tailieunhanh - Báo cáo sinh học: " Number and mode of inheritance of QTL influencing backfat thickness on SSC2p in Sino-European pig pedigrees"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học quốc tế đề tài: Number and mode of inheritance of QTL influencing backfat thickness on SSC2p in Sino-European pig pedigrees | Tortereau et al. Genetics Selection Evolution 2011 43 11 http content 43 1 11 GSE Ge n et i cs Selection Evolution RESEARCH Open Access Number and mode of inheritance of QTL influencing backfat thickness on SSC2p in Sino-European pig pedigrees 2 3 2 3 Flavie Tortereau 1 Hélène Gilbert Henri CM Heuven Jean-Pierre Bidanel Martien AM Groenen and Juliette Riquet1 Abstract Background In the pig multiple QTL associated with growth and fatness traits have been mapped to chromosome 2 SSC2 and among these at least one shows paternal expression due to the IGF2-intron3-G3072A substitution. Previously published results on the position and imprinting status of this QTL disagree between analyses from French and Dutch F2 crossbred pig populations obtained with the same breeds Meishan crossed with Large White or Landrace . Methods To study the role of paternal and maternal alleles at the IGF2 locus and to test the hypothesis of a second QTL affecting backfat thickness on the short arm of SSC2 SSC2p a QTL mapping analysis was carried out on a combined pedigree including both the French and Dutch F2 populations on the progeny of F1 males that were heterozygous A G and homozygous G G at the IGF2 locus. Simulations were performed to clarify the relations between the two QTL and to understand to what extent they can explain the discrepancies previously reported. Results The QTL analyses showed the segregation of at least two QTL on chromosome 2 in both pedigrees . the IGF2 locus and a second QTL segregating at least in the G G F1 males and located between positions 30 and 51 cM. Statistical analyses highlighted that the maternally inherited allele at the IGF2 locus had a significant effect but simulation studies showed that this is probably a spurious effect due to the segregation of the second QTL. Conclusions Our results show that two QTL on SSC2p affect backfat thickness. Differences in the pedigree structures and in the number of heterozygous females at .