Population genetic studies of worldwide populations in the toxic dinoflagellate Alexandrium catenella (Dinophyceae) by use of haplotype and microsatellite markers

Nagai, Satoshi ... et. al.-- The 16th International Conference on Harmful Algae (ICHA 2014 New Zealand), Advancement Through Shared Science, 27-31 October 2014, Wellington, New Zealand.-- 1 page
The distribution of Alexandrium catenella has been increasingly documented worldwide during the last decades. To examine the genetic relatedness of global populations, we conducted a genetic study using 2 haplotype markers and 7 microsatellite markers. Seawaters or sediment samples were collected from 11 different localities (17 samples) along 10 Japanese, 3 Chinese, 2 Mediterranean Sea, 2 New Zealand coastal waters and 839 clonal strains (temperate Asian clade) were analysed. One of the two haplotype markers showed high resolution to discriminate the difference of the geological origin in the populations. We could obtain the sequences from 673 clonal isolates. Two haplotypes were predominant of 85 haplotypes. The first one “Haplo01” (n = 316 isolates) and the second one “Haplo02” (n = 122) were predominated by Japanese isolates and Chinese isolates, respectively. Some Japanese isolates also belonged to haplo2. Interestingly, the Sea of Japan population had unique and highly diversified haplotypes derived from haplo2. New Zealand populations were mainly divided into three groups, i.e. the first one belonged to Haplo2, the second one derived from Haplo1, and the third one positioned in the middle of Haplo1 and Haplo2 groups. The half of Mediterranean Sea isolates belonged to Haplo1 and other half isolates had unique haplotypes derived from Haplo2. Microsatellite analysis data showed the significant population differentiation among most of the pairwise populations except for several Japanese pairwise populations. Results of the haplotype analysis well supported those at microsatellites analyses