Growth hormone transgene effects on growth performance are inconsistent among offspring derived from different homozygous transgenic common carp (Cyprinus carpio L.).

摘要

Higher productivity of cultivated fish is required to sustain the supply of fisheries products in the light of increasing demand. We established different lines of homozygous growth hormone (GH) transgenic common carp and analyzed their biological characteristics. Comparing transgenic and control larvae derived from the same control fish mother, we found there was no significant difference in fertilization and hatch rates, but that hatch timing was advanced and average total length was significantly longer in transgenic carp. Early growth performance and other biological characteristics were compared among homozygous, hemizygous and control fish. Both the #TG2 and #TG3 lines exhibited greater average body weight, specific growth rate (SGR), feed conversion efficiency (FCE) and protein retention efficiency (PRE), as well as lower feeding rate (FR) and lipid and energy content than control fish. The energy retention efficiency (ERE) was significantly lower in the #TG3 line, while no difference was observed between the #TG2 line and control fish. These results indicate that the GH transgene initiated effects on growth enhancement in the early developmental stages and played an important role in improving protein synthesis and lipolysis. Conversely, homozygous transgenic fish No. 14960 grew faster than the control fish, but the culture traits of its hemizygous offspring (#TG1 line) were comparatively reduced, including lower SGR, FCE, PRE and ERE levels, and higher FR and lipid contents. Our results suggest that even if fast-growing GH-transgenic homozygous parental fish are generated, we still need to practice classical selective breeding in order to produce transgenic fish with improved traits that can meet aquaculture demand.