科研之友
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摘要
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. %26lt;br%26gt;Results: To facilitate the identification of sex pheromones, 576 5%26apos;-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 SP alpha, SP alpha%26apos; and SP beta 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 SP alpha and SP alpha%26apos; 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 SP alpha-alpha%26apos; with SP beta revealed a partial structural conservation, with 37.3% identity. Translation of SP beta led to a 252-amino acid precursor containing five peptides. The occurrence of a signal peptide on SP alpha, SP alpha%26apos; and SP beta 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. %26lt;br%26gt;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 alpha 3 and beta 2 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.
- 出版日期2012-10-30
