Geng Hongwei, Hao Linlin, Cheng Yunyun, Wang Chunli, Huang Shan, Wei Wenzhen, Yang Rui, Li Haoyang, Liu Songcai, Yu Hao, Lu Huayi
College of Animal Science, Jilin University, 5333 Xi'an Road, Changchun, 130062, Jilin, China.
Five-Star Animal Health Pharmaceutical Factory of Jilin Province, Changchun, Jilin, 130062, China.
J Appl Genet. 2020 Feb;61(1):105-112. doi: 10.1007/s13353-019-00529-4. Epub 2019 Nov 1.
Insulin-like growth factor 1 (IGF1) is pivotal in the regulation of animal growth. Highly polymorphic CA repeat microsatellites have been identified in the IGF1 promoter region of different breeds of pigs. Previous studies showed that CA repeat microsatellites are associated with circulating IGF1 level. However, the mechanisms by which CA repeat microsatellites regulate IGF1 expression remain unclear. This study aimed to detect the association of CA repeat microsatellites with the transcriptional regulation of porcine IGF1 and the possible mechanisms. Results revealed that the number of CA repeats in porcine IGF1 promoter was 14-18, and a promoter with 14 or 15 CA repeats had a higher transcriptional activity (P < 0.01). Transcription factor hypoxia-inducible factor 1 subunit alpha (HIF1α) was confirmed to bind to the binding site upstream of CA repeat microsatellites. The microsatellites with 14 or 15 CA repeats were more sensitive to changes in the HIF1α expression level (P < 0.01). These results suggested that CA repeat microsatellites and HIF1α affected the transcriptional activity of each other in the regulation of IGF1 expression, thereby implying an interaction between them. Overall, this study provided novel evidence for elucidating the effects of CA repeat microsatellites on the transcriptional regulation of porcine IGF1.
胰岛素样生长因子1（IGF1）在动物生长调节中起关键作用。在不同品种猪的IGF1启动子区域已鉴定出高度多态的CA重复微卫星。先前的研究表明，CA重复微卫星与循环IGF1水平相关。然而，CA重复微卫星调节IGF1表达的机制仍不清楚。本研究旨在检测CA重复微卫星与猪IGF1转录调控的关联及可能机制。结果显示，猪IGF1启动子中CA重复的数量为14 - 18，具有14或15个CA重复的启动子具有较高的转录活性（P < 0.01）。转录因子缺氧诱导因子1α亚基（HIF1α）被证实可与CA重复微卫星上游的结合位点结合。具有14或15个CA重复的微卫星对HIF1α表达水平的变化更敏感（P < 0.01）。这些结果表明，在IGF1表达调控中，CA重复微卫星和HIF1α相互影响转录活性，从而暗示它们之间存在相互作用。总体而言，本研究为阐明CA重复微卫星对猪IGF1转录调控的影响提供了新证据。
