SPERMATOGENETIC CLONES DEVELOPING FROM REPOPULATING STEM CELLS SURVIVING A HIGH DOSE OF AN ALKYLATING AGENT: I. FIRST 15 DAYS …

CJG Keulen, DGDE RooIJ - Cell Proliferation, 1975 - Wiley Online Library
CJG Keulen, DGDE RooIJ
Cell Proliferation, 1975Wiley Online Library
We investigated stem cell renewal and differentiation in 10‐and 15‐days‐old
spermatogonial clones developing in mouse seminiferous epithelium after an extremely
large cell loss, inflicted by high doses of the alkylating agent Myleran. The spermatogonial
clones arise from cells that resemble the Ais spermatogonia but have a larger nuclear
diameter. In spite of their mitotic activity these 're‐populating stem cells' lie mainly isolated or
in pairs. This is explained by migration and differentiation. Migration appeared to occur at …
Abstract
We investigated stem cell renewal and differentiation in 10‐ and 15‐days‐old spermatogonial clones developing in mouse seminiferous epithelium after an extremely large cell loss, inflicted by high doses of the alkylating agent Myleran.
The spermatogonial clones arise from cells that resemble the Ais spermatogonia but have a larger nuclear diameter. In spite of their mitotic activity these ‘re‐populating stem cells’ lie mainly isolated or in pairs. This is explained by migration and differentiation. Migration appeared to occur at random in all directions along the basement membrane of the seminiferous tubule.
After one or more divisions of the stem cells, a second type of cell appears, which is called the ‘differentiating spermatogonium’. The time elapsing before this type of cell appears, depends on the dose of Myleran: the larger the dose the later differentiation starts. A relation could be demonstrated between the stage of the cycle of the seminiferous epithelium and the start of differentiation. Differentiating cells were found isolated or in groups of two, four, eight or sixteen cells. Hence we concluded that at least up to their fourth division differentiating cells divide synchronously without degenerations.
Three types of division of repopulating stem cells were distinguished, producing (1) two repopulating stem cells, (2) one repopulating stem cell and one cell starting spermatogonial differentiation, or (3) two differentiating cells. Type 1 divisions were found most frequently.
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