First identification of the causal mutation for coagulation F11 deficiency in hanwoo cattle

Plasma thromboplastin antecedent (factor XI or F11) deficiency is a relatively mild hemorrhagic genetic disorder reported in Holstein and Japanese black cattle that is caused by two insertional mutations. In this study, we identified a causal mutation of F11 deficiency in Hanwoo cattle and developed a more efficient method to identify this mutation. A total of 2,043 Hanwoo samples from 35 farms, representing three regions (Yeongam, Haman, Yanggu) were used in this study. The mutation is caused by the insertion of 15 bp at exon 9 of the F11 gene; the same mutation has been described in Japanese black cattle. In addition, the gene frequency of F11 deficiency was 1.52% in the Hanwoo cattle population, and all mutant alleles appeared in the heterozygous animals. Especially, this result suggests that 15 bp insertion might be caused by a semi-embryonic lethal gene, which could affect the Hanwoo population. Although, the proportion of the disorder allele is low, the system for verifying this deficiency and additional phenotypic symptoms are needed to prevent any kind of losses in Hanwoo industry. Also the novel TaqMan assay genotyping method for the identification of F11 deficiency proposed in this study offers rapid and accurate results and may be efficiently applied in Hanwoo breeding programs.