Dynamic <Emphasis Type="Italic">in vivo</Emphasis> imaging and cell tracking using a histone fluorescent protein fusion in mice

Background  

Advances in optical imaging modalities and the continued evolution of genetically-encoded fluorescent proteins are coming together to facilitate the study of cell behavior at high resolution in living organisms. As a result, imaging using autofluorescent protein reporters is gaining popularity in mouse transgenic and targeted mutagenesis applications.     

The zebrafish <Emphasis Type="Italic">lysozyme C</Emphasis> promoter drives myeloid-specific expression in transgenic fish

Background  

How different immune cell compartments contribute to a successful immune response is central to fully understanding the mechanisms behind normal processes such as tissue repair and the pathology of inflammatory diseases. However, the ability to observe and characterize such interactions, in real-time, within a living vertebrate has proved elusive. Recently, the zebrafish has been exploited to model aspects of human disease and to study specific immune cell compartments using fluorescent reporter transgenic lines. A number of blood-specific lines have provided a means to exploit the exquisite optical clarity that this vertebrate system offers and provide a level of insight into dynamic inflammatory processes previously unavailable.     

Roles of curli,cellulose and BapA in <Emphasis Type="Italic">Salmonella</Emphasis> biofilm morphology studied by atomic force microscopy

Background  

Curli, cellulose and the cell surface protein BapA are matrix components in Salmonella biofilms. In this study we have investigated the roles of these components for the morphology of bacteria grown as colonies on agar plates and within a biofilm on submerged mica surfaces by applying atomic force microscopy (AFM) and light microscopy.     

mRNA detection of individual cells with the single cell nanoprobe method compared with in situ hybridization

Background  

The localization of specific mRNA generates cell polarity by controlling the translation sites of specific proteins. Although most of these events depend on differences in gene expression, no method is available to examine time dependent gene expression of individual living cells. In situ hybridization (ISH) is a powerful and useful method for detecting the localization of mRNAs, but it does not allow a time dependent analysis of mRNA expression in single living cells because the cells have to be fixed for mRNA detection. To overcome these issues, the extraction of biomolecules such as mRNAs, proteins, and lipids from living cells should be performed without severe damage to the cells. In previous studies, we have reported a single cell nanoprobe (SCN) method to examine gene expression of individual living cells using atomic force microscopy (AFM) without killing the cells.     

Unexpected complexity of the Aquaporin gene family in the moss <Emphasis Type="Italic">Physcomitrella patens</Emphasis>

Background  

Aquaporins, also called major intrinsic proteins (MIPs), constitute an ancient superfamily of channel proteins that facilitate the transport of water and small solutes across cell membranes. MIPs are found in almost all living organisms and are particularly abundant in plants where they form a divergent group of proteins able to transport a wide selection of substrates.     

Arabinoxylan, β‐glucan and pectin in barley and malt endosperm cell walls: a microstructure study using CLSM and cryo‐SEM

The architecture of endosperm cell walls in Hordeum vulgare (barley) differs remarkably from that of other grass species and is affected by germination or malting. Here, the cell wall microstructure is investigated using (bio)chemical analyses, cryogenic scanning electron microscopy (cryo‐SEM) and confocal laser scanning microscopy (CLSM) as the main techniques. The relative proportions of β‐glucan, arabinoxylan and pectin in cell walls were 61, 34 and 5%, respectively. The average thickness of a single endosperm cell wall was 0.30 µm, as estimated by the cryo‐SEM analysis of barley seeds, which was reduced to 0.16 µm after malting. After fluorescent staining, 3D confocal multiphoton microscopy (multiphoton CLSM) imaging revealed the complex cell wall architecture. The endosperm cell wall is composed of a structure in which arabinoxylan and pectin are colocalized on the outside, with β‐glucan depositions on the inside. During germination, arabinoxylan and β‐glucan are hydrolysed, but unlike β‐glucan, arabinoxylan remains present in defined cell walls in malt. Integrating the results, an enhanced model for the endosperm cell walls in barley is proposed.     

Differential localization in cells of myosin II heavy chain kinases during cytokinesis and polarized migration

Background  

Cortical myosin-II filaments in Dictyostelium discoideum display enrichment in the posterior of the cell during cell migration and in the cleavage furrow during cytokinesis. Filament assembly in turn is regulated by phosphorylation in the tail region of the myosin heavy chain (MHC). Early studies have revealed one enzyme, MHCK-A, which participates in filament assembly control, and two other structurally related enzymes, MHCK-B and -C. In this report we evaluate the biochemical properties of MHCK-C, and using fluorescence microscopy in living cells we examine the localization of GFP-labeled MHCK-A, -B, and -C in relation to GFP-myosin-II localization.     

Reduced evolvability of <Emphasis Type="Italic">Escherichia coli</Emphasis> MDS42, an IS-less cellular chassis for molecular and synthetic biology applications

Background  

Evolvability is an intrinsic feature of all living cells. However, newly emerging, evolved features can be undesirable when genetic circuits, designed and fabricated by rational, synthetic biological approaches, are installed in the cell. Streamlined-genome E. coli MDS42 is free of mutation-generating IS elements, and can serve as a host with reduced evolutionary potential.     

Laser surgery of zebrafish (<Emphasis Type="Italic">Danio rerio</Emphasis>) embryos using femtosecond laser pulses: Optimal parameters for exogenous material delivery,and the laser's effect on short- and long-term development

Background  

Femtosecond (fs) laser pulses have recently received wide interest as an alternative tool for manipulating living biological systems. In various model organisms the excision of cellular components and the intracellular delivery of foreign exogenous materials have been reported. However, the effect of the applied fs laser pulses on cell viability and development has yet to be determined. Using the zebrafish (Danio rerio) as our animal model system, we address both the short- and long-term developmental changes following laser surgery on zebrafish embryonic cells.     

生物科学研究中的激光多光子显微技术

本文综述了生物科学中近红外（NIR）多光子激光扫描显微技术的进展,其中包括：多光子显微特点,激光光源,荧光寿命的测量,多光子多色实时杂化荧光（FISH）,非人侵性活体光学解剖,植物学中的多光子显微技术,细胞的多光子显微损伤、皮米非入侵和非接触性外科手术等。     

Electroporator with automatic change of electric field direction improves gene electrotransfer <Emphasis Type="Italic">in-vitro</Emphasis>

Background  

Gene electrotransfer is a non-viral method used to transfer genes into living cells by means of high-voltage electric pulses. An exposure of a cell to an adequate amplitude and duration of electric pulses leads to a temporary increase of cell membrane permeability. This phenomenon, termed electroporation or electropermeabilization, allows various otherwise non-permeant molecules, including DNA, to cross the membrane and enter the cell. The aim of our research was to develop and test a new system and protocol that would improve gene electrotransfer by automatic change of electric field direction between electrical pulses.     

Intravital imaging of fluorescent markers and FRET probes by DNA tattooing

Background  

Advances in fluorescence microscopy and mouse transgenesis have made it possible to image molecular events in living animals. However, the generation of transgenic mice is a lengthy process and intravital imaging requires specialized knowledge and equipment. Here, we report a rapid and undemanding intravital imaging method using generally available equipment.     

Hereditary profiles of disorderly transcription?

Background  

Microscopic examination of living cells often reveals that cells from some cell strains appear to be in a permanent state of disarray without obvious reason. In all probability such a disorderly state affects cell functioning.     

A focused antibody library for selecting scFvs expressed at high levels in the cytoplasm

Background  

Intrabodies are defined as antibody molecules which are ectopically expressed inside the cell. Such intrabodies can be used to visualize or inhibit the targeted antigen in living cells. However, most antibody fragments cannot be used as intrabodies because they do not fold under the reducing conditions of the cell cytosol and nucleus.     

No statistical support for correlation between the positions of protein interaction sites and alternatively spliced regions

Background  

Alternative splicing is an efficient mechanism for increasing the variety of functions fulfilled by proteins in a living cell. It has been previously demonstrated that alternatively spliced regions often comprise functionally important and conserved sequence motifs. The objective of this work was to test the hypothesis that alternative splicing is correlated with contact regions of protein-protein interactions.     

<Emphasis Type="Italic">AtMRP6</Emphasis>/<Emphasis Type="Italic">AtABCC6</Emphasis>, an ATP-Binding Cassette transporter gene expressed during early steps of seedling development and up-regulated by cadmium in <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis>

Background  

ABC proteins constitute one of the largest families of transporters found in all living organisms. In Arabidopsis thaliana, 120 genes encoding ABC transporters have been identified. Here, the characterization of one member of the MRP subclass, AtMRP6, is described.     

Context based mixture model for cell phase identification in automated fluorescence microscopy

Background  

Automated identification of cell cycle phases of individual live cells in a large population captured via automated fluorescence microscopy technique is important for cancer drug discovery and cell cycle studies. Time-lapse fluorescence microscopy images provide an important method to study the cell cycle process under different conditions of perturbation. Existing methods are limited in dealing with such time-lapse data sets while manual analysis is not feasible. This paper presents statistical data analysis and statistical pattern recognition to perform this task.     

Genes and pathways for CO<Subscript>2</Subscript> fixation in the obligate,chemolithoautotrophic acidophile, <Emphasis Type="Italic">Acidithiobacillus ferrooxidans</Emphasis>, Carbon fixation in <Emphasis Type="Italic">A. ferrooxidans</Emphasis>

Background  

Acidithiobacillus ferrooxidans is chemolithoautotrophic γ-proteobacterium that thrives at extremely low pH (pH 1-2). Although a substantial amount of information is available regarding CO₂ uptake and fixation in a variety of facultative autotrophs, less is known about the processes in obligate autotrophs, especially those living in extremely acidic conditions, prompting the present study.     

Prebiotic replicase evolution in a surface-bound metabolic system: parasites as a source of adaptive evolution

Background  

The remarkable potential of recent forms of life for reliably passing on genetic information through many generations now depends on the coordinated action of thousands of specialized biochemical "machines" (enzymes) that were obviously absent in prebiotic times. Thus the question how a complicated system like the living cell could have assembled on Earth seems puzzling. In seeking for a scientific explanation one has to search for step-by-step evolutionary changes from prebiotic chemistry to the emergence of the first proto-cell.