Journal: Proceedings of the National Academy of Sciences of the United States of America

Article Title: Differential phase register of Hes1 oscillations with mitoses underlies cell-cycle heterogeneity in ER + breast cancer cells

doi: 10.1073/pnas.2113527118

Figure Lengend Snippet: Dynamic Hes1 expression between two consecutive mitosis points is biphasic. ( A ) Endogenous mVenus-Hes1 traces from mixed Cl19 cells plotted as heat maps ( Upper ) ( SI Appendix , Fig. S7 ) and organized in increasing order of cell-cycle length ( Lower ). Notice the presence of the Hes1 expression dip (highlighted by a black line), preceded by a highly variable and followed by a less variable Hes1 peak, giving rise to the biphasic Hes1 profile during the cell cycle. When mVenus ( B ) or Nu-mVenus ( C ) were expressed under the Ubc promoter as controls, their expression profiles during the cell cycles showed no such characteristics. ( D ) When we plotted the same individual Hes1 tracks (as in A ) as line plots, collapsed at the second mitoses at the right-hand side of the graph, we noticed a similar biphasic Hes1 expression dynamic with a variable, first Hes1 peak, followed by a dip in its expression (again marked by a black line), which was followed by a Hes1 peak toward the end of the cell cycle. ( E ) A MATLAB-based dip-detection (ADD) method in the mVenus-Hes1 expression profile during the cell cycle detected the minimum turning point (dip) in the Hes1 expression with 92% accuracy, as compared to manual annotation ( SI Appendix , Fig. S6 ). The duration after the dip (until the second mitosis) showed a tight distribution for all the cells with a mean value of around 11 h, while the duration to the dip (from the first mitosis) showed very high variability (6.5 to 86 h) ( F ). Together, these data showed that Hes1 expression between two consecutive mitoses is biphasic.

Article Snippet: We also developed a MATLAB-based automatic dip detection (ADD) pipeline ( Materials and Methods ), which detected dips in normalized Hes1 time traces with 92% accuracy (4% false positive and 4% false negative) ( Fig. 4 E ).

Techniques: Expressing