Growth enhancement and food conversion efficiency of transgenic fish Labeo rohita

Abstract

Three family lines of fast growing transgenic rohu Labeo rohita (rohu) were generated by electroporated-sperm-mediated transfer of the vectors harboring CMV promoter or grass carp beta-actin promoter fused to endogenous rohu GH (rGH) cDNA. The gene transfer efficiency was 25%. The transgenic rohu (family line 1) with CMV promoter showed a growth enhancement of four times normal size, whereas those (family lines 2 and 3) generated with beta-actin promoter grew 4.5 and 5.8 times faster than their respective control siblings. Southern analysis confirmed the transgene extrachromosomal (Te) persistence until the 60th week in family 1. The individuals of family lines 2 and 3, however, showed integration (Ti), as well as persistence as extrachromosomal copies (Te) until the age of 30 weeks. Mosaicism of the transgene was shown at the levels of its presence and expression. The ectopic expression of rGH mRNA was confirmed by RT-PCR. Feeding experiments revealed that the transgenic rohu ate food at a lower rate but grew more efficiently than their control siblings.

Rapid growth cost in “all-fish” growth hormone gene transgenic carp: Reduced critical swimming speed

“…The same growth-promoting effect of foreign GH-gene persisting in the F 4 generation had also been demonstrated in our previous study with human GH-transgenic carp [21] . Growth-promoting effects of exogenous growth hormone gene had been observed in a number of GH-transgenic fishes, including GH-transgenic cyprinid fish [22][23][24] , GH-transgenic salmonid fish [25][26][27] , GH-transgenic channel catfish (Ictalurus punctatus) [28] , GH-transgenic tilapia (Oreochromis niloticus) [29] , GH-transgenic Ayu (Plecoglossus altivelis) [30] and GH-transgenic rohu (Labeo rohita) [31] . In this study, "all-fish" GH-transgenic fish had a mean U crit (cm/s) value 22% or a mean U crit (BL/s) value 24% smaller than controls.…”

Metabolism traits of ‘all-fish’ growth hormone transgenic common carp (Cyprinus carpio L.)

“…Therefore, transgenic fish have demonstrated an elevated routine oxygen uptake in order to meet their metabolic needs. Reasons for this may have to do with an increased feeding rate and food conversion efficiency in the transgenic fish (Devlin et al, 1995;Cook et al, 2000c;Cui et al, 1996;Venugopal et al, 2004;Fu et al, 2007). While the mechanisms for this are not completely clear, the ability to digest food, and to absorb and transport nutrition may be better in transgenic fish (Stevens et al, 1999;Devlin, 2000, 2005;Fu et al, 1998;Cook et al, 2000c).…”

Gene–environment interactions influence ecological consequences of transgenic animals

“…Several species of fish have been modified genetically and currently are being explored as a way to increase the production efficiency and yield in aquaculture (24)(25)(26)(27)(28). These transgenic fish overexpress GH and require enhanced feed consumption to achieve the increased growth rates (29).…”