Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Morphogenesis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed2003

Signaling in morphogenesis: transport cues in morphogenesis.

Extracellular transport processes play critical roles in morphogenesis. While diffusive transport effects on morphogenesis are well illustrated in examples like blood capillary architecture and in cell morphogenetic responses to the local extracellular protein environment, the effects of fluid convection, although important in many developing and regenerating tissues, are not well understood. Convective forces are present whenever a hydrated tissue undergoes dynamic mechanical strain, and so convection could not only dominate the transport of large molecules like proteins, but might also serve as a mechanism for mechanosensing. The complex interdependence of mechanical forces, protein transport and extracellular morphogen gradients needs to be elucidated in a comprehensive way in order for the importance of transport on morphogenesis to be fully appreciated.

Biological Transport↗
PubMed1985

Morphology and morphogenesis of viruses of hemorrhagic fever with renal syndrome (HFRS). I. Some peculiar aspects of the morphogenesis of various strains of HFRS virus.

The morphology and morphogenesis of viruses of hemorrhagic fever with renal syndrome (HFRS) were studied by thin-section electron microscopy. Ten strains of HFRS virus isolated in China and one strain isolated in Korea were compared. The virions varied in size as well as in the shape and character of their inner components. Both intracellular and extracellular ribosome-like, electron-dense, virus-associated granules were seen. A viral antigen layer was often visualized on the surface of HFRS virus-infected cells, as confirmed by immune electron microscopy. Aberrant tailed particles and elongated rod-like particles were seen infrequently. The morphogenesis of HFRS viruses appears to be more complex than that of other members of the family Bunyaviridae. The prototype Hantaan virus shares a common morphology and morphogenesis with the other HFRS viruses studied.

Animals↗
PubMed1994

Further analysis of the effect of Ca2+ on morphogenesis of HVJ (Sendai virus) in LLC-MK2 cells: effects on phosphorylated M protein associated with viral morphogenesis.

Previously we have reported that Ca2+ concentration in culture medium affects the morphogenesis of HVJ from infected cells. We further investigated the effects of Ca2+ on HVJ morphogenesis in LLC-MK2 cells, focusing on M (matrix) protein which plays an important role in the assembly of viral components. On culture in standard medium (containing 1.8 mM Ca2+), most of the M protein accumulated on the apical surface in patches. On double immunofluorescent staining with anti-M protein monoclonal antibody and polyclonal antibody against HVJ glycoproteins, M protein and viral glycoproteins were observed in the same patches at the cell surface. By contrast, in low Ca2+ medium, M protein was evenly dispersed over the cell surface, especially in the regions of cell-cell contact, and was not seen in patches. Immunoblot analysis for M protein in the infected cells showed that the total amount of M protein was almost the same irrespective of Ca2+ concentration in the culture medium. But, there was a distinct difference in the forms of M protein found in the cells: most of the M protein in the cells cultured in standard medium was of the non-phosphorylated form, whereas the phosphorylated form of M protein was distinctly increased in the cells cultured in low Ca2+ medium. These results suggest that Ca(2+)-deficiency in the medium blocks dephosphorylation of phosphorylated M protein necessary for patch formation, resulting in disturbance of viral morphogenesis.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1993

Serotonin and morphogenesis. Transient expression of serotonin uptake and binding protein during craniofacial morphogenesis in the mouse.

This study describes the timecourse of expression of low-affinity serotonin uptake sites in the developing craniofacial region of the mouse embryo. Whole mouse embryos were incubated in the presence of various serotonergic compounds followed by immunocytochemical localization of serotonin (5-HT) and its binding protein. In the gestational day 9 embryo (3-5 somites), 5-HT uptake was observed in the myocardium of the heart, the visceral yolk sac and foregut. A specific and transient pattern of 5-HT uptake was observed in the hindbrain neuroepithelium from day 9.5-11, where it was localized in rhombomeres 2-5 in the day 9.5 embryo. By day 10, when rhombomeres were no longer evident, uptake was present in the dorso-lateral neuroepithelium surrounding the fourth ventricle (rhombic lip; cerebellar anlage). Uptake of 5-HT was initially observed in the surface epithelium of the craniofacial region at day 10 (20-25 somites) and was greatly increased at day 11. The invaginating lens, nasal placode epithelium and otocyst also took up 5-HT at day 11. During these stages a 45 kD serotonin-binding protein (SBP) was expressed in craniofacial mesenchyme, and became progressively restricted to regions subjacent to epithelial uptake sites. These staining patterns were shown to be specific for 5-HT and SBP by their absence in embryos stained using preabsorbed antisera. The timecourse of these patterns are correlated with critical events in craniofacial morphogenesis including (1) onset of inductive epithelial-mesenchymal interactions, (2) invagination and fusion of placodal structures, (3) presence of rhombomeres, and (4) regions of low proliferative activity.

Animals↗
PubMed1984

Intracellular morphogenesis of bacteriophage T4. II. Head morphogenesis.

The relative phage yields of cells of Escherichia coli infected with both wild-type and amber mutant phages deficient in head morphogenesis were determined. The decrease in burst size as a function of the ratio of mutant:wild-type-infecting phage was linear and proportional for mutants in genes 20, 22, and 23, while for mutants in genes 21, 31, and 24 the results suggest an excess of intracellular gene product. The initiation of assembly of phage particles was not delayed at reduced gene product levels; only a reduction in the rate of phage assembly was observed. The effects on burst size of pairs of mutations in genes 20 and 23, 22 and 23, and 22 and 24, in both cis and trans arrangements, were identical. Experiments using the mutant E920g in gene 23 show that varying the kind and intracellular amounts of the major capsid protein (gp23) with respect to the major core or scaffold protein (gp22) had a profound effect on the length of the T4 head. Head length determination must therefore depend on the proper intracellular balance between these two proteins.

Escherichia coli↗
PubMed2003

Ovary development and polydnavirus morphogenesis in the parasitic wasp Chelonus inanitus. I. Ovary morphogenesis, amplification of viral DNA and ecdysteroid titres.

Polydnaviruses are unique symbiotic viruses that are replicated in the calyx cells of the ovary of some parasitic wasps. They have a segmented genome of circular double-stranded DNA and are injected along with the wasp's egg into the host, where they are essential for successful parasitism. Polydnaviruses replicate from integrated proviral DNA, and after excision of viral segments, flanking DNA is rejoined. Little is known about ovarian morphogenesis, the mode of amplification of the viral DNA and the involvement of ecdysteroids. Here we have analysed these parameters in the course of pupal-adult development in the braconid wasp Chelonus inanitus. Immediately after pupation, ovarian cells proliferated and calyx cells began to differentiate; at this stage ecdysteroids, in particular 20-hydroxyecdysone, were highest. Thereafter, calyx cells began to increase in size and DNA content and eventually became gigantic. Amplification of non-viral DNA (actin) and viral DNA in its integrated and excised form and of corresponding rejoined flanking regions was measured by quantitative real-time PCR. In the early phase of calyx cell differentiation, copy numbers of actin and integrated viral DNA increased to a similar extent. This, along with the increase in nuclear volume and DNA content in the absence of extensive cell proliferation, suggested polyploidization of the early stage calyx cells. In the following phase, integrated viral DNA was selectively and intensively amplified and eventually excised and circularized. As copy numbers of excised circular viral DNA and rejoined flanking DNA reached similarly high levels, excised viral DNA appeared not to replicate. After adult eclosion, amplification of viral DNA declined.

Animals↗
PubMed1997

[Human cervico-facial morphogenesis. Evaluation of acquired data and current outlook. (Part 1: facial morphogenesis)].

The embryonic development of the face has been studied in many reviews, this work purposes only to clear up some points which remain obscure concerning cervico-facial morphogenesis. In the first part of this study only the facial development, properly speaking, is considered, although it cannot be separate of cervical development to which a second study will be reserved. In the present study we recall the particular aspects of the neurulation in the cephalic area, then the establishment of the facial processes. Then we approach among other things the way to consider the maxillary process with regard to the other facial processes. After is considered constitution and natured of the prechordal plate which has been diversely explained. Finally, the modelling of the face is evocated, in which the dissociation between the olfactive and buccal spheres is pointed out, with the disparition of the muzzle, as it is established in the haplorhinae, a class of primates in which the human being is involved. This phenomenon raises different questions, in particular about the relation of this disposition with the nasoseptal center, the medial part of the nasodorsal center.

Animals↗
PubMed1988

Genes expressed during imaginal discs morphogenesis: IMP-L2, a gene expressed during imaginal disc and imaginal histoblast morphogenesis.

We describe our analysis of IMP-L2, one of a set of six ecdysone-inducible genes in imaginal discs of Drosophila whose transcripts are associated with membrane-bound polysomes. The spatial and temporal patterns of expression of the IMP-L2 transcript were analyzed. This transcript is first expressed in imaginal discs in areas that are precursors of head and thoracic epithelium, particularly the peripodial epithelia. It is later expressed in the imaginal histoblasts, precursors of the adult abdomen. The appearance of IMP-L2 transcript in each of these tissues precedes the spreading and fusion of the separate imaginal anlagen to form the continuous adult epidermis.

Animals↗
PubMed2003

Genetic dissection of Pitx2 in craniofacial development uncovers new functions in branchial arch morphogenesis, late aspects of tooth morphogenesis and cell migration.

Pitx2, a paired-related homeobox gene that encodes multiple isoforms, is the gene mutated in the haploinsufficient Rieger Syndrome type 1 that includes dental, ocular and abdominal wall anomalies as cardinal features. Previous analysis of the craniofacial phenotype of Pitx2-null mice revealed that Pitx2 was both a positive regulator of Fgf8 and a repressor of Bmp4-signaling, suggesting that Pitx2 may function as a coordinator of craniofacial signaling pathways. We show that Pitx2 isoforms have interchangeable functions in branchial arches and that Pitx2 target pathways respond to small changes in total Pitx2 dose. Analysis of Pitx2 allelic combinations that encode varying levels of Pitx2 showed that repression of Bmp signaling requires high Pitx2 while maintenance of Fgf8 signaling requires only low Pitx2. Fate-mapping studies with a Pitx2 cre recombinase knock in allele revealed that Pitx2 daughter cells are migratory and move aberrantly in the craniofacial region of Pitx2 mutant embryos. Our data reveal that Pitx2 function depends on total Pitx2 dose and rule out the possibility that the differential sensitivity of target pathways was a consequence of isoform target specificity. Moreover, our results uncover a new function of Pitx2 in regulation of cell motility in craniofacial development.

Abnormalities, Multiple↗
PubMed1975

Morphogenesis in Micrasterias. II. Patterns of morphogenesis.

The final form of the polar lobe and lateral wings of developing semicells of M. rotata results from combined action of three growth processes: tip growth, branching and lobe broadening. Tip growth unaccompanied by branching or broadening occurs during normal development in M. radiata, but is observed only under abnormal conditions (e.g. raised temperature) in M. rotata. When branching and broadening do occur, they occur together and for this reason may be causally related. Autoradiograms demonstrate that specific patterns of cell wall incorporation can be associated with each of the three processes in M. rotata. Autoradiographic patterns found in the polar lobe differ from those found in wings. The growing polar lobe also responds to laser irradiation differently from the wings; lasings occasionally cause duplication of the polar lobe.

Autoradiography↗