Phenotypes

Flisikowski et al. (2010) described a Finnish Ayrshire bull with an incidence of almost 50% of late abortion/stillbirth in his progeny. A half-sib linkage analysis with the BovineSNP50 BeadChip implicated the maternally imprinted PEG3 domain on chromosome BTA18. Genes in this region are not expressed when inherited from the female parent. Close examination of this region disclosed that this bull was heterozygous for a 110 kb deletion in the MI...

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...

Null et al. (2017): "A splice acceptor variant at 51,267,548 bp in the RNA Polymerase 2 Associated Protein (RPAP2) gene was the most likely causal variant in the [AH2] haplotype. RPAP2 is an essential component of the RNA polymerase 2 holoenzyme necessary for transcription of snRNA species. Experiments with mouse knockouts also found a deficiency of homozygotes, suggesting that RPAP2 is necessary for embryonic development."