Chen, F. and C.A. Suttle. 1995. Amplification of DNA polymerase gene fragments from viruses infecting microalgae. Applied and Environmental Microbiology 61:1274-1278.

Nested PCR using three highly degenerate primers was used for amplification and identification of the DNA polymerase (pol) genes from viruses which infect three genera of microalgae. Group-specific primers (AVS1, AVS2) were designed based on inferred amino acid sequences that were unique to the DNA pol genes of viruses (PBCV-1 and NY-2A) infecting an endosymbiotic Chlorella-like algae (Chlorophyceae), and a virus (MpV-SP1) which infects the photosynthetic flagellate Micromonas pusilla (Prasinophyceae). As well, a nested primer (POL) was designed based on the highly conserved amino acid sequence YGDTDS found in most B-family (*-like) DNA pol genes. These primers were used to amplify DNA from the three viruses PBCV-1, NY-2A and MpV-SP1 for which the primers were designed, as well as eight other clonal isolates of genetically distinct viruses which infect M. pusilla and viruses which infect Chrysochromulina spp., (Prymnesiophyceae) suggesting that these are a group of related viruses. The primers could also be used to amplify DNA from natural virus communities. In contrast, a product was not produced when DNA from viruses which infect the marine brown algae Ectocarpus siliculosis and Feldmannia sp. (Phaeophyceae) was used, suggesting that these viruses may not be closely related to those infecting microalgae. The primers could also be used to amplify DNA from natural virus communities. Our results indicate that nested PCR, even under low stringency conditions, can be used as a rapid method to verify the presence in seawater of a group of related viruses which infect microalgae. Sequence analysis of these fragments should provide information on the genetic diversity and possibly the phyletic relationships among these viruses. This is the first example of a PCR-based technique designed to detect viruses which infect eukaryotic algae.