# Physical, cellular, and molecular control of tissue fission and fusion

> **NIH NIH K99** · NEW YORK UNIVERSITY SCHOOL OF MEDICINE · 2024 · $106,068

## Abstract

Project Summary
Tissue fission and fusion give forms to functional organs during embryonic development. Abnormalities in these
processes can lead to congenital birth defects and syndromes such as cleft palate, Meckel-Gruber syndrome,
and persistent truncus arteriosus. During remodeling, cells must generate force, reconfigure cell contacts, and
interact with their surroundings. The mechanisms underlying the cellular and molecular regulation mechanisms
underlying tissue fission and fusion are poorly understood. The formation of mechano-sensory organs called
neuromasts in zebrafish provides an ideal model in which to decipher these processes. During neuromast
morphogenesis, the pro-neuromast splits from the migrating posterior lateral line primordium and later fuses with
skin to open tricellular junctions in skin cells; hence, I can study both tissue fission and fusion in this
morphogenetic event. In this model, my preliminary findings suggest a mechanical ‘tug of war’ between cells and
tissues in primordium splitting and neuromast fusion with the skin. In the proposed research, I will apply state-
of-the-art in vivo biophysical measurements to determine whether RhoA-mediated actomyosin drives neuromast
deposition (Aim 1). I will then use a novel protein depletion approach that offers spatial and temporal control to
test whether cell-cell and cell-extracellular matrix (ECM) adhesions mediate neuromast budding (Aim 2) and
investigate the mechanism by which neuromasts fuse with skin (Aim 3). The physical, molecular and cellular
principles revealed in this study will be widely applicable to morphogenetic events involving tissue fission and
fusion while maintaining the integrity of single cells. Moreover, findings from this study will improve our
understanding of congenital birth defects due to abnormal tissue fission and fusion and further inform strategies
to correct these defects. To accomplish the proposed research, I will combine my skills in cell mechanics
analyses developed as a graduate student; new skills acquired in my early postdoctoral training in zebrafish
genetics, molecular biology and high-resolution live imaging; and the proposed technical training during the K99
phase to implement in vivo biophysical measurements, including measuring in vivo cell-ECM stress and cell-cell
adhesion tension. As I start my own lab, I will be mentored by Drs. Holger Knaut, Daniele Panozzo, Anna-
Katerina Hadjantonakis, Jeremy Nance, Carsten Grashoff, and Johannes Stegmaier. They will offer not only
their scientific expertise in zebrafish genetics, biophysics, quantitative imaging, and modeling but also with their
valuable experience in mentoring students, grantsmanship, publication, establishing scientific collaborations,
and lab management. My long-term career goal is to head a research laboratory and uncover the genetic,
biophysical, cellular, and molecular regulation of cell and tissue mechanics in embryonic morphogenesis. I have
made significant progres...

## Key facts

- **NIH application ID:** 10931505
- **Project number:** 5K99HD112594-02
- **Recipient organization:** NEW YORK UNIVERSITY SCHOOL OF MEDICINE
- **Principal Investigator:** Weiyi Qian
- **Activity code:** K99 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $106,068
- **Award type:** 5
- **Project period:** 2023-09-19 → 2026-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10931505

## Citation

> US National Institutes of Health, RePORTER application 10931505, Physical, cellular, and molecular control of tissue fission and fusion (5K99HD112594-02). Retrieved via AI Analytics 2026-06-08 from https://api.ai-analytics.org/grant/nih/10931505. Licensed CC0.

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