| Abstract | Aim
The long history of isolation of the Antarctic continent, coupled with the harsh ecological conditions of freezing temperatures, could affect the patterns of genetic diversity in the organisms living there. We aim (a) to test whether such pattern can be seen in a mitochondrial marker of bdelloid rotifers, a group of microscopic aquatic and limno-terrestrial animals and (b) to speculate on the potential mechanisms driving the pattern.
Location
Focus on Antarctica.
Taxon
Rotifera Bdelloidea.
Methods
We analysed different metrics of genetic diversity, also spatially explicit ones, including number of haplotypes, accumulation curves, genetic distances, time to the most recent common ancestor, number of independently evolving units from DNA taxonomy, strength of the correlation between geographical and genetic distances, population genetics neutrality and differentiation indices, potential historical processes, obtained from an extensive sample of cytochrome oxidase subunit I (COI) sequences obtained from bdelloid rotifers. We included 2242 individuals from 23 species in a comparison between Antarctic and non-Antarctic taxa, correcting for sample size directly in the analyses and then by confirming the results also using only a restricted dataset of nine well-sampled species.
Results
Antarctic species had consistently lower genetic diversity and potential younger relative age than non-Antarctic species, even if they were similar in sample size, geographical extent, neutrality and differentiation indices, and correlation between genetic and geographical distances.
Main conclusions
The extensive survey of genetic diversity in one mitochondrial marker in Antarctic bdelloids supports previous suggestions from other organisms that the origin and maintenance of terrestrial Antarctic fauna are different from those of other continents. Such differences could be speculated to be due, in the case of bdelloid rotifers, to the more recent origin of the species living there in comparison to non-Antarctic species. |
| Authors | Zeyneb Vildan Cakil, Giuseppe Garlasché, Nataliia Iakovenko, Andrea Di Cesare, Ester M. Eckert, Roberto Guidetti, Lina Hamdan, Karel Janko, Dzmitry Lukashanets, Lorena Rebecchi, Stefano Schiaparelli, Tommaso Sforzi, Eva ?tefková Ka?parová, Alejandro Velasco-Castrillón, Elizabeth J. Walsh, Diego Fontaneto |
| Text | 452068 2021 10.1111/jbi.14116 rotifera antarctica Comparative phylogeography reveals consistently shallow genetic diversity in a mitochondrial marker in Antarctic bdelloid rotifers Zeyneb Vildan Cakil, Giuseppe Garlasche, Nataliia Iakovenko, Andrea Di Cesare, Ester M. Eckert, Roberto Guidetti, Lina Hamdan, Karel Janko, Dzmitry Lukashanets, Lorena Rebecchi, Stefano Schiaparelli, Tommaso Sforzi, Eva tefkova Ka parova, Alejandro Velasco Castrillon, Elizabeth J. Walsh, Diego Fontaneto National Research Council of Italy, Water Research Institute CNR IRSA , Molecular Ecology Group MEG , Verbania Pallanza, Italy Department of Molecular Biology and Genetics, Middle East Technical University, Ankara, Turkey Department of Game Management and Wildlife Biology, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czech Republic Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics AS CR, Lib chov, Czech Republic Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy Department of Biological Sciences, University of Texas at El Paso, El Paso, TX, USA Research Institute, Klaip da University, Klaip da, Lithuania Department of Earth, Environmental and Life Science DISTAV , University of Genoa, Genoa, Italy Italian National Antarctic Museum MNA, Section of Genoa , University of Genoa, Genoa, Italy Department of Genetics and Breeding, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Prague, Czech Republic South Australian Museum, Adelaide, Australia Aim The long history of isolation of the Antarctic continent, coupled with the harsh ecological conditions of freezing temperatures, could affect the patterns of genetic diversity in the organisms living there. We aim a to test whether such pattern can be seen in a mitochondrial marker of bdelloid rotifers, a group of microscopic aquatic and limno terrestrial animals and b to speculate on the potential mechanisms driving the pattern. Location Focus on Antarctica. Taxon Rotifera Bdelloidea. Methods We analysed different metrics of genetic diversity, also spatially explicit ones, including number of haplotypes, accumulation curves, genetic distances, time to the most recent common ancestor, number of independently evolving units from DNA taxonomy, strength of the correlation between geographical and genetic distances, population genetics neutrality and differentiation indices, potential historical processes, obtained from an extensive sample of cytochrome oxidase subunit I COI sequences obtained from bdelloid rotifers. We included 2242 individuals from 23 species in a comparison between Antarctic and non Antarctic taxa, correcting for sample size directly in the analyses and then by confirming the results also using only a restricted dataset of nine well sampled species. Results Antarctic species had consistently lower genetic diversity and potential younger relative age than non Antarctic species, even if they were similar in sample size, geographical extent, neutrality and differentiation indices, and correlation between genetic and geographical distances. Main conclusions The extensive survey of genetic diversity in one mitochondrial marker in Antarctic bdelloids supports previous suggestions from other organisms that the origin and maintenance of terrestrial Antarctic fauna are different from those of other continents. Such differences could be speculated to be due, in the case of bdelloid rotifers, to the more recent origin of the species living there in comparison to non Antarctic species. 48 Published version https //onlinelibrary.wiley.com/doi/10.1111/jbi.14116 anta 2021_JBiogeogr_Cakil et al.pdf Articolo in rivista Blackwell Scientific, 0305 0270 Journal of biogeography Print Journal of biogeography Print J. biogeogr. Print Journal of biogeography. Print diego.fontaneto FONTANETO DIEGO andrea.dicesare DI CESARE ANDREA estermaria.eckert ECKERT ESTER MARIA |
