The Genetic Deversity Of PP-like Cyanophage In Donghu Lake Of Wuhan And Sequences Of Genomic DNA Of Cyanophage PP

We have used two primers T7 and 159 to amplify algae nucleic acid and cyanophage PP nucleic acid and found that 159 primers can specifically amplify cyanophage PP DNA, then the amplication product was cloned and sequenced. Subsequently, 159B primers were well designed and they can effectively amplified the DNA of cyanophage PP. Further more, we used primers 159 B to amplify; the numbers of samples of PP-like cyanophages in different temporal and spatial in Wuhan Donghu Lake, then the PCR products were directly sequenced. The comparison of sequences sugguested that the difference of cyanophage PCR sequences is not big (the average difference is 2.93% and the largest one is less than 8%). So we conclude that the genetic diversity of PP-like cyanophage in enviroments is stable.This paper still uses RAPD to study the genetic diversity of PP-like cyanophage in nature environment.The result also indicates that the genetic diversity of PP-like cyanophage is stable.In orde to study the molecular biology of cyanophage PP in nature, we have tried to sequence the genomic DNA of cyanophage PP,but we got 159 contigs which can not be jointed into a integrated genomic sequence.We blast these fragments with the virus and the prokaryotes separately in the NCBI ,and the average similar value is separately 26.13% and 49.03%.The result indicates that host and bacterial DNA contamination may have been occurred. Besides, we also found that, despite cyanophage PP 132,102, 78 and 17 sequences can not be assembled into a sequence, they are similar to the No.40 open reading fragment of cyanophage Pf - WMP4, and the similar region is serried. Similar situation also appeare in the 93rd and 78th sequences (correspond to the No. 37 open reading reading frament of Pf - WMP4), and 143rd and 5th sequences (correspond to the No. 36 open reading framents of Pf - WMP4), the 81st sequence of the cyanophage PP also has 68% similarity with the cyanophage Ma - LMM01 , In all, this shows at least that some sequences are polluted.