The Sox18 gene, best known for its role in developing vasculature and hair follicles, is critical in the development and perhaps function of the lymphatic system, Australian researchers have found.

The team, led by Professor Peter Koopman and Dr Mathias Francois from the Institute for Molecular Bioscience at UQ, was alerted to the possibility by a mouse model in which one allele was inactivated.

The mice displayed similar symptoms to humans with the very rare genetic disorder hypotrichosis-lymphoedema-telangiectasia (HLT), in which eyebrows and eyelashes fail to grow and lymphatic oedemas are common.

The researchers suspected that Sox18 played a critical role in lymphatic vessel formation. They found that it acts as a molecular switch to induce differentiation of lymphatic endothelial cells.

The finding is important in understanding diseases such as lymphoedema, a painful swelling experienced when fluid is not drained by the lymphatic system correctly; and also in cancer, where the rate at which new lymphatic vessels form is thought to have a role in how quickly tumours spread.

“Sox18 induces development of the lymphatic vasculature in mice” by Mathias Francois et al is published in Nature [doi:10.1038/nature07391].