Hartke J, Schell T, Jongepier E, Schmidt H, Sprenger PP, Paule J, Bornberg-Bauer E, Schmitt T, Menzel F, Pfenninger M, Feldmeyer B.
Hybrid genome assembly of a neotropical mutualistic ant
The success of social insects is largely intertwined with their highly advanced chemical communication system that facilitates recognition and discrimination of species and nest-mates, recruitment, and division of labour. Hydrocarbons, which cover the cuticle of insects, not only serve as waterproofing agents but also constitute a major component of this communication system. Two cryptic Crematogaster species, which share their nest with Camponotus ants, show striking diversity in their cuticular hydrocarbon (CHC) profile. This mutualistic system therefore offers the great opportunity to study the genetic basis of CHC divergence between sister species. As a basis for further genome-wide studies high-quality genomes are needed. Here we present the annotated draft genome for Crematogaster levior A. By combining the three most commonly used sequencing techniques – Illumina, PacBio and Oxford Nanopore – we constructed the most contiguous de novo ant genome assembly so far. We show that even low coverage of long reads can add significantly to overall genome contiguity. Annotation of desaturase and elongase genes, which play a role in CHC biosynthesis revealed one of the largest repertoires in ants and a higher number of desaturases in general than in other Hymenoptera. This may provide a mechanistic explanation for the high diversity observed in C. levior CHC profiles.