Browsing by Subject "Physical mapping"

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Untersuchungen zur physikalischen Kartierung des Genoms der Weinrebe
(2000) Böhm, Andreas; Blaich, Rolf
In this study research on physical mapping of the grapevine genome was done and a method for preparation of high molecular weight DNA from Vitis-protoplasts was established. In the first part of the project the usefulness of megarestriction-fragments for physical mapping in different grapevine-varieties was analyzed. Hybridization experiments with a probe for repetitive DNA showed that most of the restriction fragments were only about 200 Kb in length with a maximum of 400 Kb. Due to the distance of 300 Kb/cM in the genome of Vitis most fragments only cover a distance of less than 1 cM. For this reason physical mapping with megarestriction-fragments would be less successful. As an alternative strategy for physical mapping a genomic BAC-library was constructed for the variety 'Vidal blanc' which is less sensitive to fungal pathogens. 800 BAC-clones with an average insert size of about 49 Kb have been randomly picked and analyzed. After transforming the complete ligation-mixture 30000 single BACs are expected. They represent more than 3-fold genomesize of Vitis and each single-copy sequence would be contained in the library with a probability of 95 For a first screening of the partial library specific probes for genes from the metabolism of plants or for genes with correlation to pathogen resistance have been developed. The amplification of partial sequences from these Vitis-genes was done with specific oligonucleotides. The PCR-products have been cloned and sequenced. A special probe specific for chloroplast-DNA was used to detect BACs with inserts from the genome of chloroplasts. As a first result of colony-hybridization experiments eight clones with inserts of chloroplast-DNA could be identified. One BAC-clone contains a gene similar to an osmotin-like protein.