• Animal cells and systems
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• v.12 no.1
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• pp.23-33
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• 2008

The Zic family is a group of genes encoding zinc finger proteins that are highly expressed in the mammalian cerebellum. Zic genes are the vertebrate homologue of Drosophila pair-rule gene, odd-paired(opa), which plays important roles in the parasegmental subdivision as well as in the visceral mesoderm development of Drosophila embryos. Recent studies on human, mouse, frog, fish and ascidian Zic homologues support that Zic genes are involved in a variety of developmental processes, including neurogenesis, myogenesis, skeletal patterning, and left-right axis establishment. In an effort to explore possible functions of Zic proteins during vertebrate embryogenesis, we initially examined more detailed expression pattern of zebrafish homologue of zic3(zic3z). zic3z transcripts are detected in the neuroectoderm, neural plate, dorsal neural tube, and brain regions including eye field during early embryonic development. Marker DNA studies found that zic3z transcription is modulated by BMP, Wnt, and Nodal signals particularly in the dorsal and vegetal neuroectoderm at gastrula. Interfering with zic3z translation with zic3z-specific morpholino causes abnormal brain formation and expansion of the optic stalk cells. Retinal ganglion cells(RGCs) undergo abnormal neuronal differentiation. These findings suggest that zic3z defines the dorsal and vegetal neuroectoderm to specify brain formation and retinal neurogenesis during early embryonic development.

• Molecules and Cells
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• v.44 no.10
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• pp.723-735
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• 2021

Spemann organizer is a center of dorsal mesoderm and itself retains the mesoderm character, but it has a stimulatory role for neighboring ectoderm cells in becoming neuroectoderm in gastrula embryos. Goosecoid (Gsc) overexpression in ventral region promotes secondary axis formation including neural tissues, but the role of gsc in neural specification could be indirect. We examined the neural inhibitory and stimulatory roles of gsc in the same cell and neighboring cells contexts. In the animal cap explant system, Gsc overexpression inhibited expression of neural specific genes including foxd4l1.1, zic3, ncam, and neurod. Genome-wide chromatin immunoprecipitation sequencing (ChIP-seq) and promoter analysis of early neural genes of foxd4l1.1 and zic3 were performed to show that the neural inhibitory mode of gsc was direct. Site-directed mutagenesis and serially deleted construct studies of foxd4l1.1 promoter revealed that Gsc directly binds within the foxd4l1.1 promoter to repress its expression. Conjugation assay of animal cap explants was also performed to demonstrate an indirect neural stimulatory role for gsc. The genes for secretory molecules, Chordin and Noggin, were up-regulated in gsc injected cells with the neural fate only achieved in gsc uninjected neighboring cells. These experiments suggested that gsc regulates neuroectoderm formation negatively when expressed in the same cell and positively in neighboring cells via soluble factors. One is a direct suppressive circuit of neural genes in gsc expressing mesoderm cells and the other is an indirect stimulatory circuit for neurogenesis in neighboring ectoderm cells via secreted BMP antagonizers.

• Proceedings of the Zoological Society Korea Conference
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• 1997.10b
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• pp.203.2-203
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• 1997

No Abstract, See Full Text

• Molecules and Cells
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• v.23 no.1
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• pp.49-56
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• 2007

One of the goals of stem cell technology is to control the differentiation of human embryonic stem cells (hESCs), thereby generating large numbers of specific cell types for many applications including cell replacement therapy. Although individual hESC lines resemble each other in expressing pluripotency markers and telomerase activity, it is not clear whether they are equivalent in their developmental potential in vitro. We compared the developmental competence of three hESC lines (HSF6, Miz-hES4, and Miz-hES6). All three generated the three embryonic germ layers, extraembryonic tissues, and primordial germ cells during embryoid body (EB) formation. However, HSF6 and Miz-hES6 readily formed neuroectoderm, whereas Miz-hES4 differentiated preferentially into mesoderm and endoderm. Upon terminal differentiation, HSF6 and Miz-hES6 produced mainly neuronal cells whereas Miz-hES4 mainly formed mesendodermal derivatives, including endothelial cells, leukocyte progenitors, hepatocytes, and pancreatic cells. Our observations suggest that independently-derived hESCs may differ in their developmental potential.

• Molecules and Cells
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• v.26 no.6
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• pp.576-582
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• 2008

Nervous system development takes place after positional information has been established along the dorsal-ventral (D/V) axis. The initial subdivision provided by a gradient of nuclear dorsal protein is maintained by the zygotic genes expressed along the D/V axis. In this study, an investigation was conducted to determine the range of Dpp function in repressing the expression of eagle (eg) that is present in intermediate neuroblasts defective (ind) and muscle specific homeobox (msh) gene domain. eg is expressed in neuroblast (NB) 2-4, 3-3 and 6-4 of the msh domain, and NB7-3 of the ind domain at the embryonic stage 11. In decapentaplegic (dpp) loss-of-function mutant embryos, eg was ectopically expressed in the dorsal region, while in dpp gain-of-function mutants produced by sog or sca-GAL4/UAS-dpp, eg was repressed by Dpp. It is worthy of note that Dpp produced from sim;;dpp embryos showed that Dpp could function at long range. However, Dpp produced from en-GAL4/UAS-dpp or wg-GAL4/UAS-dpp primarily acted at short-range. This result demonstrated that this discrepancy seems to be due to the repression of Dpp to EGFR signaling in sim;;dpp embryos. Taken together, these results suggest that Dpp signaling works at short-range, but can function indirectly at long-range by way of repression of EGFR signaling during embryonic neurogenesis.

• Journal of Korean Neurosurgical Society
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• v.37 no.1
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• pp.29-33
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• 2005

Objective: Congenital dermal sinus is a rare congenital disease that results from the failure of the neuroectoderm to separate from the surface ectoderm during the process of neurulation, where there is communication between the skin and the deeper structures. Their pathogenesis, clinical course and treatment strategy are well known. We analyze our series and compare our results with other series. Methods: Twenty patients were diagnosed as congenital dermal sinus and confirmed pathologically from October 1986 to July 2003 at our hospital. We studied the patients' clinical manifestations, radiological findings and pathological profiles. Results: Seven cases were located in the suboccipital area and 13 cases were located in the spinal area. Interestingly, 4 of 13 spinal lesion cutaneous openings were located lower than the 3rd sacral body level. 8 of 20 lesions were terminated at neural structures, 4 of 20 lesions were terminated at the intradural portion and others terminated at the extradural portion. Nine anomalies were combined with the dermal sinus, including 4 lipomas, 2 Currarino's triad, 1 encephalocele, 1 myelomeningocele and 1 diastematomyelia. Eleven patients had dermoid tumors. Conclusion: Congenital Dermal Sinus must be surgically removed immediately if they are diagnosed. The surgical procedure of congenital dermal sinus is complete removal, but in some cases, complete removal is impossible. In those cases, we removed all epithelial tissues. We consider sacrococcygeal dimple almost invariably have no connection with intraspinal structures. But, if other cutaneous manifestations are combined with cutaneous pits, it can communicate with the sacrococcygeal dimple.

• Korean Journal of Veterinary Research
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• v.55 no.3
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• pp.181-184
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• 2015

Ciliary rootlet coiled coil protein (CROCC), the structural component that originates from the basal body at the proximal end of the ciliary rootlet, plays a crucial role in maintaining the cellular integrity of ciliated cells. In the current study, we cloned Xenopus CROCC and performed the expression analysis. The amino acid sequence of Xenopus laevis was related to those of Drosophila, cow, goat, horse, chicken, mouse and human. Reverse transcription polymerase chain reaction analysis revealed that CROCC mRNA encoding a coiled coil protein was present maternally, as well as throughout early development. In situ hybridization indicated that CROCC mRNA occurred in the animal pole of embryo during gastrulation and subsequently in the presumptive neuroectoderm at the end of gastrulation. At tailbud stages, CROCC mRNA expression was localized in the anterior roof plate of the developing brain, pharyngeal epithelium connected to gills, esophagus, olfactory placode, intestine and nephrostomes of the pronephric kidney. Our study suggests that CROCC may be responsible for control of the development of various ciliated organs.

• Clinical and Experimental Pediatrics
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• v.49 no.2
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• pp.212-216
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• 2006

Neurocutaneous melanosis is a rare congenital syndrome characterized by the presence of large or multiple congenital melanocytic nevi and benign pigment cell tumors of the leptomeninges. Neurocutaneous melanosis is thought to represent an error in the morphogenesis of embryonal neuroectoderm. We experienced a neonate who presented with giant, dark colored pigmented nevi covering chest, abdomen, neck and arms, with satellite lesions. Magnetic resonance image showed a nodular hyperintense lesion in the amygdala of the right temporal lobe, and T1-weighted images showed hyperintensities in the adjacent leptomeninges. We report a rare case of neurocutaneous melanosis with a brief review of related literature.

• The Journal of the Korean bone and joint tumor society
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• v.13 no.2
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• pp.130-134
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• 2007

Paragangliomas arise from a multicentric system of paraganglion cells derived from the neuroectoderm. Although these tumors are the most common in the head and neck region, they may occur in diverse locations including mediastinum, retroperitoneum and visceral organs. Spinal paragangliomas arising in the intradural space of the thoracolumbar spine have been reported rarely, with the majority located in the cauda equina. Only few cases of thoracic paraganglioma have been previously reported. We present an additional case of thoracolumbar paraganglioma and review the clinical MRI and histopathological features of this unusual tumor.

• Archives of Plastic Surgery
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• v.37 no.6
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• pp.827-830
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• 2010

Purpose: Congenital spinal dermal sinus tract is a rare lesion connecting skin to deeper structures including neural tissue. It results from the failure of the neuroectoderm to separate from the cutaneous ectoderm in the third to fifth week of gestation. The common locations are the lumbosacral and occipital regions. Sometimes it extends to spinal canal. In this paper we report a case of congenital spinal dermal sinus tract in the coccyx. Methods: A 21-month-old male child born after an uncomplicated full-term pregnancy was admitted to our institute with a midline dermal sinus and a cartilaginous protrusion in the coccygeal region. There were no signs of infection. Neurologic examination showed no functional deficit in both lower limbs. He was treated with complete excision of the tract and an underlying accessory cartilage. Results: The spinal dermal sinus tract was extended from the skin to the coccyx. The stalk was loosely attached to the accessory cartilage of coccyx. At that point, it was dissected from the accessory cartilage and resected. The accessory cartilage was also resected at the bone and cartilage junction. During the follow-up period of 6 months, the wound healed well without any complication nor recurrence. Conclusion: Congenital spinal dermal sinus tract is known as a form of spinal dysraphism. In order to prevent complications, timely surgical intervention including complete resection of sinus tract with correction of associated abnormalities is of utmost importance.