Induction of tetraploidy in transgenic tilapia (Oreochromis niloticus) using physical shocks

The induction of tetraploidy by means of cold, heat and multiple heat shock treatments was investigated on male fish from a growth-enhanced transgenic tilapia C۱۱۸ line, crossed with wild type females. After the development a new multiple heat shock protocol (two heat treatments at ۴۱oC in ۶۰ and ۸۰ min. after fertilization for ۵ min. per each), chromosome and X-gal in situ staining assays demonstrated the successful production of yolk sac tetraploid transgenic tilapia in two out of ۱۵ embryos examined in this trial via direct correlation between higher level of b-galactosidase expression and karyotyping in the samples verifying complete tetraploidy in this line. In the grown fish, there was evidence to suggest mosaicism or perhaps tetraploidy in at least two grown fish using the measurement of erythrocytes and karyotyping of the G۱ offspring (p<۰.۰۵). There was, however, no evidence to indicate successful production of triploid G۱ individuals following crossing of induced fish with wild type.

کلیدواژه ها:

Transgenic tilapia ، Oreochromis niloticus ، -galactosidase ، Tetraploidy ، LacZ reporter gene ، Sterility