Psyllid Biology: Expressed Genes in Adult Asian Citrus Psyllids, Diaphorina citri Kuwayama

Where it occurs the Asian citrus psyllid, Diaphorina citri, Kuwayama (Hemiptera: Psyllidae) is considered the primary vector of Huanglongbing, HLB, disease of citrus trees. The plant pathogenic bacterium associated with HLB causes economic losses to citrus industries worldwide. To better understand the general biology of D. citri, we undertook a sequencing project from adult psyllids. Few genes have been isolated from psyllids however several insect genomic datasets are available for comparisons. We compared the psyllid data to genomic datasets of nematode, C. elegans, fruit fly, D. melanogaster, honey bee, A. mellifera, mosquito, A. aegypti, and human, H. sapiens since these have completed more thorough levels of annotation. We describe the first data set of ESTs from D. citri, the Asian citrus psyllid. A total of 5,906 cDNA clones were sequenced, resulting in 4,595 high-quality ESTs. Electronic removal of 1,487 sequences which matched to bacteria and viruses left an assembly of cDNAs resulting in a total of 636 psyllid sequences (544 contigs plus 92 singlets). The sequences underwent BLAST analyses using (Swissprot-Tremble 03-2007) and NCBI, nr databases which returned 53% with 'No significant match' in either the non-redundant protein or nucleic acid databases, providing new information to the scientific community. The D. citri gene expression data set advances current research efforts in the identification of genes and physiological processes of psyllids. Knowledge of these genes and proteins are being used in the development of novel management strategies against psyllids, and other sap feeding insects within the Order: Hemip- tera.