Morphological and immunohistochemical study on the testis of brown-banded bamboo shark (Chiloscyllium punctatum)‎

Abstract EN

The present study aimed to investigate the morphological changes in the testis of brown- banded bamboo shark using routine histological and PCNA immunohistochemical techniques in order to describe the role of cell division versus cell death in germ cells and Sertoli cells during summer and winter seasons.

Four mature brown-banded bamboo male sharks testes were used in this study; the first two were collected during winter season and the other were collected during summer season.

Testicular specimens were used for histological and PCNA immunohistochemistry.

The obtained results revealed that the testis of brown-banded bamboo shark showed a diametric pattern of development in which the testis was divided into several zones including germinal, spermatogonial, primary spermatocyte, secondary spermatocyte, spermatid, spermatozoal and degenerative zones.

Noteworthy, PCNA expression was restricted to the nucleus of spermatogonia, spermatocytes and Sertoli cells in both mitotic and pre-meiotic zones only while it was absent in the post-meiotic zone.

Moreover, the intensity of expression was different among the various zones as its expression was prominent in the nucleus of spermatogonia in the germinal zone compared with spermatogonial zone.

The intensity of PCNA expression in the testis of shark was different either during summer or winter season.

Briefly, the testis of brown-banded bamboo Shark has a polar pattern of development as it started with spermatogonial zone dorsally and ends with degenerative zone ventrally.

This pattern of development is the best paradigm to track the cascade of the spermatogenesis process as each zone represents only one type of cells.

The seasons under investigation has a non- significant effect on the PCNA expression in the testis of brown-banded bamboo Shark.