Monday 8 February 2010

Molecular identification of New Guinea mammal poo

The use of environmental DNA samples for identification and monitoring of animals has been increasingly widely used over the past five years or so. This essentially involves extracting DNA from non-tissue materials and analysing it in such a way as to discover the creatures that produced/lived in/ate/passed by the material. For example, pond water has been analysed to discover what frog species were present in the area and faecal matter has been analysed to figure out both what was eaten and who was the eater.

This last scenario has been played out on the Huon Peninsula in Papua New Guinea. Research has begun on the endangered Matschie's tree kangaroo (Dendrolagus matschiei) looking into its population structure and genetics. This research has applications to help direct the future conservation of the species by giving an indication as to how many individuals there are and how much they move around. However, the capture and collection of tissues from a rare, endangered animal that spends the majority of its time in montane rainforest canopies present both logistic and ethical concerns which are alleviated by the collection of DNA from their faeces. Finding poo is sometimes a lot easier than the beast itself!

Unfortunately, poo from one marsupial often looks the same as poo from another and so faeces were mistakenly collected from an additional two species the New Guinea pademelon (Thylogale browni) and the small dorcopsis (Dorcopsulus vanheurni). A recent paper published in Molecular Ecology Resources by Thomas McGreevy and coauthors give a method for determining which species of marsupial produced the poo of interest. The primer set they've developed amplifies a portion of DNA that is a different length in each species---making it easy to distinguish which came from what and making sure that time is not spent looking at the wrong ones.

References:
McGreevy TJ Jr, Dabek L, Husband TP. (2010). A multiplex PCR assay to distinguish among three sympatric marsupial taxa from Huon Peninsula, Papua New Guinea, using the mitochondrial control region. Molecular Ecology Resources. 10(2): 397-400.

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