Sexual development in the immature male blue fox (Alopex lagopus), investigated by testicular histology, DNA flow cytometry and measurement of plasma FSH, LH, testosterone and soluble testicular Mn2+-dependent adenylate cyclase activity

摘要

Summary. Testicular weight in young male blue foxes increased steadily from 12 weeks of age (0·4–0·7 g) to reach peak values at the time of the mating season in March–April (5·2–6·6 g), before declining rapidly during May to low values in August at 63 weeks of age (1·3–1 ·6 g). Primary spermatocytes were found in the spermatogenic epithelium at 20 weeks of age and by late December (29 weeks of age) elongated spermatids were seen. There was a good correlation between the seasonal variations in the presence of germ cell types assessed by quantitative analysis of testicular histology and the variations in numbers of haploid, diploid and tetraploid cells measured by DNA flow cytometry: no haploid cells were found before the end of November and peak numbers were observed in March.