Search results for "Gastrula"
showing 10 items of 42 documents
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.
Regulation of the sea urchin early H2A histone gene expression depends on the modulator element and on sequences located near the 3' end
1999
Abstract Transcription of the sea urchin early histone genes occurs transiently during early cleavage, reaching the maximum at the morula stage and declining to an undetectable level at the gastrula stage. To identify the regulatory elements responsible for the timing and the levels of transcription of the H2A gene, we used promoter binding studies in nuclear extracts and microinjection of a CAT transgene driven by the early H2A promoter. We found that morula and gastrula nuclear proteins produced indistinguishable DNase I footprint patterns on the H2A promoter. Two sites of interactions, centred on the modulator/enhancer and on the CCAAT box respectively, were detected. Deletion of the mod…
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–…
Sea Urchin Mitochondrial Matrix Contains a 56-kDa Chaperonine-like Protein
1997
Abstract Paracentrotus lividus mitochondrial matrix contains a constitutive hsp of 56-KDa which cross reacts with a serum anti-hsp-60 chaperonine from yeast mitochondria. The localization of hsps preexisting or newly synthesized in different subcellular fractions of gastrula embryos is also analyzed by two-dimensional electrophoresis.
Synthesis of heat-shock proteins in developing sea urchins.
1981
Heating sea urchin embryos at 31°C greatly reduces the synthesis of the bulk proteins, whereas it highly stimulates the synthesis of some new proteins, the main ones being two closely migrating proteins of about 70,000 daltons. The production of heat-shock proteins is obtained only if the embryos are heated after hatching. Stages which produce heat-shock proteins survive heating, whereas earlier stages, not producing heat-shock proteins, do not survive. Heat-shock proteins are not produced in the presence of actinomycin D.
Nickel, lead, and cadmium induce differential cellular responses in sea urchin embryos by activating the synthesis of different HSP70s.
2004
Treatment with heavy metals, such as nickel, lead or cadmium, elicits different cellular stress responses according to the metal used and the length of treatment. In Paracentrotus lividus embryos the inducible forms of HSP70 (HSP70/72) are different in molecular mass from the constitutively expressed HSP75, and they can be used as markers of cellular stress. Even a short treatment with each metal induces the synthesis of HSP70/72 which remain stable for at least 20 h and differ little in their isoelectric points. Continuous treatment from fertilization with nickel or lead produces late irregular pluteus embryos, with peak HSP70/72 synthesis at blastula followed by the arrest of synthesis by…
Primary culture of single ectodermal precursors of Drosophila reveals a dorsoventral prepattern of intrinsic neurogenic and epidermogenic capabilitie…
1992
ABSTRACT We have analyzed the development in vitro of individual precursor cells from the presumptive truncal segmental ectoderm of the Drosophila embryo to study the intrinsic component in the determination of cell fate. For each cultured cell, the original position within as well as the developmental stage of the donor embryo were known. Cells removed from the ventral neurogenic region develop neural clones. Cells from the dorsal ectoderm and from the dorsalmost part of the ventral neurogenic ectoderm develop epidermal clones. These two classes of clones differ with respect to their division pattern, adhesiveness, cell morphologies and the expression of cell-specific markers. Mixed neural…
Fate-mapping in the procephalic region of the embryonic Drosopbila head
1994
Using intracellular horseradish peroxidase injection we traced the developmental fate of early gastrula cells of the procephalic region in the stage 16/17 embryo. Morphogenetic movements in the developing brain are described in three dimensions. The results are related to head segmentation, and an early gastrula fate map of pregnathal head segments is proposed.
Sea urchin deciliation induces thermoresistance and activates the p38 mitogen-activated protein kinase pathway.
2003
In this study, we demonstrate by a variety of approaches (ie, morphological analysis, Western blots, immunolocalization, and the use of specific antibodies) that hyperosmotic deciliation stress of sea urchin embryos induces a thermotolerant response. Deciliation is also able to activate a phosphorylation signaling cascade the effector of which might be the p38 stress-activated protein kinase because we found that the administration of the p38 inhibitor SB203580 to sea urchin deciliated gastrula embryos makes the hyperosmotic deciliation stress lethal.
Territorial localization of heat shock mRNA production in sea urchin gastrulae.
1985
In situ hybridization experiments with a labeled DNA probe indicate that the ability to respond to heat shock with the production of the mRNA for the 70 kd heat shock protein is segregated into the ectodermal cells already at the gastrula stage or earlier during the embryonic development of Paracentrotus lividus.