title: Deep sequencing reveals complex mechanisms of diapause preparation in the invasive mosquito, Aedes albopictus.
abstract: Seasonal environments present fundamental physiological challenges to a wide range of insects. Many temperate insects surmount the exigencies of winter by undergoing photoperiodic diapause, in which photoperiod provides a token cue that initiates an alternative developmental programme leading to dormancy. Pre-diapause is a crucial preparatory phase of this process, preceding developmental arrest. However, the regulatory and physiological mechanisms of diapause preparation are largely unknown. Using high-throughput gene expression profiling in the Asian tiger mosquito, Aedes albopictus, we reveal major shifts in endocrine signalling, cell proliferation, metabolism, energy production and cellular structure across pre-diapause development. While some hallmarks of diapause, such as insulin signalling and stress response, were not important at the transcriptional level, two genes, Pepck and PCNA, appear to show diapause-induced transcriptional changes across insect taxa. These processes demonstrate physiological commonalities between Ae. albopictus pre-diapause and diapause strategies across insects, and support the idea of a genetic 'toolkit' for diapause. Observations of gene expression trends from a comparative developmental perspective suggest that individual physiological processes are delayed against a background of a fixed morphological ontogeny. Our results demonstrate how deep sequencing can provide new insights into elusive molecular bases of complex ecological adaptations.
authors.affiliation: Department of Biology, Georgetown University, 37th and O Streets NW, Washington, DC, USA. mpoelchau@gmail.com
authors.forename: Monica F
authors.initials: MF
authors.lastname: Poelchau
authors.forename: Julie A
authors.initials: JA
authors.lastname: Reynolds
authors.forename: Christine G
authors.initials: CG
authors.lastname: Elsik
authors.forename: David L
authors.initials: DL
authors.lastname: Denlinger
authors.forename: Peter A
authors.initials: PA
authors.lastname: Armbruster
mesh_terms: D000222:Adaptation, Physiological; D000330:Aedes / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D000818:Animals; D004331:Drosophila melanogaster / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D005786:Gene Expression Regulation; D059014:High-Throughput Nucleotide Sequencing; D008969:Molecular Sequence Data; D017440:Photoperiod; D016133:Polymerase Chain Reaction; D011679:Pupa / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D012621:Seasons; D017422:Sequence Analysis, DNA; D013997:Time Factors; D059467:Transcriptome