A forward genetic screen looking for altered gravity response identified the gene jim lovell (lov). This gene is related to the gene fruitless, which specifies male courtship ii behavior in Drosophila. Like fruitless, lovencodes a protein with BTB-POZ domain and DNA binding domain, suggesting roles in transcription and ubiquitin-mediated degradation. In order to investigate the role(s) of lov further, several approaches have been taken. Five new mutations to the locus have been generated and their effects on various behaviors and development investigated. An antibody against the Lov protein has been generated and used to determine the wild type and mutant expression pattern of Lov during embryogenesis. The effects of ectopic expression and reduction of expression of lov in components of the nervous system was analyzed using the GAIA/ VAS system. These studies establish that lov expression is limited to the nervous system beyond very early embryogenesis. In the wild type embryonic PNS, Lov is found in subsets of neurons of all three classes - External Sensory neurons, Chordotonal organs and Multiple Dendritic neurons suggesting that Lov plays a role in specifying the final identity of certain neurons. One of the mutants has reduced Lov expression in the embryonic nervous system. Results from analysis of the new mutants and from the over/under-expression studies performed using the GAIAIUAS system have identified roles of lov in several behaviors and developmental processes. The altered expression of lov in the new mutant 111 alleles of lov results in decreased levels of male courtship directed towards a courtship partner as well as an increase in non-directed courtship. Additionally, various defects in sensory inputs were identified. The defects may contribute to in part to the reduced courtship. One of the mutants, lov66, has a male-male courtship phenotype. lov66 also has a reduced fertility due to defects in spermatogenesis, egg formation, and in ability of females to use sperm effectively to fertilize eggs. Finally, both the over and underexpression of lov resulted in a reduction in courtship.