The genome sequence of the lesser marbled fritillary, Brenthis ino, and evidence for a segregating neo-Z chromosome

Abstract

The lesser marbled fritillary, Brenthis ino (Rottemburg, 1775), is a species of Palearctic butterfly. Male B. ino individuals have been reported to have between 12 and 14 pairs of chromosomes, a much reduced chromosome number than is typical in butterflies. Here we present a chromosome-level genome assembly for B. ino, as well as gene and transposable element annotations. The assembly is 411.8 Mb in span with contig and scaffold N50s of 9.6 and 29.5 Mb respectively. We also show evidence that the male individual from which we generated HiC data was heterozygous for a neo-Z chromosome, consistent with inheriting 14 chromosomes from one parent and 13 from the other. This genome assembly will be a valuable resource for studying chromosome evolution in Lepidoptera, as well as for comparative and population genomics more generally.