THE ROLE OF THE LIMK1 GENE ON SHORT-TERM MEMORY FORMATION IN DROSOPHILA MELANOGASTER Zalomaeva E.S.1,2, Falina V.S.2, Nikitina E.A.1,2, Zhuravlev A.V.1, Savvateeva‐Popova E.V.1 1Pavlov Institute of Physiology Russian academy of sciences 2The Herzen State Pedagogical University of Russia Nowadays one of the topical problem of neuro‐ biology is the research of the etiology and progres‐ sion of different neurodegenerative diseases. One of the causes of neurodegenerative diseases is dis‐ turbance of actin remodeling cascade whose key enzyme is LIMK1. Drosophila constitutes a conven‐ ient model for studying the link between genome organization and chromosome architecture ob‐ served in cognitive disorders. The revealed associa‐ tion between limk1 gene's mutational damage, changes in its expression and activity as well as cog‐ nitive impairment allows to use current model for the study of neurodegenerative and genomic dis‐ eases. INTRODUCTION Drosophila melanogaster—the most convenient model object ♦Molecular‐genetic studies of the human genome have emphasized the evolutionary conservation of homologous genes from different organisms. ♦limk1 gene D. melanogaster has 71% homology with the limk1 gene H. sapiens ♦Drosophila is especially advantageous for testing gene interactions and allows the usage of several mutant or transgenic models at a time. ♦Drosophila mutations in such genes help to under‐ stand the putative function of a newly isolated hu‐ man disease gene. ♦D. melanogaster have short life span (Figure 1) ♦Low maintenance costs ♦No legislative limitations brought about by “animal defending laws” The main purpose: to analyze the formation and dynamics of short‐term memory in D. melanogaster stocks with limk1 gene polymorphism: Canton‐S, Berlin and Oregon‐R Figure 3. Individual courtship elements Figure 1. Drosophila life cycle Canton‐S stock has a single‐nucleotide polymorphism C/T (+12 bp) in the binding site of the M1 transcription factor. Berlin stock characterized by disturbances in primer binding in intron 2 and near introns 3 and 4. Also this stock has single‐ nucleotide polymorphisms in the N‐terminal part of the gene (including the M1 binding site and the 1st part of intron 1), some of which correspond to Canton‐S stock polymorphisms. Oregon‐R stock hasn’t fragment between primers are limited the region with both LIM‐domains and part of the PDZ‐domain. Also this stock has multiple polymorphisms in the 1st intron: ♦ A/T‐rich insert 28 bp; ♦ deletions of 8 bp and 9 bp ♦ Change the CAA/AGС Conditioned courtship suppression paradigm was used to asses learning ability and short‐term memory formation. 1. A 5‐day‐old virgin male was put in a special box with a fertil‐ ized female Canton‐S and was left for 30 minutes (Figure 2). 2. Courtship behavior was analyzed in naive males and in males in 0, 15, 30 and 60 minutes after training to assess the forma‐ tion and dynamics of short‐term memory. The behavior of the male was recorded in a special program for 300 seconds. We re‐ corded the start time of individual courtship elements (Figure 3) and the execution time of non‐courtship elements (activity, prining, rest). 3. We calculated the learning index (LI) to assess the effective‐ ness of training. Randomization test was used to statistical analysis. Figure 2. Special box for training and testing RESULTS Thus, Canton‐S and Berlin stocks capable of formation short‐term memory and to preserve it, while Oregon‐R incapable of learning and formation short‐term memory. Polymorphisms in the limk1 gene apparently contribute to changes in the content and ratio of LIMK1 isoforms in the analyzed stocks, that influence in processes of learning and formation short‐term memory. Figure 4. Learning index (LI) Canton‐S, Berlin and Oregon‐R stocks * LI significantly differents from zero, p<0,05 ▲ LI significantly differents from Canton‐S ■ LI significantly differents from Berlin MATERIALS AND METHODS 0 10 20 30 40 50 60 70 80 90 100 0 min 15 min 3