this population. PMID:19928046

Reisner, Sari L; Mimiaga, Matthew J; Mayer, Kenneth H; Tinsley, Jake P; Safren, Steven A

2008-01-01

203

Male only progeny in Anastrepha suspensa by RNAi-induced sex reversion of chromosomal females  

Technology Transfer Automated Retrieval System (TEKTRAN)

In Tephritidae sex determination is established by orthologs to the Drosophila melanogaster transformer and transformer-2 genes. In contrast, primary signals for sex determination are different in these species corresponding to the number of X chromosomes (XSE) in Drosophilidae species and to the pr...

204

Concurrent modulation of neuronal and behavioural olfactory responses to sex and host plant cues in a male moth.  

PubMed

Mating has profound effects on animal physiology and behaviour, not only in females but also in males, which we show here for olfactory responses. In cotton leafworm moths, Spodoptera littoralis, odour-mediated attraction to sex pheromone and plant volatiles are modulated after mating, producing a behavioural response that matches the physiological condition of the male insect. Unmated males are attracted by upwind flight to sex pheromone released by calling females, as well as to volatiles of lilac flowers and green leaves of the host plant cotton, signalling adult food and mating sites, respectively. Mating temporarily abolishes male attraction to females and host plant odour, but does not diminish attraction to flowers. This behavioural modulation is correlated with a response modulation in the olfactory system, as shown by electro-physiological recordings from antennae and by functional imaging of the antennal lobe, using natural odours and synthetic compounds. An effect of mating on the olfactory responses to pheromone and cotton plant volatiles but not to lilac flowers indicates the presence of functionally independent neural circuits within the olfactory system. Our results indicate that these circuits interconnect and weigh perception of social and habitat odour signals to generate appropriate behavioural responses according to mating state. PMID:25621329

Kromann, Sophie H; Saveer, Ahmed M; Binyameen, Muhammad; Bengtsson, Marie; Birgersson, Göran; Hansson, Bill S; Schlyter, Fredrik; Witzgall, Peter; Ignell, Rickard; Becher, Paul G

2015-01-22

205

Function of the Male Gamete-Specific Fusion Protein, HAP2, in a Seven-Sexed Ciliate  

PubMed Central

Summary HAP2, a male gamete-specific protein conserved across vast evolutionary distances has garnered considerable attention as a potential membrane fusogen required for fertilization in taxa ranging from protozoa and green algae to flowering plants and invertebrate animals [1–6]. However, its presence in Tetrahymena thermophilaa ciliated protozoan with seven sexes or mating types that bypasses the production of male gametes raises interesting questions regarding the evolutionary origins of gamete-specific functions in sexually dimorphic species. Here we show that HAP2 is expressed in all seven mating types of T. thermophila and that fertility is only blocked when the gene is deleted from both cells of a mating pair. HAP2 deletion strains of complementary mating types can recognize one another and form pairs, however pair stability is compromised and membrane pore formation at the nuclear exchange junction is blocked. The absence of pore formation is consistent with previous studies suggesting a role for HAP2 in gamete fusion in other systems. We propose a model in which each of the several hundred membrane pores established at the conjugation junction of mating Tetrahymena represents the equivalent of a male/female interface, and that pore formation is driven on both sides of the junction by the presence of HAP2. Such a model supports the idea that many of the disparate functions of sperm and egg were shared by the “isogametes” of early eukaryotes, and became partitioned to either male or female sex cells later in evolution. PMID:25155508

Cole, Eric S.; Cassidy-Hanley, Donna; Pinello, Jennifer Fricke; Zeng, Hong; Hsueh, Marion; Kolbin, Daniel; Ozzello, Courtney; Giddings, Thomas; Winey, Mark; Clark, Theodore G.

2015-01-01

206

Social deficits in male children and adolescents with sex chromosome aneuploidy: a comparison of XXY, XYY, and XXYY syndromes.  

PubMed

We compare social skills in three groups of males with sex chromosome aneuploidies (SCAs) using the Social Responsiveness Scale (SRS). Participants included males with XXY (N=102, M=10.08 years), XYY (N=40, M=9.93 years), and XXYY (N=32, M=11.57 years). XXY had lower (better) SRS scores compared to XYY and XXYY. Scores were not significantly different between XYY and XXYY. In all groups, there were significantly more with SRS scores in the severe range compared to the SRS normative sample. All groups scored lowest (better) on Social Motivation. Relationships between SRS scores and demographic and clinical variables were examined. Results describe the social skills in males with SCA, and suggest that an additional Y chromosome may contribute to increased risk of autistic behaviors. PMID:22502852

Cordeiro, Lisa; Tartaglia, Nicole; Roeltgen, David; Ross, Judith

2012-01-01

207

Cross-sex hormone treatment in male-to-female transsexual persons reduces serum brain-derived neurotrophic factor (BDNF).  

PubMed

Serum levels of brain-derived neurotrophic factor (BDNF) are reduced in male-to-female transsexual persons (MtF) compared to male controls. It was hypothesized before that this might reflect either an involvement of BDNF in a biomechanism of transsexualism or to be the result of persistent social stress due to the condition. Here, we demonstrate that 12 month of cross-sex hormone treatment reduces serum BDNF levels in male-to-female transsexual persons independent of anthropometric measures. Participants were acquired through the European Network for the Investigation of Gender Incongruence (ENIGI). Reduced serum BDNF in MtF thus seems to be a result of hormonal treatment rather than a consequence or risk factor of transsexualism. PMID:25498415

Fuss, Johannes; Hellweg, Rainer; Van Caenegem, Eva; Briken, Peer; Stalla, Günter K; T'Sjoen, Guy; Auer, Matthias K

2015-01-01

208

Genetic method of combating the cabbage root fly. Part II. Localization of factor determining male sex in the cabbage root fly Delia brassicae bouche  

SciTech Connect

Cytogenetic analysis was conducted of 15 lines of the cabbage root fly with hereditary semisterility in the form of late embryonic lethals (LEL). In 14 lines (93%), the presence of translocations was noted. A high yield of translocations linked with the male sex was obtained, which was caused by the fact that determination of male sex in this species is apparently associated with the largest chromosome 6, and not with chromosome 1, as was believed previously.

Samoilov, Yu.B.

1986-05-01

209

Direct and Indirect Effects of a Sex?Biased Antagonist on Male and Female Fertility: Consequences for Reproductive Trait Evolution in a Gender?Dimorphic Plant  

Microsoft Academic Search

Gender-dimorphic plants are often subject to sex- differential enemy attack, but whether and how this contributes to trait evolution is unknown. To address this gap, we documented the spatiotemporal prevalence of sex-biased weevil damage in a gyno- dioecious strawberry. We then conducted path analysis to evaluate the direct and indirect pathways for weevils to affect female and male fertility and

Laurent Penet

2007-01-01

210

Caenorhabditis elegans Histone Methyltransferase MET-2 Shields the Male X Chromosome from Checkpoint Machinery and Mediates Meiotic Sex Chromosome Inactivation  

PubMed Central

Meiosis is a specialized form of cellular division that results in the precise halving of the genome to produce gametes for sexual reproduction. Checkpoints function during meiosis to detect errors and subsequently to activate a signaling cascade that prevents the formation of aneuploid gametes. Indeed, asynapsis of a homologous chromosome pair elicits a checkpoint response that can in turn trigger germline apoptosis. In a heterogametic germ line, however, sex chromosomes proceed through meiosis with unsynapsed regions and are not recognized by checkpoint machinery. We conducted a directed RNAi screen in Caenorhabditis elegans to identify regulatory factors that prevent recognition of heteromorphic sex chromosomes as unpaired and uncovered a role for the SET domain histone H3 lysine 9 histone methyltransferase (HMTase) MET-2 and two additional HMTases in shielding the male X from checkpoint machinery. We found that MET-2 also mediates the transcriptional silencing program of meiotic sex chromosome inactivation (MSCI) but not meiotic silencing of unsynapsed chromatin (MSUC), suggesting that these processes are distinct. Further, MSCI and checkpoint shielding can be uncoupled, as double-strand breaks targeted to an unpaired, transcriptionally silenced extra-chromosomal array induce checkpoint activation in germ lines depleted for met-2. In summary, our data uncover a mechanism by which repressive chromatin architecture enables checkpoint proteins to distinguish between the partnerless male X chromosome and asynapsed chromosomes thereby shielding the lone X from inappropriate activation of an apoptotic program. PMID:21909284

Checchi, Paula M.; Engebrecht, JoAnne

2011-01-01

211

On same-sex sexual behaviors among male bachelors in rural China: evidence from a female shortage context.  

PubMed

Using data from a survey conducted in the rural areas of Anhui Province, this study adopted the crosstabs and logistic regression model to analyze the same-sex sexual behaviors of forced male bachelors and the determinants when compared with married men with same ages. The prevalence of same-sex sexual behaviors among the unmarried men was reported as 17.2%, significantly higher than 8.9% among married men with same ages, indicating that same-sex sexual behaviors could be as a compensation for the absence of female sexual partners to some extent for those marriage squeezed or forced male bachelors. Among all groups, the occurrence of unprotected sexual behaviors were reported above 60%, regardless of marital status and the genders of sexual partners; the scores obtained on knowledge of acquired immune deficiency syndrome (AIDS) and sexually transmitted diseases (STDs) among bachelors (AIDS knowledge = 2.85; STDs knowledge = 2.38) are much poorer than those of married men (AIDS knowledge = 3.45; STDs knowledge = 2.79), which might exert potential negative impacts on men's health. PMID:21816858

Yang, Xueyan; Attané, Isabelle; Li, Shuzhuo; Zhang, Qunlin

2012-03-01

212

Sex hormones, gonadotropins and prolactin in male epileptic subjects in remission: role of the epileptic syndrome and of antiepileptic drugs.  

PubMed

Sex steroid peripheral pattern, pulsatile luteinizing hormone (LH) secretion, gonadotropin and prolactin responses to LH-releasing hormone (LHRH) and thyrotropin-releasing hormone (TRH) were studied in 35 male epileptics treated with phenobarbital (PB), carbamazepine (CBZ), or phenytoin (PHT), and in age-matched healthy males. Idiopathic generalized epilepsy (IGE) was diagnosed in 12 cases and partial epilepsy (PE) in 23 cases. Patients were seizure-free and did not show EEG abnormalities at repeated controls in the last 5 years, so that interfering effects of seizures were possibly excluded. The aim of the study was to evaluate both the role of epileptic syndromes and of anti-epileptic drugs on the endocrine function. Changes in sex hormone binding globulin, total and free testosterone, dihydrotestosterone and delta 4-androstenedione were found to be independent of the epileptic syndrome type. The LH response to LHRH was lower in PB-treated PE than in IGE subjects on the same drug regimen. An impairment of LH pulsatility with respect to controls was found in PE but not in IGE patients taking PB. Among antiepileptic drugs, PHT is associated with higher sex hormone binding globulin and estradiol and lower free testosterone and dihydrotestosterone levels. PB and CBZ, but not PHT, blunt the LH response to exogenous LHRH in PE. Prolactin responses to TRH were consistently enhanced in PE subjects treated with CBZ or PHT. PMID:7969856

Murialdo, G; Galimberti, C A; Fonzi, S; Manni, R; Costelli, P; Parodi, C; Torre, F; Solinas, G P; Polleri, A; Tartara, A

1994-01-01

213

Ontogeny and morphology of the bulbus, part of the male reproductive organ in Apis mellifera carnica  

E-print Network

Ontogeny and morphology of the bulbus, part of the male reproductive organ in Apis mellifera. morphology / ontogeny / ultrastructure / bulbus / endophallus / honeybees / drones 1. INTRODUCTION In most

214

The attraction of virgin female hide beetles (Dermestes maculatus) to cadavers by a combination of decomposition odour and male sex pheromones  

PubMed Central

Introduction The hide beetle Dermestes maculatus (Coleoptera: Dermestidae) feeds as an adult and larva on decomposing animal remains and can also be found on human corpses. Therefore, forensic entomological questions with regard to when and how the first receptive females appear on carcasses are important, as the developmental stages of their larvae can be used to calculate the post-mortem interval. To date, we know that freshly emerged males respond to the cadaver odour of post-bloated carcasses (approximately 9 days after death at Tmean = 27°C), being attracted by benzyl butyrate. This component occurs at its highest concentration at this stage of decay. The aim of our study was to determine the principle of attraction of virgin females to the feeding and breeding substrate. For this purpose, we tested the response of these females to headspace samples of piglet cadavers and male sex pheromones [(Z9)-unsaturated fatty acid isopropyl esters] in a Y-olfactometer. Because we expected that such an odour combination is of importance for virgin female attraction, we tested the following two questions: 1) Are virgin female hide beetles attracted by a combination of cadaver odour and male sex pheromones? 2) During which decomposition stage do the first virgin females respond to cadaver odour when combined with male sex pheromones? Results We found that young virgin females were attracted to the cadaver by a combination of cadaver odour and male sex pheromones. Neither cadaver odour alone nor male sex pheromones alone was significantly more attractive than a solvent control. Our results also gave a weak indication that the first young virgin females respond as early as the post-bloating stage to its associated decomposition odour when combined with male sex pheromones. Conclusions Our results indicate that freshly emerged males possibly respond to cadaver odour and visit carcasses before virgin females. Being attracted to cadavers when male sex pheromone is perceived as well, virgin females can optimise their reproductive possibilities. PMID:22889339

2012-01-01

215

Context matters: the moderating role of bar context in the association between substance use during sex and condom use among male clients of female sex workers in Tijuana, Mexico.  

PubMed

Tijuana is situated on Mexico's northern border with the U.S., where sex work is quasi-legal. Whereas previous work has focused on the risk behaviors of female sex workers (FSWs), less is known about the risk behaviors of their male clients. Further, research has not examined structural factors as moderators of the association between substance use and condom use, including the contexts in which sex takes place. The purpose of the current study is to examine whether having sex with FSWs in a bar moderates the link between alcohol intoxication during sex and condom use. We recruited 375 male clients of FSWs in Tijuana, Mexico from San Diego, California and Tijuana. Using computer assisted interviewing, we surveyed participants on their alcohol use, condom use, and physical contexts of sex with FSWs in the past 4 months. Results showed that more frequent intoxication during sex with FSWs is associated with more unprotected sex, but only among clients having sex with FSWs in a bar context. Results point to potential reasons for inconsistent condom use with FSWs in this context, including lower risk perceptions of sex with FSWs in bars. Future research should examine structural factors that underlie clients' risk behavior in bars in order to inform structural-level HIV prevention interventions. PMID:23640653

Pitpitan, Eileen V; Wagner, Karla D; Goodman-Meza, David; Semple, Shirley J; Chavarin, Claudia; Strathdee, Steffanie A; Patterson, Thomas L

2013-10-01

216

Childhood Attachment and Adult Attachment in Incarcerated Adult Male Sex Offenders  

Microsoft Academic Search

Forty-eight incarcerated sex offenders were compared with 16 property offenders and 16 nonoffenders on self-report measures of childhood maternal and paternal attachment and adult attachment. The combined sex-offender groups reported significantly less secure maternal, paternal, and adult attachment than did the nonoffenders and significantly less secure maternal attachment than did the property offenders. Intrafamilial child molesters were found to have

STEPHEN W. SMALLBONE; MARK R. DADDS

1998-01-01

217

Sexually Transmitted Infections among Heterosexual Male Clients of Female Sex Workers in China: A Systematic Review and Meta-Analysis  

PubMed Central

Background Female sex workers have been the target of numerous sexually transmitted infection (STI) prevention strategies in China, but their male clients have attracted considerably less public health attention and resources. We sought to systematically assess the prevalence of HIV, syphilis, gonorrhea, and chlamydia among heterosexual male clients of female sex workers in China. Methods/Principal Findings Original research manuscripts were identified by searching Chinese and English language databases, and 37 studies analyzing 26,552 male clients were included in the review. Client STI prevalence across studies was heterogeneous. Pooled prevalence estimates and 95% confidence intervals were 0.68% (0.36–1.28%) for HIV, 2.91% (2.17–3.89%) for syphilis, 2.16% (1.46–3.17%) for gonorrhea, and 8.01% (4.94–12.72%) for chlamydia. Conclusions/Significance The pooled prevalence estimates of HIV, syphilis, gonorrhea, and chlamydia among clients in this review exceed the prevalences previously reported among population-representative samples and low-risk groups in China. However, heterogeneity across studies and sampling limitations prevent definitive conclusions about how the prevalence of STIs in this population compares to the general population. These findings suggest a need for greater attention to clients’ sexual risk and disease prevalence in China’s STI research agenda in order to inform effective prevention policies. PMID:23951153

McLaughlin, Megan M.; Chow, Eric P. F.; Wang, Cheng; Yang, Li-Gang; Yang, Bin; Huang, Jennifer Z.; Wang, Yanjie; Zhang, Lei; Tucker, Joseph D.

2013-01-01

218

No evidence for increased extinction proneness with decreasing effective population size in a parasitoid with complementary sex determination and fertile diploid males  

PubMed Central

Background In species with single locus complementary sex determination (sl-CSD), the sex of individuals depends on their genotype at one single locus with multiple alleles. Haploid individuals are always males. Diploid individuals are females when heterozygous, but males when homozygous at the sex-determining locus. Diploid males are typically unviable or effectively sterile, hence imposing a genetic load on populations. Diploid males are produced from matings of partners that share an allele at the sex-determining locus. The lower the allelic diversity at the sex-determining locus, the more diploid males are produced, ultimately impairing the growth of populations and jeopardizing their persistence. The gregarious endoparasitoid wasp Cotesia glomerata is one of only two known species with sl-CSD and fertile diploid males. Results By manipulating the relatedness of the founders, we established replicated experimental populations of the parasitoid C. glomerata differing in their genetic effective size, and thus in allelic richness at the sex-determining locus and in the expected magnitude of diploid male production. Our long-term survey of population welfare and persistence did not provide evidence for increased proneness to population extinction with decreasing initial genetic effective population size. Most recorded surrogates of fitness nevertheless decayed over time and most experimental populations eventually went extinct, suggesting that the negative effects of inbreeding outweighed any premium from the fertility of diploid males. Conclusions The fertility of diploid males may have evolved as an adaptation prompted by the risk of extinction looming over small isolated populations of species with sl-CSD. However, fertility of diploid males does not negate the costs imposed by their production, and although it may temporarily stave off extinction, it is not sufficient to eradicate the negative effects of inbreeding. PMID:21110868

2010-01-01

219

Sexual competitiveness of Vienna 4\\/Tol-94 ‘genetic sexing’ sterile mediterranean fruit fly males in Israel  

Microsoft Academic Search

The sterile insect technique (SIT) is used as an environment-friendly means of suppressing Mediterranean fruit fly (Ceratitis capitata; ‘medfly’) populations in the Arava valley of Israel. The technique depends on released sterile males effectively wresting\\u000a the reproductive potential away from wild, fertile males. Studies carried out in other countries have indicated that sterile\\u000a males may sometimes be of inferior sexual

Phillip W. Taylor; Allon Bear; Yoav Gazit; Yoram Rössler

2001-01-01

220

Male-Killing Spiroplasma Induces Sex-Specific Cell Death via Host Apoptotic Pathway  

PubMed Central

Some symbiotic bacteria cause remarkable reproductive phenotypes like cytoplasmic incompatibility and male-killing in their host insects. Molecular and cellular mechanisms underlying these symbiont-induced reproductive pathologies are of great interest but poorly understood. In this study, Drosophila melanogaster and its native Spiroplasma symbiont strain MSRO were investigated as to how the host's molecular, cellular and morphogenetic pathways are involved in the symbiont-induced male-killing during embryogenesis. TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) staining, anti-cleaved-Caspase-3 antibody staining, and apoptosis-deficient mutant analysis unequivocally demonstrated that the host's apoptotic pathway is involved in Spiroplasma-induced male-specific embryonic cell death. Double-staining with TUNEL and an antibody recognizing epidermal marker showed that embryonic epithelium is the main target of Spiroplasma-induced male-specific apoptosis. Immunostaining with antibodies against markers of differentiated and precursor neural cells visualized severe neural defects specifically in Spiroplasma-infected male embryos as reported in previous studies. However, few TUNEL signals were detected in the degenerate nervous tissues of male embryos, and the Spiroplasma-induced neural defects in male embryos were not suppressed in an apoptosis-deficient host mutant. These results suggest the possibility that the apoptosis-dependent epidermal cell death and the apoptosis-independent neural malformation may represent different mechanisms underlying the Spiroplasma-induced male-killing. Despite the male-specific progressive embryonic abnormality, Spiroplasma titers remained almost constant throughout the observed stages of embryonic development and across male and female embryos. Strikingly, a few Spiroplasma-infected embryos exhibited gynandromorphism, wherein apoptotic cell death was restricted to male cells. These observations suggest that neither quantity nor proliferation of Spiroplasma cells but some Spiroplasma-derived factor(s) may be responsible for the expression of the male-killing phenotype. PMID:24550732

Harumoto, Toshiyuki; Anbutsu, Hisashi; Fukatsu, Takema

2014-01-01

221

Synchronous firing of antennal-lobe projection neurons encodes the behaviorally effective ratio of sex-pheromone components in male Manduca sexta  

PubMed Central

Olfactory stimuli that are essential to an animal's survival and reproduction are often complex mixtures of volatile organic compounds in characteristic proportions. Here, we investigated how these proportions are encoded in the primary olfactory processing center, the antennal lobe (AL), of male Manduca sexta moths. Two key components of the female's sex pheromone, present in an approximately 2:1 ratio, are processed in each of two neighboring glomeruli in the macroglomerular complex (MGC) of males of this species. In wind-tunnel flight experiments, males exhibited behavioral selectivity for ratios approximating the ratio released by conspecific females. The ratio between components was poorly represented, however, in the firing-rate output of uniglomerular MGC projection neurons (PNs). PN firing rate was mostly insensitive to the ratio between components, and individual PNs did not exhibit a preference for a particular ratio. Recording simultaneously from pairs of PNs in the same glomerulus, we found that the natural ratio between components elicited the most synchronous spikes, and altering the proportion of either component decreased the proportion of synchronous spikes. The degree of synchronous firing between PNs in the same glomerulus thus selectively encodes the natural ratio that most effectively evokes the natural behavioral response to pheromone. PMID:24002682

Martin, Joshua P.; Lei, Hong; Riffell, Jeffrey A.; Hildebrand, John G.

2013-01-01

222

Synchronous firing of antennal-lobe projection neurons encodes the behaviorally effective ratio of sex-pheromone components in male Manduca sexta.  

PubMed

Olfactory stimuli that are essential to an animal's survival and reproduction are often complex mixtures of volatile organic compounds in characteristic proportions. Here, we investigated how these proportions are encoded in the primary olfactory processing center, the antennal lobe, of male Manduca sexta moths. Two key components of the female's sex pheromone, present in an approximately 2:1 ratio, are processed in each of two neighboring glomeruli in the macroglomerular complex (MGC) of males of this species. In wind-tunnel flight experiments, males exhibited behavioral selectivity for ratios approximating the ratio released by conspecific females. The ratio between components was poorly represented, however, in the firing-rate output of uniglomerular MGC projection neurons (PNs). PN firing rate was mostly insensitive to the ratio between components, and individual PNs did not exhibit a preference for a particular ratio. Recording simultaneously from pairs of PNs in the same glomerulus, we found that the natural ratio between components elicited the most synchronous spikes, and altering the proportion of either component decreased the proportion of synchronous spikes. The degree of synchronous firing between PNs in the same glomerulus thus selectively encodes the natural ratio that most effectively evokes the natural behavioral response to pheromone. PMID:24002682

Martin, Joshua P; Lei, Hong; Riffell, Jeffrey A; Hildebrand, John G

2013-11-01

223

Expression patterns of sex-determination genes in single male and female embryos of two Bactrocera fruit fly species during early development.  

PubMed

In tephritids, the sex-determination pathway follows the sex-specific splicing of transformer (tra) mRNA, and the cooperation of tra and transformer-2 (tra-2) to effect the sex-specific splicing of doublesex (dsx), the genetic double-switch responsible for male or female somatic development. The Dominant Male Determiner (M) is the primary signal that controls this pathway. M, as yet uncharacterized, is Y-chromosome linked, expressed in the zygote and directly or indirectly diminishes active TRA protein in male embryos. Here we first demonstrated the high conservation of tra, tra-2 and dsx in two Australian tephritids, Bactrocera tryoni and Bactrocera jarvisi. We then used quantitative reverse transcription PCR on single, sexed embryos to examine expression of the key sex-determination genes during early embryogenesis. Individual embryos were sexed using molecular markers located on the B.?jarvisi?Y-chromosome that was also introgressed into a B.?tryoni line. In B.?jarvisi, sex-specific expression of tra transcripts occurred between 3 to 6?h after egg laying, and the dsx isoform was established by 7?h. These milestones were delayed in B.?tryoni lines. The results provide a time frame for transcriptomic analyses to identify M and its direct targets, plus information on genes that may be targeted for the development of male-only lines for pest management. PMID:25116961

Morrow, J L; Riegler, M; Frommer, M; Shearman, D C A

2014-12-01

224

Carotenoid-Based Ornaments of Female and Male American Goldfinches (Spinus tristis) Show Sex-Specific Correlations with Immune Function and Metabolic Rate  

Microsoft Academic Search

Conspicuous ornamentation has been linked to immunological and physiological condition in males of many species. In species where both sexes are ornamented, it is unclear whether the signal content of ornaments differs between males and females. We examined the immunological and physiological correlates of carotenoid-based bill and plumage ornamentation in American goldfinches Spinus tristis, a species in which bright orange

Ryan J. Kelly; Troy G. Murphy; Keith A. Tarvin; Gary Burness

2012-01-01

225

Battle of the sexes: forcibly inseminating male garter snakes target courtship to more vulnerable females  

Microsoft Academic Search

In communal dens of garter snakes, Thamnophis sirtalis, in Manitoba, males obtain copulations forcibly, by inducing hypoxic stress in females. Females emerging from their 8-month winter inactivity are weak and slow, but recover strength and speed within a day or two of emergence. Thus, males may benefit by target- ing newly emerged females that are too weak to resist, and

Richard Shine; Michael Wall; Tracy Langkilde; Robert T. Mason

2005-01-01

226

BROOD SEX RATIOS ARE RELATED TO MALE SIZE BUT NOT TO ATTRACTIVENESS IN COMMON YELLOWTHROATS  

E-print Network

(GEOTHLYPIS TRICHAS) B A , J C. G , M C. P , L A. W ,1 P O. D Department of Biological Sciences, P.O. Box 413. In the Common Yellowthroat (Geothlypis trichas), males with larger black facial masks are more likely to gain, Geothlypis trichas, male ornaments, paternity, sexual selection. El Cociente de Sexos en las Nidadas Está

Dunn, Peter O.

227

Effect of sex and dietary organic zinc on growth performance, carcass traits, tissue mineral content, and blood parameters of broiler chickens.  

PubMed

Zinc (Zn) is an essential mineral for animal development and function. A study was carried out to evaluate the effect of sex and dietary organic zinc (OZ) on growth performance, carcass traits, tissue mineral content, and blood parameters of broiler chickens. A total of 240 1-day-old male and 240 female broiler chicks (Cobb × Cobb) were assigned to two dietary levels of OZ (2 × 2 factorial) with six replicates per treatment (20 birds/replicate pen). The OZ supplementation levels were 0 and 25 ppm. Results showed that OZ supplementation did not affect the growth performance of male and female broilers, but the males showed significantly better (P < 0.05) growth performance than females did. Similarly, OZ supplementation did not affect the thickness of both the back and thigh skin of male and female broilers; however, males had thicker skin than females. Dietary OZ supplementation did not affect collagen contents in the skin and meat samples. Male broilers had higher skin collagen contents than females, but no sex difference was found in meat collagen contents. OZ supplementation did not affect the shear force values of skin and meat samples. Male broilers had higher shear force values of back skin than females, but not in the meat samples. Dietary OZ supplementation increased (P < 0.05) the thigh meat Zn content in both sexes. The plasma Ca content was significantly (P < 0.05) increased by dietary OZ supplementation; however, other blood parameters were not affected by dietary OZ supplementation. Males had higher plasma glucose and cholesterol content than females. It is concluded that dietary OZ supplementation at the level of 25 ppm does not affect the growth performance and skin quality of broiler chickens but increases the Zn content in thigh meat and Ca content in plasma of broiler chickens. Male broilers had better growth performance and skin quality than females. PMID:22167309

Salim, H M; Lee, H R; Jo, C; Lee, S K; Lee, Bong Duk

2012-06-01

228

DNA is organized into 46 chromosomes including sex chromosomes, 3D animation with no audioSite: DNA Interactive (www.dnai.org)  

NSDL National Science Digital Library

The millions of bases, which make up the human genome are organized into structures called chromosomes. These are arranged into 22 matching pairs plus 1 pair of sex chromosomes consisting of 2 X's in women and an X and a Y in men. So humans have a total of 46 chromosomes in each cell, known collectively as a karyotype. This set of chromosomes has a Y, so it must belong to a male.

2008-10-06

229

Assisting gay men to maintain safer sex: an evaluation of an AIDS service organization's safer sex maintenance program.  

PubMed

As the second decade of the AIDS crisis unfolds, increasing concern has been raised that the widespread adoption of condom use that occurred among gay men in the 1980s is not being maintained. Most interventions to promote condom use among gay men are delivered by community-based organizations via programs that are virtually undocumented; little is known about their effectiveness, or the processes by which they may work. This study describes safer sex practices among self-identified gay men following their participation in an intervention developed and implemented by a community-based organization. The intervention was designed to enhance men's attitudes, beliefs, and self-efficacy expectations to maintain safer sex. Among 150 men with complete data at both assessments, self-reported condom use was low. Men reported using condoms more consistently for anal sexual behavior than oral sexual behavior, but there were men who reported consistent unprotected anal sexual intercourse. The intervention had little impact on patterns of behavior over time, although desired changes in attitudes, beliefs, and self-efficacy expectations were evidenced following the intervention. The results suggest the importance of assisting community-based organizations to document program models. Findings also suggest that community-based organizations can develop interventions to successfully enhance factors that theoretically support maintenance of safer sexual behaviors. PMID:8664098

Miller, R L

1995-01-01

230

Boredom Proneness, Social Connectedness, and Sexual Addiction among Men Who Have Sex with Male Internet Users  

ERIC Educational Resources Information Center

The authors collected surveys from 517 men who have sex with men (MSM) recruited from Internet chat rooms to examine the relationships among boredom, social connectedness, and sexual addiction. The results provide addictions professionals psychosocial factors to assess when working with sexually addicted MSM. (Contains 3 tables.)

Chaney, Michael P.; Blalock, Andrew C.

2006-01-01

231

Assessment of Deviant Arousal in Adult Male Sex Offenders with Developmental Disabilities  

ERIC Educational Resources Information Center

Ten individuals, residing in a treatment facility specializing in the rehabilitation of sex offenders with developmental disabilities, participated in an arousal assessment involving the use of the penile plethysmograph. The arousal assessments involved measuring change in penile circumference to various categories of stimuli both appropriate…

Reyes, Jorge R.; Vollmer, Timothy R.; Sloman, Kimberly N.; Hall, Astrid; Reed, Robert; Jansen, Greg; Carr, Sam; Jackson, Kevin; Stoutimore, Michael

2006-01-01

232

Perceptions about HIV and condoms and consistent condom use among male clients of commercial sex workers in the Philippines.  

PubMed

Because consistent condom use is an effective strategy in the prevention of sexually transmitted infections and HIV transmission, it is important to examine social cognitive influences of consistent condom use not only among female sex workers (FSWs) but also among their male clients, for whom less is known. Because little is known about how HIV knowledge and condom attitudes affect condom use among male clients of FSWs in the Philippines, the main objective was to determine what characteristics (age, education, HIV knowledge, marital status) as well as attributes taken from protection motivation theory (perceived vulnerability, perceived severity, response efficacy) are significantly associated with consistent condom use among male clients of FSWs. Logistic regression analyses showed that the odds of using condoms consistently with an FSW are 13% higher for those with more years of education (adjusted odds ratio [AOR] = 1.13; 95% confidence interval [CI] = 1.03, 1.23), higher versus lower perception of severity of HIV/AIDS (AOR = 1.97; 95% CI = 1.04, 3.73), and had a higher score for response efficacy of condoms (AOR = 1.14; 95% CI = 1.03, 1.27). Future HIV/AIDS prevention interventions that address condom use among male clients should promote educational attainment and focus on awareness of the enduring negative health consequences of acquiring HIV/AIDS, as well as cultivate positive attitudes toward the efficacy of condom use, using creative social marketing strategies. PMID:22773598

Regan, Rotrease; Morisky, Donald E

2013-04-01

233

Sex-specific survival rates of adult roseate terns: are males paying a higher reproductive cost than females?  

USGS Publications Warehouse

A long-term mark-recapture/resighting program has been carried out on the Roseate Terns (Sterna dougallii) nesting at Falkner Island, Connecticut, USA from the late 1980s through the mid 2000s, and from 1995-1998 an intensive collaborative study of food-provisioning of chicks by their parents also was conducted on many of the banded individuals at this site. Adult female Roseate Terns have significantly higher 'local survival' rates than do males. While both sexes feed their young, males usually have higher prey delivery rates than do females and do most feeding of the (oldest if more than one) chick just before it fledges. Males usually depart at the same time as the (oldest) fledgling, while successful females parents may linger at the colony site for up to two weeks. The lower 'local survival' rate of males probably does not represent lower colony-site fidelity, but instead may reflect the price they pay for doing more 'child care,' especially if fledglings are still dependant on them for food during post breeding dispersal and (at least early) migration.

Spendelow, J.A.; Shealer, D.A.; Hatfield, J.S.; Nichols, J.D.; Nisbet, I.C.T.

2005-01-01

234

Is the rate of insertion and deletion mutation male biased?: Molecular evolutionary analysis of avian and primate sex chromosome sequences.  

PubMed Central

The rate of mutation for nucleotide substitution is generally higher among males than among females, likely owing to the larger number of DNA replications in spermatogenesis than in oogenesis. For insertion and deletion (indel) mutations, data from a few human genetic disease loci indicate that the two sexes may mutate at similar rates, possibly because such mutations arise in connection with meiotic crossing over. To address origin- and sex-specific rates of indel mutation we have conducted the first large-scale molecular evolutionary analysis of indels in noncoding DNA sequences from sex chromosomes. The rates are similar on the X and Y chromosomes of primates but about twice as high on the avian Z chromosome as on the W chromosome. The fact that indels are not uncommon on the nonrecombining Y and W chromosomes excludes meiotic crossing over as the main cause of indel mutation. On the other hand, the similar rates on X and Y indicate that the number of DNA replications (higher for Y than for X) is also not the main factor. Our observations are therefore consistent with a role of both DNA replication and recombination in the generation of short insertion and deletion mutations. A significant excess of deletion compared to insertion events is observed on the avian W chromosome, consistent with gradual DNA loss on a nonrecombining chromosome. PMID:12750337

Sundström, Hannah; Webster, Matthew T; Ellegren, Hans

2003-01-01

235

The male-produced sex pheromone of the true bug, Phthia picta, is an unusual hydrocarbon.  

PubMed

Phthia picta is part of a complex of true bugs (Heteroptera) in Brazil that attack tomatoes, being particularly damaging because nymphs and adults feed on both leaves and fruit. Gas chromatography (GC) of aeration extracts of adult males vs. females revealed the presence of a male-specific compound. GC-electroantennographic detector experiments indicated that the antennae of females are highly sensitive to this male-specific compound. GC-mass spectrometry and GC-FTIR analyses suggested a methyl branched hydrocarbon structure for this compound. After synthesis of three different proposed structures, the natural product was indentified as 5,9,17-trimethylhenicosane, which was strongly attractive to females in Y-tube olfactometer bioassays. Analysis of dissected body parts of adults revealed that the pheromone is produced in the lateral accessory glands of the metathoracic scent gland of males only. PMID:22723201

Soldi, Rafael A; Rodrigues, Mauro A C M; Aldrich, Jeffrey R; Zarbin, Paulo H G

2012-07-01

236

Dopaminergic control of male sex behavior in rats: Effects of an intracerebrally-infused agonist  

Microsoft Academic Search

Systemically-administered dopaminergic drugs have been found to facilitate sexual behavior of men and male rats. The present ex- periments investigated the localization within the brain of dopaminergic effects on copulation of male rats. Apomorphine, a dopamine agonist, was microinfused into the medial preoptic area, caudate-putamen, nucleus accumbens, lateral septum and lateral ventricle. The lowest dose of apomorphine (0.2 pg) infused

ELAINE M. HULL; DANIEL BITRAN; ELIZABETH A. PEHEK; ROBERT K. WARNER; LINDA C. BAND; GREGORY M. HOLMES

1986-01-01

237

Sex, Lies, and Video Games: The Portrayal of Male and Female Characters on Video Game Covers  

Microsoft Academic Search

Two hundred twenty-five console video game covers obtained from online retail sites were examined for portrayals of men and\\u000a women. We hypothesized that males would be portrayed more often, but that females would be portrayed in a more hyper-sexualized\\u000a manner. Male characters were almost four times more frequently portrayed than female characters and were given significantly\\u000a more game relevant action.

Melinda C. R. Burgess; Steven Paul Stermer; Stephen R. Burgess

2007-01-01

238

Sex proportion of offspring and exposure to radiation in male invasive cardiologists  

PubMed Central

High radiation exposure among male radiologists has been reported to result in a significantly higher proportion of female offspring. This study examined whether work-related radiation exposure was associated with a higher propensity for female offspring among male interventional cardiologists. On behalf of the interventional committee of the Society for Cardiovascular Angiography and Interventions, an Internet-based questionnaire was sent to the society's 2063 members. The 402 male respondents had a total of 518 biological offspring; 48.6% of them were female. Among the 172 high-volume male diagnostic operators (those who performed >300 cases annually), there were 218 biological offspring, of whom 46.8% were female. Among the 59 high-volume male interventional operators, there were 70 biological offspring, of whom 45.7% were female. P values were nonsignificant for all three groups. In conclusion, work-related radiation exposure of male invasive and interventional cardiologists was not associated with a statistically significant preponderance of female offspring. PMID:17637874

Mehrotra, Praveen; MacDonald, Lee A.; Klein, Lloyd W.; Linsky, Norm M.; Smith, Anne M.; Ricciardi, Mark J.

2007-01-01

239

Developmental alterations of the C. elegans male anal depressor morphology and function require sex-specific cell autonomous and cell non-autonomous interactions.  

PubMed

We studied the Caenorhabditis elegans anal depressor development in larval males and hermaphrodites to address how a differentiated cell sex-specifically changes its morphology prior to adulthood. In both sexes, the larval anal depressor muscle is used for defecation behavior. However in the adult males, the muscle's sarcomere is reorganized to facilitate copulation. To address when the changes occur in the anal depressor, we used YFP:actin to monitor, and mutant analysis, laser-ablation and transgenic feminization to perturb the cell's morphological dynamics. In L1 and L2 stage larva, the muscle of both sexes has similar sarcomere morphology, but the hermaphrodite sex-determination system promotes more growth. The male anal depressor begins to change in the L3 stage, first by retracting its muscle arm from the neurons of the defecation circuit. Then the muscle's ventral region develops a slit that demarcates an anterior and posterior domain. This demarcation is not dependent on the anal depressor's intrinsic genetic sex, but is influenced by extrinsic interactions with the developing male sex muscles. However, subsequent changes are dependent on the cell's sex. In the L4 stage, the anterior domain first disassembles the dorsal-ventral sarcomere region and develops filopodia that elongates anteriorly towards the spicule muscles. Later, the posterior domain dissembles the remnants of its sarcomere, but still retains a vestigial attachment to the ventral body wall. Finally, the anterior domain attaches to the sex muscles, and then reassembles an anterior-posteriorly oriented sarcomere. Our work identifies key steps in the dimorphic re-sculpting of the anal depressor that are regulated by genetic sex and by cell-cell signaling. PMID:25498482

Chen, Xin; René García, L

2015-02-01

240

Population- and Sex-Biased Gene Expression in the Excretion Organs of Drosophila melanogaster  

PubMed Central

Within species, levels of gene expression typically vary greatly between tissues, sexes, individuals, and populations. To investigate gene expression variation between sexes and populations in a single somatic tissue, we performed a quantitative analysis of the Malpighian tubule transcriptome in adult males and females of Drosophila melanogaster derived from two distinct populations (one from sub-Saharan Africa and one from northern Europe). We identified 2308 genes that differed in expression between the sexes and 2474 genes that differed in expression between populations at a false discovery rate of 5%. We also identified more than 1000 genes that showed a sex-by-population interaction in their expression. The genes that differed in expression between sexes showed enrichment for a wide variety of functions, although only 55% of them overlapped with sex-biased genes identified in whole-fly studies. The genes expressed differentially between populations included several that were previously implicated in adaptive regulatory evolution, an excess of cytochrome P450 genes, and many genes that were not detected in previous studies of whole flies. Our results demonstrate that there is abundant intraspecific gene expression variation within in a single, somatic tissue and uncover new candidates for adaptive regulatory evolution between populations. PMID:25246242

Huylmans, Ann Kathrin; Parsch, John

2014-01-01

241

Determinants of parental care and offspring survival during the post-fledging period: males care more in a species with partially reversed sex roles.  

PubMed

Sexual conflict is magnified during the post-fledging period of birds when the sexes face different trade-offs between continuing parental care or investing in self maintenance or other mating opportunities. Species with reversed sex roles provide a unique opportunity to study the relationship between mating systems and investment in parental care. Here, we provide the first detailed study of the length of care by males versus females (n = 24 pairs) during the post-fledging period, assessing factors that may promote care within and between the sexes. In the northern flicker Colaptes auratus, a species with partly reversed sex roles, males cared longer than females (average 16 versus 12 days, respectively). Overall, 36% of females but no males deserted the brood prior to fledgling independence. Parents that provisioned nestlings at a high rate also spent more days feeding fledglings. Among males, age and nestling feeding rates were positively associated with the length of care. Among females, a low level of feather corticosterone (CORTf) was associated with a longer length of care. About 45% of fledglings died within the first week, but fledglings with intermediate body mass had the highest survival suggesting stabilizing selection on mass. Fledgling survival was also higher in individuals with larger broods and lower levels of CORTf. We demonstrate that because females can be polyandrous they often desert the brood before males, and that the sexes respond to different cues relating to their energy balance when deciding the length of care given to their offspring. PMID:24496554

Gow, Elizabeth A; Wiebe, Karen L

2014-05-01

242

RNAi-Mediated Gene Silencing in a Gonad Organ Culture to Study Sex Determination Mechanisms in Sea Turtle  

PubMed Central

The autosomal Sry-related gene, Sox9, encodes a transcription factor, which performs an important role in testis differentiation in mammals. In several reptiles, Sox9 is differentially expressed in gonads, showing a significant upregulation during the thermo-sensitive period (TSP) at the male-promoting temperature, consistent with the idea that SOX9 plays a central role in the male pathway. However, in spite of numerous studies, it remains unclear how SOX9 functions during this event. In the present work, we developed an RNAi-based method for silencing Sox9 in an in vitro gonad culture system for the sea turtle, Lepidochelys olivacea. Gonads were dissected as soon as the embryos entered the TSP and were maintained in organ culture. Transfection of siRNA resulted in the decrease of both Sox9 mRNA and protein. Furthermore, we found coordinated expression patterns for Sox9 and the anti-Müllerian hormone gene, Amh, suggesting that SOX9 could directly or indirectly regulate Amh expression, as it occurs in mammals. These results demonstrate an in vitro method to knockdown endogenous genes in gonads from a sea turtle, which represents a novel approach to investigate the roles of important genes involved in sex determination or differentiation pathways in species with temperature-dependent sex determination. PMID:24705165

Sifuentes-Romero, Itzel; Merchant-Larios, Horacio; Milton, Sarah L.; Moreno-Mendoza, Norma; Díaz-Hernández, Verónica; García-Gasca, Alejandra

2013-01-01

243

Preferred and actual relative height among homosexual male partners vary with preferred dominance and sex role.  

PubMed

Previous research has shown repeatedly that human stature influences mate preferences and mate choice in heterosexuals. In general, it has been shown that tall men and average height women are most preferred by the opposite sex, and that both sexes prefer to be in a relationship where the man is taller than the woman. However, little is known about such partner preferences in homosexual individuals. Based on an online survey of a large sample of non-heterosexual men (N = 541), we found that the majority of men prefer a partner slightly taller than themselves. However, these preferences were dependent on the participant's own height, such that taller men preferred shorter partners, whereas shorter men preferred taller partners. We also examined whether height preferences predicted the preference for dominance and the adoption of particular sexual roles within a couple. Although a large proportion of men preferred to be in an egalitarian relationship with respect to preferred dominance (although not with respect to preferred sexual role), men that preferred a more dominant and more "active" sexual role preferred shorter partners, whereas those that preferred a more submissive and more "passive" sexual role preferred taller partners. Our results indicate that preferences for relative height in homosexual men are modulated by own height, preferred dominance and sex role, and do not simply resemble those of heterosexual women or men. PMID:24466136

Valentova, Jaroslava Varella; Stulp, Gert; T?ebický, Vít; Havlí?ek, Jan

2014-01-01

244

Stumbling into sexual crime: the passive perpetrator in accounts by male internet sex offenders.  

PubMed

Public reactions to internet child offending remain ambivalent in that, while there is vocal condemnation of contact child sex offending, there is less indignation about internet child abuse. This is potentially due to a lack of recognition of this type of offence as sexual offending per se. This ambiguity is reflected by internet sex offenders themselves in their verbalizations of their offending. This article presents a qualitative analysis of the accounts offered by seven individuals convicted of internet-based sexual offences involving the downloading and viewing of images of children. In particular, this article presents an analysis of the explanations of offenders for the commencement of internet activity and the progression to more illicit online materials. The data were collected through semi-structured interviews and analyzed using discursive methods, paying close attention to language use and function. The analysis documented the practices that internet child abusers employed in order to manage their identities, distance themselves from the label of sex offender, and/or reduce their personal agency and accountability. Implications of this analysis are discussed with reference to the current minimization of the downloading of sexually explicit images of children as a sexual crime per se by the public and offenders alike and the risk assessment and treatment of individuals convicted of these offences. PMID:24917484

Winder, Belinda; Gough, Brendan; Seymour-Smith, Sarah

2015-01-01

245

Preferred and Actual Relative Height among Homosexual Male Partners Vary with Preferred Dominance and Sex Role  

PubMed Central

Previous research has shown repeatedly that human stature influences mate preferences and mate choice in heterosexuals. In general, it has been shown that tall men and average height women are most preferred by the opposite sex, and that both sexes prefer to be in a relationship where the man is taller than the woman. However, little is known about such partner preferences in homosexual individuals. Based on an online survey of a large sample of non-heterosexual men (N?=?541), we found that the majority of men prefer a partner slightly taller than themselves. However, these preferences were dependent on the participant’s own height, such that taller men preferred shorter partners, whereas shorter men preferred taller partners. We also examined whether height preferences predicted the preference for dominance and the adoption of particular sexual roles within a couple. Although a large proportion of men preferred to be in an egalitarian relationship with respect to preferred dominance (although not with respect to preferred sexual role), men that preferred a more dominant and more “active” sexual role preferred shorter partners, whereas those that preferred a more submissive and more “passive” sexual role preferred taller partners. Our results indicate that preferences for relative height in homosexual men are modulated by own height, preferred dominance and sex role, and do not simply resemble those of heterosexual women or men. PMID:24466136

Valentova, Jaroslava Varella; Stulp, Gert; T?ebický, Vít; Havlí?ek, Jan

2014-01-01

246

Conserved synteny between the chicken Z sex chromosome and human chromosome 9 includes the male regulatory gene DMRT1: a comparative (re)view on avian sex determination  

Microsoft Academic Search

Sex-determination mechanisms in birds and mammals evolved independently for more than 300 million years. Unlike mammals, sex determination in birds operates through a ZZ\\/ZW sex chromosome system, in which the female is the heterogametic sex. However, the molecular mechanism remains to be elucidated. Comparative gene mapping revealed that several genes on human chromosome 9 (HSA 9) have homologs on the

I. Nanda; E. Zend-Ajusch; Z. Shan; F. Grützner; M. Schartl; D. W. Burt; M. Koehler; V. M. Fowler; G. Goodwin; W. J. Schneider; S. Mizuno; G. Dechant; T. Haaf; M. Schmid

2000-01-01

247

The YWCA as a Single Sex Organization - Would It Survive a Legal Challenge?  

Microsoft Academic Search

Section I of this article will discuss how the forces affecting all-male organizations, specifically economic constraints and legal challenges, might affect all-female organizations by using as a case study the Young Women's Christian Association (hereinafter referred to as the YWCA). This section will examine the history of the YWCA as a women's organization and the legal, psychological and sociological issues

Rosanne Calbo

2010-01-01

248

Effects of steroid sex hormones on chick embryo gonads in organ culture, with special reference to hormonal control  

E-print Network

Effects of steroid sex hormones on chick embryo gonads in organ culture, with special reference to hormonal control of gonadal sex differentiation J. JORDANOV Pavlina ANGELOVA lnstitute of Morpho. At the initial stages of sex differentiation (7.5 and 8.5 days of incubation chick embryo gonads were treated

Paris-Sud XI, Université de

249

Female sex pheromone and male behavioral responses of the bombycid moth Trilocha varians: comparison with those of the domesticated silkmoth Bombyx mori  

NASA Astrophysics Data System (ADS)

Analysis of female sex pheromone components and subsequent field trap experiments demonstrated that the bombycid moth Trilocha varians uses a mixture of ( E, Z)-10,12-hexadecadienal (bombykal) and ( E,Z)-10,12-hexadecadienyl acetate (bombykyl acetate) as a sex pheromone. Both of these components are derivatives of ( E,Z)-10,12-hexadecadienol (bombykol), the sex pheromone of the domesticated silkmoth Bombyx mori. This finding prompted us to compare the antennal and behavioral responses of T. varians and B. mori to bombykol, bombykal, and bombykyl acetate in detail. The antennae of T. varians males responded to bombykal and bombykyl acetate but not to bombykol, and males were attracted only when lures contained both bombykal and bombykyl acetate. In contrast, the antennae of B. mori males responded to all the three components. Behavioral analysis showed that B. mori males responded to neither bombykal nor bombykyl acetate. Meanwhile, the wing fluttering response of B. mori males to bombykol was strongly inhibited by bombykal and bombykyl acetate, thereby indicating that bombykal and bombykyl acetate act as behavioral antagonists for B. mori males. T. varians would serve as a reference species for B. mori in future investigations into the molecular mechanisms underlying the evolution of sex pheromone communication systems in bombycid moths.

Daimon, Takaaki; Fujii, Takeshi; Yago, Masaya; Hsu, Yu-Feng; Nakajima, Yumiko; Fujii, Tsuguru; Katsuma, Susumu; Ishikawa, Yukio; Shimada, Toru

2012-03-01

250

Genetic Control of Male Germ Unit Organization in Arabidopsis  

Microsoft Academic Search

In flowering plants, the vegetative nucleus and the two sperm cells are proposed to form a functional assemblage, the male germ unit (MGU). Here, we describe the developmental pathway of MGU assembly in Arabidopsis and report two classes of mutations that affect the integrity and\\/or the positioning of the MGU in the mature pollen grain. In germ unit malformed (gum)

Eric Lalanne; David Twell

2002-01-01

251

Age, sex, reproduction, and spatial organization of lynxes colonizing northeastern Minnesota  

USGS Publications Warehouse

From 1972 through 1978, lynxes (Felis lynx) emigrating from Canada were studied in northeastern Minnesota. Fourteen individuals were radio-tracked, 8 wefe ear-tagged, and 49 carcasses were examined. Sex ratios of the samples were equal during the first years of the study, but females predominated later. At least half of the radiotagged lynxes were killed by humans; no natural mortality was detected. Home range sizes ranged from 51 to 122 km2 for females and 145 to 243 km2 for males, up to 10 times the sizes of those reported by other workers. Ranges of females tended to overlap. Males and females appeared to be segregated in the population.

Mech, L.D.

1980-01-01

252

The Effects of Single-Sex Mathematics Classrooms on African American Males in the Ninth Grade  

ERIC Educational Resources Information Center

Research indicated that educators must consider socio-ecological accommodations because not all students learn in cooperative groups. Students must be taught how to discover the process of learning and to apply knowledge to real life situations. Gurian and Ballew (2003) identified differences in the male and female brain and the differences in how…

Faulkner-Simmons, Denise

2012-01-01

253

Sex hormones and male health: effects on components of the frailty syndrome  

Microsoft Academic Search

Physicians are seeing an increasing number of older male patients with chronic diseases and conditions. However, the potential relevance of low levels of circulating endogenous androgens in connection with these diseases and conditions is generally poorly understood. Research findings have suggested that androgens play a distinct role in bone metabolism, body composition such as muscle and fat mass and fat

Majon Muller; Diederick E. Grobbee; Jos H. H. Thijssen; Annewieke W. van den Beld; Yvonne T. van der Schouw

2003-01-01

254

The effects of topiramate and sex hormones on energy balance of male and female rats  

Microsoft Academic Search

OBJECTIVE: The effects of topiramate (TPM) on components of energy balance were tested in male and female rats that were (i) left intact, (ii) castrated or (iii) castrated with replacement therapies consisting of testosterone administration in orchidectomized (OCX) rats and of estradiol or progesterone treatments in ovariectomized (OVX) rats.METHODS: TPM was mixed into the diet and administered at a dose

D Richard; F Picard; C Lemieux; J Lalonde; P Samson; Y Deshaies

2002-01-01

255

Night flight towards a sex pheromone source by male Spodoptera littoralis (Boisd.) (Lepidoptera, Noctuidae)  

Microsoft Academic Search

PHEROMONES have been used in population monitoring traps1 and in control by `confusion'2, and a good understanding of how the male finds the female is of great practical importance in the development of these techniques. The problem of insect orientation towards distant odour sources is also intrinsically interesting and much work has been done with wind tunnels to study the

J. Murlis; B. W. Bettany

1977-01-01

256

The Cost of Sex: Quantifying Energetic Investment in Gamete Production by Males and Females  

E-print Network

, reptiles, amphibians, fishes, birds, and mammals), we compared the cost of gamete production between to the intensity of postcopulatory sexual selection in the form of sperm competition: Males experiencing greater sperm competition are expected to invest relatively more biomass in gonads and produce sperm

Gillooly, Jamie

257

Opinion: Sex, Gender and the Diagnosis of Autism--A Biosocial View of the Male Preponderance  

ERIC Educational Resources Information Center

Autism Spectrum Disorders (ASD) are behaviorally defined neurodevelopmental disorders. The best known yet less understood characteristic of autism is its unexplained male preponderance. Using a biosocial perspective, the goal of this article is to draw attention to the role of gender-based socialization practices and behavioral expectations during…

Goldman, Sylvie

2013-01-01

258

Inherited human sex reversal due to impaired nucleocytoplasmic trafficking of SRY defines a male transcriptional threshold.  

PubMed

Human testis determination is initiated by SRY (sex determining region on Y chromosome). Mutations in SRY cause gonadal dysgenesis with female somatic phenotype. Two subtle variants (V60L and I90M in the high-mobility group box) define inherited alleles shared by an XY sterile daughter and fertile father. Whereas specific DNA binding and bending are unaffected in a rat embryonic pre-Sertoli cell line, the variants exhibited selective defects in nucleocytoplasmic shuttling due to impaired nuclear import (V60L; mediated by Exportin-4) or export (I90M; mediated by chromosome region maintenance 1). Decreased shuttling limits nuclear accumulation of phosphorylated (activated) SRY, in turn reducing occupancy of DNA sites regulating Sertoli-cell differentiation [the testis-specific SRY-box 9 (Sox9) enhancer]. Despite distinct patterns of biochemical and cell-biological perturbations, V60L and I90M each attenuated Sox9 expression in transient transfection assays by twofold. Such attenuation was also observed in studies of V60A, a clinical variant associated with ovotestes and hence ambiguity between divergent cell fates. This shared twofold threshold is reminiscent of autosomal syndromes of transcription-factor haploinsufficiency, including XY sex reversal associated with mutations in SOX9. Our results demonstrate that nucleocytoplasmic shuttling of SRY is necessary for robust initiation of testicular development. Although also characteristic of ungulate orthologs, such shuttling is not conserved among rodents wherein impaired nuclear export of the high-mobility group box and import-dependent phosphorylation are compensated by a microsatellite-associated transcriptional activation domain. Human sex reversal due to subtle defects in the nucleocytoplasmic shuttling of SRY suggests that its transcriptional activity lies near the edge of developmental ambiguity. PMID:24003159

Chen, Yen-Shan; Racca, Joseph D; Phillips, Nelson B; Weiss, Michael A

2013-09-17

259

Inherited human sex reversal due to impaired nucleocytoplasmic trafficking of SRY defines a male transcriptional threshold  

PubMed Central

Human testis determination is initiated by SRY (sex determining region on Y chromosome). Mutations in SRY cause gonadal dysgenesis with female somatic phenotype. Two subtle variants (V60L and I90M in the high-mobility group box) define inherited alleles shared by an XY sterile daughter and fertile father. Whereas specific DNA binding and bending are unaffected in a rat embryonic pre-Sertoli cell line, the variants exhibited selective defects in nucleocytoplasmic shuttling due to impaired nuclear import (V60L; mediated by Exportin-4) or export (I90M; mediated by chromosome region maintenance 1). Decreased shuttling limits nuclear accumulation of phosphorylated (activated) SRY, in turn reducing occupancy of DNA sites regulating Sertoli-cell differentiation [the testis-specific SRY-box 9 (Sox9) enhancer]. Despite distinct patterns of biochemical and cell-biological perturbations, V60L and I90M each attenuated Sox9 expression in transient transfection assays by twofold. Such attenuation was also observed in studies of V60A, a clinical variant associated with ovotestes and hence ambiguity between divergent cell fates. This shared twofold threshold is reminiscent of autosomal syndromes of transcription-factor haploinsufficiency, including XY sex reversal associated with mutations in SOX9. Our results demonstrate that nucleocytoplasmic shuttling of SRY is necessary for robust initiation of testicular development. Although also characteristic of ungulate orthologs, such shuttling is not conserved among rodents wherein impaired nuclear export of the high-mobility group box and import-dependent phosphorylation are compensated by a microsatellite-associated transcriptional activation domain. Human sex reversal due to subtle defects in the nucleocytoplasmic shuttling of SRY suggests that its transcriptional activity lies near the edge of developmental ambiguity. PMID:24003159

Chen, Yen-Shan; Racca, Joseph D.; Phillips, Nelson B.; Weiss, Michael A.

2013-01-01

260

Annual cycle of plasma luteinizing hormone and sex hormones in male and female mallards (Anas platyrhynchos)  

USGS Publications Warehouse

Comparisons between 'wild'and 'game farm' mallards (Anas platyrhynchos) were made to assess the differences in the temporal changes of plasma hormones. Seasonal variation in the levels of immunoreactive luteinizing hormone (LH), testosterone, 5 -dihydrotestosterone (DHT), estrone, estradiol-17i?? and progesterone were measured in male and female mallards. In all birds there was a vernal increase in the concentrations of LH and testosterone in plasma which were correlated with the development of the testes and ovaries prior to and during the nesting season. The concentrations of estrogens in the plasma of the females were, in general, slightly higher during the nesting season but were much lower than the levels of testosterone. The highest levels of LH and testosterone in the females coincided precisely with the period of egg laying which occurred approximately one month earlier in game farm females than in wild females. The concentrations of LH and testosterone in the plasma of females decreased rapidly during incubation. In wild males, the decline in levels of these hormones temporally coincided with that of females. In contrast, plasma levels of LH and testosterone of males of the game farm stock remained elevated after the beginning of incubation in females to which they were paired. On the basis of these results and an examination of the literature, it appears that domestication results in: 1) increased reproductive potential through earlier initiation of nesting and by delay of the termination of reproduction until later in the summer; and 2) a decrease in the synchronization of the hormonal events supporting reproduction between the male and female of a pair. Testicular weights and plasma levels of testosterone become higher in game farm and domestic males than in the wild stock but levels of LH are similar.

Donham, R.S.

1979-01-01

261

Recombination Between Homologous Autosomes in Medfly ( Ceratitis Capitata ) Males: Type1 Recombination and the Implications for the Stability of Genetic Sexing Strains  

Microsoft Academic Search

The sterile insect technique (SIT) is an environmentally safe technology to control insect pests. To improve this technology, genetic sexing strains (GSS) have been developed for the Mediterranean fruit fly, Ceratitis capitata. Such strains are based on Y-autosome translocations linking a selectable marker to the male sex and their long-term stability, especially under large-scale mass rearing conditions, is threatened by

G. Franz

2002-01-01

262

Molecular cloning and quantitative expression of sexually dimorphic markers Dmrt1 and Foxl2 during female-to-male sex change in Epinephelus merra  

Microsoft Academic Search

The honeycomb grouper (Epinephelus merra) is one of the smallest members of the Serranidae family and is often used to study protogynous sex change. To determine the role of the male-determining gene Dmrt1 and the ovarian-specific gene Foxl2 in sex change, we cloned these two markers from E. merra gonads by reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification

Mohammad Ashraful Alam; Yasuhisa Kobayashi; Ryo Horiguchi; Toshiaki Hirai; Masaru Nakamura

2008-01-01

263

Genes and brain sex differences.  

PubMed

Throughout development, numerous biological events occur that differentially affect males and females. Specifically, sex-determining genes that are triggered by the sex-chromosome complement initiate a series of events that determine an organism's sex and lead to the differentiation of the body in sex-specific ways. Such events contribute to many unique sex differences, including the susceptibility to different diseases. Although it was believed that sex hormones singularly differentiated the brain and body, there is emerging research showing that genes also play a direct role. In this chapter, we review this line of work and focus on the use of a unique mouse model that separates the effect of gonadal hormones and sex chromosomes. As genetic technology continues to advance, our understanding of the role that hormones and genes play in sex differences can be used to advance the physical and mental health of both men and women. PMID:21094886

Sánchez, Francisco J; Vilain, Eric

2010-01-01

264

THE VOMERONASAL ORGAN IS REQUIRED FOR THE MALE MOUSE MEDIAL AMYGDALA RESPONSE TO CHEMICAL-COMMUNICATION  

E-print Network

THE VOMERONASAL ORGAN IS REQUIRED FOR THE MALE MOUSE MEDIAL AMYGDALA RESPONSE TO CHEMICAL chemical signals may be detected by the vomeronasal organ, which sends projections to the accessory of the chemical stimuli. However, regardless of biolog- ical relevance, vomeronasal organ removal eliminates all

Ronquist, Fredrik

265

Male reproductive organs are at risk from environmental hazards  

PubMed Central

Male reproductive disorders that are of interest from an environmental point of view include sexual dysfunction, infertility, cryptorchidism, hypospadias and testicular cancer. Several reports suggest declining sperm counts and increase of these reproductive disorders in some areas during some time periods past 50 years. Except for testicular cancer this evidence is circumstantial and needs cautious interpretation. However, the male germ line is one of the most sensitive tissues to the damaging effects of ionizing radiation, radiant heat and a number of known toxicants. So far occupational hazards are the best documented risk factors for impaired male reproductive function and include physical exposures (radiant heat, ionizing radiation, high frequency electromagnetic radiation), chemical exposures (some solvents as carbon disulfide and ethylene glycol ethers, some pesticides as dibromochloropropane, ethylendibromide and DDT/DDE, some heavy metals as inorganic lead and mercury) and work processes such as metal welding. Improved working conditions in affluent countries have dramatically decreased known hazardous workplace exposures, but millions of workers in less affluent countries are at risk from reproductive toxicants. New data show that environmental low-level exposure to biopersistent pollutants in the diet may pose a risk to people in all parts of the world. For other toxicants the evidence is only suggestive and further evaluation is needed before conclusions can be drawn. Whether compounds as phthalates, bisphenol A and boron that are present in a large number of industrial and consumer products entails a risk remains to be established. The same applies to psychosocial stressors and use of mobile phones. Finally, there are data indicating a particular vulnerability of the fetal testis to toxicants—for instance maternal tobacco smoking. Time has come where male reproductive toxicity should be addressed form entirely new angles including exposures very early in life. PMID:19966832

Bonde, Jens Peter

2010-01-01

266

Sex-specific nest defense in house sparrows ( Passer domesticus ) varies with badge size of males  

Microsoft Academic Search

According to indicator models of sexual selection, females can benefit from choosing males with above average epigamic traits,\\u000a but empirical evidence for such benefits is scarce. Here, we report results from an experiment with 29 pairs of house sparrows\\u000a (Passer domesticus) where the intensity of nest defense against a mounted mustelid predator was related to the size of the black

Heinz-Ulrich Reyer; Wiltrud Fischer; Pascale Steck; Thomas Nabulon; Philip Kessler

1998-01-01

267

Sex allocation in clonal plants: might clonal expansion enhance fitness gains through male function?  

Microsoft Academic Search

The returns on investment in sexual reproduction are described by fitness gain curves and the shapes of these curves affect,\\u000a among other things, the evolutionary stability of reproductive systems. The available evidence indicates that gain curves\\u000a for male function decelerate, corresponding to diminishing fitness returns on investment in pollen. In contrast, the gain\\u000a curve for female function is thought to

Marcel E. Dorken; Wendy E. Van Drunen

2010-01-01

268

(Patho)physiology of cross-sex hormone administration to transsexual people: the potential impact of male-female genetic differences.  

PubMed

There is a limited body of knowledge of desired and undesired effects of cross-sex hormones in transsexual people. Little attention has been given to the fact that chromosomal configurations, 46,XY in male-to-female transsexuals subjects (MtoF) and 46,XX in female-to-male transsexual subjects (FtoM), obviously, remain unchanged. These differences in their genomes cause sex differences in the functions of cells. This study reviews sex differences in metabolism/cardiovascular pathology, immune mechanisms, bone (patho)physiology and brain functions and examines whether they are, maybe partially, determined by genetic mechanisms rather than by (cross-sex) hormones. There do not appear to be major genetic impacts on the changes in bone physiology. Also immune functions are rather unaffected and the evidence for an increase of autoimmune disease in MtoF is preliminary. Brain functions of transsexuals may have differed from controls before cross-sex hormones; they do undergo shifts upon cross-sex hormone treatment, but there is no evidence for changes in sex-specific brain disease. The prevalence of cardiovascular disease is higher in MtoF receiving oestrogens than in FtoM receiving androgens. While type of oestrogen and route of administration might be significant, it is reasonable to speculate that nonhormonal/genetic factors play a role. PMID:25495275

Gooren, L J; Kreukels, B; Lapauw, B; Giltay, E J

2015-02-01

269

Unprotected Anal Intercourse With Casual Male Partners in Urban Gay, Bisexual, and Other Men Who Have Sex With Men.  

PubMed

Objectives. We investigated trends in, and predictors of, unprotected anal intercourse (UAI) with casual male partners of gay, bisexual, and other men who have sex with men (GBMSM). Methods. We analyzed data from cross-sectional intercept surveys conducted annually (2003-2008) at 2 large lesbian, gay, and bisexual community events in New York City. Survey data covered GBMSM's highest-risk behaviors for HIV acquisition (HIV-negative or unknown status GBMSM, any UAI) and transmission (HIV-positive GBMSM, any serodiscordant unprotected UAI). Results. Across years, 32.3% to 51.5% of the HIV-negative or unknown status men endorsed any UAI, and 36.9% to 52.9% of the HIV-positive men endorsed serodiscordant UAI. We observed a few statistically significant fluctuations in engagement in high-risk behavior. However, these do not appear to constitute meaningful trends. Similarly, in some years, one or another demographic predictor of UAI was significant. Across years, however, no reliable pattern emerged. Conclusions. A significant proportion of urban GBMSM engage in high-risk sex, regardless of serostatus. No consistent demographic predictors emerged, implying a need for broad-based interventions that target all GBMSM. PMID:25393176

Pantalone, David W; Tomassilli, Julia C; Starks, Tyrel J; Golub, Sarit A; Parsons, Jeffrey T

2015-01-01

270

Testicular disorder of sex development in four cats with a male karyotype (38,XY; SRY-positive).  

PubMed

The molecular background of disorders of sex development (DSD) in cats is poorly recognized. In this study we present cytogenetic, molecular and histological analyses of four cats subjected for the analysis due to ambiguous external genitalia. Three cases, with rudimentary penises and an abnormal position of the urethral orifice, represented different types of hypospadias. The fourth case had a normal penis, a blind vulva and spermatogenetically active testes. Histological studies showed structures typical of testes, but spermatogenic activity was observed in two cats only. All the cats had a normal male chromosome complement (38,XY) and the Y-chromosome linked genes (SRY and ZFY) were also detected. Fluorescent in situ hybridization (FISH), with the use of the feline BAC probe harboring the SRY gene, excluded the possibility of chromosome translocation of the Y chromosome fragment carrying the SRY gene onto another chromosome. Sequencing of four candidate genes (SRY-sex determining region Y; AR-androgen receptor; SRD5A2-steroid-5-alfa reductase 2 and MAMLD1-mastermind-like domain containing (1) revealed one SNP in the SRY gene, one common polymorphism in exon 1 of the AR gene (tandem repeat of a tri-nucleotide motif-CAG), six polymorphisms (5 SNPs and 1 indel) in the SRD5A2 gene and one SNP in the MAMLD1 gene. Molecular studies of the candidate genes showed no association with the identified polymorphisms, thus molecular background of the studied DSD phenotypes remains unknown. PMID:25455261

Nowacka-Woszuk, Joanna; Szczerbal, Izabela; Salamon, Sylwia; Kociucka, Beata; Jackowiak, Hanna; Prozorowska, Ewelina; Slaska, Brygida; Rozanska, Dorota; Orzelski, Maciej; Ochota, Malgorzata; Dzimira, Stanislaw; Lipiec, Magdalena; Nizanski, Wojciech; Switonski, Marek

2014-12-10

271

Cold acclimation in Peromyscus: individual variation and sex effects in maximum and daily metabolism, organ mass and body composition.  

PubMed

We studied metabolic and organ mass responses to thermal acclimation (7 weeks at 5 degrees C or 23 degrees C) in deer mice, Peromyscus maniculatus. Cold acclimation resulted in significantly higher maximal oxygen consumption in thermogenesis (V(O(2)max)) and daily mean oxygen consumption (V(O(2)mean)), an increase in the mass of most visceral organs, a lower absolute body fat and a marginally significant increase in hematocrit. The mass of digestive organs and body fat content differed significantly between sexes. Acclimation effects on fat content were more pronounced in females. Variation in heart and lung mass was positively correlated with V(O(2)max) and V(O(2)mean), while body fat content was negatively correlated with both traits. Nonetheless, a large fraction of the metabolic difference between cold- and warm-acclimated groups remained unexplained. Associations between traits at lower levels of biological organization measured here and whole-organism energetics remained consistent across acclimation temperatures, except for the correlation between kidney mass and V(O(2)mean), which was positive and significant in cold acclimation and negligible following warm acclimation. We conclude that: (1) V(O(2)max) and V(O(2)mean) share a common physiological basis that remains overall the same across acclimation regimes; (2) changes in these traits are associated primarily with changes in heart mass; and (3) male and female deer mice respond differently to thermal acclimation, possibly due to differences in reproductive allocation. PMID:19684213

Rezende, Enrico L; Hammond, Kimberly A; Chappell, Mark A

2009-09-01

272

Are Female Sex Workers Able to Negotiate Condom Use with Male Clients? The Case of Mobile FSWs in Four High HIV Prevalence States of India  

PubMed Central

Introduction Condom promotion among female sex workers (FSWs) is a key intervention in India’s National AIDS Control Program. However, there is limited understanding of how FSWs negotiate condom use with male clients, particularly in the context of their mobility for sex work. The objective of this study is to examine the factors associated with the mobile FSWs’ ability to refuse unsafe sex and successfully negotiate condom use with unwilling male clients. Methods Data for 5498 mobile FSWs from a cross-sectional survey conducted in 22 districts of four states in southern India were analyzed. Questions assessed FSWs’ ability to refuse clients unprotected sex, convince unwilling clients for condom use and negotiate condom use in a new location. Logistic regression models were constructed to examine the association between socio-demographics, economic vulnerability, sex work practice, and program exposure and condom negotiation ability. Results A majority of FSWs (60%) reported the ability to refuse clients for unprotected sex, but less than one-fifth reported the ability to successfully convince an unwilling client to use a condom or to negotiate condom use in a new site. Younger and older mobile FSWs compared to those who were in the middle age group, those with longer sex work experience, with an income source other than sex work, with program exposure and who purchased condoms for use, reported the ability to refuse unprotected sex, to successfully negotiate condom use with unwilling clients and to do so at new sites. Conclusion FSWs need to be empowered to not only refuse unprotected sex but also to be able to motivate and convince unwilling clients for condom use, including those in new locations. In addition to focusing on condom promotion, interventions must address the factors that impact FSWs’ ability to negotiate condom use. PMID:23840806

Bharat, Shalini; Mahapatra, Bidhubhusan; Roy, Suchismita; Saggurti, Niranjan

2013-01-01

273

Quantitative variation in ecological and hormonal variables correlates with spatial organization of pronghorn ( Antilocapra americana ) males  

Microsoft Academic Search

Whereas variation in pronghorn (Antilocapra americana) spatial organization is well documented, underlying ecological or physiological explanations are not well understood. This\\u000a study quantitatively describes spacing systems of pronghorn males and correlates of their spatial organization. I collected\\u000a behavioral data from two populations in South Dakota (Wind Cave) and Montana (Bar Diamond) to determine if males differed\\u000a in space use, response

C. R. Maher

2000-01-01

274

Effect of hypoxia (6,060 m) and cold (-5°C) on sexual organs of male rabbits  

NASA Astrophysics Data System (ADS)

Studies have been carried out on 18 adult male rabbits divided into three groups. One group (hypoxic) was exposed to a simulated altitude (6,060 m for 6 h daily for 21 days), the second group was exposed to the same altitude plus cold (-5°C) for the same duration, and the third acted as control. The results showed no difference in the body weight of the three groups, but the weights of the sex organs in the exposed groups were significantly reduced. In both these groups the number, motility and survival time of spermatozoa decreased significantly; the sex organs showed atrophy on histological examination; and there was an increase in the alkaline and acid phosphatase activity and cholesterol concentration, and a fall in GPC level. These changes were more marked in the cold plus altitude group than in the group exposed to altitude alone. It has been concluded that hypoxia affects not only the testis but also the epididymis and the vas deferens. The spermatozoal quality of rabbits deteriorates. When cold and hypoxia are combined, their effects are additive.

Riar, S. S.; Malhotra, M. S.; Bhat, K. Shankar

1980-03-01

275

Prenatal letrozole produces a subpopulation of male rats with same-sex preference and arousal as well as female sexual behavior.  

PubMed

Disruption of the sexual differentiation process during critical periods in male rodents produces changes in partner preference and sexual behavior. In this study we used prenatal (gestation days 10-22) letrozole (0.31 and 0.56?g/kg) to inhibit aromatase and alter normal sexual differentiation of males. These animals and control rats (injected with vehicle) were used when adults to study: a) sexual preference (where the experimental male could choose to interact with a receptive female or a sexually experienced male); b) masculine and feminine sexual behaviors (tested in cylindrical arenas); c) non-contact erections when exposed to a female or a male and, d) serum sex steroids and gonadotropin levels. The results showed that 30% of the males treated with letrozole (0.56?g/kg) had same-sex preference, 33% displayed lordosis and 63% showed non-contact erections in the presence of a sexually experienced male. However, 44% of these males also exhibited complete masculine sexual behavior towards receptive females. None of the control males displayed lordosis when mounted by another male and very few (12%) showed non-contact erections when exposed to a sexually experienced male. Similar low percentages were found in those males prenatally treated with the low letrozole dose (0.31?g/kg). No difference was found in the serum levels of testosterone, estradiol, LH and FSH between control and letrozole-treated males regardless of their sexual preference. These results indicate that prenatal selective inhibition of aromatization produces feminization of sexual partner preference, arousal and sexual behavior but does not affect masculine sexual behavior. PMID:25462593

Olvera-Hernández, Sandra; Chavira, Roberto; Fernández-Guasti, Alonso

2015-02-01

276

First Record of the Scarab Beetle, Phyllophaga lissopyge from South America, with Descriptions of Adult Seasonal Activity and Male Response to Sex Attractants  

PubMed Central

Phyllophaga lissopyge (Bates) (Coleoptera: Scarabaeidae: Melolonthinae) is reported for the first time from South America. Male sex pheromone response is described for P. lissopyge and two other co-occurring Phyllophaga species. Adults of P. lissopyge and P. menetriesi (Blanchard) flew to traps baited with methyl 2-(methylthio) benzoate whereas adults of P. obsoleta (Blanchard) flew irregularly to four different pheromone compounds. Adult seasonal activity is described from males captures in Rionegro, Antioquia, Colombia. PMID:21529153

Morales-Rodriguez, Anuar; Peck, Daniel C.; Robbins, Paul S.

2011-01-01

277

Risk Factors for HIV/Syphilis Infection and Male Circumcision Practices and Preferences among Men Who Have Sex with Men in China  

PubMed Central

Objective. To investigate factors associated with HIV infection and the frequency and willingness of male circumcision among men who have sex with men (MSM) in Chengdu city, China. Methods. A cross-sectional survey provided information on participants' demographics, risk behaviors, circumcision, and uptake of HIV prevention services. Results. Of 570 participants, 13.3% were infected with HIV and 15.9% with syphilis. An estimated 43.0% of respondents reported having unprotected receptive anal intercourse, and 58.9% reported having ?2 male sexual partners in the past 6 months. Multivariable logistic regression revealed that syphilis, more male sex partners, predominantly receptive anal intercourse, and exclusively receptive male sex were associated with HIV infection. Higher level of education and peer education service were inversely associated with HIV infection. Nearly a fifth (18.0%) of participants were circumcised. More than half of uncircumcised participants expressed willingness to be circumcised. Conclusion. This study reveals a high prevalence of HIV and syphilis among MSM in Chengdu province of China. The frequency of unprotected receptive anal intercourse and multiple male sexual partnerships highlight the urgency for an effective comprehensive HIV prevention strategy. Although the willingness to accept male circumcision (MC) is high, further research is needed to assess the protective effective of MC among MSM. PMID:24795883

Zhang, Linglin; Li, Tian; Lai, Wenhong; Jia, Yujiang; Aliyu, Muktar H.; Do, Mai; Huang, Wanli; Du, Shuping; Xu, Jie; Zhou, Jiushun; Liang, Shu; Yu, Fei; Zhang, Yanqing

2014-01-01

278

Intervention of d-glucose ameliorates the toxicity of streptozotocin in accessory sex organs of rat  

Microsoft Academic Search

Streptozotocin (STZ) is a naturally occurring compound isolated from Streptomyces achromogens. It is used extensively for inducing diabetes in experimental animals. Diabetes mellitus is known to have proven adverse effects on male sexual organs and their reproductive functions. The atrophy of prostate gland and other organs of the genitourinary tract were observed in experimental diabetic animals. STZ exhibits a structural

A. Vikram; D. N. Tripathi; P. Ramarao; G. B. Jena

2008-01-01

279

The role of the sex-determining region Y gene in the etiology of 46,XX maleness  

SciTech Connect

The condition of 46,XX maleness is characterized by testicular development in subjects who have two X chromosomes but who lack a normal Y chromosome. Several etiologies have been proposed to explain 46,XX maleness: (1) translocation of the testis-determining factor from the Y to the X chromosome, (2) mutation in an autosomal or X chromosome gene which permits testicular determination in the absence of TDF, and (3) undetected mosaicism with a Y-bearing cell line. The authors evaluated 10 affected subjects who were ascertained for different reasons and who had several distinct phenotypes. Six subjects had inherited sequences from the short arm of the Y chromosome including the sex-determining region Y gene (SRY). Five of the subjects were pubertal at the time of evaluation and had a phenotype similar to that of Klinefelter syndrome with evidence of Sertoli cell and Leydig cell dysfunction. One subject had evidence from Southern blot analysis and in situ hybridization for the presence of an intact Y chromosome in approximately 1% of cells. Three subjects lacked Y sequences by Southern blot analysis and by polymerase chain reaction amplification of SRY. These subjects were ascertained in the newborn period because of congenital anomalies. One had multiple anomalies including cardiac abnormalities; one had cardiac anomalies alone; and one had ambiguous genitalia. The data confirm the genetic heterogeneity of 46,XX maleness, in which some subjects have SRY while other subjects lack it. In addition, there is phenotypic heterogeneity among subjects who lack SRY suggesting that there is also genetic heterogeneity within this subgroup. 43 refs., 3 figs., 4 tabs.

Fechner, P.Y.; Marcantonio, S.M.; Jaswaney, V.; Stetten, G.; Migeon, C.J.; Smith, K.D.; Berkovitz, G.D. (Johns Hopkins Univ., Baltimore, MD (United States)); Goodfellow, P.N. (Imperial Cancer Research Fund, London (United Kingdom)); Amrhein, J.A. (Forbes Regional Health Center, Monroeville, PA (United States)); Bard, P.A. (Kaiser Permanente, Sacramento, CA (United States)); Lee, P.A. (Univ. of Pittsburgh, PA (United States)); Reid, C. (Robert Wood Johnson Medical School, Camden, NJ (United States)); Tsalikian, E. (Univ. of Iowa, Iowa City (United States)); Urban, M.D. (Wright State Univ., Dayton, OH (United States))

1993-03-01

280

The Male-Female Health-Survival Paradox and Sex Differences in Cohort Life Expectancy in Utah, Denmark and Sweden 1850-1910  

PubMed Central

Purpose In Utah, prevalence of unhealthy male risk behaviours are lower than in most other male populations while women experience higher mortality risk due to higher fertility rates. Therefore, we hypothesize that the Utah sex differential in mortality would be small and less than in Sweden and Denmark. Methods Life tables from Utah, Denmark and Sweden, were used to calculate cohort life expectancies for men and women born 1850-1910. Results The sex difference in cohort life expectancy was similar or larger in Utah when compared to Denmark and Sweden. The change over time in the sex differences in cohort life expectancy was approximately two years smaller for active Mormons in Utah than for other groups suggesting lifestyle as an important component for the overall change seen in cohort life expectancy. Sex differences in cohort life expectancy at age 50 were similar for individuals actively affiliated with the Church of Jesus Christ of Latter-day Saints and for Denmark and Sweden. Conclusions The hypothesis that a smaller sex difference in cohort life expectancies in Utah would be detected in relation to Denmark and Sweden was not supported. In Utah the male-female differences in life expectancy remain substantial pointing towards biological mechanisms, or other unmeasured risk factors. PMID:23453386

Lindahl-Jacobsen, Rune; Hanson, Heidi A.; Oksuzyan, Anna; Mineau, Geraldine P.; Christensen, Kaare; Smith, Ken R.

2013-01-01

281

Carotenoid-based ornaments of female and male American goldfinches (Spinus tristis) show sex-specific correlations with immune function and metabolic rate.  

PubMed

Conspicuous ornamentation has been linked to immunological and physiological condition in males of many species. In species where both sexes are ornamented, it is unclear whether the signal content of ornaments differs between males and females. We examined the immunological and physiological correlates of carotenoid-based bill and plumage ornamentation in American goldfinches Spinus tristis, a species in which bright orange bills are sexually monomorphic but yellow plumage is sexually dimorphic during the breeding season. Because bill color is dynamic over short periods while plumage color is static over longer time frames, we tested whether these signals have the potential to provide temporal information about immunity and condition. In both sexes, bill color (but not plumage color) was negatively related to leukocyte differential, a measure of recent stress, while plumage color (but not bill color) was positively related to resting metabolic rate. In females, bill color also positively correlated with immunoglobulin Y, a component of acquired immunity, while plumage color positively predicted natural antibody levels, a component of innate immunity. In males, neither bill color nor plumage color predicted immune function, suggesting that the mechanisms underlying these signals vary with sex. Our results demonstrate that dynamic signals such as bill coloration do not merely reflect the same information provided by static signals but that these two classes of signal provide information about different temporal aspects of phenotypic quality. Furthermore, our results indicate that a signal expressed in both sexes has the potential to provide different information depending on the sex of the bearer. PMID:22705485

Kelly, Ryan J; Murphy, Troy G; Tarvin, Keith A; Burness, Gary

2012-01-01

282

The effects of mesterolone, a male sex hormone in depressed patients (a double blind controlled study).  

PubMed

Based on computer EEG (CEEG) profiles, in high doses, antidepressant properties of mesterolone, a synthetic androgen, were predicted. In a double-blind placebo controlled study, the clinical effects of 300-450 mg daily mesterolone were investigated in 52 relatively young (age range 26-53 years, mean 42.7 years) male depressed outpatients. During 6 weeks of mesterolone treatment, there was a significant improvement of depressive symptomatology. However, since an improvement was also established during the placebo treatment, no statistically appreciable difference in the therapeutic effects of mesterolone was established compared to placebo. Mesterolone treatment significantly decreased both plasma testosterone and protein bound testosterone levels. Patients with high testosterone levels prior to treatment seem to have had more benefit from mesterolone treatment than patients with low testosterone levels. The degree of improvement weakly correlated to the decrease of testosterone levels during mesterolone treatment. PMID:6431212

Itil, T M; Michael, S T; Shapiro, D M; Itil, K Z

1984-06-01

283

Trends in Infectious Diseases and the Male to Female Ratio: Possible Clues to Changes in Behavior among Men Who Have Sex with Men  

ERIC Educational Resources Information Center

Men who have sex with men (MSM) are a priority population for HIV care and prevention programs. This report describes HIV and other sexually transmitted disease (STD) trends among MSM in metropolitan Atlanta by analyzing nine databases. We describe the use of the male-to-female (M:F) ratio, a surrogate marker for MSM in databases without…

Beltrami, John F.; Shouse, R. Luke; Blake, Paul A.

2005-01-01

284

Sexual Selection: Male-Male Competition  

E-print Network

VII.5 Sexual Selection: Male-Male Competition Christine W. Miller It is certain that amongst almost often the competing sex and females the choosy sex? 2. The processes of sexual selection 3. Male-male competition in plants 7. Total sexual selection 8. Sexual selection and ecological context Males commonly

Miller, Christine Whitney

285

The Structure, Stability and Pheromone Binding of the Male Mouse Protein Sex Pheromone Darcin  

PubMed Central

Mouse urine contains highly polymorphic major urinary proteins that have multiple functions in scent communication through their abilities to bind, transport and release hydrophobic volatile pheromones. The mouse genome encodes for about 20 of these proteins and are classified, based on amino acid sequence similarity and tissue expression patterns, as either central or peripheral major urinary proteins. Darcin is a male specific peripheral major urinary protein and is distinctive in its role in inherent female attraction. A comparison of the structure and biophysical properties of darcin with MUP11, which belongs to the central class, highlights similarity in the overall structure between the two proteins. The thermodynamic stability, however, differs between the two proteins, with darcin being much more stable. Furthermore, the affinity of a small pheromone mimetic is higher for darcin, although darcin is more discriminatory, being unable to bind bulkier ligands. These attributes are due to the hydrophobic ligand binding cavity of darcin being smaller, caused by the presence of larger amino acid side chains. Thus, the physical and chemical characteristics of the binding cavity, together with its extreme stability, are consistent with darcin being able to exert its function after release into the environment. PMID:25279835

Phelan, Marie M.; McLean, Lynn; Armstrong, Stuart D.; Hurst, Jane L.; Beynon, Robert J.; Lian, Lu-Yun

2014-01-01

286

Structure of vomeronasal organ (Jacobson organ) in male Camelus Domesticus Var. dromedaris persica.  

PubMed

The vomeronasal organ (VNO) is a tubular structure in the roof of nasal cavity. The important role of this organ is olfaction of sexual odour. In this study, position, anatomical structure and histology of VNO in Iranian camels (camelus domesticus var. dromedaris persica) were determined. Fourteen healthy male camel heads were collected from an industrial slaughterhouse in Tehran, Iran, for anatomical and histological studies (seven each). The length of VNO and width of dental pad and the number and width of palatine crests were measured. For anatomical studies, the mandible was removed, and maxilla and nasal cavity was cut longitudinally and transversely. For histological studies, the mandible was removed, and first 0.5 cm of initial part of VNO was cut. Then, nasal cavity was cut in some segments with 2 cm thickness. The width of VNO was 3.85 ± 0.31 cm and 1.57 ± 0.18 cm in front and distal parts, respectively. The length of VNO was 15.61 ± 0.59 cm. In histological examinations, VNO was surrounded by J-shape hyaline cartilage. The lining epithelium of lateral wall of VNO was originated from respiratory epithelium, while it had an olfactory epithelium origin in the medial wall. Lamina propria and tunica submucosa were a cavernous connective tissue with seromucous gland with abundant of serous secretory units. The lumen of VNO opens into nasal cavity. The presence of olfactory epithelium found in our study indicates an important role for VNO in pheromone perception and beginning of sexual behaviour. PMID:24611976

Karimi, H; Mansoori Ale Hashem, R; Ardalani, G; Sadrkhanloo, R; Hayatgheibi, H

2014-12-01

287

Sex determination in cattle based on simultaneous amplification of a new male-specific DNA sequence and an autosomal locus using the same primers.  

PubMed

A PCR-based method for sex determination of bovine DNA samples and embryo biopsies is presented. Using only one primer pair both the male-specific sequence FBNY (127 bp) and a sex-independent control PCR-fragment, the microsatellite marker FBN17 (136-140 bp) are generated in the same PCR reaction. Synteny mapping assigned the male-specific sequence to bovine chromosome Y (BTA Y), whereas FBN17 was mapped to bovine chromosome 2. Localisation of FBNY on BTA Y was confirmed by fluorescence in hybridisation of two BAC clones containing the male-specific sequence. There was no amplification of the male-specific target sequence FBNY in sheep, pig, goat, mice, man, and several wild species of the tribe Bovini. The bovine male-specific fragment was detected in dilutions containing as little as 10 pg genomic DNA and in blastomeres from embryo biopsies. The PCR assay presented here does require neither restriction endonuclease digestion of the PCR product nor additional nested PCR steps. Owing to the advantage of parallel amplification of the autosomal locus FBN17 no additional control fragment is necessary to detect PCR failure. The results of sex determination in embryo biopsies using FBNY were in agreement with the outcome from a reference assay used in commercial breeding programs. PMID:11550263

Weikard, R; Kühn, C; Brunner, R M; Roschlau, D; Pitra, C; Laurent, P; Schwerin, M

2001-09-01

288

Variation in sex allocation and male-female trade-offs in six populations of Collinsia parviflora (Scrophulariaceae s.l.).  

PubMed

Assumed trade-offs between male and female functions in hermaphroditic flowers have been difficult to demonstrate. Collinsia parviflora (Scrophulariaceae) is a winter annual that exhibits significant among-population variation in corolla size in British Columbia, Canada. We asked whether reduction in secondary male allocation (i.e., the attractive corolla), a preliminary indicator of mating system, was matched by a reduction in primary male allocation (i.e., pollen production), and whether there were allocation trade-offs between male and female function both within and among six study populations. Larger-flowered populations allocated more to male function (androecium and corolla biomass), and because populations did not vary in female biomass allocation (gynoecium and calyx), population differences were not due to simple allometric scaling. Populations also differed in per-flower gamete production (pollen and ovules). We found male-female trade-offs within populations between androecium and gynoecium mass and between corolla and calyx mass. Among populations, there was a marginal trade-off between pollen and ovule production and a significant within-male trade-off between pollen grain size and number. Trade-offs between the sexes were primarily apparent when we controlled for flower size in the analysis. Variation among populations in sex allocation may reflect different optima related to the mating system. PMID:21653477

Parachnowitsch, Amy L; Elle, Elizabeth

2004-08-01

289

Determination of genetic sex in chinook salmon (Oncorhynchus tshawytscha) using the male-linked growth hormone pseudogene by real-time PCR.  

PubMed

This study used a real-time quantitative polymerase chain reaction (qPCR) method based on the growth hormone pseudogene (GHp) in chinook salmon (Oncorhynchus tshawytscha) to determine genetic sex. The GHp is present as a single copy in the genome of the male chinook salmon but is absent in the female, providing a means of using this real-time qPCR method to discriminate genetic sex. Comparisons between genomic DNA samples from 2 geographically distinct populations of chinook salmon (Columbia River, Washington, and Yukon River, Alaska) showed, within each population examined, that the males were clearly differentiated from the females. There were no interpopulation differences between males or females. The advantages of this real-time qPCR method are that it is rapid, is amenable to high sample throughput, and provides an accurate numerical value that allows comparisons between samples by statistical methods. PMID:14612987

Nagler, James J; Cavileer, Tim; Steinhorst, Kirk; Devlin, Robert H

2004-01-01

290

Do Male and Female Cowbirds See Their World Differently? Implications for Sex Differences in the Sensory System of an Avian Brood Parasite  

PubMed Central

Background Male and female avian brood parasites are subject to different selection pressures: males compete for mates but do not provide parental care or territories and only females locate hosts to lay eggs. This sex difference may affect brain architecture in some avian brood parasites, but relatively little is known about their sensory systems and behaviors used to obtain sensory information. Our goal was to study the visual resolution and visual information gathering behavior (i.e., scanning) of brown-headed cowbirds. Methodology/Principal Findings We measured the density of single cone photoreceptors, associated with chromatic vision, and double cone photoreceptors, associated with motion detection and achromatic vision. We also measured head movement rates, as indicators of visual information gathering behavior, when exposed to an object. We found that females had significantly lower density of single and double cones than males around the fovea and in the periphery of the retina. Additionally, females had significantly higher head-movement rates than males. Conclusions Overall, we suggest that female cowbirds have lower chromatic and achromatic visual resolution than males (without sex differences in visual contrast perception). Females might compensate for the lower visual resolution by gazing alternatively with both foveae in quicker succession than males, increasing their head movement rates. However, other physiological factors may have influenced the behavioral differences observed. Our results bring up relevant questions about the sensory basis of sex differences in behavior. One possibility is that female and male cowbirds differentially allocate costly sensory resources, as a recent study found that females actually have greater auditory resolution than males. PMID:23544049

Fernández-Juricic, Esteban; Ojeda, Agustin; Deisher, Marcella; Burry, Brianna; Baumhardt, Patrice; Stark, Amy; Elmore, Amanda G.; Ensminger, Amanda L.

2013-01-01

291

The ovary retains male potential after the thermosensitive period for sex determination in the turtle Emys orbicularis.  

PubMed

Emys orbicularis is a turtle with temperature-dependent sex determination. The thermosensitive period (TSP) lies between embryonic stages 16 and 22. Gonadal differentiation begins during this period involving oestrogens. Treatment with oestrogens during TSP results in the differentiation of ovaries at a male-producing temperature (25 degrees C), whereas treatment with an antioestrogen (tamoxifen) or with nonsteroidal aromatase inhibitors results in gonadal masculinization at a female-producing temperature (30 degrees C). The present study examines the effects on the ovary of inhibiting aromatase activity after TSP. Eggs of E. orbicularis incubated at 30 degrees C were given five or seven applications of 10 micrograms aromatase inhibitor Letrozole (CGS 20267) in ethanol, between stages 22+ and 24-25 when ovarian aromatase activity strongly increases. Individuals which received five applications were sacrificed at stages 24(+)-25. Those which received seven applications were sacrificed either at stage 25+ (close to hatching), or 34-36 days after hatching. Gonadal aromatase activity and related gonadal structure were studied in each individual. In the three series, the gonadal aromatase activity in individuals treated with Letrozole varied from similar or close to that in controls to much lower, and the gonadal structure varied from ovary-like to ovotestis. Ovotestes had the lowest levels of aromatase activity, under 4 fmoles/h/gonad, close to testis levels. They were found in 7 out of 26 individuals given Letrozole. Besides ovotestes, gonads presenting various degrees of masculinization, with enlarged epithelial cords and lacunae in the medulla, were found. Therefore, by inhibiting aromatase activity and thus estrogen synthesis, we were able to obtain the differentiation of testis-like cords or tubes in ovaries of E. orbicularis, after the period of temperature sensitivity. These results show that the ovary retains male potential after this period. Thus, besides their implication during the critical embryonic period for gonadal sex differentiation, oestrogens play a role in maintaining the ovarian structure after this period. A decrease in oestrogen levels could explain some other cases of ovarian masculinization known in vertebrates. PMID:8765049

Dorizzi, M; Richard-Mercier, N; Pieau, C

1996-07-01

292

Shared Forces of Sex Chromosome Evolution in Haploid-Mating and Diploid-Mating Organisms  

PubMed Central

It is usually posited that the most important factors contributing to sex chromosome evolution in diploids are the suppression of meiotic recombination and the asymmetry that results from one chromosome (the Y) being permanently heterozygous and the other (the X) being homozygous in half of the individuals involved in mating. To distinguish between the roles of these two factors, it would be valuable to compare sex chromosomes in diploid-mating organisms and organisms where mating compatibility is determined in the haploid stage. In this latter group, no such asymmetry occurs because the sex chromosomes are equally heterozygous. Here we show in the fungus Microbotryum violaceum that the chromosomes carrying the mating-type locus, and thus determining haploid-mating compatibility, are rich in transposable elements, dimorphic in size, and carry unequal densities of functional genes. Through analysis of available complete genomes, we also show that M. violaceum is, remarkably, more similar to humans and mice than to yeast, nematodes, or fruit flies with regard to the differential accumulation of transposable elements in the chromosomes determining mating compatibility vs. the autosomes. We conclude that restricted recombination, rather than asymmetrical sheltering, hemizygosity, or dosage compensation, is sufficient to account for the common sex chromosome characteristics. PMID:15454533

Hood, Michael E.; Antonovics, Janis; Koskella, Britt

2004-01-01

293

Winter profile of plasma sex steroid levels in free-living male western diamond-backed rattlesnakes, Crotalus atrox (Serpentes: Viperidae).  

PubMed

Recent field studies on the reproductive ecology of western diamond-backed rattlesnakes (Crotalus atrox) from populations in southern Arizona showed significant differences in the concentration of plasma sex steroids (testosterone, T; 5alpha-dihydrotestosterone, DHT; and 17beta-estradiol, E2) throughout the active season (March-October), and peak levels were coincident with the two mating periods (late summer and early spring). There is, however, no information on levels of sex steroids during winter. Similar to most snakes, hibernating individuals of C. atrox are typically inaccessible, but in southern Arizona, where environmental conditions are typically mild during winter, adult males frequently bask at or near the entrances of communal dens. Basking activity, therefore, offers a unique logistical opportunity to assess the complete annual profile of plasma sex steroid levels in males of a temperate reptile in nature. From November to February, we measured levels of plasma T, DHT, and E2 in adult male C. atrox that were located basking at communal dens. Additionally, cloacal, core body, and ambient air temperatures were obtained to investigate potential relationships between body temperatures and levels of sex steroids. Mean levels of T, DHT, and E2 were relatively high, and the concentration hierarchy was T>DHT>E2. Mean levels of T, DHT, and E2 showed no significant variation across the four months of sampling; however, E2 levels decreased progressively. In the annul cycle, sex steroid levels during winter were not basal when compared to values obtained during the active season. Mean cloacal temperatures of basking males were significantly higher than core body temperatures of non-basking males (inside dens) from November-December, and in February, which suggests that one function of winter basking is to elevate body temperatures. Steroid levels, nonetheless, were not significantly correlated with cloacal temperatures. We suggest that future field studies of male C. atrox should: (a) investigate sex steroid levels in non-basking individuals and (b) test whether elevated levels of sex steroids during winter facilitate the large increases that occur in early spring, which are coincident with the second mating season. Our findings on the reproductive biology of C. atrox and other viperids are discussed in the context of the associated-dissociated model of reproduction. PMID:16828091

Schuett, Gordon W; Repp, Roger A; Taylor, Emily N; DeNardo, Dale F; Earley, Ryan L; Van Kirk, Edward A; Murdoch, William J

2006-10-01

294

The effects of sex steroids on thyroid C cells and trabecular bone structure in the rat model of male osteoporosis.  

PubMed

Androgen deficiency is one of the major factors leading to the development of osteoporosis in men. Since calcitonin (CT) is a potent antiresorptive agent, in the present study we investigated the effects of androgen deficiency and subsequent testosterone and estradiol treatment on CT-producing thyroid C cells, skeletal and hormonal changes in middle-aged orchidectomized (Orx) rats. Fifteen-month-old male Wistar rats were either Orx or sham-operated (SO). One group of Orx rats received 5 mg kg(-1) b.w. testosterone propionate (TP) subcutaneously, while another group was injected with 0.06 mg kg(-1) b.w. estradiol dipropionate (EDP) once a day for 3 weeks. A peroxidase-antiperoxidase method was applied for localization of CT in the C cells. The studies included ultrastructural microscopic observation of these cells. The metaphyseal region of the proximal tibia was measured histomorphometrically using an imagej public domain image processing program. TP or EDP treatment significantly increased C cell volume (Vc), volume densities (Vv) and serum CT concentration compared with the Orx animals. Administration of both TP and EDP significantly enhanced cancellous bone area (B.Ar), trabecular thickness (Tb.Th) and trabecular number (Tb.N) and reduced trabecular separation (Tb.Sp). Serum osteocalcin (OC) and urinary Ca concentrations were significantly lower after these treatments in comparison with Orx rats. These data suggest that testosterone and estradiol treatment in Orx middle-aged rats affect calcitonin-producing thyroid C cells, which may contribute to the bone protective effects of sex hormones in the rat model of male osteoporosis. PMID:23171170

Filipovi?, Branko; Soši?-Jurjevi?, Branka; Ajdžanovi?, Vladimir; Panteli?, Jasmina; Nestorovi?, Nataša; Miloševi?, Verica; Sekuli?, Milka

2013-03-01

295

Sex Workers, Fem Queens, and Cross-Dressers: Differential Marginalizations and HIV Vulnerabilities Among Three Ethnocultural Male-to-Female Transgender Communities in New York City  

PubMed Central

This article describes 3 distinct ethnocultural male-to-female transgender communities in New York City: the low-income African American/Black1 and Latina(o) House Ball community; low-income, often undocumented immigrant Asian sex workers; and middle-class White cross-dressers. These communities are highly socially isolated from each other and are more connected to their ethnocultural contexts than to an abstract and shared transgender identity. Whereas previous research either has viewed male-to-female transgender people as one monolithic group or has separated them into abstract racial categories unconnected to their communities and lifestyles, this article positions them within specific social networks, cultures, neighborhoods, and lifestyles. With regard to HIV vulnerabilities, violence, and rape, House Ball community members seemed to engage in the riskiest form of survival sex work, whereas Asian sex workers seemed to engage in moderate-risk survival sex work. White cross-dressers seemed to engage in very low-risk recreational sex work.2 PMID:19079558

Hwahng, Sel Julian; Nuttbrock, Larry

2008-01-01

296

Signaling in multiple modalities in male rhesus macaques: sex skin coloration and barks in relation to androgen levels, social status, and mating behavior  

PubMed Central

The past decade has seen an increasing shift in animal communication towards more studies that incorporate aspects of signaling in multiple modalities. Although nonhuman primates are an excellent group for studying the extent to which different aspects of condition may be signaled in different modalities, and how such information may be integrated during mate choice, very few studies of primate species have incorporated such analyses. Here, we present data from free-ranging male rhesus macaques on sex skin coloration (modeled to receiver perception), bark vocal signals, androgen levels, morphometric variables, dominance status, and female mate choice. We show that, consistent with data on females, most intra- and interindividual variation in sex skin appearance occurs in luminance rather than color. Sex skin luminance was significantly correlated across different skin regions. Sex skin luminance did not correlate with the majority of bark parameters, suggesting the potential for the two signals to convey different information. Sex skin appearance was not related to androgen levels although we found some evidence for links between androgen levels and bark parameters, several of which were also related to morphometric variables. We found no evidence that either signal was related to male dominance rank or used in female mate choice, though more direct measures of female proceptive behavior are needed. Overall, the function of male sex skin coloration in this species remains unclear. Our study is among the first nonhuman primate studies to incorporate measurements of multiple signals in multiple modalities, and we encourage other authors to incorporate such analyses into their work. PMID:25013266

Higham, James P.; Pfefferle, Dana; Heistermann, Michael; Maestripieri, Dario; Stevens, Martin

2014-01-01

297

Personal or relational? Examining sexual health in the context of HIV serodiscordant same-sex male couples  

PubMed Central

Couples’ ability to adopt a “we” orientation has been associated with optimal health outcomes. This study examined how personal and relational motivations are uniquely associated with unprotected anal intercourse (UAI), protected anal intercourse (PAI), and the absence of sexual activity within HIV-serodiscordant same-sex male couples. HIV-positive men and their HIV-negative partners (n = 116 couples, 232 men) completed questionnaires and HIV-positive men had blood drawn for viral load. Results of a multinomial logistic regression illustrated that sexual satisfaction was positively associated with PAI among HIV-negative partners and negatively associated with PAI among HIV-positive partners. Endorsing a “we” orientation was positively associated with PAI among HIV-positive partners. Findings suggest that HIV-positive partners who espouse a “we” orientation may be willing to forgo their personal interests to protect their HIV-negative partners from HIV transmission. Couples-based interventions are warranted to help strengthen relationship dynamics to enhance the sexual health of serodiscordant couples. PMID:23636681

Gamarel, K.E.; Starks, T.J; Dilworth, S.E.; Neilands, T.B.; Taylor, J.M.; Johnson, M.O.

2014-01-01

298

Estrogen receptor-alpha distribution in male rodents is associated with social organization.  

PubMed

It has been hypothesized that site-specific reduction of estrogen receptor-alpha (ERalpha) is associated with the expression of male prosocial behaviors. Specifically, highly social males are predicted to express significantly lower levels of ERalpha than females and less social males in brain regions associated with prosocial behavior including the bed nucleus of the stria terminalis (BST) and the medial amygdala (MeA). This hypothesis was tested by comparing ERalpha immunoreactivity (IR) in three species of microtines, the polygynous montane (Microtus montanus) and meadow (M. pennsylvanicus) voles and the monogamous pine vole (M. pinetorum), and two species of cricetines that differ in the extent of social pair-bond formation, Siberian (Phodopus sungorus) and Djungarian (P. campbelli) hamsters. As predicted, ERalpha-IR was sexually dimorphic in the BST and MeA of the highly social species, with females expressing more ERalpha-IR cells than males. Male and female montane voles did not differ. Male and female meadow voles differed in the ventromedial hypothalamus, with females expressing more ERalpha-IR cells. Male pine voles expressed lower levels of ERalpha-IR in the MeA than male montane and meadow voles and in the BST relative to montane males. Male Djungarian hamsters, which show higher levels of parental care, had fewer ERalpha-IR cells in the BST than male Siberian hamsters. Results indicate that the distribution of ERalpha differs relative to the continuum of species-typical affiliative behavior and supports the hypothesis that ERalpha has a significant role in regulating species-specific social organization. PMID:16374794

Cushing, Bruce S; Wynne-Edwards, Katherine E

2006-02-01

299

The Earliest Case of Extreme Sexual Display with Exaggerated Male Organs by Two Middle Jurassic Mecopterans  

PubMed Central

Background Many extant male animals exhibit exaggerated body parts for display, defense or offence in sexual selection, such as male birds of paradise showing off colorful and elegant feathers and male moose and reindeers bearing large structured antlers. For insects, male rhinoceros and stag beetles have huge horn-like structure for fighting and competition and some male Leptopanorpa scorpionflies have very long abdominal terminal segments for sexual display and competition. Fossil records of insects having exaggerated body parts for sexual display are fairly rare. One example is two male holcorpids with elongate abdominal segments from sixth (A6) to eighth (A8) and enlarged male genitalia from Eocene, suggesting evolution of these characters occurred fairly late. Principal Findings We document two mecopterans with exaggerated male body parts from the late Middle Jurassic Jiulongshan Formation in northeastern China. Both have extremely extended abdominal segments from A6 to A8 and enlarged genitalia, which might have been used for sexual display and, to less extent, for fighting with other males in the competition for mates. Although Fortiholcorpa paradoxa gen. et sp. nov. and Miriholcorpa forcipata gen. et sp. nov. seem to have affinities with Holcorpidae, we deem both as Family Incertae sedis mainly due to significant differences in branching pattern of Media (M) veins and relative length of A8 for F. paradoxa, and indiscernible preservation of 5-branched M veins in hind wing for M. forcipata. Conclusions/Significance These two new taxa have extended the records of exaggerated male body parts of mecopterans for sexual display and/or selection from the Early Eocene to the late Middle Jurassic. The similar character present in some Leptopanorpa of Panorpidae suggests that the sexual display and/or sexual selection due to extremely elongated male abdominal and sexual organs outweigh the negative impact of bulky body and poor mobility in the evolutionary process. PMID:23977031

Wang, Qi; Shih, Chungkun; Ren, Dong

2013-01-01

300

Epidemiology of male same-sex behaviour and associated sexual health indicators in low- and middle-income countries: 2003–2007 estimates  

PubMed Central

Objectives: To conduct a systematic review of published and unpublished data from research and public health information systems on the prevalence of male-to-male sex in the total male population; as well as among men who have sex with men (MSM), data on prevalence of heterosexual activity and heterosexual unions; prevalence of condom use with male and female partners; and prevalence of HIV infection and other sexually transmitted infections (STIs). Methods: Key indicators were defined (a) among men in the general population: prevalence of sex with a man ever and last year; (b) among MSM: prevalence of heterosexual experiences ever and last year; proportion of male-female transgenders; proportion of sex workers; prevalence of HIV and other STIs, condom use in last sexual encounter; consistent condom use with men last year; never used a condom with a man. With help from key informants, study searches were conducted in Pubmed, LILLACS, institutional databases, conference records and other sources. Methodology and quality of information were assessed, and the best data available for 2003–7 were selected. Indicator estimates from each study were used to propose regional estimate ranges. Results: A total of 83 new entries were entered into the database in addition to the previous 561, totalling 644. Of these, 107 showing 2003–7 data were selected. Many new studies came from sub-Saharan Africa, portraying hidden HIV epidemics among MSM. The most frequently reported estimate was HIV infection, with high estimate ranges in most of the regions, except for Middle East and North Africa and Eastern Europe. The next most frequently reported was lifetime frequency of heterosexual sex, showing that roughly 50% of MSM ever had sex with a woman. The small number of newer studies reporting prevalence of “sex with a man in last 12 months” between 2003 and 2007, did not warrant enough new evidence to revise our 2005 size estimates for MSM populations. Conclusions: A considerable number of new studies with estimates of relevance to understanding sexual behaviour and HIV among MSM were identified, with an encouraging amount of new data coming from sub-Saharan Africa. However, limitations in the quality, utility and comparability of available information persist. At least three measures could be promoted for use in surveillance and academic studies: standardised indicators for MSM studies; standardised operational definitions of, and instructions to describe, variables; and standardised research designs and data gathering strategies. A prerequisite for this all is intense advocacy to ensure a social climate in which research into such matters is prioritised, resources are made available as needed and the human rights of MSM are respected. PMID:18647866

Cáceres, C F; Konda, K; Segura, E R; Lyerla, R

2008-01-01

301

The effects of scale on the costs of targeted HIV prevention interventions among female and male sex workers, men who have sex with men and transgenders in India  

PubMed Central

Background The India AIDS Initiative (Avahan) project is involved in rapid scale-up of HIV-prevention interventions in high-risk populations. This study examines the cost variation of 107 non-governmental organisations (NGOs) implementing targeted interventions, over the start up (defined as period from project inception until services to the key population commenced) and first 2?years of intervention. Methods The Avahan interventions for female and male sex workers and their clients, in 62 districts of four southern states were costed for the financial years 2004/2005 and 2005/2006 using standard costing techniques. Data sources include financial and economic costs from the lead implementing partners (LPs) and subcontracted local implementing NGOs retrospectively and prospectively collected from a provider perspective. Ingredients and step-down allocation processes were used. Outcomes were measured using routinely collected project data. The average costs were estimated and a regression analysis carried out to explore causes of cost variation. Costs were calculated in US$ 2006. Results The total number of registered people was 134?391 at the end of 2?years, and 124?669 had used STI services during that period. The median average cost of Avahan programme for this period was $76 per person registered with the project. Sixty-one per cent of the cost variation could be explained by scale (positive association), number of NGOs per district (negative), number of LPs in the state (negative) and project maturity (positive) (p<0.0001). Conclusions During rapid scale-up in the initial phase of the Avahan programme, a significant reduction in average costs was observed. As full scale-up had not yet been achieved, the average cost at scale is yet to be realised and the extent of the impact of scale on costs yet to be captured. Scale effects are important to quantify for planning resource requirements of large-scale interventions. The average cost after 2?years is within the range of global scale-up costs estimates and other studies in India. PMID:20167740

Guinness, L; Kumaranayake, L; Reddy, Bhaskar; Govindraj, Y; Vickerman, P; Alary, M

2010-01-01

302

DNA damage in organs of female and male mice exposed to nonylphenol, as a single agent or in combination with ionizing irradiation: a comet assay study.  

PubMed

The effect of nonylphenol (NP; either alone or in combination with ionizing radiation) on the induction of DNA strand breaks in mouse somatic cells has been examined. Male and female mice were repeatedly irradiated with X-rays (0.05 or 0.10 Gy), injected with NP (25 or 50mg/kg bw), or both (0.05 Gy+25 mg/kg bw NP or 0.10 Gy+50 mg/kg bw NP), for 2 weeks, 5 days/week. Liver, spleen, femora, lungs and kidneys were removed from each animal for the comet assay. NP-induced DNA damage differed, depending on organ and sex. In male mice, NP induced damage in all organs examined; in females, only the kidneys were affected. The effect of irradiation alone was similar in females and males. Combined exposure of males to 0.05 Gy+25 mg/kg bw NP significantly reduced the level of DNA strand breaks, compared to the controls and to 25mg/kg bw NP alone, in the majority of organs. The higher doses significantly increased damage to DNA in all organs examined. Combined exposure of females to low doses of both agents significantly enhanced damage to DNA in bone marrow lymphocytes and in cells of the liver and kidneys, compared to controls. At 0.10 Gy+50 mg/kg bw NP, DNA damage was increased in organs except liver and spleen. Although NP alone may not be mutagenic in female mice, its co-administration with irradiation may increase DNA damage in some organs. In contrast, in male mice, damage was reduced after combined irradiation-NP exposure, compared to NP alone. PMID:25308542

Dobrzy?ska, Ma?gorzata M

2014-09-15

303

Sex-linked recessive  

MedlinePLUS

Inheritance - sex-linked recessive; Genetics - sex-linked recessive; X-linked recessive ... X-linked recessive diseases usually occur in males. Males have only one X chromosome. A single recessive ...

304

The chastity of amoebae: re-evaluating evidence for sex in amoeboid organisms  

PubMed Central

Amoebae are generally assumed to be asexual. We argue that this view is a relict of early classification schemes that lumped all amoebae together inside the ‘lower’ protozoa, separated from the ‘higher’ plants, animals and fungi. This artificial classification allowed microbial eukaryotes, including amoebae, to be dismissed as primitive, and implied that the biological rules and theories developed for macro-organisms need not apply to microbes. Eukaryotic diversity is made up of 70+ lineages, most of which are microbial. Plants, animals and fungi are nested among these microbial lineages. Thus, theories on the prevalence and maintenance of sex developed for macro-organisms should in fact apply to microbial eukaryotes, though the theories may need to be refined and generalized (e.g. to account for the variation in sexual strategies and prevalence of facultative sex in natural populations of many microbial eukaryotes). We use a revised phylogenetic framework to assess evidence for sex in several amoeboid lineages that are traditionally considered asexual, and we interpret this evidence in light of theories on the evolution of sex developed for macro-organisms. We emphasize that the limited data available for many lineages coupled with natural variation in microbial life cycles overestimate the extent of asexuality. Mapping sexuality onto the eukaryotic tree of life demonstrates that the majority of amoeboid lineages are, contrary to popular belief, anciently sexual, and that most asexual groups have probably arisen recently and independently. Additionally, several unusual genomic traits are prevalent in amoeboid lineages, including cyclic polyploidy, which may serve as alternative mechanisms to minimize the deleterious effects of asexuality. PMID:21429931

Lahr, Daniel J. G.; Parfrey, Laura Wegener; Mitchell, Edward A. D.; Katz, Laura A.; Lara, Enrique

2011-01-01

305

Human vocal organ: visible-human-male-based three-dimensional visualization  

NASA Astrophysics Data System (ADS)

The Visible Human Project planned and promoted by National Library of Medicine (NLM) provides cryosection images of the normal male and female human bodies. The anatomy of human vocal organ is difficult to understand and to imagine due to its complexity. The purpose of this study is to develop the three-dimensionally computerized atlas of the human vocal organ using Visible Human male dataset. A self-developed program with C language and a recent personal computer can show specific organs and structures separately or together, rotate them at three axes, cross-section them transparently at any angles, and zoom them in and out. As a result, our own PC-based program will be a more interactive, more detailed, and more realistic three-dimensional computerized atlas of a human vocal organ including larygopharynx.

Kim, Jae-woo; Lee, Donghun; Han, Jong H.; Kim, Bohyung; Kim, Dongsung; Kang, Heung Sik

2002-05-01

306

Is the rapid post-mating inhibition of pheromone response triggered by ecdysteroids or other factors from the sex accessory glands in the male moth Agrotis ipsilon?  

PubMed

In many animals, male copulation is dependent on the detection and processing of female-produced sex pheromones, which is generally followed by a sexual refractory post-ejaculatory interval (PEI). In the male moth, Agrotis ipsilon, this PEI is characterized by a transient post-mating inhibition of behavioral and central nervous responses to sex pheromone, which prevents males from re-mating until they have refilled their reproductive tracts for a potential new ejaculate. However, the timing and possible factors inducing this rapid olfactory switch-off are still unknown. Here, we determined the initial time delay and duration of the PEI. Moreover, we tested the hypothesis that the brain, the testis and/or the sex accessory glands (SAGs) could produce a factor inducing the PEI. Lastly, we investigated the possible involvement of ecdysteroids, hormones essential for development and reproduction in insects, in this olfactory plasticity. Using brain and SAG cross-injections in virgin and newly-mated males, surgical treatments, wind tunnel behavioral experiments and EIA quantifications of ecdysteroids, we show that the PEI starts very shortly after the onset of copulation, and that SAGs contain a factor, which is produced/accumulated after copulation to induce the PEI. Moreover, SAGs were found to be the main source of ecdysteroids, whose concentration decreased after mating, whereas it increased in the haemolymph. 20-Hydroxyecdysone (20E) was identified as the major ecdysteroid in SAGs of A. ipsilon males. Finally, 20E injections did not reduce the behavioral pheromone response of virgin males. Altogether our data indicate that 20E is probably not involved in the PEI. PMID:23562716

Vitecek, Simon; Maria, Annick; Blais, Catherine; Duportets, Line; Gaertner, Cyril; Dufour, Marie-Cécile; Siaussat, David; Debernard, Stéphane; Gadenne, Christophe

2013-05-01

307

Synthesis of syn-4,6-dimethyldodecanal, the male sex pheromone and trail-following pheromone of two species of the termite Zootermopsis  

Microsoft Academic Search

Recently, we reported that syn-4,6-dimethyldodecanal is the male sex pheromone and the trail-following pheromone of the Termopsidae Zootermopsis nevadensis and Zootermopsis angusticollis. In this article, we describe the syntheses of the mixture of the four stereoisomers of 4,6-dimethyldodecanal using a synthetic pathway where the key step is a Wittig reaction between methyl 4-methyl-5-oxo-pentanoate and 1-methylheptyl-triphenylphosphonium iodide, and of (±)-syn-4,6-dimethyldodecanal starting

J. Ghostin; C. Bordereau; J. C. Braekman

2011-01-01

308

Predictors of HIV Disclosure Among Untested, HIV-Negative and HIV-Positive Australian Men Who had Anal Intercourse with Their Most Recent Casual Male Sex Partner  

Microsoft Academic Search

We analysed HIV disclosure between Australian men who have sex with men (MSM) who reported anal intercourse with their last\\u000a casual male partner. Of 804 MSM included in the analysis, 413 reported HIV disclosure and 391 reported no disclosure. After\\u000a identifying bivariate associations with HIV disclosure, we developed three models of HIV disclosure (one for untested, one\\u000a for HIV-negative and

M. Holt; P. Rawstorne; H. Worth; M. Bittman; J. Wilkinson; S. Kippax

2011-01-01

309

Stimulation of Spermatogenesis or of Sex Reversal According to the Dose of Exogenous Estradiol17? in Juvenile Males of Protandrous Black Porgy, Acanthopagrus schlegeli  

Microsoft Academic Search

The objective was to investigate the effects of various doses of estradiol-17? (E2) on a gonadal development, gametogenesis, and plasma levels of sex steroids in 1-year-old protandrous male black porgy, Acanthopagrus schlegeli . Juvenile black porgy were divided into four groups, fed with control diet or diet mixed with E2 (0.25, 1.0, or 4.0 mg\\/kg feed) for 7 months, respectively.

Ching-Fong Chang; En-Lieng Lau; Bih-Yun Lin

1995-01-01

310

Single Sensillum responses in the male moth Adoxophyes orana (F.v.R.) to female sex pheromone components and their geometrical isomers  

Microsoft Academic Search

A technique is described for the recording of receptor and action potentials from the outer dendritic segments of the olfactory cells in individual antennalSensilla trichodea in insects. The 50 µm long olfactory hairs on the antennae of adult male summerfruit toftrix moth,Adoxophyes orana, are shown to possess two cells responsive to the female sex pheromone (a 9:1 mixture ofcis-9 andcis-11-TDA

C. J. Den Otter

1977-01-01

311

Is Audio Computer-Assisted Self-Interview (ACASI) Useful in Risk Behaviour Assessment of Female and Male Sex Workers, Mombasa, Kenya?  

Microsoft Academic Search

BackgroundAudio computer-assisted self-interview (ACASI) may elicit more frequent reporting of socially sensitive behaviours than face-to-face (FtF)-interview. However, no study compared responses to both methods in female and male sex workers (FSW; MSW) in Africa.Methodology\\/Principal FindingsWe sequentially enrolled adults recruited for an HIV-1 intervention trial into a comparative study of ACASI and FtF-interview, in a clinic near Mombasa, Kenya. Feasibility and

Elisabeth M. van der Elst; Haile Selassie Okuku; Phellister Nakamya; Allan Muhaari; Alun Davies; R. Scott McClelland; Matthew A. Price; Adrian D. Smith; Susan M. Graham; Eduard J. Sanders; Nitika Pant Pai

2009-01-01

312

Explanations of successful performance on sex-linked tasks: What is skill for the male is luck for the female  

Microsoft Academic Search

Instructed 55 male and 75 female undergraduates to evaluate the performance of either a male or female stimulus person who was heard to perform in an above-average manner on either a male- or female-related task. Analysis of the attributions made to luck vs skill in explaining the performance of the stimulus person showed that as predicted, performance by a male

Kay Deaux; Tim Emswiller

1974-01-01

313

Male or female soldiers? An evaluation of several factors which may influence soldier sex ratio in lower termites  

Microsoft Academic Search

.  In termites, the soldiers’ sex ratio is often biased toward one sex. Unlike in the Hymenoptera, this bias cannot easily be\\u000a explained by relatedness asymmetries because termites are diploid. Matsuura proposed that when large body size is adaptive\\u000a for colony defence (e.g. in case of phragmotic defence) then the larger sex (given sexual size dimorphism exists) should be\\u000a more likely

H. Muller; J. Korb

2008-01-01

314

How the Male Body Works Sexually  

MedlinePLUS

... urethra and out of the tip of the penis. The drawing below shows the male sex organs. The role of testosterone Testosterone is ... a man’s body, controls ejaculation of semen. How male orgasm ... (the tube running through the penis), so that it’s ready to be pushed out ( ...

315

Synaptonemal complex analysis of the X1X2Y trivalent in Mantis religiosa L. males: inferences on the origin and maintenance of the sex-determining mechanism.  

PubMed

Characterization of sex chromosomes in males of Mantis religiosa L. (2n = 24 + X1X2Y) was carried out by C-banding, silver staining and fluorescence in situ hybridization. They are meta- or submetacentric, their arms being designated as X1L, X1R, X2R, X2L, YL and YR. Meiotic behaviour of the sex trivalent was examined through the analysis of synaptonemal complexes (SCs), prometaphase I (metaphase I) and metaphase II nuclei. On the basis of the SC analysis, chromosomal length measurements at mitosis and prometaphase I and data from several orthopteran species, it is proposed that the breakpoints of the reciprocal translocation that originated this complex sex-determining mechanism were close to the centromeres of the X and the largest autosome, and that the asynapsed X1L and X2R regions observed in the sex trivalent at pachytene represent the original X chromosome. The X centromere being probably that of the X2 element because it lacks a partner in the SC pachytene trivalent. The relationship among synaptic pattern, chiasma localization and balanced segregation of the sex trivalent is also discussed. PMID:9580125

del Cerro, A L; Cuñado, N; Santos, J L

1998-01-01

316

Consistent condom use with regular, paying, and casual male partners and associated factors among men who have sex with men in Tamil Nadu, India: findings from an assessment of a large-scale HIV prevention program  

PubMed Central

Background Men who have sex with men (MSM) are a marginalized population at high risk for HIV infection. Promoting consistent condom use (CCU) during anal sex is a key risk reduction strategy for HIV prevention among MSM. To inform effective HIV prevention interventions, we examined the factors associated with CCU among MSM with their regular, paying, and casual partners, as well as with all three types of partners combined. Methods Data for this analysis were from a large-scale bio-behavioural survey conducted during 2009–2010 in Tamil Nadu, India. MSM aged 18 years or older were recruited for the survey using time-location cluster sampling at cruising sites in four districts of Tamil Nadu. Binary logistic regression analyses were conducted to assess the association of CCU with selected socio-demographic characteristics and other contextual factors. Results Among 1618 MSM interviewed, CCU during anal sex with regular, paying, and a casual male partner was 45.3%, 50.8% and 57.9%, respectively. CCU with all three types of partners combined was 52.6%. Characteristics associated with increased odds for CCU with MSM having all three types of partners combined were frequent receptive anal sex acts with regular partners (adjusted odds ratio [AOR] 2.17, 95% confidence interval [CI] 1.01-4.65), fewer number of casual partners (AOR 3.41, 95% CI 1.50-7.73) and membership in a community-based organization (CBO) for MSM (AOR 3.54, 95% CI 1.62-7.74). CCU with regular partners was associated with membership in a CBO (AOR 1.96, 95% CI 1.23-3.11), whereas CCU with paying, and casual male partners was associated with perceived higher risk of acquiring HIV (AOR 1.92, 95% CI 1.22-3.01) and exposure to any HIV prevention intervention (AOR 3.62, 95% CI 1.31-10.0), respectively. Being aged 26 years or older, being in debt, and alcohol use were factors associated with inconsistent condom use across partner types. Conclusion HIV interventions among MSM need to promote CCU with all types (regular, paying, and causal) of male partners, and need to reach MSM across all age groups. In addition to enhancing interventions that focus on individual level risk reduction, it is important to undertake structural interventions that promote social acceptance of same-sex sexuality and address contextual barriers to condom use such as alcohol use. PMID:24020613

2013-01-01

317

Effects of Vomeronasal Organ Removal on Individual Odor Discrimination, Sex-Odor Preference, and Scent Marking by Female Hamsters  

Microsoft Academic Search

Removal of the vomeronasal organ (VNX) did not eliminate the ability of female hamsters to discriminate between individual male’s flank gland or urine odors in a habituation\\/discrimination task nor did it impair preference for male odors over female odors from a distance. Vomeronasal organ removal did reduce overall levels of investigation of flank gland odor in the habituation\\/discrimination task. Although

Aras Petrulis; Marlene Peng; Robert E Johnston

1999-01-01

318

Organ doses for reference adult male and female undergoing computed tomography estimated by Monte Carlo simulations  

PubMed Central

Purpose: To develop a computed tomography (CT) organ dose estimation method designed to readily provide organ doses in a reference adult male and female for different scan ranges to investigate the degree to which existing commercial programs can reasonably match organ doses defined in these more anatomically realistic adult hybrid phantoms Methods: The x-ray fan beam in the SOMATOM Sensation 16 multidetector CT scanner was simulated within the Monte Carlo radiation transport code MCNPX2.6. The simulated CT scanner model was validated through comparison with experimentally measured lateral free-in-air dose profiles and computed tomography dose index (CTDI) values. The reference adult male and female hybrid phantoms were coupled with the established CT scanner model following arm removal to simulate clinical head and other body region scans. A set of organ dose matrices were calculated for a series of consecutive axial scans ranging from the top of the head to the bottom of the phantoms with a beam thickness of 10 mm and the tube potentials of 80, 100, and 120 kVp. The organ doses for head, chest, and abdomen?pelvis examinations were calculated based on the organ dose matrices and compared to those obtained from two commercial programs, CT-EXPO and CTDOSIMETRY. Organ dose calculations were repeated for an adult stylized phantom by using the same simulation method used for the adult hybrid phantom. Results: Comparisons of both lateral free-in-air dose profiles and CTDI values through experimental measurement with the Monte Carlo simulations showed good agreement to within 9%. Organ doses for head, chest, and abdomen?pelvis scans reported in the commercial programs exceeded those from the Monte Carlo calculations in both the hybrid and stylized phantoms in this study, sometimes by orders of magnitude. Conclusions: The organ dose estimation method and dose matrices established in this study readily provides organ doses for a reference adult male and female for different CT scan ranges and technical parameters. Organ doses from existing commercial programs do not reasonably match organ doses calculated for the hybrid phantoms due to differences in phantom anatomy, as well as differences in organ dose scaling parameters. The organ dose matrices developed in this study will be extended to cover different technical parameters, CT scanner models, and various age groups. PMID:21520832

Lee, Choonsik; Kim, Kwang Pyo; Long, Daniel; Fisher, Ryan; Tien, Chris; Simon, Steven L.; Bouville, Andre; Bolch, Wesley E.

2011-01-01

319

Dimensions Underlying Student Perceptions of Religion, Sex, and Alcohol: Male and Female Differences. Research Report No. 5-83.  

ERIC Educational Resources Information Center

Identifying the variables which influence student attitudes, perceptions, and behavior patterns in regard to religion, sex, and alcohol has been a major source of investigation. To determine the dimensions underlying the relationship among religion, sex, alcohol use, and alcohol knowledge among university students, 376 University of Maryland…

Patterson, Aldrich M., Jr.; Sedlacek, William E.

320

Perceptions of Female and Male Superintendents for a Middle School Principalship as Moderated by Sex and National Origin of Applicants  

ERIC Educational Resources Information Center

A 2 x 2 x 2 factorial design involving sex of superintendents, sex of applicants, and national origin of applicants (Hispanic vs. non-Hispanic) is used to assess screening decisions for a middle school principalship. Screening decisions are analyzed from a sequential model to capture selection as a process. Results indicate that biases surface…

Young, Phillip; Young, Karen Holsey

2010-01-01

321

Increase of Trap Catches by a Combination of Male Sex Pheromones and Floral Attractant in Longhorn Beetle, Anaglyptus subfasciatus  

Microsoft Academic Search

A combination of the synthetic sex pheromone [a 125:1 blend of (R)-3-hydroxy-2-hexanone and (R)-3-hydroxy-2-octanone] with methyl phenylacetate captured significantly moreAnaglyptus subfasciatus Pic females than either the sex pheromone or methyl phenylacetate did alone.

Kiyoshi Nakamuta; Walter S. Leal; Tadakazu Nakashima; Masahiko Tokoro; Mikio Ono; Michitaka Nakanishi

1997-01-01

322

Acceptability of vaginal microbicides among female sex workers and their intimate male partners in two Mexico-US border cities: a mixed methods analysis.  

PubMed

Female sex workers (FSWs) may benefit from pre-exposure prophylaxis (PrEP) including microbicides for HIV prevention. Since adherence is a key factor in PrEP efficacy, we explored microbicide acceptability and potential barriers to use within FSWs' intimate relationships in Tijuana and Ciudad Juárez, Mexico, where HIV prevalence is increasing. FSWs and their verified intimate (non-commercial) male partners completed quantitative and qualitative interviews from 2010 to 2012. Our complementary mixed methods design followed an iterative process to assess microbicide acceptability, explore related relationship dynamics and identify factors associated with concern about male partners' anger regarding microbicide use. Among 185 couples (n=370 individuals), interest in microbicides was high. In qualitative interviews with 28 couples, most participants were enthusiastic about microbicides for sex work contexts but some explained that microbicides could imply mistrust/infidelity within their intimate relationships. In the overall sample, nearly one in six participants (16%) worried that male partners would become angry about microbicides, which was associated with higher self-esteem among FSWs and lower self-esteem and past year conflicts causing injury within relationships among men. HIV prevention interventions should consider intimate relationship dynamics posing potential barriers to PrEP acceptability and adherence, involve male partners and promote risk communication skills. PMID:23398385

Robertson, Angela M; Syvertsen, Jennifer L; Martinez, Gustavo; Rangel, M Gudelia; Palinkas, Lawrence A; Stockman, Jamila K; Ulibarri, Monica D; Strathdee, Steffanie A

2013-01-01

323

Sex-Specific Differences in Hemodialysis Prevalence and Practices and the Male-to-Female Mortality Rate: The Dialysis Outcomes and Practice Patterns Study (DOPPS)  

PubMed Central

Background A comprehensive analysis of sex-specific differences in the characteristics, treatment, and outcomes of individuals with end-stage renal disease undergoing dialysis might reveal treatment inequalities and targets to improve sex-specific patient care. Here we describe hemodialysis prevalence and patient characteristics by sex, compare the adult male-to-female mortality rate with data from the general population, and evaluate sex interactions with mortality. Methods and Findings We assessed the Human Mortality Database and 206,374 patients receiving hemodialysis from 12 countries (Australia, Belgium, Canada, France, Germany, Italy, Japan, New Zealand, Spain, Sweden, the UK, and the US) participating in the international, prospective Dialysis Outcomes and Practice Patterns Study (DOPPS) between June 1996 and March 2012. Among 35,964 sampled DOPPS patients with full data collection, we studied patient characteristics (descriptively) and mortality (via Cox regression) by sex. In all age groups, more men than women were on hemodialysis (59% versus 41% overall), with large differences observed between countries. The average estimated glomerular filtration rate at hemodialysis initiation was higher in men than women. The male-to-female mortality rate ratio in the general population varied from 1.5 to 2.6 for age groups <75 y, but in hemodialysis patients was close to one. Compared to women, men were younger (mean?=?61.9±standard deviation 14.6 versus 63.1±14.5 y), were less frequently obese, were more frequently married and recipients of a kidney transplant, more frequently had coronary artery disease, and were less frequently depressed. Interaction analyses showed that the mortality risk associated with several comorbidities and hemodialysis catheter use was lower for men (hazard ratio [HR]?=?1.11) than women (HR?=?1.33, interaction p<0.001). This study is limited by its inability to establish causality for the observed sex-specific differences and does not provide information about patients not treated with dialysis or dying prior to a planned start of dialysis. Conclusions Women's survival advantage was markedly diminished in hemodialysis patients. The finding that fewer women than men were being treated with dialysis for end-stage renal disease merits detailed further study, as the large discrepancies in sex-specific hemodialysis prevalence by country and age group are likely explained by factors beyond biology. Modifiable variables, such as catheter use, showing significant sex interactions suggest interventional targeting. Please see later in the article for the Editors' Summary PMID:25350533

Hecking, Manfred; Bieber, Brian A.; Ethier, Jean; Kautzky-Willer, Alexandra; Sunder-Plassmann, Gere; Säemann, Marcus D.; Ramirez, Sylvia P. B.; Gillespie, Brenda W.; Pisoni, Ronald L.; Robinson, Bruce M.; Port, Friedrich K.

2014-01-01

324

Annual changes in testicular development and occurrence of parasperm in the male reproductive organs of fourspine sculpin, Cottus kazika  

Microsoft Academic Search

Annual changes in testicular development and occurrence of parasperm were investigated using 2-year-old male fourspine sculpins\\u000a Cottus kazika, based on the histological observation of testes. The male reproductive organ of fourspine sculpins comprised a pair of testes\\u000a and a sperm duct that functioned as a sperm-storage organ. Male maturity was divided into the following periods: spermatogonial\\u000a proliferation period (September), early

Daisuke Tahara; Ryou Hatano; Hozi Iwatani; Yasunori Koya; Youichi Hayakawa

2010-01-01

325

Sex-specific parental care strategies via nestling age: females pay more attention to nestling demands than males do in the horned lark, Eremophila alpestris.  

PubMed

In many species, nestling demands vary continuously during early development and both parents have different parental care strategies at each nestling age. Sexual conflict arises when each parent expects its partner investing more in parental care. It is largely unknown how the two parents respond to the dynamics of nestling demands and resolve the sexual conflict during nestling period, especially on Qinghai-Tibetan Plateau. To address this question, we monitored parental care behaviors of horned larks (Eremophila alpestris) using video-recording systems. We found that male horned larks invested less in parental care, but had a larger body size than females, which is consistent with the parental investment hypothesis. Only the female brooded nestlings, but both parents contributed to feeding efforts. Feeding rates of males and females were negatively correlated, indicating that they used evolutionarily stable strategies. Strategies of parental care via nestling age were sex-specific. Females continuously adjusted care behaviors to follow the dynamics of nestling demands as nestling age increased, such as decreasing brood attentiveness and increasing feeding rate. By contrast, male feeding rate showed no significant correlation with nestling age, but increased with the synchrony feeding rate. We suggest the synchrony feeding behavior may act as a control measure for females to promote and assess the males' contribution. We consider low mating opportunities drive males to act as assistants for females, and correspondingly cause males to pay less attention to nestling demands than females. PMID:24882094

Liu, Chang-Jing; Du, Bo; Liu, Nai-Fa; Bao, Shi-Jie; Zhang, Shengxiang

2014-06-01

326

Isolation of Y Chromosome-Specific Sequences from Silene Latifolia and Mapping of Male Sex-Determining Genes Using Representational Difference Analysis  

PubMed Central

The genomic subtraction method representational difference analysis (RDA) was used to identify male-specific restriction fragments in the dioecious plant Silene latifolia. Male-specific restriction fragments are linked to the male sex chromosome (the Y chromosome). Four RDA-derived male-specific restriction fragments were used to identify polymorphisms in a collection of X-ray-generated mutant plants with either hermaphroditic or asexual flowers. Some of the mutants have cytologically detectable deletions in the Y chromosome that were correlated with loss of male-specific restriction fragments. One RDA-derived probe detected a restriction fragment present in all mutants, indicating that each has retained Y chromosomal DNA. The other three probes detected genomic fragments that were linked in a region deleted in some hermaphroditic and some asexual mutants. Based on the mutant phenotypes and the correlation of cytologically visible deletions with loss of male-specific restriction fragments, these markers were assigned to positions on the Y chromosome close to the carpel suppression locus. This RDA mapping also revealed a Y-linked locus, not previously described, which is responsible for early stamen development. PMID:8978072

Donnison, I. S.; Siroky, J.; Vyskot, B.; Saedler, H.; Grant, S. R.

1996-01-01

327

Alarm pheromone is detected by the vomeronasal organ in male rats.  

PubMed

It is widely known that a stressed animal releases specific pheromones, possibly for alarming nearby conspecifics. We previously investigated an alarm pheromone in male rats and found that this alarm pheromone evokes several responses, including increases in the defensive and risk assessment behaviors in a modified open-field test, and enhancement of the acoustic startle reflex. However, the role of the vomeronasal organ in these pheromone effects remains unclear. To clarify this point, vomeronasal organ-excising or sham surgeries were performed in male rats for use in 2 experimental models, after which they were exposed to alarm pheromone. We found that the vomeronasal organ-excising surgery blocked the effects of this alarm pheromone in both the modified open-field test and acoustic startle reflex test. In addition, the results of habituation/dishabituation test and soybean agglutinin binding to the accessory olfactory bulb suggested that the vomeronasal organ-excising surgery completely ablated the vomeronasal organ while preserving the functioning of the main olfactory system. From the above results, we showed that the vomeronasal organ plays an important role in alarm pheromone effects in the modified open-field test and acoustic startle reflex test. PMID:23821727

Kiyokawa, Yasushi; Kodama, Yuka; Kubota, Takahiro; Takeuchi, Yukari; Mori, Yuji

2013-10-01

328

Involvement in Specific HIV Risk Practices among Men Who Use the Internet to Find Male Partners for Unprotected Sex  

PubMed Central

Purpose. Men who have sex with other men (MSM) account for more than one-half of all new HIV infections in the USA. This study reports on the prevalence of a variety of HIV risk behaviors in one specific subpopulation of risk-seeking MSM. Methods. The study was based on a national sample of 332 MSM who use the Internet to find partners for unprotected sex. Data collection was conducted via telephone interviews between January 2008 and May 2009. Results. Unprotected oral and anal sex was commonplace among study participants. Men engaged in a large number of other risky behaviors as well, including having had multiple recent sex partners (mean number = 11), simultaneous double-penile penetration of the anus (16%), eating semen out of another man's anus (17%), engaging in multiple-partner sexual encounters (47%), engaging in anonymous sex (51%), and having sex while “under the influence” (52%). Conclusions. HIV intervention and prevention programs need to address numerous behaviors that place MSM at risk for contracting/transmitting HIV. Merely focusing on unprotected anal sex does a disservice to members of this community, who typically engage in many types of behavioral risks, each of which requires addressing if HIV transmission rates are to be reduced. PMID:24826369

2013-01-01

329

Sex differences, effects of male presence and coordination of nest visits in prairie voles (Microtus ochrogaster) during the immediate postnatal period  

USGS Publications Warehouse

Little is known about sex differences in parental behavior of biparental mammals and if mates in such species coordinate care of young. We studied parental care displayed by prairie voles (Microtus ochrogaster) under seminatural laboratory conditions during the first 3 d of life of their offspring. Through direct observations and videotaping, we monitored members of male-female pairs to determine if sex differences in early parental behavior exist and if mothers and fathers coordinate visits to the nest. To assess the impact of fathers on survival of pups and behavior of mothers, we also examined parental care displayed by single females toward their young. Male and female members of breeding pairs differed dramatically in degree of parental care. Females spent more time in the nest with young and licked them more frequently than did males. Additionally, females maintained the nest more frequently than did males, whereas they maintained runways less frequently. Although coordination of visits to the nest was not perfect between members of pairs, pups of pairs were left alone for less time than were pups of single females. Parental behavior displayed by paired and single females did not differ, nor did survival of their young to day 3 or 15. We suggest that provision of ample space and cover to vole parents rearing young in captivity promotes expression of sex differences in parental behavior, but that even seminatural conditions are not sufficient to yield benefits of father presence to survival of young. Under more challenging conditions, such as cold temperatures or presence of predators, benefits of father presence might emerge.

Mcguire, B.; Parker, E.; Bemis, W.E.

2007-01-01

330

Spermatogenesis, epididymis morphology and plasma sex steroid secretion in the male lizard Podarcis sicula exposed to diuron.  

PubMed

The present study investigates the effects of diuron, a substituted urea-based herbicide, in the male lizard Podarcis sicula utilizing quantitative and qualitative morphological features of the reproductive system and endocrinological analysis. Besides the control group, lizards were divided into three groups ([a-c]) (n=6/group) and placed for 3 weeks in terraria on polluted soil substrate sprayed with 3.75 L/ha of herbicide Toterbane 50F (50% diuron). Each terrarium was supplemented either with drinking water contaminated by herbicide (i.e. 1.08 microg/mL of diuron; group [a]), or with food contaminated by herbicide (i.e. 5.4 mg of diuron; group [b]), or with drinking water and food contaminated as described above (group [c]). None of the animals exposed to the contaminant showed any signs of general toxicity or death during the course of the experiments. Severe testicular effects are evidenced in all herbicide-treated groups, although, such effects are of a greater magnitude in lizards exposed to contaminated water (groups [a] and [c]). The main degenerative changes observed include: (1) a significant decrease in the mean gonadosomatic index of 55% in group [a] (P<0.001), 21% in group [b] (P<0.01) and 34% in group [c] (P<0.001) compared with control group; (2) a significant shrinking (P<0.001) of seminiferous tubule diameter (more than 60% of the control) in groups [a] and [c], and about 18% in group [b] (P<0.01); (3) a significant decrease in the crude numbers of spermatogonia of 92% in group [a] (P<0.001), 27% in group [b] (P<0.01) and 62% in group [c] (P<0.001) compared with control group. A complete loss of meiotic and mature germ cells in groups [a] and [c], and a reduction of primary spermatocytes, secondary spermatocytes and spermatids (more than 27% of the control) and a decrease of spermatozoa (more than 90% of the control) in group [b]; and (4) an hypertrophy of interstitial connective tissue which contains numerous lymphocytes, neutrophils and monocytes. The decrease and/or loss of germ cells seems to be related to an induction of inflammation (necrosis) rather than to apoptotic processes. Indeed, this hypothesis is supported by a TUNEL-assay, which failed to reveal any apoptotic cells either in the seminiferous epithelium or in the interstitial space in the testis of all exposed groups. Also the epididymis appears affected by diuron exposure. In particular, in experimental groups [a] and [c] it is regressed with abundant connective tissue and low epithelial cells without secretory granules, whereas in group [b] it appears partially regressed, with some secretory granules still present. At the same time, an impairment of the plasma sex-hormone levels is observed in treated lizards, as evidenced by RIA analysis. Testosterone values significantly decreased by 43% in group [a] (P<0.001), 34% in group [b] (P<0.01) and 52% in group [c] compared with control group. Instead, 17beta-estradiol plasma content is undetectable in all diuron-exposed lizards. Taken together, the results presented here indicate that diuron exposure resulted in direct male reproductive toxicity and reveal that this lizard is suitable as a laboratory reptile species for toxicological investigations. PMID:18760409

Cardone, Anna; Comitato, Raffaella; Angelini, Francesco

2008-10-01

331

Cuelure but not zingerone make the sex pheromone of male Bactrocera tryoni (Tephritidae: Diptera) more attractive to females.  

PubMed

In tephritid fruit flies of the genus Bactrocera Macquart, a group of plant derived compounds (sensu amplo 'male lures') enhance the mating success of males that have consumed them. For flies responding to the male lure methyl eugenol, this is due to the accumulation of chemicals derived from the male lure in the male rectal gland (site of pheromone synthesis) and the subsequent release of an attractive pheromone. Cuelure, raspberry ketone and zingerone are a second, related group of male lures to which many Bactrocera species respond. Raspberry ketone and cuelure are both known to accumulate in the rectal gland of males as raspberry ketone, but it is not known if the emitted male pheromone is subsequently altered in complexity or is more attractive to females. Using Bactrocera tryoni as our test insect, and cuelure and zingerone as our test chemicals, we assess: (i) lure accumulation in the rectal gland; (ii) if the lures are released exclusively in association with the male pheromone; and (iii) if the pheromone of lure-fed males is more attractive to females than the pheromone of lure-unfed males. As previously documented, we found cuelure was stored in its hydroxyl form of raspberry ketone, while zingerone was stored largely in an unaltered state. Small but consistent amounts of raspberry ketone and ?-(4-hydroxy-3-methoxyphenyl)-propionic acid were also detected in zingerone-fed flies. Males released the ingested lures or their analogues, along with endogenous pheromone chemicals, only during the dusk courtship period. More females responded to squashed rectal glands extracted from flies fed on cuelure than to glands from control flies, while more females responded to the pheromone of calling cuelure-fed males than to control males. The response to zingerone treatments in both cases was not different from the control. The results show that male B. tryoni release ingested lures as part of their pheromone blend and, at least for cuelure, this attracts more females. PMID:25010549

Kumaran, Nagalingam; Hayes, R Andrew; Clarke, Anthony R

2014-09-01

332

On the Eyes of Male Coffee Berry Borers as Rudimentary Organs  

PubMed Central

The coffee berry borer, Hypothenemus hampei, is the most damaging insect pest of coffee worldwide. Like males in other species in the genus, male coffee berry borers have a lower number of facets in the compound eyes than females. The rudimentary eyes in male coffee berry borers could be an evolutionary response to their cryptic life habit, whereby they are born inside a coffee berry and never leave the berry. The main objective of the study was to determine if the differences in the number of facets translates into differences in visual acuity. We used low-temperature scanning electron microscopy to visualize and quantify the number of facets in the compound eyes. There was a significantly lower (p<0.0001) number of facets in males (19.1±4.10) than in females (127.5±3.88). To assess visual acuity, we conducted optomotor response experiments, which indicate that females respond to movement, while males did not respond under the conditions tested. The coffee berry borer is an example of an insect whereby disuse of an organ has led to a rudimentary compound eye. This is the first study that has experimentally tested responses to movement in bark beetles. PMID:24465752

Vega, Fernando E.; Simpkins, Ann; Bauchan, Gary; Infante, Francisco; Kramer, Matthew; Land, Michael F.

2014-01-01

333

On the eyes of male coffee berry borers as rudimentary organs.  

PubMed

The coffee berry borer, Hypothenemus hampei, is the most damaging insect pest of coffee worldwide. Like males in other species in the genus, male coffee berry borers have a lower number of facets in the compound eyes than females. The rudimentary eyes in male coffee berry borers could be an evolutionary response to their cryptic life habit, whereby they are born inside a coffee berry and never leave the berry. The main objective of the study was to determine if the differences in the number of facets translates into differences in visual acuity. We used low-temperature scanning electron microscopy to visualize and quantify the number of facets in the compound eyes. There was a significantly lower (p<0.0001) number of facets in males (19.1 ± 4.10) than in females (127.5 ± 3.88). To assess visual acuity, we conducted optomotor response experiments, which indicate that females respond to movement, while males did not respond under the conditions tested. The coffee berry borer is an example of an insect whereby disuse of an organ has led to a rudimentary compound eye. This is the first study that has experimentally tested responses to movement in bark beetles. PMID:24465752

Vega, Fernando E; Simpkins, Ann; Bauchan, Gary; Infante, Francisco; Kramer, Matthew; Land, Michael F

2014-01-01

334

Sexual compulsivity and high-risk sex among Latino men: the role of internalized homonegativity and gay organizations  

PubMed Central

The objective of this study was to measure the correlation between compulsive sexual behavior (CSB) and internalized homonegativity (IH) and determine their association with unprotected anal intercourse in Latino men who have sex with men. Nine hundred sixty-three Latino men completed an Internet survey (MINTS study) in 2002 and provided data on two scale exposures. Logistic regression was used to test interactions and generate effect estimates. Higher IH and association with gay organizations modified the effect of CSB on high-risk sex. Drug and alcohol use also contributed to risk behavior for this subgroup. Overall, CSB had a strong association with high-risk sex. IH and gay organization membership may moderate this relationship, which illuminates an additional factor to consider in studying sexual risk-taking. Further work is needed to validate a path from IH and high-risk sex that incorporates drug or alcohol use. PMID:19085219

Smolenski, Derek J.; Ross, Michael W.; Risser, Jan M.H.; Rosser, B.R. Simon

2013-01-01

335

Sex Differences in the Response to Viral Infections: TLR8 and TLR9 Ligand Stimulation Induce Higher IL10 Production in Males  

PubMed Central

Background Susceptibility to viral infections as well as their severity are higher in men than in women. Heightened antiviral responses typical of women are effective for rapid virus clearance, but if excessively high or prolonged, can result in chronic/inflammatory pathologies. We investigated whether this variability could be in part attributable to differences in the response to the Toll-Like Receptors (TLR) more involved in the virus recognition. Methods Cytokine production by peripheral blood mononuclear cells (PBMCs) from male and female healthy donors after stimulation with Toll-like receptors (TLR) 3, 7, 8, 9 ligands or with viruses (influenza and Herpes-simplex-1) was evaluated. Results Compared to females, PBMCs from males produced not only lower amounts of IFN-? in response to TLR7 ligands but also higher amounts of the immunosuppressive cytokine IL10 after stimulation with TLR8 and TLR9 ligands or viruses. IL10 production after TLR9 ligands or HSV-1 stimulation was significantly related with plasma levels of sex hormones in both groups, whereas no correlation was found in cytokines produced following TLR7 and TLR8 stimulation. Conclusions Given the role of an early production of IL10 by cells of innate immunity in modulating innate and adaptive immune response to viruses, we suggest that sex-related difference in its production following viral nucleic acid stimulation of TLRs may be involved in the sex-related variability in response to viral infections. PMID:22768144

Torcia, Maria Gabriella; Nencioni, Lucia; Clemente, Ann Maria; Civitelli, Livia; Celestino, Ignacio; Limongi, Dolores; Fadigati, Giulia; Perissi, Eloisa; Cozzolino, Federico; Garaci, Enrico; Palamara, Anna Teresa

2012-01-01

336

African American males’ civic engagement: The importance of social organization involvement and friendship diversity  

Microsoft Academic Search

Using an ecological framework this study examines the relationships of micro- (personal characteristics and community commitment),\\u000a mezzo-(trust and social network) and macro-level factors (social organization involvement and faith-based capital) and civic\\u000a engagement, in a sample of African Americans males. Two research questions were examined: When micro-level factors are controlled\\u000a for are macro- and mezzo- level factors predictive of civic engagement

G. Lawrence Farmer

2006-01-01

337

Synergistic effect of fadrozole and insulin-like growth factor-I on female-to-male sex reversal and body weight of broiler chicks.  

PubMed

The aim of this study was to investigate the effects of Fadrozole hydrochloride and recombinant human insulin-like growth factor I (rhIGF-I) on female-to-male sex reversal, hatching traits, and body weight of broiler chickens. On the third day of incubation, fertile eggs were randomly assigned to five experimental groups comprising (i) Fadrozole (0.1 mg/egg), (ii) rhIGF-I (100 ng/egg), (iii) Fadrozole (0.1 mg/egg) + rhIGF-I (100 ng/egg), (iv) vehicle injection (10 mM acetic acid and 0.1% BSA), and (v) non-injected eggs. Eggs in the rhIGF-I-injected groups showed the mode of hatching time at the 480th hour of incubation, 12 hours earlier compared to the other groups, with no statistically significant difference in mortality and hatchability. On Day 1 and 42 of production, 90% of genetically female chicks were masculinized using Fadrozole treatment, while 100% female-to-male phenotypic sex reversal was observed in the Fadrozole+rhIGF-I group. Fadrozole equalized the body weight of both genders, although rhIGF-I was effective on the body weight of male chicks only. Interestingly, combined rhIGF-I and Fadrozole could increase the body weight in both sexes compared to the individual injections (P<0.05). These findings revealed that (i) IGF-I-treated chicken embryos were shown to be an effective option for overcoming the very long chicken deprivation period, (ii) the simultaneous treatment with Fadrozole and IGF-I could maximize the female-to-male sex reversal chance, (iii) the increase in the body weight of masculinized chickens via Fadrozole could be equal to their genetically male counterparts, and (iv) the IGF-I effectiveness, specifically along with the application of aromatase inhibitors in female chicks, indicates that estrogen synthesis could be a stumbling block for the IGF-I action mechanism in female embryos. PMID:25075864

Mohammadrezaei, Mohammad; Toghyani, Majid; Gheisari, Abbasali; Toghyani, Mehdi; Eghbalsaied, Shahin

2014-01-01

338

Synergistic Effect of Fadrozole and Insulin-Like Growth Factor-I on Female-To-Male Sex Reversal and Body Weight of Broiler Chicks  

PubMed Central

The aim of this study was to investigate the effects of Fadrozole hydrochloride and recombinant human insulin-like growth factor I (rhIGF-I) on female-to-male sex reversal, hatching traits, and body weight of broiler chickens. On the third day of incubation, fertile eggs were randomly assigned to five experimental groups comprising (i) Fadrozole (0.1 mg/egg), (ii) rhIGF-I (100 ng/egg), (iii) Fadrozole (0.1 mg/egg) + rhIGF-I (100 ng/egg), (iv) vehicle injection (10 mM acetic acid and 0.1% BSA), and (v) non-injected eggs. Eggs in the rhIGF-I-injected groups showed the mode of hatching time at the 480th hour of incubation, 12 hours earlier compared to the other groups, with no statistically significant difference in mortality and hatchability. On Day 1 and 42 of production, 90% of genetically female chicks were masculinized using Fadrozole treatment, while 100% female-to-male phenotypic sex reversal was observed in the Fadrozole+rhIGF-I group. Fadrozole equalized the body weight of both genders, although rhIGF-I was effective on the body weight of male chicks only. Interestingly, combined rhIGF-I and Fadrozole could increase the body weight in both sexes compared to the individual injections (P<0.05). These findings revealed that (i) IGF-I-treated chicken embryos were shown to be an effective option for overcoming the very long chicken deprivation period, (ii) the simultaneous treatment with Fadrozole and IGF-I could maximize the female-to-male sex reversal chance, (iii) the increase in the body weight of masculinized chickens via Fadrozole could be equal to their genetically male counterparts, and (iv) the IGF-I effectiveness, specifically along with the application of aromatase inhibitors in female chicks, indicates that estrogen synthesis could be a stumbling block for the IGF-I action mechanism in female embryos. PMID:25075864

Mohammadrezaei, Mohammad; Toghyani, Majid; Gheisari, Abbasali; Toghyani, Mehdi; Eghbalsaied, Shahin

2014-01-01

339

China’s excess males, sex selective abortion, and one child policy: analysis of data from 2005 national intercensus survey  

Microsoft Academic Search

Objectives To elucidate current trends and geographical patterns in the sex ratio at birth and in the population aged under 20 in China and to determine the roles played by sex selective abortion and the one child policy.Design Analysis of household based cross sectional population survey done in November 2005.Setting All of China’s 2861 counties.Population 1% of the total population,

Wei Xing Zhu; Li Lu; Therese Hesketh

2009-01-01

340

Microtus oeconomus (Rodentia), a useful mammal for studying the induction of sex-chromosome nondisjunction and diploid gametes in male germ cells.  

PubMed Central

Preliminary data indicate that chemicals can also increase the frequency of sex-chromosome nondisjunction. Positive results--which certainly need further confirmation--have been obtained for MMS, p-fluorophenylalanine, vincristine, procarbazine, carbendazim, and bleomycin. Nocodazole, benomyl, colcemic, 6-mercaptopurine, and halothane were all negative at the concentrations tested. For the induction of diploid spermatids positive results were only obtained for MMS and parafluorophenylalanine. In view of the results obtained, the Microtus system is considered a very useful tool for analyzing factors contributing to the high frequency of aneuploidy and triploidy among abortuses and of aneuploidy in liveborn infants of men. A method is described for the detection of sex-chromosome nondisjunction and diploid spermatids in male germ cells of the field vole Microtus oeconomus. The method is based on the unique distribution pattern of heterochromatin in Microtus cells, which makes it possible to identify X and Y chromosomes in early spermatids with a simple C-banding procedure. Slide preparation is easy. Scoring of early spermatids for extra sex-chromosomes is simple and 2000-4000 cells per hour can be examined. With the Microtus system it has now been demonstrated that radiation of spermatocyte stages with doses of 50, 100 and 200 R results in a higher frequency of sex chromosome nondisjunction and of diploid gametes. Both types of aberrant gametes can be produced during the first and second meiotic division. Images FIGURE 1. FIGURE 2. FIGURE 3. FIGURE 4. PMID:387396

Tates, A D

1979-01-01

341

Unilateral and bilateral cryptorchidism and its effect on the testicular morphology, histology, accessory sex organs, and sperm count in laboratory mice  

PubMed Central

BACKGROUND: Experimental unilateral cryptorchidism (ULC) and bilateral cryptorchidism (BLC) are excellent methods to study undescended testis in relation to spermatogenesis against a temperature gradient. OBJECTIVES: In case of ULC, it is possible to compare the testicular functions between normal condition and cryptorchidism in the same animal, whereas BLC shows the necessity of testicular androgens for proper maintenance of reproductive structures and functions. MATERIALS AND METHODS: In the present study, experimental ULC and BLC was done on same-aged adult mature male mice and kept for 15 days and 30 days, respectively, to observe the changes due to the induced cryptorchidism on the different reproductive organs, viz., the testis and accessory sex organs along with epididymal sperm count. Reproductive tissues were collected from individual animals and histopathological studies of testis were done to investigate different cytological changes. RESULTS: The size of the testes and accessory sex organs were found to be significantly reduced in BLC mice, whereas only testicular weight reduction was observed in ULC mice. Histopathological studies showed degenerative changes throughout the seminiferous tubules. CONCLUSION: Thus, the present investigation showed compensatory androgen production in ULC mice, whereas absence of androgen mediated reproductive functions in BLC animals. PMID:24082651

Dutta, Soumita; Joshi, Keshab Raj; Sengupta, Pallav; Bhattacharya, Koushik

2013-01-01

342

Sex-dependent nutritional programming: fish oil intake during early pregnancy in rats reduces age-dependent insulin resistance in male, but not female, offspring.  

PubMed

Prenatal and early postnatal nutritional status may predispose offspring to impaired glucose tolerance and changes in insulin sensitivity in adult life. The long-term consequences of changes in maternal dietary fatty acid composition were determined in rats. From day 1 until day 12 of pregnancy, rats were given isocaloric diets containing 9% nonvitamin fat based on soybean, olive, fish (FO), linseed, or palm oil. Thereafter, they were maintained on the standard diet; offspring were studied at different ages. Body weight at 4, 8, and 12 mo and lumbar adipose tissue and liver weights at 12 mo did not differ between females on the different diets, whereas in males the corresponding values were all lower in the offspring from the FO group compared with the other dietary groups. Plasma glucose concentrations (both basal and after an oral glucose load) did not change with sex or dietary group, but plasma insulin concentrations were lower in females than in males and, in males, were lowest in the FO group. Similar relations were found with both the homeostasis model assessment of insulin resistance and insulin sensitivity index. In conclusion, the intake of more n-3 fatty acids (FO diet) during early pregnancy reduced both fat accretion and age-related decline in insulin sensitivity in male offspring but not in females. It is proposed that the lower adiposity caused by the increased n-3 fatty acids during the intrauterine life was responsible of the lower insulin resistance in male offspring. PMID:23255588

Sardinha, Fatima L C; Fernandes, Flavia S; Tavares do Carmo, Maria G; Herrera, Emilio

2013-02-15

343

Male pattern baldness  

MedlinePLUS

Alopecia in men; Baldness - male; Hair loss in men; Androgenetic alopecia ... Male pattern baldness is related to your genes and male sex hormones. It usually follows a pattern of receding hairline and ...

344

Men who report recent male and female sex partners in Cape Town, South Africa: an understudied and underserved population.  

PubMed

The HIV/AIDS epidemic in South Africa has largely focused on the needs of heterosexual men and women. However, little is known about the sexual risk histories of men who have sex with both men and women (MSMW). Furthermore, we know very little about the psychosocial health needs or of the possibility of a syndemic (numerous interrelated epidemics) among MSMW. We surveyed 1,203 men attending drinking establishments in a township located in Cape Town, South Africa. We compared the behaviors and experiences of MSMW to men reporting only having sex with women (MSW). Twelve percent of the sample reported having sex with both men and women in the past 4 months. MSMW were twice as likely as MSW to report being HIV positive (10.5 vs. 4.6 %). MSW were more likely to be married than MSMW but reported similar numbers of female sex partners. MSMW were more likely to report a history of childhood sexual abuse, recent experienced and perpetrated physical and sexual partner violence, both receiving and giving sex for money, drugs, or shelter, and a recent STI. These factors were found to be interrelated among MSW but not MSMW. Although MSMW demonstrate considerable risk taking and report higher rates of HIV infection than MSW, their needs are largely unmet and underemphasized. Findings suggest the need to better understand factors contributing to sexual risk taking among MSMW. HIV prevention interventions should consider psychosocial health problems unique to MSMW residing in South African townships. PMID:23519592

Eaton, Lisa A; Pitpitan, Eileen V; Kalichman, Seth C; Sikkema, Kathleen J; Skinner, Donald; Watt, Melissa H; Pieterse, Desiree

2013-10-01

345

Sex differences in a mouse model of multiple sclerosis: neuropathic pain behavior in females but not males and protection from neurological deficits during proestrus  

PubMed Central

Background Multiple sclerosis (MS), a demyelinating disease of the central nervous system, is one of the most prevalent neurological disorders in the industrialized world. This disease afflicts more than two million people worldwide, over two thirds of which are women. MS is typically diagnosed between the ages of 20–40 and can produce debilitating neurological impairments including muscle spasticity, muscle paralysis, and chronic pain. Despite the large sex disparity in MS prevalence, clinical and basic research investigations of how sex and estrous cycle impact development, duration, and severity of neurological impairments and pain symptoms are limited. To help address these questions, we evaluated behavioral signs of sensory and motor functions in one of the most widely characterized animal models of MS, the experimental autoimmune encephalomyelitis (EAE) model. Methods C57BL/6 male and female mice received flank injection of complete Freund’s adjuvant (CFA) or CFA plus myelin oligodendrocyte glycoprotein 35-55 (MOG35-55) to induce EAE. Experiment 1 evaluated sex differences of EAE-induced neurological motor deficits and neuropathic pain-like behavior over 3 weeks, while experiment 2 evaluated the effect of estrous phase in female mice on the same behavioral measures for 3 months. EAE-induced neurological motor deficits including gait analysis and forelimb grip strength were assessed. Neuropathic pain-like behaviors evaluated included sensitivity to mechanical, cold, and heat stimulations. Estrous cycle was determined daily via vaginal lavage. Results MOG35-55-induced EAE produced neurological impairments (i.e., motor dysfunction) including mild paralysis and decreases in grip strength in both females and males. MOG35-55 produced behavioral signs of neuropathic pain—mechanical and cold hypersensitivity—in females, but not males. MOG35-55 did not change cutaneous heat sensitivity in either sex. Administration of CFA or CFA?+?MOG35-55 prolonged the time spent in diestrus for 2 weeks, after which normal cycling returned. MOG35-55 produced fewer neurological motor deficits when mice were in proestrus relative to non-proestrus phases. Conclusions We conclude that female mice are superior to males for the study of neuropathic pain-like behaviors associated with MOG35-55-induced EAE. Further, proestrus may be protective against EAE-induced neurological deficits, thus necessitating further investigation into the impact that estrous cycle exerts on MS symptoms. PMID:24581045

2014-01-01

346

Synthesis of syn-4,6-dimethyldodecanal, the male sex pheromone and trail-following pheromone of two species of the termite Zootermopsis.  

PubMed

Recently, we reported that syn-4,6-dimethyldodecanal is the male sex pheromone and the trail-following pheromone of the Termopsidae Zootermopsis nevadensis and Zootermopsis angusticollis. In this article, we describe the syntheses of the mixture of the four stereoisomers of 4,6-dimethyldodecanal using a synthetic pathway where the key step is a Wittig reaction between methyl 4-methyl-5-oxo-pentanoate and 1-methylheptyl-triphenylphosphonium iodide, and of (±)-syn-4,6-dimethyldodecanal starting from 3,5-dimethyl-2-cyclohexen-1-one. Direct GC-MS comparison of these synthetic samples with the natural pheromone allowed its unambiguous identification. PMID:21391118

Ghostin, J; Bordereau, C; Braekman, J C

2011-03-01

347

Localization of /sup 3/H-estradiol in the reproductive organs of male and female baboons  

SciTech Connect

The uptake and retention of radiolabeled estradiol by both the male and female reproductive organs were examined in the baboon. Two male and two female baboons were injected intracardially with 1 microgram/kg body weight of /sup 3/H-estradiol and two animals, one male and one female, were injected with both labeled and 100 micrograms/kg body weight of unlabeled estradiol. One and a half hours after the injections, the animals were sacrificed and the uterus, cervix, vagina, oviduct, seminal vesicles, and prostate gland were removed and processed for autoradiography. The stratified squamous epithelia of the cervix and vagina demonstrated a light uptake of the label in the germinative, but not in the superficial cell layers. The columnar cells lining the oviduct and uterine glands were labeled, whereas the luminal epithelium of the uterus and the glandular epithelia of the seminal vesicles and prostate gland did not sequester the tritiated steroid. The interstitial cells of all the organs studied demonstrated a moderate to heavy uptake of the radioactivity, whereas the smooth muscle cells were lightly labeled except in the vagina, in which these cells displayed a moderate number of silver grains.

Weaker, F.J.; Sheridan, P.J.

1982-05-01

348

Morphology of the external genitalia of the adult male and female mice as an endpoint of sex differentiation  

PubMed Central

Adult external genitalia (ExG) are the endpoints of normal sex differentiation. Detailed morphometric analysis and comparison of adult mouse ExG has revealed 10 homologous features distinguishing the penis and clitoris that define masculine vs. feminine sex differentiation. These features have enabled the construction of a simple metric to evaluate various intersex conditions in mutant or hormonally manipulated mice. This review focuses on the morphology of the adult mouse penis and clitoris through detailed analysis of histologic sections, scanning electron microscopy, and three-dimensional reconstruction. We also present previous results from evaluation of “non-traditional” mammals, such as the spotted hyena and wallaby to demonstrate the complex process of sex differentiation that involves not only androgen-dependent processes, but also estrogen-dependent and hormone-independent mechanisms. PMID:21893161

Weiss, Dana A.; Rodriguez, Esequiel; Cunha, Tristan; Menshenina, Julia; Barcellos, Dale; Chan, Lok Yun; Risbridger, Gail; Baskin, Laurence; Cunha, Gerald

2013-01-01

349

"The string of this one story": erotica, HIV, and the construction of safe sex in gay male popular memory.  

PubMed

Recalibrating the critical consideration of popular memory, this essay rehabilitates the erotic narrative as an object of critical study and as a political practice via an examination of John Preston's (1985b) print collection, Hot Living: Erotic Stories About Safer Sex. It considers this collection as a use of the erotic genre to produce a popular memory within its reading community to support safer sex practices in the "Age of AIDS." It examines this collection as a communitarian project that articulates a new erotic rhetoric in response to HIV and considers its individual epistemological and epidemiological implications. PMID:23844884

Isola, Mark John

2013-01-01

350

An Examination of Lesbian\\/Queer Bathhouse Culture and the Social Organization of (Im)Personal Sex  

Microsoft Academic Search

Physical features of space shape the sex and sexual interaction that occurs within bathhouses. Although there is scholarly interest in and documentation of male public sexual cultures, lesbian\\/queer public sexualities have been sorely neglected. In examining two Canadian lesbian\\/queer bathhouses— Pussy Palace in Toronto and SheDogs in Halifax—this article fills some of this gap. Utilizing ethnographic methods (in-depth interviews and

Corie J. Hammers

2009-01-01

351

The sex pheromones of mealy plum (Hyalopterus pruni) and leaf-curl plum (Brachycaudus helichrysi) aphids: identification and field trapping of male and gynoparous aphids in prune orchards.  

PubMed

Mealy plum, Hyalopterus pruni, and leaf-curl plum, Brachycaudus helichrysi, aphids are the primary arthropod pests in orchards that produce dried plums (i.e., prunes). The sexual stage of their respective lifecycles occurs on prune trees in the fall, during which time males respond to sex pheromones produced by oviparous females. Air-entrainment collections confirmed that oviparous H. pruni and B. helichrysi emitted combinations of (4aS, 7S, 7aR)-nepetalactone and (1R, 4aS, 7S, 7aR)-nepetalactol. The responses of H. pruni and B. helichrysi to these compounds in ratios of 1:0, 0:1, 1:1, 2.6:1, 3.4:1, 5:1, 7:1, and 0:0 (no-pheromone control) using water traps were determined in field experiments conducted in prune orchards during the fall. The greatest number of male H. pruni was caught in traps releasing a 1:1 ratio of (4aS, 7S, 7aR)-nepetalactone and (1R, 4aS, 7S, 7aR)-nepetalactol, while male B. helichrysi were caught in similar numbers in traps releasing any of the two-component ratios tested. There was no evidence that any of the pheromone treatments influenced trap catches of gynoparae of either species. Results suggest that addition of sex pheromone lures increases trap catches of male H. pruni and B. helichrysi, and that this approach may improve monitoring and management of these pests in prune orchards. Knowledge gained from this study contributes to the understanding of the ecology of insect pests in prune orchards. PMID:22549554

Symmes, Emily J; Dewhirst, Sarah Y; Birkett, Michael A; Campbell, Colin A M; Chamberlain, Keith; Pickett, John A; Zalom, Frank G

2012-05-01

352

Gross anatomy of the male genital organs of the pampas deer (Ozotoceros bezoarticus, Linnaeus 1758).  

PubMed

To describe the macroscopic anatomy of the genital organs of the male pampas deer (Ozotoceros bezoarticus), organs from ten animals found dead in a captive breeding station were dissected. The unpigmented scrotum was located in the inguinal region near the body, and was covered by the thighs. In the investments of the testicles the dartos tunic was greatly developed. The cremaster muscle was located dorsocaudal to the testicle, and was divided caudally into three bundles of fibers. The right testicle was significantly heavier than the left, and there was a positive relationship between body weight and the weight of both testicles. The tail of the epididymis, ventrally located, had a caudal portion attached to the caudal extremity of the testicles by the proper ligament of the testicles, and a portion elongated free caudally located. The deferent duct was located caudomedially to the corresponding testicle. The accessory genital glands were the ampullary glands, vesicular glands, and a small pars disseminata of the prostate. The penis was fibroelastic, without sigmoid flexure, with a thick albuginea. The retractor penis muscle was very long, and ended in the distal part of the penis near the rudimentary glans. The general disposition of the male genital organs of the pampas deer were similar to that of other ruminants, with some differences, such as size and location of the testicles, the absence of the sigmoid flexure of the penis, and fewer accessory genital glands. PMID:23381482

Pérez, William; Vazquez, Noelia; Ungerfeld, Rodolfo

2013-06-01

353

Are Apparent Sex Differences in Mean IQ Scores Created in Part by Sample Restriction and Increased Male Variance?  

ERIC Educational Resources Information Center

This study investigated the possibility that apparent sex differences in IQ are at least partly created by the degree of sample restriction from the baseline population. We used a nationally representative sample, the 1970 British Cohort Study. Sample sizes varied from 6518 to 11,389 between data-collection sweeps. Principal components analysis of…

Dykiert, Dominika; Gale, Catharine R.; Deary, Ian J.

2009-01-01

354

China's One?Child Policy and the Mystery of Missing Women: Ethnic Minorities and Male?Biased Sex Ratios  

Microsoft Academic Search

AbstractRecent estimates suggest that as many as 40 million women are missing in China. We exploit a special provision in the Chinese one?child policy (OCP; allowing for preferential treatment of ethnic minority groups) to revisit the mystery of these missing women, and in particular to explore the contribution of China's OCP in distorting sex ratios. Our results imply that preference

Erwin Bulte; Nico Heerink; Xiaobo Zhang

2011-01-01

355

A Sex Difference in the Predisposition for Physical Competition: Males Play Sports Much More than Females Even in the Contemporary U.S  

PubMed Central

Much evidence indicates that men experienced an evolutionary history of physical competition, both one-on-one and in coalitions. We thus hypothesized that, compared to girls and women, boys and men will possess a greater motivational predisposition to be interested in sports, especially team sports. According to most scholars, advocacy groups, and the United States courts, however, this hypothesis is challenged by modest sex differences in organized school sports participation in the contemporary U.S., where females comprise 42% of high school participants and 43% of intercollegiate participants. We conducted three studies to test whether organized school sports participation data underestimate the actual sex difference in sports participation. Study 1 analyzed the American Time Use Survey, which interviewed 112,000 individuals regarding their activities during one day. Females accounted for 51% of exercise (i.e., non-competitive) participations, 24% of total sports participations, and 20% of team sports participations. These sex differences were similar for older and younger age groups. Study 2 was based on systematic observations of sports and exercise at 41 public parks in four states. Females accounted for 37% of exercise participations, 19% of individual sports participations, and 10% of team sports participations. Study 3 involved surveying colleges and universities about intramural sports, which primarily consist of undergraduate participation in team sports. Across 34 institutions, females accounted for 26% of registrations. Nine institutions provided historical data, and these did not indicate that the sex difference is diminishing. Therefore, although efforts to ensure more equitable access to sports in the U.S. (i.e., Title IX) have produced many benefits, patterns of sports participation do not challenge the hypothesis of a large sex difference in interest and participation in physical competition. PMID:23155459

Deaner, Robert O.; Geary, David C.; Puts, David A.; Ham, Sandra A.; Kruger, Judy; Fles, Elizabeth; Winegard, Bo; Grandis, Terry

2012-01-01

356

Female brown-headed cowbirds', Molothrus ater, organization and behaviour reflects male social dynamics  

Microsoft Academic Search

In four large aviaries, we studied social assortment and reproductive behaviour of female brown-headed cowbirds housed with males differing in age class and in corresponding levels of intrasexual interaction. Juvenile and adult females resided with either (1) adult males, (2) juvenile males, (3) adult and juvenile males, or (4) no males. We observed social behaviour of males and females from

Meredith J. West; David J. White; Andrew P. King

2002-01-01

357

HIV-Related Risk Behaviors among Kathoey (Male-to-Female Transgender) Sex Workers in Bangkok, Thailand  

PubMed Central

Based on combined methods, this study investigated substance use and HIV risk behaviors among kathoey sex workers (KSWs) in Bangkok, Thailand. The study found that only half of the KSW participants reported having been tested for HIV, and that except for one participant, all others had not seen health care providers in the past 12 months. About one third of the participants reported having engaged in unprotected anal sex with customers in the past 6 months. Almost all participants reported alcohol use, as well as having had sex with customers under the influence of alcohol. The prevalence of marijuana and ecstasy use in the past 12 months was high (32% and 36%, respectively); as was for ketamine (20%) and non-injecting methamphetamine (yaba) use (10%). A multiple regression analysis showed that the participants who were post-operative status, had used illicit drugs, or had been abused by their father and brothers were less likely to use condoms for anal sex with customers. Three quarters of the participants sent money to their families and 35% of the participants expressed their willingness to engage in unsafe sex when customers offer extra money. The qualitative interviews revealed that many identified as girl or kathoey in early age and had been exposed to transphobia and violence from father and brothers. Some reported support for gender transition from their mothers. More than half of the participants currently had difficulties in living as kathoey, such as challenges in job market and relationship with family members. Family obligation for sending money and the Buddhist concept of karma were discussed in relation to risk behaviors among KSWs. The study provided implications for facilitating HIV testing and developing future HIV prevention intervention programs for KSWs in Thailand. PMID:21780964

Nemoto, Tooru; Iwamoto, Mariko; Perngparn, Usaneya; Areesantichai, Chitlada; Kamitani, Emiko; Sakata, Maria

2011-01-01

358

Role of the pseudoautosomal region in sex-chromosome pairing during male meiosis: Meiotic studies in a man with a deletion of distal Xp  

SciTech Connect

Meiotic studies were undertaken in a 24-year-old male patient with short stature, chondrodysplasia punctata, ichthyosis, steroid sulfatase deficiency, and mild mental retardation with an inherited cytologically visible deletion of distal Xp. Molecular investigations showed that the pseudoautosomal region as well as the steroid sulfatase gene were deleted, but telomeric sequences were present at the pter on the deleted X chromosome. A complete failure of sex-chromosome pairing was observed in the primary spermatocytes of the patient. Telomeric approaches between the sex chromosomes were made at zygotene in some cells, but XY synaptonemal complex was formed. The sex chromosomes were present as univalents at metaphase I, and germ-cell development was arrested between metaphase I and metaphase II in the vast majority of cells, consistent with the azoospermia observed in the patient. The failure of XY pairing in this individual indicates that the pseudoautosomal sequences play an important role in initiating XY pairing and formation of synaptonemal complex at meiosis. 36 refs., 6 figs.

Mohandas, T.K.; Passage, M.B.; Yen, P.H.; Speed, R.M.; Chandley, A.C.; Shapiro, L.J. (Univ. of California, San Francisco, CA (United States))

1992-09-01

359

Drosophila male-specific lethal 2 protein controls sex-specific expression of the roX genes.  

PubMed Central

The MSL complex of Drosophila upregulates transcription of the male X chromosome, equalizing male and female X-linked gene expression. Five male-specific lethal proteins and at least one of the two noncoding roX RNAs are essential for this process. The roX RNAs are required for the localization of MSL complexes to the X chromosome. Although the mechanisms directing targeting remain speculative, the ratio of MSL protein to roX RNA influences localization of the complex. We examine the transcriptional regulation of the roX genes and show that MSL2 controls male-specific roX expression in the absence of any other MSL protein. We propose that this mechanism maintains a stable MSL/roX ratio that is favorable for localization of the complex to the X chromosome. PMID:15126401

Rattner, Barbara P; Meller, Victoria H

2004-01-01

360

Circuits attenuating seizures under well-fed and food-deprived conditions in C. elegans male sex muscles  

E-print Network

and propagation. Identifying the molecular components regulating behaviors will enable compensation where behavioral impediments to survival exist. To identify circuits of behavioral regulation, I studied male mating behavior in the nematode Caenorhabditis elegans...

Leboeuf, Brigitte L.

2010-07-14

361

Behavioral responses of male turnip moths, Agrotis segetum , to sex pheromone in a flight tunnel and in the field  

Microsoft Academic Search

The response of individual male turnip mothsAgrotis segetum was observed in a sustained flight tunnel to a mixture of decyl acetate, (Z)-5-decenyl acetate, (Z)-7-dodecenyl acetate, and (Z)-9-tetradecenyl acetate in proportions similar to those found in gland extracts from virgin females (0.6: 1:5:2.5). Lures containing 3–30 µg (Z)-5-decenyl acetate proved to be maximally attractive, with approximately 60% of the males completing

Christer Löfstedt; Charles E. Linn; Jan Löfqvist

1985-01-01

362

Can Sex Differences in Science Be Tied to the Long Reach of Prenatal Hormones? Brain Organization Theory, Digit Ratio (2D/4D), and Sex Differences in Preferences and Cognition.  

PubMed

Brain organization theory posits a cascade of physiological and behavioral changes initiated and shaped by prenatal hormones. Recently, this theory has been associated with outcomes including gendered toy preference, 2D/4D digit ratio, personality characteristics, sexual orientation, and cognitive profile (spatial, verbal, and mathematical abilities). We examine the evidence for this claim, focusing on 2D/4D and its putative role as a biomarker for organizational features that influence cognitive abilities/interests predisposing males toward mathematically and spatially intensive careers. Although massive support exists for early brain organization theory overall, there are myriad inconsistencies, alternative explanations, and outright contradictions that must be addressed while still taking the entire theory into account. Like a fractal within the larger theory, the 2D/4D hypothesis mirrors this overall support on a smaller scale while likewise suffering from inconsistencies (positive, negative, and sex-dependent correlations), alternative explanations (2D/4D related to spatial preferences rather than abilities per se), and contradictions (feminine 2D/4D in men associated with higher spatial ability). Using the debate over brain organization theory as the theoretical stage, we focus on 2D/4D evidence as an increasingly important player on this stage, a demonstrative case in point of the evidential complexities of the broader debate, and an increasingly important topic in its own right. PMID:22164187

Valla, Jeffrey; Ceci, Stephen J

2011-03-01

363

Can Sex Differences in Science Be Tied to the Long Reach of Prenatal Hormones? Brain Organization Theory, Digit Ratio (2D/4D), and Sex Differences in Preferences and Cognition  

PubMed Central

Brain organization theory posits a cascade of physiological and behavioral changes initiated and shaped by prenatal hormones. Recently, this theory has been associated with outcomes including gendered toy preference, 2D/4D digit ratio, personality characteristics, sexual orientation, and cognitive profile (spatial, verbal, and mathematical abilities). We examine the evidence for this claim, focusing on 2D/4D and its putative role as a biomarker for organizational features that influence cognitive abilities/interests predisposing males toward mathematically and spatially intensive careers. Although massive support exists for early brain organization theory overall, there are myriad inconsistencies, alternative explanations, and outright contradictions that must be addressed while still taking the entire theory into account. Like a fractal within the larger theory, the 2D/4D hypothesis mirrors this overall support on a smaller scale while likewise suffering from inconsistencies (positive, negative, and sex-dependent correlations), alternative explanations (2D/4D related to spatial preferences rather than abilities per se), and contradictions (feminine 2D/4D in men associated with higher spatial ability). Using the debate over brain organization theory as the theoretical stage, we focus on 2D/4D evidence as an increasingly important player on this stage, a demonstrative case in point of the evidential complexities of the broader debate, and an increasingly important topic in its own right. PMID:22164187

Valla, Jeffrey; Ceci, Stephen J.

2011-01-01

364

Cortisol Levels and Corticosteroid Administration Fail to Predict Mortality in Critical Illness The Confounding Effects of Organ Dysfunction and Sex  

Microsoft Academic Search

Background: Corticosteroid supplementation based on plasma cortisol measurement was reported to decrease mortality in vasopressor-dependent critical illness. Hypothesis: Random levels or maximal increments of plasma cortisol measured after short adrenal stimulation may predict mortality independent of concurrent organ dysfunction or sex, and corticosteroid supplementation may decrease mortality in vasopressor-dependent criti- cal illness. Design: An observational descriptive study. Patients: Critically ill

Bhavesh Patel; Joel Larson; Richard Helmers

2005-01-01

365

Caste and sex specific olfactory glomerular organization and brain architecture in two sympatric ant species Camponotus sericeus and Camponotus compressus  

E-print Network

Caste and sex specific olfactory glomerular organization and brain architecture in two sympatric Accepted 8 June 2009 Keywords: Ants Antennal lobes Glomeruli Morphological castes a b s t r a c t We use the architecture of the antennal lobes in different castes of two ant species ­ Camponotus seri- ceus

366

Sex-Specific Genetic Structure and Social Organization in Central Asia: Insights from a Multi-Locus Study  

E-print Network

Sex-Specific Genetic Structure and Social Organization in Central Asia: Insights from a Multi to patrilocality, a tendency for men to stay in their birthplace while women move to their husband's house. Yet show that in patrilineal herder groups of Central Asia, in contrast to bilineal agriculturalists

Paris-Sud XI, Université de

367

Effect of aqueous leaf extract of Azadirachta indica on the reproductive organs in male mice.  

PubMed

Effect of oral administration (50, 100, and 200 mg/kg body weight/day, for 28 days) of aqucous leaf extract of neem (Azadirachta indica) on the male reproductive organs of the Parkes (P) strain mice was investigated. The treatment had no effect on body weight and the reproductive organs weight. In treated mice, testes showed both normal and affected seminiferous tubules in the same sections; the affected seminiferous tubules showed intraepithelial vacuolation, loosening of germinal epithelium, marginal condensation of chromatin in round spermatids, occurrence of giant cells, mixing of germ cell types in stages of spermatogenesis and degenerated appearance of germ cells. In severe cases, the tubules were lined with Sertoli cells only, Sertoli cells and rare germ cells, or with Sertoli cells and several germ cells but without cellular association patterns. Also, the frequency of affected seminiferous tubules in testes of the extract-treated mice was significantly higher than the controls, though this remained unaffected in mice treated at 50 mg/kg body weight of the extract. Doses at 50 or 100 mg/kg body weight of neem leaf extract did not cause appreciable alterations in histological appearance of the epididymis, while a dose of 200 mg/kg body weight caused marked alterations both in histological appearance and the level of sialic acid in the duct. The treatment also had adverse effects on motility, morphology, and number of spermatozoa in the cauda epididymidis, level of fructose in the seminal vesicle, and on litter size. After 42 days of withdrawal of the treatment, the alterations induced in the reproductive organs recovered to control levels. Our results suggested that treatment with neem leaf extract caused reversible alterations in the male reproductive organs of P mice. PMID:16313072

Mishra, Raghav Kumar; Singh, Shio Kumar

2005-11-01

368

Attraction of Male European Tarnished Plant Bug, Lygus rugulipennis to Components of the Female Sex Pheromone in the Field  

Microsoft Academic Search

Previous work showed that females of the European tarnished plant bug, Lygus rugulipennis Poppius (Heteroptera: Miridae), produced three chemicals, hexyl butyrate, (E)-2-hexenyl butyrate, and (E)-4-oxo-2-hexenal, and that these were suspected to be components of the female sex pheromone. In field experiments, traps baited with blends of these chemicals dispensed from polyethylene vials and sachets failed to catch significant numbers of

P. J. Innocenzi; D. Hall; J. V. Cross; H. Hesketh

2005-01-01

369

Anopheles arabiensis egg treatment with dieldrin for sex separation leaves residues in male adult mosquitoes that can bioaccumulate in goldfish (Carassius auratus auratus)  

PubMed Central

The sterile insect technique (SIT) is a biological control tactic that is used as a component of area-wide integrated pest management (AW-IPM) programs. The SIT can only be applied against disease-transmitting mosquitoes when only sterile male mosquitoes are released, and the blood-sucking and potentially disease-transmitting females are eliminated from the production line. For Anopheles arabiensis, a potent vector of malaria, a genetic sexing strain was developed whereby females can be eliminated by treating the eggs or larvae with the insecticide dieldrin. To evaluate the presence of dieldrin residues in male mosquitoes designated for SIT releases, a simple, sensitive, and accurate gas chromatography–electron capture detector (GC–ECD) method was developed. In addition, bioaccumulation and food chain transfer of these residues to fish after feeding with treated mosquitoes was demonstrated. The overall recovery from method validation studies was 77.3?±?2.2% (mean?±?relative standard deviation [RSD]) for the mosquitoes, and 99.1?±?4.4% (mean?±?RSD) for the fish. The average dieldrin concentration found in adult male An. arabiensis was 28.1?±?2.9?µg/kg (mean?±?standard deviation [SD]). A range of 23.9?±?1.1?µg/kg to 73.9?±?5.2?µg/kg (mean?±?SD) of dieldrin was found in the fish samples. These findings indicate the need to reassess the environmental and health implications of control operations with a SIT component against An. arabiensis that involves using persistent organochlorines in the sexing process. PMID:23983078

Yamada, Hanano; Jandric, Zora; Chhem-Kieth, Sorivan; Vreysen, Marc JB; Rathor, Mohammad N; Gilles, Jeremie RL; Cannavan, Andrew

2013-01-01

370

Surface models of the male urogenital organs built from the Visible Korean using popular software  

PubMed Central

Unlike volume models, surface models, which are empty three-dimensional images, have a small file size, so they can be displayed, rotated, and modified in real time. Thus, surface models of male urogenital organs can be effectively applied to an interactive computer simulation and contribute to the clinical practice of urologists. To create high-quality surface models, the urogenital organs and other neighboring structures were outlined in 464 sectioned images of the Visible Korean male using Adobe Photoshop; the outlines were interpolated on Discreet Combustion; then an almost automatic volume reconstruction followed by surface reconstruction was performed on 3D-DOCTOR. The surface models were refined and assembled in their proper positions on Maya, and a surface model was coated with actual surface texture acquired from the volume model of the structure on specially programmed software. In total, 95 surface models were prepared, particularly complete models of the urinary and genital tracts. These surface models will be distributed to encourage other investigators to develop various kinds of medical training simulations. Increasingly automated surface reconstruction technology using commercial software will enable other researchers to produce their own surface models more effectively. PMID:21829759

Shin, Dong Sun; Park, Jin Seo; Shin, Byeong-Seok

2011-01-01

371

Whole adult organism transcriptional profiling of acute metal exposures in male Zebrafish  

PubMed Central

Background A convergence of technological breakthroughs in the past decade has facilitated the development of rapid screening tools for biomarkers of toxicant exposure and effect. Platforms using the whole adult organism to evaluate the genome-wide response to toxicants are especially attractive. Recent work demonstrates the feasibility of this approach in vertebrates using the experimentally robust zebrafish model. In the present study, we evaluated gene expression changes in whole adult male zebrafish following an acute 24 hr high dose exposure to three metals with known human health risks. Male adult zebrafish were exposed to nickel chloride, cobalt chloride or sodium dichromate concentrations corresponding to their respective 96 hr LC20, LC40 and LC60. Histopathology was performed on a subset of metal-exposed zebrafish to phenotypically anchor transcriptional changes associated with each metal. Results Comparative analysis identified subsets of differentially expressed transcripts both overlapping and unique to each metal. Application of gene ontology (GO) and transcription factor (TF) enrichment algorithms revealed a number of key biological processes perturbed by metal poisonings and the master transcriptional regulators mediating gene expression changes. Metal poisoning differentially activated biological processes associated with ribosome biogenesis, proteosomal degradation, and p53 signaling cascades, while repressing oxygen-generating pathways associated with amino acid and lipid metabolism. Despite appreciable effects on gene regulation, nickel poisoning did not induce any morphological alterations in male zebrafish organs and tissues. Histopathological effects of cobalt remained confined to the olfactory system, while chromium targeted the gills, pharynx, and intestinal mucosa. A number of enriched transcription factors mediated the observed gene response to metal poisoning, including known targets such as p53, HIF1?, and the myc oncogene, and novel regulatory factors such as XBP1, GATA6 and HNF3?. Conclusions This work uses an experimentally innovative approach to capture global responses to metal poisoning and provides mechanistic insights into metal toxicity. PMID:24612858

2014-01-01

372

Extinct and Extant Reptiles: A Model System for the Study of Sex Chromosome Evolution  

Microsoft Academic Search

\\u000a The evolution and functional dynamics of sex chromosomes are focuses of current biological research. Although common organismal\\u000a morphologies and functions of males and females are found among amniotes, underlying sex chromosome organizations and sex-determining\\u000a mechanisms are widely variable. This chapter investigates the role that reptiles play in the study of sex chromosome evolution.\\u000a Reptile studies have described the coevolution of

Daniel E. Janes

373

Pubertal effects of 17?-methyltestosterone on GH-IGF-related genes of the hypothalamic-pituitary-liver-gonadal axis and other biological parameters in male, female and sex-reversed Nile tilapia.  

PubMed

The influence of 17?-methyltestosterone (MT) on growth responses, biological parameters and the expression of genes involved in the GH-IGF pathway of the hypothalamic-pituitary-liver-gonadal axis were investigated in female, male, and sex-reversed Nile tilapia to evaluate the relationship between sex and MT-induced changes in these parameters. Female fish had a lower growth rate than male and sex-reversed fish, and MT increased growth performance and duodenal villi in females. Most but not all biological parameters of sex-reversed fish were similar to those of male fish. Male fish had higher red blood cell counts and hemoglobin levels than female and sex-reversed fish, suggesting that these hematological indices reflect a higher metabolic rate in male fish. Greater blood triglyceride levels indicated the vitellogenin process in female fish. MT increased the alternative complement activity in female fish (P<0.05). Sex and MT had no significant effects on the hypothalamic mRNAs of GHRH and PACAP. Although not statistically significant, females tended to have higher GH mRNA levels than male and sex-reversed fish. Additionally, MT tended to decrease and increase GH mRNA levels in female and male fish, respectively. There were significant differences among sexes in the expression of GHR, and IGF mRNAs at the peripheral level in the liver and gonads. Females had lower hepatic GHRs and higher ovarian GHRs than male and sex-reversed fish. While the mRNA levels of IGF-1 were lower in the ovary, the levels of IGF-2 were higher compared with those in testes. A significant correlation between GHRs and IGFs was demonstrated in the liver and gonad (except for IGF-1). Multiple regression analysis showed a significant relationship between GH mRNA and both GHRs and IGFs in the liver and gonad. MT exerted androgenic and, to some extent, estrogenic effects on several physiological parameters and GH-IGF action. PMID:22481004

Phumyu, Nonglak; Boonanuntanasarn, Surintorn; Jangprai, Araya; Yoshizaki, Goro; Na-Nakorn, Uthairat

2012-06-01

374

Pattern of DNA Replication of the Sex Chromosomes in Three Males, Two with XYY and One with XXYY Karyotype  

Microsoft Academic Search

INVESTIGATIONS of the pattern of DNA replication have shown that the X chromosomes in normal female cells exhibit marked asynchrony and one of them has a pronounced pattern of late replication. Other chromosomes differ also with respect to the time of DNA synthesis. In male cells it has been found that the Y chromosome replicates late compared with chromosomes of

K. Boczkowski; M. D. Casey

1967-01-01

375

Male-produced sex pheromone of the carrion beetles, Oxelytrum discicolle and its attraction to food sources.  

PubMed

Carrion beetles are part of the great diversity of insects collected on cadavers. In Brazil, beetles of the genus Oxelytrum have great forensic importance in post mortem interval (PMI) estimation. We investigated the system of chemical communication in the attraction of these necrophagous beetles. Gas chromatographic analysis (GC) of female and male aeration extracts revealed the presence of two male-specific compounds, produced in a ratio of 94:6. Bioassays showed that the combination of male produced volatiles and the odor of a food source (carcass volatiles) were attractive to females. Mass and infrared spectral analyses of the male-specific compounds suggested that they were both unsaturated hydrocarbons. Several micro-derivatizations were carried out with the natural products, and the target structures were identified as (Z)-1,8-heptadecadiene (major) and 1-heptadecene (minor). The structure of the minor component was assigned by co-injection with a commercial standard. A seven-step synthesis was developed to synthesize (Z)-1,8-heptadiene, which co-eluted with the major natural product on three different GC stationary phases. Y-tube olfactometer assays showed that the mixture of synthetic standards in the naturally occurring proportion was slightly attractive to females. The results contribute both to the understanding of the chemical ecology of O. discicolle and to its potential to improve the accuracy of PMI estimation. PMID:23918548

Fockink, Douglas H; Mise, Kleber M; Zarbin, Paulo H G

2013-08-01

376

Distribution of 24 elements in the internal organs of normal males and the metallic workers in Japan  

Microsoft Academic Search

Concentrations of 24 elements in the internal organs from 12 health males and from 7 metallic workers in Japan were recorded. Markedly high concentrations of chromium were found in the respiratory organs (e.g., hilar lymph node and lung) of chromium plating and chromate refining workers, as well as in spleen, liver, kidney, and heart. High chromium concentrations were also found

Teraoka

1981-01-01

377

Male gametophyte development and two different DNA classes of pollen grains in Rumex acetosa L., a plant with an XX\\/XY 1 Y 2 sex chromosome system and a female-biased sex ratio  

Microsoft Academic Search

Female-biased sex ratio is an interesting phenomenon observed in Rumex acetosa, a dioecious plant with an XX\\/XY1Y2 sex chromosome system. Previous authors have suggested that the biased sex ratio in this species is conditioned not only\\u000a postzygotically (sex-differential sporophytic mortality) but also prezygotically, because the sex ratio of seeds is also female-biased,\\u000a although to a lesser extent than the sex

Magdalena B?ocka-Wandas; Elwira Sliwinska; Aleksandra Grabowska-Joachimiak; Krystyna Musial; Andrzej J. Joachimiak

2007-01-01

378

Venous thrombo-embolism as a complication of cross-sex hormone treatment of male-to-female transsexual subjects: a review.  

PubMed

Administration of cross-sex hormones to male-to-female transsexual subjects, usually oestrogens + often anti-androgens, such as cyproterone acetate, carries a risk of venous thromboembolism (VTE). VTE usually occurs in the first year of oestrogen administration. Ethinyl oestradiol, due to its chemical structure, was in 2003 identified as a major factor in the occurrence of VTE. Most clinics do not prescribe ethinyl oestradiol any longer, but people who take hormones without medical supervision use often oral contraceptives containing ethinyl oestradiol, many times in overdose. Cessation of use of ethinyl oestradiol and peri-operative thrombosis prophylaxis for surgery have reduced prevalence rate of VTE. Other oral oestrogens should not be overdosed, and transdermal oestrogen is to be preferred. Thrombosis prophylaxis for surgery is mandatory. It seems advisable to stop hormone use at least 2 weeks before major surgery, to be resumed only after 3 weeks following full mobilisation. PMID:23944849

Asscheman, H; T'Sjoen, G; Lemaire, A; Mas, M; Meriggiola, M C; Mueller, A; Kuhn, A; Dhejne, C; Morel-Journel, N; Gooren, L J

2014-09-01

379

Localization of sex hormone binding globulin in the rat vomeronasal organ.  

PubMed

Volatile and non-volatile derivates of gonadal steroids are known to act as pheromones in many mammalian species. Pheromones have multiple effects on the brain via the olfactory system. Their primary port of entry seems to be the vomeronasal organ (VNO) but the underlying cellular and molecular mechanisms are unclear so far. Recently we localized sex hormone binding globulin (SHBG) in both the main and the accessory olfactory system of rat with immunocytochemistry and RT-PCR. The accessory olfactory system consisting of VNO and accessory olfactory bulb showed high expression of SHBG. In the present paper we studied SHBG expression in the VNO in greater detail. In semithin sections we found SHBG immunostaining in the perinuclear cytoplasm of some of the sensory neurons, in sensory cilia and in their axons. A portion of the basal cells and some of the goblet cells in the non-sensory epithelium showed intense SHBG staining. SHBG was abundant in exocrine cells of the vomeronasal glands, perhaps compartimentalized in secretory vesicles. In situ hybridization revealed specific signals in sensory and non-sensory cells of the VNO. Our findings indicate that SHBG expressed in the VNO may be liberated into nasal secretions to bind aerosolic steroids. SHBG in sensory cells may be involved in signaling actions of pheromones. PMID:25154024

Ploß, V M; Gebhart, V M; Gisder, D; Dölz, W; Jirikowski, G F

2014-11-01

380

Reliable sex and strain discrimination in the mouse vomeronasal organ and accessory olfactory bulb.  

PubMed

Animals modulate their courtship and territorial behaviors in response to olfactory cues produced by other animals. In rodents, detecting these cues is the primary role of the accessory olfactory system (AOS). We sought to systematically investigate the natural stimulus coding logic and robustness in neurons of the first two stages of accessory olfactory processing, the vomeronasal organ (VNO) and accessory olfactory bulb (AOB). We show that firing rate responses of just a few well-chosen mouse VNO or AOB neurons can be used to reliably encode both sex and strain of other mice from cues contained in urine. Additionally, we show that this population code can generalize to new concentrations of stimuli and appears to represent stimulus identity in terms of diverging paths in coding space. Together, the results indicate that firing rate code on the temporal order of seconds is sufficient for accurate classification of pheromonal patterns at different concentrations and may be used by AOS neural circuitry to discriminate among naturally occurring urine stimuli. PMID:23966710

Tolokh, Illya I; Fu, Xiaoyan; Holy, Timothy E

2013-08-21

381

Sex: Making the Right Decision  

MedlinePLUS

MENU Return to Web version Sex: Making the Right Decision Sex: Making the Right Decision What is sex? The word sex is used in several ways. It can refer ... by the penis. It also can mean what sex you were born (male or female) or physical ...

382

Health, trust, or "just understood": explicit and implicit condom decision-making processes among black, white, and interracial same-sex male couples.  

PubMed

Among gay and bisexual men, primary partners are a leading source of HIV infection. Trust, intimacy, and advancements in HIV treatment may impact same-sex male (SSM) couples' decisions to engage in unprotected anal intercourse (UAI). This qualitative study explored how Black, White and interracial couples discussed, and made decisions regarding condoms. Qualitative interviews were conducted with 48 SSM couples in the New York and San Francisco metropolitan areas. Stratified purposive sampling was used to include Black (n = 16), White (n = 17), and interracial (Black-White) (n = 15) couples. Twenty-six couples were concordant HIV-negative and 22 were HIV-discordant. Interviews were recorded, transcribed, coded, and analyzed using a grounded theory approach. Some couples described explicit processes, which involved active discussion, while others described implicit processes, where condom-use decisions occurred without any explicit discussion. These processes also differed by race and HIV status. Black couples tended to report condom-use as "just understood." White, HIV-discordant couples decided not to use condoms, with some identifying the HIV-positive partner's suppressed viral load and high CD4 count as deciding factors. After an unplanned episode of UAI, White, HIV-negative couples tended to discontinue condom use while Black HIV-negative couples decided to revert to using condoms. HIV prevention efforts focused on same-sex, male couples must consider the explicit/implicit nature of condom decision-making processes. Understanding differences in these processes and considering relationship dynamics, across race and HIV status, can promote the development of innovative couple-level, HIV prevention interventions. PMID:23912774

Campbell, Chadwick K; Gómez, Anu Manchikanti; Dworkin, Shari; Wilson, Patrick A; Grisham, Kirk K; McReynolds, Jaih; Vielehr, Peter; Hoff, Colleen

2014-05-01

383

SRY induced TCF21 genome-wide targets and cascade of bHLH factors during Sertoli cell differentiation and male sex determination in rats.  

PubMed

Male sex determination is initiated through the testis-determining factor SRY that promotes Sertoli cell differentiation and subsequent gonadal development. The basic helix-loop-helix (bHLH) gene Tcf21 was identified as one of the direct downstream targets of SRY. The current study was designed to identify the downstream targets of TCF21 and the potential cascade of bHLH genes that promote Sertoli cell differentiation. A modified ChIP-Chip comparative hybridization analysis identified 121 direct downstream binding targets for TCF21. The gene networks and cellular pathways potentially regulated by these TCF21 targets were identified. One of the main bHLH targets for TCF21 was the bHLH gene scleraxis (Scx). An embryonic ovarian gonadal cell culture was used to examine the functional role of Sry, Tcf21, and Scx to promote an in vitro sex reversal and induction of Sertoli cell differentiation. SRY and TCF21 were found to induce the initial stages of Sertoli cell differentiation, whereas SCX was found to induce the later stages of Sertoli cell differentiation associated with pubertal development using transferrin gene expression as a marker. Therefore, a cascade of SRY followed by TCF21 followed by SCX appears to promote, in part, Sertoli cell fate determination and subsequent differentiation. The current observations help elucidate the initial molecular events involved in the induction of Sertoli cell differentiation and testis development. PMID:23034159

Bhandari, Ramji K; Schinke, Ellyn N; Haque, Md M; Sadler-Riggleman, Ingrid; Skinner, Michael K

2012-06-01

384

Adult male emigration and a female-based social organization in swift foxes, Vulpes velox  

Microsoft Academic Search

Members of the family Canidae are distinguished from other carnivore families by pair bonding and male care of the young. Because of the importance of food provisioning and territorial defence by males, social structure among canids is shared or even dominated by males. However, small, insectivorous species of canids show little male parental care, although whether social structure differs from

Jan F Kamler; Warren B Ballard; Eric M Gese; Robert L Harrison; Seija Karki; Kevin Mote

2004-01-01

385

Sex films  

Microsoft Academic Search

human films simultaneously, one hour in small groups to dig into feelings and attitudes, and lunch with a showing of erotic art from many cultures and ages with taped erotic music. Then we deal with the varieties of sex, with male and female masturbation, male and female homosexuality, and a couple of paraphilias films--sado-masochism, beastiality, and the like--shown simultaneously. These

Robert T. Francoeur

1977-01-01

386

Predictions for sex of first born child reflect masculine and feminine characteristics in male and female undergraduates.  

PubMed

Previous research has identified physical and behavioral differences between parents who produce sons and those who produce daughters. However, the possibility that men and women have predictions about the sexes of their offspring based on these differences, or any other interoceptive cues, has not been investigated. We compared the dominance, sociosexual orientation, estradiol, testosterone, and 2D:4D ratios of men and women who predicted they would conceive a boy as their first child with those who predicted a girl. Women who predicted they would have a boy were more dominant and less sociosexually restricted than those who predicted they would have a girl. Men who predicted they would have a girl had higher salivary estradiol and higher (more feminine) 2D:4D ratios than those who predicted they would have a boy. Possible implications of these results are discussed in the context of evolutionary theory. PMID:23942345

Palmer-Hague, Jaime L; Zilioli, Samuele; Watson, Neil V

2013-01-01

387

Role of the Vomeronasal Organ in the Male-Induced Enhancement of Sexual Receptivity in Female Rats  

Microsoft Academic Search

The role of the vomeronasal organ (VNO) in the male-induced enhancement of sexual receptivity in ovariectomized estrogen-primed rats was investigated. Removal of the VNO significantly reduced the enhancement of sexual receptivity following mating, as compared with the sham-operated controls. The sham-operated females exhibited a surge of luteinizing hormone (LH) following mating; however, LH release induced by pairing with males was

Gopalan Rajendren; Carol A. Dudley; Robert L. Moss

1990-01-01

388

Hypospadias in a male (78,XY; SRY-positive) dog and sex reversal female (78,XX; SRY-negative) dogs: clinical, histological and genetic studies.  

PubMed

Hypospadias is rarely reported in dogs. In this study we pre-sent 2 novel cases of this disorder of sexual development and, in addition, a case of hereditary sex reversal in a female with an enlarged clitoris. The first case was a male Moscow watchdog with a normal karyotype (78,XY) and the presence of the SRY gene. In this dog, perineal hypospadias, bilateral inguinal cryptorchidism and testes were observed. The second case, representing the Cocker spaniel breed, had a small penis with a hypospadic orifice of the urethra, bilateral cryptorchidism, testis and a rudimentary gonad inside an ovarian bursa, a normal female karyotype (78,XX) and a lack of the SRY gene. This animal was classified as a compound sex reversal (78,XX, SRY-negative) with the hypospadias syndrome. The third case was a Cocker spaniel female with an enlarged clitoris and internally located ovotestes. Cytogenetic and molecular analyses revealed a normal female karyotype (78,XX) and a lack of the SRY gene, while histology of the gonads showed an ovotesticular structure. This case was classified as a typical hereditary sex reversal syndrome (78,XX, SRY-negative). Molecular studies were focused on coding sequences of the SRY gene (case 1) and 2 candidates for monogenic hypospadias, namely MAMLD1 (mastermind-like domain containing 1) and SRD5A2 (steroid-5-alpha-reductase, alpha polypeptide 2). Sequencing of the entire SRY gene, including 5'- and 3'-flanking regions, did not reveal any mutation. The entire coding sequence of MAMLD1 and SRD5A2 was analyzed in all the intersexes, as well as in 4 phenotypically normal control dogs (3 females and 1 male). In MAMLD1 2 SNPs, including 1 missense substitution in exon 1 (c.128A>G, Asp43Ser), were identified, whereas in SRD5A2 7 polymorphisms, including 1 missense SNP (c.358G>A, Ala120Thr), were found. None of the identified polymorphisms cosegregated with the intersexual phenotype, thus, we cannot confirm that hypospadias may be associated with polymorphism in the coding sequence of the studied genes. PMID:21893969

Switonski, M; Payan-Carreira, R; Bartz, M; Nowacka-Woszuk, J; Szczerbal, I; Colaço, B; Pires, M A; Ochota, M; Nizanski, W

2012-01-01

389

Sex expression and sex dimorphism in sporophytic populations of the desert moss Syntrichia caninervis  

Microsoft Academic Search

Ten sporophytic populations of Syntrichiacaninervis contained an average of 22 individualscm-2, with a sex ratio of 7.9 Female:1 Male: 3.1 Nonexpressing(N = 300). In each of the populations, female individuals outnumberedmale individuals. A representative population size of 50 × 25cm was estimated to contain 27,250 organically distinct individualplants. Given the wide disparity in reproductive investment in this dioeciousspecies, sex-specific traits

Lloyd Stark; Nicholas McLetchie; Brent Mishler

2001-01-01

390

Male pattern baldness (image)  

MedlinePLUS

Male pattern baldness is a sex-linked characteristic that is passed from mother to child. A man can more accurately predict his chances of developing male pattern baldness by observing his mother's father than by looking ...

391

Strong male-biased operational sex ratio in a breeding population of loggerhead turtles (Caretta caretta) inferred by paternal genotype reconstruction analysis.  

PubMed

Characterization of a species mating systems is fundamental for understanding the natural history and evolution of that species. Polyandry can result in the multiple paternity of progeny arrays. The only previous study of the loggerhead turtle (Caretta caretta) in the USA showed that within the large peninsular Florida subpopulation, multiple paternity occurs in approximately 30% of clutches. Our study tested clutches from the smaller northern subpopulation for the presence of multiple paternal contributions. We examined mothers and up to 20 offspring from 19.5% of clutches laid across three nesting seasons (2008-2010) on the small nesting beach on Wassaw Island, Georgia, USA. We found that 75% of clutches sampled had multiple fathers with an average of 2.65 fathers per nest (1-7 fathers found). The average number of fathers per clutch varied among years and increased with female size. There was no relationship between number of fathers and hatching success. Finally, we found 195 individual paternal genotypes and determined that each male contributed to no more than a single clutch over the 3-year sampling period. Together these results suggest that the operational sex ratio is male-biased at this site. PMID:24363901

Lasala, Jacob A; Harrison, J Scott; Williams, Kris L; Rostal, David C

2013-11-01

392

Sex Differences in the Effects of Neighborhood Socioeconomic Disadvantage and Social Organization on Rural Adolescents’ Aggression Trajectories  

Microsoft Academic Search

We determined whether effects of neighborhood socioeconomic disadvantage on trajectories of aggression were moderated or mediated\\u000a by neighborhood social organization and examined sex differences in neighborhood effects for rural adolescents. We used five\\u000a waves of survey data collected over 2.5 years linked with neighborhood data from interviews with parents and the US Census.\\u000a The sample (N = 5,118) was 50.1% female, 52.0% white

Katherine J. Karriker-Jaffe; Vangie A. Foshee; Susan T. Ennett; Chirayath Suchindran

2009-01-01

393

MALE HOMOSEXUAL IDENTITIES, RELATIONSHIPS, AND PRACTICES AMONG YOUNG MEN WHO HAVE SEX WITH MEN IN VIETNAM: IMPLICATIONS FOR HIV PREVENTION  

PubMed Central

Rapid socioeconomic transformation in Vietnam in last 15 years has been followed by more liberation of sexual expression and representation of sexual identity among young people. There has been an increase in the visibility of homosexual men in major cities of Vietnam who were largely an unknown population until the emergence of the HIV epidemic. Men who have sex with men (MSM) are now considered as one of the target groups in many HIV prevention programs. This qualitative study examines local identities, relationships, and sexual practices among young MSM aged 15–24 in the cities of Hanoi and Ho Chi Minh City. Our analyses were based on 26 in-depth interviews and 10 focus group discussions with young MSM recruited through public place intercepts and cruising areas. Data document the linguistic classification, sexual relationships and behaviors, identity and process of homosexual identification, and the potential linkage between sexual identity and sexual behaviors of MSM in Vietnam. Data also highlight the stages of homosexual community development in urban Vietnam and important differences between Vietnam and the West in the representation of homosexual identity, relationships, and practices. In light of the findings, we suggest that the continuing development and elaboration of a homosexual community in Hanoi and Ho Chi Minh City offers significant opportunities for targeted HIV/AIDS prevention activities in the Vietnamese MSM population. PMID:19519239

Ngo, Duc Anh; Ross, Michael W.; Phan, Ha; Ratliff, Eric A.; Trinh, Thang; Sherburne, Lisa

2010-01-01

394

Exposure to persistent organic pollutants and sperm sex chromosome ratio in men from the Faroe Islands.  

PubMed

People in the Arctic as well as fishermen on the polluted Swedish east coast are highly exposed to persistent organic pollutants (POPs). These compounds have been shown to affect the sperm Y:X chromosome ratio. In present study, the aim was to investigate whether polychlorinated biphenyl (PCB) congeners and 1,1,-dichloro-2,2,-bis(p-chlorophenyl)ethane (p,p'-DDE) influence sperm sex chromosome ratio in Faroese men, and whether these men differ regarding Y:X ratio compared to Greenland Inuit and Swedish fishermen. The study population (n=449) consisted of young men from the general population (n=276) as well as proven fertile men (n=173). The Y:X ratio was assessed by fluorescent in situ hybridization. Serum concentrations of POPs were measured using gas chromatography. Associations between POP concentrations and Y:X ratio were calculated using linear and non-linear regression models as well as trend analysis and pairwise comparison of exposure data categorized into quartiles. The selected POPs were associated with Y:X ratio in fertile Faroese men, but not in the total population; p,p'-DDE (95% CI for B=-0.005 to -0.001, p=0.005) and ?PCB (95% CI for B=-0.005 to -0.001, p=0.012). Since p,p'-DDE and ?PCB correlated significantly (r=0.927, p<0.001), the results involving the exposure variables can be regarded as a single finding. The Y:X ratio for the total Faroese population was 0.500±0.018, which was statistically significantly lower than in both Inuit and Swedish fishermen (0.512 for both). In conclusion, Faroese men presented with lower Y:X ratio than Greenland Inuit and Swedish fishermen. Although no direct health effects are expected due to the lower Faroese Y:X ratio, it could be indicative of adverse effects on the reproductive system. PMID:25222300

Kvist, L; Giwercman, A; Weihe, P; Kold Jensen, T; Grandjean, P; Halling, J; Skaalum Petersen, M; Lundberg Giwercman, Y

2014-12-01

395

Mutations in exons of the CYP17-II gene affect sex steroid concentration in male Japanese flounder ( Paralichthys olivaceus)  

NASA Astrophysics Data System (ADS)

As a specific gene of fish, cytochrome P450c17-II ( CYP17-II) gene plays a key role in the growth, development an reproduction level of fish. In this study, the single-stranded conformational polymorphism (SSCP) technique was used to characterize polymorphisms within the coding region of CYP17-II gene in a population of 75 male Japanese flounder ( Paralichthys olivaceus). Three single nucleotide polymorphisms (SNPs) were identified in CYP17-II gene of Japanese flounder. They were c.G594A (p.G188R), c.G939A and c.G1502A (p.G490D). SNP1 (c.G594A), located in exon 4 of CYP17-II gene, was significantly associated with gonadosomatic index (GSI). Individuals with genotype GG of SNP1 had significantly lower GSI ( P < 0.05) than those with genotype AA or AG. SNP2 (c.G939A) located at the CpG island of CYP17-II gene. The mutation changed the methylation of exon 6. Individuals with genotype AA of SNP2 had significantly lower serum testosterone (T) level and hepatosomatic index (HSI) compared to those with genotype GG. The results suggested that SNP2 could influence the reproductive endocrine of male Japanese flounder. However, the SNP3 (c.G1502A) located in exon 9 did not affect the four measured reproductive traits. This study showed that CYP17-II gene could be a potentially useful candidate gene for the research of genetic breeding and physiological aspects of Japanese flounder.

Ma, Ruiqin; He, Feng; Wen, Haishen; Li, Jifang; Shi, Bao; Shi, Dan; Liu, Miao; Mu, Weijie; Zhang, Yuanqing; Hu, Jian; Han, Weiguo; Zhang, Jianan; Wang, Qingqing; Yuan, Yuren; Liu, Qun

2012-03-01

396

Effects of p,p?DDE on Retinoid Homeostasis and Sex Hormones of Adult Male European Common Frogs (Rana temporaria)  

Microsoft Academic Search

Reports of declining numbers of species and individuals of amphibians in most parts of the world have caused great concern. Several causative factors have been linked to this amphibian decline, and increased environmental pollution related to pesticide use seems to be one important factor. Persistent organic pollutants may act as endocrine disrupters, and thereby exert adverse effects on development (metamorphosis,

Àngels Leiva-Presa; Bjørn Munro Jenssen

2006-01-01

397

Dietary cholesterol affects expression of prostatic acid phosphatase in reproductive organs of male rats.  

PubMed

Cholesterol homeostasis is strictly maintained to prevent abnormal biological processes that arise from excessive accumulation of cholesterol in tissues. Although dyslipidemia causes reproductive dysfunction and endocrine disruption in male rats, regulatory factors and mechanisms have not been clearly demonstrated. Therefore, the present study investigated the histology of male reproductive organs and the expression of prostatic acid phosphatase (also known as Acpp) that is secreted by cuboidal epithelium of the prostate gland in response to a normal diet and a high-cholesterol diet. The high cholesterol diet increased total cholesterol and low density lipoprotein (LDL) levels and decreased high density lipoprotein (HDL) levels. Histological analyses showed considerable alterations in the prostate indicating excessive papillary projections within the acinar lumen in response to the high cholesterol diet. In addition, Acpp expression was decreased in the penis of rats fed the high cholesterol diet and it was predominantly localized in the urethral epithelium and penile follicle that is precursor of penile spines. Moreover, Acpp was reduced slightly in the testes, but differential expression of Acpp in the prostate in response to dietary cholesterol was not detected. Furthermore, target microRNAs (miRs) of Acpp such as miR-192 and miR-215 regulated Acpp gene expression at the post-transcriptional levels by binding to specific sites within its 3'-UTR. These results indicate that Acpp plays an important role in growth and development of the penis of rats, and its expression is modulated at epigenomic levels via specific miRs. PMID:25482440

Lim, Whasun; Bae, Hyocheol; Sohn, Ji Yang; Jeong, Wooyoung; Kim, Sae Hun; Song, Gwonhwa

2015-01-01

398

Estrogen receptor-? distribution in male rodents is associated with social organization  

Microsoft Academic Search

It has been hypothesized that site-specific reduction of estrogen receptor- (ER) is associ- ated with the expression of male prosocial behaviors. Specifically, highly social males are pre- dicted to express significantly lower levels of ER than females and less social males in brain regions associated with prosocial behavior including the bed nucleus of the stria terminalis (BST) and the medial

Bruce S. Cushing; Katherine E. Wynne-Edwards

2006-01-01

399

Male-biased sex ratios and vitellogenin induction in zebrafish exposed to effluent water from a Swedish pulp mill.  

PubMed

Juvenile zebrafish (Danio rerio) were exposed to different dilutions (0, 0.67, 2.5, 10, and 50%) of effluent water from a Swedish pulp mill that previously has been reported to be androgenic to fish. Exposure was performed between days 10-38 days post-hatch. Fish were sampled for whole-body vitellogenin concentrations at day 38 post-hatch and for histological examination of gonads at day 60 post-hatch. In fish exposed to the highest concentration of pulp mill effluent, elevated concentrations of vitellogenin were measured. The androgenicity of the pulp mill water was confirmed by the increased number of males recorded at 60 days post-hatch. Image analysis of testes indicated stimulation of spennato genesis. Intersex fish were observed in all exposure groups. An androgenic activity equivalent to 5.6 ng/L dihydroxytestosterone was measured using the yeast androgen screen (YAS) assay. The present study demonstrates that both androgenic and estrogenic effects can be detected when exposing zebrafish during the juvenile period to complex mixtures of chemicals. PMID:16823521

Orn, Stefan; Svenson, Anders; Viktor, Tomas; Holbech, Henrik; Norrgren, Leif

2006-10-01

400

"You cannot do nothing in this damn place": sex and intimacy among couples with an incarcerated male partner.  

PubMed

In an effort to deepen our understanding of how circumstances of forced separation and the interdiction of physical contact affect women's sexual behavior, we investigated the development and maintenance of heterosexual couples' intimacy when the male partner is incarcerated. As HIV-prevention scientists who work with women visiting men at a California state prison, we recognize that correctional control extends to these women's bodies, both when they are within the facility's walls visiting their mates and when they are at home striving to remain connected to absent men. This paper analyzes the impact of a peculiar public "place", a penitentiary, on couples' romantic and sexual interactions, drawing out the implications of imprisonment for relationship decision making, sexual health, and HIV risk. Using qualitative interviews with 20 women who visit their incarcerated partners and 13 correctional officers who interact with prison visitors, we examined how institutional constraints such as the regulation of women's apparel, the prohibition of physical contact, and the lack of forums for privacy result in couples forging alternative "spaces" in which their relationships occur. We describe how romantic scripts, the build-up of sexual tension during the incarceration period, and conditions of parole promote unprotected sexual intercourse and other HIV/STD risk behavior following release from prison. PMID:15795799

Comfort, Megan; Grinstead, Olga; McCartney, Kathleen; Bourgois, Philippe; Knight, Kelly

2005-02-01

401

“You Can’t Do Nothing in This Damn Place”: Sex and Intimacy Among Couples With an Incarcerated Male Partner  

PubMed Central

In an effort to deepen our understanding of how circumstances of forced separation and the interdiction of physical contact affect women’s sexual behavior, we investigated the development and maintenance of heterosexual couples’ intimacy when the male partner is incarcerated. As HIV-prevention scientists who work with women visiting men at a California state prison, we recognize that correctional control extends to these women’s bodies, both when they are within the facility’s walls visiting their mates and when they are at home striving to remain connected to absent men. This paper analyzes the impact of a peculiar public “place”—a penitentiary— on couples’ romantic and sexual interactions, drawing out the implications of imprisonment for relationship decision making, sexual health, and HIV risk. Using qualitative interviews with 20 women who visit their incarcerated partners and 13 correctional officers who interact with prison visitors, we examine how institutional constraints such as the regulation of women’s apparel, the prohibition of physical contact, and the lack of privacy result in couples forging alternative “spaces” in which their relationships occur. We describe how romantic scripts, the build-up of sexual tension during the incarceration period, and conditions of parole promote unprotected sexual intercourse and other HIV/STD risk behavior following release from prison. PMID:15795799

Comfort, Megan; Grinstead, Olga; McCartney, Kathleen; Bourgois, Philippe; Knight, Kelly

2009-01-01

402

Preparatory behaviours and condom use during receptive and insertive anal sex among male-to-female transgenders (Waria) in Jakarta, Indonesia  

PubMed Central

Introduction The male-to-female transgender (waria) is part of a key population at higher risk for HIV. This study aims to test whether psychosocial determinants as defined by the theory of planned behaviour (TPB) can explain behaviours related to condom use among waria. Three preparatory behaviours (getting, carrying, and offering a condom) and two condom use behaviours (during receptive and insertive anal sex) were assessed. Methods The study involved 209 waria, recruited from five districts in Jakarta and interviewed by using structured questionnaires. Specific measures were developed to study attitudes, subjective norms and perceived behavioural control (PBC) in order to predict intentions and behaviours. Results The explained variance between intentions with regard to three preparatory behaviours and two condom uses ranged between 30 and 57%, and the variance between the actual preparatory behaviours of three preparatory and two condom uses ranged between 21 and 42%. In our study, as with several previous studies of the TPB on HIV protection behaviours, the TPB variables differed in their predictive power. With regard to intention, attitude and PBC were consistently significant predictors; attitude was the strongest predictor of intention for all three preparatory behaviours, and PBC was the strongest predictor of intention for condom use, both during receptive and insertive anal sex. TPB variables were also significantly related to the second parameter of future behaviour: actual (past) behaviour. TPB variables were differentially related to the five behaviours. Attitude was predictive in three behaviours, PBC in three behaviours and subjective norms in two behaviours. Conclusions Our results have implications for the development of interventions to target preparatory behaviours and condom use behaviours. Five behaviours and three psychological factors as defined in the TPB are to be targeted. PMID:25529498

Prabawanti, Ciptasari; Dijkstra, Arie; Riono, Pandu; Hartana Tb, Gagan

2014-01-01

403

Effect of Vomeronasal Organ Removal on Male Socio-Sexual Responses to Female in a Prosimian Primate ( Microcebus murinus)  

Microsoft Academic Search

In most mammals, olfactory cues play an important role in regulating socio-sexual behaviors, but the relative contributions of the main olfactory system and the vomeronasal system remain unclear. The lesser mouse lemur, a nocturnal prosimian, possesses well-developed chemosensory structures, including a functional vomeronasal organ (VNO). In this primitive primate, social communication and competition between males for priority access to receptive

F. Aujard

1997-01-01

404

A Gap in Science's and the Media Images of People who use Drugs and Sex Workers: Research on Organizations of the Oppressed.  

PubMed

This paper discusses organizations of the oppressed, such as drug user and sex worker groups, and the images of themselves that they construct. We suggest that analysis of these organizationally-produced collective self-images -frequently overlooked in scholarly research -is crucial to understanding the complex internal dynamics of users' and sex workers' organizations and struggles they engage in when defining their collective (organizational) identities and course of action. PMID:25544256

Dziuban, Agata; Friedman, Samuel R

2015-03-01

405

Lesions of the posterior bed nucleus of the stria terminalis eliminate opposite-sex odor preference and delay copulation in male Syrian hamsters: role of odor volatility and sexual experience  

PubMed Central

In Syrian hamsters (Mesocricetus auratus), the expression of reproductive behavior requires the perception of social odors. The behavioral response to these odors is mediated by a network of ventral forebrain nuclei, including the posterior bed nucleus of the stria terminalis (pBNST). Previous studies have tested the role of pBNST in reproductive behavior, but the use of large, fiber-damaging lesions in these studies make it difficult to attribute post-lesion deficits to pBNST specifically. Thus, the current study used discrete, excitotoxic lesions of pBNST to test the role of pBNST in opposite-sex odor preference and copulatory behavior in both sexually-naïve and sexually-experienced males. Lesions of pBNST decreased sexually-naïve males’ investigation of volatile female odors, resulting in an elimination of opposite-sex odor preference. This elimination of preference was not due to a sensory deficit, as males with pBNST lesions were able to discriminate between odors. When, however, subjects were given sexual experience prior to pBNST lesions, their preference for volatile opposite-sex odors remained intact post-lesion. Similarly, when sexually-naïve or sexually-experienced subjects were allowed to contact the social odors during the preference test, lesions of pBNST decreased males’ investigation of female odors, but did not eliminate preference for opposite-sex odors, regardless of sexual experience. Finally, lesions of pBNST delayed the copulatory sequence in sexually-naïve, but not sexually-experienced, males such that they took longer to mount, intromit, ejaculate, and display long intromissions. Together, these results demonstrate that pBNST plays a unique and critical role in both appetitive and consummatory aspects of male reproductive behaviors. PMID:20597978

Been, Laura E.; Petrulis, Aras

2010-01-01

406

Constraints on the coevolution of contemporary human males and females  

PubMed Central

Because autosomal genes in sexually reproducing organisms spend on average half their time in each sex, and because the traits that they influence encounter different selection pressures in males and females, the evolutionary responses of one sex are constrained by processes occurring in the other sex. Although intralocus sexual conflict can restrict sexes from reaching their phenotypic optima, no direct evidence currently supports its operation in humans. Here, we show that the pattern of multivariate selection acting on human height, weight, blood pressure and glucose, total cholesterol, and age at first birth differs significantly between males and females, and that the angles between male and female linear (77.8 ± 20.5°) and nonlinear (99.1 ± 25.9°) selection gradients were closer to orthogonal than zero, confirming the presence of sexually antagonistic selection. We also found evidence for intralocus sexual conflict demonstrated by significant changes in the predicted male and female responses to selection of individual traits when cross-sex genetic covariances were included and a significant reduction in the angle between male- and female-predicted responses when cross-sex covariances were included (16.9 ± 15.7°), compared with when they were excluded (87.9 ± 31.6°). We conclude that intralocus sexual conflict constrains the joint evolutionary responses of the two sexes in a contemporary human population. PMID:23034705

Stearns, Stephen C.; Govindaraju, Diddahally R.; Ewbank, Douglas; Byars, Sean G.

2012-01-01

407

BMI, male sex and IL28B genotype associated with persistently high hepatitis C virus RNA levels among chronically infected drug users up to 23 years following seroconversion.  

PubMed

The natural course of serum HCV RNA levels during chronic infection remains unclear. We investigated HCV RNA levels and factors associated with HCV RNA levels for the entire course from HCV seroconversion. We measured HCV RNA levels of 54 HCV seroconverters from the Amsterdam Cohort Studies among drug users at yearly intervals up to 23 years using bDNA (VERSANT 3.0, lower limit of detection 615 IU/mL). Samples below the cut-off of the assay were tested by TMA (Siemens VERSANT, detection limit 5 IU/mL). We used a latent class linear mixed model to examine the HCV RNA patterns and factors associated with HCV RNA levels. The median follow-up time was 10.8 years (IQR 6.5-14.9). We found two distinct HCV RNA patterns characterized by 45/54 cases and 9/54 cases. In multivariable analyses, HCV RNA levels were 0.41 log10  IU/mL (95% confidence interval (CI) 0.06-0.75) higher for males as compared to females. Individuals with the IL28B CC genotype had 0.40 log10  IU/mL (95% 0.08-0.73) higher HCV RNA levels than individuals with IL28B CT/TT genotypes. Body mass index (BMI) was associated with higher HCV RNA levels, 0.055 log10  IU/mL per BMI point (95% CI 0.027-0.083). In this unique study, which examines the HCV RNA patterns over an extended period and following seroconversion, male sex, IL28B CC genotype and BMI were independently associated with higher