Integration of cytogenetic and genetic linkage maps unveils the physical architecture of tomato chromosome 2.
We report the integration of the linkage map of tomato chromosome 2 with a high-density bacterial artificial chromosome fluorescence in situ hybridization (BAC-FISH)-based cytogenetic map. The euchromatic block of chromosome 2 resides between 13 and 142 cM and has a physical length of 48.12 microm, with 1 microm equivalent to 540 kb. BAC-FISH resolved a pair of loci that were 3.7-3.9 Mb apart and were not resolved on the linkage map. Most of the regions had crossover densities close to the mean of approximately 200 kb/cM. Relatively hot and cold spots of recombination were unevenly distributed along the chromosome. The distribution of centimorgan/micrometer values was similar to the previously reported recombination nodule distribution along the pachytene chromosome. FISH-based physical maps will play an important role in advanced genomics research for tomato, including map-based cloning of agronomically important traits and whole-genome sequencing.
Koo
Dal-Hoe
DH
Plant Genome Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 305-600, Korea.
Jo
Sung-Hwan
SH
Bang
Jae-Wook
JW
Park
Hye-Mi
HM
Lee
Sanghyeob
S
Choi
Doil
D
D020029:Base Pairing; D002874:Chromosome Mapping; D022202:Chromosomes, Artificial, Bacterial / Q000378:metabolism; D032461:Chromosomes, Plant / Q000235:genetics*; D002999:Clone Cells; D003582:Cytogenetics; D022041:Euchromatin / Q000378:metabolism; D017404:In Situ Hybridization, Fluorescence; D018551:Solanum lycopersicum / Q000235:genetics*; D020161:Physical Chromosome Mapping
D022041:Euchromatin