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Updated: Dec 18, 2025
Live Imaging of Mitosis in the Developing Mouse Embryonic Cortex
Published on: June 4, 2014
Acute Lengthening of Progenitor Mitosis Influences Progeny Fate during Cortical Development in vivo
Aaron Mitchell-Dick1, Andrea Chalem1, Louis-Jan Pilaz1,2,3
1Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA.
Background/Aims:
Prenatal microcephaly is posited to arise from aberrant mitosis of neural progenitors, which disrupts both neuronal production and survival. Although microcephaly has both a genetic and environmental etiology, the mechanisms by which dysregulation of mitosis causes microcephaly are poorly understood. We previously discovered that prolonged mitosis of mouse neural progenitors, either ex vivo or in vitro, directly alters progeny cell fate, -resulting in precocious differentiation and apoptosis. This raises questions as to whether prolonged progenitor mitosis affects cell fate and neurogenesis in vivo, and what are the underlying mechanisms?
Methods/Results:
Towards addressing these knowledge gaps, we developed an in vivo model of mitotic delay. This uses pharmacological inhibition to acutely and reversibly prolong mitosis during cortical development, and fluorescent dyes to label direct progeny. Using this model, we discovered that a causal relationship between mitotic delay of neural progenitors and altered progeny cell fate is evident in vivo. Using transcriptome analyses to investigate the state of delayed cells and their progeny, we uncovered potential molecular mechanisms by which prolonged mitosis induces altered cell fates, including DNA damage and p53 signaling. We then extended our studies to human neural progenitors, demonstrating that lengthened mitosis duration also directly alters neuronal cell fate.
Conclusions:
This study establishes a valuable new experimental paradigm towards understanding mechanisms whereby lengthened mitosis duration may explain some cases of microcephaly.
Insights
Prolonged mitosis in neural progenitors causes microcephaly by altering cell fate. This study reveals in vivo mechanisms, including DNA damage and p53 signaling, linking mitotic delay to microcephaly development.
Area of Science:
- Neuroscience
- Developmental Biology
- Cell Biology
Background:
- Microcephaly, a condition of reduced brain size, is linked to abnormal neural progenitor mitosis.
- Mechanisms connecting mitotic dysregulation to microcephaly remain unclear.
- Previous studies showed prolonged mitosis in vitro alters neural progenitor progeny fate.
Purpose of the Study:
- To investigate if prolonged neural progenitor mitosis affects cell fate and neurogenesis in vivo.
- To elucidate the molecular mechanisms underlying this effect.
- To determine if findings translate to human neural progenitors.
Main Methods:
- Developed an in vivo model using pharmacological inhibition to induce reversible mitotic delay in neural progenitors.
- Employed fluorescent dyes to track direct progeny of delayed progenitors.
- Utilized transcriptome analysis to identify molecular pathways involved.
Main Results:
- Established a causal link between in vivo mitotic delay of neural progenitors and altered progeny cell fate.
- Identified DNA damage and p53 signaling as potential mechanisms mediating altered cell fates.
- Demonstrated that lengthened mitosis also impacts human neural progenitor cell fate.
Conclusions:
- This study provides a novel in vivo model to investigate microcephaly mechanisms.
- Lengthened mitosis duration is a potential contributor to microcephaly.
- Findings offer insights into the molecular basis of microcephaly related to mitotic errors.
