Functional characterization of microRNAs and target genes associated with the formation of intermuscular bones in tambaqui (Colossoma macropomum)

Abstract

Several species of fish of importance in world aquaculture have intermuscular bones (IBs), which correspond to small spike-shaped bones arranged on both sides oft the spine. These IBs (popularly known as "thorns") are a commercially undesirable characteristic because they reduce the palatability of the fish, requiring their removal for fillet production, which results in economic impacts and reduced freshness of the product. The tambaqui Colossoma macropomum, is a Neotropical freshwater species of the order Characiformes that presents great potential for aquaculture, but which, however, it has the disadvantage of growing intermuscular bones. Recently, individuals from a cultivated tambaqui population were reported with absence of IBs, suggesting that genetic and/or epigenetic variants are associated with generation of the mutant phenotype. The present project aims to characterize the genetic regulation of bone development in tambaqui, with emphasis on the epigenetic control exerted by miRNAs in the formation of IBs. It is also proposed to perform the silencing of miRNAs and to validate miRNA interactions in vivo in the zebrafish model to obtain the desirable phenotype without IBs. The results of the proposed analyzes could contribute to a better understanding of the molecular mechanisms of the development of IBs in fish in general, as well as will allow the generation of tambaqui lineages without IBs, with great potential for improving aquaculture and for the development of patents.