PAG-I Plant Genome I Conference

Town & Country Conference Center, San Diego, CA, November, 1992.


PG-I: 88pg1

CHARACTERIZATION OF TOMATO DNA CLONES WITH SEQUENCE SIMILARITY TO THE HUMAN MINISATELLITES 33.6 AND 33.15.

Pierre Broun and Steven D. Tanksley, Department of Plant Breeding and Biometry, Cornell University, Ithaca, NY 14850.


A tomato lambda genomic library was screened with the human minisatellites 33.6 and 33-15 and 13 hybridizing clones were characterized in detail. The size of the arrays varied between 100 bp and 3 kb. Their structure was complex, as the human core sequence was interspersed with other elements and, in three cases, part of a higher order tandem repeat. Two 33.6-related sequences were microsatellite-like stretches. 10 minisatellite-related sequences could be genetically positioned on the tomato high density RFLP map and did not show any clustering pattern, which is in contrast to the organization in the human genome. The average polymorphism detected by the tomato minisatellite clones was estimated by probing a set of 10 tomato cultivars at low stringency, and the variability at two polymorphic loci was evaluated among 180 accessions. The fingerprints generated with tomato minisatellites were, in two cases, more variable than 33.6 or 33.15 equivalents. In addition, at two minisatellite loci, 4-8 alleles were detected and showed 10-15 times more polymorphism than random RFLP clones.


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