Differential gene expression in the gray lawn leafhopper, Exitianus exitiosus (Uhl.), after acquisition of Spiroplasma kunkelii

The interaction between phytopathogenic spiroplasmas and their insect vectors is not well understood. Both reduced and increased fitness have been recorded in plant infecting spiroplasma-insect vector systems, indicating that spiroplasmas have intimate molecular interactions with their vectors. To begin elucidating the vector’s response to acquisition of spiroplasmas at a transcriptomic level, the transcriptomes of Spiroplasma kunkelii-infected versus naïve gray lawn leafhoppers, Exitianus exitiosus (Uhl.), were compared. Total RNA was extracted with Trizol from three replicate pools of 10 leafhoppers (5 adult males and 5 adult females) 25 days (latent period) after a 24-hour acquisition access period from S. kunkelii-inoculated feeding sachets. Three similar replicates were simultaneously completed for the naïve leafhopper control groups after exposure to S. kunkelii-negative feeding sachets. Sequencing libraries were constructed by selecting for poly-adenylated RNA, shearing selected RNA, and synthesizing cDNA. Appropriately sized cDNA fragments were assessed for quality and quantity, and 1x75 base read sequencing was performed on the Illumina NextSeq500. Raw sequence read data was quality checked using FastQC. De novo assembly was performed, and differentially expressed transcripts were identified, annotated, and statistically analyzed. E. exitiosus had differential expression in response to S. kunkelii infection.