Histological analysis of epididymis and testis in the dynamics of postnatal ontogenesis from one month to puberty of Ouled Djellal lambs

The aim of the study was to analyze the ontogeny of the epididymal and seminiferous epithelium in the testis of Ouled Djellal lambs throughout postnatal development until puberty. A total of 24 Ouled Djellal lambs, aged between 1 and 8 months (mos), were used in this study, with three lambs selected at each mo of age. The lambs were surgically castrated monthly, and routine histology along with histomorphometry was performed on the processed epididymal and testis tissues using AxioVision Rel 4.6 software. Statistical analysis revealed that testis weight augmented at an accelerated rate between 4 and 8 mos postnatal, coinciding with significant testicular histology modifications. These changes included notable increases in the seminiferous tubules’ diameter and a rise in testosterone levels. The height of epithelium, as well as luminal and ductal diameters were found to be statistically different (P<0.05) among the epididymis’s caput, corpus, and cauda segments, with the maximum levels recorded during puberty. At 1 and 2 mos of age, there were two cell kinds present inside the epithelium of seminiferous: support cells and gonocytes. By 3 mos of age, the first spermatogonia were formed from gonocytes, coinciding with the testicles reaching an average weight of 4 g. Spermatogenesis was initiated as gonocytes underwent mitosis, giving rise to progenitors that further differentiated into spermatogonia. Around 4 and 5 mos of age, the seminiferous tubules began to exhibit a lumen and primary spermatocytes (spermatocytes I). Around the age of 6 mos, secondary spermatocytes and round spermatids formed a single row within the seminiferous tubules. At ages 7 and 8 mos, all generations of germ stem cells were present in the seminiferous tubules. At 8 mos of age, spermatozoa were became apparent in several segments of the epididymis in the Ouled Djellal breed, signaling the start of puberty.