AME 63:61-67 (2011)  -  DOI: https://doi.org/10.3354/ame01478

ABSTRACT: Extant and newly designed primers for the polymerase chain reaction (PCR) were used to amplify phycodnavirus DNA polymerase ( polB) gene fragments from numerous samples collected at different times of the year from 3 freshwater environments in Ontario, Canada. Overall, a total of 143 cloned PCR fragments were sequenced and 106 putative phycodnavirus polB gene fragments were identified. Although most of these 106 gene fragments were very closely related (i.e. >97% identical) to polB sequences from chloroviruses, or environmental sequences related to prasinoviruses, 16 represented 2 new types of phycodnavirus polB genes. More specifically, polB fragments that formed a new clade of chloroviruses were amplified from Lake Ontario using newly designed Chlorovirus-specific PCR primers, and a polB sequence most closely related to genes from the prymnesioviruses PgV-03T and CbV-PW1 was amplified from a pond sample from Mississauga, Ontario, using the degenerate algal virus-specific PCR primers AVS1 and AVS2. Thus, the results of the present study provide evidence for a new type of Chlorovirus, and the first observation of polB sequences from freshwater phycodnaviruses that are presumed to infect algae other than chlorophytes.

KEY WORDS: Phycodnaviruses · Algal viruses · Chlorella viruses · Prymnesioviruses · Freshwater · DNA polymerase ·