1. Origin and genomic organization of a sex pheromone in aquatic newts (Salamandridae)
- Author
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Janssenswillen, Sunita, Treer, Dag, Roelants, Kim, Bossuyt, Franky, Biology, Amphibian Evolution Lab, and Faculty of Sciences and Bioengineering Sciences
- Subjects
pheromone evolution ,animal diseases ,newts ,sodefrin precursor - Abstract
Males of aquatic salamandrid newts often use tail-fanning behavior to direct cloacal pheromones towards receptive females, but few of these molecules have been characterized. The Asian Cynops pyrroghaster is known to emit a pheromone called sodefrin, a decapeptide that is cleaved from the larger Sodefrin Precursor Factor (SPF). Behavioral tests have demonstrated that sodefrin has the ability to attract and excite gravid females. To understand the evolution of SPF and pinpoint the origin of sodefrin, we sequenced cloacal mRNA (transcribed DNA) from males and females in five salamandrid genera with aquatic courtship. We found a substantial difference in number of transcripts between the sexes, and recovered up to seventeen different SPF transcripts per species. Integration of genome and transcriptome analyses reveal that this SPF transcript diversity is formed by a combination of gene/exon duplications and alternative splicing. Phylogenetic analyses further indicate that sodefrin evolved from SPF by a frameshift mutation within the lineage of Asian newts, i.e. long after the origin of the tail fanning behavior. We hypothesize that other salamandrid newts are using the same behavior to deliver different pheromones that are likely derived from similar SPF precursors.
- Published
- 2011