Estimation of the duration of the cycle of the seminiferous epithelium in the non-human primate Macaca mulatta using the 5-bromodeoxyuridine technique

Abstract

A comparatively low yield of germ cells has been reported for the spermatogenic process in primates. Kinetic studies of spermatogenesis and the spermatogenic cycle are needed to investigate this phenomenon but require the application of radioactively labeled compounds or irradiation. We have therefore investigated the suitability of a non-radioactive approach, viz., administration of 5-bromodeoxyuridine, for the determination of the kinetics of the spermatogenic cycle in a non-human primate, the rhesus monkey (Macaca mulatta). Four adult in-season animals received a bolus of 33 mg/kg 5-bromodeoxyuridine, one testis from each monkey was removed 3 h later and the other testis after 10 days and 11 h. Tissue was fixed in Bouin's solution and embedded in Paraplast. 5-Bromodeoxyuridine was localized by immunogold-silver staining with a monoclonal antibody. PAS-hematoxylin counterstaining was used for spermatogenic stage identification. At 3 h, the leptotene and zygotene spermatocytes in stages VII-IX were the most advanced 5-bromodeoxyuridine-positive cells. At 10 days 11 h, the label had advanced and pachytene spermatocytes in stages VI-IX contained 5-bromodeoxyuridine. The duration of the spermatogenic cycle was 10.42+/-0.07 days (range: 10.25-10.62 days). Peritubular cells and interstitial cells were rarely 5-bromodeoxyuridine-positive, and Sertoli cells were consistently negative for 5-bromodeoxyuridine. Importantly, our kinetic data closely resemble those obtained by means of the application of irradiation for this macaque species. We conclude that administration of 5-bromodeoxyuridine represents a non-radioactive reliable approach for studying kinetic aspects of the spermatogenic process in primates.

Single-cell RNA sequencing of human, macaque, and mouse testes uncovers conserved and divergent features of mammalian spermatogenesis

“…The time required to complete a full spermatogenic cycle is variable across species (~35d in mouse 36,37 vs. ~42d in macaque 38–40 vs. ~74d in human 37,41 ). Histological analysis of pulse labelling and cell ablation have been used to determine the length of major spermatogenic processes, but to what extent germ cell trajectories and molecular states align across species is poorly understood.…”

Quantitative Analysis of Spermatogenesis and Apoptosis in the Common Marmoset (Callithrix jacchus) Reveals High Rates of Spermatogonial Turnover and High Spermatogenic Efficiency1

“…However, because marmosets diverged from the human line more than 35 ϫ 10 6 yr ago, it is tempting to speculate that the pattern of human spermatogenesis either has evolved on at least two occasions or has been (partially) lost in other primate species. In rhesus macaque (Macaca mulatta) and stumptailed macaque (M. arctoides) testes, one stage per tubular cross section is predominant [1,34], and olive baboons are intermediate [8]. Regardless of which of these two evolutionary scenarios is correct, the organizational principle of the human and chimpanzee [35] seminiferous epithelium in all likelhood is neither particular nor specific to these species but might be more common among primates than previously thought.…”

Cycle Length of Spermatogenesis in Shrews (Mammalia: Soricidae) with High and Low Metabolic Rates and Different Mating Systems1

“…The first method was that of Rosiepen et al [40,41]. Following this formula, the duration of the seminiferous epithelium cycle was calculated based on the stage frequencies and BrdU staining frequencies for two time-points.…”