Abstract: The present invention relates to Drosophila genes and methods for their use. The invention provides nucleotide sequences of Drosophila genes, amino acid sequences of the encoded proteins, and derivatives (e.g., fragments) and analogs thereof. The invention further relates to fragments (and derivatives and analogs thereof) of proteins which comprise one or more domains of a Drosophila protein. Antibodies to Drosophila proteins, and derivatives and analogs thereof, are also provided. Also provided herein are vectors and host cells comprising such nucleic acids. Methods of production of a Drosophila protein (e.g., by recombinant means), and derivatives and analogs thereof, are provided. Chimeric polypeptide molecules comprising polypeptides of the invention fused to heterologous polypeptide sequences are provided. Methods to identify the biological function of a Drosophila gene are provided, including various methods for the functional modification (e.g.