Molecular phylogenetic systematics of twelve species of acipenseriformes based on mtDNA ND4L-ND4 gene sequence analysis

Acipenseriformes is an endangered primitive fish group, which occupies a sp ecial place in the history of ideas concerning fish evolution, even in vert ebrate evolution. However, the classification and evolution of the fishes h ave been debated. The mitochondrial DNA (mtDNA) ND4L and partial ND4 genes were first sequenced in twelve species of the order Acipenseriformes, inclu ding endemic Chinese species. The following points were drawn from DNA sequ ences analysis: (i) the two species of Huso can be ascribed to Acipenser; ( ii) A. dabryanus is the mostly closely related to A. sinensis, and most lik ely the landlocked form of A. sinensis; (iii) genus Acipenser in trans-Paci fic region might have a common origin; (iv) mtDNA ND4L and ND4 genes are th e ideal genetic markers for phylogenetic analysis of the order Acipenserifo rmes.