Sperm selection in the female mammalian reproductive tract. Focus on the oviduct: Hypotheses, mechanisms, and new opportunities

摘要: Research over the past 3 decades has caused a major shift in way that oviduct, or fallopian tube, is perceived. Previously, it was regarded as little more than anatomic site for fertilization, where spermatozoa and oocytes meet they travel opposite directions. However, this view been radically altered by realization both elicit changes biochemical composition of oviductal fluid through induction novel gene expression. Moreover, also shown only privileged sperm population, selected on basis multiple criteria, permitted to enter are subjected even selection processes control their motility capacitation status, thus either inhibiting facilitating progress toward oocyte. Even recently, become apparent oviduct some ability differentiate genetic signatures X- Y-bearing spermatozoa. Although how exactly achieved unknown, prompts us speculate may be capable distinguishing other genetically encoded properties individual there must ultimately huge payoff terms selective animal breeding.