Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: March 1, 1999
Publication Date: N/A
Technical Abstract: A QTL affecting ovulation rate in swine has been identified on the terminal portion of the short arm of porcine chromosome 8 in a Meishan-White composite crossbred population. The initial results were based on phenotypic data from nearly 300 crossbred females and genotypes from markers spaced at approximately 20 cM intervals. To improve our estimates of the QTL's effect and location in the genome, we have included another 300 pigs in the study and genotyped every available microsatellite marker within the first 20 cM of the linkage group on chromosome 8. Over 650 animals have been genotyped for 10 microsatellite markers and phenotypic records from 599 females were analyzed. Some of the additional microsatellite markers were developed from isolated genomic clones presumed to reside in the region of interest. Most markers were developed from a porcine yeast artificial chromosome library. The probability that a given chromosomal segment derived from Meishan germplasm was calculated based on results from the CHROMPIC option of CRI-MAP. These probabilities were used as regression coefficients in a least-squares analysis. The most likely position for the QTL based on the current data is 1 cM from SW2611, proximal to the centromere with a 95% confidence interval of approximately ñ 15 cM. The gene action appears to be purely additive with an additive effect of an allele substitution for the Meishan allele of -1.70 ova. The comparative map between the human and porcine genomes needs to be refined to determine precisely which segment of the human genome contains the QTL and additional swine populations need to be tested to determine the importance of the QTL to the swine industry.