Isolation of A/D and C genome specific dispersed and clustered repetitive DNA sequences from Avena sativa.
DNA gel-blot and in situ hybridization with genome-specific repeated sequences have proven to be valuable tools in analyzing genome structure and relationships in species with complex allopolyploid genomes such as hexaploid oat (Avena sativa L., 2n = 6x = 42; AACCDD genome). In this report, we describe a systematic approach for isolating genome-, chromosome-, and region-specific repeated and low-copy DNA sequences from oat that can presumably be applied to any complex genome species. Genome-specific DNA sequences were first identified in a random set of A. sativa genomic DNA cosmid clones by gel-blot hybridization using labeled genomic DNA from different Avena species. Because no repetitive sequences were identified that could distinguish between the A and D gneomes, sequences specific to these two genomes are refereed to as A/D genome specific. A/D or C genome specific DNA subfragments were used as screening probes to identify additional genome-specific cosmid clones in the A. sativa genomic library. We identified clustered and dispersed repetitive DNA elements for the A/D and C genomes that could be used as cytogenetic markers for discrimination of the various oat chromosomes. Some analyzed cosmids appeared to be composed entirely of genome-specific elements, whereas others represented regions with genome- and non-specific repeated sequences with interspersed low-copy DNA sequences. Thus, genome-specific hybridization analysis of restriction digests of random and selected A. sativa cosmids also provides insight into the sequence organization of the oat genome.
Ananiev
Evgueni V
EV
Department of Agronomy and Plant Genetics and Plant Molecular Genetics Institute, University of Minnesota, St. Paul 55108-6026, USA.
Vales
M Isabel
MI
Phillips
Ronald L
RL
Rines
Howard W
HW
D018554:Avena / Q000235:genetics*; D002875:Chromosomes; D003001:Cloning, Molecular; D003360:Cosmids / Q000032:analysis; D015342:DNA Probes; D018744:DNA, Plant / Q000235:genetics* / Q000302:isolation & purification; D018745:Genome, Plant; D015698:Genomic Library; D017404:In Situ Hybridization, Fluorescence; D020071:Interspersed Repetitive Sequences; D012091:Repetitive Sequences, Nucleic Acid; D013045:Species Specificity
D015342:DNA Probes; D018744:DNA, Plant