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 hbn enhancer trap strain by reintegrating Gal4 in the hbn locus through gene targeting, which reflects the complete hbn expression during development. Eight different 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 specific 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 effects on the expression and function of hbn.
Conclusion: The complex expression of Hbn in the developing brain is regulated by several specific enhancers within the hbn locus. Each enhancer fragment drives hbn expression in several specific cell lineages, and with largely overlapping patterns, suggesting the presence of shadow enhancers and enhancer redundancy. Specific 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.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8728971 | PMC |
http://dx.doi.org/10.1186/s41065-021-00218-5 | DOI Listing |
ACS Appl Mater Interfaces
January 2025
Department of Physics, School of Physical Science and Engineering, Beijing Jiaotong University, Beijing 100044, China.
Two-dimensional (2D) materials with spontaneous polarization can exhibit large second-order nonlinear optical (NLO) effects. Here, we present a series of stable distorted monolayers by using first-principles calculations and lattice vibration analysis. The structural distortion leads to a lower polar symmetry, giving rise to intrinsic ferroelectricity with a Curie point up to room temperature.
View Article and Find Full Text PDFACS Omega
January 2025
Department of Materials Science and Engineering, Gachon University, 1342, Seongnam-daero, Sujeong-gu, Seongnam-si, Gyeonggi-do 13120, South Korea.
This study investigates the enhancement of polypropylene (PP) composites through the incorporation of exfoliated hexagonal boron nitride (h-BN) nanosheets. The preparation process involved exfoliating h-BN in a liquid phase using a high-pressure homogenizer, followed by the coating of PP pellets with the exfoliated nanosheets using an acoustic mixer. Melt extrusion was then employed to fabricate h-BN-reinforced PP composite films.
View Article and Find Full Text PDFACS Omega
January 2025
Department of Chemistry, Banaras Hindu University, Varanasi, Uttar Pradesh 221005, India.
The ZrO-embedded carboxy-functionalized -BN composite, combined with graphene oxide (GO), formed a novel BN-COOH@ZrO/GO composite. Structural characterization through IR, Raman spectroscopy, powder X-ray diffraction, and X-ray photoelectron spectroscopy supported the successful preparation of the composite, while scanning electron microscopy and transmission electron microscopy revealed its surface morphology and the presence of component materials. UV-vis spectroscopy (solid state) further supported these findings.
View Article and Find Full Text PDFSci Bull (Beijing)
January 2025
Mechanical and Construction Engineering, Faculty of Engineering and Environment, Northumbria University, Newcastle Upon Tyne, NE1 8ST, UK.
With the rapid progress of aerospace frontier engineering, the extreme space thermal environment has brought severe challenges to astronauts' space suits, putting forward higher requirements for thermal protection materials. On this basis, a unique core-shell structured hexagonal boron nitride (h-BN)/silicon dioxide (SiO) nanofiber membrane (HS) was prepared using the coaxial electrospinning method, of which both the thermal insulation SiO nanofiber cortex and the passive radiation cooling (PRC) h-BN nanofiber core make it a promising dual-effect thermal management material. Especially, when the amount of h-BN is 0.
View Article and Find Full Text PDFEnviron Res
January 2025
Department of Materials Science and Engineering, Xi'an University of Technology, Xi'an 710048, PR China; Shaanxi Province Key Laboratory of Corrosion and Protection, Xi'an University of Technology, Xi'an 710048, PR China. Electronic address:
Hexagonal boron nitride (h-BN) exhibits unique application potential in water purification due to its large specific surface area, high porosity, and chemical inertness. Designing adsorbents with highly active adsorption sites is one effective method to improve their adsorption capacities. In this study, porous h-BN aerogels containing multiple defect types (DP-BN) were synthesized by using salt templates.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!