A high-quality genome of the dobsonfly Neoneuromus ignobilis reveals molecular convergences in aquatic insects

Neoneuromus ignobilis is an archaic holometabolous aquatic predatory
insect. However, a lack of genomic resources hinders the use of whole
genome sequencing to explore their genetic basis and molecular mechanisms
for adaptive evolution. Here, we provided a high-contiguity,
chromosome-level genome assembly of N. ignobilis using high coverage
nanopore reads and the Hi-C technique. The final assembly is 481.43 MB in
size, containing 12 telomere-ended pseudochromosomes with only 23 gaps. We
then compared 42 hexapod species genomes including six independent
lineages comprising 11 aquatic insects, and found convergent expansions of
long wavelength-sensitive and blue-sensitive opsins, thermal stress
response TRP channels, and sulfotransferases in aquatic insects, which may
be related to their aquatic adaptation. We also detected strong non-random
signals of convergent amino acid substitutions in aquatic insects.
Collectively, our comparative genomic analysis revealed the evidence of
molecular convergences in aquatic insects during both gene family
evolution and convergent amino acid substitutions.