Study On Expression Of Adipose Differentiation-related Gene In Different Pig Breeds

Jiangkou Luobo Pigs were used to construct DNA pool, the polymorphisms in genes of PPARγ、C/EBPα、ADD1 rapidly screened by DNA sequencing and explored the bioinformatics information. Jiangkou Luobo Pig, Congjiang Xiang Pig and Large White Pig were slaughtered at 3, 4, 5, 6, 7 months to collect samples from Heart, Liver, Spleen, Lung, Kidney, Small intestine, Longissimus dorsi, Subcutaneous adipose, and extracted total RNA in order to investigate the developmental changes of the PPARγ, C/EBPα, ADD1 gene expression by real- time PCR. The main results obtained in this study were as follows:1. The study was to detect the polymorphism of PPARγ, C/EBPα, ADD1 genes in Jiangkou Luobu pigs. PPARγ gene was screened out of 8 polymorphic locis, which 3 polymorphic locis were located in the exon, and the other 5 locis were located in the intron. ADD1 gene was screened out of 3 polymorphic locis, which 1 polymorphic loci was located in the exon, and the other 2 locis were located in the intron. No polymorphic loci was detected in the C/EBPα gene. Three polymorphisms(exon2-C50 T, exon7-G53 T, exon9-C32T)were located in the exon of PPARγ, and all were missense mutations(exon2-C50 T, Thr→Ile; exon7-G53 T, Asp→Tyr; exon9-C32 T, Ala→Asp). Exon8-G87 A in the exon of ADD1 gene was synonymous mutation, the mutation did not cause amino acid changes. The results of the bioinformatics analysis indicted that the missense mutations could cause the change of allele frequency, mRNA secondary structure, secondary and tertiary protein structure.2.By real-time PCR, PPARγ, C/EBPα, ADD1 had the mRNA expression in all tissues of Large White Pig at 3, 4, 5, 6, 7 months, but highly in Liver, Small intestine, Longissimus dorsi, Subcutaneous adipose, lowly in Heart, Spleen, Lung, Kidney. The expression levels of PPARγ in the Small intestine, Longissimus dorsi, Subcutaneous adipose at 3, 4 months were extreme differences with 6, 7 months(P<0.01). The expression levels of C/EBPα, ADD1 in the Liver, Lung, Small intestine, Subcutaneous adipose at 3 month was extreme differences with 6, 7 months(P<0.01); The mRNA expression of PPARγ, C/EBPα, ADD1 were lower in Heart, Spleen, Lung, Kidney, Longissimus dorsi of Jiangkou Luobo Pig, higher in subcutaneous adipose with issue-specifi. The expression amount increased with the age, and the increase of subcutaneous fat was the most. The expression levels of PPARγ, ADD1 in the Small intestine, Longissimus dorsi, Subcutaneous adipose at 3, 4 months also were extreme differences with 6, 7 months(P<0.01), The expression levels of C/EBPα in the Small intestine, Subcutaneous adipose at 3 month was extreme differences with 5, 6, 7 months(P<0.01). The mRNA expression of PPARγ, C/EBPα, ADD1 in the Subcutaneous adipose of Congjiang Xiang Pig were highest. The expression of PPARγ was not significantly increased with the age, The expression of C/EBPα, ADD1 was significantly increased with the age. The expression levels of C/EBPα, ADD1 in the Small intestine, Longissimus dorsi, Subcutaneous adipose at 3, 4 months were differences with 6, 7 months(P<0.05). With growing, the mRNA expression levels of PPARγ, C/EBPα, ADD1 were basically same in the model, and showed an increasing trend, then maintained the higher expression levels in 6,7 months. The mRNA expression levels of PPARγ, C/EBPα, ADD1 were gradually increased with the increase of the age and maintained a relatively stable level in the late growth stage. The expression of PPARγ, C/EBPα, ADD1 was the highest in Subcutaneous adipose, the higher in Liver, Lung, Small intestine, and the lowest in Heart, Spleen, Kidney; The PPARγ, C/EBPα, ADD1 mRNA expression in different tissues of Jiangkou Luobo Pig, Congjiang Xiang Pig were higher than that of Large White Pig.3. The muscle marbling and pH values, shear force, intramuscular fat content, crude protein content of Congjiang XiangPig, Jiangkou Luobo pig, Large White Pig were increased with the increase of the age, Water loss rate, water loss, water content and cooking loss were decreased with the increase of the age. The meat performance of Congjiang XiangPig, Jiangkou Luobo pig were within the normal range, the marbling score, meat color score, intramuscular fat of Large White Pig in 3, 4 months were low, then with the month increased and increased to the normal value. Generally intramuscular fat of Congjiang XiangPig, Jiangkou Luobo pig were above 4 percent in 6, 7 months, and were higher than Large White Pig. The correlation of PPARγ, C/EBPα, ADD1 genes expression in Congjiang XiangPig, Jiangkou Luobo pig, Large White Pig and meat performance showed that PPARγ, C/EBPα, ADD1 expression level were positively related to meat performance. Expression of PPARγ, C/EBPα, ADD1 in heart, spleen, lung and kidney were low correlation with the color, pH value, drip loss, marbling, water loss rate, cooking loss, shear force, moisture content, crude protein content, intramuscular fat content. Expression of PPARγ, C/EBPα, ADD1 in the liver, small intestine, the back of the longest muscle, subcutaneous fat were high correlation with marble pattern, shear stress, intramuscular fat content, crude protein content.