Polyceraty in Damara Sheep — ASN Events
  1. Schedule
  2. Poster Session 1
  3. Polyceraty in Damara Sheep

Polyceraty in Damara Sheep (#116)

Coralie M Reich 1 , Ockert FC Greyvenstein 2 , Este van Marle-Koster 3 , David G Riley 2 , Ben J Hayes 1 4
  1. Biosciences Research, DEDJTR, Bundoora, VIC, Australia
  2. Department of Animal Science, Texas A&M University, Texas, USA
  3. Department of Animal and Wildlife Science, University of Pretoria, Hatfield, South Africa
  4. Queensland Alliance for Agriculture and Food Innovation, Centre for Animal Science, University of Queensland, Brisbane, Queensland, Australia

The presence of multiple horns (polyceraty) occurs in a few domestic sheep breeds. Damara – fat-tailed hair sheep from south-western Africa is one such breed that shows this trait. The horn phenotypes observed in Damara are polled, set of small horns, set of large horns, set of large and small horns or two sets of large horns. The aim of this study was to determine the genomic locations associated with this trait in Damara sheep from South Africa. Blood was collected from 43 animals with a range of horn phenotypes. The animals were genotyped using the OvineHD BeadChip (606,006 SNPs) from Illumina. A genome-wide association study for horn number found significant SNPs located on ovine chromosome 2 (OAR2). This is the same region as reported in two other independent studies (Hadfield, Cockett, & Kijas, 2015; Ren et al., 2016) that found associations with horn polyceraty in Jacob, Navajo-Churro and Sishui Fur sheep.  A different region was reported for the polled phenotype in seven Swiss sheep breeds, which is an insertion in RXFP2 on OAR10 (Wiedemar & Drogemuller, 2015). The mutation involved with horn phenotype was not identified. However, within the confidence region on OAR2, there included 9 HOXD genes. HOXD genes play a role in appendage development and patterning (Quinonez & Innis, 2014). Mutations in HOXD13 genes in human cause synpolydactyly (fusion of digits and supernumerary digits) (Goodman et al., 1998).

  1. Hadfield, T., Cockett, N., & Kijas, J. W. (2015). The polycerate trait in Jacob and Navajo-Churro Sheep may be located on ovine chromosome 2. Paper presented at the Proceedings of the Plant and Animal Genome XXIII Conference, San Diego, CA.
  2. Ren, X., Yang, G. L., Peng, W. F., Zhao, Y. X., Zhang, M., Chen, Z. H., Li, M. H. (2016). A genome-wide association study identifies a genomic region for the polycerate phenotype in sheep (Ovis aries). Sci Rep, 6, 21111. doi: 10.1038/srep21111
  3. Wiedemar, N., & Drogemuller, C. (2015). A 1.8-kb insertion in the 3'-UTR of RXFP2 is associated with polledness in sheep. Anim Genet, 46(4), 457-461. doi: 10.1111/age.12309
  4. Goodman, F., Giovannucci-Uzielli, M. L., Hall, C., Reardon, W., Winter, R., & Scambler, P. (1998). Deletions in HOXD13 segregate with an identical, novel foot malformation in two unrelated families. Am J Hum Genet, 63(4), 992-1000. doi: 10.1086/302070
  5. Quinonez, S. C., & Innis, J. W. (2014). Human HOX gene disorders. [Review]. Mol Genet Metab, 111(1), 4-15. doi: 10.1016/j.ymgme.2013.10.012
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