Genetic determinism of bone and mineral metabolism in meat-type chickens: A QTL mapping study.
Skeletal integrity in meat-type chickens is affected by many factors including rapid growth rate, nutrition and genetics. To investigate the genetic basis of bone and mineral metabolism, a QTL detection study was conducted in an intercross between two lines of meat-type chickens divergently selected for their high (D +) or low (D -) digestive efficiency. Tibia size (length, diameter, volume) and ash content were determined at 3 weeks of age as well as phosphorus (P) retention and plasma concentration. Heritability of these traits and their genetic correlations with digestive efficiency were estimated. A QTL mapping study was performed using 3379 SNP markers. Tibia size, weight, ash content and breaking strength were highly heritable (0.42 to 0.61). Relative tibia diameter and volume as well as P retention were strongly and positively genetically correlated with digestive efficiency (0.57 to 0.80). A total of 35 QTL were identified (9 for tibia weight, 13 for tibia size, 5 for bone strength, 5 for bone mineralization, 2 for plasma P concentration and 1 for P retention). Six QTL were genome-wide significant, and 3 QTL for tibia relative volume, weight and ash weight on chromosome 6 were fixed, the positive allele coming from the D-line. For two QTL for ash content on chromosome 18 and relative tibia length on chromosome 26, the confidence intervals were small enough to identify potential candidate genes. These findings support the evidence of multiple genetic loci controlling bone and mineral metabolism. The identification of candidate genes may provide new perspectives in the understanding of bone regulation, even beyond avian species.
INRA, UR83 Recherches Avicoles, F-37380 Nouzilly, France.
Sandrine
S
Mignon-Grasteau
INRA, LABOGENA, Domaine de Vilvert, F-78352 Jouy en Josas Cedex, France.
Céline
C
Chantry-Darmon
INRA, LABOGENA, Domaine de Vilvert, F-78352 Jouy en Josas Cedex, France.
Marie-Yvonne
MY
Boscher
INRA, UE1295 PEAT, F-37380 Nouzilly, France.
Nadine
N
Sellier
INRA, UR83 Recherches Avicoles, F-37380 Nouzilly, France.
Marie
M
Chabault-Dhuit
INRA, UR83 Recherches Avicoles, F-37380 Nouzilly, France.
Elisabeth
E
Le Bihan-Duval
INRA, UR83 Recherches Avicoles, F-37380 Nouzilly, France.
Agnès
A
Narcy
BBS, bone breaking strength; BW, body weight; Bone; Chicken; Environment; Genetic parameters; PP, phosphorus concentration in plasma; Phosphorus; QTL; RETP, percentage of retained phosphorus; TA, tibia ash weight; TD, tibia diameter; TDM, tibia dry matter weight; TL, tibia length; TV, tibia volume