A Novel Basal Apparatus Protein of 90 kD (BAp90) from the Flagellate Green Alga Spermatozopsis similis is a Component of the Proximal Plates and Identifies the d-(dexter)Surface of the Basal Body

Protist ◽  
1998 ◽  
Vol 149 (2) ◽  
pp. 173-184 ◽  
Author(s):  
Stefan Geimer ◽  
Karl-Ferdinand Lechtreck ◽  
Michael Melkonian
Keyword(s):  
Green Alga ◽  
Basal Body ◽  
Basal Apparatus

Ultrastructure of the basal body apparatus in epidermal cells of a sponge larva (Aplysilla SP: Demospongiae)

1992 ◽  
Vol 50 (1) ◽  
pp. 928-929
Author(s):  
R.L. Pinto ◽  
R.M. Woollacott
Keyword(s):  
Sodium Bicarbonate ◽  
Epoxy Resin ◽  
Basal Body ◽  
Phosphate Buffer ◽  
Similar Data ◽  
Basal Apparatus ◽  
Striated Rootlet ◽  
The Common ◽  
Basal Foot ◽  
Sexually Mature

The basal body and its associated rootlet are the organelles responsible for anchoring the flagellum or cilium in the cytoplasm. Structurally, the common denominators of the basal apparatus are the basal body, a basal foot from which microtubules or microfilaments emanate, and a striated rootlet. A study of the basal apparatus from cells of the epidermis of a sponge larva was initiated to provide a comparison with similar data on adult sponges.Sexually mature colonies of Aplysillasp were collected from Keehi Lagoon Marina, Honolulu, Hawaii. Larvae were fixed in 2.5% glutaraldehyde and 0.14 M NaCl in 0.2 M Millonig’s phosphate buffer (pH 7.4). Specimens were postfixed in 1% OsO4 in 1.25% sodium bicarbonate (pH 7.2) and embedded in epoxy resin. The larva ofAplysilla sp was previously described (as Dendrilla cactus) based on live observations and SEM by Woollacott and Hadfield.

Ultrastructure of Pseudocilia in Tetraspora Lubrica (Roth) AG

1971 ◽  
Vol 9 (3) ◽  
pp. 569-579
Author(s):  
CAROLE A. LEMBI ◽  
PATRICIA L. WALNE
Keyword(s):  
Green Alga ◽  
Basal Body ◽  
Progressive Decrease ◽  
Central Pair ◽  
Unicellular Green Alga ◽  
Cytoplasmic Microtubules

The flagella-like, but immobile, pseudocilia of the unicellular green alga, Tetraspora lubrica, have been characterized ultrastructurally and compared with the true flagella of the motile green alga, Chlamydomonas. The basal body and transitional regions of the 2 organelle systems are basically similar. Most of the marked differences occur in the pseudocilium proper, and a few important dissimilarities are found in the cytoplasmic portions of the apparatus. The major differences are: (1) 4 instead of 2 proximal striated fibres in the pseudociliary apparatus (2) a proximal-to-distal progressive decrease in subfibre number from 9 doublet fibres to a solitary fibre in the pseudocilium proper; (3) loss of interconnexions among the subfibres in the pseudocilium proper and a concomitant disorientation of those subfibres; (4) absence of major arms (dynein) on the A subfibre of peripheral doublets; (5) absence of the central pair of fibres. These and other differences are discussed with regard to their possible roles in loss of motility.. Additional ultrastructural details - interconnexions between cytoplasmic microtubules and basal body subfibres of pseudocilia and flagella - are described and discussed in terms of their possible roles in the regulation of flagellar movement in motile organisms.

Ultrastructure of the flagellar roots in Chlamydomonas gametes

1984 ◽  
Vol 67 (1) ◽  
pp. 133-143
Author(s):  
R.L. Weiss
Keyword(s):  
Basal Body ◽  
Direct Contact ◽  
The Other ◽  
Basal Bodies ◽  
Flagellar Roots ◽  
Mating Structure ◽  
Membrane Extension ◽  
Microtubular Root ◽  
Basal Apparatus ◽  
Microtubular System

The cytoskeleton of Chlamydomonas reinhardtii gametes has been studied by electron microscopy. The microtubular system, consisting of four flagellar roots inserted into the basal apparatus, is shown to include two daughter basal bodies and two striated fibres, newly described in this report. One new fibre associates with the 3-over-1 root and is similar to its counterpart, the striated fibre of the 2-member root. These similar root fibres connect each daughter basal body to the V-shaped microtubular root pair. The other new striated fibre joins the daughter basal body to both flagellar roots and is similar to the proximal striated fibre. In mt+ gametes, the conventional root microtubules make direct contact with the doublet zone of the non-activated mating structure. During activation, doublet zone microfilaments associate with the daughter basal body and the finely striated fibre of the 3-over-1 root. These observations suggest that the cytoskeleton acts as a scaffolding for membrane extension by the mt+ mating structure microfilaments.

F-actin localization during trochoblast differentiation embryos

Development ◽  
1991 ◽  
Vol 112 (3) ◽  
pp. 833-845
Author(s):  
F. Serras ◽  
J.E. Speksnijder
Keyword(s):  
Basal Body ◽  
Cytochalasin B ◽  
Dorsal Side ◽  
Dorsoventral Axis ◽  
Patella Vulgata ◽  
Apical Cytoplasm ◽  
Locomotory Behavior ◽  
Basal Apparatus ◽  
Actin Localization ◽  
Swimming Capacity

We have studied the development of the ciliated, Patella vulgata trochophore larvae. This organ, the different clones of trochoblasts. In each of these filamentous (F-) actin is formed at the time that which we visualized with TRITC-phalloidin, is cilia that crosses each trochoblast. Isolated quartets of animal micromeres (from which the form rows of cilia and F-actin bands at the proper embryos, the trochoblasts shift their position form a ring of differentiated prototroch cells with a encircling the entire larva. At the dorsal side, a and thus a double band of F-actin is present. In double F-actin band are found in trochophores in which dorsoventral axis is inhibited experimentally. shows that the F-actin band extends from the apical cytoplasm of the prototroch cells. At the rootlet connected to the basal body of each cilium can the cytoplasm toward the nucleus, and a band of actin- interconnect neighboring basal apparatus. Treatment of cytochalasin B disrupts the organization of the F- TRITC-phalloidin, affects the angle of the effective reduces their swimming capacity. This suggests that for the normal locomotory behavior of the Patella

scholarly journals Asymmetric properties of the Chlamydomonas reinhardtii cytoskeleton direct rhodopsin photoreceptor localization

2011 ◽  
Vol 193 (4) ◽  
pp. 741-753 ◽  
Author(s):  
Telsa M. Mittelmeier ◽  
Joseph S. Boyd ◽  
Mary Rose Lamb ◽  
Carol L. Dieckmann
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Green Alga ◽  
Basal Body ◽  
Cytoskeletal Protein ◽  
Wild Type ◽  
Unicellular Green Alga ◽  
Protein Mutations ◽  
The Relationship ◽  
Mutant Cells ◽  
In Cells

The eyespot of the unicellular green alga Chlamydomonas reinhardtii is a photoreceptive organelle required for phototaxis. Relative to the anterior flagella, the eyespot is asymmetrically positioned adjacent to the daughter four-membered rootlet (D4), a unique bundle of acetylated microtubules extending from the daughter basal body toward the posterior of the cell. Here, we detail the relationship between the rhodopsin eyespot photoreceptor Channelrhodopsin 1 (ChR1) and acetylated microtubules. In wild-type cells, ChR1 was observed in an equatorial patch adjacent to D4 near the end of the acetylated microtubules and along the D4 rootlet. In cells with cytoskeletal protein mutations, supernumerary ChR1 patches remained adjacent to acetylated microtubules. In mlt1 (multieyed) mutant cells, supernumerary photoreceptor patches were not restricted to the D4 rootlet, and more anterior eyespots correlated with shorter acetylated microtubule rootlets. The data suggest a model in which photoreceptor localization is dependent on microtubule-based trafficking selective for the D4 rootlet, which is perturbed in mlt1 mutant cells.

scholarly journals Centrin Scaffold in Chlamydomonas reinhardtii Revealed by Immunoelectron Microscopy

2005 ◽  
Vol 4 (7) ◽  
pp. 1253-1263 ◽  
Author(s):  
Stefan Geimer ◽  
Michael Melkonian
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Immunoelectron Microscopy ◽  
Basal Body ◽  
Flagellar Apparatus ◽  
Single Copy ◽  
Asymmetric Structure ◽  
Transitional Region ◽  
Ef Hand ◽  
Basal Apparatus ◽  
Postembedding Immunoelectron Microscopy

ABSTRACT In the flagellate green alga Chlamydomonas reinhardtii the Ca2+-binding EF-hand protein centrin is encoded by a single-copy gene. Previous studies have localized the protein to four distinct structures in the flagellar apparatus: the nucleus-basal body connector, the distal connecting fiber, the flagellar transitional region, and the axoneme. To explain the disjunctive distribution of centrin, the interaction of centrin with as yet unknown specific centrin-binding proteins has been implied. Here, we demonstrate using serial section postembedding immunoelectron microscopy of isolated cytoskeletons that centrin is located in additional structures (transitional fibers and basal body lumen) and that the centrin-containing structures of the basal apparatus are likely part of a continuous filamentous scaffold that extends from the nucleus to the flagellar bases. In addition, we show that centrin is located in the distal lumen of the basal body in a rotationally asymmetric structure, the V-shaped filament system. This novel centrin-containing structure has also been detected near the distal end of the probasal bodies. Taken together, these results suggest a role for a rotationally asymmetric centrin “seed” in the growth and development of the centrin scaffold following replication of the basal apparatus.

Effect of Iron Limitation on the Ultrastructure of Agmenellum Quadruplicatum

1981 ◽  
Vol 39 ◽  
pp. 410-411
Author(s):  
L. P. Hardie ◽  
D. L. Balkwill ◽  
S. E. Stevens
Keyword(s):  
Growth Medium ◽  
Green Alga ◽  
Natural Habitat ◽  
Iron Limitation ◽  
Natural Environments ◽  
Blue Green Alga ◽  
Marine Cyanobacterium ◽  
Natural Systems ◽  
Thin Sectioning ◽  
Agmenellum Quadruplicatum

Agmenellum quadruplicatum is a unicellular, non-nitrogen-fixing, marine cyanobacterium (blue-green alga). The ultrastructure of this organism, when grown in the laboratory with all necessary nutrients, has been characterized thoroughly. In contrast, little is known of its ultrastructure in the specific nutrient-limiting conditions typical of its natural habitat. Iron is one of the nutrients likely to limit this organism in such natural environments. It is also of great importance metabolically, being required for both photosynthesis and assimilation of nitrate. The purpose of this study was to assess the effects (if any) of iron limitation on the ultrastructure of A. quadruplicatum. It was part of a broader endeavor to elucidate the ultrastructure of cyanobacteria in natural systemsActively growing cells were placed in a growth medium containing 1% of its usual iron. The cultures were then sampled periodically for 10 days and prepared for thin sectioning TEM to assess the effects of iron limitation.

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