From Millions of Variants to One: Correlating the Genome and Phenome—Erik Andersen—Northwestern University

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Aug 07 2020 35 mins   11

Associate professor in molecular biosciences at Northwestern University, Erik Andersen, discusses his research in quantitative and molecular genetics.

Tune in to learn:

  • How millions of genetic variants in a section of a genome can be narrowed down to just one or two
  • How and for what purpose Andersen uses CRISPR-Cas9 in his research
  • Andersen’s short and long-term research goals

“If we could sequence a genome and then read it like a book, could we predict or understand the phenotype of an organism…how long we would live, the types of drugs we could take that would be most efficacious towards treating certain types of diseases, whether we’re predisposed to other diseases?”

In Andersen's lab, the focus is on answering this question by using roundworm nematodes to study the connection between the genome and different traits of the organism. He explains that there are many examples—not just in nematodes, but in flies and yeast and humans—of correlation between genetic sequence changes from organism to organism and trait differences. In humans, two of the most well-known are for type II diabetes risk and height.

Andersen is looking at how differences in DNA can explain phenotypic differences such as responses to chemotherapeutics and toxins. This type of work is particularly challenging because there could be millions of variants in a particular region of the genome that may correlate with the trait of interest. This is where quantitative genetics tends to stop, and Andersen’s research picks up.

He explains that by using a genetic system like the nematode, large populations of individuals can be grown, their genomes can be mixed using genetic crosses, and the correlations can be broken down and further refined. This allows for the narrowing down of millions of variants to just a few hundred variants; additional crosses at this point can eventually break down those hundreds of variants to just one.

Andersen dives into the details of this research and so much more, including what his research has shown about genetic polymorphism, what technologies have made this research possible, and the many benefits of using roundworms for this research.

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