title: A complex set of sex pheromones identified in the cuttlefish Sepia officinalis.
abstract: BACKGROUND
  The cephalopod mollusk Sepia officinalis can be considered as a relevant model for studying reproduction strategies associated to seasonal migrations. Using transcriptomic and peptidomic approaches, we aim to identify peptide sex pheromones that are thought to induce the aggregation of mature cuttlefish in their egg-laying areas.
  
  
  RESULTS
  To facilitate the identification of sex pheromones, 576 5'-expressed sequence tags (ESTs) were sequenced from a single cDNA library generated from accessory sex glands of female cuttlefish. Our analysis yielded 223 unique sequences composed of 186 singletons and 37 contigs. Three major redundant ESTs called SPα, SPα' and SPβ were identified as good candidates for putative sex pheromone transcripts and are part of the 87 unique sequences classified as unknown. The alignment of translated SPα and SPα' revealed a high level of conservation, with 98.4% identity. Translation led to a 248-amino acid precursor containing six peptides with multiple putative disulfide bonds. The alignment of SPα-α' with SPβ revealed a partial structural conservation, with 37.3% identity. Translation of SPβ led to a 252-amino acid precursor containing five peptides. The occurrence of a signal peptide on SPα, SPα' and SPβ showed that the peptides were secreted. RT-PCR and mass spectrometry analyses revealed a co-localization of transcripts and expression products in the oviduct gland. Preliminary in vitro experiments performed on gills and penises revealed target organs involved in mating and ventilation.
  
  
  CONCLUSIONS
  The analysis of the accessory sex gland transcriptome of Sepia officinalis led to the identification of peptidic sex pheromones. Although preliminary functional tests suggested the involvement of the α3 and β2 peptides in ventilation and mating stimulation, further functional investigations will make it possible to identify the complete set of biological activities expected from waterborne pheromones.
authors.affiliation: FRE CNRS 3484 BIOMEA, Biologie des Mollusques Marins et des Ecosystèmes Associés, Université de Caen Basse-Normandie, Caen, France.
authors.forename: Jérémy
authors.initials: J
authors.lastname: Enault
authors.forename: Céline
authors.initials: C
authors.lastname: Zatylny-Gaudin
authors.forename: Benoît
authors.initials: B
authors.lastname: Bernay
authors.forename: Benjamin
authors.initials: B
authors.lastname: Lefranc
authors.forename: Jérôme
authors.initials: J
authors.lastname: Leprince
authors.forename: Michèle
authors.initials: M
authors.lastname: Baudy-Floc'h
authors.forename: Joël
authors.initials: J
authors.lastname: Henry
mesh_terms: D000595:Amino Acid Sequence; D025041:Animal Migration / Q000502:physiology; D000818:Animals; D049832:Decapodiformes / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D020224:Expressed Sequence Tags / Q000378:metabolism*; D005260:Female; D020869:Gene Expression Profiling; D015723:Gene Library; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010455:Peptides / Q000235:genetics / Q000378:metabolism; D012098:Reproduction / Q000502:physiology; D012621:Seasons; D017422:Sequence Analysis, DNA; D012724:Sex Attractants / Q000235:genetics / Q000378:metabolism / Q000502:physiology
chemical_list: D010455:Peptides; D012724:Sex Attractants