Molecular biogeography of clonal lineages in a high-Arctic apomictic Daphnia complex

Authors


  • L. J. Weider is an associate research scientist at the Max-Planck-Institut für Limnologie, Plön, Germany, and has been working on different aspects of the ecology and population genetics of arctic Daphnia for the past decade. A. Hobaek is a staff scientist with the Norwegian Institute for Water Research, Bergen, Norway, and has worked on the ecology and genetics of alpine and arctic Daphnia. The authors are collaborating with colleagues in Canada and Russia, and are examining the phylogenetics and biogeography of arctic Daphnia on a circumpolar scale.

Abteilung Ökophysiologie, Max-Planck-lnstitut für Limnologie, Postfach 165, D-24302 Plön, Germany. Fax 049 4522 763 310.

Abstract

An electrophoretic survey of 81 populations of arctic Daphnia pulex from around the Svalbard archipelago revealed the presence of 49 unique allozyme clones (N= 3357). Two closely related clones accounted for 66% of the total sample, and were widespread across the archipelago. Restriction fragment length polymorphisms (RFLPs) of a 2.1-kb fragment of mtDNA (NADH-4 and NADH-5 subunits), amplified using the polymerase chain reaction (PCR), revealed the presence of eight mtDNA haplotypes. One haplotype was particularly widespread, and the two most abundant allozyme clones shared this haplotype. Nonrandom distribution patterns of clones were observed, and are most likely the result of historical events (i.e. founder effects) related to the past glacial history of the archipelago. The data are discussed with reference to past glaciation events, and attempts are made to discern the colonization history of this apomictic complex.

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