Virginia Institute of Marine Science
Diseases of Aquatic Organisms
This study reports the first serine protease gene(s) isolated from Perkinsus marinus. Using universal primers, a 518 bp subtilisin-like serine protease gene fragment was amplified from P, marinus genomic DNA and used as a probe to screen a lambda-phage P. marinus genomic library; 2 different gamma-phage clones hybridized to the digoxigenin(DIG)-labeled subtilisin-like gene fragment. Following subcloning and sequencing of the larger DNA fragment, a 1254 bp open reading frame was identified and later confirmed, by 5' and 3' random amplification of cDNA ends (RACE) and northern blot analysis, to contain the entire coding-region sequence. Sequence analysis of the 3' RACE results from 2 isolate cultures, VA-2 (P-1) and LA 10-1, revealed multiple polymorphic sites within and among isolates. We identified 2 different types of cDNA clones with 95.53% nucleotide sequence similarity, suggesting the possibility of 2 closely related genes within the P. marinus genome. Southern blot analysis of genomic DNA from 12 genetically distinct P. marinus isolate cultures revealed 2 different banding patterns among isolates.
Brown, GD and Reece, Kimberly S., Isolation and characterization of serine protease gene(s) from Perkinsus marinus (2003). Diseases of Aquatic Organisms, 57(1-2), 117-126.