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Live Cell Imaging of Chromosome Segregation During Mitosis
Published on: March 14, 2018
Chromosome-specific nonrandom sister chromatid segregation during stem-cell division
Swathi Yadlapalli1, Yukiko M Yamashita
1Life Sciences Institute, Center for Stem Cell Biology, University of Michigan, Ann Arbor, Michigan 48109, USA. swathi@umich.edu
Nature
|May 7, 2013
Summary
Adult stem cells divide asymmetrically. Researchers found that in fruit flies, X and Y chromosomes, but not others, segregate nonrandomly during this division, a process requiring specific proteins and potentially primed by parents.
Area of Science:
- Developmental Biology
- Genetics
- Cell Biology
Background:
- Adult stem cells exhibit asymmetric cell division for self-renewal and tissue regeneration.
- The potential for nonrandom sister chromatid segregation in asymmetric divisions was hypothesized but lacked direct evidence and mechanistic understanding.
Purpose of the Study:
- To investigate the mechanism and purpose of nonrandom sister chromatid segregation in asymmetrically dividing stem cells.
- To identify factors involved in nonrandom sister chromatid segregation.
- To explore the implications of nonrandom segregation in stem cell function and differentiation.
Main Methods:
- Development of a high-resolution CO-FISH (chromosome orientation fluorescence in situ hybridization) technique.
- Analysis of sister chromatid segregation in male germline stem cells of Drosophila during asymmetric divisions.
- Genetic manipulation to assess the roles of centrosomes, SUN-KASH proteins, and Dnmt2 in segregation.
Main Results:
- Demonstrated nonrandom segregation of X and Y chromosome sister chromatids, but not autosomes, in Drosophila male germline stem cells.
- Identified centrosomes, SUN-KASH nuclear envelope proteins, and Dnmt2 as crucial for nonrandom sister chromatid segregation.
- Observed randomized segregation in conditions of germline stem cell overproliferation and dedifferentiation.
Conclusions:
- Provides the first direct evidence for nonrandom sister chromatid segregation in asymmetric stem cell divisions.
- Suggests that information enabling nonrandom segregation is established during parental gametogenesis.
- Proposes that nonrandom segregation may ensure the transmission of distinct chromosomal information to daughter cells.
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