Large subunit rDNA sequences from Alexandrium catenella strains isolated during harmful algal blooms in Hong Kong

The partial sequences of the large subunit (24S) ribosomal RNA gene (LsurRNA) of three Alexandrium catenella strains isolated during the 1998 and 1989 red tide incidents in Hong Kong were compared, together with the sequences of other Asian A. catenella species complex. The sequences of two A. catenella strains isolated in 1998 were identical, despite being isolated at different time (March and April) and different locations (eastern and southern Hong Kong). In cladistic analysis, the two A. catenella HK98A & B strains, the A. catenella HK1989 strain, the Chinese strain clade and the Korean/Japanese A. catenella form a clade distinct from other A. catenella strains. Interestingly, the two A. catenella HK98A & B strains only form a clade with the A. catenella HK1989 strain/Chinese A. catenella (CCMP1493) with low bootstrap values (49%).