Phenotypes

By cloning and sequencing a very likely comparative candidate gene (based on the same disorder in humans), Shuster et al. (1992; PNAS) showed that this disorder in Holstein cattle is due to a missense mutation (c.383A>G) in the CD18 gene, now known as ITGB2. This mutation was confirmed in Daetwyler et al. (2014)'s analysis of whole-genome sequence data from 234 cattle, including key ancestors of the Holstein-Friesian, Fleckvieh and Jersey b...

This single-locus autosomal dominant trait confers increased thermotolerance within the breeds in which it originated (Senepol and Carora; Olsen et al., 2003) and also within Hosteins, into which it was introgressed (Dikmen et al., 2008; 2014). In the USA, FDA determined in March 2022 that beef cattle with a genome edit to the PRLR gene and their offspring do not raise any safety concerns. "Based on the safety of consumption of meat from conve...