rats 56 hours: Chinese hamster ≈90 hours
||de Rooij DG, Russell LD. All you wanted to know about spermatogonia but were afraid to ask. J Androl. 2000 Nov-Dec21(6):776-98 p.784 left column top paragraphPubMed ID11105904
||Huckins C. The spermatogonial stem cell population in adult rats. II. A radioautographic analysis of their cell cycle properties. Cell Tissue Kinet. 1971c 4 :313–334 AND Lok D, Jansen MT, de Rooij DG. Spermatogonial multiplication in the Chinese hamster. II. Cell cycle properties of undifferentiated spermatogonia. Cell Tissue Kinet. 1983 16: 19–29PubMed ID5127356, 6825154
||Primary source Lok et al., 1983 abstract: "The cell cycle properties of undifferentiated spermatogonia in the Chinese hamster were analysed by the fraction of labelled mitoses technique (FLM) in whole mounted seminiferous tubules."
||P.784 left column top paragraph: "For As, Apr, and Aal spermatogonia, cell cycle times have been found to be 56 hours in rats (primary source Huckins, 1971c) and about 90 hours in Chinese hamsters (primary source Lok et al, 1983)."