Congress Abstracts - Society for Developmental Biology

characterized. We used in situ hybridization to compare spatiotemporal gene expression patterns between unexposed control embryos
and embryos developmentally exposed to 1.2ppm and 2.4ppm methylmercury. Levels of gene expression of FoxP2 were quantified
using qRT-PCR. Preliminary results suggest no significant differences between treatment groups, however we also note that embryos
had a great deal of biological variation in FoxP2 levels at the stages analyzed. To further examine the effects of prenatal
methylmercury exposure, we quantified the levels of FoxP2 expressed in juvenile male brains and show that a subset of juvenile males
prenatally exposed to 2.4ppm MeHg has significantly lower FoxP2 levels. We have also conducted microarray analysis to identify
additional genes and pathways that could potentially affect song learning.
Program/Abstract # 577
Adaptation to hydrogen sulfide induces a reversible developmental plasticity in C. elegans
Fawcett, Emily; Miller, Dana (U Washington, USA)
Developmental plasticity, a phenomenon where early environmental conditions dictate adult phenotypes, is generally believed to
increase the likelihood of survival. However, there may be negative consequences if the future environment is different than predicted.
Understanding the molecular underpinnings of reversible plastic phenotypes will provide insight into how individuals respond to a
changing environment. We discovered that transient exposure to low levels of the gas hydrogen sulfide (H 2 S) allows for survival of
otherwise lethal H 2 S concentrations in C. elegans. We have found that memory of H 2 S requires the SWI/SNF chromatin-remodeling
complex, suggesting that the response to H 2 S stimulates epigenetic adaptations with long-lasting consequences. Remarkably, we have
shown that H 2 S memory is reversible. The memory of H 2 S adaptation is erased by brief periods of fasting, but not by exposure to other
environmental stresses, including hypoxia and heat shock. These results suggest that there is a specific interaction between the fasting
response and H 2 S memory. Consistent with this model, we show that the insulin/IGF1-like signaling (IIS) pathway modulates the
persistence of H 2 S memory in fasting. While loss-of-function mutations in the FOXO transcription factor DAF-16 enhances the effects
of fasting on H 2 S memory, constitutive activation of DAF-16 protects against fasting-induced memory loss. Taken together, our
results demonstrate that the cellular response to nutrient availability through the IIS pathway is required for the persistence of H 2 S
memory upon nutritional stress. We are currently working to understand the molecular underpinnings that integrate IIS signaling with
the epigenetic memory of adaptation to H 2 S.
Program/Abstract # 578
The Effects of Cadmium and Temperature on Zebrafish Development
Warren, Kerri S.; Subramaniam, Janani; Stevenson, Laura (Roger Williams Univ., USA)
Climate change and chemically-contaminated water increasingly impact coastal aquatic ecosystems and the effects of small
temperature change fluctuations on developmental metal sensitivity are not well understood. This project utilized a cadmium toxicity
bioassay in zebrafish embryo-larvae to examine the combined effect of low-level cadmium exposure with otherwise-tolerable
temperature shifts. Zebrafish embryos were exposed to 0, 0.5 and 5um of cadmium chloride (CdCl 2 ) at 25 and 32C and examined from
day 2- day 5 of development. General morphology and developmental progress was assessed as were specifics of cardiovascular
development. Vasculogenesis and angiogenesis were characterized using transgenic endothelial cell green fluorescent protein (GFP)
zebrafish, vessel maturation and patterning with alkaline phosphatase assays, and vessel integrity and patency with microscopic
observation. Temperature-specific outputs included increased rate of developmental progression and elevated heart rate and
metabolism. Cadmium-specific, temperature insensitive parameters included cadmium-induced cardiac arrhythmia and cranial
hemorrhage. The combined effect of cadmium and temperature, however, reduced cadmium-tolerance more universally, with
increased rates of edema, necrosis and disaggregation. These results suggest very low levels of metal contamination of coastal waters
pose a significant future environmental threat.
Program/Abstract # 579
Macondo crude oil from the Deepwater Horizon oil spill disrupts specific developmental processes during zebrafish
embryogenesis
Chen, Diane; Kesich, Lydia-Rose; de Soysa, Yvanka; Ulrich, Allison (Smith College, USA); Friedrich, Timo (UMass Amherst, USA);
Pite, Danielle (Smith College, USA); Compton, Shannon (UMass Amherst, USA); Ok, Deborah; Bernardos, Rebecca (Smith College,
USA); Downes, Gerald (UMass Amherst, USA); Hsieh, Shizuka; Stein, Rachel; Lagdameo, Maria Caterina; Halvorsen, Katharine;
Barresi, Michael (Smith College, USA)
On April 20 th 2010, the Deepwater Horizon oil platform sank, spilling approximately 4.93 million barrels of oil and making it the
largest accidental marine spill in history. Even though the oil has, for the most part, stopped flowing, concerns have been raised about
the effects of crude oil on the marine flora and fauna in the Gulf. Since utilizing native species is difficult due to issues of availability,
genetic variation, and domestic husbandry, a model organism must be used to assess the effects of these compounds on embryonic
development. Since development is conserved across species, the Zebrafish (Danio rerio), with its ease of maintenance, large clutch
size, and completely sequenced genome, is well suited suited to model the teratogenic effects of toxins. We investigated the effects of
the water accommodated fraction (WAF) of crude oil on the development of the zebrafish embryo, and found several defects in treated
embryos which had been previously seen, such as cardiovascular and craniofacial deformities, which we postulate could be the result
of impaired cranial neural crest cell development. In addition, we also discovered a novel locomotor phenotype, perhaps as a result of
observed deformities in slow muscle, as well as a reduction in the sensory axons of the peripheral nervous system and
166