Sequencing the Elephants

Wednesday, January 5, 2011
Michael Grose

The lab

The Biodiversity Institute’s Genetic Sequencing Facility

A recent NYTimes article highlighted research identifying the existence of two elephant species in Africa.  This is an important discovery not only for conservation purposes, but also because the researchers at Harvard, the University of Illinois and the University of York used new DNA sequencing technology that gives a much fuller picture of a critter's DNA.

My work at the Biodiversity Institute's Genetic Sequencing Facility directly relates to this kind of research.  DNA sequencing data is ideal for studying cryptic species - different organisms that appear in many ways to be the same species, but may or may not actually breed with each other.  Sequencing provides DNA characteristics that may help scientists figure out how many species are in a given population.  Simply put, they may look the same on the outside, but their DNA sometimes shows otherwise.

The elephants discussed in the article aren't cryptic per se; they were utilizing different habitats.  But there might not have been enough different physical characteristics to recognize them as distinct species. With this new study, scientists surveyed nearly 40,000 DNA base pairs. We (the Biodiversity Institute) and many other research centers do this type of thing on a regular basis, only on a smaller scale.  Instead of sequencing hundreds or thousands of pieces, we may survey 2,000 to 4,000 base pairs.

It sounds like this is the first major paper to use new generation sequencing systems (that can run a cool $500,000) for a group of species. The other outstanding thing about the study is they used DNA from an extinct North American mastodon!