Timmins-Schiffman P2010

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

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



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



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


*

=380 ppm =840 ppm

Pro

porti

on E

ggs

in C

leav

age


*

=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



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

Timmins-Schiffman P2010

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