Amplified Fragment Length Polymorphism (AFLP) Reveals Species-Specific Markers in the Daphnia Galeata-HyalinaSpecies Complex

Issue Title: Cladocera: Proc. of the VIth Int. Symp. on Cladocera, held in Wierzba, Poland, 19-23 August 2002 Daphnia often occur in species complexes that consist of two or more co-occurring species and their hybrids. Hybrid individuals are often capable of sexual reproduction and so backcrossing with introgression occurs. To better understand hybridization and backcrossing frequency, we sought to develop PCR-based, species-specific markers in the Daphnia galeata-hyalina species complex using amplified fragment length polymorphism (AFLP). This technique produces large numbers of reproducible markers for assessing diversity across the nuclear genome and provides several advantages over mtDNA and microsatellite approaches. We examined 28 clones of D. galeata, D. hyalina, and their hybrids isolated from Lake Constance on the Swiss-German border. Using a single AFLP primer combination we found five potential species-specific markers, defined as bands that occurred in >80% of one parental species and