melanogaster. Fernandez and Klowden compared the hemolymph titers of Aea-HP-1 in gravid unmated and mated female A. aegypti using a radioimmunoassay [13]. The results suggested higher levels of Aea-HP-1 in the mated females, although the difference was not statistically significant and the identity of the immunoreactivity Palbociclib order was not confirmed by chromatography. Recently, a mass spectrometric study conducted by an expert group in the field of insect

neuropeptidomics compiled a comprehensive list of mature neuroendocrine peptides present in the central nervous system, neurohemal organs and various endocrine cells (including those of the mid-gut) of A. aegypti, but failed to detect Aea-HP-1 (or Aea-HP-3) in any of these tissues [34]. It is therefore not possible to pinpoint the source of Aea-HP-1 that was originally isolated from a large quantity of heads. These results taken together with the ease in which we detect Aea-HP-1 in a single MAG suggest that the male reproductive tissue is a major site of synthesis of this peptide, at least in adult males. None of the head peptides have been found in the peptidomes of other insects and genes coding for the head peptides have been notably absent from insect genome databases, even those of other

mosquitoes, suggesting a specific role for the peptide in Montelukast Sodium reproduction of A. aegypti. Aea-HP-1 might fall into the category of male reproductive proteins which are subject to much faster evolutionary change compared to proteins Bcl-2 inhibitor of non-reproductive tissues, possibly driven by sexual conflict [3]. Transplantation of MAGs, or injection of gland

extracts, into female A. aegypti can elicit a variety of post-mating responses including refractoriness to re-mating and inhibition of host-seeking and biting behavior [13]. We have not been able to show that Aea-HP-1 can induce mating rejection by injecting Aea-HP-1 (0.1–1 μg) into the hemocoel of virgin A. aegypti females (not presented). This failure might be due to lack of accessibility and the known rapid catabolism of Aea-HP-1 in the hemolymph [4]. D. melanogaster SP has wide-ranging effects on physiology and behavior some of which are mediated primarily through activation of the SP/MIP receptor that is expressed in sensory neurons of the uterus [42]. The D. melanogaster SP receptor and its A. aegypti orthologue are also strongly activated by myoinhibitory peptides (MIPs), a family of peptides that are found in species from different insect orders and are considered to be the ancestral ligands for these receptors [19], [33] and [41]. The receptors are also activated by unidentified ligands present in whole body extract of adult A. aegypti [19].