The SNP c.1326T>G in the non-SMC condensin I complex, subunit G (NCAPG) gene encoding a p.Ile442Met variant is associated with an increase in body frame size at puberty in cattle

Recently, we had located a bovine carcass weight QTL, CW-2, to a 591-kb interval on BTA6 and have identified the SNP c. 1326T>G in the NCAPG (non-SMC condensin I complex, subunit G) gene that leads to the amino acid change p.Ile442Met in the NCAPG protein, which is a candidate causative variation. Here, we examined the association of the NCAPG:c.1326T>G locus with linear skeletal measurements of growth-associated traits during adolescence, which is a period of intensive growth, using two historically and geographically distant cattle populations: 792 Japanese Black steers and 161 F-2 bulls of an experimental cross from Charolais and German Holstein. In both populations, the SNP NCAPG:c.1326T>G was associated with each component of body frame size: height, length and width at puberty. The associations of CW-2 with height-and length-associated traits were observed at an earlier growth period compared to the associations with thickness-and width-associated traits, indicating that the primary effect of the CW-2 QTL may possibly be exerted on skeletal growth. The significant associations of the NCAPG:c.1326T>G locus with growth-associated skeletal measurements are similar to the effects of the syntenic region on human chromosome 4 that are associated with adult height in humans, supporting the hypothesis that CW-2 is analogous to the human locus and pointing to a conserved growth-associated locus or chromosomal region present in both species.