Project
422-Asai-KinetochoreBeads
Title
Dynamics of chromosomes and artificial kinetochore beads in mouse oocytes and embryos
Description
Faithful chromosome segregation requires biorientation, where the pair of kinetochores on the chromosome establish bipolar microtubule attachment. The integrity of the kinetochore, a macromolecular complex built on centromeric DNA, is required for biorientation, but components sufficient for biorientation remain unknown. The authors show that tethering the outer kinetochore heterodimer NDC80-NUF2 to the surface of apolar microbeads establishes their biorientation-like
state in mouse cells. NDC80-NUF2 microbeads align at the spindle equator and self-correct alignment errors. The alignment is associated with stable bipolar microtubule attachment and is independent of the outer kinetochore proteins SPC24-SPC25, KNL1, the Mis12 complex, inner kinetochore proteins,
and Aurora. Larger microbeads align more rapidly, suggesting a size-dependent biorientation mechanism.
Funding
RIKEN intramural grants; RIKEN Pioneering Project “Long-timescale Molecular Chronobiology” (T.S.K.); JSPS KAKENHI 23H04948, 21H02407, and 18H05549 (T.S.K.); Mitsubishi Foundation (T.S.K.).
Title
Z-series and time-lapse images of chromosomes and NDC80-deltaSPC-NUF2 microbeads in an oocyte
Description
Z-series and time-lapse images of chromosomes and NDC80-deltaSPC-NUF2 microbeads in an oocyte. NDC80-deltaSPC-NUF2 (NDC80-deltaSPC and NUF2 heterodimer) beads were formed in the oocyte as follows; The authors microinjected mRNAs encoding
C-terminally green fluorescent protein–tagged
NDC80-deltaSPC and NUF2, followed by
anti-GFP–conjugated microbeads into the cytoplasm. The mRNA for H2B-mCherry was also injected to visualize the chromosomes.
NDC80-deltaSPC is the deletion protein of NDC80 which lacks SPC-25-binding domain at its C-terminal region.
channel1; GFP, channel2; mCherry, channel3;bright field.
Description
Mouse oocyte which was microinjected mRNAs encoding NDC80-deltaSPC-NUF2 followed by anti-GFP–conjugated microbeads (1.7 to 2.6 mm in diameter). The H2B-mCherry mRNA was also injexcted.
Extrinsic variables
Mouse oocyte was microinjected mRNAs encoding NDC80-deltaSPC-NUF2 followed by
anti-GFP–conjugated microbeads (1.7 to 2.6 mm in diameter). The H2B-mCherry mRNA was also injexcted.
Gene ontology: Biological processes
Gene ontology: Cellular components
Gene ontology: Molecular functions
Protein names
Kinetochore protein NDC80 homolog (
Q9D0F1)
Kinetochore protein Nuf2 (
Q99P69)
Histone H2B type 1-J (
P06899)
Genetic methods
injection
Dimensions
512x512x25x3x150
X scales
0.075 micrometer
Y scales
0.075 micrometer
Visualization methods
Green fluorescent protein from Aequorea
mCherry
Contrast enhancing methods
Resolution enhancing methods
Airyscan
Sample preparation methods
living tissue
Objective
Zeiss 40×C-Apochromat 1.2NA