I have been meaning to post about another big Heliconius paper that came out earlier this year which made a major advance in our knowledge of the genes underlying Heliconius wing patterning. We have known for some time now, from work led by Simon Baxter in my lab, that a narrow genomic interval is responsible for controlling red wing patterns in both the co-mimics H. melpomene and H. erato. In a paper earlier this year, Bob Reed’s lab made a major advance on this by showing that the optix gene is expressed in a pattern completely correlated with red wing patterns in the developing pupa. This was first uncovered by Riccardo Papa using a microarray experiment, and then elegantly confirmed by Arnaud Martin with in situ hybridisation. Optix is a transcription factor, a gene that regulates the expression of other genes. There are no coding differences between optix sequences in different populations, which shows that regulatory changes underlie the difference in expression.
Here are some links that give more details:
Science perspective article by Sean Carroll
Link to original article