Collins, G.E.; Young, M.R.; Convey, P.; Chown, S.L.; Cary, S.C.; Adams, B.J.; Wall, D.H.; Hogg, I.D. Biogeography and Genetic Diversity of Terrestrial Mites in the Ross Sea Region, Antarctica. Genes2023, 14, 606.
Collins, G.E.; Young, M.R.; Convey, P.; Chown, S.L.; Cary, S.C.; Adams, B.J.; Wall, D.H.; Hogg, I.D. Biogeography and Genetic Diversity of Terrestrial Mites in the Ross Sea Region, Antarctica. Genes 2023, 14, 606.
Free-living terrestrial mites (Acari) have persisted through numerous glacial cycles in Antarctica. Very little is known, however, of their genetic diversity and distribution, particularly within the Ross Sea region. To redress this gap, we sampled for mites throughout the Ross Sea region, East Antarctica, including Victoria Land and the Queen Maud Mountains (QMM), covering a latitudinal range of 72-85oS, as well as from Lauft Island near Mt Siple (73oS) in West Antarctica and Macquarie Island (54oS) in the sub-Antarctic. We assessed genetic diversity using mitochondrial cytochrome c oxidase subunit I gene sequences (COI-5P DNA barcode region), and also morphologically identified voucher specimens. We obtained 130 sequences representing four genera: Nanorchestes (n = 30 sequences), Stereotydeus (n = 46), Coccorhagidia (n = 18) and Eupodes (n = 36). Tree-based analyses (maximum likelihood) revealed 13 genetic clusters, representing as many as 23 putative species indicated by Barcode Index Numbers (BINs) from the Barcode of Life Datasystems (BOLD) database. We found evidence for geographically-isolated cryptic species, e.g. within Stereotydeus belli and S. punctatus, as well as unique genetic groups occurring in sympatry (e.g. Nanorchestes spp. in QMM). Collectively, these data confirm high genetic divergence as a consequence of geographic isolation over evolutionary timescales. From a conservation perspective, additional targeted sampling of understudied areas in the Ross Sea region should be prioritised, as further diversity is likely to be found for these short-range endemic mites.
Speciation; Geographic isolation; Acari; Antarctic conservation; DNA barcoding
LIFE SCIENCES, Molecular Biology
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