1. Two “things” that stood out
The first thing that really stood out to me is how different concentrations and combinations of regulatory proteins can control the expression of genes in different areas of a developing embryo. For instance, morphogen gradients are used to determine “stripes” and the expression of various other gap, pair-rule and segment polarity genes. This is done when different regulatory proteins bind to various enhancer regions responsible for stripe expression. They can act both as enhancer or repressor proteins and may have various affinities for different bindings sites. I find this very interesting since segment/ stripe determination is more complicated than it seems due to the large network of various genes/ regulatory proteins and their expression patterns and binding affinities at different regions in the embryo.
Another thing that stood out to me were the various types of enhancers. These include fail-safe enhancers, shadow enhancers, super- enhancers, tissue-specific enhancers and HOTS (Highly Occupied Transcription Sites). All these enhancers work in various ways such as in the case of fail-safe enhancers, both pieces of enhancing regions must be present and activated in order to ensure the gene isn’t activated by accident. Even though they all work to regulate transcription, I didn’t expect there to be so many subtypes of enhancers that perform in various ways.
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Two things that stood out |
Type of knowledge |
What makes these things stand out for you |
Evidence/how you would test someone on this (select one “thing” only!) | |
| 1 | Different combinations and concentrations of regulatory control gene expression in different areas in embryo (segmentation)
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Conceptual | I was surprised by how complex controlling gene expression in various regions and segments actually is
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I would test them by presenting them with an experiment that knocks out various genes/ regulatory proteins controlling embryo development. They would be given the phenotypes of all the mutants (like on our midterm) and would be asked to hypothesize what the specific roles each protein/ gene have in development considering the mutant phenotypes. They would also have to identify where in the embryo the specific protein/ gene acts and propose their functions and a model of their interactions. If they are able to identify the functional contributions of each gene/proteins by looking at the change in phenotypes, while at the same time, describing their hypothesized interactions with one another to form specific structures, then the students will have a good understanding of how various combinations of genes/regulatory proteins act to control the development of structures in an embryo. |
| 2 | The various types of enhancers
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Factual | I didn’t expect there to be so many different types of enhancers. They all differ in size, function and their role in controlling transcription. This makes me think about the functional role of enhancers differently than what I had originally believed (eg. enhancers just upregulate transcription…) |
If I didn’t know Susan and I was using this blog to understand how she learns it seemed like she has a decent background in biology (shown by mentioning past classes in LJ1). She shows understanding in new topics by going into detail to explain things. This person could be a visual learner (she describes in learning journal 2 how the looping helped her to “visualize how the presence of inhibitors/BE functions to prevent enhancers from interacting w/ promoters”. It seems like this person put a lot of thought and effort into each post. One major strength I noticed was that her posts were well written and explained well to a point that even a person who hasn’t taken a biology class would have an idea of what she was trying to say. She provides many examples to help the reader understand the points she is trying to make (this can really be seen in learning journal 2).
Overall your blog posts seem great and really thought out, it was hard to come up with a suggestion for improvement. In my opinion you demonstrated your understanding well. You could perhaps post a few things related to the class to show you are making connections with things we’ve learning in class as well as with things you’ve read outside of class.
Thanks for letting me read your blog :). Well done!