Model Organisms
What are model organisms?
Model organisms are non-human organisms that are extensively used by biologists to understand biology phenomenas. Since the genetic material of metabolic and developmental pathways are well conserved among organisms, model organisms are great for experiments especially the ones that are not feasible and ethical to conduct on human. Examples of model organisms include zebra fish, mouse, C. Elegans, fruit flies, yeast
What are good model organisms for DYX1C1 and Dyslexia?
Since DYX1C1 is a gene that codes assembly factors in the cilia, it is necessary to choose a model organism that have ciliated neurons. So yeast is not a suitable model organism. Moreover, we need to find a model organism that have homologs of DYX1C1 by reciprocal BLAST, since the idea of using model organism is to use a gene that is from the same ancestor with the human gene. More over, since dyslexia and creativity needs to be measured behaviorally, I need a model organism whose behavior can be observed. There are only two model organisms that are suitable for this study. Mouse and zebra fish.
Mouse
Through forward genetics where exon 2-4 are deleted in DYX1C1 mouse, scientists observed Left-right symmetry, as well as cilia defects. [1] There are also mouse DYX1C1 knockout memory and learning assessment including water escape, Y-shaped maze etc [2] Both evidences suggest mouse as a good model organism for this study.
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Zebra fish
Knockout of DYX1C1 in zebrafish shows cilia defects such as body curvature, as well as body left-right symmetry. [1] Even though no specific DYX1C1 mutation behavioral assessment found, zebrafish can also be easily assessed for its memory and learning through color differences. [3] Both evidences suggest zebrafish as a good model organism for this study.
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Discussion
Both mouse and zebrafish have significant phenotypic differences between DYX1C1 mutants and wild type. Both are also great organisms to conduct behavioral tests. However, the zebra fish brain functional structure is not as closely related to the human functional structure as mouse. Therefore, Mouse is the best model organism for DYX1C1 dyslexia and creativity assessments.
[1]Tarkar, A., Loges, N., Slagle, C. et al. DYX1C1 is required for axonemal dynein assembly and ciliary motility. Nat Genet 45, 995–1003 (2013). https://doi.org/10.1038/ng.2707
[2]Rendall, A. R., Tarkar, A., Contreras-Mora, H. M., LoTurco, J. J., & Fitch, R. H. (2017). Deficits in learning and memory in mice with a mutation of the candidate dyslexia susceptibility gene Dyx1c1. Brain and language, 172, 30–38. https://doi.org/10.1016/j.bandl.2015.04.008
[3]Levin ED, Cerutti DT. Behavioral Neuroscience of Zebrafish. In: Buccafusco JJ, editor. Methods of Behavior Analysis in Neuroscience. 2nd edition. Boca Raton (FL): CRC Press/Taylor & Francis; 2009. Chapter 15. Available from: https://www.ncbi.nlm.nih.gov/books/NBK5216/
[2]Rendall, A. R., Tarkar, A., Contreras-Mora, H. M., LoTurco, J. J., & Fitch, R. H. (2017). Deficits in learning and memory in mice with a mutation of the candidate dyslexia susceptibility gene Dyx1c1. Brain and language, 172, 30–38. https://doi.org/10.1016/j.bandl.2015.04.008
[3]Levin ED, Cerutti DT. Behavioral Neuroscience of Zebrafish. In: Buccafusco JJ, editor. Methods of Behavior Analysis in Neuroscience. 2nd edition. Boca Raton (FL): CRC Press/Taylor & Francis; 2009. Chapter 15. Available from: https://www.ncbi.nlm.nih.gov/books/NBK5216/