The Mary Lyon Centre is a national facility for mouse functional genomics, providing world-class expertise and tools to generate mouse models of human disease for MRC Harwell and the wider research community.
First established in 2004, the centre has been named in recognition of the achievements of Mary Lyon, a researcher at MRC Harwell who first discovered the process of X-chromosome inactivation, also known as lyonisation.

One of the clearest examples of X-inactivation Mary used was the genetics of tortoiseshell cats. Like humans, female cats generally have two X-chromosomes (XX), whereas males only have one (XY). Two variants of a gene on the X-chromosome decide whether or not a cat will have a ginger coat. Males either have an entirely ginger or non-ginger coloured coat, as they only have one X-chromosome and one version of the gene, but for tortoiseshell females it is more complicated. One X-chromosome in each cell is randomly inactivated early in development, so the active gene is different in different groups of cells. These then give rise to their characteristic patches of ginger and non-ginger coat.

In recognition of her work, Mary Lyon was made a Fellow of the Royal Society and in 1984 received their Royal Medal, and has been awarded the Pearl Meister Greengard Prize, the March of Dimes Prize and the Wolf Prize in Medicine. Her discovery has led to great advances in our understanding of X-linked inherited diseases such as haemophilia, Duchenne muscular dystrophy, fragile X syndrome and certain cancers.

The centre has excellent facilities and offers a wide range of services for the scientific community, including specialised techniques, mouse lines and access to our genetic archives. These services include the generation of genetically altered mice, archived genetic material from our mouse lines, animal husbandry and phenotyping, as well as pathology and molecular and cellular biology services to analyse the genes, molecular pathways and tissues affected. These services are delivered by a dedicated and experienced team, and stem from the same techniques regularly employed at MRC Harwell for our research and large-scale projects.

MRC Harwell is part of the International Mouse Phenotyping Consortium (IMPC), which seeks to determine the function of 20,000 genes through the generation and systematic phenotyping of knockout mice. This is an enormous task, and the Mary Lyon Centre plays a central role in breeding and characterising mouse lines to achieve this aim. In addition, the Harwell Ageing Screen is another large-scale project that seeks to determine the underlying genetic basis for ageing and age-related conditions. This forms the basis for research both within MRC Harwell and as part of external collaborations, as well as providing the resources that underpin many of the services we offer.