Prasinophyceae pigments
T
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ia
g
ra
m
fo
r1
3C
a
s
e
s
W
a
rd
`sm
e
th
o
d
C
ity
-b
lo
c
k(M
a
n
h
a
tta
n
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is
ta
n
c
e
s
flagellate
C
_
1
flagellate
C
_
2
NOUM15
C
_
1
3
coccoid
C
_
3
Ostreococcus sp.
C
_
5
Ostreococcus tauri
C
_
6
Ostreococcus sp.
C
_
4
Ostreococcus sp.
C
_
7
Ostreococcus sp.
C
_
1
2
Micromonas sp.
C
_
1
1
Ostreococcus sp.
C
_
1
0
Prasinococcus sp.
C
_
8
Prasinoderma.
C
_
9
0
"
C
h
lo
ro
p
h
y
c
e
a
e
-lik
e
"
Culture
BL148/9
BL7817
BL8217
RCC344
RCC343
RCC116
RCC371
RCC136
RCC137
RCC393
BL122
RCC356
RCC287
"
P
ra
s
in
o
p
h
y
c
e
a
e
-lik
e
"
1
0
0
2
0
0
3
0
0
4
0
0
5
0
0
6
0
0
7
0
0
8
0
0
L
in
k
a
g
eD
is
ta
n
c
e
Latasa 2002
Key
C_1
C_2
C_3
C_4
C_5
C_6
C_7
C_8
C_9
C_10
C_11
C_12
C_13
Telonema
The heterotrophic flagellate Telonema subtile has been reisolated from the Roscoff area,
one of the original sites sampled in 1913 by its author Griessman. This characteristic
species has been reported from many parts of the world and judged by its distribution it
appears to be eurytherm and euryhaline (Buchanan 1966, Throndsen 1969, 1983,
Thomsen 1992, Vørs 1992, Patterson et al. 1993, Kuylenstierna & Karlson 1994, Vørs
et al 1995, Tong 1997, Tong et al. 1998, Brandt & Sleigh 2000). It was studied in the
light microscope by Hollande and Cachon (1950) and the first electron micrographs
appeared in the early 1990 ‘s (Thomsen 1992, Vørs 1992, Nagasaki et al. 1993). The
present investigation is the first to combine fine-structural characterization of the species
with molecular biology, both performed on a culture isolated from Roscoff on the
Atlantic coast of France. Judged only by its anatomical features Telonema subtile is
difficult to assigned to a specific class of protozoa and at present it is classified as an
insertae sedis. Telonema is heterotrophic and in the culture (RCC 404) that we study, it
thrives on the scaly haptophyte Imantonia rotunda . The cell dimensions of Telonema
are 3-4 x 6-8 um. The 2 smooth flagella are a little shorter than the length of the cell and
directed backwards during swimming. The flagella are slightly unequal in length. They
emerge from each side of a protruding pointed posterior end and the uptake of food takes
place at the opposite anterior end. Telonema subtile also contains a mitochondrion with
tubular cristae, a central nucleus (N), a conspicuous food vaculole placed in the posterior
part of the cell and some inclusions resembling trichocysts(T). Structures resembling
cortical alveoli may be visible underneath the cell mebrane (not shown). The most
prominent feature of the cell is the sub-cortical lamina(CL) which encloses the cell. It is
composed of layers of microtubules and fibers and do not seem to be connected to the
fairly simple flagellar apparatus. The sub-cortical lamina is a quite unique character so
far only found in another Telonema, Telonema antarctica sp. nov. not yet described
(Klaveness, Kamran & Thomsen in prep.), but a somewhat similar structure exists in the
enigmatic dinoflagellate Oxhyrris marina (Roberts et al. 1993). This new Telonema has
many of the same features as Telonema subtile, but its flagella are many times longer
than the cell. Also, the longest flagellum bears hairs that appear to be tripartite
(Klaveness pers. com.). Phylogenetic studies show that Telonema subtile and the new
Telonema are closely related to each other and placed at the base of the Stramenopiles
(~Heterokontophyta) and the Alveolates, the latter including the dinoflagellates and
Oxhyrris marina (Shalcian-Tabrizi pers. com.). The occurrence of ultrastructural
features like tubular cristae, cortical alveoli and tripartite hairs in the genus Telonema
supports its phylogenetic position as a possible ancestor to the major eukaryotic linage
with tubular mitochondrion cristae. We believe that Telonema should probably be
classified with the straminopiles.
Light-micrograph of T. Subtile. Fflagella
Telonema subtile. Section trough cell.
N-nucleus, T-trichocyst, NL-cortical
lamina