Phenotypes

Whole-genome sequencing of an affected calf and both its parents, followed by filtering of variants, enabled Häfliger et al. (2020) to identify a stop-lost mutation in FGFR3 as the likely causal variant, namely g.116,767,863C>A; NM_174318.3: c.2408G>T; [XM_024992994.1: p.(Ter803Leuext*93), which is "predicted to extend the sequence at the C‐terminal end with 93 additional amino acids". This variant resulted from a de novo mutation in the...

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...

As reported by Kadri et al. (2014), one of the genes in the deletion (see Mapping section), namely RNASEH2B, is "known to cause embryonic lethality when knocked-out in the mouse". Subsequent investigations confirmed that this deletion is a recessive embryonic lethal in cattle but "is associated with a positive effect on milk yield and composition", which results in selection favouring heterozygotes (balancing selection), thereby maintaining th...

The double-muscle trait in cattle is characterised by an increase in muscle mass of approx 20%, resulting in substantially higher meat yield, a higher proportion of expensive cuts of meat, and lean and very tender meat, for which a substantial premium is paid. The trait is autosomal recessive, and the locus has been given the symbol mh. It occurs at such a high frequency in Piedmontese and Belgian Blue cattle that it is characteristic of these...