New observations on the onset and duration of the meiotic prophase in the female golden hamster (Mesocricetus auratus).

The onset and evolution of the meiotic prophase were assessed by histological and cytological techniques in fetal and neonatal ovaries obtained from day 13 postcoitum to day 11 postpartum in the golden hamster (Mesocricetus auratus). The histological technique based on the Feulgen stain and the cytological technique based on the Giemsa stain of isolated nuclei were judged to be specific for staining chromatin and chromosomal DNA. The results obtained with both techniques were quite similar and confirmed most of the meiotic prophase takes place during the neonatal period. However, at variance with other reports, it was found that the meiotic prophase starts on day 14 postcoitum. This discrepancy is attributed to the greater specificity of techniques and time span covered in the present study.