不同氮能比饲粮对妊娠环江香猪脐带血管发育相关基因表达的影响

本试验旨在研究不同氮能比饲粮对妊娠环江香猪脐带血管发育相关基因表达的影响。选用首次妊娠的环江香猪48头,根据体重随机分为2组,每组8个重复(栏),每个重复3头猪。配种后分别饲喂高氮能比饲粮消化能(DE)为14.73 MJ/kg,粗蛋白质(CP)含量为13.11%,氮能比为0.89]和低氮能比饲粮(DE为12.24 MJ/kg,CP含量为9.77%,氮能比为0.80)。分别于妊娠第45、75和110天每栏取1头母猪,处死屠宰,收集每窝中最大体重、平均体重和最小体重胎猪对应的脐带,利用实时荧光定量PCR方法检测血管发育相关基因——成纤维细胞生长因子(FGF)、血管内皮生长因子(VEGF)、血管内皮生长因子受体2(VEGFR2)和内皮型一氧化氮合酶(e NOS)的表达量。结果表明:与低氮能比饲粮组相比,高氮能比饲粮显著上调了脐带血管发育相关基因的表达量(P0.05),包括妊娠45 d最大体重胎猪的VEGF和VEGFR2表达量,平均体重胎猪的VEGF表达量;妊娠75 d最大体重胎猪的VEGF、VEGFR2和e NOS表达量,平均体重胎猪的VEGF和e NOS表达量,最小体重胎猪的VEGFR2表达量;妊娠110 d最大体重胎猪的FGF、VEGFR2和e NOS表达量,平均体重胎猪的FGF和VEGFR2表达量,最小体重胎猪的VEGF和e NOS表达量。不同妊娠期相同标准体重、同一妊娠期不同标准体重胎猪的脐带血管发育相关基因的表达量均存在差异。由此可见,高氮能比饲粮可能由于其蛋白质和氨基酸水平较高而显著上调了妊娠环江香猪脐带血管发育相关基因的表达量,不同妊娠期或同一妊娠期不同标准体重胎猪的脐带血管发育相关基因的表达量也存在差异。

Effects of Different Nitrogen/Energy Diets on Expression of Genes Related to Umbilical Vessel Development of Pregnant Huanjiang Mini-Pigs

This study was conducted to investigate the effects of different nitrogen/energy diets on expression of genes related to umbilical vessel development of pregnant Huanjiang mini-pigs.A total of 48 primiparous Huanjiang mini-pigs were randomly assigned into two groups according to the body weight (BW), and reared in eight replicates (pens) with three mini-pigs per replicate.After service, the animals were fed with high nitrogen/energy diet (digestible energy was 14.73 MJ/kg, crude protein content was 13.11％, nitrogen/energy was 0.89) and low nitrogen/energy diet (digestible energy was 12.24 MJ/kg, crude protein content was9.77％, nitrogen/energy was 0.80), respectively.At 45, 75 and 110 d of gestation, one pig was randomly selected and sacrificed from each pen.The umbilical cord tissues were collected from three fetuses with maximal BW, average BW and minimal BW per litter.The expression levels of fibroblast growth factor (FGF), vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor 2 (VEGFR2) and endothelial nitric oxide synthase (eNOS), which related to umbilical vessel development, were detected by RT-qPCR technique.The results showed that compared with the low nitrogen/energy diet group, the high nitrogen/energy diet significantly increased the expression levels of genes related to umbilical vessel development (P <0.05), including VEGF and VEGFR2 genes expression levels of fetus at 45 d of gestation with maximal BW;VEGF gene expression level of fetus at 45 d of gestation with average BW;VEGF, VEGFR2 and eNOS genes expression levels of fetus at 75 d of gestation with maximal BW;VEGF and eNOS genes expression levels of fetus at 75 d of gestation with average BW, VEGFR2 gene expression level of fetus at 75 d of gestation with minimal BW;FGF, VEGFR2 and eNOS genes expression levels of fetus at 110 d of gestation with maximal BW, FGF and VEGFR2 genes expression levels of fetus at 110 d of gestation with average BW, and VEGF and eNOS genes expression levels of fetus at 110 d of gestation with minimal BW.The expression levels of umbilical vessel genes of fetuses in different gestation stages with the same standard BW were different, as well as of fetuses with different standard BW in a same gestation stage.These findings suggest that the high nitrogen/energy diet containing higher levels of protein and amino acids can significantly increase the expression levels of genes related to the umbilical vessel development in pregnant Huanjiang mini-pigs, and the tested gene expression levels are different during different gestation stages, as well as among the fetuses with different standard body weights during a same gestation stage.Chinese Journal of Animal Nutrition, 2017, 29(2) :613-619]