Tag Archives: DNA sequencing

Going International, Part II – What caught my eye at two recent botany meetings

Here are just a few of the many highlights from the two international botany conferences I recently attended: Botany 2012 (Columbus, OH, USA) and  Biodiversity and Evolutionary Biology 2012 (German Botanical Society 21st International Symposium, Mainz, Germany).

  • Plant identification goes visual, interactive and mobile

Plant identification keys are useful when you want to identify an unknown plant specimen to a species. Traditionally, keys have been found in books or other printed media, and have used written, verbal descriptions as choices that user must make (see an example here for Plantago from the 1961 New Zealand Flora). When using a conventional key, a user must proceed down the key and finally “key out” or identify the plant specimen of interest.

But keys are becoming increasingly interactive, making use of specialised computer software and including photos and drawings to aid identification (see for example Key to the Flowering Plant Genera of New Zealand). Keys are also becoming exteremely mobile, with the development of smart phone applications for plant identification (such as Leafsnap for the USA). I saw one talk by Alexander Krings about the development of these great apps for the Flora of North Carolina. Wouldn’t it be fantastic to have such mobile plant identification apps for the New Zealand flora?

I also attended a hands-on workshop about so-called “visual keys“, which rely exclusively on photos and other visual aids. At the workshop, which was run by Bruce Kirchoff from the University of North Carolina Greensboro, we were divided into groups whose task was to create our own visual key for oak tree leaves using only a set of images. Then other workshop participants tested our group’s visual key by keying out leaves from another set of images. The workshop was fun and challenging, would be a great exercise for high school or university biology courses, and got me thinking about different ways I might create plant ID keys, especially for the forget-me-nots I am currently working on.

  • DNA Sequencing: The Next Generation

Use of so-called “Next Generation Sequencing” in (NGS) evolutionary biology research was a dominant theme at both conferences I attended. (And even though this might sound more like something from a certain television programme from the 1980s and 90s, I can assure you I was attending botany conferences, not sci-fi conventions!) The relatively new technology of NGS allows sequencing of large portions of the genome quickly, giving us orders of magnitude more DNA data from the organisms we study and allowing researchers to understand them better and answer more interesting questions about them.

In fact I have come to Oldenburg, Germany to learn and perform NGS methods to study the evolution of certain polyploid New Zealand and European Veroncica species (more on that later). By the way, on the conference field trip to “Mainzer Sand”, I saw my first European Veronica species in its native habitat, check it out (with thanks to Aaron Liston for the photos):

Heidi Meudt on the botanical field trip to the "Mainzer Sand", at the “Biodiversity and Evolutionary Biology" meeting, the 21st International Symposium of the German Botanical Society (DBG) , Sept. 2012. I am kneeling just behind the European plant species Veronica spicata. Photo by Aaron Liston.

Heidi Meudt on the botanical field trip to the “Mainzer Sand”, at the “Biodiversity and Evolutionary Biology” meeting, the 21st International Symposium of the German Botanical Society (DBG) , Sept. 2012. I am kneeling just behind the European plant species Veronica spicata. Photo by Aaron Liston.

Veronica spicata flowers from the "Mainzer Sand", Mainz, Germany. Sept. 2012. Photo by Aaron Liston.

Veronica spicata flowers from the “Mainzer Sand”, Mainz, Germany. Sept. 2012. Photo by Aaron Liston.

Veronica spicata fruits from the "Mainzer Sand", Mainz, Germany. Sept. 2012. Photo by Aaron Liston.

Veronica spicata fruits from the “Mainzer Sand”, Mainz, Germany. Sept. 2012. Photo by Aaron Liston.

Caring for museum collections in a molecular world

Museums are embracing technologies, such as DNA sequencing, to both enhance understanding of their collections and showcase scientific research to the public.  Many museums around the world now have molecular laboratories.  DNA sequencing has many useful applications for museum research; for example, it can be used to distinguish new species, determine the evolutionary relationships between species and identify the region of origin of artefacts such as kahu kiwi (kiwi feather cloaks).  However, it has only recently been appreciated that care should be taken in the construction and use of museum molecular labs.  Why is the situation for museums different to universities and other institutions where molecular biology labs are commonplace?

Museums are storehouses of important biological collections and these can become contaminated with copies of DNA that are generated in molecular laboratories.  A technique routinely used in molecular labs in the polymerase chain reaction (PCR). PCR is an extremely efficient method to produce millions of copies a targeted region of DNA. If one drop (1/10th of 1 ml) of a PCR is mixed into an Olympic swimming pool then one drop of this highly diluted mixture removed it will still contain around 400 copies of DNA!

Learn more about PCR (polymerse chain reaction)

In a museum setting, if care is not taken, these millions of copies of DNA could contaminate the biological specimens in museum collections.  These specimens, such as animal bones and pressed plants, typically contain small amounts of their own DNA because DNA degrades over time, starting with the death of the organism.  It is very easy for the low levels of DNA to become swamped by the copies of DNA generated by PCR.  Future attempts to use contaminated specimens for genetic research may be compromised with the contaminating PCR products detected instead of the specimen’s own DNA. So how do we avoid this problem?

Together with Leon Perrie, a colleague in Te Papa’s Natural Environment team, I recently suggested that strict protocols should be developed for constructing and using molecular laboratories within museums.  These include having labs and collections in different buildings, or at least having separate ventilation systems for each, and having a one-way movement of people, equipment and specimens from collection areas to labs. We hope that museum researchers take up these suggestions in order to protect the research potential of their important, and often irreplaceable, collections of biological specimens.

Read our full article (requires a subscription to Nature)

Leon and Lara in the Te Papa's collections. Photo Carlos Lehnebach.Te Papa

Leon and Lara in Te Papa’s collections. Photo Carlos Lehnebach.Te Papa

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