Genetic variants in the promoter region of the KLF3 gene associated with fat deposition in Qinchuan cattle

Krüppel-like factor 3 (KLF3), a member of the Krüppel-like factor (KLF) family, plays an important role in adipogenesis and lipid metabolism. The aim of this study was to investigate whether KLF3 could be used as a candidate gene in the breeding of cattle. The expression pattern of bovine KLF3 gene revealed that it was highly expressed in abdominal fat and perirenal fat. Using DNA sequencing, three single nucleotide polymorphisms (SNPs) within the promoter regions of KLF3 gene were identified in 448 Qinchuan cattle, which are located in the recognition sequences of 11 transcription factors and the four haplotypes representing four potential different compositions of polymorphic potential cis-acting elements. Association analysis results indicated that individuals with the Hap7/7 diplotype showed higher (P < 0.05) intramuscular fat content (IFC) than those with H7/8. In addition, the H7 haplotype had much higher (P < 0.05) transcriptional activity than the H8 haplotype, consistent with the association analysis. We speculated that polymorphisms in transcription factor binding sites of the KLF3 promoter region affected transcriptional activity of KLF3, which subsequently influence intramuscular fat content in Qinchuan cattle and KLF3 gene could be used as molecular markers for fat deposition traits using early marker-assisted selection (MAS) of Qinchuan cattle breeding in the future.