Abstract

Although an organism contains genes for many specific traits, control mechanisms result in not all genes being expressed. One form of control is trans-inactivation, where the two copies of a gene interact, such that one copy of a gene silences the other copy. A model for this is the brownDominant ( b~ allele of the brown gene, found in Drosophila. It contains an insertion of a particular satellite sequence of bases (AAGAG). This trans-inactivation may be the result of either an interaction of the AAGAG sequence in the b~ allele with another AAGAG sequence, or a more general interaction of proteins in chromosomes.

To determine which mechanism is responsible for the trans-inactivation of the brown gene, the goal of this project was to create a hybrid fly that does not contain the AAGAG sequence but does contain the b~ allele. In addition, fluorescent in-situ hybridization {FISH) was done to verify that the flies did not contain the sequence AAGAG and to gain other information about the fly lines used.

This project resulted in a hybrid fly line that contained the b~ allele but no other AAGAG. The FISH analysis detected many differences between the genomes of the different fly lines used in this experiment. These results will be used in further experimentation to determine the mechanism for trans-inactivation in this model.