断奶日龄对仔猪肝脏GHR、IGF-Ⅰ、IGF-ⅠR基因表达的影响

Effects of Weaning Age on GHR,IGF-Ⅰ,IGF-ⅠR Gene Expressions of Liver in Piglets

为了研究不同断奶日龄对仔猪肝脏中生长激素受体(GHR)、胰岛素样生长因子-Ⅰ(IGF-Ⅰ)和胰岛素样生长因子Ⅰ受体(IGF-ⅠR)基因mRNA表达的影响,从8窝"杜×长×大"仔猪选取出生日龄相近、初生体重一致的仔猪24头,随机分为4个试验组中,分别于14日龄、21日龄、28日龄和35日龄断奶。所有仔猪在42日龄宰杀取样,用RT-PCR方法检测肝脏中GHR、IGF-Ⅰ和IGF-ⅠR基因mRNA的相对表达量。结果表明:试验期间,个别仔猪偶尔出现腹泻症状。至42日龄试验结束时,各组仔猪体重无显著性差异(P>0.05)。14日龄、21日龄和35日龄断奶组仔猪肝脏中GHR mRNA和IGF-ⅠmRNA的相对表达量均无显著性差异(P>0.05),但该三组上述基因的表达量均显著低于28日龄断奶组(P<0.05);不同断奶日龄组仔猪肝脏中IGF-ⅠR mRNA的相对表达量无明显差异(P>0.05)。因此,不同断奶日龄对仔猪肝脏中生长相关基因表达影响的模式不同,对42日龄时仔猪的体重无显著影响。

In order to research the effects of weaning age on GHR,IGF-Ⅰ,IGF-ⅠRgene expressions of liver,a total of 24crossed-bred（Duroc× Landrace× Yorkshine）piglets from 8litters with similar age and body weight were randomly assigned to 4groups with 6replicates in each group and 1piglet in each replicate.The 4groups were 14 days of age weaning group,21 days of age weaning group,28 days of age weaning group and 35 days of age weaning group,respectively.All piglets were slaughtered at 42 days of age and liver samples were acquired.The relative expression of GHR,IGF-Ⅰ,IGF-ⅠR mRNA in liver were measured by RT-PCR.The results showed as follows：the diarrhea symptoms of individual piglets were observed occasionally during the whole test period.At 42 days of age,the body weight of piglets was no significant difference among all groups（P〉0.05）.The relative expression of GHR mRNA and IGF-ⅠmRNA in 14,21,35 days of age weaning groups was no significant difference（P〉0.05）,but was significantly lower than that in 28 days of age weaning group（P〈0.05）.The relative expression of IGF-1RmRNA in liver at different weaning age groups was no significant difference（P〉0.05）.The results indicate that the effective patterns of different weaning ages on related growth gene expressions of liver in piglet are different,and the body weight of piglets was no significant difference at 42 days of age.