PAG-I Plant Genome I Conference

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


PG-I: CONSTRUCTION OF RICE GENOMIC LIBRARIES IN YEAST ARTIFICIAL CHROMOSOMES FOR PHYSICAL MAPPING

CONSTRUCTION OF RICE GENOMIC LIBRARIES IN YEAST ARTIFICIAL CHROMOSOMES FOR PHYSICAL MAPPING.

Yosuke Umehara, Akiko Miyazaki, Hiroshi Tanoue, Yuji Yasukochi, Shoko Saji, Yoshiaki Otsuki*, Tatsuhiko Fujimura, Nori Kurata and


Yuzo Minobe, Rice Genome Research Program, National Institute of Agrobiological Resources / Society for Techno-innovation of Agriculture, Forestry and Fisheries, and *National Agriculture Research Center, Kannondai 2-1-2, Tsukuba, 305 lbaraki, Japan. (Fax +81-298-38-7468) Use of yeast artificial chromosomes is a powerful too] for analysis of complex genomes, due to the capability of cloning large DNA fragments (50kb - 1Mb). For preparing the physical map of rice genome, we constructed genomic libraries in yeast artificial chromosomes. High molecular weight DNA was extracted from liquid-cultivated cells of japonica rice (cv. Nipponbare) embedded in agarose plugs, and digested partially with EcoRl or with Notl. Digested DNA was fractionated by pulsed-field gel electrophoresis and ligated with the YAC vector pYAC4 (for EcoRl digest) or pYAC55 (for NotI digest). Ligated products were fractionated again and used to transform yeast (Saccharomyces cerevisiae ABI380). We have obtained 8,000 YAC clones with EcoRl digests and 4,000 YAC clones with Notl digests. The average size of inserts is about 350kb and the maximum size is more than 1Mb, as revealed by the analysis of 240 randomly selected clones. These libraries cover the rice genome about 5 times. Isolation of YAC clones containing a fragment of the rice chromosome 6 is now in progress using chromosome-specific RFLP and STS markers. We have already begun chromosome walking from these marker points on chromosome 6.


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