Reduced oocyte numbers in tertiary trisomic mice with male sterility.
Oocyte counts carried out in 3- to 5-day-old tertiary trisomic Ts(5(12))31H mice revealed a mean reduction of 71% in the number of oocytes as compared with that of normal littermates. The pool of small oocytes was reduced by 75%, and the number of growing oocytes by 8%. The sperm count of the trisomic males was less than 1% of normal, with most spermatozoa being abnormal (Beechey et al., 1980). These results indicate that the presence of the extra 5(12) chromosome, which causes male sterility, also has a marked effect on oogenesis. Possible reasons for the difference in severity of the gametogenic impairment in males and females are discussed.
D000818:Animals; D002452:Cell Count; D002875:Chromosomes / Q000648:ultrastructure; D005260:Female; D007248:Infertility, Male / Q000235:genetics* / Q000473:pathology; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D009865:Oocytes / Q000166:cytology*; D013045:Species Specificity; D014314:Trisomy