Sex determination gene transformer regulates the male-female difference in Drosophila fat storage via the adipokinetic hormone pathway

Sex differences in whole-body fat storage exist in many species. For example, Drosophila females store more fat than males. Yet, the mechanisms underlying this sex difference in fat storage remain incompletely understood. Here, we identify a key role for sex determination gene transformer (tra) in regulating the male-female difference in fat storage. Normally, a functional Tra protein is present only in females, where it promotes female sexual development. We show that loss of Tra in females reduced whole-body fat storage, whereas gain of Tra in males augmented fat storage. Tra's role in promoting fat storage was largely due to its function in neurons, specifically the Adipokinetic hormone (Akh)-producing cells (APCs). Our analysis of Akh pathway regulation revealed a male bias in APC activity and Akh pathway function, where this sex-biased regulation influenced the sex difference in fat storage by limiting triglyceride accumulation in males. Importantly, Tra loss in females increased Akh pathway activity, and genetically manipulating the Akh pathway rescued Tra-dependent effects on fat storage. This identifies sex-specific regulation of Akh as one mechanism underlying the male-female difference in whole-body triglyceride levels, and provides important insight into the conserved mechanisms underlying sexual dimorphism in whole-body fat storage.

Regulators of male and female sexual development critical for transmission of a malaria parasite

The transmission of malaria parasites from vertebrate host to mosquito vector requires a developmental switch in asexually dividing blood-stage parasites to sexual reproduction. In Plasmodium berghei the transcription factor AP2-G is required and sufficient for this switch, but how a particular sex is determined in a haploid parasite remains unknown. Using a global screen of barcoded mutants, we here identify ten genes essential for the formation of either male or female sexual forms and validate their importance for transmission. High-resolution single-cell transcriptomics of wild-type and mutant parasites portrays the developmental bifurcation and reveals a regulatory cascade of putative gene functions in determination and subsequent differentiation of each sex. A male-determining gene with a LOTUS/OST-HTH domain points towards unexpected conservation of molecular mechanisms of gametogenesis in animals and a distantly related eukaryotic parasite.

Sex determination gene transformer regulates the male-female difference in Drosophila fat storage via the Adipokinetic hormone pathway

Sex differences in whole-body fat storage exist in many species. For example, Drosophila females store more fat than males. Yet, the mechanisms underlying this sex difference in fat storage remain incompletely understood. Here, we identify a key role for sex determination gene transformer (tra) in regulating the male-female difference in fat storage. Normally, a functional Tra protein is present only in females, where it promotes female sexual development. We show that loss of Tra in females reduced whole-body fat storage, whereas gain of Tra in males augmented fat storage. Tra's role in promoting fat storage was largely due to its function in neurons, specifically the Adipokinetic hormone (Akh)-producing cells (APCs). Our analysis of Akh pathway regulation revealed a male bias in APC activity and Akh pathway function, where this sex-biased regulation influenced the sex difference in fat storage by limiting triglyceride accumulation in males. Importantly, Tra loss in females increased Akh pathway activity, and genetically manipulating the Akh pathway rescued Tra-dependent effects on fat storage. This identifies sex-specific regulation of Akh as one mechanism underlying the male-female difference in whole-body triglyceride levels, and provides important insight into the conserved mechanisms underlying sexual dimorphism in whole-body fat storage.

Assessing Effects of Life History Antecedents on Age at Menarche and Sexual Debut Using a Genetically Informative Design

Life history derived models of female sexual development all propose menarche timing as a key regulatory mechanism driving subsequent sexual behavior. The current research utilized a twin subsample of the National Longitudinal Study of Adolescent to Adult Health (Add Health; n =520) to comprehensively evaluate effects of life history antecedents on menarche timing and sexual debut, and extend understanding of these life history models with a genetically informative design. The results show mixed support for each life history model and did not provide evidence any effect on age at menarche. Results of this research call to question the underlying assumptions of life history derived models of sexual development and highlight the need for more behavior genetic research in this area.

Adolescent Female Desire

The development of healthy female sexuality is a complex and multidimensional process. In understanding female adolescent sexual development, we must understand both the suppression and the celebration of female desire in its historical and structural contexts. Feminist theorists have long studied the suppression of desire and connected that desire to both subjectivity and agency. However, desire remains an elusive concept. This chapter reviews the history of desire and sexual freedom, looks at three historical and institutional influences over adolescent sexual desire (gender inequality, education, and the media), and then interrogates the idea of sexual agency to understand how adolescents and young women conceive of sexual agency today in a neoliberal context. The chapter ends with suggestions for practice, education, and activism to help promote healthier female sexual development.

Systematically improved in vitro culture conditions reveal new insights into the reproductive biology of the human parasite Schistosoma mansoni

ABSTRACTSchistosomes infect over 200 million people. The prodigious egg output of these parasites is the sole driver of pathology due to infection, yet our understanding of their sexual reproduction is limited because egg production is not sustained for more than a few days in vitro. Here, we describe culture conditions that support schistosome sexual development and sustained egg production in vitro. Female schistosomes rely on continuous pairing with male worms to fuel the maturation of their reproductive organs. Exploiting these new culture conditions, we explore the process of male-stimulated female maturation and demonstrate that physical contact with a male worm, and not insemination, is sufficient to induce female development and the production of viable parthenogenetic haploid embryos. We further report the characterization of a novel nuclear receptor, that we call vitellogenic factor 1, that is essential for female sexual development following pairing with a male worm. Taken together, these results provide a platform to study the fascinating sexual biology of these parasites on a molecular level, illuminating new strategies to control schistosome egg production.

Person of the Month: Karen Horney (1885-1952)

Karen Horney (nee Danielson) was born near Hamburg, Germany on September 16, 1885. Her father was a religious, authoritarian ship’s captain, while her mother was a well-educated, more liberal intellectual who encouraged Danielson in her studies. Her father was a widower with four teenage children. Danielson was the second child from his new marriage, the first being a favoured older brother. Unflattering comments by her father relating to both her looks and her intelligence led Danielson to decide, at the age of nine, that if she couldn’t be pretty, then she would be smart. At age nine she also battled depression for the first time and would continue the battle throughout her life. At 13, Danielson decided she wanted to become a doctor – a lofty and perhaps not very realistic goal for a young woman in the late 19th century. Without her parents’ support, Danielson nonetheless entered medical school in 1906 as one of the first women to enter a German university. While there, she met economics major and aspiring law student, Oskar Horney, and the two married in 1909. It was not a particularly happy marriage although it did result in three daughters born between 1910 and 1916. Within the space of one year, Horney gave birth to her first daughter and lost both of her parents. She sought psychoanalysis to help her cope. Her analyst was Freud disciple Karl Abraham, who became her mentor at the Berlin Psychoanalytic Society where she became an analyst in private practice in addition to her hospital work. She helped design and eventually directed the Society’s training program, taught students, and conducted psychoanalytic research. Her roles as woman doctor, wife, and mother inspired her research on female sexual development, writing about the castration complex in women in 1924 and asserting – contrary to Freud – which the true source of penis envy was in the way female children were treated by their parents.