温度胁迫对紫贻贝与翡翠贻贝生理活动的影响和Hsp27的响应

摘要

为了探究急性温度胁迫对温度适应性不同的贻贝的生理影响,以紫贻贝(Mytilus galloprovincialis)与翡翠贻贝(Perna viridis)为对象,分别用4,8,25,35℃对紫贻贝进行温度胁迫,用8,15,35,42℃对翡翠贻贝进行胁迫.通过对耗氧率与排氨率的检测,分析了贻贝的生理代谢;制作石蜡切片观察鳃组织结构的变化,用Western-blot对Hsp27在鳃组织中的表达变化进行研究.结果表明:两种贻贝的耗氧率和排氨率均随温度升高而升高,但当紫贻贝胁迫温度达到35℃,翡翠贻贝胁迫温度达到42℃时,则表现出急剧下降;急性温度胁迫破坏两种贻贝鳃组织结构,并且损伤在恢复24 h后不可逆转,同时造成贻贝鳃组织Hsp27表达量升高.说明在一定温度范围内,贻贝的代谢随温度上升而加快,但当温度超过机体耐受阈值,可能会抑制代谢;低温和高温胁迫均可以破坏贻贝的鳃组织结构,且24 h内无法恢复; Hsp27在紫贻贝应对低温胁迫可能更为积极,而在翡翠贻贝应对低温及高温胁迫均有应答.%In the present study, the impacts of cold and heat stress on physiological responses of two mussel species, blue mussel Mytilus galloprovincialis and green mussel Perna viridis, were investigated. The stimulating temperatures of blue mussels were 4 ℃, 8 ℃, 25 ℃ and 35 ℃, and the green mussels were cultured at8 ℃, 15 ℃, 35 ℃ and 42 ℃, respectively. The oxygen consumption and ammonia excretion rate of mussels were analyzed, and the changes of gill tissue structure were observed by paraffin section. The expression of Hsp27 in gills was further studied by Western-blot. The results showed that oxygen consumption rate and ammonia excretion rate of mussels enhanced with the increasing of temperature. However, when the temperature reached at 35 ℃ in M. galloprovincialis and 42 ℃ in P. viridis, the oxygen consumption and ammonia excretion rate showed a sharp decline. Gill tissue in both species was damaged after acute cold and heat stresses, and the damaged gill tissue could not return to the control structure within 24 h recovery. A significant increased expression of Hsp27 was detected in the gill tissue of both species after acute cold and heat exposures. These re-sults indicated that metabolisms of two species mussels accelerated within a certain temperature range. However, when the temperature exceeded the mussels' tolerance limits, the metabolic rate might be inhibited. The gill tissue structure of mussels was destroyed by acute cold and heat stresses, and the damage could not be recovered within 24 h. Hsp27 might be more active in response to cold stress in the gill tissue of M. galloprovincialis, and response to moderate cold and heat stress in P. viridis.