A Melosira By Any Other Name Would Still Yield DNA

By the time we arrived in Bolshie Koty (BK), we had already gotten word that it was a “Melosira year” in Lake Baikal, meaning there was an abundance of Aulacoseira in the phytoplankton off the coast near the biological station. The photos sent by our colleagues, Ted, Kirill and Katie, were unreal (see image below); almost a monoculture of what we later identified as the diatom species Aulacoseira baicalensis.

Image of Aulacoseira amongst Epischura baikalensis. Photo: Ted Ozersky.

Image of Aulacoseira baicalensis amongst Epischura baikalensis. Photo: Ted Ozersky.

The term “Melosira year”, is a holdover from an earlier taxonomic classification, when species now classified as members of the genus Aulacoseira were part of the genus Melosira.  Species of Aulacoseira from Lake Baikal are a major target for our summer sampling, so a “Melosira year” promised great things for our project.

Though the abundance of one of our target diatoms was enough to get this diatomist excited, sampling success relied on two more things: persistence of the “Melosira year” until our team from the University of Texas at Austin could get to BK; and successful isolation of DNA from many individual Aulacoseira chains.

High molecular weight genomic DNA from 10 Aulacoseira baicalensis isolates. Photo: Mariska Brady.

High molecular weight genomic DNA from ten Aulacoseira baicalensis isolates. Photo: Mariska Brady.

With the help of collaborators from Irkutsk State University in sampling lake Baikal, and the generosity of Scientists at The Limnological Institute of the Siberian division of the Russian Academy of Sciences in Irkutsk who lent me laboratory space to run a few gels and a PCR, I was able to confirm that we have boat-loads of genomic DNA from numerous Aulacoseira baicalensis that I isolated in my first few days in BK (insert fanfare here).

With this result, we will likely have comparative data between seasons, as the hard won winter sampling carried out by Ted Ozersky and Paul Wilburn yielded viable Aulacoseira baicalensis DNA. In addition, we have successfully field tested our methodology for procuring genomic DNA, a methodology that I will implement to get comparable data from the samples we collect on our 12 day circum-Baikal cruise, which I have just returned from. With any luck we will have lake-wide population genetic data on some of the endemic diatoms from Baikal come next winter.

About mariskabrady

I'm Mariska Brady, a nerdy scientist getting a Ph.D. in diatom evolution at the University of Texas at Austin. I'm interested in science, science policy, science art, scientists, scientific debate and bicycles.
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