Format: ORAL

Katie Emelianova1, Teerna Saugata Khastgir1, Jrme Munzinger2, Ovidiu Paun1

1 Department of Botany and Biodiversity Research, Faculty of Life Sciences, University of Vienna, Rennweg 14, 1030 Vienna, Austria 2 AMAP, IRD, CIRAD, CNRS, INRA, Université Montpellier, 34000 Montpellier, France

New Caledonia, a biodiversity hotspot with a mosaic of altitudinal, climatic and edaphic environments, was colonized by the Persimmon genus Diospyros four times. While three of the New Caledonian Diospyros clades have few species, one clade underwent an explosive burst of speciation over a period of ca. 1000 generations, today numbering over 30 species which have repeatedly colonized almost all habitat types on the peninsula. The genome sizes of the radiating clade are roughly double that of their non-radiating counterparts, driven largely by transposable element (TE) expansion rather than polyploidy, prompting speculation that transposable element dynamics underlie the success of the radiating clade through rapid generation of genetic diversity, ameliorating the founder effects which often follow long distance dispersal events. To investigate the origins of the adaptive variation required for Diospyros to so successfully colonize New Caledonia, we ask how TE dynamics may have contributed to the adaptive potential of radiating Diospyros species. Using long read PacBio sequencing data, we compare the TE landscapes of adaptively radiating Diospyros species to an outgroup of the radiation, asking which TE families have undergone expansion, when expansion occurred, and whether repetitive element proliferation pre-dated the burst of speciation in New Caledonian Diospyros or occurred after dispersal to the archipelago. By analysing the TE landscape of adaptively radiating and outgroup species within a comparative genomic framework, we can begin to answer questions about the interplay of the mobile genome, shifting ecological circumstances, and the drivers of biodiversity.