Scientists at Georgetown University, the National Aquarium and the University of Queensland are the first to extract DNA from dolphin blow (breath exhalations). The researchers found that blow-sampling, which involves collecting exhalations from the blowholes of whales, dolphins and porpoises, could be developed as a less invasive method for DNA collection. Their findings are explained in the Aug. 25 edition of the online journal PLoS ONE in an article titled "Thar She Blows! A Novel Method for DNA Collection from Cetacean Blow."
Scientists currently biopsy animals by using a small piece of tissue taken from a dart gun to get DNA from wild dolphins and whales for use in research projects.
"Dart biopsying is considered inappropriate for very young animals and the technique requires considerable skill to avoid injuring the animals," says Janet Mann, a senior author on the paper and a professor of biology and psychology at Georgetown. "Thus identifying alternative genetic collection techniques for cetaceans remains a priority, especially for internationally protected species."
At the National Aquarium in Baltimore, Md., blow and blood samples were collected between March and May 2010 from six bottlenose dolphins. A test tube was held inverted over the dolphin's blowhole as they were trained to exhale on cue. A control sample of seawater was taken along with each blow sample set to ensure that any DNA results were from blow samples and not seawater contamination. The blood was collected as part of routine medical examinations for the dolphins.
To estimate whether DNA profiles from the blow and blood samples matched, the scientists amplified 3 polymorphic dinucleotide microsatellite loci for each sample. To estimate whether mitochondrial DNA (mtDNA) also matched, the scientists amplified a 426 base-pair fragment of the maternally inherited mitochondrial DNA control region. For all samples, blow and blood showed a perfect match for each individual animal. The scientists were therefore able to show that DNA can be successfully extracted from dolphin blow.
The authors are currently applying their method to a wild population of bottlenose dolphins in Western Australia's Shark Bay that they have studied for more than two decades.
"Both biopsy and blow-sampling require close proximity of the boat, but blow-sampling can be achieved when dolphins voluntarily bow-ride, and it involves no harmful contact," says Mann. "While we recognize the important role played by dart-biopsying, we have provided evidence that blow-sampling is a viable and less invasive mode of DNA collection."
Citation: Frere CH, Krzyszczyk E, Patterson EM, Hunter S, Ginsburg A, et al. (2010) Thar She Blows! A Novel Method for DNA Collection from Cetacean Blow. PLoS ONE 5(8): e12299. doi:10.1371/journal.pone.0012299
Competing Interests: The authors have declared that no competing interests exist.
Funding: All research was approved and permitted through the Georgetown University Animal Care and Use Committee (Georgetown GUACUC 07-041). Funding was provided by Georgetown University and the National Science Foundation grant number 0847922. The authors thank the National Aquarium in Baltimore, USA for extensive logistical support. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Public Library of Science
[Note to reporters: Related images and video are available upon request]
PLEASE LINK TO THE SCIENTIFIC ARTICLE IN ONLINE VERSIONS OF YOUR REPORT (URL goes live after the embargo ends): http://dx.plos.org/10.1371/ journal.pone.0012299
FOR A PRESS-ONLY PREVIEW OF THE FULL ARTICLE, VISIT THE FOLLOWING URL: http://www.plos.org/press/pone-05-08-frere.pdf
This press release refers to upcoming articles in PLoS ONE. The releases have been provided by the article authors and/or journal staff. Any opinions expressed in these are the personal views of the contributors, and do not necessarily represent the views or policies of PLoS. PLoS expressly disclaims any and all warranties and liability in connection with the information found in the release and article and your use of such information.
About PLoS ONE
PLoS ONE is the first journal of primary research from all areas of science to employ a combination of peer review and post-publication rating and commenting, to maximize the impact of every report it publishes. PLoS ONE is published by the Public Library of Science (PLoS), the open-access publisher whose goal is to make the world's scientific and medical literature a public resource.
AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.