Analysis of genes influencing the feeding of Bombyx mori by genome resequencing

Abstract

Bombyx mori belonging to the Lepidoptera family of insects, is an oligophagous insect that feeds on mulberry leaves. But why the silkworm has a soft spot for mulberry leaves is still a scientific mystery. The existing silkworm genome assembly and annotation are not satisfactory, which limits further analysis of silkworm gene functions. We used next-generation and third-generation sequencing technology, Hic, and other new technologies to resequence and assemble the whole genome of Bombyx mori Jiangsu. Through Venn analysis, Bombyx mori Jiangsu, Bombyx mori_JP and Bombyx mandarina that eats mulberry leaves was compared with other 6 species, and the Bombyx-specific gene families were found. The positive selection analysis was used to find the positively selected genes among the Bombyx mori Jiangsu, Bombyx mori_JP and Bombyx mandarina. And then, GO and KEGG enrichment analysis were used to explore the functions of these genes, trying to find genes that affect silkworm feeding. The total amount of data obtained by next-generation, third-generation and Hi-C sequencing was 198.67 G, and the ratio of GC was 38.31%, with contig N50 of 3.75 Mb and scaffold N50 of 17.26 Mb. We found that UGT46A1, UGT33R1 and UGT33R2 were only found in Bombyx mori Jiangsu, Bombyx mori_JP, and Bombyx mandarina. And they were all involved in multiple pathways such as cytochrome P450 foreign body metabolism, starch and sucrose metabolism, and pentose and glucuronate conversion pathways. We found that cyclic nucleotide-gated cation channel subunit A-like (CNGA) was subject to positive selection and was involved in the olfactory transduction pathway.