In binocular animals that exhibit stereoscopic visual responses, the axons of retinal ganglion cells (RGCs) connect to brain areas bilaterally by forming a commissure called the optic chiasm (OC). Ventral anterior homeobox 1 (Vax1) contributes to the formation of the OC, acting endogenously in optic pathway cells and exogenously in growing RGC axons. Here, we generated Vax1AA/AA mice expressing the Vax1AA mutant, which is incapable of intercellular transfer. We found that RGC axons cannot take up Vax1AA protein from the Vax1AA/AA mouse optic stalk (OS) and grow slowly to arrive at the hypothalamus at a late stage. The RGC axons of Vax1AA/AA mice connect exclusively to ipsilateral brain areas after failing to access the midline, resulting in reduced visual acuity and abnormal oculomotor responses. Overall, our study provides physiological evidence for the necessity of intercellular transfer of Vax1 and the importance of the bilateral RGC axon projection in proper visuomotor responses.
|Number of pages||16|
|Journal||Experimental and Molecular Medicine|
|Publication status||Published - 2023 Feb|
Bibliographical noteFunding Information:
This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES)—Finance Code 001.
We thank Ilsong Choi and Anna Shin for helping with the mouse ocular behavioral tests. This work was supported by National Research Foundation of Korea (NRF) grants (NRF-2022R1A2C3003589; NRF-2018R1A5A1024261) funded by the Korean Ministry of Science and ICT (MSIT) and an International Collaboration Initiative grant (KAIST-N11210255) supported by KAIST, South Korea. This study was performed in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the Korean Ministry of Agriculture, Food, and Rural Affairs. All of the animals were handled according to approved institutional animal care and use committee (IACUC) protocols (#13-130) of Korea Advanced Institute of Science and Technology.
© 2023, The Author(s).
All Science Journal Classification (ASJC) codes
- Molecular Medicine
- Molecular Biology
- Clinical Biochemistry