细胞技术

Non-canonical Wnt signaling is an important regulator of gastrulation in Xenopus. In particular, it has been implicated in the control of convergent extension movements. Convergent extension in the gas-trula occurs primarily in the dorsal tissue of the marginal zone, and explants of this ...

The easy accessibility, distinctive features of early cleavage stage embryos and simple manipulation methods make Xenopusembryos an ideal model organism to study gene function and deciphering signaling pathways. For many years, investigators have analyzed putative dorsal ...

The Wnt signaling cascades are regulatory modules which are involved in embryonic patterning, cell differentiation, morphogenesis, and diseases (1, 2). The Wnt pathways are activated when secreted Wnt ligands interact with 7-trans-membrane receptors of the Frizzled (Fz) family. Sp ...

Xenopus laevis has for many years been successfully used to study Wnt signaling during early development. However, because loss of function and gain of function experiments generally involve injecting RNA, DNA, or morpholinos into early embryos (1- to 32-cell), major phenotypes are often o ...

Early development in Xenopus laevis is controlled by maternal gene products synthesized during oogen-esis. The dorsal/ventral and anterior/posterior axes are established as a result of canonical Wnt signaling activity. The functions of maternal genes in embryonic development ...

Xenopus embryos are particularly suited for functional experiments to investigate vertebrate embryonic development. Due to the large size of embryos and their development outside of the mother organism, they are very accessible, easy to manipulate, and allow for immediate observa ...

The terminal chromatin structures at the ends of eukaryotic chromosomes, the telomeres, are a focus of intensive research due to their importance for the maintenance of chromosome integrity. Their shortening due to incomplete replication functions as a molecular clock counting the n ...

Fluorescence tagging of genomic sites through the use of bacterial operator/repressor systems combined with fluorescent proteins permits high-resolution analysis of interphase chromosomes in living cells. This technique has been used to study interphase chromosome arra ...

Fluorescence in situ hybridization (FISH) of specific DNA probes has become a widely used technique mostly for chromosome analysis and for studies of the chromosomal location of specific DNA segments in metaphase preparations as well as in interphase nuclei. FISH on 3D-preserved nuclei ...

The 20S proteasome is part of a larger complex, the 26S proteasome, that is implicated in the ATP-dependent degradation of multiubiquitin-conjugated proteins (1). About 80% of intracellular protein breakdown occurs via the ubiquitinproteasome system (UPS). Key proteins such as tran ...

An emerging theme in neurodegenerative diseases is the aggregation of proteins as inclusions in neural cells. Their presence is a useful tool in the differential diagnosis of the particular illness, although in no instance is the specific role of the inclusions in disease pathogenesis und ...

A method for isolation of constitutive heterochromatin (chromocenters) from nuclei of mouse liver cells is described. This method is based on the higher resistance of chromocenters to low ionic strength treatment as compared with that of nucleoli and euchromatin. The method allows sep ...

The perinucleolar compartment (PNC) is a dynamic, irregularly shaped, and electron-dense nuclear structure that is physically associated with the nucleolus (1). It is found predominantly in transformed cells and various cancer tissues, and rarely in normal cells (1). The components of ...

The dynamics of proteins play a key role in the organization and control of nuclear functions. Techniques were developed recently to observe the movement and interactions of proteins in living cells; time-lapse microscopy using fluorescent-tagged proteins gives access to observat ...

Here we describe a new, rapid method for isolating nucleoli from Ehrlich tumor cells that preserves their morphological integrity and high transcriptional activity. Until now, methods for isolation of nucleoli were generally assumed to empty one of their three main compartments, the fi ...

The nucleus is a complex volume constituted of numerous subcompartments in which specific functions take place due to a specific spatial organization of their molecular components. To understand how these molecules are spatially organized within these machineries, it is necessary ...

Dinoflagellates are unicellular eukaryotic organisms whose nuclear structure, chromosome architecture, chromatin organization, DNA composition, and mitosis show original features. It has been necessary to adapt techniques and to create innovative methods for growing c ...

The vast evolutionary distance between the Opisthokonta (animals and yeast) and the excavata (a major group of protists, including Giardia and Trypanosoma) presents a significant challenge to in silico functional genomics and ortholog identification. Subcellular proteomic i ...

We describe a method for isolating nuclei from cultured Arabidopsis cells. The same method can be used to further isolate nucleoli. Cell walls are first digested to yield protoplasts, which are purified by flotation on a Percoll gradient. Mechanical homogenisation is used to release nuclei, ...

The giant nucleus or germinal vesicle (GV) of amphibian oocytes presents a remarkable opportunity to examine nuclear structures in unprecedented levels of detail. By making use of spread preparations of GVs, it is possible to investigate the structure and function of transcription uni ...