Chris Skalnik

Fernald Lab

Dominant male Astatotilapia burtoni dispute a territorial boundary.

Image by Russell D. Fernald and Sabrina S. Burmeister, published in Social Opportunity Produces Brain Changes in Fish. PLoS Biology Vol. 3/11/2005, e390 doi:10.1371/journal.pbio.0030390, accessed at Wikimedia Commons. Licensed under CC-BY-2.5. I have cropped the original image.

I worked in the Fernald Lab at Stanford University from March 2018 to June 2019.

I used Astatotilapia burtoni, an East African cichlid fish, as a model system to investigate the functions of androgen receptors (AR). More precisely, I examined the effects in males of disabling ARα and ARβ, particularly on phenotypes related to social status. The preliminary results of this study show ARα and ARβ to be critical for many traits typical of socially dominant male A. burtoni. Further, we have discovered that these androgen receptors control distinct components of social dominance.

Papers

  • PNAS Paper that reports my work on ARβ, as well as complementary work on A. burtoni androgen receptors by other members of the lab. It is available from PNAS under the citation:

    Modular genetic control of social status in a cichlid fish. Beau A. Alward, Vibhav A. Laud, Christopher J. Skalnik, Ryan A. York, Scott A. Juntti, Russell D. Fernald Proceedings of the National Academy of Sciences Nov 2020, 117 (45) 28167-28174; DOI: 10.1073/pnas.2008925117

    This paper is Copyright © 2020, and the copyright is held by the authors. All rights are reserved. Note that this paper is NOT released under the same license as the rest of the site. See the licensing details page.

Posters

  • BSURPS Poster that describes preliminary ARβ results from Summer 2018. This poster is also available from the Fernald Lab.

  • Neuroscience 2019 Poster that I presented at the 2019 annual meeting of the Society for Neuroscience in Chicago. It describes our findings about how ARα and ARβ mediate distinct aspects of social dominance. We discover that the two androgen receptors of the cichlids we use as our model control distinct aspects of social dominance. This shows the genetic control of social status to be modular, and it sheds light on the genetic underpinnings behind how the brain processes social information.

    This poster is Copyright © 2019 Stanford University. All Rights Reserved. Note that this poster is NOT released under the same license as the rest of the site.

Software

I use these programs in my research to reduce bias and accelerate repetitive tasks. They are all available under open-source licenses for your use (see the GitHub pages for details). If you find them helpful, please let me know! I also welcome contributions of code, documentation, bug reports, and feedback on what you think.

  • blindr: Reversibly randomizes filenames to reduce the chance of bias in subjective analyses.
  • batch_crop: Performs batch image cropping for reproducible and automatic extraction of image regions. Useful for analyzing specific areas of an animal for colors.
  • overlay: Makes multi-image composites. Useful for choosing crop regions.
  • scorevideo_lib: Library of utilities for working with the MATLAB program scorevideo. Useful for transferring marks or behaviors between log files, for example when the lights come on in a recording.
  • behaviorcodeAuto: Automates some parts of using the behaviorcode scripts.

References

Below are some useful references that describe some technical aspects of my work. They may be especially helpful for reproducing my experiments.