Phenotypes

Awasthi Mishra et al. (2017) reported a likely causal variant for this classic phene: "The belt-associated variant was a copy number variant (CNV) involving the quadruplication of a 6 kb non-coding sequence located approximately 16 kb upstream of the TWIST2 gene. Increased copy numbers at this CNV were strongly associated with the belt phenotype in a cohort of 333 cases and 1322 controls. We hypothesized that the CNV causes aberrant expression...

Excluding variants found in breeds that do not show this trait, Daetwyler et al. (2014) narrowed the field down to "a missense mutation in KRT27 (c.276C>G; p.Asn92Lys; g.41636961C>G on BTA19; ss699911276)". Strong supporting evidence of the causality of this mutation was found by studying its presence in numerous bulls of the Montbeliarde breed (in which the trait occurs, and which, like Fleckvieh, derives from the Simmental breed) compa...

In a textbook example of how to make use of clinical information to identify a comparative candidate gene (based on the homologous human disorder) namely KRT5 (keratin 5), Ford et al. (2005) showed that this disorder in the offspring of a Friesian-Jersey bull is due to a 4051G>A base substitution in the bovine KRT5 gene, leading to an E478K amino-acid substitution. The bull turned out to be mosaic for a de novo mutation. Jacinto et al. (202...

In a sign of the times, Menoud et al. (2012) needed only three affected Rotes Höhenvieh calves to identify the causative mutation of this disorder as being a "SNP in the bovine COL7A1 exon 49 (c.4756C>T) . . . which causes a premature stop codon which leads to a truncated protein representing a complete loss of COL7A1 function (p.R1586*)" Independently of the above discovery, Pausch et al. (2016) discovered exactly the same likely causal va...

Using targeted DNA capture and massively parallel resequencing of the 1.2 Mb region that contained 24 genes, Testoni et al. (2012) identified a causal mutation as a "KDM2B missense mutation (c.2503G>A) leading to an amino acid exchange (p.D835N) in an evolutionary strongly conserved domain". As the same authors report, "The KDM2B gene (also known as JHDM1B and FBXL10) encodes a histone H3 lysine 36 dimethyl (H3K36me2)-specific demethylase ....

Syndactyly has been reported in many breeds of cattle in many countries. Most of the documentation, however, concerns its occurrence in US Holsteins, where, as a result of the siring of more than 60,000 calves by a bull who was subsequently shown to be a carrier, the disorder attracted considerable attention (Anon., 1967). The possibility that artificial selection favouring heterozygotes may have contributed to the unacceptably high frequency ...