HEMIFLAGELLOCHLORIS KAZAKHSTANICA GEN. ET SP. NOV.: A NEW COCCOID GREEN ALGA WITH FLAGELLA OF CONSIDERABLY UNEQUAL LENGTHS FROM A SALINE IRRIGATION LAND IN KAZAKHSTAN (CHLOROPHYCEAE, CHLOROPHYTA)¹

Abstract

A coccoid green alga, Hemiflagellochloris kazakhstanica S. Watanabe, S. Tsujimura, T. Misono, S. Nakamura et H. Inoue, gen. et sp. nov., was described from soil samples of a saline irrigation land in Ili River basin, Kazakhstan. This alga had a parietal chloroplast with a pyrenoid, which was covered with starch segments and penetrated with thylakoid membranes. Reproduction occurred by the formation of aplanospores and zoospores. The aplanospores frequently formed tetrad aggregations in a mother cell. The zoospores were covered by a single-layered cell wall and lacked stigmata. The zoospores had two flagella of considerably unequal lengths; the longer flagellum was 17-19 lm in length and the shorter one was 9-10 lm. The flagellar apparatus architecture was of the clockwise orientation group type in the Chlorophyceae. Molecular phylogenetic analysis using 18S and 28S rDNA sequence data resolved this organism in a separate clade from the green algae that had flagella of slightly unequal lengths. It was suggested that features such as inequality in flagellar lengths, parallel exsertion of basal bodies, and subapical position of the flagellar apparatus were sporadically evolved.

Phylogeny and Molecular Evolution of the Green Algae

“…Molecular phylogenetic analyses of nuclear ribosomal DNA and chloroplast sequences have profoundly changed the concept of the class, which now includes a diverse range of taxa formally placed in the Dunaliellales, Chlorococcales, Tetrasporales, Chlorosarcinales, Volvocales and Chaetophorales Wilcox et al, 1992;Buchheim et al, 1994;Nakayama et al, 1996a;Nakayama et al, 1996b;Booton et al, 1998b;Krienitz et al, 2003;Lewis & McCourt, 2004;Watanabe et al, 2006a;Watanabe et al, 2006b;Nakada et al, 2008a;Nakada et al, 2008b). As presently conceived, the class includes non-motile or motile unicells with two or four flagella, biflagellate colonies, filaments and cells that are imbedded in a mucilage envelope (Nakazawa et al, 2004;Nozaki et al, 2006b;Yamada et al, 2008;Nakada & Nozaki, 2009;Matsuzaki et al, 2010;Novis et al, 2010;Nozaki et al, 2010).…”

“…Molecular and ultrastructural data have identified five major clades (Booton et al, 1998a;Wolf et al, 2002;Wolf et al, 2003;Turmel et al, 2008). The Chlamydomonadales is characterized by a CW flagellar apparatus orientation in biflagellate members, but quadriflagellate representatives may display various other orientations (Nakayama et al, 1996a;Nozaki et al, 2003;Watanabe et al, 2006b). The Sphaeropleales include nonmotile unicells or colonies that produce biflagellate zoospores with a DO basal body configuration (Deason et al, 1991).…”

DEEP DIVISION IN THE CHLOROPHYCEAE (CHLOROPHYTA) REVEALED BY CHLOROPLAST PHYLOGENOMIC ANALYSES1

“…The Chlamydomonadales include biflagellate unicells with the CW configuration of basal bodies as well as quadriflagellate unicells with various basal body arrangements (Nozaki et al. 2003, Lewis and McCourt 2004, Watanabe et al. 2006).…”

“…Within each group, vegetative morphology is variable, with the coccoid form being nearly ubiquitous. The Chlamydomonadales include biflagellate unicells with the CW configuration of basal bodies as well as quadriflagellate unicells with various basal body arrangements (Nozaki et al 2003, Lewis and McCourt 2004, Watanabe et al 2006. Using three chloroplast protein-coding genes, Nozaki et al (2003) determined that three distinct quadriflagellate lineages differing in the ultrastructure of their flagellar apparatus are basal to all biflagellate lineages of the Chlamydomonadales.…”

DISTINGUISHING MULTIPLE LINEAGES OF PEDIASTRUM DUPLEX WITH MORPHOMETRICS AND A PROPOSAL FOR LACUNASTRUM GEN. NOV1

“…The naming of species of microscopic green algae and other unicellular eukaryotes has relied heavily on morphological characteristics of vegetative stages (Manhart and McCourt 1992). However, many recent molecular phylogenetic studies have highlighted the difficulty of recognizing morphological species boundaries due to convergent morphological evolution, cryptic species, and phenotypic plasticity (Trainor and Morales 1999, Buchheim et al 2005, Fawley et al 2006, Kooistra and Verbruggen 2005, McManus and Lewis 2005, Verbruggen et al 2005b, Sanchez-Puerta et al 2006, Watanabe et al 2006.…”