Sperm Motility

Abstract

The rapidity of sperm ascent to the oviducts in domestic species, where the distances covered are large, and the velocity of sperm determined in-vitro is known to be too low to account for the time taken for the ascent, sustains the belief that the female tract promotes bulk transfer of sperm cells. Movements of the female tract do occur, but whether these alone are sufficient for sperm to reach the egg is still debated (see Blandau, 1969; Hunter et al., 1983). Many experiments have been poorly designed (see Overstreet and Katz, 1977); e.g. the appearance of spermatozoa in the oviducts after insemination of immotile cells is poor evidence for their passive transport, especially where motility could be reinitiated in the female tract (e.g. Howe and Black, 1963). Conversely, where immotile spermatozoa fail to pass the cervix (Noyes et al., 1958; Baker and Degen, 1972), the treatments rendering the cells immotile (temperature shock or detergents) were not considered. The damage may have altered their surfaces and their susceptibility to removal by invading leucocytes (Bedford, 1965). In addition to the use of damaged sperm to assess normal sperm transport, most studies have involved recovery of sperm post-mortem, with all the complications arising from relaxation of normally constricting muscle tone.