Molecular cloning, characterisation, and expression analysis of adipocyte fatty acid binding protein gene in Xupu goose (Anser cygnoides domesticus)

Abstract

ABSTRACT 1. Adipocyte fatty acid binding protein (A-FABP) plays a key role in fatty acid uptake and intracellular transport. The objective of the present study was to identify and characterise the A-FABP gene in Xupu goose. 2. The full-length cDNA of goose A-FABP gene was cloned from the liver tissue using reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). The distribution of the goose A-FABP in different tissues was determined by quantitative real-time PCR (qRT-PCR). 3. The results showed that the full-length cDNA sequence of goose A-FABP was 657 bp, containing a 5ʹ-UTR of 52 bp, a 3ʹ-UTR of 206 bp and an open reading frame (ORF) of 399 bp, which encoded a polypeptide of 132 amino acids (AA). 4. The AA sequence of goose A-FABP showed 76.52%, 75.00%, 93.18% and 99.24% identities with previously described homologues from humans (Homo sapiens), mouse (Mus musculus), chicken (Gallus gallus), and duck (Anas platyrhynchos), respectively, and phylogenetic analysis revealed a close relationship among them. The transcript of Xupu goose A-FABP was ubiquitously expressed in all tested tissues, and showed a high-level expression in abdominal fat, sebum and liver. 5. A significant positive correlation was identified between A-FABP mRNA abundance in the three adipose tissues and liver weight, ratio of liver to body weight, TG content, and VLDL concentration in the plasma of Xupu goose. A significant negative correlation was observed between the mRNA level of A-FABP and HDL concentration in the plasma of Xupu goose. 6. These findings provide a foundation for further research on the function and mechanism of A-FABP in the fat deposition process.