Effect of Introducing Foreign DNA into Nile Tilapia, Oreochromis Niloticus Gonads on Male Fertility of the Progeny Produced Under Salinity Stress

This work was conducted to study the effect of transfer foreign DNA isolated from sea bream, Sparus aurata or Artemia, Artemia salina into the ovaries and testes of O.niloticus adult on male fertility of the progeny produced under different salinity levels through studying the histological changes of testes. The results showed that male fertility of O. niloticus decreased as a result of introducing foreign DNA into the gonads of their parents. This decrease depends on the type of DNA since the results of the testes investigation revealed that O. niloticus received Artemia DNA displayed normal lobules of 40 %. In contrast, O. niloticus received sea bream DNA, showed only 28 % of normal lobules. The results also showed that the fertility of males decreased with increasing salinity levels up to 36 ppt. Although all fish received foreign DNA displayed low fertility, Nile tilapia received Artemia DNA showed more salinity tolerance and highest fertility than Nile tilapia received sea bream DNA.