{"id":{"repo_id":"oxford-brookes","oai_identifier":"tle:98ae7ad2-c745-1ffb-d351-a57aada795ef:d6bd9758-527a-46cd-bfe2-c433766e8fca:1"},"canonical_url":"https://search.dev.ndltd.org/etd/oxford-brookes/tle:98ae7ad2-c745-1ffb-d351-a57aada795ef:d6bd9758-527a-46cd-bfe2-c433766e8fca:1","repository":{"repo_id":"oxford-brookes","name":"Oxford Brookes University","base_url":"https://radar.brookes.ac.uk/radar/oai"},"display":{"title":"A genetic screen for genes involved in dendrite morphogenesis of central neurons in Drosophila melanogaster","abstract":"In order to produce a functional nervous system, it is essential that neurons project synaptic terminals into particular regions of the developing nervous system, so as to make connections with appropriate pre- and postsynaptic partners. While axon targeting has been studied extensively, much less is known about how the postsynaptic dendrites grow and branch. To study dendrite morphogenesis, a mosaic loss of function screen was developed and carried out in Drosophila melanogaster for chromosomal regions required for motor neuron dendrite development. Specifically, the Mosaic Analysis with a Repressible Cell Marker (MARCM) method was modified so that individual motor neurons can be made homozygous for a defined genomic aberration in an otherwise wild-type (heterozygous) background and visualised during early larval stages. In addition, 85 defined chromosomal deficiencies were recombined individually onto FRT-carrying chromosomes to be screened for genes involved in dendrite morphogenesis. These recombinant FRT-deficiency chromosomes provided a coverage of ~64.3% of chromosome 2 (3864 annotated genes). After analysis of ~35% of chromosome 2 (2092 annotated genes), 814 central nervous systems and 414 neurons, five genomic regions were identified that had a dendritic phenotype when absent. One of these regions, 2R:23D2;23E, uncovered by FRT40A Df(2L)S2590, was studied in more detail. Overlapping deficiencies were screened to define more precisely the region of chromosome 2 where the loss of gene(s) caused a dendritic phenotype in motor neurons. Of the seven candidate genes identified in this region, only one was shown to have expression in the embryonic central nervous system – the as yet uncharacterised gene CG34393. Based on sequence comparisons, CG34393 is predicted to encode a putative Ras guanyl exchange factor. Expression data from putative homologues in other species and Drosophila genes that are expressed in a similar developmental time course suggest that CG34393 may be involved in synapse development.","abstract_html":"In order to produce a functional nervous system, it is essential that neurons project synaptic terminals into particular regions of the developing nervous system, so as to make connections with appropriate pre- and postsynaptic partners. While axon targeting has been studied extensively, much less is known about how the postsynaptic dendrites grow and branch. To study dendrite morphogenesis, a mosaic loss of function screen was developed and carried out in Drosophila melanogaster for chromosomal regions required for motor neuron dendrite development. Specifically, the Mosaic Analysis with a Repressible Cell Marker (MARCM) method was modified so that individual motor neurons can be made homozygous for a defined genomic aberration in an otherwise wild-type (heterozygous) background and visualised during early larval stages. In addition, 85 defined chromosomal deficiencies were recombined individually onto FRT-carrying chromosomes to be screened for genes involved in dendrite morphogenesis. These recombinant FRT-deficiency chromosomes provided a coverage of ~64.3% of chromosome 2 (3864 annotated genes). After analysis of ~35% of chromosome 2 (2092 annotated genes), 814 central nervous systems and 414 neurons, five genomic regions were identified that had a dendritic phenotype when absent. One of these regions, 2R:23D2;23E, uncovered by FRT40A Df(2L)S2590, was studied in more detail. Overlapping deficiencies were screened to define more precisely the region of chromosome 2 where the loss of gene(s) caused a dendritic phenotype in motor neurons. Of the seven candidate genes identified in this region, only one was shown to have expression in the embryonic central nervous system – the as yet uncharacterised gene CG34393. Based on sequence comparisons, CG34393 is predicted to encode a putative Ras guanyl exchange factor. Expression data from putative homologues in other species and Drosophila genes that are expressed in a similar developmental time course suggest that CG34393 may be involved in synapse development.","abstract_has_math":false,"creators":["North, Annemarie"],"institution":"Oxford Brookes University","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011","date_published":"2011","updated_at":"2026-07-24T03:44:23Z","subjects":[],"languages":["en"],"rights":["All rights reserved"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://radar.brookes.ac.uk/radar/items/98ae7ad2-c745-1ffb-d351-a57aada795ef/1/","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["North, Annemarie"]},{"key":"dc:creator","label":"Author","values":["North, Annemarie"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011"]},{"key":"dc:publisher","label":"Institution","values":["Oxford Brookes University"]},{"key":"dc:type","label":"Dc Type","values":["thesis"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["All rights reserved"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://radar.brookes.ac.uk/radar/items/98ae7ad2-c745-1ffb-d351-a57aada795ef/1/","https://radar.brookes.ac.uk/radar/file/98ae7ad2-c745-1ffb-d351-a57aada795ef/1/north2011genetic2.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["In order to produce a functional nervous system, it is essential that neurons project synaptic terminals into particular regions of the developing nervous system, so as to make connections with appropriate pre- and postsynaptic partners. While axon targeting has been studied extensively, much less is known about how the postsynaptic dendrites grow and branch. To study dendrite morphogenesis, a mosaic loss of function screen was developed and carried out in Drosophila melanogaster for chromosomal regions required for motor neuron dendrite development. Specifically, the Mosaic Analysis with a Repressible Cell Marker (MARCM) method was modified so that individual motor neurons can be made homozygous for a defined genomic aberration in an otherwise wild-type (heterozygous) background and visualised during early larval stages. In addition, 85 defined chromosomal deficiencies were recombined individually onto FRT-carrying chromosomes to be screened for genes involved in dendrite morphogenesis. These recombinant FRT-deficiency chromosomes provided a coverage of ~64.3% of chromosome 2 (3864 annotated genes). After analysis of ~35% of chromosome 2 (2092 annotated genes), 814 central nervous systems and 414 neurons, five genomic regions were identified that had a dendritic phenotype when absent. One of these regions, 2R:23D2;23E, uncovered by FRT40A Df(2L)S2590, was studied in more detail. Overlapping deficiencies were screened to define more precisely the region of chromosome 2 where the loss of gene(s) caused a dendritic phenotype in motor neurons. Of the seven candidate genes identified in this region, only one was shown to have expression in the embryonic central nervous system – the as yet uncharacterised gene CG34393. Based on sequence comparisons, CG34393 is predicted to encode a putative Ras guanyl exchange factor. Expression data from putative homologues in other species and Drosophila genes that are expressed in a similar developmental time course suggest that CG34393 may be involved in synapse development."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["A genetic screen for genes involved in dendrite morphogenesis of central neurons in Drosophila melanogaster"]}]}],"canonical_facts":{"dc:contributor":["North, Annemarie"],"dc:creator":["North, Annemarie"],"dc:date":["2011"],"dc:description":["In order to produce a functional nervous system, it is essential that neurons project synaptic terminals into particular regions of the developing nervous system, so as to make connections with appropriate pre- and postsynaptic partners. While axon targeting has been studied extensively, much less is known about how the postsynaptic dendrites grow and branch. To study dendrite morphogenesis, a mosaic loss of function screen was developed and carried out in Drosophila melanogaster for chromosomal regions required for motor neuron dendrite development. Specifically, the Mosaic Analysis with a Repressible Cell Marker (MARCM) method was modified so that individual motor neurons can be made homozygous for a defined genomic aberration in an otherwise wild-type (heterozygous) background and visualised during early larval stages. In addition, 85 defined chromosomal deficiencies were recombined individually onto FRT-carrying chromosomes to be screened for genes involved in dendrite morphogenesis. These recombinant FRT-deficiency chromosomes provided a coverage of ~64.3% of chromosome 2 (3864 annotated genes). After analysis of ~35% of chromosome 2 (2092 annotated genes), 814 central nervous systems and 414 neurons, five genomic regions were identified that had a dendritic phenotype when absent. One of these regions, 2R:23D2;23E, uncovered by FRT40A Df(2L)S2590, was studied in more detail. Overlapping deficiencies were screened to define more precisely the region of chromosome 2 where the loss of gene(s) caused a dendritic phenotype in motor neurons. Of the seven candidate genes identified in this region, only one was shown to have expression in the embryonic central nervous system – the as yet uncharacterised gene CG34393. Based on sequence comparisons, CG34393 is predicted to encode a putative Ras guanyl exchange factor. Expression data from putative homologues in other species and Drosophila genes that are expressed in a similar developmental time course suggest that CG34393 may be involved in synapse development."],"dc:format":["application/pdf"],"dc:identifier":["https://radar.brookes.ac.uk/radar/items/98ae7ad2-c745-1ffb-d351-a57aada795ef/1/","https://radar.brookes.ac.uk/radar/file/98ae7ad2-c745-1ffb-d351-a57aada795ef/1/north2011genetic2.pdf"],"dc:language":["en"],"dc:publisher":["Oxford Brookes University"],"dc:rights":["All rights reserved"],"dc:title":["A genetic screen for genes involved in dendrite morphogenesis of central neurons in Drosophila melanogaster"],"dc:type":["thesis"]},"updated_at":"2026-07-24T03:44:23Z"}