Gap Genes Start Segmentation
Combinations of a few proteins create enormous complexity – One of the hardest concepts to learn in college level courses on embryonic development.How can a single egg become a complex Drosophila fruit fly with a head, wings, and 3 pairs of legs?
It starts with segmentation. This process is accomplished by special proteins called transcription factors. Transcription factors get their name because they interact with the DNA to change what genes are “turned on” (i.e. transcribed into mRNA and then translated into proteins).
Where a cell is in the developing fly determines what transcription factors its DNA is exposed to. For example, segment 1 is exposed to two different Gap Gene proteins (purple and red) whereas segment 5 is exposed to just one (yellow). Therefore each developing segment has a different set of genes that are turned on and off. This is the beginning of forming a body plan in which different cells take on unique identities based on their location in the organism.
Often, transcription factors turn on other transcription factors, which creates more complexity and causes cells to take on even more specific identities.
Use color to improve the communication of a scientific diagram on Drosophila larvae development. In this example, I used color to more clearly demonstrate that:
- Each segment in the developing fly has a different fate.
- E.g. only the purple segment will become the head, only the purple and red segment will become the upper thorax.
- Combinations of gap gene proteins determine segment fates.
- E.g. the purple protein determines which segment becomes the head, the overlap of purple and red proteins determines where the upper thorax will develop.
The figure was based on a color-less slide (below) that did not communicate the points above as effectively. Stanford Biology and Human Biology Core lecturers now use my improved design to illustrate concepts in developmental biology. By now, I estimate this figure will have reached about 1,000 Stanford students.
My bluegrass band, Nimbleweed, used the design on our debut album, Nimbleweed Sings Science!