Genetic mapping of quantitative trait loci for resistance to Haemonchus contortus in sheep
This paper presents results from a mapping experiment to detect quantitative trait loci (QTL) for resistance to Haemonchus contortus infestation in merino sheep. The primary trait analysed was faecal worm egg count in response to artificial challenge at 6 months of age. In the first stage of the exp...
| Autores principales: | , , , , , , , |
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| Formato: | Journal Article |
| Lenguaje: | Inglés |
| Publicado: |
Wiley
2009
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| Materias: | |
| Acceso en línea: | https://hdl.handle.net/10568/2229 |
| _version_ | 1855530454506012672 |
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| author | Marshall, Karen Maddox, J.F. Lee, S.H. Zhang, Y. Graser, H.U Gondro, C. Walken-Brown, S.W. Werf, J.H.J. van der |
| author_browse | Gondro, C. Graser, H.U Lee, S.H. Maddox, J.F. Marshall, Karen Walken-Brown, S.W. Werf, J.H.J. van der Zhang, Y. |
| author_facet | Marshall, Karen Maddox, J.F. Lee, S.H. Zhang, Y. Graser, H.U Gondro, C. Walken-Brown, S.W. Werf, J.H.J. van der |
| author_sort | Marshall, Karen |
| collection | Repository of Agricultural Research Outputs (CGSpace) |
| description | This paper presents results from a mapping experiment to detect quantitative trait loci (QTL) for resistance to Haemonchus contortus infestation in merino sheep. The primary trait analysed was faecal worm egg count in response to artificial challenge at 6 months of age. In the first stage of the experiment, whole genome linkage analysis was used for broad-scale mapping. The animal resource used was a designed flock comprising 571 individuals from four half-sib families. The average marker spacing was about 20 cM. For the primary trait, 11 QTL (as chromosomal/family combinations) were significant at the 5% chromosome-wide level, with allelic substitution effects of between 0.19 and 0.38 phenotypic standard deviation units. In general, these QTL did not have a significant effect on faecal worm egg count recorded at 13 months of age. In the second stage of the experiment, three promising regions (located on chromosomes 1, 3 and 4) were fine-mapped. This involved typing more closely spaced markers on individuals from the designed flock as well as an additional 495 individuals selected from a related population with a deeper pedigree. Analysis was performed using a linkage disequilibrium–linkage approach, under additive, dominant and multiple QTL models. Of these, the multiple QTL model resulted in the most refined QTL positions, with resolutions of <10 cM achieved for two regions. Because of the moderate size of effect of the QTL, and the apparent age and/or immune status specificity of the QTL, it is suggested that a panel of QTL will be required for significant genetic gains to be achieved within industry via marker-assisted selection. |
| format | Journal Article |
| id | CGSpace2229 |
| institution | CGIAR Consortium |
| language | Inglés |
| publishDate | 2009 |
| publishDateRange | 2009 |
| publishDateSort | 2009 |
| publisher | Wiley |
| publisherStr | Wiley |
| record_format | dspace |
| spelling | CGSpace22292023-12-27T19:43:34Z Genetic mapping of quantitative trait loci for resistance to Haemonchus contortus in sheep Marshall, Karen Maddox, J.F. Lee, S.H. Zhang, Y. Graser, H.U Gondro, C. Walken-Brown, S.W. Werf, J.H.J. van der disease resistance sheep This paper presents results from a mapping experiment to detect quantitative trait loci (QTL) for resistance to Haemonchus contortus infestation in merino sheep. The primary trait analysed was faecal worm egg count in response to artificial challenge at 6 months of age. In the first stage of the experiment, whole genome linkage analysis was used for broad-scale mapping. The animal resource used was a designed flock comprising 571 individuals from four half-sib families. The average marker spacing was about 20 cM. For the primary trait, 11 QTL (as chromosomal/family combinations) were significant at the 5% chromosome-wide level, with allelic substitution effects of between 0.19 and 0.38 phenotypic standard deviation units. In general, these QTL did not have a significant effect on faecal worm egg count recorded at 13 months of age. In the second stage of the experiment, three promising regions (located on chromosomes 1, 3 and 4) were fine-mapped. This involved typing more closely spaced markers on individuals from the designed flock as well as an additional 495 individuals selected from a related population with a deeper pedigree. Analysis was performed using a linkage disequilibrium–linkage approach, under additive, dominant and multiple QTL models. Of these, the multiple QTL model resulted in the most refined QTL positions, with resolutions of <10 cM achieved for two regions. Because of the moderate size of effect of the QTL, and the apparent age and/or immune status specificity of the QTL, it is suggested that a panel of QTL will be required for significant genetic gains to be achieved within industry via marker-assisted selection. 2009-06 2010-08-09T19:00:40Z 2010-08-09T19:00:40Z Journal Article https://hdl.handle.net/10568/2229 en Limited Access Wiley Marshall, K.; Maddox, J.F.; Lee, S.H.; Zhang, Y.; Kahn, L.; Graser, H.-U.; Gondro, C.; Walkden-Brown, S.W.; Werf, J.H.J. van der. 2009. Genetic mapping of quantitative trait loci for resistance to Haemonchus contortus in sheep. Animal Genetics 40(3):262-272. |
| spellingShingle | disease resistance sheep Marshall, Karen Maddox, J.F. Lee, S.H. Zhang, Y. Graser, H.U Gondro, C. Walken-Brown, S.W. Werf, J.H.J. van der Genetic mapping of quantitative trait loci for resistance to Haemonchus contortus in sheep |
| title | Genetic mapping of quantitative trait loci for resistance to Haemonchus contortus in sheep |
| title_full | Genetic mapping of quantitative trait loci for resistance to Haemonchus contortus in sheep |
| title_fullStr | Genetic mapping of quantitative trait loci for resistance to Haemonchus contortus in sheep |
| title_full_unstemmed | Genetic mapping of quantitative trait loci for resistance to Haemonchus contortus in sheep |
| title_short | Genetic mapping of quantitative trait loci for resistance to Haemonchus contortus in sheep |
| title_sort | genetic mapping of quantitative trait loci for resistance to haemonchus contortus in sheep |
| topic | disease resistance sheep |
| url | https://hdl.handle.net/10568/2229 |
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