Phylogeny of the Acipenseriformes: cytogenetic and molecular approaches.
This paper presents an review of the karyology and DNA content of Acipenseriformes and a study of the molecular phylogeny of representatives of all acipenseriform genera, except Psephurus sp(p). DNA was isolated from blood and muscle samples; polymerase chain reaction products of 1 nuclear, 2 mitochondrial genes and cytochrome b were sequenced and the results used to construct a phylogenetic tree. A partial sequence of the cytochrome b gene of 7 Acipenser species (A. brevirostrum, A. gueldenstaedtii, A. mikadoi, A. naccarii, A. nudriventris, A. oxyrinchus and A. stellatus) was also examined. It was concluded that there has been little cytogenetic change in Acipenseriformes, and that Polyodontidae and Acipenseridae originated from a 60-chromosome tetraploid ancestor. Relationships between Huso, Acipenser, Scaphirhynchus and Pseudoscaphirhynchus are also discussed.