Flagellar autofluorescence in forty-four chlorophyll <i>c</i>-containing algae

Kawai, Hiroshi; Inouye, Isao

doi:10.2216/i0031-8884-28-2-222.1

Cited by 40 publications

(7 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Eyespots are part of the photoreceptor apparatus (also called the eyespot apparatus), shielding light so that the other elements can more precisely determine the direction of light (Foster and Smyth, 1980). In a wide variety of heterokont and haptophyte algae, one flagellum possesses an autofluorescent substance (flavin and pterin-like in brown algae) that plays a role in phototaxis (Müller et al, 1987;Kawai and Inouye, 1989;Kawai et al, 1996). In the typical case (most heterokont algae, Pavlovophyceae), the eyespot lies just inside the chloroplast in the area immediately adjacent to the mature flagellum.…”

Section: Cell Biology-chloroplasts and Their Pigments-mentioning

confidence: 99%

Biology and systematics of heterokont and haptophyte algae

Andersen

2004

American J of Botany

178

114

View full text Add to dashboard Cite

In this paper, I review what is currently known of phylogenetic relationships of heterokont and haptophyte algae. Heterokont algae are a monophyletic group that is classified into 17 classes and represents a diverse group of marine, freshwater, and terrestrial algae. Classes are distinguished by morphology, chloroplast pigments, ultrastructural features, and gene sequence data. Electron microscopy and molecular biology have contributed significantly to our understanding of their evolutionary relationships, but even today class relationships are poorly understood. Haptophyte algae are a second monophyletic group that consists of two classes of predominately marine phytoplankton. The closest relatives of the haptophytes are currently unknown, but recent evidence indicates they may be part of a large assemblage (chromalveolates) that includes heterokont algae and other stramenopiles, alveolates, and cryptophytes. Heterokont and haptophyte algae are important primary producers in aquatic habitats, and they are probably the primary carbon source for petroleum products (crude oil, natural gas).

show abstract

Section: Cell Biology-chloroplasts and Their Pigments-mentioning

confidence: 99%

Biology and systematics of heterokont and haptophyte algae

Andersen

2004

American J of Botany

178

114

View full text Add to dashboard Cite

show abstract

“…Several authors have reported the presence of a flavin-like autofluorescent substance in the posterior smooth flagellum of phototactic flagellated cells of brown algae; the anterior flagellum or the stigma showed no autofluorescence (Miiller et al 1987;Kawai 1988). Such autofluorescence has also been observed in the smooth flagellum of some related chlorophyll-c-containing algae (Mfiller et al 1987;Coleman 1988;Kawai 1988;Kawai and Inouye 1989). Kawai et al (1990) studied the action spectrum of phototaxis in zoospores of Pseudochorda sp.…”

Section: Introductionmentioning

confidence: 99%

Phototactic responses in the gametes of the brown alga, Ectocarpus siliculosus

Kawai

Müller

Fölster

et al. 1990

Planta

Self Cite

View full text Add to dashboard Cite

The action spectrum of phototaxis was determined and the photoreceptive mechanism was studied in Ectocarpus gametes (Ectocarpales, Phaeophyceae) using a computerized cell-tracking system. The fine structures of the stigma and the flagellar swelling were analyzed, and the reflective function of the stigma was demonstrated for the first time. Under monochromatic light stimulation, Ectocarpus gametes show mainly positive phototaxis between 370 nm and 520 nm. The action spectrum has a minor peak near 380 nm, and two major peaks at 430 nm and 450 nm or 460 nm and a shoulder at 470 nm adjoining a remarkable depression near 440 nm. Under unilateral stroboscopic illumination with more than four pulses per second, the gametes show clear phototaxis. However, the response is disturbed at lower frequencies. Addition of methyl cellulose, which increases the viscosity of the medium and slows down gamete rotation, decreases the threshold frequency. These results indicate that rotation of the gamete plays an essential role in the photoreceptive mechanism. Under equal intensities of bilateral illumination at an angle of 90°, most of the gametes swim on the resultant between the two light beams. This response is disturbed when the angle of the two light beams is as large as 120°. Observations by transmission electron microscopy show that the flagellar swelling fits precisely into a concave depression of the chloroplast at the central region of the stigma. Electron-dense material is present in that sector of the flagellar swelling which faces away from the stigma. Epifluorescence microscopy without a barrier filter and epipolarization microscopy reveal that stigmata reflect blue light. A hypothesis is formulated which discusses the possibility that the reflected light is focused onto the flagellar swelling.

show abstract

“…In Polypodochrysis , the rhizoplast is associated with the non-flagellum-bearing basal body, and in some photosynthetic stramenopiles, such as Ochromonas , the rhizoplast is associated with the immature flagellum (Hibberd 1970;Bouck and Brown 1973;Andersen 1982). Also, the flagellum of Polypodochrysis did not contain a green autofluorescent material that is common in the mature flagellum of many photosynthetic stramenopiles (Kawai and Inouye 1989), including Phaeomonas (Honda and Inouye 2002). Furthermore, the typical R1 root in photosynthetic stramenopiles produces a number of cytoskeletal microtubules, but none of the microtubular roots of Polypodochrysis gave rise to secondary cytoskeletal microtubules.…”

Section: Discussionmentioning

confidence: 99%

Re-examination of the marine 'chrysophyte' Polypodochrysis teissieri (Pinguiophyceae)

Kawachi¹,

Nöel²,

Andersen³

2002

Phycological Res

View full text Add to dashboard Cite

A marine 'chrysophyte' species Polypodochrysis teissieri Magne having distinctive lorica was re-examined using both light and electron microscopy. Light microscopic observations were basically identical to Magne's descriptions (Magne 1975), except that the aplanospore in that paper was shown to be a distinctive uniflagellate zoospore. General ultrastructure of both chloroplast and mitochondria was typical of the photosynthetic stramenopiles (chromophytes). An embedded pyrenoid was found in the center of chloroplast and was penetrated by the chloroplast envelope. Two Golgi bodies were always located adjacent to the nucleus; they were arranged perpendicularly in vegetative cells, but had a parallel arrangement in zoospores. Thin sections of the lorica resembled siliceous structures such as diatom frustules, but energy dispersive X-ray analysis did not show any significant amount of silicon. Naked zoospores have a single emergent flagellum that lacked mastigonemes; a flagellar swelling and an eyespot were also absent. Zoospores showed gliding motion on the surface of substrate. Two different cytoplasmic extensions (pseudopods) were observed in the zoospore. One lingulate pseudopod originated from the base of the flagellum and was always associated with the flagellum, and the second pseudopod formed only when the cell changed direction. Investigations of the flagellar apparatus showed a single transitional plate in the transitional region of the emergent flagellum, a second basal body closely located to the flagellum-bearing basal body, three microtubular roots and a set of cytoskeletal microtubules, and a small rhizoplast that connected the non-flagellum-bearing basal body and the nucleus. Many features of the zoospore of Polypodochrysis show a similarity with that of Glossomastix chrysoplasta (Pinguiophyceae), suggesting that the single emergent flagellum of Polypodochrysis and Glossomastix is homologous. This single flagellum may correspond to the mature flagellum that is generally recognized as the short posterior flagellum in stramenopiles, and it represents a unique flagellar arrangement within stramenopiles. Based on the morphological features, in addition to the other data (18S rRNA and rbcL genes and biochemical features) published elsewhere, Polypodochrysis was removed from the class Chrysophyceae and transferred to a new class, the Pinguiophyceae.

show abstract

Flagellar autofluorescence in forty-four chlorophyll c-containing algae

Cited by 40 publications

References 11 publications

Biology and systematics of heterokont and haptophyte algae

Biology and systematics of heterokont and haptophyte algae

Phototactic responses in the gametes of the brown alga, Ectocarpus siliculosus

Re-examination of the marine 'chrysophyte' Polypodochrysis teissieri (Pinguiophyceae)

Contact Info

Product

Resources

About