User:Kdg31/Lagging Chromatin and Cytokinesis Failure

Lagging Chromatin and Cytokinesis Failure

Methods
To see if cytokinesis failure is associated with DNA damage or lagging chromatin we induced DNA damage via γ-irradiation in HeLa cells. After treatment, cells were stained using immunofluorescent anti-actin and DAPI to stain nuclei. Cells were visually assessed using fluorescence microscopy. Approximately 550 cells of untreated or γ-irradiated were examined for binucleated cells (indicating failed cytokinesis) and lagging chromatin.

Statistics and Counts
For each of the four experiments, the number of binucleated cells and instances of lagging chromatin were counted.

Because the number of binucleated cells was not statistically different between irradiation and no irradiation (p>0.05), it appears that irradiation does not increase the frequency of binucleation. Similarly, the number of lagging chromatin incidences was not different between the irradiated and control groups (p>0.05).

However, the number of lagging chromatin cases for group 3 appears to be an outlier, which may affect significance. If group 3 is excluded, then the data are as follows:

Here, the binucleation frequency is not altered by irradiation (p>0.05), but the lagging chromatin count becomes significantly higher in the irradiated cells (p<0.05). Therefore, it appears that irradiation might increase the frequency of lagging chromatin, but lagging chromatin may not increase the frequency of binucleation and cytokinesis failure.