Non-destructive sampling of maternal DNA from the external shell of bird eggs
- 290 Downloads
The use of non-destructive sampling methods to collect genetic material from wildlife allows researchers to minimize disturbance. Most avian studies employ capturing and handling of young and parents to draw blood for DNA analysis. In some cases adult female birds are difficult to catch, so maternal genotyping has required collection of contour feathers from nests, or destructive sampling of eggs. Many species do not leave contour feathers in the nest, and destructive sampling has been unreliable due to contamination with embryonic DNA. Alternative field sampling techniques for collection of maternal DNA from birds are therefore desirable. Here we demonstrate that avian maternal DNA can be isolated in a non-invasive and non-destructive way from the external surface of eggs. We used cotton swabs to collect maternal DNA from the external shells of herring gull (Larus argentatus) and Caspian tern (Sterna caspia) eggs. DNA was then amplified by the polymerase chain reaction (PCR) for microsatellite genotyping. We verified that the DNA samples were maternal by comparing microsatellite profiles to those obtained from adults and chicks from the same nests. In 100% of Caspian tern (n=16) and herring gull families (n=12), the egg swabs that amplified matched the maternal microsatellite genotype. In a screening of many nests of both species, we successfully amplified microsatellite markers from 101/115 (88%) egg swabs. Swabs from eggs with blood stains on the shell were more likely to amplify successfully than those from clean eggs. The advantages of this new method include increased parentage assignment/exclusion power, and increased availability of maternal DNA for genotyping of species that do not deposit contour feathers in nests.
Keywordsavian maternal DNA Caspian terns egg swabbing herring gulls non-destructive genotyping
Unable to display preview. Download preview PDF.
This work was supported by a grant from the National Science and Engineering Research council (NSERC) of Canada to JSQ, and by Ontario Graduate Scholarships and McMaster University graduate student scholarships to GS and to CMS. Field work was performed under permit from Environment Canada. We thank the Canadian Wildlife Service and the Canada Centre for Inland Waters for logistical support. Finally, we would like to thank two anonymous reviewers for improving the quality of this manuscript.
- Avise JC (2004) Molecular Markers, Natural History, and Evolution, 2nd edition. Sinauer.Google Scholar
- Bety J, Gauthier G (2001) Effects of nest visits on predator activity and predation rate in a Greater Snow Goose colony. J. Field Ornithol. 72, 573–586.Google Scholar
- Criscuolo F (2001) Does blood sampling during incubation induce nest desertion in the female Common Eider Somateria mollissima? Marine Ornithol. 29, 47–50.Google Scholar
- Götmark F (1992) The effects of investigator disturbance on nesting birds. Curr. Ornithol., 9, 63–104.Google Scholar
- Gregory SM, Quinn JS Microsatellite isolation from four avian species comparing two isolation techniques. Mol. Ecol. Notes, in press.Google Scholar
- Komeda, S (1983) Nest attendance of parent birds in the painted snipe (Rostratula benghalensis). Auk, 100, 48–55.Google Scholar
- Pearce JM, Fields RL, Scribner, KT (1997) Nest materials as a source of genetic data for avian ecological studies. J. Field Ornithol., 68, 471–481.Google Scholar
- Quinn JS, Morris RD (1986) Intraclutch egg-weight apportionment and chick survival in Caspian terns. Can. J. Zool., 64, 2116–2122.Google Scholar
- Quinn JS, Startek-Foote JM (2000) Smooth-billed ani (Crotophaga ani). In: The Birds of North America (eds. Poole A, Gill F), Vol. 539, pp. 1–16. The Birds of North America, Inc., Philadelphia, PAGoogle Scholar
- Stouffer, PC (1997) Interspecific Aggression in Formicarius Antthrushes? The view from Central Amazonian Brazil. Auk, 114, 780–785.Google Scholar
- Vehrencamp SL, Quinn JS (2004) Joint laying systems. In: Ecology and Evolution of Cooperative Breeding in Birds (eds. Koening WD, Dickinson JL), pp. 177–278. Cambridge University Press.Google Scholar