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Abstract

The number and type of testicular germ cells undergoing apoptosis in different age groups of mice (from 7 to 360 days of age) was determined and compared in age-matched wild type (WT) control and in a transgenic (TG) mice homozygous to rat androgen binding protein (ABP) using flow cytometry. Flow cytometric quantification revealed that the total number of germ cells undergoing apoptosis did not differ significantly in WT and TG mice up to Day 14. From Day 21 to Day 60, the number of germ cells undergoing apoptosis was consistently higher in TG than in WT mice. Starting from Day 90, the number of germ cells undergoing apoptosis in TG mice was lower than controls until Day 360. In 21–60 days old TG mice, spermatogonia, S-Phase cells, and primary spermatocytes are the cell types undergoing apoptosis at significantly greater numbers than those in WT mice. However, starting from day 60, the total number of spermatids undergoing apoptosis was significantly lower in TG mice than in age-matched WT controls. TdT-mediated dUTP-biotin nick end labeling (TUNEL) in testicular sections from TG mice of 21 and 30 days of age confirmed the presence of increased numbers of apoptotic germ cells compared to their age matched controls.These data indicate that the continuous presence of greater than physiological concentrations of ABP in the mouse testis has a biphasic effect on the frequency of apoptosis in germ cells. The initial pre-pubertal increase in testicular germ cell apoptosis may result from direct or indirect actions of ABP and is likely to determine the subsequent life-death balance of germ cell populations in TG mice, whereas the subsequent reduction may result from maturation depletion. A wave of apoptosis during the pre-pubertal period is required for normal spermatogenesis to develop, and our data indicate that this apoptotic wave may be regulated by ABP and/or androgens.

Oligozoospermia with normal fertility in male mice lacking the androgen receptor in testis peritubular myoid cells

“…Using flow cytometric scanning of propidium iodide-labeled AR ϩ/y germ cells, we detected four main histogram peaks of DNA content that correspond to haploid (1N; round and elongated spermatids and spermatozoa), diploid (2N; spermatogonia, preleptotene, and diplotene primary spermatocytes, secondary spermatocytes, and somatic cells), tetraploid cells (4N; G 2 spermatogonia, leptotene, zygotene, and pachytene primary spermatocytes), and S-phase cells between peaks 2N and 4N (spermatogonial cells and preleptotene spermatocytes synthesizing DNA). The proportion of somatic cells has been shown to comprise Ͻ3% of the total testicular cells in the mouse testis (19). PM-AR Ϫ/y mice show normal germ cell distribution ratios (Fig.…”

“…A monocellular suspension of testicular cells was prepared as described (19,40). Briefly, the tunica albuginea was removed, and the seminiferous tubules were minced in PBS to release the testicular cells.…”

Depletion of Selenoprotein GPx4 in Spermatocytes Causes Male Infertility in Mice

“…5C). Somatic cells comprise Ͻ3% of the total testicular cells in the mouse testis (33). Tg(loxP-GPx4):GPx4…”

“…MEFs derived from 13.5-day post coitum embryos were transformed by SV40 T antigen and cultured in Dulbecco's modified Eagle's medium/F-12 medium supplemented with 10% fetal bovine serum, penicillin, and streptomycin. The immortalized MEF cells were infected with a retrovirus with or without Cre cDNA using the pMXs-Puro vector (33) and incubated for 4 days with 5 g/ml puromycin with or without 400 M Trolox. The MEF cells were simultaneously infected by retrovirus with or without non-mitochondrial, mitochondrial, and nucleolar GPx4 (Sec) cDNA, non-mitochondrial GPx4(Ser), an inactive form, cDNA, SOD1, SOD2, and GPx1 cDNA using pMXs-IG vector (33).…”

“…The immortalized MEF cells were infected with a retrovirus with or without Cre cDNA using the pMXs-Puro vector (33) and incubated for 4 days with 5 g/ml puromycin with or without 400 M Trolox. The MEF cells were simultaneously infected by retrovirus with or without non-mitochondrial, mitochondrial, and nucleolar GPx4 (Sec) cDNA, non-mitochondrial GPx4(Ser), an inactive form, cDNA, SOD1, SOD2, and GPx1 cDNA using pMXs-IG vector (33). The transfection efficiency by each retrovirus was Ͼ85% as assessed using Tg wild (Tg(loxP-GPx4):GPx4 …”