mechanistic modeling of zebrafish metabolism in relationship to food level and the presence of a...
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Mechanistic modeling of zebrafish Mechanistic modeling of zebrafish metabolism in relationship to food metabolism in relationship to food level and the presence of a toxicant level and the presence of a toxicant
(uranium)(uranium)
S. AugustineB.Gagnaire
C. Adam-GuillerminS. A. L. M. Kooijman
AQUATIC SCIENCES MEETING, ASLO, PR 02/14/2011
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Processes at different levels of biological organisation
Space
Time
molecules
cells
populations
ecosystems
Individuals
AQUATIC SCIENCES MEETING, ASLO, PR 02/14/2011
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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
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
Augustine et al. subm. 2011
AQUATIC SCIENCES MEETING, ASLO, PR 02/14/2011
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DEB model applied to the whole lifecycle of Danio rerio
FoodReserve
Structure
Somatic Maintenance
Maturity
Maturity MaintenanceқX
қG
(0.67)
қR (0.95)
Eggs
Reproduction Buffer
Қ (0.44)
1 – қ
BIRTH METAMORPHOSIS PUBERTY
EMBRYO JUV I J II ADULTAGE
AQUATIC SCIENCES MEETING, ASLO, PR 02/14/2011
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age
size
Developmental milestone quantified as cumulated energy invested in maturity
(J)
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
High variability in reproduction buffer handling rules combines with low variability of cumulated reproductive output
Surface area-specific assimilation and reserve mobilization rates are higher for adults than for embryos
AQUATIC SCIENCES MEETING, ASLO, PR 02/14/2011
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1 J
Relationships between egg size, and cumulated energy invested in the different metabolic processes at birth
Relationship between egg size and resistance to starvation?
1.67 J
AQUATIC SCIENCES MEETING, ASLO, PR 02/14/2011
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Effects of compounds: URANIUM
Internalised U
Effects
Internalised U
Exposure to contaminants induces physiological deviations from the blank
No Internal Effect Concentration
Uranium is toxic for organisms (Canadian law on environmental protection 1999)
-Modified growth-Modified reproductive output
AQUATIC SCIENCES MEETING, ASLO, PR 02/14/2011
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FoodReserve
Structure
Somatic Maintenance
Maturity
Maturity Maintenance
MaturityReproduction Buffer
Scenario 1 : Bring up the cost for a unit of structureScenario 2 : Bring up the volume linked somatic maintenance costsScenario 3 : Bring up maturity maintenance costs
Effects are translated as the modification of a parameter value
AQUATIC SCIENCES MEETING, ASLO, PR 02/14/2011
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Length (mm) Maturation (kJ) Cumulated # eggs
2000
40
Age, day Age, day Age, day
5
Scenario 1 : Bring up the cost for a unit of structureScenario 2 : Bring up the volume linked somatic maintenance costsScenario 3 : Bring up maturity maintenance costs
0
8.104
0
3
BLANK
5 200 5 200
AQUATIC SCIENCES MEETING, ASLO, PR 02/14/2011
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Conclusions
Food
Compounds
Metabolic performance of an individual over a whole life cycle
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
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Thank you for your attention …