Research

Research Interests in the Craig lab:

Aquatic ecosystems face a myriad of abiotic (e.g. temperature, oxygen availability, acidification) and anthropogenic (e.g. pharmaceutical contaminants, metals, agricultural runoff) influences that have a significant impact on the health of the environment and the organisms that depend upon it. These threats are numerous and are not independent, but work cumulatively to alter our ecosystems. However, our ability to ensure ecosystem sustainability is limited by our capacity to understand and predict how the various stressors resulting from these threats interact to cause change. While individual stressors poses documented problems for aquatic ecosystems, the concern is that combinations of these effects will create even more significant challenges to these environments and, more specifically, aquatic organisms living in them. Many regulations, policies, monitoring and remediation programs are based on an understanding of only single factors (e.g., temperature or one specific pollutant) and are therefore inadequate. It is upon this that my research program is based – to gain a fundamental understanding of multiple, mixed stressors found within the environment and the impact upon aquatic species, specifically teleost fishes. My research takes an integrative approach, crossing all levels of biological organization, towards making predictions regarding the impact of mixed stressors on species health and abundance.

My current research focuses on abiotic factors associated with climate change (temperature/hypoxia) in combination with emerging organic pollutants (pharmaceuticals), which have been demonstrated to target numerous fish species. A unique and novel aspect of my research is examining the epigenetic mechanisms driving the altered phenotypes found in teleosts exposed to multiple stressors. Epigenetics is defined by examining the inheritance of variation beyond changes in DNA sequence. Epigenetic regulation, through DNA methylation, histone modification, and non-coding RNA may profoundly alter transcriptional and translational effects of gene expression, and it is now clear that these mechanisms are influenced by environmental stressors, both natural and anthropogenic, acting as the interface between the genome and the environment. I use a number of different techniques to address these questions, including next-generation sequencing, qPCR and microarray analysis, cell culture, protein abundance and enzymatic activity, cell respiration and reactive oxygen species production, and measurements of whole animal metabolism and performance.

Active research themes in the Craig Lab

The role of epigenetic regulation on phenotypic responses to environmental stressors in teleost

Studies within this theme  involve the profiling of epigenetic responses (DNA methylation, microRNA) in zebrafish and rainbow trout to environmental stressors and how they dictate the phenotypic response. Current projects under this theme are examining how multiple stressors impact metabolism and aerobic scope of zebrafish.

Transgenerational epigenetic responses to environmental stressors

Studies here examine the heritability of epigenetic mechanism from paternal and maternal sources, both intra- and inter-generationally, in teleosts. This current theme examines the abundance of microRNA in both speram and egg of zebrafish exposed to multiple stressors to evaluate the importance and downstream function impact of epigenetic inheritance

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So many babies!!

Application of epigenetic profiling to local species and conditions

Studies here build upon Themes 1 & 2 and apply epigenetic profiling in local fish species, particularly the rainbow darter found along the Grand River in effort to predict future responses to emerging organic contaminant threats.

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Colleagues Dr. Mark Servos and Dr. Patricija Marjan collecting rainbow darters in the Grand River

 

Next generation solutions to ensure healthy water resources for future generations

Working under the collaborative Global Water Futures program, a joint effort between University of Saskachewan, University of Waterloo, Wilfrid Laurier University, and McMAaster University, we are focused on the application of environmental DNA (eDNA) for bioassessment of fish and fish populations in watersheds, such as the Grand River. Our interests are directed towards improving the ability to accurately detect and assess fish communities using advanced eDNA collection and analysis, and determine how environmental factors impact these assessments.

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Postdoc Patricija Marjan and PhD candidate Heather Ikert collecting trout species in Alder Creek