Abstract: The present invention relates to a D. melanogaster insulin-like gene and methods for identifying insulin-like genes. The methods provide nucleotide sequences of a D. melanogaster insulin-like gene, 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 insulin-like proteins which comprise one or more domains of an insulin-like protein. Antibodies to an insulin-like protein, and derivatives and analogs thereof, are provided. Methods of production of an insulin-like protein (e.g., by recombinant means), and derivatives and analogs thereof, are provided. Further, methods to identify the biological function of a D. melanogaster insulin-like gene are provided, including various methods for the functional modification (e.g., overexpression, underexpression, mutation, knock-out). Still further, methods to identify a D.