Phenotypes

Khalaj et al. (2009): "A nucleotide substitution of T to A resulting in an amino acid substitution of leucine to histidine (p.Leu2153His) was identified in a highly conserved residue in the C1 domain of factor VIII. Genotyping of 254 normal animals including the pedigree of the affected animals and randomly sampled animals of different breeds confirmed that the substitution is the causative mutation of cattle haemophilia A." Analysis of whole-...

Illustrating the enormous power of genomic tools, Wiedemar et al. (2015) were able to identify a likely causal mutation for a previously unrecorded disease phenotype in just a single calf.

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 ...