title: Characterization of Aplysia enticin and temptin, two novel water-borne protein pheromones that act in concert with attractin to stimulate mate attraction.
abstract: Mate attraction in Aplysia involves a long-distance water-borne signal (attractin) that is released during egg laying. Other pheromones are predicted to be released during egg laying that act in concert with albumen gland attractin to stimulate attraction, but their identities are unknown. To identify other candidate water-borne pheromones, we employed differential library screening of an albumen gland cDNA library, Northern blot analysis, purification, characterization, cloning, and expression of albumen gland proteins, matrix-assisted laser desorption ionization mass spectrometry, pheromone secretion assays, behavioral bioassays, immunolocalization studies, and comparative genomics. Four genes, Alb-23, Alb-24, Alb-69, and Alb-172, were highly expressed in Aplysia californica albumen glands and encoded novel proteins. The products of the Alb-24 ("enticin") and Alb-172 ("temptin") precursors were soluble and highly abundant in albumen gland extracts, whereas Alb-23 and Alb-69 were membrane-associated proteins. A comparative analysis showed that the predicted Aplysia brasiliana enticin and temptin proteins were 90 and 91% identical, respectively, to their A. californica homologs. T-maze attraction bioassay studies have previously demonstrated that egg cordons alone are attractive to Aplysia but that attractin alone is not. In the present study, however, the combination of attractin, enticin, and temptin was found to be significantly attractive to potential mates and doubled the number of animals attracted to this stimulus compared with control animals. The combined data strongly suggest that enticin and temptin are novel candidate water-borne protein pheromones that act in concert with attractin to attract Aplysia to form and maintain egglaying and mating aggregations.
authors.affiliation: Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas 77555, USA.
authors.forename: Scott F
authors.initials: SF
authors.lastname: Cummins
authors.forename: Amy E
authors.initials: AE
authors.lastname: Nichols
authors.forename: Andinet
authors.initials: A
authors.lastname: Amare
authors.forename: Amanda B
authors.initials: AB
authors.lastname: Hummon
authors.forename: Jonathan V
authors.initials: JV
authors.lastname: Sweedler
authors.forename: Gregg T
authors.initials: GT
authors.lastname: Nagle
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001048:Aplysia / Q000502:physiology*; D003001:Cloning, Molecular; D005455:Fluorescent Antibody Technique; D015723:Gene Library; D006023:Glycoproteins / Q000502:physiology*; D008969:Molecular Sequence Data; D010058:Oviposition; D010675:Pheromones / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D011994:Recombinant Proteins / Q000302:isolation & purification; D012726:Sexual Behavior, Animal
chemical_list: D006023:Glycoproteins; D010675:Pheromones; D011994:Recombinant Proteins; C112624:attractin protein, Aplysia