Summary of the science
An oocyte is a special egg cell in a female's body that can turn into an embryo. It contains important instructions called DNA, which tell the body how to grow and work. These instructions are organised into chromosomes. When the oocyte is ready, it goes through a process called meiosis, where it divides and grows to get ready for fertilisation. If it meets a sperm cell from a male, it can become an embryo. During this process, the cell's internal scaffolding called the cytoskeleton plays an important role. It is made up of tiny hollow tubes called microtubules and special building block molecules called actin proteins. Microtubules act like highways, helping important materials move around inside the cell and keeping the cell's shape intact. Actin proteins form long strands that help the cell move, keep its shape, and do different tasks in the body. To make sure the genetic instructions are passed down correctly, the cell needs to break a protective wall called the nuclear envelope that surrounds the nucleus. Once the wall is broken, the chromosomes, which hold the DNA, need to be gathered together so the final egg cell is ready for the baby and has all the required genetic information. Microtubules and actin work together to perform these tasks.
About the research
Peter Lenart's lab investigates oocyte meiosis, a unique form of cell division, that requires specialised adaptations of the cytoskeleton to support the extreme geometry of these large cells. Unlike in small somatic cells, where microtubules play a dominant role, their research has shown that in oocytes, the actin cytoskeleton takes over crucial functions. Actin forms a network that transports chromosomes to the forming spindle and regulates spindle assembly. By studying marine model species like starfish oocytes, they aim to uncover the conservation and diversity of these meiosis-specific mechanisms, shedding light on fundamental principles of cellular organisation and the origins of life.
About the illustration
We wanted to highlight the idea that the cytoskeleton acts as an internal scaffold and a 'highway' to transport important molecules, and chromosomes throughout the cell. To do this, we used dark lines to illustrate a network, web-like structure, that fills the cell and surrounds the nucleus. As they are also involved in collecting the chromosomes, we included these in white underneath the network.