BioSimWare: A P Systems-based Simulation Environment for Biological - - PowerPoint PPT Presentation
BioSimWare: A P Systems-based Simulation Environment for Biological - - PowerPoint PPT Presentation
BioSimWare: A P Systems-based Simulation Environment for Biological Systems Daniela Besozzi 1 , Paolo Cazzaniga 2 , Giancarlo Mauri 2 , Dario Pescini 2 Universit` a degli Studi di Milano Dipartimento di Informatica e Comunicazione Via Comelico
Outline
1
BioSimWare
2
Stochastic Simulations Algorithms for Single and Multi-Volume Systems
3
Tools for The Analysis of Stochastic Simulations Parameter Estimation (PE) Parameter sweep applications (PSA)
4
Applications The Schl¨
- gl System
The Brussellator Stiff Systems Bacterial Chemotaxis Simulation of Fredkin Circuits by Chemical Reaction Systems
5
Conclusion
Outline
1
BioSimWare
2
Stochastic Simulations Algorithms for Single and Multi-Volume Systems
3
Tools for The Analysis of Stochastic Simulations Parameter Estimation (PE) Parameter sweep applications (PSA)
4
Applications The Schl¨
- gl System
The Brussellator Stiff Systems Bacterial Chemotaxis Simulation of Fredkin Circuits by Chemical Reaction Systems
5
Conclusion
Introduction
BioSimWare is a simulation environment based on P systems, that provides a user-friendly framework for the modeling of biological systems ranging from cellular processes to population phenomena.
1 2 3
substances (objects) reactions (evolution rules)
- rganelles (regions)
membrane
a a a a c c c b b b a c a a a b b c c c c'→(c, in2) a+c→(b, out) a+b→(c, here) c→(c', out) b+c→(a, here) a→(a, out)
User Interface: rules specification
User Interface: system conditions specification
User Interface: plot of the dynamics
Outline
1
BioSimWare
2
Stochastic Simulations Algorithms for Single and Multi-Volume Systems
3
Tools for The Analysis of Stochastic Simulations Parameter Estimation (PE) Parameter sweep applications (PSA)
4
Applications The Schl¨
- gl System
The Brussellator Stiff Systems Bacterial Chemotaxis Simulation of Fredkin Circuits by Chemical Reaction Systems
5
Conclusion
Available simualtion algorithm
Single Volume SSA tau leaping adaptive tau leaping average tau leaping dynamics ODE integrator Multi Volume DPP tau-DPP Stau-DPP
Outline
1
BioSimWare
2
Stochastic Simulations Algorithms for Single and Multi-Volume Systems
3
Tools for The Analysis of Stochastic Simulations Parameter Estimation (PE) Parameter sweep applications (PSA)
4
Applications The Schl¨
- gl System
The Brussellator Stiff Systems Bacterial Chemotaxis Simulation of Fredkin Circuits by Chemical Reaction Systems
5
Conclusion
PE: the goal
We would like to reproduce the target dynamics via stochastic simulations:
560 580 600 620 640 660 680 700 720 740 760 0.5 1 1.5 2 2.5 3 3.5 molecules time [a.u.] target generated
not necessarily using the same set of constants.
PE: the problem
Quantify the “distance” among the dynamics and find the closest one
560 580 600 620 640 660 680 700 720 740 760 0.5 1 1.5 2 2.5 3 3.5 molecules time[a.u.] target 0.00245015 0.0015 0.001 0.0005 0.0001
The fitness: Standard Distance
The fitness: tricks
Facts related to intrinsic noise that should not be neglected: each outcome j is quantitatively different {X(τi)}j
not evenly sampled {τi}j not same number of points {= X(τi)}j
in the thermodynamic limit {X(τi)} → [X](ti)
exploit ensemble behavior (may flatten oscillations, not in phase outcome) F (X(τi))
?
= F ( X(τi) )
same parameters, possibly (almost always), generate different values of the fitness function (“weak convergence”)
The fitness: “Area” distance
Reconstructed dynamics
1100 1150 1200 1250 1300 1350 1400 1450 1500 0.05 0.1 0.15 0.2 CheYp Molecules Time [a.u.] HC PSO Target
Parameter sweep applications (PSA)
A PSA consists in a repeated execution of an application (usually performed a large number of times), where each execution is achieved using a different parametrisation. In the context of biochemical stochastic models a PSA could be viewed as PSA = (P; D; M), where P = (p1; . . . ; pn) is the set of parametrisations with pi = (xi
0; ci)
D = (d1; . . . ; dn) di = (xi(0); . . . ; xi(t)) where t is the halting time of the simulation i M is the biochemical model that provides the map pi → di
PSA: EGEE Grid
EGEE project infrastructure, a wide area grid platform for scientific applications, com- posed of thousands of CPUs, which im- plements the Virtual Organisation (VO) paradigm. More than 90 partners in 32 countries, organised in 13 Federations A Grid infrastructure spanning almost 240 sites across 45 countries An infrastructure of 41,000 CPU available to users 24 hours a day, 7 days a week More than 5 Petabytes (5 million Gigabytes) of storage Sustained and regular workloads of 30K jobs/day, reaching up to 98K jobs/day
Perturbed parameters fitness
10 20 30 40 50 60 0 10 20 30 40 50 60 70 80 90 100 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 fitness ci ci perturbation fitness 5e-05 0.0001 0.00015 0.0002 0.00025 0.0003 5e-05 0.0001 0.00015 0.0002 0.00025 0.0003 0.00035 0.0004 0.00045 0.0005 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 fitness fitness
Outline
1
BioSimWare
2
Stochastic Simulations Algorithms for Single and Multi-Volume Systems
3
Tools for The Analysis of Stochastic Simulations Parameter Estimation (PE) Parameter sweep applications (PSA)
4
Applications The Schl¨
- gl System
The Brussellator Stiff Systems Bacterial Chemotaxis Simulation of Fredkin Circuits by Chemical Reaction Systems
5
Conclusion
The Schl¨
- gl System
r1 : A + 2X
3·10−7
− → 3X r2 : 3X
10−4
− → A + 2X r3 : B
10−3
− → 3X r4 : X
3.5
− → B
A = 1·105 B = 2·105 X = 250
100 200 300 400 500 600 700 5 10 15 20 X Molecules Time [a.u.] 100 200 300 400 500 600 700 800 50000 100000 150000 200000 250000 300000 350000 400000 X Molecules Time [a.u.] 100000 200000 300000 400000 500000 600000 700000 800000 900000 1e+06 100 200 300 400 500 600 700 800 Frequency X Molecules
The Brusselator
r1 :A
1
− → X r2 :B + X
5·10−3
− → Y r3 :2X + Y
2.5·10−5
− → 3X r4 :X
1.5
− → λ
A = X = 200 B = 600 Y = 300
Comparison GA & PSO: Oscillating Brusselator
5000 10000 15000 20000 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000
Average Best Fitness Fitness Evaluations
PSO1 PSO2 GA
500 1000 1500 2000 2500 5 10 15 20 25
Molecules Time [a.u.]
X Y X target Y target
0.2 0.4 0.6 0.8 1 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000
Successful Runs Fitness Evaluations
PSO1 PSO2 GA
PSO1/2 best performers GA worst average fitnesses dynamics faithfully reconstructed
Comparison GA & PSO: Damped Brusselator
400 600 800 1000 1200 1400 1600 1800 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000
Average Best Fitness Fitness Evaluations
PSO1 PSO2 GA
50 100 150 200 250 300 350 400 5 10 15 20 25
Molecules Time [a.u.]
X Y X target Y target
10 20 30 40 50 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000
Successful Runs Fitness Evaluations
PSO1 PSO2 GA
PSO1/2 best performers GA worst average fitnesses dynamics unfaithfully reconstructed
Stiff systems: an example
A system is said to be stiff if is characterized by well-separeted fast and slow dynamical modes, the fastest of which is stable. The decaying dimerization model: r1 :S1
1
− → λ r2 :S1 + S1
10
− → S2 r3 :S2
103
− → S1 + S1 r4 :S2
0.1
− → S3 S1 = 104 S2 = S3 = 0
SSA tau leaping adaptive tau leaping average number of steps 2.46 · 107 1 · 106 945 total execution time 175h 1m 11h 47m 1m 51s
Decaying dimerization: algorithms comparison
1000 2000 3000 4000 5000 0.5 1 1.5 2 2.5 3 3.5 4 Molecules Time [a.u.] S1 S2 S3 1000 2000 3000 4000 5000 0.5 1 1.5 2 2.5 3 3.5 4 Molecules Time [a.u.] S1 S2 S3 1000 2000 3000 4000 5000 0.5 1 1.5 2 2.5 3 3.5 4 Molecules Time [a.u.] S1 S2 S3 1000 2000 3000 4000 5000 0.5 1 1.5 2 2.5 3 3.5 4 Molecules Time [a.u.] S1 S2 S3 SSA tau-leaping adaptive tau-leaping
Bacterial chemotaxis
Chemotaxis allows bacteria to respond to ligand concentration gradients in their surroundings: random walk through an homogeneous environment → high switching frequency of flagellar rotation directional swimming in presence of ligand concentration gradient → reduced switching frequency of flagellar rotation adaptation: if ligand concentration remains constant → switching frequency is reset to random walk level
Sensing Responding Adapting
Reagents Products
- Methyl. state
1 2MCPm + 2CheW 2MCPm ::2CheW m = 0 2 2MCPm ::2CheW 2MCPm + 2CheW m = 0 3 2MCPm ::2CheW + 2CheA 2MCPm ::2CheW::2CheA m = 0 4 2MCPm ::2CheW::2CheA 2MCPm ::2CheW + 2CheA m = 0 5-8 2MCP m ::2CheW::2CheA + CheR 2MCPm+1::2CheW::2CheA + CheR m = 0, . . . , 3 9-12 2MCPm ::2CheW::2CheA + CheBp 2MCPm−1::2CheW::2CheA + CheBp m = 1, . . . , 4 13-17 2MCPm ::2CheW::2CheA + ATP 2MCPm ::2CheW::2CheAp m = 0, . . . , 4 18-22 2MCPm ::2CheW::2CheAp + CheY 2MCPm ::2CheW::2CheA + CheYp m = 0, . . . , 4 23-27 2MCPm ::2CheW::2CheAp + CheB 2MCPm ::2CheW::2CheA + CheBp m = 0, . . . , 4 28-32 lig + 2MCPm ::2CheW::2CheA lig::2MCPm ::2CheW::2CheA m = 0, . . . , 4 33-37 lig::2MCPm ::2CheW::2CheA lig + 2MCPm ::2CheW::2CheA m = 0, . . . , 4 38-41 lig::2MCPm ::2CheW::2CheA + CheR lig::2MCPm+1::2CheW::2CheA + CheR m = 0, . . . , 3 42-45 lig::2MCPm ::2CheW::2CheA + CheBp lig::2MCPm−1::2CheW::2CheA + CheBp m = 1, . . . , 4 46-50 lig::2MCPm ::2CheW::2CheA + ATP lig::2MCPm ::2CheW::2CheAp m = 0, · · · , 4 51-55 lig::2MCPm ::2CheW::2CheAp + CheY lig::2MCPm ::2CheW::2CheA + CheYp m = 0, . . . , 4 56-60 lig::2MCPm ::2CheW::2CheAp + CheB lig::2MCPm ::2CheW::2CheA + CheBp m = 0, . . . , 4 61 CheYp + CheZ CheY + CheZ 62 CheBp CheB
62 reactions, 32 molecular species
Sensing Responding Adapting
800 1000 1200 1400 1600 1800 2000 500 1000 1500 2000 2500 3000 3500 4000 CheYp Molecules Time [sec] ODE solution Stoch solution
Sensing Responding Adapting
CheYp and the flagellar rotation
Our assumptions: the flagellar motor switch is sensitive to a threshold level of CheYp, that is hereby evaluated as the mean value of CheYp at steady state we make a one-to-one correspondence between the behavior of a single flagellum and one temporal evolution
- f CheYp generated by one run of the tau leaping
algorithm.
50 100 150 200 Time [sec]
μ CheYp True False CW CCW
Many flagella and running or tumbling
T n
sync = {t ∈ ∆tsim | CCWsi(t) = true for all i = 1, . . . , n}
T n
sync is the set of all times during which all time series si are below
the threshold µ
time
s s
1 2
That corresponds to the running motion of the bacterium
Many flagella and running or tumbling
0.5 1 1.5 2 2.5 3 3.5 2 4 6 8 10 Time [sec] Flagella < ∆ trun >
Running < ∆trun > all flagella rotate CCW
50 100 150 200 250 300 2 4 6 8 10 Time [sec] Flagella < ∆ ttumb >
Tumbling < ∆ttumb > some flagella rotate CW
70 75 80 85 90 95 100 105 2 4 6 8 10 Time [sec] Flagella < ∆ tadapt >
Adapting < ∆tadapt > length of the negative peak
Fredkin Gate: definition
αi βi γi → αo βo γo 0 0 0 0 0 0 0 0 1 0 0 1 0 1 0 0 1 0 0 1 1 0 1 1 1 0 0 1 0 0 1 0 1 1 1 0 1 1 0 1 0 1 1 1 1 1 1 1
Reaction Constant r1 : a + b → a + d c1 = 1 · 10−3 r2 : a + c → a + e c2 = 1 · 10−3 r3 : a + B → a + D c3 = 1 · 10−3 r4 : a + C → a + E c4 = 1 · 10−3 r5 : A + b → A′ c5 = 1 · 10−3 r6 : A′ + c → A + d + e c6 = 1 · 10−1 r7 : A′ + C → A + D + e c7 = 1 · 10−1 r8 : A + B → A′′ c8 = 1 · 10−3 r9 : A′′ + c → A + d + E c9 = 1 · 10−1 r10 : A′′ + C → A + D + E c10 = 1 · 10−1 Reaction Constant r11 : a + A → λ c11 = 1 · 10−1 r12 : b + B → λ c12 = 1 · 10−1 r13 : c + C → λ c13 = 1 · 10−1 r14 : d + D → λ c14 = 1 · 10−1 r15 : e + E → λ c15 = 1 · 10−1 r16 : λ → a c16 ∈ {0, 1} r17 : λ → A c17 ∈ {0, 1} r18 : λ → b c18 ∈ {0, 1} r19 : λ → B c19 ∈ {0, 1} r20 : λ → c c20 ∈ {0, 1} r21 : λ → C c21 ∈ {0, 1}
Fredkin Gate: definition
αi βi γi → αo βo γo a b c a d e a b C a d E a B c a D e a B C a D E A b c A d e A b C A D e A B c A d E A B C A D E
Reaction Constant r1 : a + b → a + d c1 = 1 · 10−3 r2 : a + c → a + e c2 = 1 · 10−3 r3 : a + B → a + D c3 = 1 · 10−3 r4 : a + C → a + E c4 = 1 · 10−3 r5 : A + b → A′ c5 = 1 · 10−3 r6 : A′ + c → A + d + e c6 = 1 · 10−1 r7 : A′ + C → A + D + e c7 = 1 · 10−1 r8 : A + B → A′′ c8 = 1 · 10−3 r9 : A′′ + c → A + d + E c9 = 1 · 10−1 r10 : A′′ + C → A + D + E c10 = 1 · 10−1 Reaction Constant r11 : a + A → λ c11 = 1 · 10−1 r12 : b + B → λ c12 = 1 · 10−1 r13 : c + C → λ c13 = 1 · 10−1 r14 : d + D → λ c14 = 1 · 10−1 r15 : e + E → λ c15 = 1 · 10−1 r16 : λ → a c16 ∈ {0, 1} r17 : λ → A c17 ∈ {0, 1} r18 : λ → b c18 ∈ {0, 1} r19 : λ → B c19 ∈ {0, 1} r20 : λ → c c20 ∈ {0, 1} r21 : λ → C c21 ∈ {0, 1}
Fredkin Gate: simulations
200 400 600 800 1000 1200 1400 1600 200 400 600 800 1000 1200 1400
Molecules Time [a.u.]
a d E D
First input (αi , βi , γi ) = (0, 0, 1) at t = 0 Second input (αi , βi , γi ) = (0, 1, 1) at t = 500 a b C → a d E a B C → a D E
200 400 600 800 1000 1200 500 1000 1500 2000
Molecules Time [a.u.]
a A d e E D
First input (αi , βi , γi ) = (0, 0, 1) at t = 0 Second input (αi , βi , γi ) = (1, 0, 1) at t = 400 a b C → a d E A b C → A D e
Fredkin Circuits
500 1000 1500 2000 2500 y1 = 1 y2 = 0 y2 = 1 200 400 600 800 1000 1200
Molecules
y3 = 0 y3 = 1 y4 = 1 y5 = 0 200 400 600 800 1000 1200 1400 1600 1800 500 1000 1500 2000
Time [a.u.]
y6 = 1 y7 = 0
Outline
1
BioSimWare
2
Stochastic Simulations Algorithms for Single and Multi-Volume Systems
3
Tools for The Analysis of Stochastic Simulations Parameter Estimation (PE) Parameter sweep applications (PSA)
4
Applications The Schl¨
- gl System
The Brussellator Stiff Systems Bacterial Chemotaxis Simulation of Fredkin Circuits by Chemical Reaction Systems
5
Conclusion
Summary
BioSimWare is a simulation environments for the investigation
- f various biological systems that can range from cellular