A PCR TECHNIQUE BASED ON THE HIP1 INTERSPERSED REPETITIVE SEQUENCE DISTINGUISHES CYANOBACTERIAL SPECIES AND STRAINS

The use of primers based on the Hip1 sequence as a typing technique fo r cyanobacteria has been investigated. The discovery of short repetiti ve sequence structures in bacterial DNA during the last decade has led to the development of PCR-based methods for typing, i.e. distinguishi ng and identifying, bacterial species and strains. An octameric palind romic sequence known as Hip1 has been shown to be present in the chrom osomal DNA of many species of cyanobacteria as a highly repetitious in terspersed sequence. PCR primers were constructed that extended the Hi p1 sequence at the 3' end by two bases. Five of the 16 possible extend ed primers were tested. Each of the five primers produced a different set of products when used to prime PCR from cyanobacterial genomic DNA , Each primer produced a distinct set of products for each of the 15 c yanobacterial species tested. The ability of Hip1-based PCR to resolve taxonomic differences was assessed by analysis of independent isolate s of Anabaena flos-aquae and Nostoc ellipsosporum obtained from the CC AP (Culture Collection of Algae and Protozoa, IFE, Cumbria, UK), A PCR -based RFLP analysis of products amplified from the 23S-16S rDNA inter genic region was used to characterize the isolates and to compare with the Hip1 typing data. The RFLP and Hip1 typing yielded similar result s and both techniques were able to distinguish different strains. On t he basis of these results it is suggested that the Hip1 PCR technique may assist in distinguishing cyanobacterial species and strains.