Olig3, a member of the Olig family of basic helix-loop-helix transcription factors, is crucial for the development of the central nervous system. It is involved in multiple pathways related to neural cell fate specification and progenitor cell regulation. Its expression and function are significant for the proper formation of various neuronal cell types in different regions of the nervous system, and genetic models such as KO mouse models have been instrumental in understanding its roles [1,2,3,4].

In Olig3 mutant mice, the development of class A neurons (dI1-dI3) in the dorsal spinal cord is impaired. dI1 neurons are reduced in number, and dI2 and dI3 neurons are misspecified, adopting the identity of class B neurons [2]. In the hindbrain, Olig3 is essential for the development of brainstem nuclei like the nucleus of the solitary tract and precerebellar nuclei. In Olig3 -/- mice, these nuclei are absent or small, and ectopic Lbx1(+) neurons appear [3]. In the rhombic lip, Olig3 ablation affects the development of RL-derived neurons, reducing Math1 expression in the dI1 domain, compromising the formation of mossy-fiber nuclei, and leading to the misspecification of dI2-dI3 neurons and loss of climbing-fiber neurons [4].

In conclusion, Olig3 is a key factor in the development of the central nervous system, especially in the specification of dorsal neurons in the spinal cord and the development of brainstem and precerebellar nuclei. Studies using Olig3 KO mouse models have revealed its critical functions in these processes, providing insights into potential mechanisms underlying related developmental disorders.

References:

1. Takebayashi, Hirohide, Ohtsuki, Toshiaki, Uchida, Tsukasa, Chisaka, Osamu, Nabeshima, Yo-ichi. . Non-overlapping expression of Olig3 and Olig2 in the embryonic neural tube. In Mechanisms of development, 113, 169-74. doi:. https://pubmed.ncbi.nlm.nih.gov/11960707/

2. Müller, Thomas, Anlag, Katrin, Wildner, Hendrik, Treier, Mathias, Birchmeier, Carmen. . The bHLH factor Olig3 coordinates the specification of dorsal neurons in the spinal cord. In Genes & development, 19, 733-43. doi:. https://pubmed.ncbi.nlm.nih.gov/15769945/

3. Storm, Robert, Cholewa-Waclaw, Justyna, Reuter, Katja, Müller, Thomas, Birchmeier, Carmen. 2008. The bHLH transcription factor Olig3 marks the dorsal neuroepithelium of the hindbrain and is essential for the development of brainstem nuclei. In Development (Cambridge, England), 136, 295-305. doi:10.1242/dev.027193. https://pubmed.ncbi.nlm.nih.gov/19088088/

4. Liu, Zijing, Li, Hong, Hu, Xuemei, Chen, Yiping, Qiu, Mengsheng. . Control of precerebellar neuron development by Olig3 bHLH transcription factor. In The Journal of neuroscience : the official journal of the Society for Neuroscience, 28, 10124-33. doi:10.1523/JNEUROSCI.3769-08.2008. https://pubmed.ncbi.nlm.nih.gov/18829970/