Mapping quantitative trait loci (QTL) in sheep. I. A new male framework linkage map and QTL for growth rate and body weight.
A male sheep linkage map comprising 191 microsatellites was generated from a single family of 510 Awassi-Merino backcross progeny. Except for ovine chromosomes 1, 2, 10 and 17, all other chromosomes yielded a LOD score difference greater than 3.0 between the best and second-best map order. The map is on average 11% longer than the Sheep Linkage Map v4.7 male-specific map. This map was employed in quantitative trait loci (QTL) analyses on body-weight and growth-rate traits between birth and 98 weeks of age. A custom maximum likelihood program was developed to map QTL in half-sib families for non-inbred strains (QTL-MLE) and is freely available on request. The new analysis package offers the advantage of enabling QTL x fixed effect interactions to be included in the model. Fifty-four putative QTL were identified on nine chromosomes. Significant QTL with sex-specific effects (i.e. QTL x sex interaction) in the range of 0.4 to 0.7 SD were found on ovine chromosomes 1, 3, 6, 11, 21, 23, 24 and 26.
Raadsma
Herman W
HW
ReproGen--Advanced Technologies in Animal Genetics and Reproduction, Faculty of Veterinary Science, University of Sydney, 425 Werombi Road, Camden, NSW 2570, Australia. raadsma@camden.usyd.edu.au
Thomson
Peter C
PC
Zenger
Kyall R
KR
Cavanagh
Colin
C
Lam
Mary K
MK
Jonas
Elisabeth
E
Jones
Marilyn
M
Attard
Gina
G
Palmer
David
D
Nicholas
Frank W
FW
D000818:Animals; D001835:Body Weight; D002874:Chromosome Mapping / Q000379:methods*; D033481:Chromosomes, Mammalian / Q000235:genetics; D005260:Female; D007178:Inbreeding; D008297:Male; D018895:Microsatellite Repeats; D008957:Models, Genetic; D040641:Quantitative Trait Loci; D034561:Sheep, Domestic / Q000235:genetics* / Q000254:growth & development*; D013045:Species Specificity