| This study was to research the effects of different energy and protein levels on the m RNA expression of lipid metabolism related genes in the adipose tissue of Tan sheep, to provide basic data for reducing excess fat of Tan sheep, researching the lipid metabolism and regulation, and bulid the foundations for the deep study of Tan sheep fat deposition mechanism.A total of 112 healthy Tan sheep were randomly divided into four groups with 4 replicates per group(same male and female), seven sheep were used in per replicate. The experiment was divided into 3 periods according to growth stages(22~28 kg, 29~35 kg, 36~40 kg) and weight gain target. Three period diets are according to the standard of NRC about sheep, every stage have four groups: 0.84×NRC(group I), 0.96×NRC(group II), 1.08×NRC(group III), 1.20×NRC(group IV). At the end of each stage, one sheep was slaughtered at each replicate, the tail fat, perirenal fat and subcutaneous fat were taken for analyzing the m RNA expression of lipid metabolism related genes by Real-time quantitative PCR.Experiment 1: Studies on the m RNA expression of dietary energy and protein levels on lipid metabolism related genes in Tan sheep adipose tissues. The results showed as follows:1. Tail fat:In 22~28 kg stage, PPARγ and FABP4 m RNA expression levels are significantly higher in group II than other groups(P<0.05); KLF2, KLF3, KLF4, KLF5, KLF7 and KLF15 m RNA has no difference at this stage(P>0.05);In 29~35 kg stage, FABP4 m RNA expression levels are highest in group II, and lowest in group IV(P<0.05); PPARγ, KLF2, KLF3, KLF4, KLF5, KLF7 and KLF15 m RNA has no difference at this stage(P>0.05);In 36~40 kg stage, PPARγ, FABP4, KLF4, KLF5 and KLF15 m RNA expression levels are highest in group II, and KLF4 m RNA expression levels are higher in group I than gorup III and IV(P<0.05); KLF2 m RNA expression levels are highest in group IV and lowest in group II(P<0.05); there was no difference about KLF3 and KLF7 m RNA(P>0.05).2. Perirenal fat:In 22~28 kg stage,PPARγ m RNA expression levels are highest in group II, andsignificantly lower in group IV compared with group III(P<0.05); FABP4 m RNA expression levels are significantly higher in group II and III(P<0.05); KLF2, KLF3, KLF4, KLF5, KLF7 and KLF15 m RNA has no difference at this stage(P>0.05);In the end of 29~35 kg stage,PPARγ m RNA expression levels are highest in group II, and significantly lower in group IV compared with group III(P<0.05); FABP4 m RNA expression levels are significantly higher in group II compared with group IV(P<0.05);KLF2, KLF3, KLF4, KLF5, KLF7 and KLF15 m RNA has no difference at this stage(P>0.05);In 36~40 kg stage,PPARγ,KLF5 and KLF15 m RNA expression levels are highest in group II, and PPARγ m RNA expression levels are significantly lower in group IV compared with group III(P<0.05); FABP4, KLFF4 m RNA expression levels are significantly higher in group I and II(P<0.05); KLF2 m RNA expression levels are significantly higher in group I and IV(P<0.05); no difference were found about KLF3 and KLF7 m RNA(P>0.05).3. Subcutaneous fat:There was no significant difference in subcutaneous fat at three stages(P>0.05).Experiment 2: Studies on the effects of nutritional levels on the m RNA expression of FABP4 in different adipose tissues. The results showed as follows:1. The m RNA expression of FABP4 in tail and subcutaneous fat increased with the increase of body weight(except subcutaneous fat in group IV), the m RNA expression of FABP4 in perirenal fat was increased with the increase of body weight in group I(P<0.05);2. Group I: Compared with tail fat, the FABP4 m RNA expression levels are higher in perirenal fat, and higher in subcutaneous fat in the first and third stages(P<0.05);3. Group II:As body weight increased, the m RNA expression of FABP4 growth rapidly in group II, it seems the tail fat proportion in adipose tissues may be improved;4. Group III: As body weight increased, the m RNA expression of FABP4 growth slowly in group III, it seems the perirenal fat proportion in adipose tissues may be declined;5. Group IV: the FABP4 m RNA expression levels are highest in subcutaneous fat in the second stage(P<0.05).The results indicate that the effect of nutritional levels on deep fat tissue was greater than superficial fat tissue in Tan sheep. With different growth stages and tissues, the regulation of dietary nutrition on the lipid metabolism related genes m RNA expression levels was different. With different nutrirional levels, the mechanism of FABP4 m RNA expression in different adipose tissues of Tan sheep was different. |
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