Many organisms reproduce by releasing gametes into the surrounding fluid. For some such broadcast spawners, gametes are positively or negatively buoyant, and, as a result, fertilization occurs on a two-dimensional surface rather than in the bulk of the air or water. We here rationalize this behaviour by considering the encounter rates of gametes on the surface and in the fluid bulk. The advanta...

Mosquitoes are infected with Plasmodium falciparum by taking a blood meal from a gametocyte carrier. Since a mosquito takes a volume of 1 to 2 microl, a blood meal may contain 1 x 10(4) to 3 x 10(4) leukocytes (WBC). The majority of WBC are composed of neutrophils which may phagocytose and kill developing gametes inside the mosquito midgut. Phagocytosis was measured in vitro by a luminol-depend...

The basal fungus Allomyces macrogynus (A. macrogynus) produces motile male gametes displaying well-studied chemotaxis toward their female counterparts. This chemotaxis is driven by sirenin, a sexual pheromone released by the female gametes. The pheromone evokes a large calcium influx in the motile gametes, which could proceed through the cation channel of sperm (CatSper) complex. Herein, we rep...

Meiotic drivers are selfish genes that bias their transmission into gametes, defying Mendelian inheritance. Despite the significant impact of these genomic parasites on evolution and infertility, few meiotic drive loci have been identified or mechanistically characterized. Here, we demonstrate a complex landscape of meiotic drive genes on chromosome 3 of the fission yeasts Schizosaccharomyces k...

Gametes of C. reinhardi lack the cell wall which vegetative cells possess. Just below the cell apex gametes form a. fertilization tubule which is up to 2 fi long and 0-2 /* in diameter; its plasma membrane and that of the apex have slender tubular projections. At the base of the fertilization tubule regularly lies the choanoid body, a collar-shaped cytoplasmic organelle; the plasma membrane ove...

This Ethics Committee report outlines the interests, obligations, and rights of the parties involved in gamete donation: both male and female donors who choose to provide gametes for use by others, recipients of donated gametes, and any offspring resulting from gamete donation. This document replaces the document "Interests, obligations, and rights of the donor in gamete donation," last publish...

Building a family using donated gametes (semen, oocytes or embryos) is associated with specific issues which differ from building a family with gametes from both intended parents, the resulting family comprising separated biological and social parenthood. To respect the welfare of all parties involved, the 'Beratungsnetzwerk Kinderwunsch Deutschland e.V.' (Infertility Counselling Network German...