Y body association with morphologic heterogeneity of human sperm.
OBJECTIVE
The purpose of this study was to determine a possible association between the Y body and sperm head shape, since sperm head shape may be a factor that influences the rate of migration of X- and Y-bearing sperm cells.


METHODS
Sperm cell (n = 1,065) preparations from seven donors were fluorochrome stained for the Y body, and area and shape of Y body-positive and -negative cells were measured from digitized images. The distributions of the segregated cell population measurements were statistically analyzed nonparametrically.


RESULTS
Of the total cells, 528 were Y body-positive and 537 were not, and the ratio (0.983) of the two cell categories, both within and between donors, was equivalent to the theoretical ratio of 1.0 expected for the X:Y sperm cell population. Sperm head area distributions were equal between the two populations. However, the length-width ratios of Y-bearing cells were significantly higher (P < .0001) and calculated roundness was significantly (P = .006) less than non Y body-bearing cells.


CONCLUSIONS
The Y body may represent the Y chromosome. Furthermore, the Y body may impart a more ellipsoidal shape to sperm cells. Sperm shape may influence the migration rate of cells through cervical mucus such that differences in the male-to-female sex ratio of conceptuses, and at birth, may reflect a shape-imparted advantage in the migration rate of Y-bearing sperm in reaching the oocyte.
McCoshen
J A
JA
Department of Obstetrics, Gynecology and Reproductive Sciences, University of Manitoba, Winnipeg, Canada.
Chen
J
J
Wodzicki
A
A
Taylor
P
P
Fernandes
P A
PA
D005456:Fluorescent Dyes; D006801:Humans; D008297:Male; D013077:Sperm Head / Q000648:ultrastructure; D013081:Sperm Motility; D013094:Spermatozoa / Q000648:ultrastructure*; D013194:Staining and Labeling; D014998:Y Chromosome / Q000648:ultrastructure*
D005456:Fluorescent Dyes