Justin P. Gerke

Publications (2)66.73 Total impact

• Article: Natural variation in a chloride channel subunit confers avermectin resistance in C. elegans.

  Rajarshi Ghosh, Erik C Andersen, Joshua A Shapiro, Justin P Gerke, Leonid Kruglyak
  [show abstract] [hide abstract]
  ABSTRACT: Resistance of nematodes to anthelmintics such as avermectins has emerged as a major global health and agricultural problem, but genes conferring natural resistance to avermectins are unknown. We show that a naturally occurring four-amino-acid deletion in the ligand-binding domain of GLC-1, the alpha-subunit of a glutamate-gated chloride channel, confers resistance to avermectins in the model nematode Caenorhabditis elegans. We also find that the same variant confers resistance to the avermectin-producing bacterium Streptomyces avermitilis. Population-genetic analyses identified two highly divergent haplotypes at the glc-1 locus that have been maintained at intermediate frequencies by long-term balancing selection. These results implicate variation in glutamate-gated chloride channels in avermectin resistance and provide a mechanism by which such resistance can be maintained.
  Science 02/2012; 335(6068):574-8. · 31.20 Impact Factor
• Article: Chromosome-scale selective sweeps shape Caenorhabditis elegans genomic diversity.

  Erik C Andersen, Justin P Gerke, Joshua A Shapiro, Jonathan R Crissman, Rajarshi Ghosh, Joshua S Bloom, Marie-Anne Félix, Leonid Kruglyak
  [show abstract] [hide abstract]
  ABSTRACT: The nematode Caenorhabditis elegans is central to research in molecular, cell and developmental biology, but nearly all of this research has been conducted on a single strain of C. elegans. Little is known about the population genomic and evolutionary history of this species. We characterized C. elegans genetic variation using high-throughput selective sequencing of a worldwide collection of 200 wild strains and identified 41,188 SNPs. Notably, C. elegans genome variation is dominated by a set of commonly shared haplotypes on four of its six chromosomes, each spanning many megabases. Population genetic modeling showed that this pattern was generated by chromosome-scale selective sweeps that have reduced variation worldwide; at least one of these sweeps probably occurred in the last few hundred years. These sweeps, which we hypothesize to be a result of human activity, have drastically reshaped the global C. elegans population in the recent past.
  Nature Genetics 01/2012; 44(3):285-90. · 35.53 Impact Factor