Screening Of Candidate Genes For Growth Traits In Angus Cattle And The Effect Of PSEN1 On Proliferation And Differentiation Of Myogenic Cells

In this study,211 female Angus cattle reared in Ningxia were used to screen single nucleotide polymorphisms(SNPs)that were highly and significantly associated with Angus cattle crosses by genome-wide association analysis using the results of simplified genome sequencing,and to identify candidate genes by functional enrichment analysis,association analysis and tissue expression.The candidate genes were identified by functional enrichment analysis,association analysis and tissue expression.Among them,PSEN1 gene was significantly enriched in the Wnt signaling pathway and Notch signaling pathway,which have important regulatory roles in the growth and development of organisms,therefore,further functional validation of PSEN1 gene was performed at the cellular level.functional validation of the PSEN1 gene at the cellular level.The main findings are as follows:(1)Data on cross height traits of Angus cattle in Ningxia region were collected and compiled,and the average cross height of Angus cattle at birth,weaning,6 months,12 months,18 months and 24 months of age were 74.13 cm,98.36 cm,107.18 cm,119.26 cm,127.99 cm and 134.18 cm,respectively.(2)Nine SNP loci located on chromosomes 1,3,4,5,7,10,13 and 28 were significantly associated with cross height by genome-wide association analysis,combined with functional enrichment analysis and validation of gene expression profiling,and eight related genes were screened as candidates for growth traits,namely PSEN1,MEF2D,IGF1,ARID5B,PAXBP1,MEDF10,ZHX3,and SHH.(3)Transfection of specific siRNA fragments of gene PSEN1 into myogenic cells revealed that interference with gene PSEN1 decreased the number of cell proliferation,increased the number of apoptosis,and significantly downregulated the expression of related proliferation and differentiation marker genes,indicating that interference with gene PSEN1 could inhibit the proliferation and differentiation of bovine myogenic cells.(4)Overexpression of PSEN1 in bovine myogenic cells increased cell proliferation,decreased apoptosis,and significantly upregulated the expression of related proliferation and differentiation marker genes,indicating that overexpression of PSEN1 could promote the proliferation and differentiation of bovine myogenic cells.In this study,genome-wide association analysis was performed to identify genetic markers and functional genes associated with high cross traits in Angus cattle in Ningxia,and candidate genes affecting growth traits in Angus cattle were obtained,which provided a basis for the improvement of production performance and breed selection of Angus cattle in Ningxia.The function of PSEN1 gene was verified to further provide some material for molecular breeding of Angus cattle.