Reproduction of a hexactinellid sponge: first description of gastrulation by cellular delamination in the Porifera

Boury-Esnault, Nicole; Efremova, S. M.; Bézac, Chantal; Vacelet, Jean

doi:10.1080/07924259.1999.9652385

Cited by 79 publications

(50 citation statements)

References 25 publications

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“…Furthermore, the small size of embryos and larvae of hexactinellids has meant that light microscope observations of the early stages are difficult to interpret. The largest larvae found in numerous collections of Farrea sollasii by Okada (1928) were 250 m long and 100 -200 m wide; the largest larvae of Oopsacas minuta are 150 -180 m long (Boury-Esnault et al, 1999;and present study).…”

Section: Differentiation Of Scleroblastsmentioning

confidence: 90%

Comparative study of spiculogenesis in demosponge and hexactinellid larvae

Leys

2003

Microscopy Res & Technique

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Spicule deposition was studied by electron microscopy in fixed embryos and larvae of the haplosclerid sponge Reniera sp. and the hexactinellid Oopsacas minuta. Spicules form in centrally located vacuoles within cells and within syncytia, as in the adult sponges. In Reniera, scleroblasts differentiate from micromeres prior to gastrulation. At gastrulation the scleroblasts migrate to the periphery of the embryo and commence spicule deposition around a hexagonal axial filament. Sclerocytes have numerous pseudopodia and migrate to the posterior pole where they become aligned along the antero-posterior axis in the free-swimming larva. Reniera larvae possess some 40-50 oxeas, each 70-75 microm long and 1 microm wide. Mature Oopsacas larvae have up to 14 stauractin spicules, which are produced on a rectangular axial filament in tissues that lie under the smooth epithelium at the posterior pole of the larva. Young sclerocytes have many pseudopodia. The 4-rayed spicules elongate along both the antero-posterior and medial axes, until the longitudinal rays become anchored in a lipid-filled cytoplasm at the anterior of the larva and the lateral rays intersect around the midline. The length of the transverse rays of the stauractins in free-swimming larvae are 27-45 microm each, while the length of the two longitudinal rays is 40-80 microm. Although spicule deposition begins in cells with a similar morphology in both cellular and syncytial sponges, the elaboration and organization of the spicules differ markedly in cellular and syncytial sponges and appear to be an outcome of the very distinct cellular differentiation and larval morphogenesis that occur in each of these groups.

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Section: Differentiation Of Scleroblastsmentioning

confidence: 90%

Comparative study of spiculogenesis in demosponge and hexactinellid larvae

Leys

2003

Microscopy Res & Technique

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“…MCCs are absent in arthropods and nematodes (Giribet and Ribera 1998). Outside bilaterians, MCCs are found in ctenophores (Tamm and Tamm 1988) and in sponges; although, in the latter case, each BB is associated to an accessory BB (i.e., like in a centrosome), suggesting that distinct mechanisms are used for BB assembly in these cells (Boury-Esnault et al 1999). It is worth mentioning that MCCs are also found outside of animals in phyla as diverse as plants, ciliates, or amoebozoa (Tamm et al 1975;Mikrjukov and Mylnikov 1998;Hodges et al 2010).…”

Section: Multiciliated Epithelia Across Animalsmentioning

confidence: 99%

Multiciliated Cells in Animals

Meunier¹,

Azimzadeh²

2016

Cold Spring Harb Perspect Biol

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Many animal cells assemble single cilia involved in motile and/or sensory functions. In contrast, multiciliated cells (MCCs) assemble up to 300 motile cilia that beat in a coordinate fashion to generate a directional fluid flow. In the human airways, the brain, and the oviduct, MCCs allow mucus clearance, cerebrospinal fluid circulation, and egg transportation, respectively. Impairment of MCC function leads to chronic respiratory infections and increased risks of hydrocephalus and female infertility. MCC differentiation during development or repair involves the activation of a regulatory cascade triggered by the inhibition of Notch activity in MCC progenitors. The downstream events include the simultaneous assembly of a large number of basal bodies (BBs)-from which cilia are nucleated-in the cytoplasm of the differentiating MCCs, their migration and docking at the plasma membrane associated to an important remodeling of the actin cytoskeleton, and the assembly and polarization of motile cilia. The direction of ciliary beating is coordinated both within cells and at the tissue level by a combination of planar polarity cues affecting BB position and hydrodynamic forces that are both generated and sensed by the cilia. Herein, we review the mechanisms controlling the specification and differentiation of MCCs and BB assembly and organization at the apical surface, as well as ciliary assembly and coordination in MCCs.

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“…This is true for all the most basal lineages (i.e. sponges, ctenophores and cnidarians), suggesting that it is an ancestral mechanism [111,112,[125][126][127]. Besides Metazoa, a role for centrosomes and astral microtubules in controlling spindle orientation has been well demonstrated in budding yeast.…”

Section: Evolution Of Centrosome Function In Animalsmentioning

confidence: 99%

“…Like subdistal appendages, the basal foot anchors microtubules required for controlling the position of the centrioles within the plane of the membrane, which in turn determines ciliary beating orientation [105,107,108]. Unlike subdistal appendages, basal feet are observed in all basal metazoan lineages, suggesting that it is an ancestral trait associated with planar ciliary beating [109][110][111][112]. Although subdistal appendages are clearly absent from Drosophila and C. elegans, it is nevertheless possible that less…”

Section: (Iv) Evolution Of Centrosome Structure In Animalsmentioning

confidence: 99%

Exploring the evolutionary history of centrosomes

Azimzadeh

2014

Phil. Trans. R. Soc. B

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The centrosome is the main organizer of the microtubule cytoskeleton in animals, higher fungi and several other eukaryotic lineages. Centrosomes are usually located at the centre of cell in tight association with the nuclear envelope and duplicate at each cell cycle. Despite a great structural diversity between the different types of centrosomes, they are functionally equivalent and share at least some of their molecular components. In this paper, we explore the evolutionary origin of the different centrosomes, in an attempt to understand whether they are derived from an ancestral centrosome or evolved independently from the motile apparatus of distinct flagellated ancestors. We then discuss the evolution of centrosome structure and function within the animal lineage.

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Reproduction of a hexactinellid sponge: first description of gastrulation by cellular delamination in the Porifera

Cited by 79 publications

References 25 publications

Comparative study of spiculogenesis in demosponge and hexactinellid larvae

Comparative study of spiculogenesis in demosponge and hexactinellid larvae

Multiciliated Cells in Animals

Exploring the evolutionary history of centrosomes

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