Normally grown and developed intermuscular bone-deficient mutant in grass carp, <italic>Ctenopharyngodon idellus</italic>

Abstract

An intermuscular bone-deficient grass carp, Ctenopharyngodon idellus , mutant has been identified in an artificial gynogenetic group, in which traits encoded by recessive mutant genes can be detected because of the genomic homozygosis. Both the axial and appendicular skeletons in the mutant are developed as in the gynogenetic wild-type individuals. No growth or morphological abnormalities have been observed in the mutant. These results indicate that: (1) it is unlikely that intermuscular bone is essential for body support and normal movement of grass carp; (2) the developmental genetic regulatory mechanism of intermuscular bone differs from that of the axial and appendicular skeleton; and (3) the intermuscular bone-deficient grass carp strain can be bred using advanced biological techniques. Statistical analysis revealed that the ratio of mutant grass carp with no intermuscular bone is very low in gynogenetic grass carp groups, suggesting that many genes are involved in the development of intermuscular bones and the regulatory network is quite complex. This mutant provides unique experimental material for the identification of genes involved in intermuscular bone development.