Isolation and characterization of a satellite DNA family in the Saccharum complex

Abstract

EaCIR1, a 371-bp Erianthus-specific satellite DNA sequence, was cloned from TaqI restricted genomic DNA after agarose-gel electrophoresis. This sequence has 77% homology with a 365-bp satellite of Helictotrichon convolutum and 72% homology with a 353-bp tandem repeat sequence from Oryza sativa. PCR primers defined in the conserved regions of these repetitive sequences were used to isolate other satellite DNAs in different representatives of the Saccharum complex: SoCIR1 in Saccharum officinarum, SrCIR1 in Saccharum robustum, SsCIR1 and SsCIR2 in Saccharum spontaneum, and MsCIR1 in Miscanthus sinensis. EaCIR1 and SoCIR1 were localized to subtelomeric regions of the chromosomes by fluorescence in situ hybridization. Southern hybridization experiments, using two representatives of this repeat sequence family as probes, illustrated contrasting species-specificity and demonstrated the existence of similar repetitive elements in sorghum and maize.Key words: satellite DNA, sugarcane, Saccharum complex, Gramineae, fluorescence in situ hybridization, FISH.