02070cab a2200241Ia 45 0 u199531 SIRSI 120402s2010 ua ss b eng d EAL ART JVA V3 No1 6 Kassab, M. Journal of veterinary anatomy, 2010 v. 3 (1) [electronic resource]. Localization of transforming growth factor ß1 (TGF ß1) on the testis of brown banded-bamboo shark (Chiloscyllium punctatum) [electronic resource]. p.71-80. Includes references. Growth factors are shown to promote cell proliferation and apoptosis, regulate tissue differentiation, and modulate organogenesis. In the present investi-gation, the Localization of transforming growth factor ß1 (TGF ß1) was studied on the testis of brown banded-bamboo shark by immune-histochemistry. The immunehistochemical reaction was present in the somatic cells, mainly Leydig cells, in most of testis zones in summer season, while in winter season the expression was confined to the Leydig cells of the spermatocytes, spermatids and spermatozoal zones. The reaction in the germ cells was clear in the spermatogonia of the germinal zone in the summer season while in winter it was clear in the head of sperms in the spermatozoal zone and negative in other zones in both sea-sons. In conclusion, these results de-monstrate seasonal variation in the expression of TGF1 in the testes of this shark. This growth factor has a role in the differentiation and migration of spermatogonia, steroidgenesis through its effect on the Leydig cells either stimulating or inhibiting and finally apoptotic effect on either germinal epithelium or Leydig cells. Key words Transforming growth factor (TGFß1), testis, brown banded-bamboo shark. Sharks Anatomy. Testis Anatomy. Yanai, T. Journal of Veterinary Anatomy. 2010.v3(1) 1687-9988 nnas u199178 http://nile.enal.sci.eg/EALE/2010/JVA/310/1/71.pdf Full Text Article. 1 AR lcc 52201 52201