Association Of PPARα Signal Pathway Genes Related To Fatty Acids Composition In Longissimus Dorsi Muscle Of Yak

In order to research the relation between PPARα signaling pathway genes andyak intramuscular fatty acid composition, providing a theoretical basis for themolecular breeding of yak meat, we choose Gannan yak and cattle for the study, usingmolecular biology techniques to clone yak FABP4, ApoA1, LPL and SCP2gene, andthe sequence of protein were analyzed; using Real-Time PCR to detect the candidategene’s mRNA expression levels of longissimus dorsi muscle in yaks and cattle,besides the expression differences between yaks and cattle were analyzed, while thecorrelation were carried out; using Western blot technique to detect LPL proteinexpression level in yak and cattle, in order to provide molecular theory to yak meatbreeding.The results were as follows:(1) The monounsaturated fatty acid (MUFA) and polyunsaturated fatty acids(PUFA) in yak was extremely significantly higher than in cattle (P <0.01), while thesaturated fatty acid (SFA) was significantly lower than in cattle (P <0.05). EPA andDHA were undetected in cattle longissimus dorsi muscle.(2) The CDS of yak FABP4, ApoA1, LPL and SCP2gene were cloned. Thelength of CDS in FABP4mRNA is399bp and encoding132amino acids, FABP4protein contains Cytosolic fatty-acid binding family protein functional domains, nosignal peptide, containing11phosphorylation sites. The length of CDS in ApoA1mRNA is798bp and encoding265amino acids, ApoA1protein containsApolipoprotein family protein functional domains, the previous18amino acids aresignal peptide, containing11phosphorylation sites. The length of CDS in LPL mRNAis1437bp and encoding478amino acids, LPL protein contains Lipase and PLATfamily protein functional domains, the previous24amino acids are signal peptide,containing22phosphorylation sites. The length of CDS in SCP2mRNA is1632bpand encoding543amino acids, SCP2protein contains Thiolase N, Thiolase C andSCP2family protein functional domains, no signal peptide, containing20phosphorylation sites. (3)Using Real-time PCR technology to detect the candidate genes mRNAexpression of longissimus dorsi muscle in yak and cattle. The expression of FABP4(P<0.05), SCP2(P <0.05) and APOA1(P <0.01) in yaks were significantly lower thancattle. On the contrary, the expression of LPL in yaks was significantly higher than incattle (P <0.05).(4) The expression levels of FABP3(P <0.05) and LPL (P <0.01) werenegatively correlated with MUFA in yak, FABP4and SCD (P <0.01) were positivelycorrelated with PUFA, but negatively correlated with C22:0(P <0.05). CD36andAPOA1were both positively correlated with C12:0and C15:0(P <0.05), SCP2waspositively related with C10:0, C12:0and C14:0(P <0.05) in yak. Furthermore, thePLTP gene showed positive (P <0.05) correlation with C18:2n6t, while the DBIshowed (P <0.05) negative correlation with C20:0in yak. In cattle, the mRNA levelof PLTP showed positive correlation with SFA and C16:0(P <0.05), and the LPLgene showed positive correlation with MUFA and C20:0but negative correlation withC10:0(P <0.05). In addition, the APOA1gene showed negative correlation with SFA,C16:0and C18:0(P <0.05). Therefore, candidate genes may take part in theregulation and control of intramuscular fatty acid metabolism in yak, they can be ascandidate genes in fatty acid character selection in yak.(5) Using Western Blot technique to detect the expression of LPL protein in yakand cattle muscle, we found that the expression difference between yak and cattlewere not significant (P>0.05).