Identification of Three Novel Splicing Variants and Expression Analysis of Chicken GPR1 Gene

Figure 4

Structure analysis of GPR1. (a) Structure analysis of the GPR1 genomic locus (GPR1). Exons were denoted by thick boxes marked “E1, E2” with different colors. Introns were denoted as solid lines and annotated I1. Unknown region was marked “”; the size of an exon or intron was indicated by a number above the exon or intron. (b) Structure analysis of GPR1 variants (GPR1-va1, GPR1-va2 and GPR1-vb). The splicing model was labeled as 3′-ATSS (E2) (3′-alternative tailing site selection in exon 2) and intron retention in exon 2. The UTR (untranslated region) and poly(A) (polyadenylation site) of each variant were indicated by thin colored boxes and “AA…”, respectively. CDS (coding sequence) was denoted by a thick colored box; GPR1-va1 and GPR1-va2 have the same coding sequence. (c) Transmembrane domain prediction of putative proteins encoded by three GPR1 variants. GPR1-va1 and GPR1-va2 exhibited typical type GPCR features consisting of an extracellular N-terminus, 3 intracellular and extracellular loops, and 7 transmembrane a-helical domains. GPR1-vb was truncated protein, with 4 transmembrane domains. Detailed information for (c) is shown in Figure 3.