A taxonomic study of Eudorina unicocca (Volvocaceae, Chlorophyceae) and related species, based on morphology and molecular phylogeny

Figures & data

Table 1. List of rbcL gene and ITS sequences used in this study.

		Origin and DDBJ/EMBL/GenBank accession number
Taxa	Strain designation	rbcL	rDNA ITS
Yamagishiella unicocca	NIES^a-666 (UTEX^b 2428)	D86823
	UTEX 2430	D86825
	NIES-872	AB044168
	UTEX 2031	D86822
	UTEX 840	D86826
	UTEX 2127	D86824
	NIES-870	AB359064^e
	Hasu-1^c (NIES-1859)	AB359065^e
Eudorina unicocca	NIES-724 (UTEX 737, Goldstein^d:1m “E. unicocca var. unicocca”)	D86829	AB359069^e
	TKI-C-2 (NIES-1858, From Lale Tsukui)	AB359066^e	AB359070^e
	990601-IE-5 (NIES-1855, From Lake Sagami)	AB359067^e	AB359071^e
Eudorina peripheralis	NIES-725 (UTEX 1215, Goldstein:93f “E. unicocca var. unicocca”)	D63434	AF486525
	NIES-726 (UTEX 1218, Goldstein:100f “E. unicocca var. peripheralis”)	D86830	AB359072^e
	UTEX 1221 (Goldstein:4sm “E. unicocca var. peripheralis”)	AB359068 ^e	AB359073^e
Eudorina cylindrica	NIES-722 (UTEX 1197, Goldstein^d:47f)	D86833	AF182439
Eudorina illinoisensis	NIES-460	D63433
	NIES-723 (UTEX 808)	D88809
Eudorina elegans	NIES-717 (UTEX 1193, Goldstein^d:56f)	D88803
	NIES-456	D63432d
	NIES-718 (UTEX 1195, Goldstein:44f)	D88810
	NIES-719 (UTEX 1199, Goldstein:40f)	D88804
	NIES-720 (UTEX 1205, Goldstein:60f)	D88805
	NIES-568	D88808
	NIES-721 (UTEX 1212)	D88806
Eudorina minodii	NIES-856	AB047074-6
Pleodorina californica	UTEX 809	D63439
Pleodorina japonica	NIES-577	D63440
Pleodorina indica	UTEX 1990	D86834
Pleodorina thompsonii	UTEX 2804	AB214408	AF486540
Pleodorina starii	NIES-1362	AB214427
Volvox aureus	NIES-541	D63445
	NIES-891	AB076096
	NIES-892	AB076086
Volvox tertius	UTEX 132	AB076098
	NIES-544	AB086174
Volvox gigas	UTEX 1895	AB076084
Volvox obversus	UTEX 1865	AB076085
Volvox africanus	UTEX 1891	AB076101
Volvox carteri
f. kawasakiensis	NIES-732	D63446
f. nagariensis	UTEX 1885	AB076099
f. weismannia	UTEX 1875	AB076100
Volvox powersii	UTEX 1863	AB214415
Volvox dissipatrix	UTEX 2184	D63447
	Marb. 2RS 29	AB214420
Volvox rousseletii	UTEX 1862	D63448
Volvox barberi	UTEX 804	D86835
Volvox globator	UTEX 955	D86836
Platydorina caudata	UTEX 1658	D86828
Pandorina colemaniae	NIES-572	D63441
Pandorina morum	NIES-887	AB044166
^aMicrobial Culture Collection at the National Institute for Environmental Studies (Kasai et al., 2004). ^bCulture Collection of Algae at the University of Texas at Austin (Starr & Zeikus 1993). ^cExhibiting isogamous sexual reproduction when mixed with Hasu-4 (see Materials and Methods). ^dStrains used by Goldstein (1964). ^eSequenced for the present study.

Figs. 1–7 Light microscopy of an aplanosporic strain of Eudorina unicocca originating from Lake Tsukui, Kanagawa, Japan (TKI-C-2). Fig. 1. Surface view of 32-celled vegetative colony. Note a single, basal pyrenoid (P) in the chloroplast of each cell. Fig. 2. Optical section of 32-celled vegetative colony. Arrowheads indicate colonial envelope surrounding whole colony. Fig. 3. Surface view of vegetative cell, showing contractile vacuoles (arrowheads) distributed in the protoplast surface. Fig. 4. Optical section of vegetative cell, showing a single large pyrenoid (P) in the chloroplast, and contractile vacuoles (arrowheads) distributed in the protoplast surface. Fig. 5. Daughter colony formation in asexual reproduction. Note each cell is enclosed by a transparent vesicle or cellular envelope (arrows) within the parental gelatinous matrix (arrowheads). Fig. 6. Vegetative colony stained with methylene blue. Individual cellular sheaths of the colonial gelatinous matrix (asterisks) are apparent. Fig. 7. Mature aplanospores 27 days after transferring into nitrogen-deficient medium.

Fig. 8. Line drawing of 32-celled vegetative colony of an aplanosporic strain of Eudorina unicocca originating from Lake Tsukui, Kanagawa Prefecture, Japan.

Fig. 9. Neighbor-joining (NJ) tree based on rbcL genes from 17 strains of Eudorina species, 17 strains of Volvox, five strains of Pleodorina, one strain of Platydorina, eight strains of Yamagishiella, and two strains of Pandorina (Table 1). Branch lengths are propotional to Kimura (1980) distances, which are indicated by the scale bar besides the tree. Numbers above or below the branches represent 50% or more bootstrap values based on 1,000 replications of the NJ or maximum parsimony analyses, respectively.

Fig. 10. Neighbor-joining (NJ) tree based on ITS sequences from 6 strains of Eudorina species and ones strain of Pleodorina (Table 1). Branch lengths are proportional to Kimura (1980) distances, which are indicated by the scale bar besides the tree. Numbers above or below the branches represent 50% or more bootstrap values based on 1,000 replications of the NJ or maximum parsimony analyses, respectively.

Figs 11–18. Vegetative cells of Eudorina and Yamagoshiella showing two types of distribution of contractile vacuoles in the protoplasts. Figs 11–14. Eudorina. Note each cell has several contractile vacuoles (arrowheads) distributed in the protoplast surface. Figs 11, 13 give surface views of protoplasts and Figs 12, 14 provide optical sections. Figs 11, 12. E. unicocca NIES-724 (UTEX 737, 1m). Fig. 13. E. peripheralis NIES-725 (UTEX 1215, 93f). Fig. 14. E. illinoisensis NIES-723. Figs 15–18. Yamagishiella unicocca. Note only two anterior contractile vacuoles (arrowheads) in the protoplast surface. Figs 15, 17, 18 are surface views of anterior regions of protoplasts and Fig. 16 an optical section of the protoplast. No contractile vacuoles are visible in the periphery. Figs 15, 16. Hasu-2. Fig. 17. NIES-762. Fig. 18. NIES-870.

Figs. 19–22. Vegetative colonies of Eudorina unicocca and E. peripheralis stained with methylene blue. Fig. 19. E. unicocca NIES-724 (UTEX 737,1m), showing individual cellular sheaths (asterisk). Fig. 20. E. peripheralis NIES-725 (UTEX 1215, 93f). Fig. 21. E. peripheralis NIES-726 (UTEX 1218, 100f). Fig. 22. E. peripheralis UTEX 1221 (4sm). Scale bars: 10µm.

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