Visuomotor anomalies in achiasmatic mice expressing a transfer-defective Vax1 mutant

Vision: bringing the two sides together A protein regulating gene expression called Vax1 is essential for building the optic chiasm (OC), a brain structure where nerves from the left and right eyes cross to the other side of the brain. Signals from both eyes must be integrated for space and depth perception. Although some cues guiding optic nerve growth are known, those for the OC are not. Jin Woo Kim at the Korea Advanced Institute of Science and Technology, Daejeon, South Korea, and co-workers investigated visual development in mice expressing a mutant Vax1. They found that the mutant Vax1 could not support the optic nerve, which grew slowly and failed to connect to the other side of the brain. Consequently, the mice had impaired depth perception and low vision. These results show the importance of Vax1 for the development of binocular vision.