Show simple item record

dc.contributor.supervisor Eisenstat, David (Human Anatomy & Cell Science) en_US
dc.contributor.author Zhang, Qi
dc.date.accessioned 2011-08-31T15:15:58Z
dc.date.available 2011-08-31T15:15:58Z
dc.date.issued 2011-08-31
dc.identifier.uri http://hdl.handle.net/1993/4799
dc.description.abstract Introduction: The Dlx1/Dlx2 double knockout mouse has reduced numbers (33% fewer) of retinal ganglion cells (RGC), due to enhanced apoptosis. Brn3a and Brn3b are closely related members of the Class IV POU-domain gene family, and play functionally interchangeable roles in retinal development. We hypothesized that Brn3a and/or Brn3b are direct DLX transcriptional targets during retinal development. Methods: Chromatin immunoprecipitation (ChIP) assays were performed on E16.5 retinas to identify DLX proteins bound to the Brn3a or Brn3b promoters. Electrophoretic mobility shift assays (EMSA) were used to confirm the specificity of this binding. Luciferase reporter gene assays were performed to confirm the functional significance of DLX binding to the Brn3 or Brn3ba promoters in vitro. In utero retinal electroporation was used to study the effect of DLX gain-of-function on Brn3a/Brn3b expression in vivo. Compound Dlx1/Dlx2/Brn3a and Dlx1/Dlx2/Brn3b knockout mice were generated for analysis of retinal phenotypes. Results: Both DLX1 and DLX2 proteins bound to the Brn3b promoter, but only DLX2 bound to the Brn3a promoter in vivo. Using EMSA, recombinant DLX1 and DLX2 bound to Brn3b and specific supershifted bands resulted from the addition of specific DLX1 or DLX2 antibodies; only recombinant DLX2 bound to Brn3a and the supershifted band resulted from the addition of DLX2 antibody. Both DLX1 and DLX2 binding to the Brn3b promoter activated transcription of a luciferase reporter gene in vitro. Only Dlx2, but not Dlx1, co-transfection with Brn3a activated luciferase reporter gene expression. In utero retinal electroporation showed that ectopic DLX2 expression promoted both Brn3b and Brn3a expression in vivo. Loss of Dlx1/Dlx2 and Brn3b resulted in loss of 90% of RGC and increased cholinergic amacrine cell differentiation. Conclusion: Brn3b is transcriptionally regulated by both DLX1 and DLX2, whereas Brn3a is only regulated by DLX2 in vitro and in vivo. Dlx1/Dlx2 and Brn3b play combinatorial roles in retinogenesis. en_US
dc.rights info:eu-repo/semantics/openAccess
dc.subject retina en_US
dc.subject development en_US
dc.subject Dlx en_US
dc.title Identification and characterization of BRN3A/BRN3B as DLX homeobox gene transcriptional targets in retinal development en_US
dc.type info:eu-repo/semantics/doctoralThesis
dc.degree.discipline Human Anatomy and Cell Science en_US
dc.contributor.examiningcommittee Bergen, Hugo (Human Anatomy & Cell Science) Kong, Jiming (Human Anatomy & Cell Science) Wigle, Jeffrey (Biochemistry & Medical Genetics) en_US
dc.degree.level Doctor of Philosophy (Ph.D.) en_US
dc.description.note October 2011 en_US


Files in this item

This item appears in the following Collection(s)

Show simple item record

View Statistics