Biology subjects

Lubeck, L.

Publications and source records attributed to Lubeck, L..

3 recordsLinked to original sources

bioRxiv2025

Major cell type differences between larval and adult hemichordate body plans

A major gap in our understanding of animal development is how adult body plans arise in animals with indirect development, where adults emerge from the transformation of a distinct larval form during metamorphosis. We address this question by examining cellular changes in the enteropneust hemichordate Schizocardium californicum, a species with a complex lifecycle and dramatic metamorphosis. Employing whole-body single-cell RNA sequencing, we chart the cellular composition and transcriptional dynamics of larval, metamorphosis, and adult stages. Our tissue level atlas reveals that ectodermal and endodermal cell types in larvae and adults occupy distinct transcriptional spaces, showing greater similarity to other cell types within the same life stage than to their counterparts in the opposite stage. In contrast, mesodermal cell types from both larvae and adults cluster closely together, indicating conserved transcriptional profiles. These findings demonstrate that the extensive morphological reorganization during metamorphosis is paralleled by profound shifts in cell-type specific transcriptional programs, highlighting the complexity of the larva-to-adult transition.

developmental biology↗

bioRxiv2025

Regional Signaling Controls Stem Cell-Mediated Regeneration in an Invertebrate Chordate

Many tissues harbor quiescent stem cells that activate after injury, yet how local signals regulate this transition is not well understood. The solitary ascidian Ciona robusta provides a unique model, as bottom body fragments regenerate while upper fragments fail to do so. By comparing these regenerative and non-regenerative contexts, we reveal striking differences in transcriptional dynamics and signaling environments. Combining flow cytometry, scRNA-seq, transplantation, and fate mapping, we identified a candidate stem cell population with robust proliferative and differentiation potential following transplantation. However, regenerative capacity does not simply reflect stem cell abundance, but instead depends on region-specific signaling cues. Local expression of metabolic, immune and differentiation-related factors further underscores the importance of spatially distinct environments in shaping outcomes. Our findings show how a shared injury response can diverge into regeneration versus failure, highlighting principles that may be leveraged to enhance tissue repair in other systems.

developmental biology↗

bioRxiv2023

Glia detect and mount a protective response to loss of dendrite substructure integrity in C. elegans

Neurons have elaborate structures that determine their connectivity and functions. Changes in neuronal structure accompany learning and memory formation and are hallmarks of neurological disease. Here we show that glia monitor dendrite structure and respond to dendrite perturbation. In C. elegans mutants with defective sensory-organ dendrite cilia, adjacent glia accumulate extracellular matrix-laden vesicles, secrete excess matrix around cilia, alter gene expression, and change their secreted protein repertoire. Inducible cilia disruption reveals that this response is acute. DGS-1, a 7-transmembrane domain neuronal protein, and FIG-1, a multifunctional thrombospondin-domain glial protein, are required for glial detection of cilia integrity, and exhibit mutually-dependent localization to and around cilia, respectively. While inhibiting glial secretion disrupts dendritic cilia properties, hyperactivating the glial response protects against dendrite damage. Our studies uncover a homeostatic protective dendrite-glia interaction and suggest that similar signaling occurs at other sensory structures and at synapses, which resemble sensory organs in architecture and molecules.

neuroscience↗