Developmental Expression Changes Of Fat-related Genes In Adipose Tissue Between Two Pig Breeds

To investigate the developmental expression pattems of insulin like growth factor 2 (IGF2),IGF binding protein 3(IGFBP3),Stearoyl CoA desaturase(SCD),malic enzyme (ME) genes at the age of 30,60,90,120 and 150 days in back subcutaneous fat tissue of Landrace(a leaner Westem breed) and Taihu pigs(a fatty indigenous Chinese breed), Real-time fluorescence quantitative PCR was applied.In addition,the genes expression difference between breeds and ages and the effects on adipose traits were analyzed.Results showed that Taihu pigs had higher adipocyte hypertrophy and deposit capability than Landrace pigs in terms of adipocyte volume and backfat thickness at 30, 60,90,120 and 150 ages.The expression of IGF2,IGFBP3,SCD and ME mRNA in the adipose tissue of pigs exhibited specific developmental changes and different patterns between the two pig breeds.(1)the expression level of IGF2 mRNA in Landrace pigs was significantly higher than other days at 30 days(P＜0.01),then gradually declined and lowest at 120 days,obviously increased at 150 days.In Taihu pigs,it was relatively higher at 30～60 days,lowest at 90 days,increased rapidly at 120 days,and then decreased.Developmental expression patterns of IGFBP3,SCD,ME mRNA in the two pig breeds were similar,the expression level of IGFBP3 were highest at 30 days, declined significantly at 60 days(P＜0.05) then maintained steady,but a little fluctuant; the expression level of SCD was very low during 30,60 ages and increased rapidly at 90 age,then maintained the higher level;the expression level of ME was very low during 30,60 ages and increased rapidly at 90 age,then delined gradually between ages in each breed.(2) the expression level of IGF2 mRNA in Taihu pigs was significantly higher than that of Landrace pigs at the age of 120 days(P＜0.01),and the expression level of IGFBP3 mRNA in Taihu pigs was significantly lower than that of Landrace at the age of 150 days(P＜0.01),with no significant difference between the two pig breeds at other ages(P＞0.05).The expression level of SCD mRNA in Landrace pigs was significantly lower than that of Taihu pigs at the age of 30 days(P＜0.05),and was significantly higher than that of Taihu pigs at the age of 60 days(P＜0.01);the expression level of ME mRNA in Landrace pigs was significantly lower than that of Taihu at the age of 30,150 days (P＜0.01) and was significantly lower at 90 days(P＜0.05),but significantly higher than that of Taihu at the age of 60 days(P＜0.01),with no significant difference between the two pig breeds at other ages(P＞0.05).