Olig genes have been identified as the earliest known markers of oligodendrocyte lineage determination to date. Olig1 is a transcription factor which promotes formation and maturation of oligodendrocytes, especially within the brain. It is e, Xenopus/Amphibian,pressed in the ventral spinal cord as early as 9.5 dpc and by 15.5 dpc, olig1 is dispersed throughout the gray matter. In the postnatal brain, olig1 is present preferentially in the white matter, such as corpus callosum and cerebellar medulla. Olig1 has been demonstrated as necessary in the repair of brain lesions in patients with multiple sclerosis.