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1

Embryonic Temperature and Gonadal Sex Organize Male-Typical Sexual and Aggressive Behavior in a Lizard with Temperature-Dependent Sex Determination  

Microsoft Academic Search

Temperature during embryonic development determines gonadal sex in the leopard gecko, Eublepharis macularius. Moreover, both embryonic temperature and gonadal sex influence adult behavior. Yet it remains unclear whether the effects of embryonic temperature and gonadal sex on behavior are irreversibly organized during develop- ment. To address this question, we gonadectomized adult females and males generated from a temperature that produces

TURK RHEN; DAVID CREWS

2010-01-01

2

Male sex determination: insights into molecular mechanisms  

PubMed Central

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 Sertoli cells, which then direct testis morphogenesis. Once engaged, a genetic pathway promotes the testis development while actively suppressing genes involved in ovarian development. This review focuses on the events of testis determination and the struggle to maintain male fate in the face of antagonistic pressure from the underlying female programme.

McClelland, Kathryn; Bowles, Josephine; Koopman, Peter

2012-01-01

3

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

4

Male pygmy hippopotamus influence offspring sex ratio  

PubMed Central

Pre-determining fetal sex is against the random and equal opportunity that both conceptus sexes have by nature. Yet, under a wide variety of circumstances, populations shift their birth sex ratio from the expected unity. Here we show, using fluorescence in situ hybridization, that in a population of pygmy hippopotamus (Choeropsis liberiensis) with 42.5% male offspring, males bias the ratio of X- and Y-chromosome-bearing spermatozoa in their ejaculates, resulting in a 0.4337±0.0094 (mean±s.d.) proportion of Y-chromosome-bearing spermatozoa. Three alternative hypotheses for the shifted population sex ratio were compared: female counteract male, female indifferent, or male and female in agreement. We conclude that there appears little or no antagonistic sexual conflict, unexpected by prevailing theories. Our results indicate that males possess a mechanism to adjust the ratio of X- and Y-chromosome-bearing spermatozoa in the ejaculate, thereby substantially expanding currently known male options in sexual conflict.

Saragusty, Joseph; Hermes, Robert; Hofer, Heribert; Bouts, Tim; Goritz, Frank; Hildebrandt, Thomas B.

2012-01-01

5

Effects of perinatal exposure to flutamide on sex hormones and androgen-dependent organs in F1 male rats.  

PubMed

Flutamide, which has antiandrogenic properties, was administered to pregnant rats, and effects on male offspring were examined. Crj: CD (SD) IGS (SPF) females were administered flutamide (0.15, 0.6, 2.5, 10.0, 100 mg/kg, p.o.) from gestation Day 14 to post parturition Day 3. The number of pups, body weights, clinical features, anogenital distance (AGD), nipple retention, testicular descent, and urogenital malformation in F1 males were examined. Hormone measurement, necropsy and histopathological examination were carried out at post-neonatal Day 4 (PND 4) and PND 60. Sperm analysis was also carried out at PND 60. Decrease in body weight was seen in the 100 mg/kg group and the AGD was decreased at 2.5 mg/kg and above. Retention of nipples, hypospadia, vaginal pouches, penis malformation, unilateral ectopic testis, and decrease of organ weights (prostate, seminal vesicles, levator ani muscle plus bulbocavernosus muscle, testis) were observed at 10 mg/kg and above. Testicular testosterone (T) was increased significantly with 100 mg/kg at PND 4 and tendencies for increase were observed in serum T, LH and FSH at 10 mg/kg and more at the same time point. In contrast, elevated levels of LH and FSH were seen with 100 mg/kg at PND 60. Histopathological examination revealed defects or hypoplastic changes of genital organs (> or = 10 mg/kg), squamous metaplasia (10 mg/kg) or mucification (100 mg/kg) of the urethral diverticulum epithelium and inflammation of genital organs (100 mg/kg). Though only undescended testes lacked spermatogenesis at 10 mg/kg, atrophic change of seminiferous tubules and azoospermia were observed in the 100 mg/kg group, despite testicular descent. Perinatal administration of flutamide affected F1 male rats at 2.5 mg/kg and above. In addition to urogenital malformation, 100 mg/kg flutamide caused high LH and FSH levels at PND 60. This study indicates that the most sensitive parameter is AGD, whereby reduction was observed at 2.5 mg/kg. A clear no-effect level (NOEL: 0.6 mg/kg) was obtained in this perinatal study of an antiandrogenic chemical. PMID:11915366

Miyata, Kaori; Yabushita, Setsuko; Sukata, Tokuo; Sano, Masashi; Yoshino, Hiroko; Nakanishi, Takumi; Okuno, Yasuyoshi; Matsuo, Masatoshi

2002-02-01

6

Sex mosaics in a male dimorphic ant Cardiocondyla kagutsuchi  

Microsoft Academic Search

Gynandromorphy, or the development of organisms with a combination of male and female morphological features, is common in\\u000a Hymenoptera. The underlying mechanism is likely associated with the sex-determination system, and studying this phenomenon\\u000a should lead to a deeper understanding of both embryonic development and sex determination. The reproductive capabilities of\\u000a gynandromorphs (hereafter, sex mosaics) remain unclear. We studied gynandromorphy in

Juri Yoshizawa; Kohei Mimori; Katsusuke Yamauchi; Koji Tsuchida

2009-01-01

7

Male pygmy hippopotamus influence offspring sex ratio.  

PubMed

Pre-determining fetal sex is against the random and equal opportunity that both conceptus sexes have by nature. Yet, under a wide variety of circumstances, populations shift their birth sex ratio from the expected unity. Here we show, using fluorescence in situ hybridization, that in a population of pygmy hippopotamus (Choeropsis liberiensis) with 42.5% male offspring, males bias the ratio of X- and Y-chromosome-bearing spermatozoa in their ejaculates, resulting in a 0.4337±0.0094 (mean±s.d.) proportion of Y-chromosome-bearing spermatozoa. Three alternative hypotheses for the shifted population sex ratio were compared: female counteract male, female indifferent, or male and female in agreement. We conclude that there appears little or no antagonistic sexual conflict, unexpected by prevailing theories. Our results indicate that males possess a mechanism to adjust the ratio of X- and Y-chromosome-bearing spermatozoa in the ejaculate, thereby substantially expanding currently known male options in sexual conflict. PMID:22426218

Saragusty, Joseph; Hermes, Robert; Hofer, Heribert; Bouts, Tim; Göritz, Frank; Hildebrandt, Thomas B

2012-02-28

8

Sex chromosome inactivation in the male.  

PubMed

Mammalian females have two X chromosomes, while males have only one X plus a Y chromosome. In order to balance X-linked gene dosage between the sexes, one X chromosome undergoes inactivation during development of female embryos. This process has been termed X-chromosome inactivation (XCI). Inactivation of the single X chromosome also occurs in the male, but is transient and is confined to the late stages of first meiotic prophase during spermatogenesis. This phenomenon has been termed meiotic sex chromosome inactivation (MSCI). A substantial portion ( approximately 15-25%) of X-linked mRNA-encoding genes escapes XCI in female somatic cells. While no mRNA genes are known to escape MSCI in males, approximately 80% of X-linked miRNA genes have been shown to escape this process. Recent results have led to the proposal that the RNA interference mechanism may be involved in regulating XCI in female cells. We suggest that some MSCI-escaping miRNAs may play a similar role in regulating MSCI in male germ cells. PMID:19838052

Yan, Wei; McCarrey, John R

2009-10-25

9

Sex Chromosome Inactivation in the Male  

PubMed Central

Mammalian females have two X chromosomes, while males have only one X plus a Y chromosome. In order to balance X-linked gene dosage between the sexes, one X chromosome undergoes inactivation during development of female embryos. This process has been termed X-chromosome inactivation (XCI). Inactivation of the single X chromosome also occurs in the male, but is transient and is confined to the late stages of first meiotic prophase during spermatogenesis. This phenomenon has been termed meiotic sex chromosome inactivation (MSCI). A substantial portion (~15–25%) of X-linked mRNA-encoding genes escapes XCI in female somatic cells. While no mRNA genes are known to escape MSCI in males, ~80% of X-linked miRNA genes have been shown to escape this process. Recent results have led to the proposal that the RNA interference mechanism may be involved in regulating XCI in female cells. We suggest that some MSCI-escaping miRNAs may play a similar role in regulating MSCI in male germ cells.

Yan, Wei; McCarrey, John R.

2011-01-01

10

How Fairly is the Fair-Sex Treated? An Agenda for Research on Managerial Women in a Male-Dominated Organization  

Microsoft Academic Search

Though Indian women have been joining managerial ranks in growing numbers, little research has been conducted to investigate their problems in the male-dominated world of work. Based on a review of literature, this paper suggests workplace integration, non-availability of mentors, problems of token status, conflict between sex-roles stereotypes and work roles, sexuality and the workplace, evaluation and attribution of women’s

Deepti Bhatnagar

11

Transgenerational sex determination: the embryonic environment experienced by a male affects offspring sex ratio  

PubMed Central

Conditions experienced during embryonic development can have lasting effects, even carrying across generations. Most evidence for transgenerational effects comes from studies of female mammals, with much less known about egg-laying organisms or paternally-mediated effects. Here we show that offspring sex can be affected by the incubation temperature its father experiences years earlier. We incubated eggs of an Australian lizard with temperature-dependent sex determination under three thermal regimes; some eggs were given an aromatase inhibitor to produce sons at temperatures that usually produce only daughters. Offspring were raised to maturity and freely interbred within field enclosures. After incubating eggs of the subsequent generation and assigning parentage, we found that the developmental temperature experienced by a male significantly influences the sex of his future progeny. This transgenerational effect on sex ratio may reflect an epigenetic influence on paternally-inherited DNA. Clearly, sex determination in reptiles is far more complex than is currently envisaged.

Warner, Daniel A.; Uller, Tobias; Shine, Richard

2013-01-01

12

Transgenerational sex determination: the embryonic environment experienced by a male affects offspring sex ratio.  

PubMed

Conditions experienced during embryonic development can have lasting effects, even carrying across generations. Most evidence for transgenerational effects comes from studies of female mammals, with much less known about egg-laying organisms or paternally-mediated effects. Here we show that offspring sex can be affected by the incubation temperature its father experiences years earlier. We incubated eggs of an Australian lizard with temperature-dependent sex determination under three thermal regimes; some eggs were given an aromatase inhibitor to produce sons at temperatures that usually produce only daughters. Offspring were raised to maturity and freely interbred within field enclosures. After incubating eggs of the subsequent generation and assigning parentage, we found that the developmental temperature experienced by a male significantly influences the sex of his future progeny. This transgenerational effect on sex ratio may reflect an epigenetic influence on paternally-inherited DNA. Clearly, sex determination in reptiles is far more complex than is currently envisaged. PMID:24048344

Warner, Daniel A; Uller, Tobias; Shine, Richard

2013-09-19

13

Human male meiotic sex chromosome inactivation.  

PubMed

In mammalian male gametogenesis the sex chromosomes are distinctive in both gene activity and epigenetic strategy. At first meiotic prophase the heteromorphic X and Y chromosomes are placed in a separate chromatin domain called the XY body. In this process, X,Y chromatin becomes highly phosphorylated at S139 of H2AX leading to the repression of gonosomal genes, a process known as meiotic sex chromosome inactivation (MSCI), which has been studied best in mice. Post-meiotically this repression is largely maintained. Disturbance of MSCI in mice leads to harmful X,Y gene expression, eventuating in spermatocyte death and sperm heterogeneity. Sperm heterogeneity is a characteristic of the human male. For this reason we were interested in the efficiency of MSCI in human primary spermatocytes. We investigated MSCI in pachytene spermatocytes of seven probands: four infertile men and three fertile controls, using direct and indirect in situ methods. A considerable degree of variation in the degree of MSCI was detected, both between and within probands. Moreover, in post-meiotic stages this variation was observed as well, indicating survival of spermatocytes with incompletely inactivated sex chromosomes. Furthermore, we investigated the presence of H3K9me3 posttranslational modifications on the X and Y chromatin. Contrary to constitutive centromeric heterochromatin, this heterochromatin marker did not specifically accumulate on the XY body, with the exception of the heterochromatic part of the Y chromosome. This may reflect the lower degree of MSCI in man compared to mouse. These results point at relaxation of MSCI, which can be explained by genetic changes in sex chromosome composition during evolution and candidates as a mechanism behind human sperm heterogeneity. PMID:22355370

de Vries, Marieke; Vosters, Sanne; Merkx, Gerard; D'Hauwers, Kathleen; Wansink, Derick G; Ramos, Liliana; de Boer, Peter

2012-02-15

14

Musings on Male Sex Work: A “Virtual” Discussion  

Microsoft Academic Search

Contributors and editors were asked to respond to a series of questions concerning male sex work in order to stimulate an informal “conversation.” Some of the topics explored include: why people seek the services of prostitutes; is the term “sex work” favorable to “prostitution”; is it right to pay for sex; and is exploitation a necessary part of the sex

Rebecca L. Harriman; Barry Johnston; Paula M. Kenny

2007-01-01

15

More Than a Sex Machine: Accomplishing Masculinity Among Chinese Male Sex Workers in the Hong Kong Sex Industry  

Microsoft Academic Search

Situated in the masculinity and deviance literature, this article examines a “deviant” masculinity, that of the male sex worker, and presents the ways men who engage in sex work cope with the job. Based on in-depth interviews of Chinese male sex workers (n = 18) in the Hong Kong sex industry, I argue that the stigma management techniques these men employ are

Travis S. K. Kong

2009-01-01

16

Male Teachers in Early Childhood Education: Sex-Role Perceptions.  

ERIC Educational Resources Information Center

Assessed male preschool teachers' self-perceptions, and sex-role perceptions of self and others. Male and female teachers (N=60) in preschool and high school education were administered the Bem Sex Role Inventory and a repertory grid. Results indicated preschool male and female teachers were similar in levels of androgyny. (RC)

Smith, Kenneth E.

1981-01-01

17

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

18

Masculinity and Relationship Agreements among Male Same-Sex Couples  

Microsoft Academic Search

Extradyadic sex is a significant source of risk for sexually transmitted infections (STIs) among men in same-sex relationships. Nonmonogamous sexual agreements are common among male same-sex couples and may serve as effective targets for risk reduction interventions; however, there is a dearth of research reporting on the social and cultural determinants of explicit nonmonogamous agreements. In this study, it was

Christopher W. Wheldon; Elizabeth B. Pathak

2010-01-01

19

Understanding the New Context of the Male Sex Work Industry  

ERIC Educational Resources Information Center

|The article reviews past and recent research on male sex work to offer a context to understand violence in the industry. It provides a critical review of research to show, first, the assumptions made about male sex workers and violence and, second, how such discourses have shaped thinking on the topic. The article presents a case study and…

Scott, John; Minichiello, Victor; Marino, Rodrigo; Harvey, Glenn P.; Jamieson, Maggie; Browne, Jan

2005-01-01

20

Male Sex Work: Exploring Regulation in England and Wales  

Microsoft Academic Search

Whilst sex-work policy in England and Wales claims gender-neutrality, local and national prostitution strategies primarily focus on female street-based sex workers. Men who sell sex are generally absent or inadequately considered in such policies, and measures to regulate commercial sex markets are rarely considered in terms of their impact on male working practice. Drawing on the Coordinated Prostitution Strategy for

M ary W howell

2010-01-01

21

OFFSPRING SEX RATIO IN DEER MALE REPRODUCTIVE PHYSIOLOGY AND OFFSPRING SEX RATIO IN ODOCOILEUS VIRGINIANUS.  

Technology Transfer Automated Retrieval System (TEKTRAN)

The primary sex ratio of the family Cervidae may vary at conception and/or birth from an expected 50:50 (males:females). Fertilization by X- or Y- chromosome-bearing sperm (referred to simply as X- and Y- sperm) ultimately controls the sex of offspring; however, alteration of the fetal sex ratio co...

22

Sex or Food? Appetetive Learning of Sex Odors in a Male Moth  

NASA Astrophysics Data System (ADS)

Moths learn to associate a flower odor with a food reward after a few learning trials. Can a hungry, male moth learn to associate a sex attractant with food instead of with sex? We provided a hungry male with odors of single female sex pheromone components, of the full sex pheromone blend or of a flower odor component as cues in an appetitive learning assay. The male learned the single pheromone components just as well as the flower odor. Learning was, however, severely impaired when the full sex pheromone blend was used as conditioning stimulus. The "hard-wiring" between pheromone odor and sex thus seems to be restricted to those circumstances when the male moth experiences the full blend.

Hartlieb, Elke; Hansson, Bill S.; Anderson, Peter

23

Sex pheromones and aggressive behavior in male rats  

Microsoft Academic Search

Two experiments were performed to examine the relationships among the sexual cycle of the female, sex pheromones, and the\\u000a agonistic behavior of male rats. Data suggest that the presence of an inaccessible sexually receptive female provokes increased\\u000a intermale fighting. The present research investigated the possibility that a sex pheromone from the female mediates the change\\u000a in male hostilities. In Experiment

George T. Taylor

1980-01-01

24

Male\\/Male Sex in Hong Kong: Privacy, Please?  

Microsoft Academic Search

In August 2005, the age of consent for male\\/male sexual activity in Hong Kong was held to be arbitrarily and discriminatorily\\u000a targeting gay men and thus in violation of an individual’s right to privacy and his right of equality on the basis of sexual\\u000a orientation. While the decision has since been affirmed on appeal, it has been argued that judicial

Phil C. W. Chan

2008-01-01

25

Nocturnal Male Sex Drive in Drosophila  

PubMed Central

Summary Many behaviors and physiological processes including locomotor activity, feeding, sleep, mating, and migration are dependent on daily or seasonally reoccurring, external stimuli [1–3]. 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 [4, 5]. 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.

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

2008-01-01

26

Sexual systems and dwarf males in barnacles: integrating life history and sex allocation theories.  

PubMed

Barnacles, which are sedentary marine crustaceans, have diverse sexual systems that include simultaneous hermaphroditism, androdioecy (coexistence of hermaphrodites and males) and dioecy (females and males). In dioecious and androdioecious species, the males are very small and are thus called dwarf males. These sexual systems are defined by two factors: sex allocation of non-dwarf individuals and the presence or absence of dwarf males. We constructed an ESS model treating sex allocation and life history simultaneously to explain sexual systems in barnacles. We analyzed the evolutionarily stable size-dependent resource allocation strategy to male reproductive function, female reproductive function and growth in non-dwarf barnacles, and the ESS proportion of dwarf males, under conditions of varying mortality and food availability. Sex allocation in non-dwarf individuals (hermaphrodites or females) is affected by mate availability and the proportion of dwarf males. When hermaphrodites appear, all hermaphrodites become protandric simultaneous hermaphrodites. Furthermore, high mortality and poor resource availability favor dwarf males because of their early maturation and weakened sperm competition. In conclusion, we showed that combining sex allocation and life history theories is a useful way to understand various sexual systems in barnacles and perhaps in other organisms as well. PMID:23238283

Yamaguchi, Sachi; Yusa, Yoichi; Sawada, Kota; Takahashi, Satoshi

2012-12-10

27

Effects of sex chromosome aneuploidy on male sexual behavior  

PubMed Central

Incidence of sex chromosome aneuploidy in men is as high as 1:500. The predominant conditions are an additional Y chromosome (47,XYY) or an additional X chromosome (47,XXY). Behavioral studies using animal models of these conditions are rare. To assess the role of sex chromosome aneuploidy on sexual behavior, we used mice with a spontaneous mutation on the Y chromosome in which the testis-determining gene Sry is deleted (referred to as Y?) and insertion of a Sry transgene on an autosome. Dams were aneuploid (XXY?) and the sires had an inserted Sry transgene (XYSry). Litters contained six male genotypes, XY, XYY?, XXSry, XXY?Sry, XYSry and XYY?Sry. In order to eliminate possible differences in levels of testosterone, all of the subjects were castrated and received testosterone implants prior to tests for male sex behavior. Mice with an additional copy of the Y? chromosome (XYY?) had shorter latencies to intromit and achieve ejaculations than XY males. In a comparison of the four genotypes bearing the Sry transgene, males with two copies of the X chromosome (XXSry and XXY?Sry) had longer latencies to mount and thrust than males with only one copy of the X chromosome (XYSry and XYY?Sry) and decreased frequencies of mounts and intromissions as compared with XYSry males. The results implicate novel roles for sex chromosome genes in sexual behaviors.

Park, J. H.; Burns-Cusato, M.; Dominguez-Salazar, E.; Riggan, A.; Shetty, S.; Arnold, A. P.; Rissman, E. F.

2008-01-01

28

Sex-specific inbreeding depression depends on the strength of male-male competition.  

PubMed

Inbreeding depression has become a central theme in evolutionary biology and is considered to be a driving force for the evolution of reproductive morphology, physiology, behavior, and mating systems. Despite the overwhelming body of empirical work on the reproductive consequences of inbreeding, relatively little is known on whether inbreeding depresses male and female fitness to the same extent. However, sex-specific inbreeding depression has been argued to affect the evolution of selfing rates in simultaneous hermaphrodites and provides a powerful approach to test whether selection is stronger in males than in females, which is predicted to be the consequence of sexual selection. We tested for sex-specific inbreeding depression in the simultaneously hermaphroditic freshwater snail Physa acuta by comparing the reproductive performance of both sex functions between selfed and outcrossed focal individuals under different levels of male-male competition. We found that inbreeding impaired both male and female reproductive success and that the magnitude of male inbreeding depression exceeded female inbreeding depression when the opportunity for sperm competition was highest. Our study provides the first evidence for sex-specific inbreeding depression in a hermaphroditic animal and highlights the importance of considering the level of male-male competition when assessing sex differences in inbreeding depression. PMID:24094339

Janicke, Tim; Vellnow, Nikolas; Sarda, Violette; David, Patrice

2013-06-17

29

Spermatogenic failure in male mice with four sex chromosomes.  

PubMed

There is accumulating evidence that meiosis, like mitosis, is monitored by a number of checkpoints. In mammals, the presence of asynapsed chromosomes at pachytene triggers a checkpoint (the pachytene or synapsis checkpoint) that removes cells via a p53-independent apoptotic pathway. In the special case of the sex bivalent in males, it is pseudoautosomal region (PAR) asynapsis that triggers the checkpoint. In male mice with three sex chromosomes (XYY or XYY(*X)) some pachytene spermatocytes achieve full (trivalent) PAR synapsis, but in many cells one sex chromosome remains as a univalent, thus triggering the checkpoint. Sperm counts in these males have been shown to be positively correlated with trivalent frequencies. In the present study sperm production and levels of sex chromosome synapsis were studied in mice with four sex chromosomes (XYYY(*X)) and XYY(*X)Y(*X)). These mice proved to be more severely affected than XYY or XYY(*X) mice. Nevertheless, pachytene synaptonemal complex analysis revealed that full PAR synapsis was achieved through the formation of radial quadrivalents or through the formation of two sex bivalents in 21%-49% of cells analysed. Given these levels of full PAR synapsis, the sperm counts were consistently lower than would have been predicted from the relationship between levels of PAR synapsis and sperm counts in mice with three sex chromosomes. It has been suggested that the inactivation of the asynapsed non-PAR X and Y axes of the XY bivalent of normal males (MSCI), which occurs during meiotic prophase, may be driven by Xist transcripts originating from the X. If this is the case, the non-PAR Y axes of YY and YY(*X) bivalents would fail to undergo MSCI. This could be cell lethal, either because of 'inappropriate' Y gene expression, or because the non-PAR Y axis may now trigger the synapsis checkpoint. PMID:11453555

Rodriguez, T A; Burgoyne, P S

2001-05-01

30

Latino Cross-Cultural Same Sex Male Relationships  

Microsoft Academic Search

Utilizing six different gay couples this article illustrates salient issues relevant to Latino cross-cultural same-sex male relationships. It emphasizes issues of both similarities and differences in terms of ethnicity, race, class, language, and other domains of influence. It conveys the potential danger of conceptualizing Latinos as members of a same race group, or as a homogeneous group. Furthermore, it identifies

Andres Nazario

2003-01-01

31

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

32

Sex Education and Rehabilitation With Schizophrenic Male Outpatients  

Microsoft Academic Search

Research indicates that schizophrenic patients lack intimate relationships and show a high rate of sexual dysfunction. Despite increasing awareness of the rights of handicapped persons to sexual expression, the treatment of schizophrenic patients rarely addresses their sexuality. A sex education program for recent-onset male schizophrenic patients attending an outpatient clinic was developed in response to several incidents involving patients’ inappropriate

David Lukoff; Debbie Gioia-Hasick; Greer Sullivan; Joshua S. Golden

1986-01-01

33

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

PubMed

In Tephritidae sex determination is established by orthologs to the Drosophila melanogaster transformer and transformer-2 genes, though the primary signals for sex determination differ. The presence of the Y chromosome in the tephritid species is critical for male differentiation, while the ratio of X chromosomes to autosome ploidy is critical in drosophilids. Here the isolation, expression and function of tra and tra-2 orthologs are described for the agriculturally important tephritid, Anastrepha suspensa, and their possible use in genetically modified organisms for biologically-based pest management. The Astra and Astra-2 genes are highly conserved in structure, regulation and function with respect to those known from other tephritid species. Sex-specific transcripts for Astra were detected, one in females and three in males, whereas Astra-2 had a single common transcript found in both sexes. To test the function of these genes, Astra and Astra-2 dsRNA was injected into A. suspensa embryos from a transgenic strain having a Y-linked DsRed marker integration, allowing XY males to be distinguished from XX phenotypic males. Nearly all XX embryos developed into fully masculinized phenotypic male adults with no apparent female morphology. Upon dissection abnormal hypertrophic gonads were revealed in XX pseudomales but not in the XY males. Our findings suggest that Astra and Astra-2 are both necessary for female development, and that the potential exists for producing a male-only population when either gene alone, or both genes simultaneously, are knocked-down. PMID:22079281

Schetelig, Marc F; Milano, Andreina; Saccone, Giuseppe; Handler, Alfred M

2011-11-04

34

Socially-Responsive Gene Expression in Male Drosophila melanogaster Is Influenced by the Sex of the Interacting Partner  

PubMed Central

Behavior is influenced by an organism's genes and environment, including its interactions with same or opposite sex individuals. Drosophila melanogaster perform innate, yet socially modifiable, courtship behaviors that are sex specific and require rapid integration and response to multiple sensory cues. Furthermore, males must recognize and distinguish other males from female courtship objects. It is likely that perception, integration, and response to sex-specific cues is partially mediated by changes in gene expression. Reasoning that social interactions with members of either sex would impact gene expression, we compared expression profiles in heads of males that courted females, males that interacted with other males, or males that did not interact with another fly. Expression of 281 loci changes when males interact with females, whereas 505 changes occur in response to male–male interactions. Of these genes, 265 are responsive to encounters with either sex and 240 respond specifically to male–male interactions. Interestingly, 16 genes change expression only when a male courts a female, suggesting that these changes are a specific response to male–female courtship interactions. We supported our hypothesis that socially-responsive genes can function in behavior by showing that egghead (egh) expression, which increases during social interactions, is required for robust male-to-female courtship. We predict that analyzing additional socially-responsive genes will give us insight into genes and neural signaling pathways that influence reproductive and other behavioral interactions.

Ellis, Lisa L.; Carney, Ginger E.

2011-01-01

35

Operational sex ratio influences female preference and male-male competition in guppies.  

PubMed

Manipulation of the operational sex ratio (OSR) in guppies, Poecilia reticulata, causes changes in male-male competition and female mate choice. In this study OSR is defined as the number of sexually active males divided by the total number of sexually active adults of both sexes. The rate of male courtship displays decreased, and interference behaviours between males increased, at male-biased OSRs. The OSR influenced both copulatory tactics and postcopulatory guarding. All copulations followed sigmoid displays, except at an OSR of five males to one female where 60% of copulations occurred during sneak attempts. Compared with copulations that followed sigmoid displays, successful sneak copulations were followed by a shorter period of postcopulatory mate guarding and a shorter refractory period before males resumed courtship activities. Females preferred males with more orange colour whenever they had a choice, and the preference for orange colour was stronger with more male-biased OSRs. The OSR thus influences the presence, absence or relative importance of both female mate choice and male-male competition which, in turn, should affect the evolution of secondary sexual traits. Copyright 1999 The Association for the Study of Animal Behaviour. PMID:10458880

Jirotkul

1999-08-01

36

Correlates of unprotected sex with female sex workers among male clients in Tijuana, Mexico  

PubMed Central

Background Tijuana, situated adjacent to San Diego, CA on the US-Mexico border, is experiencing an emerging HIV epidemic, with prevalence among female sex workers (FSWs) having risen in recent years from <1% to 6%. Comparable data on FSWs’ clients are lacking. We explored correlates of unprotected sex with FSWs among male clients in Tijuana. Methods In 2008, males from San Diego (N=189) and Tijuana (N=211) aged 18 or older who had paid or traded for sex with a FSW in Tijuana during the past 4 months were recruited in Tijuana’s red light district. Participants underwent psychosocial interviews and were tested for HIV, syphilis (Treponema pallidum), gonorrhea (Neisseria gonorrhoeae), and Chlamydia (Chlamydia trachomatis). Results Of 394 men, median age was 36 years, 42.1% were married, and 39.3% were unemployed. Ethnic composition was 13.2% white, 79.4% Hispanic and 7.4% black or other. Half (50.3%) reported unprotected vaginal or anal sex with FSWs in Tijuana in the past 4 months. High proportions reported using drugs during sex (66%), and 36% reported frequenting the same FSW. Factors independently associated with unprotected sex with FSWs were using drugs during sex, visiting the same FSW, being married, and being unemployed. Conclusions FSWs’ clients represent an STI/HIV transmission “bridge” through unprotected sex with FSWs, wives and other partners. Tailored interventions to promote consistent condom use are needed for clients, especially within the context of drug use and ongoing relations with particular FSWs.

Goldenberg, Shira M; Cruz, Manuel Gallardo; Strathdee, Steffanie A; Nguyen, Lucie; Semple, Shirley J; Patterson, Thomas L

2010-01-01

37

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

38

A social basis for the development of primary males in a sex-changing fish  

Microsoft Academic Search

An example of alternative male strategies is seen in diandric protogynous (female first) hermaphrodites, where individuals either mature directly as male (primary males) or first reproduce as female and then change sex to male (secondary males). In some sex-changing fishes, the testes of primary males appear anatomically similar to those of non-sex-changing species, whereas the testes of secondary males have

Philip L. Munday; J. Wilson White; Robert R. Warner

2006-01-01

39

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

40

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

PubMed Central

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.

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

2013-01-01

41

Recessive sex-determining genes in human XX male syndrome.  

PubMed

Maleness is normally inherited as a dominant trait (a single copy of the Y chromosome induces testicular differentiation of the embryonic gonad), but our genealogic study of three XX males in one pedigree indicated an autosomal recessive mode of male inheritance. Subsequent study revealed the presence of H-Y antigens in the three XX males and in their mothers, and suggested that excess H-Y may be found in the fathers. Inasmuch as H-Y loci have been mapped to the human Y chromosome, these data favor the view that H-Y structural loci comprise a family of testis-determining genes, and that Y autosome (or Y-X) translocation can generate either dominant or recessive modes of XX sex reversal, depending upon the particular portion of H-Y genes transferred. PMID:569552

de la Chapelle, A; Koo, G C; Wachtel, S S

1978-11-01

42

Multiple risks among male and transgender sex workers in Pakistan.  

PubMed

Using data from a qualitative study and a subsequent quantitative survey among 918 male and transgender sex workers (MTSW), we explore the context of multiple risks they face. We show that over one-fifth of MTSW have sex with IDU clients. Combined with high levels of risk behavior and very low levels of risk reduction and knowledge, the extent of sexual networking with men who inject drugs contributes further to the sex workers' health risks. Our findings suggest that isolated interventions with single-risk groups are unlikely to be sufficient to control the spread of the epidemic in Pakistan. We highlight the need for integrated approaches to risk reduction programs among MTSW and IDUs. PMID:19856740

Collumbien, Martine; Chow, Jaime; Qureshi, Ayaz Ahmed; Rabbani, Aliya; Hawkes, Sarah

2008-01-01

43

Sex ratio bias, male aggression, and population collapse in lizards  

PubMed Central

The adult sex ratio (ASR) is a key parameter of the demography of human and other animal populations, yet the causes of variation in ASR, how individuals respond to this variation, and how their response feeds back into population dynamics remain poorly understood. A prevalent hypothesis is that ASR is regulated by intrasexual competition, which would cause more mortality or emigration in the sex of increasing frequency. Our experimental manipulation of populations of the common lizard (Lacerta vivipara) shows the opposite effect. Male mortality and emigration are not higher under male-biased ASR. Rather, an excess of adult males begets aggression toward adult females, whose survival and fecundity drop, along with their emigration rate. The ensuing prediction that adult male skew should be amplified and total population size should decline is supported by long-term data. Numerical projections show that this amplifying effect causes a major risk of population extinction. In general, such an “evolutionary trap” toward extinction threatens populations in which there is a substantial mating cost for females, and environmental changes or management practices skew the ASR toward males.

Le Galliard, Jean-Francois; Fitze, Patrick S.; Ferriere, Regis; Clobert, Jean

2005-01-01

44

When Sex is Work: Organizing for Labour Rights and Protections  

Microsoft Academic Search

Research on sex work has documented the harmful effects of criminalization on sex workers’ safety. Despite this body of research, the effects of criminalization on the organization of labour within the sex industry and sex workers’ suggestions for labour improvements have been largely ignored. In part, this is due to the mostly hypothetical nature of sex work labour organizing, as

Emily van der Meulen

2012-01-01

45

Sperm counts and sperm sex ratio in male infertility patients.  

PubMed

In recent years, investigators have noted a trend toward a declining proportion of male births in many industrialized nations. While men bear the sex-determining chromosome, the role of the female partner as it pertains to fertilization or miscarriage may also alter the gender ratio. We attempted to determine a man's secondary sex ratio (F1 generation) by directly examining the sex chromosomes of his sperm. We examined our male infertility clinic database for all men who had undergone a semen fluorescence in situ hybridization (FISH). Patient demographic and semen parameters were recorded. Chi-squared analysis was used to compare gender ratios (Y chromosomes/total chromosomes). Multivariable logistic regression was used to predict the odds of possessing a Y-bearing sperm after accounting for demographic and semen parameters. A total of 185 men underwent sperm FISH. For the entire cohort, the proportion of Y chromosome-bearing sperm was 51.5%. Men with less than five million motile sperm had a significantly lower proportion of Y chromosome-bearing sperm (50.8%) compared to men with higher sperm counts (51.6%; P=0.02). After multivariable adjustment, a higher sperm concentration, total motile sperm count and semen volume significantly increased the odds of having a Y chromosome-bearing sperm (P<0.01). As a man's sperm production declines, so does the proportion of Y chromosome-bearing sperm. Thus, a man's reproductive potential may predict his ability to sire male offspring. PMID:22842703

Eisenberg, Michael L; Murthy, Lata; Hwang, Kathleen; Lamb, Dolores J; Lipshultz, Larry I

2012-07-30

46

Sperm counts and sperm sex ratio in male infertility patients  

PubMed Central

In recent years, investigators have noted a trend toward a declining proportion of male births in many industrialized nations. While men bear the sex-determining chromosome, the role of the female partner as it pertains to fertilization or miscarriage may also alter the gender ratio. We attempted to determine a man's secondary sex ratio (F1 generation) by directly examining the sex chromosomes of his sperm. We examined our male infertility clinic database for all men who had undergone a semen fluorescence in situ hybridization (FISH). Patient demographic and semen parameters were recorded. Chi-squared analysis was used to compare gender ratios (Y chromosomes/total chromosomes). Multivariable logistic regression was used to predict the odds of possessing a Y-bearing sperm after accounting for demographic and semen parameters. A total of 185 men underwent sperm FISH. For the entire cohort, the proportion of Y chromosome-bearing sperm was 51.5%. Men with less than five million motile sperm had a significantly lower proportion of Y chromosome-bearing sperm (50.8%) compared to men with higher sperm counts (51.6% P=0.02). After multivariable adjustment, a higher sperm concentration, total motile sperm count and semen volume significantly increased the odds of having a Y chromosome-bearing sperm (P<0.01). As a man's sperm production declines, so does the proportion of Y chromosome-bearing sperm. Thus, a man's reproductive potential may predict his ability to sire male offspring.

Eisenberg, Michael L; Murthy, Lata; Hwang, Kathleen; Lamb, Dolores J; Lipshultz, Larry I

2012-01-01

47

Male sex workers in Córdoba, Argentina: sociodemographic characteristics and sex work experiences  

Microsoft Academic Search

Objective .To report on the sociodemographic characteristics and work experiences of 3 1 male sex workers (MSWs) in the city of Córdoba, Argentina. Methods .Information on each of the MSWs was collected using a questionnaire that co v - ered his personal characteristics and his work background, self-assessed general health status , and use of health and social services. Scales

Rodrigo Mariño; Victor Minichiello; Carlos Disogra

2003-01-01

48

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

2012-01-31

49

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

50

Sex chromosome silencing in the marsupial male germ line.  

PubMed

In marsupials, dosage compensation involves silencing of the father's X-chromosome. Because no XIST orthologue has been found, how imprinted X-inactivation occurs is unknown. In eutherians, the X is subject to meiotic sex chromosome inactivation (MSCI) in the paternal germ line and persists thereafter as postmeiotic sex chromatin (PMSC). One hypothesis proposes that the paternal X is inherited by the eutherian zygote as a preinactive X and raises the possibility of a similar process in the marsupial germ line. Here we demonstrate that MSCI and PMSC occur in the opossum. Surprisingly, silencing occurs before X-Y association. After MSCI, the X and Y fuse through a dense plate without obvious synapsis. Significantly, sex chromosome silencing continues after meiosis, with the opossum PMSC sharing features of eutherian PMSC. These results reveal a common gametogenic program in two diverse clades of mammals and support the idea that male germ-line silencing may have provided an ancestral form of mammalian dosage compensation. PMID:17535928

Namekawa, Satoshi H; VandeBerg, John L; McCarrey, John R; Lee, Jeannie T

2007-05-29

51

Save the Males: Backlash in Organizations  

Microsoft Academic Search

This paper reviews the literature on male backlash in organizations, proposing a research agenda. It defines backlash, examines its causes and manifestations, who is likely to exhibit it, and offers suggestions for addressing backlash. Backlash may be on the increase in organizations and society at large. Current efforts to weaken or remove the legislative support for employment equity initiatives are

Ronald J. Burke; Susan Black

1997-01-01

52

Extremely female-biased sex ratio and lethal male--male combat in a parasitoid wasp, Melittobia australica (Eulophidae)  

Microsoft Academic Search

Melittobia australica (Hymenoptera: Eulophidae) is a gregarious ectoparasitoid of the prepupae and pupae of solitary wasps and bees. The males never disperse from their natal patch, and mating takes place only on the host from which they emerged. We measured the offspring sex ratio of M. australica with differing foundress numbers and examined combat between emerged males. The offspring sex

Jun Abe; Yoshitaka Kamimura; Natsuko Kondo; Masakazu Shimadaa

2003-01-01

53

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

54

Targeted metabolomics reveals a male pheromone and sex-specific ascaroside biosynthesis in C. elegans  

PubMed Central

In the model organism Caenorhabditis elegans, a class of small molecule signals called ascarosides regulate development, mating and social behaviors. Ascaroside production has been studied in the predominant sex, the hermaphrodite, but not in males, which account for less than 1% of wild-type worms grown under typical laboratory conditions. Using HPLC-MS-based targeted metabolomics, we show that males also produce ascarosides and that their ascaroside profile differs markedly from that of hermaphrodites. Whereas hermaphrodite ascaroside profiles are dominated by ascr#3, containing an ?,?-unsaturated fatty acid, males predominantly produce the corresponding dihydro-derivative ascr#10. This small structural modification profoundly affects signaling properties: hermaphrodites are retained by attomole-amounts of male-produced ascr#10, whereas hermaphrodite-produced ascr#3 repels hermaphrodites and attracts males. Male production of ascr#10 is population density-dependent, indicating sensory regulation of ascaroside biosynthesis. Analysis of gene expression data supports a model in which sex-specific regulation of peroxisomal ?-oxidation produces functionally different ascaroside profiles.

Izrayelit, Yevgeniy; Srinivasan, Jagan; Campbell, Sydney L.; Jo, Yeara; von Reuss, Stephan H.; Genoff, Margaux C.; Sternberg, Paul W.; Schroeder, Frank C.

2012-01-01

55

Targeted metabolomics reveals a male pheromone and sex-specific ascaroside biosynthesis in Caenorhabditis elegans.  

PubMed

In the model organism Caenorhabditis elegans, a class of small molecule signals called ascarosides regulate development, mating, and social behaviors. Ascaroside production has been studied in the predominant sex, the hermaphrodite, but not in males, which account for less than 1% of wild-type worms grown under typical laboratory conditions. Using HPLC-MS-based targeted metabolomics, we show that males also produce ascarosides and that their ascaroside profile differs markedly from that of hermaphrodites. Whereas hermaphrodite ascaroside profiles are dominated by ascr#3, containing an ?,?-unsaturated fatty acid, males predominantly produce the corresponding dihydro-derivative ascr#10. This small structural modification profoundly affects signaling properties: hermaphrodites are retained by attomole-amounts of male-produced ascr#10, whereas hermaphrodite-produced ascr#3 repels hermaphrodites and attracts males. Male production of ascr#10 is population density-dependent, indicating sensory regulation of ascaroside biosynthesis. Analysis of gene expression data supports a model in which sex-specific regulation of peroxisomal ?-oxidation produces functionally different ascaroside profiles. PMID:22662967

Izrayelit, Yevgeniy; Srinivasan, Jagan; Campbell, Sydney L; Jo, Yeara; von Reuss, Stephan H; Genoff, Margaux C; Sternberg, Paul W; Schroeder, Frank C

2012-06-12

56

A qualitative study on commercial sex behaviors among male clients in Sichuan Province, China  

Microsoft Academic Search

Males who seek commercial sex have been identified as an important “bridging population” in the transmission of HIV. There is little information on the HIV-related risk perceptions and behaviors among commercial sex male clients (CSMCs) in China. This study reports qualitative findings from six focus groups and 41 in-depth interviews with CSMCs in Sichuan Province, China. Commercial sex visits were

Cui Yang; Carl A. Latkin; Peng Liu; Kenrad E. Nelson; Cunlin Wang; Rongsheng Luan

2010-01-01

57

Psychological androgyny, sex-typing, and sex-role ideology as predictors of male-female interpersonal attraction  

Microsoft Academic Search

Two studies examined the degree of sex-typing or androgyny college students desired in their ideal dating partners\\/potential spouses. In Study I, 140 males and 95 females classified according to psychological sex type rated their ideal partners on the items of the Bem Sex Role Inventory (BSRI). Consistent with the general tenor of predictions, sex-typed subjects endorsed a greater discrepancy between

Jacob L. Orlofsky

1982-01-01

58

Non-Mendelian segregation of sex chromosomes in heterospecific Drosophila males.  

PubMed Central

Interspecific hybrids and backcrossed organisms generally suffer from reduced viability and/or fertility. To identify and genetically map these defects, we introgressed regions of the Drosophila sechellia genome into the D. simulans genome. A female-biased sex ratio was observed in 24 of the 221 recombinant inbred lines, and subsequent tests attributed the skew to failure of Y-bearing sperm to fertilize the eggs. Apparently these introgressed lines fail to suppress a normally silent meiotic drive system. Using molecular markers we mapped two regions of the Drosophila genome that appear to exhibit differences between D. simulans and D. sechellia in their regulation of sex chromosome segregation distortion. The data indicate that the sex ratio phenotype results from an epistatic interaction between at least two factors. We discuss whether this observation is relevant to the meiotic drive theory of hybrid male sterility.

Dermitzakis, E T; Masly, J P; Waldrip, H M; Clark, A G

2000-01-01

59

Male Sex Workers Who Sell Sex to Men Also Engage in Anal Intercourse with Women: Evidence from Mombasa, Kenya  

PubMed Central

Objective To investigate self-report of heterosexual anal intercourse among male sex workers who sell sex to men, and to identify the socio-demographic characteristics associated with practice of the behavior. Design Two cross-sectional surveys of male sex workers who sell sex to men in Mombasa, Kenya. Methods Male sex workers selling sex to men were invited to participate in surveys undertaken in 2006 and 2008. A structured questionnaire administered by trained interviewers was used to collect information on socio-demographic characteristics, sexual behaviors, HIV and STI knowledge, and health service usage. Data were analyzed through descriptive and inferential statistics. Bivariate logistic regression, after controlling for year of survey, was used to identify socio-demographic characteristics associated with heterosexual anal intercourse. Results From a sample of 867 male sex workers, 297 men had sex with a woman during the previous 30 days – of whom 45% did so with a female client and 86% with a non-paying female partner. Within these groups, 66% and 43% of male sex workers had anal intercourse with a female client and non-paying partner respectively. Factors associated with reporting recent heterosexual anal intercourse in bivariate logistic regression after controlling for year of survey participation were being Muslim, ever or currently married, living with wife only, living with a female partner only, living with more than one sexual partner, self-identifying as basha/king/bisexual, having one’s own children, and lower education. Conclusions We found unexpectedly high levels of self-reported anal sex with women by male sex workers, including selling sex to female clients as well as with their own partners. Further investigation among women in Mombasa is needed to understand heterosexual anal sex practices, and how HIV programming may respond.

Mannava, Priya; Geibel, Scott; King'ola, Nzioki; Temmerman, Marleen; Luchters, Stanley

2013-01-01

60

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

61

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

62

Male sex workers in Antwerp, Belgium: a descriptive study.  

PubMed

The objective of this study was to describe the prevalence of sexually transmitted infections (STI), sociodemographic and behavioural characteristics in a population of male sex workers (MSW) in Antwerp, Belgium. Between September 1999 and March 2004, 129 MSW were reached by Gh@pro, an outreach programme providing preventive health care, free STI check-up and hepatitis B vaccination, to sex workers (SW). Sera were collected from 121 men, urine samples from 115 men and a questionnaire was filled in by 43 MSW. In 45.5% of MSW one or more STI were diagnosed (including hepatitis B), 76% on laboratory testing at first screening, 9% through symptomatology at first visit. The prevalence of HIV was 10.8%, hepatitis B virus (HBV) infection 28.9%, syphilis 12.5%, gonorrhoea 1.7% and Chlamydia trachomatis 9.7%. More than 50% of non-immune MSW completed their three-dose hepatitis B vaccination course. Prevalence of STI is concordant with published data on MSW; this population clearly requests and deserves particular attention and approach. There is an important difference in sociodemographic and behavioural characteristics between MSW working in the red light district and those working on the street. Health promotion should be tailored to the different subpopulations and outreach appears to be a successful tool. PMID:16303070

Leuridan, E; Wouters, K; Stalpaert, M; Van Damme, P

2005-11-01

63

Postmeiotic sex chromatin in the male germline of mice.  

PubMed

In mammals, the X and Y chromosomes are subject to meiotic sex chromosome inactivation (MSCI) during prophase I in the male germline, but their status thereafter is currently unclear. An abundance of X-linked spermatogenesis genes has spawned the view that the X must be active . On the other hand, the idea that the imprinted paternal X of the early embryo may be preinactivated by MSCI suggests that silencing may persist longer . To clarify this issue, we establish a comprehensive X-expression profile during mouse spermatogenesis. Here, we discover that the X and Y occupy a novel compartment in the postmeiotic spermatid and adopt a non-Rabl configuration. We demonstrate that this postmeiotic sex chromatin (PMSC) persists throughout spermiogenesis into mature sperm and exhibits epigenetic similarity to the XY body. In the spermatid, 87% of X-linked genes remain suppressed postmeiotically, while autosomes are largely active. We conclude that chromosome-wide X silencing continues from meiosis to the end of spermiogenesis, and we discuss implications for proposed mechanisms of imprinted X-inactivation. PMID:16581510

Namekawa, Satoshi H; Park, Peter J; Zhang, Li-Feng; Shima, James E; McCarrey, John R; Griswold, Michael D; Lee, Jeannie T

2006-04-01

64

The influence of sex-role stereotypes on evaluations of male and female supervisory behavior  

Microsoft Academic Search

Examined the way sex-role stereotypes influence evaluations of male and female supervisory behavior. 134 male and 24 female undergraduates and 83 male and 15 female bank supervisors were asked to read 1 of 6 versions of a supervisory problem (with either a male or female supervisor and male, female, or mixed subordinates), and evaluate the effectiveness of 4 supervisory styles.

Benson Rosen; Thomas H. Jerdee

1973-01-01

65

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

66

Genomic organization of the sex-determining and adjacent regions of the sex chromosomes of medaka  

PubMed Central

Sequencing of the human Y chromosome has uncovered the peculiarities of the genomic organization of a heterogametic sex chromosome of old evolutionary age, and has led to many insights into the evolutionary changes that occurred during its long history. We have studied the genomic organization of the medaka fish Y chromosome, which is one of the youngest heterogametic sex chromosomes on which molecular data are available. The Y specific and adjacent regions were sequenced and compared to the X. The male sex-determining gene, dmrt1bY, appears to be the only functional gene in the Y-specific region. The Y-specific region itself is derived from the duplication of a 43-kb fragment from linkage group 9. All other coduplicated genes except dmrt1bY degenerated. The Y-specific region has accumulated large stretches of repetitive sequences and duplicated pieces of DNA from elsewhere in the genome, thereby growing to 258 kb. Interestingly the non-recombining part of the Y did not spread out considerably from the original duplicated fragment, possibly because of a large sequence duplication bordering the Y-specific fragment. This may have conserved the more ancestral structure of the medaka Y and provides insights into some of the initial processes of Y chromosome evolution.

Kondo, Mariko; Hornung, Ute; Nanda, Indrajit; Imai, Shuichiro; Sasaki, Takashi; Shimizu, Atsushi; Asakawa, Shuichi; Hori, Hiroshi; Schmid, Michael; Shimizu, Nobuyoshi; Schartl, Manfred

2006-01-01

67

5. Hidden Patterns of Male Sex Hormones and Behaviour Vary with Life History  

Microsoft Academic Search

Androgens regulate sperm production, the expression of secondary sex characters and behavior in males and also vice versa, androgens are modulated by the male's interactions with his social environment. In search for a regular internal \\

Katharina HIRSCHENHAUSER; Didone FRIGERIO

68

Alcohol and drug use in Australian male sex workers: Its relationship to the safety outcome of the sex encounter  

Microsoft Academic Search

This paper describes the self-reporting patterns of alcohol and drug consumption among male sex workers (MSWs) in three Australian cities during commercial sex encounters, and examines to what extent alcohol and drugs are used and whether this is related to the safe\\/unsafe outcome of the commercial sex encounter. One hundred and eighty-six MSWs from Brisbane, Sydney and Melbourne completed a

V. Minichiello; R. Mariño; M. A. Khan; J. Browne

2003-01-01

69

[Lymphatic scanning in the diagnosis of tuberculosis of the male genital organs].  

PubMed

Lymphoscanning was performed in 149 patients with tuberculosis and chronic non-specific inflammatory diseases of the male sex organs. The patients were divided into 3 groups: I--73 patients with an active tuberculous process, II--22 patients with an inactive process, III--54 patients with chronic non-specific inflammatory diseases of the male sex organs. Intrafunicular (in the affection of the external sex organs) and paraprostatic (in the affection of the internal sex organs) administration of 198Au-comisole was developed and employed for lymphography followed by lymphoscanning 1 day after RP administration. The results of lymphoscanning have shown that the indices of the visualization of the groups of regional lymph nodes and the intensity of RP accumulation in them were the most informative. PMID:3683122

Gorelov, A I; Vakhmistrova, T I; Mishchenko, A S

1987-11-01

70

Tampering with the Sex of ‘Angels’: Migrant Male Minors and Young Adults Selling Sex in the EU  

Microsoft Academic Search

This article draws on the findings of two recent studies on the migration experiences of migrant male minors and young adults in the European Union, with a specific focus on their involvement in sex work. I use original research material to deconstruct North-centric understandings of minors selling sex as coinciding with ‘child exploitation’. Contrary to current hegemonic ‘one fits all’

Nick Mai

2011-01-01

71

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

PubMed Central

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.

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

2009-01-01

72

Sex differences in response to nonconspecific advertisement calls: receiver permissiveness in male and female tungara frogs  

Microsoft Academic Search

In many species, males advertise to both male and female audiences. Given the asymmetry in fitness costs of recognition errors in response to mating signals for the sexes, usually higher for females than males, males are expected to be more permissive than females in their responses to signals. Few studies, however, have investigated such differences and there is no consensus

XIMENA E. B ERNAL; A. STANLEY RAND; MICHAEL J. R YAN

2007-01-01

73

OPERATIONAL SEX RATIO AND DENSITY DO NOT AFFECT DIRECTIONAL SELECTION ON MALE SEXUAL ORNAMENTS AND BEHAVIOR  

Microsoft Academic Search

Demographic parameters including operational sex ratio (OSR) and population density may influence the opportunity for, and strength of sexual selection. Traditionally, male-biased OSRs and high population densities have been thought to increase the opportunity for sexual selection on male sexual traits due to increased male competition for mates. Recent experimental evidence, however, suggests that male-biased OSRs might reduce the opportunity

Megan L. Head; Anna K. Lindholm; Robert Brooks

2007-01-01

74

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

Microsoft Academic Search

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.

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

2008-01-01

75

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

76

Emergence of male-biased genes on the chicken Z-chromosome: sex-chromosome contrasts between male and female heterogametic systems.  

PubMed

There has been extensive traffic of male-biased genes out of the mammalian and Drosophila X-chromosomes, and there are also reports of an under-representation of male-biased genes on the X. This may reflect an adaptive process driven by natural selection where an autosomal location of male-biased genes is favored since male genes are only exposed to selection one-third of the time when X-linked. However, there are several alternative explanations to "out-of-the-X" gene movement, including mutational bias and a means for X-linked genes to escape meiotic sex chromosome inactivation (MSCI) during spermatogenesis. As a critical test of the hypothesis that genomic relocation of sex-biased genes is an adaptive process, I examined the emergence, and loss, of genes on the chicken Z-chromosome, i.e., a female heterogametic system (males ZZ, females ZW). Here, the analogous prediction would be an emergence of male-biased genes onto, not a loss from, the Z-chromosome because Z is found more often in males than autosomes are. I found that genes expressed in testis but not in ovary are highly over-represented among genes that have emerged on the Z-chromosome during avian evolution. Moreover, genes with male-biased expression are similarly over-represented among new Z-chromosomal genes. Interestingly, genes with female-biased expression have more often moved from than to the Z-chromosome. These observations show that male and female heterogametic organisms display opposing directionalities in the emergence and loss of sex-biased genes on sex chromosomes. This is consistent with theoretical models on the evolution of sexually antagonistic genes in which new mutations are at least partly dominant. PMID:21868722

Ellegren, Hans

2011-08-25

77

Female and Male Sex Offenders: A Comparison of Recidivism Patterns and Risk Factors  

ERIC Educational Resources Information Center

Few studies have empirically validated the assertion that female and male sex offenders are vastly different. Therefore, utilizing a matched sample of 780 female and male sex offenders in New York State, the current study explored differences and similarities of recidivism patterns and risk factors for the two offender groups. Results suggested…

Freeman, Naomi J.; Sandler, Jeffrey C.

2008-01-01

78

Escaping Stereotypes: Educational Attitudes of Male Alumni of Single-Sex and Coed Schools  

Microsoft Academic Search

Advocates of single-sex education claim that in the absence of girls, boys are more likely to explore school subjects traditionally ascribed to girls. If so, male graduates of single-sex schools would exhibit more positive attitudes toward the humanities and would choose more diverse careers than would their cohorts who graduated from coed schools. Male alumni (N = 412) were recruited

Abigail Norfleet James; Herbert C. Richards

2003-01-01

79

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

Microsoft Academic Search

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

Yasmina Katsulis; Alesha Durfee

2012-01-01

80

Sex role orientations of male and female collegiate athletes from selected individual and team sports  

Microsoft Academic Search

The purpose of the present study was to determine whether the sex role orientations of male and female collegiate athletes were more similar in team sports than in individual sports. It was predicted that females in masculine-oriented team sports (basketball and volleyball) would exhibit sex role orientations more similar to those of their male counterparts than would females in individual

Craig A. Wrisberg; M. Vanessa Draper; John J. Everett

1988-01-01

81

The effect of dietary supplementation with limonene or myo-inositol on the induction of neoplasia and matrix metalloproteinase and plasminogen activator activities in accessory sex organs of male Lobund-Wistar rats.  

PubMed

Prostate cancer, the most prevalent non-cutaneous cancer in men, is associated with increased age. This suggests that dietary chemopreventive measures could be effective in delaying the onset or decreasing the severity of the disease. We utilized the Lobund-Wistar rat nitrosomethylurea induced, testosterone promoted (NMU-T) model of male sex accessory gland cancer to test the potential chemopreventive effects of myo-inositol and limonene on tumor incidence and associated protease activities. Tumors were found to arise in the seminal vesicles and dorsal and anterior prostate lobes. There were also some tumors that appeared to arise in both the seminal vesicles and anterior prostate, and in some cases the tissue of origin was not clear. The distribution of tumors as to site of origin in limonene or myo-inositol treated animals did not vary from that of the starch fed control animals, and the number of animals presenting with metastases did not vary significantly between treatment groups. There was a statistically significant delay in onset of tumors in myo-inositol, but not limonene fed rats, at 10 months post-induction of carcinogenesis; however, at 12 and 15 months this was not significant. The ventral prostate and seminal vesicles expressed pro-MMP-2 and plasminogen activator (PA) activities. Based on sensitivity to amiloride, the PA activities were predominately urokinase (uPA) in the ventral prostate and a mixture of tissue-type activator (tPA) and uPA in the seminal vesicles of non-treated rats. Sex accessory gland tumors, and metastases, expressed increased levels PA and pro- and active forms of MMP-2 and -9. The PA activities of the tumors were a mixture of uPA and tPA. There was no difference in the levels of these protease activities based on the tissue of tumor origin, nor in tumor vs metastasis. These studies indicate that MMP and PA activities play a role in sex accessory gland tumor biology and that dietary supplementation with myo-inositol can delay but not ultimately prevent the development of such tumors. PMID:18675799

Wilson, Michael J; Lindgren, Bruce R; Sinha, Akhouri A

2008-07-17

82

Hepatitis B vaccination for male sex workers: the experience of a specialist GUM service  

Microsoft Academic Search

Background: Male sex workers are at risk of blood borne viruses but may have limited access to sexual health services, including vaccination. We explore factors associated with hepatitis B vaccination uptake among male sex workers in LondonMethods: Follow up study of men attending the Working Men’s Project, a specialist health project for men who sell sex, between 1994 and 2003.Results:

G Sethi; B M Holden; L Greene; J Gaffney; H Ward

2006-01-01

83

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

84

Role of insect sex pheromones in mating behavior. V. Profile of process on male flying approach toward sex pheromone source  

Microsoft Academic Search

Application of the kinetic theory of gas molecules to male zigzagging orientation, which is assumed as repeated encounter\\u000a between sex pheromone puff and a flying male moth, derived a linear relationship between the number of turnings and the distance\\u000a from the source where male began repeated turnings. Similar results are also obtained by computer simulation. This relationship\\u000a was already obtained

Yoshitoshi Hirooka

1986-01-01

85

Personal Characteristics, Sexual Behaviors, and Male Sex Work: A Quantitative Approach  

Microsoft Academic Search

Male sex workers serve multiple groups (i.e., gay-identified men, heterosexually-identified men, and their own sexual partners), making them a unique source to test theories of gender, masculinity, and sexuality. To date, most scholarship on this topic has been qualitative. I assembled a dataset from the largest online male sex worker website to conduct the first quantitative analysis of male escorts

Trevon D. Logan

2010-01-01

86

Organizing and Activating Effects of Sex Hormones in Homosexual Transsexuals  

Microsoft Academic Search

The cause of transsexualism remains unclear. The hypothesis that atypical prenatal hormone exposure could be a factor in the development of transsexualism was examined by establishing whether an atypical pattern of cognitive functioning was present in homosexual transsexuals. Possible activating effects of sex hormones as a result of cross-sex hormone treatment were also studied. Female-to-male and male-to-female transsexuals were compared

Stephanie H. M. van Goozen; Ditte Slabbekoorn; Louis J. G. Gooren; Geoff Sanders; Peggy T. Cohen-Kettenis

2002-01-01

87

Scales for sex experience for males and females  

Microsoft Academic Search

Tested 83 male and 101 female unmarried undergraduates on scales containing a range of heterosexual experiences. 2 12-item scales, one for males and one for females, were developed. Coefficients of reproducibility were .97 for both males and females, and the rank-order correlation between the ordering of items in male and female scales was .95.

Marvin Zuckerman

1973-01-01

88

Sex-specific extraction of organic anions by the rat liver  

Microsoft Academic Search

The capacity for hepatic elimination of some compounds is different in males and females and differential expression of a number of sinusoidal and canalicular transporters exists. However, the specific events underlying the functional differences are not understood. To determine how sex influences sinusoidal and canalicular organic anion transport, bile duct-cannulated livers from mature Sprague–Dawley rats of both sexes were single-pass

Penny Y. T. Wang; Meredith Boccanfuso; Anne-Marie Lemay; Haley Devries; Jie Sui; Yimin She; Ceredwyn E. Hill

2008-01-01

89

Acute effects of sex-specific sex hormones on heat shock proteins in fast muscle of male and female rats.  

PubMed

Heat shock protein (HSP) expression and sex hormone levels have been shown to influence several aspects of skeletal muscle physiology (e.g., hypertrophy, resistance to oxidative stress), suggesting that sex hormone levels can effect HSP expression. This study evaluated the effects of differing levels of sex-specific sex hormones (i.e., testosterone in males and estrogen in females) on the expression of 4: HSP70, HSC70, HSP25, and ?B-crystallin in the quadriceps muscles of male and female rats. Animals were assigned to 1 of 3 groups (n = 5 M and F/group). The first group (Ctl) consisted of typically cage-housed animals that served as controls. The second group (H) was gonadectomized and received either testosterone (males) or estradiol (females) via injection for 12 consecutive days. The third group (Gx) was gonadectomized and injected as above, but with vehicle only, rather than hormones. Significant sex by condition interactions (P < 0.05 by two-way MANOVA) were found for all 4 proteins studied, except for HSP70, which exhibited a significant effect of condition only. The expression of all HSPs was greater (1.9-2.5-fold) in males vs. females in the Ctl group, except for HSP70, which was no different. Generally, gonadectomy appeared to have greater effects in males than females, but administration of the exogenous sex hormones tended to produce more robust relative changes in females than males. There were no differences in myosin composition in any of the groups, suggesting that changes in fiber type were not a factor in the differential protein expression. These data may have implications for sex-related differences in muscular responses to exercise, disuse, and injury. PMID:23821238

Romani, William A; Russ, David W

2013-07-03

90

Male Sex Roles in Magazine Advertising, 1959-1979.  

ERIC Educational Resources Information Center

|Advertising featuring men appears to be moving gradually toward a decrease in sex-role stereotyping, although the progress is obviously slow. Of the 660 advertisements examined, only 13 were in the category showing men performing nonstereotypic roles capably or acknowledging that the sexes are fully equal. (PD)|

Skelly, Gerald U.; Lundstrom, William J.

1981-01-01

91

Male Sex Roles in Magazine Advertising, 1959-1979.  

ERIC Educational Resources Information Center

Advertising featuring men appears to be moving gradually toward a decrease in sex-role stereotyping, although the progress is obviously slow. Of the 660 advertisements examined, only 13 were in the category showing men performing nonstereotypic roles capably or acknowledging that the sexes are fully equal. (PD)

Skelly, Gerald U.; Lundstrom, William J.

1981-01-01

92

'In different situations, in different ways': male sex work in St. Petersburg, Russia.  

PubMed

We conducted a qualitative study of male sex work in St. Petersburg Russia with a focus on social vulnerabilities, HIV-risk perception and HIV-related behaviours. In-depth interviews were conducted with individuals knowledgeable about male sex work through their profession and with male sex workers themselves. Male sex work involves a variety of exchanges, including expensive vacations, negotiated monetary amounts or simply access to food. Methods of finding clients included the Internet, social venues (e.g. gay clubs and bars) and public places (e.g. parks). Use of the Internet greatly facilitated male sex work in a variety of ways. It was used by both individuals and agencies to find clients, and appeared to be increasing. Men often reported not being professionally connected to other male sex workers and limited disclosure about their work. Many were aware of the work-related risks to personal safety, including violence and robbery by clients. Perceived risk for HIV was mostly abstract and several exceptions to condom use with clients were noted. Alcohol use was reported as moderate but alcohol was consumed frequently in association with work. These data suggest that the most salient risks for male sex workers include professional isolation, threats to personal safety, limited perceived HIV risk and sub-optimal levels of condom use. PMID:23464743

Niccolai, Linda M; King, Elizabeth J; Eritsyan, Ksenia U; Safiullina, Liliya; Rusakova, Maia M

2013-01-01

93

When males call, females listen: sex differences in responsiveness to rhesus monkey, Macaca mulatta, copulation calls  

Microsoft Academic Search

In many species, males and\\/or females produce advertisement calls before, during or after mating. Respon- siveness to these calls may vary by sex because of underlying perceptual, motivational or attentional sys- tems. I conducted playback experiments on free-ranging adult rhesus monkeys to examine whether males and females differentially respond to calls from the same male or to calls from different

Marc D. Hauser

2007-01-01

94

Transactional sex risk and STI among HIV-infected female sex workers and HIV-infected male clients of FSWs in India  

Microsoft Academic Search

To describe sex risk behaviors of HIV-infected female sex workers (FSWs) and HIV-infected male clients of FSWs, to evaluate associations between risky transactional sex and number of unprotected transactional sex episodes, and to assess the association between unprotected transactional sex and self-reported sexually transmitted infection (STI). Adult HIV-infected FSWs (n=211) and HIV-infected male clients (n=205) were surveyed in Mumbai about

Anita Raj; N. Saggurti; Debbie M. Cheng; Anindita Dasgupta; Carly Bridden; Manojkumar Pradeshi; J. H. Samet

2011-01-01

95

Sex-reversed mice: XX and XO males  

Microsoft Academic Search

An autosomally inherited condition is described in the mouse which causes genetic females to develop as phenotypic males. XX males are phenotypically normal with the exception of small testes, which, in the adult, are devoid of germ cells. During late fetal and early postnatal development, male-type germ cells are present but progressively become lost, so that none is present by

B. M. Cattanach; C. E. Pollard; S. G. Hawkes

1971-01-01

96

Sex Equity in Organization Development: Numbers and Processes.  

ERIC Educational Resources Information Center

To investigate whether the proportion of males to females employed as educational organizational development (OD) practitioners is equitable, sex distribution data from three recent sources are presented in female-male ratios, in categories that define the available talent pool for educational leadership, educational leadership positions, and OD…

Gall, Joyce P.

97

Comparing performance among male and female candidates in sex-specific clinical knowledge in the MRCGP  

PubMed Central

Background Patients often seek doctors of the same sex, particularly for sex-specific complaints and also because of a perception that doctors have greater knowledge of complaints relating to their own sex. Few studies have investigated differences in knowledge by sex of candidate on sex-specific questions in medical examinations. Aim The aim was to compare the performance of males and females in sex-specific questions in a 200-item computer-based applied knowledge test for licensing UK GPs. Design and setting A cross-sectional design using routinely collected performance and demographic data from the first three versions of the Applied Knowledge Test, MRCGP, UK. Method Questions were classified as female specific, male specific, or sex neutral. The performance of males and females was analysed using multiple analysis of covariance after adjusting for sex-neutral score and demographic confounders. Results Data were included from 3627 candidates. After adjusting for sex-neutral score, age, time since qualification, year of speciality training, ethnicity, and country of primary medical qualification, there were differences in performance in sex-specific questions. Males performed worse than females on female-specific questions (–4.2%, 95% confidence interval [CI] = –5.7 to –2.6) but did not perform significantly better than females on male-specific questions (0.3%, 95% CI = –2.6 to 3.2%. Conclusion There was evidence of better performance by females in female-specific questions but this was small relative to the size of the test. Differential performance of males and females in sex-specific questions in a licensing examination may have implications for vocational and post-qualification general practice training.

Siriwardena, A Niroshan; Irish, Bill; Asghar, Zahid B; Dixon, Hilton; Milne, Paul; Neden, Catherine; Richardson, Jo; Blow, Carol

2012-01-01

98

Administrator's Overview: Questions and Answers on Issues Related to the Incarcerated Male Sex Offender.  

National Technical Information Service (NTIS)

This Administrator's Overview is intended for correctional administrators, planners, and others responsible for dealing with incarcerated male sex offenders. The Overview discusses treatment techniques that are proving effective in reducing the extremely ...

B. Schwartz H. Cellini

1988-01-01

99

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.

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

2008-01-01

100

Sexes, species, and genomes: why males and females are not like humans and chimpanzees  

Microsoft Academic Search

This paper describes, analyzes, and critiques the construction of separate “male” and “female” genomes in current human genome\\u000a research. Comparative genomic work on human sex differences conceives of the sexes as like different species, with different\\u000a genomes. I argue that this construct is empirically unsound, distortive to research, and ethically questionable. I propose\\u000a a conceptual model of biological sex that

Sarah S. Richardson

2010-01-01

101

Neonatal sex hormones have `organizational' effects on the hypothalamic-pituitary-adrenal axis of male rats  

Microsoft Academic Search

Sex hormones have activational effects on the hypothalamic-pituitary-adrenal (HPA) axis in adulthood: For example, corticosterone release is influenced by gonadal status. These experiments investigated whether sex hormones have organizational effects on the HPA axis of male rats: Do sex hormones have relatively permanent effects on its development? In adults, both neonatal (neoGDX) and adult gonadectomy (adult GDX) resulted in elevated

Cheryl M McCormick; Brinley F Furey; Meredith Child; Meghan J Sawyer; Sean M Donohue

1998-01-01

102

Determinants of safer sex patterns among gay\\/bisexual male adolescents  

Microsoft Academic Search

The cognitive-behavioral (health-belief, social cognitive, peer support), risk-taking, and stress\\/coping models were examined as predictors of safer sex practices among (141 gay and bisexual male adolescents seeking services at a gay-identified social service agency. Safer sex practices, defined as abstinence or 100% consistent condom use during oral and anal sex, were practised by 47% of youths; 24% used condoms only

Mary Jane Rotheram-Borus; Helen Reid; Margaret Rosario; Stephanie Kasen

1995-01-01

103

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

Microsoft Academic Search

In Tephritidae sex determination is established by orthologs to the Drosophila melanogaster transformer and transformer-2 genes, though the primary signals for sex determination differ. The presence of the Y chromosome in the tephritid species is critical for male differentiation, while the ratio of X chromosomes to autosome ploidy is critical in drosophilids. Here the isolation, expression and function of tra

Marc F. Schetelig; Andreina Milano; Giuseppe Saccone; Alfred M. Handler

104

Population differentiation in female sex pheromone and male preferences in a solitary bee  

Microsoft Academic Search

Population differentiation in female mating signals and associated male preferences can drive reproductive isolation among\\u000a segregated populations. We tested this assumption by investigating intraspecific variation in female sex pheromone and associated\\u000a male odour preferences among distant populations in the solitary bee Colletes cunicularius (L.) by using quantitative gas chromatography and by performing field bioassays with synthetic blends of key sex

Nicolas J. Vereecken; Jim Mant; Florian P. Schiestl

2007-01-01

105

Male ornamentation and its condition-dependence in a paternal mouthbrooding cardinalfish with extraordinary sex roles  

Microsoft Academic Search

  \\u000a Cardinalfishes, in which males alone provide mouthbrooding, are likely candidates for sex-role reversal because of a higher\\u000a potential reproductive rate for females than for males. In the gregarious cardinalfish, Apogon notatus, females establish breeding territories to form pairs prior to the breeding season. Within breeding pairs, females are more\\u000a active in courtship and in attacks against conspecific intruders. Sex

Noboru Okuda; Kayoko Fukumori; Yasunobu Yanagisawa

2003-01-01

106

Knowledge, risk perceptions and condom usage in male sex workers from three Australian cities  

Microsoft Academic Search

The study identifies factors associated with knowledge and perception of risk of HIV\\/AIDS, as well as attitudes to and usage of condoms by a sample of male sex workers (MSW). One hundred and eighty-five male sex workers completed a self-reported questionnaire, including knowledge about HIV transmission, attitudes to condom use and perceptions and personal susceptibility to HIV and sexually transmitted

V. Minichiello; R. Mariño; J. Browne

2001-01-01

107

Exploring the interpersonal relationships in street-based male sex work: results from an Australian qualitative study.  

PubMed

While the literature on male sex work has increased significantly over the past decade, few studies examine the influence of relational dynamics in the lives of those engaged in male sex work. This qualitative study, conducted with a sample of male street sex workers in Sydney, Australia, explores how relationships color their involvement with sex work. The findings reveal the complexity of their relationships and how their interactions with others shape their engagement in sex work. The data also offer insight into how exit pathways are influenced by money and relationships that occur within this particular male sex work setting. Implications for health policy and intervention are considered. PMID:18019070

Leary, David; Minichiello, Victor

2007-01-01

108

The Effectiveness of Respondent Driven Sampling for Recruiting Males Who have Sex with Males in Dhaka, Bangladesh  

Microsoft Academic Search

This paper evaluates the effectiveness of respondent driven sampling (RDS) to sample males who have sex with males (MSM) in\\u000a Dhaka, Bangladesh. A major objective for conducting this survey was to determine whether RDS can be a viable sampling method\\u000a for future routine serologic and behavioral surveillance of MSM as well as other socially networked, hard to reach populations\\u000a in

Lisa Grazina Johnston; Rasheda Khanam; Masud Reza; Sharful Islam Khan; Sarah Banu; Mahmudur Rahman; Tasnim Azim

2008-01-01

109

Sex differences in adults' relative visual interest in female and male faces, toys, and play styles.  

PubMed

An individual's reproductive potential appears to influence response to attractive faces of the opposite sex. Otherwise, relatively little is known about the characteristics of the adult observer that may influence his or her affective evaluation of male and female faces. An untested hypothesis (based on the proposed role of attractive faces in mate selection) is that most women would show greater interest in male faces whereas most men would show greater interest in female faces. Further, evidence from individuals with preferences for same-sex sexual partners suggests that response to attractive male and female faces may be influenced by gender-linked play preferences. To test these hypotheses, visual attention directed to sex-linked stimuli (faces, toys, play styles) was measured in 39 men and 44 women using eye tracking technology. Consistent with our predictions, men directed greater visual attention to all male-typical stimuli and visual attention to male and female faces was associated with visual attention to gender conforming or nonconforming stimuli in a manner consistent with previous research on sexual orientation. In contrast, women showed a visual preference for female-typical toys, but no visual preference for male faces or female-typical play styles. These findings indicate that sex differences in visual processing extend beyond stimuli associated with adult sexual behavior. We speculate that sex differences in visual processing are a component of the expression of gender phenotypes across the lifespan that may reflect sex differences in the motivational properties of gender-linked stimuli. PMID:19016319

Alexander, Gerianne M; Charles, Nora

2008-11-19

110

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

2005-10-25

111

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

PubMed

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

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

2013-05-01

112

Sex hormones and male homosexuality in comparative perspective  

Microsoft Academic Search

Animal research has demonstrated the modifiability of sex-dimorphic mating behavior by hormone and brain manipulation, especially in subprimate mammals, and has led to radical attempts at treating human homosexuality by psychosurgery and to the suggestion of preventing homosexuality by prenatal hormone manipulation. This article reviews psychoendocrine studies of human homosexuality — the effects of hormone treatments on sexual orientation, the

Heino F. L. Meyer-Bahlburg

1977-01-01

113

Male gametocyte fecundity and sex ratio of a malaria parasite, Plasmodium mexicanum.  

PubMed

Evolutionary theory predicts that the sex ratio of Plasmodium gametocytes will be determined by the number of gametes produced per male gametocyte (male fecundity), parasite clonal diversity and any factor that reduces male gametes' ability to find and combine with female gametes. Despite the importance of male gametocyte fecundity for sex ratio theory as applied to malaria parasites, few data are available on gamete production by male gametocytes. In this study, exflagellating gametes, a measure of male fecundity, were counted for 866 gametocytes from 26 natural infections of the lizard malaria parasite, Plasmodium mexicanum. The maximum male fecundity observed was 8, but most gametocytes produced 2-3 gametes, a value consistent with the typical sex ratio observed for P. mexicanum. Male gametocytes in infections with higher gametocytaemia had lower fecundity. Male fecundity was not correlated with gametocyte size, but differed among infections, suggesting genetic variation for fecundity. Fecundity and sex ratio were correlated (more female gametocytes with higher fecundity) as predicted by theory. Results agree with evolutionary theory, but also suggest a possible tradeoff between production time and fecundity, which could explain the low fecundity of this species, the variation among infections, and the correlation with gametocytaemia. PMID:21756426

Neal, A T

2011-07-15

114

Sex organ determination and differentiation in the dioecious plant Melandrium album ( Silene latifolia ): a cytological and histological analysis  

Microsoft Academic Search

Melandrium album (Silene alba) is a dioecious plant with heteromorphic sex chromosomes (XY system). Sexual dimorphism is a result of developmental blocks\\u000a in male or female reproductive organ formation within young bipotential flower buds. Progress in understanding the genetic\\u000a and molecular mechanisms controlling sex determination in this species relies on a detailed description of developmental timing\\u000a in the two sexes,

Isabelle Farbos; Margarida Oliveira; Ioan Negrutiu; A. Mouras

1997-01-01

115

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

116

Phf7 controls male sex determination in the Drosophila germline  

PubMed Central

Summary Establishment of germline sexual identity is critical for production of male and female germline stem cells, and sperm vs. 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 required 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.

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

2013-01-01

117

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

118

Induction of female-to-male sex reversal by high temperature treatment in Medaka, Oryzias latipes.  

PubMed

Medaka, Oryzias latipes, has a firm XX-XY sex-determining system with the sex-determining gene, DMY, on the Y chromosome. However, previous studies have suggested that high water temperature might affect sex determination in Medaka. In the present study, the influence of high water temperature on sex reversal was examined. Fertilized eggs of two inbred strains of Medaka were developed at high water temperature (32 degrees C) until hatching. The hatched fry were kept at normal water temperatures (27 degrees C) until adulthood, and the phenotypic and genotypic sex was examined. As a result, 24% (N=105) and 50% (N=36) of XX fish developed a male phenotype in the Hd-rR and HNI inbred strains, respectively. These XX sex-reversed males had a normal testis and were fully fertile. On the other hand, all XY fish were male in the both strains. These results demonstrate that high water temperatures can induce XX sex reversal and that elevated water temperatures during the embryonic stage is a simple and useful method for getting XX males in Medaka. PMID:16219978

Sato, Tadashi; Endo, Tomokazu; Yamahira, Kazunori; Hamaguchi, Satoshi; Sakaizumi, Mitsuru

2005-09-01

119

The C. elegans Male Exercises Directional Control during Mating through Cholinergic Regulation of Sex-Shared Command Interneurons  

PubMed Central

Background Mating behaviors in simple invertebrate model organisms represent tractable paradigms for understanding the neural bases of sex-specific behaviors, decision-making and sensorimotor integration. However, there are few examples where such neural circuits have been defined at high resolution or interrogated. Methodology/Principal Findings Here we exploit the simplicity of the nematode Caenorhabditis elegans to define the neural circuits underlying the male’s decision to initiate mating in response to contact with a mate. Mate contact is sensed by male-specific sensilla of the tail, the rays, which subsequently induce and guide a contact-based search of the hermaphrodite’s surface for the vulva (the vulva search). Atypically, search locomotion has a backward directional bias so its implementation requires overcoming an intrinsic bias for forward movement, set by activity of the sex-shared locomotory system. Using optogenetics, cell-specific ablation- and mutant behavioral analyses, we show that the male makes this shift by manipulating the activity of command cells within this sex-shared locomotory system. The rays control the command interneurons through the male-specific, decision-making interneuron PVY and its auxiliary cell PVX. Unlike many sex-shared pathways, PVY/PVX regulate the command cells via cholinergic, rather than glutamatergic transmission, a feature that likely contributes to response specificity and coordinates directional movement with other cholinergic-dependent motor behaviors of the mating sequence. PVY/PVX preferentially activate the backward, and not forward, command cells because of a bias in synaptic inputs and the distribution of key cholinergic receptors (encoded by the genes acr-18, acr-16 and unc-29) in favor of the backward command cells. Conclusion/Significance Our interrogation of male neural circuits reveals that a sex-specific response to the opposite sex is conferred by a male-specific pathway that renders subordinate, sex-shared motor programs responsive to mate cues. Circuit modifications of these types may make prominent contributions to natural variations in behavior that ultimately bring about speciation.

Sherlekar, Amrita L.; Janssen, Abbey; Siehr, Meagan S.; Koo, Pamela K.; Caflisch, Laura; Boggess, May; Lints, Robyn

2013-01-01

120

Influence of sport participation upon sex role orientation of caucasian males and their attitudes toward women  

Microsoft Academic Search

Differences in psychological androgyny and attitudes toward women were examined in male Caucasian intercollegiate contact and noncontact sport athletes and male Caucasian college nonathletes. Contact athletes in the sports of football and wrestling, noncontact athletes in the sports of baseball and track and field, and nonathletes completed the Attitudes Toward Women Scale (ATWS) and the Bem Sex Role Inventory (BSRI)

Steve Houseworth; Kenneth Peplow; Joel Thirer

1989-01-01

121

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…

Martino, Wayne; Frank, Blye

2006-01-01

122

The tyranny of surveillance: male teachers and the policing of masculinities in a single sex school  

Microsoft Academic Search

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 and the US and provides further

Wayne Martino; Blye Frank

2006-01-01

123

SEX HORMONES DURING ALCOHOL WITHDRAWAL: A LONGITUDINAL STUDY OF 29 MALE ALCOHOLICS DURING DETOXIFICATION  

Microsoft Academic Search

It is a well-known fact that alcohol affects sex hormone levels in males. Even in the absence of liver dysfunction, there is still a direct toxic effect of ethanol on testosterone synthesis resulting in acutely decreased values. This study is based on 29 male alcoholics without severe signs of liver disease treated on the alcohol detoxification ward at Huddinge hospital

JAAN RUUSA; BO BERGMAN; MONA-LISA SUNDELL

124

Differential Response of Males and Females to Work Situations Which Evoke Sex Role Stereotypes.  

ERIC Educational Resources Information Center

|The hypothesis in the present study is that in work situations which evoke sex role stereotypes, women will respond less stereotypically than males since it is in their best interest to do so. The method comes from the Rosen et al. (1975) study of male managers. In the present study, 293 introductory psychology students were asked to role play an…

Gutek, Barbara A.; Stevens, Denise A.

125

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

126

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

127

The battle of the sexes over the distribution of male surplus  

Microsoft Academic Search

Female primates carry and nurse the fetus, and thus have the first responsibility for rearing the offspring. Assuming males are at least equally adept at obtaining food, males might either share surplus food with females or consume the food themselves. The distribution of this surplus is the subject of a battle of the sexes. If females succeed in obtaining a

Myrna Wooders; Hugo van den Berg

2001-01-01

128

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

129

Prenatal Hormones Organize Sex Differences of the Neuroendocrine Reproductive System: Observations on Guinea Pigs and Nonhuman Primates  

Microsoft Academic Search

SUMMARY 1. The central nervous systems (CNS) of males and females differ in the control mechanisms for the release of gonadotropins from the anterior pituitary gland as well as the capacity to display sex specific behaviors. 2. In guinea pigs and monkeys, these differences are organized through the actions of prenatal androgens secreted by the fetal testes. In both males

John A. Resko; Charles E. Roselli

1997-01-01

130

Sex pheromone blend discrimination by male moths from E and Z strains of European corn borer  

Microsoft Academic Search

Sex pheromone behavioral responses were analyzed in a flight tunnel with European corn borer,Ostrinia nubilalis (Hübner), males from three distinct populations. Males from a bivoltine and a univoltine biotype using a 97.8:2.2 blend (Z strains) of (Z)- and (E)-11-tetradecenyl acetate were assayed with treatments containing 0, 0.5, 1, and 3% of theE isomer. Males from neither population oriented in the

T. J. Glover; X.-H. Tang; W. L. Roelofs

1987-01-01

131

Sex steroid hormones enhance immune function in male and female Siberian hamsters  

Microsoft Academic Search

Bilbo, Staci D., and Randy J. Nelson. Sex steroid hor-mones enhance immune function in male and female Sibe-rian hamsters. Am J Physiol Regulatory Integrative Comp Physiol 280: R207?R213, 2001.DImmune function is better in females than in males of many vertebrate species, and this dimorphism has been attributed to the presence of immuno-suppressive androgens in males. We investigated the in?u-ence of

STACI D. BILBO; RANDY J. NELSON

132

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.

H.W. Biedermann, Peter

2010-01-01

133

Sex and Gender Considerations in Male Patients With Osteoporosis  

Microsoft Academic Search

Background  Osteoporosis remains underrecognized and undertreated in both men and women, but men who sustain fragility fractures experience\\u000a greater morbidity and mortality. While men exhibit advanced comorbidity at the time of hip fracture presentation, there are\\u000a distinct sex- and gender-specific factors related to the pathophysiology and treatment of osteoporosis that further influence\\u000a morbidity and mortality.\\u000a \\u000a \\u000a \\u000a \\u000a Questions\\/purposes  With a selective review of the

Christopher J. Dy; Lauren E. LaMont; Quang V. Ton

2011-01-01

134

Factors distinguishing homosexual males practicing risky and safer sex  

Microsoft Academic Search

A longitudinal study of patterns of sexual behavior among asymptomatic, homosexual males in New York City was conducted. Participants were interviewed at two time points, 6 months apart. Based on their reports of sexual behavior during a recent 'typical' month, respondents were classified at each time point as engaging in safer (or low-risk) sexual practices versus high-risk sexual behaviors. Discriminant

Karolynn Siegel; Frances Palamara Mesagno; Jin-Yi Chen; Grace Christ

1989-01-01

135

Cuticular lipids and odors induce sex-specific behaviors in the male cricket Gryllus bimaculatus.  

PubMed

Male crickets display sex-specific (e.g., mating and agonistic) behaviors towards conspecific individuals. One of the key signals for these behaviors is the chemical substance on the cricket body surface. In the present study, we analyzed female and male cuticular substances in behavioral assays. Antennal contact stimulation using female forewings elicited a mating behavior in males, while that using male forewings elicited an agonistic behavior in males. Thin-layer-chromatographic and other techniques analysis showed that saturated cuticular lipids were present in both female and male cuticles and that unsaturated lipids were present only in the male cuticle. Filter papers soaked with saturated or unsaturated cuticular lipids were applied to antennae of male crickets. Males showed mating behavior in response to stimulation with saturated lipids from both females and males but showed avoidance behavior in response to stimulation with male unsaturated lipids. Because cuticular lipids did not induce agonistic behavior in males, we collected odors from male crickets and found that these odors induced agonistic behavior in males. Therefore, we concluded that the key signals for mating, avoidance and agonistic behaviors of male crickets are comprised of at least three different components, saturated and unsaturated cuticular lipids and male odors, respectively. PMID:18262814

Iwasaki, Masazumi; Katagiri, Chihiro

2008-01-17

136

Alcohol Use Among Female Sex Workers and Male Clients: An Integrative Review of Global Literature  

PubMed Central

Aims: To review the patterns, contexts and impacts of alcohol use associated with commercial sex reported in the global literature. Methods: We identified peer-reviewed English-language articles from 1980 to 2008 reporting alcohol consumption among female sex workers (FSWs) or male clients. We retrieved 70 articles describing 76 studies, in which 64 were quantitative (52 for FSWs, 12 for male clients) and 12 qualitative. Results: Studies increased over the past three decades, with geographic concentration of the research in Asia and North America. Alcohol use was prevalent among FSWs and clients. Integrating quantitative and qualitative studies, multilevel contexts of alcohol use in the sex work environment were identified, including workplace and occupation-related use, the use of alcohol to facilitate the transition into and practice of commercial sex among both FSWs and male clients, and self-medication among FSWs. Alcohol use was associated with adverse physical health, illicit drug use, mental health problems, and victimization of sexual violence, although its associations with HIV/sexually transmitted infections and unprotected sex among FSWs were inconclusive. Conclusions: Alcohol use in the context of commercial sex is prevalent, harmful among FSWs and male clients, but under-researched. Research in this area in more diverse settings and with standardized measures is required. The review underscores the importance of integrated intervention for alcohol use and related problems in multilevel contexts and with multiple components in order to effectively reduce alcohol use and its harmful effects among FSWs and their clients.

Li, Qing; Li, Xiaoming; Stanton, Bonita

2010-01-01

137

Brain organization in a reptile lacking sex chromosomes: effects of gonadectomy and exogenous testosterone.  

PubMed

In mammals, males and females differ both genetically and hormonally, making it difficult to assess the relative contributions of genetic constitution and fetal environment in the process of sexual differentiation. Many reptiles lack sex chromosomes, relying instead on the temperature of incubation to determine sex. In the leopard gecko (Eublepharis macularius), an incubation temperature of 26 degrees C produces all females, whereas 32.5 degrees C results in mostly males. Incubation temperature is the primary determinant of differences both within and between the sexes in growth, physiology, and sociosexual behavior, as well as the volume and metabolic capacity of specific brain nuclei. To determine if incubation temperature organizes the brain directly rather than via gonadal sex hormones, the gonads of male and female leopard geckos from the two incubation temperatures were removed and, in some instances, animals were given exogenous testosterone. In vertebrates with sex chromosomes, the size of sexually dimorphic nuclei are sensitive to hormone levels in adulthood, but in all species studied to date, these changes are restricted to the male. Therefore, after behavior tests, morphometrics of certain limbic and nonlimbic brain areas were determined. Because nervous system tissue depends on oxidative metabolism for energy production and the level of cytochrome oxidase activity is coupled to the functional level of neuronal activity, cytochrome oxidase histochemistry also was performed on the same brains. Hormonal manipulation had little effect on the volume of the preoptic area or ventromedial hypothalamus in geckos from the all-female incubation temperature, but significantly influenced the volumes of these brain areas in males and females from the male-biased incubation temperature. A similar relationship was found for cytochrome oxidase activity of the anterior hypothalamus, amygdala, dorsal ventricular ridge, and septum. The only sex difference observed was found in the ventromedial hypothalamus; males showed no significant changes in cytochrome oxidase activity with hormonal manipulation, but females from both incubation temperatures were affected similarly. The results indicate that incubation temperature organizes the brain directly rather than via hormones arising from its sex-determining function. This is the first demonstration in a vertebrate that factors other than steroid hormones can modify the organization and functional activity of sexually differentiated brain areas. PMID:9047272

Crews, D; Coomber, P; Baldwin, R; Azad, N; Gonzalez-Lima, F

1996-12-01

138

SEX-RATIO EVOLUTION IN SEX CHANGING ANIMALS  

Microsoft Academic Search

Sex allocation theory is often able to make clear predictions about when individuals should facultatively adjust their offspring sex ratio (proportion male) in response to local conditions, but not the consequences for the overall population sex ratio. A notable exception to this is in sex changing organisms, where theory predicts that: (1) organisms should have a sex ratio biased toward

David J. Allsop; Stuart A. West

2004-01-01

139

Social context, sexual risk perceptions and stigma: HIV vulnerability among male sex workers in Mombasa, Kenya  

Microsoft Academic Search

Knowledge about sexual practices and life experiences of men having sex with men in Kenya, and indeed in East Africa, is limited. Although the impact of male same-sex HIV transmission in Africa is increasingly acknowledged, HIV prevention initiatives remain focused largely on heterosexual and mother-to-child transmission. Using data from ten in-depth interviews and three focus group discussions (36 men), this

Jerry Okal; Scott Geibel; Matthew F. Chersich; Daniel Lango; Marleen Temmerman

2009-01-01

140

Effects of Sex Steroids on Plasma Total Homocysteine Levels: A Study in Transsexual Males and Females  

Microsoft Academic Search

Plasma total homocysteine (tHcy) levels are higher in men vs. premenopausal women, but it is not known whether this difference is related to sex steroids. The effects of cross-sex hormone administra- tion on plasma tHcy levels were therefore investigated. Plasma tHcy levels were measured at baseline and after 4 months of treatment in 17 male-to-female (M3 F) transsexuals treated with

E. J. Giltay; E. K. HOOGEVEEN; J. M. H. ELBERS; L. J. G. GOOREN; H. ASSCHEMAN; C. D. A. STEHOUWER

1998-01-01

141

Males are sensitive — sex-dependent effect of rearing conditions on nestling growth  

Microsoft Academic Search

The sex-dependent effect of environmental conditions on nestlings has been extensively studied in size dimorphic birds. Whether\\u000a males or females are more sensitive to poor conditions is not yet clear; however, the degree of sexual size-dimorphism, brood\\u000a size and their interactions seem to influence the pattern. Much less is known about sex-dependent environmental sensitivity\\u000a in size-monomorphic species, even though it

Balázs Rosivall; Eszter Szöll?si; Dennis Hasselquist; János Török

2010-01-01

142

Transactional sex risk and STI among HIV-infected female sex workers and HIV-infected male clients of FSWs in India.  

PubMed

To describe sex risk behaviors of HIV-infected female sex workers (FSWs) and HIV-infected male clients of FSWs, to evaluate associations between risky transactional sex and number of unprotected transactional sex episodes, and to assess the association between unprotected transactional sex and self-reported sexually transmitted infection (STI). Adult HIV-infected FSWs (n = 211) and HIV-infected male clients (n = 205) were surveyed in Mumbai about demographics, STI, and past 90-day and past year sex and substance use histories. Gender-stratified Poisson regression models were used to evaluate associations between four risky transactional sex behaviors (number of transactional sex partners; alcohol use before transactional sex; anal transactional sex; and transactional sex with a known HIV-infected partner) and number of unprotected transactional sex episodes; logistic regression was used to assess the association between unprotected transactional sex and self-reported STI. Twenty-nine percent of females and 7% of males reported any unprotected transactional sex episodes in the past 90 days. Thirty-nine percent of females and 12% of males reported past year STI. Among males, a greater number of transactional sex partners was associated with more unprotected transactional sex episodes (adjusted incidence rate ratio [IRR] = 8.2, 95% confidence interval [CI] = 1.8-38.4 highest vs. lowest tertile), and any unprotected transactional sex was associated with a higher odds of self-reported STI in the past year (adjusted odds ratio [AOR] = 5.6, 95% CI = 1.4-22.4). For women, risky transactional sex behaviors were not associated with condom non-use, and unprotected sex was negatively associated with STI (AOR = 0.4, 95% CI = 0.2-0.9). Reports of condom use during transactional sex were high for these samples. However, standard predictors of unprotected transactional sex (i.e., greater number of partners) and STI (i.e., unprotected sex) only held true for males. Further research is needed to guide an understanding of sex risk and STI among HIV-infected FSWs in India. PMID:21711167

Raj, Anita; Saggurti, N; Cheng, Debbie M; Dasgupta, Anindita; Bridden, Carly; Pradeshi, Manojkumar; Samet, J H

2011-06-28

143

On becoming a male sex worker in Mysore: sexual subjectivity, "empowerment," and community-based HIV prevention research.  

PubMed

Growing public health attention has been placed on the HIV vulnerability of males who sell sex to males in India. However, there is little research that outlines the trajectories through which males come to be involved in practicing sex work in India. Locating "male sex work" within a vibrant social, political, and erotic landscape, this article explores the intertwining of "sexual subjectivity" and "sex work." The authors refer to 70 sexual life histories generated from research conducted in Mysore to unsettle dominant public health notions that regard male sex work as rooted solely in poverty or as a decontexualized "behavioral risk factor." Such perspectives are countered by demonstrating how male sex work in Mysore encompasses a complex interplay between self-realization, sexual desire, social interaction, and public health discourse. Local conceptualizations of selfhood are discussed to suggest the limitations of prevailing empowerment discourses that advance Western notions of individuality. PMID:19562953

Lorway, Robert; Reza-Paul, Sushena; Pasha, Akram

2009-06-01

144

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.

Shukla, Jayendra Nath; Palli, Subba Reddy

2012-01-01

145

Fluorochemicals used in food packaging inhibit male sex hormone synthesis.  

PubMed

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. PMID:23142464

Rosenmai, A K; Nielsen, F K; Pedersen, M; Hadrup, N; Trier, X; Christensen, J H; Vinggaard, A M

2012-11-07

146

A regulatory cascade hypothesis for mammalian sex determination: SRY represses a negative regulator of male development.  

PubMed Central

The mammalian Y chromosome carries the SRY gene, which determines testis formation. Here we review data on individuals who are XX but exhibit male characteristics: some have SRY; others do not. We have analyzed three families containing more than one such individual and show that these individuals lack SRY. Pedigree analysis leads to the hypothesis that they carry recessive mutations (in a gene termed Z) that allow expression of male characteristics. We propose that wild-type Z product is a negative regulator of male sex determination and is functional in wild-type females. In males, SRY product represses or otherwise negatively regulates Z and thereby allows male sex determination. This hypothesis can also explain other types of sex reversal in mammals, in particular, XY females containing SRY. Some of these individuals may have mutations at the Z locus rendering them insensitive to SRY. Recessive mutations (such as the polled mutation of goats) leading to sex reversal are known in a variety of animals and might be used to map and ultimately clone the human Z gene. Images Fig. 1 Fig. 2 Fig. 3 Fig. 5

McElreavey, K; Vilain, E; Abbas, N; Herskowitz, I; Fellous, M

1993-01-01

147

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 language1-4. 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 females5,6, but attempts to demonstrate this have been inconclusive7-17. Here we use echo-planar functional magnetic resonance imaging18-21

Bennett A. Shaywitz; Sally E. Shaywltz; Kenneth R. Pugh; 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

148

Evidence of a Male Sex Pheromone in the Round Goby ( Neogobius melanostomus )  

Microsoft Academic Search

The reproductive success of the round goby (Neogobius melanostomus), an invasive fish, may be mediated by the use of pheromones. We hypothesized that reproductive male (RM) round gobies release\\u000a sex pheromone to which reproductive females (RF) respond. In this study, we compared behavioural and electrophysiological\\u000a responses of reproductive and non-reproductive female round gobies to conspeci fic males. Results of behavioural

Lynda D. Corkum; Wes J. Arbuckle; Andrea J. Belanger; Donald B. Gammon; Weiming Li; Alexander P. Scott; Barbara Zielinski

2006-01-01

149

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

150

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

Microsoft Academic Search

Pear psylla, Cacopsylla pyricola (Förster) (Hemiptera: Psyllidae), a major economic pest of pears, uses a female-produced sex attractant pheromone. We compared\\u000a the chemical profiles obtained from cuticular extracts of diapausing and post-diapause winterform males and females to isolate\\u000a and identify the pheromone. Post-diapause females produced significantly more of the cuticular hydrocarbon, 13-methylheptacosane,\\u000a than post-diapause males and diapausing females. In olfactometer

Christelle Guédot; Jocelyn G. Millar; David R. Horton; Peter J. Landolt

2009-01-01

151

Oligodendrocyte Progenitor Proliferation and Maturation Is Differentially Regulated by Male and Female Sex Steroid Hormones  

Microsoft Academic Search

Using primary cultures of oligodendrocyte progenitors isolated from male and female neonatal rodent brains, we observed more oligodendrocytes in female-derived compared to male-derived cultures. To determine whether the observed differences were due to a differential effect of sex hormones on proliferation, we treated cultures with increasing doses of 17?-estradiol, testosterone or progesterone and labeled cells with bromodeoxyuridine to identify cells

Mireya Marin-Husstege; Michela Muggironi; David Raban; Robert P. Skoff; Patrizia Casaccia-Bonnefil

2004-01-01

152

STI prevention and the male sex industry in London: evaluating a pilot peer education programme  

Microsoft Academic Search

Objective: To evaluate the effectiveness of a pilot peer education STI prevention programme with male sex workers.Design: A process and outcome evaluation of the pilot programme undertaken in three London male escort agencies, using a quasi-experimental design.Subjects: Workers in three London escort agencies, including 88 who completed a questionnaire, five peer educators, and a further 16 men (including management) working

A Ziersch; J Gaffney; D R Tomlinson

2000-01-01

153

Apparent heterosexuality in two male patients requesting change-of-sex operation  

Microsoft Academic Search

Twenty-four male patients presenting with the request for change-of-sex surgery were studied. They were asked to estimate the strength of their sexual interest in men as compared with sexual interest in women. An independent and objective measure of sexual orientation was obtained by measuring penile volume responses to film sequences of male and female nudes. With two exceptions, the patients

R. F. Barr; B. Raphael; Norma Hennessey

1974-01-01

154

Operational sex ratio and density do not affect directional selection on male sexual ornaments and behavior.  

PubMed

Demographic parameters including operational sex ratio (OSR) and population density may influence the opportunity for, and strength of sexual selection. Traditionally, male-biased OSRs and high population densities have been thought to increase the opportunity for sexual selection on male sexual traits due to increased male competition for mates. Recent experimental evidence, however, suggests that male-biased OSRs might reduce the opportunity for sexual selection due to increased sexual coercion experienced by females. How OSR, density, and any resultant changes in the opportunity for sexual selection actually affect selection on male sexual traits is unclear. In this study, we independently manipulated OSR and density in the guppy (Poecilia reticulata) without altering the number of males present. We recorded male and female behavior and used DNA microsatellite data to assign paternity to offspring and estimate male reproductive success. We then used linear selection analyses to examine the effects of OSR and density on directional sexual selection on male behavioral and morphological traits. We found that females were pursued more by males in male-biased treatments, despite no change in individual male behavior. There were no differences in sexual behavior experienced by females or performed by males in relation to density. Neither OSR nor density significantly altered the opportunity for sexual selection. Also, Although there was significant multivariate linear selection operating on males, neither OSR nor density altered the pattern of sexual selection on male traits. Our results suggest that differences in either OSR or density (independent of the number of males present) are unlikely to alter directional evolutionary change in male sexual traits. PMID:18067568

Head, Megan L; Lindholm, Anna K; Brooks, Robert

2007-12-06

155

Male-specific suppression of hepatic microsomal UDP-glucuronosyl transferase activities toward sex hormones in the adult male rat administered bisphenol A.  

PubMed Central

Various adverse effects of endocrine disruptors on the reproductive organs of male animals have been reported. We found that UDP-glucuronosyltransferase (UGT) activities towards bisphenol A, testosterone and oestradiol were significantly decreased in liver microsomes prepared from adult male Wistar rats administered with the endocrine disruptor bisphenol A (1 mg/2 days for 2 or 4 weeks). However, suppression of the transferase activities was not observed in female rats, even after bisphenol A treatment for 4 weeks. Diethylstilbestrol, which is well known as an endocrine disruptor, had the same effects, but p -cumylphenol had no effect on UGT activities towards sex hormones. Co-administration of an anti-oestrogen, tamoxifen, inhibited the suppression of the transferase activities by bisphenol A. Western blotting analysis showed that the amount of UGT2B1, an isoform of UGT which glucuronidates bisphenol A, was decreased in the rat liver microsomes by the treatment. Northern blotting analysis also indicated that UGT2B1 mRNA in the liver was decreased by bisphenol A treatment. The suppression of UGT activities, UGT2B1 protein and UGT2B1 mRNA expression did not occur in female rats. The results indicate that bisphenol A treatment reduces the mRNA expression of UGT2B1 and other UGT isoforms that mediate the glucuronidation of sex hormones in adult male rats, and this suggests that the endocrine balance may be disrupted by suppression of glucuronidation.

Shibata, Noriaki; Matsumoto, Junya; Nakada, Ken; Yuasa, Akira; Yokota, Hiroshi

2002-01-01

156

A further analysis of the affective meanings associated with male and female sex-trait stereotypes  

Microsoft Academic Search

This study was concerned with the qualitative differences in the male and female sex-trait stereotypes. Previous research employing the item pool of the Adjective Check List (ACL) had indicated no relationship between the stereotype loading of the adjectives and their “favorability” ratings. In the present study, university students rated the ACL items for “strength” and “activity,” and these ratings were

Deborah L. Best; John E. Williams; Stephen R. Briggs

1980-01-01

157

Proteome Analysis of Separated Male and Female Gametocytes Reveals Novel Sex-Specific Plasmodium Biology  

Microsoft Academic Search

Summary Gametocytes, the precursor cells of malaria-parasite gametes, circulate in the blood and are responsible for transmission from host to mosquito vector. The individual proteomes of male and female gametocytes were analyzed using mass spectrometry, following separation by flow sorting of transgenic parasites ex- pressing green fluorescent protein, in a sex-specific manner. Promoter tagging in transgenic parasites confirmed the designation

Shahid M. Khan; Blandine Franke-Fayard; Gunnar R. Mair; Edwin Lasonder; Chris J. Janse; Matthias Mann; Andrew P. Waters

2005-01-01

158

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...

159

Sex-Based Differences in School Content and the Male-Female Wage Gap  

Microsoft Academic Search

In high school and college, men and women take significantly different courses. Using data from the Survey of Income and Program Participation and the National Longitudinal Study class of 1972, the authors relate these differences in school content to sex differences in adult wages. Differences in field of highest degree account for a significant part of the male-female wage gap

Charles Brown; Mary Corcoran

1997-01-01

160

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...

161

Modulation of aortic vascular reactivity by sex hormones in a male rat model of metabolic syndrome  

Microsoft Academic Search

Modulation by sex hormones of aortic reactivity in rats with the metabolic syndrome (MS) was investigated. The following groups of weanling male Wistar rats were used: control rats (C) received regular tap water while MS rats received 30% sucrose in their drinking water; both had rodent chow for 24 weeks. These two groups were further subdivided into the following four groups:

Israel Pérez Torres; Mohammed El Hafidi; José Zamora-González; Oscar Infante; Roberto Chavira; Guadalupe Baños

2007-01-01

162

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

2013-05-16

163

A case study of a male sex offender with zoosexual interests and behaviours  

Microsoft Academic Search

This paper reviews assessment, treatment and supervision issues in relation to a high-risk, borderline functioning, male sex offender with zoosexual interests and behaviours. Mr Z was convicted of multiple sexual offences including rape, indecent assault and indecent exposure as well as actual and threatened bodily harm. He was convicted for two counts of attempted buggery of horses and he received

D. T. Wilcox; C. M. Foss; M. L. Donathy

2005-01-01

164

What Else Don't Real Men Do? Sex Role Orientation and Adjustment in College Males.  

ERIC Educational Resources Information Center

|Bem's androgyny theory predicts better psychological adjustment in androgynous males and females (those with a balance of masculine and feminine traits) than in traditionally masculine men or feminine women. However, recent research suggests that androgynous individuals have no advantage over masculine-typed individuals of either sex. To explore…

Adams, Carol; Sherer, Mark

165

Bisexual feelings and opposite-sex behavior in male Malaysian medical students  

Microsoft Academic Search

The sexual identity of 65 Malaysian male medical students was investigated by anonymous questionnaire. Of these students, 40% were aware of homosexual feelings prior to age 15 years, and 16% were so aware currently. There were correlations between current homosexual feelings and feminine sex dimorphic behavior during childhood and between current homosexual feelings and feminine gender identity. The results are

N. Buhrich; M. S. Armstrong; N. McConaghy

1982-01-01

166

Female-to-male sex pheromones of low volatility in the Asian elephant, Elephas maximus  

Microsoft Academic Search

In their natural ecosystems, the sexes of Asian elephants,Elephas maximus, live separately. For several weeks prior to ovulation, the urine and cervical mucus of female Asian elephants contain extractable chemical agents of low volatility that elicit a high frequency of flehmen responses from bull elephants as an integral part of mating. Subsequent to flehmen responses, male sexual arousal occurs and,

L. E. L. Rasmussen; Terry D. Lee; G. Doyle Daves; Michael J. Schmidt

1993-01-01

167

Principles, virtues and care: ethical dilemmas in research with male sex offenders  

Microsoft Academic Search

This paper considers ethical dilemmas associated with research with male sex offenders. It examines two particular areas in detail: dealing with the disclosure of previously undisclosed offences and managing the distress of research participants during interview. Within these areas there is discussion of ethical approaches to research. Principle-based approaches offer abstract guidelines that help to resolve certain issues, but at

Malcolm Cowburn

2010-01-01

168

Sexual selection in an isopod with Wolbachia-induced sex reversal: males prefer real females  

Microsoft Academic Search

A variety of genetic elements encode traits beneficial to their own transmis- sion. Despite their 'selfish' behaviour, most of these elements are often found at relatively low frequencies in host populations. This is the case of intracytoplasmic Wolbachia bacteria hosted by the isopod Armadillidium vulgare that distort the host sex ratio towards females by feminizing the genetic males they infect.

J. Moreau; A. Bertin; Y. Caubet; T. Rigaud

2001-01-01

169

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...

170

Activation of PPAR? by Rosiglitazone Does Not Negatively Impact Male Sex Steroid Hormones in Diabetic Rats  

PubMed Central

Peroxisome proliferator-activated receptor gamma (PPAR?) activation decreased serum testosterone (T) in women with hyperthecosis and/or polycystic ovary syndrome and reduced the conversion of androgens to estradiol (E2) in female rats. This implies modulation of female sex steroid hormones by PPAR?. It is not clear if PPAR? modulates sex steroid hormones in diabetic males. Because PPAR? activation by thiazolidinedione increased insulin sensitivity in type 2 diabetes, understanding the long term impact of PPAR? activation on steroid sex hormones in males is critical. Our objective was to determine the effect of PPAR? activation on serum and intratesticular T, luteinizing hormone (LH), follicle stimulating hormone (FSH) and E2 concentrations in male Zucker diabetic fatty (ZDF) rats treated with the PPAR? agonist rosiglitazone (a thiazolidinedione). Treatment for eight weeks increased PPAR? mRNA and protein in the testis and elevated serum adiponectin, an adipokine marker for PPAR? activation. PPAR? activation did not alter serum or intratesticular T concentrations. In contrast, serum T level but not intratesticular T was reduced by diabetes. Neither diabetes nor PPAR? activation altered serum E2 or gonadotropins FSH and LH concentrations. The results suggest that activation of PPAR? by rosiglitazone has no negative impact on sex hormones in male ZDF rats.

Mansour, Mahmoud; Coleman, Elaine; Dennis, John; Akingbemi, Benson; Schwartz, Dean; Braden, Tim; Judd, Robert; Plaisance, Eric; Stewart, Laura Ken; Morrison, Edward

2009-01-01

171

Goals of male and female college students: Do traditional sex differences still exist?  

Microsoft Academic Search

Importance ratings of reasons for attending college were obtained from male and female undergraduates. Responses were compared for sex differences and were compared to the responses of subjects in the Constantinople (1967) study. The picture of college students that emerged is very different from those of previous studies. Current females did not emphasize career goals less, nor social goals more,

Andrea Schlissel Goldberg; Samuel Shiflett

1981-01-01

172

Differential sex allocation in sand lizards: bright males induce daughter production in a species with heteromorphic sex chromosomes.  

PubMed

In sand lizards (Lacerta agilis), males with more and brighter nuptial coloration also have more DNA fragments visualized in restriction fragment length polymorphism analysis of their major histocompatibility complex class I loci (and, hence, are probably more heterozygous at these loci). Such males produce more viable offspring, with a particularly strong viability effect on daughters. This suggests that females should adjust both their reproductive investment and offspring sex ratio in relation to male coloration (i.e. differential allocation). Our results show that experimental manipulation of partner coloration in the wild results in significantly higher maternal effort and a 10% higher proportion of daughters than sons. This supports the hypothesis that females increase their maternal energetic expenditure and adjust their offspring sex ratio in response to high-quality partners. However, it also suggests that this has probably evolved through natural selection for increased offspring viability (primarily through production of daughters), rather than through increased mate attraction (e.g. sexy sons). PMID:17148211

Olsson, Mats; Wapstra, Erik; Uller, Tobias

2005-09-22

173

Do sex-changing male snails use mate choice to get a jump on their “size advantage”?  

Microsoft Academic Search

Individuals of species that change sex from male to female may gain a “size advantage” from that sex change; that is, as males\\u000a become larger, they become female, thus increasing their fecundity with their size. However, males could also gain an early\\u000a and different reproductive size advantage by choosing large females as mates. While male preference for large females has

Olivia V. Ambrogio; Jan A. Pechenik

2009-01-01

174

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

PubMed

I examined the intrinsic postzygotic incompatibilities between two pupfishes, Cyprinodon elegans and Cyprinodon variegatus. Laboratory hybridization experiments revealed evidence of strong postzygotic isolation. Male hybrids have very low fertility, and the survival of backcrosses into C. elegans was substantially reduced. In addition, several crosses produced female-biased sex ratios. Crosses involving C. elegans females and C. variegatus males produced only females, and in backcrosses involving hybrid females and C. elegans males, males made up approximately 25% of the offspring. All other crosses produced approximately 50% males. These sex ratios could be explained by genetic incompatibilities that occur, at least in part, on sex chromosomes. Thus, these results provide strong albeit indirect evidence that pupfish have XY chromosomal sex determination. The results of this study provide insight on the evolution of reproductive isolating mechanisms, particularly the role of Haldane's rule and the 'faster-male' theory in taxa lacking well-differentiated sex chromosomes. PMID:17040380

Tech, C

2006-11-01

175

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.

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

2012-01-01

176

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

2012-07-26

177

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.

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

2012-01-01

178

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.

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

2010-01-01

179

Putative aromatase inhibitor induces male sex determination in a female unisexual lizard and in a turtle with temperature-dependent sex determination.  

PubMed

Treatment of developing embryos of two diverse species of reptiles with fadrozole (a potent and specific nonsteroidal inhibitor of aromatase activity in mammals) resulted in the induction of male sex determination. In the first experiment, males were produced in an all-female parthenogenic species of lizard (Cnemidophorus uniparens). In the second experiment, male sex determination was induced in a turtle (Trachemys scripta) with temperature-dependent sex determination. The results support the hypothesis that the endogenous production of oestrogen may represent a pivotal step in the sex determination cascade of reptiles. Further, the production of male C uniparens indicates that the genes required for male sexual differentiation have not been lost in this parthenogenic lizard. PMID:8046299

Wibbels, T; Crews, D

1994-05-01

180

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

181

Common spontaneous sex-reversed XX males of the medaka Oryzias latipes.  

PubMed Central

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 uncompromised fertility, but lacking dmrt1bY. The frequency of such males was >10% in some strains and zero in others. Analysis for the presence of other Y-linked markers by FISH analysis, PCR, and phenotype indicated that their genotype is XX. Crossing such males with XX females led to a strong female bias in the offspring and also to a reappearance of XX males in the following generations. This indicated that the candidate male sex-determining gene dmrt1bY may not be necessary for male development in every case, but that its function can be taken over by so far unidentified autosomal modifiers.

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

2003-01-01

182

[Sex-change operations in disorders of the reproductive organs].  

PubMed

The authors analyze the experience gained in the surgical treatment of more than 5300 patients aged 2 days to 42 years, suffering from various abnormalities of the reproductive organs. They describe the surgical policy in sex-transforming surgery (masculinizing or feminizing plasty of the genitals) and give recommendations on rehabilitation of the patients with involvement of the reproductive system organs in the postoperative period. PMID:8016047

Okulov, A B; Negmadzhanov, B B

183

The potential for sexual selection in males: Effect of sex ratio and spatiotemporal distribution of receptive females  

Microsoft Academic Search

Summary An animal mating system characterized by male-male competition and active searching for sexually receptive females was modelled to study how varying sex ratio and spatiotemporal distribution of receptive females can affect the variance in male mating success (i. e. potential for sexual selection) in males. The temporal distribution of female receptivity periods appeared to be the variable that had

Rolf Anker Ims

1988-01-01

184

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

PubMed

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

2004-07-01

185

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.

Cowan, David P.; Stahlhut, Julie K.

2004-01-01

186

Secular Trends in Uncertain-Sex Births and Proportion of Male Births in Norway, 1967-1998  

Microsoft Academic Search

It has been hypothesized that environmental factors influence sex differentiation in the fetus, thus causing a reduced sex ratio (male\\/female) at birth, an increase in the prevalence of ambiguous-sex infants, and possibly an increase in spontaneous abortion rates. In Norway, subsequent to 1967, all deliveries, including late abortions after 16 wk of gestation, have been reported to the Medical Birth

ÅGOT Irgens; Lorentz M. Irgens

2003-01-01

187

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.

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

2013-01-01

188

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

PubMed

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

2013-08-27

189

Effects of male sex hormones on gender identity, sexual behavior, and cognitive function.  

PubMed

Androgens, the male sex hormones, play an essential role in male sexual differentiation and development. However, the influence of these sex hormones extends beyond their roles in sexual differentiation and development. In many animal species, sex hormones have been shown to be essential for sexual differentiation of the brain during development and for maintaining sexually dimorphic behavior throughout life. The principals of sex determination in humans have been demonstrated to be similar to other mammals. However, the hormonal influence on sexual dimorphic differences in the nervous system in humans, sex differences in behaviors, and its correlations with those of other mammals is still an emerging field. In this review, the roles of androgens in gender and cognitive function are discussed with the emphasis on subjects with androgen action defects including complete androgen insensitivity due to androgen receptor mutations and 5alpha-reductase-2 deficiency syndromes due to 5alpha-reductase-2 gene mutations. The issue of the complex interaction of nature versus nurture is addressed. PMID:16706106

Zhu, Yuan-shan; Cai, Li-qun

2006-04-01

190

Handedness, Functional Cerebral Hemispheric Lateralization, and Cognition in Male-to-Female Transsexuals Receiving Cross-Sex Hormone Treatment  

Microsoft Academic Search

This study examined the impact of sex hormones on functional cerebral hemispheric lateralization and cognition in a group of male-to-female transsexuals receiving cross-sex hormone therapy compared to eugonadal men with a male gender identity. Cerebral lateralization was measured with a handedness questionnaire and a visual-split-field paradigm and cognitive tests sensitive to sex hormone exposure (identical pictures, 3-D mental rotation, building

Amy B. Wisniewski; Mary T. Prendeville; Adrian S. Dobs

2005-01-01

191

Increased sex chromosome expression and epigenetic abnormalities in spermatids from male mice with Y chromosome deletions.  

PubMed

During male meiosis, the X and Y chromosomes are transcriptionally silenced, a process termed meiotic sex chromosome inactivation (MSCI). Recent studies have shown that the sex chromosomes remain substantially transcriptionally repressed after meiosis in round spermatids, but the mechanisms involved in this later repression are poorly understood. Mice with deletions of the Y chromosome long arm (MSYq-) have increased spermatid expression of multicopy X and Y genes, and so represent a model for studying post-meiotic sex chromosome repression. Here, we show that the increase in sex chromosome transcription in spermatids from MSYq- mice affects not only multicopy but also single-copy XY genes, as well as an X-linked reporter gene. This increase in transcription is accompanied by specific changes in the sex chromosome histone code, including almost complete loss of H4K8Ac and reduction of H3K9me3 and CBX1. Together, these data show that an MSYq gene regulates sex chromosome gene expression as well as chromatin remodelling in spermatids. PMID:19861498

Reynard, Louise N; Turner, James M A

2009-10-27

192

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

193

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.

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

2009-01-01

194

Two males with SRY-positive 46,XX testicular disorder of sex development.  

PubMed

The 46,XX testicular disorder of sex development (46,XX testicular DSD) is a rare phenotype associated with disorder of the sex chromosomes. We describe the clinical, molecular, and cytogenetic findings of a 16- and a 30-year-old male patient with sex-determining region Y (SRY)-positive 46,XX testicular DSD. Chromosomal analysis revealed 46,XX karyotype. Fluorescence in situ hybridization (FISH) showed the SRY region translocated to the short arm of the X chromosome. The presence of the SRY gene was also confirmed by polymerase chain reaction (PCR). The X chromosome inactivation (XCI) assay showed that both patients have a random pattern of X chromosome inactivation. This report compares the symptoms and features of the SRY-positive 46,XX testicular DSD patients. PMID:23110663

Gunes, Sezgin; Asci, Ramazan; Okten, Gülsen; Atac, Fatih; Onat, Onur E; Ogur, Gonul; Aydin, Oguz; Ozcelik, Tayfun; Bagci, Hasan

2012-10-30

195

Molecular Analysis of NOZZLE, a Gene Involved in Pattern Formation and Early Sporogenesis during Sex Organ Development in Arabidopsis thaliana  

Microsoft Academic Search

Sexual reproduction is a salient aspect of plants, and elaborate structures, such as the flowers of angiosperms, have evolved that aid in this process. Within the flower the corresponding sex organs, the anther and the ovule, form the male and female sporangia, the pollen sac and the nucellus, respectively. However, despite their central role for sexual reproduction little is known

Ursula Schiefthaler; Sureshkumar Balasubramanian; Patrick Sieber; David Chevalier; Ellen Wisman; Kay Schneitz

1999-01-01

196

Male-Produced Sex Pheromone of the Cerambycid Beetle Hedypathes betulinus : Chemical Identification and Biological Activity  

Microsoft Academic Search

We identified, synthesized, determined the diel periodicity of release, and tested the bioactivity of components of the male-produced\\u000a sex pheromone of Hedypathes betulinus (Coleoptera: Cerambycidae: Lamiinae). Gas chromatographic-mass spectrometric analysis of headspace volatiles from adult beetles\\u000a showed three male-specific compounds, which were identified as (E)-6,10-dimethyl-5,9-undecadien-2-yl acetate (major component), (E)-6,10-dimethyl-5,9-undecadien-2-one (geranylacetone), and (E)-6,10-dimethyl-5,9-undecadien-2-ol. Release of these chemicals was dependent on time

Marcy G. Fonseca; Diogo M. Vidal; Paulo H. G. Zarbin

2010-01-01

197

Meiotic sex chromosome inactivation in male mice with targeted disruptions of Xist.  

PubMed

X chromosome inactivation occurs twice during the life cycle of placental mammals. In normal females, one X chromosome in each cell is inactivated early in embryogenesis, while in the male, the X chromosome is inactivated together with the Y chromosome in spermatogenic cells shortly before or during early meiotic prophase. Inactivation of one X chromosome in somatic cells of females serves to equalise X-linked gene dosage between males and females, but the role of male meiotic sex chromosome inactivation (MSCI) is unknown. The inactive X-chromosome of somatic cells and male meiotic cells share similar properties such as late replication and enrichment for histone macroH2A1.2, suggesting a common mechanism of inactivation. This possibility is supported by the fact that Xist RNA that mediates somatic X-inactivation is expressed in the testis of male mice and humans. In the present study we show that both Xist RNA and Tsix RNA, an antisense RNA that controls Xist function in the soma, are expressed in the testis in a germ-cell-dependent manner. However, our finding that MSCI and sex-body formation are unaltered in mice with targeted mutations of Xist that prevent somatic X inactivation suggests that somatic X-inactivation and MSCI occur by fundamentally different mechanisms. PMID:12356914

Turner, James M A; Mahadevaiah, Shantha K; Elliott, David J; Garchon, Henri-Jean; Pehrson, John R; Jaenisch, Rudolf; Burgoyne, Paul S

2002-11-01

198

Evolution of DMY, a newly emergent male sex-determination gene of medaka fish.  

PubMed Central

The Japanese medaka fish Oryzias latipes has an XX/XY sex-determination system. The Y-linked sex-determination 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 evolutionary study of the initial steps that led to the new gene and new sex-determination system. Here I analyze the publicly available DMRT1 and DMY gene sequences of Oryzias species and report the following findings. First, the synonymous substitution rate in DMY is 1.73 times that in DMRT1, consistent with the male-driven evolution hypothesis. Second, the ratio of the rate of nonsynonymous nucleotide substitution (d(N)) to that of synonymous substitution (d(S)) is significantly higher in DMY than in DMRT1. Third, in DMRT1, the d(N)/d(S) ratio for the DM domain is lower than that for non-DM regions, as expected from the functional importance of the DM domain. But in DMY, the opposite is observed and the DM domain is likely under positive Darwinian selection. Fourth, only one characteristic amino acid distinguishes all DMY sequences from all DMRT1 sequences, suggesting that a single amino acid change may be largely responsible for the establishment of DMY as the male sex-determination gene in medaka fish.

Zhang, Jianzhi

2004-01-01

199

Sex Differences in Adults’ Relative Visual Interest in Female and Male Faces, Toys, and Play Styles  

Microsoft Academic Search

An individual’s reproductive potential appears to influence response to attractive faces of the opposite sex. Otherwise, relatively\\u000a little is known about the characteristics of the adult observer that may influence his or her affective evaluation of male\\u000a and female faces. An untested hypothesis (based on the proposed role of attractive faces in mate selection) is that most women\\u000a would show

Gerianne M. Alexander; Nora Charles

2009-01-01

200

Distribution of putative male sex pheromones among Lutzomyia sandflies (Diptera: Psychodidae).  

PubMed

Male Lutzomyia longipalpis produce terpene sex pheromones in glandular tissue underlying the cuticle. The pheromones are transmitted to the surface via cuticle-lined ducts (measuring 0.25 microm in diameter), each of which reaches the surface in the centre of a papule (measuring 3-3.5 microm in diameter). Similar papules, in a range of shapes but all characterized by the presence of a central pore and absence of macroserae, occur in some other species of sandfly. The aim of the present study was to determine the distribution of sex pheromones in sandflies of the genus Lutzomyia that do and do not have the papules. The results indicate that sex pheromones are not widely distributed amongst male Lutzomyia spp. Male members of the genus can be subdivided into three groups: those that produce terpenes and have cuticular papules; those that do not produce terpenes but still have the associated papules; and those that have neither terpenes nor papules. The papules seen in the species that do not synthesise sex pheromones are presumably vestigial, non-functional structures. Such species may have stopped producing pheromone as the result of changes in the way in which the females found and selected mates or changing feeding preferences. A similar event has occurred in the Lepidoptera, where vestigial pheromone-secreting structures remain in some species which no longer produce pheromone. Lutzomyia lenti collected in southern Brazil produced a novel diterpene whereas male L. lenti from north-eastern Brazil did not, supporting suggestions by others that L. lenti is, like L. longipalpis, a species complex. PMID:11989537

Hamilton, J G C; Brazil, R P; Campbell-Lendrum, D; Davies, C R; Kelly, D W; Pessoa, F A C; de Queiroz, R G

2002-01-01

201

Birth order and sibling sex ratio in two samples of Dutch gender-dysphoric homosexual males  

Microsoft Academic Search

Two studies were undertaken to confirm the previous findings that homosexual men in general tend to have a later than expected\\u000a birth order and that extremely feminine homosexual men also tend to have a higher than expected proportion of brothers (i.e.\\u000a a highersibling sex ratio). Subjects in Study 1 were Dutch, adult and adolescent, biological male patients with gender dysphoria

Ray Blanchard; Kenneth J. Zucker; Petty T. Cohen-Kettenis; Louis J. G. Gooren; J. Michael Bailey

1996-01-01

202

Male Dan: the Paradox of Sex, Acting, and Perception of Female Impersonation in Traditional  

Microsoft Academic Search

The art of male dan—specialists in female roles—is one of the most important issues in traditional Chinese theatre, especially in jingju (Beijing or Peking opera). In this article, Min Tian considers the problem from a combined gender-sociocultural-historical perspective. Tian traces the convention’s historical development, examines its contemporary status, and deals with such issues as the dynamics of sex and the

Chinese Theatre

2000-01-01

203

HIV, syphilis, hepatitis C and risk behaviours among commercial sex male clients in Sichuan province, China  

Microsoft Academic Search

ObjectivesCommercial sex male clients (CSMC) are at risk of sexually transmitted infections (STI) including HIV. This study reports the prevalence of HIV, syphilis and hepatitis C virus (HCV), a history of STI and HIV-related risk behaviours in a sample of 600 CSMC in three urban areas in Sichuan province, China. The risk factors for prevalent syphilis infection are also examined.MethodsA

Cui Yang; Carl Latkin; Rongsheng Luan; Cunling Wang; Kenrad Nelson

2010-01-01

204

Analysis of male meiotic "sex body" proteins during XY female meiosis provides new insights into their functions.  

PubMed

During male meiosis in mammals the X and Y chromosomes become condensed to form the sex body (XY body), which is the morphological manifestation of the process of meiotic sex chromosome inactivation (MSCI). An increasing number of sex body located proteins are being identified, but their functions in relation to MSCI are unclear. Here we demonstrate that assaying male sex body located proteins during XY female mouse meiosis, where MSCI does not take place, is one way in which to begin to discriminate between potential functions. We show that a newly identified protein, "Asynaptin" (ASY), detected in male meiosis exclusively in association with the X and Y chromatin of the sex body, is also expressed in pachytene oocytes of XY females where it coats the chromatin of the asynapsed X in the absence of MSCI. Furthermore, in pachytene oocytes of females carrying a reciprocal autosomal translocation, ASY associates with asynapsed autosomal chromatin. Thus the location of ASY to the sex body during male meiosis is likely to be a response to the asynapsis of the non-homologous regions [outside the pseudoautosomal region (PAR)] of the heteromorphic X-Y bivalent, rather than being related to MSCI. In contrast to ASY, the previously described sex body protein XY77 proved to be male sex body specific. Potential functions for MSCI and the sex body are discussed together with the possible roles of these two proteins. PMID:11072798

Turner, J M; Mahadevaiah, S K; Benavente, R; Offenberg, H H; Heyting, C; Burgoyne, P S

2000-09-01

205

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

206

Psychosocial Factors in Association with Condom Use During Commercial Sex Among Migrant Male Sex Workers Living in Shenzhen, Mainland China Who Serve Cross-Border Hong Kong Male Clients  

Microsoft Academic Search

Male sex workers serving Hong Kong male clients in Shenzhen were surveyed (n = 199); 98.9% had been in Shenzhen for ?3 years; 83.4% served local male clients; 82.8% had no family members\\/relatives in\\u000a Shenzhen; 58.3% depended exclusively on sex work; 73% were bothered by one’s sex work; and 81.7% found financial support unavailable\\u000a when needed. About 29.1% had had unprotected anal intercourse

Joseph T. F. Lau; Wen-De Cai; Hi Yi Tsui; Lin Chen; Jin-Quan Cheng

2009-01-01

207

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

Microsoft Academic Search

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

Cornelia Voigt; Gregory F. Ball; Jacques Balthazart

2011-01-01

208

Female Sex Pheromone-Mediated Effects on Behavior and Consequences of Male Competition in the Shore Crab ( Carcinus maenas )  

Microsoft Academic Search

Exposure to receptive female pheromone elicits guarding behavior in shore crab males (Carcinus maenas), but little is known about the effects of sex pheromone on male competition or if the female plays an active role in mate choice. This study examined whether female pheromone enhanced agonistic behavior between males and what effects visual and chemical cues had on the rules

Lynne U. Sneddon; Felicity A. Huntingford; Alan C. Taylor; Anthony S. Clare

2003-01-01

209

Inconsistent condom use among young men who have sex with men, male sex workers, and transgenders in Thailand.  

PubMed

Young men who have sex with men (MSM) are at risk for HIV infection. We investigated inconsistent condom use among 827 sexually active young MSM (15-24 years), enrolled using venue-day-time sampling in Bangkok, Chiang Mai and Phuket, Thailand. Data was collected using palmtop computer-assisted self-interviewing. Of participants, 33.1% were regular MSM, 37.7% were male sex workers (MSWs) and 29.1% were transgenders (TGs). Of MSM, 46.7%, of MSWs, 34.9% and of TGs, 52.3% reported recent inconsistent condom use. In multivariate analysis, receptive anal intercourse (MSM, MSWs), receptive and insertive anal intercourse, living alone and a history of sexual coercion (MSWs), not carrying a condom when interviewed (MSM, TGs), lower education, worrying about HIV infection and a history of sexually transmitted infections (TGs) were significantly and independently associated with inconsistent condom use. Interventions for young MSM are needed and must consider the distinct risk factors of MSM, MSWs, and TGs. PMID:20387981

Chemnasiri, Tareerat; Netwong, Taweesak; Visarutratana, Surasing; Varangrat, Anchalee; Li, Andrea; Phanuphak, Praphan; Jommaroeng, Rapeepun; Akarasewi, Pasakorn; van Griensven, Frits

2010-04-01

210

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.

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

2008-01-01

211

Genetic manipulation of sex ratio for the large-scale breeding of YY super-male and XY all-male yellow catfish (Pelteobagrus fulvidraco (Richardson)).  

PubMed

Yellow catfish has become one of the most important freshwater aquaculture species in China. The mono-sex male yellow catfish has important application value in aquaculture because the male grows generally faster than the sibling females under the same conditions. This study has screened YY super-male and YY physiological female yellow catfish by sex reversal, gynogenesis, and progeny testing, which can help to achieve the large-scale production of YY super-male and XY all-male. From 2008 to 2010, about 123,000 YY super-male were produced, and about 81 million XY all-male fry were produced with 100% male rate by random sampling. Therefore, these results indicate that YY super-male and YY physiological female yellow catfish can be viable and fertile. We conclude that the mono-sex breeding technique by YY super-male yellow catfish is stable and reliable, which has great potential for application in yellow catfish aquaculture. PMID:23053056

Liu, Hanqin; Guan, Bo; Xu, Jiang; Hou, Changchun; Tian, Hua; Chen, Hongxi

2012-10-02

212

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

2010-11-18

213

Androgenic/estrogenic balance in the male rat cerebral circulation: metabolic enzymes and sex steroid receptors  

PubMed Central

Tissues from males can be regulated by a balance of androgenic and estrogenic effects because of local metabolism of testosterone and expression of relevant steroid hormone receptors. As a critical first step to understanding sex hormone influences in the cerebral circulation of males, we investigated the presence of enzymes that metabolize testosterone to active products and their respective receptors. We found that cerebral blood vessels from male rats express 5?-reductase type 2 and aromatase, enzymes responsible for conversion of testosterone into dihydrotestosterone (DHT) and 17?-estradiol, respectively. Protein levels of these enzymes, however, were not modulated by long-term in vivo hormone treatment. We also showed the presence of receptors for both androgens (AR) and estrogens (ER) from male cerebral vessels. Western blot analysis showed bands corresponding to the full-length AR (110 kDa) and ER? (66 kDa). Long-term in vivo treatment of orchiectomized rats with testosterone or DHT, but not estrogen, increased AR levels in cerebral vessels. In contrast, ER? protein levels were increased after in vivo treatment with estrogen but not testosterone. Fluorescent immunostaining revealed ER?, AR, and 5?-reductase type 2 in both the endothelial and smooth muscle layers of cerebral arteries, whereas aromatase staining was solely localized to the endothelium. Thus, cerebral vessels from males are target tissues for both androgens and estrogen. Furthermore, local metabolism of testosterone might balance opposing androgenic and estrogenic influences on cerebrovascular as well as brain function in males.

Gonzales, Rayna J; Ansar, Saema; Duckles, Sue P; Krause, Diana N

2008-01-01

214

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.

Larsson, D G Joakim; Forlin, Lars

2002-01-01

215

Sox3 is required for gonadal function, but not sex determination, in males and females.  

PubMed

Sox3 is expressed in developing gonads and in the brain. Evolutionary evidence suggests that the X-chromosomal Sox3 gene may be the ancestral precursor of Sry, a sex-determining gene, and Sox3 has been proposed to play a role in sex determination. However, patients with mutations in SOX3 exhibit normal gonadal determination but are mentally retarded and have short stature secondary to growth hormone (GH) deficiency. We used Cre-LoxP targeted mutagenesis to delete Sox3 from mice. Null mice of both sexes had no overt behavioral deficits and exhibited normal GH gene expression. Low body weight was observed for some mice; overgrowth and misalignment of the front teeth was observed consistently. Female Sox3 null mice (-/-) developed ovaries but had excess follicular atresia, ovulation of defective oocytes, and severely reduced fertility. Pituitary (luteinizing hormone and follicle-stimulating hormone) and uterine functions were normal in females. Hemizygous male null mice (-/Y) developed testes but were hypogonadal. Testis weight was reduced by 42%, and there was extensive Sertoli cell vacuolization, loss of germ cells, reduced sperm counts, and disruption of the seminiferous tubules. We conclude that Sox3 is not required for gonadal determination but is important for normal oocyte development and male testis differentiation and gametogenesis. PMID:14585968

Weiss, Jeffrey; Meeks, Joshua J; Hurley, Lisa; Raverot, Gerald; Frassetto, Andrea; Jameson, J Larry

2003-11-01

216

Fine structure and meiotic behaviour of the male multiple sex chromosomes in the genus Alouatta.  

PubMed

The meiotic cytology and fine structure of the sex multiples in males from two species of the genus Alouatta are presented and compared with descriptions from other species of this genus. As shown in pachytene by synaptonemal complex analysis and in metaphase I by spreading, there is a quadrivalent in male meiosis in A. caraya, which is formed by an X(1)X(2)Y(1)Y(2) complex, while in A. palliata there is a trivalent formed by an X(1)X(2)Y(1) complex. Chromosome painting with human probes shows that A. caraya sex multiples share the same components as those of A. seniculus sara and A. seniculus arctoidea. However, as shown here for A. palliata and by others in A. fusca, there are differences among the multiples of some species. It is shown that in this genus there are several varieties of sex multiples that share some features, and that the origin of these multiples is most probably a primitive development in the genus Alouatta. PMID:15545739

Solari, A J; Rahn, M I

2005-01-01

217

First evidence of sex chromosome pre-reduction in male meiosis in the Miridae bugs (Heteroptera).  

PubMed

The karyotype and male meiosis of Macrolophus costalis Fieber (Insecta, Heteroptera, Miridae) were studied using C-banding, AgNOR-banding and DNA sequence specific fluorochrome staining. The chromosome formula of the species is 2n = 28(24+X1X2X3Y). Male meiotic prophase is characterized by a prominent condensation stage. At this stage, two sex chromosomes, "X" and Y are positively heteropycnotic and always appeared together, while in autosomal bivalents homologous chromosomes were aligned side by side along their entire length, that is, meiosis is achiasmatic. At metaphase I, "X" and Y form a pseudobivalent and orient to the opposite poles. At early anaphase I, the "X" chromosome disintegrates into three separate small chromosomes, X1, X2, and X3. Hence both the autosomes and sex chromosomes segregate reductionally in the first anaphase, and separate equationally in the second anaphase. This is the first evidence of sex chromosome pre-reduction in the family Miridae. Data on C-heterochromatin distribution and its composition in the chromosomes of this species are discussed. PMID:17044253

Grozeva, Snejana; Nokkala, Seppo; Simov, Nikolay

2006-01-01

218

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

2012-07-09

219

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

PubMed

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 sociocultural 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

Nureña, César R; Zúñiga, Mario; Zunt, Joseph; Mejía, Carolina; Montano, Silvia; Sánchez, Jorge L

2011-09-21

220

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.

Zuniga, Mario; Zunt, Joseph; Mejia, Carolina; Montano, Silvia; Sanchez, Jorge L.

2011-01-01

221

Sex ratios of triploids and gynogenetic diploids induced in the hybrid sturgeon, the bester ( Huso huso female× Acipenser ruthenus male)  

Microsoft Academic Search

The sex ratios of triploids and gynogenetic diploids in the hybrid sturgeon, the bester (Huso huso female×Acipenser ruthenus male), have been investigated to confirm the possibilities of sex control by chromosome manipulation in sturgeon. Viable gynogenetic diploids were produced by activating eggs with ultraviolet-irradiated bester sperm followed by heatshock treatment. Triploids were induced by the same method after fertilization of

Naotaka Omoto; Mamoru Maebayashi; Shinji Adachi; Katsutoshi Arai; Kohei Yamauchi

2005-01-01

222

Conserved repetitive DNA sequences (Bkm) in normal equine males and sex-reversed females detected by in situ hybridization  

Microsoft Academic Search

In situ hybridization with a cloned banded krait sex-XY males and XY sex-reversed females. Lesser, but still signifi-specific repetitive DNA probe (Bkm) indicates a high concentracant, concentrations of Bkm sequences were mapped to horse tion of Bkm sequences on the horse Y chromosome in both normal chromosomes 3, 4, and 30.Copyright © 1988 S. Karger AG, Basel

M. G. Kent; K. O. Elliston; W. Shroeder; K. S. Guise; S. S. Wachtel

1988-01-01

223

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

224

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.

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

2010-01-01

225

Sex differences in scent-marking in sifaka: Mating conflict or male services?  

PubMed

Male and female interests can either be in conflict or serve as a basis for exchange. Communication is thus an important aspect of intersexual relationships. Verreaux's sifaka (Propithecus verreauxi verreauxi), like many prosimians, uses chemical signals as one form of communication. The goals of this study were to determine 1) if males and females exhibit sex differences in their scent-marking behavior, and 2) if scent-marking is an example of mating conflict or cooperation. All occurrences of scent-marks, scent-mark context, and scent-mark style were collected on 23 sifaka in the Kirindy Forest of western Madagascar for 7 months (September 2001-March 2002). Scent-mark rates were collected using continuous focal animal sampling from November 2000-March 2002. Home-range data were collected using monthly censuses and instantaneous focal sampling throughout those 17 months. The pressures of behavioral ecology seem to have shaped scent-marking in sifaka: the sexes exhibited significantly different scent-marking behavior. Results from this study are consistent with the hypotheses that 1) females scent-mark to advertise their presence and mark their resources, 2) clean-chested males use scent-marks as between-group communication to advertise their presence, and 3) stained-chested males use scent-marks as a form of olfactory mate-guarding. Scent-marking does not appear to be a "service" that males provide to females, because overmarking limits female communication rather than adding to the overall number of scent-marks. Scent-marking behavior is a crucial aspect of the mating conflict and for understanding intersexual relationships in sifaka. PMID:15795894

Lewis, Rebecca J

2005-10-01

226

Polymorphisms in the maternal sex steroid pathway are associated with behavior problems in male offspring  

PubMed Central

Objective Slight perturbations in maternal sex steroid production and metabolism may interfere with normal fetal neurodevelopment. The balance of maternal estrogens and androgens may have direct fetal effects, may influence the fetal hypothalamic-pituitary-gonadal axis or may alter local hormonal activity within the fetal brain. We investigated maternal functional polymorphisms of CYP17, CYP19 and CYP1B1, which control three major enzymatic steps in sex steroid biosynthesis and metabolism, in relation to childhood behaviors. Methods The Mount Sinai Children’s Environmental Health Study enrolled a multiethnic urban pregnancy cohort from 1998–2002 (n = 404). DNA was obtained from maternal blood (n=149) and from neonatal cord blood (n=53). At each visit, mothers completed the Behavior Assessment System for Children (BASC), a parent-reported questionnaire used to evaluate children for behavior problems. We focused on problem behaviors more commonly associated with ADHD (hyperactivity, attention problems, externalizing behaviors, conduct disorder, poor adaptability) to see if maternal genetic variants in sex steroid production and metabolism influence sexually-dimorphic behaviors in offspring. Results The more active gene variants were significantly associated with Attention Problems and poorer Adaptive Skills in male compared to female offspring. The CYP19 variant allele was also significantly associated with worse scores for boys on the Hyperactivity, Externalizing Problems Composite and Adaptive Skills Composite scales (p < 0.05). Conclusion We observed maladaptive behaviors in the male offspring of mothers who carried functional polymorphisms in the sex steroid pathway. The strongest associations were in domains commonly affected in Attention Deficit-Hyperactivity Disorder.

Miodovnik, Amir; Diplas, Andreas I.; Chen, Jia; Zhu, Chenbo; Engel, Stephanie M.; Wolff, Mary S.

2012-01-01

227

Modeling the suppression of sea lamprey populations by use of the male sex pheromone  

USGS Publications Warehouse

The suppression of sea lamprey populations, Petromyzon marinus (Linnaeus), was modeled using four different applications of the male sex pheromone: (1) pheromone-baited traps that remove females from the spawning population, (2) pheromone-baited decoys that exhaust females before they are able to spawn, (3) pheromone-enhanced sterile males that increase the proportion of non-fertile matings, and (4) camouflaging of the pheromone emitted by calling males to make it difficult for females to find a mate. The models indicated that thousands of traps or hundreds of thousands of decoys would be required to suppress a population of 100,000 animals. The potential efficacy of pheromone camouflages is largely unknown, and additional research is required to estimate how much pheromone is needed to camouflage the pheromone plumes of calling males. Pheromone-enhanced sterile males appear to be a promising application in the Great Lakes. Using this technique for three generations each of ca. 7 years duration could reduce sea lamprey populations by 90% for Lakes Huron and Ontario and by 98% for Lake Michigan, based on current trapping operations that capture 20 to 30% of the population each year.

Klassen, Waldemar; Adams, Jean V.; Twohey, Michael B.

2005-01-01

228

Rapid modulation of gene expression profiles in the telencephalon of male goldfish following exposure to waterborne sex pheromones.  

PubMed

Sex pheromones rapidly affect endocrine physiology and behaviour, but little is known about their effects on gene expression in the neural tissues that mediate olfactory processing. In this study, we exposed male goldfish for 6h to waterborne 17,20?P (4.3nM) and PGF2? (3nM), the main pre-ovulatory and post-ovulatory pheromones, respectively. Both treatments elevated milt volume (P=0.001). Microarray analysis of male telencephalon following PGF2? treatment identified 71 unique transcripts that were differentially expressed (q<5%; 67 up, 4 down). Functional annotation of these regulated genes indicates that PGF2? pheromone exposure affects diverse biological processes including nervous system functions, energy metabolism, cholesterol/lipoprotein transport, translational regulation, transcription and chromatin remodelling, protein processing, cytoskeletal organization, and signalling. By using real-time RT-PCR, we further validated three candidate genes, ependymin-II, calmodulin-A and aldolase C, which exhibited 3-5-fold increase in expression following PGF2? exposure. Expression levels of some other genes that are thought to be important for reproduction were also determined using real-time RT-PCR. Expression of sGnRH was increased by PGF2?, but not 17,20?P, whereas cGnRH expression was increased by 17,20?P but not PGF2?. In contrast, both pheromones increase the expression of glutamate (GluR2a, NR2A) and ?-aminobutyric acid (GABAA ?2) receptor subunit mRNAs. Milt release and rapid modulation of neuronal transcription are part of the response of males to female sex pheromones. PMID:23800560

Lado, Wudu E; Zhang, Dapeng; Mennigen, Jan A; Zamora, Jacob M; Popesku, Jason T; Trudeau, Vance L

2013-06-22

229

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.

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

2012-01-01

230

Sex and condom use in a large jail unit for men who have sex with men (MSM) and male-to-female transgenders.  

PubMed

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

2010-08-01

231

Induction of female-to-male sex change in the honeycomb grouper (Epinephelus merra) by 11-ketotestosterone treatments.  

PubMed

The honeycomb grouper, Epinephelus merra, is a protogynous hermaphrodite fish. Sex steroid hormones play key roles in sex change of this species. A significant drop in endogenous estradiol-17beta (E2) levels alone triggers female-to-male sex change, and the subsequent elevation of 11-ketotestosterone (11KT) levels correlates with the progression of spermatogenesis. To elucidate the role of an androgen in sex change, we attempted to induce female-to-male sex change by exogenous 11KT treatments. The 75-day 11KT treatment caused 100% masculinization of pre-spawning females. Ovaries of the control (vehicle-treated) fish had oocytes at various stages of oogenesis, while the gonads of the 11KT-treated fish had transformed into testes; these contained spermatogenic germ cells at various stages, including an accumulation of spermatozoa in the sperm duct. In the sex-changed fish, plasma levels of E2 were significantly low, while both testosterone (T) and 11KT were significantly increased. Our results suggest that 11KT plays an important role in sex change in the honeycomb grouper. Whether the mechanism of 11KT-induced female-to-male sex change acts through direct stimulation of spermatogenesis in the ovary or via the inhibition of estrogen synthesis remains to be clarified. PMID:16547407

Bhandari, Ramji Kumar; Alam, Mohammad Ashraful; Soyano, Kiyoshi; Nakamura, Masaru

2006-01-01

232

Why do some social insect queens mate with several males? Testing the sex-ratio manipulation hypothesis in Lasius niger.  

PubMed

Although multiple mating most likely increases mortality risk for social insect queens and lowers the kin benefits for nonreproductive workers, a significant proportion of hymenopteran queens mate with several males. It has been suggested that queens may mate multiply as a means to manipulate sex ratios to their advantage. Multiple paternity reduces the extreme relatedness value of females for workers, selecting for workers to invest more in males. In populations with female-biased sex ratios, queens heading such male-producing colonies would achieve a higher fitness. We tested this hypothesis in a Swiss and a Swedish population of the ant Lasius niger. There was substantial and consistent variation in queen mating frequency and colony sex allocation within and among populations, but no evidence that workers regulated sex allocation in response to queen mating frequency; the investment in females did not differ among paternity classes. Moreover, population-mean sex ratios were consistently less female biased than expected under worker control and were close to the queen optimum. Queens therefore had no incentive to manipulate sex ratios because their fitness did not depend on the sex ratio of their colony. Thus, we found no evidence that the sex-ratio manipulation theory can explain the evolution and maintenance of multiple mating in L. niger. PMID:11989685

Fjerdingstad, Else J; Gertsch, Pia J; Keller, Laurent

2002-03-01

233

When is sex environmentally determined?  

Microsoft Academic Search

THERE are several sex determining mechanisms which produce two sexes in a population (dioecy or gonochorism)1-5. In many of these, the offspring's sex is determined at or before conception, as in male or female heterogamety. In several organisms, however, the offspring's sex is determined later than conception, by some environmental influence upon the offspring. We consider here why these environmental

Eric L. Charnov; James Bull

1977-01-01

234

Sex chromosomes and brain gender  

Microsoft Academic Search

In birds and mammals, differences in development between the sexes arise from the differential actions of genes that are encoded on the sex chromosomes. These genes are differentially represented in the cells of males and females, and have been selected for sex-specific roles. The brain is a sexually dimorphic organ and is also shaped by sex-specific selection pressures. Genes on

Arthur P. Arnold

2004-01-01

235

Male response to natural sex pheromone of Migdolus fryanus westwood (Coleoptera: Cerambycidae) females as affected by daily climatic factors  

Microsoft Academic Search

Males of the sugarcane borer,Migdolus fryanus (Coleoptera: Cerambycidae), are attracted to females by means of a sex pheromone. Mating usually occurs during a few days from October to March under field conditions in São Paulo State, Brazil. This work reports on mating of this species as affected by daily climatic factors, during a single nuptial flight. Maximum male capture by

José Maurício S. Bento; Terezinha M. C. Lucia; Rosa T. S. Frighetto

1993-01-01

236

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

237

A profile of clients of male sex workers in Córdoba, Argentina.  

PubMed

This paper provides a profile of clients seen by male sex workers (MSWs) in Córdoba, Argentina. Thirty-two MSWs completed a diary after each paid sexual encounter with a client over a two-week period. The results show that 254 commercial sex encounters were reported. More than half of these encounters were with first time clients. The most common source of recruiting clients was advertisements followed by street contact. The majority of the clients were aged in their 30s or 20s, and identified as 'middle class' and 'bisexual' or 'gay'. In the majority of the encounters, alcohol or drugs were not used by clients, and in about less than half of the cases, the MSWs had some personal tracing information about the client. Most of the clients indicated to the MSW what sexual activity they wanted and unsafe anal sex was requested in a minority (6%) of the encounters. While most workers reported having no or little attraction to the client, most indicated that they would serve the client again. The implications of the results for public health education and further research are discussed. PMID:15075022

Mariño, Rodrigo; Minichiello, Victor; Disogra, Carlos

2004-04-01

238

MDC1 directs chromosome-wide silencing of the sex chromosomes in male germ cells.  

PubMed

Chromosome-wide inactivation is an epigenetic signature of sex chromosomes. The mechanism by which the chromosome-wide domain is recognized and gene silencing is induced remains unclear. Here we identify an essential mechanism underlying the recognition of the chromosome-wide domain in the male germline. We show that mediator of DNA damage checkpoint 1 (MDC1), a binding partner of phosphorylated histone H2AX (?H2AX), defines the chromosome-wide domain, initiates meiotic sex chromosome inactivation (MSCI), and leads to XY body formation. Importantly, MSCI consists of two genetically separable steps. The first step is the MDC1-independent recognition of the unsynapsed axis by DNA damage response (DDR) factors such as ataxia telangiectasia and Rad3-related (ATR), TOPBP1, and ?H2AX. The second step is the MDC1-dependent chromosome-wide spreading of DDR factors to the entire chromatin. Furthermore, we demonstrate that, in somatic cells, MDC1-dependent amplification of the ?H2AX signal occurs following replicative stress and is associated with transcriptional silencing. We propose that a common DDR pathway underlies both MSCI and the response of somatic cells to replicative stress. These results establish that the DDR pathway centered on MDC1 triggers epigenetic silencing of sex chromosomes in germ cells. PMID:21536735

Ichijima, Yosuke; Ichijima, Misako; Lou, Zhenkun; Nussenzweig, André; Camerini-Otero, R Daniel; Chen, Junjie; Andreassen, Paul R; Namekawa, Satoshi H

2011-05-01

239

Meiotic sex chromosome inactivation is disrupted in sterile hybrid male house mice.  

PubMed

In male mammals, the X and Y chromosomes are transcriptionally silenced in primary spermatocytes by meiotic sex chromosome inactivation (MSCI) and remain repressed for the duration of spermatogenesis. Here, we test the longstanding hypothesis that disrupted MSCI might contribute to the preferential sterility of heterogametic hybrid males. We studied a cross between wild-derived inbred strains of Mus musculus musculus and M. m. domesticus in which sterility is asymmetric: F1 males with a M. m. musculus mother are sterile or nearly so while F1 males with a M. m. domesticus mother are normal. In previous work, we discovered widespread overexpression of X-linked genes in the testes of sterile but not fertile F1 males. Here, we ask whether this overexpression is specifically a result of disrupted MSCI. To do this, we isolated cells from different stages of spermatogenesis and measured the expression of several genes using quantitative PCR. We found that X overexpression in sterile F1 primary spermatocytes is coincident with the onset of MSCI and persists in postmeiotic spermatids. Using a series of recombinant X genotypes, we then asked whether X overexpression in hybrids is controlled by cis-acting loci across the X chromosome. We found that it is not. Instead, one large interval in the proximal portion of the M. m. musculus X chromosome is associated with both overexpression and the severity of sterility phenotypes in hybrids. These results demonstrate a strong association between X-linked hybrid male sterility and disruption of MSCI and suggest that trans-acting loci on the X are important for the transcriptional regulation of the X chromosome during spermatogenesis. PMID:23307891

Campbell, Polly; Good, Jeffrey M; Nachman, Michael W

2013-01-10

240

Sex pheromone of the bud borer Epinotia aporema: chemical identification and male behavioral response.  

PubMed

Epinotia aporema (Walsingham) is a Neotropical pest of legumes in southern South America. Its importance has increased during the last decade owing to the significant growth of soybean production in the region. Monitoring of E. aporema is difficult due to the cryptic behavior of the larvae, and hence, chemical control is carried out preventively. We analyzed the female-produced sex pheromone so as to develop monitoring traps and explore pheromone-based control methods. We analyzed pheromone gland extracts by combined chromatographic, spectrometric, and electrophysiological methods. Based on the comparison of retention indices, mass spectra, and electroantennogram (EAD) activity of the insect-produced compounds with those of synthetic standards, we identified two EAD-active compounds, (Z,Z)-7,9-dodecadienol and (Z,Z)-7,9-dodecadienyl acetate (15:1 ratio), as sex pheromone components of E. aporema. We also studied the behavior of males in wind tunnel tests using virgin females and different combinations of synthetic standards (15:1, 1:1, and 1:0 alcohol/acetate) as stimuli. A significantly greater percentage of males reached the chemical source with the 15:1 synthetic mixture than with any of the other treatments, indicating that these two compounds are pheromone components. PMID:19263170

Altesor, Paula; Rossini, Carmen; Zarbin, Paulo H G; González, Andrés

2009-03-05

241

Sex-specific antennal sensory system in the ant Camponotus japonicus: glomerular organizations of antennal lobes.  

PubMed

Ants have well-developed chemosensory systems for social lives. The goal of our study is to understand the functional organization of the ant chemosensory system based on caste- and sex-specific differences. Here we describe the common and sex-specific glomerular organizations in the primary olfactory center, the antennal lobe of the carpenter ant Camponotus japonicus. Differential labeling of the two antennal nerves revealed distinct glomerular clusters innervated by seven sensory tracts (T1-T7 from ventral to dorsal) in the antennal lobe. T7 innervated 10 glomeruli, nine of which received thick axon terminals almost exclusively from the ventral antennal nerve. Coelocapitular (hygro-/thermoreceptive), coeloconic (thermoreceptive), and ampullaceal (CO2-receptive) sensilla, closely appositioned in the flagellum, housed one or three large sensory neurons supplying thick axons exclusively to the ventral antennal nerve. These axons, therefore, were thought to project into T7 glomeruli in all three castes. Workers and virgin females had about 140 T6 glomeruli, whereas males completely lacked these glomeruli. Female-specific basiconic sensilla (cuticular hydrocarbon-receptive) contained over 130 sensory neurons and were completely lacking in males' antennae. These sensory neurons may project into T6 glomeruli in the antennal lobe of workers and virgin females. Serotonin-immunopositive neurons innervated T1-T5 and T7 glomeruli but not T6 glomeruli in workers and virgin females. Because males had no equivalents to T6 glomeruli, serotonin-immunopositive neurons appeared to innervate all glomeruli in the male's antennal lobe. T6 glomeruli in workers and virgin females are therefore female-specific and may have functions related to female-specific tasks in the colony rather than sexual behaviors. PMID:20437523

Nakanishi, Aki; Nishino, Hiroshi; Watanabe, Hidehiro; Yokohari, Fumio; Nishikawa, Michiko

2010-06-15

242

Genes and brain sex differences  

Microsoft Academic Search

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

Francisco J. Sánchez; Eric Vilain

2010-01-01

243

Responses of male and female mosquitoes to repellents in the World Health Organization insecticide irritability test system.  

PubMed

A study was conducted to compare responses of male and female Aedes aegypti (Linn.) and Aedes taeniorhynchus (Wiedemann) to 9 olfactory repellents in the World Health Organization insecticide irritability test system. An irritant insecticide (permethrin) and a control were included for comparison. Aedes aegypti exhibited significantly more takeoffs than Ae. taeniorhynchus, and female mosquitoes exhibited significantly more takeoffs than males. Permethrin induced significantly more takeoffs than the control, but olfactory repellents did not. Certain 2- and 3-factor interactions of test materials, species, and sexes were statistically significant. This study supports a previous conclusion that the World Health Organization test method does not measure contact repellency (irritancy) and olfactory repellency equally. PMID:10342270

Rutledge, L C; Echano, N M; Gupta, R K

1999-03-01

244

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

PubMed

Species that have temperature-dependent sex determination (TSD) often produce highly skewed offspring sex ratios contrary to long-standing theoretical predictions. This ecological enigma has provoked concern that climate change may induce the production of single-sex generations and hence lead to population extirpation. All species of sea turtles exhibit TSD, many are already endangered, and most already produce sex ratios skewed to the sex produced at warmer temperatures (females). We tracked male loggerhead turtles (Caretta caretta) from Zakynthos, Greece, throughout the entire interval between successive breeding seasons and identified individuals on their breeding grounds, using photoidentification, to determine breeding periodicity and operational sex ratios. Males returned to breed at least twice as frequently as females. We estimated that the hatchling sex ratio of 70:30 female to male for this rookery will translate into an overall operational sex ratio (OSR) (i.e., ratio of total number of males vs females breeding each year) of close to 50:50 female to male. We followed three male turtles for between 10 and 12 months during which time they all traveled back to the breeding grounds. Flipper tagging revealed the proportion of females returning to nest after intervals of 1, 2, 3, and 4 years were 0.21, 0.38, 0.29, and 0.12, respectively (mean interval 2.3 years). A further nine male turtles were tracked for short periods to determine their departure date from the breeding grounds. These departure dates were combined with a photoidentification data set of 165 individuals identified on in-water transect surveys at the start of the breeding season to develop a statistical model of the population dynamics. This model produced a maximum likelihood estimate that males visit the breeding site 2.6 times more often than females (95%CI 2.1, 3.1), which was consistent with the data from satellite tracking and flipper tagging. Increased frequency of male breeding will help ameliorate female-biased hatchling sex ratios. Combined with the ability of males to fertilize the eggs of many females and for females to store sperm to fertilize many clutches, our results imply that effects of climate change on the viability of sea turtle populations are likely to be less acute than previously suspected. PMID:20497201

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

2010-12-01

245

Decreased serum chemerin levels in male Japanese patients with type 2 diabetes: sex dimorphism.  

PubMed

Chemerin, a recently discovered adipocytokine plays an important role in obesity and obesity-associated metabolic complications. However, the role of chemerin in the pathogenesis of type 2 diabetes mellitus (T2DM) has not fully been elucidated. We compared the serum chemerin levels and metabolic parameters between 88 control subjects, 86 patients with metabolic syndrome (MS), and 147 patients with T2DM in a Japanese population and further analyzed their correlation. Enzyme-linked immunosorbent assay was used to measure the serum chemerin levels. The chemerin levels were significantly higher in male than in female control subjects (p < 0.005), with significant decreases in patients with T2DM compared with those with MS and control subjects (164.9 ± 6.3 ng/mL vs. 209.8 ± 7.7 and 218.7 ± 7.3 ng/mL; p < 0.0001 vs. p < 0.0001, respectively) but no significant differences in female subjects. The multiple regression analysis revealed that the chemerin levels negatively correlated with the fasting glucose and HbA1c levels in total and male subjects. In the patients with T2DM, the chemerin levels negatively correlated with fasting glucose and high-density lipoprotein cholesterol but positively correlated with body mass index (BMI), and total cholesterol and triglyceride levels. The negative correlation between the chemerin and fasting glucose levels remained significant after adjustment for age, sex, and BMI in the total and male subjects and those with T2DM. These results suggest the role of chemerin in sex dimorphism and a potential link between chemerin levels and T2DM pathogenesis in a Japanese population. PMID:22986456

Takahashi, Michiko; Inomata, Sumie; Okimura, Yasuhiko; Iguchi, Genzo; Fukuoka, Hidenori; Miyake, Kazuaki; Koga, Daisuke; Akamatsu, Suguru; Kasuga, Masato; Takahashi, Yutaka

2012-10-13

246

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?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

2013-06-14

247

Effects of zinc on male sex hormones and semen quality in rats.  

PubMed

This study assessed the effects of zinc on male sex hormones and semen quality in male albino wistar rats. Forty rats weighing between 150- 210g, grouped into 5 of 8 rats each, were used for the research that lasted for six weeks. Group I, the control group, received normal rat chow and water ad libitum. The four test groups II-V, received 20g, 40g, 60g and 80g of zinc sulphate mixed with their rat chow respectively in addition to water for six weeks. Blood samples were collected and assayed for Luteinizing hormone (LH), follicle stimulating hormone (FSH), Prolactin (PL), testosterone (T), progesterone and oestradiol. Semen was also analysed for sperm motility, sperm count and morphology. Results showed statistically significant decrease in serum levels of follicle stimulating hormone (FSH) (p< 0.05) in groups II and IV with mean values of 0.10±0.00 and 1.20±0.00 respectively when compared with the control (1.10±0.10). The results also revealed statistically significant increase in the serum levels of testosterone in groups II, III and IV with mean values of 3.60±1.40, 4.5±0.30 and 0.80±0.70 respectively when compared with the control with a value of 0.35±0.15. The increase in testosterone levels were dose dependent as there were consistent increment in groups II and III after which the levels decreased with increasing zinc concentrations. There was statistically significant dose dependent decrease in sperm motility and morphology in the test groups compared with the control (p<0.05). In conclusion, zinc sulphate has some significant positive effects on male sex hormones and sperm quality at doses within physiological levels but harmful at higher doses. PMID:23955401

Egwurugwu, J N; Ifedi, C U; Uchefuna, R C; Ezeokafor, E N; Alagwu, E A

2013-06-30

248

Defensive compounds and male-produced sex pheromone of the stink bug, Agroecus griseus.  

PubMed

Agroecus griseus is a serious corn pest in Brazil. Contents of the dorsal abdominal glands (DAGs) in nymphs, and the metathoracic gland (MTG) in adults of this species were characterized and quantified. Compounds found were similar to those of other Pentatomidae species and included aliphatic hydrocarbons, aldehydes, oxo-alkenals, and esters. However, two compounds were found in the MTG that have not been described previously for this family. Mass spectrometry, infrared spectroscopy, and gas chromatographic analysis using coinjection with authentic standards confirmed the identities of the compounds as enantiopure (S)-2-methylbutyl acetate and 3-methyl-2-butenyl acetate. The five nymphal instars showed significantly different ratios of components, mainly between those of the first and later instars. No significant differences were detected in MTG contents between sexes. Gas chromatography (GC) analysis of aeration extracts of males and females showed the presence of a compound released exclusively by males. Gas chromatography - electroantennographic detection (GC-EAD) assays indicated that the male-specific compound is bioactive in females, suggesting the presence of an attractant pheromone. The mass spectrum and infrared data for this compound matched with methyl 2,6,10-trimethyltridecanoate, a sex pheromone component previously detected in the stink bugs, Euschistus heros and E. obscurus. The synthetic standard coeluted with the natural pheromone on two different GC stationary phases, confirming the proposed structure. Y-tube olfactometer assays showed that the synthetic standard was strongly attractive to females, and GC-EAD tests produced responses with antennae from females similar to those of the natural pheromone. PMID:22914958

Fávaro, Carla F; Santos, Tatiana B; Zarbin, Paulo H G

2012-08-23

249

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

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

2013-01-01

250

Factors associated with sex trade involvement among male participants in a prospective study of injection drug users  

PubMed Central

Objectives: While much research to date has examined female sex trade work, little has been done to evaluate factors associated with male sex trade involvement or to assess their health service needs. This is particularly true for male sex trade workers who are also injection drug users (IDUs). Therefore, the present analyses were undertaken to evaluate factors associated with sex trade work in a prospective cohort study of male IDUs. Methods: We identified factors associated with sex trade involvement among male participants enrolled in the Vancouver Injection Drug Users Study (VIDUS). Since serial measures for each individual were available at semiannual intervals, variables potentially associated with sex trade involvement were evaluated with adjusted odds ratios (AOR) and 95% confidence intervals (CI) computed using generalised estimating equations (GEE). Results: Between 1996 and 2003, 995 male IDUs were enrolled into the VIDUS cohort among whom 108 (11%) reported being involved in the sex trade at enrolment and 102 (10%) individuals initiated sex trade involvement during the follow up period. In multivariate analyses, factors independently associated with sex trade involvement included HIV positive serostatus (AOR: 1.77 (95% CI: 1.44 to 2.17)), daily cocaine injection (AOR: 1.37 (95% CI: 1.11 to 1.70)), daily crack smoking (AOR: 1.36 (95% CI: 1.07 to 1.72)), borrowing syringes (AOR: 1.73 (95% CI: 1.32 to 2.25)), and inconsistent use of condoms with casual sexual partners (AOR 0.66, CI 0.53 to 0.82). We also found that male sex trade workers were more likely to report having sought but been unable to access substance abuse treatment (AOR: 1.28 (95% CI: 0.98 to 1.67); p = 0.076). Conclusions: Males involved in the sex trade in this setting have higher levels of HIV infection and engage in risky injection behaviours at an elevated rate. Since these behaviours have major implications for HIV acquisition and public health, prevention efforts and targeted provision of addiction treatment to this population should be expanded.

Kuyper, L; Lampinen, T; Li, K; Spittal, P; Hogg, R; Schechter, M; Wood, E

2004-01-01

251

Unprotected anal intercourse behavior and intention among male sex workers in Shenzhen serving cross-boundary male clients coming from Hong Kong, China - prevalence and associated factors.  

PubMed

The HIV epidemic among men who have sex with men (MSM) in China is becoming very serious. Unprotected anal intercourse (UAI) among MSM during cross-boundary commercial sex spread HIV across geographic areas. This study interviewed 186 Chinese male sex workers (MSW) in Shenzhen, China, serving cross-boundary Hong Kong male clients; 49.5% had had UAI with their Hong Kong male clients (last six months) and 24.2% intended to do so (future six months). Multivariate analyses showed that perceived efficacy of condom use for HIV prevention, perceived prevalence of HIV among Hong Kong MSM (>4%), and perceived ability to convince Hong Kong male clients to use condoms during anal sex were associated with lower likelihoods of UAI with such clients (OR = 0.04-0.09); the reverse was true for those who left the decision of condom use to their Hong Kong male clients (OR = 6.44). Perceived condom efficacy, self-efficacy in protection against HIV infection, and perceived control over condom use were associated with an intention for UAI (OR = 0.06-80.44). Adjusting for background variables, the scales representing contextual (Clients Characteristics, Substance Use, or Environmental Influences) and affective factors (Fear of Diseases) were associated with UAI (adjusted OR = 0.44-32.61). Except the Fear of Diseases scale, other scales were associated with an intention for UAI (adjusted OR = 4.59-43.32). MSW are at high risk of HIV transmission. Various factors are associated with UAI with male cross-boundary clients; these factors and the context of sex work need to be considered when designing HIV prevention programs. PMID:21745021

Lau, Joseph T F; Cai, Wende; Tsui, Hi Yi; Chen, Lin; Cheng, Jinquan; Lin, Chunqing; Gu, Jing; Hao, Chun

2011-07-11

252

Sex Education for Male Adolescent Sex Offenders in a Group Setting Led by General Psychiatry Residents: A Literature Review and Example in Practice  

ERIC Educational Resources Information Center

Male adolescents have been credited with a significant percentage of sex crimes in recent years. They are a heterogeneous population with offenses spanning the same range found among adult offenders. A lack of interpersonal social skills relevant to intimate relationships and inaccurate knowledge regarding appropriate sexual behaviors contribute…

Dwyer, R. Gregg; Boyd, Mary S.

2009-01-01

253

1-Tridecene—male-produced sex pheromone of the tenebrionid beetle Parastizopus transgariepinus  

NASA Astrophysics Data System (ADS)

Males of the genus Parastizopus (Coleoptera: Tenebrionidae) exhibit a special pheromone-emitting behaviour. They do a headstand, expose the aedeagus and remain in this posture for a few seconds. The pheromone emitted by P. transgariepinus was collected by solid-phase micro-extraction (100 ?m polydimethylsiloxane fibre) and identified as 1-tridecene by gas chromatography/mass spectrometry. Presumably, this compound originates from the aedeagal gland, a special feature in Parastizopus, as 1-tridecene is the main compound in the gland reservoirs (23.6 ± 3.8%), accompanied by various less volatile fatty acid esters (25.2 ± 2.0%) and hydrocarbons (51.2 ± 5.7%). 1-Tridecene is also part of the pygidial defensive secretion of both sexes, together with other 1-alkenes, monoterpene hydrocarbons and 1,4-benzoquinones, but as none of these other compounds was detected during calling, the pygidial gland could be ruled out as pheromone source. Extracts of the aedeagal gland reservoirs and the pygidial defensive secretion contained comparable amounts of 1-tridecene, 1.24 ± 0.41 and 1.88 ± 0.54 ?g/male, respectively. Chemo-orientation experiments using a servosphere showed that 1 ?g of 1-tridecene was attractive to females but not to males.

Geiselhardt, Sven; Ockenfels, Peter; Peschke, Klaus

2008-03-01

254

Male-produced sex pheromone of the cerambycid beetle Hedypathes betulinus: chemical identification and biological activity.  

PubMed

We identified, synthesized, determined the diel periodicity of release, and tested the bioactivity of components of the male-produced sex pheromone of Hedypathes betulinus (Coleoptera: Cerambycidae: Lamiinae). Gas chromatographic-mass spectrometric analysis of headspace volatiles from adult beetles showed three male-specific compounds, which were identified as (E)-6,10-dimethyl-5,9-undecadien-2-yl acetate (major component), (E)-6,10-dimethyl-5,9-undecadien-2-one (geranylacetone), and (E)-6,10-dimethyl-5,9-undecadien-2-ol. Release of these chemicals was dependent on time of the photoperiod and presence of the host plant. Pheromone release took place primarily during the photophase, with maximum release occurring between 4 and 6 hr after the onset of photophase. The amount of pheromone released by males was much greater when they were in the presence of their host plant than when they were not. In Y-tube olfactometer tests, a ternary mixture of the compounds was attractive to female beetles, although the individual compounds were not attractive by themselves. Addition of volatiles from the host plant greatly increased the attractiveness of the ternary pheromone mixture and of the major pheromone component alone. PMID:20809143

Fonseca, Marcy G; Vidal, Diogo M; Zarbin, Paulo H G

2010-08-31

255

Biased sex ratio and low population density increase male mating success in the bug Nysius huttoni (Heteroptera: Lygaeidae)  

NASA Astrophysics Data System (ADS)

Demographic factors such as operational sex ratio (OSR) and local population density (LPD) are temporally and spatially dynamic in the natural environment but the influence of these variables on male mating success and the mechanisms behind it are still poorly understood and highly controversial. Here, we manipulated the OSR and LPD of a seed bug, Nysius huttoni, and carried out a series of mating trials to test how these variables affected male mating success. The two demographic factors had no significant interactions, suggesting that they affect male mating success independently in N. huttoni. In this species male mating success was significantly higher in both male- and female-biased OSR than in even OSR. It is suggested that, in male-biased OSR, the increased intensity of competition and interference does not result in lower male mating success; rather, males may make more effort in courting and females may have more chance to encounter better males, resulting in higher male mating success. In female-biased OSR, females may become less choosy and less likely to reject male mating attempt, leading to the higher male mating success. Lower male mating success in N. huttoni in high LPD may be due to increased interference between males and/or delayed female receptiveness for mating. OSR had a stronger effect on male mating success than LPD in N. huttoni, suggesting that OSR and LPD affect mating success in different ways and intensities.

Wang, Qiao; He, Xiong Zhao; Yang, Linghuan; Hedderley, Duncan; Davis, Lorraine K.

2009-01-01

256

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

SciTech Connect

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 resemblance to D-glucose due to the presence of sugar moiety in its structure. Pancreatic {beta}-cells mainly contain GLUT1 and GLUT2 glucose transporters. Possibly due to structural resemblance, STZ and D-glucose, share a common recognition site for entry into the {beta}-cells. The objective of the present study is to evaluate the effect of D-glucose on STZ-induced toxicity in accessory sex organs of male rats. Animals were kept on overnight fasting. One group received vehicle and served as negative control, while all other groups were given STZ (45 mg/kg). Animals that received only STZ served as positive control. The effect of D-glucose was studied on STZ treated animals with different dosage of D-glucose (250, 500, 1000 and 2000 mg/kg). Restoration of body weight, plasma glucose and plasma insulin was evident only at 1000 and 2000 mg/kg of D-glucose. The protective effect of D-glucose is evident only when it is administered simultaneously with STZ. In the present investigation, we report that simultaneous administration of D-glucose along with STZ ameliorates STZ-induced toxicity. This is evident from the restoration of accessory sex organ's weight, cellular morphology as well as insulin level.

Vikram, A.; Tripathi, D.N.; Ramarao, P. [Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research, Sector-67, S.A.S. Nagar, Punjab-160062 (India); Jena, G.B. [Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research, Sector-67, S.A.S. Nagar, Punjab-160062 (India)], E-mail: gbjena@gmail.com

2008-01-01

257

Gender performances as spatial acts: (fe)male Thai migrant sex workers in Denmark  

Microsoft Academic Search

The objective of this article is to investigate how Thai migrant sex workers in Denmark understand normative heterosexuality and femininity\\/masculinity as they are reproduced in the Danish sex industry. To do so I analyse the ways that gender plays a part in sex work and the ways in which sex work plays a significant role in how Thai migrant sex

Marlene Spanger

2011-01-01

258

Sex differences in gender characteristics of Australian nurses and male engineers: a comparative cross-sectional survey.  

PubMed

There continue to be assumptions within the nursing literature that nursing is synonymous with a feminine sex role identity. A comparative cross-sectional survey consisting of the Bem Sex Role Inventory and the Australian sex role scale was used to determine sex difference in gender characteristics of Australian nurses and with male engineers. A statistically significant difference in femininity was found between all the samples (F((2,908)) = 20.24, p < 0.00001; F((2,908)) = 60.13, p < 0.00001). A statistical difference in masculinity was found between female nurses and the two male samples on the two masculine scales (F((2,908)) = 12.48, p < 0.000001; F((2,908)) = 6.94, p = 0.001). Path analysis found strong significant direct relationships between the samples and expressive orientation (t = 27.67) and self display (t = 12.42). Whilst differences in expressive characteristics were found between male and female nurses, a similar difference was found between male nurses and male engineers, supporting the notion that male nurses perceive themselves as having feminine characteristics essentially required for nursing. PMID:21955265

J Fisher, Murray

2011-08-01

259

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.

Rekers, George A.; Lovaas, O. Ivar

1974-01-01

260

Behavioral treatment of deviant sex-role behaviors in a male child.  

PubMed

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, G A; Lovaas, O I

1974-01-01

261

Understanding the diversity of male clients of sex workers in China and the implications for HIV prevention programmes  

Microsoft Academic Search

Male clients of sex workers have been overlooked in China's HIV prevention efforts. This study aims to examine men's practices and attitudes toward extramarital sexual relationships, motivations for visiting female sex workers (FSWs), perceptions of sexually transmitted infection (STI)\\/HIV risk and risk prevention strategies used. One hundred and eighty-six clients of FSWs with varying socio-economic statuses were interviewed in different

Yingying Huang; Suzanne Maman; Suiming Pan

2012-01-01

262

On Same-Sex Sexual Behaviors Among Male Bachelors in Rural China: Evidence From a Female Shortage Context  

Microsoft Academic Search

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

Xueyan Yang; Isabelle Attané; Shuzhuo Li; Qunlin Zhang

2012-01-01

263

Non-monogamy and sexual relationship quality among same-sex male couples.  

PubMed

Relationship arrangements about sex with outside partners are common among gay couples, and meaningful distinctions in psychological and behavioral health correlates have been found among nonmonogamous agreement types. The goal of this study was to investigate the relationship between sexual agreements and partners' sexual relationship quality. Data were collected from both members of 161 gay male couples (n = 322 individuals). Couples were categorized as monogamous (52.8%), open (13.0%), monogamish (14.9%), and discrepant (19.3%). We used the actor-partner interdependence model (APIM) to assess associations of relationship arrangement with four aspects of sexual relationship quality: sexual satisfaction, sexual communication, sexual jealousy, and the occurrence of at-least weekly sex between main partners. We found that sexual arrangements were not associated with sexual satisfaction, communication, or frequency. However, monogamous men reported significantly higher levels of sexual jealousy. Our findings indicate that gay men engage in a range of relationship agreements, and nonmonogamous agreements are associated with levels of sexual relationship quality equivalent to monogamous agreements. PMID:22906124

Parsons, Jeffrey T; Starks, Tyrel J; Gamarel, Kristi E; Grov, Christian

2012-08-20

264

Prevalence and correlates of non-disclosure of HIV serostatus to sex partners among HIV-infected female sex workers and HIV-infected male clients of female sex workers in India.  

PubMed

This study examines non-disclosure of HIV serostatus to sex partners among HIV-infected adults involved with transactional sex in Mumbai, India. Surveys were conducted with HIV-infected female sex workers (n = 211) and infected male clients (n = 205) regarding HIV knowledge, awareness of sex partners' HIV serostatus, alcohol use, transactional sex involvement post-HIV diagnosis and non-disclosure of HIV serostatus. Gender-stratified multiple logistic regression models were used for analysis. Non-disclosure of one's serostatus to all sex partners was reported by almost three-fifths of females and two-fifths of males. Predictors of non-disclosure included lack of correct knowledge about HIV and no knowledge of sex partners' HIV serostatus. Among females, recent alcohol consumption also predicted non-disclosure. Among males, 10 + paid sexual partners in the year following HIV diagnosis predicted non-disclosure. Secondary HIV prevention efforts in India require greater focus on HIV disclosure communication and integrated alcohol and sexual risk reduction. PMID:22810892

Saggurti, Niranjan; Raj, Anita; Mahapatra, Bidhubhusan; Cheng, Debbie M; Coleman, Sharon; Bridden, Carly; Battala, Madhusudana; Silverman, Jay G; Pardeshi, Manoj H; Samet, Jeffrey H

2013-01-01

265

H2AX is required for chromatin remodeling and inactivation of sex chromosomes in male mouse meiosis.  

PubMed

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 implicated in DNA repair, accumulates in the sex body in a manner independent of meiotic recombination-associated double-strand breaks. Here we show that the X and Y chromosomes of histone H2AX-deficient spermatocytes fail to condense to form a sex body, do not initiate MSCI, and exhibit severe defects in meiotic pairing. Moreover, other sex body proteins, including macroH2A1.2 and XMR, do not preferentially localize with the sex chromosomes in the absence of H2AX. Thus, H2AX is required for the chromatin remodeling and associated silencing in male meiosis. PMID:12689589

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

2003-04-01

266

Brain Organization in a Reptile Lacking Sex Chromosomes: Effects of Gonadectomy and Exogenous Testosterone  

Microsoft Academic Search

In mammals, males and females differ both genetically and hormonally, making it difficult to assess the relative contributions of genetic constitution and fetal environment in the process of sexual differentiation. Many reptiles lack sex chromosomes, relying instead on the temperature of incubation to determine sex. In the leopard gecko (Eublepharis macularius), an incubation temperature of 26°C produces all females, whereas

David Crews; Patricia Coomber; Ryan Baldwin; Nilofer Azad; Francisco Gonzalez-Lima

1996-01-01

267

Effects of helper sex, recipient attractiveness, and recipient femininity on helping behavior in organizations  

Microsoft Academic Search

Purpose – This paper aims to investigate the effects of sex, attractiveness, and sex role of helping behavior in a simulated work situation. Design\\/methodology\\/approach – A 2 × 2×2 randomized experimental design was used, in which 81 participants worked on cooperative task building models. Male or female participants were asked for help from a female confederate who was either high

Deborah A. Danzis; Eugene F. Stone-Romero

2009-01-01

268

Application of condoms on male clients by female sex workers in Yerevan, Armenia: prevalence and correlates.  

PubMed

This study sought to assess the prevalence of consistent condom application on male clients by female sex workers (FSWs) in Armenia and its association with demographic, psychosocial and behavioural factors. In this cross-sectional study, 120 street-based FSWs aged 20-52 completed an interviewer-administered questionnaire. The primary outcome measure was consistent application of condoms by FSWs on their male clients. A total of 21.7% of participants reported consistently applying condoms on clients. Logistic regression analysis demonstrated that higher condom use self-efficacy (Adjusted Odds Ratio, AOR=1.1; p=0.01), lower perceived condom use barriers (AOR=0.9; p=0.04) and not using douching as a method to prevent STI/HIV (AOR=4.8; p=0.04) significantly predicted consistent condom application. Higher HIV/AIDS knowledge was a marginally significant predictor of condom application (AOR=1.3; p=0.05). Future interventions should address these modifiable factors to encourage FSWs to apply condoms on clients themselves, which may reduce condom failure and exposure to HIV transmission. PMID:21535906

Darbinyan, Nelli; Lang, Delia L; Diclemente, Ralph J; Joseph, Jesse B; Markosyan, Karine

2011-05-03

269

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

270

Paneth cells in colonic adenomas: association with male sex and adenoma burden.  

PubMed

Paneth cells have been reported in colorectal adenomas and adenocarcinomas; however, the frequency of colonic Paneth cell-containing adenomas is unknown as are their clinicopathologic features. A total of 152 consecutive colorectal adenomas from 103 patients (57 males and 46 females) were reviewed. The frequency of Paneth cells in this cohort of adenomas was determined and correlated with patient demographics. Twenty-six adenomas (17.1%) from 22 (21.4%) patients harbored Paneth cells, which were not limited to the base of the crypts but aberrantly located throughout the crypts. Patient age, adenoma size, villous features, and grade of dysplasia were not different between these 2 groups. Not surprisingly, Paneth cell-containing adenomas were more likely to occur in the proximal colon (84.6% vs. 55.6%; P=0.006). There was a strong association between male sex and Paneth cell-containing adenomas, as 23 of 26 (88.5%) of these adenomas occurred in male individuals compared with 71 of 126 (56.3%) non-Paneth cell-containing adenomas (P=0.002). Upon review of an additional 460 adenomas from 200 patients with varying numbers of adenomas (68 with 1 adenoma, 68 with 2 adenomas, and 64 with 3 or more adenomas), the risk of harboring synchronous adenomas was associated with villous morphology, proximal location, and the presence of a Paneth cell-containing adenoma. Thus, the presence of a Paneth cell-containing adenoma may be a marker for increased risk of developing colorectal neoplasia. PMID:23232853

Pai, Rish K; Rybicki, Lisa A; Goldblum, John R; Shen, Bo; Xiao, Shu-Yuan; Liu, Xiuli

2013-01-01

271

A Protective Effect of Circumcision Among Receptive Male Sex Partners of Indian Men Who Have Sex with Men  

Microsoft Academic Search

The role of circumcision in the transmission of human immunodeficiency virus (HIV) among men who have sex with men (MSM) in\\u000a resource restricted regions is poorly understood. This study explored the association of circumcision with HIV seroprevalence,\\u000a in conjunction with other risk factors such as marriage and sex position, for a population of MSM in India. Participants (n = 387) were recruited

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

272

Psychosexual and social-cognitive correlates of sexual risk behavior among male clients of female sex workers in Tijuana, Mexico  

Microsoft Academic Search

Male clients of female sex workers (FSWs) may act as a bridge to the general population contributing to the spread of HIV and other sexually transmitted infections (STIs) in the USA and Mexico. This study used cross-sectional data to identify psychosexual and social-cognitive factors associated with sexual risk behavior in a bi-national sample of 300 male clients of FSWs recruited

Shirley J. Semple; Steffanie A. Strathdee; Manuel Gallardo Cruz; Angela Robertson; Shira Goldenberg; Thomas L. Patterson

2010-01-01

273

Effects of different calcineurin inhibitors on sex hormone levels in transplanted male patients.  

PubMed

Hormonal abnormalities in male patients with end-stage renal diseases are primarily organic and related to uremia as well as the other comorbid factors that frequently contribute to chronic renal failure and concomitant drug administration. The restoration of hormonal profiles after successful renal transplantation is still controversial. Immunosuppressive drugs may influence hormonal profiles. Our cross-sectional study of 37 male kidney transplant recipients investigated two groups according to their calcineurin inhibitor therapy, namely 21 cyclosporine versus 16 tacrolimus patients. The two groups were matched for age, graft function, mean duration of dialysis before transplantation, and duration of follow-up after transplantation. There was no statistical significant difference in baseline circulating levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone (TTE), and prolactin (PRL) between the two groups. We found that calcineurin inhibitors have favorable effects on sexual hormone levels of male renal transplant patients and that there is no difference in baseline hormone levels between cyclosporine- and tacrolimus-treated male patients. PMID:15013339

Kantarci, G; Sahin, S; Uras, A R; Ergin, H

274

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 ...

275

Prevalence of needle sharing, commercial sex behaviors and associated factors in Chinese male and female injecting drug user populations.  

PubMed

The objective of this study is to investigate prevalence and associated factors of commercial sex behaviors and condom use at commercial sex, as well as prevalence of needle sharing among injecting drug users (IDUs) in China. In this study, 162 IDUs were recruited by peer workers in Dazhou, Sichuan and were anonymously interviewed by using a structured questionnaire. Univariate and multivariate logistic regression analyses were performed and interaction between gender and the studied independent variables were tested for significance. The results of this study showed that the male and female respondents, respectively 11.7 and 16.9% were HIV positive; 34.0 and 40.7% engaged in commercial sex and 23.3 and 11.9% shared needles with others in the last six months. Percent using a condom in the last episode of commercial sex was 30.3% for males and 76.2% for females. The multivariate analyses showed that higher drug dosage (OR=0.3, 95% CI: 0.1-0.9) and reduced sexual drive (OR=0.3, 95% CI: 0.1-0.9) were associated with lower likelihood for commercial sex among male IDUs while higher drug dosage (OR=9.1, 95% CI: 1.0-86.0), perceived difficulty in finding a job (OR=5.1, 95% CI: 1.3-20.1) and lack of family support (OR=4.0, 95% CI: 1.1-15.4) were associated with commercial sex among female IDUs. Similarly, unknown HIV status (OR=8.2, 95% CI: 1.7-9.2) and having a regular sex partner (OR=3.7, 95% CI: 1.3-10.9) was associated with needle sharing. It is concluded that male and female IDUs were sexually active and often engaged in commercial sex. Drug dosage and reduced sexual drive were relevant but did not stop commercial sex behaviors. More supportive social environment is required to prevent female IDUs to enter sex work. PMID:19085218

Gu, Jing; Wang, Renfan; Chen, Hongyao; Lau, Joseph T F; Zhang, Linglin; Hu, Xianyou; Lei, Zhangquan; Li, Zhenglin; Cai, Hua; Wang, Tao; Tsui, Hiyi

2009-01-01

276

Have Sex Differences in Spatial Ability Evolved from Male Competition for Mating and Female Concern for Survival?  

ERIC Educational Resources Information Center

Drawing on the theoretical and empirical foundations of two evolutionary models, we argue that, among humans and other mammals, a twofold selection process would parsimoniously account for sex-linked advantages in spatial contexts. In males, a superiority for both solving navigation-related spatial problems and understanding physical principles…

Ecuyer-Dab, Isabelle; Robert, Michele

2004-01-01

277

Sex differences in (+)amphetamine and (+)-methamphetamine-induced behavioral response in male and female Sprague–Dawley rats  

Microsoft Academic Search

(+)-Methamphetamine (METH) and (+)-amphetamine (AMP) are structurally similar drugs that are reported to induce similar pharmacological effects in rats of the same sex. Because pharmacokinetic data suggest female rats should be more affected than males, the current studies sought to test the hypothesis that the behavioral and temporal actions of METH and AMP should be greater in female Sprague–Dawley rats

Alessandra Milesi-Hallé; Donald E. McMillan; Elizabeth M. Laurenzana; Kelly A. Byrnes-Blake; S. Michael Owens

2007-01-01

278

Perception of self and others in male sex offenders against children: Schema content and its relation to criminal sexual behaviour  

Microsoft Academic Search

Thirty-four civilly committed male sex offenders against children (SOs) chose from a list of traits to describe self, mother, father, best friend, past lover, victim and therapist. Cluster analysis (INDCLAS) uncovered five patterns (i.e. schemas) in Sos’ social perception data: “sexual lover” (past lover described as sexual, arousing, etc. as well as anxious, lonely and worried), “benevolent parent” (mother and

Warren A. Reich; Uri Amit; Harold I. Siegel

2009-01-01

279

WHY DO SOME SOCIAL INSECT QUEENS MATE WITH SEVERAL MALES? TESTING THE SEX-RATIO MANIPULATION HYPOTHESIS IN LASIUS NIGER  

Microsoft Academic Search

Although multiple mating most likely increases mortality risk for social insect queens and lowers the kin benefits for nonreproductive workers, a significant proportion of hymenopteran queens mate with several males. It has been suggested that queens may mate multiply as a means to manipulate sex ratios to their advantage. Multiple paternity reduces the extreme relatedness value of females for workers,

Else J. Fjerdingstad; Pia J. Gertsch; Laurent Keller

2002-01-01

280

Male-Biased Sex Ratios of Fish Embryos near a Pulp Mill: Temporary Recovery after a Short-Term Shutdown  

Microsoft Academic Search

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

D. G. Joakim Larsson; Lars Förlin

281

Frequency and inheritance of non-male producing clones in Daphnia magna: evolution towards sex specialization in a cyclical parthenogen?  

PubMed

In Daphnia (Cladocera, Crustacea), parthenogenetic reproduction alternates with sexual reproduction. Individuals of both sexes that belong to the same parthenogenetic line are genetically identical, and their sex is determined by the environment. Previously, non-male producing (NMP) genotypes have been described in species of the Daphnia pulex group. Such genotypes can only persist through phases of sexual reproduction if they co-occur with normal (MP) genotypes that produce both males and females, and thus the breeding system polymorphism is similar to gynodioecy (coexistence of females with hermaphrodites), which is well known in plants. Here we show that the same breeding system polymorphism also occurs in Daphnia magna, a species that has diverged from D. pulex more than 100 MY ago. Depending on the population, between 0% and 40% of D. magna females do not produce males when experimentally exposed to a concentration of the putative sex hormone methyl farnesoate that normally leads to male-only clutches. Natural broods of these NMP females never contained males, contrasting with high proportions of male offspring in MP females from the same populations. The results from a series of crossing experiments suggest that NMP is determined by a dominant allele at a single nuclear locus (or a several closely linked loci): NMP × MP crosses always yielded 50% NMP and 50% MP offspring, whereas MP × MP crosses always yielded 100% MP offspring. Based on cytochrome c oxidase subunit I-sequences, we found that NMP genotypes from different populations belong to three highly divergent mitochondrial lineages, potentially representing three independent evolutionary origins of NMP in D. magna. Thus, the evolution of NMP genotypes in cyclical parthenogens may be more common than previously thought. Moreover, MP genotypes that coexist with NMP genotypes may have responded to the presence of the latter by partially specializing on male production. Hence, these populations of D. magna may be a model for an evolutionary transition from a purely environmental to a partially genetic sex determination system. PMID:21599772

Galimov, Y; Walser, B; Haag, C R

2011-05-23

282

The cost of sex revisited: effects of male gamete output of hermaphrodites that are asexual in their female capacity.  

PubMed

The genetic cost of sexual reproduction has been attributed to two causes in mathematical formulations: male function or genome dilution. We develop and analyse a genetic model that shows that both costs occur, depending upon the conditions. The model differs from previous formulations in that the level of output and fertilization success of male gametes produced by hermaphrodites that are asexual in their female function (henceforth "parthenogenetic hermaphrodites") are treated as variables, rather than constants fixed at 0 or 1, as has previously been the case. By expressing the cost of sex in terms of per capita egg loss of sexual individuals and parthenogenetic hermaphrodites, we partition the cost into components due to male function and genome dilution. Which component dominates the cost of sex depends upon the relative male gamete output of the parthenogenetic hermaphrodites. The cost of sex is observed to increase, or remain unchanged in some marginal cases, with increases in (i) frequency of parthenogenetic hermaphrodites, (ii) fertilization success of male gametes produced by parthenogenetic hermaphrodites and (iii) potential eggs lost by diverting resources to male gamete production. In certain situations, parthenogenetic hermaphrodites with an intermediate level of male gamete output have the greatest fitness advantage over sexual individuals. If heritable variation for levels of male gamete output exists among parthenogenetic hermaphrodites, this raises the possibility of the evolution of optimal levels of male gamete production by parthenogenetic hermaphrodites through natural selection, in situations of recurring invasion of asexual populations by propagules from sexual populations, a scenario that is increasingly being appreciated as potentially fairly likely to occur in nature. PMID:9837707

Joshi, A; Moody, M E

1998-12-21

283

Male-only care and classical polyandry in birds: phylogeny, ecology and sex differences in remating opportunities.  

PubMed Central

It has been argued recently that the combination of male-only parental care and classical polyandry in birds is the most interesting and yet the least understood of all avian breeding systems. Despite a huge number of hypotheses, careful comparative analyses have repeatedly failed to identify consistent ecological differences between species showing male-only care and closely related species showing other patterns of care. This has led to the suggestion that such analyses fail because the crucial differences are between ancient lineages rather than between closely related species. Here, therefore, I use comparisons between families to test three well-known hypotheses: that male-only care is associated with: (i) a low rate of fecundity; (ii) large egg size relative to female size; or (iii) female-biased opportunities for remating. Families showing male-only care do not differ from families showing female-only care with respect to rate of fecundity or relative egg size. There is, however, a significant difference between these two groups of families with respect to an index of remating opportunities, nesting density. Families showing female-only care nest at high density, while those showing male-only care nest at very low density. This is one of the first times a consistent ecological correlate has been identified for male-only care in birds. It suggests that female-only care arises (or persists) in families where remating opportunities are abundant for both sexes, whereas male-only care arises (or persists) in families where remating opportunities are rare for both sexes and particularly scarce for males. This in turn suggests that sex differences in remating opportunities are the key ecological factor in determining male-only care and classical polyandry in birds.

Owens, Ian P F

2002-01-01

284

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

2013-09-04

285

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.

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

2013-01-01

286

Pheromonal Discrimination of Sex by Male and Female Leopard Geckos ( Eublepharis macularius)  

Microsoft Academic Search

The ability of male and female Eublepharis macularius to discriminate among pheromones of males and females and a blank control was investigated. Stimuli were presented on ceramic tiles in the animal's home cages. Males tongue-flicked at significantly lower rates in response to male stimuli than to female and control stimuli. Males also performed aggressive behaviors toward male, but not female

William E. Cooper; Laura J. Steele

1997-01-01

287

Anatomical organization of antennal-lobe glomeruli in males and females of the scarab beetle Holotrichia diomphalia (Coleoptera: Melolonthidae).  

PubMed

The glomerular organization of the primary olfactory brain center, the antennal lobe, was studied in males and females of Holotrichia diomphalia adults using serial histological sections labeled by the reduced silver-stain technique. The results revealed an apparent sexual dimorphism. Whereas an enlarged cap-shaped glomerulus was found at the antennal nerve entrance into the antennal lobe in males, no such unit was present in females. Also the size of the antennal lobe differed between the sexes, the antennal lobe of males being larger than that of females. We estimated the total number of glomeruli at approximately 60 units in the female antennal lobe. In males, we could discriminate only those glomeruli that were located in the anterior area of the antennal lobe. PMID:21889404

Hu, Ji-Hua; Wang, Zhi-Ying; Sun, Fan

2011-09-01

288

Prevalence and Timing of Oral Sex with Opposite-sex Partners Among Females and Males Aged 15-24 Years: United States 2007-2010. National Health Statistics Reports Number 56.  

National Technical Information Service (NTIS)

This report presents data on the prevalence of oral sex with opposite-sex partners and the timing of first oral sex relative to first vaginal intercourse among females and males aged 15-24 based on the National Survey of Family Growth (NSFG) data from 200...

A. Chandra C. E. Copen G. Martinez

2012-01-01

289

Sex hormone receptors in the hypothalamus and their role in sexual differentiation of the male rat brain  

SciTech Connect

In this investigation, changes in the level of receptors for sex hormones in the hypothalamus and cerebral cortex of male rats were studied on the first through fifth days of postnatal life, and the results obtained were compared with the levels of luteinizing hormone and sex hormones in the peripheral blood in order to discover any correlation between these parameters. 2,4,6,7,-/sup 3/H-estradiol-17..beta.. and 1,2,6,7-/sup 3/H-testosterone were used as labeled hormones. The values of the association constant and concentration of specific binding sites for estradiol and testosterone in hypothalamus and cerebral cortex of male rats during neonatal development is shown. It is found that in male rats on the first day after birth, receptors for estradiol and testosterone are present and they enable the action both of the testicular hormone and that of estradiol to be realized.

Shishkina, I.V.; Babichev, V.N.; Ozol', L.Yu.

1986-09-01

290

Bioavailability of organic and inorganic zinc sources in male broilers.  

PubMed

The objective of the current study was to determine the bioavailability of an organic zinc source (Availa-Zn) compared with zinc sulfate in a European-type broiler diet. A total of 480 one-day-old male Ross 308 broilers were housed in 48 digestibility cages (10 birds per cage), being randomly divided over 9 treatments. At d 3, the number of birds was standardized to 8. Birds were fed a basal wheat-maize-soya diet (containing 33.5 mg of Zn/kg) with different supplementation levels of zinc (reference zinc source: inorganic zinc sulfate: 0, 5, 10, 15, 20, and 40 mg of Zn/kg of feed; test zinc source: Availa-Zn: 0, 5, 10, 15 mg of Zn/kg of feed). Production performance and tibia zinc content were measured. There were no differences in production performance between the different zinc sources when fed to broilers until 21 d of age. Tibia zinc content was increased linearly with the dietary zinc content up to 20 mg/kg zinc sulfate. The relative biological value of organic zinc was 1.64 compared with zinc sulfate as a reference zinc source (1.00), as indicated by the slope ratio of the linear response curves for both zinc sources, using tibia zinc content as a response parameter. In a practical European broiler diet, the organic Availa-Zn had a higher bioavailability than inorganic zinc sulfate. PMID:23155021

Star, L; van der Klis, J D; Rapp, C; Ward, T L

2012-12-01

291

Opposite sex-linked behaviors and homosexual feelings in the predominantly heterosexual male majority  

Microsoft Academic Search

Whether homosexual feelings are distributed categorically or dimensionally remains controversial. In an earlier series of studies, medical students anonymously reported a dimensional distribution of homosexual feelings, the ratio of homosexual to heterosexual feelings in men correlating with opposite sex-linked behaviors in childhood and adolescence, and, in both sexes, with current degree of opposite sex identity. Prevalence of homosexual feelings was

Nathaniel McConaghy; Neil Buhrich; Derrick Silove

1994-01-01

292

Behavioural profiles: individual consistency in male mating behaviour under varying sex ratios  

Microsoft Academic Search

Variation in sex ratio can affect mating behaviour, with more intense competition predicted at biased sex ratios. In species with alternative mating behaviours, sex ratio variation can induce switches between be- haviour types and this, together with the consistency with which behaviours are expressed, may also affect the intensity of sexual selection. All these factors can be combined to elucidate

Kit Magellan; Anne E. Magurran

2007-01-01

293

A Comparative Analysis of Male and Female Managerial Communication Style in Two Organizations.  

ERIC Educational Resources Information Center

|Compared male and female managers' communication style with subordinates in staff meetings. A category system was developed for coding communicative behaviors. Managers were administered the Bem Sex Role Inventory. Results indicated that male and female managers demonstrated similar communication styles and similar masculine perceptions of…

Birdsall, Paige

1980-01-01

294

The patient's motivation during bicycle stress ECG test is dependent on the investigator's sex in male patients.  

PubMed

The exercise electrocardiogram is a commonly used non-invasive method for detection of electrocardiogram (ECG) changes secondary to myocardial ischemia. Studies showed the importance of the patient's motivation to reach the estimated submaximal heart rate. The purpose of this study was to test whether the patient's motivation is dependent on the investigator's sex. We included 1170 patients (in-hospital patients and out-clinic patients; 63.5% male, 36.5% female) in this study. Stress test data (stationary bicycle with gradually increasing intensity) were collected retrospectively: patient's age, sex, maximal power stage, ECG-abnormalities, angina pectoris, and attending physician's sex. Male patients achieved a higher power stage than their female counterparts (126.5+/-47.7 W vs. 89.7+/-30.4 W). When male patients were supervised by a female doctor they reached higher maximum power stages (136.6+/-53.5 W vs. 121.6+/-43.3 W; p=0,001), more often the submaximal heart rate (47.9% vs. 38.3%; p=0.02) but complained less frequent about angina pectoris (5.6% vs. 17.3%). In contrast, none of these parameters was dependent on the attending physician's sex in female patients. The attending physician's sex influences the maximum exercise ability and the incidence of complaints during bicycle stress in male patients but not in females. We would speculate that men try to impress women with physical strength and try to dissimulate physical discomfort or pain. This could possibly influence the validity of such non-invasive methods with exercise dependent detection of myocardial ischemia. PMID:18597870

Jung, Christian; Ferrari, Markus; Goebel, Bjoern; Figulla, Hans R

2008-07-01

295

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

296

Differential display analysis of gene expression in female-to-male sex-reversing gonads of the frog Rana rugosa.  

PubMed

Sex steroids play pivotal roles in gonadal differentiation in many species of vertebrates. The sex can be reversed from female to male by testosterone in the Japanese wrinkled frog Rana rugosa, but it is still unclear what genes are up- or down-regulated during the XX sex-reversal in this species. To search the genes for the female-to-male sex-reversal, we employed differential display and 5'/3'-RACE. Consequently, we isolated from the gonads at day 8 after testosterone injection 24 different cDNA fragments showing a testosterone treatment-related change and then obtained three full-length cDNAs, which we termed Zfp64, Zfp112, and Rrp54. The former two cDNAs encoded different proteins with zinc-finger domains, whereas the latter cDNA encoded an unknown protein. Transcripts of the three genes were hardly detectable in the sex-reversing gonads at day 24 after the injection; at this time few growing oocytes were observed in the sex-reversing gonad. Besides, in situ hybridization analysis showed positive signals of the three genes in the cytoplasm of growing oocytes of an ovary when testosterone was injected into a tadpole. Thus, the decrease in expression of these three genes was probably due to the disappearance of growing oocytes and not to their direct involvement in the testis formation. To find the key-gene for testis formation, it will be necessary to analyze, by the differential display method, more genes showing a change in expression pattern during sex reversal. PMID:17942098

Okada, Goro; Maruo, Koichi; Funada, Sadahiro; Nakamura, Masahisa

2007-08-30

297

HIV-Related Risk Behaviors and History of Sexually Transmitted Diseases Among Male Migrants Who Patronize Commercial Sex in China  

PubMed Central

Background and Objective Men who pay for sexual services are at increased risk for HIV/sexually transmitted disease. Data on the sociodemographic and behavioral characteristics of such men in China are limited. Study Design Two cross-sectional surveys, using similar instruments, were completed among Chinese migrants in Beijing, Shanghai, and Nanjing in 2002. A total of 1304 rural-to-urban migrant men from community settings (“community sample”) and 465 migrant men attending sexually transmitted disease clinics (“STD clinic sample”) were included in the current study. Results Ten percent of men in the community sample and 32.7% of men in the STD clinic sample reported having ever paid for sex. Nearly 20% of clients from the community sample and 60% of clients from the STD clinic sample reported a history of STDs. For both the community and STD clinic samples, working at industrial or construction sectors, multiple sexual partners, regular sex partner having sex with others, and a history of drug use were associated with being a male client. In addition, perceived peer sexual risk and perceived vulnerability to STD were associated with being a male client in the community sample, and a history of STD and being tested for STD/HIV were associated with being a male client in the STD sample. Conclusion Male migrants who paid for sex in China were vulnerable to HIV/STDs. HIV prevention efforts should target young migrant men who work at factory and construction sectors. STD clinics may be important sites for outreach and intervention efforts among male clients.

WANG, BO; LI, XIAOMING; STANTON, BONITA; FANG, XIAOYI; LIN, DANHUA; MAO, RONG

2007-01-01

298

Prenatal testosterone induces sex-specific dysfunction in endothelium-dependent relaxation pathways in adult male and female rats.  

PubMed

Prenatal testosterone (T) exposure impacts postnatal cardiovascular function, leading to increases in blood pressure with associated decreased endothelium-dependent vascular relaxation in adult females. Endothelial function in males is not known. Furthermore, which of the endothelial pathways contributes to endothelial dysfunction and if there exists sex differences are not known. The objective of this study was to characterize the relative contribution of nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF) to the impaired endothelium-dependent vasodilation in prenatal T-exposed adult males and females. Offspring of pregnant rats treated with T propionate or its vehicle were examined. Telemetric blood pressure levels and endothelium-dependent vascular reactivity were assessed with wire myography. Levels of nitric oxide synthase (NOS3) and Kcnn3 and Kcnn4 channel expression were examined in mesenteric arteries. Mean arterial pressure was significantly higher in T males and females than in controls. Endothelium-dependent acetylcholine relaxation was significantly lower in both T males and females. EDHF-mediated relaxation was specifically blunted in T males (Emax = 48.64% ± 3.73%) compared to that in control males (Emax = 81.71% ± 3.18%); however, NO-mediated relaxation was specifically impaired in T females (Emax = 36.01% ± 4.29%) compared with that in control females (Emax = 54.56% ± 6.37%). Relaxation to sodium nitroprusside and levcromakalim were unaffected with T-treatment. NOS3 protein was decreased in T females but not in T males. Kcnn3 expression was decreased in both T males and females compared to controls. These findings suggest that prenatal T leads to an increase in blood pressure in the adult offspring, associated with blunting of endothelial cell-associated relaxation and that the effects are sex-specific: EDHF-related in males and NO-related in females. PMID:23966325

Chinnathambi, Vijayakumar; Yallampalli, Chandrasekhar; Sathishkumar, Kunju

2013-10-24

299

AIDS/other STIs prevention in China: the effect of sex worker migration and the organization of the sex industry.  

PubMed

HIV/AIDS prevention projects that pay special attention to the socio-cultural context of a community have been implemented in a number of Asian and African countries recently. Such projects integrate scientific approaches, such as condom promotion, with cultural approaches that focus on regional social norms. This paper explores effective intervention strategies in the context of sex workers' mobility patterns, and the sex industry's internal organization in China. It argues that a social network based on quasi-familial relations and regional ties recruits young women into the business, helps them move vertically as well as horizontally within the business, and facilitates the smooth operation of the business. A sound understanding of the specific characteristics of sex work in China, therefore, is instrumental in formulating effective intervention tactics. PMID:23514622

Zhuang, Kongshao; McQuaide, Shiling

2013-03-21

300

Sex Role Stereotypes, Gender Identity and Parental Relationships in Male Homosexuals and Hetersexuals  

Microsoft Academic Search

The sex-role stereotypes held by heterosexual and homosexual men were examined by comparing their Repertory Grid scores. It was found that homosexual men held less rigid sex-role stereotypes than heterosexuals. Degree of opposite-sex identification was marginally greater in homosexuals, but neither group showed strong masculine or feminine stereotypic identification. Homosexual men perceived themselves as psychologically more distant for their fathers

C. Anne Mallen

1983-01-01

301

Sex chromosome-specific regulation in the Drosophila male germline but little evidence for chromosomal dosage compensation or meiotic inactivation.  

PubMed

The evolution of heteromorphic sex chromosomes (e.g., XY in males or ZW in females) has repeatedly elicited the evolution of two kinds of chromosome-specific regulation: dosage compensation--the equalization of X chromosome gene expression in males and females--and meiotic sex chromosome inactivation (MSCI)--the transcriptional silencing and heterochromatinization of the X during meiosis in the male (or Z in the female) germline. How the X chromosome is regulated in the Drosophila melanogaster male germline is unclear. Here we report three new findings concerning gene expression from the X in Drosophila testes. First, X chromosome-wide dosage compensation appears to be absent from most of the Drosophila male germline. Second, microarray analysis provides no evidence for X chromosome-specific inactivation during meiosis. Third, we confirm the previous discovery that the expression of transgene reporters driven by autosomal spermatogenesis-specific promoters is strongly reduced when inserted on the X chromosome versus the autosomes; but we show that this chromosomal difference in expression is established in premeiotic cells and persists in meiotic cells. The magnitude of the X-autosome difference in transgene expression cannot be explained by the absence of dosage compensation, suggesting that a previously unrecognized mechanism limits expression from the X during spermatogenesis in Drosophila. These findings help to resolve several previously conflicting reports and have implications for patterns of genome evolution and speciation in Drosophila. PMID:21857805

Meiklejohn, Colin D; Landeen, Emily L; Cook, Jodi M; Kingan, Sarah B; Presgraves, Daven C

2011-08-16

302

Sex Chromosome-Specific Regulation in the Drosophila Male Germline But Little Evidence for Chromosomal Dosage Compensation or Meiotic Inactivation  

PubMed Central

The evolution of heteromorphic sex chromosomes (e.g., XY in males or ZW in females) has repeatedly elicited the evolution of two kinds of chromosome-specific regulation: dosage compensation—the equalization of X chromosome gene expression in males and females— and meiotic sex chromosome inactivation (MSCI)—the transcriptional silencing and heterochromatinization of the X during meiosis in the male (or Z in the female) germline. How the X chromosome is regulated in the Drosophila melanogaster male germline is unclear. Here we report three new findings concerning gene expression from the X in Drosophila testes. First, X chromosome-wide dosage compensation appears to be absent from most of the Drosophila male germline. Second, microarray analysis provides no evidence for X chromosome-specific inactivation during meiosis. Third, we confirm the previous discovery that the expression of transgene reporters driven by autosomal spermatogenesis-specific promoters is strongly reduced when inserted on the X chromosome versus the autosomes; but we show that this chromosomal difference in expression is established in premeiotic cells and persists in meiotic cells. The magnitude of the X-autosome difference in transgene expression cannot be explained by the absence of dosage compensation, suggesting that a previously unrecognized mechanism limits expression from the X during spermatogenesis in Drosophila. These findings help to resolve several previously conflicting reports and have implications for patterns of genome evolution and speciation in Drosophila.

Meiklejohn, Colin D.; Landeen, Emily L.; Cook, Jodi M.; Kingan, Sarah B.; Presgraves, Daven C.

2011-01-01

303

Understanding the diversity of male clients of sex workers in China and the implications for HIV prevention programmes.  

PubMed

Male clients of sex workers have been overlooked in China's HIV prevention efforts. This study aims to examine men's practices and attitudes toward extramarital sexual relationships, motivations for visiting female sex workers (FSWs), perceptions of sexually transmitted infection (STI)/HIV risk and risk prevention strategies used. One hundred and eighty-six clients of FSWs with varying socio-economic statuses were interviewed in different sex work settings. Men described no conflict between their role as a client and a responsible family provider. They described social pressure from peers and business partners to visit FSWs, sexual pleasure and companionship as motivators to seek commercial sex. While some men reported no risks associated with visiting FSWs, others identified risks such as being arrested by the police, robbed by gangs and threatening the health of their families by contracting a STI. This study underscores the diversity of FSW clients and the need to understand the beliefs and behaviours of different client types to develop appropriate HIV prevention programmes. It also demonstrates the feasibility of recruiting different types of male clients, a hard-to-reach population for Chinese HIV prevention efforts. PMID:22313090

Huang, Yingying; Maman, Suzanne; Pan, Suiming

2012-02-07

304

Effect of sex-pheromone concentration on behavior of three strains of western spruce budworm male moths  

Microsoft Academic Search

The responses of male western spruce budworm moths,Choristoneura occidentalis Freeman, to a range of concentrations of the major sex pheromone, 92:8 (E\\/Z)-11-tetradecenal (Ald), in polyvinyl chloride lures, were observed using the electroantennogram technique, a flight tunnel, and field-trapping bioassays. The responses to virgin female moths were also observed in the flight tunnel and field bioassays. The moths were from three

J. D. Sweeney; J. A. McLean

1990-01-01

305

HIV and associated risk factors among male clients of female sex workers in a Chinese border region  

PubMed Central

Background Male clients of female sex workers (FSWs) serve as a potential bridge of HIV to the general population. Little is known about the characteristics and risk factors for HIV infection among male clients patronizing FSWs in Hekou County, Yunnan Province in southern China bordering with Vietnam. Methods Male clients were recruited through outreach of study staff, referrals by Vietnamese FSWs, their bosses, and snowball sampling. Each participant completed a questionnaire survey and donated a blood specimen to test for HIV, herpes simplex virus type 2 (HSV-2), and syphilis. Logistic regression models were fitted to identify factors associated with HIV infection. Results Among 306 participants, 28 (9.2%) were HIV positive, 81 (26.5%) were HSV-2 positive, and none were infected with syphilis. Approximately half (n=149, 49.2%) reported always using condoms with sex workers in the past year; 36 (11.8%) reported a history of injection drug use (IDU). Compared to HIV negative men, HIV positive men were more likely to have a history of IDU (64.3% vs. 6.5%) and be co-infected with HSV-2 (50.0% vs. 24.1%). Conclusions IDU was the most salient risk factor for HIV infection in this study, which suggests that male clients may acquire HIV from routes other than commercial sex, but the significance of HSV-2 infection indicates that sexual transmission is also of concern. HIV prevention intervention programs for this often ignored and hard-to-reach risk group should be two-pronged, addressing both drug use and commercial sex.

Reilly, Kathleen H.; Wang, Junjie; Zhu, Zhibin; Li, Shuanghe; Yang, Tinghua; Ding, Guowei; Qian, Han-Zhu; Kissinger, Patricia; Wang, Ning

2012-01-01

306

Effects of Sex Steroids on Secretory Granule Formation in Gonadotropes of Castrated Male Rats with Respect to Granin Expression  

Microsoft Academic Search

Pituitary gonadotropes show sex-related differences in their ul- trastructure. Typical gonadotropes of male rats exhibit both large granules, which contain chromogranin A (CgA), and small granules, which contain secretogranin II (SgII). In contrast, typical female rat gonadotropes show only a very few large granules among the numer- ous small granules. To clarify the nature of the biogenesis of these secretory

TSUYOSHI WATANABE; TOMOHIRO BANNO; THOMAS JEZIOROWSKI; YOSHIYUKI OHSAWA; SATOSHI WAGURI; DIETRICH GRUBE; YASUO UCHIYAMA

2010-01-01

307

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

308

THE POSTERIOR BED NUCLEUS OF THE STRIA TERMINALIS MEDIATES OPPOSITE SEX ODOR PREFERENCE IN MALE SYRIAN HAMSTERS (MESOCRICETUS AURATUS)  

Microsoft Academic Search

In Syrian hamsters, social behavior is mediated exclusively by chemosensory cues and circulating gonadal steroid hormones. Where these two signals are processed in the brain is unknown, but the posterior bed nucleus of the stria terminalis (pBNST) has been suggested as a candidate site. Therefore, we tested male hamsters' preference for opposite-sex odors following excitotoxic lesions of the pBNST. Lesions

309

Biased sex ratio and low population density increase male mating success in the bug Nysius huttoni (Heteroptera: Lygaeidae)  

Microsoft Academic Search

Demographic factors such as operational sex ratio (OSR) and local population density (LPD) are temporally and spatially dynamic\\u000a in the natural environment but the influence of these variables on male mating success and the mechanisms behind it are still\\u000a poorly understood and highly controversial. Here, we manipulated the OSR and LPD of a seed bug, Nysius huttoni, and carried out

Qiao Wang; Xiong Zhao He; Linghuan Yang; Duncan Hedderley; Lorraine K. Davis

2009-01-01

310

Response of male codling moths ( Cydia pomonella ) to components of conspecific female sex pheromone glands in flight tunnel tests  

Microsoft Academic Search

In flight tunnel tests, the percentages of oriented upwind flights of male codling moths culminating in contacting a source of different compositions of female sex pheromone gland components were determined over a dosage range of 0.1–100,000?g. The following compositions were tested: (1) (E,E)-8,10-dodecadien-1-ol of 99.7% isomeric purity; (2) 1 + dodecanl-ol + tetradecan-1-ol; (3) 2 + decan-1-ol + (E)-9-dodecen-1-ol; and

L. M. McDonough; H. G. Davis; P. S. Chapman; C. L. Smithhisler

1993-01-01

311

Annual changes in testicular development and plasma sex steroids in the captive male dojo loach Misgurnus anguillicaudatus  

Microsoft Academic Search

Testicular development in the captive male dojo loach Misgurnus anguillicaudatus was examined monthly in relation to the levels of plasma sex steroids [testosterone (T), 11-ketotestostrone (11-KT), and\\u000a 17,20?-dihydroxy-4-pregnen-3-one (DHP)]. On the basis of testicular histology, the annual gonadal cycle was found to be divisible\\u000a into 3 periods: the recovery and proliferation period, which mainly consists of early spermatogenic testis from

Solomon Kiros; Jun-ya Aoki; Chang-Beom Park; Kiyoshi Soyano

312

Refocusing HIV\\/AIDS interventions in Thailand: the case for male sex workers and other homosexually active men  

Microsoft Academic Search

Although seroprevalence studies have shown that Thai male sex workers are at heightened risk of HIV infection, no sustained preventive strategies have so far targeted homosexually active men in Thailand. In this paper, we bring together data from qualitative research carried out in Pattaya (McCamish and Sittitrai 1995, 1997) and Bangkok (Storer 1999a, 1999b), with data generated during a bar-based

GRAEME STORER; GREG CARL

313

Why do males and females differ? Children's beliefs about sex differences  

Microsoft Academic Search

The present paper focuses on children's beliefs about sex differences and how these are related to age and gender. Seven, ten, and fifteen year olds (N=427) were asked to give explanations for their beliefs about sex differences. In strong agreement with previous research and the cognitive-developmental theoretical framework, marked age differences were found: younger children were more likely than older

Jacqui Smith; Graeme Russell

1984-01-01

314

The Effects of Sex and Gender Role Orientation on Mentorship in Male-Dominated Occupations.  

ERIC Educational Resources Information Center

|Responses from 608 certified public accountants who had mentors showed that biological sex was not related to mentoring, but gender role orientation was. Those with androgynous sex role orientation reported more mentoring functions than did those with masculine or feminine orientations. (SK)|

Scandura, Terri A.; Ragins, Belle Rose

1993-01-01

315

Male Sex Hormones Exacerbate Lung Function Impairment after Bleomycin-Induced Pulmonary Fibrosis  

Microsoft Academic Search

all change or percentage of baseline change (P , 0.05). In contrast, there were no significant differences between the sexes in immune cell infiltration into the lung or in total lung collagen content after bleomycin. Total lung histopathology scores measured using the Ashcroft method did not differ between the sexes, while a quantita- tive histopathology scoring system designed to determine

James W. Voltz; Jeffrey W. Card; Michelle A. Carey; Laura M. DeGraff; Catherine D. Ferguson; Gordon P. Flake; James C. Bonner; Kenneth S. Korach; Darryl C. Zeldin

2008-01-01

316

Sex Difference in Attraction Thresholds for Volatile Odors from Male and Estrous Female Mouse Urine  

Microsoft Academic Search

Volatile urinary odors from opposite sex conspecifics contribute to mate recognition in numerous mammalian species, including mice. We used a simple habituation\\/dishabituation testing procedure to ask whether the capacity to detect and investigate decreasing concentrations of volatile urinary odors is sexually differentiated in mice. Beginning 2 months after gonadectomy and in the absence of any sex steroid treatment, adult, sexually

M. J. Baum; E. B. Keverne

2002-01-01

317

How can the therapist deal with a couple with male demands for anal sex  

Microsoft Academic Search

We report a case that was referred to us as sexual reluctance in a wife and conflict over anal sex. The wife was a survivor of child sexual abuse. Subsequently, it was felt that the presenting problems were a reflection of difficulties in their general marital relationship. In addition to traditional behavioural sex therapy, structural interventions within sessions and strategic

Kevan R. Wylie; Michael J. Crowe; Daphne Boddington

1995-01-01

318

Sex and social networking: the influence of male presence on social structure of female shark groups  

Microsoft Academic Search

Marine predators such as sharks often form single-sex aggregations as part of their diel behavioral cycle. Such aggregations are potentially driven by contrasting reproductive and behavioral strategies between the sexes, leading to distinct sexual segregation. There is, however, no experimental evidence that such predator aggregations are governed by intrinsic social systems, demonstrating long-term temporal stability. Social network structure, temporal stability,

David M. P. Jacoby; Dheeraj S. Busawon; David W. Sims

2010-01-01

319

Covariance of paternity and sex with laying order explains male bias in extra-pair offspring in a wild bird population.  

PubMed

It has been hypothesized that parents increase their fitness by biasing the sex ratio of extra-pair offspring (EPO) towards males. Here, we report a male bias among EPO in a wild population of blue tits (Cyanistes caeruleus). This resulted from a decline in both the proportion of males and EPO over the laying order of eggs in the clutch. However, previous studies suggest that, unlike the decline in EPO with laying order, the relationship between offspring sex ratio and laying order is not consistent between years and populations in this species. Hence, we caution against treating the decline in proportion of males with laying order, and the resulting male bias among EPO, as support for the above hypothesis. Variable patterns of offspring sex and paternity over the laying order may explain inconsistent associations between offspring sex and paternity, between and within species. PMID:24026349

Vedder, Oscar; Magrath, Michael J L; van der Velde, Marco; Komdeur, Jan

2013-09-11

320

Epigenetics and Sex-Specific Fitness: An Experimental Test Using Male-Limited Evolution in Drosophila melanogaster  

PubMed Central

When males and females have different fitness optima for the same trait but share loci, intralocus sexual conflict is likely to occur. Epigenetic mechanisms such as genomic imprinting (in which expression is altered according to parent-of-origin) and sex-specific maternal effects have been suggested as ways by which this conflict can be resolved. However these ideas have not yet been empirically tested. We designed an experimental evolution protocol in Drosophila melanogaster that enabled us to look for epigenetic effects on the X-chromosome–a hotspot for sexually antagonistic loci. We used special compound-X females to enforce father-to-son transmission of the X-chromosome for many generations, and compared fitness and gene expression levels between Control males, males with a Control X-chromosome that had undergone one generation of father-son transmission, and males with an X-chromosome that had undergone many generations of father-son transmission. Fitness differences were dramatic, with experimentally-evolved males approximately 20% greater than controls, and with males inheriting a non-evolved X from their father about 20% lower than controls. These data are consistent with both strong intralocus sexual conflict and misimprinting of the X-chromosome under paternal inheritance. However, expression differences suggested that reduced fitness under paternal X inheritance was largely due to deleterious maternal effects. Our data confirm the sexually-antagonistic nature of Drosophila’s X-chromosome and suggest that the response to male-limited X-chromosome evolution entails compensatory evolution for maternal effects, and perhaps modification of other epigenetic effects via coevolution of the sex chromosomes.

Abbott, Jessica K.; Innocenti, Paolo; Chippindale, Adam K.; Morrow, Edward H.

2013-01-01

321

Sex role stereotypes, gender identity and parental relationships in male homosexuals and heterosexuals.  

PubMed

The sex-role stereotypes held by heterosexual and homosexual men were examined by comparing their Repertory Grid scores. It was found that homosexual men held less rigid sex-role stereotypes than heterosexuals. Degree of opposite-sex identification was marginally greater in homosexuals, but neither group showed strong masculine or feminine stereotypic identification. Homosexual men perceived themselves as psychologically more distant from their fathers than did their heterosexual counterparts; this was probably an effect of homosexuality rather than a cause. PMID:6644001

Mallen, C A

1983-01-01

322

Effect of Dominance Status on Sex Hormone Levels in Laboratory and Wild-Spawning Male Trout  

Microsoft Academic Search

We investigated the relationship between male social status and hormone levels in salmonids spawning under laboratory and field conditions. In small groups of rainbow trout (Onchorhynchus mykiss) spawning in the laboratory, dominant males had higher plasma levels of testosterone (T) and 17?,20?-dihydroxy-4-pregnen-3-one (17,20?-P) compared with subordinates. Steroid levels increased in subordinate males that became dominant after dominant males were experimentally

James R. Cardwell; Peter W. Sorensen; Glen J. Van Der Kraak; N. Robin Liley

1996-01-01

323

A Psychological Needs Analysis of Male and Female Sex Trait Stereotypes in Malaysia  

Microsoft Academic Search

As part of a cross-cultural project, 100 Malaysian university students completed Gough and Heilbrun's (1965) Adjective Check List to assess existing stereotypes of males and females. After the construction of 100 item stereotypes for males and females the data were analyzed in terms of Murray's (1938) personality theory of psychological needs. Analysis revealed that the male “personality” reflected high needs

Colleen Ward; John E. Williams

1982-01-01

324

The Sertoli Cell Only Syndrome and Glaucoma in a Sex - Determining Region Y (SRY) Positive XX Infertile Male  

PubMed Central

The XX male syndrome is a rare genetic disorder. The phenotype is variable; it ranges from a severe impairment of the external genitalia to a normal male phenotype with infertility. It generally results from an unequal crossing over between the short arms of the sex chromosomes (X and Y). We are reporting a case of a 38-year-old man who presented with infertility and the features of hypogonadism and glaucoma. The examinations revealed normal external male genitalia, soft small testes, gynaecomastia and glaucoma. The semen analysis showed azoospermia. The serum gonadotropins were high, with low Anti Mullerian Hormone (AMH) and Inhibin B levels. The chromosomal analysis demonstrated a 46, XX karyotype. Fluorescent In-Situ Hybridization (FISH) and Polymerase Chain Reaction (PCR) revealed the presence of a Sex-determining Region Y (SRY). Testicular Fine Needle Aspiration Cytology (FNAC) revealed the Sertoli Cell Only Syndrome (SCOS). The presence of only Sertoli Cells in the testes, with glaucoma in the XX male syndrome, to our knowledge, has not been reported in the literature.

Jain, Manish; V, Veeramohan; Chaudhary, Isha; Halder, Ashutosh

2013-01-01

325

Prevalence of HIV, Herpes Simplex Virus-2, and Syphilis in male sex partners of pregnant women in Peru  

PubMed Central

Background: Sexually active heterosexual men may represent an important risk factor for HIV infection and STI transmission to their female partners and unborn children, though little is known about the prevalence of STIs in this population. We sought to determine the prevalence of HIV, herpes simplex virus type 2 (HSV-2), and syphilis infection and associated risk behaviors among male sex partners of pregnant women in Peru. Methods: Survey and seroprevalence data were collected from 1,835 male partners of pregnant women in four cities in Peru. Serum was tested for antibodies to HIV, HSV-2, and syphilis. Results: Among the 1,835 male participants, HIV prevalence was 0.8% (95% CI = 0.5–1.4%), HSV-2 16.0% (95% CI = 14.3–17.8%), and syphilis 1.6% (95% CI = 1.0–2.2%). Additionally, 11.0% reported a lifetime history of intercourse with men, and 37.1% with female sex workers. Unprotected intercourse with men during the previous year was reported by 0.9% and with female sex workers by 1.2%. Conclusion: Pregnant women's sex partners reported lifetime sexual contact with core risk groups, had an elevated prevalence of HSV-2, and demonstrated the potential to spread HIV and other STIs to their partners. Though the prevalence of HIV in the population was not significantly higher than observed in other samples of heterosexuals in Peru, the risk of HIV transmission to their female partners may be exacerbated by their increased prevalence of HSV-2 infection. Further study of heterosexual populations is necessary to fully understand the epidemiology of HIV/STIs in Latin America.

Clark, Jesse L; Konda, Kelika A; Munayco, Cesar V; Pun, Monica; Lescano, Andres G; Leon, Segundo R; Pajuelo, Jose; Suarez-Ognio, Luis; Klausner, Jeffrey D; Coates, Thomas J; Caceres, Carlos F

2008-01-01

326

Sex typing and the social perception of gender stereotypic and nonstereotypic behavior: the uniqueness of feminine males.  

PubMed

The social perception of masculine, feminine, androgynous and undifferentiated males was examined. Preadolescent boys (n = 251) were shown a video film portraying a male target playing either a masculine game with boys, a feminine game with girls, a neutral game with boys, or a neutral game with girls and were required to make a variety of inferences about him. All 4 groups made similar cognitive stereotypic inferences that varied in accordance with the gender stereotypic nature of the target's behavior. However, for the affective judgments (e.g., liking the target and wanting to engage in activities with him), the feminine males showed a pattern of inferences that was not only different from other sex role orientations, but often the reverse. The implications of these results for S. L. Bem's gender schema theory (1981) and H. Markus's self schema theory (H. Markus, M. Crane, S. L. Bernstein, & M. Siladi, 1982) are discussed. PMID:8195993

Lobel, T E

1994-02-01

327

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

PubMed Central

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.

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

2012-01-01

328

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

2012-03-23

329

Are sex-role attitudes useful in explaining male\\/female differences in rates of depression?  

Microsoft Academic Search

This study used an untreated sample of husbands and wives to investigate the effect of a wife's employment status on her spouse's depression score. A consistency between attitudes toward appropriate sex-role behavior and actual situation was expected to enhance mental well-being. Data demonstrate that when a measure of sex-role attitudes was paired with situation, it was a significant indicator of

Dorothy Williams Kingery

1985-01-01

330

Sox3 Is Required for Gonadal Function, but Not Sex Determination, in Males and Females  

Microsoft Academic Search

Sox3 is expressed in developing gonads and in the brain. Evolutionary evidence suggests that the X-chro- mosomal Sox3 gene may be the ancestral precursor of Sry, a sex-determining gene, and Sox3 has been proposed to play a role in sex determination. However, patients with mutations in SOX3 exhibit normal gonadal determination but are mentally retarded and have short stature secondary

Jeffrey Weiss; Joshua J. Meeks; Lisa Hurley; Gerald Raverot; Andrea Frassetto; J. Larry Jameson

2003-01-01

331

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

332

A male-killing Wolbachia carries a feminizing factor and is associated with degradation of the sex-determining system of its host  

PubMed Central

Endosymbiotic bacteria of the genus Wolbachia induce diverse reproductive alterations in their insect hosts. Wolbachia (wSca) infecting the moth Ostrinia scapulalis causes unusual male killing, in which males (genotype: ZZ) selectively die during embryonic and larval development, whereas females (genotype: ZW), in turn, selectively die when cured of infection. To gain insight into the interaction between wSca and the host, we analysed phenotypic and genetic sexes of the embryos and larvae of normal, wSca-infected, and infected-and-cured O. scapulalis by diagnosing the sex-specifically spliced transcripts of Osdsx—a homologue of the sex-determining gene doublesex—and sex chromatin in interphase nuclei, respectively. It was observed that the female-type Osdsx was expressed in the infected male (ZZ) progenies destined to die, whereas the male-type Osdsx was expressed in the cured female (ZW) progenies destined to die. These findings suggest that (i) wSca, a male killer, carries a genetic factor that feminizes the male host, (ii) the sex-determining system of the host is degraded, and (iii) a mismatch between the genetic and phenotypic sexes underlies the sex-specific death.

Sugimoto, Takafumi N.; Ishikawa, Yukio

2012-01-01

333

Variation and Evolution of Male Sex Combs in Drosophila: Nature of Selection Response and Theories of Genetic Variation for Sexual Traits  

PubMed Central

We investigated the genetic architecture of variation in male sex comb bristle number, a rapidly evolving secondary sexual character of Drosophila. Twenty-four generations of divergent artificial selection for sex comb bristle number in a heterogeneous population of Drosophila melanogaster resulted in a significant response that was more pronounced in the direction of low bristle numbers. We observed a strong positive correlated response to selection in the corresponding female transverse bristle row. The correlated response in male abdominal and sternopleural bristle numbers, on the other hand, did not follow the same pattern as sex comb bristle number differences between selection lines. Relaxation-of-selection experiments along with mate choice and fecundity assays using the selection lines developed demonstrated the action of stabilizing selection on sex comb bristle number. Our results show (1) substantial genetic variation underlying sex comb bristle number variation; (2) a weak relationship between the sex comb and developmentally related, non-sex bristle systems; and (3) that sexual selection may be a driving force in sex comb evolution, indicating the potential of sex combs to diversify rapidly during population differentiation and speciation. We discuss the implications of these results for theories of genetic variation in display and nondisplay male sex traits.

Ahuja, Abha; Singh, Rama S.

2008-01-01

334

Effects of progesterone and dihydrotestosterone on stimulation of androgen-dependent sex behavior, accessory sex structures, and in vitro binding characteristics of cytosolic androgen receptors in male whiptail lizards (Cnemidophorus inornatus).  

PubMed

Progestins often act as potent antiandrogens in male birds and mammals. Experiments with lizards find that progestins can both inhibit (when given in high dosages) or stimulate (when given in low dosages) male-typical sex behavior in gonadectomized individuals. This study shows that in the little striped whiptail lizard exogenous progesterone (P) facilitates androgen-dependent sex behaviors in males yet fails to stimulate seasonal activation of androgen-dependent accessory sex structures. Analysis of androgen receptors (AR) in brain and kidney cytosol of the little striped whiptail lizard reveals similarities with the AR of the mouse. The data indicate that despite the ability of P to mimic the actions of androgens in activating sex behaviors in males of this species, the characteristics of the AR are conserved with respect to other vertebrate species. PMID:8349284

Lindzey, J; Crews, D

1993-06-01

335

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

2011-08-03

336

Caenorhabditis elegans histone methyltransferase MET-2 shields the male X chromosome from checkpoint machinery and mediates meiotic sex chromosome inactivation.  

PubMed

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

2011-09-01

337

Sex, stress and social status: patterns in fecal testosterone and glucocorticoid metabolites in male Ethiopian wolves.  

PubMed

Ethiopian wolves, Canis simensis, live in large multi-male family packs, where males are philopatric and do not disperse. Within a pack, mating and breeding is largely monopolized by the dominant male and female, although extra-pack copulations are common, and subordinate males may sire pups in neighboring packs. Regardless of paternity, all males in a pack help rear the pups. We non-invasively studied patterns in fecal testosterone and glucocorticoid metabolite concentrations using radioimmunoassays of fecal samples collected from nine wild male Ethiopian wolves between August 2007 and February 2008. We tested the predictions of the Challenge Hypothesis, namely that fecal testosterone metabolite concentrations would be higher during the annual mating season, which is the portion of the reproductive cycle when mating and increased aggression typically occur, and lower when there were pups in the pack for which to care. Contrary to the predictions of the Challenge Hypothesis, we did not detect patterns in fecal testosterone metabolite concentrations associated with reproductive stage during our study period. Similarly, we found no patterns associated with reproductive stage in male fecal glucocorticoid metabolite concentrations. Dominant males had higher average fecal testosterone and glucocorticoid metabolite concentrations than did subordinates, which may be related to higher rates of aggression and mate guarding in dominant males of group-living canids, a pattern also reported in African wild dogs, Lycaon pictus. PMID:22841807

van Kesteren, Freya; Sillero-Zubiri, Claudio; Millar, Robert; Argaw, Kifle; Macdonald, David W; Paris, Monique

2012-07-27

338

Testing models of sex ratio evolution in a gynodioecious plant: female frequency covaries with the cost of male fertility restoration.  

PubMed

In many gynodioecious species, cytoplasmic male sterility genes (CMS) and nuclear male fertility restorers (Rf) jointly determine whether a plant is female or hermaphrodite. Equilibrium models of cytonuclear gynodioecy, which describe the effect of natural selection within populations on the sex ratio, predict that the frequency of females in a population will primarily depend on the cost of male fertility restoration, a negative pleiotropic effect of Rf alleles on hermaphrodite fitness. Specifically, when the cost of restoration is higher, the frequency of females at equilibrium is predicted to be higher. To test this prediction, we estimated variation in the cost of restoration across 26 populations of Lobelia siphilitica, a species in which Rf alleles can have negative pleiotropic effects on pollen viability. We found that L. siphilitica populations with many females were more likely to contain hermaphrodites with low pollen viability. This is consistent with the prediction that the cost of restoration is a key determinant of variation in female frequency. Our results suggest that equilibrium models can explain variation in sex ratio among natural populations of gynodioecious species. PMID:23356626

Caruso, Christina M; Case, Andrea L

2012-09-27

339

“Nobody's Ever Going to Make a Fag Pretty Woman: Stigma Awareness and the Putative Effects of Stigma Among a Sample of Canadian Male Sex Workers  

Microsoft Academic Search

The purpose of this study was to examine male sex workers' awareness of the social stigma surrounding involvement in the sex industry and the possible effects of that stigma. Personal interviews were conducted with 21 men (9 independent escorts who advertised via the Internet and 12 escorts\\/erotic masseurs who were on contract with an agency). Results indicated that a majority

Todd G. Morrison; Bruce W. Whitehead

2007-01-01

340

Age-related foetal sex ratio bias in Iberian red deer ( Cervus elaphus hispanicus ): are male calves too expensive for growing mothers?  

Microsoft Academic Search

Several theories predict offspring biases towards males or females with increasing reproductive resources of the mother to maximize reproductive returns by offspring, or as a result of prohibitive cost of the most expensive sex for young mothers or those in poor condition. This study examines foetus sex of 221 harvested hinds in a food-supplemented game estate for 10 years, according to

Tomás Landete-Castillejos; Christian Gortázar; Joaquin Vicente; Yolanda Fierro; Andres Garcia; Laureano Gallego

2004-01-01

341

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

342

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

343

Sex Pheromone Produced by the Female Japanese Beetle: Specificity of Male Response to Enantiomers.  

National Technical Information Service (NTIS)

(Z)-5-(l-decenyl)dihydro-2(3H)-furanone, isolated from virgin female Japanese beetles, Popilla japonica, attracted males of the species in field bioassays. However, the synthesized racemic mixture of this compound did not attract male Japanese beetles. Th...

J. A. Tumlinson M. G. Klein R. E. Doolittle T. L. Ladd

1978-01-01

344

Effects of Visual Exposure to the Opposite Sex: Cognitive Aspects of Mate Attraction in Human Males  

Microsoft Academic Search

This research is an investigation into the cognitive aspects of mate attraction in human males. Two experiments demonstrate that visual exposure to women (in person or within photo- graphs) can prime large changes in the attitudes, mood states, and personality trait descriptions of male participants. These changes, furthermore, are such that participants show greater conformity to female mate preferences as

James R. Roney

2003-01-01

345

Sex-Role Orientation and Attitudes towards Male Day Care Workers.  

ERIC Educational Resources Information Center

Although developmental specialists have called for more male teachers in the fields of day care and early education, it is possible that parents with children in day care would be prejudiced against male day care workers. The work sample evaluation technique in which participants are asked to evaluate identical pieces of work was used in a study…

Wessell, Marja Elizabeth

346

Sex Differences in Political Communication: A Study of Female and Male State Legislators.  

ERIC Educational Resources Information Center

In an investigation of the communication similarities and differences between male and female legislators, the nine female representatives in the Michigan House of Representatives were matched with nine male representatives on four variables: political party, length of legislative service, district represented, and race. The representatives were…

Leenhouts, Thelma K.

347

The weaker sex: Is being male a legally cognizable defect, impairment, or disability?  

Microsoft Academic Search

Compared with women, men die from cancer and coronary artery disease in disproportionately higher numbers and are more susceptible to a host of emotional and developmental disorders. The authors of this article consider what scientific proof or evidence would be required to legally recognize “being male” as a disability, based on the overwhelming number of physical deficiencies to which males

Louis M. Solomon; Rebekka C. Noll; Rebecca Guttman

2008-01-01

348

Species recognition and sex discrimination by males of the notchtongue goby, Bathygobius curacao (Pisces: Gobiidae)  

Microsoft Academic Search

A study on the sensory stimuli used by males of Bathygobius curacao to recognize conspecific females is presented. An ethogram of the reproductive and agonistic behavior of B. curacao revealed that it followed the typical gobiid reproductive pattern. During courtship, the male develops a distinctive color pattern, the courtship \\

John Harris Stadler

2000-01-01

349

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

350

Spinal cord processing of cardiac nociception: Are there sex differences between male and proestrous female rats?  

Microsoft Academic Search

Sex differences in the characteristics of cardiac pain have been reported from clinical studies. For example, women experience chest pain less frequently than men. Women describe their chest pain as sharp and stabbing, while men have chest pain that is felt as a pressure or heaviness. Pain is also referred to the back more often in women than men. The

Janine M. Little; Chao Qin; Jay P. Farber; Robert D. Foreman

2011-01-01

351

Sex ratio manipulation and decreased growth of male offspring of undernourished golden hamsters ( Mesocricetus auratus )  

Microsoft Academic Search

The theory that female mammals in poor condition may increase individual fitness by skewing the sex ratio of their offspring toward daughters and by investing more resources in daughters than in sons was tested in hamsters. Newly mated experimental females were food-restricted during pregnancy and lactation (RR) or during lactation only (AR). Controls received food ad libitum. Maternal body weights

Jay B. Labov; U. William Huck; Prabha Vaswani; Robert D. Lisk

1986-01-01

352

Perception of Parental Sex Role Behavior and Psychopathology in Adult Males  

ERIC Educational Resources Information Center

The results indicated that normal Ss generally perceived their parents as exhibiting sex-appropriate behaviors to a greater extent than did disturbed Ss; a smaller proportion of individuals in the disturbed groups viewed their fathers as possessing masculine-instrumental traits, and their mothers as having feminine-expressive characteristics.…

Kayton, Robert; Biller, Henry B.

1971-01-01

353

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

354

The Association between the Levels of Serum Ferritin and Sex Hormones in a Large Scale of Chinese Male Population  

PubMed Central

Background The ferritin is an important participant of iron-storage but its regulation and related factors were not well defined. The present objective was to explore the potential association between serum ferritin levels and sex hormones. Methods 1999 Chinese men in the Fangchenggang Area Male Health and Examination Survey (FAMHES) were recruited in this cross-sectional study. Levels of serum ferritin, total testosterone (free testosterone was calculated from the total one), estradiol and sex hormone-binding protein were detected in venous blood samples. The effects of age, BMI, smoking as well as alcohol consumption were analyzed on ferritin levels, respectively, and then the Pearson’s correlation analysis was used to evaluate the association between ferritin levels and sex hormones adjusting for the above factors. Results The age, BMI and alcohol consumption significantly affected serum ferritin levels, but there was no significant difference between smokers and nonsmokers. Ferritin levels were significantly and negatively associated with total testosterone (R?=??0.205, P< 0.001), sex hormone-binding protein (R?=??0.161, P<0.001) and free testosterone (R?=??0.097, P<0.001). After age and alcohol consumption were adjusted, the above associations were still significant (R?=??0.200, ?0.181 and ?0.083, respectively, all P<0.001). However, there was only borderline negative association between ferritin levels and estradiol (adjusted R?=??0.039, P?=?0.083). Conclusion The large scale of epidemic results showed the significantly negative associations between serum ferritin levels and sex hormones, which may provide more clues to explore the potential regulation and biological mechanism of ferritin.

Zhang, Haiying; Gao, Yong; Tan, Aihua; Zhang, Shijun; Xiao, Qiang; Zhang, Bing; Huang, Lulu; Ye, Bingbing; Qin, Xue; Wu, Chunlei; Lu, Zheng; Zhang, Youjie; Liao, Ming; Yang, Xiaobo; Mo, Zengnan

2013-01-01

355

Frequency of sexual activity with most recent male partner among young, internet-using men who have sex with men in the United States.  

PubMed

Sex frequency, defined here as the number of oral or anal sex acts with the most recent partner in the past year, is a potential driver of risk for sexually transmitted infections. However, few data on sex frequency have been reported for men who have sex with men (MSM). Data from an Internet survey of MSM were used to describe sex frequency with most recent main and casual male partners and to estimate factors associated with higher sex frequency. Among 5,193 MSM, higher sex frequency was associated with younger age, shorter relationship duration, and reporting a main (vs. casual) partner; and lower sex frequency with male partners was associated with heterosexual or bisexual (vs. homosexual) identity or Black race (vs. non-Hispanic White). Secondary analyses of estimates of sex frequency from 2 publicly available nationally representative datasets comprised of primarily heterosexual survey respondents (the 2008 General Social Survey and the 1992 National Health and Social Life Survey) were performed. Sex frequency among MSM respondents was similar to that reported by heterosexuals. PMID:24059971

Wall, Kristin M; Stephenson, Robert; Sullivan, Patrick S

2013-10-01

356

Gender in plants: sex chromosomes are emerging from the fog  

Microsoft Academic Search

Although most plants have flowers with both male and female sex organs, there are several thousands of plant species where male or female flowers form on different individuals. Surprisingly, the presence of well-established sex chromosomes in these dioecious plants is rare. The best-described example is white campion, for which large sex chromosomes have been identified and mapped partially. A recent

Boris Vyskot; Roman Hobza

2004-01-01

357

Sex and the public: Social eavesdropping, sperm competition risk and male mate choice.  

PubMed

Mate choice can be sensitive to social cues from neighboring individuals, e.g., animals can copy mate choice decisions. Males that are at risk of being copied by others may respond to this with reduced preference expression ("audience effects"). We review the various pathways by which sperm competition risk affects (1) male mate copying behavior and (2) audience effects. For example, a recent study suggests that males gather complex social information on rivals' sexual competitiveness (sexual activity and attractiveness to females) and respond with reduced expression of mating preferences only "when it matters," i.e., when a sexually competitive rival is present. PMID:21980557

Plath, Martin; Bierbach, David

2011-05-01

358

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

359

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

NASA Astrophysics Data System (ADS)

The profiles of cortisol, testosterone, 11-ketotestosterone and 17?, 20?-dihydroxy-4-pregnene-3-one in male rainbow trout reared under constant water temperature and natural photoperiod were determined by radioimmunoassay. Gonads of male rainbow trout reached maturity when the fish were two years old. Changes in the plasma levels of both sex steroid hormones and cortisol were closely related to the GSI. Plasma levels of testosterone, 11-ketotestosterone and 17?; 20?-dihydroxy 4-pregnene-3-one showed a clear peak in the annual breeding season, when the GSI reached their maxima. Plasma cortisol levels also showed clearly seasonal changes in both two- and three-year-old fish. The results suggest that the elevated plasma levels of cortisol may not just be due to stresses during the breeding season but have certain physiological functions in the reproduction of rainbow trout.

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

2001-09-01

360

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

2012-06-07

361

Inactivation or non-reactivation: what accounts better for the silence of sex chromosomes during mammalian male meiosis?  

PubMed

During the first meiotic prophase in male mammals, sex chromosomes undergo a program of transcriptional silencing called meiotic sex chromosome inactivation (MSCI). MSCI is triggered by accumulation of proteins like BRCA1, ATR, and ?H2AX on unsynapsed chromosomes, followed by local changes on the sex chromatin, including histone modifications, incorporation of specific histone variants, non-histone proteins, and RNAs. It is generally thought that MSCI represents the transition of unsynapsed chromatin from a transcriptionally active state to a repressed state. However, transcription is generally low in the whole nucleus during the early stages of the first meiotic prophase, when markers of MSCI first appear, and is then reactivated globally during pachytene. Thus, an alternative possibility is that MSCI represents the targeted maintenance and/or reinforcement of a prior repressed state, i.e., a failure to reactivate. Here, we present an analysis of the temporal and spatial appearance of transcriptional and MSCI markers, as well as chromatin modifications related to transcriptional regulation. We show that levels of RNA pol II and histone H3 acetylated at lysine 9 (H3K9ac) are low during leptotene, zygotene, and early pachytene, but increase strongly in mid-pachytene, indicating that reactivation occurs with some delay after synapsis. However, while transcription markers appear abundantly on the autosomes at mid-pachytene, they are not directed to the sex chromosomes. Interestingly, we found that chromatin modifications related to transcriptional silencing and/or MSCI, namely, histone H3 trimethylated at lysine 9 (H3K9me3), histone H3 monomethylated at lysine 4 (H3K4me1), ?H2AX, SUMO1, and XMR, appear on the sex chromosomes before autosomes become reactivated. These results suggest that the onset of MSCI during late zygotene and early pachytene may prevent sex chromosome reactivation during mid-pachytene instead of promoting inactivation de novo. Additionally, we found temporal differences between the X and Y chromosomes in the recruitment of DNA repair and MSCI markers, indicating a differential regulation of these processes. We propose that many of the meiotic defects attributed to failure to silence sex chromosomes could be interpreted as a more general process of transcriptional misregulation that occurs under certain pathological circumstances in zygotene and early pachytene. PMID:22366883

Page, Jesús; de la Fuente, Roberto; Manterola, Marcia; Parra, María Teresa; Viera, Alberto; Berríos, Soledad; Fernández-Donoso, Raúl; Rufas, Julio S

2012-02-26

362

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

2013-09-04

363

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

364

Analysis of Male Pheromones That Accelerate Female Reproductive Organ Development  

PubMed Central

Male odors can influence a female's reproductive physiology. In the mouse, the odor of male urine results in an early onset of female puberty. Several volatile and protein pheromones have previously been reported to each account for this bioactivity. Here we bioassay inbred BALB/cJ females to study pheromone-accelerated uterine growth, a developmental hallmark of puberty. We evaluate the response of wild-type and mutant mice lacking a specialized sensory transduction channel, TrpC2, and find TrpC2 function to be necessary for pheromone-mediated uterine growth. We analyze the relative effectiveness of pheromones previously identified to accelerate puberty through direct bioassay and find none to significantly accelerate uterine growth in BALB/cJ females. Complementary to this analysis, we have devised a strategy of partial purification of the uterine growth bioactivity from male urine and applied it to purify bioactivity from three different laboratory strains. The biochemical characteristics of the active fraction of all three strains are inconsistent with that of previously known pheromones. When directly analyzed, we are unable to detect previously known pheromones in urine fractions that generate uterine growth. Our analysis indicates that pheromones emitted by males to advance female puberty remain to be identified.

Flanagan, Kelly A.; Webb, William; Stowers, Lisa

2011-01-01

365

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

366

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

2011-12-14

367

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.

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

2007-01-01

368

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

369

Factors associated with treatment acceptance and compliance among incarcerated male sex offenders.  

PubMed

The files of sex offenders who had been offered treatment at a medium-security state prison were divided into three groups: treatment refusal (n = 59), treatment noncompliance (n = 61), and treatment compliance (n = 36). Demographic, offense-related, clinical, and psychological assessment data were collected. Significant differences were found between groups on years to parole eligibility; plea; relation to victim; childhood sexual victimization; and Minnesota Multiphasic Personality Inventory-2 Variable Response Inconsistency (VRIN), Lie (L), and Masculinity-Femininity (Mf) scale scores. Logistic regression analyses revealed that significant predictors of treatment refusal include increased time until parole eligibility and lower VRIN and Mf scores (vs. noncompliant) as well as no history of childhood sexual victimization and higher L scores (vs. compliant). Having entered a not-guilty plea was the only significant predictor of noncompliance among those who initially accepted treatment. These findings are discussed in relation to previous studies of sex offender treatment compliance and directions for future research. PMID:20622252

Clegg, Carl; Fremouw, William; Horacek, Thomas; Cole, Angel; Schwartz, Rebecca

2010-07-09

370

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

Microsoft Academic Search

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

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

2008-01-01

371

Behavioral response of mature males of acipenseridae to female sex pheromone  

Microsoft Academic Search

It was established that, as in many other representatives of Teleostei, there is a pheromonal regulation of reproductive behavior\\u000a in Acipenseridae. The postovulatory releasing sex pheromone in Russian sturgeon Acipenser gueldenstaedtii, Persian sturgeon A. persicus, and starred sturgeon A. stellatus is in the ovarian fluid of females, whose odor has an interspecific efficiency and causes manifestation of typical spawning\\u000a behavior

A. O. Kasumyan; Ch. A. Mamedov

2011-01-01

372

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

2012-07-06

373

Effects of Atrazine on CYP19 Gene Expression and Aromatase Activity in Testes and on Plasma Sex Steroid Concentrations of Male African Clawed Frogs (Xenopus laevis)  

Microsoft Academic Search

Some investigators have suggested that the triazine herbicide atrazine can cause demasculinization of male amphibians via upregulation of the enzyme aromatase. Male adult African clawed frogs (Xenopus laevis) were exposed to three nominal concentrations of atrazine (1, 25, or 250mg atrazine\\/l) for 36 days, and testicular aromatase activity and CYP19 gene expression, as well as concentrations of the plasma sex

Markus Hecker; June-Woo Park; Margaret B. Murphy; Paul D. Jones; Keith R. Solomon; Glen Van Der Kraak

2005-01-01

374

MEDFLY (DIPTERA: TEPHRITIDAE) GENETIC SEXING: LARGE-SCALE FIELD COMPARISON OF MALES-ONLY AND BISEXUAL STERILE FLY RELEASES IN GUATEMALA  

Technology Transfer Automated Retrieval System (TEKTRAN)

The effect of releases of bisexual (males and female) and unisexual (male only) sterilized medflies was compared in three large field evaluations over a 3-year period (1995 - 1997) in southwestern Guatemala. The two strains tested were a genetic sexing strain, Vienna-4/Tol-94, carrying the temperatu...

375

A Detailed Study on the Role of Sex Steroid Milieu in Determining Plasma Leptin Concentrations in Adult Male and Female Rats  

Microsoft Academic Search

We examined the effects of sex steroid milieu on plasma leptin levels in adult male and female rats. Since the body weight is known to influence leptin concentrations, the hormone was measured in rats with a very similar body weight (about 250 g) throughout this study. Plasma leptin levels were significantly higher in female than in male rats. Orchidectomy (ODX)

Hajime Watanobe; Toshihiro Suda

1999-01-01

376

The effects of source dosage, flight altitude, wind speed, and ground pattern on the sex pheromone?mediated flight manoeuvres of male lightbrown apple moth, Epiphyas postvittana (Walker)  

Microsoft Academic Search

The flight tracks (plan view) of male Epiphyas postvittana flying in a sex pheromone plume in a wind tunnel were recorded. With increasing source dosages (10, 100, 300 ?g), males steered a more upwind course, with corresponding track angles more upwind, and had smaller intertrack reversal distances (i.e., they showed less lateral movement). Although net ground speed tended to increase

S. P. Foster; A. J. Howard

1999-01-01

377

BRCA1, histone H2AX phosphorylation, and male meiotic sex chromosome inactivation.  

PubMed

In mammalian spermatogenesis, the X and Y chromosomes are transcriptionally silenced during the pachytene stage of meiotic prophase (meiotic sex chromosome inactivation, MSCI), forming a condensed chromatin domain termed the sex or XY body. The nucleosomal core histone H2AX is phosphorylated within the XY chromatin domain just prior to MSCI, and it has been hypothesized that this triggers the chromatin condensation and transcriptional repression. Here, we show that the kinase ATR localizes to XY chromatin at the onset of MSCI and that this localization is disrupted in mice with a mutant form of the tumor suppressor protein BRCA1. In the mutant pachytene cells, ATR is usually present at nonsex chromosomal sites, where it colocalizes with aberrant sites of H2AX phosphorylation; in these cells, there is MSCI failure. In rare pachytene cells, ATR does locate to XY chromatin, H2AX is then phosphorylated, a sex body forms, and MSCI ensues. These observations highlight an important role for BRCA1 in recruiting the kinase ATR to XY chromatin at the onset of MSCI and provide compelling evidence that it is ATR that phosphorylates H2AX and triggers MSCI. PMID:15589157

Turner, James M A; Aprelikova, Olga; Xu, Xiaoling; Wang, Ruihong; Kim, Sangsoo; Chandramouli, Gadisetti V R; Barrett, J Carl; Burgoyne, Paul S; Deng, Chu-Xia

2004-12-14

378

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.

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

2003-01-01

379

[Genotypic sex and phenotypic sex: clinical, biochemical and molecular aspects in a patient with male hypogonadism and 46XX-45XO karyotype].  

PubMed

We report here the case of a patient with primary male ipogonadism, with small testes and deficient virilization of the external genitalia, but with 46XX, 45X0 karyotype. Hormonal determinations showed high LH and FSH and low testosterone levels. Ultrasonography confirmed the presence of small testes within the scrotum. Cytogenetic analysis demonstrated a female karyotype, with 90% 46XX, 10% 45X0 mosaicism. Using DNA probes for genes located on the Y chromosome, the presence of the "Sex-Determining Region" of the Y chromosome (SRY) was evidenced in the genomic DNA of this patient. By Fluorescence in Situ Hybridization (FISH), SRY locus was localized in the p terminal region of an X chromosome. SRY is the primary inducer of testis development; it acts as a transcription factor leading to a sequence of gene activations critical in the process of testicular differentiation and morphogenesis. A condition characterized by testicular development in subjects who lack a normal Y chromosome has been described; most of these patients are carriers of the short arm of the Y chromosome transferred to one of the two X chromosome, suggesting a form of X-Y paternal interchange. In our patient, the development of male gonade in the absence of an Y chromosome was explained by the demonstration of the SRY gene in an X chromosome. PMID:11822095

Torre, R; Savino, A; Venturi, P; Taverna, R; Triacca, R; Coli, A; Bernasconi, D; Del Monte, P; Marugo, M

2001-12-01

380

Autoradiographic localization of sex steroid hormones in the lymphatic organs of baboons  

Microsoft Academic Search

The localization of radiolabeled estradiol and dihydrotestosterone was examined in the lymphatic organs of both male and female baboons. A total of 12 baboons were divided into two groups, each containing three males and three females. Each animal in one group, both males and females, was injected intravenously with 1 µg\\/kg body weight of 3H-estradiol while those in the second

Frank J. Weaker; Peter J. Sheridan

1983-01-01

381

A Sex-Linked Gene Controlling the Onset of Sexual Maturity in Female and Male Platyfish (XIPHOPHORUS MACULATUS), Fecundity in Females and Adult Size in Males  

PubMed Central

A sex-linked gene, P, controls the onset of sexual maturity in the platyfish, Xiphophorus maculatus. The activity of this gene is correlated with the age and size at which the gonadotropic zone of the adenohypophysis differentiates and becomes physiologically active. Immature fish of all genotypes grow at the same rate; however, as adults, males with "early" genotypes are significantly smaller than males of "late" genotypes, since growth rate declines strongly under the influence of androgenic hormone. Five alleles, P1... P5, have been identified from natural populations that under controlled conditions cause gonad maturation between eight and 73 weeks. P1P1 males become mature at eight weeks and 21 mm, P2P2 and P3P3 males between eleven and 13.5 weeks and 25 to 29 mm, and P4P4 males at 25 weeks and 37 mm. Since P5 is X-linked, no males homozygous for P5 could be produced. The difference between P2 and P3 is largely based upon their interaction with P5. P3P5 males mature at 17.5 weeks and 33.5 mm and P2P5 males at 28 weeks and 38 mm. The rate of transformation of the unmodified anal fin into a gonopodium, which is under androgenic control, is directly related to the age at initiation of sexual maturity, ranging from 3.2 weeks in P1P1 males to seven weeks in P2P 5 males. These differences may reflect different levels of circulating gonadotropic and androgenic hormones.—In two genotypes of females, initiation of vitellogenesis was closely correlated with size and this critical size was independent of age (e.g., 21 mm for P1P1 ). In a third genotype (P1P5) the minimum size for vitellogenesis decreased with increasing age, so that females would mature as early as eleven weeks, provided they had attained at least 29 mm, but at 25 weeks even females as small as 23 mm possessed ripe gonads. For P5P5 females, which become mature between 34 and 73 weeks of age, there is no correlation between size and initiation of vitellogenesis. In all four genotypes of females examined, egg number is strongly correlated with size, but the regression of egg number on standard length is distinct for each genotype. Late maturation of P5P 5 females is not offset by an increased number of eggs; for this genotype there is a strong negative correlation between age and number of eggs. Heterozygous fish always mature later than those homozygous for the "earlier" allele. The site of action of the P locus could be the pituitary gland, the hypothalamus or higher centers of the brain where peripheral information is transduced into an appropriate signal required for the activation of the hypothalamus-pituitary-gonadal axis. The P gene could also control the peripheral information. The platyfish may be a useful model to test theories concerning the evolution of life history strategies.

Kallman, Klaus D.; Borkoski, Valerie

1978-01-01

382

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.

Bonde, Jens Peter

2010-01-01

383

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

384

Structural Composition of Myocardial Infarction Scar in Middle-aged Male and Female Rats: Does Sex Matter?  

PubMed

The present study was designed to determine whether the structural composition of the scar in middle-aged post-myocardial infraction (MI) rats is affected by the biological sex of the animals. A large MI was induced in 12-month-old male (M-MI) and female (F-MI) Sprague-Dawley rats by ligation of the left coronary artery. Four weeks after the MI, rats with transmural infarctions, greater than 50% of the left ventricular (LV) free wall, were evaluated. The extent of LV remodeling and fractional volumes of fibrillar collagen (FC), myofibroblasts, vascular smooth muscle (SM) cells, and surviving cardiac myocytes (CM) in the scars were compared between the two sexes. The left ventricle of post-MI male and female rats underwent a similar degree of remodeling as evidenced by the analogous scar thinning ratio (0.46 ± 0.02 vs. 0.42 ± 0.05) and infarct expansion index (1.06 ± 0.07 vs. 1.12 ± 0.08), respectively. Most important, the contents of major structural components of the scar revealed no evident difference between M-MI and F-MI rats (interstitial FC, 80.74 ± 2.08 vs. 82.57 ± 4.53; myofibroblasts, 9.59 ± 1.68 vs.9.56 ± 1.15; vascular SM cells, 2.27 ± 0.51 vs. 3.38 ± 0.47; and surviving CM, 3.26 ± 0.39 vs. 3.05 ± 0.38, respectively). Our data are the first to demonstrate that biological sex does not influence the structural composition of a mature scar in middle-aged post-MI rats. PMID:23867842

Bogatyryov, Yevgen; Tomanek, Robert J; Dedkov, Eduard I

2013-07-18

385

The influence of sex difference on self-reference effects in a male-dominated culture.  

PubMed

52 secondary school students from the Chaoshan, China, area, where males are highly valued, were examined for self-reference, mother-reference, and father-reference effects. Because the father is the primary role model in Chaoshan culture, it was predicted that male participants would demonstrate a father-reference effect while females would show a mother-reference effect. The results confirmed that females showed significant self-, mother-, and father-reference effects in terms of memory performance, while males showed only a significant father-reference effect and a marginally significant self-reference effect. This study highlights the importance of researching subcultures such as the Chaoshan subculture to gain a comprehensive understanding of self-construct. PMID:23234084

Song, Xuan; Shang, Rui; Bi, Qi; Zhang, Xin; Wu, Yanhong

2012-10-01

386

Diversity, abundance, and sex-specific expression of chemosensory proteins in the reproductive organs of the locust Locusta migratoria manilensis.  

PubMed

Chemosensory proteins (CSPs) are small soluble proteins often associated with chemosensory organs in insects but include members involved in other functions, such as pheromone delivery and development. Although the CSPs of the sensory organs have been extensively studied, little is known on their functions in other parts of the body. A first screening of the available databases has identified 70 sequences encoding CSPs in the oriental locust Locusta migratoria manilensis. Applying proteomic analysis, we have identified 17 of them abundantly expressed in the female reproductive organs, but only one (CSP91) in male organs. Bacterially expressed CSP91 binds fatty acids with a specificity for oleic and linoleic acid, as well as medium-length alcohols and esters. The same acids have been detected as the main gas chromatographic peaks in the dichloromethane extracts of reproductive organs of both sexes. The abundance and the number of CSPs in female reproductive organs indicates important roles for these proteins. We cannot exclude that different functions can be associated with each of the 17 CSPs, including delivery of semiochemicals, solubilization of hormones, direct control of development, or other unknown tasks. PMID:23096575

Zhou, Xian-Hong; Ban, Li-Ping; Iovinella, Immacolata; Zhao, Li-Jing; Gao, Qian; Felicioli, Antonio; Sagona, Simona; Pieraccini, Giuseppe; Pelosi, Paolo; Zhang, Long; Dani, Francesca Romana

2013-01-01

387

Organization of the sex-ratio Meiotic Drive Region in Drosophila simulans  

PubMed Central

Sex-ratio meiotic drive is the preferential transmission of the X chromosome by XY males, which occurs in several Drosophila species and results in female-biased progeny. Although the trait has long been known to exist, its molecular basis remains completely unknown. Here we report a fine-mapping experiment designed to characterize the major drive locus on a sex-ratio X chromosome of Drosophila simulans originating from the Seychelles (XSR6). This primary locus was found to contain two interacting elements at least, both of which are required for drive expression. One of them was genetically tracked to a tandem duplication containing six annotated genes (Trf2, CG32712, CG12125, CG1440, CG12123, org-1), and the other to a candidate region located ?110 kb away and spanning seven annotated genes. RT–PCR showed that all but two of these genes were expressed in the testis of both sex-ratio and standard males. In situ hybridization to polytene chromosomes revealed a complete association of the duplication with the sex-ratio trait in random samples of X chromosomes from Madagascar and Reunion.

Montchamp-Moreau, Catherine; Ogereau, David; Chaminade, Nicole; Colard, Alexandre; Aulard, Sylvie

2006-01-01

388

Individual differences in cognitive abilities and brain organization: I. Sex and handedness differences in ability  

Microsoft Academic Search

Analyzed data on cognitive abilities from 3 samples of normal Ss: (1) 195 undergraduates, (2) 215 18–30 yr old newly married couples, and (3) 122 pairs of monozygotic and dizygotic twins (aged 12–38 yrs). Findings reveal a common Sex by Handedness by Reasoning-Ability interaction: For Ss with above-median reasoning ability, spatial scores of left-handed males were reduced but those of

Richard A. Harshman; Elizabeth Hampson; Sheri A. Berenbaum

1983-01-01

389

Females prefer to associate with males with longer intromittent organs in mosquitofish  

PubMed Central

Sexual selection is a major force behind the rapid evolution of male genital morphology among species. Most within-species studies have focused on sexual selection on male genital traits owing to events during or after copulation that increase a male's share of paternity. Very little attention has been given to whether genitalia are visual signals that cause males to vary in their attractiveness to females and are therefore under pre-copulatory sexual selection. Here we show that, on average, female eastern mosquitofish Gambusia holbrooki spent more time in association with males who received only a slight reduction in the length of the intromittent organ (‘gonopodium’) than males that received a greater reduction. This preference was, however, only expressed when females chose between two large males; for small males, there was no effect of genital size on female association time.

Kahn, Andrew T.; Mautz, Brian; Jennions, Michael D.

2010-01-01

390

HIV Risk Behaviors Among a Sample of Heterosexually Identified Men who Occasionally Have Sex with Another Male and\\/or a Transwoman  

Microsoft Academic Search

Discordance between sexual identity and sexual behavior is not new; however, little is known about the HIV risk behaviors of heterosexually identified men who have occasional sex with a male and\\/or a male-to-female transgender woman. Open-ended qualitative interviews were conducted with 31 heterosexually identified men who reported at least one sexual encounter with a male and\\/or a transwoman in the

Cathy J. Reback; Sherry Larkins

2011-01-01

391

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

2013-09-03

392

Heterogeneity of characteristics, structure, and dynamics of male and hijra sex workers in selected cities of Pakistan  

PubMed Central

Background We sought to describe the characteristics and operational dynamics of male sex workers (MSW) and hijra sex workers (HSWs) in 11 cities across Pakistan in 2011. Methods We report descriptive statistics of self-reported sexual behaviour data from cross-sectional mapping and biological and behavioural surveys conducted among 1431 MSWs and 1415 HSWs in four cities across Pakistan in 2011. Results While Karachi had the largest numbers of MSWs and HSWs, Quetta had the largest relative population sizes, with 3.6?MSWs per 1000 male adults and 3.3?HSWs per 1000 male adults. There was considerable variability in the proportion of HSWs who operate through deras, ranging from 2.2% in Peshawar to 62.7% in Karachi. The number of HSWs per guru varies by city, from 1.5 in Quetta to 16.5?HSWs per guru in Karachi. Among HSWs, the use of mobile phones for solicitation ranged from 37.6% in Quetta to 83% in Peshawar and among MSWs the use of mobile phones ranged from 27% in Karachi to 52% in Quetta. In Quetta, a large proportion of HSWs (41%) find clients through gurus. Client volume tended to be higher among HSWs and among both MSWs and HSWs in Quetta and Peshawar. Condom use with clients was most consistent in Quetta, with 31% of MSWs and 41% of HSWs reporting always using condoms with clients. Peshawar had the greatest proportion reporting never using condoms. Conclusions There is considerable geographic heterogeneity in the characteristics and operational dynamics of MSWs and HSWs across Pakistan.

Thompson, Laura H; Salim, Momina; Baloch, Chaker Riaz; Musa, Nighat; Reza, Tahira; Dar, Nosheen; Arian, Shahzad; Blanchard, James F; Emmanuel, Faran

2013-01-01

393

Birth order, sibling sex ratio, handedness, and sexual orientation of male and female participants in a BBC internet research project.  

PubMed

This study investigated the relations among sexual orientation, fraternal birth order (number of older brothers), and hand-preference. The participants were 87,798 men and 71,981 women who took part in a Web-based research project sponsored by the British Broadcasting Corporation (BBC). The results yielded some evidence confirming prior findings that non-right-handedness is associated with homosexuality in men and women, that older brothers increase the odds of homosexuality in men, and that the effect of older brothers on sexual orientation is limited to right-handed men. The evidence was weaker than in previous studies, however, probably because the usual relations among the variables of interest were partially obscured by the effects of other factors. Thus, the homosexual men and women had higher rates of non-right-handedness than their heterosexual counterparts, but the strongest handedness finding for both sexes was a marked tendency for participants who described themselves as ambidextrous also to describe themselves as bisexual. The birth order data were strongly affected by a tendency for the male participants to report an excess of older sisters, and the female participants to report an excess of older brothers. Statistical analyses confirmed that this was an artifact of the parental stopping rule, "Continue having children until you have offspring of both sexes." In subsequent analyses, participants were divided into those who did and did not have younger siblings, on the grounds that the data of the former would be less contaminated by the stopping rule. In the former subsample, the right-handed homo/bisexual males showed the typical high ratio of older brothers to older sisters, whereas the non-right-handed homo/bisexual males did not. PMID:17345165

Blanchard, Ray; Lippa, Richard A

2007-04-01

394

The Gendered Stereotype of the ?Good Manager? Sex Role Expectations towards Male and Female Managers  

Microsoft Academic Search

In the past 30 years, U.S. and international studies have shown that societal expectations of the ?good manager? are closely related to the male stereotype. However, it is not clear, whether this stereotype is the same for men and women alike in managerial positions. The results of a German study with 625 students and 376 professionals participating between 1997 and

Markus Gmuer

2006-01-01

395

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

396

A Regulatory Cascade Hypothesis for Mammalian Sex Determination: SRY Represses a Negative Regulator of Male Development  

Microsoft Academic Search

The mammalian Y chromosome carries the SRY gene, which determines testis formation. Here we review data on individuals who are XX but exhibit male characteristics: some have SRY; others do not. We have analyzed three families containing more than one such individual and show that these individuals lack SRY. Pedigree analysis leads to the hypothesis that they carry recessive mutations

Ken McElreavey; Eric Vilain; Nacer Abbas; Ira Herskowitz; Marc Fellous

1993-01-01

397

Males' and females' conversational behavior in cross-sex dyads: From gender differences to gender similarities  

Microsoft Academic Search

We investigated gender differences in conversational behavior in an experimental setting. Twenty men and 20 women were randomly paired in 20 dyads and were asked to discuss a given topic. We examined the transcripts through a varied range of behavioral variables. First we analyzed the sequential ordering of utterances in order to establish the way male and female speakers take

Agnesa Pillon; Catherine Degauquier; François Duquesne

1992-01-01

398

On the Borders of Sexuality Research: Young People Who Have Sex with Both Males and Females  

ERIC Educational Resources Information Center

|As D'Augelli and Grossman point out, there is an underrepresentation in LGB research of "youth who have had sexual experiences with both males and females." Most of the information on bisexuality has been obtained from studies with adult samples, and it is "unclear to what extent a separate bisexual cultural identity is consolidated during…

Pallotta-Chiarolli, Maria

2006-01-01

399

Sex, Contraception and Childbearing Among High-Risk Youth: Do Different Factors Influence Males and Females?  

Microsoft Academic Search

Context: The likelihood that adolescents will engage in sexual activity, use contraceptives or become parents is influenced by a range of attitudes and behaviors. These factors may differ for males and females. Methods: Data on female respondents to the 1979-1992 waves of the National Longitudinal Survey of Youth and the linked 1994 young adult data file on their children provided

Lori Kowaleski-Jones; Frank L. Mott

1998-01-01

400

Disorder of sex development (XX male, SRY negative) in a French bulldog  

PubMed Central

A female French bulldog was presented with an enlarged clitoris. Abdominal surgery revealed a normal uterus and gonads resembling testes. Histologically, the gonads contained seminiferous tubules. The karyotype was XX, and the SRY gene was not detected. A diagnosis of XX male, SRY negative disorder of sexual development was made.

Silversides, David W.; Benoit, Jean-Marc; Collard, Fabien; Gilson, Catherine

2011-01-01

401

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…

Goldman, Sylvie

2013-01-01

402

Histidine decarboxylase deficiency in gene knockout mice elevates male sex steroid production  

Microsoft Academic Search

Histamine is synthesized in cells by histidine decarboxylase (HDC). HDC-deficient knockout (KO) mice lack func- tional HDC and histamine in the tissues. In the present study we used this in vivo model for studying the role of HDC deficiency in the regulation of male steroid hormone metabolism. In agreement with earlier studies showing the lack of effects of central histamine

E Pap; K Rácz; J K Kovács; I Varga; E Buzás; B Madarász; A Földes; C Szalai; T Watanabe; H Ohtsu; A Ichikawa; A Nagy; A Falus

2002-01-01

403

Plasticity of the electric organ discharge waveform of male Brachyhypopomus pinnicaudatus . II. Social effects  

Microsoft Academic Search

Many electric fish produce sexually dimorphic electric organ discharges. Although electric organ discharges are comprised of action potentials, those of the Gymnotiform family Hypopomidae show significant plasticity in response to stress and time of day. We show here that male Brachyhypopomus pinnicaudatus (Hopkins 1991), adjusts the degree of sexual dimorphism in its electric organ discharge depending on immediate social conditions.

Cheryl R. Franchina; Vielka L. Salazar; Claude-Henry Volmar; Philip K. Stoddard

2001-01-01

404

Genetic and Epigenetic Effects on Sexual Brain Organization Mediated by Sex Hormones  

Microsoft Academic Search

sexual brain organization; genetic and epigenetic effects; enzyme defi ciencies Abstract Alterations of sex hormone levels during pre- or perinatal sexual brain organiza- tion - responsible for long-term changes of gonadotropin secretion, sexual ori- entation, and gender role behavior - can be caused by: 1. Genetic effects, i.e. mutations or polymorphisms of a) 21-hydroxylase genes on chromosome 6, b) 3?-hydro

Günter Dörner; Franziska Götz; Wolfgang Rohde; Andreas Plagemann; Rolf Lindner; Hartmut Peters; Zhara Ghanaati

2001-01-01

405

Moving to mate: the evolution of separate and combined sexes in multicellular organisms  

Microsoft Academic Search

Which conditions favour the evolution of hermaphroditism or separate sexes? One classical hypothesis states that an organism's mode of locomotion (if any) when searching for a mate should influence breeding system evolution. We used published phylogenies to reconstruct evolutionary changes in adult mate-search efficiency and breeding systems among multicellular organisms. Employing maximum-likelihood analyses, we found that changes in adult mate-search

S. M. EPPLEY; L. K. JESSON

2008-01-01

406

Experiments with digital organisms on the origin and maintenance of sex in changing environments.  

PubMed

Many theories have been proposed to explain the evolution of sex, but the question remains unsettled owing to a paucity of compelling empirical tests. The crux of the problem is to understand the prevalence of sexual reproduction in the natural world, despite obvious costs relative to asexual reproduction. Here we perform experiments with digital organisms (evolving computer programs) to test the hypothesis that sexual reproduction is advantageous in changing environments. We varied the frequency and magnitude of environmental change, while the digital organisms could evolve their mode of reproduction as well as the traits affecting their fitness (reproductive rate) under the various conditions. Sex became the dominant mode of reproduction only when the environment changed rapidly and substantially (with particular functions changing from maladaptive to adaptive and vice versa). Even under these conditions, it was easier to maintain sexual reproduction than for sex to invade a formerly asexual population, although sometimes sex did invade and spread despite the obstacles to becoming established. Several diverse properties of the ancestral genomes, including epistasis and modularity, had no effect on the subsequent evolution of reproductive mode. Our study provides some limited support for the importance of changing environments to the evolution of sex, while also reinforcing the difficulty of evolving and maintaining sexual reproduction. PMID:20200140

Misevic, Dusan; Ofria, Charles; Lenski, Richard E

2010-03-03

407

Ablatio penis: normal male infant sex-reassigned as a girl.  

PubMed

Forty-five cases of genetic males were assigned and habilitated as females, 43 because of a congenitally defective penis (micropenis with or without hypospadias), and two because of infantile ablatio penis. One of the latter has an identical twin brother as a control. Now 9 years old, she has differentiated a female gender identity in marked contrast to the male gender identity of her brother. Some of the other patients are now adolescent or adult in age. They demonstrate that the twin can expect to be feminine in erotic expression and sexual life. Maintained on estrogen therapy, she will have normal feminine physique and a sexually attractive appearance. She will be able to establish motherhood by adoption. PMID:1130980

Money, J

1975-01-01

408

Localization of ³H-estradiol in the reproductive organs of male and female baboons  

Microsoft Academic Search

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 ³H-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

Frank J. Weaker; Peter J. Sheridan

1982-01-01

409

[Sex behavior of male rats after gamma-irradiation: various radiobiological characteristics].  

PubMed

The authors showed a pronounced and stable decrease in sexual motivation of male rats immediately after gamma-irradiation of the head with a dose of 2.58 C/kg. Exposure of the body to 1.29-2.58 C/kg radiation also inhibited sexual behaviour but only by the 45th-55th minute following irradiation: with higher doses some increase in sexual activity was observed immediately after irradiation. PMID:3704121

Ushakov, I B; Rogacheva, I V; Stroganova, E A

410

Homelessness and hunger as HIV risk factors for African American male commercial sex workers  

Microsoft Academic Search

Conclusion  To make health education efforts more effective with this population, researchers and health promotion professionals need\\u000a to collect additional data to formulate health policy specific to AA male CSWs. While these findings support the current available\\u000a research on the subject, little attention has been placed on addressing primary motives and their relationship to risk taking\\u000a among the target population. We

Torrance T. Stephens; Ronald Braithwaite; Judy Lubin; Sha Juan Colbert; Rudolph H. Carn

2000-01-01

411

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

412

Male-biased sex-ratio distortion caused by Octosporea bayeri, a vertically and horizontally-transmitted parasite of Daphnia magna  

Microsoft Academic Search

Female-biased sex-ratio distortion is often observed in hosts infected with vertically-transmitted microsporidian parasites. This bias is assumed to benefit the spread of the parasite, because male offspring usually do not transmit the parasite further. The present study reports on sex-ratio distortion in a host–parasite system with both horizontal and vertical parasite transmission: the microsporidium Octosporea bayeri and its host, the

Olivia Roth; Dieter Ebert; Dita B. Vizoso; Annette Bieger; Sandra Lass

2008-01-01

413

Sex of the cell dictates its response: differential gene expression and sensitivity to cell death inducing stress in male and female cells  

PubMed Central

Sexual dimorphisms are typically attributed to the hormonal differences arising once sex differentiation has occurred. However, in some sexually dimorphic diseases that differ in frequency but not severity, the differences cannot be logically connected to the sex hormones. Therefore, we asked whether any aspect of sexual dimorphism could be attributed to chromosomal rather than hormonal differences. Cells taken from mice at d 10.5 postconception (PC) before sexual differentiation, at d 17.5 PC after the first embryonic assertion of sexual hormones, and at postnatal day 17 (puberty) were cultured and exposed to 400 ?M ethanol or 20 ?M camptothecin or to infection with influenza A virus (multiplicity of infection of 5). The results showed that untreated male and female cells of the same age grew at similar rates and manifested similar morphology. However, they responded differently to the applied stressors, even before the production of fetal sex hormones. Furthermore, microarray and qPCR analyses of the whole 10.5 PC embryos also revealed differences in gene expression between male and female tissues. Likewise, the exposure of cells isolated from fetuses and adolescent mice to the stressors and/or sex hormones yielded expression patterns that reflected chromosomal sex, with ethanol feminizing male cells and masculinizing female cells. We conclude that cells differ innately according to sex irrespective of their history of exposure to sex hormones. These differences may have consequences in the course of sexually dimorphic diseases and their therapy.—Penaloza, C., Estevez, B., Orlanski, S., Sikorska, M., Walker, R., Smith, C., Smith, B., Lockshin R. A., Zakeri, Z. Sex of the cell dictates its response: differential gene expression and sensitivity to cell death inducing stress in male and female cells.

Penaloza, Carlos; Estevez, Brian; Orlanski, Shari; Sikorska, Marianna; Walker, Roy; Smith, Catherine; Smith, Brandon; Lockshin, Richard A.; Zakeri, Zahra

2009-01-01

414

Female sex workers, male circumcision and HIV: a qualitative study of their understanding, experience, and HIV risk in Zambia.  

PubMed

Several sub-Saharan African countries, including Zambia, have initiated national voluntary medical male circumcision (MC) programs to reduce HIV incidence. In-depth interviews were conducted with twenty female sex workers (FSWs) in Lusaka to examine their understanding of MC and experiences with circumcised clients. Knowledge of MC was derived primarily through informal sources, with very few FSWs reporting exposure to MC educational campaigns. MC was not widely believed to be protective against HIV, however it was viewed by some as protective against STIs. Three FSWs reported having sex with recently circumcised clients, and most reported that men often used their MC status to try to convince FSWs to forego condoms. Findings suggest that FSWs, already at high risk for HIV infection, may face additional pressure toward higher risk behavior as a result of MC. As MC services are expanded, programs should support FSWs' efforts to protect themselves by providing information about what MC can--and cannot--offer for HIV/STI infection prevention. PMID:23349745

Abbott, Sharon A; Haberland, Nicole A; Mulenga, Drosin M; Hewett, Paul C

2013-01-17

415

Interventions among male clients of female sex workers in Benin, West Africa: an essential component of targeted HIV preventive interventions  

PubMed Central

Objectives To assess the impact of interventions targeted towards female sex workers (FSWs) and their male clients on client HIV/STI prevalence and sexual behaviour. Methods From 1993 to 2006, an HIV/STI preventive intervention focusing on condom promotion and STI care was implemented among FSWs in Cotonou, Benin, and then expanded to cover their male sexual partners in 2000. The interventions were scaled up to five other cities of Benin in 2001–2002. Serial cross?sectional surveys of HIV/STI prevalence and sexual behaviour were carried out among clients in Cotonou in 1998, 2002 and 2005; and in the five other cities (O/Cotonou) in 2002 and 2005. Results Significant declines in gonorrhoea prevalence among clients of FSWs: Cotonou, from 5.4% in 1998 to 1.6% in 2005; O/Cotonou: from 3.5% in 2002 to 0.59% in 2005. Chlamydia prevalence also declined O/Cotonou, from 4.8% to 1.8%, while HIV prevalence remained stable. Reported condom use by clients with both FSWs and casual non?FSW partners, but not regular partners, increased significantly. While condom use at last sex with an FSW was similar in Cotonou to O/Cotonou around the time of implementation of the interventions (56% in 1998 vs 49% in 2002, respectively), it had risen to similar levels by 2005 (95% and 96%, respectively). Conclusions These results demonstrate that it is possible to implement preventive and clinical services for clients of FSWs, and suggest that such interventions, integrated with those targeted towards FSWs, can have a significant effect on sexual behaviour and STI prevalence (particularly gonorrhoea) among this population.

Lowndes, C M; Alary, M; Labbe, A-C; Gnintoungbe, C; Belleau, M; Mukenge, L; Meda, H; Ndour, M; Anagonou, S; Gbaguidi, A

2007-01-01

416

Serotonin transporter (SERT) mRNA and binding site densities in male rat brain affected by sex steroids.  

PubMed

Estrogen increases serotonin transporter (SERT) mRNA and binding sites in female rat brain. In order to determine whether changes in SERT are gender- and steroid-specific we have now carried out studies on adult male Wistar rats which were either intact or castrated (under halothane anesthesia) and injected with arachis oil, estradiol benzoate (EB), testosterone propionate (TP) or the non-aromatizable androgen, 5alpha-dihydrotestosterone (5alpha-DHT). The number of SERT mRNA-expressing cells in the dorsal raphe (DR) nucleus was decreased by castration and increased by treatment (for approximately 32 h) with EB or TP, but not 5alpha-DHT. Sex steroids had no effect on the number of SERT mRNA-expressing cells in the median raphe nucleus. The density of SERT sites, assessed by autoradiography of [3H]paroxetine binding, was significantly reduced in arcuate nucleus and median raphe after castration, and increased in arcuate, basolateral amygdala and ventromedial hypothalamic nucleus by treatment with EB or TP, but not 5alpha-DHT. Estradiol, but not testosterone or 5alpha-DHT reduced the density of SERT sites in midbrain central grey. These data show that testosterone as well as estrogen affects SERT expression in male brain, and that the action of testosterone probably depends upon its enzymatic conversion, by aromatase, to estradiol. Our findings may have implications for sex steroid control of mood and behavior, and the action of neurotoxic derivatives of amphetamine, such as 3, 4-methylenedioxymethamphetamine, in the human. PMID:9878762

McQueen, J K; Wilson, H; Sumner, B E; Fink, G

1999-01-01

417

TBI sex dependently upregulates ET-1 to impair autoregulation, which is aggravated by phenylephrine in males but is abrogated in females.  

PubMed

Traumatic brain injury (TBI) contributes to morbidity in children, and boys are disproportionately represented. Endothelin-1 (ET-1) contributes to impaired autoregulation via oxygen (O??) after TBI in piglets, but its relative role in males compared with females has not been previously investigated. Increased cerebral perfusion pressure (CPP) via phenylephrine (Phe) sex dependently improves impairment of autoregulation after TBI through modulation of extracellular signal-related kinase (ERK) mitogen-activated protein kinase (MAPK) upregulation, aggravated in males, but blocked in females. Activation of adenosine-5'-triphosphate (ATP) and Ca sensitive K channels produce vasodilation, contributing to autoregulation. We hypothesized that ET-1 upregulation is greater in males after TBI and that disturbed autoregulation will be prevented by Phe in a sex-dependent manner through modulation of ET-1, O??, and ERK. Results show that ET-1 release was greater in males after fluid percussion injury (FPI), blunted by Phe in females, but aggravated in males. K channel vasodilation was impaired more in males than in females after TBI. Phe prevented reductions in K channel vasodilation in females, but further reduced dilation in males after TBI. Co-administration of BQ-123, U0126, or PEG-SOD (ET-1, ERK antagonist, and O?? scavenger) with Phe restored dilation to K agonists and hypotension in males after TBI. ERK upregulation was blocked by BQ-123 and PEG-SOD. These data indicate that TBI upregulates ET-1 more in males than in females. Elevation of CPP with Phe sex dependently prevents impairment of cerebral autoregulation after TBI through modulation of ET-1, O??, and ERK mediated impairment of K channel vasodilation. These observations advocate for the consideration of development of sex-based therapies for the treatment of hemodynamic sequelae of pediatric TBI. PMID:22335188

Armstead, William M; Riley, John; Vavilala, Monica S

2012-03-29

418

TBI Sex Dependently Upregulates ET-1 To Impair Autoregulation, which Is Aggravated by Phenylephrine in Males but Is Abrogated in Females  

PubMed Central

Abstract Traumatic brain injury (TBI) contributes to morbidity in children, and boys are disproportionately represented. Endothelin-1 (ET-1) contributes to impaired autoregulation via oxygen (O2-) after TBI in piglets, but its relative role in males compared with females has not been previously investigated. Increased cerebral perfusion pressure (CPP) via phenylephrine (Phe) sex dependently improves impairment of autoregulation after TBI through modulation of extracellular signal-related kinase (ERK) mitogen-activated protein kinase (MAPK) upregulation, aggravated in males, but blocked in females. Activation of adenosine-5'-triphosphate (ATP) and Ca sensitive K channels produce vasodilation, contributing to autoregulation. We hypothesized that ET-1 upregulation is greater in males after TBI and that disturbed autoregulation will be prevented by Phe in a sex-dependent manner through modulation of ET-1, O2-, and ERK. Results show that ET-1 release was greater in males after fluid percussion injury (FPI), blunted by Phe in females, but aggravated in males. K channel vasodilation was impaired more in males than in females after TBI. Phe prevented reductions in K channel vasodilation in females, but further reduced dilation in males after TBI. Co-administration of BQ-123, U0126, or PEG-SOD (ET-1, ERK antagonist, and O2-scavenger) with Phe restored dilation to K agonists and hypotension in males after TBI. ERK upregulation was blocked by BQ-123 and PEG-SOD. These data indicate that TBI upregulates ET-1 more in males than in females. Elevation of CPP with Phe sex dependently prevents impairment of cerebral autoregulation after TBI through modulation of ET-1, O2-, and ERK mediated impairment of K channel vasodilation. These observations advocate for the consideration of development of sex-based therapies for the treatment of hemodynamic sequelae of pediatric TBI.

Riley, John; Vavilala, Monica S.

2012-01-01

419

Male Same Sex Couple Dynamics and Received Social Support for HIV Medication Adherence  

PubMed Central

This qualitative study examines received social support by analyzing relationship dynamics concerning antiretroviral therapy (ART) adherence among HIV+ seroconcordant and serodiscordant male couples. Using narrative data from forty participants (20 couples interviewed separately), we describe patterns of relationship dynamics and support preferences. One group viewed adherence as a Personal Responsibility. A second group viewed adherence as a Couple Responsibility and integrated support for medication adherence into the relationship. A third group was in the process of ending their relationships and adherence support was one-sided or withdrawn altogether. Examining support exchanges contexts at cultural, situational, relational, and personal levels illuminated adherence processes. Qualitative methods provided a framework for investigating these complex relationships and their associations with HIV treatment adherence.

Wrubel, Judith; Stumbo, Scott; Johnson, Mallory O.

2010-01-01

420

Regret after sex reassignment surgery in a male-to-female transsexual: a long-term follow-up.  

PubMed

This case report describes a four-decade presentation of a non-homosexual gender dysphoric male patient. The case material was collected from two main sources. One of the authors had weekly therapy sessions with the patient over a period of 2 years almost 15 years after sex reassignment surgery. Information was also gained from the patient's medical records covering the period from the early 1960s to the early 1990s. Over the years, the patient fulfilled the criteria for different diagnoses: overanxious reaction of childhood, fetishism and transvestism during adolescence, and transsexualism during adolescence and early adulthood. The purpose of this report was to shed light on aspects of regret, its manifestation in a male-to-female transsexual with psychiatric co-morbidity, and to show the complexity of the process of adjustment when regret is involved. The present case is an argument for a strict interpretation of the Standards of Care provided by the Harry Benjamin International Gender Dysphoria Association in terms of evaluating patients' mental health, apart from the evaluation of the gender identity disorder, and the patients' subsequent need for treatment interventions. PMID:16900416

Olsson, Stig-Eric; Möller, Anders

2006-08-11

421

Male-Dominant Activation of Rat Renal Organic Anion Transporter 1 (Oat1) and 3 (Oat3) Expression by Transcription Factor BCL6  

PubMed Central

Background Organic anion transporters 1 (Oat1) and 3 (Oat3) mediate the transport of organic anions, including frequently prescribed drugs, across cell membranes in kidney proximal tubule cells. In rats, these transporters are known to be male-dominant and testosterone-dependently expressed. The molecular mechanisms that are involved in the sex-dependent expression are unknown. Our aim was to identify genes that show a sex-dependent expression and could be involved in male-dominant regulation of Oat1 and Oat3. Methodology/Principal Findings Promoter activities of Oat1 and Oat3 were analyzed using luciferase assays. Expression profiling was done using a SurePrint G3 rat GE 8×60K microarray. RNA was isolated from renal cortical slices of four adult rats per sex. To filter the achieved microarray data for genes expressed in proximal tubule cells, transcription database alignment was carried out. We demonstrate that predicted androgen response elements in the promoters of Oat1 and Oat3 are not functional when the promoters were expressed in OK cells. Using microarray analyses we analyzed 17,406 different genes. Out of these genes, 56 exhibit a sex-dependent expression in rat proximal tubule cells. As genes potentially involved in the regulation of Oat1 and Oat3 expression, we identified, amongst others, the male-dominant hydroxysteroid (17-beta) dehydrogenase 1 (Hsd17b1), B-cell CLL/lymphoma 6 (BCL6), and polymerase (RNA) III (DNA directed) polypeptide G (Polr3g). Moreover, our results revealed that the transcription factor BCL6 activates promoter constructs of Oat1 and Oat3. Conclusion The results indicate that the male-dominant expression of both transporters, Oat1 and Oat3, is possibly not directly regulated by the classical androgen receptor mediated transcriptional pathway but appears to be regulated by the transcription factor BCL6.

Wegner, Waja; Burckhardt, Birgitta Christina; Burckhardt, Gerhard; Henjakovic, Maja

2012-01-01

422

Effects of the absence of a father and other male models on the development of boys' sex roles  

Microsoft Academic Search

58 2nd-grade boys, 29 with fathers present and 29 with fathers absent, were given the Draw-A-Person and the Drawing Completion Tests to measure sex role orientation, the Drake Preference Test to measure sex role performance, and the Vroegh Test to measure sex role adoption. Results show that father absence had significant effects on sex role orientation.

Charles T. Drake; Daniel McDugall

1977-01-01

423

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 propos