细胞技术

Analogs of naturally occurring substances obtained by chemical modifications are powerful tools to study intra- and intermolecular interactions. We have used the phosphorothioate technique to analyze RNA-protein interactions, here the interactions of transfer RNAs (tRNA ...

Mammalian fertilization is traditionally viewed as a process during which the fertilizing spermatozoon penetrates the egg vestments to plant its chromosomes into the fertile environment of oocyte cytoplasm. Much less attention has been paid to the events that occur between gamete f ...

Conventional PCR screens of genomic DNA will often yield a substantial fragment of the gene of interest. However, identification of flanking sequences on either side of a known sequence can be problematic with conventional PCR. in which primers extend a complementary chain in a 5′ → 3′ direction. H ...

Their large size and their relative resistance to proteolytic cleavage (1) make myosins particularly difficult substrates for the acquisition of their peptide sequences by standard protocols. For this reason, instead of identifying myosins first according to their biochemical ...

In this chapter, we describe our methods to evaluate the dynein heavy chain genes expressed in a cell. Dynein is the high molecular weight molecular motor that produces directed movement along microtubules. All known dyneins travel to the proximal or minus end of the microtubule. The large dynein ...

The cytoskeleton is a dynamic network of filaments in the cytoplasm of cells and functions as the roadways for vesicular transport. Of the three types of cytoskeletal filaments, both microtubules and actin filaments have been shown to support vesicle transport. The transport of vesicles is ...

Almost all eukaryotic cells move or are moved sometime in their life time. In the evolution of eukaryotic cells, two forms of single cell locomotion have evolved, flagellar or ciliary locomotion, and amoeboid locomotion. The latter represents the more general method of cellular locomotion. ...

The shape of a cell reflects cell-substratum and cell-cell attachment and organization of the cytoskeleton (1–4). Many studies on cell morphology have until recently been purely qualitative for the simple reason that morphological changes resulting from e.g., modulation of cell attac ...

The coordinated displacement of a cell is a highly complex process which relies on the integration of a series of signaling pathways and on the function of a large number of molecular components including all main structures of the cytoskeleton (1,2). Thus, a detailed knowledge of the regulation a ...

Rapidly swimming cells, like the ciliated protozoa, offer an interesting opportunity to study the chemosensory behaviour involved in chemo-attraction/repulsion in response to external chemical stimuli. The membrane ultrastructure of ciliates resembles that of the chemos ...

Immunogold labeling has been used extensively to study the localization and distribution of antigens within cells and tissue. Gold-antibody complexes are generated by charge interaction of the colloidal gold with the antibody, although the exact nature of this interaction is not ful ...

The cytoskeleton is a complex structure composed of three distinct filament systems, micro filaments (actin), intermediate filaments, and microtubules. Each filament system consists of filamentous polymers and their associated proteins. Some of the associated proteins are ca ...

Many questions concerning the function of the cytoskeleton can be addressed using functional antibodies either in in vitro assays or in whole cell systems. Ultimately, the function of a component has to be studied within intact cell systems. A problem, which one has to be overcome, is the delivery of ...

The actin system is involved in different cellular processes such as exo- and endocytosis, organelle motions, maintenance of organelle distribution, motility, cell division, and cytoplasmic streaming in plant cells. Several substances are known to influence these processes by al ...

The cytoskeleton is a dynamic structure comprised of at least three distinct cellular filament systems: microfilaments, intermediate filaments, and microtubules. Microfilaments are composed of assembled globular actin monomers that form a filamentous system involved in the ...

The green fluorescent protein (GFP) from the Pacific Northwest jellyfish Aequorea victoria is a member of a small but important class of proteins that exhibit strong visible fluorescence without the requirement of cofactors or other enzymes. In vivo, the photoprotein aequorin binds di ...

All eukaryotic cells contain three distinct cytoskeletal networks: microtubules, microfilaments, and intermediate filaments (IF). In epithelial cells in vivo, the IF cytoskeleton is composed of heteropolymers of type I (acidic) and type II (neutral-basic) keratins, whose expre ...

Chromatophores are pigmented cells found in a variety of animals. In lower vertebrates, i.e., fish and amphibia, chromatophores are present in the dermis, and in response to various stimuli, the pigment in these cells is transported to or from the cell center, conferring upon the cell a light or dark ap ...

Marine oocytes and embryos have long been favored systems for the study of cell division and the cytoskeletal dynamics that accompany karyokinesis and cytokinesis. Several characteristics make marine egg systems ideal for the study of cell replication including: 1) the clarity of the eg ...

It has long been apparent that the three cytoskeletal systems of eukaryotic cells, microtubules, f-actin, and intermediate filaments, act in a cooperative fashion, both to achieve their characteristic distributions within cells (1–3), and to execute a variety of complex cellular phen ...