The Dynamics of Spermatogenesis in Quail

The cells of male gonads, including spermatogonia, are considered as a valuable genetic material for cryoconservation in the framework of animal and poultry breeds’ gene pool preservation. To select the appropriate age for collecting quail spermatogonia it is necessary to know the specific features of spermatogenesis. The objective was to study the dynamics of spermatogenesis in quail. Histological structure of testes (n=48) was investigated in six age categories: from 1 to 6 weeks. The diameter of seminiferous tubules and the distribution of different types of spermatogenic cells therein were determined. The types of spermatogenic cells were identified by their morphology. Histological structure of quail testes was similar to those of mammals. Cell population of the seminiferous tubules was represented by Sertoli cells and generative cells at different stages of differentiation (spermatogonia, spermatocytes, spermatids, spermatozoa). The diameter of the seminiferous tubules increased with age and reached 42±1, 71±2, 91±2, 117±2, 237±4 and 278±5 μm at the age of 1, 2, 3, 4, 5 and 6 weeks, respectively. This was due to the increasing number of spermatogenic cells in the seminiferous tubules to 18±1, 24±1, 58±4, 80±6, 249±16 and to 587±34 cells, respectively. At the age of 1-3 weeks, Sertoli cells and spermatogonia were the most distributed type of cells of seminiferous tubules. The highest ratio of spermatogonia was observed at the age of 3 weeks - 76±2%. Spermatocytes of the first and the second orders were found in the seminiferous tubules starting from the age of 4 weeks, and spermatids - from the age of 5 weeks. The sperm cells in the seminiferous tubules of quail were identified at the age of 5 weeks. Thus, the age of 1 to 3 weeks is the most optimal for manipulation with quail testicular germ cells, when the population of the generative cells of seminiferous tubules are presented primarily by spermatogonia.

The study was supported by the Russian Science Foundation within Project no.16-16-04104.