High impact information on SOX9

• Here, we show that in Xenopus, Sox8 accumulates at the lateral edges of the neural plate at the mid-gastrula stage; in contrast to its mouse and chick orthologs, Sox8 expression precedes that of Sox9 and Sox10 in neural crest progenitors [1].
• By misexpressing SOX9 in the mesoderm of the gizzard, we show that SOX9 is able to transdifferentiate the adjacent gizzard epithelium into pyloric sphincter-like epithelium through the control of mesodermal-epithelial signals mediated in part by Gremlin (a modulator of the BMP pathway) [2].
• SOX9 specifies the pyloric sphincter epithelium through mesenchymal-epithelial signals [2].
• SOX9 is expressed in the endoderm of the GI tract (with the exclusion of the gizzard) and its derivate organs, the lung and pancreas [2].
• Moreover, SOX9 is also expressed at the mesoderm of the pyloric sphincter, a structure that demarcates the gizzard from the duodenum [2].

Biological context of SOX9

• Calcineurin was found as a positive regulator of chondrogenesis in chondrifying chicken micromass cultures (HDCs), as cyclosporine A (CsA) reduced both the amount of cartilage and the expression of mRNAs of aggrecan and the chondrogenic transcription factor Sox9 [3].
• The ERK inhibitor PD098059 attenuated the depletion of cartilage matrix as well as decreased the expression and phosphorylation of Sox9 in cultures treated with H(2)O(2) or CsA [3].
• The up-regulation is concomitant with the beginning of SOX9 expression and a sex dimorphic level of DMRT1 transcripts [4].
• This gene shows a high degree of sequence homology to SOX9 and SOX10 [5].
• SOX3 expression was observed prior to clear SOX9 expression and was up-regulated in both sexes at the onset of gonadal sex differentiation (but declined later in development) [6].

Anatomical context of SOX9

• To clarify the role SOX9 plays in vertebrate sex determination, we have investigated its expression during gonad development in mouse and chicken embryos [7].
• The conservation of sexually dimorphic expression in two vertebrate classes which have significant differences in their sex determination mechanisms, points to a fundamental role for SOX9 in testis determination in vertebrates [7].
• Coexpression of the three genes, of which SOX9 is a specific Sertoli-cell marker, provides strong evidence for the transdifferentiation of ovarian into testicular epithelium in gonads of female chickens treated with Fadrozole [8].
• We previously demonstrated that, unlike in mammals, the onset of AMH expression occurs in chick embryo in the absence of SOX9 [4].
• Sox9 expression is normally limited to the region of the posterior gizzard under the regulation of BMP signaling from the adjacent midgut [9].

Associations of SOX9 with chemical compounds

• Hydrogen peroxide inhibits formation of cartilage in chicken micromass cultures and decreases the activity of calcineurin: implication of ERK1/2 and Sox9 pathways [3].

Regulatory relationships of SOX9

• SOX9 expression was also activated during female-to-male sex reversal but appeared delayed relative to DMRT1 upregulation [10].

Analytical, diagnostic and therapeutic context of SOX9

• In the present study we have isolated Sox9 cDNAs from quail and duck, and examined the expression patterns of the corresponding genes in early embryonic gonads by whole-mount in situ hybridization [11].

References