Plant & Animal Genomes XIV Conference

January 14-18, 2006
Town & Country Convention Center
San Diego, CA

High Resolution Physical Map Of Porcine Chromosome 7 QTL Region And Comparative Mapping Of This Region Among Vertebrate Genomes

Julie Demars¹ , Juliette Riquet¹ , Katia Feve¹ , Mathieu Gauthier² , Mireille Morisson¹ , Olivier Demeure³ , Christine Renard⁴ , Patrick Chardon⁴ , Denis Milan¹

¹  Laboratoire de Génétique Cellulaire, INRA, BP, 31326 Castanet-Tolosan, France

²  Laboratoire de Génétique Biochimique et de Cytogénétique, INRA, 78352 Jouy en Josas, France

³  Laboratoire de Génétique animale, INRA, 35042 Rennes, France

⁴  Laboratoire de Radiobiologie et d'Etude du Génome, INRA-CEA, 78352 Jouy en Josas, France

On porcine chromosome 7, the region surrounding the MHC contains QTL influencing many traits including growth, back fat thickness and carcass composition. Previous studies put highlighted in evidence in this region the presence of a fragment of approximately 3.7 Mb located 23 Mb above the position expected on the basis of the human map.
In the present study, 17 genes and 2 microsatellites were ordered on the high resolution IMNpRH2 Radiation Hybrid panel. A framework 1000:1 map covering 550 cR was established. This study was completed by the development of a complete contig of the region taking advantage of the fingerprinting of the INRA BAC library and of the anchoring of BAC ends sequences on the human genome. New micro rearrangements were highlighted and the extent of three sub-fragments ordered differently between porcine and human genomes have been precisely defined. A bovine RH map was also developed in this region by mapping 18 genes. The comparison of the organization of this region in pig, cattle, human and mouse, dog and chicken genomes revealed that if the translocation of the whole fragment is observed on bovine and porcine genomes, internal rearrangements are specific of the porcine genome.
We estimate that rearranged fragments cover 5.2 Mb of the porcine genome. The study of this complete BAC contig revealed that human chromosomal fragments homologs of this heavily rearranged QTL region are all located in the region of HSA6 surrounding the centromere.