U.S. researchers have determined the gene Six3 activates the Pax6 gene as part of the development of the eye lens in the mammalian embryo.

A report on the work appears in the pre-publication online issue of The EMBO Journal. Investigators at St. Jude Children's Research Hospital made their discovery using mouse models.

Mutations in Six3 have been previously identified in patients with holoprosencephaly, a disease that can cause the part of the brain called the cerebrum to fail to divide normally into two lobes.

Holoprosencephaly is the most common abnormality of the development of the forebrain in humans. A few years ago the St. Jude team demonstrated that Six3 activity is critical for the normal development of the forebrain in mice.

St. Jude researchers have now extended those results by showing in the developing eye that Six3 normally exerts its effect by directly activating Pax6, a gene considered the "master regulator of eye development." In the absence of Six3, Pax6 fails to coordinate the activity of a series of additional genes that cooperate to form the lens.

Source: Xinhua