In two related Drosophila species, a so-called paintbrush gene is activated to "paint" the pigment on the body. In one species, an extra switch activates the gene, resulting in spotted wings.
Paintbrush Gene Background
Both Drosophila melanogaster and Drosophila biarmipes have a so-called paintbrush gene that controls pigmentation, including wing color. Although the two fly species have similarly colored bodies, D. biarmipes has spots on its wings and D. melanogaster does not. Expression of the paintbrush gene is controlled by special switch regions of DNA. D. biarmipes has a "wing switch" region that controls expression of the paintbrush gene in the wings, thereby creating the spots. There is no wing switch in D. melanogaster. The paintbrush gene is not expressed in this fly's wings, and thus the wings are not spotted.
From Lecture Four of the 2005 Holiday Lectures Series "Evolution: Constant Change and Common Threads"
Paintbrush Gene Teaching Tips
The animations in this section have a wide variety of classroom applications. Use the tips below to get started but look for more specific teaching tips in the near future. Please tell us how you are using the animations in your classroom by sending e-mail to firstname.lastname@example.org.
Use the animations to make abstract scientific ideas visible and concrete.
Explain important scientific principles through the animations. For example, the biological clocks animations can be used to demonstrate the fundamentals of transcription and translation.
Make sure that students learn the material by repeating sections of the animations as often as you think necessary to reinforce underlying scientific principles. You can start, restart, and play back sections of the animations.
Urge students to use the animations in accordance with their own learning styles. Students who are more visually oriented can watch the animations first and read the text later, while others might prefer to read the explanations first and then view the graphics.
Incorporate the animations into Web-based learning modules that you create to supplement your classroom curricula.
Encourage students to incorporate the animations into their own Web-based projects.
The 2005 Holiday Lectures Series "Evolution: Constant Change and Common Threads"