Alexandrium genetic diversity and phylogenetic studies
|Keywords||Alexandrium Ribosomal Sequence Microsatellite markers Genetic Diversity Phylogenetic|
Alexandrium (Alexandrium tamarense) is a widely distributed and can produce paralytic shellfish poisoning (Paralytic Shellfish Poisoning, PSP) of the red tide dinoflagellate, is China's coastal waters toxic algae typical. This study selected a different waters collected Alexandrium its analysis of genetic diversity within species, between different populations in order to understand the genetic structure to determine its degree of genetic variation within species. Study first marking method using ribosome analyzed 11 Alexandrium 5.8S rDNA and internal transcribed spacer (ITS), LSU rDNAD1-D2 region sequence information of the two groups, the results showed: (1) CCMP116 sequences associated with Alexandrium homology higher, it should be identified as relevant Alexandrium; (2) the remaining 10 genetic differences between strains of algae small; (3) studied 10 Alexandrium can be divided into at least three genetic type, that type in Western Europe, temperate Asia, type, type of tropical Asia, China's six coastal algal type is tropical Asia. After that, we help more sensitive microsatellite markers on 10 Alexandrium analyze the genetic diversity and to explore different geographic strains of algae and the degree of genetic differentiation between the level of gene flow. The results showed that: (1) 10 Alexandrium 37 alleles were detected, 12 microsatellite markers in 11 polymorphic loci, percentage of polymorphic loci was 91.67%. 11 polymorphic loci effective number of alleles is 1 to 5.3333, with an average 2.5798. Alexandrium intraspecific genetic diversity of 0.2778 ~ 0.8125, with an average of 0.5125; (2) the study Alexandrium can be roughly divided into four clades. Clade location with associated algal strains. Geographic distribution of different genetic differentiation Alexandrium high level, reaching 0.6056; (3) estimation of gene flow between populations lower level of three populations may not exist between genetic exchange. Geographic distribution of different genetic differentiation Alexandrium higher level, it may be a long time alone in different geographical populations of evolution, and the lack of gene flow between them caused. Research shows that in Alexandrium intraspecific genetic diversity research, microsatellite markers are more powerful and able to reflect Alexandrium intraspecific genetic diversity; Chinese coastal Alexandrium is not a single evolutionary system, there may be at least three clade.