ИСТИНА

Black garden ant Lasius niger is ubiquitous in the Northern hemisphere. It is common in both natural and urban environments, being tolerant to hard urbanization and habitat degradation in big cities. We used SPAdes (Bankevich et al, 2012) to produce draft genome from 272M Illumina reads, resulting in a 245Mb assembly in 41406 contigs of at least 500 bp. With cutoff set at 1000 bp, the numbers were 237Mb and 30191 contigs accordingly, while N50 reached 16382 bp. СG content was 37.65 - close to that of C.floridanus (34%). We used AUGUSTUS (Stanke et al, 2004) trained for Nasonia vitripennis to perform gene prediction in both strands; partial genes were kept. We analyzed genes from CYP9, CYP4 and CYP6 cytochrome P450 families in eight ant species for which genomes are available and also A.mellifera and N.vitripennis. Detox system genes are highly duplicated in L.niger. We found 72 sequences matching CYP450 genes from 11 families, said sequences being at least half the length of the gene in question. Compared to A. mellifera we see less CYP450 families and at the same time more genes in them (just 40 CYP450 genes found in Apis). CYP9 is the most abundant CYP450 family in L.niger. With 29 genes and just three speculated pseudogenes, L.niger also has more CYP9 genes than any other species examined. Most CYP9 genes in all examined species are under positive selection, as confirmed by pair-wise Z test. While exact function of CYP9 proteins remains unknown, virtual screening and molecular docking showed minimal free energy for a complex with macrofusin (mycotoxin of Fusarium fungi) in three CYP9 predicted proteins. This, combined with the fact that Lasius survives well in polluted urban environments, may lead us to assume that CYP9 amplification, initially providing tolerance to mycotoxins, was also fit to detoxify diverse urban pollutants and thus became a preadaptation to city dwelling.