However, for clearly comparing the difference of progesterone levels between control and treatment groups, we designed to harvest the ovaries at 48 hr after treatment to provide enough time for progesterone production and accumulation. This may lead us to miss the best time point for quantification of these genes. In addition, down-regulation of Lhr, steroidogenic genes and other yet uncharacterized candidates in Lgr4-ED treated animals may also cause synergetic effects on suppression of progesterone production. Taken together, our findings suggest that the Lgr4 signaling may help to accelerate the ovarian luteinization process. However, there is a need to consider the possibility that the lack of apparent phenotypes in the Lgr4-null mouse ovaries may be due to signal compensation by other ovary-RAD001 expressed receptors such as Lgr5, Lgr6, and frizzled, which are also involved in similar downstream to activate the Wnt/b-catenin signaling as Lgr4. One possibility to explain our data is that administration of the recombinant Lgr4ED protein may absorb all the potential Wnt activators, such as Rspondins and norrin, and thus there will be a magnification of Lgr4-ED��s ovarian effects because of the interruption of other potential Wnt/b-catenin signaling driven by other group B LGRs and frizzled proteins. This hypothesis suggests that there is a need to characterize the detailed expression profiles of all the group B LGR members and to identify their ligand signatures across the various ovarian compartments; this will greatly help our understanding of their interplay and relationships. Mating triggers comprehensive physiological and behavioral changes in female insects to maximize reproductive success. Notably, sex peptide, a seminal fluid protein transferred during copulation, activates oviposition, enhances locomotor activity, decreases sexual receptivity, shortens daytime sleep, and alters immunity and food choice in Drosophila melanogaster.While broadly present in the reproductive, Oligomycin A endocrine and nervous systems, the sex peptide receptor expressed in the fruitless, pickpocket and doublesex neurons in particular plays a central role in reducing sexual receptivity and increasing oviposition processes that directly and substantially contribute to fecundity.