Molecular Systematics Of Bisexual Artemia Populations

The brine shrimp Artemia is normally restricted to saline inland lakes and coastal salterns. It belongs to Crustasea, Branchiopoda, Anostacea, Artemidae and Artemia. At least six bisexual species and mangy parthenogenetic species are currently recognized in Artemia.The six bisexual species are: A. franciscana, A. persimilis, A. monica, A. urmiana, , A. tunisiana, A. sinica. The parthenogenetic species are defined as one spesie: A. parthenogenetica.With the development of molecular genetic marker application in molecular systematics, rRNA genes and COI gene have been widely used in the molecular systematics of marine animals, which based on the rRNA genes and COI gene special structure and mode of evolvement.This paper detailedly introduces the compasions and characters of rRNA genes,and its application in the Phylogeny , taxonomy, genetic diversity and so on. rRNA genes and COI have been widely used in molecular systematics of the marine animals, and manily focused on the study of primary structure of rRNA genes and COI gene. To help resolve phylogenetic relationships among bisexual Artemia populations, phylogenetic analysis was conducted using DNA sequences from the nuclear DNA internal transcribed spacer 1 (ITS-1) and portions of the mitochondrial genome corresponding to the cytochrome oxidase I (COI). DNA sequences were generated for nine bisexual Artemia populations living in different regions of the world. Phylogenetic trees based on ITS-1 and COI sequences indicated that bisexual Artemia populations consist of four groups. The bisexual Artemia populations from Tibet and Kazakstan always clustered with A. urmiana in the same group, there is small sequence divergence and genetic distance among them. So we deduced that bisexual Artemia populations from Tibet and Kazakstan maybe belong to the A. urmiana group. Our study did not support that bisexual Artemia populations from Tibet is a new, separate species A. tibetiana. We also found that Artemia sinica and Artemia urmiana have a small genetic distance, so A. urmiana maybe play an important roll in the evolution of A. sinica.