Cytogenetic mapping with centromeric bacterial artificial chromosomes contigs shows that this recombination-poor region comprises more than half of barley chromosome 3H.
Genetic maps are based on the frequency of recombination and often show different positions of molecular markers in comparison to physical maps, particularly in the centromere that is generally poor in meiotic recombinations. To decipher the position and order of DNA sequences genetically mapped to the centromere of barley (Hordeum vulgare) chromosome 3H, fluorescence in situ hybridization with mitotic metaphase and meiotic pachytene chromosomes was performed with 70 genomic single-copy probes derived from 65 fingerprinted bacterial artificial chromosomes (BAC) contigs genetically assigned to this recombination cold spot. The total physical distribution of the centromeric 5.5 cM bin of 3H comprises 58% of the mitotic metaphase chromosome length. Mitotic and meiotic chromatin of this recombination-poor region is preferentially marked by a heterochromatin-typical histone mark (H3K9me2), while recombination enriched subterminal chromosome regions are enriched in euchromatin-typical histone marks (H3K4me2, H3K4me3, H3K27me3) suggesting that the meiotic recombination rate could be influenced by the chromatin landscape.
Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, 06466, Stadt Seeland, Germany.
Lala
L
Aliyeva-Schnorr
Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, 06466, Stadt Seeland, Germany.
Sebastian
S
Beier
Institute of Experimental Biology, Centre of the Region Hana for Biotechnological and Agricultural Research, Olomouc, Czech Republic.
Miroslava
M
Karafiátová
Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, 06466, Stadt Seeland, Germany.
Thomas
T
Schmutzer
Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, 06466, Stadt Seeland, Germany.
Uwe
U
Scholz
Institute of Experimental Biology, Centre of the Region Hana for Biotechnological and Agricultural Research, Olomouc, Czech Republic.
Jaroslav
J
Doležel
Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, 06466, Stadt Seeland, Germany.
Nils
N
Stein
Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, 06466, Stadt Seeland, Germany.
Andreas
A
Houben
D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000235:genetics*; D001467:Hordeum / Q000235:genetics*
BAC FISH; centromere; chromatin; pachytene chromosomes; physical map; posttranslational histone modifications; recombination