Genes encoding proteins involved in sperm-egg interaction and fertilization exhibit a particularly fast evolution and may participate in prezygotic species isolation , . However, the genes involved in this biological function have not been systematically and exhaustively studied with an evolutionary perspective, in particular across vertebrates with internal and external fertilization. Here we show that 33 genes among the 69 that have been experimentally shown to be involved in fertilization in at least one taxon in vertebrates are under positive selection.
Portuguese researchers recently made a breakthrough discovery while they were studying a particular fish known as Squalius alburnoides from the Ocreza River. These were a hybrid between female Squalius pyrenaicus and a now-extinct male species. Since the genetic makeup matched up perfectly with the father, this told the researchers that there was no genetic intervention from a female.
Modulators of hypothalamic-pituitary-gonadal axis for the control of spermatogenesis and sperm quality in vertebrates View all 19 Articles. Spermatogenesis, a highly conserved process in vertebrates, is mainly under the hypothalamic—pituitary control, being regulated by the secretion of pituitary gonadotropins, follicle stimulating hormone, and luteinizing hormone, in response to stimulation exerted by gonadotropin releasing hormone from hypothalamic neurons. At testicular level, gonadotropins bind specific receptors located on the somatic cells regulating the production of steroids and factors necessary to ensure a correct spermatogenesis.
The reproductive system or genital system is a system of sex organs within an organism which work together for the purpose of sexual reproduction. Many non-living substances such as fluids, hormonesand pheromones are also important accessories to the reproductive system. These differences allow for a combination of genetic material between two individuals, which allows for the possibility of greater genetic fitness of the offspring.
Sperm is the male reproductive cell. In the types of sexual reproduction known as anisogamy and its subtype oogamythere is a marked difference in the size of the gametes with the smaller one being termed the "male" or sperm cell. A uniflagellar sperm cell that is motile is referred to as a spermatozoonwhereas a non-motile sperm cell is referred to as a spermatium.
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About Translations. Nelsen OE. The union or fusion syngamy of the oocyte or egg female gamete with the sperm male gamete to form a zygote is known as fertilization.
Germplasm, the essential material concerned in reproduction, consists of sperm cells and eggs in sexual animals. The detachable germinal units derived from the male individual are sperm cells. They are frequently called spermatozoa sperma, seed; zoon, animalan awkward and misleading word, embalming the historical fact that when these cells were first discovered by early microscopists, they were thought to be tiny independent parasitic animals.
Janice P. Data that were presented are reviewed here and discussed with respect to conserved and divergent features of gamete functions. Presentations in this session covered multiple molecules, multiple species, and multiple events of fertilization, and they highlighted several issues concerning the mechanisms of fertilization and evolution as well as species specificity in gamete functions and interactions.