title: Visualizing Molecular Functions and Cross-Species Activity of Sex-Peptide in Drosophila.
abstract: The Drosophila melanogaster sex-peptide (melSP) is a seminal fluid component that induces postmating responses (PMR) of females via the sex-peptide receptor (SPR) . Although SP orthologs are found in many Drosophila species, their functions remain poorly characterized. It is unknown whether SP functions are conserved across species or rather specific to each species. Here, we developed a GFP-tagged melSP (G-SP) and used it to visualize cross-species binding activity to the female reproductive system of various species. First we demonstrated that ectopically expressed G-SP induced PMR in D. melanogaster females and bound to the female reproductive system, most notably to the common oviduct. No binding occurred in the females lacking SPR, indicating that G-SP binding was dependent on SPR. Next we tested whether G-SP binds to the common oviducts from 11 Drosophila species using dissected reproductive tracts. The binding was observed in six species belonging to the D. melanogaster species group, but not to those outside the group. Injection of melSP reduced the receptivity of females belonging to the D. melanogaster species group, but not of those outside the group, being consistent with the ability to bind G-SP. Thus the SP-mediated PMR appears to be limited to this species group. SPR was expressed in the oviducts at high levels in this group; therefore, we speculate that an enhanced expression of SPR in the oviduct was critical to establish the SP-mediated PMR during evolution.
authors.affiliation: Department of Biological Sciences, Tokyo Metropolitan University, Tokyo 192-0397, Japan Department of Liberal Arts and Human Development, Kanagawa University of Human Services, Kanagawa 238-8522, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Tsuda
authors.affiliation: Department of Biological Sciences, Tokyo Metropolitan University, Tokyo 192-0397, Japan.
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Peyre
authors.affiliation: Department of Biological Sciences, Tokyo Metropolitan University, Tokyo 192-0397, Japan.
authors.forename: Tsunaki
authors.initials: T
authors.lastname: Asano
authors.affiliation: Department of Biological Sciences, Tokyo Metropolitan University, Tokyo 192-0397, Japan aigaki-toshiro@tmu.ac.jp.
authors.forename: Toshiro
authors.initials: T
authors.lastname: Aigaki
mesh_terms: D000818:Animals; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000378:metabolism* / Q000502:physiology; D019143:Evolution, Molecular; D005260:Female; D008297:Male; D010455:Peptides / Q000378:metabolism*; D011485:Protein Binding; D018000:Receptors, Peptide; D012098:Reproduction; D013045:Species Specificity; D013094:Spermatozoa / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; D010455:Peptides; D018000:Receptors, Peptide; C526291:sex peptide receptor, Drosophila
keywords: GFP-tag; SP receptor; postmating response; sex-peptide