Week three was a busy one. This week we set up PCR reactions for many of our nemertean samples. PCR stands for polymerase chain reaction. It is a process widely used in biological research that allows us to select just a small piece of an organism’s large genome and make tons of copies of it. This amplification of a small portion of DNA is essential to get enough copies of the DNA segment to have it sequenced so that we can read what the DNA says. The small DNA segment I am focusing on is the protein coding gene, cytochrome c oxidase subunit 1 (CO1). This is a gene that is found in the mitochondria of a cell rather than the nucleus. CO1 is a widely used gene for DNA barcoding because it mutates fairly quickly but has sections on either side of the gene that have stayed almost the same. Because the edges of the gene segment are the same in most animals – from worms to humans – we can use those “conserved” sequences to find the gene and amplify it with PCR. Using this particular gene has its advantages not only because it has conserved edges that allow us to find the gene, but also because other scientists studying all sorts of organisms all over the world also look at CO1. These scientists upload their CO1 sequences online so that we, and anyone else, can compare our DNA barcoding segments to theirs and see if we have the same species, a closely related organism, or something entirely different. It is an extremely powerful tool. After we amplify the DNA sequence that we want with PCR, we purify the DNA and send it off to be sequenced. Once we receive those sequences, we will compare them to the Maslakova lab database of Nemertean sequences from the Caribbean, and GenBank, which will help us verify the identity of the worms in our samples and establish whether we have any new species. We expect that we will find several new species (and have already found a few!) because the Nemerteans were collected from a location that has never before been sampled. This was a shortened week due to the Fourth of July, but it feels like we accomplished a lot in the days that we worked. On Friday, we got out of the lab for the morning and checked out a new tidepooling location… Middle Cove! We found more a few more Nemerteans to bring back to the lab as well as plenty of other fun invertebrates. The evenings have been filled with bonfires on the beach and hiking. Last weekend we went to Eugene to check out the University of Oregon main campus, and I think we all agreed we like it better out here at OIMB. This weekend we have a camping trip that everyone is getting excited about, so tune in next week to hear about that adventure.
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AuthorHi! I’m Megan Powers, a fourth year Biology and Environmental Sciences student at the University of Iowa. Throughout my summer at OIMB, I will be working with the Maslakova lab to assess Nemertean diversity in the Caribbean. Archives
August 2019
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