OBJECTIVETo probe into the morphological and histological characteristics of the telencephalon of Onychodactylus fischeri, and to enrich the comparable neurobiology.

METHODHE-staining method was used to describe the characters of the telencephalon of Onychodactylus fischeri.

RESULTSThe olfactory bulb of Onychodactylus fischeri locates in the rastral and lateral to the cerebral hemisphere, and six distinct layers can be identified from the lateral to the medial, quite similar to Batrachuperus tibetanus and Hynobius leechii. In the cerebrum, the primordial hippocampus developed better than the primordial piriform. The former belongs to archipallium and the latter is paleopallium. Ventral to the primordial hippocampus there is a septal area which cannot be divided into medial and lateral parts. In the ventrical wall, there is neither medial limiting sulcus nor lateral limiting sulcus to separate the primordial hippocampus and the septal area, or the primordial piriform and the corpus striatum. The corpus striatum of Onychodactylus fischeri is paleostriatum. There is choroids plexus anterior in the lateral ventricle. The cell group that located at two sides of the third ventricle is the amygdale. Besides, the shape and size of neurons within the telencephalon are poorly differentiated.

CONCLUSIONOnychodactylus fischeri is a relatively primitive type in the amphibian. The present data will help us to further understand the nerve system of tailed amphibian.

Ambystoma mexicanum/immunology* ; Amputation ; Animals ; Biomarkers/metabolism* ; Blastomeres/immunology* ; Cell Lineage/immunology* ; Connective Tissue Cells/immunology* ; Epithelial Cells/immunology* ; Forelimb ; Gene Expression ; High-Throughput Nucleotide Sequencing ; Humans ; Immunity ; Peroxiredoxins/immunology* ; Regeneration/immunology* ; Regenerative Medicine/methods* ; Single-Cell Analysis/methods*

A virus was isolated from cultured sick giant salmander (Andrias davidianus ) in a farm, Shanxi Province, China. Skin ulceration and necrosis of the distal limbs are main clinical symptoms. Virus propagated and caused CPE at 10 degrees C to 30 degrees C in BF-2, CO, CHSE, FHM cells. The optimum condition of replication was in BF-2 cells at 25 degrees C. The virus was proved to be senstive to chloroform, heat, pH3 and pH10 treatment. Viral replication was inhibited by 5-Fluoro-2-deoxyuridine (FUDR). These results indicated that the virus possessed an envelope and DNA as the genome. Electron-microscopic observation of thin-section showed numerous hexagonal viral particles measuring 130 nm to 150 nm in diameter orderly arranged in a lattice form in cytoplasm of BF-2 cells. The particles showed typical iridovirus morphology. A 413 bp fragment was amplified from the viral main capsid protein gene by PCR. The fragments was sequenced and analysed. The results showed the isolate shared more than 96% nucleotide identity with some Ranaviruses. We suggested that this virus was named as Andrias davidianus iridovirus (ADIV) tentatively.
Animals ; Base Sequence ; Iridovirus ; genetics ; isolation & purification ; Molecular Sequence Data ; Urodela ; virology

No abstract available.
Cilia* ; Demecolcine* ; Lung* ; Salamandridae*

No abstract available.
Demecolcine* ; Lung* ; Salamandridae*

Differentiation, the stepwise specialization of cells, and transdifferentiation, the apparent switching of one cell type into another, capture much of the stem cell spotlight. But dedifferentiation, the developmental reversal of a cell before it reinvents itself, is an important process too. In multicellular organisms, cellular dedifferentiation is the major process underlying totipotency, regeneration and formation of new stem cell lineages. In humans, dedifferentiation is often associated with carcinogenesis. The study of cellular dedifferentiation in animals, particularly early events related to cell fate-switch and determination, is limited by the lack of a suitable, convenient experimental system. The classic example of dedifferentiation is limb and tail regeneration in urodele amphibians, such as salamanders. Recently, several investigators have shown that certain mammalian cell types can be induced to dedifferentiate to progenitor cells when stimulated with the appropriate signals or materials. These discoveries open the possibility that researchers might enhance the endogenous regenerative capacity of mammals by inducing cellular dedifferentiation in vivo.
Animals ; Cell Differentiation ; Cells, Cultured ; Epidermal Growth Factor ; physiology ; Humans ; Regeneration ; Salamandridae ; physiology ; Serum ; physiology ; Thrombin ; pharmacology