title: Cell progression and radiosensitivity of T1-prospermatogonia in Wistar rats.
abstract: T1-prospermatogonia pass through a quiescent stage which lasts from before birth until day 4 after birth (p.n.). They progress into DNA synthesis and mitosis in two synchronous waves which are separated by 24 hours in the evenings of day 4 and 5. The first wave contains about 25 per cent of the total population, the second 75 per cent. The mean duration of S-phase is 10 hours, the mean duration of G2-phase is 4 hours. After irradiation, the capacity of T1-prospermatogonia to produce the normal number of proliferating and differentiating cells in the testes is reduced. During maturation, between day 21 post-conception (p.c.) and day 5 p.n. the radiosensitivity of T1-prospermatogonia decreases by a factor of over 5.
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000528:radiation effects; D002588:Cesium Radioisotopes; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D007399:Interphase / Q000528:radiation effects; D008297:Male; D008938:Mitosis / Q000528:radiation effects; D051381:Rats; D011919:Rats, Inbred Strains; D013093:Spermatogonia / Q000166:cytology / Q000528:radiation effects*; D013094:Spermatozoa / Q000528:radiation effects*
chemical_list: D002588:Cesium Radioisotopes