Full Length Research Paper

A comparative study of the gross structure and distribution of spermatogonia-like cells in the testis of pre-pubertal and mature adult rats

U. A. Osunkwo¹*, N. Ezeunala Mercy², M. O. Duru Osunkwo,  A. Damaris⁴, A. Ajoku Gloria², A. Anyalewechi Ngozi¹, G. A. Etuk-Udo² and U. S. Inyang³

¹Stem Cell Research Laboratory, Department of Pharmacology and Toxicology, Abuja-Nigeria.

²Department of Microbiology and Biotechnology, Abuja-Nigeria.

³National Institute for Pharmaceutical Research and Development, Idu, Abuja-Nigeria.

⁴Department of Medicine, National Hospital, Abuja, Nigeria.

*Corresponding author. E-mail: ucheosunkwo@yahoo.com. Tel: +234 803 329 6137

Accepted 8 September, 2009

   Abstract

The testis of pre-pubertal and those of mature adult albino rats were physically divided into three segments with a view to studying histologically the gross structure and distribution of spermatogonia-derived cells (spermatogonia, spermatocytes, spermatids and mature spermatozoa) in the seminiferous tubules in these segments.  After using 50% Mezo stain (organic), spermatogonia-derived cells were manually counted on slide-view. A mixed population of dense uninucleated single or paired type A-like spermatogonia was clearly identifiable in both upper and lower segments as well as in the middle segment of the testis of pre-pubertal rats. In the mature adult rat testis, a mixed population of spermatocytes, oval spermatids and mature spermatozoa, in addition to a mixed population of dense uninucleated and multinucleated type A-like spermatogonia were identified in seminiferous tubules of all three segments. However, there were larger numbers of clump-forming spermatogonia-like cells in the middle segment of the testis than in other segments in mature adult rats. A ratio of 2:1:1 for middle, upper and lower segments respectively was manually determined. These results suggest that the middle segment of the mature adult albino rat testis contains a highly enriched population of both single and multinucleated A-type spermatogonia-like cells and may be most suitable site for the harvesting of these cells.

Key words: Rat, pre-pubertal, testis, spermatogonia, spermatogenesis, mezo stain.