Spermatogenesis in the Roborovski hamster (Phodopus roborovskii) and the Chinese hamster (Cricetulus griseus)

Abstract

Background: Spermatogenesis is an elaborately organized and tightly regulated differentiation process. The spermatogenesis duration is stable within a certain species but highly variable between species of the same family.Objectives: In this study, the spermatogenesis duration of the Roborovski hamster was measured for the first time, and the spermatogenesis duration of the Chinese hamster was re-assessed. Materials and methods:Stage classification and cycle length measurement were carried out by labeling the dividing cells with bromodeoxyuridine and an antibody-based chromogen as well as with the periodic acid-Schiff/hematoxylin stain. Analysis was conducted using reference calculation and linear regression. Morphological measurements completed our set of methods. Results:The mean duration of one seminiferous epithelium cycle was 8.58 ± 0.34 days (mean ± SEM; Phodopus roborovskii) and 16.59 ± 0.47 days (Cricetulus griseus) based on the reference calculation. Slightly higher results were obtained using linear regression analysis: 9.72 ± 0.41 days for P. roborovskii and 17.64 ± 0.61 days for C. griseus.Additionally, a newly developed exemplary flowchart was proposed for the Roborovski hamster to facilitate spermatogenesis stage classification also in other species. The Chinese hamster presented an unexpectedly high paired epididymides weight of 1.701 ± 0.046 g (mean ± SEM) although having a body weight of only 40.5 ± 0.7 g. However, no significant correlation between the relative epididymis weight and spermatogenesis duration in mammals (Spearman rank correlation: r = −0.119, p = 0.607, n = 21) or rodents could be found (r = 0.045, p = 0.903, n = 11). Conclusion:Our data emphasize the stability of the spermatogenesis duration within species and its remarkable variability between species. Further research is needed to identify the principal mechanisms and selection drivers that are responsible for such stability within species and the variability between species.

Small RNA-seq and hormones in the testes of dwarf hamsters (Cricetulus barabensis) reveal the potential pathways in photoperiod regulated reproduction

“…Small mammals such as rodents generally reproduce in the long days [ 20 ]. Although most studies believe long daylength promotes rodent reproduction, some researchers point out that long daylength can affect the spermatogenic cycle and inhibit spermatogenesis [ 21 ]. This divergence may be due to the differences in the duration and intensity of animal treatment.…”

Study of spermatogenic and Sertoli cells in the Hu sheep testes at different developmental stages

“…First, undifferentiated spermatogonia commit to differentiation and undergo several rounds of mitotic division to give rise to spermatocytes, which then enter meiosis and eventually produce sperm. Sertoli cells are found in the spermatogenic tubules, which support the development of immature spermatozoa into highly specialized spermatozoa 1 . Therefore, studying the development of Sertoli cells is critical for understanding spermatogenesis.…”

“…Sertoli cells are found in the spermatogenic tubules, which support the development of immature spermatozoa into highly specialized spermatozoa. 1 Therefore, studying the development of Sertoli cells is critical for understanding spermatogenesis.…”

“…After birth, gonocytes progressively migrate from the center toward the periphery of the seminiferous cords 4 . After migrating to the basement membrane of the tubule, gonocytes divide to form undifferentiated spermatogonia (including SSCs), differentiating spermatogonia, and differentiated spermatogonia 1,5 . The number of types of spermatogonia present in rats and humans has been determined 6,7 .…”

“…4 After migrating to the basement membrane of the tubule, gonocytes divide to form undifferentiated spermatogonia (including SSCs), differentiating spermatogonia, and differentiated spermatogonia. 1,5 The number of types of spermatogonia present in rats and humans has been determined. 6,7 However, few studies have focused on other higher mammals.…”