Acquisition of Equipment by a Group of Emory University Developmental Geneticists for Sorting Multicellular Organisms

Emory University, Atlanta GA

Investigators

Abstract

A grant has been awarded to Dr. Steven W. L'Hernault at Emory University to support the purchase of a COPAS (Complex Object Parametric Analyzer and Sorter) cell sorter instrument. These funds will be used to purchase instrumentation that will be utilized by seven investigators that study either the fruit fly Drosophila melanogaster or the roundworm Caenorhabditis elegans, which are species that are extensively utilized in developmental genetic experiments. Genetic experiments in these species usually employ relatively small numbers of animals because these multi-cellular animals are usually sorted by hand. Consequently, obtaining and analyzing large numbers of mutant animals is frequently impossible, especially if the mutant either dies during its maturation (is lethal) or is sterile. Biochemical approaches require large populations of such mutants and, until recently, this was not possible. However, the newly developed COPAS technology now permits accurate sorting and dispensing of multi-cellular animals based on size and/or fluorescence differences. The COPAS can be used to sort either Drosophila or Caenorhabditis, and this permits two different experimental approaches. It is possible to construct Drosophila and Caenorhabditis strains where a specified chromosome is "marked" by the presence of a fluorescent green signal. Mutants can be sorted away from non-mutant siblings by selecting non-Green individuals, so this machine makes it feasible to purify large numbers of lethal or sterile animals. Secondly, it is possible to rapidly dispense a defined number of individuals of a chosen sex or life cycle stage with ~98% accuracy. This permits evaluating individual animals on a scale that is not possible by manual techniques and allows isolated mutants to be assessed for desired, but rare, events. The relevance of Drosophila and Caenorhabditis to significant human problems is well established; Drosophila is a model for the Mediterranean fruit fly, a significant agricultural pest, and Caenorhabditis is a model for a wide variety of parasitic nematodes that infect man, pets, domestic livestock and agriculturally significant plants. The COPAS technology permits application of innovative biochemical techniques to organisms that have traditionally been used for genetic analyses. Additionally, the COPAS is a single machine, cost-effective way for both Drosophila and Caenorhabditis investigators to gain access to a technology that permits these exciting, new experimental approaches.