Genetic variation and mRNA expression of the <i>ELOVL6</i> and <i>CRTC2</i> genes in Kalmyk cattle

Kalmyk cattle are an important meat breed in Kazakhstan, valued for their strong physique, genetic stability, and adaptability. In this study, we investigated the mRNA expression of ELOVL fatty acid elongase 6 (<i>ELOVL6</i>) and CREB-regulated transcription coactivator 2 (<i>CRTC2</i>) across multiple tissues, and further examined their genetic variations and associations with growth and carcass traits in 200 Kalmyk cattle. Expression analysis showed that <i>CRTC2</i> was most highly expressed in the heart and liver, whereas <i>ELOVL6</i> was predominantly expressed in the spleen and large intestine, highlighting their tissue-specific expression patterns. In addition, we identified a polymorphic SNP (g.16511290A > G) in the 3'UTR of <i>ELOVL6</i>, with three genotypes (AA, AG, GG) and the G allele being dominant (0.520). Polymorphism information content (PIC) analysis indicated high genetic diversity at this locus. Importantly, this SNP was significantly associated with live weight and body oblique length (<i>p</i> < 0.05), and individuals carrying heterozygous AG genotype showed higher body weight and length. Collectively, these findings suggest that g.16511290A > G within <i>ELOVL6</i> may serve as useful molecular markers for body measurements and meat traits, providing valuable resources for marker-assisted selection in beef cattle breeding programs.