Conversion from mitosis to meiosis: Morphology and expression of proliferating cell nuclear antigen (PCNA) and Dmc1 during newt spermatogenesis

Abstract

The conversion from mitosis to meiosis is a phenomenon specific to the cellular progenitors of gametes

Hormonal Control of Meiosis Initiation in the Testis from Japanese Newt, Cynops pyrrhogaster

“…2) (Yazawa et al ., 2000a). The primary spermatogonial nuclei are lightly stained and the largest among the spermatogenic cells (Figs.…”

Evidence for biological rhythm in spermatogenesis in the pubertal hamster (Mesocricetus auratus): a flow cytometric study

“…However, these two methods cannot be undertaken on material obtained postmortem (Blottner and Roelants, 1998). Other techniques use the immunohistochemical detection of specific antigens, such as nuclear antigen PCNA, Ki 67 and TPS (Blottner and Roelants, 1998;Klein et al, 2000;Yazawa et al, 2000), which are selectively expressed during defined stages of the cell cycle. Using these techniques, however, antibody and species specificity must be taken into consideration.…”

The First and The Second Mitotic Phases of Spermatogonial Stage in Xenopus laevis: Secondary Spermatogonia Which Have Differentiated after Completion of The First Mitotic Phase Acquire an Ability of Mitosis to Meiosis Conversion

“…Recently, Yazawa et al (2000) revealed that the spermatogonial stage in the newt could be divided into the following two phases similar to that in Xenopus; early (the first to the fourth generations) and late (the fifth to the eighth generations) phases. In contrast with Xenopus secondary spermatogonia which are able to convert mitotic phase to meiotic phase after the merely five mitotic divisions, the newt spermatogonia usually do not enter the meiotic phase until the completion of the eight mitotic divisions.…”

“…Recently, Yazawa et al (2000) observed the features of mitotic divisions during the spermatogonial stage and showed that there were two kinds of mitotic phases. The nuclear diameter of spermatogonia progressively decreased after the division during early phase and then remained constant throughout late phase.…”