Differences in motility of human X- and Y-bearing spermatozoa

Abstract

Human Y-bearing spermatozoa, as identified by the quinacrine staining technique, were found to be significantly more motile than X-bearing spermatozoa under laboratory conditions. This difference is consistent with current estimates of the difference in mean head DNA content.It has often been surmised that male-determining Y-chromosome bearing spermatozoa may differ in some respects from female-determining X-bearing spermatozoa. Although early attempts to separate the two kinds on the basis of supposed differences in mass, density or surface charge met with little apparent success (Beatty, 1970), the recently developed quinacrine technique for detecting the human Y chromosome in spermatozoa (Barlow & Vosa, 1970; Sumner, Robinson & Evans, 1971) now enables these possibilities to be investigated without the necessity for experiments involving insemination. Results have been obtained which suggest that Y spermatozoa may be more motile than X spermatozoa (Rohde, Portsmann & Dörner, 1973; Ericsson, Langevin & Nishino, 1973), although the results of Ericsson et al are not confirmed by others (Evans, Douglas & Renton, 1975; Ross, Robinson & Evans, 1975). We describe here an experiment, based on the quinacrine staining method, which was designed to detect possible differences in motility between the two types of spermatozoon. Motile spermatozoa were layered at the bottom of a vertical column of fluid and were then allowed to swim upwards into the medium. If Y spermatozoa are more motile then they should outnumber X spermatozoa in the upper regions of the column (Roberts, 1972). This system possesses two useful features; firstly, equilibrium is eventually reached in which the numbers of organisms at given heights show no further changes, which simplifies the experimental procedures involved, and secondly, the degree of separation obtained can be used to estimate the difference in motility between X and Y spermatozoa. Methods and resultsSemen was provided by volunteer donors and used within 2-3 hr. Each sample was diluted to 10 ml with warmed Tyrode's solution (pH 7-8) and centrifuged at 1000 g for 15 min. The pellet was resuspended in 5% bovine serum albumin (25% BSA in Tyrode's solution (Sigma) diluted with Tyrode's solution to 5 % final concentration), the final sperm concentration being about 5 107 ml-1 as determined by haemocytometer. A portion of this suspension was set aside as a control. Experi¬ ments were performed on columns 18 mm in total height, each of which comprised a cylindrical portion of 21 mm diameter and 10 mm height and an upper conical portion of 8 mm height through the apex of which the contents of the column could be expelled. The columns consisted of Tyrode's solution stabilized with a BSA gradient, varying continuously from 0-2% at the top to 2-0% at the bottom, which was delivered from a small two-compartment gradient former. A suspension contain¬ ing about 5 106 spermatozoa was introduced through a side port at the bottom of the column as a layer 300 µ thick. After 1 hr, when spermatozoa had dis...

Morphological selection of human spermatozoa in vivo and in vitro

“…Botella-Llusia, 1956;Kremer, 1965;Ericsson, Langevin & Nishino, 1973;Goodall & Roberts, 1976). Any system has technical problems, but the present apparatus (Text- fig.…”

Sex predetermination by separation of X and Y chromosome-bearing sperm: a review

“…There is further support for motility separation technique in the findings of Goodall and Roberts (1976) that F1 sperm are more motile than FO sperm. F-body sperm are also better able to penetrate cervical mucus in vitro (Rohde et al 1973), but this effect is apparently less evident in vivo (Broer et al 1976) The albumin technique has also been tested on a number of animal species.…”

Influence of the Semen Deposition Site on the Calves’ Sex Ratio in Simmental Dairy Cattle

“…1973; Martinez et al. 2004) and the capacitation rate (Goodall and Roberts 1976; Martinez et al. 2004) of the X and Y spermatozoa.…”