Maize chromosomal knobs are located in gene-dense areas and suppress local recombination

• DOI: 10.1007/s00412-012-0391-8
• Publication Date: 2012-12-08T07:49:23Z
• Authors: Rashin Ghaffari; Ethalinda K. S. C...; Lisa B. Kanizay; Carolyn J. Lawrence; R. Kelly Dawe
• Keywords: Inbred strain; Linkage Disequilibrium

Knobs are conspicuous heterochromatic regions found on the chromosomes of maize and its relatives. The number, locations, sizes knobs vary dramatically, with most lines containing between four eight in mid-arm positions. Prior data suggest that some may reduce recombination. However, comprehensive tests have not been carried out, primarily because placed genetic map. We used fluorescent situ hybridization two recombinant inbred populations to map seven accurately place three from B73 genomic sequence assembly. show lie gene-dense genome. Comparisons 23 other segregating for at same sites confirm large can locally crossing over by as much twofold a cM/Mb scale. These effects do extend beyond ~10 cM either side appear affect linkage disequilibrium among genes within near knob repeat RefGen_v2