Data/hora: 20/06/2024 16:15:58

Biblioteca(s): 	Embrapa Gado de Leite.	
Data corrente: 	15/12/2011	
Data da última atualização: 	05/02/2024	
Autoria: 	SILVA, M. V. G. B.; SOSTENGARD, T. S.; HANOTTE, O.; MUGAMBI, J. M.; GARCIA, J. F.; NAGDA, S.; GIBSON, J. P.; IRAQI, F. A.; McCLINTOCK, A. E.; KEMP, S. J.; BOETTCHER, P. J.; MALEK, M.; TASSELL, C. P. Van; BAKER, R. L.	
Afiliação: 	MARCOS VINICIUS GUALBERTO B SILVA, CNPGL; TAD S. SOSTENGARD, USDA; O. HANOTTE, International Livestock Research Institute; J. M. MUGAMBI, International Livestock Research Institute; J. F. GARCIA, UNESP; FAO; S. NAGDA, International Livestock Research Institute; J. P. GIBSON, International Livestock Research Institute; University of New England Armidale; F. A. IRAQI, International Livestock Research Institute; Tel Aviv University; A. E. McCLINTOCK, International Livestock Research Institute; S. J. KEMP, International Livestock Research Institute; P. J. BOETTCHER, FAO/IAEA; M. MALEK, FAO/IAEA; C. P. Van TASSEL, USDA; R. L. BAKER, International Livestock Research Institute.	
Título: 	Identification of quantitative trait loci affecting resistance to gastrointestinal parasites in a double backcross population of Red Maasai and Dorper sheep.	
Ano de publicação: 	2012	
Fonte/Imprenta: 	Animal Genetics, v. 43, n. 1, p. 63-71, 2012.	
DOI: 	https://doi.org/10.1111/j.1365-2052.2011.02202.x	
Idioma: 	Inglês	
Conteúdo: 	A genome-wide scan for quantitative trait loci (QTL) affecting gastrointestinal nematode resistance in sheep was completed using a double backcross population derived from Red Maasai and Dorper ewes bred to F(1) rams. This design provided an opportunity to map potentially unique genetic variation associated with a parasite-tolerant breed like Red Maasai, a breed developed to survive East African grazing conditions. Parasite indicator phenotypes (blood packed cell volume - PCV and faecal egg count - FEC) were collected on a weekly basis from 1064 lambs during a single 3-month post-weaning grazing challenge on infected pastures. The averages of last measurements for FEC (AVFEC) and PCV (AVPCV), along with decline in PCV from challenge start to end (PCVD), were used to select lambs (N = 371) for genotyping that represented the tails (10% threshold) of the phenotypic distributions. Marker genotypes for 172 microsatellite loci covering 25 of 26 autosomes (1560.7 cm) were scored and corrected by Genoprob prior to qxpak analysis that included Box-Cox transformed AVFEC and arcsine transformed PCV statistics. Significant QTL for AVFEC and AVPCV were detected on four chromosomes, and this included a novel AVFEC QTL on chromosome 6 that would have remained undetected without Box-Cox transformation methods. The most significant P-values for AVFEC, AVPCV and PCVD overlapped the same marker interval on chromosome 22, suggesting the potential for a single causative mutation, which remains unknown. In all cases, the favourable QTL allele was always contributed from Red Maasai, providing support for the idea that future marker-assisted selection for genetic improvement of production in East Africa will rely on markers in linkage disequilibrium with these QTL.	
Palavras-Chave: 	East Africa; Gastrointestinal parasites.	
Thesaurus Nal: 	marker-assisted selection; quantitative trait loci; sheep.	
Categoria do assunto: 	L Ciência Animal e Produtos de Origem Animal	
Registro original: 	Embrapa Gado de Leite (CNPGL)	
Exemplares: 	CNPGL - (18592-1) - UPC - AP - DD -  -  -  - DIS