We have been delighted to host Dr Mark Brown (University of Georgia), the 15th Patton Lecturer for the academic year 2015/16. Dr Brown presented his research in a lecture entitled “Different neuropeptides convergently activate egg maturation in mosquitoes”, and we had the opportunity for individual discussions with faculty, graduate students and researchers.
The abstract for Dr Brown’s presentation is provided below, and more information about the Patton Lecture series is here.
Reproduction in mosquitoes is a relatively quick and highly regulated sequence of behavioral and physiological processes that result in the production of eggs. This is because females of most species steal a blood meal from a vertebrate host to acquire nutrients for yolk protein synthesis, but some do not and instead mobilize teneral reserves for this purpose. Both strategies depend on the release of neuropeptides from brain neurosecretory cells. Two such neuropeptides, ovary ecdysteroidogenic hormone (OEH) and insulin-like peptides (ILPs), activate production of ecdysteroid hormone by ovaries in female mosquitoes. The peptides bind to different but related receptors that signal through the insulin pathway to initiate gene expression and cell processes required for ecdysteroid production that are further enhanced through amino acid sensing/target of rapamycin and calcium signaling. The rise in ecdysteroid titer drives yolk production and ultimately egg maturation. ILPs also activate key processes in other tissues associated with egg maturation, but not OEH. Studies to date indicate this endocrine cascade is conserved across all groups of non- and blood feeding mosquitoes, but the most significant question of what stimulates the release of these neuropeptides has yet to be answered.