Analyzing Meiosis in Maize

Meiosis is central to sexual reproduction and the main source of genetic diversity in plants. Understanding how meiotic processes are regulated has direct relevance to agriculture. As meiotic recombination is the vehicle of plant breeding, gaining the ability to influence recombination patterns can accelerate crop improvement. Maize is a powerful model for studying plant meiosis, thanks to its large chromosomes, well-developed genetics, and the availability of diverse cytogenetic and molecular tools. Insights gained from maize studies can extend to other species. In this review, we describe a variety of approaches for examining meiosis and meiotic recombination in maize. Cytological techniques, including protein immunolocalization and fluorescence in situ hybridization (FISH), enable visualization of chromosome structure and behavior, as well as crossover (CO) formation. Chromatin immunoprecipitation (ChIP) is used in meiosis research to determine locations of recombination proteins, identify recombination sites, and elucidate chromatin features, such as histone modifications. Quantification of COs at specific genomic sites through pollen typing by droplet digital PCR allows precise high-resolution measurement of recombination rates. Combining cytology, protein localization, and molecular assays provides a multiscale picture of meiosis, linking molecular mechanisms to chromosome behavior and, ultimately, to genetic variation.