Related Experiment Video
Updated: Apr 20, 2026

Blastomere Explants to Test for Cell Fate Commitment During Embryonic Development
Published on: January 26, 2013
Fragmentation of human cleavage-stage embryos is related to the progression through meiotic and mitotic cell cycles
Mette Haug Stensen1, Tom Gunnar Tanbo2, Ritsa Storeng1
1Norwegian National Advisory Unit on Women's Health, Women and Children's Division, Oslo University Hospital Rikshospitalet, Oslo, Norway.
Objective:
To study whether fragmentation of human embryos is related to the progression through meiotic and mitotic cell cycles.
Design:
This report consists of two observational studies.
Setting:
Not applicable.
Patient(S):
A total of 1,943 oocytes from 297 patients and 372 embryos from 100 patients were imaged in the Polscope instrument and monitored in the Embryoscope, respectively.
Intervention(S):
Completion of the first meiotic division was determined by visualization of the meiotic metaphase II spindle in human oocytes, and the duration of the first three mitotic cell cycles was determined with time-lapse microscopy. The percentage of embryo fragmentation was recorded 42-45 hours after insemination.
Main Outcome Measure(S):
Appearance of the meiotic spindle; durations of the first, second, and third mitoses.
Result(S):
Human embryos with a low degree of fragmentation (<10%) at 42-45 hours after insemination originated from oocytes with an early appearance of the meiotic spindle (mean 35.5 hours after hCG injection), early first mitosis (28.2 hours after insemination), late start of the second mitosis (38.0 hours after insemination), and a shorter duration of the third mitosis (1.1 hours). Highly fragmented embryos (>50% fragmentation) originated from oocytes with a late-appearing meiotic spindle (36.5 hours after hCG injection), delayed initiation of the first mitosis (29.8 hours after insemination), early start of the second mitosis (36.4 hours after insemination), and a longer duration of the third mitotic cell cycle (4.1 hours).
Conclusion(S):
The observed associations suggest that the process of fragmentation of in vitro-derived embryos was related to the progress of the meiotic and the mitotic cell cycles.
Related Concept Videos
Cleavage and Blastulation
Meiosis vs. Mitosis
Before the start of mitosis and meiosis I, the cell synthesizes DNA, resulting in two homologous copies of each chromosome. DNA synthesis is...
Meiosis II
Meiosis II
The timing and cell division patterns of meiosis differ between males and females. In male meiosis, the centrosomes are part of the formation of the meiotic spindle. However, in oocytes, including that of humans, Drosophila,...
Determining the Plane of Cell Division
Animal cells
In animal cells, the cleavage furrow forms along the plane of cell division...
Nondisjunction

