Plant, Animal & Microbe Genomes X Conference Plant, Animal & Microbe Genomes X ConferenceJanuary 12-16, 2002
Town & Country Convention Center
San Diego, CA
Poster: Large Insert Libraries
Yeast artificitial chromosome (YAC) libraries have been very useful in the positional cloning of a number of plant disease resistance genes in tomato, Arabidopsis , rice, pepper. No YAC library has been reported yet for soybean (Glycine max L.), the third most important crop in United States. Such a library is especially important in soybean because physical mapping and positional cloning is complicated both by its large genome size and by the presence of duplicated chromosomal regions. Here, we report the progress of construction of a YAC library using the cultivar Conrad 94, which carries the Phytopthora resistance genes Rps1-k and Rps6. Insert DNA was prepared by partial digestion with using EcoRI-EcoRI methylase, followed by electrophoretic fractionation and in-gel ligation to the pJS97/pJS98 YAC vector. Ligation products were subjected to a second electrophoretic size selection before use in yeast spheroplast transformation. The library is being characterized for insert size range, average insert size and presence of chloroplast genome specific sequences. The library currently consists of about 8,000 clones with an average insert size of about 400kb representing approximately three haploid genome equivalents. DNA markers tightly linked to the soybean resistance genes Rps1-k and Rps6 will be evaluated used to assess the utility of this library for positional cloning.