A5070368274- Pluripotent Stem Cells Research
- CRISPR and Genetic Engineering
- Reproductive Biology and Fertility
- Renal and related cancers
- Hippo pathway signaling and YAP/TAZ
- Epigenetics and DNA Methylation
- Skin and Cellular Biology Research
- Genomics and Chromatin Dynamics
- Gene Regulatory Network Analysis
- Retinal Development and Disorders
- Advanced biosensing and bioanalysis techniques
- Cell Adhesion Molecules Research
- Cellular Mechanics and Interactions
- Single-cell and spatial transcriptomics
- Molecular Biology Techniques and Applications
- Tissue Engineering and Regenerative Medicine
- RNA Research and Splicing
- Cell Image Analysis Techniques
- Cancer Cells and Metastasis
- Genetic and Clinical Aspects of Sex Determination and Chromosomal Abnormalities
- Wnt/β-catenin signaling in development and cancer
- Genetics, Aging, and Longevity in Model Organisms
- Chromosomal and Genetic Variations
- Developmental Biology and Gene Regulation
- Cancer-related gene regulation
Princeton University
2020-2025
Hospital for Sick Children
2014-2023
University of Toronto
2016-2019
SickKids Foundation
2016-2019
Biologie du Développement et Cellules Souches
2017
Friedrich Miescher Institute
2007-2012
University of California, San Francisco
2010
The first cell fate bifurcation in mammalian development directs cells toward either the trophectoderm (TE) or inner mass (ICM) compartments preimplantation embryos. This decision is regulated by subcellular localization of a transcriptional co-activator YAP and takes place over several progressively asyn-chronous cleavage divisions. As result this asynchrony variable arrangement blastomeres, reconstructing dynamics TE/ICM specification from fixed embryos extremely challenging. To address...
The segregation of the trophectoderm (TE) from inner cell mass (ICM) in mouse blastocyst is determined by position-dependent Hippo signaling. However, window responsiveness to signaling, exact timing lineage commitment and overall relationship between global gene expression changes are still unclear. Single-cell RNA sequencing during revealed that TE transcriptional profile stabilizes earlier than ICM prior formation. Using quantitative Cdx2-eGFP as a readout signaling activity, we assessed...
In mammals, totipotent embryos are formed by fusion of highly differentiated gametes. Acquisition totipotency concurs with chromatin remodeling parental genomes, changes in the maternal transcriptome and proteome, zygotic genome activation (ZGA). The inefficiency reprogramming somatic nuclei reproductive cloning suggests that intergenerational inheritance germline contributes to developmental proficiency after natural conception. Here we show Ring1 Rnf2 , components Polycomb-repressive...
Using transient inhibition of DNA mismatch repair during a permissive stage development, we demonstrate highly efficient prime editing mouse embryos with few unwanted, local byproducts (average 58% precise edit frequency, 0.5% on-target error frequency across 13 substitution edits at 8 sites), enabling same-generation phenotyping founders. Whole-genome sequencing reveals that increases off-target indels low-complexity regions in the genome without any obvious phenotype mice.
Pluripotent stem cells (PSCs) exist in multiple stable states, each with specific cellular properties and molecular signatures. The mechanisms that maintain pluripotency, or cause its destabilization to initiate development, are complex incompletely understood. We have developed a model predict stabilized PSC gene regulatory network (GRN) states response input signals. Our strategy used random asynchronous Boolean simulations (R-ABS) simulate single-cell fate transitions strongly connected...
ABSTRACT For investigations into fate specification and morphogenesis in time-lapse images of preimplantation embryos, automated 3D instance segmentation tracking nuclei are invaluable. Low signal-to-noise ratio, high voxel anisotropy, nuclear density, variable shapes can limit the performance methods, while is complicated by cell divisions, low frame rates, sample movements. Supervised machine learning approaches radically improve accuracy enable easier tracking, but they often require...
Abstract Generating large‐fragment knock‐ins, such as reporters, conditional alleles, or humanized directly in mouse embryos is still a challenging feat. We have developed 2C‐HR‐CRISPR, technology that allows highly efficient (10‐50%) and rapid (generating founders 2 months) targeting of large DNA fragments. Key to this strategy the delivery CRISPR reagents into 2‐cell‐stage embryos, taking advantage high homologous recombination activity during long G cell cycle phase at stage. Furthermore,...
A lack of tools for detecting receptor activity in vivo has limited our ability to fully explore receptor-level control developmental patterning. Here, we extend a new class biosensors tyrosine kinase (RTK) activity, the pYtag system, visualize endogenous RTK Drosophila . We build three RTKs that function across stages and tissues. By characterizing Torso::pYtag during terminal patterning early embryo, find Torso differs from downstream ERK two surprising ways: is narrowly restricted poles...
During the first cell fate decision in mammalian embryos inner mass cells, which will give rise to embryo proper and other extraembryonic tissues, segregate from trophectoderm precursors of placenta. Cell segregation proceeds a gradual manner encompassing two rounds division, as well positional morphological changes. While it is known that activity Hippo signaling pathway subcellular localization its downstream effector YAP dictate lineage specific gene expression, response these dynamic...
For cells to polarize collectively along a tissue plane, asymmetrically localized planar cell polarity (PCP) complexes must form intercellular contacts between neighboring cells. Yet, it is unknown whether asymmetric segregation of PCP requires cell-cell contact, or if autonomous, antagonistic interactions are sufficient for polarization. To test this, we generated mouse chimeras consisting dual PCP-reporter mixed with unlabeled that cannot bridges. In the absence interactions, proteins...
Basement membranes (BMs) are specialized sheets of extracellular matrix that underlie epithelial and endothelial tissues. BMs regulate the traffic cells molecules between compartments, participate in signaling, cell migration, organogenesis. The dynamics mammalian BMs, however, poorly understood, largely due to a lack models which core BM components endogenously labeled. Here, we describe mTurquoise2-Col4a1 mouse fluorescently tag collagen IV, main component BMs. Using an innovative...
Abstract Totipotency is the ability of a single cell to give rise all differentiated cells that build conceptus, yet how capture this property in vitro remains incompletely understood. Defining totipotency relies upon variety assays variable stringency. Here we describe criteria define totipotency. We illustrate distinct increasing stringency can be used judge by evaluating candidate totipotent types mouse, including early blastomeres and expanded or extended pluripotent stem cells. Our data...
ABSTRACT The collective polarization of cellular structures and behaviors across a tissue plane is near universal feature epithelia known as planar cell polarity (PCP). This property controlled by the core PCP pathway, which consists highly conserved membrane-associated protein complexes that localize asymmetrically at junctions. Here, we introduce three new mouse models for investigating localization dynamics transmembrane proteins: Celsr1, Fz6 Vangl2. Using skin epidermis model,...
Specification of the epiblast (EPI) and primitive endoderm (PE) in mouse embryo involves fibroblast growth factor (FGF) signaling through RAS/MAP kinase pathway. FGFR1 FGFR2 are thought to mediate this inner cell mass (ICM) blastocyst BMP can also influence PE specification. In study, we further explored dynamics expression an enhanced green fluorescent protein (eGFP) reporter line (FGFR2-eGFP). We observed that FGFR2-eGFP is present late 8-cell stage; however, it absent or reduced ICM early...
The GGCC-specific restriction endonuclease BspRI is one of the few Type IIP endonucleases, which were suggested to be a monomer. Amino acid sequence information obtained by Edman sequencing and mass spectrometry analysis was used clone gene encoding BspRI. bspRIR located adjacently cognate modification methyltransferase encodes 304 aa protein. Expression in Escherichia coli dependent on replacement native TTG initiation codon with an ATG codon, explaining previous failures cloning using...
For investigations into fate specification and cell rearrangements in live images of preimplantation embryos, automated accurate 3D instance segmentation nuclei is invaluable; however, the performance methods limited by images' low signal-to-noise ratio high voxel anisotropy nuclei's dense packing variable shapes. Supervised machine learning approaches have potential to radically improve accuracy but are hampered a lack fully annotated data. In this work, we first establish novel mouse line...