Methods

Results

The Effect of Temperature on DISC-1 Expression in Zebrafish Embryos

Tyler JermynDepartment of Biological Sciences, York College of Pennsylvania

Introduction• Schizophrenia is a serious psychological disorder that

encompasses positive and negative neurological symptoms and affects approximately 1% of the world’s population (Camargo et al. 2007; Wood et al. 2009).

• Studies suggest that abnormal synaptic activity in schizophrenic adults is the result of improper neurodevelopment (Camargo et al. 2007).

• Twin and adoption studies have shown that a combination of genetic and environmental factors contributes to improper neurodevelopment leading to schizophrenia (Wood et al. 2009).

• Disrupted in Schizophrenia-1 (DISC-1) is a gene that

has been studied in relation to the development of schizophrenia due to its up-regulated expression in affected patients and its requirement for proper neuronal development in vertebrates (Wood et al. 2009).

• The symptoms that define schizophrenia may be a

product of gene expression triggered by prenatal stress (Matrisciano et al. 2012).

• Danio rerio is an ideal research subject because it

possesses DISC-1 homologs, it exhibits a fast gestation period, and its embryonic phases are visible, as zebrafish embryos develop outside of the adult fish (Morris 2009).

• Gene expression in larval zebrafish is partially modified

by a variety of environmental stressors, including temperature changes (Long et al. 2012).

Conclusions• The semi-quantitative PCR analysis failed to

determine a significant difference between temperature stress and DISC-1 expression.

Objective• To determine the extent of DISC-1 expression in zebrafish

(ZF) exposed to environmental stress.

• Hypothesis: DISC-1 will be more highly expressed in samples that have experienced high-temperature (30.0°C) and low-temperature (21.0°C) stress relative to those in control (28.5°C) temperatures.

References•Camargo, L.M., Collura, V., Rain, J-C., Mizuguchi, K., Herjakob, H., Kerrien, S., Bonnert, T.P., Whiting,

P.J. & Brandon, N.J. 2007. Disrupted in Schizophrenia 1 interactome: Evidence for the close connectivity of risk genes and a potential synaptic basis for schizophrenia. Molecular Psychiatry 12: 74-86.• Long, Y., Li, L., Li, Q., He, X. & Cui, Z. 2012. Transcriptomic characterization of temperature stress

responses in larval zebrafish. PLoS One 7(5): 1-15.•Matrisciano, F., Tueting, P., Maccari, S., Ferdinando, N. & Guidotti, A. 2012. Pharmacological

activation of group-II metabotropic glutamate receptors corrects a schizophrenia-like phenotype induced by prenatal stress in mice. Neuropsychopharmacology 37: 929-938.•Morris, J.A. 2009. Zebrafish: A model system to examine the neurodevelopmental basis of

schizophrenia. Progress in Brain Research 179(9): 97-106. •Wood, J. D., Bonath, F., Kumar, S., Ross, C. A., Cunliffe, V. T. 2009. Disrupted-in-schizophrenia 1 and

neuregulin 1 are required for the specification of oligodendrocytes and neurones in the zebrafish brain. Human Molecular Genetics 18: 391-404.

Acknowledgments• I would like to thank Dr. Wendy Boehmler for her guidance in this

research, as well as for her extensive patience! I’d also like to thank the York College Department of Biology for its support.

http://neurosciencenews.com/healing-thalamus-strokes-genetic-lhx2-lhx9/

Figure 1. Semi-quantitative PCR analysis of Actin (left half of gel, lanes A1-B3) and DISC-1 (right half of gel, lanes A1-B3), results of electrophoresis gel. Band intensity and density represent gene expression. 1.5% agarose gel run at 170V for 15 minutes.

Figure 2. Mean PCR band intensities for gene expression among three temperatures: 21.0°C, 28.5°C, and 30.0°C. Band intensities correlate to gene expression of Actin and DISC-1. Error bars show standard error of the mean.

Future Studies• Real-time PCR should be attempted in order to

support the semi-quantitative data from the intensity and density of the electrophoresis bands.

• Temperature range could be expanded to expose embryos to more stressful conditions.

• After exposing embryos to stress, allow embryos to grow into adults (3-4 months) then test for DISC-1 expression in order to observe any changes that may occur once the ZF has matured.

• Inflict other forms of environmental stress; for example, expose adult ZF to changes in pH or a small electric shock and observe effects on DISC-1 expression.

Breed zebrafish Induce stress (temperature)

RNAcDNA

Design primersPCRElectrophoresis

and quantify bands

Extract RNA

21.0°C 28.5°C 30.0°C

Figure 3. One-way ANOVA, n=2. No significant difference between control and experimental expression

http://www.unsolvedmysteries.oregonstate.edu/embryo http://en.wikipedia.org/wiki/Zebrafish