We have played a leading role in the Heliconius Genome Consortium, which has generated a reference sequence for Heliconius melpomene. Our contribution included the scaffolding of the reference genome onto chromosomal linkage groups using a RAD-seq linkage map, and the gene annotation and databasing. We are now working to improve genome scaffolding using full genome sequencing of a large mapping family and long-read sequencing.
This reference genome has opened exciting opportunities to explore the adaptive radiation in these butterflies at a genomic level.
Among 12,657 predicted genes for Heliconius, we found expansions of families of chemosensory and Hox genes. The diversity of chemosensory proteins in butterfly genomes was particularly surprising given the evolution of diurnal behaviour and greater visual acuity.
Comparison of synteny between lepidopteran genomes shows that the chromosomal organization of Lepidoptera has remained broadly conserved since the Cretaceous period, when butterflies split from the Bombyx (silkmoth) lineage.
The reference genome has also facilitated studies of hybridisation, speciation genomics and populations genetics – see other research themes for more details.