title: Long-range physical mapping of the alpha-amylase-1 (alpha-Amy-1) loci on homoeologous group 6 chromosomes of wheat.
abstract: Long-range physical maps of the small multigene family of the malt alpha-amylase genes (alpha-Amy-1) located on the long arms of wheat chromosomes 6A (the alpha-Amy-A1 locus) and 6B (alpha-Amy-B1) were generated by pulsed-field gel electrophoresis analysis. By using three methylation-sensitive rare-cutter restriction endonucleases, NotI, NruI and MluI, and an alpha-Amy-1 cDNA probe and four gene-specific genomic probes from the alpha-Amy-B1 locus, the size of the alpha-Amy-A1 locus was estimated to be about 700 kb and of the alpha-Amy-B1 locus to be about approximately 4300 kb. These two maps indicate clustering of GC-rich and C-methylation-sensitive restriction enzyme recognition sites. At least five regions reminiscent of 'CpG islands' are apparent in alpha-Amy-B1, and three in alpha-Amy-A1. Correlation between recombination frequency and physical distance within the alpha-Amy-B1 locus suggests that 1 cM approximates to 1 Mb in physical distance.
authors.affiliation: Cambridge Laboratory, Norwich, UK.
authors.forename: W Y
authors.initials: WY
authors.lastname: Cheung
authors.forename: S
authors.initials: S
authors.lastname: Chao
authors.forename: M D
authors.initials: MD
authors.lastname: Gale
mesh_terms: D001426:Bacterial Proteins; D015139:Blotting, Southern; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D016521:Electrophoresis, Gel, Pulsed-Field; D015183:Restriction Mapping; D014908:Triticum / Q000235:genetics*; D000516:alpha-Amylases / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; C035041:endodeoxyribonuclease MluI; C055654:endodeoxyribonuclease NruI; D015252:Deoxyribonucleases, Type II Site-Specific; C038565:GCGGCCGC-specific type II deoxyribonucleases; D000516:alpha-Amylases