title: Construction of a YAC library from a Beta vulgaris fragment addition and isolation of a major satellite DNA cluster linked to the beet cyst nematode resistance locus Hs1 (pat-1.).
abstract: A YAC library was constructed from the Beta vulgaris fragment addition AN5-203b. This monosomic fragment addition harbors an approximate 12-Mbp fragment of B.patellaris chromosome 1 accomodating the Hs1 (pat-1) conferring resistance to the beet cyst nematode (Heterodera schachtii). The YAC library consists of 20,000 YAC clones having an average size of 140 kb. Screening with organelle-specific probes showed that 12% of the clones contain chloroplast DNA while only 0.2% of the clones hybridizes with a mitochondrial specific probe. On the basis of a sugar beet haploid genome size of 750 Mbp this library represents 3.3 haploid genome equivalents. The addition fragment present in AN5-203b harbors a major satellite DNA cluster that is tightly linked to the Hs1 (pat-1) locus. The cluster is located on a single 250-kb EcoRI restriction fragment and consists of an estimated 700-800 copies of a 159-bp core sequence, most of which are arranged in tandem. Using this core sequence as a probe, we were able to isolate 1 YAC clone from the library that contains the entire 250-kb satellite DNA cluster.
authors.affiliation: Department of Molecular Biology, DLO-Center for Plant Breeding and Reproduction Research (CPRO-DLO), P.O. Box 16, NL-6700 AA, Wageningen, The Netherlands.
authors.forename: R M
authors.initials: RM
authors.lastname: Klein-Lankhorst
authors.forename: E M
authors.initials: EM
authors.lastname: Salentijn
authors.forename: W G
authors.initials: WG
authors.lastname: Dirkse
authors.forename: M
authors.initials: M
authors.lastname: Arens-de Reuver
authors.forename: W J
authors.initials: WJ
authors.lastname: Stiekema