Genomics of ecological adaptation in cactophilic Drosophila.

Cactophilic Drosophila species provide a valuable model to study gene-environment interactions and ecological adaptation. Drosophila buzzatii and Drosophila mojavensis are two cactophilic species that belong to the repleta group, but have very different geographical distributions and primary host plants. To investigate the genomic basis of ecological adaptation, we sequenced the genome and developmental transcriptome of D.

Diversity of transposable elements and repeats in a 600 kb region of the fly Calliphora vicina.

Background: Transposable elements (TEs) are a very dynamic component of eukaryotic genomes with important implications (e.g., in evolution) and applications (e.

An arthropod cis-regulatory element functioning in sensory organ precursor development dates back to the Cambrian.

Background: An increasing number of publications demonstrate conservation of function of cis-regulatory elements without sequence similarity. In invertebrates such functional conservation has only been shown for closely related species. Here we demonstrate the existence of an ancient arthropod regulatory element that functions during the selection of neural precursors.

The transposon Galileo generates natural chromosomal inversions in Drosophila by ectopic recombination.

Background: Transposable elements (TEs) are responsible for the generation of chromosomal inversions in several groups of organisms. However, in Drosophila and other Dipterans, where inversions are abundant both as intraspecific polymorphisms and interspecific fixed differences, the evidence for a role of TEs is scarce. Previous work revealed that the transposon Galileo was involved in the generation of two polymorphic inversions of Drosophila buzzatii.

Evolution of the achaete-scute complex in insects: convergent duplication of proneural genes.

Proneural genes encode transcriptional activators of the basic Helix-loop-helix class that are involved in neuronal specification and differentiation. We have used the recent availability of genome sequences of multiple distant insect species to study the evolution of a family of proneural genes, the achaete-scute genes, and to examine their genomic organization and evolution. We document independent evolution of multiple copies of achaete-scute homologues and argue that this might have contributed to morphological diversity in Diptera and Lepidoptera.

Evolution of genes and genomes on the Drosophila phylogeny.

Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution.

HOM-C evolution in Drosophila: is there a need for Hox gene clustering?

The conservation of Homeotic (Hox) gene clustering and colinearity in many metazoans indicates that functional constraints operate on this genome organization. However, several studies have questioned its relevance in Drosophila. Here, we analyse the genomic organization of Hox and Hox-derived genes in 13 fruitfly species and the mosquito Anopheles gambiae.

Fast sequence evolution of Hox and Hox-derived genes in the genus Drosophila.

Background: It is expected that genes that are expressed early in development and have a complex expression pattern are under strong purifying selection and thus evolve slowly. Hox genes fulfill these criteria and thus, should have a low evolutionary rate. However, some observations point to a completely different scenario.

Conservation of regulatory sequences and gene expression patterns in the disintegrating Drosophila Hox gene complex.

Homeotic (Hox) genes are usually clustered and arranged in the same order as they are expressed along the anteroposterior body axis of metazoans. The mechanistic explanation for this colinearity has been elusive, and it may well be that a single and universal cause does not exist. The Hox-gene complex (HOM-C) has been rearranged differently in several Drosophila species, producing a striking diversity of Hox gene organizations.

A new split of the Hox gene complex in Drosophila: relocation and evolution of the gene labial.

Hox genes encode transcription factors involved in the specification of segment identity in the early metazoan embryo. These genes are usually clustered and arranged in the same order as they are expressed along the anteroposterior body axis. This conserved genomic organization has suggested the existence of functional constraints acting on the genome organization.