Identification of two novel chicken GPR133 variants and their expression in different tissues

GPR133 (G protein-coupled receptor 133) plays significant roles in various physiological processes. Alternatively splicing (AS) variants of GPR133 in many species have been predicted in multiple databases, but there is no available information about the AS events of chicken GPR133 (cGPR133). In the present study, two chicken GPR133 variants, cGPR133-va and cGPR133-vb, were identified by a combination of reverse transcription PCR (RT-PCR) and rapid amplification of cDNA 5'-ends (5' RACE). Sequence analysis shows that cGPR133-va and cGPR133-vb are resulting from different AS modules and their sequences are predicted to encode two distinct putative proteins, respectively. Quantitative real-time PCR (qRT-PCR) analysis revealed that cGPR133-va and cGPR133-vb are widely expressed in different tissues, while exhibiting specific expression profile. Altogether, our results first demonstrate the existence of novel cGPR133 variants and illustrate its transcriptional diversity and their widespread distribution, which provides a foundation for the further research of GPR133.