Post on 01-Dec-2014
description
transcript
Pacific Oyster Physiological Response to Disease under Variable Environmental
Regimes
Emma Timmins-Schiffman, Elene Dorfmeier, Paul McElhany, Shallin Busch, Steven Roberts & Carolyn Friedman
University of Washington
PCSGA 2010
Objective How do environmental stressors, such as ocean
acidification (OA) and elevated temperature, affect oyster larvae survival and physiology when challenged by disease?
Experimental Plan
Vibrio photo: Waldor & RayChaudhuri, 2000, Nature
Host
Pathogen
OA High Temp.
How do environmental changes affect the host-pathogen relationship?
Outline Ocean acidification Environmental stress and physiology Temperature and the C. gigas-V. tubiashii
relationship OA effects on C. gigas Current work: OA & V. tubiashii
OA Hi T
Outline Ocean acidification Environmental stress and physiology Temperature and the C. gigas-V. tubiashii
relationship OA effects on C. gigas Current work: OA & V. tubiashii
OA Hi T
Ocean Acidification
1000 ppm
380 ppm
Increased CO2 in atmosphere
Increased oceanic CO2 = lower oceanic pH
Environmental Stress Growth Reproduction
General metabolism Immune response
Normal Environment
Growth Reproduction
Immune response General metabolism
Environmental Stress
pH
Outline Ocean acidification Environmental stress and physiology Temperature and the C. gigas-V. tubiashii
relationship OA effects on C. gigas Current work: OA & V. tubiashii
OA Hi T
Temperature & V. tubiashii Two temperatures: 12oC & 25oC V. tubiashii challenge in both temperatures 3 day trial Immune response genes:
C-jun kinase NfkB
Up-regulate immune defenses: -ROS -inflammatory response
Temperature & V. tubiashii = 12oC
= 25oC
1 2 3
* *
=12oC + Vt =25oC + Vt
Temperature & V. tubiashii
Assay Development
n=3 n=4
n=4
n=2 n=3 n=2
n=4
n=2
12oC 12oC 12oC 12oC 25oC 25oC 25oC 25oC
Outline Ocean acidification Environmental stress and physiology Temperature and the C. gigas-V. tubiashii
relationship OA effects on C. gigas Current work: OA & V. tubiashii
OA Hi T
Effects of OA on Development Strip-spawned and pooled sperm and eggs Fertilized eggs in pCO2-equilibrated water
380 ppm 840 ppm
Time to developmental stage at 1 hour (2-cell) 2 hours (>4-cell) 5 hours (hatched) 17 hours 24 hours
Effects of OA on Development
Time Post-Fertilization
Developmental Stage
Timeline of C. gigas Larval Development
0h
1h
2h
5h
17h
24h
Fertilization 2-cell
4-cell
hatching
veliger
Effects of OA on Development
*
=380 ppm =840 ppm
Pro
porti
on E
ggs
in C
leav
age
Effects of OA on Development
*
=380 ppm =840 ppm
Pro
porti
on L
arva
e H
atch
ed
Effects of OA on Development A smaller proportion of larvae in elevated pCO2
develop at the “normal” rate Implications for physiological anomalies and
calcification
SEM Photo: Carla Stehr
Effects of OA on Development General stress response genes
Cytochrome P450 oxidase (CytP450) Peroxiredoxin 6 (Prx6) Heat shock protein 70 (Hsp70)
5 5 17 17 24 24Time Post Fertilization (Hours)
Prop
ortio
n H
atch
ed0.0
0.2
0.4
0.6
0.8
1.0
Outline Ocean acidification Environmental stress and physiology Temperature and the C. gigas-V. tubiashii
relationship OA effects on C. gigas Current work: OA & V. tubiashii
OA Hi T
OA & V. tubiashii Study in progress in collaboration with NWFSC (P.
McElhany et al.) Planned 3 weeks: spawning through settlement 4 pCO2 treatments
280, 380, 750, 2000 ppm 24-hour V. tubiashii exposure Data collection:
Mortality Physiology (gene expression) Morphology & calcification Genotype-linked survival
OA & V. tubiashii Calcification at 48 hours post-fertilization
= calcified = partially calcified = uncalcified
Conclusions Ocean acidification has significant effects on C.
gigas larval development. OA may inhibit and depress larval response to other
environmental stressors, including disease. Elevated temperatures, such as 25oC, have effects
on the host-pathogen interaction.
Acknowledgements Funding: Saltonstall-Kennedy Grant (NOAA),
NOAA Aquaculture Program student support University of Washington
Moose O’Donnell Sam White
Taylor Shellfish Joth Davis Ed Jones Vicki Jones
NOAA Northwest Fisheries Science Center Jason Miller Mike Maher Sarah Norberg