21689185
not annotated - annotated - LINNAEUS only
Synganglion transcriptome and developmental global gene expression in adult females of the American dog tick, Dermacentor variabilis (Acari: Ixodidae).
454 Pyrosequencing was used to characterize the expressed genes from the synganglion and associated neurosecretory organs of unfed and partially fed virgin and mated replete females of the American dog tick, Dermacentor variabilis. A total of 14,881 contiguous sequences (contigs) was assembled, with an average size of 229 bp. Gene ontology terms for Level 2 biological processes were assigned to 4366 contigs. Seven acetylcholinesterases, a muscarinic acetylcholine (ACh) receptor, two nicotinic ACh receptor Beta-subunits, two ACh unc-18 regulators, two dopamine receptors, two gamma aminobutyric acid (GABA) receptors, two GABA transporters, two norepinephrine transporters and an octopamine receptor are described. Microarrays were conducted to examine global gene expression and quantitative real-time polymerase chain reaction was used to verify expression of selected neuropeptides. Hierarchical clustering of all differentially expressed transcripts grouped part-fed and replete ticks as being more similar in terms of differentially expressed genes with unfed ticks as the outgroup. Nine putative neuropeptides (allatostatin, bursicon-Beta, preprocorazonin, glycoprotein hormone alpha, insulin-like peptide, three orcokinins, preprosulphakinin) and a gonadotropin releasing hormone receptor were differentially expressed, and their developmental expression and role in reproduction was investigated. The presence of eclosion hormone, corazonin and bursicon in the synganglion, which in insects regulate behaviour and cuticle development associated with moulting, suggest that this system may be used in ticks to regulate blood feeding, cuticle expansion and development related to female reproduction; adult ticks do not moult.
Ann file
T1 Species 91 108 American dog tick
N1 Reference T1 Taxonomy:34621
T2 Species 110 132 Dermacentor variabilis
N2 Reference T2 Taxonomy:34621
T3 Species 343 360 American dog tick
N3 Reference T3 Taxonomy:34621
T4 Species 362 384 Dermacentor variabilis
N4 Reference T4 Taxonomy:34621