Search results for "gastrulation"
showing 10 items of 27 documents
EFFECT OF THE IMPase INHIBITOR L690,330 ON SEA URCHIN DEVELOPMENT
1998
Abstract A variety of concentrations of the IMPase inhibitor L690,330 were added to sea urchin embryos. Immediate arrest of development was obtained for concentrations from 7.5 m m on. Concentrations lower than 3.5 m m permitted gastrulation but inhibited skeletogenesis and disturbed elongation along the animal–vegetal axis. The latter results are similar to those obtained by counteracting lithium effect with myoinositol, which are suggested to be due to partial relief of IMPase inhibition.
An Incremental Analysis of the Embryonic Development of the Tobacco Hornworm,Manduca sexta
1987
Summary A timetable of the embryonic development of Manduca sexta has been compiled to serve as a basis for physiological studies. Embryogenesis is complete within 117 hr at 24° C and was analyzed by examining specimens representing 20 stages, i.e. intervals of 5% of the total developmental time. Stage 0 denotes the newly deposited egg. Germ band formation, gastrulation, differentiation of tissues and organs, and blastokinesis are described in detail. By stage 1 (6 hr post-oviposition) the cellular blastoderm is evident and the presumptive serosal and embryonic cells are distinguishable. At stage 2 the germ band has separated from the blastoderm, and by stage 3 it has elongated enormously, …
Highly restricted expression at the ectoderm–endoderm boundary of PIHbox 9, a sea urchin homeobox gene related to the human HB9 gene
1998
Abstract Characterisation of a sea urchin (P. lividus) homeobox gene PIHbox 9 is reported. The homeodomain of PIHbox9 is 95% identical to the homeodomain of the human HB9 gene, indicating that the two genes are highly related. Temporal expression analysis during sea urchin embryogenesis showed an absence of transcripts at early cleavage stages. At late gastrula stage, transcripts were barely detectable and reached the highest abundance at prism/early pluteus stages. By whole mount in situ hybridisation we observed a highly restricted expression in a few cells of the ectoderm–endoderm boundary of embryos at the prism stage. At pluteus stages, expression of PIHbox 9 was confined around the an…
Astacins: proteases in development and tissue differentiation
2013
Capítulo en: Stöker, Walter; Brix, Klaudia (eds.). Proteases: structure and function. Wien: Springer, 2013
α5β1 integrin-mediated adhesion to fibronectin is required for axis elongation and somitogenesis in mice.
2011
The arginine-glycine-aspartate (RGD) motif in fibronectin (FN) represents the major binding site for α5β1 and αvβ3 integrins. Mice lacking a functional RGD motif in FN (FN(RGE/RGE)) or α5 integrin develop identical phenotypes characterized by embryonic lethality and a severely shortened posterior trunk with kinked neural tubes. Here we show that the FN(RGE/RGE) embryos arrest both segmentation and axis elongation. The arrest is evident at about E9.0, corresponding to a stage when gastrulation ceases and the tail bud-derived presomitic mesoderm (PSM) induces α5 integrin expression and assumes axis elongation. At this stage cells of the posterior part of the PSM in wild type embryos are tight…
WNT Signaling Perturbations Underlie the Genetic Heterogeneity of Robinow Syndrome
2018
International audience; Locus heterogeneity characterizes a variety of skeletal dysplasias often due to interacting or overlapping signaling pathways. Robinow syndrome is a skeletal disorder historically refractory to molecular diagnosis, potentially stemming from substantial genetic heterogeneity. All current known pathogenic variants reside in genes within the noncanonical Wnt signaling pathway including ROR2, WNT5A, and more recently, DVL1 and DVL3. However, ∼70% of autosomal-dominant Robinow syndrome cases remain molecularly unsolved. To investigate this missing heritability, we recruited 21 families with at least one family member clinically diagnosed with Robinow or Robinow-like pheno…
Identification and characterization of a constitutive HSP75 in sea urchin embryos.
1997
Abstract An antiserum against a hsp of the 70-kDa family was prepared, by means of a fusion protein, which was able to detect a constitutive 75-kDa hsc in the sea urchinP. lividus.This hsc was present both during oogenesis and at all developmental stages. A two-dimensional electrophoresis has revealed four isolectric forms of this 75-kDa hsc. The amino acid sequence of the fragment used to prepare the anti-hsp70 antibodies revealed a 43% identity with the corresponding part of sea urchin sperm receptor, and in mature eggs a brighter immunofluorescence was seen all around the cell cortex where the receptor for sea urchin sperm is localized. In oocytes the hsp75 was localized in the cytoplasm…
Ricerche sulla induzione del sistema nervoso nelle larve delle Ascidie
1959
Summary Phallusia mamillata embryos at the 8-, 16-, 32- and 61-cell stages have been deprived of determined vegetative anterior blastomeres (deriving from, the A4.1 cells), with the purpose to sec which influence is exerted by such blastomeres in the induction of the nervous system. The results have been the following. 1 — The nervous system is not yet determined at the 64-cell stage. 2 — A neurali induction can be exerted even by a few blastomeres of the 64-ccll stage, containing cither entodermic or chordal material. 3 — Such inducing blastomeres arc those which give rise to the archenteron roof of the gastrula.
Distribution of protease activity in the blastula and early gastrula ofDiscoglossus pictus
1957
E stata determinata l'attivita proteasica nelle differenti regioni della blastula e della gastrula diDiscoglossus pictus. Nella blastula non esiste una differenza di attivita fra meta animale e vegetativa, quando si prenda come riferimento l'azoto citoplasmatico. Nella giovane gastrula il territorio presuntivo della corda e del sistema nervoso mostra una attivita piu elevata della epidermide presuntiva.
Intraflagellar transport protein 172 is essential for primary cilia formation and plays a vital role in patterning the mammalian brain
2008
AbstractIFT172, also known as Selective Lim-domain Binding protein (SLB), is a component of the intraflagellar transport (IFT) complex. In order to evaluate the biological role of the Ift172 gene, we generated a loss-of-function mutation in the mouse. The resulting Slb mutant embryos die between E12.5 and 13.0, and exhibit severe cranio-facial malformations, failure to close the cranial neural tube, holoprosencephaly, heart edema and extensive hemorrhages. Cilia outgrowth in cells of the neuroepithelium is initiated but the axonemes are severely truncated and do not contain visible microtubules. Morphological and molecular analyses revealed a global brain-patterning defect along the dorsal–…