| Aestivation is a special type of dormancy that allows sea cucumber to surviveduring periods of extreme heat condition.The metabolism variation and its regulationmechanism and the global gene expression was studied1、The activities of metabolic enzymes,digestive enzymes and antioxidant capacityunder raising temperature was studied.The activities of GDH and PK in body walldecreased to a peak value at8and10d，and rose after10d，getting to a level belowand above the that of control group at20d.The activities of G-6-PDH,GDH and PK ofrespiratory trees in ST group increased to a peak value at10,8and6d,while increasedto a peak value at10d in experiment in LT group.The activities of G-6-PDH stabilizedbut GDH and PK decreased in10-20d.The activities of amylase and lipase showedsignificant reduction as temperature rose while the activity of trypsin increased to apeak value at15d before decreasing.Antioxidant capacity of two experiment groupincreased to a peak value at6and8d respectively and decreased to the level in controlgroup.The activities of SOD decreased to a peak value at6d and stabilized.The ratioof GSH/GSSG was above before15d and below after15d the level of control group.2、The concentration of bioamine in coelomic fluid,body wall and respiratory treesunder temperature change was studied.The NE in coelomic fluid of two experimentgroup decreased to peak value and DA increased to a peak value at6and10drespectively.Both NE and DA of two experiment group return to the level of controlgroup except NE of experiment LT group.The concentration of5-HT showed asignificant reduction during experiment time.The concentration DA and5-HT ofrespiratory trees increased to a peak at10d while the concentration of NE of two experiment group decreased to a peak value at6d.the concentration of5-HT and NEreturn to the level of control group while DA show a positive correlation totemperature.Both DA and5-HT of respiratory trees increased to a peak value at10dwhile NE decreased to a peak value at10d and show a negative correlation andpositive correlation to temperature.DA of LT group was above the level of controlgroup while both NE and5-HT of experiment group were below the level of controlgroup.3、The signal transduction factors under under temperature change was studied.Theconcentration of cAMP of two experiment in bady wall decreased to a peak value at6d while cGMP decreased a peak value at8and10d.Both cAMP and cGMP returnedto the level of control group.The activities of PKA decreased to a peak value at6dwhile PKG decreased a peak value at8and10d.The activities of Both PKA and PKGof returned to the level of control group in ST group after10d,which were below andabove the level of control group. Concentration of cAMP in respiratory treesincreased to peak value at8and10d,while cGMP of two experiment group get thisvalue at10d.And then cAMP decreased to the level equal to and above the level of thecontrol group in10-20d while cGMP decreased to the value below and above thelevel of the control group.The activities of PKA of two experiment group reachedmaximum at8and10d while PKG get this value at10d and both showed positivecorrelation to temperature.And then activities of PKA returned to the value of controlgroup at20d while PKG was below and above control group respectively.4、Suppression subtractive hybridisation (SSH) method was employed and asubtracted cDNA library was constructed. The mRNAs, isolated from intestine of thetemperature-induced aestivation sea cucumber exposed to rising temperature was usedas "tester", and mRNAs from normal sea cucumber were used as "driver". Thedifferentially expressed cDNA fragments were identified. Of the309analyzed cloneswhich get from the library of500clones,115ESTs were significantly matched withknown genes (BLAST E-value <10–5). Expression of selected gens were analysedusing fluorescent real-time quantitative PCR technology.The expression of most gens showed a temporal and dose-dependent response within a limit range. |
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