Egg and Embryo Ultrastructure

Schmekel, L.

doi:10.1007/978-3-642-65964-5_11

Cited by 10 publications

(4 citation statements)

References 103 publications

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“…There have been many immunofluorescence and transmission electron microscopic studies of MTs prior to and during initiation of furrowing (for example, Gross et al, 1958;Tilney and Marsland, 1969;Harris, 1970;Asnes and Schroeder, 1979;Harris et al, 1980b;Schroeder and Battaglia, 1985), but few have investigated MT structure during the period when furrow MTs would be present (Longo, 1972;Schmekel, 1975). Furrow MTs have not been visible in most of the immunofluorescence images published, possibly due to quality of fixation, but more likely due to the dimness of furrow MTs relative to the brightly stained mitotic apparatus (Harris et al, 1980a;Schroeder, 1987).…”

Section: -D Analysis Of Furrow Mts 271mentioning

confidence: 99%

Three-dimensional Analysis of Laser Scanning Confocal Microscope Sections Reveals an Array of Microtubules in the Cleavage Furrow of Sea Urchin Eggs

Larkin¹,

Danilchik²

2001

Microsc Microanal

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Our recent observation that microtubules (MTs) are required for completion of division (abscission) led us to analyze MT organization during cytokinesis. Although many studies of MTs in sea urchin eggs have been done, computer-aided analysis of optical sections described herein reveals a new MT assemblage, which we call furrow MTs. This assemblage comprises bundles of MTs that lie in the cleavage furrow. Furrow MTs become apparent when the furrow has progressed approximately one-third of the way through the egg and persist to abscission. Furrow MTs are 8–24-µm long and arc across the base of the cleavage furrow. Acetylated tubulin is localized primarily in the furrow suggesting a distinct MT population. Three-dimensional analysis of optical sections suggests that furrow MTs are spatially distinct from midbody and astral MTs.

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Section: -D Analysis Of Furrow Mts 271mentioning

confidence: 99%

Three-dimensional Analysis of Laser Scanning Confocal Microscope Sections Reveals an Array of Microtubules in the Cleavage Furrow of Sea Urchin Eggs

Larkin¹,

Danilchik²

2001

Microsc Microanal

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“…It usually has the same refractive index as water and cannot be seen without staining. Staining reveals the micropyle in the jelly like membrane, in which polar bodies can then be identified (Boveri, 1901;Lindahl, 1932;Harvey, 1956;Piatigorsky, 1975;Schmekel, 1975). In the sand dollars Echinarachnius brevis (Onada, 1938), E. parma, and Scaphechinus mirabilis, the jellylike membrane contains pigment cells (Chia and Atwood, 1982), has a fine fibrillar structure, and is clearly visible under a microscope.…”

Section: Ecologymentioning

confidence: 99%

Larvae of marine bivalves and echinoderms

Kasʹi︠a︡nov¹,

Pawson²

1998

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“…They are found in many diverse species of marine and aquatic invertebrates such as adult sponges (Fjerdingstad, 19611, adult and larval cnidarians (Goreau and Philpot, 1956;Bilbaut and Pavons de CeCatty, 1971;Lyons, 1973a,b;Clark and Dewel, 1974;Chia and Crawford, 1977;Goldberg and Taylor, 1989a,b), ascidians (Milanisi, 1971), enteropneusts (Norrevang, 19641, and molluscs (Stauffacher, 1898;Schneider, 1902). They have also been reported in the epithelial cells of larvae of echinoids and asteroids (Wolpert and Mercer, 1963;Lyons et al, 1964;Norrevang and Wingstrand, 1970;Immers and Lundgren 1972;Lundgren, 1973;Schemkel, 1975;Walker, 1979;Anstrom, 1992) review see Walker, 1979) (Martinez et. al., 1991).…”

mentioning

confidence: 90%

The microvilli and hyaline layer of embryonic asteroid epithelial collar cells: A sensory structure to determine the position of locomotory cilia?

Crawford

Campbell

1993

Anat. Rec.

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Early stage embryos of the starfish Pisaster ochraceus exhibit one cilium per cell which is primarily involved in locomotion. SEM observations have demonstrated two types of microvilli "stage horn"-like and "finger-like" microvilli (CMs), both of which probably serve to anchor and support the hyaline layer (HL). The CMs arise from the cellular membrane a short distance from the base of the ciliary shaft and form a circle around the base of each cilium. This arrangement is found in embryos and larvae as well as in adult tissues of many other marine organisms. TEM observations of material prepared by freeze substitution has demonstrated that the HL unites the circle of CMs and forms two collars. The outer ECM collar is single and attached directly to the CMs, while the inner collar consists of multiple rings of ECM located between the cilium and the CMs. The inner collar elements are not attached to the cilium but are attached to the inner aspects of the CMs by a complex arrangement consisting of a loop of ECM and two short ECM fibers. The arrangement of the ECM of the collars could provide an excellent way to transmit the movements of the cilium to the surrounding microvilli. Although the bases of the CMs always encircle the ciliary shaft, the shafts of the CMs are seen in different positions. This suggests that the CM/ECM collar may be able to change position relative to the cilium. Confocal laser scanning microscopy demonstrates that the CMs contain phalloidin positive material which extends into a phalloidin positive region located in the apex of the cells. The CMs and apical web contain microfilaments which are probably actin and could be involved in movement of the CMs. A movable circle of CMs with their associated ECM could represent a mechanism to sense the position of the cilium and/or to define the direction and extent of the stroke.

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Egg and Embryo Ultrastructure

Cited by 10 publications

References 103 publications

Three-dimensional Analysis of Laser Scanning Confocal Microscope Sections Reveals an Array of Microtubules in the Cleavage Furrow of Sea Urchin Eggs

Three-dimensional Analysis of Laser Scanning Confocal Microscope Sections Reveals an Array of Microtubules in the Cleavage Furrow of Sea Urchin Eggs

Larvae of marine bivalves and echinoderms

The microvilli and hyaline layer of embryonic asteroid epithelial collar cells: A sensory structure to determine the position of locomotory cilia?

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