Seeds of flowering plants can be formed sexually or asexually through apomixis. Apomixis occurs in about 400 species and is of great interest for agriculture as it produces clonal offspring. It differs from sexual reproduction in three major aspects: (1) While the sexual megaspore mother cell (MMC) undergoes meiosis, the apomictic initial cell (AIC) omits or aborts meiosis (apomeiosis); (2) the...

Reproductive aging in males is characterized by a diminution in sexual behavior beginning in middle age. We investigated the relationships among testosterone, androgen receptor (AR) and estrogen receptor alpha (ERalpha) cell numbers in the hypothalamus, and their relationship to sexual performance in male rats. Young (3months) and middle-aged (12months) rats were given sexual behavior tests, th...

Our understanding of how cell cycle regulation and virulence are coordinated during the induction of fungal pathogenesis is limited. In the maize smut fungus Ustilago maydis, pathogenesis and sexual development are intricately interconnected. Furthermore, the first step in the infection process is mating, and this is linked to the cell cycle. In this study, we have identified a new G1 cyclin ge...

lishes its sexual identity at the same time that X-chromosome dosage is regulated. However, even in Drosophila, a cell’s sexual identity can be overridden by secreted signals. How should Zhao and colleagues’ results be reconciled with the substantial body of work involving hormone-induced sex reversal in chickens? Seventy-five years of research have definitively demonstrated that oestrogen is n...

Unprotected sexual intercourse between individuals who are both infected with HIV-1 can lead to exposure to their partner's virus, and potentially to super-infection. However, the immunological consequences of continued exposure to HIV-1 by individuals already infected, has to our knowledge never been reported. We measured T cell responses in 49 HIV-1 infected individuals who were on antiretrov...

This prospective study described the trajectory of sexual well-being from before hematopoietic cell transplantation (HCT) to 3 years after in 131 allogeneic and 146 autologous HCT recipients using Derogatis Interview for Sexual Function and Derogatis Global Sexual Satisfaction Index. Sixty-one percent of men and 37% of women were sexually active pre-HCT; the prevalence declined to 51% (P = .01)...

409 E ighteen months after undergoing unrelated hematopoietic stem cell transplantation (HSCT) for acute myelogenous leukemia, 28-year-old E.M. was experiencing sexual difficulties. For E.M. and her husband, sexual intimacy had been an integral part of their relationship. However, since the transplantation, on the few occasions that she and her husband had attempted to reinitiate sexual intimac...