Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 1/17/2002
Publication Date: 1/17/2002
Citation: Zhang, L., Dong, J., Decanini, L., Le, M.K., Ren, C., Yan, B., Kohel, R.J., Yu, J., Zhang, H., Stelly, D.M. 2002. Development of molecular cytogenetic markers in cotton [abstract]. Plant, Animal, and Microbe Genomes X Conference. Paper No. P285.
Technical Abstract: Molecular cytogenetic markers are very important for plant genome analysis and genetic manipulation, especially as related to species for which reliable methods for karyotyping are lacking. Upland cotton (G. hirsutum, AADD, 2n = 4x = 52) has very small and closely graded-size chromosomes with near-metacentric morphology. These chromosome characteristics severely constrain potential utility of conventional banding methods for identification of plant chromosomes. To investigate the structural genomic resources in development of molecular cytogenetic markers in cotton, we selected 8 RFLP markers which are located near the ends of linkage groups of cotton (G. hirsutum,)linkage map. A cotton TM1 / HindIII pECBAC1 library (53,376 clones) was screened using the 8 RFLP probes. A total of 89 positive clones were obtained. After assembling contigs from DNA fingerprints, and determining the relative abundance of repetitive sequences from Southern blots, 8 BAC clones from the different contigs were selected for FISH to somatic cells. Upon FISH, six of these 8 selected BAC clones yielded unambiguous signals on the distal region of A or D subgenomes. Of these 6 probes, 2 BAC probes (L56 & L72) yielded only one pair of major signals on D subgenome chromosomes or long arms of A subgenome chromosomes, respectively. The other 4 probes all yielded two pairs of signals (one major, one minor) on chromosomes of A and D subgenomes. Combined with meiotic FISH analysis, it is feasible to orient linkage map positions relative to arms and cytogenetic breakpoints.