Genetic effects of the EIF5A2 gene on chicken growth and skeletal muscle development

Abstract

Eukaryotic translation initiation factor 5A2 (EIF5A2) is an essential protein closely related to cellular polyamine homeostasis. It is the only cellular protein that contains the unusual amino acid hypusine [Nɛ-(4-amino-2-hydroxybutyl) lysine] which is necessary for the biochemical activity of EIF5A2 and cellular proliferation. In this study, we aim to characterize chicken EIF5A2 and explore its potential effects on skeletal muscle cell proliferation and differentiation. Here, we found that chicken EIF5A2 has four variant transcripts. The single nucleotide polymorphisms (SNPs) in the 5′-flanking region of EIF5A2 were significantly associated with the chicken growth and fatness traits. Expression pattern of EIF5A2 in skeletal muscle revealed that it was highly expressed at an early embryonic age and then decreased sharply after d 15 of the embryonic age. The luciferase reporter assays confirmed that EIF5A2 was directly targeted by miRNA-223. EIF5A2 was negatively regulated by miR-223 in myoblast. Both 5-Ethynyl-2′-deoxyuridine staining assays and flow cytometry analyses of the cell cycle showed that down-regulation of EIF5A2 could markedly inhibit myoblast proliferation. We found that down-regulation of EIF5A2 could promote myoblast differentiation through promoting the expression of Myogenin (MYOG). MYOG is a muscle-specific transcription factor involved in myogenesis. Altogether, the results indicated that EIF5A2 is an important candidate gene in chicken growth, and down-regulation of EIF5A2 could suppress myoblast proliferation and promote myoblast differentiation by targeting miR-223.