Objetivo Genetic function and molecular organization of heterochromatin still remains largely elusive. In order to delucidate the genetic and molecular nature of this peculiar genomic component new approaches and tight cooperation of specialists in different fields are required.The discovery of a new gene, named Su(UR)ES, controlling the degree of underreplication of pericentric heterochromatin provides a good opportunity to study the gene involved in the process of incomplete polytenization and to characterize the newly polytenized portions of heterochromatin. Cloning the gene, sequencing, and expression analysis will be performed in order to understand the genetic mechanisms underlying polytenization (underreplication) of both pericentric and intercalary heterochromatin.Microdissection and cloning of portions of pericentric heterochomatin that polytenize in Su(UR)ES mutants will provide a new approach to the molecular analysis of heterochromatic regions which are usually cytologically "invisible" in all Drosophila stocks. Moreover, the newly isolated heterochromatic portions will be used as additional markers of pericentric heterochromatin. This will permit to construct new, highly resolutive map of pericentric heterochromatin. For these purposes a set of breakpoints of chromosomal rearrangements will be simultaneously mapped on mitotic and polytene heterochromatin maps.Preliminary data from microclone analysis show that newly polytenized heterochromatic regions are enriched in I elements and also contain about 20 unique sequences. Analysis of I-element distribution in the Su(UR)ES as well as several strains from the wild will be performed.Finally, the use of the unique sequences as probes will allow the recovery of long stretches of heterochromatic DNA from BAC, P1 cosmids, and L phage libraries, and to study the molecular organization of these DNA sequences in known regions of heterochromatin. Programa(s) IC-INTAS - International Association for the promotion of cooperation with scientists from the independent states of the former Soviet Union (INTAS), 1993- Tema(s) 4 - Life Sciences OPEN - OPEN Call Convocatoria de propuestas Data not available Régimen de financiación Data not available Coordinador University of Rome, " La Sapienza" Aportación de la UE Sin datos Dirección 24 Piazzale A. Moro 5, 00185 Rome Italia Ver en el mapa Coste total Sin datos Participantes (4) Ordenar alfabéticamente Ordenar por aportación de la UE Ampliar todo Contraer todo Russian Academy of Sciences Rusia Aportación de la UE Sin datos Dirección Vavilov street 34/5 117334 Moscow Ver en el mapa Coste total Sin datos Siberian branch of Russian Academy of Sciences Rusia Aportación de la UE Sin datos Dirección Lavrentiev prospect, 10 630900 Novosibirsk Ver en el mapa Coste total Sin datos State University of Novosibirsk Rusia Aportación de la UE Sin datos Dirección Pirogov Street, 2 630090 Novosibirsk Ver en el mapa Coste total Sin datos Université de Genève Suiza Aportación de la UE Sin datos Dirección 30 quai Ernest Ansermet 1211 Geneva Ver en el mapa Coste total Sin datos