This web page was produced as an assignment for Genetics 564, an undergraduate capstone course at UW-Madison.
What Are Model Organisms?
Model Organisms are animals used to study biological mechanisms, usually with the goal of better understanding human biology. Many of them have similar biological systems to humans which makes model organisms a good way to study phenomena that are unethical to study in humans. The model organism a scientist chooses to use depends on the question they are trying to answer. [1]
Choosing a Model Organism
Mus musculus (mouse)
The mouse is the most used mammal model because its biology is already well-characterized. Its complex biology allows for more complicated analyses that can better simulate human biology. However, its embryos are inaccessible due to intrauterine development, and it reproduces more slowly. It also is more expensive than most other model organisms. [2] |
Drosophila melanogaster (Fruit Fly)
The fly is a good model organism for a variety of experiments. It can be used to study development because it produces large amounts of offspring extremely quickly. This along with its well-characterized genome also makes it a good model for large mutational screens. |
Saccharomyces cerivisiae (Yeast)
Yeast is a good model organism because it is simple, and its entire genome has been sequenced. This sequencing data in combination with its high genetic homology to humans makes it very valuable for linkage mapping and other genetic manipulations. [3] |
Caenorhabditis elegans (Roundworm)
C. Elegans is very conducive to genetic screens because the organism is hermaphroditic which means it is able to self-fertilize. This allows fast production of homozygous mutants. The clear body also makes it easy to see body structures. The entire genome of C. elegans has also been sequenced. |
Arabidopsis thaliana (Mustard Seed)
Arabidopsis is valuable for studying human and plant biology. Its genome has been sequenced, and it reproduces quickly and is hermaphroditic. This makes it an excellent model for genetic screens. It also serves as a good model for understanding plant development. [2] |
Discussion: What Model is Best to Study MTHFR and Spina Bifida?
Danio rerio (zebrafish) will be used as a model organism due to the ease with which spinal defects can be observed in zebrafish embryos as well as the rapid development and closure of the zebrafish neural tube, which occurs within 24 hours of fertilization.[4] The transparency of developing zebrafish embryos will also facilitate analysis of neurulation in vivo. Zebrafish also display an obvious disease phenotype of a kinked tail, curved spine, and deflated gas bladder, all of which correlate to the human disease phenotype that includes symptoms like muscle weakness, bladder dysfunction, and spine deformities.
References:
[1] NIH. (2017, October). Using Research Organisms to Study Health and Disease. Retrieved from: https://www.nigms.nih.gov/education/Pages/modelorg_factsheet.aspx
[2] Murphy, P. (n.d.) Lecture 2: Model Organisms. Retreived from: http://virtuallaboratory.colorado.edu/DEVO@CU/papers/pmby1101-lecture2-2013.pdf
[3] Botstein, D., Chervitz, S.A., Cherry, J.M. (2011). Yeast as a model organism. Science, 277, 1259-1260.
[4] Araya, C., Ward, L., Girdler, G.C. & Miranda, M. (2016). Coordinating cell and tissue behavior during zebrafish neural tube morphogenesis. Developmental Dynamics, 245, 197-208.
Images:
Header: https://elifesciences.org/collections/8de90445/the-natural-history-of-model-organisms
Mouse: https://www.sperietori.ro/en/daunator/178-house-mouse
Zebrafish: https://www.zebrafishfilm.org/
Fly: https://www.carolina.com/drosophila-fruit-fly-genetics/drosophila-living-wild-type/172100.pr
C. Elegans: http://commonsciencespace.com/life-expectancy-genes/
Yeast: https://www.fenologica.com/news/whyyeastisimportant
Arabidopsis: https://www.eurekalert.org/multimedia/pub/159783.php
[1] NIH. (2017, October). Using Research Organisms to Study Health and Disease. Retrieved from: https://www.nigms.nih.gov/education/Pages/modelorg_factsheet.aspx
[2] Murphy, P. (n.d.) Lecture 2: Model Organisms. Retreived from: http://virtuallaboratory.colorado.edu/DEVO@CU/papers/pmby1101-lecture2-2013.pdf
[3] Botstein, D., Chervitz, S.A., Cherry, J.M. (2011). Yeast as a model organism. Science, 277, 1259-1260.
[4] Araya, C., Ward, L., Girdler, G.C. & Miranda, M. (2016). Coordinating cell and tissue behavior during zebrafish neural tube morphogenesis. Developmental Dynamics, 245, 197-208.
Images:
Header: https://elifesciences.org/collections/8de90445/the-natural-history-of-model-organisms
Mouse: https://www.sperietori.ro/en/daunator/178-house-mouse
Zebrafish: https://www.zebrafishfilm.org/
Fly: https://www.carolina.com/drosophila-fruit-fly-genetics/drosophila-living-wild-type/172100.pr
C. Elegans: http://commonsciencespace.com/life-expectancy-genes/
Yeast: https://www.fenologica.com/news/whyyeastisimportant
Arabidopsis: https://www.eurekalert.org/multimedia/pub/159783.php