ORCID Profile
0000-0002-4085-3206
Current Organisation
Institute of Molecular Pathology
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Publisher: Wiley
Date: 31-12-2020
DOI: 10.1002/DVDY.282
Abstract: The axolotl is a highly regenerative organism and has been studied in laboratories for over 150 years. Despite a long‐standing fascination with regeneration in general and axolotl specifically, we are still scratching the surface trying to visualize and understand the complex cellular behavior that underlies axolotl regeneration. In this review, we will discuss the progress that has been made in visualizing these processes focusing on four major aspects: cell labeling approaches, the removal of pigmentation, reductionist approaches to perform live cell imaging, and finally recent developments applying tissue clearing strategies to visualize the processes that underly regeneration. We also provide several suggestions that the community could consider exploring, notably the generation of novel alleles that further reduce pigmentation as well as improvements in tissue clearing strategies.
Publisher: Wiley
Date: 10-05-2022
DOI: 10.1002/DVDY.481
Abstract: The third annual meeting on “Salamander Models in Cross‐disciplinary Biological Research” took place online on August 2021, bringing together over 200 international researchers using salamanders as research models and encompassing erse fields, ranging from Development and Regeneration through to Immunology, Pathogenesis, and Evolution. The event was organized by Maximina H. Yun (Center for Regenerative Therapies Dresden, Germany) and Tatiana Sandoval‐Guzmán (TU Dresden, Germany) with the generous support of the Deutsche Forschungsgemeinschaft, the Center for Regenerative Therapies Dresden, Technische Universität Dresden, and the Company of Biologists. Showcasing a number of emerging salamander models, innovative techniques and resources, and providing a platform for sharing both published and ongoing research, this meeting proved to be an excellent forum for exchanging ideas and moving research forwards. Here, we discuss the highlights stemming from this exciting scientific event.
Publisher: Oxford University Press (OUP)
Date: 25-04-2020
Abstract: High refractive index organic solvents are commonly used as an imaging medium in tissue clearing approaches. While effective, such solvents provide serious concerns for the safety of users and the equipment, especially in a central microscopy unit. To overcome these concerns, we have developed a large and reusable imaging chamber compatible with the universal mounting frame AK (PeCon GmbH). This chamber is easy to assemble and significantly improves the working environment in a central microscopy unit, where hazardous chemicals could negatively affect equipment and people. To encourage the uptake of these chambers, the design is made publicly available for download.
Publisher: Springer Science and Business Media LLC
Date: 18-03-2021
Publisher: Mary Ann Liebert Inc
Date: 02-2014
Abstract: Due to their size and optical clarity, zebrafish embryos have long been appreciated for their usefulness in time-lapse confocal microscopy. Current methods of mounting zebrafish embryos and larvae for imaging consist mainly of mounting in low percentage, low melting temperature agarose in a Petri dish. Whereas imaging methods have advanced greatly over the last two decades, the methods for mounting embryos have not changed significantly. In this article, we describe the development and use of 3D printed plastic molds. These molds can be used to create silicone casts and allow embryos and larvae to be mounted with a consistent and reproducible angle, and position in X, Y, and Z. These molds are made on a 3D printer and can be easily and cheaply reproduced by anyone with access to a 3D printer, making this method accessible to the entire zebrafish community. Molds can be reused to create additional casts, which can be reused after imaging. These casts are compatible with any upright microscope and can be adapted for use on an inverted microscope, taking the working distance of the objective used into account. This technique should prove to be useful to any researcher imaging zebrafish embryos.
Publisher: Cold Spring Harbor Laboratory
Date: 13-06-2018
DOI: 10.1101/346247
Abstract: Turbidity and opaqueness are inherent properties of tissues which limit the capacity to acquire microscopic images through large tissues. Creating a uniform refractive index, known as tissue clearing, overcomes most of these issues. These methods have enabled researchers to image large and complex 3D structures with unprecedented depth and resolution. However, tissue clearing has been adopted to a limited extent due to a combination of cost, time, complexity of existing methods and potential negative impact on fluorescence signal. Here we describe 2Eci (2 nd generation Ethyl cinnamate based clearing method) which can be used to clear a wide range of tissues, including cerebral organoids, Drosophila melanogaster, zebrafish, axolotl, and Xenopus laevis in as little as 1-5 days while preserving a broad range of fluorescence proteins including GFP, mCherry, Brainbow, and alexa-fluorophores. Ethyl cinnamate is non-toxic and can easily be used in multi-user microscope facilities. This method will open up clearing to a much broader group of researchers, due to its broad applicability, ease of use, and non-toxic nature of Ethyl cinnamate. The non-toxic, broadly applicable, and simplified protocol of 2Eci tissue clearing makes it possible for non-specialist labs to use clearing approaches on conventional inverted microscopes.
Publisher: Springer Science and Business Media LLC
Date: 09-12-2015
DOI: 10.1186/S12861-015-0098-1
Abstract: Salamanders regenerate their tails after utation anywhere along their length. How the system faithfully reconstitutes the original number of segments and length is not yet known. To gain quantitative insight into how the system regenerates the appropriate length, we utated tails at 4 or 16 myotomes post-cloaca and measured blastema size, cell cycle kinetics via cumulative Bromodeoxyuridine (BrdU) incorporation and the method of Nowakowski, and myotome differentiation rate. In early stages until day 15, blastema cells were all proliferative and ided at the same rate at both utation levels. A larger blastema was formed in 4th versus 16th myotome utations indicating a larger founding population. Myotome differentiation started at the same timepoint in the 4th and 16 th level blastemas. The rate of myotome formation was more rapid in 4th myotome blastemas so that by day 21 the residual blastema from the two utation levels achieved equivalent size. At that time point, only a fraction of blastema cells remain in cycle, with the 4th myotome blastema harboring double the number of cycling cells as the 16th myotome blastema allowing it to grow faster and further reconstitute the larger number of missing myotomes. These data suggest that there are two separable phases of blastema growth. The first is level-independent, with cells displaying unrestrained proliferation. In the second phase, the level-specific growth is revealed, where differing fractions of cells remain in the cell cycle over time.
Publisher: Public Library of Science (PLoS)
Date: 24-04-2012
Publisher: American Association for the Advancement of Science (AAAS)
Date: 26-10-2018
Abstract: Unlike most vertebrate limbs, the axolotl limb regenerates the skeleton after utation. Dermal and interstitial fibroblasts have been thought to provide sources for skeletal regeneration, but it has been unclear whether preexisting stem cells or dedifferentiation of fibroblasts formed the blastema. Gerber et al. developed transgenic reporter animals to compare periskeletal cell and fibroblast contributions to regeneration. Callus-forming periskeletal cells extended existing bone, but fibroblasts built new limb segments. Single-cell transcriptomics and Brainbow-based lineage tracing revealed the lack of a preexisting stem cell. Instead, the heterogeneous population of fibroblasts lost their adult features to form a multipotent skeletal progenitor expressing the embryonic limb program. Science , this issue p. eaaq0681
Publisher: The Company of Biologists
Date: 2019
DOI: 10.1242/DEV.166884
Abstract: Turbidity and opaqueness are inherent properties of tissues which limit the capacity to acquire microscopic images through large tissues. Creating a uniform refractive index, known as tissue clearing, overcomes most of these issues. These methods have enabled researchers to image large and complex 3D structures with unprecedented depth and resolution. However, tissue clearing has been adopted to a limited extent due to a combination of cost, time, complexity of existing methods and potential negative impact on fluorescence signal. Here we describe 2Eci (2nd generation Ethyl cinnamate based clearing) which can be used to clear a wide range of tissues, including cerebral organoids, Drosophila melanogaster, zebrafish, axolotl, and Xenopus laevis in as little as 1-5 days while preserving a broad range of fluorescent proteins including GFP, mCherry, Brainbow, as well as alexa-fluorophores. Ethyl cinnamate is non-toxic and can easily be used in multi-user microscope facilities. This method opens up tissue clearing to a much broader group of researchers, due to its ease of use, non-toxic nature of Ethyl cinnamate and broad applicability.
Publisher: Cold Spring Harbor Laboratory
Date: 15-11-2022
DOI: 10.1101/2022.11.14.516253
Abstract: The salamander limb regenerates only the missing portion. Each limb segment can only form segments equivalent to- or more distal to their own identity, relying on a property termed “positional information”. How positional information is encoded in limb cells has been unknown. By cell-type-specific chromatin profiling of upper arm, lower arm, and hand, we found segment-specific levels of histone H3K27me3 at limb homeoprotein gene loci but not their upstream regulators, constituting an intrinsic segment information code. During regeneration, regeneration-specific regulatory elements became active prior to the re-appearance of developmental regulatory elements. This means that, in the hand segment, the permissive chromatin state of the hand homeoprotein gene HoxA13 engages with regeneration regulatory elements, bypassing the upper limb program.
Publisher: Elsevier BV
Date: 10-2017
DOI: 10.1016/J.YDBIO.2017.08.025
Abstract: The migration of limb myogenic precursors from limb level somites to their ultimate site of differentiation in the limb is a paradigmatic ex le of a set of dynamic and orchestrated migratory cell behaviours. The homeobox containing transcription factor ladybird homeobox 1 (Lbx1) is a central regulator of limb myoblast migration, null mutations of Lbx1 result in severe disruptions to limb muscle formation, particularly in the distal region of the limb in mice (Gross et al., 2000). As such Lbx1 has been hypothesized to control lateral migration of myoblasts into the distal limb anlage. It acts as a core regulator of the limb myoblast migration machinery, controlled by Pax3. A secondary role for Lbx1 in the differentiation and commitment of limb musculature has also been proposed (Brohmann et al., 2000 Uchiyama et al., 2000). Here we show that lateral migration, but not differentiation or commitment of limb myoblasts, is controlled by the phosphorylation of three adjacent serine residues of LBX1. Electroporation of limb level somites in the chick embryo with a dephosphomimetic form of Lbx1 results in a specific defect in the lateral migration of limb myoblasts. Although the initial delamination and migration of myoblasts is unaffected, migration into the distal limb bud is severely disrupted. Interestingly, myoblasts undergo normal differentiation independent of their migratory status, suggesting that the differentiation potential of hypaxial muscle is not regulated by the phosphorylation state of LBX1. Furthermore, we show that FGF8 and ERK mediated signal transduction, both critical regulators of the developing limb bud, have the capacity to induce the phosphorylation of LBX1 at these residues. Overall, this suggests a mechanism whereby the phosphorylation of LBX1, potentially through FGF8 and ERK signalling, controls the lateral migration of myoblasts into the distal limb bud.
Location: Netherlands
Start Date: 2022
End Date: 2025
Funder: Austrian Science Fund
View Funded ActivityStart Date: 2018
End Date: 2020
Funder: FWF Austrian Science Fund
View Funded ActivityStart Date: 2011
End Date: 2012
Funder: Australian Education International, Australian Government
View Funded Activity