摘要：
H. Cheng, G. Dai, L. Yu, X. Zhong, P. Juneau and B. Qiu. 2008. Influence of CO2 concentrating mechanism on photoinhibition in Synechococcus sp. PCC7942 (Cyanophyceae). Phycologia 47: 588–598. DOI: 10.2216/07-44.1. In this study the effects of inorganic carbon transport in the cyanobacterium Synechococcus sp. PCC7942 on its photoinhibition were investigated. The photosynthetic oxygen evolution of samples under a strong irradiance treatment at 100 µM KHCO3 was much higher than that at 10,000 µM KHCO3. After strong irradiance treatment, the abundance of the sbtA transcript encoding a Na+-dependent transporter was significantly higher under treatment at 100 µM KHCO3 than at 10,000 µM KHCO3. Lincomycin had little effect on the difference of photosystem II (PSII) activity decline under these two treatments, which suggests that CCM activity reduces photodamage but does not boost the rate of PSII repair. The maximal photosynthetic efficiency was decreased significantly during the strong irradiance treatment, and its decrease was enhanced when the external DIC concentration was raised from 100 to 10,000 µM KHCO3. The JIP test showed that there were more active reaction centres under low Ci conditions after high light treatment. Studies on 77-K fluorescence emission spectra showed that the fluorescence peaks F692 nm and F710 nm in 10,000-µM KHCO3 treated samples both decreased after strong irradiance treatment and were significantly smaller than those of 100-µM KHCO3 treated samples. Samples treated with 100 µM KHCO3, compared to 10,000 µM KHCO3 had a higher possibility of transmitting an exciton to a closed reaction centre rather than to an open reaction centre and thus to reduce the overexcitation of the reaction centres. These results indicated that higher external inorganic carbon concentration was associated with more severe photoinhibition under high irradiance and that the operation of CO2 concentrating mechanism might reduce the overexcitation of reaction centres to reduce photodamage.
摘要：
以鲫鱼为试验鱼类,采用室内人工水族箱培养法,研究氯氰菊酯对鲫鱼的急性毒性效应,并在此基础上研究不同浓度的氯氰菊酯对鲫鱼血清Na+,K+-ATPase、谷草转氨酶GOT和超氧化物歧化酶SOD活力的影响.结果表明,氯氰菊酯对鲫鱼的96 h LC50为20.74μg/L,属于剧毒物质.经2μg/L、5μg/L、10μg/L3个浓度组染毒处理4 d,鲫鱼血清中3种酶的活性相比对照组均发生了明显的变化.随着氯氰菊酯浓度的升高,GOT活性升高,SOD活性先升高后降低,Na+,K+-ATPase则迅速下降.以上现象表明低浓度的氯氰菊酯能够对鲫鱼机体代谢造成一定的损伤.
通讯机构：
[Geng, Hui] H;Huazhong Normal Univ, Coll Life Sci, Dept Biochem & Mol Biol, 100 Luoyurd, Wuhan 430079, Peoples R China.
关键词：
Cartilage Oligomeric Matrix Protein;Cartilage Oligomeric Matrix Protein;Multiple Epiphyseal Dysplasia;Cartilage Oligomeric Matrix Protein Level;Serum Cartilage Oligomeric Matrix Protein Level
摘要：
Cartilage oligomeric matrix protein (COMP) is a homopentameric protein in cartilage. The development of arthritis, like collagen-induced arthritis (CIA), involves cartilage as a target tissue. We have investigated the development of CIA in COMP-deficient mice. COMP-deficient mice in the 129/Sv background were backcrossed for 10 generations against B10.Q mice, which are susceptible to chronic CIA. COMP-deficient and wild-type mice were tested for onset, incidence, and severity of arthritis in both the collagen and collagen antibody-induced arthritis models. Serum anti-collagen II and anti-COMP antibodies as well as serum COMP levels in arthritic and wild-type mice were measured by enzyme-linked immunosorbent assay. COMP-deficient mice showed a significant early onset and increase in the severity of CIA in the chronic phase, whereas collagen II-antibody titers were similar in COMP-deficient and wild-type controls. COMP antibodies were not found in wild-type mice. Finally, COMP-deficient and wild-type mice responded similarly to collagen antibody-induced arthritis, indicating no difference in how collagen II antibodies interact with COMP-deficient cartilage during the initial stages of arthritis. COMP deficiency enhances the early onset and development of chronic arthritis but does not affect collagen II autoimmunity. These findings accentuate the importance of COMP in cartilage stability.
