Evolution of chemosensory tissues and cells across ecologically diverse Drosophilids.

Chemosensory tissues exhibit significant between-species variability, yet the evolution of gene expression and cell types underlying this diversity remain poorly understood. To address these questions, we conducted transcriptomic analyses of five chemosensory tissues from six Drosophila species and integrated the findings with single-cell datasets. While stabilizing selection predominantly shapes chemosensory transcriptomes, thousands of genes in each tissue have evolved expression differences.

Adaptive evolution of an essential telomere protein restricts telomeric retrotransposons.

Essential, conserved cellular processes depend not only on essential, strictly conserved proteins but also on essential proteins that evolve rapidly. To probe this poorly understood paradox, we exploited the rapidly evolving telomere-binding protein, /HOAP, which protects chromosomes from lethal end-to-end fusions. We replaced the HOAP with a highly diverged version from its close relative, .

piRNA and Transposon Dynamics in Drosophila: A Female Story.

The germlines of metazoans contain transposable elements (TEs) causing genetic instability and affecting fitness. To protect the germline from TE activity, gonads of metazoans produce TE-derived PIWI-interacting RNAs (piRNAs) that silence TE expression. In Drosophila, our understanding of piRNA biogenesis is mainly based on studies of the Drosophila melanogaster female germline.

The Telomere Paradox: Stable Genome Preservation with Rapidly Evolving Proteins.

Telomeres ensure chromosome length homeostasis and protection from catastrophic end-to-end chromosome fusions. All eukaryotes require this essential, strictly conserved telomere-dependent genome preservation. However, recent evolutionary analyses of mammals, plants, and flies report pervasive rapid evolution of telomere proteins.

Diversification and collapse of a telomere elongation mechanism.

In most eukaryotes, telomerase counteracts chromosome erosion by adding repetitive sequence to terminal ends. instead relies on specialized retrotransposons that insert exclusively at telomeres. This exchange of goods between host and mobile element-wherein the mobile element provides an essential genome service and the host provides a hospitable niche for mobile element propagation-has been called a "genomic symbiosis.

Transcriptional polymorphism of piRNA regulatory genes underlies the mariner activity in Drosophila simulans testes.

During colonization of new areas, natural populations have to deal with changing environments, and transposable elements (TEs) can be useful "tools" in the adaptation process as they are major contributor to the structural and functional evolution of genomes. In this general context, the activity (copy number, transcriptional and excision rate) of the mariner mos1 element was estimated in 19 natural populations of D. simulans.