Analyses of diplotene chiasma frequencies in mouse oocytes and spermatocytes in relation to ageing and sexual dimorphism

Cytogenet Cell Genet. 1979;23(1-2):53-60. doi: 10.1159/000131302.


Diplotene chiasma frequencies from "early" (day 16) fetal oocytes are significantly greater than the average from "late" (day 18) oocytes. A decrease in chiasma frequencies from both ages was found at diakinesis/MI in oocytes of young or old adults females, indicating a loss of chiasmata and/or terminalization. A greater number of type I univalents was found in "late" oocytes than "early" oocytes entering diplotene. No difference were found in chiasma frequencies of male diplotene spermatocytes studied at 23 days, 2 months, or 24 months of age. A greater chiasma frequency was generally found in the female than the male at all ages studied.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Age Factors
  • Animals
  • Chromosomes / ultrastructure*
  • Crossing Over, Genetic*
  • Female
  • Gestational Age
  • Male
  • Meiosis*
  • Mice
  • Oocytes / ultrastructure*
  • Ovum / ultrastructure*
  • Sex Factors
  • Spermatocytes / ultrastructure*
  • Spermatozoa / ultrastructure*