About

Daniel P. Kiehart is a Professor of Biology at Duke University, with a focus on identifying determinants of cell shape during development. Utilizing molecular genetic and reverse genetic approaches in Drosophila, his research has shown that conventional nonmuscle myosin is essential for driving cell division and post-mitotic cell shape changes involved in morphogenesis. His current investigations explore how myosin elicits cell shape change and how its function is regulated through filament formation, phosphorylation, sub-cellular targeting, small GTP-binding proteins, kinase, and phosphatase activities. His work includes using novel, near-saturating screens to identify mutations affecting dorsal closure, a model cell sheet movement requiring multiple filamentous actin and actomyosin arrays for proper morphogenesis. These screens have revealed that nearly all aspects of dorsal closure are mutable, with projections indicating over 300 genes are involved in this complex process. He has identified gene products necessary for myosin function through genetic and biochemical methods, establishing that the Rho signaling pathway is required alongside nonmuscle myosin II for morphogenesis. Additionally, his research employs laser microsurgery and micro-manipulation studies to understand the forces driving morphogenesis, demonstrating contributions from the amnioserosa and the leading edge of the lateral epidermis during dorsal closure, as well as examining protein roles in wound healing.

Research topics

• Computer Science
• Artificial Intelligence
• Anatomy
• Computer vision
• Biology
• Mathematics
• Algorithm
• Biological system
• Geometry

Selected publications

• BPS2026 - Purification of native Drosophila Act5C actin from Komagataella phaffii

  Biophysical Journal · 2026-02-01

  article1st authorCorresponding
  PublisherDOI

• A minimal vertex model explains how the amnioserosa avoids fluidization during <i>Drosophila</i> dorsal closure

  Proceedings of the National Academy of Sciences · 2024-12-30 · 12 citations

  articleOpen accessCorresponding

  . During dorsal closure, the amnioserosa (AS), a one-cell thick epithelial tissue that fills the dorsal opening, shrinks as the lateral epidermis sheets converge and eventually merge. During this process, both shape index and aspect ratio of amnioserosa cells increase markedly. The standard 2-dimensional vertex model, which successfully describes tissue sheet mechanics in multiple contexts, would in this case predict that the tissue should fluidize via cell neighbor changes. Surprisingly, however, the amnioserosa remains an elastic solid with no such events. We here present a minimal extension to the vertex model that explains how the amnioserosa can achieve this unexpected behavior. We show that continuous shrinkage of the preferred cell perimeter and cell perimeter polydispersity lead to the retention of the solid state of the amnioserosa. Our model accurately captures measured cell shape and orientation changes and predicts nonmonotonic junction tension that we confirm with laser ablation experiments.

  PublisherOA PDFDOI

• Notochord segmentation in zebrafish controlled by iterative mechanical signaling

  Developmental Cell · 2024-05-01 · 7 citations

  articleOpen access
  PublisherOA PDFDOI

• Minimal vertex model explains how the amnioserosa avoids fluidization during Drosophila dorsal closure

  arXiv (Cornell University) · 2023-12-20 · 7 citations

  preprintOpen access

  Dorsal closure is a process that occurs during embryogenesis of Drosophila melanogaster. During dorsal closure, the amnioserosa (AS), a one-cell thick epithelial tissue that fills the dorsal opening, shrinks as the lateral epidermis sheets converge and eventually merge. During this process, the aspect ratio of amnioserosa cells increases markedly. The standard 2-dimensional vertex model, which successfully describes tissue sheet mechanics in multiple contexts, would in this case predict that the tissue should fluidize via cell neighbor changes. Surprisingly, however, the amnioserosa remains an elastic solid with no such events. We here present a minimal extension to the vertex model that explains how the amnioserosa can achieve this unexpected behavior. We show that continuous shrinkage of the preferred cell perimeter and cell perimeter polydispersity lead to the retention of the solid state of the amnioserosa. Our model accurately captures measured cell shape and orientation changes and predicts non-monotonic junction tension that we confirm with laser ablation experiments.

  PublisherOA PDFDOI

• Minimal vertex model explains how the amnioserosa avoids fluidization during <i>Drosophila</i> dorsal closure

  bioRxiv (Cold Spring Harbor Laboratory) · 2023-12-21 · 3 citations

  preprintOpen accessCorresponding

  Dorsal closure is a process that occurs during embryogenesis of Drosophila melanogaster . During dorsal closure, the amnioserosa (AS), a one-cell thick epithelial tissue that fills the dorsal opening, shrinks as the lateral epidermis sheets converge and eventually merge. During this process, both shape index and aspect ratio of amnioserosa cells increase markedly. The standard 2-dimensional vertex model, which successfully describes tissue sheet mechanics in multiple contexts, would in this case predict that the tissue should fluidize via cell neighbor changes. Surprisingly, however, the amnioserosa remains an elastic solid with no such events. We here present a minimal extension to the vertex model that explains how the amnioserosa can achieve this unexpected behavior. We show that continuous shrinkage of the preferred cell perimeter and cell perimeter polydispersity lead to the retention of the solid state of the amnioserosa. Our model accurately captures measured cell shape and orientation changes and predicts non-monotonic junction tension that we confirm with laser ablation experiments. Significance Statement During embryogenesis, cells in tissues can undergo significant shape changes. Many epithelial tissues fluidize, i.e. cells exchange neighbors, when the average cell shape index increases above a threshold value, consistent with the standard vertex model. During dorsal closure in Drosophila melanogaster , however, the amnioserosa tissue remains solid even as the average cell shape index increases well above threshold. We introduce perimeter polydispersity and allow the preferred cell perimeters, usually held fixed in vertex models, to decrease linearly with time as seen experimentally. With these extensions to the standard vertex model, we capture experimental observations quantitatively. Our results demonstrate that vertex models can describe the behavior of the amnioserosa in dorsal closure by allowing normally fixed parameters to vary with time.

  PublisherOA PDFDOI

• Axial segmentation by iterative mechanical signaling

  bioRxiv (Cold Spring Harbor Laboratory) · 2023-03-28 · 2 citations

  preprintOpen access

  In bony fishes, formation of the vertebral column, or spine, is guided by a metameric blueprint established in the epithelial sheath of the notochord. Generation of the notochord template begins days after somitogenesis and even occurs in the absence of somite segmentation. However, patterning defects in the somites lead to imprecise notochord segmentation, suggesting these processes are linked. Here, we reveal that spatial coordination between the notochord and the axial musculature is necessary to ensure segmentation of the zebrafish spine both in time and space. We find that the connective tissues that anchor the axial skeletal musculature, known as the myosepta in zebrafish, transmit spatial patterning cues necessary to initiate notochord segment formation, a critical pre-patterning step in spine morphogenesis. When an irregular pattern of muscle segments and myosepta interact with the notochord sheath, segments form non-sequentially, initiate at atypical locations, and eventually display altered morphology later in development. We determine that locations of myoseptum-notochord connections are hubs for mechanical signal transmission, which are characterized by localized sites of deformation of the extracellular matrix (ECM) layer encasing the notochord. The notochord sheath responds to the external mechanical changes by locally augmenting focal adhesion machinery to define the initiation site for segmentation. Using a coarse-grained mathematical model that captures the spatial patterns of myoseptum-notochord interactions, we find that a fixed-length scale of external cues is critical for driving sequential segment patterning in the notochord. Together, this work identifies a robust segmentation mechanism that hinges upon mechanical coupling of adjacent tissues to control patterning dynamics.

  PublisherOA PDFDOI

• Wound repair in sea urchin larvae involves pigment cells and blastocoelar cells

  Developmental Biology · 2022-09-05 · 14 citations

  articleOpen access
  PublisherOA PDFDOI

• DeepProjection: specific and robust projection of curved 2D tissue sheets from 3D microscopy using deep learning

  Development · 2022 · 23 citations

  • Artificial Intelligence
  • Computer Science
  • Biology

  The efficient extraction of image data from curved tissue sheets embedded in volumetric imaging data remains a serious and unsolved problem in quantitative studies of embryogenesis. Here, we present DeepProjection (DP), a trainable projection algorithm based on deep learning. This algorithm is trained on user-generated training data to locally classify 3D stack content, and to rapidly and robustly predict binary masks containing the target content, e.g. tissue boundaries, while masking highly fluorescent out-of-plane artifacts. A projection of the masked 3D stack then yields background-free 2D images with undistorted fluorescence intensity values. The binary masks can further be applied to other fluorescent channels or to extract local tissue curvature. DP is designed as a first processing step than can be followed, for example, by segmentation to track cell fate. We apply DP to follow the dynamic movements of 2D-tissue sheets during dorsal closure in Drosophila embryos and of the periderm layer in the elongating Danio embryo. DeepProjection is available as a fully documented Python package.

  PublisherOA PDFDOI

• A minimal model predicts cell shapes and tissue mechanics in the amnioserosa during dorsal closure

  Biophysical Journal · 2022-02-01 · 1 citations

  article
  PublisherDOI

• Superresolution microscopy reveals actomyosin dynamics in medioapical arrays

  Molecular Biology of the Cell · 2022-05-11 · 4 citations

  articleOpen accessSenior author

  . In expanded cells, F-actin and myosin form loose, apically domed meshworks at the plasma membrane. The arrays condense as cells contract, drawing the domes into the plane of the junctional belts. As condensation continues, individual filaments are no longer uniformly apparent. As cells expand, arrays of actomyosin are again resolved-some F-actin turnover likely occurs, but a large fraction of existing filaments rearrange. In morphologically isotropic cells, actin filaments are randomly oriented and during contraction are drawn together but remain essentially randomly oriented. In anisotropic cells, largely parallel actin filaments are drawn closer to one another. Our images offer unparalleled resolution of F-actin in embryonic tissue, show that medioapical arrays are tightly apposed to the plasma membrane and are continuous with meshworks of lamellar F-actin. Medioapical arrays thereby constitute modified cell cortex. In concert with other tagged array components, superresolution imaging of live specimens will offer new understanding of cortical architecture and function.

  PublisherOA PDFDOI

Recent grants

• NIH Grant R01GM061240

  NIH · $746k · 2004

• NIH Grant R01GM033830

  NIH · $10.9M · 2018

• NIH Grant R01DC007673

  NIH · $1.7M · 2011

• Morphogenesis: Biophysics and Genetics of Dorsal Closure

  NIH · $4.0M · 2018–2028

Frequent coauthors

• Kevin A. Edwards

  Illinois State University

  41 shared

• Janice M. Crawford

  Duke University

  37 shared

• Ruth A. Montague

  Duke University

  27 shared

• Andrew Ketchum

  24 shared

• Glenn S. Edwards

  21 shared

• Josef D. Franke

  Creighton University

  17 shared

• Daniel Haertter

  University of Göttingen

  17 shared

• Stefano Di Talia

  Duke Medical Center

  16 shared

Awards & honors

• Behold: the Cell’s Skeleton in Motion (2022)
• Dan Kiehart Reappointed as Trinity Dean of Natural Sciences…
• 3-D Movies of Life at Nanoscale Named Best Science Paper of…