Submitted to: Animal Genome Research National Workshop Proceedings
Publication Type: Proceedings
Publication Acceptance Date: December 1, 1996
Publication Date: N/A
Chromosomal regions harboring QTL in porcine and murine reproduction are being identified using unique long-term selection lines. In pigs, an F2 resource population (n=450 females) was obtained by crossing selection lines I (index of increased ovulation rate (OR) and embryonic survival (ES)) and C (random control). A preliminary marker evaluation in a subset of females (n=114) and covering approximately 50% of the genome in wide intervals has indicated strong evidence for one ovulation rate QTL on Chromosome 8 (additive effect of 3.07 ova; P<.001) and weaker evidence for three additional QTL on Chromosomes 4 (P<.1), 13 and 15 (P<.05). In mice, an F2 intercross (n=445 females) was produced originating from the selection lines M16i (rapid weight gain) and L6 (small body weight). A genome-wide scan indicated the presence of at least 6, 5 and 3 QTL with significant additive effects (P<.001) for OR, ES and LS, respectively, on Chromosomes 2, 3, 8, 9, 10, 11, 13, 18 and 19. Additive effects were in the range of 0.4-0.5 CL for OR, 3.6-6.8% for ES and 0.65-1.0 live pups for LS. Based on comparative mapping of anchor loci, it is possible that the ovulation rate QTL on porcine Chromosomes 8 and 15 may be homologues of murine QTL for reproduction found on Chromosomes 3 and 2, respectively. While further characterization of QTL is necessary, comparative mapping will help identify candidate genes to positionally clone reproduction QTL in pigs.