Browsing by Author "Liu, Xiaojun"
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- Domain-dependent evolution explains functional homology of protostome and deuterostome complement C3-like proteinsPublication . Peng, Maoxiao; Li, Zhi; Cardoso, João; Niu, Donghong; Liu, Xiaojun; Dong, Zhiguo; Li, Jiale; Power, DeborahComplement proteins emerged early in evolution but outside the vertebrate clade they are poorly characterized. An evolutionary model of C3 family members revealed that in contrast to vertebrates the evolutionary trajectory of C3-like genes in cnidarian, protostomes and invertebrate deuterostomes was highly divergent due to independent lineage and species-specific duplications. The deduced C3-like and vertebrate C3, C4 and C5 proteins had low sequence conservation, but extraordinarily high structural conservation and 2-chain and 3-chain protein isoforms repeatedly emerged. Functional characterization of three C3-like isoforms in a bivalve representative revealed that in common with vertebrates complement proteins they were cleaved into two subunits, b and a, and the latter regulated inflammation-related genes, chemotaxis and phagocytosis. Changes within the thioester bond cleavage sites and the a-subunit protein (ANATO domain) explained the functional differentiation of bivalve C3-like. The emergence of domain-related functions early during evolution explains the overlapping functions of bivalve C3-like and vertebrate C3, C4 and C5, despite low sequence conservation and indicates that evolutionary pressure acted to conserve protein domain organization rather than the primary sequence.
- Inland alkaline brackish water aquaculture of juvenile razor clam: survival, growth, physiology and immune responsesPublication . Peng, Maoxiao; Li, Zhi; Liu, Xiaojun; Niu, Donghong; Li, JialeIn this study, we investigated rearing and breeding razor clam (Sinonovacula constricta) in inland alkaline brackish water. During 45 days of the experiment in candidate target inland area brackish water (TBW), survival, growth, enzyme activity and immune responses were analysed. The results showed that shell length and weight were significantly inhibited in the TBW group (p <0.001). Although the cumulative mortality was 81.479 ± 7.028 (p < 0.001) at 15 days, it increased slowly to 92.915 ± 2.271 (p < 0.001) at 45 days. The enzyme activities of Na+/K+-ATPase, aspartate aminotransferase and superoxide dismutase peaked at 15 days, and juvenile S. constricta (JSC) may engaged in partial anaerobic metabolism or damage to gill tissue, which may explain the high mortality rate at this time. Additionally, the phagocytic ability of haemocytes was inhibited (p < 0.001), but the metabolic activity was enhanced (p < 0.001). This implies that 15 days was the peak of TBW stress, and stress gradually decreased by days 30 and 45. TBW affected metabolism, osmotic regulation, and immune responses. There was an independent ionic interaction perhaps effect on JSC, primarily through Na+/K+ rate. Approximately 7 % of animals adapted successfully to TBW after 45 days. In summary, S. constricta has a great potential in further anti-TBW conditions selective breeding research.