Sequencing and de novo assembly of the Asian gypsy moth transcriptome using the Illumina platform

Abstract

The Asian gypsy moth (Lymantria dispar) is a serious pest of forest and shade trees in many Asian and some European countries. However, there have been few studies of L. dispar genetic information and comprehensive genetic analyses of this species are needed in order to understand its genetic and metabolic sensitivities, such as the molting mechanism during larval development. In this study, high-throughput sequencing technology was used to sequence the transcriptome of the Asian subspecies of the gyspy moth, after which a comprehensive analysis of chitin metabolism was undertaken. We generated 37,750,380 high-quality reads and assembled them into contigs. A total of 37,098 unigenes were identified, of which 15,901 were annotated in the NCBI non-redundant protein database and 9,613 were annotated in the Swiss-Prot database. We mapped 4,329 unigenes onto 317 pathways using the Kyoto Encyclopedia of Genes and Genomes Pathway database. Chitin metabolism unigenes were found in the transcriptome and the data indicated that a variety of enzymes was involved in chitin catabolic and biosynthetic pathways.

Expansion of LINEs and species-specific DNA repeats drives genome expansion in Asian Gypsy Moths

“…4). A recent large-scale metabolic investigation in AGM, based on transcriptomics, revealed a significantly greater number of unique transcripts associated with chitin degradation than chitin biosynthesis, two crucial processes taking place during growth and development 12 . We confirmed this trend, identifying 32 genes involved in chitin catabolism (mostly chitinases) and 16 genes involved in chitin biosynthetic pathways (Supplementary Tables S5 and S6).…”

“…Only partial transcriptome sequences are available for EGM 10 and L.d. asiatica 11,12 . Although a draft genome sequence was recently published for EGM 13 , no whole genome sequences currently exist for any AGM subspecies.…”