Live Imaging of Chromosome Dynamics

Progression of meiosis has been traditionally reconstructed from microscopic images collected from fixed cells. However, studies conducted in a number of species, including plants, indicate that this approach has clear shortcomings in accurately portraying the dynamic nature of meiotic processes. Here, we describe two methods to study chromosome dynamics in live meiocytes in maize, a protocol to observe chromosomes during meiotic prophase I and a technique to monitor chromosome segregation in anaphase I and anaphase II. The first method relies on culturing intact maize anthers and observing meiocytes embedded in the anthers with multiphoton excitation (MPE) microscopy. This approach circumvents difficulties in culturing isolated prophase I meiocytes in plants. The second technique uses culturing isolated meiocytes, which is possible with anaphase cells. Both methods can be fairly easily adapted for use in other plant species. We also detail the kinds of time-lapse movies that can be captured and analyzed using this technique, and describe software that can be utilized for analysis of movies chromosome dynamic in live meiocytes.