Collaborative Research: Mechanisms and consequences of centromere drive in monkeyflowers

University Of Montana, Missoula MT

Investigators

Abstract

Mendel's first law states that parents transmit their own genes at random to the next generation. However, some genes and chromosomes can cheat to get more than their fair share of copies in eggs and sperm, a process known as drive. Centromeres, which guide chromosomes through cell division (mitosis and meiosis), can selfishly drive to gain unfair access to the sole egg cell in females. By disrupting fair transmission, such drive can damage the health and fertility of plants and animals. Scientists must study drive in action to understand how and when centromeres cheat, whether linked fertility costs are inevitable, and if resistance is possible. This project studies a driving centromere found in the model plant yellow monkeyflower (Mimulus guttatus). It investigates how genes and other DNA sequences work together to cause drive, how some plants resist drive, and whether the same processes cause seed and pollen loss. The research will increase knowledge key for maintaining human and crop health, train diverse scientists in modern genomic methods, and create shared resources. An integrated course immerses college students in real genetics research and a summer camp activity for middle school students supports hands-on learning about plants and genes. A collaborative scientific team from a large research institution and a small liberal arts college builds on new chromosome-scale genome assemblies in yellow monkeyflowers to explore the mechanisms and consequences of selfish centromere evolution. Project 1 unpacks the mechanism of drive with genetic and epigenetic characterization of functionally-distinct centromeres and evolutionary genomic analyses of the selfish centromere's novel gene content. Project 2 examines drive through the lens of the losers, using known and predicted variation in resistance to explore the functional mechanisms of drive and its multiple effects on fitness in natural populations. Project 3 asks what forces shape the spread of a driving centromere across complex landscapes and enhances undergraduate education via course-embedded and summer research on drive’s interactions with environmental factors. Together, these projects advance knowledge of the mechanisms, consequences, and dynamics of centromere evolution and reveal how natural selection acts across scales of organization. This project is jointly funded by Evolutionary Processes (BIO-DEB), the Established Program to Stimulate Competitive Research (EPSCoR), and Genetic Mechanisms (BIO-MCB). This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.