Seasonal changes in spermatogenesis in the blue fox (Alopex lagopus), quantified by DNA flow cytometry and measurement of soluble Mn2+-dependent adenylate cyclase activity

Abstract

The testes of the blue fox (Alopex lagopus) showed marked seasonal variations in size. Testicular weight and volume increased rapidly during January and February to reach maximal values by the beginning of the breeding season (approximately 15 March). During May and June the weights and volumes of the testes declined gradually to the quiescent state which lasted from July until October. Quantitation by DNA flow cytometry of the seasonal changes in the relative numbers of haploid (1C), diploid (2C) and tetraploid (4C) cell numbers in the testis showed that the increase in testis size from December to February was associated with a rapid expansion of the haploid cell compartment as spermatogenesis resumed. In addition, an increase in number of more mature cell types within the haploid cell population was observed over a 2-month period before the breeding season. The decline in testicular size from the middle of April until October was associated with a reduction in both the absolute and relative sizes of the haploid and tetraploid cell populations and a concomitant increase in the relative numbers of diploid cells. Measurements of the activity of the soluble Mn2+ -dependent adenylate cyclase revealed seasonal variations that closely paralleled those of the haploid cell population, indicating that, as in other species, the enzyme may be associated with maturing germ cells.

Effect of Refractoriness to Long Photoperiod on Sperm Production and Quality in Tomcats

“…In some short‐day breeders like the male silver and blue fox, short days are necessary if gonadal stimulation is to occur (Smith et al. , ; Forsberg et al. ).…”

Photoperiodic regulation of reproduction in the male silver fox (Vulpes vulpes)

“…The most striking result was the low (P < 0-01) post-thaw motility of the semen frozen in June. (Smith et al, 1984(Smith et al, , 1985(Smith et al, , 1986(Smith et al, , 1987, which are also short-day breeders. Furthermore, our experiments show that short days not only stimulate redevelopment of the testes but can also inhibit testicular regression.…”

Seasonal changes in testicular structure and function in the blue fox (Alopex lagopus), as quantified by morphometric analysis and measurement of adenylate cyclase activity

“…Details of the analysis of frozen testicular tissue by DNA flow cytometry have been published elsewhere (Smith et al 1984b). The relative numbers (%) of cells in each DNA population (haploid, diploid or tetraploid) were multiplied by testicular weight to give arbitrary values for the absolute number of cells per testis.…”

“…Likewise, the testes show marked seasonal variations in cellular composition. We have previously described the use of DNA flow cytometry to study seasonal variations in the populations of haploid, diploid and tetraploid cells in the blue fox testis (Smith et al 1984b). Histological studies have until now concentrated on the ultrastructure of Leydig cells (Andersen 1978a), Sertoli cells (Andersen et al 198 1) and various germ cell types (Andersen 1974;1978b,c).…”