Vitreoscilla Hemoglobin (VHb) Overexpression Increases Hypoxia Tolerance in Zebrafish (Danio rerio)

Abstract

Aquaculture farming may benefit from genetically engineering fish to tolerate environmental stress. Here, we used the vector pCVCG expressing the Vitreoscilla hemoglobin (vhb) gene driven by the common carp β-actin promoter to create stable transgenic zebrafish. The survival rate of the 7-day-old F 2 transgenic fish was significantly greater than that of the sibling controls under 2.5% O 2 (dissolved oxygen (DO), 0.91 mg/l). Meanwhile, we investigated the relative expression levels of several marker genes (hypoxia-inducible factor alpha 1, heat shock cognate 70-kDa protein, erythropoietin, beta and alpha globin genes, lactate dehydrogenase, catalase, superoxide dismutase, and glutathione peroxidase) of transgenic fish and siblings after hypoxia exposure for 156 h. The expression profiles of the vhb transgenic zebrafish revealed that VHb could partially alleviate the hypoxia stress response to improve the survival rate of the fish. These results suggest that that vhb gene may be an efficient candidate for genetically modifying hypoxia tolerance in fish.

Molecular basis and genetic improvement of economically important traits in aquaculture animals

“…A novel function of p53 that directly suppresses BNIP3 expression to protect against hypoxia-induced cell death has been found in model fish zebrafish [141]. Also in zebrafish, a stable transgenic fish has been created by expressing the Vitreoscilla hemoglobin (vhb) gene driven by common carp beta-actin promoter, and the expressed VHb can partially alleviate the hypoxia stress response to improve the survival rate has been confirmed by comparing the expression profiles of the vhb transgenic zebrafish [142].…”

Increased food intake in growth hormone-transgenic common carp (Cyprinus carpio L.) may be mediated by upregulating Agouti-related protein (AgRP)

“…PCR was conducted under the following conditions: 30°C for 10 min, 42°C for 60 min and 95°C for 5 min. Real-time PCR was performed as previously described (Guan et al, 2011). The primers used in this study are listed in Table 1.…”

Effects of growth hormone over-expression on reproduction in the common carp Cyprinus carpio L.

“…However, because of the potential ecological risk of transgenic fish, none of these fish have yet been produced for the intended goal of commercial use and human consumption (Devlin et al, 2006;Hu et al, 2006Hu et al, , 2007Hu and Zhu, 2010). The over-expression of GH causes numerous biological effects such as changes in growth rates, feeding behavior, swimming speed, energy metabolism, osmoregulation, and hypoxia tolerance (Almeida et al, 2013;Caelers et al, 2005;Duan et al, 2011;Guan et al, 2008Guan et al, , 2011Li et al, 2007;Lohmus et al, 2008;Mori et al, 2007;Rahman et al, 2001;Raven et al, 2008;Wang et al, 2001;Zhong et al, 2013Zhong et al, , 2012. Growth hormone over-expression could also affect reproduction.…”