Pleomorphic adenoma gene 1 (PLAG1) belongs to the PLAG family of zinc finger transcription factors. In cattle, a 19-bp insertion/deletion (indel) was identified in intron 1 of the PLAG1 gene (GenBank Accession No. AC_000171.1). Researches showed that the indel is polymorphic in Chinese cattle breeds such as Qinchuan cattle, Pinan cattle, Xianan cattle, and Jiaxian red cattle, and correlation analysis showed that the polymorphism is related to the height of these cattle breeds. Chinese cattle breeds show a difference in height related to geographical distribution. We investigated the distribution of the 19-bp indel polymorphism in 37 cattle breeds, including 1354 individuals. The results showed that there were three genotypes and two alleles (W, 366 bp; D, 347 bp). From northern cattle to southern cattle, the frequency of W allele gradually decreased, while the frequency of D allele showed an opposite trend, which was consistent with the distribution of cattle breeds of different height in China. Therefore, the polymorphism of this indel may be related to the regional distribution of cattle breeds in China. In addition, we chose Yunling cattle with a mixed genetic background to study the genetic effects of the 19-bp indel on body size traits. Statistical analysis showed that PLAG1 was significantly associated with the body height, cross height, and chest circumference of Yunling cattle (p < 0.05). This study provides new evidence that the 19-bp indel of the PLAG1 gene is a highly effective trait marker that can be used as a candidate molecular marker for cattle breeding.
Keywords: PLAG1 gene; cattle; growth traits; indel; polymorphism.