Submitted to: Insect Molecular Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/30/2000
Publication Date: N/A
Interpretive Summary: Although the southern cattle tick (SCT) and the disease it transmits, babesiosis, were eradicated from the US after a 50-year eradication program of dipping cattle and temporarily vacating tick-infested pastures, they are still widespread in Mexico and other parts of America. Quarantine by vat dipping with chemical acaricides has prevented reinfestation in the US, but SCT has developed resistance to acaricides currently in use. It is desirable to develop new acaricides that are more environmentally friendly and more selective in their targets. One way to achieve this is to understand potential targets, such as a physiological function in specific pests, and then develop strategies that can disrupt such targets. Because ticks and other bloodsucking pests have a unique requirement for rapid excretion, the excretory function appears to be a good candidate as a target for the development of new pest control strategies. In this study we cloned a DNA encoding the receptor for leucokinin-like peptides from th SCT. Leucokinins are invertebrate neuropeptides that stimulate muscle contraction and excretion in invertebrate animals. With more understanding of these receptors, we could design chemicals that would disrupt the normal function of excretory organs, achieving control of these pests. Since there are differences in receptors of different species, it is possible to develop agents that will only target the pest species.
Technical Abstract: Leucokinins are invertebrate neuropeptides that exhibit myotropic and diuretic activity. Only one leucokinin-like peptide receptor is known, the lymnokinin receptor from the mollusc Lymnaea stagnalis. A cDNA encoding a leucokinin-like peptide receptor was cloned from the southern cattle tick, Boophilus microplus. This is the first neuropeptide receptor known from the Acari and the second known in the subfamily of leucokinin-like peptide G protein-coupled receptors. The deduced amino acid sequence is 45% identical to that of the lymnokinin receptor. The receptor transcript is present in all tick life stages as determined by semi-quantitative RT-PCR. B. microplus is a serious pest and disease vector of cattle worldwide. This receptor may represent a target for the development of novel control approaches.