Study On Early Lipid Characteristics And Key Lipid Metabolism Enzymes Of Schizothorax Grahami

The early stage of fish development is the most vulnerable stage in the entire life history of an individual fish,Therefore,it is imperative to understand its developmental laws,It has important practical significance for protecting endangered fish and optimizing aquaculture.In the early stages of fish development,lipids are an important source of energy,Lipids can not only provide energy for early development through metabolism,but also participate in the body’s tissue construction,Provide essential fatty acids for embryonic development,It plays an important role in early development,fertilization rate,hatching rate,etc.Therefore,this study explored the early developmental morphology,lipid metabolism enzymes and fatty acid change characteristics of Schizothorax grahami through developmental biology,enzymology and molecular studies.On the one hand,we explored the effects of glucose and vitamin C on lipid metabolism enzymes and PPARs genes.The purpose is to provide a reference for the occurrence of lipid metabolism in the early development of S.grahami.The main findings are as follows:1.By observing that the fertilized eggs of S.grahami are sinking eggs,beige round sphere,Measure the egg diameter as(3.14±0.18)mm and the egg weight as(14.21±0.49)mg,After fertilization,the egg diameter of the fertilized egg is(4.24±0.15)mm,and the egg weight is(37.50±1.64)mg.Under the water temperature of14.7～15.6℃,the film will be released after 151.6h.Photographed and described the external morphological characteristics of each developmental stage.2.Explored the activity characteristics of FAS,ACC,CPT I,LPL,HL in the early development of S.grahami,The results show that:1 FAS、ACC、CPT I、LPL and HL exist in mature eggs during embryonic development,And has high activity,During the blastocyst stage,the lipid metabolism2 enzyme activity is significantly reduced,ACC、CPT I、LPL、and HL are significantly increased in the gastrulation stage,The overall change was irregular.the result shows:The ACC、FAS、 LPL、 HL and CPT I of S.grahami are all maternal enzymes.That zygotic genes begin to be expressed in the gastrulation stage.3 The activities of FAS 、 ACC 、 LPL and HL at the post-embryonic developmental stage showed a trend of first decreasing and then increasing,CPT I activity is on the rise,Except for HL,the activity of other enzymes reaches the highest during the exogenous vegetative period.4 Use 15g/L glucose and 35mg/L vitamin C solution to soak S.grahami embryos,The activities of FAS、ACC、CPT I、LPL and HL were induced to increase in the blastocyst stage and gastrulation stage.The result shows:Glucose and vitamin C solution can promote the activity of lipometabolism enzymes during embryonic development of S.grahami.15g/L glucose solution and 35mg/L vitamin C solution can promote lipid metabolism enzymes in the blastocyst stage and gastrulation stage.3.Explored the fatty acid composition and relative content of S.grahami endogenous vegetative period,mixed vegetative period and exogenous vegetative period,A total of 32 fatty acids were detected,including 11 saturated fatty acids(EPA),8 types of monounsaturated fatty acids(MUFA),12 kinds of polyunsaturated fatty acids(PUFA),Relative content of three fatty acids ∑PUFA>∑SFA>∑MUFA,The order of fatty acid consumption is MUFA>SFA>n-3HUFA>n-6PUFA.4.The PPARs gene expression levels in various stages of early development were explored,and the results showed that:1 PPARs are expressed at the stage of fertilized eggs,and PPARα and PPARγgenes show a decreasing-increasing-decreasing trend.The expression of PPARβ gene increased from the fertilized egg to the tail bud stage,and it was suppressed and decreased in the pre-emergence stage.2 When immersed in 15g/L glucose solution,the expression of PPARα gene is significantly inhibited in the fertilized egg,gastrulation stage,and pre-emergence stage.The expression of PPARβ gene is induced from the blastocyst stage,and the3 expression of PPARγ gene is induced during the cleavage and tail bud stages.4 Under the immersion of 35mg/L vitamin C solution,the change trend of PPARα gene is similar to that of the normal group.It is significantly induced to express in the gastrulation stage,The expression of PPARβ gene is significantly induced from the blastocyst stage,The expression of PPARγ gene was significantly induced in the tail bud stage.5 The result shows:Glucose and vitamin C solution are the activator of PPARβgene in the early development of S.grahami,And PPARβ perform cell differentiation function in early development.