Genetic sequencing of terrestrial invertebrates along the latitudinal range of the Ross Dependency to determine patterns of biodiversity, phylogenetic relationships and levels of gene flow among populations
Abstract:
Molecular techniques (allozyme electrophoresis and mitochondrial gene sequencing) were used to characterise the Antarctic terrestrial biodiversity along the latitudinal range of the Ross Dependency to assess existing levels of biodiversity and to provide information on the origin, evolutionary relationships and present day dispersal patterns of Antarctic invertebrate taxa. Arthropods (springtails ... and mites) nematodes, rotifers and tardigrades were collected from Ross Island (Cape Evans, Cape Royds, Cape Bird, Cape Crozier, Observation Hill, around Scott Base), Cape Hallett, Granite Harbour (Cape Geology, Botany Bay, Mt England, Flatiron, Mt Suess and Sperm Bluff), Beaufort Island, Marble Point, the ice free areas of Wright and Victoria Valley’s, the Taylor Valley, the Miers Valley, the Garwood Valley, Lake Penny, Lake Morning and Minna Bluff, the Darwin Glacier area (mites and nematodes only from the Brown Hills region, the base of the Foggydog Glacier and the eastern end of Diamond Hill) and Mt Kyffin.
The springtails (Collembola) species collected include Desoria klovstadi, Fresia grisea, Cryptopygus cisantarcticus, Gomphiocephalus hodgsoni, Antarctophorus sudpolaris, Biscoia subpolaris and Neocryptopygus nivicolis. The mite (Acari) species collected were Stereotydeus mollis and Nanorchestes spp. Some genetic work was completed on one species of nematode Scottnema lindsayae from Mt Kyffin Traditional, morphologically-based, taxonomic approaches for assessing biodiversity were combined with more recent molecular techniques (e.g. allozyme and DNA analyses) with individuals from each study site evaluated using protein electrophoresis, mtDNA and morphological analyses. Allozyme electrophoresis was used to determine genetic differences within and among populations. Genotype frequencies were recorded for each locus at each site. Detailed and quantitative observations were made on modes of dispersal through the use of windsocks, pitfall traps and stream drift nets. These analyses are designed to accurately assess existing levels of biodiversity and to provide information on the origin, evolutionary relationships and present day dispersal patterns of Antarctic invertebrate taxa. It could also be used in understanding a species ability to track environmental changes and defining units for conservation management. This programme will improve our knowledge of the Antarctic terrestrial fauna and provide information for the better management and conservation of Antarctic terrestrial habitats.
