Chen Zhang

Publications (2)4.12 Total impact

• Article: Molecular evidence for the subspecific differentiation of blue sheep (Pseudois nayaur) and polyphyletic origin of dwarf blue sheep (Pseudois schaeferi).

  Shuai Tan, Dandan Zou, Lei Tang, Gaochao Wang, Quekun Peng, Bo Zeng, Chen Zhang, Fangdong Zou
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  ABSTRACT: Blue sheep (Pseudois nayaur), a Central Asian ungulate with restricted geographic distribution, exhibits unclear variation in morphology and phylogeographic structure. The composition of species and subspecies in the genus Pseudois is controversial, particularly with respect to the taxonomic designation of geographically restricted populations. Here, 26 specimens including 5 dwarf blue sheep (Pseudois schaeferi), which were collected from a broad geographic region in China, were analyzed for 2 mitochondrial DNA fragments (cytochrome b and control region sequences). In a pattern consistent with geographically defined subspecies, we found three deeply divergent mitochondrial lineages restricted to different geographic regions. The currently designated two subspecies of blue sheep, Pseudois nayaur nayaur and Pseudois nayaur szechuanensis, were recognized in the phylogenetic trees. In addition, the Helan Mountain population showed distinct genetic characteristics from other geographic populations, and thus should be classified as a new subspecies. In contrast, dwarf blue sheep clustered closely with some blue sheep from Sichuan Province in the phylogenetic trees. Therefore, dwarf blue sheep appear to be a subset of Pseudois nayaur szechuanensis. After considering both population genetic information and molecular clock analysis, we obtained some relevant molecular phylogeographic information concerning the historical biogeography of blue sheep. These results also indicate that western Sichuan was a potential refugium for blue sheep during the Quaternary period.
  Genetica 07/2012; 140(4-6):159-67. · 2.15 Impact Factor
• Source

  Available from: Ming Shi

  Article: Ginsenoside Rd protects neurons against glutamate-induced excitotoxicity by inhibiting ca(2+) influx.

  Chen Zhang, Fang Du, Ming Shi, Ruidong Ye, Haoran Cheng, Junliang Han, Lei Ma, Rong Cao, Zhiren Rao, Gang Zhao
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  ABSTRACT: Our previous studies have demonstrated that ginsenoside Rd (GSRd), one of the principal ingredients of Pana notoginseng, has neuroprotective effects against ischemic stroke. However, the possible mechanism(s) underlying the neuroprotection of GSRd is/are still largely unknown. In this study, we treated glutamate-injured cultured rat hippocampal neurons with different concentrations of GSRd, and then examined the changes in neuronal apoptosis and intracellular free Ca(2+) concentration. Our MTT assay showed that GSRd significantly increased the survival of neurons injured by glutamate in a dose-dependent manner. Consistently, TUNEL and Caspase-3 staining showed that GSRd attenuated glutamate-induced cell death. Furthermore, calcium imaging assay revealed that GSRd significantly attenuated the glutamate-induced increase of intracellular free Ca(2+) and also inhibited NMDA-triggered Ca(2+) influx. Thus, the present study demonstrates that GSRd protects the cultured hippocampal neurons against glutamate-induced excitotoxicity, and that this neuroprotective effect may result from the inhibitory effects of GSRd on Ca(2+) influx.
  Cellular and Molecular Neurobiology 08/2011; 32(1):121-8. · 1.97 Impact Factor