Shared and divergent expression domains on mimetic Heliconius wings

Area of Science:

• Evolutionary biology
• Genetics
• Biochemistry

Background:

• Heliconius butterfly wing patterns exhibit convergent evolution, driven by mimicry and mate choice.
• Understanding the genetic basis of these adaptive phenotypes is crucial for connecting genotype and phenotype.

Purpose of the Study:

• To investigate the genetic basis of forewing ommochrome pigmentation in Heliconius melpomene.
• To compare gene expression patterns of ommochrome pathway genes between the co-mimic species Heliconius erato and Heliconius melpomene.

Main Methods:

• Cloning of two new ommochrome pathway genes: karmoisin and kynurenine formamidase (kf).
• Analysis of expression patterns for known ommochrome genes during pupal wing development.
• Comparative gene expression analysis between Heliconius erato and Heliconius melpomene.

Main Results:

• Cinnabar gene expression correlates with forewing bands in both species.
• Vermillion gene expression patterns differ significantly between the co-mimic species.
• Scarlet and potentially kf genes show enhanced expression in the forewing band of Heliconius melpomene, suggesting coordinated pathway upregulation.

Conclusions:

• Both conserved and divergent gene expression patterns contribute to mimetic phenotypes in Heliconius.
• Coordinated upregulation of ommochrome biosynthetic pathway genes is involved in Heliconius wing pattern formation.