Download Final Project Outline Aaron Loewen 33334137 Name: Aaron

Final Project Outline
Aaron Loewen
33334137
Name:
Aaron Loewen
Topic:
Knockout of Eurl on chromosome 16 in Mus musculus (house mouse) to model Homo
sapiens sapiens (human) Eurl in chromosome 21.
Specific Question:
Is Eurl necessary for healthy brain development in regard to brain size in Mus musculus?
How this is novel and original:
Eurl is a relatively new gene that has been only recently found to affect the brain in
humans. The human chromosome 21 is homologous to the mouse chromosome 16,
which allows us to use the mouse as a model organism for human brain development
when it comes to genes associated with chromosome 21. Knockout of the gene has not
been done in literature (according to PubMed) so seeing the outcomes of the
experiment will show us novel information on Eurl in mice and therefore in humans by
inference.
Impact:
With this proposed experiment we will be able to look into this new gene that has been
only recently described briefly in both humans and mice. Because the mouse
chromosome is homologous with the human one, we can use the model to infer
changes in humans based on the changes that occur in mice. This gene in humans may
be an important factor in brain development in the fetus if there is a change in human
brain size. As well, there would also be implications in the mechanism that Downs
Syndrome affects humans, as microcephaly is a symptom of said condition.
Hypothesis:
HA :
Knockout of Eurl will cause a change in expression levels of Eurl in Mus
musculus, therefore changing the volume of the brain of Mus musculus.
HO :
Knockout of Eurl will not cause a change in expression levels of Eurl in Mus
musculus, therefore not changing the volume of the brain of Mus musculus.
Final Project Outline
Aaron Loewen
33334137
Evidence:
There has been some correlation between Eurl expression and progenitor proliferation
and differentiation in neurons (Li et al. 2016). This relationship allows us to infer that it
may also affect brain development, particularly in brain size. The less Eurl there is, the
less brain size should occur. Therefore knocking it out should reduce brain size in theory.
The introduction of Downs Syndrome into this experiment stems from the fact the the
Eurl gene in humans is found in the region where Downs Syndrome is likely to be caused
by (Li et al. 2016). Microcephaly has been found in Downs Syndrome patients, and
therefore would allow us to connect a decreased brain size to lowered Eurl levels (Tyler
and Haydar 2013 and NCBI1 2016).
Chromosome 16 in mice is orthologous/homologous to chromosome 21 in humans
(Gitton et al. 2002 and NCBI1 2016) which makes it a good model for brain development.
Brain size experiments have been done before with mice, which show that it can be a
strong model for human development (Tyler and Haydar 2013).
Prediction:
When Eurl is knocked out, we should see that expression of Eurl will decrease. This will
lead to microcephaly in the mice with the decreased levels of Eurl.
Proposed Method *:
1. Obtain mouse embryos
2. Knockout Eurl in half of the embryos, creating a group that has the inactive Eurl and
a group that has the wildtype Eurl
- Knockout method is currently unknown
3. Allow mice to age to 30 days
4. Measure Eurl expression using a gene reporter construct
- Use a LacZ reporter for this to quantify product
- Do this at day 1, 6, 12, 18, 24, and 30.
5. Measure mice brains at day 30
Final Project Outline
Aaron Loewen
33334137
Annotated Bibliography *:
Gitton, Y., Dahmane, N., Baik, S., Altaba, A.R., Neidhardt, L., Scholze, M., Herrmann, B.G., … & Yaspo, M.
(2002). A gene expression map of human chromosome 21 orthologues in the mouse. Nature,
420, 586-590.
Chromosome 21 in humans is orthologous with chromosome 16 in mice.
Li, S.S., Qu, Z., Haas, M., Ngo, L., Heo, Y.J., Kang, H.J., Britto, J.M., … & Heng, J.I. (2016). The HSA21 gene
EURL/C21ORF91 controls neurogenesis within the cerebral cortex and is implicated in the
pathogenesis of Down Syndrome. Scientific Reports, 6, 29514.
This article is what lead me into the Eurl gene, allowing me to see how it works with
neural cells and spine, as well as its wild-type expression levels.
https://www.ncbi.nlm.nih.gov/homologene/9696 NCBI 1
This link from NCBI shows homology within the Eurl genes from different species (Will
create citation for this site when I figure out how…).
Tyler, W.A. & Haydar, T.F. (2013). Multiplex Genetic Fate Mapping Reveals a Novel Route of Neocortical
Neurogenesis, Which Is Altered in the Ts65Dn Mouse Model of Down Syndrome.The Journal of
Neuroscience, 33(12), 5109-5119.
Gives us genetic information about Downs Syndrome.
Family / friends report info:
I will try to talk up its relationship with Downs Syndrome, as it is a fairly common issue
and any new info about it can help. No direct cure from this, but in terms of
mechanisms we can say that this could help lessen the effects of it. May also help with
microcephaly if other conditions affect this area (unknown at the moment but further
studies can look into it).
Finished info: I have finished what is here, as well as gathered some other info about Downs, Zika
(assists with proving microcephaly in mice is a good model for human brain
development) as well as other small bits of info that can be added later on.
Bioinformatics can also be used to create primers, so some knowledge of that will be
tagged onto a much more in-depth discussion of the methods used.
Final Project Outline
Feedback:
Aaron Loewen
33334137
I was hoping to get feedback on whether I used sufficient controls in the experiment? As
well, any feedback on the method would be much appreciated.
* denotes unfinished sections