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United States Department of Agriculture

Agricultural Research Service

Title: Genome-Wide Linkage Analysis to Identify Chromosomal Regions Affecting Phenotypic Traits in the Chicken. Iv. Skeletal Integrity

Authors
item Zhou, H. - IOWA STATE UNIVERSITY
item Deeb, N. - IOWA STATE UNIVERSITY
item Clover, Christina
item Mitchell, Alva
item Ashwell, C. - NORTH CAROLINA STATE
item Lamont, S. - IOWA STATE UNIVERSITY

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 7, 2006
Publication Date: February 1, 2007
Citation: Zhou, H., Deeb, N., Evock-Clover, C.M., Mitchell, A.D., Ashwell, C.M., Lamont, S.J. 2007. Genome-wide linkage analysis to identify chromosomal regions affecting phenotypic traits in the chicken. III. Skeletal integrity Poultry Science. 86(2):255-266.

Interpretive Summary: Improvement in the growth rate and meat yield in broilers over the last 50 years has resulted, in part, in selection for skeletal integrity. The impact of skeletal integrity across poultry production from breeders to processing is far reaching and when the skeleton is insufficient, it contributes to significant economic loss. The aim of this study was to perform a genome-wide analysis for quantitative trait loci (QTL) associated with skeletal traits in a well-characterized resource population to determine both the number of loci and their relative effects on bone integrity traits in chickens. Several biological candidate genes near QTL regions for bone traits at chromosome-wise significance level are noted. Study of associations of these genes with skeletal integrity traits in chickens will reveal new knowledge of understanding biological process of skeletal homeostasis. The results of the current study have identified markers for bone strength traits, which may be used to genetically improve skeletal integrity in chickens by marker-assisted selection, and to identify the causal genes for these traits.

Technical Abstract: Two unique chicken F2 populations generated from a broiler breeder male line and two genetically distinct inbred (greater than 99%) chicken lines (Leghom and Fayoumi), were used for whole genome QTL analysis. Twelve phenotypic skeletal integrity traits (6 absolute and 6 relative traits) were measured or calculated, including bone mineral content (BMC), %BMC, bone mineral density (BMD), %BMD, tibia length (TBL), %TBL, shank length (SHL), %SHL, shank weight (SHW), %SHW, and ratio of shank length by shank weight (SHR) and %SHR. Birds were genotyped for 269 microsatellite markers across the entire genome. The QTL affecting bone traits in chickens were detected by QTL express program. Significance levels were obtained using the permutation test. For the twelve traits, a total of 56 significant QTL were detected at the 5% chromosome-wise significance level, of which 14 and 10 were significant at the 5% genome-wise level for the broiler-Leghom cross and broiler-Fayoumi cross, respectively. Phenotypic variation for each trait explained by all detected QTL across the genome ranged from 12.0% to 35.6% in the broiler-Leghom cross, and 2.9% to 31.3% in broiler-Fayoumi cross. Different QTL profiles identified between the two related F2 crosses for most traits suggested that genetic background is an important factor for QTL analysis. Several biological candidate genes near QTL regions for bone traits at I% chromosome-wise significance level are discussed. Study of associations of these genes with skeletal integrity traits in chickens will reveal new knowledge of understanding biological process of skeletal homeostasis. The results of the current study have identified markers for bone strength traits, which may be used to genetically improve skeletal integrity in chickens by marker-assisted selection, and to identify the causal genes for these traits.

Last Modified: 9/23/2014
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