Cloning, expression and function analysis of chicken FBX038tl

Abstract

F-box proteins are widely present in eukaryotes, and their biological functions are diverse in animals. In this study, the full-length coding sequence of an unnamed gene LOC416151 (GenBank accession XM-414482) was cloned from the chicken abdominal adipose tissue by reverse transcriptase (RT)-PCR, and the sequence analysis showed that the acquired sequence (GenBank accession. JX290204) is one of the transcript variants of chicken FBX038, which was designated as gFBX038tl. Real-time RT-PCR analysis showed that gFBX038tl was widely expressed in various chicken tissues, with a relatively higher expression level in the pancreas, ileum and abdominal fat tissue. In addition, gFBX038tl was expressed in all the chicken abdominal fat tissues used in the present study, and at 3 and 4 weeks of age, the gFBX038tl expression in lean males was significantly greater than that in fat males (P< 0.05) and no significant difference was observed at the other ages (P> 0.05). The gFBX038tl expression decreased followed by the differentiation of chicken preadipocytes induced by oleate, and gFBX038tl expressed more highly in chicken preadipocytes than in mature adipocytes (P< 0.05), suggesting that gFBX038tl might play a negative role in the chicken adipogenesis. Additionally, The luciferase reporter assay showed that gFBX038tl overexpression inhibited the promoter activities of chicken CCAAT/enhancer-binding protein α(C/EBPα), lipoprotein lipase (LPL), fatty acid synthase (FASN) and fatty acid-binding protein 4 (FABP4). The combined overexpression of gKLF7 and gFBX038tl did not lead to an enhanced ability for gFBX038tl to regulate the promoter activities of chicken LPL, FABP4 and FA SN, indicating that gFBX038tl may regulate promoter activities of these genes through a KLF7-independent manner. The current study provides evidence that the gFBX038tl is involved in chicken adipogenesis.