Molecular characterization and expression analysis of cathepsin C in Chinese giant salamander (Andrias davidianus) after Aeromonas hydrophila infection

Background: Cathepsin C (CTSC) (dipeptidyl peptidase I, DPPI), is a member of the papain superfamily of cysteine proteases and involves in a variety of host reactions. However, the information of CTST in Chinese giant salamander (Andrias davidianus), an amphibian species with important evolutionary position and economic values, remained unclear. Results: The full-length salamander CTSC cDNA contained a 96 bp of 5'-UTR, a 1392 bp of ORF encoding 463 amino acids, and a 95 bp of 3'-UTR. The salamander CTSC possessed several sequence features similar to other reported CTSCs such as a signal peptide, a propeptide and a mature peptide. The active site triad of Cys, His and Asn were also found existing in salamander CTSC. Salamander CTSC mRNA was constitutively expressed in all the examined tissues with significantly variant expression level. The highest expression of CTSC was in intestine, followed with stomach, spleen, lung and brain. Following Aeromonas hydrophila infection for 12 h, salamander CTSC was significantly up-regulated in several tissues including lung, spleen, brain, kidney, heart, stomach and skin. Conclusion: CTSC plays roles in the immune response to bacterial infection, which provided valuable information for further studying the functions of CTSC in salamander.

Isolation and characterization of an iridovirus from sick giant salamander (Andrias davidianus) / 病毒学报

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.

Morphological and histological studies on the telencephalon of the salamander Onychodactylus fischeri / 神经科学通报·英文版

<p><b>OBJECTIVE</b>To probe into the morphological and histological characteristics of the telencephalon of Onychodactylus fischeri, and to enrich the comparable neurobiology.</p><p><b>METHOD</b>HE-staining method was used to describe the characters of the telencephalon of Onychodactylus fischeri.</p><p><b>RESULTS</b>The 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.</p><p><b>CONCLUSION</b>Onychodactylus fischeri is a relatively primitive type in the amphibian. The present data will help us to further understand the nerve system of tailed amphibian.</p>

Estratégias de regeneração em anfíbios urodelos / Regeneration strategies in urodele amphibians

Na era das células-tronco, é interessante observar que a natureza resolveu o problema da regeneração com estratégias diferentes da restauração de tecidos por células indiferenciadas. Anfíbios urodelos são únicos, entre vertebrados, que têm a capacidade de regenerar córnea, retina, mandíbula, membros e secções do coração. A proliferação de células especializadas, transdiferenciação e desdiferenciação são importantes estratégias da regeneração de tritões e salamandras. De modo importante, algumas vias sinalizadoras estão conservadas em mamíferos, incluindo os seres humanos, e o potencial papel do conhecimento sobre a regeneração de urodelos no contexto de mamíferos é discutido nesta revisão.