Resources for the Calopteryx splendens genome sequence

Insects comprise the most diverse and successful animal group with over one million described species that are found in almost every terrestrial and limnic habitat, with many being used as important models in genetics, ecology, and evolutionary research. Genome sequencing projects have greatly expanded the sampling of species from many insect orders, but genomic resources for species of early-diverged insect lineages have remained relatively limited to date. To address this paucity, we sequenced the genome of the banded demoiselle, Calopteryx splendens, a damselfly (Odonata: Zygoptera) belonging to Palaeoptera, the clade resulting from the earliest divergence within the winged insect lineage. The 1.6 Gbp C. splendens draft genome assembly is one of the largest insect genomes sequenced to date and encodes a predicted set of 22,523 protein-coding genes. Comparative genomics analyses with other sequenced insects identified a relatively small repertoire of C. splendens detoxification genes, which could explain its previously noted sensitivity to habitat pollution. Intriguingly, this repertoire includes a cytochrome P450 gene not previously described in any insect genome. The C. splendens immune gene repertoire appears relatively complete and features several genes encoding novel multi-domain peptidoglycan recognition proteins. Analysis of chemosensory genes revealed the presence of both gustatory and ionotropic receptors, as well as the insect odorant receptor coreceptor gene (Orco) but no partner odorant receptors (ORs). Since formation of an OR/Orco complex is generally thought to be indispensable for odor perception in insects this finding is very intriguing. The C. splendens genome improves the sampling of early-diverged insect lineages and offers new opportunities for molecular-level evolutionary, ecological, and behavioral studies.

Genome sequence (scaffolds)

Official Gene Set (OGS), v1.0

Multiple sequence alignments (amino acids)

Additional, short genomic scaffolds (<15 Kbp)

Curated chemoreceptor sequences (amino acids)

Damselfly transcriptomes used in the study