The transcription factor Sox10 is an essential determinant of branching morphogenesis and involution in the mouse mammary gland.

The high mobility group-domain containing transcription factor Sox10 is an essential regulator of developmental processes and homeostasis in the neural crest, several neural crest-derived lineages and myelinating glia. Recent studies have also implicated Sox10 as an important factor in mammary stem and precursor cells. Here we employ a series of mouse mutants with constitutive and conditional Sox10 deficiencies to show that Sox10 has multiple functions in the developing mammary gland.

Olfactory ensheathing cells abutting the embryonic olfactory bulb express Frzb, whose deletion disrupts olfactory axon targeting.

We and others previously showed that in mouse embryos lacking the transcription factor Sox10, olfactory ensheathing cell (OEC) differentiation is disrupted, resulting in defective olfactory axon targeting and fewer gonadotropin-releasing hormone (GnRH) neurons entering the embryonic forebrain. The underlying mechanisms are unclear. Here, we report that OECs in the olfactory nerve layer express Frzb-encoding a secreted Wnt inhibitor with roles in axon targeting and basement membrane breakdown-from embryonic day (E)12.

Onset of Spinal Cord Astrocyte Precursor Emigration from the Ventricular Zone Involves the Zeb1 Transcription Factor.

During spinal cord development, astrocyte precursors arise from neuroepithelial progenitors, delaminate from the ventricular zone, and migrate toward their final locations where they differentiate. Although the mechanisms underlying their early specification and late differentiation are being deciphered, less is known about the temporal control of their migration. Here, we show that the epithelial-mesenchymal transition regulator Zeb1 is expressed in glial precursors and report that loss of Zeb1 function specifically delays the onset of astrocyte precursor delamination from the ventricular zone, correlating with transient deregulation of the adhesion protein Cadherin-1.

Heme Oxygenase-1 and Carbon Monoxide Promote Burkholderia pseudomallei Infection.

The environmental bacterium and potential biothreat agent Burkholderia pseudomallei causes melioidosis, an often fatal infectious disease. Increased serum bilirubin has been shown to be a negative predictive factor in melioidosis patients. We therefore investigated the role of heme oxygenase-1 (HO-1), which catalyzes the degradation of heme into the bilirubin precursor biliverdin, ferrous iron, and CO during B.

Erythropoietin production by PDGFR-β(+) cells.

PDGFR-β-expressing cells of the kidneys are considered as a relevant site of erythropoietin (EPO) production. The origin of these cells, their contribution to renal EPO production, and if PDGFR-β-positive cells in other organs are also capable to express EPO are less clear. We addressed these questions in mice, in which hypoxia-inducible transcription factors were stabilized in PDGFR-β(+) cells by inducible deletion of the von Hippel-Lindau (Vhl) protein.

Sox13 functionally complements the related Sox5 and Sox6 as important developmental modulators in mouse spinal cord oligodendrocytes.

The role of transcription factor Sox13, which together with Sox5 and Sox6 belongs to the SoxD family, is only poorly characterized in central nervous system development. Therefore, we analysed whether Sox13 expression and function overlaps with or differs from that of its close relatives Sox5 and Sox6. In the developing mouse spinal cord, we found Sox13 predominantly expressed in neuroepithelial precursors, oligodendroglial and astroglial cells.

Schwann cells and their transcriptional network: Evolution of key regulators of peripheral myelination.

As derivatives of the neural crest, Schwann cells represent a vertebrate invention. Their development and differentiation is under control of a newly constructed, vertebrate-specific regulatory network that contains Sox10, Oct6 and Krox20 as cornerstones and central regulators of peripheral myelination. In this review, we discuss the function and relationship of these transcription factors among each other and in the context of their regulatory network, and present ideas of how neofunctionalization may have helped to recruit them to their novel task in Schwann cells.

Transcription factors Sox5 and Sox6 exert direct and indirect influences on oligodendroglial migration in spinal cord and forebrain.

Transcription factors of the SoxD protein family have previously been shown to prevent precocious specification and terminal differentiation of oligodendrocyte progenitor cells in the developing spinal cord. Using mice with specific deletion of the SoxD proteins Sox5 and Sox6 in the central nervous system, we now show that SoxD proteins additionally influence migration of oligodendrocyte progenitors in the spinal cord as well as in the forebrain. In mutant mice, emigration of oligodendrocyte progenitors from the ventricular zone and colonization of the mantle zone are significantly delayed probably because of reduced expression of Pdgf receptor alpha and decreased responsiveness toward Pdgf-A as a main migratory cue.

Selective expression of sense and antisense transcripts of the sushi-ichi-related retrotransposon--derived family during mouse placentogenesis.

Background: LTR-retrotransposons became functional neogenes through evolution by acquiring promoter sequences, regulatory elements and sequence modification. Mammalian retrotransposon transcripts (Mart1-9), also called sushi-ichi-related retrotransposon-homolog (SIRH) genes, are a class of Ty3/gypsy LTR-retroelements showing moderate homology to the sushi-ichi LTR-retrotransposon in pufferfish. Rtl1/Mart1 and Peg10/Mart2 expression in mouse placenta and demonstration of their functional roles during placental development exemplifies their importance in cellular processes.

Sox5 controls dorsal progenitor and interneuron specification in the spinal cord.

The basic organization of somatosensory circuits in the spinal cord is already setup during the initial patterning of the dorsal neural tube. Extrinsic signals, such as Wnt and TGF-β pathways, activate combinatorial codes of transcription factors that are responsible for generating a pattern of discrete domains of dorsal progenitors (dp). These progenitors will give rise to distinct dorsal interneurons (dI).

Mutual antagonism between Sox10 and NFIA regulates diversification of glial lineages and glioma subtypes.

Lineage progression and diversification is regulated by the coordinated action of unique sets of transcription factors. Oligodendrocytes (OL) and astrocytes (AS) comprise the glial sub-lineages in the CNS, and the manner in which their associated regulatory factors orchestrate lineage diversification during development and disease remains an open question. Sox10 and NFIA are key transcriptional regulators of gliogenesis associated with OL and AS.

Radial glia phagocytose axonal debris from degenerating overextending axons in the developing olfactory bulb.

Axon targeting during the development of the olfactory system is not always accurate, and numerous axons overextend past the target layer into the deeper layers of the olfactory bulb. To date, the fate of the mis-targeted axons has not been determined. We hypothesized that following overextension, the axons degenerate, and cells within the deeper layers of the olfactory bulb phagocytose the axonal debris.

Activation and regulation of endogenous retroviral genes in the human pituitary gland and related endocrine tumours.

Aims: Adenohypophysis (AH) hormone-producing cells represent the origin of diverse groups of pituitary adenomas (PA). Deregulation of hypothalamic hormone receptors, growth factors and cAMP signalling have been implicated in the aetiology of PA. Endogenous retroviruses (ERVs) are derived from past exogenous retroviral infections and represent more than 8% of the human genome.

Neural crest origin of retinal and choroidal pericytes.

Purpose: The origin of pericytes (PCs) has been controversially discussed and at least three different sources of PCs are proposed: a neural crest, mesodermal, or bone marrow origin. In the present study we investigated a potential neural crest origin of ocular PCs in a transgenic Rosa26-YFP-Sox10-Cre neural crest-specific reporter mouse model at different developmental stages.

Methods: The Rosa26-YFP-Sox10-Cre mouse model expresses the yellow fluorescent protein (YFP) reporter in cells with an active Sox10 promoter and was here used for cell fate studies of Sox10-positive neural crest derived progeny cells.

Olfactory ensheathing glia are required for embryonic olfactory axon targeting and the migration of gonadotropin-releasing hormone neurons.

Kallmann's syndrome is caused by the failure of olfactory axons and gonadotropin-releasing hormone (GnRH) neurons to enter the embryonic forebrain, resulting in anosmia and sterility. Sox10 mutations have been associated with Kallmann's syndrome phenotypes, but their effect on olfactory system development is unknown. We recently showed that Sox10 is expressed by neural crest-derived olfactory ensheathing cells (OECs).

Regulation of murine placentogenesis by the retroviral genes Syncytin-A, Syncytin-B and Peg10.

The murine placenta has a trichorial structure with two multinucleated syncytiotrophoblast (SCT) layers representing a barrier between the maternal and fetal blood system. Genes of endogenous retroviruses and retrotransposon-derived paternally expressed genes (Peg), remnants of past infections and integrations in the genome, have essential functions in placentogenesis. Previous studies showed that the envelope genes Syncytin-A and Syncytin-B were essential for cell-cell fusion of the SCT.

Glial but not neuronal development in the cochleo-vestibular ganglion requires Sox10.

The cochleo-vestibular ganglion contains neural crest-derived glial cells and sensory neurons that are derived from the neurogenic otic placode. Little is known about the molecular mechanisms that regulate the tightly orchestrated development of this structure. Here, we report that Sox10, a high-mobility group DNA-binding domain transcription factor that is required for the proper development of neural crest cell derivatives, is specifically expressed in post-migratory neural crest cells in the cochleo-vestibular ganglion.

Disruption of ST5 is associated with mental retardation and multiple congenital anomalies.

Background: The authors observed a patient with a cryptic subtelomeric de novo balanced translocation 46,XY.ish t(11;20)(p15.4;q13.

SoxE function in vertebrate nervous system development.

Sox8, Sox9, and Sox10 as transcription factors of subgroup E of the Sox protein family are essential for many aspects of nervous system development. These SoxE proteins are already required for the initial neural crest induction, but also guarantee survival and maintenance of pluripotency in migrating neural crest stem cells. SoxE proteins are furthermore key regulators of glial specification in both the peripheral and the central nervous systems.

Replacement of related POU transcription factors leads to severe defects in mouse forebrain development.

Related transcription factors of the POU protein family show extensive overlap of expression in vivo and exhibit very similar biochemical properties in vitro. To study functional equivalence of class III POU proteins in vivo, we exchanged the Oct-6 gene by Brn-1 in the mouse. Brn-1 can fully replace Oct-6 in Schwann cells and rescue peripheral nervous system development in these mice.

The transcription factor Sox5 modulates Sox10 function during melanocyte development.

The transcription factor Sox5 has previously been shown in chicken to be expressed in early neural crest cells and neural crest-derived peripheral glia. Here, we show in mouse that Sox5 expression also continues after neural crest specification in the melanocyte lineage. Despite its continued expression, Sox5 has little impact on melanocyte development on its own as generation of melanoblasts and melanocytes is unaltered in Sox5-deficient mice.

[Traditional midwife texts].

We report an hermeneutic text study in two early midwife text books. In Louise Bourgeois book from early 17th century the individual caring perspective is more present than in Helena Malhiems book from the middle of the 18th century. In both books, however, non-technological aspects of child birth delivery is more prominent than in books written by doctors.

Neural crest origin of perivascular mesenchyme in the adult thymus.

The endodermal epithelial thymus anlage develops in tight association with neural crest (NC)-derived mesenchyme. This epithelial-NC interaction is crucial for thymus development, but it is not known how NC supports thymus development or whether NC cells or their progeny make any significant contribution to the adult thymus. By nude mouse blastocyst complementation and by cell surface phenotype, we could previously separate thymus stroma into Foxn1-dependent epithelial cells and a Foxn1-independent mesenchymal cell population.

SoxE proteins are differentially required in mouse adrenal gland development.

Sry-box (Sox)8, Sox9, and Sox10 are all strongly expressed in the neural crest. Here, we studied the influence of these closely related transcription factors on the developing adrenal medulla as one prominent neural crest derivative. Whereas Sox9 was not expressed, both Sox8 and Sox10 occurred widely in neural crest cells migrating to the adrenal gland and in the gland itself, and they were down-regulated in cells expressing catecholaminergic traits.

Sox9 and Sox10 influence survival and migration of oligodendrocyte precursors in the spinal cord by regulating PDGF receptor alpha expression.

Specification of the myelin-forming oligodendrocytes of the central nervous system requires the Sox9 transcription factor, whereas terminal differentiation depends on the closely related Sox10. Between specification and terminal differentiation, Sox9 and Sox10 are co-expressed in oligodendrocyte precursors and are believed to exert additional functions. To identify such functions, we have deleted Sox9 specifically in already specified oligodendrocyte precursors of the spinal cord.