Positive Darwinian selection drives the evolution of several female reproductive proteins in mammals

Rapid evolution driven by positive Darwinian selection is a recurrent theme in male reproductive protein evolution. In contrast, positive selection has never been demonstrated for female reproductive proteins. Here, we perform phylogeny-based tests on three female mammalian fertilization proteins and demonstrate positive selection promoting their divergence. Two of these female fertilization proteins, the zona pellucida glycoproteins ZP2 and ZP3, are part of the mammalian egg coat. Several sites identified in ZP3 as likely to be under positive selection are located in a region previously demonstrated to be involved in species-specific sperm-egg interaction, suggesting the selective pressure is related to male-female interaction. The results provide long-sought evidence for two evolutionary hypotheses: sperm competition and sexual conflict.

Traumatic insemination and sexual conflict in the bed bug Cimex lectularius

The bed bug, Cimex lectularius, has a unique mode of copulation termed “traumatic” insemination [Carayon, J. (1966) in Monograph of the Cimicidae, ed. Usinger, R. (Entomol. Soc. Am., Philadelphia), pp. 81–167] during which the male pierces the female's abdominal wall with his external genitalia and inseminates into her body cavity [Carayon, J. (1966) in Monograph of the Cimicidae, ed. Usinger, R. (Entomol. Soc. Am., Philadelphia), pp. 81–167]. Under controlled natural conditions, traumatic insemination was frequent and temporally restricted. We show for the first time, to our knowledge, that traumatic insemination results in (i) last-male sperm precedence, (ii) suboptimal remating frequencies for the maintenance of female fertility, and (iii) reduced longevity and reproductive success in females. Experimental females did not receive indirect benefits from multiple mating. We conclude that traumatic insemination is probably a coercive male copulatory strategy that results in a sexual conflict of interests.

Incipient speciation by sexual isolation in Drosophila: Concurrent evolution at multiple loci

Drosophila melanogaster from Zimbabwe and nearby regions shows strong but asymmetric sexual isolation from its cosmopolitan counterparts. By creating stable chromosome-substitution lines, earlier studies were able to show that the two major autosomes have very large effects on both male mating success and female mating preference. In this study, we genetically dissect this sexual isolation by recombination analysis between a whole-chromosome substitution line (which carries a Zimbabwe-derived third chromosome) and a strain with seven visible markers on that chromosome. Four loci are responsible for male mating success and three others are found to control female mating preference. Because male and female traits are not closely linked, their strong association among isofemale lines is most likely a reflection of sexual selection in nature. The results suggest that a large number of behavioral loci may evolve concurrently in the incipient stage of speciation before other aspects of reproductive isolation (such as hybrid sterility) have become evident. The results shed light on the population genetic processes underlying the formation of nascent species, as well as modes of speciation.

Excitatory versus inhibitory GABA as a divergence point in steroid-mediated sexual differentiation of the brain

Whereas adult sex differences in brain morphology and behavior result from developmental exposure to steroid hormones, the mechanism by which steroids differentiate the brain is unknown. Studies to date have described subtle sex differences in levels of proteins and neurotransmitters during brain development, but these have lacked explanatory power for the profound sex differences induced by steroids. We report here a major divergence in the response to injection of the γ-aminobutyric acid type A (GABAA) agonist, muscimol, in newborn male and female rats. In females, muscimol treatment primarily decreased the phosphorylation of cAMP response element binding protein (CREB) within the hypothalamus and the CA1 region of the hippocampus. In contrast, muscimol increased the phosphorylation of CREB in males within these same brain regions. Within the arcuate nucleus, muscimol treatment increased the phosphorylation of CREB in both females and males. Thus, the response to GABA can be excitatory or inhibitory on signal-transduction pathways that alter CREB phosphorylation depending on the sex and the region in developing brain. This divergence in response to GABA allows for a previously unknown form of steroid-mediated neuronal plasticity and may be an initial step in establishing sexually dimorphic signal-transduction pathways in developing brain.

Female mating preference for bold males in the guppy, Poecilia reticulata.

Although females prefer to mate with brightly colored males in numerous species, the benefits accruing to such females are virtually unknown. According to one hypothesis of sexual selection theory, if the expression of costly preferred traits in males (such as conspicuous colors) is proportional to the male's overall quality or reveals his quality, a well-developed trait should indicate good condition and/or viability for example. A female choosing such a male would therefore stand to gain direct or indirect fitness benefits, or both. Among potential phenotypic indicators of an individual's quality are the amount and brightness of its carotenoid-based colors and its boldness, as measured by its willingness to risk approaching predators without being killed. Here, we show experimentally that in the Trinidadian guppy (Poecilia reticulata) the visual conspicuousness of the color pattern of males correlates positively with boldness toward, and with escape distance from, a cichlid fish predator. Bold individuals are thus more informed about nearby predators and more likely to survive encounters with them. Mate-choice experiments showed that females prefer colorful males as mates, but prefer bolder males irrespective of their coloration when given the opportunity to observe their behavior toward a potential fish predator. By preferentially mating with colorful males, female guppies are thus choosing on average, relatively bold, and perhaps more viable, individuals. In doing so, and to the extent that viability is heritable, they potentially gain indirect fitness benefits by producing more viable offspring than otherwise.

Sexual orientation in Drosophila is altered by the satori mutation in the sex-determination gene fruitless that encodes a zinc finger protein with a BTB domain.

We have isolated a new Drosophila mutant, satori (sat), the males of which do not court or copulate with female flies. The sat mutation comaps with fruitless (fru) at 91B and does not rescue the bisexual phenotype of fru, indicating that sat is allelic to fru (fru(sat)). The fru(sat) adult males lack a male-specific muscle, the muscle of Lawrence, as do adult males with other fru alleles. Molecular cloning and analyses of the genomic and complementary DNAs indicated that transcription of the fru locus yields several different transcripts. The sequence of fru cDNA clones revealed a long open reading frame that potentially encodes a putative transcription regulator with a BTB domain and two zinc finger motifs. In the 5' noncoding region, three putative transformer binding sites were identified in the female transcript but not in male transcripts. The fru gene is expressed in a population of brain cells, including those in the antennal lobe, that have been suggested to be involved in determination of male sexual orientation. We suggest that fru functions downstream of tra in the sex-determination cascade in some neural cells and that inappropriate sexual development of these cells in the fru mutants results in altered sexual orientation of the fly.

Localization of pheromonal sexual dimorphism in Drosophila melanogaster and its effect on sexual isolation.

Drosophila melanogaster is sexually dimorphic for cuticular hydrocarbons, with males and females having strikingly different profiles of the long-chain compounds that act as contact pheromones. Gas-chromatographic analysis of sexual mosaics reveals that the sex specificity of hydrocarbons is located in the abdomen. This explains previous observations that D. melanogaster males display the strongest courtship toward mosaics with female abdomens. We also show that males of the sibling species Drosophila simulans preferentially court D. melanogaster mosaics with male abdomens. Because the primary male hydrocarbon in D. melanogaster is also the primary female hydrocarbon in D. simulans, this supports the idea that interspecific differences in cuticular hydrocarbons contribute to sexual isolation.

Sexual isolation in Drosophila melanogaster: a possible case of incipient speciation.

It is generally believed that Drosophila melanogaster has no closely related species with which it can produce the viable and fertile hybrids that are essential for the genetic analysis of speciation. Following the recent report of molecular differentiation between a Zimbabwe, Africa, population and two United States populations, we provide evidence that strong sexual isolation exists between the D. melanogaster population in Zimbabwe and populations of other continents. In the presence of males of their own kind, females from most isofemale lines of Zimbabwe would not mate with males from elsewhere; the reciprocal mating is also significantly reduced, but to a lesser degree. The genes for sexual behaviors are apparently polymorphic in Zimbabwe and postmating reproductive isolation between this and other populations has not yet evolved. Whole chromosome substitutions indicate significant genetic contributions to male mating success by both major autosomes, whereas the X chromosome effect is too weak to measure. In addition, the relative mating success between hybrid and pure line males supports the interpretation of strong female choice. These observations suggest that we are seeing the early stages of speciation in this group and that it is driven by sexual selection. The genetic and molecular tractability of D. melanogaster offers great promise for the detailed analysis of this apparent case of incipient speciation.

The Relationship Between Feminine Gender Norm Conformity and Purpose and Meaning in Life Among Female College Students.

This study explores the relationship between conformity to traditional feminine gender norms and meaning and purpose in life among female college students. Based on previous research findings that show a negative correlation between specific traditional feminine gender norm conformity factors and psychological well-being, we posited that participants with higher levels of traditional gender norm conformity will experience a lower sense of meaning and purpose in life. Self-report data was obtained from 338 female undergraduate college students using the Conformity to Feminine Norms Inventory (CFNI) and the Purpose in Life Test (PIL). A standard multiple regression assessed the accuracy of eight feminine norms in predicting purpose and meaning in life. Results partially supported the hypothesis, with Modesty as the most significant contributor to meaning and purpose. Inconsistent with our hypothesis, participants who endorsed high scores on Nice in Relationships, Involvement with Children, Sexual Fidelity, and Domestic, scored higher on the PIL.

Male/Female Manifestations of Narcissistic Personality and Behavioral Disorders.

Specifically, this paper will address the following topics : 1. The history of psychoanalytic thinking onnarcissism will be discussed, leading up to more recent ideas on the narcissistic personality disorder. 2. Drawing on historical and current ideas, an integrated definition of the narcissistic personality disorder will be presented and elaborated upon, including an examination of differing male/female narcissistic compensatory styles. 3. To foster an understanding of the development of narcissistic defenses and of differing gender styles of defense, various theories relating to gender differences in the narcissistic personality disorder will be explored: self/object relations theories, Kohut's theory on narcissism, psychosexual development theories, behavioral manifestation theories, and bodily development theories.4. The role of preoedipal development, as it relates to the formation of the male/female narcissistic personality disorder, will be examined. This section of the paper will propose that, in the narcissistic personality disorder, a pathological arrest occurred during the second or third year of life in response to trauma experienced at that time. The degree and timing of the trauma and the degree of structuralization preceding the trauma all contribute to the rigidity of the narcissistic disorder and the severity of the pathology. 5. The role of oedipal development in the male/female narcissistic personality disorder will be discussed. This discussion will address the intrapsychic configurations which arise during the oedipal period, after narcissistic defenses have solidified during the preoedipal years. While narcissism can be seen as a developmental line, with narcissistic defenses arising at any time during development, this paper will focus primarily on defenses which arise during the separation/individuation phases of development.

The Experience of Minority Female Coaches within Intercollegiate Athletics

It has been suggested that the United States has shown an increase of acceptance and positive attitudes toward diverse cultures and populations. However, there continues to be a drought in research that examines the experience of minority women. In addition, few studies have focused on minority female coaches within athletic environments, which have been known to be both heterosexist and homonegative (Griffin, 1992; Griffin, 1998; Krane, 1996; Krane & Barber, 2003; Krane & Barber, 2005; Roper & Halloran, 2007; Schreibstein, 2010). A person who holds a minority identity has been defined by this paper as belonging to an underrepresented group, including: race, ethnicity, gender, disability, age, religion, and/or sexual orientation. This study, in particular, focused on three specific minority groups: race, gender, and sexual orientation. The proposed study assessed the experiences, challenges, and strategies to overcome obstacles of female coaches who hold minority statuses within National Collegiate Athletic Association (NCAA) athletic departments.

Social determinants of sexual satisfaction in Spain considered from the gender perspective

Aims: To describe gender- and social class-related inequalities in sexual satisfaction and analyze their relationship with self-perceived health status. Methods: This population-based, cross-sectional study included 7384 sexually active people aged 16 years and over residing in Spain in 2009 (3951 men and 3433 women). The explanatory variables were gender, age, social class, share in performing domestic tasks, spend time looking after oneself, collaborate economically in supporting the family, caring for children, self-perceived health status, and the desire to increase or decrease frequency of having sexual relations. Bivariate and multivariate logistic regression models were fitted. Results: Among women, sexual satisfaction declines progressively after age 45. Sexual satisfaction is 1.7 times higher among women who look after themselves and who feel good compared with those who do not. The odds of wanting to increase sex is 3.3 times higher for women who are satisfied compared with women who desire a lower frequency of sexual intercourses; and good perceived health was associated with sexual satisfaction. In satisfied men, the corresponding odds is 1.9 times that of men desiring to reduce their frequency of sex. Conclusions: Gender and social class inequalities are found in sexual satisfaction. This is associated with perceived health status, adding evidence in support of the World Health Organization definition of sexual health.

Straight but not Narrow; Within-Gender Variation in the Gender-Specificity of Women's Sexual Response

Gender differences in the specificity of sexual response have been a primary focus in sexual psychophysiology research, however, within-gender variability suggests sexual orientation moderates category-specific responding among women; only heterosexual women show gender-nonspecific genital responses to sexual stimuli depicting men and women. But heterosexually-identified or “straight” women are heterogeneous in their sexual attractions and include women who are exclusively androphilic (sexually attracted to men) and women who are predominantly androphilic with concurrent gynephilia (sexually attracted to women). It is therefore unclear if gender-nonspecific responding is found in both exclusively and predominantly androphilic women. The current studies investigated within-gender variability in the gender-specificity of women’s sexual response. Two samples of women reporting concurrent andro/gynephilia viewed (Study 1, n = 29) or listened (Study 2, n = 30) to erotic stimuli varying by gender of sexual partner depicted while their genital and subjective sexual responses were assessed. Data were combined with larger datasets of predominantly gyne- and androphilic women (total N = 78 for both studies). In both studies, women reporting any degree of gynephilia, including those who self-identified as heterosexual, showed significantly greater genital response to female stimuli, similar to predominantly gynephilic women; gender-nonspecific genital response was observed for exclusively androphilic women only. Subjective sexual arousal patterns were more variable with respect to sexual attractions, likely reflecting stimulus intensity effects. Heterosexually-identified women are therefore not a homogenous group with respect to sexual responses to gender cues. Implications for within-gender variation in women’s sexual orientation and sexual responses are discussed.

46,XX doença do desenvolvimento sexual testicular : a propósito de um caso clínico

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

Transmissão sexual e tratamento na hepatite C aguda : dois casos clinicos

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014