Abstract:
:Ascidian embryos are useful for examining how events that occur during fertilization and cleavage affect gastrulation because they gastrulate early in development, during the seventh cleavage. In ascidians, both dorsal-ventral and anterior-posterior axes are determined before first cleavage. The dorsal-ventral axis is fixed along the animal-vegetal axis of the fertilized egg following the first phase of ooplasmic segregation, perhaps due to determinants moved to the vegetal pole in concert with the myoplasm and plasma membrane components. The first ooplasmic movements appear to be driven by the actin network in the cortical myoplasm. The anterior-posterior axis becomes apparent after the second phase of ooplasmic segregation, when the cortical myoplasm becomes detached from the egg membrane, and moves to the posterior pole of the embryo. This movement is dependent on microtubules and has been attributed to the formation and movement of the sperm aster. A major component of the cortical myoplasm, p58, is co-localized along the microtubules emanating from the sperm aster. Gastrulation begins during the seventh cleavage with the invagination of the large endodermal cells at the vegetal pole of the embryo. The neural plate appears as a thickening of the epidermis on the dorsal side of the larva during the ninth cleavage; then the neural folds are formed, join, and close, elaborating the neural tube. Following neurulation, the tail is elongated as the neural tube and notochord cells intercalate at the midline of the embryo. Investigations using anural (tailless) ascidian larvae suggest that some of the processes underlying elongation can be restored by the zygotic genome. Although ascidian larvae contain fewer cells and cell types than vertebrate embryos, ascidian gastrulation and morphogenesis appear to employ similar mechanisms to those in vertebrate embryos. The extent of our current knowledge about the mechanisms involved in gastrulation and tail formation is summarized, and further experiments are suggested to explore the molecular mechanisms underlying these processes.
journal_name
Microsc Res Techjournal_title
Microscopy research and techniqueauthors
Swalla BJdoi
10.1002/jemt.1070260403subject
Has Abstractpub_date
1993-11-01 00:00:00pages
274-84issue
4eissn
1059-910Xissn
1097-0029journal_volume
26pub_type
杂志文章,评审abstract::This bibliography is compiled to assist in locating papers related to the application of scanning electron microscopy (SEM) to cerebrospinal-fluid-contacting surfaces in vertebrates. The use of SEM by neuroscientists has continued apace since the publication of the first bibliography in 1980. SEM studies now include m...
journal_title:Microscopy research and technique
pub_type:
doi:10.1002/(SICI)1097-0029(19980415)41:2<158::AID-JEM
更新日期:1998-04-15 00:00:00
abstract::This work investigates recording bits on recordable and rewritable blu-ray discs using atomic force microscopy and conducting atomic force microscopy with high contrast, respectively. The geometric structure of the recording bits is clearly observed in images, which, when coupled with cross-section analysis, yields pr...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/jemt.20745
更新日期:2010-01-01 00:00:00
abstract::The perivitelline space of mammalian oocytes changes in size and composition during preimplantation development. Often overlooked in the past, this space contains a hyaluronan-rich extracellular matrix prior to fertilization and a cortical granule envelope following release of the cortical granules at fertilization. T...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/jemt.10348
更新日期:2003-07-01 00:00:00
abstract::Atomic force microscopy has been used to study self-assembled structures of two alpha-hemolysin mutants. For a mutant (alphaHL-H5) that was locked into the prepore state on fluid phase egg-PC membranes, we visualized, for the first time, heptameric prepores and showed that the 7-fold axis in the prepore lies perpendic...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0029(19990301)44:5<353::AID-JEM
更新日期:1999-03-01 00:00:00
abstract::The mint beetle or green mint beetle, Chrysolina herbacea, is one of the most important insect pests of mint herb. These insects are associated with plants belonging to the Lamiaceae family, in particular the Mentha genus. They cause serious damages to plants by consuming their leaves. For this reason, it is an import...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/jemt.23671
更新日期:2020-12-11 00:00:00
abstract::Cytochrome c oxidase is a complex integral membrane protein consisting of 13 different polypeptide chains and four metal centers having a total molecular weight of approximately 200,000 daltons. It can be isolated in two 2-dimensional crystalline forms differing in aggregation state of the enzyme. One crystal form con...
journal_title:Microscopy research and technique
pub_type: 杂志文章,评审
doi:10.1002/jemt.1070270407
更新日期:1994-03-01 00:00:00
abstract::Several processing techniques of digital images allowed us to quantify the percentage of cell surface covered by microprojections (microvilli or microplicae) (SCM), the adhesion between epithelial cells by the parameter intercellular junctions (IJ), the size (cell area), shape (cell shape) and shade (cell shade) of ce...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/jemt.20833
更新日期:2010-10-01 00:00:00
abstract::We report on the microstructure and interfacial chemistry of thin films of pure and La-doped multiferroic bismuth ferrite (Bi1-x Lax FeO3 or BLFO), synthesized on Indium Tin Oxide-coated glass substrates by solution-deposition technique and studied using scanning transmission electron microscopy. Our results show that...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/jemt.22302
更新日期:2013-12-01 00:00:00
abstract:OBJECTIVES:This study investigated the effects of sliding on the ultrastructure of three representative esthetic superelastic 0.014 inch nickel-titanium (NiTi) archwires. METHODS:Atomic force microscopy, scanning electron microscopy, and light microscopy were used to estimate the surface roughness of archwires and bra...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/jemt.22557
更新日期:2015-10-01 00:00:00
abstract::A common feature in the configuration of germinal vesicle (GV) chromatin in most species is that diffuse chromatin condenses into a perinucleolar ring during follicular growth; however, no such ring was observed in goat oocytes. Reports on whether bovine GV chromatin condenses into a perinucleolar ring are controversi...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/jemt.20349
更新日期:2006-10-01 00:00:00
abstract::Non-alcoholic fatty liver disease (NAFLD) is a clinical-pathological syndrome that includes a wide spectrum of morphological alterations. In research, animal models are crucial in evaluating not only the pathogenesis of NAFLD and its progression, but also the therapeutic effects of various agents. Investigations on th...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/jemt.22401
更新日期:2014-10-01 00:00:00
abstract::Several studies searching for methods to control Rhipicephalus sanguineus s.l., (dog tick) infestations have been developed aiming to minimize the damages caused by these ectoparasites to the hosts and the environment, which is harmed by the indiscriminate use of toxic acaricide products. In this scenario, neem oil ha...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/jemt.22871
更新日期:2017-08-01 00:00:00
abstract::In this paper we present the state of knowledge on cell-cell interactions in the testis of two groups of anamniote vertebrates--teleosts and elasmobranchs--which include most fish. In these fish, the structural organization of the testis differs fundamentally from that which characterizes amniotes in which the germina...
journal_title:Microscopy research and technique
pub_type: 杂志文章,评审
doi:10.1002/jemt.1070320606
更新日期:1995-12-15 00:00:00
abstract::The density of nodes of Ranvier was examined at CNS, PNS, and transitional zone (TZ) levels of rat lumbar ventral motoneurone fibres. It was found to be significantly greater in the TZ than at the other levels: The difference was sevenfold for the ventral root and at least fourfold for central fibre levels. Node distr...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0029(19960815)34:6<507::AID-JEM
更新日期:1996-08-15 00:00:00
abstract:BACKGROUND:Ultrasonic excitation (US) was applied to glass ionomer cement (GIC) during early set time to increase the advantageous properties of this material. PURPOSE:The aim of this in vitro study was to assess the inner porosity of GIC after US. STUDY DESIGN:A total of 16 specimens, for each material, were prepare...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/jemt.20873
更新日期:2011-01-01 00:00:00
abstract::Iris L. is one of the important genus of family Iridaceae, consist of 56 taxa naturally occurred in Turkey. The similarities and variations in the subgenus overlapping the taxonomic positions of the species in the subgenera and needs anatomical assessment especially by microscopic techniques. In this study, the taxono...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/jemt.23221
更新日期:2019-06-01 00:00:00
abstract::This paper presents a snapshot view of the influence and direction of microcomputer technology for image analysis techniques in diagnostic pathology. Microcomputers have had considerable impact in bringing image analysis to wider application. Semi-automated tracing techniques are a simple means of providing objective ...
journal_title:Microscopy research and technique
pub_type: 杂志文章,评审
doi:10.1002/jemt.1070210406
更新日期:1992-06-01 00:00:00
abstract::A homemade colloidal probe atomic force microscope was used to perform nanoindentation with a spherical probe of 5 microm in diameter, at different approach velocities in order to extract the Young's modulus, E0, of poly(L-lysine)/hyaluronan (PLL/HA) films. This parameter is of prime importance to control cellular adh...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/jemt.20275
更新日期:2006-02-01 00:00:00
abstract::The possibility that tannic acid and other classical mordants can be used in the electron microscopical section staining technique has been tested. A mordant can be defined as a chemical that combines with both a certain specific tissue component and the staining substance and thereby permits a staining reaction that ...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/jemt.1070210110
更新日期:1992-03-01 00:00:00
abstract::Skin is the largest organ of the human body. Thus far, tissue engineering of skin has developed rapidly and has used many types of growth factors and nanofibrous scaffolds. In this study, we differentiated neonate keratinocytes for epithelialization on the polycaprolactone-Platelet gel (PCL-PG) scaffold. Fabricated PC...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/jemt.22821
更新日期:2017-05-01 00:00:00
abstract::The ionic liquids (ILs) are recognized as the potential solvents for the pretreatment of lignocellulosic materials before biomass conversion. However, little knowledge of how the cell wall of biomass responds to the IL locally and dynamically during the pretreatment is available. In the current work, the process of IL...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/jemt.22379
更新日期:2014-08-01 00:00:00
abstract::Fatty acid and alkyl compositions of 1-alkyl-2,3-diacylglycerols (ADG) in the Harderian gland of the golden hamster were determined. Fatty acids of male ADG consisted of straight chain saturated acids ranging from C12 to C22. Both even- and odd-numbered acids were observed, indicating that acetyl- and propionyl-CoAs w...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0029(19960501)34:1<71::AID-JEMT
更新日期:1996-05-01 00:00:00
abstract::GABA is a likely feedback transmitter from H1 horizontal cells to cone photoreceptors in fish retinas. Spinules arise from H1 cell dendrites in light-adapted retinas, are correlated with responses attributed to feedback, and have been proposed to be the GABA release sites. We used mAb 62-3G1, an antibody against the b...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0029(19970101)36:1<43::AID-JEMT
更新日期:1997-01-01 00:00:00
abstract::We compared physiological and ultrastructural indices of acute lung injury (ALI) during septic shock caused by taxonomically diverse pathogens to distinguish ALI due to endogenous inflammatory mediators vs. microbial exotoxins or other factors. Conscious rats were infected i.v. with gram-negative Escherichia coli (EC,...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/jemt.1070260512
更新日期:1993-12-01 00:00:00
abstract::This study analyzed the quality of obturation and physical properties of MTA Fillapex and AH Plus sealer. A sample of 30 human maxillary central incisors were instrumented with Protaper until a F5 (50/05) file. Both sealers were mixed with Rhodamine-B dye to allow visualization on a confocal laser-scanning microscope ...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/jemt.22432
更新日期:2014-12-01 00:00:00
abstract::In addition to pesticidal activity, the capacity of natural compounds to inhibit the reproduction of parasites emerge as an important alternative tick control method. In this context, Satureja spp. stand out due to their recognized pesticidal properties. Among parasites of veterinary importance, the cattle tick, Rhipi...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/jemt.23693
更新日期:2021-01-06 00:00:00
abstract::In the current investigation, 16 samples of six species of the genus Polygonatum were collected from different geographical regions in China. Leaf micromorphological traits were studied in detail using scanning electron microscopy. About five-leaf samples were used for each species collected from different geographica...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/jemt.23529
更新日期:2020-11-01 00:00:00
abstract::Nowadays, infertility is no longer considered as an unsolvable disorder due to progresses in germ cells derived from stem lineage with diverse origins. Technical and ethical challenges push researchers to investigate various tissue sources to approach more efficient gametes. The purpose of the current study is to inve...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/jemt.22880
更新日期:2017-11-01 00:00:00
abstract::The intravacuolar network inside the parasitophorous vacuole of Toxoplasma gondii consists of an intricate system of membrane-limited tubules of uncertain role in parasite development. We propose that it is an important structural support to the maintenance of the parasites in the characteristic rosette arrangement of...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/jemt.20182
更新日期:2005-05-01 00:00:00
abstract::Research into the POU transcription factor Oct-6 has been the focus of much current attention, in particular its role in Schwann cell development and differentiation. Based on published data and data presented here, we propose a model for Oct-6 function at two distinct stages of Schwann cell maturation. First, Oct-6 f...
journal_title:Microscopy research and technique
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0029(19980601)41:5<372::AID-JEM
更新日期:1998-06-01 00:00:00