Duration of meiosis and spermiogenesis in the dog

Abstract

The duration of meiosis and spermiogenesis was studied in the dog by following the kinetics of [3H]thymidine-labeled canine spermatocytes autoradiographically. Leptotene appears to last for at least 4.20 days, zygotene for less than a day, and pachytene for about 15.50 days. The transition from diplotene to metaphase II is extremely rapid and requires approximately a day. The duration of spermiogenesis is at least 19.60 days. Both meiosis and spermiogenesis are completed by 42.15 days.

Autoradiographic studies of spermatogenesis in Dugesia bengalensis, Kawakatsu

“…Specimens were killed and sectioned at intervals from 4 h to 48 h .Kodak AR-10 film strips were exposed to the histological sections (Ghosal et al ., 1983) . Spermatogonia and spermatocytes became readily labelled within 4 h, but spermatozoa first displayed labelling at 35 h signifying that both meiosis and spermiogenesis were completed by then (Table 1) .…”