An expressed sequence tag (EST) library for Drosophila serrata, a model system for sexual selection and climatic adaptation studies.

Francesca D Frentiu,Stephen F Chenoweth,Mark W Blows,Elizabeth A Mcgraw,Marcin Adamski

doi:10.1186/1471-2164-10-40

Francesca D Frentiu, Stephen F Chenoweth + Show 3 more

Open Access

https://doi.org/10.1186/1471-2164-10-40

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Abstract

BackgroundThe native Australian fly Drosophila serrata belongs to the highly speciose montium subgroup of the melanogaster species group. It has recently emerged as an excellent model system with which to address a number of important questions, including the evolution of traits under sexual selection and traits involved in climatic adaptation along latitudinal gradients. Understanding the molecular genetic basis of such traits has been limited by a lack of genomic resources for this species. Here, we present the first expressed sequence tag (EST) collection for D. serrata that will enable the identification of genes underlying sexually-selected phenotypes and physiological responses to environmental change and may help resolve controversial phylogenetic relationships within the montium subgroup.ResultsA normalized cDNA library was constructed from whole fly bodies at several developmental stages, including larvae and adults. Assembly of 11,616 clones sequenced from the 3' end allowed us to identify 6,607 unique contigs, of which at least 90% encoded peptides. Partial transcripts were discovered from a variety of genes of evolutionary interest by BLASTing contigs against the 12 Drosophila genomes currently sequenced. By incorporating into the cDNA library multiple individuals from populations spanning a large portion of the geographical range of D. serrata, we were able to identify 11,057 putative single nucleotide polymorphisms (SNPs), with 278 different contigs having at least one "double hit" SNP that is highly likely to be a real polymorphism. At least 394 EST-associated microsatellite markers, representing 355 different contigs, were also found, providing an additional set of genetic markers. The assembled EST library is available online at .ConclusionWe have provided the first gene collection and largest set of polymorphic genetic markers, to date, for the fly D. serrata. The EST collection will provide much needed genomic resources for this model species and facilitate comparative evolutionary studies within the montium subgroup of the D. melanogaster lineage.

Highlights

The native Australian fly Drosophila serrata belongs to the highly speciose montium subgroup of the melanogaster species group
Partial transcripts from several genes of phylogenetic interest were found in our expressed sequence tag (EST) collection and Drosophila serrata is a native Australian fly that has recently become a prominent model system with which to investigate the evolution of traits under sexual selection and traits involved in climatic adaptation
Understanding the molecular genetic basis of traits of interest to evolutionary biologists has been hampered by a lack of genomic resources for this species

Summary

Introduction

The native Australian fly Drosophila serrata belongs to the highly speciose montium subgroup of the melanogaster species group It has recently emerged as an excellent model system with which to address a number of important questions, including the evolution of traits under sexual selection and traits involved in climatic adaptation along latitudinal gradients. The utility of D. serrata in addressing evolutionary questions has been long recognized, for example in studies of speciation [4,5] It has gained prominence as a model species for investigating the evolution of traits involved in sexual selection and mate recognition [6,7,8] and climatic adaptation [9,10,11]. The identification of functional genetic variants underlying phenotypes of interest, has been limited by the absence of a species-specific gene collection

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