The Expression Profile Of Porcine Olfactory Receptor And Nonoic Acid Activates OR51E1 To Inhibit Lipid Accumulation In Preadipocytes

During the genome-wide association analysis(GWAS)of pig feed efficiency,the previous project team found that there are multiple olfactory receptor(OR)SNP sites that are significantly related to the remaining feed intake(RFI)of pigs.Recent literature studies have also shown that OR genes have an important impact on the function of non-olfactory tissues.In order to explore the distribution and expression of OR genes in pigs and their possible non-olfactory functions related to feeding or metabolism,this experiment carried out a porcine OR transcriptome expression analysis,and selected one that is widely expressed in vivo and highly expressed in adipose tissue The olfactory receptors are tested for functional verification in pre-adipocytes.The results of the study can expand human cognition on the distribution and function of olfactory receptor genes.Collect 13 kinds of tissues from 3 randomly selected 60-day-old boars(body weight about 30kg),olfactory epithelium,heart,liver,spleen,lung,kidney,duodenum,jejunum,ileum,brain,testis,A total of 39 sets of samples from muscle and subcutaneous fat were used for high-throughput transcriptome sequencing(RNA-Seq)using the Illumina Hi Seq 4000 platform,and bowtie,Top Hat,Samtools,Cufflinks software and tools such as R,Python,and excel were used to control the quality of the sequencing results,Genome mapping,annotation,FPKM calculation,gene differential expression analysis,and RT-PCR verification of sequencing results.According to the results of RNA-Seq,the olfactory receptor gene OR51E1,which is widely expressed in the body and highly expressed in adipose tissue,was selected to stimulate the precursor adipocytes with nonanoic acid to activate the receptor OR51E1 and detect triglycerides,cholesterol and signal transduction genes The changes in the expression levels of lipogenic and lipolytic genes reveal the role of OR51E1 in the process of lipid metabolism.The research results are as follows:1.A total of 1125 OR genes expressions were identified from the transcriptome level of 13 tissues of pigs,including 1010 functional genes and 115 pseudogenes,accounting for all 1379 OR genes annotation sites annotated in the pig genome(Sscrofa 11.1)81% of it.Olfactory epithelial tissue has the most OR gene expression,with a number of 968,followed by 356 OR genes expression in testis tissue.The overall expression level of OR genes is low,of which 84.7% of FPKM is lower than 0.1,13.9% of FPKM is 0.1-1,and only 1.4% of FPKM is greater than 1.2.In 12 non-olfactory tissues,a total of 548 OR genes were detected,and 12 OR genes were widely expressed(and also expressed in olfactory epithelial tissues).110 OR genes are specifically expressed in non-olfactory tissues,the numbers are 53 in the testis,12 in the spleen,10 in the ileum,7 in the liver,7 in the heart,6 in the brain,and 5 in the lung.3 in the kidney,2 in the fat,2 in the jejunum,2 in the duodenum,and 1 in the muscle.The characteristic sequence analysis of the tissue-specific OR gene revealed that there are different numbers of characteristic sequences among different tissues.3.Through the analysis of the difference in gene expression between porcine olfactory epithelium(OE)tissue and other tissues,255 genes that are highly expressed in OE were identified.It is speculated that these may be genes involved in the process of olfactory transduction,of which 87 genes were previously related There are no corresponding reports for 168 genes.4.The downstream key genes of signal transduction after the specific combination of OR and odor molecules can be detected in OE tissues.Among them,ADCY3,GNAL,REEP1 and RIC8 B are widely expressed in all tissues,and the expression level and OR genes expression level are significant Related.CNGA2,CNGA4,CNGB1,ANO2 are mainly expressed in OE tissues.5.OR51E1 is a widely expressed gene,and its expression is high in adipose tissue.When OR51E1 is activated with nonanoic acid,the lipid accumulation of pre-adipocytes is significantly inhibited,and this inhibition disappears when the expression of OR51E1 is disturbed.Inhibition of the transduction cascade pathway gene ADCY3 can improve the reduction of lipid accumulation caused by the activation of OR51E1.The activation of OR51E1 through the c AMP/PKA pathway affects the expression levels of the key genes for adipogenesis,C/EBPa and FASN,and the transcription levels of the key genes for lipolysis,LPL and PPARGC1 b,and ultimately leads to the reduction of lipid accumulation.