Kirsten Hildebrandt1, Sabrina Kübel1,2, Marie Minet1,3, Nora Fürst1,4, Christine Klöppel1, Eva Steinmetz1,5, Uwe Walldorf6. 1. Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Germany. 2. Present address: Clinical and Molecular Virology, Friedrich-Alexander University, 91054, Erlangen, Germany. 3. Present address: Human Genetics, Saarland University, Building 60, 66421, Homburg/Saar, Germany. 4. Present address: Genetics/Epigenetics, Saarland University, Building A2.4, 66123, Saarbrücken, Germany. 5. Present address: Zoology and Physiology, Saarland University, Building B2.1, 66123, Saarbrücken, Germany. 6. Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Germany. uwe.walldorf@uks.eu.
Abstract
BACKGROUND: Many transcription factors are involved in the formation of the brain during the development of Drosophila melanogaster. The transcription factor Earmuff (Erm), a member of the forebrain embryonic zinc finger family (Fezf), is one of these important factors for brain development. One major function of Earmuff is the regulation of proliferation within type II neuroblast lineages in the brain; here, Earmuff is expressed in intermediate neural progenitor cells (INPs) and balances neuronal differentiation versus stem cell maintenance. Erm expression during development is regulated by several enhancers. RESULTS: In this work we show a functional analysis of erm and some of its enhancers. We generated a new erm mutant allele by gene targeting and reintegrated Gal4 to make an erm enhancer trap strain that could also be used on an erm mutant background. The deletion of three of the previously analysed enhancers showing the most prominent expression patterns of erm by gene targeting resulted in specific temporal and spatial defects in defined brain structures. These defects were already known but here could be assigned to specific enhancer regions. CONCLUSION: This analysis is to our knowledge the first systematic analysis of several large enhancer deletions of a Drosophila gene by gene targeting and will enable deeper analysis of erm enhancer functions in the future.
BACKGROUND: Many transcription factors are involved in the formation of the brain during the development of Drosophila melanogaster. The transcription factor Earmuff (Erm), a member of the forebrain embryonic zinc finger family (Fezf), is one of these important factors for brain development. One major function of Earmuff is the regulation of proliferation within type II neuroblast lineages in the brain; here, Earmuff is expressed in intermediate neural progenitor cells (INPs) and balances neuronal differentiation versus stem cell maintenance. Erm expression during development is regulated by several enhancers. RESULTS: In this work we show a functional analysis of erm and some of its enhancers. We generated a new erm mutant allele by gene targeting and reintegrated Gal4 to make an erm enhancer trap strain that could also be used on an erm mutant background. The deletion of three of the previously analysed enhancers showing the most prominent expression patterns of erm by gene targeting resulted in specific temporal and spatial defects in defined brain structures. These defects were already known but here could be assigned to specific enhancer regions. CONCLUSION: This analysis is to our knowledge the first systematic analysis of several large enhancer deletions of a Drosophila gene by gene targeting and will enable deeper analysis of erm enhancer functions in the future.
Authors: Barret D Pfeiffer; Arnim Jenett; Ann S Hammonds; Teri-T B Ngo; Sima Misra; Christine Murphy; Audra Scully; Joseph W Carlson; Kenneth H Wan; Todd R Laverty; Chris Mungall; Rob Svirskas; James T Kadonaga; Chris Q Doe; Michael B Eisen; Susan E Celniker; Gerald M Rubin Journal: Proc Natl Acad Sci U S A Date: 2008-07-09 Impact factor: 11.205
Authors: Koen J T Venken; Joseph W Carlson; Karen L Schulze; Hongling Pan; Yuchun He; Rebecca Spokony; Kenneth H Wan; Maxim Koriabine; Pieter J de Jong; Kevin P White; Hugo J Bellen; Roger A Hoskins Journal: Nat Methods Date: 2009-06 Impact factor: 28.547