BackgroundMany temperate insects survive the harsh conditions of winter by undergoing photoperiodic diapause, a pre-programmed developmental arrest initiated by short day lengths. Despite the well-established ecological significance of photoperiodic diapause, the molecular basis of this crucial adaptation remains largely unresolved. The Asian tiger mosquito, Aedes albopictus (Skuse), represents an outstanding emerging model to investigate the molecular basis of photoperiodic diapause in a well-defined ecological and evolutionary context. Ae. albopictus is a medically significant vector and is currently considered the most invasive mosquito in the world. Traits related to diapause appear to be important factors contributing to the rapid spread of this mosquito. To generate novel sequence information for this species, as well as to discover transcripts involved in diapause preparation, we sequenced the transcriptome of Ae. albopictus oocytes destined to become diapausing or non-diapausing pharate larvae.Results454 GS-FLX transcriptome sequencing yielded >1.1 million quality-filtered reads, which we assembled into 69,474 contigs (N50 = 1,009 bp). Our contig filtering approach, where we took advantage of strong sequence similarity to the fully sequenced genome of Aedes aegypti, as well as other reference organisms, resulted in 11,561 high-quality, conservative ESTs. Differential expression estimates based on normalized read counts revealed 57 genes with higher expression, and 257 with lower expression under diapause-inducing conditions. Analysis of expression by qPCR for 47 of these genes indicated a high correlation of expression levels between 454 sequence data and qPCR, but congruence of statistically significant differential expression was low. Seven genes identified as differentially expressed based on qPCR have putative functions that are consistent with the insect diapause syndrome; three genes have unknown function and represent novel candidates for the transcriptional basis of diapause.ConclusionsOur transcriptome database provides a rich resource for the comparative genomics and functional genetics of Ae. albopictus, an invasive and medically important mosquito. Additionally, the identification of differentially expressed transcripts related to diapause enriches the limited knowledge base for the molecular basis of insect diapause, in particular for the preparatory stage. Finally, our analysis illustrates a useful approach that draws from a closely related reference genome to generate high-confidence ESTs in a non-model organism.
A de novo transcriptome of the Asian tiger mosquito, Aedes albopictus, to identify candidate transcripts for diapause preparation
Monica F. Poelchau,Julie A. Reynolds,D. Denlinger,C. Elsik,P. Armbruster
Published 2011 in BMC Genomics
ABSTRACT
PUBLICATION RECORD
- Publication year
2011
- Venue
BMC Genomics
- Publication date
2011-12-20
- Fields of study
Biology, Medicine, Environmental Science
- Identifiers
- External record
- Source metadata
Semantic Scholar, PubMed
CITATION MAP
EXTRACTION MAP
CLAIMS
CONCEPTS
- 454 gs-flx transcriptome sequencing
A 454 pyrosequencing platform used to generate transcriptome reads from Ae. albopictus oocytes in this work.
Aliases: 454 sequencing, 454 GS-FLX
- 454 sequence data
The transcript abundance information derived from the 454 sequencing reads.
Aliases: 454 data
- aedes aegypti genome
The reference genome of the related mosquito species used to help evaluate and filter assembled contigs.
Aliases: Ae. aegypti genome
- contig assembly
The computational merging of transcriptome reads into longer contiguous sequences.
Aliases: assembly, contigs
- contig filtering approach
A sequence curation strategy that retained contigs supported by similarity to reference genomes and organisms.
Aliases: filtering approach, contig filtering
- diapause-inducing conditions
Short-day environmental conditions used to trigger the diapause developmental program in the mosquito eggs/oocytes.
Aliases: diapause conditions, short-day conditions
- diapause syndrome
The set of physiological and developmental traits associated with entry into diapause in insects.
Aliases: insect diapause syndrome
- differential expression estimates
Estimated expression differences between diapause-inducing and non-diapause conditions derived from sequencing counts.
Aliases: expression estimates
- high-quality conservative ests
A filtered set of expressed sequence tags retained as reliable transcript candidates after assembly curation.
Aliases: conservative ESTs, ESTs
- n50
An assembly statistic summarizing contig length distribution by the contig length at which half of assembled bases are in contigs of that length or longer.
- normalized read counts
Read-count data adjusted for library size or comparable normalization to estimate transcript abundance.
Aliases: normalized counts
- qpcr
Quantitative PCR used here to validate transcript abundance differences for selected genes.
Aliases: quantitative PCR
REFERENCES
Showing 1-85 of 85 references · Page 1 of 1