Developmental hotspots drive transcriptional variability and convergence in the Drosophila olfactory system

The goal of this study was to identify the preponderance of developmental hotspots in the Drosophila olfactory system. Using RNASeq-derived transcriptome profiles of the developing and adult antennae for six different Drosophila species, we show that a few highly variable transcription factors may drive, likely in a combinatorial fashion, high variability in a few select olfactory receptor neuron (ORN) developmental lineages (i.e. developmental hotspots) in an otherwise mostly conserved background. Furthermore, the high variability of these few ORN lineages leads to a correspondingly high probability that they will recruited during the adaptation of the Drosophila olfactory system to specific ecological pressures, one potential example being the remarkably convergent antennal transcriptome profiles in two Drosophila species that have independently evolved the ability to specialize on specific host plants.  Overall design: mRNA profiles from antenna and antennal discs across 4 developmental time points for 6 Drosophila species