{"id":{"repo_id":"lsu-thes","oai_identifier":"oai:repository.lsu.edu:gradschool_dissertations-2490"},"canonical_url":"https://search.dev.ndltd.org/etd/lsu-thes/oai:repository.lsu.edu:gradschool_dissertations-2490","repository":{"repo_id":"lsu-thes","name":"Lousiana State University","base_url":"https://repository.lsu.edu/do/oai/"},"display":{"title":"Evidence that the Boundary Element-Associated Factors BEAF-32A and BEAF-32B affect chromatin structure in Drosophila melanogaster","abstract":"The Boundary Element-Associated Factors, BEAF-32A and BEAF-32B bind to hundreds of loci on Drosophila chromosomes. These proteins function as insulators; they can prevent promoter activation by an enhancer when placed between them and protect transgenes from chromosomal position effects. To gain insight into BEAF function we designed and expressed a transgene encoding a dominant-negative form of BEAF. This peptide, BID, consists of the BEAF self-interaction domain. We demonstrate here that this peptide interferes with BEAF’s ability to bind DNA and prevents it from functioning as an insulator. In addition, expression of BID leads to a global disruption of polytene chromosome structure. Subsequent work using a fly line with a null mutation in the BEAF gene (BEAF AB-KO) also demonstrates a perturbation to polytene chromosome structure, although it is limited to the X-chromosome. Using Micrococcal nuclease and DNase I we analyzed hypersensitive site alterations in the BEAF AB-KO line, and observed alterations that are consistent with the shifting of positioned nucleosomes. This effect appears limited to regions near promoters. Finally, using fluorescently-tagged BEAF-32A and BEAF- 32B we attempt to characterize the localization and behavior of these proteins. We find that they localize very differently on polytene chromosomes, that BEAF-32B disassociates from mitotic chromosomes while BEAF-32A remains associated, and FRAP experiments indicate different recovery dynamics. This data is consistent with a model that BEAF-dependent insulators function by affecting chromatin structure or dynamics.","abstract_html":"The Boundary Element-Associated Factors, BEAF-32A and BEAF-32B bind to hundreds of loci on Drosophila chromosomes. These proteins function as insulators; they can prevent promoter activation by an enhancer when placed between them and protect transgenes from chromosomal position effects. To gain insight into BEAF function we designed and expressed a transgene encoding a dominant-negative form of BEAF. This peptide, BID, consists of the BEAF self-interaction domain. We demonstrate here that this peptide interferes with BEAF’s ability to bind DNA and prevents it from functioning as an insulator. In addition, expression of BID leads to a global disruption of polytene chromosome structure. Subsequent work using a fly line with a null mutation in the BEAF gene (BEAF AB-KO) also demonstrates a perturbation to polytene chromosome structure, although it is limited to the X-chromosome. Using Micrococcal nuclease and DNase I we analyzed hypersensitive site alterations in the BEAF AB-KO line, and observed alterations that are consistent with the shifting of positioned nucleosomes. This effect appears limited to regions near promoters. Finally, using fluorescently-tagged BEAF-32A and BEAF- 32B we attempt to characterize the localization and behavior of these proteins. We find that they localize very differently on polytene chromosomes, that BEAF-32B disassociates from mitotic chromosomes while BEAF-32A remains associated, and FRAP experiments indicate different recovery dynamics. This data is consistent with a model that BEAF-dependent insulators function by affecting chromatin structure or dynamics.","abstract_has_math":false,"creators":["Gilbert, Matthew Kenneth"],"institution":"Biological Sciences","degree_name":"Doctor of Philosophy (PhD)","degree_level":"Dissertation","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2009,"date_issued":"2009-01-01T08:00:00Z","date_published":"2009-01-01T08:00:00Z","updated_at":"2026-07-24T02:59:31Z","subjects":["chromatin structure","insulators"],"languages":[],"rights":["unrestricted","Release the entire work immediately for access worldwide."],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["etd-04132009-142305","https://repository.lsu.edu/gradschool_dissertations/1491"],"render_values":[{"text":"etd-04132009-142305","href":null,"code":true},{"text":"https://repository.lsu.edu/gradschool_dissertations/1491","href":"https://repository.lsu.edu/gradschool_dissertations/1491","code":true}]}]},"links":{"outbound_url":"https://doi.org/10.31390/gradschool_dissertations.1491","outbound_label":"DOI","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Gilbert, Matthew Kenneth"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2009-04-03"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2022-05-12T23:12:18Z"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy (PhD)"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Biological Sciences"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["chromatin structure","insulators"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["unrestricted","Release the entire work immediately for access worldwide."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["etd-04132009-142305","10.31390/gradschool_dissertations.1491","https://repository.lsu.edu/gradschool_dissertations/1491"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The Boundary Element-Associated Factors, BEAF-32A and BEAF-32B bind to hundreds of loci on Drosophila chromosomes. These proteins function as insulators; they can prevent promoter activation by an enhancer when placed between them and protect transgenes from chromosomal position effects. To gain insight into BEAF function we designed and expressed a transgene encoding a dominant-negative form of BEAF. This peptide, BID, consists of the BEAF self-interaction domain. We demonstrate here that this peptide interferes with BEAF’s ability to bind DNA and prevents it from functioning as an insulator. In addition, expression of BID leads to a global disruption of polytene chromosome structure. Subsequent work using a fly line with a null mutation in the BEAF gene (BEAF AB-KO) also demonstrates a perturbation to polytene chromosome structure, although it is limited to the X-chromosome. Using Micrococcal nuclease and DNase I we analyzed hypersensitive site alterations in the BEAF AB-KO line, and observed alterations that are consistent with the shifting of positioned nucleosomes. This effect appears limited to regions near promoters. Finally, using fluorescently-tagged BEAF-32A and BEAF- 32B we attempt to characterize the localization and behavior of these proteins. We find that they localize very differently on polytene chromosomes, that BEAF-32B disassociates from mitotic chromosomes while BEAF-32A remains associated, and FRAP experiments indicate different recovery dynamics. This data is consistent with a model that BEAF-dependent insulators function by affecting chromatin structure or dynamics."]},{"key":"dc:title","label":"Title","values":["Evidence that the Boundary Element-Associated Factors BEAF-32A and BEAF-32B affect chromatin structure in Drosophila melanogaster"]}]}],"canonical_facts":{"dc:creator":["Gilbert, Matthew Kenneth"],"dc:date":["2009-04-03"],"dc:date.available":["2022-05-12T23:12:18Z"],"dc:description.abstract":["The Boundary Element-Associated Factors, BEAF-32A and BEAF-32B bind to hundreds of loci on Drosophila chromosomes. These proteins function as insulators; they can prevent promoter activation by an enhancer when placed between them and protect transgenes from chromosomal position effects. To gain insight into BEAF function we designed and expressed a transgene encoding a dominant-negative form of BEAF. This peptide, BID, consists of the BEAF self-interaction domain. We demonstrate here that this peptide interferes with BEAF’s ability to bind DNA and prevents it from functioning as an insulator. In addition, expression of BID leads to a global disruption of polytene chromosome structure. Subsequent work using a fly line with a null mutation in the BEAF gene (BEAF AB-KO) also demonstrates a perturbation to polytene chromosome structure, although it is limited to the X-chromosome. Using Micrococcal nuclease and DNase I we analyzed hypersensitive site alterations in the BEAF AB-KO line, and observed alterations that are consistent with the shifting of positioned nucleosomes. This effect appears limited to regions near promoters. Finally, using fluorescently-tagged BEAF-32A and BEAF- 32B we attempt to characterize the localization and behavior of these proteins. We find that they localize very differently on polytene chromosomes, that BEAF-32B disassociates from mitotic chromosomes while BEAF-32A remains associated, and FRAP experiments indicate different recovery dynamics. This data is consistent with a model that BEAF-dependent insulators function by affecting chromatin structure or dynamics."],"dc:identifier":["etd-04132009-142305","10.31390/gradschool_dissertations.1491","https://repository.lsu.edu/gradschool_dissertations/1491"],"dc:rights":["unrestricted","Release the entire work immediately for access worldwide."],"dc:subject":["chromatin structure","insulators"],"dc:title":["Evidence that the Boundary Element-Associated Factors BEAF-32A and BEAF-32B affect chromatin structure in Drosophila melanogaster"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Doctor of Philosophy (PhD)"],"thesis:institution_name":["Biological Sciences"]},"updated_at":"2026-07-24T02:59:31Z"}