Somatic and gametic loss of imprinting (LOI) in mammalian development: studies using a novel imprinted transgene on the mouse distal choromosome 7 (MMU7) imprinted region

Genetic inheritance in an offspring primarily results from the interplay of dominant and recessive genes between two parents. With certain genes, however, gene expression is parent-of-origin-specific: these genes will always be expressed from either the maternal or paternal chromosome. This process is known as genomic imprinting, which creates a mark, or “imprint”, on the chromosome. Loss of imprinting (LOI) is often studied in the context of disease, especially in cancers, but it is also a normal part of development. For example, in germ cells, imprints are erased and re-set early in development every generation, resulting in a normal period of LOI. Meaghan Jones is investigating a hypothesis that non-germ cells may also experience some normal LOI during development. She will examine the timing, stimulus and duration of LOI in germ cells and somatic cells during development. By determining the various causes of LOI in both types of tissues, she hopes to uncover factors regulating normal LOI and help alleviate the risk of imprinting defects.