The investigators are pursueing the molecular characterization of four new Drosophila genes, latheo, linotte, nalyot and golovan, all of which were identified in a P element (transposon) insertional mutagenesis for mutants affecting 3-hr memory after Pavlovian olfactory conditioning. Behavioral analyses of latheo, linotte and nalyot mutants suggest that learning is disrupted (golovan mutants have not yet been tested), while each mutant's abilities to sense, and react to, odors and electric shock appear normal. Capitalizing on the fact that these genes were P element-tagged, molecular genetic analyses have begun. The latheo and linotte transcription units have been identified and each encodes a novel protein. Complete rescue of the leaning/memory defects has been achieved in adult transgenic latheo and linotte mutants, each carrying inducible constructs of their respective wild-type sequences. Genomic DNA flanking and nalyot and golovan P element insertions has been plasmid rescued and sequenced. Comparisons of these sequences to the databases have revealed that the nalyot P element is inserted in an intron of the Adf-1 gene and that the golovan P element is inserted 70 bp 5' of extra macrochaetae (emc). The applicants propose to extend our characterizations of these genes by pursuing the following: 1. Characterization of olfactory leaning and memory in mutant and transgenic flies 2. Molecular characterization of the transcripts and genomic regulatory regions of these genes 3. In situ characterizations of RNA and protein patterns of expressions 4. Characterization of gene interactions using double-mutants, immunocytological co-localization, yeast two-hybrid selection and differential screens. Given the extensive homologies for behavioral properties of learning and memory and for genes involved with learning among fruit flies, other invertebrates and vertebrates, the applicants expect knowledge gained from their studies of fruit flies to contribute to our understanding of the molecular mechanisms underlying learning and memory. Ultimately such information will be used to develop new diagnostic tools, pharmaceuticals and gene therapies for cognitive dysfunction in humans.
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| Pinto, S; Quintana, D G; Smith, P et al. (1999) latheo encodes a subunit of the origin recognition complex and disrupts neuronal proliferation and adult olfactory memory when mutant. Neuron 23:45-54 |
| DeZazzo, J; Xia, S; Christensen, J et al. (1999) Developmental expression of an amn(+) transgene rescues the mutant memory defect of amnesiac adults. J Neurosci 19:8740-6 |
| Rohrbough, J; Pinto, S; Mihalek, R M et al. (1999) latheo, a Drosophila gene involved in learning, regulates functional synaptic plasticity. Neuron 23:55-70 |
