title: Proteinaceous Pheromone Homologs Identified from the Cloacal Gland Transcriptome of a Male Axolotl, Ambystoma mexicanum.
abstract: Pheromones play an important role in modifying vertebrate behavior, especially during courtship and mating. Courtship behavior in urodele amphibians often includes female exposure to secretions from the cloacal gland, as well as other scent glands. The first vertebrate proteinaceous pheromone discovered, the decapeptide sodefrin, is a female attracting pheromone secreted by the cloacal gland of male Cynops pyrrhogaster. Other proteinaceous pheromones in salamanders have been shown to elicit responses from females towards conspecific males. The presence and levels of expression of proteinaceous pheromones have not been identified in the family Ambystomatidae, which includes several important research models. The objective of this research was therefore to identify putative proteinaceous pheromones from male axolotls, Ambystoma mexicanum, as well as their relative expression levels. The results indicate that axolotls possess two different forms of sodefrin precursor-like factor (alpha and beta), as well as a putative ortholog of plethodontid modulating factor. The beta form of sodefrin precursor-like factor was amongst the most highly expressed transcripts within the cloacal gland. The ortholog of plethodontid modulating factor was expressed at a level equivalent to the beta sodefrin precursor-like factor. The results are from a single male axolotl; therefore, we are unable to assess how representative our results may be. Nevertheless, the presence of these highly expressed proteinaceous pheromones suggests that male axolotls use multiple chemical cues to attract female conspecifics. Behavioral assays would indicate whether the putative protein pheromones elicit courtship activity from female axolotls.
authors.affiliation: Department of Integrative Biology and BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, Michigan, United States of America.
authors.forename: Kevin W
authors.initials: KW
authors.lastname: Hall
authors.affiliation: Department of Integrative Biology and BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, Michigan, United States of America.
authors.forename: Heather L
authors.initials: HL
authors.lastname: Eisthen
authors.affiliation: Department of Integrative Biology and BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, Michigan, United States of America.
authors.forename: Barry L
authors.initials: BL
authors.lastname: Williams
mesh_terms: D000558:Ambystoma mexicanum / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D002988:Cloaca / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D063990:Gene Ontology; D008297:Male; D058977:Molecular Sequence Annotation; D008969:Molecular Sequence Data; D010675:Pheromones / Q000737:chemistry / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017423:Sequence Analysis, RNA; D017386:Sequence Homology, Amino Acid; D059467:Transcriptome / Q000187:drug effects*; D014981:Xenopus / Q000235:genetics
chemical_list: D010675:Pheromones; D012333:RNA, Messenger