latheo encodes a subunit of the origin recognition complex and disrupts neuronal proliferation and adult olfactory memory when mutant.

The Drosophila latheo (lat) gene was identified in a behavioral screen for olfactory memory mutants. The original hypomorphic latP1 mutant (Boynton and Tully, 1992) shows a structural defect in adult brain. Homozygous lethal lat mutants lack imaginal discs, show little cell proliferation in the CNS of third instar larvae, and die as early pupae. latP1 was cloned, and all of the above mentioned defects of hypomorphic or homozygous lethal lat mutants were rescued with a lat+ transgene. lat encodes a novel protein with homology to a subunit of the origin recognition complex (ORC). Human and Drosophila LAT both associate with ORC2 and are related to yeast ORC3, suggesting that LAT functions in DNA replication during cell proliferation.