Spermatogenic cells and stages of the seminiferous epithelial cycle in the Indian gerbil field rat, Tatera indica.

Four types of spermatogonia (A0, A, In, B) are distinguished in T. indica. Four generations of A type, a single generation of intermediate (In) and two generations of B type spermatogonia are identified. Seven divisions of spermatogonia have been observed, in Stages 1b, 2b, 3b, 4b, 5, 6 and 7 respectively. Spermatocytes have been observed in prophase, metaphase, anaphase and telophase; in terms of size and morphology, the phases of prophase could be further divided. Pre-leptotene and leptotene appear in Stage 8 and Stage 1 respectively. Round spermatids become asymmetrical in Stage 1b. For the first time in rodents, Stages 1, 2, 3, 4 and 8 have been subdivided. The percentage frequencies of Stages 1-8 are 12.93, 10.69, 17.54, 10.33, 3.76, 11.20, 7.88 and 25.67 respectively. Although the morphology of the spermatogenic cells and associations of these cell types are basically similar to those in albino rats, T. indica markedly differs from all other rodents studied in having two generations of B spermatogonia and subdivisions of Stages 1, 2, 3, 4 and 8; in addition, the relative frequencies of the stages distinctly differ from those recorded in previous studies of rats. Hence, the durations of different cell types in T. indica may differ markedly from those in other rodents.