DESIALYLATION OF THE ROOSTER SPERMS GLYCOCALYX DECREASES SPERM SEQUESTRATION FOLLOWING INTRAVAGINAL INSEMINATION OF THE HEN

Competitive fertilization was used to study sequestration of neuramini dase-treated sperm within the hen's sperm-storage tubules. The feather color inhibitor gene, I, was used to determine paternity of chicks ha tched from eggs laid over a 121-day interval following a single intrav aginal insemination. The insemination dose was 1 x 10(8) sperm per hen . The insemination of New Hampshire hens (i/i) with a 50:50 ratio of w ashed Brown (i/i) and washed White (I/I) Leghorn sperm yielded a 45:55 ratio of brown (i/i) to yellow (I/i) chicks. In contrast, a 14:86 rat io of brown to yellow chicks was obtained when Brown Leghorn sperm wer e treated with neuraminidase and then washed free of the enzyme before admixture with nontreated washed White Leghorn sperm. The effective i nsemination dose was reduced, as 18% fewer chicks were sired when Brow n leghorn sperm were pretreated with neuraminidase. When percentages o f brown chicks mere plotted as a function of time, both plots conforme d to a straight line. Neither slope differed from zero (p > 0.05). How ever, insemination of neuraminidase-treated Brown Leghorn sperm decrea sed the y-intercept by 31.6 percentage units (p < 0.001). Therefore, s ialyl residues in the spermatozoal glycocalyx affect the extent of spe rmatozoal sequestration following intravaginal insemination.