Molecular Characterization and Expression Analysis of Insulin-like Growth Factor-1 and Insulin-like Growth Factor Binding Protein-1 Genes in Qinghai-Tibet Plateau Bos grunniens and Lowland Bos taurus

Abstract

Insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding protein-1 (IGFBP-1) play a pivotal role in regulating cellular hypoxic response. In this study, we cloned and characterized the genes encoding IGF-1 and IGFBP-1 to improve the current knowledge on their roles in highland Bos grunniens (Yak). We also compared their expression levels in the liver and kidney tissues between yaks and lowland cattle. We obtained full-length 465 bp IGF-1 and 792 bp IGFBP-1, encoding 154 amino acids (AA) IGF-1, and 263 AA IGFBP-1 protein, respectively using reverse transcriptase-polyerase chain reaction (RT-PCR) technology. Analysis of their corresponding amino acid sequences showed a high identity between B. grunniens and lowland mammals. Moreover, the two genes were proved to be widely distributed in the examined tissues through expression pattern analysis. Real-time PCR results revealed that IGF-1 expression was higher in the liver and kidney tissues in B. grunniens than in Bos taurus (p<0.05). The IGFBP-1 gene was expressed at a higher level in the liver (p<0.05) of B. taurus than B. grunniens, but it has a similar expression level in the kidneys of the two species. These results indicated that upregulated IGF-1 and downregulated IGFBP-1 are associated with hypoxia adaptive response in B. grunniens.

Yak rumen microbial diversity at different forage growth stages of an alpine meadow on the Qinghai-Tibet Plateau

“…It has been reported that the yak has a special molecular mechanisms to adapt to the harsh living environment in the cold and low-oxygen environment (Chen et al, 2015a; Xue et al, 2017) and yaks have adapted to the poor forage resources of the QTP. The rumen as the first chamber of the ruminant stomach, is populated by bacteria, fungi, archaea (methanogens), and protozoa with important functions in the digestion of the complex cellulolytic biomass.…”

The uniqueness and superiority of energy utilization in yaks compared with cattle in the highlands: A review

“…They are well adapted to this unique environment which has limited forage resource availability during the cold season. Over the past decades, many researchers have studied the adaptability of yaks to the plateau environment from several facets ( Qiu et al., 2012 ), including molecular phylogeny, morphological adaptations and physiological functions ( Lalthantluanga et al., 1985 ; Guo et al., 1995 ; Shao et al., 2010 ; Mipam et al., 2012 ; Chen et al., 2015 ; Lan et al., 2018 ). In the context of energy metabolism, yaks have a higher ability to utilize energy sources, absorb nutrients and require less energy for their maintenance compared with domestic cattle ( Bos taurus ) ( Brosh et al., 2004 ; Wei et al., 2016a ; Zhang et al., 2016 ).…”

Peer Review #2 of "Yak rumen microbial diversity at different forage growth stages of an alpine meadow on the Qinghai-Tibet Plateau (v0.1)"

“…To avoid the death of yaks in spring and their decrease in body weight (BW) over winter, supplementary feeding with total mixed rations of available roughage and grains is widely used as the grazing system (Xue et al 2017). It has been reported that the yak has a special molecular mechanisms to adapt to the harsh living environment in the cold and low-oxygen environment (Chen et al 2015a;Xue et al 2017) and yaks have adapted to the poor forage resources of the QTP. The rumen as the first chamber of the ruminant stomach, is populated by bacteria, fungi, archaea (methanogens), and protozoa with important functions in the digestion of the complex cellulolytic biomass.…”