The complete mitochondrial cytb gene and the partial nuclear c-mos gene of Oligodon ningshaanensis Yuan, 1983 were sequenced and used for reconstructing the phylogenetic relationship of this taxon amongst alethinophid...The complete mitochondrial cytb gene and the partial nuclear c-mos gene of Oligodon ningshaanensis Yuan, 1983 were sequenced and used for reconstructing the phylogenetic relationship of this taxon amongst alethinophidian snakes. Its strong affinity to the New World subfamily Dipsadinae and the Old World species Thermophis baileyi was inferred. Hemipenial morphology found by authors conflicts with the original description and its similarity with those of the dipsadid snakes is in accordance with our molecular results. Feeding tests show that O. ningshaanensis is a malacophagous predator, which is another matchless character for this species. This behavior is described and compared with other known slug- and snail-feeding snakes. The discovery of the particular position of our subject indicates that erecting a new genus is necessary accommodate this unique species.展开更多
Ubiquitin-proteasome pathway (UPP) is a significant way of protein degradation and modification in eukaryotic cell and involved in a complex series of intracellular processes. As a key component in UPP,?ubiquitin-conj...Ubiquitin-proteasome pathway (UPP) is a significant way of protein degradation and modification in eukaryotic cell and involved in a complex series of intracellular processes. As a key component in UPP,?ubiquitin-conjugating enzyme (E2) plays an extremely important role in ubiquitin (Ub) transferring and substrate specific recognition. Abundant evidences have proved that UPP is involved in cells immune reaction caused by pathogens and the attendance of E2 has a significant effect on host cells and pathogen. This article presents an overview of the current research on E2s that is involved in immune response caused by viruses and bacteria.展开更多
The impact of the Quaternary glaciation on eastern China’s local fauna and flora is a topic of considerable interest. We use mitochondrial DNA(mtDNA) sequences and coalescent simulations to test two general biogeogra...The impact of the Quaternary glaciation on eastern China’s local fauna and flora is a topic of considerable interest. We use mitochondrial DNA(mtDNA) sequences and coalescent simulations to test two general biogeographic hypotheses related to the effect of the Pleistocene climatic fluctuations on a widespread, eastern Chinese amphibian, Pseudepidalea raddei. Genealogical reconstructions are made and they detect major western and eastern lineages, which overlap in northwestern China, and possibly indicate the secondary contact of the populations that had entered the region from separate glacial refugia. Coalescent tests rejected alternative hypotheses of fragmentation of either a widespread ancestor or panmixia. The tests instead supported the hypothesis of geographic isolation and a remarkable dispersal pattern in one of the lineages. Though the Pleistocene climatic events are known to have affected the historical distributions and intra-specific divergence of Chinese squamates, coalescent and non-coalescent demographic analyses indicated that the toad P. raddei was not adversely affected by glacial cycling. Presumably, an increase in the amount of climatically mild habitats in East Asia is due to the development of monsoons since the Mid-late Pleistocene is responsible for the relatively mild effects.展开更多
文摘The complete mitochondrial cytb gene and the partial nuclear c-mos gene of Oligodon ningshaanensis Yuan, 1983 were sequenced and used for reconstructing the phylogenetic relationship of this taxon amongst alethinophidian snakes. Its strong affinity to the New World subfamily Dipsadinae and the Old World species Thermophis baileyi was inferred. Hemipenial morphology found by authors conflicts with the original description and its similarity with those of the dipsadid snakes is in accordance with our molecular results. Feeding tests show that O. ningshaanensis is a malacophagous predator, which is another matchless character for this species. This behavior is described and compared with other known slug- and snail-feeding snakes. The discovery of the particular position of our subject indicates that erecting a new genus is necessary accommodate this unique species.
文摘Ubiquitin-proteasome pathway (UPP) is a significant way of protein degradation and modification in eukaryotic cell and involved in a complex series of intracellular processes. As a key component in UPP,?ubiquitin-conjugating enzyme (E2) plays an extremely important role in ubiquitin (Ub) transferring and substrate specific recognition. Abundant evidences have proved that UPP is involved in cells immune reaction caused by pathogens and the attendance of E2 has a significant effect on host cells and pathogen. This article presents an overview of the current research on E2s that is involved in immune response caused by viruses and bacteria.
基金supported by the Director Foundation of Experimental Centre, Shenyang Normal University (Syzx1104)a Visiting Professorship for Senior International Scientists from the Chinese Academy of Sciences to Robert W. MURPHYsupported by a Discovery Grant of the Natural Sciences and Engineering Research Council of Canada (A3148)
文摘The impact of the Quaternary glaciation on eastern China’s local fauna and flora is a topic of considerable interest. We use mitochondrial DNA(mtDNA) sequences and coalescent simulations to test two general biogeographic hypotheses related to the effect of the Pleistocene climatic fluctuations on a widespread, eastern Chinese amphibian, Pseudepidalea raddei. Genealogical reconstructions are made and they detect major western and eastern lineages, which overlap in northwestern China, and possibly indicate the secondary contact of the populations that had entered the region from separate glacial refugia. Coalescent tests rejected alternative hypotheses of fragmentation of either a widespread ancestor or panmixia. The tests instead supported the hypothesis of geographic isolation and a remarkable dispersal pattern in one of the lineages. Though the Pleistocene climatic events are known to have affected the historical distributions and intra-specific divergence of Chinese squamates, coalescent and non-coalescent demographic analyses indicated that the toad P. raddei was not adversely affected by glacial cycling. Presumably, an increase in the amount of climatically mild habitats in East Asia is due to the development of monsoons since the Mid-late Pleistocene is responsible for the relatively mild effects.
