Intramuscular Fat Deposition Related Genes MRNA Expression And Functional Analysis In Pigs

With the improvement of the living standard, the quality of pork has attracted extensive attention by consumers and producers. Intramuscular fat (IMF) content and backfat thickness (BFT) are two important indicators of measuring meat quality, which, IMF on meat tenderness, juiciness and flavor, and has a significant positive effect on these marks. In this study, differences in genetic background pigs: local varieties of Laiwu pig, cultivars of Lulai Black pig, the introduction of the Large Yorkshire pig as the research object. DGAT1, DGAT2, ADD1, PPARγ, ADRP, and PID1 were associated with intramuscular fat quantitative expression of candidate genes were detected and analyzed; and selected PID1 gene, with the intramuscular fat was significantly associated, constructed eukaryotic expression vector for the functional verification. The aim of this thesis is to provide the theoretical basis of molecular markers in MAS breeding for improving the meat quality. The results are summarized as follows:1. Established a TaqMan probe optimized quantitative analysis ADD1 gene mRNA expression, it is more rapid and accurate when compared with SYBR Green real-time PCR, and does not affect the correlation analysis results. In Laiwu pigs, ADD1 gene mRNA expression is the highest expression in adipose tissue, no significant expression in the liver. Between fat and muscle tissue mRNA expression were significantly differentially expressed (P <0.05). ADD1 mRNA expression in muscle was positively correlated with the IMF (P < 0.05).2. DGAT1 and DGAT2 mRNA expression levels were significantly different in three tissues of the same breed of pig (P < 0.05), as the follows: liver > fat> muscle; in three breeds of pig, mRNA expression as follows: LW> LL > LY; but the DGAT1 gene in different tissues of pig as the order: LY > LL > LW; correlation analysis showed that, DGAT1 gene mRNA expression of the liver was significantly positively correlated with BFT in three breeds of pig (P < 0.05); in muscle DGAT2 gene mRNA expression significant positive correlation with IMF content in three breeds of pig (P < 0.05). 3. PPARγand ADRP gene in three breeds of pig, the mRNA expression in muscle as follows: LW> LL> LY, but no significant difference among them (P > 0.05). In three pig breeds, ADRP gene's mRNA expression of muscle as follows: LL> LW> LY, no significant difference among the three breeds of pig (P > 0.05).PPARγand ADRP gene mRNA expression associated with the content analysis showed that, PPARγmRNA expression in muscle mRNA expression was significantly and positively correlated with IMF (P <0.05) in three breeds of pig, ADRP mRNA expression in muscle no significant correlation with the IMF (P >0.05). PPARγand ADRP mRNA expression was significantly correlated (P < 0.01). Confirmed PPARγhas a certain relationship with fat deposition traits, the results were provided the new information to study intramuscular fat deposition molecular mechanism of Laiwu pig.4. PID1 mRNA expression have significant influence effect in breeds (P <0.05), the order is: LW > LL > LY. Tissues factors had significant effect on PID1 mRNA aboundance(P < 0.05), on the whole, tended to be liver > fat > muscle. The intercation between breeds and tissues factors had significant effect on PID1 mRNA aboundance(P < 0.05). Correlation analysis showed that: Varieties tissues mRNA expression showed significant positively correlated with IMF content (P < 0.05). The results suggest that: PID1 gene may be associated with fat deposition traits.5. PID1 eukaryotic expression vector was constructed and detectedThe coding sequence of PID1 gene was cloned, and constructed the eukaryotic expression vector, named as: pcDNA3.1(+)/PID1. It was used lipid-mediated to transfective in goat hair follicle cells, RT-PCR detected of PID1 mRNA levels. The results showed that the expression of transfected pcDNA3.1(+)/PID1 plasmid cells was significantly higher than those transfected with empty plasmid follicle cells; Western blotting detected the expression of PID1 translation level, the results showed that PID1 protein was effective expressive in cells. It provides a foundation for research the gene.