Assessment of genotypic identity of cyanobacterial strains in culture collections using HIP1-based primers

Abstract

We examined 32 cyanobacterial strains, representative of 11 different genera, for the presence of the highly iterated genomic palindrome, called HIP1, using HIP1 extended PCR primers. Cryolysates or cell suspensions, and even single colonies, of Microcystis aeruginosa, strain PCC 7806, yielded PCR products equivalent to those obtained with purified DNA, as judged from the banding patterns obtained by gel electrophoresis. Cryolysates were used for amplification and genotyping of all other strains. Representatives of different genera differed extensively in HIP1-based migration patterns, and the amplification products of axenic cyanobacteria were comparable to those obtained with duplicate, non-axenic strains. In addition, HIP1 repeats were present in 11 strains of the species Microcystis aeruginosa and in isolates assignable to Planktothrix agardhii and P. rubescens. Based on available 16S rDNA sequence data and DNA/DNA hybridization results for members of these genera, the differences detected by HIP1-based profiling correlate with the interspecies distinctions between Planktothrix agardhii and P. rubescens, and reflect intraspecific diversity for members of Microcystis aeruginosa. Thus, we have confirmed the value of this method for rapid genotyping and verification of presumably identical strains from different culture collections.