Cloning And Analysis Of Goose G Protein-coupled Receptor 103 And Its Splice Variants

G protein-coupled receptor 103 (GPR103), also named QRFPR, is a member of A family in G protein-coupled receptors super family. GPR103 maybe play a key role in lipid metabolism in mammals. However, There is little research about the structure and function of GPR103 in poultry, and it is also unknown how many subtypes are there in mammals.Based on ESTs of GPR103, which were obtained by suppression subtractive hybridization (SSH) between Landes geese (Anser anser) and Sichuan white geese(Anser cygnoides), we employed Sichuan white geese as materials to study the mRNA and DNA sequence of goose GPR103, and to analyze the alternative splicing of this gene. The main results of this study are as follows:(1) RT-PCR, RACE, cloning & sequencing, and sequences assembly were used for obtaining complete mRNA sequence of five different variants, which were named as gGPR103-a, gGPR103-b, gGPR103-c, gGPR103-d, and gGPR103-e. Six ESTs of 3'end of goose GPR103 also were cloned and sequenced, named as gGPR103-I4A, gGPR103-I4B, gGPR103-I4C, gGPR103-I5A, gGPR103-E6A, and gGPR103-E6B respectively.(2) Based on obtained sequence of exons, PCR, cloning and sequcencing, and sequence assembly were used to get a 7002 bp DNA sequence of goose GPR103.(3) Based the comparison between each mRNA variant and the DNA sequence, we found that all the intron splicing of goose GPR103 are consistent with GU-AG rule, and has two alternative splicing methods. gGPR103-b and gGPR103-c are belong to exon skipping, gGPR103-d and gGPR103-e are belong to 3'SSs selective using, gGPR 103-d also occurred a kind of exon acquiring.(4) There are at least seven ways of selective termination in goose GPR103 were found. gGPR103-a, gGPR103-b, gGPR103-c, gGPR103-d and gGPR103-e are with same 3'end and belong to the same way of selective termination. The other six ESTs are with complete structure of 3'end but totally different, so they belong to six different ways of selective termination.(5) Structure and function of goose GPR103 spliceosome might by changed by alternative splicing. gGPR103-a have seven transmembrane domain, and not only has the GPR superfamily domain, but also has Aa-Trans superfamily domain. gGPR103-b, gGPR103-c, gGPR103-d and gGPR103-e occurred the early termination, with only 4,3,5 and 5 times of transmembrane, respectively. gGPR103-b and gGPR103-e had only Aa-Trans superfamily domain, and gGPR103-c, gGPR103-d had only the GPR superfamily domain.