A Pair of Centromeric Proteins Mediates Reproductive Isolation in Drosophila Species

• The Drosophila speciation factors HMR and LHR form a centromeric complex
• The HMR/LHR complex has a critical function in chromosome segregation
• The HMR/LHR complex acts as a transcriptional repressor of transposable elements
• Differing levels of HMR/LHR among species cause hybrid incompatibility

SummarySpeciation involves the reproductive isolation of natural populations due to the sterility or lethality of their hybrids. However, the molecular basis of hybrid lethality and the evolutionary driving forces that provoke it remain largely elusive. The hybrid male rescue (Hmr) and the lethal hybrid rescue (Lhr) genes serve as a model to study speciation in Drosophilids because their interaction causes lethality in male hybrid offspring. Here, we show that HMR and LHR form a centromeric complex necessary for proper chromosome segregation. We find that the Hmr expression level is substantially higher in Drosophila melanogaster, whereas Lhr expression levels are increased in Drosophila simulans. The resulting elevated amount of HMR/LHR complex in hybrids results in an extensive mislocalization of the complex, an interference with the regulation of transposable elements, and an impairment of cell proliferation. Our findings provide evidence for a major role of centromere divergence in the generation of biodiversity.PaperClip To listen to this audio, enable JavaScript on your browser. However, you can download and play the audio by clicking on the icon belowHelp with MP3 filesOptionsDownload audio (6413 K)

Graphical AbstractFigure optionsDownload high-quality image (126 K)Download as PowerPoint slide