Germ cell suicide: new insights into apoptosis during spermatogenesis

Mice overexpression of <i>human augmenter of liver regeneration</i> (hALR) in male germ cells shows abnormal spermatogenesis and reduced fertility

“…4A). A germ cells and Sertoli cells at each stage of spermatogenesis, and is essential for the development of normal mature spermatozoa [38]. In hALR transgenic mice, the number of primary spermatocytes showed an abnormal excess during transgenic testes development, as assessed by flow cytometry and histological examination.…”

Effects of age on DNA double-strand breaks and apoptosis in human sperm

“…For two-group comparisons, different ages were used as cut points to divide the subjects into two groups ("younger" and "older"). The following ages were used as cut points: 25,27,30,32,33,34,35,36,38,40, and 43 years. At least nine subjects remained in the smaller of the two groups.…”

Recovery of a low mutant frequency after ionizing radiation-induced mutagenesis during spermatogenesis

“…Postnatal spermatogenesis is initiated when prospermatogonia differentiate into spermatogonia. In the mouse, this occurs between birth and 5-days-old (d/o), and in human between birth and 6 months of age [16]. Some spermatogonia divide mitotically to become germline stem cells and most differentiate into type B spermatogonia [17].…”

“…Type B spermatogonia then undergo spermatogenesis and give rise sequentially to spermatocytes, spermatids and eventually mature spermatozoa. In the mouse, spermatozoa first appear in the lumen of seminiferous tubules by day 35 [16]. Initiating at puberty, germline stem cells (within the type A spermatogonial population) continue to replicate and ultimately to produce mature spermatozoa throughout the entire reproductive life of the male.…”