Reed College Biology Professor Receives Funding to Study Behavior and Genetics in East African Cichlid Fishes
A Murdock Charitable Trust grant supports Suzy Renn’s
project to research the genetic basis of behavior from an evolutionary
Portland, OR (May 22, 2007) – Reed assistant professor of biology Suzy Renn has received a two-year grant of $42,000 from the M.J. Murdock Charitable Trust’s Research Program for the Life Sciences for her project, "Identification of Rapidly Evolving Genes in the East African Cichlid Species Flock by Heterologous Comparative Genomic Hybridization."
The many species of African Cichlid Fishes provide a fabulous opportunity to investigate the process by which new species evolve, explains Renn. There are over 2,000 species of cichlid fishes that now inhabit the three great lakes in East Africa—Lake Tanganyika, Lake Malawi, and Lake Victoria—as well as river systems in the area. More astonishing even than the number of species is the great diversity of form and behavior among this group of fishes. This instance of adaptive radiation—the phenomenon in which many species evolve rapidly from a common ancestor—caused the late evolutionary biologist Ernst Mayr to refer to the rapid and recent evolutionary radiation of African cichlid fishes as “the cichlid problem.” Renn aims to address that “problem” with modern genomic techniques. “Because the radiation has been recent,” she says, “there is a relatively low level sequence divergence among the genomes of these diverse species. This genomic similarity allows us to use one genomic tool to address the molecular basis of the great diversity of morphology and behavior.”
The novelty of her current project, says Renn, is that she will be looking at 12,000 genes at the same time, whereas researchers in the past have been limited to a few genes at a time. Renn, who will work with two Reed students each summer on the project, will use a genomic tool called a microarray—a collection of pieces of DNA from each gene that are “spotted” onto a glass microscope slide—to identify genes that have evolved very rapidly and have very different DNA sequence. DNA evolution will be quantified for all 12,000 genes by measuring how well the gene sequences in each species match the pieces of DNA that are spotted onto the microarray.
The goal of the project is to discover whether the evolution of complex behaviors—for example, aggressive territorial behavior or monogamous bi-parental care—is the result of divergence in gene sequence in the same genes each time the behavior has evolved or, conversely, whether it is caused by divergence in different genes each time. “While this won’t solve ‘the cichlid problem,’” says Renn, “it will put us one step closer to understanding the molecular basis of adaptive evolutionary radiation.”
The M.J. Murdock Charitable Trust is based in Vancouver, WA. The Trust’s mission is to enrich the quality of life in the Pacific Northwest by providing grants to organizations that seek to strengthen the region’s educational and cultural base in creative and sustainable ways.