I often come across methodologies that are just so cool that I need to tell someone about them. More than that I wanted to be doing the experiments themselves. One of these has just been published in PLoS ONE
Céline Frère and colleagues from the University of Queensland, Australia and Georgetown University, USA have worked out a way to collect and sequence the genomic and mitochondrial DNA from dolphins and, hopefully, other cetaceans1. They trained six bottlenose dolphins at the National Aquarium in Baltimore, Maryland to blow on demand into a sample tube.
But I’m not talking about exhaling through their mouths. Nope, they blew through their blow holes, the characteristic structure on the top of the heads of dolphins, whales and porpoises through which they so dramatically vent when at the water’s surface. The researchers looked for both nuclear and mitochondrial DNA in this cetacean snot and showed that the sequences produced were identical to the sequences obtained from blood samples from each individual dolphin. With this successful proof of principle under their belts the researchers are now trying to apply this to a population of wild dolphins in Shark Bay, Western Australia.
Being able to collect DNA samples in a non-invasive way is hugely preferable to the current standard procedure, dart biopsy.
“Dart biopsying is considered inappropriate for very young animals and the technique requires considerable skill to avoid injuring the animals,” says Janet Mann, one of the authors 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.”
The technique isn’t yet perfect.
Both biopsy and blow-sampling require close proximity of the boat, but blow-sampling can be achieved when dolphins voluntarily bow-ride and involves no harmful contact. While we recognise the important role played by dart-biopsying, we provide evidence that blow-sampling is a viable alternative and less invasive mode of DNA collection.
Now there’s an experiment I’d love to try myself.
1 Frère, C.H., et al. Thar She Blows! A Novel Method for DNA Collection from Cetacean Blow. PLoS ONE 5, e12299 (2010). doi: 10.1371/journal.pone.0012299
2 Acevedo-Whitehouse, K., Rocha-Gosselin, A. & Gendron, D. A novel noninvasive tool for disease surveillance of free-ranging whales and its relevance to conservation programs. Anim. Cons. 13, 217-225 (2009). doi: 10.1111/j.1469-1795.2009.00326.x