Mouse anti-Human SOX8 monoclonal antibody, clone 9H8

Although Muller glial cells play pivotal roles in the vertebrate retina, the regulation of their development is poorly understood. While Notch-Hes5 signaling has been shown to be involved in this developmental process, the presence of Muller glial cells in Hes5-deficient mice suggests the involvement of other molecules. We found that two group E Sox genes, Sox8 and Sox9, are expressed in proliferating progenitors and then exclusively in Muller glial cells in mouse retina. Knocking-down Sox8 and Sox9 by shRNA significantly reduced the population of Muller glial cells and relatively increased the proportion of rod photoreceptors, suggesting that the Sox genes play roles in the specification of Muller glial cells. Using an activated form of Notch and the g-secretase inhibitor DAPT, we also found that Notch signaling regulates the transcription of Sox8 and Sox9. This is the first evidence that group E Sox genes play important roles in the developing vertebrate retina. (C) 2009 Elsevier Ltd. All rights reserved.

Somatic cell nuclear transfer (SCNT) provides an excellent model for studying epigenomic reprogramming during mammalian development. We mapped the whole genome and whole methylome for potential anomalies of mutations or epimutations in SCNT-generated dogs with XY chromosomal sex but complete gonadal dysgenesis, which is classified as 78, XY disorder of sex development (DSD). Whole genome sequencing revealed no potential genomic variations that could explain the pathogenesis of DSD. However, extensive but stochastic anomalies of genome-wide DNA methylation were discovered in these SCNT DSD dogs. Persistent abnormal hypermethylation of the SRY gene was observed together with its down-regulated mRNA and protein expression. Failure of SRY expression due to hypermethylation was further correlated with silencing of a serial of testis determining genes, including SOX9, SF1, SOX8, AMH and DMRT1 in an early embryonic development stage at E34 in the XYDSD gonad, and high activation of the female specific genes, including FOXL2, RSPO1, CYP19A1, WNT4, ERa and ER beta, after one postnatal year in the ovotestis. Our results demonstrate that incomplete demethylation on the SRY gene is the driving cause of XYDSD in these XY DSD dogs, indicating a central role of epigenetic regulation in sex determination.