The 2019 Colworth Medal will be presented to Melina Schuh from the Max-Planck-Institute for Biophysical Chemistry, Germany. Melina investigates how chromosome segregation errors arise during the meiotic divisions of mammalian eggs. Aneuploidy in eggs is a leading cause of pregnancy loss, congenital disorders and the age-related decline in female fertility. During the early stages of her career, Melina Schuh established methods for high-resolution microscopy of live mouse oocytes, the progenitor cells of eggs. This work paved the way for in-depth intracellular studies of meiosis in mouse oocytes, which had only been observed at very low resolution up to this point. Using this technology, she revealed how the spindle, the machinery that separates the chromosomes, assembles. She also uncovered key mechanisms that are involved in the extremely asymmetric divisions of the oocyte, which are essential to preserve the oocyte’s material for the development of the embryo. Moreover, she developed technology for high-content screens in mouse oocytes. This technology overcame multiple obstacles that had precluded high-content screens for meiotic genes in mammals in the past. Her laboratory then went on to establish methods that allowed them to carry out the first studies of meiosis in live human oocytes. Through this work, they could determine the precise sequence of events that is involved in the formation of a fertilisable egg in humans, and identify steps in this process that are particularly error-prone. Unexpectedly, they found that spindles in human oocytes are highly unstable and frequently incorrectly attached to chromosomes. These incorrect attachments lead to problems when the chromosomes of the oocyte need to be separated in preparation for fertilization. Melina Schuh’s work also shed light on why aneuploidy in eggs increases as women get older: They found that chromosomes in human eggs disintegrate as women get older. This disintegration causes chromosomes to orient abnormally on the spindle and precludes their accurate separation. More recently, her laboratory developed a new method for protein degradation that is called Trim-Away. This method is the first widely applicable protein degradation method that acts directly on the level of the endogenous protein.
Melina said: "I was absolutely excited when I found out that I will receive the Colworth Medal. This is a great honour, and I would like to thank the Biochemical Society for this prestigious recognition of our work. A significant part of my independent research has been carried out at the MRC Laboratory of Molecular Biology (LMB) in Cambridge, UK. The time that I have spent at the LMB has been a scientifically fruitful and personally very enriching time. I would like to take this opportunity to thank the many wonderful colleagues and mentors at the LMB who have supported me throughout this time. I am also grateful to the fantastic PhD students and postdocs I have had the pleasure to work with. Studying mammalian oocytes is technically very challenging – none of this would have been possible without their curiosity, perseverance and enthusiasm."