Effects of feeding methods on intramuscular fat deposition and differential expression of related genes in Tan sheep
This experiment was based on transcriptomic techniques to investigate the differences in fat deposition and the screening and analysis of related expressed genes between housed and grazed Tan sheep.Twelve 4-month-old Tan sheep of similar body condition were randomly divided into 2 groups of 6 animals each and were reared in grazing and housing mode.The longest back muscle and biceps femoris were slaughtered at 6 months of age.The results showed that the intramuscular fat(IMF)content in the longest dorsal muscle was significantly higher in the housed group than in the grazing group(P＜0.05).The IMF content of the longest dorsal muscle of Tan sheep in the grazing group was(1.4567±0.0987)％,and that of the longest dorsal muscle of beach goats in the housed group was(2.0700±0.1493)％.The IMF content in the biceps brachii muscle was higher in the housed group than in the grazing group,but the difference was not significant.Compared with the housed group,the saturated fatty acid contents of the longest dorsal muscle and biceps femoris of the grazing group were lower,with the longest dorsal muscle having lower contents of hexanoic acid(C6∶0),caprylic acid(C10∶0),myristic acid(C14∶0),pentadecanoic acid(C15∶0),palmitoleic acid(C16∶1),heptadecanoic acid(C17∶0),heptadecenoic acid(C17∶1),stearic acid(C18∶0).The content of long-chain fatty acids and unsaturated fatty acids with carbon atoms ≥18 was higher in the grazing group of Tan sheep,with the longest dorsal muscle 21-carbon alkanoic acid(C21∶0)and biceps femoris 17-carbon alkanoic acid(C17∶0)being significantly lower than in the grazing group(P＜0.05).Based on transcriptomic analysis,compared with the housed group,the expression of the longest dorsal muscle fat metabolism genes in the grazing group of Tan sheep was significantly downregulated by acyl coenzyme A thioesterase 7(ACOT7),adipocyte differentiation transcription factor(ADIG)and acyl coenzyme A oxidase 2(ACOX2)(P＜0.05),and significantly upregulated by solute carrier family 7 member 8(SLC7A8),free fatty acid receptor 4(FFAR4)and insulin-like growth factor 2(IGF2)(P＜0.05).The expression of Tan sheep fat metabolism genes was significantly downregulated by ACOT7,ADIG,fatty acid binding protein 4(FABP4)and lipase A(LIPA)in the grazing group(P＜0.05),and significantly upregulated by arachidonic acid 15-lipoxygenase(ALOX 15)and diacylglycerol O-acyltransferase 2(DGAT2)(P＜0.05).
Tan sheeptranscriptomefat metabolismdifferential gene screening
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万方数据
