High impact information on Sox1

• Here we report that expression of the transcription factors Sox1, Sox2 and Sox3 (Sox1-3) is a critical determinant of neurogenesis [1].
• During fetal development, Sox1 is expressed by proliferating progenitor cells throughout the central nervous system and in no tissue but the lens [2].
• Intermediate-filament Nestin and group B1 SOX transcription factors (SOX1/2/3) are often employed as markers for neural primordium, suggesting their regulatory link [3].
• Here we show that SOX1, an HMG-box protein related to SRY, is one of the earliest transcription factors to be expressed in ectodermal cells committed to the neural fate: the onset of expression of SOX1 appears to coincide with the induction of neural ectoderm [4].
• SOX1, therefore, defines the dividing neural precursors of the embryonic central nervous system (CNS) [4].

Biological context of Sox1

• The Sox1, Sox4 and Sox14 genes do not have introns in the HMG box region [5].
• Using a series of antigenic markers which identify early neural cell types in combination with BrdU labeling, we demonstrate a temporal and spatial correlation between the differentiation of cell types along the dorsoventral axis of the neural tube and the downregulation of SOX1 expression [4].
• SOX2 (or SOX1/SOX3) is essential for activation of the enhancer under all conditions [6].
• Thus, the regulation of SOX2 (and SOX1/3) and its partner factors, exemplified by Pax6, determines the spatio-temporal order of the occurrence of cell differentiation [7].
• These factors have been identified as SOX1/2/3 (Group B1 SOX proteins, SOX2 being the major player) and Pax6, and have been shown to bind cooperatively to DC5 and form a ternary complex having a robust potency for transcriptional activation [7].

Anatomical context of Sox1

• Sox1 transcripts are first detected in the neural fold ectoderm at the headfold stage [8].
• Comparative expression of the mouse Sox1, Sox2 and Sox3 genes from pre-gastrulation to early somite stages [8].
• In order to investigate the identity of these cells in the adult cerebellum, we have analyzed the expression of Sox1, a transcription factor from the SoxB1 subgroup and widely used marker of neural stem cells [9].
• We report that forced expression of Sox1 or Sox2 did not impair propagation of undifferentiated ES cells, but upon release from self-renewal promoted differentiation into neuroectoderm at the expense of mesoderm and endoderm [10].
• Sx1TV2/16C is a mouse embryonic stem (ES) cell line in which one copy of the Sox1 gene, an early neuroectodermal marker, has been targeted with a neomycin (G418) selection cassette [11].

Associations of Sox1 with chemical compounds

• Misexpression of SOX1 can substitute for the requirement of retinoic acid to impart neural fate to competent ectodermal P19 cells [4].

Other interactions of Sox1

• Our results identify these radial glia as a previously unreported Sox1/Sox2/Sox9 positive adult cell population, suggesting that these cells may represent the recently reported stem cells in the adult cerebellum [9].
• Among 15 Sry-related genes, TS41, TS42, AS41, and AS42 shared 80, 72, 81, and 79% amino acid identity, respectively, with each HMG-box domain of the mouse Sox-1, -2, and -3 genes by Blast analysis [12].
• Here we present the characterization of an epilepsy syndrome caused by the absence of the transcription factor SOX1 in mice [13].
• The local inhibitory GABAergic neurotransmission remained normal in the OC of SOX1-deficient brains, but there was a severe developmental deficit of OC postsynaptic target neurons, mainly GABAergic projection neurons within the olfactory tubercle and the nucleus accumbens shell [13].
• In situ hybridization and the use of a transgenic mouse model show that, in the adult cerebellum, Sox 1 is only expressed in the Bergmann glia, a population of radial glia present in the Purkinje cell layer [9].

Analytical, diagnostic and therapeutic context of Sox1

• To test this hypothesis, we differentiated sox1-green fluorescent protein (GFP) knock-in ES cells in vitro, purified neural precursor cells by fluorescence-activated cell sorting (FACS), and characterized the purified cells in vitro as well as in vivo [14].
• Isolation and Sequence Analysis of the Sox-1, -2, -3 Homologs in Trionyx sinensis and Alligator sinensis Having Temperature-Dependent Sex Determination [12].

References