TreeBASE Search-Analyses for study 10057

@ARTICLE{TreeBASE2Ref18548, author = {Hisayoshi Nozaki and Takashi Nakada and Shin Watanabe}, title = {Evolutionary origin of Gloeomonas (Volvocales, Chlorophyceae), based on ultrastructure of chloroplasts and molecular phylogeny.}, year = {2010}, keywords = {}, doi = {10.1111/j.1529-8817.2009.00773.x}, url = {}, pmid = {}, journal = {Journal of Phycology}, volume = {46}, number = {1}, pages = {195--201}, abstract = {Gloeomonas is a peculiar unicellular volvocalean genus because it lacks pyrenoids in the chloroplasts under the light microscope and has two flagellar bases that are remote from each other. However, ultrastructural features of chloroplasts are very limited and no molecular phylogenetic analyses have been carried out in Gloeomonas. In this study we observed ultrastructural features of chloroplasts of three species of Gloeomonas and Chloromonas rubrifilum SAG 3.85, and phylogenetic analyses were carried based on the combined data set from 18S ribosomal RNA, ATP synthase beta subunit and P700 chlorophyll a apoprotein A2 gene sequences, in order to deduce the natural phylogenetic positions of the genus Gloeomonas. The present electron microscopy demonstrated that the chloroplasts of the three Gloeomonas species and C. rubrifilum SAG 3.85 do not have typical pyrenoids with associated starch grains, but they possessed pyrenoid matrices that protruded interiorly within the stroma regions of the chloroplast. The pyrenoid matrices were large and broad in C. rubrifilum whereas those of the three Gloeomonas species were recognized in only the small protruded regions of the chloroplast lobes. The present multigene phylogenetic analyses resolved that the three species of Gloeomonas belong to the Chloromonas lineage or Chloromonadinia of the Volvocales, and Chloromonas insignis NIES 446 and C. rubrifilum SAG 3.85, both of which have pyrenoids without associated starch grains, were positioned basally to the clade composed of the three species of Gloeomonas. Therefore, Gloeomonas might have evolved from such a Chloromonas species through reduction in pyrenoid matrix size within the chloroplast and by separating their two flagellar bases.} }