Characterization of the turkey MHC chromosome through genetic and physical mappingChaves L.D. · Krueth S.B. · Reed K.M.
Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN (USA)
Previous studies in the chicken have identified a single microchromosome (GGA16) containing the ribosomal DNA (rDNA) and two genetically unlinked MHC regions, MHC-B and MHC-Y. Chicken DNA sequence from these loci was used to develop PCR primers for amplification of homologous fragments from the turkey (Meleagris gallopavo). PCR products were sequenced and overgo probes were designed to screen the CHORI 260 turkey BAC library. BAC clones corresponding to the turkey rDNA, MHC-B and MHC-Y were identified. BAC end and subclone sequencing confirmed identity and homology of the turkey BAC clones to the respective chicken loci. Based on subclone sequences, single-nucleotide polymorphisms (SNPs) segregating within the UMN/NTBF mapping population were identified and genotyped. Analysis of SNP genotypes found the B and Y to be genetically unlinked in the turkey. Silver staining of metaphase chromosomes identified a single pair of microchromosomes with nucleolar organizer regions (NORs). Physical locations of the rDNA and MHC loci were determined by fluorescence in situ hybridization (FISH) of the BAC clones to metaphase chromosomes. FISH clearly positioned the rDNA distal to the Y locus on the q-arm of the MHC chromosome and the MHC-B on the p-arm. An internal telomere array on the MHC chromosome separates the B and Y loci.
© 2007 S. Karger AG, Basel
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Department of Veterinary and Biomedical Sciences
295 ASVM, 1988 Fitch Ave, University of Minnesota
St. Paul, MN 55108 (USA)
telephone: +1 612 624 1287; fax: +1 612 625 0204
This project was supported by grants from the Minnesota Agricultural Experiment Station and from the United States Department of Agriculture, National Research Initiative Competitive Grants program (2004-35205-14217).
Manuscript received: 7 July 2006
Accepted in revised form for publication by J. Smith,: 7 September 2006.
Number of Print Pages : 8
Number of Figures : 5, Number of Tables : 3, Number of References : 26
Cytogenetic and Genome Research
Vol. 117, No. 1-4, Year 2007 (Cover Date: July 2007)
Journal Editor: Schmid, M. (Würzburg)
ISSN: 1424–8581 (print), 1424–859X (Online)
For additional information: http://www.karger.com/CGR