Transcriptome of the tarnished plant bug, Lygus lineolaris with emphasis on digestion related genes

Messenger RNA pooled from tarnished plant bugs that included developmental stages from embryos (12 hour intervals) to 5th instar nymphs, and 3rd to 5th instar nymphs and adults treated with 5 different classes of insecticides (to induce genes involved in detoxification) was used to obtain nucleotide sequence reads (over 500,000 Roche 454 sequence reads and 18 million Illumina GAII reads) of expressed genes. The initial assembly resulted in a total of 79,444 contigs, of which 52,054 were 80 nucleotides or longer. The longest contig assembled was 7,318 nt with 20.5-fold coverage. A total of 3,833,035 sequence reads containing 317,782,637 nucleotides contributed to the assembly of contigs ≥80 nt with an N50 of 973 nt. The coverage of contigs ≥80 nt ranged from 1482.9 to 1.3-fold with an average of 10.4. The cumulative length of assembled contigs was 29,644,105 nt. Refinement of the transcriptome assembly with additional Illumina HiSeq2000 reads resulted in 37,934 unique transcripts of 300 nucleotides or longer, of which 19,460 sequences had one or more BLAST description and 13,788 sequences were mapped to at least one gene ontology (GO) term. Illumina HiSeq2000 reads obtained from RNA-Seq libraries were used in profiling gene expression patterns in salivary glands and guts of the adult plant bugs. Several novel genes that may be involved in plant tissue disruption were identified from the salivary gland.