Please use this identifier to cite or link to this item: doi:10.22028/D291-36374
Title: Regulatory modules mediating the complex neural expression patterns of the homeobrain gene during Drosophila brain development
Author(s): Hildebrandt, Kirsten
Kolb, Dieter
Klöppel, Christine
Kaspar, Petra
Wittling, Fabienne
Hartwig, Olga
Federspiel, Jannic
Findji, India
Walldorf, Uwe
Language: English
Title: Hereditas
Volume: 159
Issue: 1
Publisher/Platform: BMC
Year of Publication: 2022
Free key words: Homeobrain (Hbn)
Transcription factor
Gene targeting
DDC notations: 610 Medicine and health
Publikation type: Journal Article
Abstract: Background: The homeobox gene homeobrain (hbn) is located in the 57B region together with two other homeobox genes, Drosophila Retinal homeobox (DRx) and orthopedia (otp). All three genes encode transcription factors with important functions in brain development. Hbn mutants are embryonic lethal and characterized by a reduction in the anterior protocerebrum, including the mushroom bodies, and a loss of the supraoesophageal brain commissure. Results: In this study we conducted a detailed expression analysis of Hbn in later developmental stages. In the larval brain, Hbn is expressed in all type II lineages and the optic lobes, including the medulla and lobula plug. The gene is expressed in the cortex of the medulla and the lobula rim in the adult brain. We generated a new hbnKOGal4 enhancer trap strain by reintegrating Gal4 in the hbn locus through gene targeting, which refects the complete hbn expression during development. Eight diferent enhancer-Gal4 strains covering 12 kb upstream of hbn, the two large introns and 5 kb downstream of the gene, were established and hbn expression was investigated. We characterized several enhancers that drive expression in specifc areas of the brain throughout development, from embryo to the adulthood. Finally, we generated deletions of four of these enhancer regions through gene targeting and analysed their efects on the expression and function of hbn. Conclusion: The complex expression of Hbn in the developing brain is regulated by several specifc enhancers within the hbn locus. Each enhancer fragment drives hbn expression in several specifc cell lineages, and with largely overlapping patterns, suggesting the presence of shadow enhancers and enhancer redundancy. Specifc enhancer deletion strains generated by gene targeting display developmental defects in the brain. This analysis opens an avenue for a deeper analysis of hbn regulatory elements in the future.
DOI of the first publication: 10.1186/s41065-021-00218-5
URL of the first publication:
Link to this record: urn:nbn:de:bsz:291--ds-363747
ISSN: 1601-5223
Date of registration: 7-Jun-2022
Faculty: M - Medizinische Fakultät
Department: M - Anatomie und Zellbiologie
Professorship: M - Prof. Dr. Uwe Walldorf
Collections:SciDok - Der Wissenschaftsserver der Universität des Saarlandes

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