Download Different levels of biological organization

Understanding the Effects of
Environmental Stress from the Cell
to the Community
Ken M. Jeffries and Richard E. Connon
What is environmental stress?
• Environmental disturbances caused by one or more stressors.
– Stressors cause stress.
• Types of stressors:
– Natural (e.g., temperature, salinity, predation,
disease).
– Non-natural (e.g., pollution, dams, fishing).
• Disrupts normal processes
(i.e., homeostasis).
– Organism responds to the
stressor(s).
• Measurable responses can occur
at various levels of biological
organism.
Different Levels of Biological Organization
Ecosystem Effects
- Productivity, food webs, ecosystem services
Community Effects
- Species diversity, predator-prey interactions
Population Effects
-Abundance, sex-ratios
Whole Organism Effects
-Mortality, metabolic rates
Tissue Effects
-Gonad growth, development
Cellular and Molecular Effects
-Proteins, gene expression, “omics”
Modified from: Geist (2011) Ecological Indicators 11: 1507-1516.
Ecosystem Effects
- Productivity, food webs, ecosystem
services
Community Effects
- Species diversity, predator-prey
interactions
Population Effects
-Abundance, sex-ratios
Mesocosms
Realistic exposures in
“environmental” setting.
Long-term community effects
(direct/indirect) of multiple
species.
H. azteca Abundance
Determine ecologically-relevant responses
over a long exposure period!!
p < 0.05
Exposures to a mixture of 3 pesticides (chlorpyrifos, permethrin, lambda cyhalothrin)
Applied at concentrations that are equally toxic as determined for hyalella and chironomids.
S. Hasenbein, Ph.D. thesis, in progress
Ecosystem Effects
- Productivity, food webs, ecosystem
services
Mesocosms
Tolerance
Population Effects
-Abundance, sex-ratios
Sensitivity
Community Effects
- Species diversity, predator-prey
interactions
S. Hasenbein, Ph.D. thesis, in progress
Mortality
(e.g., 24 h,
96 h, 14 d).
Whole Organism Effects
-Mortality, metabolic rates
Tissue Effects
-Gonad growth, development
Control
Behavior >
(ammonia
exposure).
Exposed
Behavior (ammonia exposure).
Control (normal)
Exposed (aberrant)
Delta Smelt: thermal tolerance
30
(B)
A
Critical Thermal Maximum (°C)
a
B
a
a
a
28
26
24
Acute temperature
tolerance decreases
with age!!
B,C
C
b
b
b
b
D
25.4°C
Acclimation
Temperature (°C)
Low
Medium
High
Larval
cat.temp
high
medium
low
Late-Larval
Swanson et al. (2000)
Oecologia 123: 384-390
c
Juvenile
Adult
PS-Adult
Ontogenetic Stage
Age
Komoroske et al. (2014) Conservation Physiology 2: cou008
Pesticide exposure (Bifenthrin)
Egg protein
Log2 Fold-change
Reproduction
Tissue Effects
-Gonad growth, development
Cellular and Molecular Effects
-Proteins, gene expression, “omics”
Brander et al., unpublished data
Case Study: Effects of Ibuprofen on Inland
Silverside
• Often detected in municipal wastewater effluent.
• Ibuprofen is one of the most commonly detected
pharmaceuticals in the environment.
– May have unknown consequences on fish populations.
• Emerging contaminant of concern in California.
• Ibuprofen is cleared from the body quickly and much of the
dose is not used.
• Continually reintroduced into aquatic
systems.
– “Pseudo” persistent in aquatic systems.
Inland Silverside
• Silverside species are abundant in estuaries throughout
North America.
– US EPA approved estuarine species for toxicity testing (inland
silverside).
– Can be raised and spawned in the laboratory.
– Useful species for monitoring the effects of contaminants in
estuaries.
• Attempt to understand how ibuprofen affects inland
silversides at multiple levels of biological organization.
Reproductive Effects
Gonad size
Genomics!!!!
• Genomics revolution.
• Studying biology at genome-wide scales.
– Many types of “omics” research.
– LOTS of data!
• Human genome project.
– Map the genome.
• 1990 – 2003.
• Only take a couple of
months now!
• Recent abalone die off on
CA coast.
Genomics football analogy: you heard it here first….
Microarrays!!!!
•
Microarrays are a tool to screen the expression of
thousands of genes at the same time.
- “Omics” technology.
- Understand biological pathways involved in
responses to stressors (football analogy).
- Finding unexpected results!
•
Sequenced molecular information for inland silverside.
•
Sequences used to develop a species-specific microarray.
•
14,393 unique genes (in triplicate) this custom designed microarray.
Different Levels of Biological Organization
Ecosystem Effects
- Productivity, food webs, ecosystem services
Community Effects
- Species diversity, predator-prey interactions
Population Effects
-Abundance, sex-ratios
Whole Organism Effects
-Mortality, metabolic rates
Tissue Effects
-Gonad growth, development
Future
Cellular and Molecular Effects
Directions
-Proteins,
gene expression, “omics”
Modified from: Geist (2011) Ecological Indicators 11: 1507-1516.
Summary
• Important to evaluate the impacts of exposure at multiple levels of
biological organization.
• Mesocosms – monitor responses over long periods of time.
– Ecologically-relevant.
• Whole organism responses – monitor fitness-level consequences.
– Reproductive output – may lead to population declines.
• Cellular responses – very sensitive, mechanistic effects.
– Understand why responses happen.
• Combining these approaches can help us understand complex
environmental problems relevant to Northern California.
– e.g., ibuprofen case study.
Acknowledgements
• Connon Lab.
–
–
–
–
–
Bryan Cole
Lisa Komoroske
Matthias Hasenbein
Simone Hasenbein
Jen Truong
• Nann Fangue Lab.
– Dennis Cocherell
• Susanne Brander Lab.
– Bethany DeCourten
• Stephanie Fong, Valerie
Connor
• UC Davis Aquatic Toxicology
Laboratory.
– Linda Deanovic, Marie Stillway.
• Delta Science Postdoctoral
Fellowship.
• California Fish & Wildlife.
• California Department of Water
Resources.
• California Department of
Pesticide Regulation.
Delta Stewardship Council