2013). Pax6 is a homeodomain transcription factor. This gene has been highly conserved, and as such, can be found in both vertebrate and invertebrate organisms (Klimova and Kozmik 2014). Pax6 is thought of as a master control gene for eye development because it regulates many other genes that lead to proper eye formation (Shaham et al. 2013). This gene is expressed in the developing eye as well as the central nervous system (He et al. 2015). Specifically, Pax6 has been shown to regulate retinal and lens development (Klimova and Kozmik 2014). Mutations in this gene can lead to a multitude of genetic disorders, the most common being aniridia. This disease is characterized by loss of the iris, either completely or partially. This disease can subsequently lead to other disorders, such as cataracts, lens dislocation, corneal disorder, and optic nerve abnormalities (He et al. 2015). Because of this, Pax6 shows to be essential for accurate eye development to allow for proper vision …show more content…
Xie et al. (2013) demonstrated the necessity of this gene for the formation of the lens placode. To do this, the authors performed comparative chromatin immunoprecipitation (ChIP) studies in mice to determine which genes were regulated by Pax6. PAX6-specific antibodies were used for this analysis, as well as chromatin from the eye lenses of newborn mice. Chromatin from lenses, the forebrain, and pancreatic cells was analyzed to determine how many genes were controlled by Pax6 based on promoter sequences, in which 133 were found. To determine which genes regulate lens development, total Pax6 gene expression was compared to that of the lens chromatin Pax6 expression. Pax6 was then conditionally inactivated to determine what genes require both copies of the gene for functioning. It was found that the lens placode did not form in these embryos. Xie et al. (2013) also performed RNA expression profiling and determined that 19 genes were directly regulated by Pax6 in the formation of the lens (Xie et al.