bioRxiv Science⌕ Search

bioRxiv · 10.1101/2024.08.21.606117

Regional differences in cell characteristics in electric eel electric organs indicate electrocyte development with ventral to dorsal migration.

Abstract

Electric eels (Electrophorus) are renowned for their ability to generate electric discharge, which is used for prey capture and defense. Their electric organs (EOs) are located along the lateral-ventral region of the tail and contain electrocytes, which are multinucleated syncytium cells. The developmental origin of the electrocyte is mesodermal lineage cells observed in the ventral part of the myotome. However, it is unclear whether these precursor cells are also maintained in later stages and contribute to electric organ growth in adulthood. In this study, we report regional differences in cell morphology within the main EO (mEO) and identify a candidate cell population for electrocyte progenitors at the juvenile stages of Electrophorus. The cell morphology and distribution from the ventral terminal to the dorsal region of the mEO suggest the segregation of progenitors from the ventral cluster and their gradual transformation into mature multinucleated electrocytes via cell fusion and layering along the dorsal axis. Immunohistochemistry revealed strong expression of sodium-potassium adenosine triphosphatase (Na+/K+-ATPase), a key component in generating electric discharge in the mEO, across most mEO regions, except in the ventral cluster cells. Based on these observations, we propose that electrocyte progenitors develop from ventral cluster cells in the mEO and differentiate into mature multinucleated cells as they migrate dorsally. This is the first report to approach the developmental process of Electrophorus electrocytes from cell morphology and genetic profiles. Our findings represent a breakthrough in understanding the differentiation of electrocytes during the growth stages of Electrophorus.

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Senarat, S., Matsumoto, A., Sakaki, S., Tsuzuki, D., Uchida, K., Kuwahara, M., Hondo, E., Iida, A.. 2024-08-22. Regional differences in cell characteristics in electric eel electric organs indicate electrocyte development with ventral to dorsal migration.. https://doi.org/10.1101/2024.08.21.606117

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Cell Position-Associated Division Orders and Cell Cycle Durations Shape Asymmetric Trajectories of Cell Fates and Morphological Events in Pre- and Peri-implantation Mouse Embryos

A central question in developmental biology is how spatiotemporal embryo morphological events and cell differentiation are precisely coordinated to eventually develop into a mature organism. Previous research has shown cell positions and asymmetric division stages are related to cell lineage specification since morula stage. However, the detailed spatiotemporal dynamics and histories of embryonic cells and their relations with cell lineage specification remain incompletely understood from the onset of embryo development onward. My study on in-vitro embryos showed that continuous live cell tracking mapped community-like patterns in cell origin and differentiation. Cell positions, cell temporal factors (such as cell division order and cell cycle) and their histories intricately interacted over pre- and peri-implantation stages. These interactions of spatiotemporal cellular activities directed embryo morphological events and asymmetric cell lineage origin and differentiation throughout 2-cell to around 100-cell stage. In conclusion, this study provides comprehensive insights into the cellular spatiotemporal dynamics of cell inheritance and differentiation during pre- and peri-implantation morphological events and cell lineage specification. By longitudinally integrating spatial and temporal parameters relating to early embryogenesis, the findings not only bridge divergent explanations stemmed from different studies in the field but also offers a refined foundation for evaluating embryo potential and improving outcomes in assisted reproductive technologies, stem cell research, and regenerative medicine.

developmental biology↗

Proteome-wide quantification of protein turnover in frog and fly embryos reveals divergent strategies of maternal inheritance

Every embryo inherits a maternal proteome that it must remodel with zygotic proteins to build its many cell types. The fate of the maternal proteome remains contested because indirect measurements cannot resolve it. Here, we combine 18O-water labeling with multiplexed proteomics to quantify protein turnover proteome-wide in frog and fly embryos. Through hatching, the frog preserves the bulk of its maternal proteome, confining rapid degradation to a small regulatory module. The fly cannot meet its synthesis demand from yolk alone and instead degrades nearly all maternal proteins, including housekeeping proteins long assumed stable, recycling them into new protein. Yet the turnover hierarchy is conserved, with disordered and regulatory proteins degrading fastest, while the fly rescales the whole proteome ~eightfold faster. These results recast the developmental proteome as both informational inheritance and metabolic reserve, establish 18O-water labeling as a turnover method for non-feeding organisms, and provide a resource of embryonic half-lives.

developmental biology↗

The MAPK phosphatase VHP-1 buffers pharynx-to-body proportions against tissue-specific growth imbalance in C. elegans

Maintaining appropriate organ size ratios in the face of growth fluctuations is critical for the development of a reproducible body plan. Yet the mechanisms involved remain poorly understood. Here, we investigated how pharynx-to-body proportions are maintained in Caenorhabditis elegans, combining tissue-specific perturbations, genetic screening, and longitudinal live imaging. A genome-wide RNAi screen revealed that knock-down of the dual-specificity MAPK phosphatase VHP-1 turns animals hypersensitive to inter-tissue growth imbalance caused by pharyngeal or epidermal depletion of the mTORC1 activator RAGA-1 or the ribosomal protein RPL-22. In contrast, vhp-1 mutants tolerated global raga-1 loss, indicating a specific requirement for vhp-1 under tissue growth imbalance. Knock-down of the p38 pathway suppressed the imbalance-specific defects of vhp-1 mutants. In contrast, JNK knock-down effectively rescued the pleiotropic phenotypes of vhp-1 mutants but only weakly reduced their sensitivity to RAGA-1 imbalance, indicating that these two stress-MAPK pathways make distinct contributions to the response to growth imbalance. Finally, whole-animal VHP-1 levels increased upon epidermal RAGA-1 depletion, and epidermal VHP-1 depletion did not reproduce the sensitivity caused by global vhp-1 loss, consistent with a contribution from VHP-1 outside the growth-perturbed epidermis in buffering against local growth imbalance.

developmental biology↗