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This study explores the relationship between food availability and the presence of uranium on zebrafish metabolism. The Dynamic Energy Budget (DEB) theory is used to create a mechanistic model that captures all aspects of metabolism, including embryonic development, growth, reproduction, and survival. The effects of uranium toxicity on various metabolic processes are also investigated. The model provides valuable insights into the metabolic performance of individual zebrafish throughout their lifecycle and can be used to analyze chemically induced environmental risks.
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Mechanistic modeling of zebrafish metabolism in relationship to food level and the presence of a toxicant (uranium) S. Augustine B.Gagnaire C. Adam-Guillermin S. A. L. M. Kooijman
Processes at different levels of biological organisation Role of differences in individuals + selection in evolution Time ecosystems Energy + Mass Balances populations Role of behavior on food intake and mate preference Individuals cells Differences between individuals = differences in parameter values molecules Space AQUATIC SCIENCES MEETING, ASLO, PR 02/14/2011
Dynamic Energy Budget (DEB) Theory (Kooijman 2010) Specifies uptake and use of substrate by all organisms Standard DEB model Mechanistic parameter sparse model which specifies individual mass and energy fluxes for all animals over a whole lifecycle To what extent does a single combination of parameters capture all aspects of metabolism for each life stage for a particular animal? Estimation of a single set of parameters for zebrafish, Danio rerio based on observations of: - Embryonic development - Growth - Reproduction - Survival Augustine et al. subm. 2011 AQUATIC SCIENCES MEETING, ASLO, PR 02/14/2011
Structure Somatic Maintenance Maturity Maintenance Maturity DEB model applied to the whole lifecycle of Danio rerio EMBRYO JUV I J II ADULT AGE BIRTH METAMORPHOSIS PUBERTY қG (0.67) Қ(0.44) Food Reserve қX Reproduction Buffer 1 – қ қR (0.95) AQUATIC SCIENCES MEETING, ASLO, PR 02/14/2011 Eggs
Effects of feeding history accumulate over time Maturity is a good quantifier for developmental stage The value of қ is close to the one that maximises reproduction size High variability in reproduction buffer handling rules combines with low variability of cumulated reproductive output age Surface area-specific assimilation and reserve mobilization rates are higher for adults than for embryos Developmental milestone quantified as cumulated energy invested in maturity (J) AQUATIC SCIENCES MEETING, ASLO, PR 02/14/2011
Relationships between egg size, and cumulated energy invested in the different metabolic processes at birth 1 J 1.67 J Relationship between egg size and resistance to starvation? AQUATIC SCIENCES MEETING, ASLO, PR 02/14/2011
Effects of compounds: URANIUM Uranium is toxic for organisms (Canadian law on environmental protection 1999) Effects Internalised U Internalised U No Internal Effect Concentration Exposure to contaminants induces physiological deviations from the blank • Modified growth • Modified reproductive output AQUATIC SCIENCES MEETING, ASLO, PR 02/14/2011
Effects are translated as the modification of a parameter value Structure Somatic Maintenance Food Reserve Maturity Maintenance Maturity Maturity Reproduction Buffer Scenario 1 : Bring up the cost for a unit of structure Scenario 2 : Bring up the volume linked somatic maintenance costs Scenario 3 : Bring up maturity maintenance costs AQUATIC SCIENCES MEETING, ASLO, PR 02/14/2011
Scenario 1 : Bring up the cost for a unit of structure Scenario 2 : Bring up the volume linked somatic maintenance costs Scenario 3 : Bring up maturity maintenance costs BLANK Length (mm) Maturation (kJ) Cumulated # eggs 40 8.104 3 0 0 0 5 200 200 200 5 5 Age, day Age, day Age, day AQUATIC SCIENCES MEETING, ASLO, PR 02/14/2011
Conclusions Food Metabolic performance of an individual over a whole life cycle Compounds For effects of compounds the predictive power of the model is linked to the quality of parameter values of the blank The model can be applied to data to determine the mode action of substances on the metabolism and so contributes analysis of chemically induced environmental risks AQUATIC SCIENCES MEETING, ASLO, PR 02/14/2011
Thank you for your attention … AQUATIC SCIENCES MEETING, ASLO, PR 02/14/2011