Dynamic expression of basic helix-loop-helix Olig family members: implication of Olig2 in neuron and oligodendrocyte differentiation and identification of a new member, Olig3

Abstract

Basic helix-loop-helix (bHLH) transcription factors have been shown to be essential for specification of various cell types. Here, we describe a novel bHLH family consisting of three members, two of which (Olig1, Olig2) are expressed in a nervous tissue-specific manner, whereas the third, Olig3 is found mainly in non-neural tissues. Olig1 and Olig2, which recently have been implicated in oligodendrogenesis, are expressed in the region of the ventral ventricular zone of late embryonic spinal cord where oligodendrocyte progenitors appear. In the embryonic brain, the Olig2 expression domain is broader than that of Olig1 and does not overlap with an oligodendrocyte progenitor marker, CNP. Furthermore, Olig2 is expressed in most cells in the ventral half of the early embryonic spinal cord, which do not yet express an early neuronal marker TuJ1. These results indicate that Olig2 expression is not limited to the oligodendrocyte lineage but includes immature neuronal progenitors and multipotential neuron/glia progenitors as well as embryonic olfactory neurons.

Anti-Human Olig2 Antibody as a Useful Immunohistochemical Marker of Normal Oligodendrocytes and Gliomas

“…24 Olig1 and Olig2 were first identified as basic helix-loop-helix transcription factors that regulate oligodendroglial development. 9,10 The expression of Olig1 and Olig2 mostly overlaps, however, Olig2 expression in the early spinal cord is higher than that of Olig1, 9,10,25 and Olig2 has a broader expression domain in the embryonic forebrain. 25 Olig2-knockout mice cannot survive beyond the neonatal period because of lack of motoneurons and oligodendrocytes, 26,27 whereas Olig1-null mice show delayed myelination, otherwise no significant changes, indicating that Olig1 functions in oligodendrocyte maturation.…”

“…9,10 The expression of Olig1 and Olig2 mostly overlaps, however, Olig2 expression in the early spinal cord is higher than that of Olig1, 9,10,25 and Olig2 has a broader expression domain in the embryonic forebrain. 25 Olig2-knockout mice cannot survive beyond the neonatal period because of lack of motoneurons and oligodendrocytes, 26,27 whereas Olig1-null mice show delayed myelination, otherwise no significant changes, indicating that Olig1 functions in oligodendrocyte maturation. 26 Olig1 and Olig2 are also expressed in motoneuron precursors, while the expression is restricted in oligodendrocytes in adults, 11 yet the reason is uncertain.…”

Transcription Factor Expression and Notch-Dependent Regulation of Neural Progenitors in the Adult Rat Spinal Cord

“…Affinity-purified rabbit polyclonal antibodies (pAbs) against nestin (diluted 1:1000; Nakaf uku and Nakamura, 1995), Prox1 (1:2000; Torii et al, 1999), Olig2 (1:3000), Mash1 (1:5000; Takebayashi et al, 2000), and Notch1 (1:2000; Shawber et al, 1996) were described previously. In some experiments, biotinconjugated anti-Olig2 antibody was used for double-staining.…”

“…1 F, J, Table 1). The bHLH factor Olig2 is expressed in cells of the oligodendrocyte lineage (Lu et al, 2000;Takebayashi et al, 2000;Zhou et al, 2000). Many adult cells expressing Olig2 were detected, and the majority of O4 ϩ oligodendrocytes were Olig2 ϩ (Fig.…”

OC29 is preferentially expressed in the presumptive sensory organ region of the otocyst

“…NBT/BCIP (Roche) was used to visualize the signal. In situ hybridization to tissue sections was performed on rat embryos between E10.5 and E17.5 as described (Takebayashi et al, 2000). Rat embryos were fixed overnight in 4% paraformaldehyde in phosphate buffered saline, and 10-m frozen sections were attached onto MAS-coated slide glass (Matsunami) were prepared by standard procedures.…”