title: What's in the Gift? Towards a Molecular Dissection of Nuptial Feeding in a Cricket.
abstract: Nuptial gifts produced by males and transferred to females during copulation are common in insects. Yet, their precise composition and subsequent physiological effects on the female recipient remain unresolved. Male decorated crickets Gryllodes sigillatus transfer a spermatophore to the female during copulation that is composed of an edible gift, the spermatophylax, and the ampulla that contains the ejaculate. After transfer of the spermatophore, the female detaches the spermatophylax and starts to eat it while sperm from the ampulla are evacuated into the female reproductive tract. When the female has finished consuming the spermatophylax, she detaches the ampulla and terminates sperm transfer. Hence, one simple function of the spermatophylax is to ensure complete sperm transfer by distracting the female from prematurely removing the ampulla. However, the majority of orally active components of the spermatophylax itself and their subsequent effects on female behavior have not been identified. Here, we report the first analysis of the proteome of the G. sigillatus spermatophylax and the transcriptome of the male accessory glands that make these proteins. The accessory gland transcriptome was assembled into 17,691 transcripts whilst about 30 proteins were detected within the mature spermatophylax itself. Of these 30 proteins, 18 were encoded by accessory gland encoded messages. Most spermatophylax proteins show no similarity to proteins with known biological functions and are therefore largely novel. A spermatophylax protein shows similarity to protease inhibitors suggesting that it may protect the biologically active components from digestion within the gut of the female recipient. Another protein shares similarity with previously characterized insect polypeptide growth factors suggesting that it may play a role in altering female reproductive physiology concurrent with fertilization. Characterization of the spermatophylax proteome provides the first step in identifying the genes encoding these proteins in males and in understanding their biological functions in the female recipient.
authors.affiliation: Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany.
authors.forename: Yannick
authors.initials: Y
authors.lastname: Pauchet
authors.affiliation: Mass spectrometry, Max Planck Institute for Chemical Ecology, Jena, Germany.
authors.forename: Natalie
authors.initials: N
authors.lastname: Wielsch
authors.affiliation: Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall Campus, Penryn, United Kingdom.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Wilkinson
authors.affiliation: Behavior, Ecology, Evolution & Systematics Section, School of Biological Sciences, Illinois State University, Normal, IL, United States of America.
authors.forename: Scott K
authors.initials: SK
authors.lastname: Sakaluk
authors.affiliation: Mass spectrometry, Max Planck Institute for Chemical Ecology, Jena, Germany.
authors.forename: Aleš
authors.initials: A
authors.lastname: Svatoš
authors.affiliation: Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall Campus, Penryn, United Kingdom.
authors.forename: Richard H
authors.initials: RH
authors.lastname: ffrench-Constant
authors.affiliation: Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall Campus, Penryn, United Kingdom.
authors.forename: John
authors.initials: J
authors.lastname: Hunt
authors.affiliation: Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany.
authors.forename: David G
authors.initials: DG
authors.lastname: Heckel
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002256:Carbonic Anhydrases / Q000032:analysis / Q000235:genetics; D003307:Copulation; D005247:Feeding Behavior; D005260:Female; D037921:Gift Giving; D006135:Gryllidae / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D019476:Insect Proteins / Q000032:analysis / Q000235:genetics*; D036341:Intercellular Signaling Peptides and Proteins / Q000032:analysis / Q000235:genetics; D008297:Male; D008969:Molecular Sequence Data; D012098:Reproduction; D016415:Sequence Alignment; D012726:Sexual Behavior, Animal; D013093:Spermatogonia / Q000737:chemistry / Q000502:physiology; D059467:Transcriptome
chemical_list: D019476:Insect Proteins; D036341:Intercellular Signaling Peptides and Proteins; D002256:Carbonic Anhydrases