Draft Summary of project needs to include:
Overview:
- Description of activities
- Statement of objectives
- Methods
Intellectual Merit
- Potential to advance knowledge
Broader Impacts
- Potential to benefit society, outreach
Draft summary & outline submitted for class, 01-16-2017
Overview: This project seeks to elucidate Ostrea lurida's potential
for phenotypic plasticity by examining transgenerational inheritance in
response to dual climate stressors. By examining how genetic and epigenetic
modifications over three generations correspond to climate resilience, we will
reveal whether O. lurida populations
may be able to persist in our rapidly changing world. We will condition O. lurida broodstock of known lineages
in elevated temperature and dissolved CO2, breed them, rear the
progeny in a common garden, then repeat the previous steps with the progeny,
and continue through a third generation. We will compare overall larval
quality, production and development, and will measure differential gene
expression (transcriptome) and epigenetic markers (methylation, histone
modification, transposable element expression) in broodstock gonads and larvae
for each generation. We anticipate that O. lurida broodstock conditioned
in elevated pCO2 and temperature will: differentially express genes
compared to oysters reared in ambient conditions; present different rates and
loci of histone modification, DNA methylation, or transposable element
expression; produce a greater percentage of progeny that are more resilient to
the dual climate stressors, as determined by growth rate and survival; and
transfer heritable, climate stress related epigenetic markers to successive
generation.
Intellectual Merit: A broadening body of work indicates that low pH and high
temperature negatively affect fertilization and early life stages of many
marine invertebrates. Oyster
may, however, contain a unique capacity to keep pace with rapidly shifting
climate stressors. The oyster genome is highly polymorphic, communities
may differ significantly between generations via the Sweepstakes Reproductive
Success hypothesis, and the newly emerging field of epigenetics suggests that
adult responses to environment conditions can be passed on to offspring.
Indeed, offspring of Sydney rock oysters (Saccostrea glomerata) exposed
to elevated pCO2 during reproductive conditioning performed better
in OA conditions compared to larvae of broodstock conditioned in ambient pCO2 levels. Still unknown, however, are the persistence of these adaptations
through the generations, and the underlying mechanisms by which inheritance
occurs. This project seeks to answer these questions, and will be the first to
explore mechanisms underlying potential differential gene expression and
transgenerational inheritance in oysters reared in dual climate stressors.
Results will have implications on future community-level resilience in O.
lurida, and other invertebrates with similar genetic polymorphism and
epigenetic mechanisms.
Broader Impact: The ecologic and economic void left by the near
collapse of Ostrea lurida, the Northeast Pacific Ocean’s only native
oyster, has spurred major efforts to restore populations along its historic
distribution from Alaska to Baja California. While shoreline enhancement and
seeding projects are making headway, there is growing concern that changing
ocean conditions further threaten existing populations and may stymie
restoration investments. This research will explore new territory of O.
lurida epigenetic and transgenerational inheritance of climate stressor
resiliency, with the primary goal to inform commercial and restoration hatchery
breeders to select for OA- and high temperature-resilient oysters, or to induce
an multi-generational “immune-like” response by exposing broodstock to future
climate conditions. Secondly, results will inform further climate-related
reproduction research in other species of wild and farmed bivalves such as Crassostrea
virginica and Crassostrea gigas. Thirdly, a deeper understanding of
CO2 and temperature related drivers in O. lurida reproduction
will help to expose its vulnerability or adaptability to the climate model
predictions of steadily decreasing ocean pH and increasing temperatures, and
could have profound implications for wild community-level population dynamics. Finally,
results from this project would need to be considered in ecological models, and
restoration groups could refine selection processes for shoreline enhancement
and seeding processes, or amplify efforts in locations with variable pH and
temperature swings to allow for maximum adaptability.
Draft Proposal Outline
Cover Page: Working title: Transgenerational epigenetic
inheritance of climate adaptability in Ostrea lurida
Summary (1 page)
Overview: This project seeks to elucidate Ostrea lurida's potential
for phenotypic plasticity by examining transgenerational inheritance in
response to dual climate stressors.
Intellectual merit: A broadening body of work indicates that low pH and high
temperature negatively affect fertilization and early life stages of many
marine invertebrates. Oyster
may, however, contain a unique capacity to keep pace with rapidly shifting
climate stressors. Still unknown, however, are the persistence of these
adaptations through the generations, and the underlying mechanisms by which
inheritance occurs. This project seeks to answer these questions.
Broader Impacts:This research will explore new territory of O. lurida epigenetic and transgenerational inheritance of climate stressor resiliency,
with the primary goal to inform commercial and restoration hatchery breeders to
select for OA- and high temperature-resilient oysters, or to induce an
multi-generational “immune-like” response by exposing broodstock to future
climate conditions.
Project
Description (4 pages)
Background
- Oysters are ecologically vital to intertidal communities;
oysters and ecosystem engineers
- Oysters are economically vital to many coastal communities
in the United States, France, Australia, etc.
- Oysters aquaculture is extremely sustainable, and the industry
has been identified as a NOAA priority, necessary to provide sufficient,
efficient, and healthy protein sources in the future.
See NOAA Marine
Aquaculture Strategic Plan 2016-202- Ocean acidification and rising ocean temperatures threaten
many marine organisms. Calcifying invertebrates are at risk, and there has been
a surge of research seeking to understand how populations will change in
response to climate projections. Most research identifies fertilization and
larval stages as the “bottleneck.” Oysters are intertidal animals, experiencing
extreme environmental changes. As such, researchers are exploring how oyster
genetic polymorphism, generational shifts due to Sweepstakes Reproductive
Hypothesis, and epigenetic transfer of environmental memory may allow for rapid
adaptation and resiliency to climate stressors.
Rationale: Researchers hypothesize that epigenetic mechanisms
(methylation, histone modification, non-coding RNA, transposable elements) may
increase the plasticity of oysters. Unknown is a direct linking of differential
epigenomes, induced by climate stressor treatments, and rates of survival,
reproductive success, and subsequent generational transfer of these successful
epigenetic markers.
Goals/Questions
- Do brooding oysters respond to climate stressors via
epigenetic mechanism? If so, which ones? DNA Methylation, Histone Modification,
lncRNA, transposable element expression, or other?
- Do different epigenomes (in response to OA and high T)
correspond to fecundity?
- Are epigenetic traits passed on to their progeny?
- Can memory of environmental stress persist through
generations? If so, what is the mechanism? Do they increase or decrease
fecundity and resiliency in first or second, and/or third generations?
Approach
- In early winter 600 O. lurida hatchery-born (F1) individuals from known lineages will
divided into 2 separate flow-through seawater culture tanks, and conditioned
for ~6 weeks in two temperatures: ambient (~8degC), and high (~12degC).
- Directly
subsequent to the temperature treatments, individuals will be moved into two
pCO2 treatments and conditioned for ~6 weeks @ ambient temperature (~8degC):
ambient (~400ppm), and high (~1000ppm). In both treatments water temperature
will be gradually increased to ~10degC.
- Directly subsequent pCO2 treatments, oysters
will be conditioned in “separate but equal” culture tanks, fed well, and
temperature gradually increased to ~14degC, and monitored for spawning
activity. Larvae from each treatment group will be collected and reared. Post
settlement, oysters will be grown off-dock in ambient conditions, until the
following season when the experiment will be repeated with these experimentally
produced F2 individuals.
- Broodstock gonads & whole-body
larvae will be sampled for:
* DNA
* Genetic variation
* Protein?
* RNA
Transcriptome
Bisulfite treated for methylation
Histone Modification
Transposable element location and
expression
Outputs
- SAFS Thesis
- Publication
- Guideline memo to restoration and commercial hatcheries on
potential method of selecting for climate-resilient family lines.
Budget: TBD
Budget Justification (1 page): TBD
References: TBD