ABSTRACT
Chromosome painting and genomic in situ hybridization (GISH) are both effective methods for basic genetic research and practical breeding. These methods were applied even in the typically small chromosomes of rice. This manuscript describes in detail, highly reproducible, complete protocols for chromosome painting and GISH in rice chromosomes. Examples of useful applications of these methods are also presented.
Subject(s)
Breeding/methods , Chromosome Painting/methods , Oryza/genetics , DNA, Plant , RetroelementsABSTRACT
rDNA (18S-5.8S-25S rDNA) and 5S rDNA loci were visualized on the chromosomes of six species of the genus Oryza by fluorescence in situ hybridization (FISH) and the labeled rice chromosomes were identified based on their condensation patterns. As a result, the chromosomes harboring rDNA and/or 5S rDNA loci were determined in the complement for all the known rice genomes. Variation in the location of the rDNA loci indicated the transpositional nature of the rDNAs in the genus Oryza, as also suggested in Triticeae and Allium. Comparative analysis of the locations of rDNA loci among rice, maize and wheat revealed that variability in the physical location of the rDNA loci was characteristic of the genus Oryza and also of the genera of Gramineae. This variability in the location of the rDNA loci between evolutionarily related species is in sharp contrast to the conservation of the general order of genes in their genomes.
