Details:

Alternative Title:
Nat Cell Biol
Personal Author:
Feric, Marina ; Brangwynne, Clifford P.
Feric, Marina ; Brangwynne, Clifford P. Less -
Description:
The size of a typical eukaryotic cell is of the order of ∼10 μm. However, some cell types grow to very large sizes, including oocytes (immature eggs) of organisms from humans to starfish. For example, oocytes of the frog Xenopus laevis grow to a diameter ≥1 mm. They have a correspondingly large nucleus (germinal vesicle) of ∼450 μm in diameter, which is similar to smaller somatic nuclei, but contains a significantly higher concentration of actin. The form and structure of this nuclear actin remain controversial, and its potential mechanical role within these large nuclei is unknown. Here, we use a microrheology and quantitative imaging approach to show that germinal vesicles contain an elastic F-actin scaffold that mechanically stabilizes these large nuclei against gravitational forces, which are usually considered negligible within cells. We find that on actin disruption, ribonucleoprotein droplets, including nucleoli and histone locus bodies, undergo gravitational sedimentation and fusion. We develop a model that reveals how gravity becomes an increasingly potent force as cells and their nuclei grow larger than ∼10 μm, explaining the requirement for a stabilizing nuclear F-actin scaffold in large Xenopus oocytes. All life forms are subject to gravity, and our results may have broad implications for cell growth and size control.
Subject:
[+]
Actins Animals Article Cell Nucleus Cell Size Female Gravitation Humans Microscopy, Confocal Models, Biological Nuclear Matrix Oocytes Ribonucleoproteins Xenopus
Source:
Nat Cell Biol. 15(10):1253-1259.
Pubmed ID:
23995731
Pubmed Central ID:
PMC3789854
Document Type:
Journal Article
Funding:
1DP2GM105437-01/DP/NCCDPHP CDC HHS/United States ; DP2 GM105437/GM/NIGMS NIH HHS/United States
1DP2GM105437-01/DP/NCCDPHP CDC HHS/United States ; DP2 GM105437/GM/NIGMS NIH HHS/United States Less -
Collection(s):
CDC Public Access
Main Document Checksum:
[+]
urn:sha256:fe7db7c64e94aa10666afbf5e1c9fb39809b7db838dd8ccacfbac5404206f8b7
Download URL:
https://stacks.cdc.gov/view/cdc/22528/cdc_22528_DS1.pdf
File Type:

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