In other species: taurine cattle , indicine cattle (zebu) , goat , sheep , bighorn sheep , water buffalo , kouprey

Categories: Craniofacial phene

Links to possible relevant human trait(s) and/or gene(s) in OMIM: 110100 (trait)

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal dominant

Disease-related: unknown

Key variant known: yes

Year key variant first reported: 2017

Cross-species summary: Horns are paired appendages with a bony core that is attached to the skull and a keratin outer sheath. There is substantial variation in the extent of horn growth, making classification difficult. However, in general, the presence or absence of horns can be attributed to the action of two alleles at an autosomal locus. The type of gene action varies considerably between and among species. Absence of horns is called 'polled'. See also entries for 'scurs'.

Mapping: Using a comparative candidate region strategy, Liu et al. (2014) genotyped 50 polled Datong domestic yaks and 51 horned yaks, each with 12 genes located in the polled region on chromosome BTA1 of cattle. They concluded that "a 147-kb segment that included three protein-coding genes C1H21orf62, GCFC1 and SYNJ1 was the most likely location of the POLL mutation in domestic yaks". Liang et al. (2017) confirmed this result "with a panel of 10 horned and 10 polled yaks using whole genome sequencing".

Molecular basis: Medugorac et al. (2017) identified a polled allele in domestic yak that is identical to the third polled allele reported in cattle, namely the "Mongolian" allele that these same authors discovered in Mongolian Turano cattle (reported in the same paper). The sharing of this allele by yaks and cattle that have been herded together for more than 1,500 years is strongly indicative of natural introgression resulting from backcrossing female yak-cattle hybrids to male yaks. Medugorac et al. (2017) reported that the Mongolian allele is "a complex 219-bp duplication–insertion (P219ID) beginning at 1,976,128 bp and a 7-bp deletion and 6-bp insertion (P1ID) located 621 bp upstream of this position . . . . This rearrangement results in duplication of an 11-bp motif (5′-AAAGAAGCAAA-3′) that is entirely conserved among Bovidae . . . and that is also duplicated in the 80-kb duplication responsible for Friesian polledness".

Breeds: Datong, China (Domestic yak) (VBO_0016868), Mongolian Yak, Mongolia (Yak (domestic)) (VBO_0016813).
Breeds in which the phene has been documented. (If a likely causal variant has been documented for the phene, see the variant table breeds in which the variant has been reported).

Associated gene: