Biology subjects

Materna, S. C.

Publications and source records attributed to Materna, S. C..

3 recordsLinked to original sources

bioRxiv2026

Met regulates endoderm migration in zebrafish

Cells can employ different modes of migration, switching between them depending on context. However, how migration modes are determined remains incompletely understood. The mode of migration depends not only on external signals and guidance cues but also on which cell surface receptors a cell expresses. Receptor tyrosine kinases (RTKs) are central mediators of many processes including cell migration, yet whether RTK signaling mediates shifts in migratory behavior in vivo remains unclear. Here, we show that the RTK Met promotes persistent, directional migration of endodermal cells during gastrulation in zebrafish. met is broadly expressed across migrating endoderm, and pharmacological inhibition or genetic loss of its function delays endoderm convergence. Quantitative live imaging and cell tracking reveal that loss of Met reduces displacement and persistence without substantially affecting velocity, indicating that Met promotes directional migration rather than motility per se. Although Met is canonically activated by hepatocyte growth factor (Hgf), expression of hgfa and hgfb during gastrulation is spatially restricted and temporally limited. Consistent with this, genetic loss of Hgf function indicates that it is dispensable for endoderm convergence and migration. Together, these findings identify Met as a regulator of migratory persistence during endoderm convergence and suggest a ligand-independent mode of RTK function in the regulation of cell behavior during development. HighlightsO_LIMet promotes directional migration of endoderm cells during convergence. C_LIO_LILoss of Met delays convergence by reducing cell displacement and persistence without affecting velocity. C_LIO_LIHgf signaling is dispensable for endoderm convergence despite being the canonical Met ligand. C_LI

developmental biology↗

bioRxiv2024

Tissue-specific and endogenous protein labeling with split fluorescent proteins

The ability to label proteins by fusion with genetically encoded fluorescent proteins is a powerful tool for understanding dynamic biological processes. However, current approaches for expressing fluorescent protein fusions possess drawbacks, especially at the whole organism level. Expression by transgenesis risks potential overexpression artifacts while fluorescent protein insertion at endogenous loci is technically difficult and, more importantly, does not allow for tissue-specific study of broadly expressed proteins. To overcome these limitations, we have adopted the split fluorescent protein system mNeonGreen21-10/11 (split-mNG2) to achieve tissue-specific and endogenous protein labeling in zebrafish. In our approach, mNG21-10 is expressed under a tissue-specific promoter using standard transgenesis while mNG211 is inserted into protein-coding genes of interest using CRISPR/Cas-directed gene editing. Each mNG2 fragment on its own is not fluorescent, but when co-expressed the fragments self-assemble into a fluorescent complex. Here, we report successful use of split-mNG2 to achieve differential labeling of the cytoskeleton genes tubb4b and krt8 in various tissues. We also demonstrate that by anchoring the mNG21-10 component to specific cellular compartments, the split-mNG2 system can be used to manipulate protein function. Our approach should be broadly useful for a wide range of applications.

developmental biology↗

bioRxiv2020

TAEL 2.0: An Improved Optogenetic Expression System for Zebrafish

Inducible gene expression systems are valuable tools for studying biological processes. We previously developed an optogenetic gene expression system called TAEL that is optimized for use in zebrafish. When illuminated with blue light, TAEL transcription factors dimerize and activate gene expression downstream of the TAEL-responsive C120 promoter. By using light as the inducing agent, the TAEL/C120 system overcomes limitations of traditional inducible expression systems by enabling fine spatial and temporal regulation of gene expression. Here, we describe ongoing efforts to improve the TAEL/C120 system. We made modifications to both the TAEL transcriptional activator and the C120 regulatory element, collectively referred to as TAEL 2.0. We demonstrate that TAEL 2.0 consistently induces higher levels of reporter gene expression and at a faster rate, but with comparable background and toxicity as the original TAEL system. With these improvements, we were able to create functional stable transgenic lines to express the TAEL 2.0 transcription factor either ubiquitously or with a tissue-specific promoter. We demonstrate that the ubiquitous line in particular can be used to induce expression at late embryonic and larval stages, addressing a major deficiency of the original TAEL system. This improved optogenetic expression system will be a broadly useful resource for the zebrafish community.

developmental biology↗