Identification Of The Short-Chain Fatty Acid Receptor GPR41and GPR43Genes Of Rabbit

Short-chain fatty acids (SCFAs), mainly including acetate, propionate and butyrate, largely are produced in lumen of large intestine through complex fermentation reaction carried out by a rich and diverse bacterial ecosystem. The principal substrates for fermentation are carbohydrates, which either cannot be or are not digested in the small intestine. SCFAs are not only the main resource of energy in vivo, but also play a regulatory role in various physiological processes. In2003, two orphan G protein coupled receptors (GPRs), GPR41and GPR43, have been cloned and demonstrated to be receptors for SCFAs. The activation of GPR41and GPR43may be involved in several metabolic effects and certain immunological reaction. Researches referring to GPR41and GPR43mainly focused on human, rats and other rodents. Study about the gene structure, function and tissue expression of GPR41and GPR43in rabbit is few, which mainly discuss in this study.In this study, we determine firstly whether rabbit genome contains GPR41and GPR43genes similar to the sequences of GPR41and GPR43genes in human and rodents, secondly whether these two genes are expressed in different tissues in rabbit, and thirdly determine the mRNA expression and protein expression of GPR41and GPR43in different tissues in rabbit through nested PCR and Western-blot.Homology Analysis of sequence of GPR41and GPR43gene between rabbit and human, bovine, rat, mouse, goat used BLAST and DNANAN software. The result showed that the gene similarity between rabbit GPR41and human, bovine, rat, mouse, goat was84%,84%,80%,81%and84%, respectively. The similarity between rabbit GPR43and human, bovine, rat, mouse, goat was83%,72%,81%,82%and73%, respectively. The amino acid similarity between porcine GPR41and human, bovine, rat, mouse, goat was70%,74%,75%,75%and74%, respectively. The similarity between rabbit GPR43and human, bovine, rat, mouse, goat was79%,79%,85%,84%and81%, respectively. Determination of mRNA expression of GPR41and GPR43gene by nested PCR The expression levels of GPR.41and GPR43mRNA in various tissues of rabbit were determined by nested PCR. The results showed that GPR41gene was expressed in various tissues except in hypothalamus and pituitary gland. The expression levels of this gene were higher in liver, spleen, ileum and adipose tissue and lower in heart and muscle. GPR43gene was expressed in various tissues and the expression levels of this gene were higher in hypothalamus and adipose tissue, and lower in adrenal glands and muscle.Determination of protein expression of GPR41and GPR43gene by western-blot The protein expression levels of GPR41and GPR43gene in various tissues of rabbit were determined by western-blot. The results showed GPR41protein was expressed in various tissues except in hypothalamus and pituitary gland. The expression levels of this protein were higher in liver. GPR43protein was expressed in various tissues and the expression levels of this protein were higher in lung and muscle tissue. The predominant bands for rabbit GPR41and GPR43were higher than theoretical molecular weights, suggesting that these two proteins may be modified after translated.