Apoptosis phenomenon of gonadal cells during sex-reversal in the bony fish Rhabdosargtts haffaro

The purpose of this study was to demonstrate the normal occurrence of programmed cell death (apoptosis) in the gonads (testes and ovaries) of the fish Rhahdosargus haffara during sex-reversal process. Histological evidence marked apoptosis in function male during transformation of gonads from male to female, where there was decrease in size of testis with condensed spermatogonia and closed spermatic ducts with residual sperm. On the other hand, oocyte apoptosis in R. haffara occurs in three common stages, which start at the wall of oocytes. The first stage includes shrinkage of oocyte size. Theca and granulosa of apoptotic oocyte transformed to phagocytic cells. In the second type protrusions appear in the oocyte wall until the oocyte looses its identity and displayed amoeboid shape with liquefied content. The third stage depends on the breaking down of oocytes wall into small fragments. Finally, all types of apoptosis lead to lysis and loss of oocyte content. The importance of this phenomenon with sex-reversal may lead to social interactions and the natural balance in the R. haffara population