A novel 79-bp insertion/deletion polymorphism in 3′-flanking region ofIGF-Igene is associated with growth-related traits in common carp (Cyprinus carpioL.)

Abstract

Insulin-like growth factor-I (IGF-I) participates in the modulation of the cellular development, differentiation and proliferation in various vertebrate tissues. Therefore, variations in IGF-I gene are good candidates as growth regulators. In this study, a novel 79-bp insertion/deletion (I/D) polymorphism was identified in 3′-flanking region of IGF-I gene by polymerase chain reaction (PCR) and sequencing approaches in common carp Cyprinus carpio. To gain insight into the association of the 79-bp I/D polymorphism with growth-related traits, a total of 747 individuals from Heilongjiang carp Cyprinus cario haematopterus (YL) (n = 263), selective line of German mirror carp Cyprinus carpio L. mirror (JL) (n = 229), and cold-resistance line of Hebao red carp Cyprinus carpio var. wuyuanensis (HL) (n = 255) were genotyped. The DD genotype of the polymorphism was significantly associated with higher body length (135), body weight (325, 385, and 445 days), net weight (445 days) and lower overwintering body loss rate in JL. In addition, in pooled population (YL+JL+HL), fish with DD genotype also showed significantly higher body weight (445 days) and net weight (445 days) than those with II genotype. Taken together, these results suggest that the novel polymorphism in IGF-I gene could be considered as a potential genetic marker for selection of growth performance in common carp.