Explaining the maintenance of sexual reproduction remains one of the greatest challenges in biology. The theoretical oddity of sex is based on at least three advantages that asexual organisms have over sexual ones: 1Asexuals, by not producing males, have a two fold advantage over sexuals, regarding the number of reproductive individuals; 2Sexuals have an evolutionary disadvantage over asexuals,...

Malaria, caused by the apicomplexan parasite Plasmodium, threatens 40% of the world's population. Transmission between vertebrate and insect hosts depends on the sexual stages of the life-cycle. The male gamete of Plasmodium parasite is the only developmental stage that possesses a flagellum. Very little is known about the identity or function of proteins in the parasite's flagellar biology. He...

Spermatogenesis is a fundamental biological process that ensures the transition of a gene from one ganeration to another via male gametes. This process relies on a rare population of testicular cells called spermatogonial stem cells (SSCs), which self-renew throughout adult male life and differentiate into mature gametes. Despite the longstanding study of SSCs, their biological properties remai...

during recent decades, the third person intervention in human artificial insemination has created new hopes for infertile couples. however these new progresses have propounded new ethical and legal concerns for families. one of them is confidentiality regarding gamete donor's identity, and its disclosure to the future child and others. of course, negligence to this ethical issue would produce a...

To discuss the psychological impact of disclosure decisions on donor gamete participants including gamete donors, intended parents, and the children conceived through these third party reproductive techniques. In the past decade, there has been a dramatic increase worldwide in the number of children born as a result of gamete donation. The growing demand for these programs has resulted in a tre...

Studies on the evolution of reproductive proteins have shown that they tend to evolve more rapidly than other proteins, frequently under positive selection. Progress on understanding the implications of these patterns is possible for marine invertebrates, where molecular evolution can be linked to gamete compatibility. In this study, we surveyed data from the literature from five genera of sea ...

Fertilization is the process by which sperm and egg unite. An expanded understanding of the mechanisms that underlie these events has provided insights into an important aspect of early development and also has proven to be a valuable model in which to study cellular function. In addition, many emerging strategies for contraception and for the treatment of infertility are based on the mechanism...

Germ cells play a unique role in gamete production, heredity and evolution. Therefore, to understand the mechanisms that specify germ cells is a central challenge in developmental and evolutionary biology. Data from model organisms show that germ cells can be specified either by maternally inherited determinants (preformation) or by inductive signals (epigenesis). Here we review existing data o...