This research aimed to develop a cold-tolerant Nile tilapia, Oreochromis niloticus, via genetically modified breeding by incorporating fragmented pure DNA extracted from Atlantic salmon into the gonads. The results indicated a significant enhancement (P ≤ 0.05) in the majority of growth performance and feed utilization metrics of genetically modified Oreochromis niloticus treated with the gsr gene and reared at various low temperature levels up to 8ºC, in comparison to the control fish maintained at the same temperatures.
Genetically modified O. niloticus displayed better traits results (P ≤ 0.05) compared to the other fish within the same conditions. The results of the Inter Simple Sequence Repeat (ISSR) fingerprinting showed a highly genetic polymorphic percentage (35.95%) among fish receiving foreign DNA and their control using different primers. The results of this study indicate that genetically modified O. niloticus exhibiting enhanced growth rates and cold temperature resistance can be developed by an efficient and rapid process.