title: The use of archived tags in retrospective genetic analysis of fish.
abstract: Collections of historical tissue samples from fish (e.g. scales and otoliths) stored in museums and fisheries institutions are precious sources of DNA for conducting retrospective genetic analysis. However, in some cases, only external tags used for documentation of spatial dynamics of fish populations have been preserved. Here, we test the usefulness of fish tags as a source of DNA for genetic analysis. We extract DNA from historical tags from cod collected in Greenlandic waters between 1950 and 1968. We show that the quantity and quality of DNA recovered from tags is comparable to DNA from archived otoliths from the same individuals. Surprisingly, levels of cross-contamination do not seem to be significantly higher in DNA from external (tag) than internal (otolith) sources. Our study therefore demonstrates that historical tags can be a highly valuable source of DNA for retrospective genetic analysis of fish.
authors.affiliation: Technical University of Denmark, Section for Marine Living Resources, National Institute of Aquatic Resources, Vejlsøvej 39, DK-8600, Silkeborg, Denmark; Greenland Climate Research Centre, Greenland Institute of Natural Resources, Kivioq 2, PO Box 570, 3900, Nuuk, Greenland.
authors.forename: Sara
authors.initials: S
authors.lastname: Bonanomi
authors.forename: Nina Overgaard
authors.initials: NO
authors.lastname: Therkildsen
authors.forename: Rasmus Berg
authors.initials: RB
authors.lastname: Hedeholm
authors.forename: Jakob
authors.initials: J
authors.lastname: Hemmer-Hansen
authors.forename: Einar E
authors.initials: EE
authors.lastname: Nielsen
mesh_terms: D000818:Animals; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D048389:Gadus morhua / Q000145:classification / Q000235:genetics*; D008386:Marine Biology / Q000295:instrumentation*; D009144:Museums; D010037:Otolithic Membrane / Q000737:chemistry
chemical_list: D004247:DNA
keywords: Atlantic cod; DNA extraction; fish tags; historical samples; temporal genetic analysis