Genetic analysis of sex-chromosome arrangement in Drosophila americana: a laboratory exercise for undergraduate or advanced placement

This paper describes a crossing design for determining the arrangement of the X and 4 chromosomes in Drosophila americana. Implementation of this crossing design in a teaching laboratory with undergraduate or advanced placement students provides a clear demonstration of sex-linked vs. autosomal inheritance and the connection between linkage relationship and chromosomal arrangement. Analyses can be performed on newly collected material, or on established stocks available from the Tucson Stock Center (University of Arizona) or the author. The procedure requires minimal setup, takes about 10 weeks to complete, and generates easily interpretable results. In this description of the procedure, an example is provided where four undergraduate students analyzed a sample (OR01) of D. americana collected near Toledo, Ohio. An electronic copy of the procedure is available from the author upon request ([email protected]).