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Conference paper - Peer-reviewed, 2013

A SNP association study verifies a major locus for fibre diameter related traits on chromosome 25 in sheep

Raadsma, Herman W.; Jonas, Elisabeth; Thomson, Peter C.


The present paper reports on the fine mapping of a previously identified quantitative trait locus (QTL) for fibre diameter and fibre diameter variability on chromosome 25 in sheep. A medium-density SNP panel was used to narrow down a major linked region using 319 animals from an Awassi-Merino backcross population. We could narrow down the QTL region of interest to 5000 kbp (3000 to 6000 kbp) on chromosome 25. Strong pleiotrophic effects were previously seen for this QTL as linkage had been identified for mean fibre diameter, fibre diameter variability, proportion of coarse fibres and comfort factor. Histological examination of animals with extreme fibre diameter characteristics showed strong effects for mean diameter of primary follicles, and a much higher ratio of secondary to primary follicles (S:P ratio) for animals inheriting the fineness QTL allele. A possible mode of action of the QTL on secondary follicle branching has been proposed. A strong positional candidate gene has been suggested in a companion paper (Jonas et al. 2013-these proceedings), however, further investigations are needed for a better understanding of the underlying causal mutations.

Published in

Proceedings of the Association for the Advancement of Animal Breeding and Genetics
2013, Volume: 20, pages: 507-510
Book title: Proceedings of the twentieth conference. Association for the Advancement of Animal Breeding and Genetics AAABG
Publisher: Association for the Advancement of Animal Breeding and Genetics


The AAABG 20th Conference (Association for the Advancement of Animal Breeding and Genetics)

    SLU Authors

    UKÄ Subject classification

    Genetics and Breeding

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