Chloroplast small-subunit ribosomal RNA gene sequence fromChlamydomonas parkeae(Chlorophyta): molecular phylogeny of a green alga with a peculiar pigment composition

Abstract

The unicellular marine flagellate Chlamydomonas parkeae (Chlorophyta) is reported to have a peculiar pigment composition which is similar to that of the prasinophycean algae. We studied the phylogeny of this species on the basis of DNA sequence data. The chloroplast small-subunit ribosomal RNA gene of C. parkeae was amplified by polymerase chain reaction, sequenced, and compared with those of typical volvocalean algae and the prasinophycean alga Pyramimonas parkeae. The phylogenetic tree inferred from the sequence data indicated that C. parkeae is solidly placed within the typical volvocalean lineage as a sister to C. moewusii, being more distant from the higher plants, their closest relatives and P. parkeae. It is considered, therefore, that the pigment composition data for C. parkeae does not reflect the phylogenetic position of this species within the Chlorophyta.