The management of ectodermal dysplasia and severe hypodontia. International conference statements.

PubMed

Hobkirk, J A; Nohl, F; Bergendal, B; Storhaug, K; Richter, M K

2006-09-01

An international conference on ectodermal dysplasias and hypodontia, held in London in 2004, featured a session devoted to the management of the ectodermal dysplasias and severe hypodontia. This paper presents a set of statements prepared by an international specialist panel, including representatives of patient support groups, who presented and subsequently debated a series of papers on this subject. The following topics were explored: potential roles of patient support groups; core care standards, including the roles and composition of medical and dental multidisciplinary teams for treating these conditions; the format of a baseline data set for patients with an ED; and priorities for research in ectodermal dysplasias, with particular regard to laboratory and clinical studies, and research methodology. The statements are intended to form an international framework for developing patient care pathways, and collaborative research in this field.

Integrative genomic analyses identify LIN28 and OLIG2 as markers of survival and metastatic potential in childhood central nervous system primitive neuro-ectodermal brain tumours

PubMed Central

Picard, Daniel; Miller, Suzanne; Hawkins, Cynthia E; Bouffet, Eric; Rogers, Hazel A; Chan, Tiffany SY; Kim, Seung-Ki; Ra, Young-Shin; Fangusaro, Jason; Korshunov, Andrey; Toledano, Helen; Nakamura, Hideo; Hayden, James T; Chan, Jennifer; Lafay-Cousin, Lucie; Hu, Ping X; Fan, Xing; Muraszko, Karin M; Pomeroy, Scott L; Lau, Ching C; Ng, Ho-Keung; Jones, Chris; Meter, Timothy Van; Clifford, Steven C; Eberhart, Charles; Gajjar, Amar; Pfister, Stefan M; Grundy, Richard G; Huang, Annie

2013-01-01

Background Childhood Central Nervous System Primitive Neuro-Ectodermal brain Tumours (CNS-PNETs) are highly aggressive brain tumours for which molecular features and best therapeutic strategy remains unknown. We interrogated a large cohort of these rare tumours in order to identify molecular markers that will enhance clinical management of CNS-PNET. Methods Transcriptional and copy number profiles from primary hemispheric CNS-PNETs were examined using clustering, gene and pathways enrichment analyses to discover tumour sub-groups and group-specific molecular markers. Immuno-histochemical and/or gene expression analyses were used to validate and examine the clinical significance of novel sub-group markers in 123 primary CNS-PNETs. Findings Three molecular sub-groups of CNS-PNETs distinguished by primitive neural (Group 1), oligo-neural (Group 2) and mesenchymal lineage (Group 3) gene expression signature were identified. Tumour sub-groups exhibited differential expression of cell lineage markers, LIN28 and OLIG2, and correlated with distinct demographics, survival and metastatic incidence. Group 1 tumours affected primarily younger females; male: female ratios were respectively 0.61 (median age 2.9 years; 95% CI: 2.4–5.2; p≤ 0.005), 1.25 (median age 7.9 years; 95% CI: 6–9.7) and 1.63 (median age 5.9 years; 95% CI: 4.9–7.8) for group 1, 2 and 3 patients. Overall outcome was poorest in group 1 patients which had a median survival of 0.8 years (95% CI: 0.47–1.2; p=0.019) as compared to 1.8 years (95% CI: 1.4–2.3) and 4.3 years; (95% CI: 0.82–7.8) respectively for group 2 and 3 patients. Group 3 tumours had the highest incidence of metastases at diagnosis; M0: M+ ratio were respectively 0.9 and 3.9 for group 3, versus group 1 and 2 tumours combined (p=0.037). Interpretation LIN28 and OLIG2 represent highly promising, novel diagnostic and prognostic molecular markers for CNS PNET that warrants further evaluation in prospective clinical trials. PMID:22691720

Mouth development.

PubMed

Chen, Justin; Jacox, Laura A; Saldanha, Francesca; Sive, Hazel

2017-09-01

A mouth is present in all animals, and comprises an opening from the outside into the oral cavity and the beginnings of the digestive tract to allow eating. This review focuses on the earliest steps in mouth formation. In the first half, we conclude that the mouth arose once during evolution. In all animals, the mouth forms from ectoderm and endoderm. A direct association of oral ectoderm and digestive endoderm is present even in triploblastic animals, and in chordates, this region is known as the extreme anterior domain (EAD). Further support for a single origin of the mouth is a conserved set of genes that form a 'mouth gene program' including foxA and otx2. In the second half of this review, we discuss steps involved in vertebrate mouth formation, using the frog Xenopus as a model. The vertebrate mouth derives from oral ectoderm from the anterior neural ridge, pharyngeal endoderm and cranial neural crest (NC). Vertebrates form a mouth by breaking through the body covering in a precise sequence including specification of EAD ectoderm and endoderm as well as NC, formation of a 'pre-mouth array,' basement membrane dissolution, stomodeum formation, and buccopharyngeal membrane perforation. In Xenopus, the EAD is also a craniofacial organizer that guides NC, while reciprocally, the NC signals to the EAD to elicit its morphogenesis into a pre-mouth array. Human mouth anomalies are prevalent and are affected by genetic and environmental factors, with understanding guided in part by use of animal models. WIREs Dev Biol 2017, 6:e275. doi: 10.1002/wdev.275 For further resources related to this article, please visit the WIREs website. © 2017 The Authors. WIREs Developmental Biology published by Wiley Periodicals, Inc.

Ectoderm gene activation in sea urchin embryos mediated by the CCAAT-binding factor.

PubMed

Li, Xiaotao; Bhattacharya, Chitralekha; Dayal, Sandeep; Maity, Sankar; Klein, William H

2002-05-01

Transcriptional enhancers are short stretches of DNA that function to achieve highly specific patterns of gene expression. To identify the mechanisms by which enhancers achieve their specificity, we made use of an enhancer from the aboral ectoderm-specific spec2a gene of the sea urchin Strongylocentrotus purpuratus. The spec2a enhancer contains five cis-regulatory elements within 78 base pairs that interact with five distinct DNA-binding proteins to confer aboral ectoderm expression. Here, we present an analysis of the sea urchin CCAAT binding factor (CBF), which binds to a CCAAT motif within the spec2a enhancer. S. purpuratus CBF and SpOtx, a ubiquitously expressed factor, act together at closely placed cis-regulatory elements to mediate spec2a transcription in the ectoderm. SpCBF was the sole factor that bound to the spec2a CCAAT element, and two of the three subunits that make up the CBF holoprotein were cloned and shown to have high sequence conservation with their vertebrate orthologs. Based on its involvement in the regulation of several other sea urchin genes, SpCBF appears to be a major transcription factor in the sea urchin embryo for positive regulation of ectoderm gene expression. In addition to its role in vertebrate cell growth and proliferation, our results indicate that CBF also functions at the early stages of germ layer formation, namely ectoderm differentiation.

A Novel Splicesite Mutation in the EDAR Gene Causes Severe Autosomal Recessive Hypohydrotic (Anhidrotic) Ectodermal Dysplasia in an Iranian Family.

PubMed

Torkamandi, Shahram; Gholami, Milad; Mohammadi-Asl, Javad; Rezaie, Somaye; Zaimy, Mohammad Ali; Omrani, Mir Davood

2016-01-01

Hypohidrotic ectodermal dysplasia (HED) is a rare congenital disorder arising from deficient development of ectoderm-derived structures including skin, nails, glands and teeth. The phenotype of HED is associated with mutation in EDA, EDAR, EDARADD and NEMO genes, all of them disruptingNF-κB signaling cascade necessary for initiation, formation and differentiation in the embryo and adult. Here we describe a novel acceptor splice site mutation c.730-2 A>G(IVS 8-2 A>G) in EDAR gene in homozygous form in all affected members of a family,and in heterozygous form in carriers. Bioinformatics analysis showed that this mutation can create a new broken splicing site and lead to aberrant splicing.

Molecular stages of rapid and uniform neuralization of human embryonic stem cells.

PubMed

Bajpai, R; Coppola, G; Kaul, M; Talantova, M; Cimadamore, F; Nilbratt, M; Geschwind, D H; Lipton, S A; Terskikh, A V

2009-06-01

Insights into early human development are fundamental for our understanding of human biology. Efficient differentiation of human embryonic stem cells (hESCs) into neural precursor cells is critical for future cell-based therapies. Here, using defined conditions, we characterized a new method for rapid and uniform differentiation of hESCs into committed neural precursor cells (designated C-NPCs). Dynamic gene expression analysis identified several distinct stages of ESC neuralization and revealed functional modules of coregulated genes and pathways. The first wave of gene expression changes, likely corresponding to the transition through primitive ectoderm, started at day 3, preceding the formation of columnar neuroepithelial rosettes. The second wave started at day 5, coinciding with the formation of rosettes. The majority of C-NPCs were positive for both anterior and posterior markers of developing neuroepithelium. In culture, C-NPCs became electrophysiologically functional neurons; on transplantation into neonatal mouse brains, C-NPCs integrated into the cortex and olfactory bulb, acquiring appropriate neuronal morphologies and markers. Compared to rosette-NPCs,(1) C-NPCs exhibited limited in vitro expansion capacity and did not express potent oncogenes such as PLAG1 or RSPO3. Concordantly, we never detected tumors or excessive neural proliferation after transplantation of C-NPCs into mouse brains. In conclusion, our study provides a framework for future analysis of molecular signaling during ESC neuralization.

An evaluation of clinical, radiological and three-dimensional dental tomography findings in ectodermal dysplasia cases

PubMed Central

Doğan, Mehmet-Sinan; Callea, Michele; Aksoy, Orhan; Clarich, Gabriella; Günay, Ayşe; Günay, Ahmet; Güven, Sedat; Maglione, Michele; Akkuş, Zeki

2015-01-01

Background This study aimed to review the results related to head and jaw disorders in cases of ectodermal dysplasia. The evaluation of ectodermal dysplasia cases was made by clincal examination and examination of the jaw and facial areas radiologically and on cone-beam 3-dimensional dental tomography (CBCT) images. Material and Methods In the 36 cases evaluated in the study, typical clinical findings of pure hypohidrotic ectodermal displasia (HED) were seen, such as missing teeth, dry skin, hair and nail disorders. CBCT images were obtained from 12 of the 36 cases, aged 1.5- 45 years, and orthodontic analyses were made on these images. Results The clinical and radiological evaluations determined, hypodontia or oligodontia, breathing problems, sweating problems, a history of fever, sparse hair, saddle nose, skin peeling, hypopigmentation, hyperpigmentation, finger and nail deformities, conical teeth anomalies, abnormal tooth root formation, tooth resorption in the root, gingivitis, history of epilepsy, absent lachrymal canals and vision problems in the cases which included to the study. Conclusions Ectodermal dysplasia cases have a particular place in dentistry and require a professional, multi-disciplinary approach in respect of the chewing function, orthognathic problems, growth, oral and dental health. It has been understood that with data obtained from modern technologies such as three-dimensional dental tomography and the treatments applied, the quality of life of these cases can be improved. Key words: Ectodermal dysplasia, three-dimensional dental tomography. PMID:25662550

A Novel Splicesite Mutation in the EDAR Gene Causes Severe Autosomal Recessive Hypohydrotic (Anhidrotic) Ectodermal Dysplasia in an Iranian Family

PubMed Central

Torkamandi, Shahram; Gholami, Milad; Mohammadi-asl, Javad; Rezaie, Somaye; Zaimy, Mohammad Ali; Omrani, Mir Davood

2016-01-01

Hypohidrotic ectodermal dysplasia (HED) is a rare congenital disorder arising from deficient development of ectoderm-derived structures including skin, nails, glands and teeth. The phenotype of HED is associated with mutation in EDA, EDAR, EDARADD and NEMO genes, all of them disruptingNF-κB signaling cascade necessary for initiation, formation and differentiation in the embryo and adult. Here we describe a novel acceptor splice site mutation c.730-2 A>G(IVS 8-2 A>G) in EDAR gene in homozygous form in all affected members of a family,and in heterozygous form in carriers. Bioinformatics analysis showed that this mutation can create a new broken splicing site and lead to aberrant splicing. PMID:28357203

Ophthalmic manifestations in patients with ectodermal dysplasia syndromes.

PubMed

Keklikci, Ugur; Yavuz, Izzet; Tunik, Selcuk; Ulku, Zelal Baskan; Akdeniz, Sedat

2014-01-01

Ectodermal dysplasia (ED) is a disorder that results from abnormal formation of at least two of the four major ectodermal derivatives in the developing embryo. The ectoderm of the embryo forms the skin, teeth, hair and nails, sweat glands and part of the eyes. The aim of this article is to reveal ophthalmologic symptoms and signs as multidisciplinary, reliable criteria for ectodermal dysplasia. In this retrospective study, 24 patients with ED were analyzed from the recorded data. Ophthalmological examination of the patients, who had previously received the diagnosis of ED in the dental department, was done. During the examination, ocular symptoms related to tear film, corneal changes, lacrimal duct, periorbital hyperpigmentation, alteration lashes and eyebrows were evaluated. The age ranged between 3-45, and the mean and standard deviation (Mean ± SD) was 15.8 ± 7.4 years. The number of males was 13 (54.2%) and females, 11 (45.8%). Eighteen patients (75.0%) suffered from ocular complaints related to the ocular surface. In 11 of the patients with ED, there were dry eye symptoms. While the mean age of cases with eye involvement was 17.5, it was 23.1 in cases with dry eye symptoms. In the study, it was observed that, in patients with ED, ocular complaints, particularly dry eye symptoms, may increase as age advances.

Signaling by Bone Morphogenetic Proteins directs formation of an ectodermal signaling center that regulates craniofacial development

PubMed Central

Foppiano, Silvia; Hu, Diane; Marcucio, Ralph S.

2008-01-01

We previously described a signaling center, the Frontonasal Ectodermal Zone (FEZ) that regulates growth and patterning of the frontonasal process (FNP). The FEZ is comprised of FNP ectoderm flanking a boundary between Sonic hedgehog (Shh) and Fibroblast growth factor 8 (Fgf8) expression domains. Our objective was to examine BMP signaling during formation of the FEZ. We blocked BMP signaling throughout the FNP prior to FEZ formation by infecting chick embryos at stage 10 (HH10) with a replication competent avian retrovirus encoding the BMP antagonist Noggin. We assessed gene expression patterns in the FNP 72 hours after infection (~HH22) and observed that Shh expression was reduced or absent. In the mesenchyme we observed that Bmp2 transcripts were absent while the Bmp4 expression domain was expanded proximally. In addition to the molecular changes, infected embryos also exhibited facial malformations at 72 and 96 hours after infection suggesting that the FEZ did not form. Our data indicate that reduced cell proliferation, but not apoptosis, in the mesenchyme contributed to the phenotype that we observed. Additionally, adding exogenous SHH into the mesenchyme of RCAS-Noggin infected embryos did not restore Bmp2 and Bmp4 to a normal pattern of expression. These data indicate that BMP signaling mediates interactions between tissues in the FNP that regulate FEZ formation; and that the correct pattern of Bmp2 and Bmp4, but not Bmp7, expression in the FNP mesenchyme requires signaling by the BMP pathway. PMID:18028903

Novel homozygous mutation, c.400C>T (p.Arg134*), in the PVRL1 gene underlies cleft lip/palate-ectodermal dysplasia syndrome in an Asian patient.

PubMed

Yoshida, Kazue; Hayashi, Ryota; Fujita, Hideki; Kubota, Masaya; Kondo, Mai; Shimomura, Yutaka; Niizeki, Hironori

2015-07-01

Cleft lip/palate-ectodermal dysplasia syndrome is a rare, autosomal recessive disorder caused by homozygous loss-of-function mutations of the poliovirus receptor-like 1 (PVRL1) gene encoding nectin-1. Nectin-1 is a cell-cell adhesion molecule that is important for the initial step in the formation of adherens junctions and tight junctions; it is expressed in keratinocytes, neurons, and the developing face and palate. Clinical manifestations comprise a unique facial appearance with cleft lip/palate, ectodermal dysplasia, cutaneous syndactyly of the fingers and/or toes, and in some cases, mental retardation. We present the first report, to our knowledge, of an Asian individual with cleft lip/palate-ectodermal dysplasia syndrome with a novel PVRL1 mutation. A 7-year-old Japanese boy, the first child of a consanguineous marriage, showed hypohidrotic ectodermal dysplasia with sparse, brittle, fine, dry hair and hypodontia, the unique facial appearance with cleft lip/palate, cutaneous syndactyly of the fingers and mild mental retardation. Scanning electron microscopic examination of the hair demonstrated pili torti and pili trianguli et canaliculi. Mutation analysis of exon 2 of PVRL1 revealed a novel homozygous nonsense mutation, c.400C>T (p.Arg134*). His parents were heterozygous for the mutant alleles. All four PVRL1 mutations identified in cleft lip/palate-ectodermal dysplasia syndrome to date, including this study, resulted in truncated proteins that lack the transmembrane domain and intracellular domain of nectin-1, which is necessary to initiate the cell-cell adhesion process. © 2015 Japanese Dermatological Association.

In situ hybridization analysis of the temporospatial expression of the midkine/pleiotrophin family in rat embryonic pituitary gland.

PubMed

Fujiwara, Ken; Maliza, Rita; Tofrizal, Alimuddin; Batchuluun, Khongorzul; Ramadhani, Dini; Tsukada, Takehiro; Azuma, Morio; Horiguchi, Kotaro; Kikuchi, Motoshi; Yashiro, Takashi

2014-07-01

Pituitary gland development is controlled by numerous signaling molecules, which are produced in the oral ectoderm and diencephalon. A newly described family of heparin-binding growth factors, namely midkine (MK)/pleiotrophin (PTN), is involved in regulating the growth and differentiation of many tissues and organs. Using in situ hybridization with digoxigenin-labeled cRNA probes, we detected cells expressing MK and PTN in the developing rat pituitary gland. At embryonic day 12.5 (E12.5), MK expression was localized in Rathke's pouch (derived from the oral ectoderm) and in the neurohypophyseal bud (derived from the diencephalon). From E12.5 to E19.5, MK mRNA was expressed in the developing neurohypophysis, and expression gradually decreased in the developing adenohypophysis. To characterize MK-expressing cells, we performed double-staining of MK mRNA and anterior pituitary hormones. At E19.5, no MK-expressing cells were stained with any hormone. In contrast, PTN was expressed only in the neurohypophysis primordium during all embryonic stages. In situ hybridization clearly showed that MK was expressed in primitive (immature/undifferentiated) adenohypophyseal cells and neurohypophyseal cells, whereas PTN was expressed only in neurohypophyseal cells. Thus, MK and PTN might play roles as signaling molecules during pituitary development.

An evaluation of clinical, radiological and three-dimensional dental tomography findings in ectodermal dysplasia cases.

PubMed

Doğan, Mehmet-Sinan; Callea, Michele; Yavuz, Ìzzet; Aksoy, Orhan; Clarich, Gabriella; Günay, Ayse; Günay, Ahmet; Güven, Sedat; Maglione, Michele; Akkuş, Zeki

2015-05-01

This study aimed to review the results related to head and jaw disorders in cases of ectodermal dysplasia. The evaluation of ectodermal dysplasia cases was made by clinical examination and examination of the jaw and facial areas radiologically and on cone-beam 3-dimensional dental tomography (CBCT) images. In the 36 cases evaluated in the study, typical clinical findings of pure hypohidrotic ectodermal displasia (HED) were seen, such as missing teeth, dry skin, hair and nail disorders. CBCT images were obtained from 12 of the 36 cases, aged 1.5- 45 years, and orthodontic analyses were made on these images. The clinical and radiological evaluations determined, hypodontia or oligodontia, breathing problems, sweating problems, a history of fever, sparse hair, saddle nose, skin peeling, hypopigmentation, hyperpigmentation, finger and nail deformities, conical teeth anomalies, abnormal tooth root formation, tooth resorption in the root, gingivitis, history of epilepsy, absent lachrymal canals and vision problems in the cases which included to the study. Ectodermal dysplasia cases have a particular place in dentistry and require a professional, multi-disciplinary approach in respect of the chewing function, orthognathic problems, growth, oral and dental health. It has been understood that with data obtained from modern technologies such as three-dimensional dental tomography and the treatments applied, the quality of life of these cases can be improved.

Familial ectodermal dysplasia: a peers' agony.

PubMed

Hegde, Karthik; Kashyap, Roopashri Rajesh; Nair, Gopakumar; Nair, Preeti P

2013-07-23

Ectodermal dysplasias include a various group of inherited disorders which share primary defect in the development of two or more tissues of embryonic ectodermal origin. Though there are many subtypes, ectodermal dysplasias are mainly hidrotic ectodermal dysplasia and hypohidrotic ectodermal dysplasia, among which the most common variety is X linked hypohidrotic ectodermal dysplasia. We report a rare case of X linked hypohidrotic ectodermal dysplasia occurring in a family with various skin, hair and oral abnormalities.

The role of Foxi family transcription factors in otic placode and neural crest cell development

PubMed Central

Edlund, Renée K.; Birol, Onur; Groves, Andrew K.

2015-01-01

The mammalian outer, middle and inner ears have different embryonic origins and evolved at different times in the vertebrate lineage. The outer ear is derived from first and second branchial arch ectoderm and mesoderm, the middle ear ossicles are derived from neural crest mesenchymal cells that invade the first and second branchial arches, whereas the inner ear and its associated vestibule-acoustic (VIIIth) ganglion are derived from the otic placode. In this review, we discuss recent findings in the development of these structures and describe the contributions of members of a Forkhead transcription factor family, the Foxi family to their formation. Foxi transcription factors are critical for formation of the otic placode, survival of the branchial arch neural crest, and developmental remodeling of the branchial arch ectoderm. PMID:25662269

FGF signaling induces mesoderm in the hemichordate Saccoglossus kowalevskii

PubMed Central

Green, Stephen A.; Norris, Rachael P.; Terasaki, Mark; Lowe, Christopher J.

2013-01-01

FGFs act in vertebrate mesoderm induction and also play key roles in early mesoderm formation in ascidians and amphioxus. However, in sea urchins initial characterizations of FGF function do not support a role in early mesoderm induction, making the ancestral roles of FGF signaling and mechanisms of mesoderm specification in deuterostomes unclear. In order to better characterize the evolution of mesoderm formation, we have examined the role of FGF signaling during mesoderm development in Saccoglossus kowalevskii, an experimentally tractable representative of hemichordates. We report the expression of an FGF ligand, fgf8/17/18, in ectoderm overlying sites of mesoderm specification within the archenteron endomesoderm. Embryological experiments demonstrate that mesoderm induction in the archenteron requires contact with ectoderm, and loss-of-function experiments indicate that both FGF ligand and receptor are necessary for mesoderm specification. fgf8/17/18 gain-of-function experiments establish that FGF8/17/18 is sufficient to induce mesoderm in adjacent endomesoderm. These experiments suggest that FGF signaling is necessary from the earliest stages of mesoderm specification and is required for all mesoderm development. Furthermore, they suggest that the archenteron is competent to form mesoderm or endoderm, and that FGF signaling from the ectoderm defines the location and amount of mesoderm. When considered in a comparative context, these data support a phylogenetically broad requirement for FGF8/17/18 signaling in mesoderm specification and suggest that FGF signaling played an ancestral role in deuterostome mesoderm formation. PMID:23344709

Regional neural tube closure defined by the Grainy head-like transcription factors.

PubMed

Rifat, Yeliz; Parekh, Vishwas; Wilanowski, Tomasz; Hislop, Nikki R; Auden, Alana; Ting, Stephen B; Cunningham, John M; Jane, Stephen M

2010-09-15

Primary neurulation in mammals has been defined by distinct anatomical closure sites, at the hindbrain/cervical spine (closure 1), forebrain/midbrain boundary (closure 2), and rostral end of the forebrain (closure 3). Zones of neurulation have also been characterized by morphologic differences in neural fold elevation, with non-neural ectoderm-induced formation of paired dorso-lateral hinge points (DLHP) essential for neural tube closure in the cranial and lower spinal cord regions, and notochord-induced bending at the median hinge point (MHP) sufficient for closure in the upper spinal region. Here we identify a unifying molecular basis for these observations based on the function of the non-neural ectoderm-specific Grainy head-like genes in mice. Using a gene-targeting approach we show that deletion of Grhl2 results in failed closure 3, with mutants exhibiting a split-face malformation and exencephaly, associated with failure of neuro-epithelial folding at the DLHP. Loss of Grhl3 alone defines a distinct lower spinal closure defect, also with defective DLHP formation. The two genes contribute equally to closure 2, where only Grhl gene dosage is limiting. Combined deletion of Grhl2 and Grhl3 induces severe rostral and caudal neural tube defects, but DLHP-independent closure 1 proceeds normally in the upper spinal region. These findings provide a molecular basis for non-neural ectoderm mediated formation of the DLHP that is critical for complete neuraxis closure. (c) 2010 Elsevier Inc. All rights reserved.

Development and evolution of the vertebrate primary mouth

PubMed Central

Soukup, Vladimír; Horácek, Ivan; Cerny, Robert

2013-01-01

The vertebrate oral region represents a key interface between outer and inner environments, and its structural and functional design is among the limiting factors for survival of its owners. Both formation of the respective oral opening (primary mouth) and establishment of the food-processing apparatus (secondary mouth) require interplay between several embryonic tissues and complex embryonic rearrangements. Although many aspects of the secondary mouth formation, including development of the jaws, teeth or taste buds, are known in considerable detail, general knowledge about primary mouth formation is regrettably low. In this paper, primary mouth formation is reviewed from a comparative point of view in order to reveal its underestimated morphogenetic diversity among, and also within, particular vertebrate clades. In general, three main developmental modes were identified. The most common is characterized by primary mouth formation via a deeply invaginated ectodermal stomodeum and subsequent rupture of the bilaminar oral membrane. However, in salamander, lungfish and also in some frog species, the mouth develops alternatively via stomodeal collar formation contributed both by the ecto- and endoderm. In ray-finned fishes, on the other hand, the mouth forms via an ectoderm wedge and later horizontal detachment of the initially compressed oral epithelia with probably a mixed germ-layer derivation. A very intriguing situation can be seen in agnathan fishes: whereas lampreys develop their primary mouth in a manner similar to the most common gnathostome pattern, hagfishes seem to undergo a unique oropharyngeal morphogenesis when compared with other vertebrates. In discussing the early formative embryonic correlates of primary mouth formation likely to be responsible for evolutionary–developmental modifications of this area, we stress an essential role of four factors: first, positioning and amount of yolk tissue; closely related to, second, endoderm formation during gastrulation, which initiates the process and constrains possible evolutionary changes within this area; third, incipient structure of the stomodeal primordium at the anterior neural plate border, where the ectoderm component of the prospective primary mouth is formed; and fourth, the prime role of Pitx genes for establishment and later morphogenesis of oral region both in vertebrates and non-vertebrate chordates. PMID:22804777

Keratoprosthesis in Ectodermal Dysplasia.

PubMed

Wozniak, Rachel A F; Gonzalez, Mithra; Aquavella, James V

2016-07-01

To describe the complex surgical management and novel medical approach for a keratoprosthesis (KPro Boston type I) in a monocular, 73-year-old patient with ectodermal dysplasia and chronic, noninfectious corneal necrosis. Best-corrected visual acuity (BCVA) was measured with Snellen letters. Surgical intervention included an amniotic membrane graft, complete replacement of the KPro, conjunctival flap graft, corneal donor tissue grafts combined with inferior rectus muscle advancement, periosteal tissue graft, tarso-conjunctival flap construction, and symblepharolysis. Infliximab was used as a medical adjunctive therapy. Initial KPro placement provided a BCVA of 20/25 and long-term stability. Subsequent chronic melting at the optic border necessitated numerous surgeries to prevent extrusion and failure. Ultimate fistulization was addressed with the formation of a surgical pocket. The addition of infliximab promoted ocular surface stability, and the patient has maintained a BCVA of 20/80. Ectodermal dysplasia can result in eyelid and corneal abnormalities, requiring a KPro for visual restoration. In the setting of chronic, sterile corneal melt, novel surgical approaches and the off-label use of infliximab allowed for visual rehabilitation.

Regulation of cell protrusions by small GTPases during fusion of the neural folds

PubMed Central

Rolo, Ana; Savery, Dawn; Escuin, Sarah; de Castro, Sandra C; Armer, Hannah EJ; Munro, Peter MG; Molè, Matteo A; Greene, Nicholas DE; Copp, Andrew J

2016-01-01

Epithelial fusion is a crucial process in embryonic development, and its failure underlies several clinically important birth defects. For example, failure of neural fold fusion during neurulation leads to open neural tube defects including spina bifida. Using mouse embryos, we show that cell protrusions emanating from the apposed neural fold tips, at the interface between the neuroepithelium and the surface ectoderm, are required for completion of neural tube closure. By genetically ablating the cytoskeletal regulators Rac1 or Cdc42 in the dorsal neuroepithelium, or in the surface ectoderm, we show that these protrusions originate from surface ectodermal cells and that Rac1 is necessary for the formation of membrane ruffles which typify late closure stages, whereas Cdc42 is required for the predominance of filopodia in early neurulation. This study provides evidence for the essential role and molecular regulation of membrane protrusions prior to fusion of a key organ primordium in mammalian development. DOI: http://dx.doi.org/10.7554/eLife.13273.001 PMID:27114066

WNT/β-catenin signaling mediates human neural crest induction via a pre-neural border intermediate.

PubMed

Leung, Alan W; Murdoch, Barbara; Salem, Ahmed F; Prasad, Maneeshi S; Gomez, Gustavo A; García-Castro, Martín I

2016-02-01

Neural crest (NC) cells arise early in vertebrate development, migrate extensively and contribute to a diverse array of ectodermal and mesenchymal derivatives. Previous models of NC formation suggested derivation from neuralized ectoderm, via meso-ectodermal, or neural-non-neural ectoderm interactions. Recent studies using bird and amphibian embryos suggest an earlier origin of NC, independent of neural and mesodermal tissues. Here, we set out to generate a model in which to decipher signaling and tissue interactions involved in human NC induction. Our novel human embryonic stem cell (ESC)-based model yields high proportions of multipotent NC cells (expressing SOX10, PAX7 and TFAP2A) in 5 days. We demonstrate a crucial role for WNT/β-catenin signaling in launching NC development, while blocking placodal and surface ectoderm fates. We provide evidence of the delicate temporal effects of BMP and FGF signaling, and find that NC development is separable from neural and/or mesodermal contributions. We further substantiate the notion of a neural-independent origin of NC through PAX6 expression and knockdown studies. Finally, we identify a novel pre-neural border state characterized by early WNT/β-catenin signaling targets that displays distinct responses to BMP and FGF signaling from the traditional neural border genes. In summary, our work provides a fast and efficient protocol for human NC differentiation under signaling constraints similar to those identified in vivo in model organisms, and strengthens a framework for neural crest ontogeny that is separable from neural and mesodermal fates. © 2016. Published by The Company of Biologists Ltd.

Ectrodactyly-ectodermal dysplasia clefting syndrome (EEC syndrome).

PubMed

Koul, Monika; Dwivedi, Rahul; Upadhyay, Vinod

2014-01-01

Ectrodactyly-ectodermal dysplasia- clefting syndrome (also k/a. split hand- split foot malformation /split hand-split foot ectodermal dysplasia- cleft syndrome/ectodermal dysplasia cleft lip/cleft palate syndrome) a rare form of ectodermal dysplasia, is an autosomal dominant disorder inherited as a genetic trait and characterized by a triad of (i) ectrodactyly, (ii) ectodermal dysplasia and, (iii) & facial clefts.

Apoptosis generates mechanical forces that close the lens vesicle in the chick embryo

NASA Astrophysics Data System (ADS)

Oltean, Alina; Taber, Larry A.

2018-03-01

During the initial stages of eye development, optic vesicles grow laterally outward from both sides of the forebrain and come into contact with the surrounding surface ectoderm (SE). Within the region of contact, these layers then thicken locally to create placodes and invaginate to form the optic cup (primitive retina) and lens vesicle (LV), respectively. This paper examines the biophysical mechanisms involved in LV formation, which consists of three phases: (1) lens placode formation; (2) invagination to create the lens pit (LP); and (3) closure to form a complete ellipsoidally shaped LV. Previous studies have suggested that extracellular matrix deposited between the SE and optic vesicle causes the lens placode to form by locally constraining expansion of the SE as it grows, while actomyosin contraction causes this structure to invaginate. Here, using computational modeling and experiments on chick embryos, we confirm that these mechanisms for Phases 1 and 2 are physically plausible. Our results also suggest, however, that they are not sufficient to close the LP during Phase 3. We postulate that apoptosis provides an additional mechanism by removing cells near the LP opening, thereby decreasing its circumference and generating tension that closes the LP. This hypothesis is supported by staining that shows a ring of cell death located around the LP opening during closure. Inhibiting apoptosis in cultured embryos using caspase inhibitors significantly reduced LP closure, and results from a finite-element model indicate that closure driven by cell death is plausible. Taken together, our results suggest an important mechanical role for apoptosis in lens development.

Anhidrotic ectodermal dysplasia presenting as atrophic rhinitis.

PubMed

Barman, Debasis; Mandal, Satadal; Nandi, Santanu; Banerjee, Pranabashish; Rashid, M A

2011-11-01

Ectodermal dysplasia is a complex group of familial disorders with numerous clinical characteristics, with an incidence of 7 in 10000 born alive children. Ectodermal dysplasia affects structures of ectodermal origin like the skin and its appendages as well as other non-ectodermal structures. The most common sites of involvement are the defects in the skin, hair, teeth, nails and sweat glands,which are of ectodermal origin. Though the dermatologists and paediatricians often manage such cases, we report one case of ectodermal dysplasia presenting with atrophic rhinitis.

Identification of a spatially specific enhancer element in the chicken Msx-2 gene that regulates its expression in the apical ectodermal ridge of the developing limb buds of transgenic mice.

PubMed

Sumoy, L; Wang, C K; Lichtler, A C; Pierro, L J; Kosher, R A; Upholt, W B

1995-07-01

Msx-2 is a member of the Msx family of homeobox-containing genes expressed in a variety of embryonic tissues involved in epithelial-mesenchymal interactions and pattern formation. In the developing chick limb bud, Msx-2 is expressed in the apical ectodermal ridge, which plays a crucial role in directing the growth and patterning of limb mesoderm. In addition, Msx-2 is expressed in the anterior nonskeletal-forming mesoderm of the limb bud, in the posterior necrotic zone, and in the interdigital mesenchyme. Studies of the altered expression patterns of Msx-2 in amelic and polydactylous mutant chick limbs have suggested that the apical ectodermal ridge and mesodermal domains of Msx-2 expression are independently regulated and that there might be separate cis-regulatory elements in the Msx-2 gene controlling its spatially distinct domains of expression. To test this hypothesis, we have isolated the chicken Msx-2 gene and have tested the ability of various regions of the gene to target expression of LacZ reporter gene to specific regions of the limbs of transgenic mice. A variety of these constructs are consistently expressed only in the apical ectodermal ridge and the ectoderm of the genital tubercle and are not expressed in the mesoderm of the limb bud or in other regions of the embryo where the endogenous Msx-2 gene is expressed. These results suggest the presence of spatially specific cis-regulatory elements in the Msx-2 gene. We identified a 348-bp region in the 5' flanking region of the Msx-2 gene which can act as an apical ectodermal ridge enhancer element when placed in reverse orientation in front of the reporter gene with transcription initiation directed by the minimal hsp68 promoter.

Hypohidrotic and hidrotic ectodermal dysplasia: a report of two cases.

PubMed

Vasconcelos Carvalho, Marianne; Romero Souto de Sousa, José; Paiva Correa de Melo, Filipe; Fonseca Faro, Tatiane; Nunes Santos, Ana Clara; Carvalho, Silvia; Veras Sobral, Ana Paula

2013-07-14

Ectodermal dysplasias are a large group of syndromes characterized by anomalies in the structures of ectodermal origin. There are 2 major types of this disorder, based on clinical findings: hypohidrotic ectodermal dysplasia and hidrotic ectodermal dysplasia. This clinical classification is very important because clinical professionals involved with this disease need first a clear and practical method of diagnosis. The main oral manifestation of ectodermal dysplasia may be expressed as hypodontia. Thus, dental professionals may be the first to diagnose ectodermal dysplasia. The present article reports one case of each of the main types (hypohidrotic and hidrotic) of ectodermal dysplasia and the authors review the literature regarding the pathogenesis, clinical features, and therapeutic management of this condition.

Amphioxus and lamprey AP-2 genes: implications for neural crest evolution and migration patterns

NASA Technical Reports Server (NTRS)

Meulemans, Daniel; Bronner-Fraser, Marianne

2002-01-01

The neural crest is a uniquely vertebrate cell type present in the most basal vertebrates, but not in cephalochordates. We have studied differences in regulation of the neural crest marker AP-2 across two evolutionary transitions: invertebrate to vertebrate, and agnathan to gnathostome. Isolation and comparison of amphioxus, lamprey and axolotl AP-2 reveals its extensive expansion in the vertebrate dorsal neural tube and pharyngeal arches, implying co-option of AP-2 genes by neural crest cells early in vertebrate evolution. Expression in non-neural ectoderm is a conserved feature in amphioxus and vertebrates, suggesting an ancient role for AP-2 genes in this tissue. There is also common expression in subsets of ventrolateral neurons in the anterior neural tube, consistent with a primitive role in brain development. Comparison of AP-2 expression in axolotl and lamprey suggests an elaboration of cranial neural crest patterning in gnathostomes. However, migration of AP-2-expressing neural crest cells medial to the pharyngeal arch mesoderm appears to be a primitive feature retained in all vertebrates. Because AP-2 has essential roles in cranial neural crest differentiation and proliferation, the co-option of AP-2 by neural crest cells in the vertebrate lineage was a potentially crucial event in vertebrate evolution.

Wise promotes coalescence of cells of neural crest and placode origins in the trigeminal region during head development.

PubMed

Shigetani, Yasuyo; Howard, Sara; Guidato, Sonia; Furushima, Kenryo; Abe, Takaya; Itasaki, Nobue

2008-07-15

While most cranial ganglia contain neurons of either neural crest or placodal origin, neurons of the trigeminal ganglion derive from both populations. The Wnt signaling pathway is known to be required for the development of neural crest cells and for trigeminal ganglion formation, however, migrating neural crest cells do not express any known Wnt ligands. Here we demonstrate that Wise, a Wnt modulator expressed in the surface ectoderm overlying the trigeminal ganglion, play a role in promoting the assembly of placodal and neural crest cells. When overexpressed in chick, Wise causes delamination of ectodermal cells and attracts migrating neural crest cells. Overexpression of Wise is thus sufficient to ectopically induce ganglion-like structures consisting of both origins. The function of Wise is likely synergized with Wnt6, expressed in an overlapping manner with Wise in the surface ectoderm. Electroporation of morpholino antisense oligonucleotides against Wise and Wnt6 causes decrease in the contact of neural crest cells with the delaminated placode-derived cells. In addition, targeted deletion of Wise in mouse causes phenotypes that can be explained by a decrease in the contribution of neural crest cells to the ophthalmic lobe of the trigeminal ganglion. These data suggest that Wise is able to function cell non-autonomously on neural crest cells and promote trigeminal ganglion formation.

Src Family Kinases and p38 Mitogen-Activated Protein Kinases Regulate Pluripotent Cell Differentiation in Culture

PubMed Central

Tan, Boon Siang Nicholas; Kwek, Joly; Wong, Chong Kum Edwin; Saner, Nicholas J.; Yap, Charlotte; Felquer, Fernando; Morris, Michael B.; Gardner, David K.; Rathjen, Peter D.; Rathjen, Joy

2016-01-01

Multiple pluripotent cell populations, which together comprise the pluripotent cell lineage, have been identified. The mechanisms that control the progression between these populations are still poorly understood. The formation of early primitive ectoderm-like (EPL) cells from mouse embryonic stem (mES) cells provides a model to understand how one such transition is regulated. EPL cells form from mES cells in response to l-proline uptake through the transporter Slc38a2. Using inhibitors of cell signaling we have shown that Src family kinases, p38 MAPK, ERK1/2 and GSK3β are required for the transition between mES and EPL cells. ERK1/2, c-Src and GSK3β are likely to be enforcing a receptive, primed state in mES cells, while Src family kinases and p38 MAPK are involved in the establishment of EPL cells. Inhibition of these pathways prevented the acquisition of most, but not all, features of EPL cells, suggesting that other pathways are required. L-proline activation of differentiation is mediated through metabolism and changes to intracellular metabolite levels, specifically reactive oxygen species. The implication of multiple signaling pathways in the process suggests a model in which the context of Src family kinase activation determines the outcomes of pluripotent cell differentiation. PMID:27723793

The DP-1 transcription factor is required for keratinocyte growth and epidermal stratification.

PubMed

Chang, Wing Y; Bryce, Dawn M; D'Souza, Sudhir J A; Dagnino, Lina

2004-12-03

The epidermis is a stratified epithelium constantly replenished through the ability of keratinocytes in its basal layer to proliferate and self-renew. The epidermis arises from a single-cell layer ectoderm during embryogenesis. Large proliferative capacity is central to ectodermal cell and basal keratinocyte function. DP-1, a heterodimeric partner of E2F transcription factors, is highly expressed in the ectoderm and all epidermal layers during embryogenesis. To investigate the role of DP-1 in epidermal morphogenesis, we inhibited DP-1 activity through exogenous expression of a dominant-negative mutant (dnDP-1). Expression of the dnDP-1 mutant interferes with binding of E2F/DP-1 heterodimers to DNA and inhibits DNA replication, as well as cyclin A mRNA and protein expression. Chromatin immunoprecipitation analysis demonstrated that the cyclin A promoter is predominantly bound in proliferating keratinocytes by complexes containing E2F-3 and E2F-4. Thus, the mechanisms of decreased expression of cyclin A in the presence of dnDP-1 seem to involve inactivation of DP-1 complexes containing E2F-3 and E2F-4. To assess the consequences on epidermal morphogenesis of inhibiting DP-1 activity, we expressed dnDP-1 in rat epithelial keratinocytes in organotypic culture and observed that DP-1 inhibition negatively affected stratification of these cells. Likewise, expression of dnDP-1 in embryonic ectoderm explants produced extensive disorganization of subsequently formed epidermal basal and suprabasal layers, interfering with normal epidermal formation. We conclude that DP-1 activity is required for normal epidermal morphogenesis and ectoderm-to-epidermis transition.

The functional relationship between ectodermal and mesodermal segmentation in the crustacean, Parhyale hawaiensis.

PubMed

Hannibal, Roberta L; Price, Alivia L; Patel, Nipam H

2012-01-15

In arthropods, annelids and chordates, segmentation of the body axis encompasses both ectodermal and mesodermal derivatives. In vertebrates, trunk mesoderm segments autonomously and induces segmental arrangement of the ectoderm-derived nervous system. In contrast, in the arthropod Drosophila melanogaster, the ectoderm segments autonomously and mesoderm segmentation is at least partially dependent on the ectoderm. While segmentation has been proposed to be a feature of the common ancestor of vertebrates and arthropods, considering vertebrates and Drosophila alone, it is impossible to conclude whether the ancestral primary segmented tissue was the ectoderm or the mesoderm. Furthermore, much of Drosophila segmentation occurs before gastrulation and thus may not accurately represent the mechanisms of segmentation in all arthropods. To better understand the relationship between segmented germ layers in arthropods, we asked whether segmentation is an intrinsic property of the ectoderm and/or the mesoderm in the crustacean Parhyale hawaiensis by ablating either the ectoderm or the mesoderm and then assaying for segmentation in the remaining tissue layer. We found that the ectoderm segments autonomously. However, mesoderm segmentation requires at least a permissive signal from the ectoderm. Although mesodermal stem cells undergo normal rounds of division in the absence of ectoderm, they do not migrate properly in respect to migration direction and distance. In addition, their progeny neither divide nor express the mesoderm segmentation markers Ph-twist and Ph-Even-skipped. As segmentation is ectoderm-dependent in both Parhyale and holometabola insects, we hypothesize that segmentation is primarily a property of the ectoderm in pancrustacea. Copyright © 2011 Elsevier Inc. All rights reserved.

Non-neural ectoderm is really neural: evolution of developmental patterning mechanisms in the non-neural ectoderm of chordates and the problem of sensory cell homologies.

PubMed

Holland, Linda Z

2005-07-15

In chordates, the ectoderm is divided into the neuroectoderm and the so-called non-neural ectoderm. In spite of its name, however, the non-neural ectoderm contains numerous sensory cells. Therefore, the term "non-neural" ectoderm should be replaced by "general ectoderm." At least in amphioxus and tunicates and possibly in vertebrates as well, both the neuroectoderm and the general ectoderm are patterned anterior/posteriorly by mechanisms involving retinoic acid and Hox genes. In amphioxus and tunicates the ectodermal sensory cells, which have a wide range of ciliary and microvillar configurations, are mostly primary neurons sending axons to the CNS, although a minority lack axons. In contrast, vertebrate mechanosensory cells, called hair cells, are all secondary neurons that lack axons and have a characteristic eccentric cilium adjacent to a group of microvilli of graded lengths. It has been highly controversial whether the ectodermal sensory cells in the oral siphons of adult tunicates are homologous to vertebrate hair cells. In some species of tunicates, these cells appear to be secondary neurons, and microvillar and ciliary configurations of some of these cells approach those of vertebrate hair cells. However, none of the tunicate cells has all the characteristics of a hair cell, and there is a high degree of variation among ectodermal sensory cells within and between different species. Thus, similarities between the ectodermal sensory cells of any one species of tunicate and craniate hair cells may well represent convergent evolution rather than homology. Copyright 2005 Wiley-Liss, Inc.

KDF1, encoding keratinocyte differentiation factor 1, is mutated in a multigenerational family with ectodermal dysplasia.

PubMed

Shamseldin, Hanan E; Khalifa, Ola; Binamer, Yousef M; Almutawa, Abdulmonem; Arold, Stefan T; Zaidan, Hamad; Alkuraya, Fowzan S

2017-01-01

Ectodermal dysplasia is a highly heterogeneous group of disorders that variably affect the derivatives of the ectoderm, primarily skin, hair, nails and teeth. TP63, itself mutated in ectodermal dysplasia, links many other ectodermal dysplasia disease genes through a regulatory network that maintains the balance between proliferation and differentiation of the epidermis and other ectodermal derivatives. The ectodermal knockout phenotype of five mouse genes that regulate and/or are regulated by TP63 (Irf6, Ikkα, Ripk4, Stratifin, and Kdf1) is strikingly similar and involves abnormal balance towards proliferation at the expense of differentiation, but only the first three have corresponding ectodermal phenotypes in humans. We describe a multigenerational Saudi family with an autosomal dominant form of hypohidrotic ectodermal dysplasia in which positional mapping and exome sequencing identified a novel variant in KDF1 that fully segregates with the phenotype. The recapitulation of the phenotype we observe in this family by the Kdf1-/- mouse suggests a causal role played by the KDF1 variant.

Perinatal Autopsy Findings in a Case of De Novo Hypohidrotic Ectodermal Dysplasia.

PubMed

Chikkannaiah, Panduranga; Nagaraju, Smitha; Kangle, Rajit; Gosavi, Mansi

2015-01-01

Ectodermal dysplasia are group of inherited disorders involving the developmental defects of ectodermal structures like hair, teeth, nails, sweat glands, and others. X-linked recessive inheritance is most common. Here we describe perinatal autopsy findings in a case of de novo ectodermal dysplasia in a female fetus. To the best of our knowledge, this is the first fetal autopsy description in a case of ectodermal dysplasia.

Lysophosphatidic acid acts as a nutrient-derived developmental cue to regulate early hematopoiesis

PubMed Central

Li, Haisen; Yue, Rui; Wei, Bin; Gao, Ge; Du, Jiulin; Pei, Gang

2014-01-01

Primitive hematopoiesis occurs in the yolk sac blood islands during vertebrate embryogenesis, where abundant phosphatidylcholines (PC) are available as important nutrients for the developing embryo. However, whether these phospholipids also generate developmental cues to promote hematopoiesis is largely unknown. Here, we show that lysophosphatidic acid (LPA), a signaling molecule derived from PC, regulated hemangioblast formation and primitive hematopoiesis. Pharmacological and genetic blockage of LPA receptor 1 (LPAR1) or autotoxin (ATX), a secretory lysophospholipase that catalyzes LPA production, inhibited hematopoietic differentiation of mouse embryonic stem cells and impaired the formation of hemangioblasts. Mechanistic experiments revealed that the regulatory effect of ATX-LPA signaling was mediated by PI3K/Akt-Smad pathway. Furthermore, during in vivo embryogenesis in zebrafish, LPA functioned as a developmental cue for hemangioblast formation and primitive hematopoiesis. Taken together, we identified LPA as an important nutrient-derived developmental cue for primitive hematopoiesis as well as a novel mechanism of hemangioblast regulation. PMID:24829209

Lysophosphatidic acid acts as a nutrient-derived developmental cue to regulate early hematopoiesis.

PubMed

Li, Haisen; Yue, Rui; Wei, Bin; Gao, Ge; Du, Jiulin; Pei, Gang

2014-06-17

Primitive hematopoiesis occurs in the yolk sac blood islands during vertebrate embryogenesis, where abundant phosphatidylcholines (PC) are available as important nutrients for the developing embryo. However, whether these phospholipids also generate developmental cues to promote hematopoiesis is largely unknown. Here, we show that lysophosphatidic acid (LPA), a signaling molecule derived from PC, regulated hemangioblast formation and primitive hematopoiesis. Pharmacological and genetic blockage of LPA receptor 1 (LPAR1) or autotoxin (ATX), a secretory lysophospholipase that catalyzes LPA production, inhibited hematopoietic differentiation of mouse embryonic stem cells and impaired the formation of hemangioblasts. Mechanistic experiments revealed that the regulatory effect of ATX-LPA signaling was mediated by PI3K/Akt-Smad pathway. Furthermore, during in vivo embryogenesis in zebrafish, LPA functioned as a developmental cue for hemangioblast formation and primitive hematopoiesis. Taken together, we identified LPA as an important nutrient-derived developmental cue for primitive hematopoiesis as well as a novel mechanism of hemangioblast regulation. © 2014 The Authors.

Transcriptional Profiling of Ectoderm Specification to Keratinocyte Fate in Human Embryonic Stem Cells

PubMed Central

Tadeu, Ana Mafalda Baptista; Lin, Samantha; Hou, Lin; Chung, Lisa; Zhong, Mei; Zhao, Hongyu; Horsley, Valerie

2015-01-01

In recent years, several studies have shed light into the processes that regulate epidermal specification and homeostasis. We previously showed that a broad-spectrum γ–secretase inhibitor DAPT promoted early keratinocyte specification in human embryonic stem cells triggered to undergo ectoderm specification. Here, we show that DAPT accelerates human embryonic stem cell differentiation and induces expression of the ectoderm protein AP2. Furthermore, we utilize RNA sequencing to identify several candidate regulators of ectoderm specification including those involved in epithelial and epidermal development in human embryonic stem cells. Genes associated with transcriptional regulation and growth factor activity are significantly enriched upon DAPT treatment during specification of human embryonic stem cells to the ectoderm lineage. The human ectoderm cell signature identified in this study contains several genes expressed in ectodermal and epithelial tissues. Importantly, these genes are also associated with skin disorders and ectodermal defects, providing a platform for understanding the biology of human epidermal keratinocyte development under diseased and homeostatic conditions. PMID:25849374

Müllerian agenesis with hypohidrotic ectodermal dysplasia syndrome.

PubMed

Whaley, Katie; Winter, Jordan; Eyster, Kathleen M; Hansen, Keith A

2012-04-01

To describe the association of müllerian agenesis with hypohidrotic ectodermal dysplasia. Case report. University medical center. A 17-year-old woman with hypohidrotic ectodermal dysplasia referred for evaluation of primary amenorrhea. History, physical examination, and ultrasound. Physical findings of these two syndromes. Physical examination and ultrasound demonstrated müllerian agenesis with findings of hypohidrotic ectodermal dysplasia. This is the first description of the association of müllerian agenesis with ectodermal dysplasia. This rare case might provide further insight into the development of the uterus and the ectoderm as well as its derivatives. Copyright © 2012 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Retinal tear presenting in a patient with ectrodactyly ectodermal dysplasia.

PubMed

Grogg, Jane Ann; Port, Nicholas; Graham, Trevor

2014-04-01

This article aims to report a case of known ectrodactyly ectodermal dysplasia in a young male patient who subsequently was found to have a retinal tear and localized retinal detachment. This is a case report of a 22-year-old white male patient with a history of ectrodactyly ectodermal dysplasia. Our patient initially presented with an acute exacerbation of bilateral, red, irritated eyes. No recent changes in vision were reported. The patient's ocular surface disease was consistent with ectrodermal dysplasia syndrome. However, a dilated fundus examination revealed an asymptomatic retinal tear with a surrounding localized retinal detachment. In this case, the patient presented with longstanding ocular surface disease known to be associated with this patient's inherited ectoderm disorder. In addition, this patient revealed a retinal tear, raising the possibility that patients with inherited congenital ectodermal dysplasia could be at risk for damaged structures originating from the neural ectoderm. In this heterogeneous disease, we are contributing to the existing literature a case of ectodermal dysplasia syndrome with obvious ectodermal complications that also had retinal findings leading us to speculate question if neural ectoderm could also be involved in this inherited disease.

A retrospective study of clinical and mutational findings in 45 Danish families with ectodermal dysplasia.

PubMed

Tiedemann Svendsen, Mathias; Henningsen, Emil; Hertz, Jens Michael; Vestergaard Grejsen, Dorthe; Bygum, Anette

2014-09-01

Ectodermal dysplasias form a complex, nosologic group of diseases with defects in at least 2 ectodermal structures. A retrospective study of patients with ectodermal dysplasia seen at our department over a period of 19 years (1994-2013) was performed. The study population consisted of 67 patients covering 17 different diagnoses. Forty-five families were identified of which 26 were sporadic cases with no affected family members. In 27 tested families a disease-causing mutation was identified in 23 families. Eleven mutations were novel mutations. To our knowledge, we present the first large ectodermal dysplasia cohort focusing on clinical manifestations in combination with mutational analysis. We recommend a nationwide study to estimate the prevalence of the ectodermal dysplasia and to ensure relevant molecular genetic testing which may form the basis of a national ectodermal dysplasia database.

The type I BMP receptors, Bmpr1a and Acvr1, activate multiple signaling pathways to regulate lens formation

PubMed Central

Rajagopal, Ramya; Huang, Jie; Dattilo, Lisa K.; Kaartinen, Vesa; Mishina, Yuji; Deng, Chu-Xia; Umans, Lieve; Zwijsen, An; Roberts, Anita B.; Beebe, David C.

2009-01-01

BMPs play multiple roles in development and BMP signaling is essential for lens formation. However, the mechanisms by which BMP receptors function in vertebrate development are incompletely understood. To determine the downstream effectors of BMP signaling and their functions in the ectoderm that will form the lens, we deleted the genes encoding the type I BMP receptors, Bmpr1a and Acvr1, and the canonical transducers of BMP signaling, Smad4, Smad1 and Smad5. Bmpr1a and Acvr1 regulated cell survival and proliferation, respectively. Absence of both receptors interfered with the expression of proteins involved in normal lens development and prevented lens formation, demonstrating that BMPs induce lens formation by acting directly on the prospective lens ectoderm. Remarkably, the canonical Smad signaling pathway was not needed for most of these processes. Lens formation, placode cell proliferation, the expression of FoxE3, a lens-specific transcription factor, and the lens protein, αA-crystallin were regulated by BMP receptors in a Smad-independent manner. Placode cell survival was promoted by R-Smad signaling, but in a manner that did not involve Smad4. Of the responses tested, only maintaining a high level of Sox2 protein, a transcription factor expressed early in placode formation, required the canonical Smad pathway. A key function of Smad-independent BMP receptor signaling may be reorganization of actin cytoskeleton to drive lens invagination. PMID:19733164

Expression and evolution of Tiki1 and Tiki2 genes in vertebrates

PubMed Central

FEISTEL, KERSTIN; BRITO, JOSE M.; AMADO, NATHALIA G.; XU, CHIWEI; ABREU, JOSE G.; HE, XI

2015-01-01

Tiki1 is a Wnt protease and antagonist specifically expressed in the Spemann-Mangold Organizer and is required for head formation in Xenopus embryos. Here we report neighbor-joining phylogenetic analysis of vertebrate Tiki genes and their mRNA expression patterns in chick, mouse, and rabbit embryos. Tiki1 and Tiki2 orthologues are highly conserved, and exhibit similar but also different developmental expression patterns among the vertebrate/mammalian species analyzed. The Tiki1 gene is noticeably absent in the rodent lineage, but is present in lagomorphs and all other vertebrate/mammalian species examined. Expression in Hensen’s node, the equivalent of the Xenopus Organizer, was observed for Chick Tiki2 and Rabbit Tiki1 and Tiki2. Mouse Tiki2 was detected at low levels at gastrulation and head fold stages, but not in the node. Mouse Tiki2 and chick Tiki1 display similar expression in the dorsal spinal cord. Chick Tiki1 expression was also detected in the surface ectoderm and maxillary bud, while chick Tiki2 was found in the anterior intestinal portal, head mensenchyme and primitive atrium. Our expression analyses provide evidence that Tiki1 and Tiki2 are evolutionary conserved among vertebrate species and their expression in the Organizer and other regions suggests contributions of these Wnt inhibitors to embryonic patterning as well as organogenesis. Our analyses further reveal mis-regulation of TIKI1 and TIKI2 in human cancer and diseases. PMID:25354456

The origin and evolution of the ectodermal placodes

PubMed Central

Graham, Anthony; Shimeld, Sebastian M

2013-01-01

Many of the features that distinguish the vertebrates from other chordates are found in the head. Prominent amongst these differences are the paired sense organs and associated cranial ganglia. Significantly, these structures are derived developmentally from the ectodermal placodes. It has therefore been proposed that the emergence of the ectodermal placodes was concomitant with and central to the evolution of the vertebrates. More recent studies, however, indicate forerunners of the ectodermal placodes can be readily identified outside the vertebrates, particularly in urochordates. Thus the evolutionary history of the ectodermal placodes is deeper and more complex than was previously appreciated with the full repertoire of vertebrate ectodermal placodes, and their derivatives, being assembled over a protracted period rather than arising collectively with the vertebrates. PMID:22512454

Phenotypic heterogeneity and mutational spectrum in a cohort of 45 Italian males subjects with X-linked ectodermal dysplasia.

PubMed

Guazzarotti, L; Tadini, G; Mancini, G E; Giglio, S; Willoughby, C E; Callea, M; Sani, I; Nannini, P; Mameli, C; Tenconi, A A; Mauri, S; Bottero, A; Caimi, A; Morelli, M; Zuccotti, G V

2015-04-01

Ectodermal dysplasias (EDs) are a group of genetic disorders characterized by the abnormal development of the ectodermal-derived structures. X-linked hypohidrotic ectodermal dysplasia, resulting from mutations in ED1 gene, is the most common form. The main purpose of this study was to characterize the phenotype spectrum in 45 males harboring ED1 mutations. The study showed that in addition to the involvement of the major ectodermal tissues, the majority of patients also have alterations of several minor ectodermal-derived structures. Characterizing the clinical spectrum resulting from ED1 gene mutations improves diagnosis and can direct clinical care. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Skin symptoms in four ectodermal dysplasia syndromes including two case reports of Rapp-Hodgkin-Syndrome.

PubMed

Knaudt, Björn; Volz, Thomas; Krug, Markus; Burgdorf, Walter; Röcken, Martin; Berneburg, Mark

2012-01-01

The skin, hair and nail changes in four distinct ectodermal dysplasia syndromes are compared and reviewed. These syndromes comprise Christ-Siemens-Touraine syndrome; ectrodactyly, ectodermal dysplasia and cleft lip/palate syndrome; ankyloblepharon-ectodermal defects-cleft lip/palate syndrome and Rapp-Hodgkin syndrome. A comprehensive overview of the dermatological signs and symptoms in these syndromes was generated from the database of the Ectodermal Dysplasia Network Germany, the clinical findings in the patients seen in our department and an extensive review of the literature. The findings included abnormalities of skin, sweating, hair and nails. These clinical findings are discussed in relation to the underlying molecular defects known to play a role in these four ectodermal dysplasia syndromes.

Tissue interactions in the induction of anterior pituitary: role of the ventral diencephalon, mesenchyme, and notochord.

PubMed

Gleiberman, A S; Fedtsova, N G; Rosenfeld, M G

1999-09-15

Rathke's pouch, the epithelial primordium of the anterior pituitary, differentiates in close topographical and functional association with the ventral diencephalon. It is still not known whether the ventral diencephalon acts as the initial inducer of pituitary development. The roles of the adjacent mesenchyme and notochord, two other tissues located in close proximity to Rathke's pouch, in this process are even less clear. In this report we describe an in vitro experimental system that reproduces the earliest steps of anterior pituitary development. We provide evidence that the ventral diencephalon from 2- to 4-day-old chick embryos is able to function as an inducer of pituitary development and can convert early chick embryonic head ectoderm, which is not involved normally in pituitary development, into typical anterior pituitary tissue. This induction is contact-dependent. In our experimental system, there is a requirement for the supporting action of mesenchyme, which is independent of the mesenchyme source. Transplantation of the notochord into the lateral head region of a six-somite chick embryo induces an epithelial invagination, suggesting that the notochord induces the outpouching of the roof of the stomodeal ectoderm that results in formation of Rathke's pouch and causes the close contact between this ectoderm and the ventral diencephalon. Finally, we demonstrate that the ventral diencephalon from e9.5-e11.5 mouse embryos is also an efficient inducer of anterior pituitary differentiation in chick embryonic lateral head ectoderm, suggesting that the mechanism of anterior pituitary induction is conserved between mammals and birds, using the same, or similar, signaling pathways. Copyright 1999 Academic Press.

ECTODERMAL WNT/β-CATENIN SIGNALING SHAPES THE MOUSE FACE

PubMed Central

Reid, Bethany S.; Yang, Hui; Melvin, Vida Senkus; Taketo, Makoto M.; Williams, Trevor

2010-01-01

The canonical Wnt/β-catenin pathway is an essential component of multiple developmental processes. To investigate the role of this pathway in the ectoderm during facial morphogenesis, we generated conditional β-catenin mouse mutants using a novel ectoderm-specific Cre recombinase transgenic line. Our results demonstrate that ablating or stabilizing β-catenin in the embryonic ectoderm causes dramatic changes in facial morphology. There are accompanying alterations in the expression of Fgf8 and Shh, key molecules that establish a signaling center critical for facial patterning, the frontonasal ectodermal zone (FEZ). These data indicate that Wnt/β-catenin signaling within the ectoderm is critical for facial development and further suggest that this pathway is an important mechanism for generating the diverse facial shapes of vertebrates during evolution. PMID:21087601

Prosthodontic management of a patient with ectodermal dysplasia.

PubMed

Nandini, Yamini

2013-12-01

Ectodermal dysplasia is a rare congenital disease that affects the ectodermal structures. It is characterized by hypotrichosis, hypohidrosis and hypodontia. A 14-year-old boy with ectodermal dysplasia presenting with oligodontia and marked resorption of the maxillary and mandibular alveolar ridges is reported. Prosthetic rehabilitation in the form of a maxillary and mandibular partial denture was made with metal crowns on existing lower teeth to achieve appropriate vertical dimension. Significant improvement in speech, masticatory function and facial esthetics was achieved. Removable prosthodontics can provide an acceptable solution to esthetic, functional and psychological rehabilitation in patients with ectodermal dysplasia.

Overdenture restoration in a growing patient with hypohidrotic ectodermal dysplasia: a clinical report.

PubMed

Pae, Ahran; Kim, Kyu; Kim, Hyeong-Seob; Kwon, Kung-Rock

2011-03-01

Ectodermal dysplasia is a hereditary disorder of ectodermal origin. A 12-year-old boy was referred for management of the oral manifestations of his ectodermal dysplasia. An overdenture retained by natural teeth for the maxilla and a double-crown-retained denture for the mandible were made. Double-crown-retained dentures may be modified into complete dentures if the abutment teeth are lost. The patient was instructed to maintain oral hygiene and return periodically for follow-up visits. This report describes a potential routine approach to restoring the appearance, function, and psyche of a growing boy with ectodermal dysplasia.

Ectodermal Dysplasia: A Case Report

PubMed Central

2011-01-01

Ectodermal dysplasia is a hereditary disease characterized by dysplasia of tissues of ectodermal origin. The incidence of ectodermal dysplasia is rare (1 in 100,000 birth). This case report discusses the features, classification and prosthetic treatment plan (upper partial denture and lower complete denture for upper partial and lower complete edentulous arches respectively). This treatment plan would be able to provide psychological and functional boost to the sufferer. PMID:27678241

A new scenario for the evolutionary origin of hair, feather, and avian scales

PubMed Central

Dhouailly, Danielle

2009-01-01

In zoology it is well known that birds are characterized by the presence of feathers, and mammals by hairs. Another common point of view is that avian scales are directly related to reptilian scales. As a skin embryologist, I have been fascinated by the problem of regionalization of skin appendages in amniotes throughout my scientific life. Here I have collected the arguments that result from classical experimental embryology, from the modern molecular biology era, and from the recent discovery of new fossils. These arguments shape my view that avian ectoderm is primarily programmed toward forming feathers, and mammalian ectoderm toward forming hairs. The other ectoderm derivatives – scales in birds, glands in mammals, or cornea in both classes – can become feathers or hairs through metaplastic process, and appear to have a negative regulatory mechanism over this basic program. How this program is altered remains, in most part, to be determined. However, it is clear that the regulation of the Wnt/beta-catenin pathway is a critical hub. The level of beta-catenin is crucial for feather and hair formation, as its down-regulation appears to be linked with the formation of avian scales in chick, and cutaneous glands in mice. Furthermore, its inhibition leads to the formation of nude skin and is required for that of corneal epithelium. Here I propose a new theory, to be further considered and tested when we have new information from genomic studies. With this theory, I suggest that the alpha-keratinized hairs from living synapsids may have evolved from the hypothetical glandular integument of the first amniotes, which may have presented similarities with common day terrestrial amphibians. Concerning feathers, they may have evolved independently of squamate scales, each originating from the hypothetical roughened beta-keratinized integument of the first sauropsids. The avian overlapping scales, which cover the feet in some bird species, may have developed later in evolution, being secondarily derived from feathers. PMID:19422430

Acquisition of the dorsal structures in chordate amphioxus.

PubMed

Morov, Arseniy R; Ukizintambara, Tharcisse; Sabirov, Rushan M; Yasui, Kinya

2016-06-01

Acquisition of dorsal structures, such as notochord and hollow nerve cord, is likely to have had a profound influence upon vertebrate evolution. Dorsal formation in chordate development thus has been intensively studied in vertebrates and ascidians. However, the present understanding does not explain how chordates acquired dorsal structures. Here we show that amphioxus retains a key clue to answer this question. In amphioxus embryos, maternal nodal mRNA distributes asymmetrically in accordance with the remodelling of the cortical cytoskeleton in the fertilized egg, and subsequently lefty is first expressed in a patch of blastomeres across the equator where wnt8 is expressed circularly and which will become the margin of the blastopore. The lefty domain co-expresses zygotic nodal by the initial gastrula stage on the one side of the blastopore margin and induces the expression of goosecoid, not-like, chordin and brachyury1 genes in this region, as in the oral ectoderm of sea urchin embryos, which provides a basis for the formation of the dorsal structures. The striking similarity in the gene regulations and their respective expression domains when comparing dorsal formation in amphioxus and the determination of the oral ectoderm in sea urchin embryos suggests that chordates derived from an ambulacrarian-type blastula with dorsoventral inversion. © 2016 The Authors.

Acquisition of the dorsal structures in chordate amphioxus

PubMed Central

Morov, Arseniy R.; Ukizintambara, Tharcisse; Sabirov, Rushan M.

2016-01-01

Acquisition of dorsal structures, such as notochord and hollow nerve cord, is likely to have had a profound influence upon vertebrate evolution. Dorsal formation in chordate development thus has been intensively studied in vertebrates and ascidians. However, the present understanding does not explain how chordates acquired dorsal structures. Here we show that amphioxus retains a key clue to answer this question. In amphioxus embryos, maternal nodal mRNA distributes asymmetrically in accordance with the remodelling of the cortical cytoskeleton in the fertilized egg, and subsequently lefty is first expressed in a patch of blastomeres across the equator where wnt8 is expressed circularly and which will become the margin of the blastopore. The lefty domain co-expresses zygotic nodal by the initial gastrula stage on the one side of the blastopore margin and induces the expression of goosecoid, not-like, chordin and brachyury1 genes in this region, as in the oral ectoderm of sea urchin embryos, which provides a basis for the formation of the dorsal structures. The striking similarity in the gene regulations and their respective expression domains when comparing dorsal formation in amphioxus and the determination of the oral ectoderm in sea urchin embryos suggests that chordates derived from an ambulacrarian-type blastula with dorsoventral inversion. PMID:27307516

Ectoderm exerts the driving force for gastrulation in the sand dollar Scaphechinus mirabilis.

PubMed

Takata, H; Kominami, T

2001-06-01

How the ectodermal layer relates to the invagination processes was examined in the sand dollar Scaphechinus mirabilis. When the turgor pressure of blastocoele was increased, invagination was completely blocked. In contrast, an increase in turgor pressure did not affect elongation of the gut rudiment in the regular echinoid Hemicentrotus pulcherrimus. Rhodamine-phalloidin staining showed that the distribution of actin filaments was different between two species of embryos. In S. mirabilis gastrulating embryos, abundant actin filaments were seen at the basal cortex of ectoderm in addition to archenteron cells, while the intense signal was restricted to the archenteron in H. pulcherrimus. To investigate whether actin filaments contained in the ectodermal layer exert the force of invagination, a small part of the ectodermal layer was aspirated with a micropipette. If S. mirabilis embryos were aspirated from the onset of gastrulation, invagination did not occur at all, irrespective of the suction site. Even after the archenteron had invaginated to one-half of its full length, further elongation of the archenteron was severely blocked by suction of the lateral ectoderm. In contrast, suction of the ectodermal layer did not affect the elongation processes in H. pulcherrimus. These results strongly suggest that the ectodermal layer, especially in the vegetal half, exerts the driving force of invagination in S. mirabilis.

Dlx proteins position the neural plate border and determine adjacent cell fates.

PubMed

Woda, Juliana M; Pastagia, Julie; Mercola, Mark; Artinger, Kristin Bruk

2003-01-01

The lateral border of the neural plate is a major source of signals that induce primary neurons, neural crest cells and cranial placodes as well as provide patterning cues to mesodermal structures such as somites and heart. Whereas secreted BMP, FGF and Wnt proteins influence the differentiation of neural and non-neural ectoderm, we show here that members of the Dlx family of transcription factors position the border between neural and non-neural ectoderm and are required for the specification of adjacent cell fates. Inhibition of endogenous Dlx activity in Xenopus embryos with an EnR-Dlx homeodomain fusion protein expands the neural plate into non-neural ectoderm tissue whereas ectopic activation of Dlx target genes inhibits neural plate differentiation. Importantly, the stereotypic pattern of border cell fates in the adjacent ectoderm is re-established only under conditions where the expanded neural plate abuts Dlx-positive non-neural ectoderm. Experiments in which presumptive neural plate was grafted to ventral ectoderm reiterate induction of neural crest and placodal lineages and also demonstrate that Dlx activity is required in non-neural ectoderm for the production of signals needed for induction of these cells. We propose that Dlx proteins regulate intercellular signaling across the interface between neural and non-neural ectoderm that is critical for inducing and patterning adjacent cell fates.

Hypohidrotic ectodermal dysplasia: a felicitous approach to esthetic and prosthetic management.

PubMed

Singh, Tapan; Singh, Ronauk; Singh, Gurendra Pal; Singh, Jitender Pal

2013-05-01

Ectodermal dysplasia is a hereditary disease characterized by congenital dysplasia of one or more ectodermal structure and other accessory appendages. The oral manifestations are anodontia and poor bony foundation which impairs both esthetic as well as the masticatory function. The prosthodontic management of patients with such dysplastic condition necessitates a multidisciplinary approach. This case report describes the prosthodontic oral rehabilitation of a 16 years old female pediatric patient with ectodermal dysplasia. How to cite this article: Singh T, Singh R, Singh GP, Singh JP. Hypohidrotic Ectodermal Dysplasia: A Felicitous Approach to Esthetic and Prosthetic Management. Int J Clin Pediatr Dent 2013;6(2):140-145.

Eph and Ephrin function in dispersal and epithelial insertion of pigmented immunocytes in sea urchin embryos

PubMed Central

Krupke, Oliver A; Zysk, Ivona; Mellott, Dan O; Burke, Robert D

2016-01-01

The mechanisms that underlie directional cell migration are incompletely understood. Eph receptors usually guide migrations of cells by exclusion from regions expressing Ephrin. In sea urchin embryos, pigmented immunocytes are specified in vegetal epithelium, transition to mesenchyme, migrate, and re-enter ectoderm, distributing in dorsal ectoderm and ciliary band, but not ventral ectoderm. Immunocytes express Sp-Eph and Sp-Efn is expressed throughout dorsal and ciliary band ectoderm. Interfering with expression or function of Sp-Eph results in rounded immunocytes entering ectoderm but not adopting a dendritic form. Expressing Sp-Efn throughout embryos permits immunocyte insertion in ventral ectoderm. In mosaic embryos, immunocytes insert preferentially in ectoderm expressing Sp-Efn. We conclude that Sp-Eph signaling is necessary and sufficient for epithelial insertion. As well, we propose that immunocytes disperse when Sp-Eph enhances adhesion, causing haptotactic movement to regions of higher ligand abundance. This is a distinctive example of Eph/Ephrin signaling acting positively to pattern migrating cells. DOI: http://dx.doi.org/10.7554/eLife.16000.001 PMID:27474796

A Guide to FASTGEN Target Geometric Modeling

DTIC Science & Technology

1993-10-01

component part is described in plate mode. These rules apply to all primitives with the exception of rod mode primitives which are always accompanied by a...format. A detailed discussion of the rules for preparing the target description file, where components are described using primitives defined as triangles...NN position is 99, the diameter of a rod mode component is limited to a maximum of 1.98-inches. Theie are several rules and cautions associated with

The development of the eyelids. Part I. External features.

PubMed

Pearson, A A

1980-01-01

The sequence of developmental events leading to the formation of the eyelids is described in staged human embryos. By the end of the fourth week the optic vesicle lies close to the surface ectoderm. The surface ectoderm overlying the optic vesicle, in response to this contact, has thickened to form the lense placode (Stage 13). A few days later (about 32 days, Stage 14) the lens placode is indented by the lens pit. A day or two later (about 33 days, Stage 15) the lens pit is closed: however, the lens vesicle and optic cup lie close to the surface ectoderm and appear to press against the surface. Prior to the development of the eyelids, one small sulcus or groove forms above the eye (eyelid groove) and another below it (stage 16, 37 days). As these grooves deepen, in Stages 17--19, eyelid folds develop, first below, and then above, the eye. In Stages 19--22 the eyelid folds develop into the eyelids and cover more of the eye as the palpebral fissure takes shape. The upper and the lower eyelids meet at the outer canthus in Stage 19. The inner canthus is established a few days later in Stage 20. Closure of the eyelids is complete in Stage 23.

Foxi2 Is an Animally Localized Maternal mRNA in Xenopus, and an Activator of the Zygotic Ectoderm Activator Foxi1e

PubMed Central

Cha, Sang-Wook; McAdams, Meredith; Kormish, Jay; Wylie, Christopher; Kofron, Matthew

2012-01-01

Foxi1e is a zygotic transcription factor that is essential for the expression of early ectodermal genes. It is expressed in a highly specific pattern, only in the deep cell layers of the animal hemisphere, and in a mosaic pattern in which expressing cells are interspersed with non-expressing cells. Previous work has shown that several signals in the blastula control this expression pattern, including nodals, the TGFβ family member Vg1, and Notch. However, these are all inhibitory, which raises the question of what activates Foxi1e. In this work, we show that a related Forkhead family protein, Foxi2, is a maternal activator of Foxi1e. Foxi2 mRNA is maternally encoded, and highly enriched in animal hemisphere cells of the blastula. ChIP assays show that it acts directly on upstream regulatory elements of Foxi1e. Its effect is specific, since animal cells depleted of Foxi2 are able to respond normally to mesoderm inducing signals from vegetal cells. Foxi2 thus acts as a link between the oocyte and the early pathway to ectoderm, in a similar fashion to the vegetally localized VegT acts to initiate endoderm and mesoderm formation. PMID:22848601

Evolution of neural crest and placodes: amphioxus as a model for the ancestral vertebrate?

NASA Technical Reports Server (NTRS)

Holland, L. Z.; Holland, N. D.

2001-01-01

Recent studies of protochordates (ascidian tunicates and amphioxus) have given insights into possible ancestors of 2 of the characteristic features of the vertebrate head: neural crest and placodes. The neural crest probably evolved from cells on either side of the neural plate-epidermis boundary in a protochordate ancestral to the vertebrates. In amphioxus, homologues of several vertebrate neural crest marker genes (BMP2/4, Pax3/7, Msx, Dll and Snail) are expressed at the edges of the neural plate and/or adjacent nonneural ectoderm. Some of these markers are also similarly expressed in tunicates. In protochordates, however, these cells, unlike vertebrate neural crest, neither migrate as individuals through embryonic tissues nor differentiate into a wide spectrum of cell types. Therefore, while the protochordate ancestor of the vertebrates probably had the beginnings of a genetic programme for neural crest formation, this programme was augmented in the earliest vertebrates to attain definitive neural crest. Clear homologues of vertebrate placodes are lacking in protochordates. However, both amphioxus and tunicates have ectodermal sensory cells. In tunicates these are all primary neurons, sending axons to the central nervous system, while in amphioxus, the ectodermal sensory cells include both primary neurons and secondary neurons lacking axons. Comparisons of developmental gene expression suggest that the anterior ectoderm in amphioxus may be homologous to the vertebrate olfactory placode, the only vertebrate placode with primary, not secondary, neurons. Similarly, biochemical, morphological and gene expression data suggest that amphioxus and tunicates also have homologues of the adenohypophysis, one of the few vertebrate structures derived from nonneurogenic placodes. In contrast, the origin of the other vertebrate placodes is very uncertain.

[Clinical and molecular study in a child with X-linked hypohidrotic ectodermal dysplasia].

PubMed

Callea, Michele; Yavuz, Izzet; Clarich, Gabriella; Cammarata-Scalisi, Francisco

2015-12-01

Ectodermal dysplasia encompasses more than 200 clinically distinct entities, which affect at least two structures derived from the ectoderm, including the skin, hair, nails, teeth, sweat glands, and sebaceous glands. X-linked hypohidrotic ectodermal dysplasia is the most common type and is caused by mutation of the EDA gene that encodes Ectodysplasin-A. It occurs in less than 1 in 100 000 individuals and is clinically characterized by hypodontia, hypohidrosis, hypotrichosis, and eye dis orders. We present a child evaluated in a multidisciplinary manner with clinical and molecular diagnosis of X-linked hypohidrotic ectodermal dysplasia with type missense mutation c.1133C> T; p.T378M in EDA gene.

Ectodermal dysplasia (ED) syndrome.

PubMed

Chee, Siew-Yin; Wanga, Chung-Hsing; Lina, Wei-De; Tsaia, Fuu-Jen

2014-01-01

Ectodermal dysplasia (ED) syndrome comprises a large, heterogeneous group of inherited disorders that are defined by primary defects in the development of 2 or more tissues derived from the embryonic ectoderm. The tissues primarily involved are the skin and its appendages (including hair follicles, eccrine glands, sebaceous glands, nails) and teeth. The clinical features include sparse hair, abnormal or missing teeth, and an inability to sweat due to lack of sweat glands. One such case report of ectodermal dysplasia is presented here.

Hereditary hypohidrotic ectodermal dysplasia: report of a rare case.

PubMed

Paramkusam, Geetha; Meduri, Venkateswarlu; Nadendla, Lakshmi Kavitha; Shetty, Namratha

2013-09-01

Hereditary Hypohidrotic Ectodermal Dysplasia (HHED), an X-linked, recessive, Mendelian character, is seen usually in males and it is inherited through female carriers. It is characterised by congenital dysplasia of one or more ectodermal structures and it is manifested by hypohidrosis, hypotrichosis and hypodontia. It results from abnormal morphogenesis of cutaneous and oral embryonic ectoderm. Here, we are presenting a rare case of HHED in a 19 year female with classic features of this condition.

Hereditary Hypohidrotic Ectodermal Dysplasia: Report of a Rare Case

PubMed Central

Paramkusam, Geetha; Meduri, Venkateswarlu; Nadendla, Lakshmi Kavitha; Shetty, Namratha

2013-01-01

Hereditary Hypohidrotic Ectodermal Dysplasia (HHED), an X-linked, recessive, Mendelian character, is seen usually in males and it is inherited through female carriers. It is characterised by congenital dysplasia of one or more ectodermal structures and it is manifested by hypohidrosis, hypotrichosis and hypodontia. It results from abnormal morphogenesis of cutaneous and oral embryonic ectoderm. Here, we are presenting a rare case of HHED in a 19 year female with classic features of this condition. PMID:24179947

Ectodermal dysplasia: otolaryngologic evaluation of 23 cases.

PubMed

Yildirim, Muzeyyen; Yorgancilar, Ediz; Gun, Ramazan; Topcu, Ismail

2012-02-01

The aim of this prospective study was to improve the quality of life of and reduce morbidity for patients with ectodermal dysplasia by assessing their actual and potential ENT pathologies, and offering methods of prevention and treatment. The study was conducted between 2006 and 2008 and included 23 patients diagnosed with ectodermal dysplasia. The major symptoms of ectodermal dysplasia were evaluated. Patient histories were obtained in all cases, and a complete head and neck examination was carried out. Of the 23 patients (11 males and 12 females, aged 5 to 45 years) diagnosed with ectodermal dysplasia, 22 had hypohidrotic ectodermal dysplasia and 1 had ectrodactyly-ectodermal dysplasia-clefting syndrome. In all patients diagnosed with hypohidrotic ectodermal dysplasia, the salivary glands were examined by ultrasonography and, when necessary, by scintigraphy. Hearing defects in patients with otologic problems were determined by audiometric examination: 39.1% of the patients had hearing loss, 43.5% had otitis media, and 39.1% had impacted cerumen. The most common rhinologic findings were saddle nose deformity in 56.5%, nasal obstruction and nasal dryness (52.2% each), and chronic rhinitis/rhinosinusitis (34.8%). The most common oral and oropharyngeal findings were difficulty chewing in 82.6% and dry mouth in 78.3%. All 23 patients had required dental work. Because this disorder affects several aspects of the body, its treatment requires a multidisciplinary approach, with the otolaryngologist being a vital part of the management team.

Stem Cell Fate Determination during Development and Regeneration of Ectodermal Organs

PubMed Central

Jiménez-Rojo, Lucía; Granchi, Zoraide; Graf, Daniel; Mitsiadis, Thimios A.

2012-01-01

The development of ectoderm-derived appendages results in a large variety of highly specialized organs such as hair follicles, mammary glands, salivary glands, and teeth. Despite varying in number, shape, and function, all these ectodermal organs develop through continuous and reciprocal epithelial–mesenchymal interactions, sharing common morphological and molecular features especially during their embryonic development. Diseases such as ectodermal dysplasias can affect simultaneously these organs, suggesting that they may arise from common multipotent precursors residing in the embryonic ectoderm. During embryogenesis, these putative ectodermal stem cells may adopt different fates and consequently be able to generate a variety of tissue-specific stem cells, which are the sources for the various cell lineages that form the diverse organs. The specification of those common epithelial precursors, as well as their further lineage commitment to tissue-specific stem cells, might be controlled by specific signals. It has been well documented that Notch, Wnt, bone morphogenetic protein, and fibroblast growth factor signaling pathways regulate cell fate decisions during the various stages of ectodermal organ development. However, the in vivo spatial and temporal dynamics of these signaling pathways are not yet well understood. Improving the current knowledge on the mechanisms involved in stem cell fate determination during organogenesis and homeostasis of ectodermal organs is crucial to develop effective stem cell-based therapies in order to regenerate or replace pathological and damaged tissues. PMID:22539926

Dlx proteins position the neural plate border and determine adjacent cell fates

PubMed Central

Woda, Juliana M.; Pastagia, Julie; Mercola, Mark; Artinger, Kristin Bruk

2014-01-01

Summary The lateral border of the neural plate is a major source of signals that induce primary neurons, neural crest cells and cranial placodes as well as provide patterning cues to mesodermal structures such as somites and heart. Whereas secreted BMP, FGF and Wnt proteins influence the differentiation of neural and non-neural ectoderm, we show here that members of the Dlx family of transcription factors position the border between neural and non-neural ectoderm and are required for the specification of adjacent cell fates. Inhibition of endogenous Dlx activity in Xenopus embryos with an EnR-Dlx homeodomain fusion protein expands the neural plate into non-neural ectoderm tissue whereas ectopic activation of Dlx target genes inhibits neural plate differentiation. Importantly, the stereotypic pattern of border cell fates in the adjacent ectoderm is re-established only under conditions where the expanded neural plate abuts Dlx-positive non-neural ectoderm. Experiments in which presumptive neural plate was grafted to ventral ectoderm reiterate induction of neural crest and placodal lineages and also demonstrate that Dlx activity is required in non-neural ectoderm for the production of signals needed for induction of these cells. We propose that Dlx proteins regulate intercellular signaling across the interface between neural and non-neural ectoderm that is critical for inducing and patterning adjacent cell fates. PMID:12466200

Stem Cell Fate Determination during Development and Regeneration of Ectodermal Organs.

PubMed

Jiménez-Rojo, Lucía; Granchi, Zoraide; Graf, Daniel; Mitsiadis, Thimios A

2012-01-01

The development of ectoderm-derived appendages results in a large variety of highly specialized organs such as hair follicles, mammary glands, salivary glands, and teeth. Despite varying in number, shape, and function, all these ectodermal organs develop through continuous and reciprocal epithelial-mesenchymal interactions, sharing common morphological and molecular features especially during their embryonic development. Diseases such as ectodermal dysplasias can affect simultaneously these organs, suggesting that they may arise from common multipotent precursors residing in the embryonic ectoderm. During embryogenesis, these putative ectodermal stem cells may adopt different fates and consequently be able to generate a variety of tissue-specific stem cells, which are the sources for the various cell lineages that form the diverse organs. The specification of those common epithelial precursors, as well as their further lineage commitment to tissue-specific stem cells, might be controlled by specific signals. It has been well documented that Notch, Wnt, bone morphogenetic protein, and fibroblast growth factor signaling pathways regulate cell fate decisions during the various stages of ectodermal organ development. However, the in vivo spatial and temporal dynamics of these signaling pathways are not yet well understood. Improving the current knowledge on the mechanisms involved in stem cell fate determination during organogenesis and homeostasis of ectodermal organs is crucial to develop effective stem cell-based therapies in order to regenerate or replace pathological and damaged tissues.

Ectodermal dysplasia associated with sickle cell disease.

PubMed

Volpato, Luiz Evaristo Ricci; Volpato, Maria Carmen Palma Faria; de Carvalhosa, Artur Aburad; Palma, Vinicius Canavarros; Borges, Alvaro Henrique

2014-01-01

Ectodermal dysplasia and sickle cell anaemia are inherited disorders that affect, respectively, the tissues derived from the embryonic ectoderm and the production of erythrocytes by the bone marrow. The simultaneous occurrence of both disorders is extremely rare. This is a case of both ectodermal dysplasia and sickle cell anaemia reported in a 6-year-old. The patient had been diagnosed with sickle cell anaemia for only six months when he sought treatment presenting with the following: hypotrichosis, dry skin, periocular hyperpigmentation, protruding lips, hypodontia, and morphologically altered teeth. The clinical features combined with his medical history led to the diagnosis of ectodermal dysplasia. Dentists should be prepared to recognise patterns that escape normality to aid in the diagnosis of systemic changes, even in patients with other previous diagnoses.

Infantile bilateral glaucoma in a child with ectodermal dysplasia.

PubMed

Callea, Michele; Vinciguerra, Agatino; Willoughby, Colin E; Deroma, Laura; Clarich, Gabriella

2013-01-01

Ectodermal dysplasia is a rare disease which affects at least two ectodermal-derived structures such as hair, nails, skin, sweat glands and teeth. Approximately 200 different conditions have been classified as an ectodermal dysplasia and X-linked hypohidrotic ectodermal dysplasia (XHED) represents the commonest form. Clinically, XHED is characterized by hypotrichosis, hypohidrosis and hypodontia. A variety of ocular manifestations have been reported in XHED, the most common being dryness of eyes due to tear deficiency and instability of the film secondary to the absence of meibomian gland function. Here we report a child with the distinctive clinical features of XHED confirmed with molecular diagnosis who presented with infantile bilateral glaucoma, in addition to the classical ocular involvement in XHED.

Molluscan engrailed expression, serial organization, and shell evolution

NASA Technical Reports Server (NTRS)

Jacobs, D. K.; Wray, C. G.; Wedeen, C. J.; Kostriken, R.; DeSalle, R.; Staton, J. L.; Gates, R. D.; Lindberg, D. R.

2000-01-01

Whether the serial features found in some molluscs are ancestral or derived is considered controversial. Here, in situ hybridization and antibody studies show iterated engrailed-gene expression in transverse rows of ectodermal cells bounding plate field development and spicule formation in the chiton, Lepidochitona cavema, as well as in cells surrounding the valves and in the early development of the shell hinge in the clam, Transennella tantilla. Ectodermal expression of engrailed is associated with skeletogenesis across a range of bilaterian phyla, suggesting a single evolutionary origin of invertebrate skeletons. The shared ancestry of bilaterian-invertebrate skeletons may help explain the sudden appearance of shelly fossils in the Cambrian. Our interpretation departs from the consideration of canonical metameres or segments as units of evolutionary analysis. In this interpretation, the shared ancestry of engrailed-gene function in the terminal/posterior addition of serially repeated elements during development explains the iterative expression of engrailed genes in a range of metazoan body plans.

Drosophila heart cell movement to the midline occurs through both cell autonomous migration and dorsal closure.

PubMed

Haack, Timm; Schneider, Matthias; Schwendele, Bernd; Renault, Andrew D

2014-12-15

The Drosophila heart is a linear organ formed by the movement of bilaterally specified progenitor cells to the midline and adherence of contralateral heart cells. This movement occurs through the attachment of heart cells to the overlying ectoderm which is undergoing dorsal closure. Therefore heart cells are thought to move to the midline passively. Through live imaging experiments and analysis of mutants that affect the speed of dorsal closure we show that heart cells in Drosophila are autonomously migratory and part of their movement to the midline is independent of the ectoderm. This means that heart formation in flies is more similar to that in vertebrates than previously thought. We also show that defects in dorsal closure can result in failure of the amnioserosa to properly degenerate, which can physically hinder joining of contralateral heart cells leading to a broken heart phenotype. Copyright © 2014 Elsevier Inc. All rights reserved.

RNA-Seq identifies SPGs as a ventral skeletal patterning cue in sea urchins.

PubMed

Piacentino, Michael L; Zuch, Daniel T; Fishman, Julie; Rose, Sviatlana; Speranza, Emily E; Li, Christy; Yu, Jia; Chung, Oliver; Ramachandran, Janani; Ferrell, Patrick; Patel, Vijeta; Reyna, Arlene; Hameeduddin, Hajerah; Chaves, James; Hewitt, Finnegan B; Bardot, Evan; Lee, David; Core, Amanda B; Hogan, John D; Keenan, Jessica L; Luo, Lingqi; Coulombe-Huntington, Jasmin; Blute, Todd A; Oleinik, Ekaterina; Ibn-Salem, Jonas; Poustka, Albert J; Bradham, Cynthia A

2016-02-15

The sea urchin larval skeleton offers a simple model for formation of developmental patterns. The calcium carbonate skeleton is secreted by primary mesenchyme cells (PMCs) in response to largely unknown patterning cues expressed by the ectoderm. To discover novel ectodermal cues, we performed an unbiased RNA-Seq-based screen and functionally tested candidates; we thereby identified several novel skeletal patterning cues. Among these, we show that SLC26a2/7 is a ventrally expressed sulfate transporter that promotes a ventral accumulation of sulfated proteoglycans, which is required for ventral PMC positioning and skeletal patterning. We show that the effects of SLC perturbation are mimicked by manipulation of either external sulfate levels or proteoglycan sulfation. These results identify novel skeletal patterning genes and demonstrate that ventral proteoglycan sulfation serves as a positional cue for sea urchin skeletal patterning. © 2016. Published by The Company of Biologists Ltd.

Ectrodactyly-ectodermal dysplasia-cleft lip and palate syndrome.

PubMed

Dhar, Reema Sharma; Bora, Amitava

2014-01-01

Ectrodactyly-ectodermal dysplasia-cleft (EEC) syndrome is an autosomal dominant disorder characterized by the triad of ectrodactyly-ectodermal dysplasia, and facial clefting along with some associated features. Presence of all the three major features in a single individual is extremely rare. We report a case of 4 year 11 months old child with EEC syndrome having ectodermal dysplasia-cleft lip and cleft palate and ectrodactyly with some associated features. Clinical features, diagnosis and role of a dentist in the multidisciplinary treatment approach have been elaborated in this case report.

Ectodermal Dysplasia Associated with Sickle Cell Disease

PubMed Central

Volpato, Luiz Evaristo Ricci; Volpato, Maria Carmen Palma Faria; de Carvalhosa, Artur Aburad; Palma, Vinicius Canavarros; Borges, Álvaro Henrique

2014-01-01

Ectodermal dysplasia and sickle cell anaemia are inherited disorders that affect, respectively, the tissues derived from the embryonic ectoderm and the production of erythrocytes by the bone marrow. The simultaneous occurrence of both disorders is extremely rare. This is a case of both ectodermal dysplasia and sickle cell anaemia reported in a 6-year-old. The patient had been diagnosed with sickle cell anaemia for only six months when he sought treatment presenting with the following: hypotrichosis, dry skin, periocular hyperpigmentation, protruding lips, hypodontia, and morphologically altered teeth. The clinical features combined with his medical history led to the diagnosis of ectodermal dysplasia. Dentists should be prepared to recognise patterns that escape normality to aid in the diagnosis of systemic changes, even in patients with other previous diagnoses. PMID:25343049

Individualized Plastic Reconstruction Strategy for Patients With Ectodermal Dysplasia Syndrome.

PubMed

Hou, Yikang; Jin, Yunbo; Lin, Xiaoxi; Chai, Gang; Zhang, Yan; Qi, Zuoliang

2017-06-01

Ectodermal dysplasia syndrome is a hereditary disease of ectodermal origin. Appearances of nail dystrophy, alopecia or hypotrichosis, saddle nose deformity, and palmoplantar hyperkeratosis are usually associated with a lack of sweat glands as well as partial or complete absence of teeth. These manifestations are usually corrected only with oral rehabilitation by mounting dentures. In this study, plastic rehabilitation was developed to correct the special features of patients with ectodermal dysplasia. Four men and 1 woman with ectodermal dysplasia syndrome were treated. Four patients showed dysostosis of the midface, and rhinoplasty with costal bone was performed, whereas cosmetic operation aiming to repair soft tissue defects was adopted for the last patient. After plastic corrections, all 5 patients were satisfied with the results and had no social embarrassment.

Physics of the primitive solar nebula and of giant gaseous protoplanets

NASA Technical Reports Server (NTRS)

Cameron, A. G. W.

1978-01-01

It has been proposed that the supernova responsible for injecting Al-26 into the early solar system was in fact responsible for triggering the collapse of an interstellar cloud in order to produce a system of stars, one of which would be the solar system. Details concerning the mechanism involved in such a process are discussed. Attention is given to the evolution of the primitive solar nebula, the instabilities in the primitive solar nebula, and the giant gaseous protoplanets. The principal conclusion to be drawn from the material presented is that the primitive solar nebula was a rather chaotic place, highly turbulent, with the multiple formation of giant gaseous protoplanets.

Tissue-specific Requirements of β-Catenin in External Genitalia Development

PubMed Central

Lin, Congxing; Yin, Yan; Long, Fanxin; Ma, Liang

2008-01-01

SUMMARY External genitalia are body appendages specialized for internal fertilization. Its development can be divided into two phases, an early androgen-independent phase and a late androgen-dependant sexual differentiation phase. In the early phase, the embryonic anlage of external genitalia, the genital tubercle (GT), are morphologically identical in both sexes. Although congenital external genitalia malformations represent the second most common birth defect in humans, the genetic pathways governing early external genitalia development and urethra formation are poorly understood. Proper development of the GT requires coordinated outgrowth of the mesodermally-derived mesenchyme and extension of the endodermal urethra within an ectodermal epithelial capsule. Here we demonstrate that β-Catenin plays indispensable and distinct roles in each of the aforementioned three tissue layers in early androgen-independent GT development. WNT-β-Catenin signaling is required in the endodermal urethra to activate and maintain Fgf8 expression and direct GT outgrowth, as well as to maintain homeostasis of the urethra. Moreover, β-Catenin is required in the mesenchyme to promote cell proliferation. In contrast, β-Catenin is required in the ectoderm to maintain tissue integrity possibly through cell-cell adhesion during GT outgrowth. The fact that both endodermal and ectodermal β-Catenin knockout animals develop severe hypospadias in both sexes raises the possibility that deregulation of any of these functions can contribute to the etiology of congenital external genital defects in humans. PMID:18635608

Requirement of Smad4 from Ocular Surface Ectoderm for Retinal Development.

PubMed

Li, Jing; Wang, Shusheng; Anderson, Chastain; Zhao, Fangkun; Qin, Yu; Wu, Di; Wu, Xinwei; Liu, Jia; He, Xuefei; Zhao, Jiangyue; Zhang, Jinsong

2016-01-01

Microphthalmia is characterized by abnormally small eyes and usually retinal dysplasia, accounting for up to 11% of the blindness in children. Right now there is no effective treatment for the disease, and the underlying mechanisms, especially how retinal dysplasia develops from microphthalmia and whether it depends on the signals from lens ectoderm are still unclear. Mutations in genes of the TGF-β superfamily have been noted in patients with microphthalmia. Using conditional knockout mice, here we address the question that whether ocular surface ectoderm-derived Smad4 modulates retinal development. We found that loss of Smad4 specifically on surface lens ectoderm leads to microphthalmia and dysplasia of retina. Retinal dysplasia in the knockout mice is caused by the delayed or failed differentiation and apoptosis of retinal cells. Microarray analyses revealed that members of Hedgehog and Wnt signaling pathways are affected in the knockout retinas, suggesting that ocular surface ectoderm-derived Smad4 can regulate Hedgehog and Wnt signaling in the retina. Our studies suggest that defective of ocular surface ectoderm may affect retinal development.

Requirement of Smad4 from Ocular Surface Ectoderm for Retinal Development

PubMed Central

Li, Jing; Wang, Shusheng; Anderson, Chastain; Zhao, Fangkun; Qin, Yu; Wu, Di; Wu, Xinwei; Liu, Jia; He, Xuefei; Zhao, Jiangyue; Zhang, Jinsong

2016-01-01

Microphthalmia is characterized by abnormally small eyes and usually retinal dysplasia, accounting for up to 11% of the blindness in children. Right now there is no effective treatment for the disease, and the underlying mechanisms, especially how retinal dysplasia develops from microphthalmia and whether it depends on the signals from lens ectoderm are still unclear. Mutations in genes of the TGF-β superfamily have been noted in patients with microphthalmia. Using conditional knockout mice, here we address the question that whether ocular surface ectoderm-derived Smad4 modulates retinal development. We found that loss of Smad4 specifically on surface lens ectoderm leads to microphthalmia and dysplasia of retina. Retinal dysplasia in the knockout mice is caused by the delayed or failed differentiation and apoptosis of retinal cells. Microarray analyses revealed that members of Hedgehog and Wnt signaling pathways are affected in the knockout retinas, suggesting that ocular surface ectoderm-derived Smad4 can regulate Hedgehog and Wnt signaling in the retina. Our studies suggest that defective of ocular surface ectoderm may affect retinal development. PMID:27494603

Representation primitives, process models and patient data in computer-interpretable clinical practice guidelines: a literature review of guideline representation models.

PubMed

Wang, Dongwen; Peleg, Mor; Tu, Samson W; Boxwala, Aziz A; Greenes, Robert A; Patel, Vimla L; Shortliffe, Edward H

2002-12-18

Representation of clinical practice guidelines in a computer-interpretable format is a critical issue for guideline development, implementation, and evaluation. We studied 11 types of guideline representation models that can be used to encode guidelines in computer-interpretable formats. We have consistently found in all reviewed models that primitives for representation of actions and decisions are necessary components of a guideline representation model. Patient states and execution states are important concepts that closely relate to each other. Scheduling constraints on representation primitives can be modeled as sequences, concurrences, alternatives, and loops in a guideline's application process. Nesting of guidelines provides multiple views to a guideline with different granularities. Integration of guidelines with electronic medical records can be facilitated by the introduction of a formal model for patient data. Data collection, decision, patient state, and intervention constitute four basic types of primitives in a guideline's logic flow. Decisions clarify our understanding on a patient's clinical state, while interventions lead to the change from one patient state to another.

Search for Primitive Matter in the Solar System

NASA Technical Reports Server (NTRS)

Libourel, G.; Michel, P.; Delbo, M.; Ganino, C.; Recio-Blanco, A.; de Laverny, P.; Zolensky, M. E.; Krot, A. N.

2017-01-01

Recent astronomical observations and theoretical modeling led to a consensus regarding the global scenario of the formation of young stellar objects (YSO) from a cold molecular cloud of interstellar dust (organics and minerals) and gas that, in some cases, leads to the formation of a planetary system. In the case of our Solar System, which has already evolved for approximately 4567 Ma, the quest is to access, through the investigation of planets, moons, cometary and asteroidal bodies, meteorites, micrometeorites, and interplanetary dust particles, the primitive material that contains the key information about the early Solar System processes and its evolution. However, laboratory analyses of extraterrestrial samples, astronomical observations and dynamical models of the Solar System evolution have not brought yet any conclusive evidence on the nature and location of primitive matter in the Solar System, preventing a clear understanding of its early stages.

A molecular atlas of the developing ectoderm defines neural, neural crest, placode, and nonneural progenitor identity in vertebrates.

PubMed

Plouhinec, Jean-Louis; Medina-Ruiz, Sofía; Borday, Caroline; Bernard, Elsa; Vert, Jean-Philippe; Eisen, Michael B; Harland, Richard M; Monsoro-Burq, Anne H

2017-10-01

During vertebrate neurulation, the embryonic ectoderm is patterned into lineage progenitors for neural plate, neural crest, placodes and epidermis. Here, we use Xenopus laevis embryos to analyze the spatial and temporal transcriptome of distinct ectodermal domains in the course of neurulation, during the establishment of cell lineages. In order to define the transcriptome of small groups of cells from a single germ layer and to retain spatial information, dorsal and ventral ectoderm was subdivided along the anterior-posterior and medial-lateral axes by microdissections. Principal component analysis on the transcriptomes of these ectoderm fragments primarily identifies embryonic axes and temporal dynamics. This provides a genetic code to define positional information of any ectoderm sample along the anterior-posterior and dorsal-ventral axes directly from its transcriptome. In parallel, we use nonnegative matrix factorization to predict enhanced gene expression maps onto early and mid-neurula embryos, and specific signatures for each ectoderm area. The clustering of spatial and temporal datasets allowed detection of multiple biologically relevant groups (e.g., Wnt signaling, neural crest development, sensory placode specification, ciliogenesis, germ layer specification). We provide an interactive network interface, EctoMap, for exploring synexpression relationships among genes expressed in the neurula, and suggest several strategies to use this comprehensive dataset to address questions in developmental biology as well as stem cell or cancer research.

Hypohidrotic ectodermal dysplasia: a clinical case with a longitudinal approach.

PubMed

Fraiz, Fabian Calixto; Gugisch, Renato Cordeiro; Cavalcante-Leão, Bianca Lopes; Macedo, Liliane Moreira

2014-11-01

This paper describes a clinical case of a male with hypohidrotic ectodermal dysplasia submitted to rehabilitation and occlusal dental interventions with follow-up from 3 to 14 years of age. Due to the severe effects on function and esthetics, the clinical manifestations of ectodermal dysplasia exert a negative impact on quality of life. However, oral rehabilitation in childhood poses a challenge due to growth and development. A male with hypohidrotic ectodermal dysplasia began dental intervention at the age of 3 years. The clinical and radiographic exams revealed the absence of several primary and permanent teeth and abnormal shape of the primary maxillary incisors. The facial characteristics were compatible with hypohidrotic ectodermal dysplasia, such as a prominent brow, everted lips, fattened bridge of the nose and small vertical facial height. The treatment proposed involved rehabilitation through successive temporary partial dentures, functional orthopedics of the jaws, esthetic reconstruction of the anterior teeth, timely occlusal intervention and preventive actions for the control of dental caries and plaque. The present case demonstrates that early care plays a fundamental role in minimizing the biopsychosocial consequences of hypohidrotic ectodermal dysplasia and preparing the patient for future oral rehabilitation. Although, the literature offers a number of papers describing dental treatment for ectodermal dysplasia, few cases include long-term follow-up and the use of a functional orthopedic appliance in combination with removable dentures in such patients.

A molecular atlas of the developing ectoderm defines neural, neural crest, placode, and nonneural progenitor identity in vertebrates

PubMed Central

Borday, Caroline; Bernard, Elsa; Vert, Jean-Philippe; Eisen, Michael B.; Harland, Richard M.

2017-01-01

During vertebrate neurulation, the embryonic ectoderm is patterned into lineage progenitors for neural plate, neural crest, placodes and epidermis. Here, we use Xenopus laevis embryos to analyze the spatial and temporal transcriptome of distinct ectodermal domains in the course of neurulation, during the establishment of cell lineages. In order to define the transcriptome of small groups of cells from a single germ layer and to retain spatial information, dorsal and ventral ectoderm was subdivided along the anterior-posterior and medial-lateral axes by microdissections. Principal component analysis on the transcriptomes of these ectoderm fragments primarily identifies embryonic axes and temporal dynamics. This provides a genetic code to define positional information of any ectoderm sample along the anterior-posterior and dorsal-ventral axes directly from its transcriptome. In parallel, we use nonnegative matrix factorization to predict enhanced gene expression maps onto early and mid-neurula embryos, and specific signatures for each ectoderm area. The clustering of spatial and temporal datasets allowed detection of multiple biologically relevant groups (e.g., Wnt signaling, neural crest development, sensory placode specification, ciliogenesis, germ layer specification). We provide an interactive network interface, EctoMap, for exploring synexpression relationships among genes expressed in the neurula, and suggest several strategies to use this comprehensive dataset to address questions in developmental biology as well as stem cell or cancer research. PMID:29049289

Multidisciplinary management of hypohydrotic ectodermal dysplasia – a case report

PubMed Central

Joseph, Suja; Cherackal, George J; Jacob, Jose; Varghese, Alex K

2015-01-01

Key Clinical Message Hypohydrotic ectodermal dysplasia is a hereditary disorder, which affects ectodermal derivatives. It manifests several abnormalities of the teeth, and is commonly inherited through female carriers. This case report presents a patient with compromised esthetics and function. A multidisciplinary approach was planned involving an oral pathologist, endodontist, orthodontist and a prosthodontist. PMID:25984305

Death due to complications of anhidrotic ectodermal dysplasia.

PubMed

Ogden, Emily; Schandl, Cynthia; Tormos, Lee Marie

2014-11-01

Ectodermal dysplasia comprises a group of disorders affecting ectodermal tissues. Severity depends on the genetic aberration; hyperpyrexia secondary to absence of sweat glands is a common complication. Treatment is supportive. This case report describes a 1-month, 27-day-old male infant with a diagnosis of X-linked recessive anhidrotic ectodermal dysplasia. On the day of his death, his mother swaddled him in a blanket and placed him on the couch at 5:30 am. When she picked him up at 8:00 am, he was unresponsive. At the emergency department, his rectal temperature was 40°C. Postmortem blood culture was positive for group B streptococcus, a possible etiology for fever. It is vital to teach parents that close monitoring of children with ectodermal dysplasia is necessary, as an increase in body temperature can become life threatening. © 2014 American Academy of Forensic Sciences.

Mini-implants: alternative for oral rehabilitation of a child with ectodermal dysplasia.

PubMed

Mello, Bianca Zeponi Fernandes; Silva, Thiago Cruvinel; Rios, Daniela; Machado, Maria Aparecida Andrade Moreira; Valarelli, Fabrício Pinelli; Oliveira, Thais Marchini

2015-01-01

Ectodermal dysplasia is a rare congenital disease that affects several structures of ectodermal origin. The most commonly related oral characteristics are hypodontia, malformed teeth and underdeveloped alveolar ridges. New alternative treatments are needed due to the failure of the conventional prosthesis retention. This case report outlines the oral rehabilitation treatment of a 9-year-old girl with ectodermal dysplasia. The treatment was performed with conventional prosthesis upon mini-implants. The mini-implants provided prosthetic retention. The patient reported a good adaptation of the dental prosthesis and satisfaction with the treatment. The increased self-esteem improved the socialization skills of the girl. In this case report, use of prosthesis with mini-implants was satisfactory for prosthetic retention. However, clinical studies with long-term follow-up are needed to test the mini-implants as an alternative for oral rehabilitation of children with ectodermal dysplasia.

Ectodermal Dysplasia with Anodontia: A Report of Two Cases

PubMed Central

Bani, Mehmet; Tezkirecioglu, Ali Melih; Akal, Nese; Tuzuner, Tamer

2010-01-01

Ectodermal dysplasia is a hereditary disorder that occurs as a consequence of disturbances in the ectoderm of the developing embryo. The triad of nail dystrophy, alopecia or hypotrichosis and palmoplantar hyperkeratosis is usually accompanied by a lack of sweat glands and a partial or complete absence of primary and/or permanent dentition. Two case reports illustrating the prosthetic rehabilitation of 2 young boys with anhidrotic ectodermal dysplasia associated with severe anodontia are presented. Since the oral rehabilitation of these cases is often difficult; particularly in pediatric patients, treatment should be administered by a multidisciplinary team involving pediatric dentistry, orthodontics, prosthodontics and oral-maxillofacial surgery. PMID:20396456

Ectodermal Dysplasia: A Clinical Overview for the Dental Practitioner.

PubMed

Halai, Tina; Stevens, Claire

2015-10-01

The term ectodermal dysplasia (ED) is used to describe a group of rare congenital disorders characterized by abnormalities of two or more ectodermal structures such as the skin, hair, nails, teeth and sweat glands. This paper will give an overview of the aetiology of ED and describe the manifestations and dental management of this condition. In particular, the important role of the dental practitioner in the identification and management of patients with ED will be highlighted. CPD/Clinical Relevance: Dental practitioners should be aware of the oral features of ectodermal dysplasia and be able to make timely referrals and provide appropriate continuing care for these patients.

Acro-Dermato-Ungual-Lacrimal-Tooth Syndrome: An Uncommon Member of the Ectodermal Dysplasias.

PubMed

Whittington, Adam; Stein, Sarah; Kenner-Bell, Brandi

2016-09-01

Acro-dermato-ungual-lacrimal-tooth (ADULT) syndrome is a rare form of autosomal dominant ectodermal dysplasia due to mutations in the TP63 gene, a locus that has also been implicated in other syndromic forms of ectodermal dysplasia. It shares many phenotypic characteristics with other TP63 gene mutation syndromes, often making an accurate diagnosis difficult. Long-term management and follow-up of the various sequelae of ectodermal dysplasia require an accurate diagnosis. We report a familial case of ADULT syndrome in a daughter, mother, and son and provide a brief review of the clinical characteristics of this syndrome. © 2016 Wiley Periodicals, Inc.

Ectodermal Dysplasia: A Genetic Review

PubMed Central

Prashanth, S

2012-01-01

Abstract Ectodermal dysplasia is a rare hereditary disorder with a characteristic physiognomy. It is a genetic disorder affecting the development or function of the teeth, hair, nails and sweat glands. Depending on the particular syndrome ectodermal dysplasia can also affect the skin, the lens or retina of the eye, parts of the inner ear, the development of fingers and toes, the nerves and other parts of the body. Each syndrome usually involves a different combination of symptoms, which can range from mild to severe. The history and lessons learned from hypohidrotic ectodermal dysplasia (HED) may serve as an example for unraveling of the cause and pathogenesis of other ectodermal dysplasia syndromes by demonstrating that phenotypically identical syndromes can be caused by mutations in different genes (EDA, EDAR, EDARADD), that mutations in the same gene can lead to different phenotypes and that mutations in the genes further downstream in the same signaling pathway (NEMO) may modify the phenotype quite profoundly. The aim of this paper is to describe and discuss the etiology, genetic review, clinical manifestations and treatment options of this hereditary disorder. How to cite this article: Deshmukh S, Prashanth S. Ectodermal Dysplasia: A Genetic Review. Int J Clin Pediatr Dent 2012; 5(3):197-202. PMID:25206167

Ectodermal dysplasia: a genetic review.

PubMed

Deshmukh, Seema; Prashanth, S

2012-09-01

Ectodermal dysplasia is a rare hereditary disorder with a characteristic physiognomy. It is a genetic disorder affecting the development or function of the teeth, hair, nails and sweat glands. Depending on the particular syndrome ectodermal dysplasia can also affect the skin, the lens or retina of the eye, parts of the inner ear, the development of fingers and toes, the nerves and other parts of the body. Each syndrome usually involves a different combination of symptoms, which can range from mild to severe. The history and lessons learned from hypohidrotic ectodermal dysplasia (HED) may serve as an example for unraveling of the cause and pathogenesis of other ectodermal dysplasia syndromes by demonstrating that phenotypically identical syndromes can be caused by mutations in different genes (EDA, EDAR, EDARADD), that mutations in the same gene can lead to different phenotypes and that mutations in the genes further downstream in the same signaling pathway (NEMO) may modify the phenotype quite profoundly. The aim of this paper is to describe and discuss the etiology, genetic review, clinical manifestations and treatment options of this hereditary disorder. How to cite this article: Deshmukh S, Prashanth S. Ectodermal Dysplasia: A Genetic Review. Int J Clin Pediatr Dent 2012; 5(3):197-202.

Correct Patterning of the Primitive Streak Requires the Anterior Visceral Endoderm

PubMed Central

Stuckey, Daniel W.; Di Gregorio, Aida; Clements, Melanie; Rodriguez, Tristan A.

2011-01-01

Anterior-posterior axis specification in the mouse requires signalling from a specialised extra-embryonic tissue called the anterior visceral endoderm (AVE). AVE precursors are induced at the distal tip of the embryo and move to the prospective anterior. Embryological and genetic analysis has demonstrated that the AVE is required for anterior patterning and for correctly positioning the site of primitive streak formation by inhibiting Nodal activity. We have carried out a genetic ablation of the Hex-expressing cells of the AVE (Hex-AVE) by knocking the Diphtheria toxin subunit A into the Hex locus in an inducible manner. Using this model we have identified that, in addition to its requirement in the anterior of the embryo, the Hex-AVE sub-population has a novel role between 5.5 and 6.5dpc in patterning the primitive streak. Embryos lacking the Hex-AVE display delayed initiation of primitive streak formation and miss-patterning of the anterior primitive streak. We demonstrate that in the absence of the Hex-AVE the restriction of Bmp2 expression to the proximal visceral endoderm is also defective and expression of Wnt3 and Nodal is not correctly restricted to the posterior epiblast. These results, coupled with the observation that reducing Nodal signalling in Hex-AVE ablated embryos increases the frequency of phenotypes observed, suggests that these primitive streak patterning defects are due to defective Nodal signalling. Together, our experiments demonstrate that the AVE is not only required for anterior patterning, but also that specific sub-populations of this tissue are required to pattern the posterior of the embryo. PMID:21445260

A computational model for BMP movement in sea urchin embryos.

PubMed

van Heijster, Peter; Hardway, Heather; Kaper, Tasso J; Bradham, Cynthia A

2014-12-21

Bone morphogen proteins (BMPs) are distributed along a dorsal-ventral (DV) gradient in many developing embryos. The spatial distribution of this signaling ligand is critical for correct DV axis specification. In various species, BMP expression is spatially localized, and BMP gradient formation relies on BMP transport, which in turn requires interactions with the extracellular proteins Short gastrulation/Chordin (Chd) and Twisted gastrulation (Tsg). These binding interactions promote BMP movement and concomitantly inhibit BMP signaling. The protease Tolloid (Tld) cleaves Chd, which releases BMP from the complex and permits it to bind the BMP receptor and signal. In sea urchin embryos, BMP is produced in the ventral ectoderm, but signals in the dorsal ectoderm. The transport of BMP from the ventral ectoderm to the dorsal ectoderm in sea urchin embryos is not understood. Therefore, using information from a series of experiments, we adapt the mathematical model of Mizutani et al. (2005) and embed it as the reaction part of a one-dimensional reaction-diffusion model. We use it to study aspects of this transport process in sea urchin embryos. We demonstrate that the receptor-bound BMP concentration exhibits dorsally centered peaks of the same type as those observed experimentally when the ternary transport complex (Chd-Tsg-BMP) forms relatively quickly and BMP receptor binding is relatively slow. Similarly, dorsally centered peaks are created when the diffusivities of BMP, Chd, and Chd-Tsg are relatively low and that of Chd-Tsg-BMP is relatively high, and the model dynamics also suggest that Tld is a principal regulator of the system. At the end of this paper, we briefly compare the observed dynamics in the sea urchin model to a version that applies to the fly embryo, and we find that the same conditions can account for BMP transport in the two types of embryos only if Tld levels are reduced in sea urchin compared to fly. Copyright © 2014 Elsevier Ltd. All rights reserved.

Spatial and temporal expression of the Grainyhead-like transcription factor family during murine development.

PubMed

Auden, Alana; Caddy, Jacinta; Wilanowski, Tomasz; Ting, Stephen B; Cunningham, John M; Jane, Stephen M

2006-10-01

The Drosophila transcription factor Grainyhead (grh) is expressed in ectoderm-derived tissues where it regulates several key developmental events including cuticle formation, tracheal elongation and dorsal closure. Our laboratory has recently identified three novel mammalian homologues of the grh gene, Grainyhead-like 1, -2 and -3 (Grhl1-3) that rewrite the phylogeny of this family. Using gene targeting in mice, we have shown that Grhl3 is essential for neural tube closure, skin barrier formation and wound healing. Despite their extensive sequence homology, Grhl1 and Grhl2 are unable to compensate for loss of Grhl3 in these developmental processes. To explore this lack of redundancy, and to gain further insights into the functions of this gene family in mammalian development we have performed an extensive in situ hybridisation analysis. We demonstrate that, although all three Grhl genes are highly expressed in the developing epidermis, they display subtle differences in the timing and level of expression. Surprisingly, we also demonstrate differential expression patterns in non-ectoderm-derived tissues, including the heart, the lung, and the metanephric kidney. These findings expand our understanding of the unique role of Grhl3 in neurulation and epidermal morphogenesis, and provide a focus for further functional analysis of the Grhl genes during mouse embryogenesis.

Inner ear development: building a spiral ganglion and an organ of Corti out of unspecified ectoderm.

PubMed

Fritzsch, Bernd; Pan, Ning; Jahan, Israt; Elliott, Karen L

2015-07-01

The mammalian inner ear develops from a placodal thickening into a complex labyrinth of ducts with five sensory organs specialized to detect position and movement in space. The mammalian ear also develops a spiraled cochlear duct containing the auditory organ, the organ of Corti (OC), specialized to translate sound into hearing. Development of the OC from a uniform sheet of ectoderm requires unparalleled precision in the topological developmental engineering of four different general cell types, namely sensory neurons, hair cells, supporting cells, and general otic epithelium, into a mosaic of ten distinctly recognizable cell types in and around the OC, each with a unique distribution. Moreover, the OC receives unique innervation by ear-derived spiral ganglion afferents and brainstem-derived motor neurons as efferents and requires neural-crest-derived Schwann cells to form myelin and neural-crest-derived cells to induce the stria vascularis. This transformation of a sheet of cells into a complicated interdigitating set of cells necessitates the orchestrated expression of multiple transcription factors that enable the cellular transformation from ectoderm into neurosensory cells forming the spiral ganglion neurons (SGNs), while simultaneously transforming the flat epithelium into a tube, the cochlear duct, housing the OC. In addition to the cellular and conformational changes forming the cochlear duct with the OC, changes in the surrounding periotic mesenchyme form passageways for sound to stimulate the OC. We review molecular developmental data, generated predominantly in mice, in order to integrate the well-described expression changes of transcription factors and their actions, as revealed in mutants, in the formation of SGNs and OC in the correct position and orientation with suitable innervation. Understanding the molecular basis of these developmental changes leading to the formation of the mammalian OC and highlighting the gaps in our knowledge might guide in vivo attempts to regenerate this most complicated cellular mosaic of the mammalian body for the reconstitution of hearing in a rapidly growing population of aging people suffering from hearing loss.

LGN plays distinct roles in oral epithelial stratification, filiform papilla morphogenesis and hair follicle development

PubMed Central

Lough, Kendall J.; Patel, Jeet H.; Descovich, Carlos Patiño; Curtis, T. Anthony

2016-01-01

Oral epithelia protect against constant challenges by bacteria, viruses, toxins and injury while also contributing to the formation of ectodermal appendages such as teeth, salivary glands and lingual papillae. Despite increasing evidence that differentiation pathway genes are frequently mutated in oral cancers, comparatively little is known about the mechanisms that regulate normal oral epithelial development. Here, we characterize oral epithelial stratification and describe multiple distinct functions for the mitotic spindle orientation gene LGN (Gpsm2) in promoting differentiation and tissue patterning in the mouse oral cavity. Similar to its function in epidermis, apically localized LGN directs perpendicular divisions that promote stratification of the palatal, buccogingival and ventral tongue epithelia. Surprisingly, however, in dorsal tongue LGN is predominantly localized basally, circumferentially or bilaterally and promotes planar divisions. Loss of LGN disrupts the organization and morphogenesis of filiform papillae but appears to be dispensable for embryonic hair follicle development. Thus, LGN has crucial tissue-specific functions in patterning surface ectoderm and its appendages by controlling division orientation. PMID:27317810

Unusual manifestations of ectodermal dysplasia-syndactyly syndrome type I in two Yemeni siblings.

PubMed

Mohammad, Alshami

2015-01-15

Ectodermal dysplasias (EDs) are a group of genodermatoses characterized by malformations of tissues derived from the ectoderm, including the skin, its appendages (hair, nails, sweat glands), teeth, and the breasts. Ectodermal dysplasia syndactyly syndrome (EDSS) is a rare, newly described type of ED involving syndactyly. We report 2 Yemeni siblings with typical EDSS manifestations, including bilateral, partial cutaneous syndactyly of the fingers and toes; sparse, coarse, brittle scalp hair, eyebrows, and eyelashes; and conical, widely spaced teeth with enamel notches. In addition, the siblings presented with other features hitherto not described for this syndrome, such as adermatoglyphia, onychogryphosis, hypoplastic widely spaced nipples, hypoplastic thumbs, and red scalp hair.

Molecular basis of hypohidrotic ectodermal dysplasia: an update.

PubMed

Trzeciak, Wieslaw H; Koczorowski, Ryszard

2016-02-01

Recent advances in understanding the molecular events underlying hypohidrotic ectodermal dysplasia (HED) caused by mutations of the genes encoding proteins of the tumor necrosis factor α (TNFα)-related signaling pathway have been presented. These proteins are involved in signal transduction from ectoderm to mesenchyme during development of the fetus and are indispensable for the differentiation of ectoderm-derived structures such as eccrine sweat glands, teeth, hair, skin, and/or nails. Novel data were reviewed and discussed on the structure and functions of the components of TNFα-related signaling pathway, the consequences of mutations of the genes encoding these proteins, and the prospect for further investigations, which might elucidate the origin of HED.

SMP: A solid modeling program version 2.0

NASA Technical Reports Server (NTRS)

Randall, D. P.; Jones, K. H.; Vonofenheim, W. H.; Gates, R. L.; Matthews, C. G.

1986-01-01

The Solid Modeling Program (SMP) provides the capability to model complex solid objects through the composition of primitive geometric entities. In addition to the construction of solid models, SMP has extensive facilities for model editing, display, and analysis. The geometric model produced by the software system can be output in a format compatible with existing analysis programs such as PATRAN-G. The present version of the SMP software supports six primitives: boxes, cones, spheres, paraboloids, tori, and trusses. The details for creating each of the major primitive types is presented. The analysis capabilities of SMP, including interfaces to existing analysis programs, are discussed.

The development of the eyelids. Part I. External features.

PubMed Central

Pearson, A A

1980-01-01

The sequence of developmental events leading to the formation of the eyelids is described in staged human embryos. By the end of the fourth week the optic vesicle lies close to the surface ectoderm. The surface ectoderm overlying the optic vesicle, in response to this contact, has thickened to form the lense placode (Stage 13). A few days later (about 32 days, Stage 14) the lens placode is indented by the lens pit. A day or two later (about 33 days, Stage 15) the lens pit is closed: however, the lens vesicle and optic cup lie close to the surface ectoderm and appear to press against the surface. Prior to the development of the eyelids, one small sulcus or groove forms above the eye (eyelid groove) and another below it (stage 16, 37 days). As these grooves deepen, in Stages 17--19, eyelid folds develop, first below, and then above, the eye. In Stages 19--22 the eyelid folds develop into the eyelids and cover more of the eye as the palpebral fissure takes shape. The upper and the lower eyelids meet at the outer canthus in Stage 19. The inner canthus is established a few days later in Stage 20. Closure of the eyelids is complete in Stage 23. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 Fig. 15 Fig. 16 PMID:7364662

Chicken homeobox gene Msx-1: structure, expression in limb buds and effect of retinoic acid.

PubMed

Yokouchi, Y; Ohsugi, K; Sasaki, H; Kuroiwa, A

1991-10-01

A chicken gene carrying a homeobox highly homologous to the Drosophila muscle segment homeobox (msh) gene was isolated and designated as Msx-1. Conceptual translation from the longest ORF gave a protein of 259 amino acids lacking the conserved hexapeptide. Northern analysis detected a single 2.6 kb transcript. As early as day 2 of incubation, the transcript was detected but was not found in adult tissue. In situ hybridization analysis revealed that Msx-1 expression is closely related to a particular mesenchymal cell lineage during limb bud formation. In early stage embryos, Msx-1 was expressed in the somatopleure. When primordial mesenchyme cells for limb bud were generated from the Wolffian ridge of the somatopleure, Msx-1 expression began to diminish in the posterior half of the limb bud then in the presumptive cartilage-forming mesenchyme. In developing limb buds, remarkable expression was seen in the apical ectodermal ridge (AER), which is responsible for the sustained outgrowth and development of the limb. The Msx-1 transcripts were found in the limb mesenchymal cells in the region covering the necrotic zone and ectodermal cells overlying such mesenchymal cells. Both ectodermal and mesenchymal expression in limb bud were rapidly suppressed by local treatment of retinoic acid which can generate mirror-image duplication of digits. This indicates that retinoic acid alters the marginal presumptive non-cartilage forming mesenchyme cell lineage through suppression of Msx-1 expression.

Tooth, hair and claw: comparing epithelial stem cell niches of ectodermal appendages

PubMed Central

Naveau, Adrien; Seidel, Kerstin; Klein, Ophir D.

2014-01-01

The vertebrate ectoderm gives rise to organs that produce mineralized or keratinized substances, including teeth, hair, and claws. Most of these ectodermal derivatives grow continuously throughout the animal’s life and have active pools of adult stem cells that generate all the necessary cell types. These organs provide powerful systems for understanding the mechanisms that enable stem cells to regenerate or renew ectodermally derived tissues, and remarkable progress in our understanding of these systems has been made in recent years using mouse models. We briefly compare what is known about stem cells and their niches in incisors, hair follicles, and claws, and we examine expression of Gli1 as a potential example of a shared stem cell marker. We summarize some of the features, structures, and functions of the stem cell niches in these ectodermal derivatives; definition of the basic elements of the stem cell niches in these organs will provide guiding principles for identification and characterization of the niche in similar systems. PMID:24530577

FOXI2: a possible gene contributing to ectodermal dysplasia.

PubMed

Kurban, Mazen; Zeineddine, Savo Bou; Hamie, Lamiaa; Safi, Remi; Abbas, Ossama; Kibbi, Abdul Ghani; Bitar, Fadi; Nemer, Georges

2017-12-01

Cardio-facio-cutaneous syndrome (CFC), Noonan syndrome (NS), and Costello syndrome are a group of diseases that belong to the RASopathies. The syndromes share clinical features making diagnosis a challenge. To investigate the phenotype and genotype of a 10-year-old Iraqi girl with overlapping features of CFC, NS, and Costello syndromes, with additional features of ectodermal dysplasia. DNA was examined by exome sequencing and protein expression by immunohistochemistry. Exome sequencing identified a mutation in the SOS1 gene and a de novo deletion in the FOXI2 gene which was neither present in the international databases, nor in 400 chromosomes from the same population. Based on immunohistochemical staining, FOXI2 was identified in the basal cell layer of the skin and overlapped with the expression of P63, a major player in ectodermal dysplasia. We therefore suggest screening for FOXI2 mutation in the setting of ectodermal features that are not associated with genes known to contribute to ectodermal dysplasia.

Topical cetirizine and oral vitamin D: a valid treatment for hypotrichosis caused by ectodermal dysplasia.

PubMed

Rossi, A; Miraglia, E; Fortuna, M C; Calvieri, S; Giustini, S

2017-02-01

Ectodermal dysplasia is a clinically and genetically heterogeneous group of inherited disorders characterized by abnormal development of two or more of the following ectodermal-derived structures: hair, teeth, nails and sweat glands. The hair is the most frequently affected structure. Hair shaft abnormalities are of great concern to these patients, but no effective treatments are available. We describe three girls with congenital hypotrichosis (9, 5 and 6 years old) caused by ectodermal dysplasia treated with topical cetirizine solution (2 mL. once daily) and oral vitamin D supplementation (1000 IU daily). After 6 months of treatment, the density of hair on the scalp increased in all patients. The vellus hair was replaced by terminal hair. Hair regrowth was evaluated both from the clinical and trichoscopic point of view. We propose a combination of topical cetirizine and oral vitamin D as a rational treatment of choice in congenital hypotrichosis caused by ectodermal dysplasia. © 2016 European Academy of Dermatology and Venereology.

Generation and characterization of function-blocking anti-ectodysplasin A (EDA) monoclonal antibodies that induce ectodermal dysplasia.

PubMed

Kowalczyk-Quintas, Christine; Willen, Laure; Dang, Anh Thu; Sarrasin, Heidi; Tardivel, Aubry; Hermes, Katharina; Schneider, Holm; Gaide, Olivier; Donzé, Olivier; Kirby, Neil; Headon, Denis J; Schneider, Pascal

2014-02-14

Development of ectodermal appendages, such as hair, teeth, sweat glands, sebaceous glands, and mammary glands, requires the action of the TNF family ligand ectodysplasin A (EDA). Mutations of the X-linked EDA gene cause reduction or absence of many ectodermal appendages and have been identified as a cause of ectodermal dysplasia in humans, mice, dogs, and cattle. We have generated blocking antibodies, raised in Eda-deficient mice, against the conserved, receptor-binding domain of EDA. These antibodies recognize epitopes overlapping the receptor-binding site and prevent EDA from binding and activating EDAR at close to stoichiometric ratios in in vitro binding and activity assays. The antibodies block EDA1 and EDA2 of both mammalian and avian origin and, in vivo, suppress the ability of recombinant Fc-EDA1 to rescue ectodermal dysplasia in Eda-deficient Tabby mice. Moreover, administration of EDA blocking antibodies to pregnant wild type mice induced in developing wild type fetuses a marked and permanent ectodermal dysplasia. These function-blocking anti-EDA antibodies with wide cross-species reactivity will enable study of the developmental and postdevelopmental roles of EDA in a variety of organisms and open the route to therapeutic intervention in conditions in which EDA may be implicated.

Generation and Characterization of Function-blocking Anti-ectodysplasin A (EDA) Monoclonal Antibodies That Induce Ectodermal Dysplasia*

PubMed Central

Kowalczyk-Quintas, Christine; Willen, Laure; Dang, Anh Thu; Sarrasin, Heidi; Tardivel, Aubry; Hermes, Katharina; Schneider, Holm; Gaide, Olivier; Donzé, Olivier; Kirby, Neil; Headon, Denis J.; Schneider, Pascal

2014-01-01

Development of ectodermal appendages, such as hair, teeth, sweat glands, sebaceous glands, and mammary glands, requires the action of the TNF family ligand ectodysplasin A (EDA). Mutations of the X-linked EDA gene cause reduction or absence of many ectodermal appendages and have been identified as a cause of ectodermal dysplasia in humans, mice, dogs, and cattle. We have generated blocking antibodies, raised in Eda-deficient mice, against the conserved, receptor-binding domain of EDA. These antibodies recognize epitopes overlapping the receptor-binding site and prevent EDA from binding and activating EDAR at close to stoichiometric ratios in in vitro binding and activity assays. The antibodies block EDA1 and EDA2 of both mammalian and avian origin and, in vivo, suppress the ability of recombinant Fc-EDA1 to rescue ectodermal dysplasia in Eda-deficient Tabby mice. Moreover, administration of EDA blocking antibodies to pregnant wild type mice induced in developing wild type fetuses a marked and permanent ectodermal dysplasia. These function-blocking anti-EDA antibodies with wide cross-species reactivity will enable study of the developmental and postdevelopmental roles of EDA in a variety of organisms and open the route to therapeutic intervention in conditions in which EDA may be implicated. PMID:24391090

Molecular genetic analysis of consanguineous Pakistani families with autosomal recessive hypohidrotic ectodermal dysplasia.

PubMed

Bibi, Nosheen; Ahmad, Saeed; Ahmad, Wasim; Naeem, Muhammad

2011-02-01

Hypohidrotic ectodermal dysplasia is an inherited disorder characterized by defective development of teeth, hairs and sweat glands. X-linked hypohidrotic ectodermal dysplasia is caused by mutations in the EDA gene, and autosomal forms of hypohidrotic ectodermal dysplasia are caused by mutations in either the EDAR or the EDARADD genes. To study the molecular genetic cause of autosomal recessive hypohidrotic ectodermal dysplasia in three consanguineous Pakistani families (A, B and C), genotyping of 13 individuals was carried out by using polymorphic microsatellite markers that are closely linked to the EDAR gene on chromosome 2q11-q13 and the EDARADD gene on chromosome 1q42.2-q43. The results revealed linkage in the three families to the EDAR locus. Sequence analysis of the coding exons and splice junctions of the EDAR gene revealed two mutations: a novel non-sense mutation (p.E124X) in the probands of families A and B and a missense mutation (p.G382S) in the proband of family C. In addition, two synonymous single-nucleotide polymorphisms were also identified. The finding of mutations in Pakistani families extends the body of evidence that supports the importance of EDAR for the development of hypohidrotic ectodermal dysplasia. © 2010 The Authors. Australasian Journal of Dermatology © 2010 The Australasian College of Dermatologists.

Dental and maxillofacial characteristics of six Japanese individuals with ectrodactyly-ectodermal dysplasia-clefting syndrome.

PubMed

Okamura, Erika; Suda, Naoto; Baba, Yoshiyuki; Fukuoka, Hiroki; Ogawa, Takuya; Ohkuma, Mizue; Ahiko, Nozomi; Yasue, Akihiro; Tengan, Toshimoto; Shiga, Momotoshi; Tsuji, Michiko; Moriyama, Keiji

2013-03-01

Objective : Ectrodactyly-ectodermal dysplasia-clefting syndrome is a congenital anomaly characterized by ectodermal dysplasia, ectrodactyly, cleft lip and palate, and lacrimal duct anomalies. Because this syndrome is frequently accompanied by a congenital lack of teeth, narrow palate, and malocclusion, comprehensive orthodontic intervention is required. Design : To highlight the specific dental and maxillofacial characteristics of ectrodactyly-ectodermal dysplasia-clefting syndrome, six Japanese individuals diagnosed with the syndrome are described here. Patients : The subjects consisted of two boys and four girls (age range, 6.0 to 13.9 years) diagnosed with ectrodactyly-ectodermal dysplasia-clefting syndrome by medical and dental specialists. Their conditions included ectodermal dysplasia (hypodontia, microdontia, enamel hypoplasia, and abnormalities in hair and nails), cleft lip and/or palate, and ectrodactyly. Cephalograms, panoramic x-rays, and dental casts were taken; systemic complications were recorded at the first visit to our dental hospital. Results : All individuals had severe oligodontia with 9 to 18 missing teeth. The missing teeth were mainly maxillary and mandibular incisors and second bicuspids, arranged in a symmetrical manner. Cephalometric analysis showed retruded and short maxilla due to cleft lip and/or palate. It is interesting that all individuals showed a characteristically shaped mandibular symphysis with a retruded point B. It is likely that this unusual symphyseal morphology is due to the lack of mandibular incisors. Conclusions : This study demonstrates the presence of severe oligodontia in the incisal and premolar regions and describes a characteristic maxillary and mandibular structure in Japanese individuals with ectrodactyly-ectodermal dysplasia-clefting syndrome.

Tissue distribution of cells derived from the area opaca in heterospecific quail-chick blastodermal chimeras

PubMed Central

Karagenç, Levent; Sandikci, Mustafa

2010-01-01

The objective of the current study was to determine the tissue distribution of cells derived from the area opaca in heterospecific quail-chick blastodermal chimeras. Quail-chick chimeras were constructed by transferring dissociated cells from the area opaca of the stage X–XII (EG&K) quail embryo into the subgerminal cavity of the unincubated chick blastoderm. The distribution of quail cells in embryonic as well as extra-embryonic tissues of the recipient embryo were examined using the QCPN monoclonal antibody after 6 days of incubation in serial sections taken at 100-μm intervals. Data gathered in the present study demonstrated that, when introduced into the subgerminal cavity of a recipient embryo, cells of the area opaca are able to populate not only extra-embryonic structures such as the amnion and the yolk sac, but also various embryonic tissues derived from the ectoderm and less frequently the mesoderm. Ectodermal chimerism was confined mainly to the head region and was observed in tissues derived from the neural ectoderm and the surface ectoderm, including the optic cup, diencephalon and lens. Although the possibility of random incorporation of transplanted cells into these embryonic structures cannot be excluded, these results would suggest that area opaca, a peripheral ring of cells in the avian embryo destined to form the extra-embryonic ectoderm and endoderm of the yolk sac, might harbor cells that have the potential to give rise to various cell types in the recipient chick embryo, including those derived from the surface ectoderm and neural ectoderm. PMID:19900180

Ectoderm-targeted overexpression of the glucocorticoid receptor induces hypohidrotic ectodermal dysplasia.

PubMed

Cascallana, Jose Luis; Bravo, Ana; Donet, Eva; Leis, Hugo; Lara, Maria Fernanda; Paramio, Jesús M; Jorcano, José L; Pérez, Paloma

2005-06-01

Hypohidrotic ectodermal dysplasia is a human syndrome defined by maldevelopment of one or more ectodermal-derived tissues, including the epidermis and cutaneous appendices, teeth, and exocrine glands. The molecular bases of this pathology converge in a dysfunction of the transcription factor nuclear factor of the kappa-enhancer in B cells (NF-kappaB), which is essential to epithelial homeostasis and development. A number of mouse models bearing disruptions in NF-kappaB signaling have been reported to manifest defects in ectodermal derivatives. In ectoderm-targeted transgenic mice overexpressing the glucocorticoid receptor (GR) [keratin 5 (K5)-GR mice], the NF-kappaB activity is greatly decreased due to functional antagonism between GR and NF-kappaB. Here, we report that K5-GR mice exhibit multiple epithelial defects in hair follicle, tooth, and palate development. Additionally, these mice lack Meibomian glands and display underdeveloped sweat and preputial glands. These phenotypic features appear to be mediated specifically by ligand-activated GR because the synthetic analog dexamethasone induced similar defects in epithelial morphogenesis, including odontogenesis, in wild-type mice. We have focused on tooth development in K5-GR mice and found that an inhibitor of steroid synthesis partially reversed the abnormal phenotype. Immunostaining revealed reduced expression of the inhibitor of kappaB kinase subunits, IKKalpha and IKKgamma, and diminished p65 protein levels in K5-GR embryonic tooth, resulting in a significantly reduced kappaB-binding activity. Remarkably, altered NF-kappaB activity elicited by GR overexpression correlated with a dramatic decrease in the protein levels of DeltaNp63 in tooth epithelia without affecting Akt, BMP4, or Foxo3a. Given that many of the 170 clinically distinct ectodermal dysplasia syndromes still remain without cognate genes, deciphering the molecular mechanisms of this mouse model with epithelial NF-kappaB and p63 dysfunction may provide important clues to understanding the basis of other ectodermal dysplasia syndromes.

The formation of endoderm-derived taste sensory organs requires a Pax9-dependent expansion of embryonic taste bud progenitor cells.

PubMed

Kist, Ralf; Watson, Michelle; Crosier, Moira; Robinson, Max; Fuchs, Jennifer; Reichelt, Julia; Peters, Heiko

2014-10-01

In mammals, taste buds develop in different regions of the oral cavity. Small epithelial protrusions form fungiform papillae on the ectoderm-derived dorsum of the tongue and contain one or few taste buds, while taste buds in the soft palate develop without distinct papilla structures. In contrast, the endoderm-derived circumvallate and foliate papillae located at the back of the tongue contain a large number of taste buds. These taste buds cluster in deep epithelial trenches, which are generated by intercalating a period of epithelial growth between initial placode formation and conversion of epithelial cells into sensory cells. How epithelial trench formation is genetically regulated during development is largely unknown. Here we show that Pax9 acts upstream of Pax1 and Sox9 in the expanding taste progenitor field of the mouse circumvallate papilla. While a reduced number of taste buds develop in a growth-retarded circumvallate papilla of Pax1 mutant mice, its development arrests completely in Pax9-deficient mice. In addition, the Pax9 mutant circumvallate papilla trenches lack expression of K8 and Prox1 in the taste bud progenitor cells, and gradually differentiate into an epidermal-like epithelium. We also demonstrate that taste placodes of the soft palate develop through a Pax9-dependent induction. Unexpectedly, Pax9 is dispensable for patterning, morphogenesis and maintenance of taste buds that develop in ectoderm-derived fungiform papillae. Collectively, our data reveal an endoderm-specific developmental program for the formation of taste buds and their associated papilla structures. In this pathway, Pax9 is essential to generate a pool of taste bud progenitors and to maintain their competence towards prosensory cell fate induction.

Possible complex organic compounds on Mars.

PubMed

Kobayashi, K; Sato, T; Kajishima, S; Kaneko, T; Ishikawa, Y; Saito, T

1997-01-01

It is suggested that primitive Mars had somehow similar environments as primitive Earth. If life was born on the primitive earth using organic compounds which were produced from the early Earth environment, the same types of organic compounds were also formed on primitive Mars. Such organic compounds might have been preserved on Mars still now. We are studying possible organic formation on primitive and present Mars. A gaseous mixture of CO2, CO, N2 and H2O with various mixing ratios were irradiated with high energy protons (major components of cosmic rays). Hydrogen cyanide and formaldehyde were detected among volatile products, and yellow-brown-colored water-soluble non-volatile substances were produced, which gave amino acids after acid-hydrolysis. Major part of "amino acid precursors" were not simple molecules like aminonitriles, but complex compounds which eluted earlier than free amino acids in cation-exchange HPLC. These organic compounds should be major targets in the future Mars mission. Strategy for the detection of the complex organics on Mars will be discussed.

ARCGRAPH SYSTEM - AMES RESEARCH GRAPHICS SYSTEM

NASA Technical Reports Server (NTRS)

Hibbard, E. A.

1994-01-01

Ames Research Graphics System, ARCGRAPH, is a collection of libraries and utilities which assist researchers in generating, manipulating, and visualizing graphical data. In addition, ARCGRAPH defines a metafile format that contains device independent graphical data. This file format is used with various computer graphics manipulation and animation packages at Ames, including SURF (COSMIC Program ARC-12381) and GAS (COSMIC Program ARC-12379). In its full configuration, the ARCGRAPH system consists of a two stage pipeline which may be used to output graphical primitives. Stage one is associated with the graphical primitives (i.e. moves, draws, color, etc.) along with the creation and manipulation of the metafiles. Five distinct data filters make up stage one. They are: 1) PLO which handles all 2D vector primitives, 2) POL which handles all 3D polygonal primitives, 3) RAS which handles all 2D raster primitives, 4) VEC which handles all 3D raster primitives, and 5) PO2 which handles all 2D polygonal primitives. Stage two is associated with the process of displaying graphical primitives on a device. To generate the various graphical primitives, create and reprocess ARCGRAPH metafiles, and access the device drivers in the VDI (Video Device Interface) library, users link their applications to ARCGRAPH's GRAFIX library routines. Both FORTRAN and C language versions of the GRAFIX and VDI libraries exist for enhanced portability within these respective programming environments. The ARCGRAPH libraries were developed on a VAX running VMS. Minor documented modification of various routines, however, allows the system to run on the following computers: Cray X-MP running COS (no C version); Cray 2 running UNICOS; DEC VAX running BSD 4.3 UNIX, or Ultrix; SGI IRIS Turbo running GL2-W3.5 and GL2-W3.6; Convex C1 running UNIX; Amhdahl 5840 running UTS; Alliant FX8 running UNIX; Sun 3/160 running UNIX (no native device driver); Stellar GS1000 running Stellex (no native device driver); and an SGI IRIS 4D running IRIX (no native device driver). Currently with version 7.0 of ARCGRAPH, the VDI library supports the following output devices: A VT100 terminal with a RETRO-GRAPHICS board installed, a VT240 using the Tektronix 4010 emulation capability, an SGI IRIS turbo using the native GL2 library, a Tektronix 4010, a Tektronix 4105, and the Tektronix 4014. ARCGRAPH version 7.0 was developed in 1988.

Odonto-onycho-dermal dysplasia in a patient homozygous for a WNT10A nonsense mutation and mild manifestations of ectodermal dysplasia in carriers of the mutation.

PubMed

Krøigård, Anne Bruun; Clemmensen, Ole; Gjørup, Hans; Hertz, Jens Michael; Bygum, Anette

2016-03-10

Odonto-onycho-dermal dysplasia (OODD) is a rare form of ectodermal dysplasia characterized by severe oligodontia, onychodysplasia, palmoplantar hyperkeratosis, dry skin, hypotrichosis, and hyperhidrosis of the palms and soles. The ectodermal dysplasias resulting from biallelic mutations in the WNT10A gene result in highly variable phenotypes, ranging from isolated tooth agenesis to OODD and Schöpf-Schulz-Passarge syndrome (SSPS). We identified a female patient, with consanguineous parents, who was clinically diagnosed with OODD. Genetic testing showed that she was homozygous for a previously reported pathogenic mutation in the WNT10A gene, c.321C > A, p.Cys107*. The skin and nail abnormalities were for many years interpreted as psoriasis and treated accordingly. A thorough clinical examination revealed hypotrichosis and hyperhidrosis of the soles and dental examination revealed agenesis of permanent teeth except the two maxillary central incisors. Skin biopsies from the hyperkeratotic palms and soles showed the characteristic changes of eccrine syringofibroadenomatosis, which has been described in patients with ectodermal dysplasias. Together with a family history of tooth anomalies, this lead to the clinical suspicion of a hereditary ectodermal dysplasia. This case illustrates the challenges of diagnosing ectodermal dysplasia like OODD and highlights the relevance of interdisciplinary cooperation in the diagnosis of rare conditions.

Abnormal primary and permanent dentitions with ectodermal symptoms predict WNT10A deficiency.

PubMed

Bergendal, Birgitta; Norderyd, Johanna; Zhou, Xiaolei; Klar, Joakim; Dahl, Niklas

2016-11-24

The WNT10A protein is critical for the development of ectodermal appendages. Variants in the WNT10A gene may be associated with a spectrum of ectodermal abnormalities including extensive tooth agenesis. In seven patients with severe tooth agenesis we identified anomalies in primary dentition and additional ectodermal symptoms, and assessed WNT10A mutations by genetic analysis. Investigation of primary dentition revealed peg-shaped crowns of primary mandibular incisors and three individuals had agenesis of at least two primary teeth. The permanent dentition was severely affected in all individuals with a mean of 21 missing teeth. Primary teeth were most often present in positions were succedaneous teeth were missing. Furthermore, most existing molars had taurodontism. Light, brittle or coarse hair was reported in all seven individuals, hyperhidrosis of palms and soles in six individuals and nail anomalies in two individuals. The anomalies in primary dentition preceded most of the additional ectodermal symptoms. Genetic analysis revealed that all seven individuals were homozygous or compound heterozygous for WNT10A mutations resulting in C107X, E222X and F228I. We conclude that tooth agenesis and/or peg-shaped crowns of primary mandibular incisors, severe oligodontia of permanent dentition as well as ectodermal symptoms of varying severity may be predictors of bi-allelic WNT10A mutations of importance for diagnosis, counselling and follow-up.

Ear nose throat manifestations in hypoidrotic ectodermal dysplasia.

PubMed

Callea, Michele; Teggi, Roberto; Yavuz, Izzet; Tadini, Gianluca; Priolo, Manuela; Crovella, Sergio; Clarich, Gabriella; Grasso, Domenico Leonardo

2013-11-01

The ectodermal dysplasias (EDs) are a large and complex group of inherited disorders. In various combinations, they all share anomalies in ectodermal derived structures: hair, teeth, nails and sweat gland function. Clinical overlap is present among EDs. Few causative genes have been identified, to date. Altered gene expression is not limited to the ectoderm but a concomitant effect on developing mesenchymal structures, with modification of ectodermal-mesenchymal signaling, takes place. The two major categories of ED include the hidrotic and hypohidrotic form, the latter more frequent; they differentiate each other for the presence or absence of sweat glands. We report Ear Nose Throat manifestations of ED, linked to the reduction of mucous glands in the nasal fossae with reduced ciliar function, and decrease salivary glands function. Often patients report an increased rate of infections of the upper respiratory tract and of the ear. Nasal obstruction due to the presence of nasal crusting, hearing loss and throat hoarseness are the most represented symptoms. Environmental measures, including a correct air temperature and humidification, is mandatory above all in subjects affected by hypohidrotic form. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Development and Evolution of the Muscles of the Pelvic Fin

PubMed Central

Cole, Nicholas J.; Hall, Thomas E.; Don, Emily K.; Berger, Silke; Boisvert, Catherine A.; Neyt, Christine; Ericsson, Rolf; Joss, Jean; Gurevich, David B.; Currie, Peter D.

2011-01-01

Locomotor strategies in terrestrial tetrapods have evolved from the utilisation of sinusoidal contractions of axial musculature, evident in ancestral fish species, to the reliance on powerful and complex limb muscles to provide propulsive force. Within tetrapods, a hindlimb-dominant locomotor strategy predominates, and its evolution is considered critical for the evident success of the tetrapod transition onto land. Here, we determine the developmental mechanisms of pelvic fin muscle formation in living fish species at critical points within the vertebrate phylogeny and reveal a stepwise modification from a primitive to a more derived mode of pelvic fin muscle formation. A distinct process generates pelvic fin muscle in bony fishes that incorporates both primitive and derived characteristics of vertebrate appendicular muscle formation. We propose that the adoption of the fully derived mode of hindlimb muscle formation from this bimodal character state is an evolutionary innovation that was critical to the success of the tetrapod transition. PMID:21990962

Avian skin development and the evolutionary origin of feathers.

PubMed

Sawyer, Roger H; Knapp, Loren W

2003-08-15

The discovery of several dinosaurs with filamentous integumentary appendages of different morphologies has stimulated models for the evolutionary origin of feathers. In order to understand these models, knowledge of the development of the avian integument must be put into an evolutionary context. Thus, we present a review of avian scale and feather development, which summarizes the morphogenetic events involved, as well as the expression of the beta (beta) keratin multigene family that characterizes the epidermal appendages of reptiles and birds. First we review information on the evolution of the ectodermal epidermis and its beta (beta) keratins. Then we examine the morphogenesis of scutate scales and feathers including studies in which the extraembryonic ectoderm of the chorion is used to examine dermal induction. We also present studies on the scaleless (sc) mutant, and, because of the recent discovery of "four-winged" dinosaurs, we review earlier studies of a chicken strain, Silkie, that expresses ptilopody (pti), "feathered feet." We conclude that the ability of the ectodermal epidermis to generate discrete cell populations capable of forming functional structural elements consisting of specific members of the beta keratin multigene family was a plesiomorphic feature of the archosaurian ancestor of crocodilians and birds. Evidence suggests that the discrete epidermal lineages that make up the embryonic feather filament of extant birds are homologous with similar embryonic lineages of the developing scutate scales of birds and the scales of alligators. We believe that the early expression of conserved signaling modules in the embryonic skin of the avian ancestor led to the early morphogenesis of the embryonic feather filament, with its periderm, sheath, and barb ridge lineages forming the first protofeather. Invagination of the epidermis of the protofeather led to formation of the follicle providing for feather renewal and diversification. The observations that scale formation in birds involves an inhibition of feather formation coupled with observations on the feathered feet of the scaleless (High-line) and Silkie strains support the view that the ancestor of modern birds may have had feathered hind limbs similar to those recently discovered in nonavian dromaeosaurids. And finally, our recent observation on the bristles of the wild turkey beard raises the possibility that similar integumentary appendages may have adorned nonavian dinosaurs, and thus all filamentous integumentary appendages may not be homologous to modern feathers. Copyright 2003 Wiley-Liss, Inc.

Synthesis of phosphatidylcholine under possible primitive earth conditions

NASA Technical Reports Server (NTRS)

Rao, M.; Eichberg, J.; Oro, J.

1982-01-01

Using a primitive earth evaporating pond model, the synthesis of phosphatidylcholine was accomplished when a reaction mixture of choline chloride and disodium phosphatidate, in the presence of cyanamide and traces of acid, was evaporated and heated at temperatures ranging from 25 to 100 C for 7 hours. Optimum yields of about 15% were obtained at 80 C. Phosphatidylcholine was identified by chromatographic, chemical and enzymatic degradation methods. On enzymatic hydrolysis with phospholipase A2 and phospholipase C, lysophosphatidylcholine and phosphorylcholine were formed, respectively. Alkaline hydrolysis gave glycerophosphorylcholine. The synthesis of phosphatidylcholine as the major compound was accompanied by the formation of lysophosphatidylcholine in smaller amounts. Cyanamide was found to be essential for the formation of phosphatidylcholine, and only traces of HCl, of the order of that required to convert the disodium phosphatidate to free phosphatidic acid were found necessary for the synthesis. This work suggests that phosphatidylcholine, which is an essential component of most biological membranes, could have been synthesized on the primitive earth.

Developmental mechanisms of the tympanic membrane in mammals and non-mammalian amniotes.

PubMed

Takechi, Masaki; Kitazawa, Taro; Hirasawa, Tatsuya; Hirai, Tamami; Iseki, Sachiko; Kurihara, Hiroki; Kuratani, Shigeru

2016-01-01

The tympanic membrane is a thin layer that originates from the ectoderm, endoderm, and mesenchyme. Molecular-genetic investigations have revealed that interaction between epithelial and mesenchymal cells in the pharyngeal arches is essential for development of the tympanic membrane. We have recently reported that developmental mechanisms underlying the tympanic membrane seem to be different between mouse and chicken, suggesting that the tympanic membrane evolved independently in mammals and non-mammalian amniotes. In this review, we summarize previous studies of tympanic membrane formation in the mouse. We also discuss its formation in amniotes from an evolutionary point of view. © 2015 Japanese Teratology Society.

Prebiotic significance of extraterrestrial ice photochemistry: detection of hydantoin in organic residues.

PubMed

de Marcellus, Pierre; Bertrand, Marylène; Nuevo, Michel; Westall, Frances; Le Sergeant d'Hendecourt, Louis

2011-11-01

The delivery of extraterrestrial organic materials to primitive Earth from meteorites or micrometeorites has long been postulated to be one of the origins of the prebiotic molecules involved in the subsequent apparition of life. Here, we report on experiments in which vacuum UV photo-irradiation of interstellar/circumstellar ice analogues containing H(2)O, CH(3)OH, and NH(3) led to the production of several molecules of prebiotic interest. These were recovered at room temperature in the semi-refractory, water-soluble residues after evaporation of the ice. In particular, we detected small quantities of hydantoin (2,4-imidazolidinedione), a species suspected to play an important role in the formation of poly- and oligopeptides. In addition, hydantoin is known to form under extraterrestrial, abiotic conditions, since it has been detected, along with various other derivatives, in the soluble part of organic matter of primitive carbonaceous meteorites. This result, together with other related experiments reported recently, points to the potential importance of the photochemistry of interstellar "dirty" ices in the formation of organics in Solar System materials. Such molecules could then have been delivered to the surface of primitive Earth, as well as other telluric (exo-) planets, to help trigger first prebiotic reactions with the capacity to lead to some form of primitive biomolecular activity.

Hypohidrotic ectodermal dysplasia with ankylosis of temporomandibular joint and cleft palate: A rare presentation

PubMed Central

Goyal, Manisha; Pradhan, Gaurav; Gupta, Sunita; Kapoor, Seema

2015-01-01

The ectodermal dysplasias are a heterogenous group of diseases, which have one or more anomalies of the hair, teeth, nails, and sweat glands. Hypohidrotic ectodermal dysplasia (HED) is the most common type and is usually transmitted as an X-linked recessive trait. It is characterized by classical triad of hypotrichosis, anhidrosis/hypohidrosis, and hypodontia/anodontia. Here, we describe an Indian boy affected with HED and rare features including ankylosis of temporomandibular joint and cleft palate. PMID:25684924

EDARV370A associated facial characteristics in Uyghur population revealing further pleiotropic effects.

PubMed

Peng, Qianqian; Li, Jinxi; Tan, Jingze; Yang, Yajun; Zhang, Manfei; Wu, Sijie; Liu, Yu; Zhang, Juan; Qin, Pengfei; Guan, Yaqun; Jiao, Yi; Zhang, Zhaoxia; Sabeti, Pardis C; Tang, Kun; Xu, Shuhua; Jin, Li; Wang, Sijia

2016-01-01

An adaptive variant of human Ectodysplasin receptor, EDARV370A, had undergone strong positive selection in East Asia. In mice and humans, EDARV370A was found to affect ectodermal-derived characteristics, including hair thickness, hair shape, active sweat gland density and teeth formation. Facial characteristics are also largely ectodermal derived. In this study, taking advantage of an admixed population of East Asian and European ancestry-the Uyghur, we aim to test whether EDARV370A is affecting facial characteristics and to investigate its pleiotropic nature and genetic model. In a sample of 1027 Uyghurs, we discover that EDARV370A is significantly associated with several facial characteristics, in particular shape of earlobe (P = 3.64 × 10 (-6) ) and type of chin (P = 9.23 × 10 (-5) ), with successful replication in other East Asian populations. Additionally, in this Uyghur population, we replicate previous association findings of incisors shoveling (P = 1.02 × 10 (-7) ), double incisors shoveling (P = 1.86 × 10 (-12) ) and hair straightness (P = 3.99 × 10 (-16) ), providing strong evidence supporting an additive model for the EDARV370A associations. Partial least square path model confirms EDARV370A systematically affect these weakly related ectodermal-derived characteristics, suggesting the pleiotropic effect of EDARV370A mainly plays roles in early embryo development. This study extends our knowledge about the pleiotropic nature of EDARV370A and provides potential clues to its adaptation fitness in human evolution.

Anesthetic management of a pediatric patient with hypohidrotic ectodermal dysplasia undergoing emergency surgery.

PubMed

Ahiskalioglu, Elif Oral; Ahiskalioglu, Ali; Firinci, Binali; Dostbil, Aysenur; Aksoy, Mehmet

2015-01-01

Ectodermal dysplasias are rare conditions with a triad of hypotrichosis, anodontia and anhidrosis. In literature review there have been only a few reports of anesthetic management of patients with ectodermal dysplasias. Hyperthermia is a very serious risk which may occur due to the defect of sweat glands. The present case involves a 10-year-old child with ectodermal dysplasia who presented with an acute abdomen and was considered for an emergency surgery. Our aim was to demonstrate the successful management of this case using a combination of general and epidural anesthesia. It is important for anesthesiologist to have information about this syndrome in case of emergency operations, since it can prevent serious complications and even save lives. Copyright © 2013 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

SNW1 Is a Critical Regulator of Spatial BMP Activity, Neural Plate Border Formation, and Neural Crest Specification in Vertebrate Embryos

PubMed Central

Wu, Mary Y.; Ramel, Marie-Christine; Howell, Michael; Hill, Caroline S.

2011-01-01

Bone morphogenetic protein (BMP) gradients provide positional information to direct cell fate specification, such as patterning of the vertebrate ectoderm into neural, neural crest, and epidermal tissues, with precise borders segregating these domains. However, little is known about how BMP activity is regulated spatially and temporally during vertebrate development to contribute to embryonic patterning, and more specifically to neural crest formation. Through a large-scale in vivo functional screen in Xenopus for neural crest fate, we identified an essential regulator of BMP activity, SNW1. SNW1 is a nuclear protein known to regulate gene expression. Using antisense morpholinos to deplete SNW1 protein in both Xenopus and zebrafish embryos, we demonstrate that dorsally expressed SNW1 is required for neural crest specification, and this is independent of mesoderm formation and gastrulation morphogenetic movements. By exploiting a combination of immunostaining for phosphorylated Smad1 in Xenopus embryos and a BMP-dependent reporter transgenic zebrafish line, we show that SNW1 regulates a specific domain of BMP activity in the dorsal ectoderm at the neural plate border at post-gastrula stages. We use double in situ hybridizations and immunofluorescence to show how this domain of BMP activity is spatially positioned relative to the neural crest domain and that of SNW1 expression. Further in vivo and in vitro assays using cell culture and tissue explants allow us to conclude that SNW1 acts upstream of the BMP receptors. Finally, we show that the requirement of SNW1 for neural crest specification is through its ability to regulate BMP activity, as we demonstrate that targeted overexpression of BMP to the neural plate border is sufficient to restore neural crest formation in Xenopus SNW1 morphants. We conclude that through its ability to regulate a specific domain of BMP activity in the vertebrate embryo, SNW1 is a critical regulator of neural plate border formation and thus neural crest specification. PMID:21358802

Reciprocal Signaling between the Ectoderm and a Mesendodermal Left-Right Organizer Directs Left-Right Determination in the Sea Urchin Embryo

PubMed Central

Bessodes, Nathalie; Haillot, Emmanuel; Duboc, Véronique; Röttinger, Eric; Lahaye, François; Lepage, Thierry

2012-01-01

During echinoderm development, expression of nodal on the right side plays a crucial role in positioning of the rudiment on the left side, but the mechanisms that restrict nodal expression to the right side are not known. Here we show that establishment of left-right asymmetry in the sea urchin embryo relies on reciprocal signaling between the ectoderm and a left-right organizer located in the endomesoderm. FGF/ERK and BMP2/4 signaling are required to initiate nodal expression in this organizer, while Delta/Notch signaling is required to suppress formation of this organizer on the left side of the archenteron. Furthermore, we report that the H+/K+-ATPase is critically required in the Notch signaling pathway upstream of the S3 cleavage of Notch. Our results identify several novel players and key early steps responsible for initiation, restriction, and propagation of left-right asymmetry during embryogenesis of a non-chordate deuterostome and uncover a functional link between the H+/K+-ATPase and the Notch signaling pathway. PMID:23271979

Maternal xNorrin, a Canonical Wnt Signaling Agonist and TGF-β Antagonist, Controls Early Neuroectoderm Specification in Xenopus

PubMed Central

Xu, Suhong; Cheng, Feng; Liang, Juan; Wu, Wei; Zhang, Jian

2012-01-01

Dorsal–ventral specification in the amphibian embryo is controlled by β-catenin, whose activation in all dorsal cells is dependent on maternal Wnt11. However, it remains unknown whether other maternally secreted factors contribute to β-catenin activation in the dorsal ectoderm. Here, we show that maternal Xenopus Norrin (xNorrin) promotes anterior neural tissue formation in ventralized embryos. Conversely, when xNorrin function is inhibited, early canonical Wnt signaling in the dorsal ectoderm and the early expression of the zygotic neural inducers Chordin, Noggin, and Xnr3 are severely suppressed, causing the loss of anterior structures. In addition, xNorrin potently inhibits BMP- and Nodal/Activin-related functions through direct binding to the ligands. Moreover, a subset of Norrin mutants identified in humans with Norrie disease retain Wnt activation but show defective inhibition of Nodal/Activin-related signaling in mesoderm induction, suggesting that this disinhibition causes Norrie disease. Thus, xNorrin is an unusual molecule that acts on two major signaling pathways, Wnt and TGF-β, in opposite ways and is essential for early neuroectoderm specification. PMID:22448144

Epithelial stratification and placode invagination are separable functions in early morphogenesis of the molar tooth

PubMed Central

Li, Jingjing; Chatzeli, Lemonia; Panousopoulou, Eleni; Tucker, Abigail S.; Green, Jeremy B. A.

2016-01-01

Ectodermal organs, which include teeth, hair follicles, mammary ducts, and glands such as sweat, mucous and sebaceous glands, are initiated in development as placodes, which are epithelial thickenings that invaginate and bud into the underlying mesenchyme. These placodes are stratified into a basal and several suprabasal layers of cells. The mechanisms driving stratification and invagination are poorly understood. Using the mouse molar tooth as a model for ectodermal organ morphogenesis, we show here that vertical, stratifying cell divisions are enriched in the forming placode and that stratification is cell division dependent. Using inhibitor and gain-of-function experiments, we show that FGF signalling is necessary and sufficient for stratification but not invagination as such. We show that, instead, Shh signalling is necessary for, and promotes, invagination once suprabasal tissue is generated. Shh-dependent suprabasal cell shape suggests convergent migration and intercalation, potentially accounting for post-stratification placode invagination to bud stage. We present a model in which FGF generates suprabasal tissue by asymmetric cell division, while Shh triggers cell rearrangement in this tissue to drive invagination all the way to bud formation. PMID:26755699

Generation of organized germ layers from a single mouse embryonic stem cell.

PubMed

Poh, Yeh-Chuin; Chen, Junwei; Hong, Ying; Yi, Haiying; Zhang, Shuang; Chen, Junjian; Wu, Douglas C; Wang, Lili; Jia, Qiong; Singh, Rishi; Yao, Wenting; Tan, Youhua; Tajik, Arash; Tanaka, Tetsuya S; Wang, Ning

2014-05-30

Mammalian inner cell mass cells undergo lineage-specific differentiation into germ layers of endoderm, mesoderm and ectoderm during gastrulation. It has been a long-standing challenge in developmental biology to replicate these organized germ layer patterns in culture. Here we present a method of generating organized germ layers from a single mouse embryonic stem cell cultured in a soft fibrin matrix. Spatial organization of germ layers is regulated by cortical tension of the colony, matrix dimensionality and softness, and cell-cell adhesion. Remarkably, anchorage of the embryoid colony from the 3D matrix to collagen-1-coated 2D substrates of ~1 kPa results in self-organization of all three germ layers: ectoderm on the outside layer, mesoderm in the middle and endoderm at the centre of the colony, reminiscent of generalized gastrulating chordate embryos. These results suggest that mechanical forces via cell-matrix and cell-cell interactions are crucial in spatial organization of germ layers during mammalian gastrulation. This new in vitro method could be used to gain insights on the mechanisms responsible for the regulation of germ layer formation.

PI3K inhibitors block skeletogenesis but not patterning in sea urchin embryos.

PubMed

Bradham, C A; Miranda, E L; McClay, D R

2004-04-01

Skeletogenesis in the sea urchin embryo is a simple model of biomineralization, pattern formation, and cell-cell communication during embryonic development. The calcium carbonate skeletal spicules are secreted by primary mesenchyme cells (PMCs), but the skeletal pattern is dictated by the embryonic ectoderm. Although the process of skeletogenesis is well characterized, there is little molecular understanding of the basis of patterning within this system. In this study, we examined the contribution of phosphatidylinositide 3-kinase (PI3K)-mediated signaling to the skeletogenic process in sea urchin embryos by using the well-established PI3K inhibitors LY294002 and wortmannin. Our results show that PI3K inhibitors specifically and reversibly block skeletogenesis, and that this blockade occurs within the PMCs rather than in the ectoderm, because the inhibitors block spiculogenesis in cultured micromeres. Our results are consistent with a model in which PI3K signaling is required, not for pattern sensing or interpretation but rather for the biomineralization process itself in the sea urchin embryo. Copyright 2004 Wiley-Liss, Inc.

Deictic primitives for general purpose navigation

NASA Technical Reports Server (NTRS)

Crismann, Jill D.

1994-01-01

A visually-based deictic primative used as an elementary command set for general purpose navigation was investigated. It was shown that a simple 'follow your eyes' scenario is sufficient for tracking a moving target. Limitations of velocity, acceleration, and modeling of the response of the mechanical systems were enforced. Realistic paths of the robots were produced during the simulation. Scientists could remotely command a planetary rover to go to a particular rock formation that may be interesting. Similarly an expert at plant maintenance could obtain diagnostic information remotely by using deictic primitives on a mobile are used in the deictic primitives, we could imagine that the exact same control software could be used for all of these applications.

The position of symbrachydactyly in the classification of congenital hand anomalies.

PubMed

Miura, T; Nakamura, R; Horii, E

1994-06-01

The clinical features of 53 cases of intercalated hypoplasia and 113 cases of distal aplasia are reviewed and compared with each other and with 129 cases of syndactyly. Tri-, di- and mono-phalangeal symbrachydactyly, and adactyly with nubbin digits are consecutive anomalies. Transverse deficiency may result if the mesenchyme is damaged severely, and if damage is mild and formation has continued, intercalated transverse deficiency may occur. Webbing in symbrachydactyly may result from failure of the apical ectodermal ridge under the influence of damaged mesenchyme.

The extracellular matrix architecture relating to myotendinous pattern formation in the distal part of the developing chick limb: an ultrastructural, histochemical and immunocytochemical analysis.

PubMed

Hurle, J M; Hinchliffe, J R; Ros, M A; Critchlow, M A; Genis-Galvez, J M

1989-07-01

In the later developmental stages (Hamburger and Hamilton, 25-34) the distal part of the chick leg possesses a distinctive extracellular matrix (ECM) architecture which relates to myotendinous patterning. There are two components: firstly, a system of dorsoventrally oriented fibrils which link the two ectodermal surfaces through the undifferentiated distal mesenchyme and secondly, a 'mesenchyme lamina' originates at the basement membrane distally, but proximally runs through the mesoderm, subjacent and parallel to the basement membrane. The 'mesenchyme lamina' appears to be a precursor of developing tendons and is spatially related to the distal tips of the myogenic blocks. As developing tendons form on the inner surface of the lamina at its proximal end, it becomes less distinct and disappears. Further dorsoventral fibrils run from the 'mesenchyme lamina' into the developing condensations and chondrogenic elements of the phalanges. The architecture of the ECM was revealed by silver and lectin staining (peanut and Ricinus communis agglutinins, PNA and RCA I), by immunocytochemistry (for fibronectin, tenascin, collagen type I) and by ultrastructural analysis. Both components stain with silver, PNA following neuraminidase digestion, RCA I, tenascin and collagen type I. However, the dorsoventral fibrils are positive for fibronectin and negative for PNA, while conversely the mesenchyme lamina is positive for PNA but much less so for fibronectin. Tenascin has been shown to be a specialized mesenchyme component of tendons and myotendinous junctions (Chiquet and Fambrough, 1984). Such a basement membrane forming a 'mesenchyme lamina' appears to be unique in epithelial-mesenchymal developing systems and points to an ectodermal role in tendon pattern formation within the mesenchyme. We discuss the possible role of mechanical force in converting the dorsoventral tenascin-positive fibrils into the localized pattern of tendon insertions into the proximal parts of the phalanges. Distally the dorsoventral fibrils may shape the digital plate by pulling together the two ectodermal surfaces. A similar ECM architecture is found in corresponding stages in the developing wing.

Inner ear development: Building a spiral ganglion and an organ of Corti out of unspecified ectoderm

PubMed Central

Fritzsch, Bernd; Pan, Ning; Jahan, Israt; Elliott, Karen L.

2014-01-01

The mammalian inner ear develops from a placodal thickening into a complex labyrinth of ducts with five sensory organs specialized to detect position and movement in space. In addition, the mammalian ear develops a spiraled cochlear duct containing the auditory organ, the organ of Corti (OC), specialized to translate sound into hearing. Developing the OC out of a uniform sheet of ectoderm requires an unparalleled precision in topological developmental engineering of four different general cell types, sensory neurons, hair cells, supporting cells, and general otic epithelium, into a mosaic of ten distinctly recognizable cell types in and around the OC, each with a unique distribution. In addition, the OC receives a unique innervation by ear-derived spiral ganglion afferents and brainstem-derived motor neurons as efferents, and requires neural crest-derived Schwann cells to form myelin and neural crest-derived cells to induce the stria vascularis. To achieve this transformation of a sheet of cells into a complicated interdigitating set of cells necessitates the orchestrated expression of multiple transcription factors that enable the cellular transformation from ectoderm into neurosensory cells forming the spiral ganglion neurons (SGN) while simultaneously transforming the flat epithelium into a tube, the cochlear duct housing the OC. In addition to the cellular and conformational changes to make the cochlear duct with the OC, additional changes in the surrounding periotic mesenchyme form passageways for sound to stimulate the OC. This article reviews molecular developmental data generated predominantly in mice. The available data are ordered into a plausible scenario that integrates the well described expression changes of transcription factors and their actions revealed in mouse mutants for formation of SGNs and OC in the right position and orientation with the right kind of innervation. Understanding the molecular basis of these developmental changes leading to the formation of the mammalian OC and highlighting the gaps in our knowledge may guide in vivo attempts to regenerate this most complicated cellular mosaic of the mammalian body to reconstitute hearing in a rapidly growing population of aging people suffering from hearing loss. PMID:25381571

Ectrodactyly, Ectodermal dysplasia, and Cleft Lip-Palate Syndrome; Its Association with Conductive Hearing Loss

ERIC Educational Resources Information Center

Robinson, Geoffrey C.; And Others

1973-01-01

Conductive hearing loss associated with the ectrodactyly, ectodermal dysplasia, and cleft lip palate syndrome was reported in one sporadic case and in a pedigree with four cases in three generations. (GW)

Sox5 is a DNA binding co-factor for BMP R-Smads that directs target specificity during patterning of the early ectoderm

PubMed Central

Nordin, Kara; LaBonne, Carole

2014-01-01

SUMMARY The SoxD factor, Sox5, is expressed in ectodermal cells at times and places where BMP signaling is active, including the cells of the animal hemisphere at blastula stages, and the neural plate border (NPB) and neural crest (NC) at neurula stages. Sox5 is required for proper ectoderm development, and deficient embryos display patterning defects characteristic of perturbations of BMP signaling, including loss of neural crest and epidermis and expansion of the neural plate. We show that Sox5 is essential for activation of BMP target genes in embryos and explants, that it physically interacts with BMP R-Smads, and that it is essential for recruitment of Smad1/4 to BMP regulatory elements. Our findings identify Sox5 as the long sought DNA binding partner for BMP R-Smads essential to plasticity and pattern in the early ectoderm. PMID:25453832

Prosthodontic Management of Hypohidrotic Ectodermal Dysplasia with Anodontia: A Case Report in Pediatric Patient and Review of Literature

PubMed Central

Ladda, R; Gangadhar, SA; Kasat, VO; Bhandari, AJ

2013-01-01

Ectodermal dysplasias are rare hereditary disorders characterized by abnormal development of certain tissues and structures of ectodermal origin. The condition is important for dentists as it affects teeth resulting in hypodontia or anodontia and dentist plays an important role in rehabilitation of the patient. Affected young children with anodontia not only have difficulties in eating and speaking but can also feel that they look different from their contemporaries. Well-fitting and functioning prosthesis could be a great help during their schooling years as it will improve appearance and thus boost their self confidence. We report a case of hypohidrotic ectodermal dysplasia in an 8-year-old boy who exhibited anodontia and was successfully rehabilitated with conventional complete dentures in both maxillary and mandibular arches. The aim of the treatment was to improve psychological development apart from promoting better functioning of the stomatognathic system. PMID:23919206

A case of probable autosomal recessive ectodermal dysplasia with corkscrew hairs and mental retardation in a family with tuberous sclerosis.

PubMed

Argenziano, G; Monsurrò, M R; Pazienza, R; Delfino, M

1998-02-01

We describe a woman with a probable autosomal recessive ectodermal dysplasia with corkscrew hairs and mental retardation in a family with tuberous sclerosis. Other findings included syndactyly, typical facies, dental abnormalities, dermatoglyphic hypoplasia, epidermal ridge sweat pore count slightly below normal, and keratosis pilaris. Clinical studies and genetic analysis excluded the diagnosis of tuberous sclerosis in our patient. We conclude that she has ectodermal dysplasia associated with mental retardation. This association has been described previously; it suggests the possible interrelationship of a community of ectodermal dysplasia syndromes with a distinctive structural hair abnormality (pili torti et canaliculi), variable midfacial malformations, limb defects, and other features such as mental retardation. The similarity of our patient to that described by Whiting et al. and Abramovits-Ackerman et al. suggests the autonomy of this syndrome.

Neuropeptides: Developmental Signals in Placode Progenitor Formation

PubMed Central

Lleras-Forero, Laura; Tambalo, Monica; Christophorou, Nicolas; Chambers, David; Houart, Corinne; Streit, Andrea

2013-01-01

Summary Few families of signaling factors have been implicated in the control of development. Here, we identify the neuropeptides nociceptin and somatostatin, a neurotransmitter and neuroendocrine hormone, as a class of developmental signals in both chick and zebrafish. We show that signals from the anterior mesendoderm are required for the formation of anterior placode progenitors, with one of the signals being somatostatin. Somatostatin controls ectodermal expression of nociceptin, and both peptides regulate Pax6 in lens and olfactory progenitors. Consequently, loss of somatostatin and nociceptin signaling leads to severe reduction of lens formation. Our findings not only uncover these neuropeptides as developmental signals but also identify a long-sought-after mechanism that initiates Pax6 in placode progenitors and may explain the ancient evolutionary origin of neuropeptides, predating a complex nervous system. PMID:23906067

Deletion of OTX2 in neural ectoderm delays anterior pituitary development

PubMed Central

Mortensen, Amanda H.; Schade, Vanessa; Lamonerie, Thomas; Camper, Sally A.

2015-01-01

OTX2 is a homeodomain transcription factor that is necessary for normal head development in mouse and man. Heterozygosity for loss-of-function alleles causes an incompletely penetrant, haploinsufficiency disorder. Affected individuals exhibit a spectrum of features that range from developmental defects in eye and/or pituitary development to acephaly. To investigate the mechanism underlying the pituitary defects, we used different cre lines to inactivate Otx2 in early head development and in the prospective anterior and posterior lobes. Mice homozygous for Otx2 deficiency in early head development and pituitary oral ectoderm exhibit craniofacial defects and pituitary gland dysmorphology, but normal pituitary cell specification. The morphological defects mimic those observed in humans and mice with OTX2 heterozygous mutations. Mice homozygous for Otx2 deficiency in the pituitary neural ectoderm exhibited altered patterning of gene expression and ablation of FGF signaling. The posterior pituitary lobe and stalk, which normally arise from neural ectoderm, were extremely hypoplastic. Otx2 expression was intact in Rathke's pouch, the precursor to the anterior lobe, but the anterior lobe was hypoplastic. The lack of FGF signaling from the neural ectoderm was sufficient to impair anterior lobe growth, but not the differentiation of hormone-producing cells. This study demonstrates that Otx2 expression in the neural ectoderm is important intrinsically for the development of the posterior lobe and pituitary stalk, and it has significant extrinsic effects on anterior pituitary growth. Otx2 expression early in head development is important for establishing normal craniofacial features including development of the brain, eyes and pituitary gland. PMID:25315894

Comet Dust: The Story of Planet Formation as Told by the Tiniest of Particles

NASA Technical Reports Server (NTRS)

Wooden, D. H.

2005-01-01

Our planetary system formed out of a gas-rich disk-shaped nebula with the early Sun at its center. Many small icy bodies were consumed by the formation of the giant planets. However, many km-size icy bodies were tossed out of the giant-planet region to the cold, distant reaches of our solar system. Comets remained in their places of cold storage until perturbed into orbits that carry them into the inner solar system where they pass relatively close to the Sun. Comets are warmed by the Sun and shed material from their outer layers. The ices and gases shed by comets reveal simple and complex organic molecules were present at the time and in the region of the formation of the giant planets. Where the Earth was forming was too hot and had too intense sunlight for many of these ices and molecules to survive. The dust shed by comets tells us that some stardust survived unaltered but much of the dust was heated and crystallized before becoming part of the comet. Therefore, comet dust grains tell of large radial migrations from the cold outer reaches near Neptune into the hot regions near the forming Sun, and then back out to the cold regions where icy comets were accreting and forming. On 2005 July 4, the NASA Deep Impact Mission hit a comet and ejected primitive materials fiom its interior. These materials were not released into the comet s coma during normal activity. Despite the many passages of this comet close to the Sun, these primitive volatile gases and dust grains survived in its interior. Comet dust grains show that cold and hot materials were mixed into the same tiny particle very early in the formation of the solar system, and these aggregate dust grains never saw high temperatures again. The survival of primitive materials in comet nuclei suggests comets could have delivered organic molecules and primitive dust grains to early Earth.

[Ectodermal Capdepont syndrome and oral prosthetic rehabilitation. About a clinical case].

PubMed

Kumpanya, P; Matshumba, M; Sekele, I B; Mayunga, M; Lutula, P S; Ntumba, M K

2015-03-01

The authors describe the ectodermal Capdepont syndrome as an anomaly characterized by anhidrosis, hypotrichosis and anodontia diagnosed in a 22 year-old adult. In front of this anodontia, oral prosthetic rehabilitation remains the only solution.

Evaluation of the pair-culture effect in Ophyryotrocha puerilis (Polychaeta: Dorvilleidae). II. Conditions for the moult of the upper jaw

NASA Astrophysics Data System (ADS)

Kegel, B.; Pfannenstiel, H.-D.

1983-06-01

The conditions for moult of the upper jaw of Ophryotrocha puerilis were determined in isolated individuals and in groups of various sizes. The frequency of formation of the complicated upper jaw in both isolated individuals and in groups varies to a considerable extent. Although formation of the upper jaw and sex reversal normally are associated processes, the relationship of these two processes is not very well understood. Histological investigations at the light microscopic level demonstrate that the dental apparatus is an elaboration of the ectodermal stomodaeum which is considered to be a highly specialized part of the cuticle in the pharyngeal region of the gut.

Creation and Distribution of CAIs in the Protoplanetary Nebula

NASA Technical Reports Server (NTRS)

Cuzzi, J. N.; Davis, S. S.; Dobrovolskis, A. R.

2003-01-01

CaAl rich refractory mineral inclusions (CAIs) found at 1 - 10% mass fraction in primitive chondrites appear to be several million years older than the dominant (chondrule) components in the same parent bodies. A prevalent concern is that it is difficult to retain CAIs for this long against gas-drag-induced radial drift into the sun. We assess a hot inner (turbulent) nebula context for CAI formation, using analytical models of nebula evolution and particle diffusion. We show that outward radial diffusion in a weakly turbulent nebula can prevent significant numbers of CAI-size particles from being lost into the sun for times of 1 - 3 x 10(exp 6) years. To match the CAI abundances quantitatively, we advocate an enhancement of the inner hot nebula in silicate-forming material, due to rapid inward migration of very primitive, silicate and carbon rich, meter-sized objects. 'Combustion' of the carbon into CO would make the CAI formation environment more reduced than solar, as certain observations imply. Abundant CO might also play a role in mass-independent chemical fractionation of oxygen isotopes as seen in CAIs and associated primitive, high-temperature condensates.

Volatile trace elements and the characterization of the Cayley Formation and the primitive lunar crust

NASA Technical Reports Server (NTRS)

Jovanovic, S.; Reed, G. W., Jr.

1973-01-01

Two types of highland terrain appear to be present at the Apollo 16 landing site. The Plains Formation called Cayley is ubiquitous and blankets even those regions that were presumably a part of the mountainous Descartes Formation. The second type of terrain is that associated with the ejectae from North and South Ray craters. The stratigraphy sampled by the ejectae underlays the Cayley layer as characterized above and may permit a redefinition of Descartes Formation as that which underlays the smooth Plains deposits. These conclusions are based on the concentrations and chemical coherence between elements such as Cl-F-P2O5 and Ru-Os. The primitive lunar crust may be characterized by the type of feldspathic rocks which are enriched in trace elements, such as Cl, Br, U, Te, Ru, and Os, as found in 'rusty' rock 66095 and in 61016; other feldspathic rocks are depleted and may be of secondary origin.

Genetic and epigenetic mechanisms of gene regulation during lens development

PubMed Central

Cvekl, Ales; Duncan, Melinda K.

2007-01-01

Recent studies demonstrated a number of links between chromatin structure, gene expression, extracellular signaling and cellular differentiation during lens development. Lens progenitor cells originate from a pool of common progenitor cells, the pre-placodal region (PPR) which is formed due to a complex exchange of extracellular signals between the neural plate, naïve ectoderm and mesendoderm. A specific commitment to the lens program over alternate choices such as the formation of olfactory epithelium or the anterior pituitary is manifested by the formation of a thickened surface ectoderm, the lens placode. Mouse lens progenitor cells are characterized by the expression of a complement of lens lineage-specific transcription factors including Pax6, Six3 and Sox2, controlled by FGF and BMP signaling, followed later by c-Maf, Mab21like1, Prox1 and FoxE3. Proliferation of lens progenitors together with their morphogenetic movements results in the formation of the lens vesicle. This transient structure, comprised of lens precursor cells, is polarized with its anterior cells retaining their epithelial morphology and proliferative capacity, whereas the posterior lens precursor cells initiate terminal differentiation forming the primary lens fibers. Lens differentiation is marked by expression and accumulation of crystallins and other structural proteins. The transcriptional control of crystallin genes is characterized by the reiterative use of transcription factors required for the establishment of lens precursors in combination with more ubiquitously expressed factors (e.g. AP-1, AP-2α, CREB and USF) and recruitment of histone acetyltransferases (HATs) CBP and p300, and chromatin remodeling complexes SWI/SNF and ISWI. These studies have poised the study of lens development at the forefront of efforts to understand the connections between development, cell signaling, gene transcription and chromatin remodeling. PMID:17905638

Cellular basis of gastrulation in the sand dollar Scaphechinus mirabilis.

PubMed

Kominami, T; Takata, H

2000-12-01

The processes of gastrulation in the sand dollar Scaphechinus mirabilis are quite different from those in regular echinoids. In this study, we explored the cellular basis of gastrulation in this species with several methods. Cell-tracing experiments revealed that the prospective endodermal cells were convoluted throughout the invagination processes. Histological observation showed that the ectodermal layer remained thickened, and the vegetal cells retained an elongated shape until the last step of invagination. Further, most of the vegetal ectodermal cells were skewed or distorted. Wedge-shaped cells were common in the vegetal ectoderm, especially at the subequatorial region. In these embryos, unlike the embryos of regular echinoids, secondary mesenchyme cells did not seem to exert the force to pull up the archenteron toward the inner surface of the apical plate. In fact, the archenteron cells were not stretched along the axis of elongation and were in close contact with each other. Here we found that gastrulation was completely blocked when the embryos were attached to a glass dish coated with poly-L-lysine, in which the movement of the ectodermal layer was inhibited. These results suggest that a force generated by the thickened ectoderm, rather than rearrangement of the archenteron cells, may play a key role in the archenteron elongation in S. mirabilis embryos.

Ectodermal dysplasias: a new clinical-genetic classification

PubMed Central

Priolo, M.; Lagana, C.

2001-01-01

The ectodermal dysplasias (EDs) are a large and complex nosological group of diseases, first described by Thurnam in 1848. In the last 10 years more than 170 different pathological clinical conditions have been recognised and defined as EDs, all sharing in common anomalies of the hair, teeth, nails, and sweat glands. Many are associated with anomalies in other organs and systems and, in some conditions, with mental retardation.
The anomalies affecting the epidermis and epidermal appendages are extremely variable and clinical overlap is present among the majority of EDs. Most EDs are defined by particular clinical signs (for example, eyelid adhesion in AEC syndrome, ectrodactyly in EEC). To date, few causative genes have been identified for these diseases.
We recently reviewed genes known to be responsible for EDs in light of their molecular and biological function and proposed a new approach to EDs, integrating both molecular-genetic data and corresponding clinical findings. Based on our previous report, we now propose a clinical-genetic classification of EDs, expand it to other entities in which no causative genes have been identified based on the phenotype, and speculate on possible candidate genes suggested by associated "non-ectodermal" features.


Keywords: ectodermal dysplasia; clinical-functional correlation; epithelial-mesenchymal interaction; ectodermal structural proteins PMID:11546825

Impaired epithelial differentiation of induced pluripotent stem cells from ectodermal dysplasia-related patients is rescued by the small compound APR-246/PRIMA-1MET.

PubMed

Shalom-Feuerstein, Ruby; Serror, Laura; Aberdam, Edith; Müller, Franz-Josef; van Bokhoven, Hans; Wiman, Klas G; Zhou, Huiqing; Aberdam, Daniel; Petit, Isabelle

2013-02-05

Ectodermal dysplasia is a group of congenital syndromes affecting a variety of ectodermal derivatives. Among them, ectrodactyly, ectodermal dysplasia, and cleft lip/palate (EEC) syndrome is caused by single point mutations in the p63 gene, which controls epidermal development and homeostasis. Phenotypic defects of the EEC syndrome include skin defects and limbal stem-cell deficiency. In this study, we designed a unique cellular model that recapitulated major embryonic defects related to EEC. Fibroblasts from healthy donors and EEC patients carrying two different point mutations in the DNA binding domain of p63 were reprogrammed into induced pluripotent stem cell (iPSC) lines. EEC-iPSC from both patients showed early ectodermal commitment into K18(+) cells but failed to further differentiate into K14(+) cells (epidermis/limbus) or K3/K12(+) cells (corneal epithelium). APR-246 (PRIMA-1(MET)), a small compound that restores functionality of mutant p53 in human tumor cells, could revert corneal epithelial lineage commitment and reinstate a normal p63-related signaling pathway. This study illustrates the relevance of iPSC for p63 related disorders and paves the way for future therapy of EEC.

Use of mini dental implants in ectodermal dysplasia children: follow-up of three cases.

PubMed

Sfeir, E; Nassif, N; Moukarzel, C

2014-07-01

Ectodermal dysplasia is a hereditary genodermatosis characterised by a congenital defect of ectodermal structures, causing tooth malformations and anomalies. Implantology has become accepted in these subjects. However cases are often complicated by a reduction in the size of the alveolar process, making the insertion of conventional implants difficult without bone grafting. The reduced diameter of mini-implants and their ease of insertion provide an interesting solution in supporting removable or fixed prosthesis. The purpose of this paper is to report the follow-up of three cases of children (11-12 year- old) with ectodermal dysplasia in which mini-implants were used to support the prostheses. In the first case, two mini-implants were inserted into the anterior part of the mandible for stabilising a removable denture (2 years follow-up). In the other two cases, mini- implants were inserted in the maxilla and mandible to replace missing front teeth with fixed prostheses. Patients were called for follow- up every 6 months: in the sencod case follow-up lasted 4 years in the mandible and 2 years in the maxilla; in the third case, 2 years in the maxilla and 1 year in the mandible. The use of mini-implants in children with ectodermal dysplasia can enhance aesthetics, and functional and psychosocial development.

Quantitative Analysis of the Area of the Apical Ectodermal Ridge in Chick Appendages Using Image-J.

PubMed

Syed, Hamd Binte Shahab; Khan, Muhammad Yunus

2018-06-01

To determine the effect of sodium phenytoin on the apical ectodermal ridges (AER) of chick wing buds by using the software program Image-J. An experimental study. Department of Anatomy, Regional Center, College of Physicians and Surgeons Pakistan (CPSP), Islamabad, from January 2014 to January 2015. Sixty fertilised chicken eggs of 'Egyptian fayoumi' breed were selected and separated into experimental (B) and control (A) groups, each having 30 eggs. A single dose of 3.5 mg sodium phenytoin was injected into each egg of the experimental group. The controls were injected with the same volume of normal saline. Developing embryos were extracted 96 hours (day 4) after incubation and histological sections were cut at 5 μm thickness. These sections were stained with Feulgen Nuclear and Light Green. The area of apical ectodermal ridges of chick wing buds was calculated by employing Image-J and subjected to statistical analysis. The difference between the mean values of the area of apical ectodermal ridges of experimental and control groups, as calculated by Image-J, was found to be statistically insignificant. Change in the area of the apical ectodermal ridges in experimental chicks, following phenytoin exposure, was insignificant as proven on the basis of quantification by Image-J.

[Pigmentosum retinis and tubulo-interstitial nephronophtisis in Sensenbrenner syndrome: a case report].

PubMed

Costet, C; Betis, F; Bérard, E; Tsimaratos, M; Sigaudy, S; Antignac, C; Gastaud, P

2000-02-01

Sensenbrenner syndrome or cranio-ectodermal dysplasia is an extremely rare autosomal recessive condition (12 cases reported in literature). Our observation shows the possibility of both ocular and renal involvement associated with cranio-ectodermal abnormalities. and method:We report the case of a girl who presented a typical cranio-ectodermal syndrome with dolicocephaly, short thorax, short limbs, short fingers and teeth abnormalities. At five years, she was found to have pigmentosum retinitis with amblyopy and moderate hyperopia. A chronic renal failure with uncontrollable hypertension underwent a cadaveric-donor transplantation at the age of six years. Two years later, the pigmentosum retinitis was stable. The kidney histology revealed a tubulo-interstitial nephronophtisis. The molecular analysis of the NPH 1 locus, which was associated with nephronophtisis, was negative. Our observation and two recent publications have in common ocular and renal abnormalities associated with cranio-ectodermal dysplasia. The underlying genetic defect would involve not only morphogenesis but also development and maturation of organs as eye and kidney. Sensenbrenner syndrome would thus be similar to certain disorders affecting the eye, kidney, skeleton and ectodermal structures such as the EEM, Senior-Loken, Mainzer-Saldino, and Jeune syndromes. The retinal dystrophy falls within the spectrum of clinical and genetic forms of pigmentosum retinitis. Our observation would confirm possible links between Sensenbrenner syndrome and oculorenal syndromes.

Properties of Massive Stars in Primitive Galaxies

NASA Technical Reports Server (NTRS)

Heap, Sara

2012-01-01

According to R. Dave, the phases of galaxy formation are distinguished by their halo mass and governing feedback mechanism. Galaxies in the birth phase (our "primitive galaxies") have a low halo mass (M<10(exp 9) Msun); and star formation is affected by photoionizing radiation of massive stars. In contrast, galaxies in the growth phase (e.g. Lyman Break galaxies) are more massive (M=10(exp 9)-10(exp 12) Msun); star formation is fueled by cold accretion but modulated by strong outflows from massive stars. I Zw 18 is a local blue, compact dwarf galaxy that meets the requirements for a birth-phase galaxy: halo mass <10(exp 9) Msun, strong photo ionizing radiation, no galactic outflow, and very low metallicity, log(O/H)=7.2. We will describe the properties of massive stars in I Zw 18 based on analysis of ultraviolet spectra obtained with HST.

β-Catenin specifies the endomesoderm and defines the posterior organizer of the hemichordate Saccoglossus kowalevskii

PubMed Central

Darras, Sébastien; Gerhart, John; Terasaki, Mark; Kirschner, Marc; Lowe, Christopher J.

2011-01-01

The canonical Wnt/β-catenin pathway is a key regulator of body plan organization and axis formation in metazoans, being involved in germ layer specification, posterior growth and patterning of the anteroposterior axis. Results from animals spanning a wide phylogenetic range suggest that a unifying function of β-catenin in metazoans is to define the posterior/vegetal part of the embryo. Although the specification of vegetal territories (endoderm) by β-catenin has been demonstrated in distantly related animals (cnidarians, a protostome, echinoderms and ascidians), the definition of the posterior part of the embryo is well supported only for vertebrates and planarians. To gain insights into β-catenin functions during deuterostome evolution, we have studied the early development of the direct developing hemichordate Saccoglossus kowalevskii. We show that the zygote is polarized after fertilization along the animal-vegetal axis by cytoplasmic rearrangements resembling the ascidian vegetal contraction. This early asymmetry is translated into nuclear accumulation of β-catenin at the vegetal pole, which is necessary and sufficient to specify endomesoderm. We show that endomesoderm specification is crucial for anteroposterior axis establishment in the ectoderm. The endomesoderm secretes as yet unidentified signals that posteriorize the ectoderm, which would otherwise adopt an anterior fate. Our results point to a conserved function at the base of deuterostomes for β-catenin in germ layer specification and to a causal link in the definition of the posterior part of the embryonic ectoderm by way of activating posteriorizing endomesodermal factors. Consequently, the definition of the vegetal and the posterior regions of the embryo by β-catenin should be distinguished and carefully re-examined. PMID:21303849

Loss of Sip1 leads to migration defects and retention of ectodermal markers during lens development.

PubMed

Manthey, Abby L; Lachke, Salil A; FitzGerald, Paul G; Mason, Robert W; Scheiblin, David A; McDonald, John H; Duncan, Melinda K

2014-02-01

SIP1 encodes a DNA-binding transcription factor that regulates multiple developmental processes, as highlighted by the pleiotropic defects observed in Mowat-Wilson syndrome, which results from mutations in this gene. Further, in adults, dysregulated SIP1 expression has been implicated in both cancer and fibrotic diseases, where it functionally links TGFβ signaling to the loss of epithelial cell characteristics and gene expression. In the ocular lens, an epithelial tissue important for vision, Sip1 is co-expressed with epithelial markers, such as E-cadherin, and is required for the complete separation of the lens vesicle from the head ectoderm during early ocular morphogenesis. However, the function of Sip1 after early lens morphogenesis is still unknown. Here, we conditionally deleted Sip1 from the developing mouse lens shortly after lens vesicle closure, leading to defects in coordinated fiber cell tip migration, defective suture formation, and cataract. Interestingly, RNA-Sequencing analysis on Sip1 knockout lenses identified 190 differentially expressed genes, all of which are distinct from previously described Sip1 target genes. Furthermore, 34% of the genes with increased expression in the Sip1 knockout lenses are normally downregulated as the lens transitions from the lens vesicle to early lens, while 49% of the genes with decreased expression in the Sip1 knockout lenses are normally upregulated during early lens development. Overall, these data imply that Sip1 plays a major role in reprogramming the lens vesicle away from a surface ectoderm cell fate towards that necessary for the development of a transparent lens and demonstrate that Sip1 regulates distinctly different sets of genes in different cellular contexts. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Loss of Sip1 leads to migration defects and retention of ectodermal markers during lens development

PubMed Central

Manthey, Abby L.; Lachke, Salil A.; FitzGerald, Paul G.; Mason, Robert W.; Scheiblin, David A.; McDonald, John H.; Duncan, Melinda K.

2014-01-01

SIP1 encodes a DNA-binding transcription factor that regulates multiple developmental processes, as highlighted by the pleiotropic defects observed in Mowat-Wilson Syndrome, which results from mutations in this gene. Further, in adults, dysregulated SIP1 expression has been implicated in both cancer and fibrotic diseases, where it functionally links TGFβ signaling to the loss of epithelial cell characteristics and gene expression. In the ocular lens, an epithelial tissue important for vision, Sip1 is co-expressed with epithelial markers, such as E-cadherin, and is required for the complete separation of the lens vesicle from the head ectoderm during early ocular morphogenesis. However, the function of Sip1 after early lens morphogenesis is still unknown. Here, we conditionally deleted Sip1 from the developing mouse lens shortly after lens vesicle closure, leading to defects in coordinated fiber cell tip migration, defective suture formation, and cataract. Interestingly, RNA-Sequencing analysis on Sip1 knockout lenses identified 190 differentially expressed genes, all of which are distinct from previously described Sip1 target genes. Furthermore, 34% of the genes with increased expression in the Sip1 knockout lenses are normally downregulated as the lens transitions from the lens vesicle to early lens, while 49% of the genes with decreased expression in the Sip1 knockout lenses are normally upregulated during early lens development. Overall, these data imply that Sip1 plays a major role in reprogramming the lens vesicle away from a surface ectoderm cell fate towards that necessary for the development of a transparent lens and demonstrate that Sip1 regulates distinctly different sets of genes in different cellular contexts. PMID:24161570

Innexin 3, a New Gene Required for Dorsal Closure in Drosophila Embryo

PubMed Central

Giuliani, Fabrizio; Giuliani, Giuliano; Bauer, Reinhard; Rabouille, Catherine

2013-01-01

Background Dorsal closure is a morphogenetic event that occurs during mid-embryogenesis in many insects including Drosophila, during which the ectoderm migrates on the extraembryonic amnioserosa to seal the embryo dorsally. The contribution of the ectoderm in this event has been known for a long time. However, amnioserosa tension and contractibility have recently been shown also to be instrumental to the closure. A critical pre-requisite for dorsal closure is integrity of these tissues that in part is mediated by cell-cell junctions and cell adhesion. In this regard, mutations impairing junction formation and/or adhesion lead to dorsal closure. However, no role for the gap junction proteins Innexins has so far been described. Results and Discussion Here, we show that Innexin 1, 2 and 3, are present in the ectoderm but also in the amnioserosa in plaques consistent with gap junctions. However, only the loss of Inx3 leads to dorsal closure defects that are completely rescued by overexpression of inx3::GFP in the whole embryo. Loss of Inx3 leads to the destabilisation of Inx1, Inx2 and DE-cadherin at the plasma membrane, suggesting that these four proteins form a complex. Accordingly, in addition to the known interaction of Inx2 with DE-cadherin, we show that Inx3 can bind to DE-cadherin. Furthermore, Inx3-GFP overexpression recruits DE-cadherin from its wildtype plasma membrane domain to typical Innexin plaques, strengthening the notion that they form a complex. Finally, we show that Inx3 stability is directly dependent on tissue tension. Taken together, we propose that Inx3 is a critical factor for dorsal closure and that it mediates the stability of Inx1, 2 and DE-cadherin by forming a complex. PMID:23894431

15N Fractionation in Star-Forming Regions and Solar System Objects

NASA Technical Reports Server (NTRS)

Wirstrom, Eva; Milam, Stefanie; Adande, GIlles; Charnley, Steven; Cordiner, Martin

2015-01-01

A central issue for understanding the formation and evolution of matter in the early Solar System is the relationship between the chemical composition of star-forming interstellar clouds and that of primitive Solar System materials. The pristinemolecular content of comets, interplanetary dust particles and carbonaceous chondrites show significant bulk nitrogen isotopic fractionation relative to the solar value, 14N15N 440. In addition, high spatial resolution measurements in primitive materials locally show even more extreme enhancements of 14N15N 100.

Clinical Variability in a Family with an Ectodermal Dysplasia Syndrome and a Nonsense Mutation in the TP63 Gene.

PubMed

Eisenkraft, Arik; Pode-Shakked, Ben; Goldstein, Nurit; Shpirer, Zvi; van Bokhoven, Hans; Anikster, Yair

2015-01-01

Mutations in the TP63 gene have been associated with a variety of ectodermal dysplasia syndromes, among which the clinically overlapping Ankyloblepharon-Ectodermal defects-Cleft lip/palate (AEC) and the Rapp-Hodgkin syndromes. We report a multiplex nonconsanguineous family of Ashkenazi-Jewish descent, in which the index patient presented with a persistent scalp skin lesion, dystrophic nails and light thin hair. Further evaluation revealed over 10 affected individuals in the kindred, over four generations, exhibiting varying degrees of ectodermal involvement. Analysis of the TP63 gene from four of the patients and from two healthy individuals of the same family was performed. Gene sequencing of the patients revealed a nonsense mutation leading to a premature termination codon (PTC) (p.Gln16X). The same mutation was found in all tested affected individuals in the family, but gave rise to marked phenotypic variability with minor clinical manifestations in some individuals, underscoring the clinical heterogeneity associated with the recently described PTC-causing mutations.

Early implant placement for a patient with ectodermal dysplasia: Thirteen years of clinical care.

PubMed

Knobloch, Lisa A; Larsen, Peter E; Saponaro, Paola C; L'Homme-Langlois, Emilie

2017-11-29

Patients with ectodermal dysplasia have abnormalities of 2 or more structures that originate from the ectoderm. The oral manifestations often include the congenital absence of teeth and malformed teeth. This clinical report describes the interdisciplinary care from childhood through the definitive dental rehabilitation completed at skeletal maturation to replace the missing teeth in a patient with ectodermal dysplasia. Treatment began at 9 years of age with an implant-assisted mandibular overdenture to improve function and replace the missing mandibular teeth. Orthodontic treatment for the consolidation of space, composite resin restorations, and interim removable dental prostheses were provided to improve esthetics and replace the missing maxillary teeth. Skeletal growth was monitored, and orthognathic surgery was performed at the cessation of growth. The definitive rehabilitation consisted of a mandibular fixed dental prosthesis supported by dental implants and a maxillary removable dental prosthesis to restore the patient to esthetics and function. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Conventional Complete Denture in Patients with Ectodermal Dysplasia

PubMed Central

Vilanova, Larissa Soares Reis; Sánchez-Ayala, Alfonso; Ribeiro, Giselle Rodrigues; Campos, Camila Heitor; Farias-Neto, Arcelino

2015-01-01

Ectodermal dysplasia is described as heritable conditions that involve anomalies of structures derived from the ectoderm, including hypodontia. In the cases of edentulous young patients, who did not finish their craniofacial growth, treatment with conventional complete denture is a suitable alternative. The aim of this study was to report a case of mandibular edentulism treated with conventional complete denture in a thirteen-year-old patient diagnosed with hidrotic ectodermal dysplasia. Typical features, such as frontal bossing, depressed nasal bridge, protuberant lips, scarce hair, and brittle nails, were visualized during the extraoral examination. The intraoral inspection and radiographic analysis revealed oligodontia, dental malformation, and prolonged retention of deciduous teeth at maxilla and total edentulism at mandible. A conventional complete denture was planned and constructed following the same steps of technique as recommended in adults. Although this option is not a definitive treatment, the patient and his parents were satisfied with his improvement in chewing and speech, as well as with the aesthetic benefits. PMID:26425372

Hypohidrotic Ectodermal Dysplasia: Breastfeeding Complications Due to Impaired Breast Development.

PubMed

Wahlbuhl-Becker, Mandy; Faschingbauer, Florian; Beckmann, Matthias W; Schneider, Holm

2017-04-01

Background X-linked hypohidrotic ectodermal dysplasia (XLHED), the most common form of ectodermal dysplasia, is caused by mutations in the gene EDA. While only affected men develop the full-blown clinical picture, females who are heterozygous for an EDA mutation often also show symptoms such as hypodontia, hypotrichosis and hypohidrosis. These women may also suffer from malformations of the mammary gland which represent not just a cosmetic problem but can limit their breastfeeding capability. This paper summarizes the findings of the first systematic study on the impact of hypohidrotic ectodermal dysplasia on breastfeeding. Patients Thirty-eight adult female members of the German-Swiss-Austrian ectodermal dysplasia patient support group participated in a structured interview; most of them also agreed to a photodocumentation of their mammary region. Thirty-one women carried mutations in EDA (Group A) and seven were affected by other forms of hypohidrotic ectodermal dysplasia (Group B). Results 39 % of the women of Group A reported that their breasts were of different size or entirely absent on one side. In Group B, 86 % of the women reported differently sized or even absent breasts; two of these women lacked both breasts entirely. Most women described their nipples as exceptionally flat. 10 % of the women of Group A had more than two nipples. The high percentage of deviations from the norm was confirmed in the photodocumentation. Both groups had few or no sebaceous glands of Montgomery in the areolar region. Around 80 % of interviewed women had children and had attempted to breastfeed their first child. 67 % of the mothers in Group A had had difficulty in breastfeeding their infants and generally attributed this difficulty to their flat nipples. All of the mothers in Group B reported difficulties in breastfeeding; 60 % had not been able to breastfeed their first child. Conclusion Mothers with hypohidrotic ectodermal dysplasia very often have difficulty in breastfeeding because of their impaired breast development. This causal relationship needs to be taken into account in lactation counseling.

Prosthetic rehabilitation in a pediatric patient with hypohidrotic ectodermal dysplasia: a case report.

PubMed

Quintanilha, Luís Eduardo Lavigne Paranhos; Carneiro-Campos, Luís Eduardo; Antunes, Lívia Azeredo Alves; Antunes, Leonardo Santos; Fernandes, Claudio Pinheiro; Abreu, Fernanda Volpe

2017-01-01

Hypohidrotic ectodermal dysplasia (HED) is a rare ectodermal disease with a systemic expression. Oral abnormalities are common and may include hypodontia and shape irregularities in the primary and permanent dentitions. Rehabilitation of the dental arches in pediatric patients with HED is a challenge because HED is a multifactorial disease that demands a complicated treatment approach and most dentists have limited experience or training in the necessary treatment. In addition, pediatric patients often lack the patience or ability to cooperate with complex prosthetic treatment. This case report describes a simplified technique used to fabricate complete dentures for a 4-year-old HED patient in 4 sessions.

Prosthetic Rehabilitation of a Child Suffering from Hypohidrotic Ectodermal Dysplasia with Complete Anodontia

PubMed Central

Nikhil, M; Chugh, Anshul; Narwal, Anjali

2012-01-01

ABSTRACT A 7-year-old male, described in the case report, exhibited many of the manifestations of ectodermal dysplasia as well as behavioral problems. The treatment to improve his appearance and oral function included a removable prosthesis. The results were significant improvements in speech, masticatory function, and facial esthetics, contributing to the development of normal dietary habits, and the improved and more rapid social integration of the child. How to cite this article: Bala S, Nikhil M, Chugh A, Narwal A. Prosthetic Rehabilitation of a Child Suffering from Hypohidrotic Ectodermal Dysplasia with Complete Anodontia. Int J Clin Pediatr Dent 2012;5(2):148-150. PMID:25206157

Influence of oral rehabilitation on the oral health-related quality of life of a child with ectodermal dysplasia.

PubMed

de Alencar, Nashalie Andrade; Reis, Kátia Rodrigues; Antonio, Andréa Gonçalves; Maia, Lucianne Cople

2015-01-01

Ectodermal dysplasia (ED) is a rare congenital hereditary disorder among a group of syndromes characterized by abnormalities of ectodermic structures. The purpose of this report is to compare the oral health-related quality of life (OHRQoL) before and after complete oral rehabilitation of a five-year-old boy with ED. Delivery of upper and lower dentures resulted in immediate improvement of the child's OHRQoL. Although ED affects patients physically and emotionally, the early oral rehabilitation of young patients is crucial to improve their social interaction and restore their speech and masticatory function.

Ectodermal dysplasia with blindness in sibs on the island of Rodrigues.

PubMed Central

Wallis, C E; Beighton, P

1992-01-01

A brother and sister from the island of Rodrigues had mental retardation, blindness owing to severe ocular malformations, short stature, dysmorphic facial features, hypotrichosis, and dental abnormalities. It is likely that they have a hitherto unrecognised autosomal recessive ectodermal dysplasia syndrome. Images PMID:1583659

The Nature and Origin of Interplanetary Dust: High Temperature Components

NASA Technical Reports Server (NTRS)

Keller, L. P.; Messenger, S.

2004-01-01

The specific parent bodies of individual interplanetary dust particles (IDPs) are un-known, but the anhydrous chondritic-porous (CP) sub-set has been linked directly to cometary sources [1]. The CP IDPs escaped the thermal processing and water-rock interactions that have severely modified or destroyed the original mineralogy of primitive meteorites. Their origin in the outer regions of the solar system suggests they should retain primitive chemical and physical characteristics from the earliest stages of solar system formation (including abundant presolar materials). Indeed, CP IDPs are the most primitive extraterrestrial materials available for laboratory studies based on their unequilibrated mineralogy [2], high concentrations of carbon, nitrogen and volatile trace elements relative to CI chondrites [3, 4, 5], presolar hydrogen and nitrogen isotopic signatures [6, 7] and abundant presolar silicates [8].

Morphological Study of Insoluble Organic Matter Residues from Primitive

NASA Technical Reports Server (NTRS)

Changela, H. G.; Stroud, R. M.; Peeters, Z.; Nittler, L. R.; Alexander, C. M. O'D.; DeGregorio, B. T.; Cody, G. D.

2012-01-01

Insoluble organic matter (IOM) constitutes a major proportion, 70-99%, of the total organic carbon found in primitive chondrites [1, 2]. One characteristic morphological component of IOM is nanoglobules [3, 4]. Some nanoglobules exhibit large N-15 and D enrichments relative to solar values, indicating that they likely originated in the ISM or the outskirts of the protoplanetary disk [3]. A recent study of samples from the Tagish Lake meteorite with varying levels of hydrothermal alteration suggest that nanoglobule abundance decreases with increasing hydrothermal alteration [5]. The aim of this study is to further document the morphologies of IOM from a range of primitive chondrites in order to determine any correlation of morphology with petrographic grade and chondrite class that could constrain the formation and/or alteration mechanisms.

Craniofacial morphometric analysis of individuals with X-linked hypohidrotic ectodermal dysplasia.

PubMed

Goodwin, Alice F; Larson, Jacinda R; Jones, Kyle B; Liberton, Denise K; Landan, Maya; Wang, Zhifeng; Boekelheide, Anne; Langham, Margaret; Mushegyan, Vagan; Oberoi, Snehlata; Brao, Rosalie; Wen, Timothy; Johnson, Ramsey; Huttner, Kenneth; Grange, Dorothy K; Spritz, Richard A; Hallgrímsson, Benedikt; Jheon, Andrew H; Klein, Ophir D

2014-09-01

Hypohidrotic ectodermal dysplasia (HED) is the most prevalent type of ectodermal dysplasia (ED). ED is an umbrella term for a group of syndromes characterized by missing or malformed ectodermal structures, including skin, hair, sweat glands, and teeth. The X-linked recessive (XL), autosomal recessive (AR), and autosomal dominant (AD) types of HED are caused by mutations in the genes encoding ectodysplasin (EDA1), EDA receptor (EDAR), or EDAR-associated death domain (EDARADD). Patients with HED have a distinctive facial appearance, yet a quantitative analysis of the HED craniofacial phenotype using advanced three-dimensional (3D) technologies has not been reported. In this study, we characterized craniofacial morphology in subjects with X-linked hypohidrotic ectodermal dysplasia (XLHED) by use of 3D imaging and geometric morphometrics (GM), a technique that uses defined landmarks to quantify size and shape in complex craniofacial morphologies. We found that the XLHED craniofacial phenotype differed significantly from controls. Patients had a smaller and shorter face with a proportionally longer chin and midface, prominent midfacial hypoplasia, a more protrusive chin and mandible, a narrower and more pointed nose, shorter philtrum, a narrower mouth, and a fuller and more rounded lower lip. Our findings refine the phenotype of XLHED and may be useful both for clinical diagnosis of XLHED and to extend understanding of the role of EDA in craniofacial development.

Characterization of X-linked Hypohidrotic Ectodermal Dysplasia (XL-HED) Hair and Sweat Gland Phenotypes Using Phototrichogram Analysis and Live Confocal Imaging

PubMed Central

Jones, Kyle B.; Goodwin, Alice F.; Landan, Maya; Seidel, Kerstin; Tran, Dong-Kha; Hogue, Jacob; Chavez, Miquella; Fete, Mary; Yu, Wenli; Hussein, Tarek; Johnson, Ramsey; Huttner, Kenneth; Jheon, Andrew H.; Klein, Ophir D.

2015-01-01

Hypohidrotic ectodermal dysplasia (HED) is the most common type of ectodermal dysplasia (ED), which encompasses a large group of syndromes that share several phenotypic features such as missing or malformed ectodermal structures, including skin, hair, sweat glands, and teeth. X-linked hypohidrotic ectodermal dysplasia (XL-HED) is associated with mutations in ectodysplasin (EDA1). Hypohidrosis due to hypoplastic sweat glands and thin, sparse hair are phenotypic features that significantly affect the daily lives of XL-HED individuals and therefore require systematic analysis. We sought to determine the quality of life of individuals with XL-HED and to quantify sweat duct and hair phenotypes using confocal imaging, pilocarpine iontophoresis, and phototrichogram analysis. Using these highly sensitive and non-invasive techniques, we demonstrated that 11/12 XL-HED individuals presented with a complete absence of sweat ducts and that none produced sweat. We determined that the thin hair phenotype observed in XL-HED was due to multiple factors, such as fewer terminal hairs with decreased thickness and slower growth rate, as well as fewer follicular units and fewer hairs per unit. The precise characterization of XL-HED phenotypes using sensitive and non-invasive techniques presented in our study will improve upon larger genotype-phenotype studies and in the assessment of future therapies in XL-HED. PMID:23687000

Ectodysplasin A Pathway Contributes to Human and Murine Skin Repair.

PubMed

Garcin, Clare L; Huttner, Kenneth M; Kirby, Neil; Schneider, Pascal; Hardman, Matthew J

2016-05-01

The highly conserved ectodysplasin A (EDA)/EDA receptor signaling pathway is critical during development for the formation of skin appendages. Mutations in genes encoding components of the EDA pathway disrupt normal appendage development, leading to the human disorder hypohidrotic ectodermal dysplasia. Spontaneous mutations in the murine Eda (Tabby) phenocopy human X-linked hypohidrotic ectodermal dysplasia. Little is known about the role of EDA signaling in adult skin homeostasis or repair. Because wound healing largely mimics the morphogenic events that occur during development, we propose a role for EDA signaling in adult wound repair. Here we report a pronounced delay in healing in Tabby mice, demonstrating a functional role for EDA signaling in adult skin. Moreover, pharmacological activation of the EDA pathway in both Tabby and wild-type mice significantly accelerates healing, influencing multiple processes including re-epithelialization and granulation tissue matrix deposition. Finally, we show that the healing promoting effects of EDA receptor activation are conserved in human skin repair. Thus, targeted manipulation of the EDA/EDA receptor pathway has clear therapeutic potential for the future treatment of human pathological wound healing. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

The Late Devonian Gogo Formation Lägerstatte of Western Australia: Exceptional Early Vertebrate Preservation and Diversity

NASA Astrophysics Data System (ADS)

Long, John A.; Trinajstic, Kate

2010-05-01

The Gogo Formation of Western Australia preserves a unique Late Devonian (Frasnian) reef fauna. The exceptional three-dimensional preservation of macrofossils combined with unprecedented soft-tissue preservation (including muscle bundles, nerve cells, and umbilical structures) has yielded a particularly rich assemblage with almost 50 species of fishes described. The most significant discoveries have contributed to resolving placoderm phylogeny and elucidating their reproductive physiology. Specifically, these discoveries have produced data on the oldest known vertebrate embryos; the anatomy of the primitive actinopterygian neurocranium and phylogeny of the earliest actinopterygians; the histology, radiation, and plasticity of dipnoan (lungfish) dental and cranial structures; the anatomy and functional morphology of the extinct onychodonts; and the anatomy of the primitive tetrapodomorph head and pectoral fin.

Planar induction of anteroposterior pattern in the developing central nervous system of Xenopus laevis

NASA Technical Reports Server (NTRS)

Doniach, T.; Phillips, C. R.; Gerhart, J. C.

1992-01-01

It has long been thought that anteroposterior (A-P) pattern in the vertebrate central nervous system is induced in the embryo's dorsal ectoderm exclusively by signals passing vertically from underlying, patterned dorsal mesoderm. Explants from early gastrulae of the frog Xenopus laevis were prepared in which vertical contact between dorsal ectoderm and mesoderm was prevented but planar contact was maintained. In these, four position-specific neural markers (engrailed-2, Krox-20, XlHbox 1, and XlHbox 6) were expressed in the ectoderm in the same A-P order as in the embryo. Thus, planar signals alone, following a path available in the normal embryo, can induce A-P neural pattern.

Uncoupling neurogenic gene networks in the Drosophila embryo.

PubMed

Rogers, William A; Goyal, Yogesh; Yamaya, Kei; Shvartsman, Stanislav Y; Levine, Michael S

2017-04-01

The EGF signaling pathway specifies neuronal identities in the Drosophila embryo by regulating developmental patterning genes such as intermediate neuroblasts defective ( ind ). EGFR is activated in the ventral midline and neurogenic ectoderm by the Spitz ligand, which is processed by the Rhomboid protease. CRISPR/Cas9 was used to delete defined rhomboid enhancers mediating expression at each site of Spitz processing. Surprisingly, the neurogenic ectoderm, not the ventral midline, was found to be the dominant source of EGF patterning activity. We suggest that Drosophila is undergoing an evolutionary transition in central nervous system (CNS)-organizing activity from the ventral midline to the neurogenic ectoderm. © 2017 Rogers et al.; Published by Cold Spring Harbor Laboratory Press.

Bilateral congenital lacrimal fistulas in an adult as part of ectrodactyly-ectodermal dysplasia-clefting syndrome: A rare anomaly.

PubMed

Ghosh, Debangshu; Saha, Somnath; Basu, Sumit Kumar

2015-10-01

Ectrodactyly-ectodermal dysplasia and clefting syndrome or "Lobster claw" deformity is a rare congenital anomaly that affects tissues of ectodermal and mesodermal origin. Nasolacrimal duct (NLD) obstruction with or without atresia of lacrimal passage is a common finding of such a syndrome. The authors report here even a rarer presentation of the syndrome which manifested as bilateral NLD obstruction and lacrimal fistula along with cleft lip and palate, syndactyly affecting all four limbs, mild mental retardation, otitis media, and sinusitis. Lacrimal duct obstruction and fistula were managed successfully with endoscopic dacryocystorhinostomy (DCR) which is a good alternative to lacrimal probing or open DCR in such a case.

Formation of amino acids and nucleic acid constituents from simulated primitive planetary atmospheres by irradiation with high-energy protons

NASA Astrophysics Data System (ADS)

Kobayashi, K.; Yamanashi, H.; Ohashi, A.; Kaneko, T.; Miyakawa, S.; Saito, T.

It is suggested that primitive Earth atmosphere was only slightly reduced, which w as composed of carbon dioxide, carbon monoxide, nitrogen and water. It has been shown that bioorganic compounds can be hardly formed by energies as UV light, heat and spark discharges. We therefore examined possible formation pat hways of bioorganic compounds in the primitive E arth. A mixt ure of carbon monoxide, nitrogen and water was irradiated with high-energy prot ons generated by a van de Graaff accelerator, whi c h simulated an action of cosm ic rays. Aqueous solution of the product was hydr olyzed, and then analyzed by chromatography and mass spectrometry. A wide variety of amino acids and uracil, one of the nucle ic acid bases, wer e identified. Ribose, the RNA sugar, has not been identified, but formation of reducing polyols was suggested. A mino acids and uracil were also formed from a mixture of carbo n dioxide, carbon monoxide, nitrogen and water, and their yields correlated to the ratio of carbon monoxide and nitrogen in the mixture. Since a certain percentage of carbon monoxide could be expected to be in it [1], cosmic radiation can be regarded as an effective energ so urce for prebiotic formation of life's building blocks in they primitive Earth [2]. In the conventional scenario of chemical evolution, amino acids were formed in t he primitive ocean from such intermediates as HCN an d HCHO formed in t he atmosphere. T his scenario seem s not to be possible due to the following reasons: (1) The irradiation products were quit e complex organic com pound s whose molecular weights were ca. 1000, and they gave amino acids after hydrolysis. (2) Energy yields of amino ac ids in the hydrolysates were comparable to those of HCN and HCHO in the irradiation pro duct s. (3) Irradiation products from a mixture of carbon monoxide and nitrogen without water als o gave amino acids aft er hydrolysis. T hes e observations strongly sugge s t e d that complex precursors of bioor ganic com poun ds could be formed directly in the atmosphere. A new scenario of chemical evolution via complex organics toward the origin of life will be prop o s e d. [1] J. Kasting, Origins Life Evol. Biosph ere, 20, 199 (1990). [2] K. Kobay ashi , et al., Origins Life Evol. Biosphere, 28, 155 (1998). * Present address: Rensselaer Polytechnic Ins titut e.

The evolutionary and genetic origins of consciousness in the Cambrian Period over 500 million years ago

PubMed Central

Feinberg, Todd E.; Mallatt, Jon

2013-01-01

Vertebrates evolved in the Cambrian Period before 520 million years ago, but we do not know when or how consciousness arose in the history of the vertebrate brain. Here we propose multiple levels of isomorphic or somatotopic neural representations as an objective marker for sensory consciousness. All extant vertebrates have these, so we deduce that consciousness extends back to the group's origin. The first conscious sense may have been vision. Then vision, coupled with additional sensory systems derived from ectodermal placodes and neural crest, transformed primitive reflexive systems into image forming brains that map and perceive the external world and the body's interior. We posit that the minimum requirement for sensory consciousness and qualia is a brain including a forebrain (but not necessarily a developed cerebral cortex/pallium), midbrain, and hindbrain. This brain must also have (1) hierarchical systems of intercommunicating, isomorphically organized, processing nuclei that extensively integrate the different senses into representations that emerge in upper levels of the neural hierarchy; and (2) a widespread reticular formation that integrates the sensory inputs and contributes to attention, awareness, and neural synchronization. We propose a two-step evolutionary history, in which the optic tectum was the original center of multi-sensory conscious perception (as in fish and amphibians: step 1), followed by a gradual shift of this center to the dorsal pallium or its cerebral cortex (in mammals, reptiles, birds: step 2). We address objections to the hypothesis and call for more studies of fish and amphibians. In our view, the lamprey has all the neural requisites and is likely the simplest extant vertebrate with sensory consciousness and qualia. Genes that pattern the proposed elements of consciousness (isomorphism, neural crest, placodes) have been identified in all vertebrates. Thus, consciousness is in the genes, some of which are already known. PMID:24109460

The evolutionary and genetic origins of consciousness in the Cambrian Period over 500 million years ago.

PubMed

Feinberg, Todd E; Mallatt, Jon

2013-01-01

Vertebrates evolved in the Cambrian Period before 520 million years ago, but we do not know when or how consciousness arose in the history of the vertebrate brain. Here we propose multiple levels of isomorphic or somatotopic neural representations as an objective marker for sensory consciousness. All extant vertebrates have these, so we deduce that consciousness extends back to the group's origin. The first conscious sense may have been vision. Then vision, coupled with additional sensory systems derived from ectodermal placodes and neural crest, transformed primitive reflexive systems into image forming brains that map and perceive the external world and the body's interior. We posit that the minimum requirement for sensory consciousness and qualia is a brain including a forebrain (but not necessarily a developed cerebral cortex/pallium), midbrain, and hindbrain. This brain must also have (1) hierarchical systems of intercommunicating, isomorphically organized, processing nuclei that extensively integrate the different senses into representations that emerge in upper levels of the neural hierarchy; and (2) a widespread reticular formation that integrates the sensory inputs and contributes to attention, awareness, and neural synchronization. We propose a two-step evolutionary history, in which the optic tectum was the original center of multi-sensory conscious perception (as in fish and amphibians: step 1), followed by a gradual shift of this center to the dorsal pallium or its cerebral cortex (in mammals, reptiles, birds: step 2). We address objections to the hypothesis and call for more studies of fish and amphibians. In our view, the lamprey has all the neural requisites and is likely the simplest extant vertebrate with sensory consciousness and qualia. Genes that pattern the proposed elements of consciousness (isomorphism, neural crest, placodes) have been identified in all vertebrates. Thus, consciousness is in the genes, some of which are already known.

Element Mapping in Anhydrous IDPs: Identification of the Host Phases of Major/Minor Elements as a Test of Nebula Condensation Models

NASA Technical Reports Server (NTRS)

Flynn, G. J.; Keller, L. P.; Wirick, S.; Jacobsen, C.

2004-01-01

Many anhydrous interplanetary dust particles (IDPs) are the most pristine samples of primitive solar system dust currently available for laboratory analysis. Their primitive nature is demonstrated by: 1) the high content of moderately volatile elements, indicating they have not been heated significantly since formation, 2) the absence of hydrated material, indicating they never experienced aqueous processing, 3) the presence of unequilibrated mineral assemblages, 4) the presence of large isotopic anomalies (e.g., D and 15N enrichment), in these IDPs.

Isolation and characterization of the human CDX1 gene: A candidate gene for diastrophic dysplasia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bonner, C.; Loftus, S.; Wasmuth, J.J.

1994-09-01

Diastrophic dysplasia is an autosomal recessive disorder characterized by short stature, dislocation of the joints, spinal deformities and malformation of the hands and feet. Multipoint linkage analysis places the diastrophic dysplasia (DTD) locus in 5q31-5q34. Linkage disequilibrium mapping places the DTD locus near CSFIR in the direction of PDGFRB (which is tandem to CSFIR). This same study tentatively placed PDGFRB and DTD proximal to CSFIR. Our results, as well as recently reported work from other laboratories, suggest that PDGFRB (and possibly DTD) is distal rather than proximal to CSFIR. We have constructed a cosmid contig covering approximately 200 kb ofmore » the region containing CSFIR. Several exons have been {open_quotes}trapped{close_quotes} from these cosmids using exon amplification. One of these exons was trapped from a cosmid isolated from a walk from PDGFRB, approximately 80 kb from CSFIR. This exon was sequenced and was determined to be 89% identical to the nucleotide sequence of exon two of the murine CDX1 gene (100% amino acid identity). The exon was used to isolate the human CDX gene. Sequence analysis of the human CDX1 gene indicates a very high degree of homology to the murine gene. CDX1 is a caudal type homeobox gene expressed during gastrulation. In the mouse, expression during gastrulation begins in the primitive streak and subsequently localizes to the ectodermal and mesodermal cells of the primitive streak, neural tube, somites, and limb buds. Later in gastrulation, CDX1 expression becomes most prominent in the mesoderm of the forelimbs, and, to a lesser extent, the hindlimbs. CDX1 is an intriguing candidate gene for diastrophic dysplasia. We are currently screening DNA from affected individuals and hope to shortly determine whether CDX1 is involved in this disorder.« less

Embryological Development: Evolutionary History, Genetic Bias, and Cellular Environment Control the Flow of Developmental Events, Part II.

ERIC Educational Resources Information Center

Caplan, Arnold I.

1981-01-01

Emphasizes ectodermal-mesodermal interaction but focuses on the genesis of specialized structures like feathers (ectodermal) and muscles, cartilage, and bone. The sum of these interactions and other factors which govern normal development may be important in regulating the regeneration of particular structures in postembryonic individuals.…

A survey of children affected by ectomermal dysplasia syndromes shows an increased prevalence of atopic disorders and immune deficiency

USDA-ARS?s Scientific Manuscript database

Ectodermal dysplasia (ED) syndromes are rare genetic disorders that affect the development of tissues derived from the embryonic ectoderm. Studies and anecdotal experience have indicated that atopic disorders (AD) and immune deficiencies (ID) may be associated with ED in children. Some ED genotypes ...

Kindler syndrome protein Kindlin-1 is mainly expressed in adult tissues originating from ectoderm/endoderm.

PubMed

Zhan, Jun; Yang, Mei; Zhang, Jing; Guo, YongQing; Liu, Wei; Zhang, HongQuan

2015-05-01

Mutations of integrin-interacting protein Kindlin-1 cause Kindler syndrome and deregulation of Kindlin-1 is implicated in human cancers. The Kindlin-1-related diseases are confined in limited tissue types. However, Kindlin-1 tissue distribution and the dogma that governs Kindlin-1 expression in normal human body are elusive. This study examined Kindlin-1 expression in normal human adult organs, human and mouse embryonic organs by immunohistochemical analyses. We identified a general principle that the level of Kindlin-1 expression in tissues is tightly correlated with the corresponding germ layers from which these tissues originate. We compared the expression of Kindlin-1 with Kindlin-2 and found that Kindlin-1 is highly expressed in epithelial tissues derived from ectoderm and endoderm, whereas Kindlin-2 is mainly expressed in mesoderm-derived tissues. Likewise, Kindlin-1 was also found highly expressed in endoderm/ectoderm-derived tissues in human and mouse embryos. Our findings indicate that Kindlin-1 may play an importance role in the development of endoderm/ectoderm related tissues.

Prosthodontic rehabilitation in patient with ectodermal dysplasia combining preprosthetic techniques: a case report.

PubMed

Pombo Castro, María; Luaces Rey, Ramón; Arenaz Búa, Jorge; Santana-Mora, Urbano; López-Cedrún Cembranos, José Luís

2013-10-01

Oral manifestations in ectodermal dysplasia include oligodontia, alveolar ridges hypoplasia, and others. Due to the special conditions in terms of unhealthy teeth and lack of bone, implant-supported rehabilitation seems to offer the most satisfactory outcome. A 27-year-old male diagnosed with ectodermal dysplasia was referred to our department for oral rehabilitation. Oral manifestations included oligodontia, maxillary and mandibular atrophy, mandibular alveolar ridge with knife-edge morphology, and conical teeth. Treatment planning consisted of a Le Fort I osteotomy with interpositional grafts, bilateral sinus lift, and placement of maxillary and mandibular inlay and onlay corticocancellous grafts, using autologous iliac crest bone. In the second surgery, all remaining teeth were removed and 11 endosteal implants were placed. Six months after implant placement, a bimaxillary fixed implant-supported prosthesis was delivered, maintaining a satisfactory esthetic and functional result after a 2-year follow-up. The use of combined preprosthetic techniques allows the placement of endosteal implants and a fixed implant-supported prosthesis in patients with oligodontia and ectodermal dysplasia, providing an esthetic and functional oral rehabilitation.

Dentomaxillofacial characteristics of ectodermal dysplasia.

PubMed

Nakayama, Yumiko; Baba, Yoshiyuki; Tsuji, Michiko; Fukuoka, Hiroki; Ogawa, Takuya; Ohkuma, Mizue; Moriyama, Keiji

2015-02-01

The aim of this retrospective hospital-based study was to elucidate the dentomaxillofacial characteristics of ectodermal dysplasia. Six Japanese individuals (one male and five female; age range, 12.7-27.2 years) underwent comprehensive examinations, including history recording, cephalometric analysis, panoramic radiography, and analysis of dental models. All the subjects had two or more major manifestations for clinical diagnosis of ectodermal dysplasia (e.g., defects of hair, teeth, nails, and sweat glands). They presented hypodontia (mean number of missing teeth, 9.5; range, 5-14), especially in the premolar region, and enamel dysplasia. Five subjects had bilateral molar occlusion, whereas one subject had unilateral molar occlusion. The common skeletal features were small facial height, maxillary hypoplasia, counterclockwise rotation of the mandible, and mandibular protrusion. Interestingly, the maxillary first molars were located in higher positions and the upper anterior facial height was smaller than the Japanese norm. The results suggest that vertical and anteroposterior maxillary growth retardation, rather than lack of occlusal support due to hypodontia, leads to reduced anterior facial height in individuals with ectodermal dysplasia. © 2014 Japanese Teratology Society.

Cell tracking supports secondary gastrulation in the moon jellyfish Aurelia.

PubMed

Gold, David A; Nakanishi, Nagayasu; Hensley, Nicholai M; Hartenstein, Volker; Jacobs, David K

2016-11-01

The moon jellyfish Aurelia exhibits a dramatic reorganization of tissue during its metamorphosis from planula larva to polyp. There are currently two competing hypotheses regarding the fate of embryonic germ layers during this metamorphosis. In one scenario, the original endoderm undergoes apoptosis and is replaced by a secondary endoderm derived from ectodermal cells. In the second scenario, both ectoderm and endoderm remain intact through development. In this study, we performed a pulse-chase experiment to trace the fate of larval ectodermal cells. We observed that prior to metamorphosis, ectodermal cells that proliferated early in larval development concentrate at the future oral end of the polyp. During metamorphosis, these cells migrate into the endoderm, extending all the way to the aboral portion of the gut. We therefore reject the hypothesis that larval endoderm remains intact during metamorphosis and provide additional support for the "secondary gastrulation" hypothesis. Aurelia appears to offer the first and only described case where a cnidarian derives its endoderm twice during normal development, adding to a growing body of evidence that germ layers can be dramatically reorganized in cnidarian life cycles.

Self-organization of neural tissue architectures from pluripotent stem cells.

PubMed

Karus, Michael; Blaess, Sandra; Brüstle, Oliver

2014-08-15

Despite being a subject of intensive research, the mechanisms underlying the formation of neural tissue architectures during development of the central nervous system remain largely enigmatic. So far, studies into neural pattern formation have been restricted mainly to animal experiments. With the advent of pluripotent stem cells it has become possible to explore early steps of nervous system development in vitro. These studies have unraveled a remarkable propensity of primitive neural cells to self-organize into primitive patterns such as neural tube-like rosettes in vitro. Data from more advanced 3D culture systems indicate that this intrinsic propensity for self-organization can even extend to the formation of complex architectures such as a multilayered cortical neuroepithelium or an entire optic cup. These novel experimental paradigms not only demonstrate the enormous self-organization capacity of neural stem cells, they also provide exciting prospects for studying the earliest steps of human neural tissue development and the pathogenesis of brain malformations in reductionist in vitro paradigms. © 2014 Wiley Periodicals, Inc.

A Splice Defect in the EDA Gene in Dogs with an X-Linked Hypohidrotic Ectodermal Dysplasia (XLHED) Phenotype.

PubMed

Waluk, Dominik P; Zur, Gila; Kaufmann, Ronnie; Welle, Monika M; Jagannathan, Vidhya; Drögemüller, Cord; Müller, Eliane J; Leeb, Tosso; Galichet, Arnaud

2016-09-08

X-linked hypohidrotic ectodermal dysplasia (XLHED) caused by variants in the EDA gene represents the most common ectodermal dysplasia in humans. We investigated three male mixed-breed dogs with an ectodermal dysplasia phenotype characterized by marked hypotrichosis and multifocal complete alopecia, almost complete absence of sweat and sebaceous glands, and altered dentition with missing and abnormally shaped teeth. Analysis of SNP chip genotypes and whole genome sequence data from the three affected dogs revealed that the affected dogs shared the same haplotype on a large segment of the X-chromosome, including the EDA gene. Unexpectedly, the whole genome sequence data did not reveal any nonsynonymous EDA variant in the affected dogs. We therefore performed an RNA-seq experiment on skin biopsies to search for changes in the transcriptome. This analysis revealed that the EDA transcript in the affected dogs lacked 103 nucleotides encoded by exon 2. We speculate that this exon skipping is caused by a genetic variant located in one of the large introns flanking this exon, which was missed by whole genome sequencing with the illumina short read technology. The altered EDA transcript splicing most likely causes the observed ectodermal dysplasia in the affected dogs. These dogs thus offer an excellent opportunity to gain insights into the complex splicing processes required for expression of the EDA gene, and other genes with large introns. Copyright © 2016 Waluk et al.

Genotype-phenotype correlation in boys with X-linked hypohidrotic ectodermal dysplasia.

PubMed

Burger, Kristin; Schneider, Anne-Theres; Wohlfart, Sigrun; Kiesewetter, Franklin; Huttner, Kenneth; Johnson, Ramsey; Schneider, Holm

2014-10-01

X-linked hypohidrotic ectodermal dysplasia (XLHED), the most frequent form of ectodermal dysplasia, is a genetic disorder of ectoderm development characterized by malformation of multiple ectodermal structures such as skin, hair, sweat and sebaceous glands, and teeth. The disease is caused by a broad spectrum of mutations in the gene EDA. Although XLHED symptoms show inter-familial and intra-familial variability, genotype-phenotype correlation has been demonstrated with respect to sweat gland function. In this study, we investigated to which extent the EDA genotype correlates with the severity of XLHED-related skin and hair signs. Nineteen male children with XLHED (age range 3-14 years) and seven controls (aged 6-14 years) were examined by confocal microscopy of the skin, quantification of pilocarpine-induced sweating, semi-quantitative evaluation of full facial photographs with respect to XLHED-related skin issues, and phototrichogram analysis. All eight boys with known hypomorphic EDA mutations were able to produce at least some sweat and showed less severe cutaneous signs of XLHED than the anhidrotic XLHED patients (e.g., perioral and periorbital eczema or hyperpigmentation, regional hyperkeratosis, characteristic wrinkles under the eyes). As expected, individuals with XLHED had significantly less and thinner hair than healthy controls. However, there were also significant differences in hair number, diameter, and other hair characteristics between the group with hypomorphic EDA mutations and the anhidrotic patients. In summary, this study indicated a remarkable genotype-phenotype correlation of skin and hair findings in prepubescent males with XLHED. © 2014 Wiley Periodicals, Inc.

Natural and Artificial Intelligence, Language, Consciousness, Emotion, and Anticipation

NASA Astrophysics Data System (ADS)

Dubois, Daniel M.

2010-11-01

The classical paradigm of the neural brain as the seat of human natural intelligence is too restrictive. This paper defends the idea that the neural ectoderm is the actual brain, based on the development of the human embryo. Indeed, the neural ectoderm includes the neural crest, given by pigment cells in the skin and ganglia of the autonomic nervous system, and the neural tube, given by the brain, the spinal cord, and motor neurons. So the brain is completely integrated in the ectoderm, and cannot work alone. The paper presents fundamental properties of the brain as follows. Firstly, Paul D. MacLean proposed the triune human brain, which consists to three brains in one, following the species evolution, given by the reptilian complex, the limbic system, and the neo-cortex. Secondly, the consciousness and conscious awareness are analysed. Thirdly, the anticipatory unconscious free will and conscious free veto are described in agreement with the experiments of Benjamin Libet. Fourthly, the main section explains the development of the human embryo and shows that the neural ectoderm is the whole neural brain. Fifthly, a conjecture is proposed that the neural brain is completely programmed with scripts written in biological low-level and high-level languages, in a manner similar to the programmed cells by the genetic code. Finally, it is concluded that the proposition of the neural ectoderm as the whole neural brain is a breakthrough in the understanding of the natural intelligence, and also in the future design of robots with artificial intelligence.

Regulation of scapula development.

PubMed

Huang, Ruijin; Christ, Bodo; Patel, Ketan

2006-12-01

The scapula is a component of the shoulder girdle. Its structure has changed greatly during evolution. For example, in humans it is a large quite flat triangular bone whereas in chicks it is a long blade like structure. In this review we describe the mechanisms that control the formation of the scapula. To assimilate our understanding regarding the development of the scapula blade we start by addressing the issue concerning the origin of the scapula. Experiments using somite extirpation, chick-quail cell marking system and genetic cell labelling techniques in a variety of species have suggested that the scapula had its origin in the somites. For example we have shown in the chick that the scapula blade originates from the somite, while the cranial part, which articulates with the upper limb, is derived from the somatopleure of the forelimb field. In the second and third part of the review we discuss the compartmental origin of this bone and the signalling molecules that control the scapula development. It is very interesting that the scapula blade originates from the dorsal compartment, dermomyotome, which has been previously been associated as a source of muscle and dermis, but not of cartilage. Thus, the development of the scapula blade can be considered a case of dermomyotomal chondrogenesis. Our results show that the dermomyotomal chondrogenesis differ from the sclerotomal chondrogenesis. Firstly, the scapula precursors are located in the hypaxial domain of the dermomyotome, from which the hypaxial muscles are derived. The fate of the scapula precursors, like the hypaxial muscle, is controlled by ectoderm-derived signals and BMPs from the lateral plate mesoderm. Ectoderm ablation and inhibition of BMP activity interfers the scapula-specific Pax1 expression and scapula blade formation. However, only somite cells in the cervicothoracic transition region appear to be committed to form scapula. This indicates that the intrinsic segment specific information determines the scapula forming competence of the somite cells. Taken together, we conclude that the scapula forming cells located within the hypaxial somitic domain require BMP signals derived from the somatopleure and as yet unidentified signals from ectoderm for activation of their coded intrinsic segment specific chondrogenic programme. In the last part we discuss the new data that provides evidence that neural crest contributes for the development of the scapula.

Initiation of olfactory placode development and neurogenesis is blocked in mice lacking both Six1 and Six4.

PubMed

Chen, Binglai; Kim, Eun-Hee; Xu, Pin-Xian

2009-02-01

Mouse olfactory epithelium (OE) originates from ectodermally derived placode, the olfactory placode that arises at the anterior end of the neural plate. Tissue grafting and recombination experiments suggest that the placode is derived from a common preplacodal domain around the neural plate and its development is directed by signals arising from the underlying mesoderm and adjacent neuroectoderm. In mice, loss of Six1 affects OE morphogenesis but not placode formation. We show here that embryos lacking both Six1 and Six4 failed to form the olfactory placode but the preplacodal region appeared to be specified as judged by the expression of Eya2, which marks the common preplacodal domain, suggesting a synergistic requirement of Six1 and Six4 in patterning the preplacodal ectoderm to a morphologic placode. Our results show that Six1 and Six4 are coexpressed in the preplacodal ectoderm from E8.0. In the olfactory pit, Six4 expression was observed in the peripheral precursors that overlap with Mash1-expressing cells, the early committed neuronal lineage. In contrast, Six1 is highly distributed in the peripheral regions where stem cells reside at E10.5 and it overlaps with Sox2 expression. Both genes are expressed in the basal and apical neuronal progenitors in the OE. Analyses of Six1;Six4 double mutant embryos demonstrated that the slightly thickened epithelium observed in the mutant was not induced for neuronal development. In contrast, in Six1(-/-) embryos, all neuronal lineage markers were initially expressed but the pattern of their expression was altered. Although very few, the pioneer neurons were initially present in the Six1 mutant OE. However, neurogenesis ceased by E12.5 due to markedly increased cell apoptosis and reduced proliferation, thus defining the cellular defects occurring in Six1(-/-) OE that have not been previously observed. Our findings demonstrate that Six1/4 function at the top of early events controlling olfactory placode formation and neuronal development. Our analyses show that the threshold of Six1/4 may be crucial for the expression of olfactory specific genes and that Six1 and Six4 may act synergistically to mediate olfactory placode specification and patterning through Fgf and Bmp signaling pathways.

Friend of GATA (FOG) Interacts with the Nucleosome Remodeling and Deacetylase Complex (NuRD) to Support Primitive Erythropoiesis in Xenopus laevis

PubMed Central

Mimoto, Mizuho S.; Christian, Jan L.

2012-01-01

Friend of GATA (FOG) plays many diverse roles in adult and embryonic hematopoiesis, however the mechanisms by which it functions and the roles of potential interaction partners are not completely understood. Previous work has shown that overexpression of FOG in Xenopus laevis causes loss of blood suggesting that in contrast to its role in mammals, FOG might normally function to repress erythropoiesis in this species. Using loss-of-function analysis, we demonstrate that FOG is essential to support primitive red blood cell (RBC) development in Xenopus. Moreover, we show that it is specifically required to prevent excess apoptosis of circulating primitive RBCs and that in the absence of FOG, the pro-apoptotic gene Bim-1 is strongly upregulated. To identify domains of FOG that are essential for blood development and, conversely, to begin to understand the mechanism by which overexpressed FOG represses primitive erythropoiesis, we asked whether FOG mutants that are unable to interact with known co-factors retain their ability to rescue blood formation in FOG morphants and whether they repress erythropoiesis when overexpressed in wild type embryos. We find that interaction of FOG with the Nucleosome Remodeling and Deacetylase complex (NuRD), but not with C-terminal Binding Protein, is essential for normal primitive RBC development. In contrast, overexpression of all mutant and wild type constructs causes a comparable repression of primitive erythropoiesis. Together, our data suggest that a requirement for FOG and its interaction with NuRD during primitive erythropoiesis are conserved in Xenopus and that loss of blood upon FOG overexpression is due to a dominant-interfering effect. PMID:22235346

Ectodysplasin signalling deficiency in mouse models of hypohidrotic ectodermal dysplasia leads to middle ear and nasal pathology

PubMed Central

Azar, Ali; Piccinelli, Chiara; Brown, Helen; Headon, Denis; Cheeseman, Michael

2016-01-01

Hypohidrotic ectodermal dysplasia (HED) results from mutation of the EDA, EDAR or EDARADD genes and is characterized by reduced or absent eccrine sweat glands, hair follicles and teeth, and defective formation of salivary, mammary and craniofacial glands. Mouse models with HED also carry Eda, Edar or Edaradd mutations and have defects that map to the same structures. Patients with HED have ear, nose and throat disease, but this has not been investigated in mice bearing comparable genetic mutations. We report that otitis media, rhinitis and nasopharyngitis occur at high frequency in Eda and Edar mutant mice and explore the pathogenic mechanisms related to glandular function, microbial and immune parameters in these lines. Nasopharynx auditory tube glands fail to develop in HED mutant mice and the functional implications include loss of lysozyme secretion, reduced mucociliary clearance and overgrowth of nasal commensal bacteria accompanied by neutrophil exudation. Heavy nasopharynx foreign body load and loss of gland protection alters the auditory tube gating function and the auditory tubes can become pathologically dilated. Accumulation of large foreign body particles in the bulla stimulates granuloma formation. Analysis of immune cell populations and myeloid cell function shows no evidence of overt immune deficiency in HED mutant mice. Our findings using HED mutant mice as a model for the human condition support the idea that ear and nose pathology in HED patients arises as a result of nasal and nasopharyngeal gland deficits, reduced mucociliary clearance and impaired auditory tube gating function underlies the pathological sequelae in the bulla. PMID:27378689

PubMed Central

Wahlbuhl-Becker, Mandy; Faschingbauer, Florian; Beckmann, Matthias W.; Schneider, Holm

2017-01-01

Background X-linked hypohidrotic ectodermal dysplasia (XLHED), the most common form of ectodermal dysplasia, is caused by mutations in the gene EDA. While only affected men develop the full-blown clinical picture, females who are heterozygous for an EDA mutation often also show symptoms such as hypodontia, hypotrichosis and hypohidrosis. These women may also suffer from malformations of the mammary gland which represent not just a cosmetic problem but can limit their breastfeeding capability. This paper summarizes the findings of the first systematic study on the impact of hypohidrotic ectodermal dysplasia on breastfeeding. Patients Thirty-eight adult female members of the German-Swiss-Austrian ectodermal dysplasia patient support group participated in a structured interview; most of them also agreed to a photodocumentation of their mammary region. Thirty-one women carried mutations in EDA (Group A) and seven were affected by other forms of hypohidrotic ectodermal dysplasia (Group B). Results 39 % of the women of Group A reported that their breasts were of different size or entirely absent on one side. In Group B, 86 % of the women reported differently sized or even absent breasts; two of these women lacked both breasts entirely. Most women described their nipples as exceptionally flat. 10 % of the women of Group A had more than two nipples. The high percentage of deviations from the norm was confirmed in the photodocumentation. Both groups had few or no sebaceous glands of Montgomery in the areolar region. Around 80 % of interviewed women had children and had attempted to breastfeed their first child. 67 % of the mothers in Group A had had difficulty in breastfeeding their infants and generally attributed this difficulty to their flat nipples. All of the mothers in Group B reported difficulties in breastfeeding; 60 % had not been able to breastfeed their first child. Conclusion Mothers with hypohidrotic ectodermal dysplasia very often have difficulty in breastfeeding because of their impaired breast development. This causal relationship needs to be taken into account in lactation counseling. PMID:28553001

The canonical Wnt signaling activator, R-spondin2, regulates craniofacial patterning and morphogenesis within the branchial arch through ectodermal-mesenchymal interaction

PubMed Central

Jin, Yong-Ri; Turcotte, Taryn J.; Crocker, Alison L.; Han, Xiang Hua; Yoon, Jeong Kyo

2011-01-01

R-spondins are a recently characterized family of secreted proteins that activate Wnt/β-catenin signaling. Herein, we determine R-spondin2 (Rspo2) function in craniofacial development in mice. Mice lacking a functional Rspo2 gene exhibit craniofacial abnormalities such as mandibular hypoplasia, maxillary and mandibular skeletal deformation, and cleft palate. We found that loss of the mouse Rspo2 gene significantly disrupted Wnt/β-catenin signaling and gene expression within the first branchial arch (BA1). Rspo2, which is normally expressed in BA1 mesenchymal cells, regulates gene expression through a unique ectoderm-mesenchyme interaction loop. The Rspo2 protein, potentially in combination with ectoderm-derived Wnt ligands, up-regulates Msx1 and Msx2 expression within mesenchymal cells. In contrast, Rspo2 regulates expression of the Dlx5, Dlx6, and Hand2 genes in mesenchymal cells via inducing expression of their upstream activator, Endothelin1 (Edn1), within ectodermal cells. Loss of Rspo2 also causes increased cell apoptosis, especially within the aboral (or caudal) domain of the BA1, resulting in hypoplasia of the BA1. Severely reduced expression of Fgf8, a survival factor for mesenchymal cells, in the ectoderm of Rspo2−/− embryos is likely responsible for increased cell apoptosis. Additionally, we found that cleft palate in Rspo2−/− mice is not associated with defects intrinsic to the palatal shelves. A possible cause of cleft palate is a delay of proper palatal shelf elevation that may result from the small mandible and a failure of lowering the tongue. Thus, our study identifies Rspo2 as a mesenchyme-derived factor that plays critical roles in regulating BA1 patterning and morphogenesis through ectodermal-mesenchymal interaction and a novel genetic factor for cleft palate. PMID:21237142

Regional differences in BMP-dependence of dorsoventral patterning in the leech Helobdella.

PubMed

Kuo, Dian-Han; Shankland, Marty; Weisblat, David A

2012-08-01

In the leech Helobdella, the ectoderm exhibits a high degree of morphological homonomy between body segments, but pattern elements in lateral ectoderm arise via distinct cell lineages in the segments of the rostral and midbody regions. In each of the four rostral segments, a complete set of ventrolateral (O fate) and dorsolateral (P fate) ectodermal pattern elements arises from a single founder cell, op. In the 28 midbody and caudal segments, however, there are two initially indeterminate o/p founder cells; the more dorsal of these is induced to adopt the P fate by BMP5-8 emanating from the dorsalmost ectoderm, while the more ventral cell assumes the O fate. Previous work has suggested that the dorsoventral patterning of O and P fates differs in the rostral region, but the role of BMP signaling in those segments has not been investigated. We show here that suppression of dorsal BMP5-8 signaling (which effects a P-to-O fate change in the midbody) has no effect on the patterning of O and P fates in the rostral region. Furthermore, ectopic expression of BMP5-8 in the ventral ectoderm (which induces an O-to-P fate change in the midbody) has no effect in the rostral region. Finally, expression of a dominant-negative BMP receptor (which induces a P-to-O fate change in the midbody) fails to affect O/P patterning in the rostral region. Thus, the rostral segments appear to use some mechanism other than BMP signaling to pattern O and P cell fates along the dorsoventral axis. From a mechanistic standpoint, the OP lineage of the rostral segments and the O-P equivalence group of the midbody and caudal segments constitute distinct developmental modules that rely to differing degrees on positional cues from surrounding ectoderm in order to specify homonomous cell fates. Copyright © 2012 Elsevier Inc. All rights reserved.

Limited hair cell induction from human induced pluripotent stem cells using a simple stepwise method.

PubMed

Ohnishi, Hiroe; Skerleva, Desislava; Kitajiri, Shin-ichiro; Sakamoto, Tatsunori; Yamamoto, Norio; Ito, Juichi; Nakagawa, Takayuki

2015-07-10

Disease-specific induced pluripotent stem cells (iPS) cells are expected to contribute to exploring useful tools for studying the pathophysiology of inner ear diseases and to drug discovery for treating inner ear diseases. For this purpose, stable induction methods for the differentiation of human iPS cells into inner ear hair cells are required. In the present study, we examined the efficacy of a simple induction method for inducing the differentiation of human iPS cells into hair cells. The induction of inner ear hair cell-like cells was performed using a stepwise method mimicking inner ear development. Human iPS cells were sequentially transformed into the preplacodal ectoderm, otic placode, and hair cell-like cells. As a first step, preplacodal ectoderm induction, human iPS cells were seeded on a Matrigel-coated plate and cultured in a serum free N2/B27 medium for 8 days according to a previous study that demonstrated spontaneous differentiation of human ES cells into the preplacodal ectoderm. As the second step, the cells after preplacodal ectoderm induction were treated with basic fibroblast growth factor (bFGF) for induction of differentiation into otic-placode-like cells for 15 days. As the final step, cultured cells were incubated in a serum free medium containing Matrigel for 48 days. After preplacodal ectoderm induction, over 90% of cultured cells expressed the genes that express in preplacodal ectoderm. By culture with bFGF, otic placode marker-positive cells were obtained, although their number was limited. Further 48-day culture in serum free media resulted in the induction of hair cell-like cells, which expressed a hair cell marker and had stereocilia bundle-like constructions on their apical surface. Our results indicate that hair cell-like cells are induced from human iPS cells using a simple stepwise method with only bFGF, without the use of xenogeneic cells. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Morphogenesis and evolution of vertebrate appendicular muscle

PubMed Central

HAINES, LYNN; CURRIE, PETER D.

2001-01-01

Two different modes are utilised by vertebrate species to generate the appendicular muscle present within fins and limbs. Primitive Chondricthyan or cartilaginous fishes use a primitive mode of muscle formation to generate the muscle of the fins. Direct epithelial myotomal extensions invade the fin and generate the fin muscles while remaining in contact with the myotome. Embryos of amniotes such as chick and mouse use a similar mechanism to that deployed in the bony teleost species, zebrafish. Migratory mesenchymal myoblasts delaminate from fin/limb level somites, migrate to the fin/limb field and differentiate entirely within the context of the fin/limb bud. Migratory fin and limb myoblasts express identical genes suggesting that they possess both morphogenetic and molecular identity. We conclude that the mechanisms controlling tetrapod limb muscle formation arose prior to the Sarcopterygian or tetrapod radiation. PMID:11523824

Experimental studies of nucleation and growth processes related to the formation of presolar grains

NASA Technical Reports Server (NTRS)

Berg, Otto E.

1992-01-01

An understanding was sought for the mechanisms of nucleation of refractory materials, and the relative importance of factors controlling the rate of cluster formation and growth for astrophysically important species. The structure and composition of the condensates is being studied, with the goal of characterizing the grains present in the primitive solar nebula.

Growth, nutritional, and gastrointestinal aspects of ankyloblepharon-ectodermal defect-cleft lip and/or palate (AEC) syndrome

USDA-ARS?s Scientific Manuscript database

Ankyloblepharon-ectodermal defect-cleft lip and/or palate (AEC), is a rare genetic disorder due to mutations in the TP63 gene. In the present study, we characterized the pattern of growth and body composition, and the nutritional and gastrointestinal aspects of children and adults (n = 18) affected ...

An unusual case of ectodermal dysplasia: combating senile features at an early age

PubMed Central

Gupta, Mudit; Sundaresh, Kumbar Jayadevappa; Batra, Manu; Rathva, Vandana J

2014-01-01

Ectodermal dysplasia (ED) refers to a group of inherited diseases that have developmental defects in at least two major structures derived from the ectoderm, that is, hair, teeth, nails and sweat glands. Although more than 192 distinct disorders have been described, the most common is X-linked recessive hypohidrotic ED (Christ-Siemens-Touraine syndrome). Since such patients usually presents with missing teeth, dentists are usually the first person to diagnose such cases. Diagnosis of such cases is important because absence of sweat glands can lead to hyperthermia which can be life-threatening if proper care is not taken. Through this manuscript, we report a case of anhidrotic ED affecting deciduous and permanent dentition, which is rare. PMID:24493109

Ocular and non-ocular manifestations of hypohidrotic ectodermal dysplasia

PubMed Central

Tyagi, Pallavi; Tyagi, Vipin; Hashim, Adnan A

2011-01-01

Hypohidrotic ectodermal dysplasia (HED) is a group of rare multisystemic genetic syndromes that affects ectodermal structures such as skin, hair, nails, teeth and sweat glands. The authors present a case of a child with ocular and dermatological signs of HED along with severe involvement of other multiple organ systems. The family history could be traced to four generations and there was an observed trend of increase in severity of signs and symptoms occurring at younger age. The purpose of this case report is to create awareness in ophthalmic community of its diagnosis and clinical manifestations. This case highlights the role of multidisciplinary approach for management of systemic disease, genetic evaluation of affected individuals and carriers and genetic counselling. PMID:22700604

Blue Cell Tumour at Unusual Site: Retropritoneal Ewings Sarcoma.

PubMed

Javalgi, Anita P; Karigoudar, Mahesh H; Palur, Katyayani

2016-04-01

Ewing's sarcoma is a highly malignant tumour of osseous or non-osseous origin, tremed as extra-skeletal Ewings sarcoma if arising from soft tissue. It is rare occurrence tumor most commonly occurring in paravertebral area, chest wall, head & neck and retroperitoneum. Reporting an interesting case of retroperitoneal Ewing's sarcoma in 39 years old female. Patient had complains of abdominal discomfort & vague pain since 2 months, following weakness in lower limb and loss of weight. On detail history and examination she was further referred to detail pathological and radiological investigations. Haematological profile, renal function test and liver function test were in normal limits. USG abdomen was normal, MRI showed a mass in pelvis retroperitoneum measuring 10x10cms, bilateral ovaries and tubes were normal. Because of retroperitoneal nature of tumor and suspicion of uterine sarcoma, laparotomy was performed. The large retroperitoneal mass adherent to posterior of uterus was excised and send for histopathological diagnosis. On gross and microscopy examination the diagnosis of blue cell tumor with PAS positivity, possibility of extraskeletal Ewing's sarcoma/primitive neuro-ectodermal tumor was made which was further confirmed by immunohistochemistry, positive for S100, Vementin and CD99 and negative for desmin and CK. Confirmed diagnosis help in accurate management and improves survival rate.

Regional primitive equation modeling and analysis of the polymode data set

NASA Astrophysics Data System (ADS)

Spall, Michael A.

A regional, hybrid coordinate, primitive equation (PE) model is applied to a 60-day period of the POLYMODE data set. The initialization techniques and open boundary conditions introduced by Spall and Robinson are shown to produce stable, realistic, and reasonably accurate hindcasts for the 2-month data set. Comparisons with quasi-geostrophic (QG) modeling studies indicate that the PE model reproduced the jet formation that dominates the region more accurately than did the QG model. When the PE model used boundary conditions that were partially adjusted by the QG model, the resulting fields were very similar to the QG fields, indicating a rapid degradation of small-scale features near the boundaries in the QG calculation. A local term-by-term primitive equation energy and vorticity analysis package is also introduced. The full vorticity, horizontal divergence, kinetic energy, and available gravitational energy equations are solved diagnostically from the output of the regional PE model. Through the analysis of a time series of horizontal maps, the dominant processes in the flow are illustrated. The individual terms are also integrated over the region of jet formation to highlight the net balances as a function of time. The formation of the deep thermocline jet is shown to be due to horizontal advection through the boundary, baroclinic conversion in the deep thermocline and vertical pressure work, which exports the deep energy to the upper thermocline levels. It is concluded here that the PE model reproduces the observed jet formation better than the QG model because of the increased horizontal advection and stronger vertical pressure work. Although the PE model is shown to be superior to the QG model in this application, it is believed that both PE and QG models can play an important role in the regional study of mid-ocean mesoscale eddies.

How the embryo makes a limb: determination, polarity and identity

PubMed Central

Tickle, Cheryll

2015-01-01

The vertebrate limb with its complex anatomy develops from a small bud of undifferentiated mesoderm cells encased in ectoderm. The bud has its own intrinsic polarity and can develop autonomously into a limb without reference to the rest of the embryo. In this review, recent advances are integrated with classical embryology, carried out mainly in chick embryos, to present an overview of how the embryo makes a limb bud. We will focus on how mesoderm cells in precise locations in the embryo become determined to form a limb and express the key transcription factors Tbx4 (leg/hindlimb) or Tbx5 (wing/forelimb). These Tbx transcription factors have equivalent functions in the control of bud formation by initiating a signalling cascade involving Wnts and fibroblast growth factors (FGFs) and by regulating recruitment of mesenchymal cells from the coelomic epithelium into the bud. The mesoderm that will form limb buds and the polarity of the buds is determined with respect to both antero-posterior and dorso-ventral axes of the body. The position in which a bud develops along the antero-posterior axis of the body will also determine its identity – wing/forelimb or leg/hindlimb. Hox gene activity, under the influence of retinoic acid signalling, is directly linked with the initiation of Tbx5 gene expression in the region along the antero-posterior axis of the body that will form wings/forelimbs and determines antero-posterior polarity of the buds. In contrast, Tbx4 expression in the regions that will form legs/hindlimbs is regulated by the homeoprotein Pitx1 and there is no evidence that Hox genes determine antero-posterior polarity of the buds. Bone morphogenetic protein (BMP) signalling determines the region along the dorso-ventral axis of the body in which both wings/forelimbs and legs/hindlimbs develop and dorso-ventral polarity of the buds. The polarity of the buds leads to the establishment of signalling regions – the dorsal and ventral ectoderm, producing Wnts and BMPs, respectively, the apical ectodermal ridge producing fibroblast growth factors and the polarizing region, Sonic hedgehog (Shh). These signals are the same in both wings/forelimbs and legs/hindlimbs and control growth and pattern formation by providing the mesoderm cells of the limb bud as it develops with positional information. The precise anatomy of the limb depends on the mesoderm cells in the developing bud interpreting positional information according to their identity – determined by Pitx1 in hindlimbs – and genotype. The competence to form a limb extends along the entire antero-posterior axis of the trunk – with Hox gene activity inhibiting the formation of forelimbs in the interlimb region – and also along the dorso-ventral axis. PMID:26249743

How the embryo makes a limb: determination, polarity and identity.

PubMed

Tickle, Cheryll

2015-10-01

The vertebrate limb with its complex anatomy develops from a small bud of undifferentiated mesoderm cells encased in ectoderm. The bud has its own intrinsic polarity and can develop autonomously into a limb without reference to the rest of the embryo. In this review, recent advances are integrated with classical embryology, carried out mainly in chick embryos, to present an overview of how the embryo makes a limb bud. We will focus on how mesoderm cells in precise locations in the embryo become determined to form a limb and express the key transcription factors Tbx4 (leg/hindlimb) or Tbx5 (wing/forelimb). These Tbx transcription factors have equivalent functions in the control of bud formation by initiating a signalling cascade involving Wnts and fibroblast growth factors (FGFs) and by regulating recruitment of mesenchymal cells from the coelomic epithelium into the bud. The mesoderm that will form limb buds and the polarity of the buds is determined with respect to both antero-posterior and dorso-ventral axes of the body. The position in which a bud develops along the antero-posterior axis of the body will also determine its identity - wing/forelimb or leg/hindlimb. Hox gene activity, under the influence of retinoic acid signalling, is directly linked with the initiation of Tbx5 gene expression in the region along the antero-posterior axis of the body that will form wings/forelimbs and determines antero-posterior polarity of the buds. In contrast, Tbx4 expression in the regions that will form legs/hindlimbs is regulated by the homeoprotein Pitx1 and there is no evidence that Hox genes determine antero-posterior polarity of the buds. Bone morphogenetic protein (BMP) signalling determines the region along the dorso-ventral axis of the body in which both wings/forelimbs and legs/hindlimbs develop and dorso-ventral polarity of the buds. The polarity of the buds leads to the establishment of signalling regions - the dorsal and ventral ectoderm, producing Wnts and BMPs, respectively, the apical ectodermal ridge producing fibroblast growth factors and the polarizing region, Sonic hedgehog (Shh). These signals are the same in both wings/forelimbs and legs/hindlimbs and control growth and pattern formation by providing the mesoderm cells of the limb bud as it develops with positional information. The precise anatomy of the limb depends on the mesoderm cells in the developing bud interpreting positional information according to their identity - determined by Pitx1 in hindlimbs - and genotype. The competence to form a limb extends along the entire antero-posterior axis of the trunk - with Hox gene activity inhibiting the formation of forelimbs in the interlimb region - and also along the dorso-ventral axis. © 2015 Anatomical Society.

The composition of the primitive atmosphere and the synthesis of organic compounds on the early Earth

NASA Technical Reports Server (NTRS)

Bada, J. L.; Miller, S. L.

1985-01-01

The generally accepted theory for the origin of life on the Earth requires that a large variety of organic compounds be present to form the first living organisms and to provide the energy sources for primitive life either directly or through various fermentation reactions. This can provide a strong constraint on discussions of the formation of the Earth and on the composition of the primitive atmosphere. In order for substantial amounts of organic compounds to have been present on the prebiological Earth, certain conditions must have existed. There is a large body of literature on the prebiotic synthesis of organic compounds in various postulated atmospheres. In this mixture of abiotically synthesized organic compounds, the amino acids are of special interest since they are utilized by modern organisms to synthesize structural materials and a large array of catalytic peptides.

Management of Severely Atrophic Maxilla in Ectrodactyly Ectodermal Dysplasia-cleft Syndrome.

PubMed

Rachmiel, Adi; Turgeman, Shahar; Emodi, Omri; Aizenbud, Dror; Shilo, Dekel

2018-02-01

Ectrodactyly ectodermal dysplasia-cleft syndrome is a rare genetic syndrome with an incidence of 1/90,000 live births, characterized by cleft lip and palate, severely hypoplastic maxilla, and hypodontia. Patients diagnosed with ectrodactyly ectodermal dysplasia-cleft syndrome suffer from a severely hypoplastic maxilla that is highly difficult to treat using traditional orthognathic methods. In this study, we propose using distraction osteogenesis to achieve a major advancement while maintaining good stability and minimal relapse. To our knowledge, this is the first description of patients with this syndrome treated using distraction osteogenesis. Five patients diagnosed with ectrodactyly ectodermal dysplasia-cleft syndrome were included in the study. All patients had been operated on according to the well-established protocol of cleft lip and palate reconstruction before maxillary distraction osteogenesis. Hard and soft-tissue changes were evaluated by cone beam computed tomography and lateral cephalograms before distraction osteogenesis (T1), at the postdistraction point (T2) and after 1 year of follow-up (T3). Examination revealed marked maxillary advancement in all our patients with a significant mean difference in hard tissue parameters (condylion to A point = 18 mm; nasion-sella line to A point = 15.2 degrees) and a notable improvement in facial convexity (20.9 degrees). One year follow-up measurements demonstrated mild relapse rates of 6% in the horizontal plane. We conclude that despite the challenging anatomic and physiological features of ectrodactyly ectodermal dysplasia-cleft patients, by enhancing current surgical techniques, there is promising potential for improved patient outcomes, achieving normognathic facial appearance with implant supported rehabilitation.

Major regulatory factors in the evolution of development: the roles of goosecoid and Msx in the evolution of the direct-developing sea urchin Heliocidaris erythrogramma.

PubMed

Wilson, Keen A; Andrews, Mary E; Rudolf Turner, F; Raff, Rudolf A

2005-01-01

The transcription factors Gsc and Msx are expressed in the oral ectoderm of the indirect-developing sea urchin Heliocidaris tuberculata. Their patterns of expression are highly modified in the direct developer Heliocidaris erythrogramma, which lacks an oral ectoderm. We here test the hypothesis that they are large effect genes responsible for the loss of the oral ectoderm module in the direct-developing larva of H. erythrogramma as well as for the restoration of an overt oral ectoderm in H.e. xH.t. hybrids. We undertook misexpression/overexpression and knockdown assays in the two species and in hybrids by mRNA injection. The results indicate that dramatic changes of function of these transcription factors has occurred. One of these genes, Gsc, has the ability when misexpressed to partially restore oral ectoderm in H. erythrogramma. On the other hand, Msx has lost any oral function and instead has a role in mesoderm proliferation and patterning. In addition, we found that the H. tuberculataGsc is up regulated in H.e. xH.t. hybrids, showing a preferential use of the indirect developing parental gene in the development of the hybrid. We suggest that Gsc qualifies as a gene of large evolutionary effect and is partially responsible for the evolution of direct development of H. erythrogramma. We discuss these results in light of modularity and genetic networks in development, as well as in their implications for the rapid evolution of large morphological changes in development.

Management of Severely Atrophic Maxilla in Ectrodactyly Ectodermal Dysplasia-cleft Syndrome

PubMed Central

Rachmiel, Adi; Emodi, Omri; Aizenbud, Dror; Shilo, Dekel

2018-01-01

Background: Ectrodactyly ectodermal dysplasia-cleft syndrome is a rare genetic syndrome with an incidence of 1/90,000 live births, characterized by cleft lip and palate, severely hypoplastic maxilla, and hypodontia. Patients diagnosed with ectrodactyly ectodermal dysplasia-cleft syndrome suffer from a severely hypoplastic maxilla that is highly difficult to treat using traditional orthognathic methods. In this study, we propose using distraction osteogenesis to achieve a major advancement while maintaining good stability and minimal relapse. To our knowledge, this is the first description of patients with this syndrome treated using distraction osteogenesis. Methods: Five patients diagnosed with ectrodactyly ectodermal dysplasia-cleft syndrome were included in the study. All patients had been operated on according to the well-established protocol of cleft lip and palate reconstruction before maxillary distraction osteogenesis. Hard and soft-tissue changes were evaluated by cone beam computed tomography and lateral cephalograms before distraction osteogenesis (T1), at the postdistraction point (T2) and after 1 year of follow-up (T3). Results: Examination revealed marked maxillary advancement in all our patients with a significant mean difference in hard tissue parameters (condylion to A point = 18 mm; nasion-sella line to A point = 15.2 degrees) and a notable improvement in facial convexity (20.9 degrees). One year follow-up measurements demonstrated mild relapse rates of 6% in the horizontal plane. Conclusions: We conclude that despite the challenging anatomic and physiological features of ectrodactyly ectodermal dysplasia-cleft patients, by enhancing current surgical techniques, there is promising potential for improved patient outcomes, achieving normognathic facial appearance with implant supported rehabilitation. PMID:29616174

Dust formation in a galaxy with primitive abundances.

PubMed

Sloan, G C; Matsuura, M; Zijlstra, A A; Lagadec, E; Groenewegen, M A T; Wood, P R; Szyszka, C; Bernard-Salas, J; van Loon, J Th

2009-01-16

Interstellar dust plays a crucial role in the evolution of galaxies. It governs the chemistry and physics of the interstellar medium. In the local universe, dust forms primarily in the ejecta from stars, but its composition and origin in galaxies at very early times remain controversial. We report observational evidence of dust forming around a carbon star in a nearby galaxy with a low abundance of heavy elements, 25 times lower than the solar abundance. The production of dust by a carbon star in a galaxy with such primitive abundances raises the possibility that carbon stars contributed carbonaceous dust in the early universe.

Local bone marrow renin-angiotensin system in primitive, definitive and neoplastic haematopoiesis.

PubMed

Haznedaroglu, Ibrahim C; Beyazit, Yavuz

2013-03-01

The locally active ligand peptides, mediators, receptors and signalling pathways of the haematopoietic BM (bone marrow) autocrine/paracrine RAS (renin-angiotensin system) affect the essential steps of definitive blood cell production. Haematopoiesis, erythropoiesis, myelopoiesis, formation of monocytic and lymphocytic lineages, thrombopoiesis and other stromal cellular elements are regulated by the local BM RAS. The local BM RAS is present and active even in primitive embryonic haematopoiesis. ACE (angiotensin-converting enzyme) is expressed on the surface of the first endothelial and haematopoietic cells, forming the marrow cavity in the embryo. ACE marks early haematopoietic precursor cells and long-term blood-forming CD34(+) BM cells. The local autocrine tissue BM RAS may also be active in neoplastic haematopoiesis. Critical RAS mediators such as renin, ACE, AngII (angiotensin II) and angiotensinogen have been identified in leukaemic blast cells. The local tissue RAS influences tumour growth and metastases in an autocrine and paracrine fashion via the modulation of numerous carcinogenic events, such as angiogenesis, apoptosis, cellular proliferation, immune responses, cell signalling and extracellular matrix formation. The aim of the present review is to outline the known functions of the local BM RAS within the context of primitive, definitive and neoplastic haematopoiesis. Targeting the actions of local RAS molecules could represent a valuable therapeutic option for the management of neoplastic disorders.

Noninvasive Prenatal Diagnosis of Hypohidrotic Ectodermal Dysplasia by Tooth Germ Sonography.

PubMed

Wünsche, S; Jüngert, J; Faschingbauer, F; Mommsen, H; Goecke, T; Schwanitz, K; Stepan, H; Schneider, H

2015-08-01

Hypohidrotic ectodermal dysplasia, a potentially life-threatening heritable disorder, may be recognized already in utero by characteristic features such as oligodontia and mandibular hypoplasia. As therapeutic options and prognosis depend on the time point of diagnosis, early recognition was attempted during routine prenatal ultrasound examinations. Fetuses of nine pregnant women (one triplet and eight singleton pregnancies) with family histories of hypohidrotic ectodermal dysplasia were investigated by sonography between the 20th and 24th week of gestation. In 4 male and 2 female fetuses reduced amounts of tooth germs were detected, whereas 5 fetal subjects showed the normal amount. Three-dimensional ultrasound evaluation revealed mandibular hypoplasia in 5 of the 6 fetuses with oligodontia. Molecular genetic analysis and/or clinical findings after birth confirmed the prenatal sonographic diagnosis in each subject. In subjects with a family history of hypohidrotic ectodermal dysplasia, the diagnosis of this rare condition can be established noninvasively by sonography in the second trimester of pregnancy. Early recognition of the disorder may help to prevent dangerous hyperthermic episodes in infancy and may allow timely therapeutic interventions. © Georg Thieme Verlag KG Stuttgart · New York.

Molecular and Therapeutic Characterization of Anti-ectodysplasin A Receptor (EDAR) Agonist Monoclonal Antibodies*

PubMed Central

Kowalczyk, Christine; Dunkel, Nathalie; Willen, Laure; Casal, Margret L.; Mauldin, Elizabeth A.; Gaide, Olivier; Tardivel, Aubry; Badic, Giovanna; Etter, Anne-Lise; Favre, Manuel; Jefferson, Douglas M.; Headon, Denis J.; Demotz, Stéphane; Schneider, Pascal

2011-01-01

The TNF family ligand ectodysplasin A (EDA) and its receptor EDAR are required for proper development of skin appendages such as hair, teeth, and eccrine sweat glands. Loss of function mutations in the Eda gene cause X-linked hypohidrotic ectodermal dysplasia (XLHED), a condition that can be ameliorated in mice and dogs by timely administration of recombinant EDA. In this study, several agonist anti-EDAR monoclonal antibodies were generated that cross-react with the extracellular domains of human, dog, rat, mouse, and chicken EDAR. Their half-life in adult mice was about 11 days. They induced tail hair and sweat gland formation when administered to newborn EDA-deficient Tabby mice, with an EC50 of 0.1 to 0.7 mg/kg. Divalency was necessary and sufficient for this therapeutic activity. Only some antibodies were also agonists in an in vitro surrogate activity assay based on the activation of the apoptotic Fas pathway. Activity in this assay correlated with small dissociation constants. When administered in utero in mice or at birth in dogs, agonist antibodies reverted several ectodermal dysplasia features, including tooth morphology. These antibodies are therefore predicted to efficiently trigger EDAR signaling in many vertebrate species and will be particularly suited for long term treatments. PMID:21730053

β-Catenin is essential for patterning the maternally specified animal-vegetal axis in the sea urchin embryo

PubMed Central

Wikramanayake, Athula H.; Huang, Ling; Klein, William H.

1998-01-01

In sea urchin embryos, the animal-vegetal axis is specified during oogenesis. After fertilization, this axis is patterned to produce five distinct territories by the 60-cell stage. Territorial specification is thought to occur by a signal transduction cascade that is initiated by the large micromeres located at the vegetal pole. The molecular mechanisms that mediate the specification events along the animal–vegetal axis in sea urchin embryos are largely unknown. Nuclear β-catenin is seen in vegetal cells of the early embryo, suggesting that this protein plays a role in specifying vegetal cell fates. Here, we test this hypothesis and show that β-catenin is necessary for vegetal plate specification and is also sufficient for endoderm formation. In addition, we show that β-catenin has pronounced effects on animal blastomeres and is critical for specification of aboral ectoderm and for ectoderm patterning, presumably via a noncell-autonomous mechanism. These results support a model in which a Wnt-like signal released by vegetal cells patterns the early embryo along the animal–vegetal axis. Our results also reveal similarities between the sea urchin animal–vegetal axis and the vertebrate dorsal–ventral axis, suggesting that these axes share a common evolutionary origin. PMID:9689082

Formation of TiC-core, Graphitic-mantle Grains from CO Gas

NASA Technical Reports Server (NTRS)

Kimura, Yuki; Nuth, Joseph A., III; Ferguson, Frank T.

2005-01-01

We demonstrate a new formation route for TiC-core, graphitic-mantle spherules that does not require c-atom addition and the very long timescales associated with such growth (Bernatowicz et al. 1996). Carbonaceous materials can also be formed from C2H2 and its derivatives, as well as from CO gas. In this paper, we will demonstrate that large cage structure carbon particles can be produced from CO gas by the Boudouard reaction. Since the sublimation temperature for such fullerenes is low, the large cages can be deposited onto previously-nucleated TiC and produce TiC-core, graphitic-mantle spherules. New constraints for the formation conditions and the timescale for the formation of TiC-core, graphitic-mantle spherules are suggested by the results of this study. In particular, TiC-core, graphitic-mantle grains found in primitive meteorites that have never experienced hydration could be mantled by fullerenes or carbon nanotubes rather than by graphite. In situ observations of these grains in primitive anhydrous meteoritic matrix could confirm or refute this prediction and would demonstrate that the graphitic mantle on such grains is a metamorphic feature due to interaction of the pre-solar fullerenes with water within the meteorite matrix.

Using implants for prosthodontic rehabilitation of a 4-year-old with ectodermal dysplasia.

PubMed

Toomarian, Lida; Ardakani, Mohammad Reza Talebi; Ramezani, Jamileh; Adli, Amin Rezaei; Tabari, Zahra Alizadeh

2014-01-01

Ectodermal dysplasia (ED) is an inherited disorder that affects ectodermally derived organs, such as teeth. Pathogenesis is thought to involve an altered epithelium-mesenchymal interaction. ED patients have oligodontia (or sometimes anodontia) in addition to other abnormalities involving the skin, sweat glands, or hair. Many different subtypes have been introduced in the literature. This article describes the case of a 4-year-old patient who, after being diagnosed with ED, was put on a treatment plan that involved mandibular implants, reshaping of the maxillary primary central incisors, and prosthetic dental rehabilitation. Due to the child's rapid growth, both dentures were changed 9 months post-treatment. Two years post-treatment, the maxillary denture was changed again and the child was placed under close supervision.

Genitourinary malformations: an under-recognized feature of ectrodactyly, ectodermal dysplasia and cleft lip/palate syndrome.

PubMed

Hyder, Zerin; Beale, Victoria; O'Connor, Ruth; Clayton-Smith, Jill

2017-04-01

The ectodermal dysplasia and cleft lip/palate (EEC) syndrome describes the association of ectrodactyly, ectodermal dysplasia and orofacial clefting. As with many autosomal dominant disorders, there is variability in expression and not all of these three core features are present in every individual with the condition. Moreover, there may be additional associated features, which are under-recognized. One of these is the presence of genitourinary anomalies, some of which cause significant morbidity. This report details a further two patients with EEC syndrome and genitourinary involvement, including flaccid megacystis with detrusor muscle failure, bilateral hydronephrosis and megaureter, requiring significant renal and urological involvement during their childhood. We go on to review the literature on the diagnosis and management of genitourinary malformations in EEC syndrome.

A novel mutation in the EDAR gene causes severe autosomal recessive hypohidrotic ectodermal dysplasia.

PubMed

Henningsen, Emil; Svendsen, Mathias Tiedemann; Lildballe, Dorte Launholt; Jensen, Peter Kjestrup Axel

2014-08-01

We report on a 2-year-old girl presenting with a severe form of hypohidrotic ectodermal dysplasia (HED). The patient presented with hypotrichosis, anodontia, hypohidrosis, frontal bossing, prominent lips and ears, dry, pale skin, and dermatitis. The patient had chronic rhinitis with malodorous nasal discharge. The girl was the second born child of first-cousin immigrants from Northern Iraq. A novel homozygous mutation (c.84delC) in the EDAR gene was identified. This mutation most likely causes a frameshift in the protein product (p.S29fs*74). This results in abolition of all ectodysplasin-mediated NF-kB signalling. This complete loss-of-function mutation likely accounts for the severe clinical abnormalities in ectodermal structures in the described patient. © 2014 Wiley Periodicals, Inc.

Life on Earth: From Chemicals in Space?

ERIC Educational Resources Information Center

Chemical and Engineering News, 1973

1973-01-01

Discusses experimental evidence for the existence of organic material in the solar system prior to the earth's formation. Indicates that the earth could have received much of its organic compounds from meteors falling on its primitive surface. (CC)

Self assembly properties of primitive organic compounds

NASA Technical Reports Server (NTRS)

Deamer, D. W.

1991-01-01

A central event in the origin of life was the self-assembly of amphiphilic, lipid-like compounds into closed microenvironments. If a primitive macromolecular replicating system could be encapsulated within a vesicular membrane, the components of the system would share the same microenvironment, and the result would be a step toward true cellular function. The goal of our research has been to determine what amphiphilic molecules might plausibly have been available on the early Earth to participate in the formation of such boundary structures. To this end, we have investigated primitive organic mixtures present in carbonaceous meteorites such as the Murchison meteorite, which contains 1-2 percent of its mass in the form of organic carbon compounds. It is likely that such compounds contributed to the inventory of organic carbon on the prebiotic earth, and were available to participate in chemical evolution leading to the emergence of the first cellular life forms. We found that Murchison components extracted into non-polar solvent systems are surface active, a clear indication of amphiphilic character. One acidic fraction self-assembles into vesicular membranes that provide permeability barriers to polar solutes. Other evidence indicates that the membranes are bimolecular layers similar to those formed by contemporary membrane lipids. We conclude that bilayer membrane formation by primitive amphiphiles on the early Earth is feasible. However, only a minor fraction of acidic amphiphiles assembles into bilayers, and the resulting membranes require narrowly defined conditions of pH and ionic composition to be stable. It seems unlikely, therefore, that meteoritic infall was a direct source of membrane amphiphiles. Instead, the hydrocarbon components and their derivatives more probably would provide an organic stock available for chemical evolution. Our current research is directed at possible reactions which would generate substantial quantities of membranogenic amphiphiles. One possibility is photochemical oxidation of hydrocarbons.

Ectodermal dysplasias: A clinical classification and a causal review

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pinheiro, M.; Freire-Maia, N.

1994-11-01

The authors present a causal review of 154 ectodermal dysplasias (EDs) as classified into 11 clinical subgroups. The number of EDs in each subgroup varies from one to 43. The numbers of conditions due to autosomal dominant, autosomal recessive, and X-linked genes are, respectively, 41, 52, and 8. In 53 conditions cause is unknown; 35 of them present some causal (genetic) suggestion.

The autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome.

PubMed

LeBoeuf, Nicole; Garg, Amit; Worobec, Sophie

2007-01-01

The autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome is characterized by the presence of chronic mucocutaneous candidiasis, adrenal insufficiency, and hypoparathyroidism. Almost all patients have skin or nail findings early in the course of the disease. Therefore, the dermatologist is in the unique position of being able to identify patients with this syndrome early in its course and to facilitate careful monitoring of potentially lethal complications.

Cannabinoid receptor signaling in progenitor/stem cell proliferation and differentiation.

PubMed

Galve-Roperh, Ismael; Chiurchiù, Valerio; Díaz-Alonso, Javier; Bari, Monica; Guzmán, Manuel; Maccarrone, Mauro

2013-10-01

Cannabinoids, the active components of cannabis (Cannabis sativa) extracts, have attracted the attention of human civilizations for centuries, much earlier than the discovery and characterization of their substrate of action, the endocannabinoid system (ECS). The latter is an ensemble of endogenous lipids, their receptors [in particular type-1 (CB1) and type-2 (CB2) cannabinoid receptors] and metabolic enzymes. Cannabinoid signaling regulates cell proliferation, differentiation and survival, with different outcomes depending on the molecular targets and cellular context involved. Cannabinoid receptors are expressed and functional from the very early developmental stages, when they regulate embryonic and trophoblast stem cell survival and differentiation, and thus may affect the formation of manifold adult specialized tissues derived from the three different germ layers (ectoderm, mesoderm and endoderm). In the ectoderm-derived nervous system, both CB1 and CB2 receptors are present in neural progenitor/stem cells and control their self-renewal, proliferation and differentiation. CB1 and CB2 show opposite patterns of expression, the former increasing and the latter decreasing along neuronal differentiation. Recently, endocannabinoid (eCB) signaling has also been shown to regulate proliferation and differentiation of mesoderm-derived hematopoietic and mesenchymal stem cells, with a key role in determining the formation of several cell types in peripheral tissues, including blood cells, adipocytes, osteoblasts/osteoclasts and epithelial cells. Here, we will review these new findings, which unveil the involvement of eCB signaling in the regulation of progenitor/stem cell fate in the nervous system and in the periphery. The developmental regulation of cannabinoid receptor expression and cellular/subcellular localization, together with their role in progenitor/stem cell biology, may have important implications in human health and disease. Copyright © 2013 Elsevier Ltd. All rights reserved.

Evolution of Axis Specification Mechanisms in Jawed Vertebrates: Insights from a Chondrichthyan

PubMed Central

Coolen, Marion; Sauka-Spengler, Tatjana; Nicolle, Delphine; Le-Mentec, Chantal; Lallemand, Yvan; Silva, Corinne Da; Plouhinec, Jean-Louis; Robert, Benoît; Wincker, Patrick; Shi, De-Li; Mazan, Sylvie

2007-01-01

The genetic mechanisms that control the establishment of early polarities and their link with embryonic axis specification and patterning seem to substantially diverge across vertebrates. In amphibians and teleosts, the establishment of an early dorso-ventral polarity determines both the site of axis formation and its rostro-caudal orientation. In contrast, amniotes retain a considerable plasticity for their site of axis formation until blastula stages and rely on signals secreted by extraembryonic tissues, which have no clear equivalents in the former, for the establishment of their rostro-caudal pattern. The rationale for these differences remains unknown. Through detailed expression analyses of key development genes in a chondrichthyan, the dogfish Scyliorhinus canicula, we have reconstructed the ancestral pattern of axis specification in jawed vertebrates. We show that the dogfish displays compelling similarities with amniotes at blastula and early gastrula stages, including the presence of clear homologs of the hypoblast and extraembryonic ectoderm. In the ancestral state, these territories are specified at opposite poles of an early axis of bilateral symmetry, homologous to the dorso-ventral axis of amphibians or teleosts, and aligned with the later forming embryonic axis, from head to tail. Comparisons with amniotes suggest that a dorsal expansion of extraembryonic ectoderm, resulting in an apparently radial symmetry at late blastula stages, has taken place in their lineage. The synthesis of these results with those of functional analyses in model organisms supports an evolutionary link between the dorso-ventral polarity of amphibians and teleosts and the embryonic-extraembryonic organisation of amniotes. It leads to a general model of axis specification in gnathostomes, which provides a comparative framework for a reassessment of conservations both among vertebrates and with more distant metazoans. PMID:17440610

Prkci is required for a non-autonomous signal that coordinates cell polarity during cavitation.

PubMed

Mah, In Kyoung; Soloff, Rachel; Izuhara, Audrey K; Lakeland, Daniel L; Wang, Charles; Mariani, Francesca V

2016-08-01

Polarized epithelia define boundaries, spaces, and cavities within organisms. Cavitation, a process by which multicellular hollow balls or tubes are produced, is typically associated with the formation of organized epithelia. In order for these epithelial layers to form, cells must ultimately establish a distinct apical-basal polarity. Atypical PKCs have been proposed to be required for apical-basal polarity in diverse species. Here we show that while cells null for the Prkci isozyme exhibit some polarity characteristics, they fail to properly segregate apical-basal proteins, form a coordinated ectodermal epithelium, or participate in normal cavitation. A failure to cavitate could be due to an overgrowth of interior cells or to an inability of interior cells to die. Null cells however, do not have a marked change in proliferation rate and are still capable of undergoing cell death, suggesting that alterations in these processes are not the predominant cause of the failed cavitation. Overexpression of BMP4 or EZRIN can partially rescue the phenotype possibly by promoting cell death, polarity, and differentiation. However, neither is sufficient to provide the required cues to generate a polarized epithelium and fully rescue cavitation. Interestingly, when wildtype and Prkci(-/-) ES cells are mixed together, a polarized ectodermal epithelium forms and cavitation is rescued, likely due to the ability of wildtype cells to produce non-autonomous polarity cues. We conclude that Prkci is not required for cells to respond to these cues, though it is required to produce them. Together these findings indicate that environmental cues can facilitate the formation of polarized epithelia and that cavitation requires the proper coordination of multiple basic cellular processes including proliferation, differentiation, cell death, and apical-basal polarization. Copyright © 2016 Elsevier Inc. All rights reserved.

Establishment of Functional Genomics Pipeline in Mouse Epiblast-Like Tissue by Combining Transcriptomic Analysis and Gene Knockdown/Knockin/Knockout, Using RNA Interference and CRISPR/Cas9.

PubMed

Takata, Nozomu; Sakakura, Eriko; Kasukawa, Takeya; Sakuma, Tetsushi; Yamamoto, Takashi; Sasai, Yoshiki

2016-06-01

The epiblast (foremost embryonic ectoderm) generates all three germ layers and therefore has crucial roles in the formation of all mammalian body cells. However, regulation of epiblast gene expression is poorly understood because of the difficulty of manipulating epiblast tissues in vivo. In the present study, using the self-organizing properties of mouse embryonic stem cell (ESC), we generated and characterized epiblast-like tissue in three-dimensional culture. We identified significant genome-wide gene expression changes in this epiblast-like tissue by transcriptomic analysis. In addition, we identified the particular significance of the Erk/Mapk and integrin-linked kinase pathways, and genes related to ectoderm/epithelial formation, using the bioinformatics resources IPA and DAVID. Here, we focused on Fgf5, which ranked in the top 10 among the discovered genes. To develop a functional analysis of Fgf5, we created an efficient method combining CRISPR/Cas9-mediated genome engineering and RNA interference (RNAi). Notably, we show one-step generation of various Fgf5 reporter lines including heterozygous and homozygous knockins (the GET method). For time- and dose-dependent depletion of fgf5 over the course of development, we generated an ESC line harboring Tol2 transposon-mediated integration of an inducible short hairpin RNA interference system (pdiRNAi). Our findings raised the possibility that Fgf/Erk signaling and apicobasal epithelial integrity are important factors in epiblast development. In addition, our methods provide a framework for a broad array of applications in the areas of mammalian genetics and molecular biology to understand development and to improve future therapeutics.

The evolutionary history of vertebrate cranial placodes II. Evolution of ectodermal patterning.

PubMed

Schlosser, Gerhard; Patthey, Cedric; Shimeld, Sebastian M

2014-05-01

Cranial placodes are evolutionary innovations of vertebrates. However, they most likely evolved by redeployment, rewiring and diversification of preexisting cell types and patterning mechanisms. In the second part of this review we compare vertebrates with other animal groups to elucidate the evolutionary history of ectodermal patterning. We show that several transcription factors have ancient bilaterian roles in dorsoventral and anteroposterior regionalisation of the ectoderm. Evidence from amphioxus suggests that ancestral chordates then concentrated neurosecretory cells in the anteriormost non-neural ectoderm. This anterior proto-placodal domain subsequently gave rise to the oral siphon primordia in tunicates (with neurosecretory cells being lost) and anterior (adenohypophyseal, olfactory, and lens) placodes of vertebrates. Likewise, tunicate atrial siphon primordia and posterior (otic, lateral line, and epibranchial) placodes of vertebrates probably evolved from a posterior proto-placodal region in the tunicate-vertebrate ancestor. Since both siphon primordia in tunicates give rise to sparse populations of sensory cells, both proto-placodal domains probably also gave rise to some sensory receptors in the tunicate-vertebrate ancestor. However, proper cranial placodes, which give rise to high density arrays of specialised sensory receptors and neurons, evolved from these domains only in the vertebrate lineage. We propose that this may have involved rewiring of the regulatory network upstream and downstream of Six1/2 and Six4/5 transcription factors and their Eya family cofactors. These proteins, which play ancient roles in neuronal differentiation were first recruited to the dorsal non-neural ectoderm in the tunicate-vertebrate ancestor but subsequently probably acquired new target genes in the vertebrate lineage, allowing them to adopt new functions in regulating proliferation and patterning of neuronal progenitors. Copyright © 2014 Elsevier Inc. All rights reserved.

A Novel Homozygous Missense Mutation in HOXC13 Leads to Autosomal Recessive Pure Hair and Nail Ectodermal Dysplasia.

PubMed

Li, Xiaoxiao; Orseth, Meredith Lee; Smith, J Michael; Brehm, Mary Abigail; Agim, Nnenna Gebechi; Glass, Donald Alexander

2017-03-01

Pure hair and nail ectodermal dysplasia (PHNED) is a rare disorder that presents with hypotrichosis and nail dystrophy while sparing other ectodermal structures such as teeth and sweat glands. We describe a homozygous novel missense mutation in the HOXC13 gene that resulted in autosomal recessive PHNED in a Hispanic child. The mutation c.812A>G (p.Gln271Arg) is located within the DNA-binding domain of the HOXC13 gene, cosegregates within the family, and is predicted to be maximally damaging. This is the first reported case of a missense HOXC13 mutation resulting in PHNED and the first reported case of PHNED identified in a North American family. Our findings illustrate the critical role of HOXC13 in human hair and nail development. © 2017 Wiley Periodicals, Inc.

A novel homozygous missense variant in NECTIN4 (PVRL4) causing ectodermal dysplasia cutaneous syndactyly syndrome.

PubMed

Ahmad, Farooq; Nasir, Abdul; Thiele, Holger; Umair, Muhammad; Borck, Guntram; Ahmad, Wasim

2018-02-12

Ectodermal dysplasia syndactyly syndrome 1 (EDSS1) is a rare form of ectodermal dysplasia including anomalies of hair, nails, and teeth along with bilateral cutaneous syndactyly of hands and feet. In the present report, we performed a clinical and genetic characterization of a consanguineous Pakistani family with four individuals affected by EDSS1. We performed exome sequencing using DNA of one affected individual. Exome data analysis identified a novel homozygous missense variant (c.242T>C; p.(Leu81Pro)) in NECTIN4 (PVRL4). Sanger sequencing validated this variant and confirmed its cosegregation with the disease phenotype in the family members. Thus, our report adds a novel variant to the NECTIN4 mutation spectrum and contributes to the NECTIN4-related clinical characterization. © 2018 John Wiley & Sons Ltd/University College London.

Dermatopathia pigmentosa reticularis: A rare reticulate pigmentary disorder

PubMed Central

Shanker, Vinay; Gupta, Mudita

2013-01-01

Dermatopathia pigmentosa reticularis is a rare ectodermal dysplasia with a triad of generalized reticulate hyperpigmentation, noncicatricial alopecia, and onychodystrophy. We report a case of a 21 year old woman who had generalized reticulate pigmentation, diffuse noncicatricial alopecia and onychodystrophy of finger and toe nails. Along with this triad she had palmoplantar keratoderma and poorly developed dermatoglyphics. There was no evidence of involvement of other ectodermally derived organ. PMID:23440032

Ectodermal fragments from normal frog gastrulae condition substrata to support normal and hybrid mesodermal cell migration in vitro.

PubMed

Nakatsuji, N; Johnson, K E

1984-06-01

Using time-lapse cinemicrography and scanning electron microscopy, we have shown that normal Rana embryos and gastrulating hybrid embryos have extracellular fibrils on the inner surface of the ectodermal layer. These fibrils are absent prior to gastrulation and appear in increasing numbers during gastrulation. They can also be deposited in vitro where they condition substrata in such a way that normal presumptive mesodermal cells placed on them show extensive attachment and unoriented cell movement. These fibrils are also present in some arrested hybrid embryos, but in reduced numbers, or are lacking in other arrested hybrid embryos. Explanted ectodermal fragments from arrested hybrid embryos fail both to condition culture substrata by the deposition of fibrils and to promote cell attachment and translocation. In contrast, ectodermal fragments from normal embryos can condition culture substrata so as to promote moderate cell attachment and, for one particular gamete combination, even cell translocation of presumptive mesodermal cells taken from arrested hybrid embryos. These results provide new evidence to support the hypothesis that extracellular fibrils represent a system that promotes mesodermal cell migration in amphibian embryos. Differences in the fibrillar system in urodele and anuran embryos are discussed in relation to fundamental differences in the mode of mesodermal cell migration in these two classes of Amphibia.

Hypohidrotic ectodermal dysplasia, osteopetrosis, lymphedema, and immunodeficiency in an infant with multiple opportunistic infections.

PubMed

Carlberg, Valerie M; Lofgren, Sabra M; Mann, Julianne A; Austin, Jared P; Nolt, Dawn; Shereck, Evan B; Davila-Saldana, Blachy; Zonana, Jonathan; Krol, Alfons L

2014-01-01

Osteopetrosis, lymphedema, hypohidrotic ectodermal dysplasia, and immunodeficiency (OL-HED-ID) is a rare X-linked disorder with only three reported prior cases in the English-language literature. We describe a case of OL-HED-ID in a male infant who initially presented with congenital lymphedema, leukocytosis, and thrombocytopenia of unknown etiology at 7 days of age. He subsequently developed gram-negative sepsis and multiple opportunistic infections including high-level cytomegalovirus viremia and Pneumocystis jiroveci pneumonia. The infant was noted to have mildly xerotic skin, fine sparse hair, and periorbital wrinkling, all features suggestive of ectodermal dysplasia. Skeletal imaging showed findings consistent with osteopetrosis, and immunologic investigation revealed hypogammaglobulinemia and mixed T- and B-cell dysfunction. Genetic testing revealed a novel mutation in the nuclear factor kappa beta (NF-KB) essential modulator (NEMO) gene, confirming the diagnosis of OL-HED-ID. Mutations in the NEMO gene have been reported in association with hypohidrotic ectodermal dysplasia with immunodeficiency (HED-ID), OL-HED-ID, and incontinentia pigmenti. In this case, we report a novel mutation in the NEMO gene associated with OL-HED-ID. This article highlights the dermatologic manifestations of a rare disorder, OL-HED-ID, and underscores the importance of early recognition and prompt intervention to prevent life-threatening infections. © 2013 Wiley Periodicals, Inc.

Prebiotic chemistry and nucleic acid replication

NASA Technical Reports Server (NTRS)

Orgel, L. E.; Lohrmann, R.

1974-01-01

Recent work is reviewed on some reactions that could have occurred on the primitive earth and that could have played a part in the evolution of a self-replicating system. The transition from the primitive atmosphere to the simplest replicating molecules is considered in four stages: (1) the formation of a 'prebiotic soup' of organic precursors, including the purine and pyrimidine bases and the pentose sugars; (2) the condensation of these precursors and inorganic phosphate to form monomeric nucleotides and activated nucleotide derivatives; (3) the polymerization of nucleotide derivatives to oligonucleotides; and (4) the complementary replication of oligonucleotides in a template-directed process that depends on Watson-Crick base pairing.

Clues to the origin of metal in Almahata Sitta EL and EH chondrites and implications for primitive E chondrite thermal histories

NASA Astrophysics Data System (ADS)

Horstmann, Marian; Humayun, Munir; Bischoff, Addi

2014-09-01

Enstatite (E) chondrites are a group of texturally highly variable meteorites formed under strongly reducing conditions giving rise to unique mineral and chemical characteristics (e.g., high abundances of various sulfides and Si-bearing metal). In particular the abundant metal comprises a range of textures in E chondrites of different petrologic type, but available in situ siderophile trace element data on metal are limited. Nine samples of E chondrites from the recent Almahata Sitta fall [one EH3, two EL3/4, two EL6, two EL impact melt rocks (IMR), two EH IMR] were investigated in this study in addition to St. Mark's (EH5) and Grein 002 (EL4/5), with a focus on the nature of their metal constituents. Special attention was given to metal-silicate intergrowths (MSSI) that occur in many primitive E chondrites, which have been interpreted as post-accretionary asteroidal impact melts or primitive nebular condensates. This study shows that siderophile trace element systematics in E chondrite metal are independent of petrologic type of the host rock and distinct from condensation signatures. Three basic types of siderophile trace element signatures can be distinguished, indicating crystallization from a melt, thermal equilibration upon metamorphism/complete melting, and exsolution of schreibersite-perryite-sulfide. Textural and mineral-chemical constraints from EL3/4s are used to evaluate previously proposed formation processes of MSSI (impact melting vs. nebular condensation) and elucidate which other formation scenarios are feasible. It is shown that post-accretionary (in situ) impact melting or metallic melt injection forming MSSI on the thin section scale, and nebular condensation, are unlikely formation processes. This leads to the conclusion that MSSIs are pre-accretionary melt objects that were formed during melting processes prior to the accretion of the primitive E chondrites. The same can be concluded for metal nodules in the EH3 chondrite examined. The pre-accretionary origin of MSSIs in E chondrites is consistent with a growing body of evidence for early differentiation followed by impact disruption of early formed planetesimals in all major chondrite types.

Fgf16 is essential for pectoral fin bud formation in zebrafish

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nomura, Ryohei; Kamei, Eriko; Hotta, Yuuhei

2006-08-18

Zebrafish pectoral fin bud formation is an excellent model for studying morphogenesis. Fibroblast growth factors (Fgfs) and sonic hedgehog (shh) are essential for pectoral fin bud formation. We found that Fgf16 was expressed in the apical ectodermal ridge (AER) of fin buds. A knockdown of Fgf16 function resulted in no fin bud outgrowth. Fgf16 is required for cell proliferation and differentiation in the mesenchyme and the AER of the fin buds, respectively. Fgf16 functions downstream of Fgf10, a mesenchymal factor, signaling to induce the expression of Fgf4 and Fgf8 in the AER. Fgf16 in the AER and shh in themore » zone of polarizing activity (ZPA) interact to induce and/or maintain each other's expression. These findings have revealed that Fgf16, a newly identified AER factor, plays a crucial role in pectoral fin bud outgrowth by mediating the interactions of AER-mesenchyme and AER-ZPA.« less

Herediatary anhidrotic ectodermal dysplasia. Studies in a Nigerian famil.

PubMed

Familusi, J B; Jaiyesimi, F; Ojo, C O; Attah, E B

1975-08-01

Studies in a Nigerian family with hereditary anhidrous ectodermal dysplasia are reported. Microscopical examinations of finger tips for sweat pores were diagnostic in phenotypes, and it is suggested that this simple nonsurgical procedure is a preferred alternative to skin biopsies in the diagnosis of the syndrome. The clinical implications of a tropical environment for the syndrome, as well as the factors that may favour maintenance of the gene in such an environment are discussed.

Irregular chiasm-C-roughest, a member of the immunoglobulin superfamily, affects sense organ spacing on the Drosophila antenna by influencing the positioning of founder cells on the disc ectoderm.

PubMed

Venugopala Reddy, G; Reiter, C; Shanbhag, S; Fischbach, K F; Rodrigues, V

1999-10-01

We describe a role for Irregular chiasmC-roughest (IrreC-rst), an immunoglobulin (Ig) superfamily member, in patterning sense organs on the Drosophila antenna. IrreC-rst protein is initially expressed homogeneously on apical profiles of ectodermal cells in regions of the antennal disc. During specification of founder cells (FCs), the intracellular protein distribution changes and becomes concentrated in regions where specific intercellular contacts presumably occur. Loss of function mutations as well as misexpression of irreC-rst results in an altered arrangement of FCs within the disc compared to wildtype. Sense organ development occurs normally, although spacing is affected. Unlike its role in interommatidial spacing, irreC-rst does not affect apoptosis during antennal development. We propose that IrreC-rst affects the spatial relationship between sensory and ectodermal cells during FC delamination.

[Clinical and molecular study in a family with autosomal dominant hypohidrotic ectodermal dysplasia].

PubMed

Callea, Michele; Cammarata-Scalisi, Francisco; Willoughby, Colin E; Giglio, Sabrina R; Sani, Ilaria; Bargiacchi, Sara; Traficante, Giovanna; Bellacchio, Emanuele; Tadini, Gianluca; Yavuz, Izzet; Galeotti, Angela; Clarich, Gabriella

2017-02-01

Hypohidrotic ectodermal dysplasia (HED) is a rare disease characterized by deficiency in development of structure derived from the ectoderm and is caused by mutations in the genes EDA, EDAR, or EDARADD. Phenotypes caused by mutations in these three may exhibit similar clinical features, explained by a common signaling pathway. Mutations in EDA gene cause X linked HED, which is the most common form. Mutations in EDAR and EDARADD genes cause autosomal dominant and recessive form of HED. The most striking clinical findings in HED are hypodontia, hypotrichosis and hypohidrosis that can lead to episodes of hyperthermia. We report on clinical findings in a child with HED with autosomal dominant inheritance pattern with a heterozygous mutation c.1072C>T (p.Arg358X) in the EDAR gene. A review of the literature with regard to other cases presenting the same mutation has been carried out and discussed. Sociedad Argentina de Pediatría.

Respiratory problems in patients with ectodermal dysplasia syndromes.

PubMed

Fete, Timothy

2014-10-01

The ectodermal dysplasias (EDs) are a heterogeneous group of disorders characterized by a deficiency of ectoderm- and mesoderm-derived tissues and appendages, particularly hair, skin, teeth, and nails. Many of these disorders are associated with a greater risk of respiratory disease than found in the general population. There are no published papers that comprehensively describe these findings and the possible etiologies. Patients have been reported with dramatic decrease in mucous glands in the respiratory tract. Anatomic defects, including cleft palate, that predispose to respiratory infection, are associated with several of the ED syndromes. Atopy and immune deficiencies have been shown to have a higher prevalence in ED syndromes. Clinicians who care for patients affected by ED syndromes should be aware of the potential respiratory complications, and consider evaluation for structural anomalies, atopy and immunodeficiency in individuals with recurrent or chronic respiratory symptoms. © 2014 Wiley Periodicals, Inc.

Genipin-crosslinked gelatin-silk fibroin hydrogels for modulating the behaviour of pluripotent cells.

PubMed

Sun, Wei; Incitti, Tania; Migliaresi, Claudio; Quattrone, Alessandro; Casarosa, Simona; Motta, Antonella

2016-10-01

Different hydrogel materials have been prepared to investigate the effects of culture substrate on the behaviour of pluripotent cells. In particular, genipin-crosslinked gelatin-silk fibroin hydrogels of different compositions have been prepared, physically characterized and used as substrates for the culture of pluripotent cells. Pluripotent cells cultured on hydrogels remained viable and proliferated. Gelatin and silk fibroin promoted the proliferation of cells in the short and long term, respectively. Moreover, cells cultured on genipin-crosslinked gelatin-silk fibroin blended hydrogels were induced to an epithelial ectodermal differentiation fate, instead of the neural ectodermal fate obtained by culturing on tissue culture plates. This work confirms that specific culture substrates can be used to modulate the behaviour of pluripotent cells and that our genipin-crosslinked gelatin-silk fibroin blended hydrogels can induce pluripotent cells differentiation to an epithelial ectodermal fate. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd.

Formation of biologically relevant carboxylic acids during the gamma irradiation of acetic acid

NASA Technical Reports Server (NTRS)

Negron-Mendoza, A.; Ponnamperuma, C.

1976-01-01

Irradiation of aqueous solutions of acetic acid with gamma rays produced several carboxylic acids in small yield. Their identification was based on the technique of gas chromatography combined with mass spectrometry. Some of these acids are Krebs Cycle intermediates. Their simultaneous formation in experiments simulating the primitive conditions on the earth suggests that metabolic pathways may have had their origin in prebiotic chemical processes.

Formation of TiC core-graphitic mantle grains from CO gas

NASA Astrophysics Data System (ADS)

Kimura, Yuki; Nuth, Joseph A.; Ferguson, Frank T.

2006-05-01

We demonstrate a new formation route for TiC core-graphitic mantle spherules that does not require carbon-atom addition and the very long time scales associated with such growth (Bernatowicz et al. 1996). Carbonaceous materials can be formed from C2H2 and its derivatives, as well as from CO gas. In this paper, we will demonstrate that large-cage-structure carbon particles can be produced from CO gas by the Boudouard reaction. Since the sublimation temperature for such fullerenes is low, the large cages can be deposited onto previously nucleated TiC and produce TiC core-graphitic mantle spherules. New constraints for the formation conditions and the time scale for the formation of TiC core-graphitic mantle spherules are suggested by the results of this study. In particular, TiC core-graphitic mantle grains that are found in primitive meteorites that have never experienced hydration could be mantled by fullerenes or carbon nanotubes rather than by graphite. In situ observations of these grains in primitive anhydrous meteoritic matrix could confirm or refute this prediction and would demonstrate that the graphitic mantle on such grains is a metamorphic feature due to interaction of the presolar fullerenes with water within the meteorite matrix.

A kinetic study of the formation of organic solids from formaldehyde: Implications for the origin of extraterrestrial organic solids in primitive Solar System objects

NASA Astrophysics Data System (ADS)

Kebukawa, Yoko; Cody, George D.

2015-03-01

Aqueous organic solid formation from formaldehyde via the formose reaction and subsequent reactions is a possible candidate for the origin of complex primitive chondritic insoluble organic matter (IOM) and refractory carbon in comets. The rate of formation of organic solids from formaldehyde was studied as a function of temperature and time, with and without ammonia, in order to derive kinetic expressions for polymer yield. The evolution in molecular structure as a function of time and temperature was studied using infrared spectroscopy. Using these kinetic expressions, the yield of organic solids is estimated for extended time and temperature ranges. For example, the half-life for organic solid formation is ∼5 days at 373 K, ∼200 days at 323 K, and ∼70 years at 273 K with ammonia, and ∼25 days at 373 K, ∼13 years at 323 K, and ∼2 × 104 years at 273 K without ammonia. These results indicate that organic solids could form during the aqueous alteration in meteorite parent bodies. If liquid water existed early in the interiors of Kuiper belt objects (KBOs), formaldehyde could convert into organic solids at temperatures close to 273 K, and possibly even below 273 K in the ammonia-water system.

Intact cluster and chordate-like expression of ParaHox genes in a sea star

PubMed Central

2013-01-01

Background The ParaHox genes are thought to be major players in patterning the gut of several bilaterian taxa. Though this is a fundamental role that these transcription factors play, their activities are not limited to the endoderm and extend to both ectodermal and mesodermal tissues. Three genes compose the ParaHox group: Gsx, Xlox and Cdx. In some taxa (mostly chordates but to some degree also in protostomes) the three genes are arranged into a genomic cluster, in a similar fashion to what has been shown for the better-known Hox genes. Sea urchins possess the full complement of ParaHox genes but they are all dispersed throughout the genome, an arrangement that, perhaps, represented the primitive condition for all echinoderms. In order to understand the evolutionary history of this group of genes we cloned and characterized all ParaHox genes, studied their expression patterns and identified their genomic loci in a member of an earlier branching group of echinoderms, the asteroid Patiria miniata. Results We identified the three ParaHox orthologs in the genome of P. miniata. While one of them, PmGsx is provided as maternal message, with no zygotic activation afterwards, the other two, PmLox and PmCdx are expressed during embryogenesis, within restricted domains of both endoderm and ectoderm. Screening of a Patiria bacterial artificial chromosome (BAC) library led to the identification of a clone containing the three genes. The transcriptional directions of PmGsx and PmLox are opposed to that of the PmCdx gene within the cluster. Conclusions The identification of P. miniata ParaHox genes has revealed the fact that these genes are clustered in the genome, in contrast to what has been reported for echinoids. Since the presence of an intact cluster, or at least a partial cluster, has been reported in chordates and polychaetes respectively, it becomes clear that within echinoderms, sea urchins have modified the original bilaterian arrangement. Moreover, the sea star ParaHox domains of expression show chordate-like features not found in the sea urchin, confirming that the dynamics of gene expression for the respective genes and their putative regulatory interactions have clearly changed over evolutionary time within the echinoid lineage. PMID:23803323

Synthesis of refractory organic matter in the ionized gas phase of the solar nebula.

PubMed

Kuga, Maïa; Marty, Bernard; Marrocchi, Yves; Tissandier, Laurent

2015-06-09

In the nascent solar system, primitive organic matter was a major contributor of volatile elements to planetary bodies, and could have played a key role in the development of the biosphere. However, the origin of primitive organics is poorly understood. Most scenarios advocate cold synthesis in the interstellar medium or in the outer solar system. Here, we report the synthesis of solid organics under ionizing conditions in a plasma setup from gas mixtures (H2(O)-CO-N2-noble gases) reminiscent of the protosolar nebula composition. Ionization of the gas phase was achieved at temperatures up to 1,000 K. Synthesized solid compounds share chemical and structural features with chondritic organics, and noble gases trapped during the experiments reproduce the elemental and isotopic fractionations observed in primitive organics. These results strongly suggest that both the formation of chondritic refractory organics and the trapping of noble gases took place simultaneously in the ionized areas of the protoplanetary disk, via photon- and/or electron-driven reactions and processing. Thus, synthesis of primitive organics might not have required a cold environment and could have occurred anywhere the disk is ionized, including in its warm regions. This scenario also supports N2 photodissociation as the cause of the large nitrogen isotopic range in the solar system.

Synthesis of refractory organic matter in the ionized gas phase of the solar nebula

PubMed Central

Kuga, Maïa; Marty, Bernard; Marrocchi, Yves; Tissandier, Laurent

2015-01-01

In the nascent solar system, primitive organic matter was a major contributor of volatile elements to planetary bodies, and could have played a key role in the development of the biosphere. However, the origin of primitive organics is poorly understood. Most scenarios advocate cold synthesis in the interstellar medium or in the outer solar system. Here, we report the synthesis of solid organics under ionizing conditions in a plasma setup from gas mixtures (H2(O)−CO−N2−noble gases) reminiscent of the protosolar nebula composition. Ionization of the gas phase was achieved at temperatures up to 1,000 K. Synthesized solid compounds share chemical and structural features with chondritic organics, and noble gases trapped during the experiments reproduce the elemental and isotopic fractionations observed in primitive organics. These results strongly suggest that both the formation of chondritic refractory organics and the trapping of noble gases took place simultaneously in the ionized areas of the protoplanetary disk, via photon- and/or electron-driven reactions and processing. Thus, synthesis of primitive organics might not have required a cold environment and could have occurred anywhere the disk is ionized, including in its warm regions. This scenario also supports N2 photodissociation as the cause of the large nitrogen isotopic range in the solar system. PMID:26039983

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Ying, E-mail: yingliu@doheny.org; Sun Yet-sen University, Zhongshan Ophthalmic Center, State Key Ophthalmic Laboratory, Guangzhou 510060; Kawai, Kirio

Research highlights: {yields} Inactivation of Smad4 caused disruption in the development of the anterior segment. {yields} Inactivation of Smad4 failed to disrupt early lens development. {yields} Smad4 controlled lens cell cycle and cell death processes. {yields} Smad4 may regulate actin stress fiber assembly and eyelid epithelial movement. -- Abstract: Purpose: Signaling by members of the TGF{beta} superfamily of molecules is essential for embryonic development and homeostasis. Smad4, a key intracellular mediator in TGF{beta} signaling, forms transcriptional activator complexes with Activin-, BMP-, and TGF{beta}-restricted Smad proteins. However, the functional role of Smad4 in controlling different visual system compartments has not beenmore » fully investigated. Methods: Using the Pax6 promoter-driven Cre transgenic, smad4 was conditionally inactivated in the lens, cornea and ectoderm of the eyelids. Standard histological and molecular analytical approaches were employed to reveal morphological and cellular changes. Results: Inactivation of Smad4 in the lens led to microphthalmia and cataract formation in addition to the persistent adhesion of the retina to the lens and the iris to the cornea. Inactivation of Smad4 from the ectoderm of the eyelid and cornea caused disruption to eyelid fusion and proper development of the corneal epithelium and corneal stroma. Conclusions: Smad4 is required for the development and maintenance of the lens in addition to the proper development of the cornea, eyelids, and retina.« less

Repression of mesodermal fate by foxa, a key endoderm regulator of the sea urchin embryo.

PubMed

Oliveri, Paola; Walton, Katherine D; Davidson, Eric H; McClay, David R

2006-11-01

The foxa gene is an integral component of the endoderm specification subcircuit of the endomesoderm gene regulatory network in the Strongylocentrotus purpuratus embryo. Its transcripts become confined to veg2, then veg1 endodermal territories, and, following gastrulation, throughout the gut. It is also expressed in the stomodeal ectoderm. gatae and otx genes provide input into the pregastrular regulatory system of foxa, and Foxa represses its own transcription, resulting in an oscillatory temporal expression profile. Here, we report three separate essential functions of the foxa gene: it represses mesodermal fate in the veg2 endomesoderm; it is required in postgastrular development for the expression of gut-specific genes; and it is necessary for stomodaeum formation. If its expression is reduced by a morpholino, more endomesoderm cells become pigment and other mesenchymal cell types, less gut is specified, and the larva has no mouth. Experiments in which blastomere transplantation is combined with foxa MASO treatment demonstrate that, in the normal endoderm, a crucial role of Foxa is to repress gcm expression in response to a Notch signal, and hence to repress mesodermal fate. Chimeric recombination experiments in which veg2, veg1 or ectoderm cells contained foxa MASO show which region of foxa expression controls each of the three functions. These experiments show that the foxa gene is a component of three distinct embryonic gene regulatory networks.

Evolution of bilaterian central nervous systems: a single origin?

PubMed Central

2013-01-01

The question of whether the ancestral bilaterian had a central nervous system (CNS) or a diffuse ectodermal nervous system has been hotly debated. Considerable evidence supports the theory that a CNS evolved just once. However, an alternative view proposes that the chordate CNS evolved from the ectodermal nerve net of a hemichordate-like ancestral deuterostome, implying independent evolution of the CNS in chordates and protostomes. To specify morphological divisions along the anterior/posterior axis, this ancestor used gene networks homologous to those patterning three organizing centers in the vertebrate brain: the anterior neural ridge, the zona limitans intrathalamica and the isthmic organizer, and subsequent evolution of the vertebrate brain involved elaboration of these ancestral signaling centers; however, all or part of these signaling centers were lost from the CNS of invertebrate chordates. The present review analyzes the evidence for and against these theories. The bulk of the evidence indicates that a CNS evolved just once – in the ancestral bilaterian. Importantly, in both protostomes and deuterostomes, the CNS represents a portion of a generally neurogenic ectoderm that is internalized and receives and integrates inputs from sensory cells in the remainder of the ectoderm. The expression patterns of genes involved in medio/lateral (dorso/ventral) patterning of the CNS are similar in protostomes and chordates; however, these genes are not similarly expressed in the ectoderm outside the CNS. Thus, their expression is a better criterion for CNS homologs than the expression of anterior/posterior patterning genes, many of which (for example, Hox genes) are similarly expressed both in the CNS and in the remainder of the ectoderm in many bilaterians. The evidence leaves hemichordates in an ambiguous position – either CNS centralization was lost to some extent at the base of the hemichordates, or even earlier, at the base of the hemichordates + echinoderms, or one of the two hemichordate nerve cords is homologous to the CNS of protostomes and chordates. In any event, the presence of part of the genetic machinery for the anterior neural ridge, the zona limitans intrathalamica and the isthmic organizer in invertebrate chordates together with similar morphology indicates that these organizers were present, at least in part, at the base of the chordates and were probably elaborated upon in the vertebrate lineage. PMID:24098981

Oligomerization reactions of deoxyribonucleotides on montmorillonite clay - The effect of mononucleotide structure on phosphodiester bond formation

NASA Technical Reports Server (NTRS)

Ferris, James P.; KAMALUDDIN

1989-01-01

The formation of oligomers from deoxynucleotides, catalyzed by Na(+)-montmorillonite, was investigated with special attention given to the effect of the monomer structure on the phosphodiester bond formation. It was found that adenine deoxynucleotides bind more strongly to montmorillonite than do the corresponding ribonucleotides and thymidine nucleotides. Tetramers of 2-prime-dpA were detected in the reaction of 2-prime-d-5-prime-AMP with a water-soluble carbodiimide EDAC in the presence of Na(+)-montmorillonite, illustrating the possible role of minerals in the formation of biopolymers on the primitive earth.

The birth of embryonic pluripotency

PubMed Central

Boroviak, Thorsten; Nichols, Jennifer

2014-01-01

Formation of a eutherian mammal requires concurrent establishment of embryonic and extraembryonic lineages. The functions of the trophectoderm and primitive endoderm are to enable implantation in the maternal uterus, axis specification and delivery of nutrients. The pluripotent epiblast represents the founding cell population of the embryo proper, which is protected from ectopic and premature differentiation until it is required to respond to inductive cues to form the fetus. While positional information plays a major role in specifying the trophoblast lineage, segregation of primitive endoderm from epiblast depends upon gradual acquisition of transcriptional identity, directed but not initiated by fibroblast growth factor (FGF) signalling. Following early cleavage divisions and formation of the blastocyst, cells of the inner cell mass lose totipotency. Developing epiblast cells transiently attain the state of naive pluripotency and competence to self-renew in vitro as embryonic stem cells and in vivo by means of diapause. This property is lost after implantation as the epiblast epithelializes and becomes primed in preparation for gastrulation and subsequent organogenesis. PMID:25349450

Structure and function of primitive immunoglobulin superfamily neural cell adhesion molecules: a lesson from studies on planarian.

PubMed

Fusaoka, Eri; Inoue, Takeshi; Mineta, Katsuhiko; Agata, Kiyokazu; Takeuchi, Kosei

2006-05-01

Precise wiring and proper remodeling of the neural network are essential for its normal function. The freshwater planarian is an attractive animal in which to study the formation and maintenance of the neural network due to its high regenerative capability and developmental plasticity. Although a recent study revealed that homologs of netrin and its receptors are required for regeneration and maintenance of the planarian central nervous system (CNS), the roles of cell adhesion in the formation and maintenance of the planarian neural network remain poorly understood. In the present study, we found primitive immunoglobulin superfamily cell adhesion molecules (IgCAMs) in a planarian that are homologous to vertebrate neural IgCAMs. We identified planarian orthologs of NCAM, L1CAM, contactin and DSCAM, and designated them DjCAM, DjLCAM, DjCTCAM and DjDSCAM, respectively. We further confirmed that they function as cell adhesion molecules using cell aggregation assays. DjCAM and DjDSCAM were found to be differentially expressed in the CNS. Functional analyses using RNA interference revealed that DjCAM is partly involved in axon formation, and that DjDSCAM plays crucial roles in neuronal cell migration, axon outgrowth, fasciculation and projection.

Genetic origin, admixture and population history of aurochs (Bos primigenius) and primitive European cattle

PubMed Central

Upadhyay, M R; Chen, W; Lenstra, J A; Goderie, C R J; MacHugh, D E; Park, S D E; Magee, D A; Matassino, D; Ciani, F; Megens, H-J; van Arendonk, J A M; Groenen, M A M; Marsan, P A; Balteanu, V; Dunner, S; Garcia, J F; Ginja, C; Kantanen, J

2017-01-01

The domestication of taurine cattle initiated ~10 000 years ago in the Near East from a wild aurochs (Bos primigenius) population followed by their dispersal through migration of agriculturalists to Europe. Although gene flow from wild aurochs still present at the time of this early dispersion is still debated, some of the extant primitive cattle populations are believed to possess the aurochs-like primitive features. In this study, we use genome-wide single nucleotide polymorphisms to assess relationship, admixture patterns and demographic history of an ancient aurochs sample and European cattle populations, several of which have primitive features and are suitable for extensive management. The principal component analysis, the model-based clustering and a distance-based network analysis support previous works suggesting different histories for north-western and southern European cattle. Population admixture analysis indicates a zebu gene flow in the Balkan and Italian Podolic cattle populations. Our analysis supports the previous report of gene flow between British and Irish primitive cattle populations and local aurochs. In addition, we show evidence of aurochs gene flow in the Iberian cattle populations indicating wide geographical distribution of the aurochs. Runs of homozygosity (ROH) reveal that demographic processes like genetic isolation and breed formation have contributed to genomic variations of European cattle populations. The ROH also indicate recent inbreeding in southern European cattle populations. We conclude that in addition to factors such as ancient human migrations, isolation by distance and cross-breeding, gene flow between domestic and wild-cattle populations also has shaped genomic composition of European cattle populations. PMID:27677498

Genetic origin, admixture and population history of aurochs (Bos primigenius) and primitive European cattle.

PubMed

Upadhyay, M R; Chen, W; Lenstra, J A; Goderie, C R J; MacHugh, D E; Park, S D E; Magee, D A; Matassino, D; Ciani, F; Megens, H-J; van Arendonk, J A M; Groenen, M A M

2017-02-01

The domestication of taurine cattle initiated ~10 000 years ago in the Near East from a wild aurochs (Bos primigenius) population followed by their dispersal through migration of agriculturalists to Europe. Although gene flow from wild aurochs still present at the time of this early dispersion is still debated, some of the extant primitive cattle populations are believed to possess the aurochs-like primitive features. In this study, we use genome-wide single nucleotide polymorphisms to assess relationship, admixture patterns and demographic history of an ancient aurochs sample and European cattle populations, several of which have primitive features and are suitable for extensive management. The principal component analysis, the model-based clustering and a distance-based network analysis support previous works suggesting different histories for north-western and southern European cattle. Population admixture analysis indicates a zebu gene flow in the Balkan and Italian Podolic cattle populations. Our analysis supports the previous report of gene flow between British and Irish primitive cattle populations and local aurochs. In addition, we show evidence of aurochs gene flow in the Iberian cattle populations indicating wide geographical distribution of the aurochs. Runs of homozygosity (ROH) reveal that demographic processes like genetic isolation and breed formation have contributed to genomic variations of European cattle populations. The ROH also indicate recent inbreeding in southern European cattle populations. We conclude that in addition to factors such as ancient human migrations, isolation by distance and cross-breeding, gene flow between domestic and wild-cattle populations also has shaped genomic composition of European cattle populations.

Biomolecules from HCN

NASA Technical Reports Server (NTRS)

Ferris, J. P.; Wos, J. D.; Ryan, T. J.; Lobo, A. P.; Donner, D. B.

1974-01-01

It has been suggested by Sanchez et al. (1967) that HCN might have been one of the more important precursors of biological molecules on the primitive earth. Studies were conducted to determine the mechanisms involved in HCN oligomerizations in dilute aqueous solutions and to identify the compounds which are produced in these oligomerization mixtures. Indirect evidence for the formation of cyanate was obtained along with direct evidence for the formation of citrulline, aspartic acid, and orotic acid.

Origin of the solar system

NASA Technical Reports Server (NTRS)

Cameron, A. G. W.

1988-01-01

The current status of the classical model of solar-system formation is surveyed, reviewing the results of recent observational and theoretical investigations. Topics addressed include interstellar clouds, the collapse of interstellar gas, the primitive solar nebula, the formation of the sun, planetesimal accumulation, planetary accumulation, major planetary collisions, the development of planetary atmospheres, and comets. The relative merits of conflicting theories on many key problems are indicated, with reference to more detailed reviews in the literature.

Star formation and extinct radioactivities

NASA Technical Reports Server (NTRS)

Cameron, A. G. W.

1984-01-01

An assessment is made of the evidence for the existence of now-extinct radioactivities in primitive solar system material, giving attention to implications for the early stages of sun and solar system formation. The characteristics of possible disturbances in dense molecular clouds which can initiate the formation of cloud cores is discussed, with emphasis on these disturbances able to generate fresh radioactivities. A one-solar mass red giant star on the asymptotic giant branch appears to have been the best candidate to account for the short-lived extinct radioactivities in the early solar system.

Embryonic wound healing by apical contraction and ingression in Xenopus laevis.

PubMed

Davidson, Lance A; Ezin, Akouavi M; Keller, Ray

2002-11-01

We have characterized excisional wounds in the animal cap of early embryos of the frog Xenopus laevis and found that these wounds close accompanied by three distinct processes: (1) the assembly of an actin purse-string in the epithelial cells at the wound margin, (2) contraction and ingression of exposed deep cells, and (3) protrusive activity of epithelial cells at the margin. Microsurgical manipulation allowing fine control over the area and depth of the wound combined with videomicroscopy and confocal analysis enabled us to describe the kinematics and challenge the mechanics of the closing wound. Full closure typically occurs only when the deep, mesenchymal cell-layer of the ectoderm is left intact; in contrast, when deep cells are removed along with the superficial, epithelial cell-layer of the ectoderm, wounds do not close. Actin localizes to the superficial epithelial cell-layer at the wound margin immediately after wounding and forms a contiguous "purse-string" in those cells within 15 min. However, manipulation and closure kinematics of shaped wounds and microsurgical cuts made through the purse-string rule out a major force-generating role for the purse-string. Further analysis of the cell behaviors within the wound show that deep, mesenchymal cells contract their apical surfaces and ingress from the exposed surface. High resolution time-lapse sequences of cells at the leading edge of the wound show that these cells undergo protrusive activity only during the final phases of wound closure as the ectoderm reseals. We propose that assembly of the actin purse-string works to organize and maintain the epithelial sheet at the wound margin, that contraction and ingression of deep cells pulls the wound margins together, and that protrusive activity of epithelial cells at the wound margin reseals the ectoderm and re-establishes tissue integrity during wound healing in the Xenopus embryonic ectoderm. Copyright 2002 Wiley-Liss, Inc.

Veins in Silicates of IIE Iron Mont Dieu II: Melt Migration Caused by Impact?

NASA Astrophysics Data System (ADS)

Van Roosbroek, N.; Debaille, V.; Pittarello, L.; Hecht, L.; Claeys, Ph.

2014-09-01

Mont Dieu II is a ~450kg meteorite classified as IIE iron. The primitive silicate inclusions can be linked to the H-chondrites. Thick metal veins with angular clasts crosscut these inclusions and could point to an impact-melt migration formation.

Formation of the Mont Dieu IIE Non Magmatic Iron Meteorite, and Origin of its Silicate Inclusions

NASA Astrophysics Data System (ADS)

van Roosbroek, N.; Goderis, S.; Debaille, V.; Valley, J. W.; Claeys, Ph.

2012-03-01

Mont Dieu is an IIE nonmagmatic iron meteorite showing primitive features such as preserved chondrules and glass. SEM and geochemical analyses demonstrate that it most likely originated from an H-chondrite parent body impacted by a Fe-Ni projectile.

Expression of an Msx homeobox gene in ascidians: insights into the archetypal chordate expression pattern.

PubMed

Ma, L; Swalla, B J; Zhou, J; Dobias, S L; Bell, J R; Chen, J; Maxson, R E; Jeffery, W R

1996-03-01

The Msx homeobox genes are expressed in complex patterns during vertebrate development in conjunction with inductive tissue interactions. As a means of understanding the archetypal role of Msx genes in chordates, we have isolated and characterized an Msx gene in ascidians, protochordates with a relatively simple body plan. The Mocu Msx-a and McMsx-a genes, isolated from the ascidians Molgula oculata and Molgula citrina, respectively, have homeodomains that place them in the msh-like subclass of Msx genes. Therefore, the Molgula Msx-a genes are most closely related to the msh genes previously identified in a number of invertebrates. Southern blot analysis suggests that there are one or two copies of the Msx-a gene in the Molgula genome. Northern blot and RNase protection analysis indicate that Msx-a transcripts are restricted to the developmental stages of the life cycle. In situ hybridization showed that Msx-a mRNA first appears just before gastrulation in the mesoderm (presumptive notochord and muscle) and ectoderm (neural plate) cells. Transcript levels decline in mesoderm cells after the completion of gastrulation, but are enhanced in the folding neural plate during neurulation. Later, Msx-a mRNA is also expressed in the posterior ectoderm and in a subset of the tail muscle cells. The ectoderm and mesoderm cells that express Msx-a are undergoing morphogenetic movements during gastrulation, neurulation, and tail formation. Msx-a expression ceases after these cells stop migrating. The ascidian M. citrina, in which adult tissues and organs begin to develop precociously in the larva, was used to study Msx-a expression during adult development. Msx-a transcripts are expressed in the heart primordium and the rudiments of the ampullae, epidermal protrusions with diverse functions in the juvenile. The heart and ampullae develop in regions where mesenchyme cells interact with endodermal or epidermal epithelia. A comparison of the expression patterns of the Molgula genes with those of their vertebrate congeners suggests that the archetypal roles of the Msx genes may be in morphogenetic movements during embryogenesis and in mesenchymal-epithelial interactions during organogenesis.

Long-lived magnetism on chondrite parent bodies

NASA Astrophysics Data System (ADS)

Shah, Jay; Bates, Helena C.; Muxworthy, Adrian R.; Hezel, Dominik C.; Russell, Sara S.; Genge, Matthew J.

2017-10-01

We present evidence for both early- and late-stage magnetic activity on the CV and L/LL parent bodies respectively from chondrules in Vigarano and Bjurböle. Using micro-CT scans to re-orientate chondrules to their in-situ positions, we present a new micron-scale protocol for the paleomagnetic conglomerate test. The paleomagnetic conglomerate test determines at 95% confidence, whether clasts within a conglomerate were magnetized before or after agglomeration, i.e., for a chondritic meteorite whether the chondrules carry a pre- or post-accretionary remanent magnetization. We found both meteorites passed the conglomerate test, i.e., the chondrules had randomly orientated magnetizations. Vigarano's heterogeneous magnetization is likely of shock origin, due to the 10 to 20 GPa impacts that brecciated its precursor material on the parent body and transported it to re-accrete as the Vigarano breccia. The magnetization was likely acquired during the break-up of the original body, indicating a CV parent body dynamo was active ∼9 Ma after Solar System formation. Bjurböle's magnetization is due to tetrataenite, which transformed from taenite as the parent body cooled to below 320 °C, when an ambient magnetic field imparted a remanence. We argue either the high intrinsic anisotropy of tetrataenite or brecciation on the parent body manifests as a randomly orientated distribution, and a L/LL parent body dynamo must have been active at least 80 to 140 Ma after peak metamorphism. Primitive chondrites did not originate from entirely primitive, never molten and/or differentiated parent bodies. Primitive chondrite parent bodies consisted of a differentiated interior sustaining a long-lived magnetic dynamo, encrusted by a layer of incrementally accreted primitive meteoritic material. The different ages of carbonaceous and ordinary chondrite parent bodies might indicate a general difference between carbonaceous and ordinary chondrite parent bodies, and/or formation location in the protoplanetary disk.

Gas Phase Chemistry and Molecular Complexity: How Far Do They Go?

NASA Astrophysics Data System (ADS)

Balucani, Nadia

2016-07-01

The accumulation of organic molecules of increasing complexity is believed to be an important step toward the emergence of life. But how massive organic synthesis could occur in primitive Earth, i.e. a water-dominated environment, is a matter of debate. Two alternative theories have been suggested so far: endogenous and exogenous synthesis. In the first theory, the synthesis of simple organic molecules having a strong prebiotic potential (simple prebiotic molecules SPMs, such as H2CO, HCN, HC3N, NH2CHO) occurred directly on our planet starting from simple parent molecules of the atmosphere, liquid water and various energy sources. Miller's experiment was a milestone in this theory, but it was later recognized that the complexity of a planet cannot be reproduced in a single laboratory experiment. Some SPMs have been identified in the N2-dominated atmosphere of Titan (a massive moon of Saturn), which is believed to be reminiscent of the primitive terrestrial atmosphere. As such, the atmosphere of Titan represents a planetary scale laboratory for the comprehension of SPM formation in an environment close enough to primitive Earth and is the current frontier in the endogenous theory exploration. In the exogenous theory, SPMs came from space, the carriers being comets, asteroids and meteorites. The rationale behind this suggestion is that plenty of SPMs have been observed in interstellar clouds (ISCs), including star-forming regions, and in small bodies like comets, asteroids and meteorites. Therefore, the basic idea is that SPMs were formed in the solar nebula, preserved during the early phases of the Solar System formation in the body of comets/asteroids/meteorites and finally delivered to Earth by cometary and meteoritic falls. In this contribution, the status of our knowledge on how SPMs can be formed in the gas phase, either in the primitive terrestrial atmosphere or in the cold nebula from which the Solar System originated, will be presented. Particular attention will be given to neutral-neutral reactions.

Ectodermal Differentiation of Wharton's Jelly Mesenchymal Stem Cells for Tissue Engineering and Regenerative Medicine Applications.

PubMed

Jadalannagari, Sushma; Aljitawi, Omar S

2015-06-01

Mesenchymal stem cells (MSCs) from Wharton's jelly (WJ) of the human umbilical cord are perinatal stem cells that have self-renewal ability, extended proliferation potential, immunosuppressive properties, and are accordingly excellent candidates for tissue engineering. These MSCs are unique, easily accessible, and a noncontroversial cell source of regeneration in medicine. Wharton's jelly mesenchymal stem cells (WJMSCs) are multipotent and capable of multilineage differentiation into cells like adipocytes, bone, cartilage, and skeletal muscle upon exposure to appropriate conditions. The ectoderm is one of the three primary germ layers found in the very early embryo that differentiates into the epidermis, nervous system (spine, peripheral nerves, brain), and exocrine glands (mammary, sweat, salivary, and lacrimal glands). Accumulating evidence shows that MSCs obtained from WJ have an ectodermal differentiation potential. The current review examines this differentiation potential of WJMSC into the hair follicle, skin, neurons, and sweat glands along with discussing the potential utilization of such differentiation in regenerative medicine.

Drosophila TNF Modulates Tissue Tension in the Embryo to Facilitate Macrophage Invasive Migration.

PubMed

Ratheesh, Aparna; Biebl, Julia; Vesela, Jana; Smutny, Michael; Papusheva, Ekaterina; Krens, S F Gabriel; Kaufmann, Walter; Gyoergy, Attila; Casano, Alessandra Maria; Siekhaus, Daria E

2018-05-07

Migrating cells penetrate tissue barriers during development, inflammatory responses, and tumor metastasis. We study if migration in vivo in such three-dimensionally confined environments requires changes in the mechanical properties of the surrounding cells using embryonic Drosophila melanogaster hemocytes, also called macrophages, as a model. We find that macrophage invasion into the germband through transient separation of the apposing ectoderm and mesoderm requires cell deformations and reductions in apical tension in the ectoderm. Interestingly, the genetic pathway governing these mechanical shifts acts downstream of the only known tumor necrosis factor superfamily member in Drosophila, Eiger, and its receptor, Grindelwald. Eiger-Grindelwald signaling reduces levels of active Myosin in the germband ectodermal cortex through the localization of a Crumbs complex component, Patj (Pals-1-associated tight junction protein). We therefore elucidate a distinct molecular pathway that controls tissue tension and demonstrate the importance of such regulation for invasive migration in vivo. Copyright © 2018 Elsevier Inc. All rights reserved.

A novel missense mutation in the gene EDARADD associated with an unusual phenotype of hypohidrotic ectodermal dysplasia.

PubMed

Wohlfart, Sigrun; Söder, Stephan; Smahi, Asma; Schneider, Holm

2016-01-01

Hypohidrotic ectodermal dysplasia (HED) is a rare disorder characterized by deficient development of structures derived from the ectoderm including hair, nails, eccrine glands, and teeth. HED forms that are caused by mutations in the genes EDA, EDAR, or EDARADD may show almost identical phenotypes, explained by a common signaling pathway. Proper interaction of the proteins encoded by these three genes is important for the activation of the NF-κB signaling pathway and subsequent transcription of the target genes. Mutations in the gene EDARADD are most rarely implicated in HED. Here we describe a novel missense mutation, c.367G>A (p.Asp123Asn), in this gene which did not appear to influence the interaction between EDAR and EDARADD proteins, but led to an impaired ability to activate NF-κB signaling. Female members of the affected family showed either unilateral or bilateral amazia. In addition, an affected girl developed bilateral ovarian teratomas, possibly associated with her genetic condition. © 2015 Wiley Periodicals, Inc.

EDA mutation as a cause of hypohidrotic ectodermal dysplasia: a case report and review of the literature.

PubMed

Huang, S X; Liang, J L; Sui, W G; Lin, H; Xue, W; Chen, J J; Zhang, Y; Gong, W W; Dai, Y; Ou, M L

2015-08-28

Ectodermal dysplasia (ED) represents a collection of rare disorders that result from a failure of development of the tissues derived from the embryonic ectoderm. ED is often associated with hair, teeth, and skin abnormalities, which are serious conditions affecting the quality of life of the patient. To date, a large number of genes have been found to be associated with this syndrome. Here, we report a patient with hypohidrotic ED (HED) without family history. We identified that this patient's disorder arises from an X-linked HED with a mutation in the EDA gene (G299D) found by whole-exome sequencing. In addition, in this paper we summarize the disease-causing mutations based on current literature. Overall, recent clinical and genetic research involving patients with HED have uncovered a large number of pathogenic mutations in EDA, which might contribute to a full understanding of the function of EDA and the underlying mechanisms of HED caused by EDA mutations.

Novel variant in the TP63 gene associated to ankyloblepharon-ectodermal dysplasia-cleft lip/palate (AEC) syndrome.

PubMed

Gonzalez, Francisco; Loidi, Lourdes; Abalo-Lojo, Jose M

2017-01-01

Ankyloblepharon-ectodermal dysplasia-cleft lip/palate (AEC) syndrome is a disorder resulting from anomalous embryonic development of ectodermal tissues. There is evidence that AEC syndrome is caused by mutations in the TP63 gene, which encodes the p63 protein. This is an important regulatory protein involved in epidermal proliferation and differentiation. Genome sequencing was performed in DNA from peripheral blood leukocytes of a newborn with AEC syndrome and her parents. Variants were searched in all coding exons and intron-exon boundaries of the TP63 gene. A heterozygous missense variant (NM_003722.4:c.1063G>C (p.Asp355His) was found in the newborn patient. No variants were found in either of the parents. We identified a previously unreported variant in TP63 gene which seems to be involved in the somatic malformations found in the AEC syndrome. The absence of this variant in both parents suggests that the variant appeared de novo.

AmphiFoxQ2, a novel winged helix/forkhead gene, exclusively marks the anterior end of the amphioxus embryo

NASA Technical Reports Server (NTRS)

Yu, Jr-Kai; Holland, Nicholas D.; Holland, Linda Z.

2003-01-01

A full-length FoxQ-related gene (AmphiFoxQ2) was isolated from amphioxus. Expression is first detectable in the animal/anterior hemisphere at the mid blastula stage. The midpoint of this expression domain coincides with the anterior pole of the embryo and is offset dorsally by about 20 degrees from the animal pole. During the gastrula stage, expression is limited to the anterior ectoderm. By the early neurula stage, expression remains in the anterior ectoderm and also appears in the adjacent anterior mesendoderm. By the early larval stages, expression is detectable in the anteriormost ectoderm and in the rostral tip of the notochord. AmphiFoxQ2 is never expressed anywhere except at the anterior tip of amphioxus embryos and larvae. This is the first gene known that exclusively marks the anterior pole of chordate embryos. It may, therefore, play an important role in establishing and/or maintaining the anterior/posterior axis.

Review of ectodermal dysplasia: case report on treatment planning and surgical management of oligodontia with implant restorations.

PubMed

Li, Dehua; Liu, Yanpu; Ma, Wei; Song, Yingliang

2011-10-01

Dental implants have proven to be a reliable modality for the rehabilitation of missing teeth. However, there are limited reports on managing anodontia related to ectodermal dysplasia in the scientific literature. The severely reduced bone quantity due to the congenital absence of multiple natural teeth is the biggest challenge for the surgeon. There are a variety of bone augmentation procedures to establish adequate bone quantity, and the surgical planning should be used on an individual case basis. This is a report of a 19-year-old male patient affected by hypohidrotic ectodermal dysplasia. Oligodontia associated with severe atrophy of jaws was the chief complaint for seeking treatment. Based on clinical and radiographic examinations, 2 bone augmentation procedures were used to obtain sufficient width of alveolus for implant placement by performing an onlay bone graft in the maxilla and vertical distraction osteogenesis in the mandible. The treatment planning was discussed and informed consent was obtained.

Implant-supported Oral Rehabilitation in Child with Ectodermal Dysplasia - 4-year Follow-up.

PubMed

Cezária Triches, Thaisa; Ximenes, Marcos; Oliveira de Souza, João Gustavo; Rodrigues Lopes Pereira Neto, Armando; Cardoso, Antônio Carlos; Bolan, Michele

2017-01-01

Ectodermal dysplasia (ED) is an anomaly determined by genetic factors that alter ectodermal structures such as skin, hair, nails, glands, and teeth. Children affected by this condition require extensive, comprehensive, and multidisciplinary treatment. An 8-year-old female patient visited the Dentistry Clinic of the Federal University of Santa Catarina with the chief complaint of multiple missing teeth. The mother reported that the patient had ED. Clinical and radiographic examination revealed the congenital absence of several primary and permanent teeth and tooth germs. Subsequent oral rehabilitation comprised the application of a maxillary denture and mandibular implant-supported fixed prosthesis. The child was also supplied with a wig for further enhancement of esthetics aimed at improving her emotional wellbeing. Psychological follow-up and speech therapy were also provided. After 4 years of follow-up, implant-supported oral rehabilitation has proved to be a satisfactory treatment option, allowing restoration of masticatory, phonetic, and esthetic function, as well as an improvement in the patient's self-esteem and social wellbeing.

p63 protein is essential for the embryonic development of vibrissae and teeth

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rufini, Alessandro; Weil, Miguel; McKeon, Frank

2006-02-17

Development of skin appendages strongly depends on epithelial-mesenchymal interactions. One of the genes involved in this process is p63, a member of the p53 family of transcription factors, essential for ectodermal development, as elucidated by the phenotype of p63 knock-out mice. Surprisingly, no information on p63 expression in tooth and hair is yet available. Here, we show p63 expression during teeth and vibrissae morphogenesis in mouse embryos and we also show a correlation with the expression patterns of the epithelial marker keratin 5 and the proliferation marker Ki67. Our results show that p63 colocalizes with both K5 and Ki67 inmore » the epithelium of developing vibrissae, while in teeth p63 is expressed, together with K5, in the undifferentiated ectoderm (enamel organ), and in ameloblasts, a subpopulation of differentiated ectodermal cells. Moreover, p63 expression in tooth seems not to be fully colocalized with nuclear Ki67 expression.« less

Concepts in Practice as Sources of Order

ERIC Educational Resources Information Center

Hutchins, Edwin

2012-01-01

The framework for the study of concept formation embraced by the articles in this special issue makes it possible to observe and catalog the mechanisms by which conceptual structures in the wild achieve and maintain organization. I propose a provisional inventory of such mechanisms that includes the primitive mechanisms of dimensionality…

Mechanics of Fluid-Filled Interstitial Gaps. II. Gap Characteristics in Xenopus Embryonic Ectoderm.

PubMed

Barua, Debanjan; Parent, Serge E; Winklbauer, Rudolf

2017-08-22

The ectoderm of the Xenopus embryo is permeated by a network of channels that appear in histological sections as interstitial gaps. We characterized this interstitial space by measuring gap sizes, angles formed between adjacent cells, and curvatures of cell surfaces at gaps. From these parameters, and from surface-tension values measured previously, we estimated the values of critical mechanical variables that determine gap sizes and shapes in the ectoderm, using a general model of interstitial gap mechanics. We concluded that gaps of 1-4 μm side length can be formed by the insertion of extracellular matrix fluid at three-cell junctions such that cell adhesion is locally disrupted and a tension difference between cell-cell contacts and the free cell surface at gaps of 0.003 mJ/m 2 is generated. Furthermore, a cell hydrostatic pressure of 16.8 ± 1.7 Pa and an interstitial pressure of 3.9 ± 3.6 Pa, relative to the central blastocoel cavity of the embryo, was found to be consistent with the observed gap size and shape distribution. Reduction of cell adhesion by the knockdown of C-cadherin increased gap volume while leaving intracellular and interstitial pressures essentially unchanged. In both normal and adhesion-reduced ectoderm, cortical tension of the free cell surfaces at gaps does not return to the high values characteristic of the free surface of the whole tissue. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Transcriptional regulation of cranial sensory placode development

PubMed Central

Moody, Sally A.; LaMantia, Anthony-Samuel

2015-01-01

Cranial sensory placodes derive from discrete patches of the head ectoderm, and give rise to numerous sensory structures. During gastrulation, a specialized “neural border zone” forms around the neural plate in response to interactions between the neural and non-neural ectoderm and signals from adjacent mesodermal and/or endodermal tissues. This zone subsequently gives rise to two distinct precursor populations of the peripheral nervous system: the neural crest and the pre-placodal ectoderm (PPE). The PPE is a common field from which all cranial sensory placodes arise (adenohypophyseal, olfactory, lens, trigeminal, epibranchial, otic). Members of the Six family of transcription factors are major regulators of PPE specification, in partnership with co-factor proteins such as Eya. Six gene activity also maintains tissue boundaries between the PPE, neural crest and epidermis by repressing genes that specify the fates of those adjacent ectodermally-derived domains. As the embryo acquires anterior-posterior identity, the PPE becomes transcriptionally regionalized, and it subsequently subdivides into specific placodes with distinct developmental fates in response to signaling from adjacent tissues. Each placode is characterized by a unique transcriptional program that leads to the differentiation of highly specialized cells, such as neurosecretory cells, somatic sensory receptor cells, chemosensory neurons, peripheral glia and supporting cells. In this review, we summarize the transcriptional and signaling factors that regulate key steps of placode development, influence subsequent sensory neuron specification, and discuss what is known about mutations in some of the essential PPE genes that underlie human congenital syndromes. PMID:25662264

Post-embryonic larval development and metamorphosis of the hydroid Eudendrium racemosum (Cavolini) (Hydrozoa, Cnidaria)

NASA Astrophysics Data System (ADS)

Sommer, C.

1990-09-01

The morphology and histology of the planula larva of Eudendrium racemosum (Cavolini) and its metamorphosis into the primary polyp are described from light microscopic observations. The planula hatches as a differentiated gastrula. During the lecithotrophic larval period, large ectodermal mucous cells, embedded between epitheliomuscular cells, secrete a sticky slime. Two granulated cell types occur in the ectoderm that are interpreted as secretory and sensorynervous cells, but might also be representatives of only one cell type with a multiple function. The entoderm consists of yolk-storing gastrodermal cells, digestive gland cells, interstitial cells, cnidoblasts, and premature cnidocytes. The larva starts metamorphosis by affixing its blunt aboral pole to a substratum. While the planula flattens down, the mucous cells penetrate the mesolamella and migrate through the entoderm into the gastral cavity where they are lysed. Subsequently, interstitial cells, cnidoblasts, and premature cnidocytes migrate in the opposite direction, i.e. from entoderm to ectoderm. Then, the polypoid body organization, comprising head (hydranth), stem and foot, all covered by peridermal secretion, becomes recognisable. An oral constriction divides the hypostomal portion of the gastral cavity from the stomachic portion. Within the hypostomal entoderm, cells containing secretory granules differentiate. Following growth and the multiplication of tentacles, the head periderm disappears. A ring of gland cells differentiates at the hydranth's base. The positioning of cnidae in the tentacle ectoderm, penetration of the mouth opening and the multiplication of digestive gland cells enable the polyp to change from lecithotrophic to planktotrophic nutrition.

Diagnosis of X-Linked Hypohidrotic Ectodermal Dysplasia by Meibography and Infrared Thermography of the Eye.

PubMed

Kaercher, Thomas; Dietz, Jasna; Jacobi, Christina; Berz, Reinhold; Schneider, Holm

2015-09-01

X-linked hypohidrotic ectodermal dysplasia (XLHED) is the most common form of ectodermal dysplasia. Clinical characteristics include meibomian gland disorder and the resulting hyperevaporative dry eye. In this study, we evaluated meibography and ocular infrared thermography as novel methods to diagnose XLHED. Eight infants, 12 boys and 14 male adults with XLHED and 12 healthy control subjects were subjected to a panel of tests including the ocular surface disease index (OSDI), meibography and infrared thermography, non-invasive measurement of tear film break-up time (NIBUT) and osmolarity, Schirmer's test, lissamine green staining and fluorescein staining. Sensitivity and specificity were determined for single tests and selected test combinations. Meibography had 100% sensitivity and specificity for identifying XLHED. Infrared thermography, a completely non-invasive procedure, revealed a typical pattern for male subjects with XLHED. It was, however, less sensitive (86% for adults and 67% for children) than meibography or a combination of established routine tests. In adults, OSDI and NIBUT were the best single routine tests (sensitivity of 86% and 71%, respectively), whereas increased tear osmolarity appeared as a rather unspecific ophthalmic symptom. In children, NIBUT was the most convincing routine test (sensitivity of 91%). Meibography is the most reliable ophthalmic examination to establish a clinical diagnosis in individuals with suspected hypohidrotic ectodermal dysplasia, even before genetic test results are available. Tear film tests and ocular surface staining are less sensitive in children, but very helpful for estimating the severity of ocular surface disease in individuals with known XLHED.

Ocular surface involvements in ectrodactyly-ectodermal dysplasia-cleft syndrome.

PubMed

Kennedy, David P; Chandler, John W; McCulley, James P

2015-06-01

To present the ocular manifestation of 2 cases of ectrodactyly-ectodermal dysplasia-cleft syndrome, a multiple congenital anomaly syndrome caused by a single point mutation of the p63 gene that controls epidermal development and homeostasis and to present treatment options. Patient 1 presented with mild signs and symptoms of dry eye and limbal stem cell deficiency with retention of 20/30 vision. Patient 2 presented with severe signs and symptoms of limbal stem cell deficiency with diffuse corneal scarring and counting fingers vision. This second patient's course was complicated by allergic conjunctivitis and advanced steroid-induced glaucoma. The cause of visual loss in ectrodactyly-ectodermal dysplasia-cleft syndrome appears to be multifactorial and likely includes inflammation of the ocular surface, tear film abnormalities, eyelid abnormalities, and limbal stem cell deficiency. Treatment modalities including lubrication, contact lenses, and limbal stem cell transplantation are reviewed. The ophthalmic conditions seen in ectrodactyly-ectodermal dysplasia-cleft syndrome frequently lead to vision loss. Early correct diagnosis and appropriate therapy are paramount because p63 gene mutations have a critical role in maintaining the integrity of the ocular surface in the setting of limbal stem cell deficiency, especially if there are other ocular surface insults such as lid disease, meibomian gland dysfunction and toxicity from topical medications. Patients should be monitored at regular, frequent intervals; and particular attention should be taken to avoid adverse secondary effects of these conditions and medications. Copyright © 2015 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Xwnt-8 and lithium can act upon either dorsal mesodermal or neurectodermal cells to cause a loss of forebrain in Xenopus embryos

NASA Technical Reports Server (NTRS)

Fredieu, J. R.; Cui, Y.; Maier, D.; Danilchik, M. V.; Christian, J. L.

1997-01-01

When Xenopus gastrulae are made to misexpress Xwnt-8, or are exposed to lithium ions, they develop with a loss of anterior structures. In the current study, we have characterized the neural defects produced by either Xwnt-8 or lithium and have examined potential cellular mechanisms underlying this anterior truncation. We find that the primary defect in embryos exposed to lithium at successively earlier stages during gastrulation is a progressive rostral to caudal deletion of the forebrain, while hindbrain and spinal regions of the CNS remain intact. Misexpression of Xwnt-8 during gastrulation produces an identical loss of forebrain. Our results demonstrate that lithium and Wnts can act upon either prospective neural ectodermal cells, or upon dorsal mesodermal cells, to cause a loss of anterior pattern. Specifically, ectodermal cells isolated from lithium- or Wnt-exposed embryos are unable to form anterior neural tissue in response to inductive signals from normal dorsal mesoderm. In addition, although dorsal mesodermal cells from lithium- or Wnt-exposed embryos are specified properly, and produce normal levels of the anterior neural inducing molecules noggin and chordin, they show a greatly reduced capacity to induce anterior neural tissue in conjugated ectoderm. Taken together, our results are consistent with a model in which Wnt- or lithium-mediated signals can induce either mesodermal or ectodermal cells to produce a dominant posteriorizing morphogen which respecifies anterior neural tissue as posterior.

Co-ordinated ocular development from human iPS cells and recovery of corneal function.

PubMed

Hayashi, Ryuhei; Ishikawa, Yuki; Sasamoto, Yuzuru; Katori, Ryosuke; Nomura, Naoki; Ichikawa, Tatsuya; Araki, Saori; Soma, Takeshi; Kawasaki, Satoshi; Sekiguchi, Kiyotoshi; Quantock, Andrew J; Tsujikawa, Motokazu; Nishida, Kohji

2016-03-17

The eye is a complex organ with highly specialized constituent tissues derived from different primordial cell lineages. The retina, for example, develops from neuroectoderm via the optic vesicle, the corneal epithelium is descended from surface ectoderm, while the iris and collagen-rich stroma of the cornea have a neural crest origin. Recent work with pluripotent stem cells in culture has revealed a previously under-appreciated level of intrinsic cellular self-organization, with a focus on the retina and retinal cells. Moreover, we and others have demonstrated the in vitro induction of a corneal epithelial cell phenotype from pluripotent stem cells. These studies, however, have a single, tissue-specific focus and fail to reflect the complexity of whole eye development. Here we demonstrate the generation from human induced pluripotent stem cells of a self-formed ectodermal autonomous multi-zone (SEAM) of ocular cells. In some respects the concentric SEAM mimics whole-eye development because cell location within different zones is indicative of lineage, spanning the ocular surface ectoderm, lens, neuro-retina, and retinal pigment epithelium. It thus represents a promising resource for new and ongoing studies of ocular morphogenesis. The approach also has translational potential and to illustrate this we show that cells isolated from the ocular surface ectodermal zone of the SEAM can be sorted and expanded ex vivo to form a corneal epithelium that recovers function in an experimentally induced animal model of corneal blindness.

How rare is complex life in the Milky Way?

PubMed

Bounama, Christine; von Bloh, Werner; Franck, Siegfried

2007-10-01

An integrated Earth system model was applied to calculate the number of habitable Earth-analog planets that are likely to have developed primitive (unicellular) and complex (multicellular) life in extrasolar planetary systems. The model is based on the global carbon cycle mediated by life and driven by increasing stellar luminosity and plate tectonics. We assumed that the hypothetical primitive and complex life forms differed in their temperature limits and CO(2) tolerances. Though complex life would be more vulnerable to environmental stress, its presence would amplify weathering processes on a terrestrial planet. The model allowed us to calculate the average number of Earth-analog planets that may harbor such life by using the formation rate of Earth-like planets in the Milky Way as well as the size of a habitable zone that could support primitive and complex life forms. The number of planets predicted to bear complex life was found to be approximately 2 orders of magnitude lower than the number predicted for primitive life forms. Our model predicted a maximum abundance of such planets around 1.8 Ga ago and allowed us to calculate the average distance between potentially habitable planets in the Milky Way. If the model predictions are accurate, the future missions DARWIN (up to a probability of 65%) and TPF (up to 20%) are likely to detect at least one planet with a biosphere composed of complex life.

CD71(high) population represents primitive erythroblasts derived from mouse embryonic stem cells.

PubMed

Chao, Ruihua; Gong, Xueping; Wang, Libo; Wang, Pengxiang; Wang, Yuan

2015-01-01

The CD71/Ter119 combination has been widely used to reflect dynamic maturation of erythrocytes in vivo. However, because CD71 is expressed on all proliferating cells, it is unclear whether it can be utilized as an erythrocyte-specific marker during differentiation of embryonic stem cells (ESCs). In this study, we revealed that a population expressing high level of CD71 (CD71(high)) during mouse ESC differentiation represented an in vitro counterpart of yolk sac-derived primitive erythroblasts (EryPs) isolated at 8.5days post coitum. In addition, these CD71(high) cells went through "maturational globin switching" and enucleated during terminal differentiation in vitro that were similar to the yolk sac-derived EryPs in vivo. We further demonstrated that the formation of CD71(high) population was regulated differentially by key factors including Scl, HoxB4, Eaf1, and Klf1. Taken together, our study provides a technical advance that allows efficient segregation of EryPs from differentiated ESCs in vitro for further understanding molecular regulation during primitive erythropoiesis. Copyright © 2014. Published by Elsevier B.V.

First finding of impact melt in the IIE Netschaëvo meteorite

NASA Astrophysics Data System (ADS)

Roosbroek, N.; Pittarello, L.; Greshake, A.; Debaille, V.; Claeys, P.

2016-02-01

About half of the IIE nonmagmatic iron meteorites contain silicate inclusions with a primitive to differentiated nature. The presence of preserved chondrules has been reported for two IIE meteorites so far, Netschaëvo and Mont Dieu, which represent the most primitive silicate material within this group. In this study, silicate inclusions from two samples of Netschaëvo were examined. Both silicate inclusions are characterized by a porphyritic texture dominated by clusters of coarse-grained olivine and pyroxene, set in a fine-grained groundmass that consists of new crystals of olivine and a glassy appearing matrix. This texture does not correspond to the description of the previously examined pieces of Netschaëvo, which consist of primitive chondrule-bearing angular clasts. Detailed petrographic observations and geochemical analyses suggest that the investigated samples of Netschaëvo consist of quenched impact melt. This implies that Netschaëvo is a breccia containing metamorphosed and impact-melt rock (IMR) clasts and that collisions played a major role in the formation of the IIE group.

SUPERNOVA NEUTRINO NUCLEOSYNTHESIS OF THE RADIOACTIVE {sup 92}Nb OBSERVED IN PRIMITIVE METEORITES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayakawa, T.; Chiba, S.; Iwamoto, N.

2013-12-10

The isotope {sup 92}Nb decays to {sup 92}Zr with a half-life of 3.47 × 10{sup 7} yr. Although this isotope does not exist in the current solar system, initial abundance ratios for {sup 92}Nb/{sup 93}Nb at the time of solar system formation have been measured in primitive meteorites. The astrophysical origin of this material, however, has remained unknown. In this Letter, we present new calculations which demonstrate a novel origin for {sup 92}Nb via neutrino-induced reactions in core-collapse supernovae (ν-process). Our calculated result shows that the observed ratio of {sup 92}Nb/{sup 93}Nb ∼ 10{sup –5} can be explained by the ν-process.

Chemical evolution and the origin of life

NASA Technical Reports Server (NTRS)

Oro, J.

1983-01-01

A review is presented of recent advances made in the understanding of the formation of carbon compounds in the universe and the occurrence of processes of chemical evolution. Topics discussed include the principle of evolutionary continuity, evolution as a fundamental principle of the physical universe, the nuclear synthesis of biogenic elements, organic cosmochemistry and interstellar molecules, the solar nebula and the solar system in chemical evolution, the giant planets and Titan in chemical evolution, and comets and their interaction with the earth. Also examined are carbonaceous chondrites, environment of the primitive earth, energy sources available on the primitive earth, the synthesis of biochemical monomers and oligomers, the abiotic transcription of nucleotides, unified prebiotic and enzymatic mechanisms, phospholipids and membranes, and protobiological evolution.

Why we need asteroid sample return mission?

NASA Astrophysics Data System (ADS)

Barucci, Maria Antonietta

2016-07-01

Small bodies retain evidence of the primordial solar nebula and the earliest solar system processes that shaped their evolution. They may also contain pre-solar material as well as complex organic molecules, which could have a major role to the development of life on Earth. For these reasons, asteroids and comets have been targets of interest for missions for over three decades. However, our knowledge of these bodies is still very limited, and each asteroid or comet visited by space mission has revealed unexpected scientific results, e.g. the structure and nature of comet 67P/Churyumov-Gerasimenko (67P/C-G) visited by the Rosetta mission. Only in the laboratory can instruments with the necessary precision and sensitivity be applied to individual components of the complex mixture of materials that forms a small body regolith, to determine their precise chemical and isotopic composition. Such measurements are vital for revealing the evidence of stellar, interstellar medium, pre-solar nebula and parent body processes that are retained in primitive material, unaltered by atmospheric entry or terrestrial contamination. For those reasons, sample return missions are considered a high priority by a number of the leading space agencies. Abundant within the inner Solar System and the main impactors on terrestrial planets, small bodies may have been the principal contributors of the water and organic material essential to create life on Earth. Small bodies can therefore be considered to be equivalent to DNA for unravelling our solar system's history, offering us a unique window to investigate both the formation of planets and the origin of life. A sample return mission to a primitive Near-Earth Asteroid (NEA) has been study at ESA from 2008 in the framework of ESA's Cosmic Vision (CV) programme, with the objective to answer to the fundamental CV questions "How does the Solar System work?" and "What are the conditions for life and planetary formations?". The returned material will allow us to study in terrestrial laboratories some of the most primitive materials available to investigate early solar system formation processes, to explore initial stages of habitable planet formation, to identify and characterize the organics and volatiles in a primitive asteroid. The ideal easy target body for such mission is a D type NEA. D types are the most abundant asteroids beyond the outer edge of the main belt. It is likely that they formed much further out in the Solar System, possibly as far as the transneptunian objects, and were subsequently captured in their present locations following the migration of the gas giants. Spectral features indicate that these bodies are organic rich, contain fine anhydrous minerals but also may be volatile rich and appear to be the most primitive rocky material present in the solar system. In addition to addressing the major science goals, sample return mission from a NEA also involved innovative European technologies. The key sample return capabilities, i.e. asteroid navigation, touch and go, sampling mechanism and the re-entry capsule have reached at ESA a validation status to enter implementation phase. The development of sample return technology represents in Europe a crucial element for planetary science and for the space technology development.

The formation of the avian scapula blade takes place in the hypaxial domain of the somites and requires somatopleure-derived BMP signals.

PubMed

Wang, Baigang; He, Liwen; Ehehalt, Florian; Geetha-Loganathan, Poongodi; Nimmagadda, Suresh; Christ, Bodo; Scaal, Martin; Huang, Ruijin

2005-11-01

The avian scapula is a long bone located dorsally on the thorax. The cranial part that articulates with the upper limb is derived from the somatopleure of the forelimb field, while the caudal part, the scapula blade, originates from the dermomyotomes of brachial and thoracic somites. In previous studies, we have shown that scapula blade formation is intrinsically controlled by segment-specific information as well as extrinsically by ectoderm-derived signals. Here, we addressed the role of signals derived from the lateral plate mesoderm on scapula development. Chick-quail chimera experiments revealed that scapula precursor cells are located within the hypaxial domain of the dermomyotome adjacent to somatopleural cells. Barrier implantation between these two cell populations inhibited scapula blade formation. Furthermore, we identified BMPs as scapula-inducing signals from the somatopleure using injection of Noggin-producing cells into the hypaxial domain of scapula-forming dermomyotomes. We found that inhibition of BMP activity interfered with scapula-specific Pax1 expression and scapula blade formation. Taken together, we demonstrate that the scapula-forming cells located within the hypaxial somitic domain require BMP signals derived from the somatopleure for their specification and differentiation.

Development, triploblastism, physics of wetting and the Cambrian explosion.

PubMed

Fleury, Vincent

2013-09-01

The Cambrian explosion is characterized by the sudden outburst of organized animal plans, which occurred circa 530 M years ago. Around that time, many forms of animal life appeared, including several which have since disappeared. There is no general consensus about "why" this happened, and why it had any form of suddenness. However, all organized animal plans share a common feature: they are triploblastic, i.e., composed of 3 layers of tissue, endoderm, ectoderm and mesoderm. I show here that, within simple hypotheses, the formation of the mesoderm has intrinsically a physical exponential dynamics, leading rapidly to triploblastism, and eventually, to animal formation. A novel physico-mathematical framework including epithelium-mesenchyme transition, visco-elastic constitutive equations, and conservation laws, is presented which allows one to describe gastrulation as a self-wetting phenomenon of a soft solid onto itself. This phenomenon couples differentiation and migration during gastrulation, and leads in a closed form to an exponential scaling law for the formation of the mesoderm. Therefore, the Cambrian explosion might have started, actually, by a true viscoelastic "explosion": the exponential run-away of mesenchymal cells.

Herediatary anhidrotic ectodermal dysplasia. Studies in a Nigerian famil.

PubMed Central

Familusi, J B; Jaiyesimi, F; Ojo, C O; Attah, E B

1975-01-01

Studies in a Nigerian family with hereditary anhidrous ectodermal dysplasia are reported. Microscopical examinations of finger tips for sweat pores were diagnostic in phenotypes, and it is suggested that this simple nonsurgical procedure is a preferred alternative to skin biopsies in the diagnosis of the syndrome. The clinical implications of a tropical environment for the syndrome, as well as the factors that may favour maintenance of the gene in such an environment are discussed. Images FIG. 1 FIG. 2 FIG. 4 FIG. 5 FIG. 6 PMID:1200681

Oral health considerations in a patient with oligosymptomatic ectrodactyly-ectodermal dysplasia-cleft syndrome.

PubMed

Sharma, Gaurav; Nagpal, Archna

2017-01-01

Ectrodactyly-ectodermal dysplasia-cleft (EEC) syndrome-a complex, pleiotropic disorder resulting in multiple congenital anomalies-has an unpredictable clinical expression and is typically manifested as an autosomal-dominant trait. This article presents a rare case of oligosymptomatic EEC syndrome in a 19-year-old man who exhibited atypical dental findings but no cleft lip or palate. This article is intended to create awareness about this rare syndrome and highlight the role of oral healthcare specialists in improving the quality of life for patients with EEC.

Anhidrotic ectodermal dysplasia gene region cloned in yeast artificial chromosomes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kere, J.; Grzeschik, K.H.; Limon, J.

1993-05-01

Anhidrotic ectodermal dysplasia (EDA), an X-chromosomal recessive disorder, is expressed in a few females with chromosomal translocations involving bands Xq12-q13. Using available DNA markers from the region and somatic cell hybrids the authors mapped the X-chromosomal breakpoints in two such translocations. The breakpoints were further mapped within a yeast artificial chromosome contig constructed by chromosome walking techniques. Genomic DNA markers that map between the two translocation breakpoints were recovered representing putative portions of the EDA gene. 32 refs., 3 figs., 1 tab.

Apoptosis contributes to placode morphogenesis in the posterior placodal area of mice.

PubMed

Washausen, Stefan; Knabe, Wolfgang

2013-05-01

In the embryonic head of vertebrates, neurogenic and non-neurogenic ectodermal placodes arise from the panplacodal primordium. Whether and how growth processes of the ectodermal layer, changes in the transcriptional precursor cell profile, or positional changes among precursor cells contribute to interplacodal boundary formation is subject to intense investigation. We demonstrate that large scale apoptosis in the multiplacodal posterior placodal area (PPA) of C57BL/6 mice assists in the segregation of otic and epibranchial placodes. Complex patterns of interplacodal apoptosis precede and parallel the structural individualization of high-grade thickened placodes, with the fundamental separation between otic and epibranchial precursor cells being seemingly prevalent. Interplacodal apoptosis between the emerging epibranchial placodes, which express Neurogenin2 prior to their complete structural individualization, comes out most strongly between the epibranchial placodes 1 and 2. Apoptosis then moves from interplacodal to intraplacodal positions in dorsal and, with a delay, ventral parts of the epibranchial placodes. Intraplacodal apoptosis appears to exert corrective actions among premigratory neuroblasts, and helps to eliminate the epibranchial placodes. The present findings confirm and extend earlier observations in Tupaia belangeri (Washausen et al. in Dev Biol 278:86-102, 2005), regarded as an intermediate between primates and other eutherian orders. Having now available maps of apoptosis in the PPA of embryonic mice, further investigations into the functions of inter- and intraplacodal apoptosis can be carried out in an experimentally and genetically more accessible mammalian model organism.

Mechanical Effects of the Surface Ectoderm on Optic Vesicle Morphogenesis in the Chick Embryo

PubMed Central

Hosseini, Hadi S.; Beebe, David C.; Taber, Larry A.

2014-01-01

Precise shaping of the eye is crucial for proper vision. Here, we use experiments on chick embryos along with computational models to examine the mechanical factors involved in the formation of the optic vesicles (OVs), which grow outward from the forebrain of the early embryo. First, mechanical dissections were used to remove the surface ectoderm (SE), a membrane that contacts the outer surfaces of the OVs. Principal components analysis of OV shapes suggests that the SE exerts asymmetric loads that cause the OVs to flatten and shear caudally during the earliest stages of eye development and later to bend in the caudal and dorsal directions. These deformations cause the initially spherical OVs to become pear-shaped. Exposure to the myosin II inhibitor blebbistatin reduced these effects, suggesting that cytoskeletal contraction controls OV shape by regulating tension in the SE. To test the physical plausibility of these interpretations, we developed 2-D finite-element models for frontal and transverse cross-sections of the forebrain, including frictionless contact between the SE and OVs. With geometric data used to specify differential growth in the OVs, these models were used to simulate each experiment (control, SE removed, no contraction). For each case, the predicted shape of the OV agrees reasonably well with experiments. The results of this study indicate that differential growth in the OV and external pressure exerted by the SE are suffcient to cause the global changes in OV shape observed during the earliest stages of eye development. PMID:25458577

Bud detachment in hydra requires activation of fibroblast growth factor receptor and a Rho–ROCK–myosin II signaling pathway to ensure formation of a basal constriction

PubMed Central

Holz, Oliver; Apel, David; Steinmetz, Patrick; Lange, Ellen; Hopfenmüller, Simon; Ohler, Kerstin; Sudhop, Stefanie

2017-01-01

Background: Hydra propagates asexually by exporting tissue into a bud, which detaches 4 days later as a fully differentiated young polyp. Prerequisite for detachment is activation of fibroblast growth factor receptor (FGFR) signaling. The mechanism which enables constriction and tissue separation within the monolayered ecto‐ and endodermal epithelia is unknown. Results: Histological sections and staining of F‐actin by phalloidin revealed conspicuous cell shape changes at the bud detachment site indicating a localized generation of mechanical forces and the potential enhancement of secretory functions in ectodermal cells. By gene expression analysis and pharmacological inhibition, we identified a candidate signaling pathway through Rho, ROCK, and myosin II, which controls bud base constriction and rearrangement of the actin cytoskeleton. Specific regional myosin phosphorylation suggests a crucial role of ectodermal cells at the detachment site. Inhibition of FGFR, Rho, ROCK, or myosin II kinase activity is permissive for budding, but represses myosin phosphorylation, rearrangement of F‐actin and constriction. The young polyp remains permanently connected to the parent by a broad tissue bridge. Conclusions: Our data suggest an essential role of FGFR and a Rho‐ROCK‐myosin II pathway in the control of cell shape changes required for bud detachment. Developmental Dynamics 246:502–516, 2017. © 2017 The Authors Developmental Dynamics published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists PMID:28411398

Bud detachment in hydra requires activation of fibroblast growth factor receptor and a Rho-ROCK-myosin II signaling pathway to ensure formation of a basal constriction.

PubMed

Holz, Oliver; Apel, David; Steinmetz, Patrick; Lange, Ellen; Hopfenmüller, Simon; Ohler, Kerstin; Sudhop, Stefanie; Hassel, Monika

2017-07-01

Hydra propagates asexually by exporting tissue into a bud, which detaches 4 days later as a fully differentiated young polyp. Prerequisite for detachment is activation of fibroblast growth factor receptor (FGFR) signaling. The mechanism which enables constriction and tissue separation within the monolayered ecto- and endodermal epithelia is unknown. Histological sections and staining of F-actin by phalloidin revealed conspicuous cell shape changes at the bud detachment site indicating a localized generation of mechanical forces and the potential enhancement of secretory functions in ectodermal cells. By gene expression analysis and pharmacological inhibition, we identified a candidate signaling pathway through Rho, ROCK, and myosin II, which controls bud base constriction and rearrangement of the actin cytoskeleton. Specific regional myosin phosphorylation suggests a crucial role of ectodermal cells at the detachment site. Inhibition of FGFR, Rho, ROCK, or myosin II kinase activity is permissive for budding, but represses myosin phosphorylation, rearrangement of F-actin and constriction. The young polyp remains permanently connected to the parent by a broad tissue bridge. Our data suggest an essential role of FGFR and a Rho-ROCK-myosin II pathway in the control of cell shape changes required for bud detachment. Developmental Dynamics 246:502-516, 2017. © 2017 The Authors Developmental Dynamics published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists. © 2017 The Authors Developmental Dynamics published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists.

Cell Fate and Differentiation of the Developing Ocular Lens

PubMed Central

Greiling, Teri M. S.; Aose, Masamoto

2010-01-01

Purpose. Even though zebrafish development does not include the formation of a lens vesicle, the authors' hypothesis is that the processes of cell differentiation are similar in zebrafish and mammals and determine cell fates in the lens. Methods. Two-photon live embryo imaging was used to follow individual fluorescently labeled cells in real-time from the placode stage at 16 hours postfertilization (hpf) until obvious morphologic differentiation into epithelium or fiber cells had occurred at approximately 28 hpf. Immunohistochemistry was used to label proliferating, differentiating, and apoptotic cells. Results. Similar to the mammal, cells in the teleost peripheral lens placode migrated to the anterior lens mass and differentiated into an anterior epithelium. Cells in the central lens placode migrated to the posterior lens mass and differentiated into primary fiber cells. Anterior and posterior polarization in the zebrafish lens mass was similar to mammalian lens vesicle polarization. Primary fiber cell differentiation was apparent at approximately 21 hpf, before separation of the lens from the surface ectoderm, as evidenced by cell elongation, exit from the cell cycle, and expression of Zl-1, a marker for fiber differentiation. TUNEL labeling demonstrated that apoptosis was not a primary mechanism for lens separation from the surface ectoderm. Conclusions. Despite the absence of a lens vesicle in the zebrafish embryo, lens organogenesis appears to be well conserved among vertebrates. Results using three-dimensional live embryo imaging of zebrafish development showed minimal differences and strong similarities in the fate of cells in the zebrafish and mammalian lens placode. PMID:19834024

The embryologic development of the human external auditory meatus. Preliminary report.

PubMed

Nishimura, Y; Kumoi, T

1992-01-01

During the final period of embryogenesis, a funnel-shaped tube continues medially into the mesenchymal tissue forming a curved path. Although this may sound simple, the development occurring during early fetal life is in fact very complex. At first, ectodermal cells proliferate to fill the lumen of the meatus, forming the meatal plug, and then at 10 weeks the bottom of the plug extends in a disc-like fashion, so that in the horizontal plane the meatus is boot-shaped with a narrow neck and the sole of the meatal plug spreading widely to form the future tympanic membrane medially. At the same time, the plug in the proximal portion of the neck starts to be resorbed. In the 13-week fetus, the disc-like plug begins to show signs of its final destiny; the innermost surface of the plug in contact with the anlage of the malleus is ready to contribute to the formation of the tympanic membrane. In the 15-week fetus, the innermost portion of the disc-like plug splits, leaving a thin ectodermal cell layer of immature tympanic membrane. The neck of the boot forms the border between the primary and secondary meatus, and is the last part to split. In the 16.5-week fetus, the meatus is fully patent throughout its entire length, although the lumen is still narrow and curved. In the 18-week fetus, the meatus is already fully expanded to its complete form.

Formation of nucleoside 5'-polyphosphates under potentially prebiological conditions

NASA Technical Reports Server (NTRS)

Lohrmann, R.

1976-01-01

The characteristics and efficiencies of biochemical reactions involving nucleoside 5'-diphosphates and -triphosphates (important substrates of RNA and DNA synthesis) under conditions corresponding to the primitive prebiotic earth are investigated. Urea catalysis of the formation of linear inorganic polyphosphates and metal ions promoting the reactions are discussed. Linear polyphosphate was incubated with Mg(++) in the presence of a nucleoside 5'-phosphate, to yield nucleoside 5'-polyphosphates when products are dried, while Mg(++) prompts depolymerization to trimetaphosphate in aqueous solutions. Plausible biogenetic pathways are examined.

The formation of IIE iron meteorites investigated by the chondrule-bearing Mont Dieu meteorite

NASA Astrophysics Data System (ADS)

van Roosbroek, N.; Debaille, V.; Pittarello, L.; Goderis, S.; Humayun, M.; Hecht, L.; Jourdan, F.; Spicuzza, M. J.; Vanhaecke, F.; Claeys, Ph.

2015-07-01

A 435 kg piece of the Mont Dieu iron meteorite (MD) contains cm-sized silicate inclusions. Based on the concentration of Ni, Ga, Ge, and Ir (8.59 ± 0.32 wt%, 25.4 ± 0.9 ppm, 61 ± 2 ppm, 7.1 ± 0.4 ppm, respectively) in the metal host, this piece can be classified as a IIE nonmagmatic iron. The silicate inclusions possess a chondritic mineralogy and relict chondrules occur throughout the inclusions. Major element analysis, oxygen isotopic analysis (Δ17O = 0.71 ± 0.02‰), and mean Fa and Fs molar contents (Fa15.7 ± 0.4 and Fs14.4 ± 0.5) indicate that MD originated as an H chondrite. Because of strong similarities with Netschaëvo IIE, MD can be classified in the most primitive subgroup of the IIE sequence. 40Ar/39Ar ages of 4536 ± 59 Ma and 4494 ± 95 Ma obtained on pyroxene and plagioclase inclusions show that MD belongs to the old (~4.5 Ga) group of IIE iron meteorites and that it has not been perturbed by any subsequent heating event following its formation. The primitive character of MD sheds light on the nature of its formation process, its thermal history, and the evolution of its parent body.

Drama for Classroom and Stage.

ERIC Educational Resources Information Center

Johnson, Albert and Bertha

This book with a three-part format contains information which the would-be thespian needs to know for maximum enjoyment and success in stage activities. The first part, "Heritage," traces the history and development of the theater from primitive ritual through the drama of classical Greece and Rome, the Renaissance, and modern Europe and America,…

The Suffix "-oso" in Central American Spanish.

ERIC Educational Resources Information Center

Scavnicky, Gary Eugene A.

1982-01-01

Examines the lexical formative "-oso," which is added to nominal and verbal roots to form adjectives to denote possession of the quality contained in the primitive, in Central American Spanish. Concludes it is used with traditional Spanish denotations and has undergone various semantic shifts and is being applied to roots in a completely…

Complex igneous processes and the formation of the primitive lunar crustal rocks

NASA Technical Reports Server (NTRS)

Longhi, J.; Boudreau, A. E.

1979-01-01

Crystallization of a magma ocean with initial chondritic Ca/Al and REE ratios such as proposed by Taylor and Bence (TB, 1975), is capable of producing the suite of primitive crustal rocks if the magma ocean underwent locally extensive assimilation and mixing in its upper layers as preliminary steps in formation of an anorthositic crust. Lunar anorthosites were the earliest permanent crustal rocks to form the result of multiple cycles of suspension and assimilation of plagioclase in liquids fractionating olivine and pyroxene. There may be two series of Mg-rich cumulate rocks: one which developed as a result of the equilibration of anorthositic crust with the magma ocean; the other which formed in the later stages of the magma ocean during an epoch of magma mixing and ilmenite crystallization. This second series may be related to KREEP genesis. It is noted that crystallization of the magma ocean had two components: a low pressure component which produced a highly fractionated and heterogeneous crust growing downward and a high pressure component which filled in the ocean from the bottom up, mostly with olivine and low-Ca pyroxene.

Water Delivery and Giant Impacts in the 'Grand Tack' Scenario

NASA Technical Reports Server (NTRS)

O'Brien, David P.; Walsh, Kevin J.; Morbidelli, Alessandro; Raymond, Sean N.; Mandell, Avi M.

2014-01-01

A new model for terrestrial planet formation has explored accretion in a truncated protoplanetary disk, and found that such a configuration is able to reproduce the distribution of mass among the planets in the Solar System, especially the Earth/Mars mass ratio, which earlier simulations have generally not been able to match. Walsh et al. tested a possible mechanism to truncate the disk-a two-stage, inward-then-outward migration of Jupiter and Saturn, as found in numerous hydrodynamical simulations of giant planet formation. In addition to truncating the disk and producing a more realistic Earth/Mars mass ratio, the migration of the giant planets also populates the asteroid belt with two distinct populations of bodies-the inner belt is filled by bodies originating inside of 3 AU, and the outer belt is filled with bodies originating from between and beyond the giant planets (which are hereafter referred to as 'primitive' bodies). One implication of the truncation mechanism proposed in Walsh et al. is the scattering of primitive planetesimals onto planet-crossing orbits during the formation of the planets. We find here that the planets will accrete on order 1-2% of their total mass from these bodies. For an assumed value of 10% for the water mass fraction of the primitive planetesimals, this model delivers a total amount of water comparable to that estimated to be on the Earth today. The radial distribution of the planetary masses and the dynamical excitation of their orbits are a good match to the observed system. However, we find that a truncated disk leads to formation timescales more rapid than suggested by radiometric chronometers. In particular, the last giant impact is typically earlier than 20 Myr, and a substantial amount of mass is accreted after that event. This is at odds with the dating of the Moon-forming impact and the estimated amount of mass accreted by Earth following that event. However, 5 of the 27 planets larger than half an Earth mass formed in all simulations do experience large late impacts and subsequent accretion consistent with those constraints.

ORAI1 mutations abolishing store-operated Ca2+ entry cause anhidrotic ectodermal dysplasia with immunodeficiency.

PubMed

Lian, Jayson; Cuk, Mario; Kahlfuss, Sascha; Kozhaya, Lina; Vaeth, Martin; Rieux-Laucat, Frédéric; Picard, Capucine; Benson, Melina J; Jakovcevic, Antonia; Bilic, Karmen; Martinac, Iva; Stathopulos, Peter; Kacskovics, Imre; Vraetz, Thomas; Speckmann, Carsten; Ehl, Stephan; Issekutz, Thomas; Unutmaz, Derya; Feske, Stefan

2017-11-16

Store-operated Ca 2+ entry (SOCE) through Ca 2+ release-activated Ca 2+ channels is an essential signaling pathway in many cell types. Ca 2+ release-activated Ca 2+ channels are formed by ORAI1, ORAI2, and ORAI3 proteins and activated by stromal interaction molecule (STIM) 1 and STIM2. Mutations in the ORAI1 and STIM1 genes that abolish SOCE cause a combined immunodeficiency (CID) syndrome that is accompanied by autoimmunity and nonimmunologic symptoms. We performed molecular and immunologic analysis of patients with CID, anhidrosis, and ectodermal dysplasia of unknown etiology. We performed DNA sequencing of the ORAI1 gene, modeling of mutations on ORAI1 crystal structure, analysis of ORAI1 mRNA and protein expression, SOCE measurements, immunologic analysis of peripheral blood lymphocyte populations by using flow cytometry, and histologic and ultrastructural analysis of patient tissues. We identified 3 novel autosomal recessive mutations in ORAI1 in unrelated kindreds with CID, autoimmunity, ectodermal dysplasia with anhidrosis, and muscular dysplasia. The patients were homozygous for p.V181SfsX8, p.L194P, and p.G98R mutations in the ORAI1 gene that suppressed ORAI1 protein expression and SOCE in the patients' lymphocytes and fibroblasts. In addition to impaired T-cell cytokine production, ORAI1 mutations were associated with strongly reduced numbers of invariant natural killer T and regulatory T (Treg) cells and altered composition of γδ T-cell and natural killer cell subsets. ORAI1 null mutations are associated with reduced numbers of invariant natural killer T and Treg cells that likely contribute to the patients' immunodeficiency and autoimmunity. ORAI1-deficient patients have dental enamel defects and anhidrosis, representing a new form of anhidrotic ectodermal dysplasia with immunodeficiency that is distinct from previously reported patients with anhidrotic ectodermal dysplasia with immunodeficiency caused by mutations in the nuclear factor κB signaling pathway (IKBKG and NFKBIA). Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Gene p63: In ectrodactyly-ectodermal dysplasia clefting, ankyloblepharon-ectodermal dysplasia, Rapp-Hodgkin syndrome.

PubMed

van Straten, Cornelia; Butow, Kurt-W

2013-01-01

An analysis was made of three different syndromes associated with p63 gene mutations, known as ectrodactyly-ectodermal dysplasia-clefting syndrome (EEC), ankyloblepharon-ectodermal dysplasia clefting syndrome (AEC or Hay-Wells) and Rapp-Hodgkin syndrome (RHS). The postoperative complications associated with their cleft reconstructions were also evaluated. Extensive demographic information, in particular of the clinical appearances, associated malformations, and the types and complications of the reconstructive surgical procedures, were recorded of these syndromic cases occurring in a database of 3621 facial cleft deformity patients. The data was analyzed using the Microsoft Excel program. A total of 10 (0.28%) cases of p63 associated syndromes were recorded: EEC (6), RHS (3), and AEC (1). The following clinical cleft appearances were noted - EEC = 6: CLA 1 -right side unilateral (female); CLAP 4 - right side (1) + left side (1) unilateral (male + female); bilateral (2) (males); hPsP 1 (female) (divided in 3 Black, 2 White, 1 Indian); RHS = 3: CLAP 2 (White males); hPsP 1 (White female); AEC = 1: CLAP bilateral (White male). Other features of the syndromes were: skin, hand, foot, tooth, hair and nail involvement, and light sensitivity. Postoperative complications included: (i) stenosis of nasal opening, especially after reconstruction of the bilateral cleft lip and the columella lengthening (2 cases), (ii) premaxilla-prolabium fusion (2 cases), (iii) repeated occurrence of oro-nasal fistula in the hard palate (4 cases), and (iv) dysgnathial development of midfacial structures (3 cases). Three different p63 associated syndromes (EEC, AEC, and RHS) were diagnosed (0.27% of the total facial cleft deformities database). The majority of the cases presented with a bilateral CLAP in males only. A number of females and males had unilateral CLA. The hPsP-cleft was recorded in females only. The associated ectodermal component most probably had a profoundly negative influence on postoperatively wound healing, which was observed in particular at the nasal openings, the premaxilla sulcus and in the hard palate mucosa. The reconstruction of p63 associated syndromes is a greater challenge than the usual cleft reconstruction to the surgeon.

Oxygen isotope and trace element compositions of platiniferous dunite pipes of the Bushveld Complex, South Africa - Signals from a recycled mantle component?

NASA Astrophysics Data System (ADS)

Günther, T.; Haase, K. M.; Junge, M.; Oberthür, T.; Woelki, D.; Krumm, S.

2018-06-01

Platiniferous dunite pipes occur in the lower mafic/ultramafic portion of the Rustenburg Layered Suite of the Bushveld large igneous province (LIP). Olivine compositions in these pipes range from forsterite (Fo) 80 to 35 mol% and suggest crystallization from variably evolved magmas at high temperatures ( 1200 °C). The most primitive olivines are from a stock unit and have the highest contents of Ni (>0.15 wt%) and lowest contents of Mn (<0.3 wt%). Fractional crystallization and partial melting of pyroxenite host rock play a significant role in the formation of the fayalitic olivines with its high Mn contents (>0.3 wt%). High δ18O values of olivine (5.7-7.0‰) and pyroxene (6.7-7.4‰) are akin to those of the Lower and Critical Zone of the Bushveld intrusion suggesting a common origin. The constant high O isotope ratios with variable Fo contents in the olivines are unlike trends observed in olivine phenocrysts in magmas forming by assimilation-fractional crystallization. We suggest that the high δ18O in the most primitive dunites reflect that of the primary melt of the Bushveld pipes, indicating either a bulk assimilation of crust prior to pipe formation or a contribution from recycled oceanic crust in the sub-continental lithospheric mantle (SCLM). The latter scenario is supported by the high Ni/Mn ratios in primitive pipe olivine that might be inherited from melting of a pyroxene-rich mantle source.

Construction of protocellular structures under simulated primitive earth conditions

NASA Astrophysics Data System (ADS)

Yanagawa, Hiroshi; Ogawa, Yoko; Kojima, Kiyotsugu; Ito, Masahiko

1988-09-01

We have developed experimental approaches for the construction of protocellular structures under simulated primitive earth conditions and studied their formation and characteristics. Three types of envelopes; protein envelopes, lipid envelopes, and lipid-protein envelopes are considered as candidates for protocellular structures. Simple protein envelopes and lipid envelopes are presumed to have originated at an early stage of chemical evolution, interaction mutually and then evolved into more complex envelopes composed of both lipids and proteins. Three kinds of protein envelopes were constructedin situ from amino acids under simulated primitive earth conditions such as a fresh water tide pool, a warm sea, and a submarine hydrothermal vent. One protein envelope was formed from a mixture of amino acid amides at 80 °C using multiple hydration-dehydration cycles. Marigranules, protein envelope structures, were produced from mixtures of glycine and acidic, basic and aromatic amino acids at 105 °C in a modified sea medium enriched with essential transition elements. Thermostable microspheres were also formed from a mixture of glycine, alanine, valine, and aspartic acid at 250 °C and above. The microspheres did not form at lower temperatures and consist of silicates and peptide-like polymers containing imide bonds and amino acid residues enriched in valine. Amphiphilic proteins with molecular weights of 2000 were necessary for the formation of the protein envelopes. Stable lipid envelopes were formed from different dialkyl phospholipids and fatty acids. Large, stable, lipid-protein envelopes were formed from egg lecithin and the solubilized marigranules. Polycations such as polylysine and polyhistidine, or basic proteins such as lysozyme and cytochromec also stabilized lipid-protein envelopes.

An RGDS peptide-binding receptor, FR-1R, localizes to the basal side of the ectoderm and to primary mesenchyme cells in sand dollar embryos.

PubMed

Katow, H; Sofuku, S

2001-10-01

Immunoblotting using polyclonal antibodies (pAb) raised against an FR-1 receptor (FR-1R), a 57 kDa Arg-Gly-Asp-Ser (RGDS)-binding protein, of the sand dollar Clypeaster japonicus showed that the pAb monospecifically bound to the protein. FR-1R was present in purified plasma membrane, suggesting that the protein is a membrane-bound protein. The molecular structure of FR-1R did not change throughout the early embryogenesis, whereas its expression changed significantly during this period. FR-1R was present in the cortex of unfertilized eggs and was then transferred to the hyaline layer soon after the fertilization. The hyaline layer retained FR-1R immunoreactivity during early embryogenesis. FR-1R appeared on the basal side of the ectoderm at the morula stage and was retained basolaterally, at least, to the early gastrula stage. In mesenchyme blastulae, FR-1R was also present on the surface of primary mesenchyme cells (PMC). FR-1R was localized on the basal side of the ectoderm in early gastrulae, exclusively at the place where PMC formed ventrolateral aggregates, and at the apical tuft ectoderm. In vitro, PMC bound to FR-1R and its binding was inhibited in the presence of a synthetic RGDS peptide or the pAb. The pAb introduced into the blastocoele perturbed PMC migration and gastrulation. FR-1R was weakly recognized by antihuman integrin beta5 subunit pAb.

A rat model of hypohidrotic ectodermal dysplasia carries a missense mutation in the Edaradd gene

PubMed Central

2011-01-01

Background Hypohidrotic ectodermal dysplasia (HED) is a congenital disorder characterized by sparse hair, oligodontia, and inability to sweat. It is caused by mutations in any of three Eda pathway genes: ectodysplasin (Eda), Eda receptor (Edar), and Edar-associated death domain (Edaradd), which encode ligand, receptor, and intracellular adaptor molecule, respectively. The Eda signaling pathway activates NF-κB, which is central to ectodermal differentiation. Although the causative genes and the molecular pathway affecting HED have been identified, no curative treatment for HED has been established. Previously, we found a rat spontaneous mutation that caused defects in hair follicles and named it sparse-and-wavy (swh). Here, we have established the swh rat as the first rat model of HED and successfully identified the swh mutation. Results The swh/swh rat showed sparse hair, abnormal morphology of teeth, and absence of sweat glands. The ectoderm-derived glands, meibomian, preputial, and tongue glands, were absent. We mapped the swh mutation to the most telomeric part of rat Chr 7 and found a Pro153Ser missense mutation in the Edaradd gene. This mutation was located in the death domain of EDARADD, which is crucial for signal transduction and resulted in failure to activate NF-κB. Conclusions These findings suggest that swh is a loss-of-function mutation in the rat Edaradd and indicate that the swh/swh rat would be an excellent animal model of HED that could be used to investigate the pathological basis of the disease and the development of new therapies. PMID:22013926

Karyotyping, dermatoglyphic, and sweat pore analysis of five families affected with ectodermal dysplasia

PubMed Central

Sidhu, Manpreet; Kale, Alka D; Kotrashetti, Vijayalakshmi S

2012-01-01

Background: Hereditary ectodermal dysplasia is a genetic recessive trait characterized by hypohydrosis, hypotrichosis, and hypodontia. The affected individual show characteristic physiognomy like protruded forehead, depressed nasal bridge, periorbital wrinkling, protruded lips, etc. There is marked decrease in sweat and salivary secretion. Due to skin involvement palm and sole ridge patterns are disrupted. Aim: In this study an attempt has been made to classify the affected members according to the degree of penetrance by pedigree analysis and also study karyotyping for cytogenetics, dermatoglyphic analysis for the various ridge patterns and variations in the number of sweat glands by sweat pore analysis in affected individuals. Materials and Methods: A total of five families who were affected with ectodermal dysplasia were considered. Pedigree analysis was drawn up to three generation by obtaining history. Dermatoglyphics and sweat pore analysis was done by obtaining palm and finger print impression using stamp pad ink. Karyotyping was done by collecting 3–5 ml peripheral blood. Karyotyping was prepared using lymphocyte culture. Chromosomes were examined at 20 spreads selected randomly under ×100 magnification. Results were analyzed by calculating mean values and percentage was obtained. Results: Karyotyping did not show any abnormalities, dermatoglyphic analysis and sweat pore counts showed marked variations when compared with normal. Moreover, pedigree analysis confirmed the status of the disease as that of the recessive trait. Conclusion: Large number of affected patients needs to be evaluated for dermatoglypic analysis. Genetic aspect of the disease needs to be looked into the molecular level in an attempt to locate the gene locus responsible for ectodermal dysplasia and its manifestation. PMID:23248471

Novel hypomorphic mutation in IKBKG impairs NEMO-ubiquitylation causing ectodermal dysplasia, immunodeficiency, incontinentia pigmenti, and immune thrombocytopenic purpura.

PubMed

Ramírez-Alejo, Noé; Alcántara-Montiel, Julio C; Yamazaki-Nakashimada, Marco; Duran-McKinster, Carola; Valenzuela-León, Paola; Rivas-Larrauri, Francisco; Cedillo-Barrón, Leticia; Hernández-Rivas, Rosaura; Santos-Argumedo, Leopoldo

2015-10-01

NF-κB essential modulator (NEMO) is a component of the IKK complex, which participates in the activation of the NF-κB pathway. Hypomorphic mutations in the IKBKG gene result in different forms of anhidrotic ectodermal dysplasia with immunodeficiency (EDA-ID) in males without affecting carrier females. Here, we describe a hypomorphic and missense mutation, designated c.916G>A (p.D306N), which affects our patient, his mother, and his sister. This mutation did not affect NEMO expression; however, an immunoprecipitation assay revealed reduced ubiquitylation upon CD40-stimulation in the patient's cells. Functional studies have demonstrated reduced phosphorylation and degradation of IκBα, affecting NF-κB recruitment into the nucleus. The patient presented with clinical features of ectodermal dysplasia, immunodeficiency, and immune thrombocytopenic purpura, the latter of which has not been previously reported in a patient with NEMO deficiency. His mother and sister displayed incontinentia pigmenti indicating that, in addition to amorphic mutations, hypomorphic mutations in NEMO can affect females. Copyright © 2015 Elsevier Inc. All rights reserved.

Branching out: origins of the sea urchin larval skeleton in development and evolution

PubMed Central

McIntyre, Daniel C.; Lyons, Deirdre C.; Martik, Megan; McClay, David R.

2014-01-01

It is a challenge to understand how the information encoded in DNA is used to build a three dimensional structure. To explore how this works the assembly of a relatively simple skeleton has been examined at multiple control levels. The skeleton of the sea urchin embryo consists of a number of calcite rods produced by 64 skeletogenic cells. The ectoderm supplies spatial cues for patterning, essentially telling the skeletogenic cells where to position themselves and providing the factors for skeletal growth. Here we describe the information known about how this works. First the ectoderm must be patterned so that the signaling cues are released from precise positions. The skeletogenic cells respond by initiating skeletogenesis immediately beneath two regions (one on the right and the other on the left side). Growth of the skeletal rods requires additional signaling from defined ectodermal locations, and the skeletogenic cells respond to produce a membrane-bound template in which the calcite crystal grows. Important in this process are three signals, FGF, VEGF, and Wnt5. Each is necessary for explicit tasks in skeleton production. PMID:24549853

Combinatorial Fgf and Bmp signalling patterns the gastrula ectoderm into prospective neural and epidermal domains

PubMed Central

Kudoh, Tetsuhiro; Concha, Miguel L.; Houart, Corinne; Dawid, Igor B.; Wilson, Stephen W.

2009-01-01

Summary Studies in fish and amphibia have shown that graded Bmp signalling activity regulates dorsal-to-ventral (DV) patterning of the gastrula embryo. In the ectoderm, it is thought that high levels of Bmp activity promote epidermal development ventrally, whereas secreted Bmp antagonists emanating from the organiser induce neural tissue dorsally. However, in zebrafish embryos, the domain of cells destined to contribute to the spinal cord extends all the way to the ventral side of the gastrula, a long way from the organiser. We show that in vegetal (trunk and tail) regions of the zebrafish gastrula, neural specification is initiated at all DV positions of the ectoderm in a manner that is unaffected by levels of Bmp activity and independent of organiser-derived signals. Instead, we find that Fgf activity is required to induce vegetal prospective neural markers and can do so without suppressing Bmp activity. We further show that Bmp signalling does occur within the vegetal prospective neural domain and that Bmp activity promotes the adoption of caudal fate by this tissue. PMID:15262889

IGF-1 Signaling Plays an Important Role in the Formation of Three-Dimensional Laminated Neural Retina and Other Ocular Structures From Human Embryonic Stem Cells.

PubMed

Mellough, Carla B; Collin, Joseph; Khazim, Mahmoud; White, Kathryn; Sernagor, Evelyne; Steel, David H W; Lako, Majlinda

2015-08-01

We and others have previously demonstrated that retinal cells can be derived from human embryonic stem cells (hESCs) and induced pluripotent stem cells under defined culture conditions. While both cell types can give rise to retinal derivatives in the absence of inductive cues, this requires extended culture periods and gives lower overall yield. Further understanding of this innate differentiation ability, the identification of key factors that drive the differentiation process, and the development of clinically compatible culture conditions to reproducibly generate functional neural retina is an important goal for clinical cell based therapies. We now report that insulin-like growth factor 1 (IGF-1) can orchestrate the formation of three-dimensional ocular-like structures from hESCs which, in addition to retinal pigmented epithelium and neural retina, also contain primitive lens and corneal-like structures. Inhibition of IGF-1 receptor signaling significantly reduces the formation of optic vesicle and optic cups, while exogenous IGF-1 treatment enhances the formation of correctly laminated retinal tissue composed of multiple retinal phenotypes that is reminiscent of the developing vertebrate retina. Most importantly, hESC-derived photoreceptors exhibit advanced maturation features such as the presence of primitive rod- and cone-like photoreceptor inner and outer segments and phototransduction-related functional responses as early as 6.5 weeks of differentiation, making these derivatives promising candidates for cell replacement studies and in vitro disease modeling. © 2015 AlphaMed Press.

[Clinicopathologic study of sinonasal teratocarcinosarcoma and its contrast with olfactory neuroblastoma].

PubMed

Li, Xue; Liu, Hong-Gang; Xie, Xin-Ji; Han, Yi-Ding; Li, Ming

2008-07-01

To study the clinicopathologic features, diagnosis and differential diagnosis of sinonasal teratocarcinosarcoma (SNTCS) and olfactory neuroblastoma (ONB), and to discuss the histogenesis and possible relationship between SNTCS and ONB. Seven cases of SNTCS and 34 cases of ONB were retrieved from the pathological archives together with one case each of malignant teratoma and immature embryonic tissue at 8 weeks were collected from Beijing Tongren Hospital. The clinicopathologic features were analyzed and immunohistochemical staining was performed on paraffin sections. Six of the SNTCS patients were male and one was female. The patients age range was 25 to 69 years (mean age 46). Four cases were initial presentation and three were recurrences. Histologically, the tumor shows multiple tissue components derived from three germ layers. There were mixture of teratoma-like tissue and carcinosarcoma. The components include fetal clear cell squamous epithelium derived from ectoderm. Glandular and tubular structures and ciliated columnar epithelium derived from endoderm. Fibroblasts, striated muscle, smooth muscle, cartilage and osteoid matrix derived from mesoderm. The carcinoma component exhibited mostly adenocarcinoma and squamous cell carcinoma, whereas the sarcoma component mostly exhibited rhabdomyosarcoma, leiomyosarcoma, and fibrosarcoma. In addition, carcinoid, and primitive mesenchymal tissue and the ONB component were also seen. The morphological characteristics of SNTCS comprised fetal clear cell squamous epithelium, carcinosarcoma and the ONB component. By immunohistochemistry, the epithelial component and cells with epithelium differentiation were positive for cytokeratin (pan) and EMA. The ONB component was positive for Syn, NSE, CD99, NF and CgA to different degrees. Neurofibril bundles were positive for S-100, and Flexner-Wintersteiner rosettes expressed cytokeratin (pan) and EMA. The spindle cells expressed vimentin, SMA, desmin, myosin and myoglobin. The primitive mesenchymal tissue expressed vimentin, and the mucoid materials and glycogen were positive for PAS. GFAP was negative in all cases. The 34 cases of ONB, included 18 men and 16 women, the age ranged from 12 to 72 years (mean 42.8 years). Microscopically, the tumor shows epithelial nests, net of angioma-like fibrous connective tissues, small round and spindle cells, glandular, squamous-like cells, and cells of rhabdomyoblastic differentiation, Homer-Wright and Flexner rosette, bundles of neurofibrils, etc. NSE and CgA were expressed in small cells. S-100 protein was positive in the areas of bunches of neurofibril. Cytokeratin (pan) was positive in epithelial cells. Myoglobin was positive in the cells of rhabdomyoblastic differentiation. The single case of immature malignant teratoma exhibited primitive nerve tissue, but fetal clear cell squamous epithelium was not found. In the immature embryonic tissue, rudimentary organs were formed, with fetal clear cell squamous epithelium lining present on the nasal and oral cavities surface. SNTCS is a rare and aggressive malignant neoplasm. Most of ONB are low-grade malignant tumors. Morphological differences are the most important basis to make differentiate SNTCS from ONB. As SNTCS may demonstrate a multiplicity of structures and pleomorphism, inadequate sampling at biopsy, therefore, may lead to errors in diagnosis. No evidence show that SNTCS are derived from germ cells and sinonasal teratoid carcinosarcoma may be a more proper name. SNTCS probably arises from primitive totipotential cells of olfactory/sinonasal membrane, and the relationship between SNTCS and ONB needs further study.

A distinct type of hidrotic ectodermal dysplasia.

PubMed

Halal, F; Setton, N; Wang, N S

1991-03-15

Four individuals from 2 generations of a family had a hidrotic type of ectodermal dysplasia (ED). Males and females were similarly affected. They had trichodysplasia, with absent eyebrows and eyelashes; normal teeth, onychodysplasia; normal sweating; mild retrognathia; abnormal dermatoglyphics; and mental retardation. Additional variable manifestations included irregular menses, high implanted or prominent ears, café-au-lait spot, keratosis pilaris, supernumerary nipple, and mild hearing loss. Their previously undescribed condition could be classified as an ED of 1-3 (trichoonychial) subgroup of group A according to Freire-Maia's classification and is inherited as an autosomal recessive trait.

Wnt-dependent epithelial transitions drive pharyngeal pouch formation

PubMed Central

Choe, Chong Pyo; Collazo, Andres; Trinh, Le A.; Pan, Luyuan; Moens, Cecilia B.; Crump, J. Gage

2013-01-01

SUMMARY The pharyngeal pouches, which form by budding of the foregut endoderm, are essential for segmentation of the vertebrate face. To date, the cellular mechanism and segmental nature of such budding have remained elusive. Here, we find that Wnt11r and Wnt4a from the head mesoderm and ectoderm, respectively, play distinct roles in the segmental formation of pouches in zebrafish. Time-lapse microscopy, combined with mutant and tissue-specific transgenic experiments, reveal requirements of Wnt signaling in two phases of endodermal epithelial transitions. Initially, Wnt11r and Rac1 destabilize the endodermal epithelium to promote the lateral movement of pouch-forming cells. Next, Wnt4a and Cdc42 signaling induce the rearrangement of maturing pouch cells into bilayers through junctional localization of the Alcama immunoglobulin-domain protein, which functions to restabilize adherens junctions. We propose that this dynamic control of epithelial morphology by Wnt signaling may be a common theme for the budding of organ anlagen from the endoderm. PMID:23375584

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dolan, Daniel H.; Ao, Tommy

The Sandia Data Archive (SDA) format is a specific implementation of the HDF5 (Hierarchal Data Format version 5) standard. The format was developed for storing data in a universally accessible manner. SDA files may contain one or more data records, each associated with a distinct text label. Primitive records provide basic data storage, while compound records support more elaborate grouping. External records allow text/binary files to be carried inside an archive and later recovered. This report documents version 1.0 of the SDA standard. The information provided here is sufficient for reading from and writing to an archive. Although the formatmore » was original designed for use in MATLAB, broader use is encouraged.« less

Lineage specific expression of Polycomb Group Proteins in human embryonic stem cells in vitro.

PubMed

Pethe, Prasad; Pursani, Varsha; Bhartiya, Deepa

2015-05-01

Human embryonic (hES) stem cells are an excellent model to study lineage specification and differentiation into various cell types. Differentiation necessitates repression of specific genes not required for a particular lineage. Polycomb Group (PcG) proteins are key histone modifiers, whose primary function is gene repression. PcG proteins form complexes called Polycomb Repressive Complexes (PRCs), which catalyze histone modifications such as H2AK119ub1, H3K27me3, and H3K9me3. PcG proteins play a crucial role during differentiation of stem cells. The expression of PcG transcripts during differentiation of hES cells into endoderm, mesoderm, and ectoderm lineage is yet to be shown. In-house derived hES cell line KIND1 was differentiated into endoderm, mesoderm, and ectoderm lineages; followed by characterization using RT-PCR for HNF4A, CDX2, MEF2C, TBX5, SOX1, and MAP2. qRT-PCR and western blotting was performed to compare expression of PcG transcripts and proteins across all the three lineages. We observed that cells differentiated into endoderm showed upregulation of RING1B, BMI1, EZH2, and EED transcripts. Mesoderm differentiation was characterized by significant downregulation of all PcG transcripts during later stages. BMI1 and RING1B were upregulated while EZH2, SUZ12, and EED remained low during ectoderm differentiation. Western blotting also showed distinct expression of BMI1 and EZH2 during differentiation into three germ layers. Our study shows that hES cells differentiating into endoderm, mesoderm, and ectoderm lineages show distinct PcG expression profile at transcript and protein level. © 2015 International Federation for Cell Biology.

Mosaic epigenetic dysregulation of ectodermal cells in autism spectrum disorder.

PubMed

Berko, Esther R; Suzuki, Masako; Beren, Faygel; Lemetre, Christophe; Alaimo, Christine M; Calder, R Brent; Ballaban-Gil, Karen; Gounder, Batya; Kampf, Kaylee; Kirschen, Jill; Maqbool, Shahina B; Momin, Zeineen; Reynolds, David M; Russo, Natalie; Shulman, Lisa; Stasiek, Edyta; Tozour, Jessica; Valicenti-McDermott, Maria; Wang, Shenglong; Abrahams, Brett S; Hargitai, Joseph; Inbar, Dov; Zhang, Zhengdong; Buxbaum, Joseph D; Molholm, Sophie; Foxe, John J; Marion, Robert W; Auton, Adam; Greally, John M

2014-01-01

DNA mutational events are increasingly being identified in autism spectrum disorder (ASD), but the potential additional role of dysregulation of the epigenome in the pathogenesis of the condition remains unclear. The epigenome is of interest as a possible mediator of environmental effects during development, encoding a cellular memory reflected by altered function of progeny cells. Advanced maternal age (AMA) is associated with an increased risk of having a child with ASD for reasons that are not understood. To explore whether AMA involves covert aneuploidy or epigenetic dysregulation leading to ASD in the offspring, we tested a homogeneous ectodermal cell type from 47 individuals with ASD compared with 48 typically developing (TD) controls born to mothers of ≥35 years, using a quantitative genome-wide DNA methylation assay. We show that DNA methylation patterns are dysregulated in ectodermal cells in these individuals, having accounted for confounding effects due to subject age, sex and ancestral haplotype. We did not find mosaic aneuploidy or copy number variability to occur at differentially-methylated regions in these subjects. Of note, the loci with distinctive DNA methylation were found at genes expressed in the brain and encoding protein products significantly enriched for interactions with those produced by known ASD-causing genes, representing a perturbation by epigenomic dysregulation of the same networks compromised by DNA mutational mechanisms. The results indicate the presence of a mosaic subpopulation of epigenetically-dysregulated, ectodermally-derived cells in subjects with ASD. The epigenetic dysregulation observed in these ASD subjects born to older mothers may be associated with aging parental gametes, environmental influences during embryogenesis or could be the consequence of mutations of the chromatin regulatory genes increasingly implicated in ASD. The results indicate that epigenetic dysregulatory mechanisms may complement and interact with DNA mutations in the pathogenesis of the disorder.

Prevalence of atopic disorders and immunodeficiency in patients with ectodermal dysplasia syndromes

PubMed Central

Mark, Barry J.; Becker, Bradley A.; Halloran, Donna R.; Bree, Alanna F.; Sindwani, Raj; Fete, Mary D.; Motil, Kathleen J.; Srun, Sopheak W.; Fete, Timothy J.

2013-01-01

Background Ectodermal dysplasia (ED) syndromes are a diverse group of disorders that affect multiple ectodermally derived tissues. Small studies and case reports suggest an increase in atopy and primary immunodeficiencies (PIDs) among patients with ED syndromes. Objective To determine the prevalence of clinical symptoms suggestive of atopy or immunodeficiency among a large cohort of children with ED syndromes. Methods A 9-page questionnaire was mailed to families who were members of the National Foundation for Ectodermal Dysplasias. The surveys were completed by parents of children younger than 18 years with a diagnosis of an ED syndrome or carrier state. Portions of the questionnaire were adapted from previously validated questionnaires developed by the International Study of Asthma and Allergies in Childhood (ISAAC). Results We received 347 completed questionnaires (41%). When compared with the 13- to 14-year-old children surveyed by ISAAC, we found both all-aged and age-matched children with ED syndromes, respectively, had significantly higher rates of asthma (32.2% and 37.2% vs 16.4%), rhinitis symptoms (76.1% and 78.3% vs 38.9%), and eczema (58.9% and 48.9% vs 8.2%). The prevalence of physician-diagnosed food allergies (20.7%) and PIDs (6.1%) in these ED patients also exceeded known rates in the general pediatric population. Conclusion This large-scale, retrospective study demonstrates a greater reported prevalence of symptoms suggestive of atopic disorders and PIDs among children with ED syndromes than the general pediatric population. A combination of genetic and environmental factors in ED syndromes may contribute to breaches of skin and mucosal barriers, permitting enhanced transmission and sensitization to irritants, allergens, and pathogens. PMID:22626597

Autosomal dominant anhidrotic ectodermal dysplasia with immunodeficiency caused by a novel NFKBIA mutation, p.Ser36Tyr, presents with mild ectodermal dysplasia and non-infectious systemic inflammation.

PubMed

Yoshioka, Takakazu; Nishikomori, Ryuta; Hara, Junichi; Okada, Keiko; Hashii, Yoshiko; Okafuji, Ikuo; Nodomi, Seishiro; Kawai, Tomoki; Izawa, Kazushi; Ohnishi, Hidenori; Yasumi, Takahiro; Nakahata, Tatsutoshi; Heike, Toshio

2013-10-01

Anhidrotic ectodermal dysplasia with immunodeficiency (EDA-ID) is characterized by hypohidrosis, dental abnormalities, sparse hair, and immunodeficiency. Autosomal dominant (AD)-EDA-ID, caused by a heterozygous mutation within NFKBIA, is very rare and its clinical features remain largely unknown. This study describes a patient with AD-EDA-ID harboring a novel NFKBIA mutation who presented with mild EDA and non-infectious systemic inflammation. The clinical presentation of an AD-EDA-ID patient was described and immunological, genetic, and biochemical analyses were performed, with a focus on nuclear factor kappa B (NF-κB) activation. The patient presented with symptoms of mild EDA-ID, namely sparse hair and hypohidrosis, although a skin biopsy confirmed the presence of sweat glands. There were no dental abnormalities. The patient also suffered from non-infectious inflammation, which responded to systemic corticosteroid therapy; however, the patient remained ill. Immunological analyses revealed reduced Toll-like receptor/IL-1 (TLR/IL-1) and tumor necrosis factor (TNF) receptor family responses to various stimuli. Genetic analysis identified a de novo heterozygous missense mutation, p.Ser36Tyr, in NFKBIA, resulting in defective NFKBIA degradation and impaired NF-κB activation. The patient was diagnosed with AD-EDA-ID and underwent hematopoietic stem cell transplantation. Engraftment was successful, with few signs of acute graft versus host disease. However, the patient suffered hemolytic anemia and thrombocytopenia, and died from a brain hemorrhage due to intractable thrombocytopenia. AD-EDA-ID patients can present with mild ectodermal dysplasia and non-infectious inflammation, rather than with recurrent infections. Also, hematopoietic stem cell transplantation for AD-EDA-ID is still a clinical challenge.

Primitive material surviving in chondrites - Mineral grains

NASA Astrophysics Data System (ADS)

Steele, Ian M.

Besides chondrules and various kinds of polymineralic inclusion, carbonaceous chondrites commonly contain, embedded in their matrices, isolated grains of mafic silicates and metallic iron. Most of the silicate grains probably originated in chondrules, but some appear to predate chondrule formation and may have formed as individual grains in the solar nebula. If that was the case, their compositions suggest some departure from equilibrium condensation from a gas of solar composition. Metal-grain compositions are broadly suggestive of nebular formation but the exact nature of the conditions in which they were formed remains problematical.

Photochemistry of methane and the formation of hydrocyanic acid (HCN) in the earth's early atmosphere

NASA Technical Reports Server (NTRS)

Zahnle, K. J.

1986-01-01

A one-dimensional photochemical model is used to analyze the photochemistries of CH4 and HCN in the primitive terrestrial atmosphere. CH4, N2, and HCN photolysis are examined. The background atmosphere and boundary conditions applied in the analysis are described. The formation of HCN as a by-product of N2 and CH4 photolysis is investigated; the effects of photodissociation and rainfall on HCN is discussed. The low and high CH4 mixing ratios and radical densities are studied.

Combination Chemotherapy in Treating Patients With Non-Metastatic Extracranial Ewing Sarcoma

ClinicalTrials.gov

2018-02-09

Adult Supratentorial Primitive Neuroectodermal Tumor (PNET); Childhood Supratentorial Primitive Neuroectodermal Tumor; Ewing Sarcoma of Bone; Extraosseous Ewing Sarcoma; Extraosseous Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Localized Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Peripheral Primitive Neuroectodermal Tumor of the Kidney; Untreated Childhood Supratentorial Primitive Neuroectodermal Tumor

The formation conditions of chondrules and chondrites

USGS Publications Warehouse

Alexander, C.M. O'D.; Grossman, Jeffrey N.; Ebel, D.S.; Ciesla, F.J.

2008-01-01

Chondrules, which are roughly millimeter-sized silicate-rich spherules, dominate the most primitive meteorites, the chondrites. They formed as molten droplets and, judging from their abundances in chondrites, are the products of one of the most energetic processes that operated in the early inner solar system. The conditions and mechanism of chondrule formation remain poorly understood. Here we show that the abundance of the volatile element sodium remained relatively constant during chondrule formation. Prevention of the evaporation of sodium requires that chondrules formed in regions with much higher solid densities than predicted by known nebular concentration mechanisms. These regions would probably have been self-gravitating. Our model explains many other chemical characteristics of chondrules and also implies that chondrule and planetesimal formation were linked.

Developmental characteristics of somatic cell hybrids between totipotent mouse teratocarcinoma and rat intestinal villus cells.

PubMed

van der Kamp, A W; Roza-de Jongh, E J; Houwen, R H; Magrane, G G; van Dongen, J M; Evans, M J

1984-09-01

Hybrids between mouse PCC4-azal teratocarcinoma cells and rat epithelial intestinal villus cells (PCI hybrids) are phenotypically teratocarcinoma cells. They express several teratocarcinoma-specific traits but do not express functions specific for differentiated cells. Tumour formation is partially or completely suppressed. Some of the hybrids show more extensive differentiation both in vitro and in vivo than the PCC4-azal parental line. The hybrids are capable of endoderm formation in monolayer cultures and of the formation of embryoid bodies in suspension cultures. Two of the tumour-forming hybrids generate derivatives of all three germ layers, whereas differentiation in the PCC4-azal tumours is restricted to the formation of primitive neuronal tissues.

Comparative gene expression analysis of Dtg, a novel target gene of Dpp signaling pathway in the early Drosophila melanogaster embryo.

PubMed

Hodar, Christian; Zuñiga, Alejandro; Pulgar, Rodrigo; Travisany, Dante; Chacon, Carlos; Pino, Michael; Maass, Alejandro; Cambiazo, Verónica

2014-02-10

In the early Drosophila melanogaster embryo, Dpp, a secreted molecule that belongs to the TGF-β superfamily of growth factors, activates a set of downstream genes to subdivide the dorsal region into amnioserosa and dorsal epidermis. Here, we examined the expression pattern and transcriptional regulation of Dtg, a new target gene of Dpp signaling pathway that is required for proper amnioserosa differentiation. We showed that the expression of Dtg was controlled by Dpp and characterized a 524-bp enhancer that mediated expression in the dorsal midline, as well as, in the differentiated amnioserosa in transgenic reporter embryos. This enhancer contained a highly conserved region of 48-bp in which bioinformatic predictions and in vitro assays identified three Mad binding motifs. Mutational analysis revealed that these three motifs were necessary for proper expression of a reporter gene in transgenic embryos, suggesting that short and highly conserved genomic sequences may be indicative of functional regulatory regions in D. melanogaster genes. Dtg orthologs were not detected in basal lineages of Dipterans, which unlike D. melanogaster develop two extra-embryonic membranes, amnion and serosa, nevertheless Dtg orthologs were identified in the transcriptome of Musca domestica, in which dorsal ectoderm patterning leads to the formation of a single extra-embryonic membrane. These results suggest that Dtg was recruited as a new component of the network that controls dorsal ectoderm patterning in the lineage leading to higher Cyclorrhaphan flies, such as D. melanogaster and M. domestica. Copyright © 2013 Elsevier B.V. All rights reserved.

Characterization of a human X-linked gene from the DXS732E locus in the candidate region for the anhidrotic ectodermal dysplasia (EDA) gene (Xq13.1)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gault, J.; Zonana, J.; Zeltinger, J.

A conserved mouse genomic clone was used to identify a homologous human genomic clone (the DXS732E locus), which was subsequently employed to isolate cDNAs from a human fetal brain library. Nine unique overlapping cDNAs were isolated, and sequences analysis of 3.9 kb identified a putative 1 kb ORF. GRAIL analysis of the sequence supported the hypothesis that the putative ORF was coding sequence, and Prosite analysis of the putative ORF identified potential glycosylation and phosphorylation sites. The 5{prime} end of the gene maps within a CpG island, and comparison of cDNA sequences indicate the gene is alternatively spliced at itsmore » 3{prime} end. Northern analysis and RT-PCR indicate that two different sized messages appear to be expressed with the gene expressed in human fetal kidney, intestine, brain, and muscle. The gene is expressed in 77 day human skin, a time when hair follicle formation occurs. Anhidrotic ectodermal dysplasia (EDA) results in the abnormal morphogenesis of hair, teeth and eccrine sweat glands. A positional cloning strategy towards cloning the EDA gene had been used, and deletion and X-autosome translocation patients have been useful in further delimiting the EDA region. The present gene at the DXS732E locus is partially deleted in one EDA patient who does not have other apparent abnormalities. No rearrangements of the gene have been detected in two female X-autosome translocation EDA patients, nor in four additional male patients with submicroscopic molecular deletions.« less

Msx genes are expressed in the carapacial ridge of turtle shell: a study of the European pond turtle, Emys orbicularis.

PubMed

Vincent, Christine; Bontoux, Martine; Le Douarin, Nicole M; Pieau, Claude; Monsoro-Burq, Anne-Hélène

2003-09-01

The turtle shell forms by extensive ossification of dermis ventrally and dorsally. The carapacial ridge (CR) controls early dorsal shell formation and is thought to play a similar role in shell growth as the apical ectodermal ridge during limb development. However, the molecular mechanisms underlying carapace development are still unknown. Msx genes are involved in the development of limb mesenchyme and of various skeletal structures. In particular, precocious Msx expression is recorded in skeletal precursors that develop close to the ectoderm, such as vertebral spinous processes or skull. Here, we have studied the embryonic expression of Msx genes in the European pond turtle, Emys orbicularis. The overall Msx expression in head, limb, and trunk is similar to what is observed in other vertebrates. We have focused on the CR area and pre-skeletal shell condensations. The CR expresses Msx genes transiently, in a pattern similar to that of fgf10. In the future carapace domain, the dermis located dorsal to the spinal cord expresses Msx genes, as in other vertebrates, but we did not see expansion of this expression in the dermis located more laterally, on top of the dermomyotomes. In the ventral plastron, although the dermal osseous condensations form in the embryonic Msx-positive somatopleura, we did not observe enhanced Msx expression around these elements. These observations may indicate that common mechanisms participate in limb bud and CR early development, but that pre-differentiation steps differ between shell and other skeletal structures and involve other gene activities than that of Msx genes.

Functions of Huntingtin in Germ Layer Specification and Organogenesis

PubMed Central

Nguyen, Giang D.; Molero, Aldrin E.; Gokhan, Solen; Mehler, Mark F.

2013-01-01

Huntington’s disease (HD) is a neurodegenerative disease caused by abnormal polyglutamine expansion in the huntingtin protein (Htt). Although both Htt and the HD pathogenic mutation (mHtt) are implicated in early developmental events, their individual involvement has not been adequately explored. In order to better define the developmental functions and pathological consequences of the normal and mutant proteins, respectively, we employed embryonic stem cell (ESC) expansion, differentiation and induction experiments using huntingtin knock-out (KO) and mutant huntingtin knock-in (Q111) mouse ESC lines. In KO ESCs, we observed impairments in the spontaneous specification and survival of ectodermal and mesodermal lineages during embryoid body formation and under inductive conditions using retinoic acid and Wnt3A, respectively. Ablation of BAX improves cell survival, but failed to correct defects in germ layer specification. In addition, we observed ensuing impairments in the specification and maturation of neural, hepatic, pancreatic and cardiomyocyte lineages. These developmental deficits occurred in concert with alterations in Notch, Hes1 and STAT3 signaling pathways. Moreover, in Q111 ESCs, we observed differential developmental stage-specific alterations in lineage specification and maturation. We also observed changes in Notch/STAT3 expression and activation. Our observations underscore essential roles of Htt in the specification of ectoderm, endoderm and mesoderm, in the specification of neural and non-neural organ-specific lineages, as well as cell survival during early embryogenesis. Remarkably, these developmental events are differentially deregulated by mHtt, raising the possibility that HD-associated early developmental impairments may contribute not only to region-specific neurodegeneration, but also to non-neural co-morbidities. PMID:23967334

Inactivation of the Huntington's disease gene (Hdh) impairs anterior streak formation and early patterning of the mouse embryo.

PubMed

Woda, Juliana M; Calzonetti, Teresa; Hilditch-Maguire, Paige; Duyao, Mabel P; Conlon, Ronald A; MacDonald, Marcy E

2005-08-18

Huntingtin, the HD gene encoded protein mutated by polyglutamine expansion in Huntington's disease, is required in extraembryonic tissues for proper gastrulation, implicating its activities in nutrition or patterning of the developing embryo. To test these possibilities, we have used whole mount in situ hybridization to examine embryonic patterning and morphogenesis in homozygous Hdh(ex4/5) huntingtin deficient embryos. In the absence of huntingtin, expression of nutritive genes appears normal but E7.0-7.5 embryos exhibit a unique combination of patterning defects. Notable are a shortened primitive streak, absence of a proper node and diminished production of anterior streak derivatives. Reduced Wnt3a, Tbx6 and Dll1 expression signify decreased paraxial mesoderm and reduced Otx2 expression and lack of headfolds denote a failure of head development. In addition, genes initially broadly expressed are not properly restricted to the posterior, as evidenced by the ectopic expression of Nodal, Fgf8 and Gsc in the epiblast and T (Brachyury) and Evx1 in proximal mesoderm derivatives. Despite impaired posterior restriction and anterior streak deficits, overall anterior/posterior polarity is established. A single primitive streak forms and marker expression shows that the anterior epiblast and anterior visceral endoderm (AVE) are specified. Huntingtin is essential in the early patterning of the embryo for formation of the anterior region of the primitive streak, and for down-regulation of a subset of dynamic growth and transcription factor genes. These findings provide fundamental starting points for identifying the novel cellular and molecular activities of huntingtin in the extraembryonic tissues that govern normal anterior streak development. This knowledge may prove to be important for understanding the mechanism by which the dominant polyglutamine expansion in huntingtin determines the loss of neurons in Huntington's disease.

Ion and electron microprobe study of troctolites, norite, and anorthosites from Apollo 14: Evidence for urKREEP assimilation during petrogenesis of Apollo 14 Mg-suite rocks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shervais, J.W.; McGee, J.J.

1998-09-01

Most of the Moon`s highland crust comprises Fe-rich anorthosites with calcic plagioclase compositions. Subsequent evolution of the highland crust was dominated by troctolites, anorthosites, and norites of the Mg-suite. This plutonic series is characterized by calcic plagioclase, and mafic minerals with high mg{number_sign} (=100{sup *}Mg/[Mg + Fe]). In an effort to distinguish the origin of this important lunar rock series, the authors have analyzed the REE content of primary cumulus phases in ten Mg-suite cumulates using SIMS, along with their major and minor element compositions by electron microprobe analysis. Nine of these samples have high mg{number_sign}s, consistent with their formationmore » from the most primitive parent melts of the Mg-suite. The data presented here show that Mg-suite troctolites and anorthosites preserve major and trace element characteristics acquired during their formation as igneous cumulate rocks and that these characteristics can be used to reconstruct related aspects of the parent magma composition. Data show that primitive cumulates of the Mg-suite crystallized from magmas with REE contents similar to high-K KREEP in both concentration and relative abundance. The highly enriched nature of this parent magma contrasts with its primitive major element characteristics, as pointed out by previous workers. This enigma is best explained by the mixing of residual magma ocean urKREEP melts with ultramagnesian komatiitic partial melts from the deep lunar interior. The data do not support earlier models that invoke crustal metasomatism to enrich the Mg-suite cumulates after formation, or models which call for a superKREEP parent for the troctolites and anorthosites.« less

On Synchronization Primitive Systems.

DTIC Science & Technology

The report studies the question: what synchronization primitive should be used to handle inter-process communication. A formal model is presented...between these synchronization primitives. Although only four synchronization primitives are compared, the general methods can be used to compare other... synchronization primitives. Moreover, in the definitions of these synchronization primitives, conditional branches are explicitly allowed. In addition

Observations of Nitrogen Fractionation in Prestellar Cores: Nitriles Tracing Interstellar Chemistry

NASA Technical Reports Server (NTRS)

Milam, S. N.; Charnley, S. B.

2012-01-01

Primitive materials provide important clues on the processes that occurred during the formation and early evolution of the Solar System. Space-based and ground-based observations of cometary comae show that comets appear to contain a mixture of the products of both interstellar and nebular chemistries. Significant 15-nitrogen enrichments have been measured in CN and HCN towards a number of comets and may suggest an origin of interstellar chemical fractionation. Additionally, large N-15 enhancements are found in meteorites and has also led to to the view that the N-15 traces material formed in the interstellar medium (ISM), although multiple sources cannot be excluded. Here, we show the results of observations of the nitrogen and carbon fractionation in prestellar cores for various N-bearing species to decipher the origin of primitive material isotopic enrichments.

Amorphous Silicate Smokes as Catalysts for the Production of Complex Organic Species in the Primitive Solar Nebula

NASA Technical Reports Server (NTRS)

Nuth, J. A., III; Hill, H. G. M.

2002-01-01

Amorphous Mg-silicates are excellent Fischer-Tropsch catalysts that convert H2 and CO into hydrocarbons almost as well as Fe-silicates. Mg-silicates do not catalyze formation of ammonia. N is incorporated into the organics if CO, N2 and H2 are used. Additional information is contained in the original extended abstract.

A Symphony of Regulations Centered on p63 to Control Development of Ectoderm-Derived Structures

PubMed Central

Guerrini, Luisa; Costanzo, Antonio; Merlo, Giorgio R.

2011-01-01

The p53-related transcription factor p63 is critically important for basic cellular functions during development of the ectoderm and derived structure and tissues, including skin, limb, palate, and hair. On the one side, p63 is required to sustain the proliferation of keratinocyte progenitors, while on the other side it is required for cell stratification, commitment to differentiate, cell adhesion, and epithelial-mesenchymal signaling. Molecules that are components or regulators of the p63 pathway(s) are rapidly being identified, and it comes with no surprise that alterations in the p63 pathway lead to congenital conditions in which the skin and other ectoderm-derived structures are affected. In this paper, we summarize the current knowledge of the molecular and cellular regulations centered on p63, derived from the comprehension of p63-linked human diseases and the corresponding animal models, as well as from cellular models and high-throughput molecular approaches. We point out common themes and features, that allow to speculate on the possible role of p63 downstream events and their potential exploitation in future attempts to correct the congenital defect in preclinical studies. PMID:21716671

Cleft palate and ADULT phenotype in a patient with a novel TP63 mutation suggests lumping of EEC/LM/ADULT syndromes into a unique entity: ELA syndrome.

PubMed

Prontera, Paolo; Garelli, Emanuela; Isidori, Ilenia; Mencarelli, Amedea; Carando, Adriana; Silengo, Margherita Cirillo; Donti, Emilio

2011-11-01

Acro-dermato-ungual-lacrimal-tooth (ADULT) syndrome is a rare condition belonging to the group of ectodermal dysplasias caused by TP63 mutations. Its clinical phenotype is similar to ectrodactyly-ectodermal dysplasia-cleft lip/palate (EEC) and limb-mammary syndrome (LMS), and differs from these disorders mainly by the absence of cleft lip and/or palate. We report on a 39-year-old patient who was found to be heterozygous for a c.401G > T (p.Gly134Val) de novo mutation of TP63. This patient had the ADULT phenotype associated with cleft palate. Our findings, rather than extend the clinical spectrum of ADULT syndrome, suggest that cleft palate can no longer be considered an element for differential diagnosis for ADULT, EEC, and LMS. Our data, added to other reports on overlapping phenotypes, support the combining of these three phenotypes into a unique entity that we propose to call "ELA syndrome," which is an acronym of ectrodactyly-ectodermal dysplasia-cleft lip and palate, limb-mammary, and ADULT syndromes. Copyright © 2011 Wiley Periodicals, Inc.

The origin of mesoderm in phoronids

NASA Technical Reports Server (NTRS)

Freeman, Gary; Martindale, Mark Q.

2002-01-01

Descriptive studies of phoronid development have concluded that the mesoderm of these animals originates from the endoderm during gastrulation. This interpretation has been tested by labeling one blastomere of 4- through 16-cell embryos and examining the position and germ layers occupied by the labeled clones of cells in the larva. No 2 injections gave rise to identical clones of cells, suggesting that the cleavage program does not generate cells of unique identity and that cell fates are established at later developmental time points. In many cases, a relatively large sector composed of ectodermal cells was labeled. When these labeled cells were adjacent to the mouth or anus of the larva, muscle and mesenchyme cells originated from the labeled clones. Under these circumstances, nerve cells also originated from these labeled sectors. These labeling studies also showed that endodermal cells can give rise to mesodermal and neural cells. These results suggest that nerve and muscle cells are induced to form at ectodermal-endodermal boundaries from both germ layers. These marking experiments also confirmed the observation that nerve cells originate both from the apical organ and the trunk region and show for the first time that the intestine originates by ingression of posterior ectoderm.

The two nerve rings of the hypostomal nervous system of Hydra vulgaris-an immunohistochemical analysis.

PubMed

Hufnagel, L A; Kass-Simon, G

2016-11-01

In Hydra vulgaris, physiological and pharmacological evidence exists for a hypostomal circumferential neuro-effector pathway that initiates ectodermal pacemaker activity at tentacular-hypostomal loci coordinating body and tentacle contractions. Here, we describe an ectodermal nerve ring that runs below and between the tentacles, and an anti-GABA B receptor antibody-labeled ring coincident with it. The location of this ring is consistent with the physiology of the hypostomal pacemaker systems of hydra. We also describe a distally located, ectodermal ring of nerve fibers that is not associated with anti-GABA B receptor antibody labeling. The neurites and cell bodies of sensory cells contribute to both rings. The location of the distal ring and its sensory cell neurites suggests an involvement in the behavior of the mouth. Between the two rings is a network of anastomosing sensory and ganglion cell bodies and their neurites. Phase contrast, darkfield, and antibody-labeled images reveal that the mouth of hydra comprises five or six epithelial folds whose endoderm extensively labels with anti-GABA B receptor antibody, suggesting that endodermal metabotrobic GABA receptors are also involved in regulating mouth behavior.

Branching out: origins of the sea urchin larval skeleton in development and evolution.

PubMed

McIntyre, Daniel C; Lyons, Deirdre C; Martik, Megan; McClay, David R

2014-03-01

It is a challenge to understand how the information encoded in DNA is used to build a three-dimensional structure. To explore how this works the assembly of a relatively simple skeleton has been examined at multiple control levels. The skeleton of the sea urchin embryo consists of a number of calcite rods produced by 64 skeletogenic cells. The ectoderm supplies spatial cues for patterning, essentially telling the skeletogenic cells where to position themselves and providing the factors for skeletal growth. Here, we describe the information known about how this works. First the ectoderm must be patterned so that the signaling cues are released from precise positions. The skeletogenic cells respond by initiating skeletogenesis immediately beneath two regions (one on the right and the other on the left side). Growth of the skeletal rods requires additional signaling from defined ectodermal locations, and the skeletogenic cells respond to produce a membrane-bound template in which the calcite crystal grows. Important in this process are three signals, fibroblast growth factor, vascular endothelial growth factor, and Wnt5. Each is necessary for explicit tasks in skeleton production. Copyright © 2014 Wiley Periodicals, Inc.

A rare case of malignant pediatric ectomesenchymoma arising from the cerebrum.

PubMed

Kun, Yao; Duan, Zejun; Mei, Xi; Xu, Ying; Li, Jiuzhou; Li, Shouwei; Qi, Xueling

2015-01-01

Malignant ectomesenchymoma is a rare tumor that contains both ectodermal and mesenchymal elements. So far, only 7 patients with a manifestation in the cerebrum (with confirmed clinicopathological data) have been reported. A 4-year-old girl was present at our hospital with a 3-week history of intermittent sudden dizzy with no apparent cause. MRI showed an irregular enhanced lesion in the left frontal-parietal lobe and lateral ventricle with peripheral gadolinium-enhancement with a significant surrounding edema. Total removal of the tumor was performed. Histological examination of the resected tumor revealed a mixed astrocytoma and anaplastic ependymoma component with undifferentiated mesenchymal spindle cell component. Generally speaking, the main malignant part in most cases of malignant ectomesenchymoma (MEM) is the mesenchymal component. In the present case, the malignant component was both in the mesenchymal and ectodermal part. In particular, the mesenchymal part was mainly composed of spindle cells, and the ectodermal part primarily consisted of gliomatous component and anaplastic ependymoma component. The patient was then treated with chemotherapy and as regard to the prognosis, there was no evidence of tumor recurrence at the 5 months' follow-up. The long term follow-up is still in progress.

Laminin and integrin expression in the ventral ectodermal ridge of the mouse embryo: implications for regulation of BMP signalling.

PubMed

Lopez-Escobar, Beatriz; De Felipe, Beatriz; Sanchez-Alcazar, Jose Antonio; Sasaki, Takako; Copp, Andrew J; Ybot-Gonzalez, Patricia

2012-11-01

The ventral ectodermal ridge (VER) is an important signalling centre in the mouse tail-bud following completion of gastrulation. BMP regulation is essential for VER function, but how these signals are transmitted between adjacent tissues is unclear. We investigated the idea that extracellular matrix components might be involved, using immunohistochemistry and in situ hybridisation to detect all known α, β, and γ laminin chains and their mRNAs in the early tail bud. We identified an apparently novel laminin variant, comprising α5, β3 and γ2 chains, as a major component of the VER basement membrane at E9.5. Strikingly, only the mRNAs for these chains were co-expressed in VER cells, suggesting that lamin532 may be the sole basement membrane laminin at this stage. Since α6 integrin was also expressed in VER cells, this raises the possibility of cell-matrix interactions regulating BMP signalling at this site of caudal morphogenesis. Laminin532 could interact with α6-containing integrin to direct differentiation of the specialised VER cells from surface ectoderm. Copyright © 2012 Wiley Periodicals, Inc.

Laminin and integrin expression in the ventral ectodermal ridge of the mouse embryo: implications for regulation of BMP signalling

PubMed Central

Lopez-Escobar, Beatriz; de Felipe, Beatriz; Sanchez-Alcazar, Jose Antonio; Sasaki, Takako; Copp, Andrew J.; Ybot-Gonzalez, Patricia

2013-01-01

Background The ventral ectodermal ridge (VER) is an important signalling centre in the mouse tail-bud following completion of gastrulation. BMP regulation is essential for VER function, but how these signals are transmitted between adjacent tissues is unclear. Results We investigated the idea that extracellular matrix components might be involved, using immunohistochemistry and in situ hybridisation to detect all known α, β and γ laminin chains and their mRNAs in the early tail bud. We identified an apparently novel laminin variant, comprising α5, β3 and γ2 chains, as a major component of the VER basement membrane at E9.5. Strikingly, only the mRNAs for these chains were co-expressed in VER cells, suggesting that lamin532 may be the sole basement membrane laminin at this stage. Since α6 integrin was also expressed in VER cells, this raises the possibility of cell-matrix interactions regulating BMP signalling at this site of caudal morphogenesis. Conclusions Laminin532 could interact with α6-containing integrin to direct differentiation of the specialised VER cells from surface ectoderm. PMID:22911573

ART culture conditions change the probability of mouse embryo gestation through defined cellular and molecular responses.

PubMed

Schwarzer, Caroline; Esteves, Telma Cristina; Araúzo-Bravo, Marcos J; Le Gac, Séverine; Nordhoff, Verena; Schlatt, Stefan; Boiani, Michele

2012-09-01

Do different human ART culture protocols prepare embryos differently for post-implantation development? The type of ART culture protocol results in distinct cellular and molecular phenotypes in vitro at the blastocyst stage as well as subsequently during in vivo development. It has been reported that ART culture medium affects human development as measured by gestation rates and birthweights. However, due to individual variation across ART patients, it is not possible as yet to pinpoint a cause-effect relationship between choice of culture medium and developmental outcome. In a prospective study, 13 human ART culture protocols were compared two at a time against in vivo and in vitro controls. Superovulated mouse oocytes were fertilized in vivo using outbred and inbred mating schemes. Zygotes were cultured in medium or in the oviduct and scored for developmental parameters 96 h later. Blastocysts were either analyzed or transferred into fosters to measure implantation rates and fetal development. In total, 5735 fertilized mouse oocytes, 1732 blastocysts, 605 fetuses and 178 newborns were examined during the course of the study (December 2010-December 2011). Mice of the B6C3F1, C57Bl/6 and CD1 strains were used as oocyte donors, sperm donors and recipients for embryo transfer, respectively. In vivo fertilized B6C3F1 oocytes were allowed to cleave in 13 human ART culture protocols compared with mouse oviduct and optimized mouse medium (KSOM(aa)). Cell lineage composition of resultant blastocysts was analyzed by immunostaining and confocal microscopy (trophectoderm, Cdx2; primitive ectoderm, Nanog; primitive endoderm, Sox17), global gene expression by microarray analysis, and rates of development to midgestation and to term. Mouse zygotes show profound variation in blastocyst (49.9-91.9%) and fetal (15.7-62.0%) development rates across the 13 ART culture protocols tested (R(2)= 0.337). Two opposite protocols, human tubal fluid/multiblast (high fetal rate) and ISM1/ISM2 (low fetal rate), were analyzed in depth using outbred and inbred fertilization schemes. Resultant blastocysts show imbalances of cell lineage composition; culture medium-specific deviation of gene expression (38 genes, ≥ 4-fold) compared with the in vivo pattern; and produce different litter sizes (P ≤ 0.0076) after transfer into fosters. Confounding effects of subfertility, life style and genetic heterogeneity are reduced to a minimum in the mouse model compared with ART patients. This is an animal model study. Mouse embryo responses to human ART media are not transferable 1-to-1 to human development due to structural and physiologic differences between oocytes of the two species. Our data promote awareness that human ART culture media affect embryo development. Effects reported here in the mouse may apply also in human, because no ART medium presently available on the market has been optimized for human embryo development. The mouse embryo assay (MEA), which requires ART media to support at least 80% blastocyst formation, is in need of reform and should be extended to include post-implantation development.

Senseless, a Zn finger transcription factor, is necessary and sufficient for sensory organ development in Drosophila

NASA Technical Reports Server (NTRS)

Nolo, R.; Abbott, L. A.; Bellen, H. J.

2000-01-01

The senseless (sens) gene is required for proper development of most cell types of the embryonic and adult peripheral nervous system (PNS) of Drosophila. Sens is a nuclear protein with four Zn fingers that is expressed and required in the sensory organ precursors (SOP) for proper proneural gene expression. Ectopic expression of Sens in many ectodermal cells causes induction of PNS external sensory organ formation and is able to recreate an ectopic proneural field. Hence, sens is both necessary and sufficient for PNS development. Our data indicate that proneural genes activate sens expression. Sens is then in turn required to further activate and maintain proneural gene expression. This feedback mechanism is essential for selective enhancement and maintenance of proneural gene expression in the SOPs.

Developmental disorders of the dentition: an update

PubMed Central

Klein, Ophir D.; Oberoi, Snehlata; Huysseune, Ann; Hovorakova, Maria; Peterka, Miroslav; Peterkova, Renata

2013-01-01

Dental anomalies are common congenital malformations that can occur either as isolated findings or as part of a syndrome. This review focuses on genetic causes of abnormal tooth development and the implications of these abnormalities for clinical care. As an introduction, we describe general insights into the genetics of tooth development obtained from mouse and zebrafish models. This is followed by a discussion of isolated as well as syndromic tooth agenesis, including Van der Woude syndrome, ectodermal dysplasias, oral-facial-digital syndrome type I, Rieger syndrome, holoprosencephaly, and tooth anomalies associated with cleft lip and palate. Next, we review delayed formation and eruption of teeth, as well as abnormalities in tooth size, shape and form. Finally, isolated and syndromic causes of supernumerary teeth are considered, including cleidocranial dysplasia and Gardner syndrome. PMID:24124058

The fine structure of human germ layers in vivo: clues to the early differentiation of embryonic stem cells in vitro.

PubMed

Sathananthan, Henry; Selvaraj, Kamala; Clark, Joan

2011-08-01

The fine structure of the three germ layers in human ectopic embryos (stage 7) have been documented by digital light and electron microscopy. The formation of ectoderm, endoderm and mesoderm and notochordal cells, and also the extraembryonic membranes, amnion and yolk sac, are imaged. The germ layers give rise to all the cells and tissues of the human body. Possible clues to the early differentiation of embryonic stem cells (ESC) in vitro were obtained, since these events are more or less mimicked in cultures of ESC derived from the inner cell mass of human blastocysts. The findings are discussed with reference to previous studies on the fine structure of ESC using the same technique. Copyright © 2011. Published by Elsevier Ltd.

ROCKY PLANETESIMAL FORMATION VIA FLUFFY AGGREGATES OF NANOGRAINS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arakawa, Sota; Nakamoto, Taishi, E-mail: arakawa.s.ac@m.titech.ac.jp

2016-12-01

Several pieces of evidence suggest that silicate grains in primitive meteorites are not interstellar grains but condensates formed in the early solar system. Moreover, the size distribution of matrix grains in chondrites implies that these condensates might be formed as nanometer-sized grains. Therefore, we propose a novel scenario for rocky planetesimal formation in which nanometer-sized silicate grains are produced by evaporation and recondensation events in early solar nebula, and rocky planetesimals are formed via aggregation of these nanograins. We reveal that silicate nanograins can grow into rocky planetesimals via direct aggregation without catastrophic fragmentation and serious radial drift, and ourmore » results provide a suitable condition for protoplanet formation in our solar system.« less

Microfluidic assay of the deformability of primitive erythroblasts.

PubMed

Zhou, Sitong; Huang, Yu-Shan; Kingsley, Paul D; Cyr, Kathryn H; Palis, James; Wan, Jiandi

2017-09-01

Primitive erythroblasts (precursors of red blood cells) enter vascular circulation during the embryonic period and mature while circulating. As a result, primitive erythroblasts constantly experience significant hemodynamic shear stress. Shear-induced deformation of primitive erythroblasts however, is poorly studied. In this work, we examined the deformability of primitive erythroblasts at physiologically relevant flow conditions in microfluidic channels and identified the regulatory roles of the maturation stage of primitive erythroblasts and cytoskeletal protein 4.1 R in shear-induced cell deformation. The results showed that the maturation stage affected the deformability of primitive erythroblasts significantly and that primitive erythroblasts at later maturational stages exhibited a better deformability due to a matured cytoskeletal structure in the cell membrane.

Variable phenotypic penetrance of thrombosis in adult mice after tissue-selective and temporally controlled Thbd gene inactivation

PubMed Central

van Mens, Thijs E.; Liang, Hai-Po H.; Basu, Sreemanti; Hernandez, Irene; Zogg, Mark; May, Jennifer; Zhan, Min; Yang, Qiuhui; Foeckler, Jamie; Kalloway, Shawn; Sood, Rashmi; Karlson, Caren Sue

2017-01-01

Thrombomodulin (Thbd) exerts pleiotropic effects on blood coagulation, fibrinolysis, and complement system activity by facilitating the thrombin-mediated activation of protein C and thrombin-activatable fibrinolysis inhibitor and may have additional thrombin- and protein C (pC)-independent functions. In mice, complete Thbd deficiency causes embryonic death due to defective placental development. In this study, we used tissue-selective and temporally controlled Thbd gene ablation to examine the function of Thbd in adult mice. Selective preservation of Thbd function in the extraembryonic ectoderm and primitive endoderm via the Meox2Cre-transgene enabled normal intrauterine development of Thbd-deficient (Thbd−/−) mice to term. Half of the Thbd−/− offspring expired perinatally due to thrombohemorrhagic lesions. Surviving Thbd−/− animals only rarely developed overt thrombotic lesions, exhibited low-grade compensated consumptive coagulopathy, and yet exhibited marked, sudden-onset mortality. A corresponding pathology was seen in mice in which the Thbd gene was ablated after reaching adulthood. Supplementation of activated PC by transgenic expression of a partially Thbd-independent murine pC zymogen prevented the pathologies of Thbd−/− mice. However, Thbd−/− females expressing the PC transgene exhibited pregnancy-induced morbidity and mortality with near-complete penetrance. These findings suggest that Thbd function in nonendothelial embryonic tissues of the placenta and yolk sac affects through as-yet-unknown mechanisms the penetrance and severity of thrombosis after birth and provide novel opportunities to study the role of the natural Thbd-pC pathway in adult mice and during pregnancy. PMID:28920104

DNA in soil: adsorption, genetic transformation, molecular evolution and genetic microchip.

PubMed

Trevors, J T

1996-07-01

This review examines interactions between DNA and soil with an emphasis on the persistence and stability of DNA in soil. The role of DNA in genetic transformation in soil microorganisms will also be discussed. In addition, a postulated mechanism for stabilization and elongation/assembly of primitive genetic material and the role of soil particles, salt concentrations, temperature cycling and crystal formation is examined.

Shock synthesis of amino acids in simulated primitive environments.

NASA Technical Reports Server (NTRS)

Bar-Nun, A.; Bar-Nun, N.; Bauer, S. H.; Sagan, C.

1971-01-01

A single pulse shock tube of a uniform bore was used in the experiments. The reaction mixture consisted of 3.3 per cent methane, 11 per cent ethane, and 5.6 per cent ammonia, diluted with ultra-pure argon. The formation of glycine, alanine, valine, and leucine under conditions of shock heating was observed. Thermodynamic relations are discussed together with questions of conversion efficiency.

Studies of Peptide-Mineral Interactions and Biosilicification

DTIC Science & Technology

2010-07-16

His). The effect of zinc oxide -binding peptides ( ZnO -BPs) on the morphology and formation of ZnO were studied using G-12 (GLHVMHKVAPPR) and EM-12...interactions with silica and zinc oxide . Detailed quantitative experimental studies together with molecular modeling studies have shown that G12 (GLHVMHKVAPPR...studies of a primitive 15. SUBJECT TERMS Peptides, zinc oxide , silica, silver, peptide-mineral interactions, computational chemistry, molecular

Early formation of planetary building blocks inferred from Pb isotopic ages of chondrules

PubMed Central

Bollard, Jean; Connelly, James N.; Whitehouse, Martin J.; Pringle, Emily A.; Bonal, Lydie; Jørgensen, Jes K.; Nordlund, Åke; Moynier, Frédéric; Bizzarro, Martin

2017-01-01

The most abundant components of primitive meteorites (chondrites) are millimeter-sized glassy spherical chondrules formed by transient melting events in the solar protoplanetary disk. Using Pb-Pb dates of 22 individual chondrules, we show that primary production of chondrules in the early solar system was restricted to the first million years after the formation of the Sun and that these existing chondrules were recycled for the remaining lifetime of the protoplanetary disk. This finding is consistent with a primary chondrule formation episode during the early high-mass accretion phase of the protoplanetary disk that transitions into a longer period of chondrule reworking. An abundance of chondrules at early times provides the precursor material required to drive the efficient and rapid formation of planetary objects via chondrule accretion. PMID:28808680

Chondrule-forming Shock Fronts in the Solar Nebula: A Possible Unified Scenario for Planet and Chondrite Formation

NASA Astrophysics Data System (ADS)

Boss, A. P.; Durisen, R. H.

2005-03-01

Chondrules are millimeter-sized spherules found throughout primitive chondritic meteorites. Flash heating by a shock front is the leading explanation of their formation. However, identifying a mechanism for creating shock fronts inside the solar nebula has been difficult. In a gaseous disk capable of forming Jupiter, the disk must have been marginally gravitationally unstable at and beyond Jupiter's orbit. We show that this instability can drive inward spiral shock fronts with shock speeds of up to ~10 km s-1 at asteroidal orbits, sufficient to account for chondrule formation. The mixing and transport of solids in such a disk, combined with the planet-forming tendencies of gravitational instabilities, results in a unified scenario linking chondrite production with gas giant planet formation.

The origin and early evolution of life on earth

NASA Technical Reports Server (NTRS)

Oro, J.; Miller, Stanley L.; Lazcano, Antonio

1990-01-01

Results of the studies that have provided insights into the cosmic and primitive earth environments are reviewed with emphasis on those environments in which life is thought to have originated. The evidence bearing on the antiquity of life on the earth and the prebiotic significance of organic compounds found in interstellar clouds and in primitive solar-system bodies such as comets, dark asteroids, and carbonaceous chondrites are assessed. The environmental models of the Hadean and early Archean earth are discussed, as well as the prebiotic formation of organic monomers and polymers essential to life. The processes that may have led to the appearance in the Archean of the first cells are considered, and possible effects of these processes on the early steps of biological evolution are analyzed. The significance of these results to the study of the distribution of life in the universe is evaluated.

The solar system/interstellar medium connection - Gas phase abundances

NASA Technical Reports Server (NTRS)

Lutz, Barry L.

1987-01-01

Gas-phase abundances in the outer solar system are presented as diagnostics of the interstellar medium at the time of the solar system formation, some 4.55 billion years ago. Possible influences of the thermal and chemical histories of the primitive solar nebula and of the processes which led to the formation and evolution of the outer planets and comets on the elemental and molecular composition of the primordial matter are outlined. The major components of the atmospheres of the outer planets and of the comae of comets are identified, and the cosmogonical and cosmological implications are discussed.

Astrophysical dust grains in stars, the interstellar medium, and the solar system

NASA Technical Reports Server (NTRS)

Gehrz, Robert D.

1991-01-01

Studies of astrophysical dust grains in circumstellar shells, the interstellar medium, and the solar system may provide information about stellar evolution and about physical conditions in the primitive solar nebula. The following subject areas are covered: (1) the cycling of dust in stellar evolution and the formation of planetary systems; (2) astrophysical dust grains in circumstellar environments; (3) circumstellar grain formation and mass loss; (4) interstellar dust grains; (5) comet dust and the zodiacal cloud; (6) the survival of dust grains during stellar evolution; and (7) establishing connections between stardust and dust in the solar system.

[Rathke cysts, craniopharyngioma, and colloid cysts : What are the differences between these pathologies?

PubMed

Eymann, R; Kiefer, M

2018-05-17

Headache is the most common symptom of colloid cysts, Rathke cysts, and craniopharyngioma due to their location in the midline, being extra-axial and typically presenting in the parasellar region. Although these tumors are generally considered benign, each has its typical characteristics defined by its location and histology. These individual characteristics define whether surgery is necessary at all and if so, the preferred surgical approach and resection's totality. The histopathological findings primarily indicate that embryonic malformations-at the first glance, ectodermal in nature-cause these tumors. Due to the fact that these disturbances occur at the boundary between ectodermal stomodeum and endodermal cephalogaster, however, does leave some doubts.

Whole-Body Radiation Therapy, Systemic Chemotherapy, and High-Dose Chemotherapy Followed By Stem Cell Rescue in Treating Patients With Poor-Risk Ewing Sarcoma

ClinicalTrials.gov

2015-01-07

Adult Supratentorial Primitive Neuroectodermal Tumor (PNET); Ewing Sarcoma of Bone; Extraosseous Ewing Sarcoma; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Untreated Childhood Supratentorial Primitive Neuroectodermal Tumor

Frontal dermoid cyst coexisting with suprasellar craniopharyngioma: a spectrum of ectodermally derived epithelial-lined cystic lesions?

PubMed

Abou-Al-Shaar, Hussam; Abd-El-Barr, Muhammad M; Zaidi, Hasan A; Russell-Goldman, Eleanor; Folkerth, Rebecca D; Laws, Edward R; Chiocca, E Antonio

2016-12-01

There is a wide group of lesions that may exist in the sellar and suprasellar regions. Embryologically, there is varying evidence that many of these entities may in fact represent a continuum of pathology deriving from a common ectodermal origin. The authors report a case of a concomitant suprasellar craniopharyngioma invading the third ventricle with a concurrent frontal lobe cystic dermoid tumor. A 21-year-old man presented to the authors' service with a 3-day history of worsening headache, nausea, vomiting, and blurry vision. Magnetic resonance imaging depicted a right frontal lobe lesion associated with a separate suprasellar cystic lesion invading the third ventricle. The patient underwent a right pterional craniotomy for resection of both lesions. Gross-total resection of the right frontal lesion was achieved, and subtotal resection of the suprasellar lesion was accomplished with some residual tumor adherent to the walls of the third ventricle. Histopathological examination of the resected right frontal lesion documented a diagnosis of dermoid cyst and, for the suprasellar lesion, a diagnosis of adamantinomatous craniopharyngioma. The occurrence of craniopharyngioma with dermoid cyst has not been reported in the literature before. Such an association might indeed suggest the previously reported hypothesis that these lesions represent a spectrum of ectodermally derived epithelial-lined cystic lesions.

Neurotoxin localization to ectodermal gland cells uncovers an alternative mechanism of venom delivery in sea anemones.

PubMed

Moran, Yehu; Genikhovich, Grigory; Gordon, Dalia; Wienkoop, Stefanie; Zenkert, Claudia; Ozbek, Suat; Technau, Ulrich; Gurevitz, Michael

2012-04-07

Jellyfish, hydras, corals and sea anemones (phylum Cnidaria) are known for their venomous stinging cells, nematocytes, used for prey and defence. Here we show, however, that the potent Type I neurotoxin of the sea anemone Nematostella vectensis, Nv1, is confined to ectodermal gland cells rather than nematocytes. We demonstrate massive Nv1 secretion upon encounter with a crustacean prey. Concomitant discharge of nematocysts probably pierces the prey, expediting toxin penetration. Toxin efficiency in sea water is further demonstrated by the rapid paralysis of fish or crustacean larvae upon application of recombinant Nv1 into their medium. Analysis of other anemone species reveals that in Anthopleura elegantissima, Type I neurotoxins also appear in gland cells, whereas in the common species Anemonia viridis, Type I toxins are localized to both nematocytes and ectodermal gland cells. The nematocyte-based and gland cell-based envenomation mechanisms may reflect substantial differences in the ecology and feeding habits of sea anemone species. Overall, the immunolocalization of neurotoxins to gland cells changes the common view in the literature that sea anemone neurotoxins are produced and delivered only by stinging nematocytes, and raises the possibility that this toxin-secretion mechanism is an ancestral evolutionary state of the venom delivery machinery in sea anemones.

Activin- and Nodal-related factors control antero-posterior patterning of the zebrafish embryo.

PubMed

Thisse, B; Wright, C V; Thisse, C

2000-01-27

Definition of cell fates along the dorso-ventral axis depends on an antagonistic relationship between ventralizing transforming growth factor-beta superfamily members, the bone morphogenetic proteins and factors secreted from the dorsal organizer, such as Noggin and Chordin. The extracellular binding of the last group to the bone morphogenetic proteins prevents them from activating their receptors, and the relative ventralizer:antagonist ratio is thought to specify different dorso-ventral cell fates. Here, by taking advantage of a non-genetic interference method using a specific competitive inhibitor, the Lefty-related gene product Antivin, we provide evidence that cell fate along the antero-posterior axis of the zebrafish embryo is controlled by the morphogenetic activity of another transforming growth factor-beta superfamily subgroup--the Activin and Nodal-related factors. Increasing antivin doses progressively deleted posterior fates within the ectoderm, eventually resulting in the removal of all fates except forebrain and eyes. In contrast, overexpression of activin or nodal-related factors converted ectoderm that was fated to be forebrain into more posterior ectodermal or mesendodermal fates. We propose that modulation of intercellular signalling by Antivin/Activin and Nodal-related factors provides a mechanism for the graded establishment of cell fates along the antero-posterior axis of the zebrafish embryo.

An historical perspective on the pioneering experiments of John Saunders.

PubMed

Tickle, Cheryll

2017-09-15

John Saunders was a highly skilled embryologist who pioneered the study of limb development. His studies on chick embryos provided the fundamental framework for understanding how vertebrate limbs develop. This framework inspired generations of scientists and formed the bridge from experimental embryology to molecular mechanisms. Saunders investigated how feathers become organized into tracts in the skin of the chick wing and also identified regions of programmed cell death. He discovered that a region of thickened ectoderm that rims the chick wing bud - the apical ectodermal ridge - is required for outgrowth and the laying down of structures along the proximo-distal axis (long axis) of the wing, identified the zone of polarizing activity (ZPA; polarizing region) that controls development across the anteroposterior axis ("thumb to little finger "axis) and contributed to uncovering the importance of the ectoderm in development of structures along the dorso-ventral axis ( "back of hand to palm" axis). This review looks in depth at some of his original papers and traces how he made the crucial findings about how limbs develop, considering these findings both in the context of contemporary knowledge at the time and also in terms of their immediate impact on the field. Copyright © 2017 Elsevier Inc. All rights reserved.

Quantitative proteomics of the human skin secretome reveal a reduction in immune defense mediators in ectodermal dysplasia patients.

PubMed

Burian, Marc; Velic, Ana; Matic, Katarina; Günther, Stephanie; Kraft, Beatrice; Gonser, Lena; Forchhammer, Stephan; Tiffert, Yvonne; Naumer, Christian; Krohn, Michael; Berneburg, Mark; Yazdi, Amir S; Maček, Boris; Schittek, Birgit

2015-03-01

In healthy human skin host defense molecules such as antimicrobial peptides (AMPs) contribute to skin immune homeostasis. In patients with the congenital disease ectodermal dysplasia (ED) skin integrity is disturbed and as a result patients have recurrent skin infections. The disease is characterized by developmental abnormalities of ectodermal derivatives and absent or reduced sweating. We hypothesized that ED patients have a reduced skin immune defense because of the reduced ability to sweat. Therefore, we performed a label-free quantitative proteome analysis of wash solution of human skin from ED patients or healthy individuals. A clear-cut difference between both cohorts could be observed in cellular processes related to immunity and host defense. In line with the extensive underrepresentation of proteins of the immune system, dermcidin, a sweat-derived AMP, was reduced in its abundance in the skin secretome of ED patients. In contrast, proteins involved in metabolic/catabolic and biosynthetic processes were enriched in the skin secretome of ED patients. In summary, our proteome profiling provides insights into the actual situation of healthy versus diseased skin. The systematic reduction in immune system and defense-related proteins may contribute to the high susceptibility of ED patients to skin infections and altered skin colonization.

The Ca2+-induced methyltransferase xPRMT1b controls neural fate in amphibian embryo.

PubMed

Batut, Julie; Vandel, Laurence; Leclerc, Catherine; Daguzan, Christiane; Moreau, Marc; Néant, Isabelle

2005-10-18

We have previously shown that an increase in intracellular Ca2+ is both necessary and sufficient to commit ectoderm to a neural fate in Xenopus embryos. However, the relationship between this Ca2+ increase and the expression of early neural genes has yet to be defined. Using a subtractive cDNA library between untreated and caffeine-treated animal caps, i.e., control ectoderm and ectoderm induced toward a neural fate by a release of Ca2+, we have isolated the arginine N-methyltransferase, xPRMT1b, a Ca2+-induced target gene, which plays a pivotal role in this process. First, we show in embryo and in animal cap that xPRMT1b expression is Ca2+-regulated. Second, overexpression of xPRMT1b induces the expression of early neural genes such as Zic3. Finally, in the whole embryo, antisense approach with morpholino oligonucleotide against xPRMT1b impairs neural development and in animal caps blocks the expression of neural markers induced by a release of internal Ca2+. Our results implicate an instructive role of an enzyme, an arginine methyltransferase protein, in the embryonic choice of determination between epidermal and neural fate. The results presented provide insights by which a Ca2+ increase induces neural fate.

Ordered progression of nematogenesis from stem cells through differentiation stages in the tentacle bulb of Clytia hemisphaerica (Hydrozoa, Cnidaria).

PubMed

Denker, Elsa; Manuel, Michaël; Leclère, Lucas; Le Guyader, Hervé; Rabet, Nicolas

2008-03-01

Nematogenesis, the production of stinging cells (nematocytes) in Cnidaria, can be considered as a model neurogenic process. Most molecular data concern the freshwater polyp Hydra, in which nematocyte production is scattered throughout the body column ectoderm, the mature cells then migrating to the tentacles. We have characterized tentacular nematogenesis in the Clytia hemisphaerica hydromedusa and found it to be confined to the ectoderm of the tentacle bulb, a specialized swelling at the tentacle base. Analysis by a variety of light and electron microscope techniques revealed that while cellular aspects of nematogenesis are similar to Hydra, the spatio-temporal characteristics are markedly more ordered. The tentacle bulb nematogenic ectoderm (TBE) was found to be polarized, with a clear progression of successive nematoblast stages from a proximal zone (comprising a majority of undifferentiated cells) to the distal end where the tentacle starts. Pulse-chase labelling experiments demonstrated a continuous displacement of differentiating nematoblasts towards the tentacle tip, and that nematogenesis proceeds more rapidly in Clytia than in Hydra. Compact expression domains of orthologues of known nematogenesis-associated genes (Piwi, dickkopf-3, minicollagens and NOWA) were correspondingly staggered along the TBE. These distinct characteristics make the Clytia TBE a promising experimental system for understanding the mechanisms regulating nematogenesis.

Calcium transport into the cells of the sea urchin larva in relation to spicule formation

PubMed Central

Vidavsky, Netta; Addadi, Sefi; Schertel, Andreas; Ben-Ezra, David; Shpigel, Muki; Addadi, Lia; Weiner, Steve

2016-01-01

We investigated the manner in which the sea urchin larva takes up calcium from its body cavity into the primary mesenchymal cells (PMCs) that are responsible for spicule formation. We used the membrane-impermeable fluorescent dye calcein and alexa-dextran, with or without a calcium channel inhibitor, and imaged the larvae in vivo with selective-plane illumination microscopy. Both fluorescent molecules are taken up from the body cavity into the PMCs and ectoderm cells, where the two labels are predominantly colocalized in particles, whereas the calcium-binding calcein label is mainly excluded from the endoderm and is concentrated in the spicules. The presence of vesicles and vacuoles inside the PMCs that have openings through the plasma membrane directly to the body cavity was documented using high-resolution cryo-focused ion beam-SEM serial imaging. Some of the vesicles and vacuoles are interconnected to form large networks. We suggest that these vacuolar networks are involved in direct sea water uptake. We conclude that the calcium pathway from the body cavity into cells involves nonspecific endocytosis of sea water with its calcium. PMID:27791140

Calcium transport into the cells of the sea urchin larva in relation to spicule formation.

PubMed

Vidavsky, Netta; Addadi, Sefi; Schertel, Andreas; Ben-Ezra, David; Shpigel, Muki; Addadi, Lia; Weiner, Steve

2016-10-24

We investigated the manner in which the sea urchin larva takes up calcium from its body cavity into the primary mesenchymal cells (PMCs) that are responsible for spicule formation. We used the membrane-impermeable fluorescent dye calcein and alexa-dextran, with or without a calcium channel inhibitor, and imaged the larvae in vivo with selective-plane illumination microscopy. Both fluorescent molecules are taken up from the body cavity into the PMCs and ectoderm cells, where the two labels are predominantly colocalized in particles, whereas the calcium-binding calcein label is mainly excluded from the endoderm and is concentrated in the spicules. The presence of vesicles and vacuoles inside the PMCs that have openings through the plasma membrane directly to the body cavity was documented using high-resolution cryo-focused ion beam-SEM serial imaging. Some of the vesicles and vacuoles are interconnected to form large networks. We suggest that these vacuolar networks are involved in direct sea water uptake. We conclude that the calcium pathway from the body cavity into cells involves nonspecific endocytosis of sea water with its calcium.

Fox (forkhead) genes are involved in the dorso-ventral patterning of the Xenopus mesoderm.

PubMed

El-Hodiri, H; Bhatia-Dey, N; Kenyon, K; Ault, K; Dirksen, M; Jamrich, M

2001-01-01

Fox (forkhead/winged helix) genes encode a family of transcription factors that are involved in embryonic pattern formation, regulation of tissue specific gene expression and tumorigenesis. Several of them are transcribed during Xenopus embryogenesis and are important for the patterning of ectoderm, mesoderm and endoderm. We have isolated three forkhead genes that are activated during gastrulation and play an important role in the dorso-ventral patterning of the mesoderm. XFKH1 (FoxA4b), the first vertebrate forkhead gene to be implicated in embryonic pattern formation, is expressed in the Spemann-Mangold organizer region and later in the embryonic notochord. XFKH7, the Xenopus orthologue of the murine Mfh1(Foxc2), is expressed in the presomitic mesoderm, but not in the notochord or lateral plate mesoderm. Finally, XFD-13'(FoxF1b)1 is expressed in the lateral plate mesoderm, but not in the notochord or presomitic mesoderm. Expression pattern and functional experiments indicate that these three forkhead genes are involved in the dorso-ventral patterning of the mesoderm.

Zebrafish narrowminded suggests a genetic link between formation of neural crest and primary sensory neurons

PubMed Central

Bruk Artinger, Kristin; Chitnis, Ajay B.; Mercola, Mark; Driever, Wolfgang

2014-01-01

SUMMARY In the developing vertebrate nervous system, both neural crest and sensory neurons form at the boundary between non-neural ectoderm and the neural plate. From an in situ hybridization based expression analysis screen, we have identified a novel zebrafish mutation, narrowminded (nrd), which reduces the number of early neural crest cells and eliminates Rohon-Beard (RB) sensory neurons. Mosaic analysis has shown that the mutation acts cell autonomously suggesting that nrd is involved in either the reception or interpretation of signals at the lateral neural plate boundary. Characterization of the mutant phenotype indicates that nrd is required for a primary wave of neural crest cell formation during which progenitors generate both RB sensory neurons and neural crest cells. Moreover, the early deficit in neural crest cells in nrd homozygotes is compensated later in development. Thus, we propose that a later wave can compensate for the loss of early neural crest cells but, interestingly, not the RB sensory neurons. We discuss the implications of these findings for the possibility that RB sensory neurons and neural crest cells share a common evolutionary origin. PMID:10457007

Secure Heterogeneous Multicore Platform Through Diversity and Redundancy

DTIC Science & Technology

2012-03-31

implementation detects synchronization in this way. If a programmer uses custom synchronization primitives , our approach assumes that such primitives ... synchronization primitives . Primitives such as barriers and spinlocks explicitly enforce a pre- determined ordering among threads. Therefore, the outcome of...these synchronization operations are deterministic. In the discussion, we will refer to these primitives as ordering synchronization operations. On the

Split-Hand/Split-Foot Malformation Is Caused by Mutations in the p63 Gene on 3q27

PubMed Central

Ianakiev, Peter; Kilpatrick, Michael W.; Toudjarska, Iva; Basel, Donald; Beighton, Peter; Tsipouras, Petros

2000-01-01

Split-hand/split-foot malformation (SHFM), a limb malformation involving the central rays of the autopod and presenting with syndactyly, median clefts of the hands and feet, and aplasia and/or hypoplasia of the phalanges, metacarpals, and metatarsals, is phenotypically analogous to the naturally occurring murine Dactylaplasia mutant (Dac). Results of recent studies have shown that, in heterozygous Dac embryos, the central segment of the apical ectodermal ridge (AER) degenerates, leaving the anterior and posterior segments intact; this finding suggests that localized failure of ridge maintenance activity is the fundamental developmental defect in Dac and, by inference, in SHFM. Results of gene-targeting studies have demonstrated that p63, a homologue of the cell-cycle regulator TP53, plays a critically important role in regulation of the formation and differentiation of the AER. Two missense mutations, 724A→G, which predicts amino acid substitution K194E, and 982T→C, which predicts amino acid substitution R280C, were identified in exons 5 and 7, respectively, of the p63 gene in two families with SHFM. Two additional mutations (279R→H and 304R→Q) were identified in families with EEC (ectrodactyly, ectodermal dysplasia, and facial cleft) syndrome. All four mutations are found in exons that fall within the DNA-binding domain of p63. The two amino acids mutated in the families with SHFM appear to be primarily involved in maintenance of the overall structure of the domain, in contrast to the p63 mutations responsible for EEC syndrome, which reside in amino acid residues that directly interact with the DNA. PMID:10839977

Compartmentalization of the somite and myogenesis in chick embryos are influenced by wnt expression.

PubMed

Wagner, J; Schmidt, C; Nikowits, W; Christ, B

2000-12-01

Muscles of the body and bones of the axial skeleton derive from specialized regions of somites. Somite development is influenced by adjacent structures. In particular, the dorsal neural tube and the overlying ectoderm have been shown to be necessary for the induction of myogenic precursor cells in the dermomyotome. Members of the Wnt family of signaling molecules, which are expressed in the dorsal neural tube and the ectoderm, are postulated to be responsible for this process. It is shown here that ectopically implanted Wnt-1-, -3a-, and -4-expressing cells alter the process of somite compartmentalization in vivo. An enlarged dorsal compartment results from the implantation of Wnt-expressing cells ventrally between the neural tube/notochord and epithelial somites, at the expense of the ventral compartment, the sclerotome. Thus, ectopic Wnt expression is able to override the influence of ventralizing signals arising from notochord and floor plate. This shift of the border between the two compartments was identified by an increase in the domain of Pax-3 expression and a complete loss of Pax-1 expression in somites close to the ectopic Wnt signal. The expanded expression of MyoD and desmin provides evidence that it is the myotome which increases as a result of Wnt signaling. Paraxis expression is also drastically amplified after implantation of Wnt-expressing cells indicating that Wnts are involved in the formation and maintenance of somite epithelium and suggesting that Paraxis is activated through Wnt signaling pathways. Taken together these results suggest that ectopic Wnts disturb the normal balance of signaling molecules within the somite, resulting in an enhanced recruitment of somitic cells into the myogenic lineage. Copyright 2000 Academic Press.

DLX5, FGF8 and the Pin1 isomerase control ΔNp63α protein stability during limb development: a regulatory loop at the basis of the SHFM and EEC congenital malformations

PubMed Central

Restelli, Michela; Lopardo, Teresa; Lo Iacono, Nadia; Garaffo, Giulia; Conte, Daniele; Rustighi, Alessandra; Napoli, Marco; Del Sal, Giannino; Perez-Morga, David; Costanzo, Antonio; Merlo, Giorgio Roberto; Guerrini, Luisa

2014-01-01

Ectrodactyly, or Split-Hand/Foot Malformation (SHFM), is a congenital condition characterized by the loss of central rays of hands and feet. The p63 and the DLX5;DLX6 transcription factors, expressed in the embryonic limb buds and ectoderm, are disease genes for these conditions. Mutations of p63 also cause the ectodermal dysplasia–ectrodactyly–cleft lip/palate (EEC) syndrome, comprising SHFM. Ectrodactyly is linked to defects of the apical ectodermal ridge (AER) of the developing limb buds. FGF8 is the key signaling molecule in this process, able to direct proximo-distal growth and patterning of the skeletal primordial of the limbs. In the limb buds of both p63 and Dlx5;Dlx6 murine models of SHFM, the AER is poorly stratified and FGF8 expression is severely reduced. We show here that the FGF8 locus is a downstream target of DLX5 and that FGF8 counteracts Pin1–ΔNp63α interaction. In vivo, lack of Pin1 leads to accumulation of the p63 protein in the embryonic limbs and ectoderm. We show also that ΔNp63α protein stability is negatively regulated by the interaction with the prolyl-isomerase Pin1, via proteasome-mediated degradation; p63 mutant proteins associated with SHFM or EEC syndromes are resistant to Pin1 action. Thus, DLX5, p63, Pin1 and FGF8 participate to the same time- and location-restricted regulatory loop essential for AER stratification, hence for normal patterning and skeletal morphogenesis of the limb buds. These results shed new light on the molecular mechanisms at the basis of the SHFM and EEC limb malformations. PMID:24569166

SVGenes: a library for rendering genomic features in scalable vector graphic format.

PubMed

Etherington, Graham J; MacLean, Daniel

2013-08-01

Drawing genomic features in attractive and informative ways is a key task in visualization of genomics data. Scalable Vector Graphics (SVG) format is a modern and flexible open standard that provides advanced features including modular graphic design, advanced web interactivity and animation within a suitable client. SVGs do not suffer from loss of image quality on re-scaling and provide the ability to edit individual elements of a graphic on the whole object level independent of the whole image. These features make SVG a potentially useful format for the preparation of publication quality figures including genomic objects such as genes or sequencing coverage and for web applications that require rich user-interaction with the graphical elements. SVGenes is a Ruby-language library that uses SVG primitives to render typical genomic glyphs through a simple and flexible Ruby interface. The library implements a simple Page object that spaces and contains horizontal Track objects that in turn style, colour and positions features within them. Tracks are the level at which visual information is supplied providing the full styling capability of the SVG standard. Genomic entities like genes, transcripts and histograms are modelled in Glyph objects that are attached to a track and take advantage of SVG primitives to render the genomic features in a track as any of a selection of defined glyphs. The feature model within SVGenes is simple but flexible and not dependent on particular existing gene feature formats meaning graphics for any existing datasets can easily be created without need for conversion. The library is provided as a Ruby Gem from https://rubygems.org/gems/bio-svgenes under the MIT license, and open source code is available at https://github.com/danmaclean/bioruby-svgenes also under the MIT License. dan.maclean@tsl.ac.uk.

EDAR-induced hypohidrotic ectodermal dysplasia: a clinical study on signs and symptoms in individuals with a heterozygous c.1072C > T mutation

PubMed Central

2014-01-01

Background Mutations in the EDAR-gene cause hypohidrotic ectodermal dysplasia, however, the oral phenotype has been described in a limited number of cases. The aim of the present study was to clinically describe individuals with the c.1072C > T mutation (p. Arg358X) in the EDAR gene with respect to dental signs and saliva secretion, symptoms from other ectodermal structures and to assess orofacial function. Methods Individuals in three families living in Sweden, where some members had a known c.1072C > T mutation in the EDAR gene with an autosomal dominant inheritance (AD), were included in a clinical investigation on oral signs and symptoms and self-reported symptoms from other ectodermal structures (n = 37). Confirmation of the c.1072C > T mutation in the EDAR gene were performed by genomic sequencing. Orofacial function was evaluated with NOT-S. Results The mutation was identified in 17 of 37 family members. The mean number of missing teeth due to agenesis was 10.3 ± 4.1, (range 4–17) in the mutation group and 0.1 ± 0.3, (range 0–1) in the non-mutation group (p < 0.01). All individuals with the mutation were missing the maxillary lateral incisors and one or more of the mandibular incisors; and 81.3% were missing all four. Stimulated saliva secretion was 0.9 ± 0.5 ml/min in the mutation group vs 1.7 ± 0.6 ml/min in the non-mutation group (p < 0.01). Reduced ability to sweat was reported by 82% in the mutation group and by 20% in the non-mutation group (p < 0.01). The mean NOT-S score was 3.0 ± 1.9 (range 0–6) in the mutation group and 1.5 ± 1.1 (range 0–5) in the non-mutation group (p < 0.01). Lisping was present in 56% of individuals in the mutation group. Conclusions Individuals with a c.1072C > T mutation in the EDAR-gene displayed a typical pattern of congenitally missing teeth in the frontal area with functional consequences. They therefore have a need for special attention in dental care, both with reference to tooth agenesis and low salivary secretion with an increased risk for caries. Sweating problems were the most frequently reported symptom from other ectodermal structures. PMID:24884697

The catalytic effect of L- and D-histidine on alanine and lysine peptide formation.

PubMed

Fitz, Daniel; Jakschitz, Thomas; Rode, Bernd M

2008-12-01

A starting phase of chemical evolution on our ancient Earth around 4 billion years ago was the formation of amino acids and their combination to peptides and proteins. The salt-induced peptide formation (SIPF) reaction has been shown to be appropriate for this condensation reaction under moderate and plausible primitive Earth conditions, forming short peptides from amino acids in aqueous solution containing sodium chloride and Cu(II) ions. In this paper we report results about the formation of dialanine and dilysine from their monomers in this reaction. The catalytic influence of l- and d-histidine dramatically increases dialanine yields when starting from lower alanine concentrations, but also dilysine formation is markedly boosted by these catalysts. Attention is paid to measurable preferences for one enantiomeric form of alanine and lysine in the SIPF reaction. Alanine, especially, shows stereospecific behaviour, mostly in favour of the l-form.

Staging Life in an Early Warm ‘Seltzer’ Ocean

DOE PAGES

Schoonen, Martin; Smirnov, Alexander

2016-12-01

A period as short as 20 million years within the first 100 million years after the formation of the Moon may have set the stage for the origin of life. This atmosphere contained more carbon dioxide than any other period afterwards. The carbon dioxide sustained greenhouse conditions, accelerated the weathering of a primitive crust and may have led to conditions conducive to the formation of the building blocks of life. The conversion of CO 2 as well as N 2 may have been facilitated by clays, zeolites, sulfides and metal alloys formed as the crust reacted with a warm ‘seltzer’more » ocean. We used geochemical modeling to constrain the conditions favorable for the formation of these potential mineral catalysts.« less

Staging Life in an Early Warm ‘Seltzer’ Ocean

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schoonen, Martin; Smirnov, Alexander

A period as short as 20 million years within the first 100 million years after the formation of the Moon may have set the stage for the origin of life. This atmosphere contained more carbon dioxide than any other period afterwards. The carbon dioxide sustained greenhouse conditions, accelerated the weathering of a primitive crust and may have led to conditions conducive to the formation of the building blocks of life. The conversion of CO 2 as well as N 2 may have been facilitated by clays, zeolites, sulfides and metal alloys formed as the crust reacted with a warm ‘seltzer’more » ocean. We used geochemical modeling to constrain the conditions favorable for the formation of these potential mineral catalysts.« less

Characteristics and formation of amino acids and hydroxy acids of the Murchison meteorite

NASA Technical Reports Server (NTRS)

Cronin, J. R.; Cooper, G. W.; Pizzarello, S.

1995-01-01

Eight characteristics of the unique suite of amino acids and hydroxy acids found in the Murchison meteorite can be recognized on the basis of detailed molecular and isotopic analyses. The marked structural correspondence between the alpha-amino acids and alpha-hydroxy acids and the high deuterium/hydrogen ratio argue persuasively for their formation by aqueous phase Strecker reactions in the meteorite parent body from presolar, i.e., interstellar, aldehydes, ketones, ammonia, and hydrogen cyanide. The characteristics of the meteoritic suite of amino acids and hydroxy acids are briefly enumerated and discussed with regard to their consonance with this interstellar-parent body formation hypothesis. The hypothesis has interesting implications for the organic composition of both the primitive parent body and the presolar nebula.

Life Cycle Reversal in Aurelia sp.1 (Cnidaria, Scyphozoa)

PubMed Central

He, Jinru; Zheng, Lianming; Zhang, Wenjing; Lin, Yuanshao

2015-01-01

The genus Aurelia is one of the major contributors to jellyfish blooms in coastal waters, possibly due in part to hydroclimatic and anthropogenic causes, as well as their highly adaptive reproductive traits. Despite the wide plasticity of cnidarian life cycles, especially those recognized in certain Hydroza species, the known modifications of Aurelia life history were mostly restricted to its polyp stage. In this study, we document the formation of polyps directly from the ectoderm of degenerating juvenile medusae, cell masses from medusa tissue fragments, and subumbrella of living medusae. This is the first evidence for back-transformation of sexually mature medusae into polyps in Aurelia sp.1. The resulting reconstruction of the schematic life cycle of Aurelia reveals the underestimated potential of life cycle reversal in scyphozoan medusae, with possible implications for biological and ecological studies. PMID:26690755

A comparative study of prebiotic and present day translational models

NASA Technical Reports Server (NTRS)

Rein, R.; Raghunathan, G.; Mcdonald, J.; Shibata, M.; Srinivasan, S.

1986-01-01

It is generally recognized that the understanding of the molecular basis of primitive translation is a fundamental step in developing a theory of the origin of life. However, even in modern molecular biology, the mechanism for the decoding of messenger RNA triplet codons into an amino acid sequence of a protein on the ribosome is understood incompletely. Most of the proposed models for prebiotic translation lack, not only experimental support, but also a careful theoretical scrutiny of their compatibility with well understood stereochemical and energetic principles of nucleic acid structure, molecular recognition principles, and the chemistry of peptide bond formation. Present studies are concerned with comparative structural modelling and mechanistic simulation of the decoding apparatus ranging from those proposed for prebiotic conditions to the ones involved in modern biology. Any primitive decoding machinery based on nucleic acids and proteins, and most likely the modern day system, has to satisfy certain geometrical constraints. The charged amino acyl and the peptidyl termini of successive adaptors have to be adjacent in space in order to satisfy the stereochemical requirements for amide bond formation. Simultaneously, the same adaptors have to recognize successive codons on the messenger. This translational complex has to be realized by components that obey nucleic acid conformational principles, stabilities, and specificities. This generalized condition greatly restricts the number of acceptable adaptor structures.

Grhl3 and Lmo4 play coordinate roles in epidermal migration.

PubMed

Hislop, Nikki R; Caddy, Jacinta; Ting, Stephen B; Auden, Alana; Vasudevan, Sumitha; King, Sarah L; Lindeman, Geoffrey J; Visvader, Jane E; Cunningham, John M; Jane, Stephen M

2008-09-01

In addition to its role in formation of the epidermal barrier, the mammalian transcription factor Grainy head-like 3 (Grhl3) is also essential for neural tube closure and wound repair, processes that are dependent in part on epidermal migration. Here, we demonstrate that the LIM-only domain protein, LMO4 serves as a functional partner of GRHL3 in its established roles, and define a new cooperative role for these factors in another developmental epidermal migration event, eyelid fusion. GRHL3 and LMO4 interact biochemically and genetically, with mutant mice exhibiting fully penetrant exencephaly, thoraco-lumbo-sacral spina bifida, defective skin barrier formation, and a co-incident eyes-open-at-birth (EOB) phenotype, which is not observed in the original individual null lines. The two genes are co-expressed in the surface ectoderm of the migrating eyelid root, and electron microscopy of Grhl3/Lmo4-null eyes reveals a failure in epithelial extension and a lack of peridermal clump formation at the eyelid margins. Accumulation of actin fibers is also absent in the circumference of these eyelids, and ERK1/2 phosphorylation is lost in the epidermis and eyelids of Grhl3(-/-)/Lmo4(-/-) embryos. Keratinocytes from mutant mice fail to "heal" in in vitro scratch assays, consistent with a general epidermal migratory defect that is dependent on ERK activation and actin cable formation.

The Role of AIRE in the Immunity Against Candida Albicans in a Model of Human Macrophages.

PubMed

de Albuquerque, Jose Antonio Tavares; Banerjee, Pinaki Prosad; Castoldi, Angela; Ma, Royce; Zurro, Nuria Bengala; Ynoue, Leandro Hideki; Arslanian, Christina; Barbosa-Carvalho, Marina Uchoa Wall; Correia-Deur, Joya Emilie de Menezes; Weiler, Fernanda Guimarães; Dias-da-Silva, Magnus Regios; Lazaretti-Castro, Marise; Pedroza, Luis Alberto; Câmara, Niels Olsen Saraiva; Mace, Emily; Orange, Jordan Scott; Condino-Neto, Antonio

2018-01-01

Autoimmune-polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a primary immunodeficiency caused by mutations in the autoimmune regulator gene ( AIRE ). Patients with AIRE mutations are susceptible to Candida albicans infection and present with autoimmune disorders. We previously demonstrated that cytoplasmic AIRE regulates the Syk-dependent Dectin-1 pathway. In this study, we further evaluated direct contact with fungal elements, synapse formation, and the response of macrophage-like THP-1 cells to C. albicans hyphae to determine the role of AIRE upon Dectin receptors function and signaling. We examined the fungal synapse (FS) formation in wild-type and AIRE-knockdown THP-1 cells differentiated to macrophages, as well as monocyte-derived macrophages from APECED patients. We evaluated Dectin-2 receptor signaling, phagocytosis, and cytokine secretion upon hyphal stimulation. AIRE co-localized with Dectin-2 and Syk at the FS upon hyphal stimulation of macrophage-like THP-1 cells. AIRE-knockdown macrophage-like THP-1 cells exhibited less Dectin-1 and Dectin-2 receptors accumulation, decreased signaling pathway activity at the FS, lower C. albicans phagocytosis, and less lysosome formation. Furthermore, IL-1β, IL-6, or TNF-α secretion by AIRE-knockdown macrophage-like THP-1 cells and AIRE-deficient patient macrophages was decreased compared to control cells. Our results suggest that AIRE modulates the FS formation and hyphal recognition and help to orchestrate an effective immune response against C. albicans .

Type II first branchial cleft anomaly.

PubMed

Al-Mahdi, Akmam H; Al-Khurri, Luay E; Atto, Ghada Z; Dhaher, Ameer

2013-01-01

First branchial cleft anomaly is a rare disease of the head and neck. It accounts for less than 8% of all branchial abnormalities. It is classified into type I, which is thought to arise from the duplication of the membranous external ear canal and are composed of ectoderm only, and type II that have ectoderm and mesoderm. Because of its rarity, first branchial cleft anomaly is often misdiagnosed and results in inappropriate management. A 9-year-old girl presented to us with fistula in the submandibular region and discharge in the external ear. Under general anesthesia, complete surgical excision of the fistula tract was done through step-ladder approach, and the histopathologic examination confirmed the diagnosis of type II first branchial cleft anomaly.

Prenatal Correction of X-Linked Hypohidrotic Ectodermal Dysplasia.

PubMed

Schneider, Holm; Faschingbauer, Florian; Schuepbach-Mallepell, Sonia; Körber, Iris; Wohlfart, Sigrun; Dick, Angela; Wahlbuhl, Mandy; Kowalczyk-Quintas, Christine; Vigolo, Michele; Kirby, Neil; Tannert, Corinna; Rompel, Oliver; Rascher, Wolfgang; Beckmann, Matthias W; Schneider, Pascal

2018-04-26

Genetic deficiency of ectodysplasin A (EDA) causes X-linked hypohidrotic ectodermal dysplasia (XLHED), in which the development of sweat glands is irreversibly impaired, an condition that can lead to life-threatening hyperthermia. We observed normal development of mouse fetuses with Eda mutations after they had been exposed in utero to a recombinant protein that includes the receptor-binding domain of EDA. We administered this protein intraamniotically to two affected human twins at gestational weeks 26 and 31 and to a single affected human fetus at gestational week 26; the infants, born in week 33 (twins) and week 39 (singleton), were able to sweat normally, and XLHED-related illness had not developed by 14 to 22 months of age. (Funded by Edimer Pharmaceuticals and others.).

Physiological responses to heat of resting man with impaired sweating capacity

NASA Technical Reports Server (NTRS)

Totel, G. L.

1974-01-01

The effects of total-body heat exposure were studied in three groups of subjects with varied degrees of impaired sweating capacity. The responses of two ectodermal dysplasic men, six quadriplegic men, and a man with widespread burned scar tissue were compared with the responses of three able-bodied men resting in the heat. It was found that the able-bodied and burned subjects competed successfully with a controlled environment of 38 C and 20% relative humidity for up to 150 min, whereas the quadriplegic and ectodermal dysplasic men developed hyperthermia, hyperventilation, and distress after only 120 and 75 min of heat exposure, respectively. The intolerance to heat is thus ascribed directly to the inability to produce and evaporate sweat.

Conservation of Pax gene expression in ectodermal placodes of the lamprey

NASA Technical Reports Server (NTRS)

McCauley, David W.; Bronner-Fraser, Marianne

2002-01-01

Ectodermal placodes contribute to the cranial ganglia and sense organs of the head and, together with neural crest cells, represent defining features of the vertebrate embryo. The identity of different placodes appears to be specified in part by the expression of different Pax genes, with Pax-3/7 class genes being expressed in the trigeminal placode of mice, chick, frogs and fish, and Pax-2/5/8 class genes expressed in the otic placode. Here, we present the cloning and expression pattern of lamprey Pax-7 and Pax-2, which mark the trigeminal and otic placodes, respectively, as well as other structures characteristic of vertebrate Pax genes. These results suggest conservation of Pax genes and placodal structures in basal and derived vertebrates.

Dynamic Primitives of Motor Behavior

PubMed Central

Hogan, Neville; Sternad, Dagmar

2013-01-01

We present in outline a theory of sensorimotor control based on dynamic primitives, which we define as attractors. To account for the broad class of human interactive behaviors—especially tool use—we propose three distinct primitives: submovements, oscillations and mechanical impedances, the latter necessary for interaction with objects. Due to fundamental features of the neuromuscular system, most notably its slow response, we argue that encoding in terms of parameterized primitives may be an essential simplification required for learning, performance, and retention of complex skills. Primitives may simultaneously and sequentially be combined to produce observable forces and motions. This may be achieved by defining a virtual trajectory composed of submovements and/or oscillations interacting with impedances. Identifying primitives requires care: in principle, overlapping submovements would be sufficient to compose all observed movements but biological evidence shows that oscillations are a distinct primitive. Conversely, we suggest that kinematic synergies, frequently discussed as primitives of complex actions, may be an emergent consequence of neuromuscular impedance. To illustrate how these dynamic primitives may account for complex actions, we briefly review three types of interactive behaviors: constrained motion, impact tasks, and manipulation of dynamic objects. PMID:23124919

Compositional study of asteroids in the Erigone collisional family using visible spectroscopy at the 10.4m GTC

NASA Astrophysics Data System (ADS)

Morate, David; de León, Julia; De Prá, Mário; Licandro, Javier; Cabrera-Lavers, Antonio; Campins, Humberto; Pinilla-Alonso, Noemí; Alí-Lagoa, Víctor

2015-11-01

Asteroid families are formed by the fragments produced by the disruption of a common parent body (Bendjoya & Zappalà 2002). Primitive asteroids in the solar system are believed to have undergone less thermal processing than the S-complex asteroids. Thus, study of primitive asteroid families provides information about the solar system formation period. The Erigone collisional family, together with other three families (Polana, Clarissa and Sulamitis), are believed to be the origin of the two primitive Near-Earth asteroids that are the main targets of the NASA’s OSIRIS-REx ((101955) Bennu) and JAXA’s Hayabusa 2 ((162173) 1999 JU3) missions (Campins et al. 2010; Campins et al. 2013; Lauretta et al. 2010; Tsuda et al. 2013). These spacecrafts will visit the asteroids, and a sample of their surface material will be returned to Earth. Understanding of the families that are considered potential sources will enhance the scientific return of the missions. The main goal of the work presented here is to characterize the Erigone collisional family. Asteroid (163) Erigone has been classified as a primitive object (Bus 1999; Bus & Binzel 2002), and we expect the members of this family to be consistent with the spectral type of the parent body. We have obtained visible spectra (0.5-0.9 μm) for 101 members of the Erigone family, using the OSIRIS instrument at the 10.4m Gran Telescopio Canarias. We performed a taxonomical classification of these asteroids, finding that the number of primitive objects in our sample is in agreement with the hypothesis of a common parent body. In addition, we have found a significant fraction of asteroids in our sample that present evidences of aqueous alteration. Study of aqueous alterations is important, as it can give information on the heating processes of the early Solar System, and for the associated astrobiological implications (it has been suggested that the Earth’s present water supply was brought here by asteroids, instead of comets, in opposition to previous explanations (Morbidelli et al. 2000).

Formation of Complex Amino Acid Precursors in Simulated Primitive Atmosphere and Their Alteration under Simulated Submarine Hydrothermal Conditions

NASA Astrophysics Data System (ADS)

Kobayashi, Kensei; Kurihara, Hironari; Hirako, Tomoaki; Obayashi, Yumiko; Kaneko, Takeo; Takano, Yoshinori; Yoshimura, Yoshitaka

Since late 1970's a great number of submarine hydrothermal systems (SHSs) has been dis-covered, and they are considered possible sites of chemical evolution and generation of life on the Earth since their discovery in late 1970s. A number of experiments simulating the con-ditions of SHSs were conducted, and abiotic production and polymerization of amino acids were reported. Free amino acids were frequently used as starting materials to examine possible organic reactions in the simulation experiments. In our early studies, not free amino acids but complex amino acids precursors with large molecular weights were formed abiotically from simulated primitive Earth atmosphere (a mixture of CO, N2 and H2 O) (Takano et al., 2004). Such complex organics (hereafter referred as to CNWs) should have been delivered to SHSs in Primitive Ocean, where they were subjected to further alteration. We examined possible alteration of the complex organics in high-temperature high-pressure environments by the su-percritical water flow reactor (SCWFR) (Islam et al.. 2003) and an autoclave. CNWs were quite hydrophilic compounds whose molecular weights were ca. 3000. After heating 573 K for 2 min in the SCWFR, aggregates of organics were formed, which were separated from aque-ous solution with a Nucleopore filter (pore size: 200 nm). We propose the following scenario of chemical evolution: (1) Complex organics including amino acid precursors were formed in primitive atmosphere and/or extraterrestrial environments, (ii) they were delivered to primor-dial SHSs, (iii) hydrothermal alteration occurred in SHSs to give organic aggregates, (iv) quite primitive molecular systems with subtle biological functions were generated in the competition among such aggregates. References: Islam, Md. N., Kaneko, T., and Kobayashi, K (2003). Reactions of Amino Acids with a Newly ConstructedSupercritical Water Flow Reactor Simulating Submarine Hydrothermal Systems. Bull. Chem. Soc. Jpn., 76, 1171. Takano, Y., Marumo, K., Yabashi, S., Kaneko, T., and Kobayashi, K., (2004). Curie-Point Pyrolysis of Complex Organics Simulated by Cosmic Rays Irradiation of Simple Inorganic Gas Mixture. Appl Phys. Lett., 85, 1633.

Dosage requirement and allelic expression of PAX6 during lens placode formation.

PubMed

van Raamsdonk, C D; Tilghman, S M

2000-12-01

Pax6 is a member of the mammalian Pax transcription factor family. Many of the Pax genes display semi-dominant loss-of-function heterozygous phenotypes, yet the underlying cause for this dosage requirement is not known. Mice heterozygous for Pax6 mutations exhibit small eyes (Sey) and in embryos the most obvious defect is a small lens. We have studied lens development in Pax6(Sey)(-1Neu)/+ embryos to understand the basis of the haploinsufficiency. The formation of the lens pre-placode appears to be unaffected in heterozygotes, as deduced from the number of cells, the mitotic index, the amount of apoptosis and the expression of SOX2 and Pax6 in the pre-placode. However, the formation of the lens placode is delayed. The cells at the edge of the lens cup fail to express N-cadherin and undergo apoptosis and the lens fails to detach completely from the surface ectoderm. After formation, the lens, which has 50% of the cells found in wild-type embryos, grows at a rate that is indistinguishable from wild type. We rule out the possibility that monoallelic expression of Pax6 at the time of lens placode formation accounts for the 50% reduction in cell number by showing that expression of Pax6 is biallelic in the lens placode and optic vesicle. We propose instead that a critical threshold of PAX6 protein is required for lens placode formation and that the time in development at which this level is reached is delayed in heterozygotes.

Acetylcholinesterase Regulates Skeletal In Ovo Development of Chicken Limbs by ACh-Dependent and -Independent Mechanisms

PubMed Central

Spieker, Janine; Ackermann, Anica; Salfelder, Anika; Vogel-Höpker, Astrid; Layer, Paul G.

2016-01-01

Formation of the vertebrate limb presents an excellent model to analyze a non-neuronal cholinergic system (NNCS). Here, we first analyzed the expression of acetylcholinesterase (AChE) by IHC and of choline acetyltransferase (ChAT) by ISH in developing embryonic chicken limbs (stages HH17-37). AChE outlined formation of bones, being strongest at their distal tips, and later also marked areas of cell death. At onset, AChE and ChAT were elevated in two organizing centers of the limb anlage, the apical ectodermal ridge (AER) and zone of polarizing activity (ZPA), respectively. Thereby ChAT was expressed shortly after AChE, thus strongly supporting a leading role of AChE in limb formation. Then, we conducted loss-of-function studies via unilateral implantation of beads into chicken limb anlagen, which were soaked in cholinergic components. After varying periods, the formation of cartilage matrix and of mineralizing bones was followed by Alcian blue (AB) and Alizarin red (AR) stainings, respectively. Both acetylcholine (ACh)- and ChAT-soaked beads accelerated bone formation in ovo. Notably, inhibition of AChE by BW284c51, or by the monoclonal antibody MAB304 delayed cartilage formation. Since bead inhibition of BChE was mostly ineffective, an ACh-independent action during BW284c51 and MAB304 inhibition was indicated, which possibly could be due to an enzymatic side activity of AChE. In conclusion, skeletogenesis in chick is regulated by an ACh-dependent cholinergic system, but to some extent also by an ACh-independent aspect of the AChE protein. PMID:27574787

Acetylcholinesterase Regulates Skeletal In Ovo Development of Chicken Limbs by ACh-Dependent and -Independent Mechanisms.

PubMed

Spieker, Janine; Ackermann, Anica; Salfelder, Anika; Vogel-Höpker, Astrid; Layer, Paul G

2016-01-01

Formation of the vertebrate limb presents an excellent model to analyze a non-neuronal cholinergic system (NNCS). Here, we first analyzed the expression of acetylcholinesterase (AChE) by IHC and of choline acetyltransferase (ChAT) by ISH in developing embryonic chicken limbs (stages HH17-37). AChE outlined formation of bones, being strongest at their distal tips, and later also marked areas of cell death. At onset, AChE and ChAT were elevated in two organizing centers of the limb anlage, the apical ectodermal ridge (AER) and zone of polarizing activity (ZPA), respectively. Thereby ChAT was expressed shortly after AChE, thus strongly supporting a leading role of AChE in limb formation. Then, we conducted loss-of-function studies via unilateral implantation of beads into chicken limb anlagen, which were soaked in cholinergic components. After varying periods, the formation of cartilage matrix and of mineralizing bones was followed by Alcian blue (AB) and Alizarin red (AR) stainings, respectively. Both acetylcholine (ACh)- and ChAT-soaked beads accelerated bone formation in ovo. Notably, inhibition of AChE by BW284c51, or by the monoclonal antibody MAB304 delayed cartilage formation. Since bead inhibition of BChE was mostly ineffective, an ACh-independent action during BW284c51 and MAB304 inhibition was indicated, which possibly could be due to an enzymatic side activity of AChE. In conclusion, skeletogenesis in chick is regulated by an ACh-dependent cholinergic system, but to some extent also by an ACh-independent aspect of the AChE protein.

Msx1-modulated muscle satellite cells retain a primitive state and exhibit an enhanced capacity for osteogenic differentiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ding, Ke, E-mail: dingke@med.uestc.edu.cn; Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu 610072; Department of Orthopaedics, Southwest Hospital, Third Military Medical University, Chongqing 400038

Multipotent muscle satellite cells (MuSCs) have been identified as potential seed cells for bone tissue engineering. However, MuSCs exhibit a rapid loss of stemness after in vitro culturing, thereby compromising their therapeutic efficiency. Muscle segment homeobox gene 1 (msx1) has been found to induce the dedifferentiation of committed progenitor cells, as well as terminally differentiated myotubes. In this study, a Tet-off retroviral gene delivery system was used to modulate msx1 expression. After ten passages, MuSCs that did not express msx-1 (e.g., the non-msx1 group) were compared with MuSCs with induced msx-1 expression (e.g., the msx1 group). The latter group exhibitedmore » a more juvenile morphology, it contained a significantly lower percentage of senescent cells characterized by positive β-galactosidase staining, and it exhibited increased proliferation and a higher proliferation index. Immunocytochemical stainings further detected a more primitive gene expression profile for the msx1 group, while osteogenic differentiation assays and ectopic bone formation assays demonstrated an improved capacity for the msx1 group to undergo osteogenic differentiation. These results suggest that transient expression of msx1 in MuSCs can retain a primitive state, thereby enhancing their capacity for osteogenic differentiation and restoring the potential for MuSCs to serve as seed cells for bone tissue engineering.« less

Msx1-modulated muscle satellite cells retain a primitive state and exhibit an enhanced capacity for osteogenic differentiation.

PubMed

Ding, Ke; Liu, Wen-Ying; Zeng, Qiang; Hou, Fang; Xu, Jian-Zhong; Yang, Zhong

2017-03-01

Multipotent muscle satellite cells (MuSCs) have been identified as potential seed cells for bone tissue engineering. However, MuSCs exhibit a rapid loss of stemness after in vitro culturing, thereby compromising their therapeutic efficiency. Muscle segment homeobox gene 1 (msx1) has been found to induce the dedifferentiation of committed progenitor cells, as well as terminally differentiated myotubes. In this study, a Tet-off retroviral gene delivery system was used to modulate msx1 expression. After ten passages, MuSCs that did not express msx-1 (e.g., the non-msx1 group) were compared with MuSCs with induced msx-1 expression (e.g., the msx1 group). The latter group exhibited a more juvenile morphology, it contained a significantly lower percentage of senescent cells characterized by positive β-galactosidase staining, and it exhibited increased proliferation and a higher proliferation index. Immunocytochemical stainings further detected a more primitive gene expression profile for the msx1 group, while osteogenic differentiation assays and ectopic bone formation assays demonstrated an improved capacity for the msx1 group to undergo osteogenic differentiation. These results suggest that transient expression of msx1 in MuSCs can retain a primitive state, thereby enhancing their capacity for osteogenic differentiation and restoring the potential for MuSCs to serve as seed cells for bone tissue engineering. Copyright © 2017 Elsevier Inc. All rights reserved.

Inactivation of the Huntington's disease gene (Hdh) impairs anterior streak formation and early patterning of the mouse embryo

PubMed Central

Woda, Juliana M; Calzonetti, Teresa; Hilditch-Maguire, Paige; Duyao, Mabel P; Conlon, Ronald A; MacDonald, Marcy E

2005-01-01

Background Huntingtin, the HD gene encoded protein mutated by polyglutamine expansion in Huntington's disease, is required in extraembryonic tissues for proper gastrulation, implicating its activities in nutrition or patterning of the developing embryo. To test these possibilities, we have used whole mount in situ hybridization to examine embryonic patterning and morphogenesis in homozygous Hdhex4/5 huntingtin deficient embryos. Results In the absence of huntingtin, expression of nutritive genes appears normal but E7.0–7.5 embryos exhibit a unique combination of patterning defects. Notable are a shortened primitive streak, absence of a proper node and diminished production of anterior streak derivatives. Reduced Wnt3a, Tbx6 and Dll1 expression signify decreased paraxial mesoderm and reduced Otx2 expression and lack of headfolds denote a failure of head development. In addition, genes initially broadly expressed are not properly restricted to the posterior, as evidenced by the ectopic expression of Nodal, Fgf8 and Gsc in the epiblast and T (Brachyury) and Evx1 in proximal mesoderm derivatives. Despite impaired posterior restriction and anterior streak deficits, overall anterior/posterior polarity is established. A single primitive streak forms and marker expression shows that the anterior epiblast and anterior visceral endoderm (AVE) are specified. Conclusion Huntingtin is essential in the early patterning of the embryo for formation of the anterior region of the primitive streak, and for down-regulation of a subset of dynamic growth and transcription factor genes. These findings provide fundamental starting points for identifying the novel cellular and molecular activities of huntingtin in the extraembryonic tissues that govern normal anterior streak development. This knowledge may prove to be important for understanding the mechanism by which the dominant polyglutamine expansion in huntingtin determines the loss of neurons in Huntington's disease. PMID:16109169

Blowing in the Wind: II. Creation and Redistribution of Refractory Inclusions in a Turbulent Protoplanetary Nebula

NASA Technical Reports Server (NTRS)

Cuzzi, Jeffrey N.; Davis, Sanford S.; Dobrovolskis, Anthony R.

2003-01-01

Ca-A1 rich refractory mineral inclusions (CAIs) found at 1-6% mass fraction in primitive chondrites appear to be 1-3 million years older than the dominant (chondrule) components which were accreted into the same parent bodies. A prevalent concern is that it is difficult to retain CAIs for this long against gas-drag-induced radial drift into the sun. We reassess the situation in terms of a hot inner (turbulent) nebula context for CAI formation, using analytical models of nebula evolution and particle diffusion. We show that outward radial diffusion in a weakly turbulent nebula can overwhelm inward drift, and prevent significant numbers of CAI-size particles from being lost into the sun for times on the order of 10(exp 6) years. CAIs can form early, when the inner nebula was hot, and persist in sufficient abundance to be incorporated into primitive planetesimals at a much later time. Small (less than or approximately 0.1 mm diameter) CAIs persist for longer times than large (greater than or approximately 5mm diameter ones. To obtain a quantitative match to the observed volume fractions of CAIs in chondrites, another process must be allowed for: a substantial enhancement of the inner hot nebula in silicate-forming material, which we suggest was caused by rapid inward drift of meter-sized objects. This early in nebula history, the drifting rubble would have a carbon content probably an order of magnitude larger than even the most primitive (CI) carbonaceous chondrites. Abundant carbon in the evaporating material would help keep the nebula oxygen fugacity low, plausibly solar; as inferred for the formation environment of CAIs. The associated production of a larger than canonical amount of CO2 might also play a role in mass-independent fractionation of oxygen isotopes, leaving the gas rich in O-16 as inferred from CAIs and other high temperature condensates.

Blowing in the Wind: II. Creation and Redistribution of Refractory Inclusions in a Turbulent Protoplanetary Nebula

NASA Technical Reports Server (NTRS)

Cuzzi, Jeffrey N.; Davis, Sanford S.; Dobrovolskis, Anthony R.

2003-01-01

Ca-Al rich refractory mineral inclusions (CAIs) found at 1-6% mass fraction in primitive chondrites appear to be 1-3 million years older than the dominant (chondrule) components which were accreted into the same parent bodies. A prevalent concern is that it is difficult to retain CAIs for this long against gas-drag-induced radial drift into the sun. We reassess the situation in terms of a hot inner (turbulent) nebula context for CAI formation, using analytical models of nebula evolution and particle diffusion. We show that outward radial diffusion in a weakly turbulent nebula can overwhelm inward drift, and prevent significant numbers of CAI-size particles from being lost into the sun for times on the order of 10(exp 6) years. CAIs can form early, when the inner nebula was hot, and persist in sufficient abundance to be incorporated into primitive planetesimals at a much later time. Small (less than or approx. equal to 0.1 mm diameter) CAIs persist for longer times than large (greater than or approx. equal to 5mm diameter ones). To obtain a quantitative match t o the observed volume fractions of CAIs in chondrites, another process must be allowed for: a substantial enhancement of the inner hot nebula in silicate-forming material, which we suggest was caused by rapid inward drift of meter-sized objects. This early in nebula history, the drifting rubble would have a carbon content probably an order of magnitude larger than even the most primitive (CI) carbonaceous chondrites. Abundant carbon in the evaporating material would help keep the nebula oxygen fugacity low, plausably solar, as inferred for the formation environment of CAIs. The associated production of a larger than canonical amount of CO2 might also play a role in mass-independent fractionation of oxygen isotopes, leaving the gas rich in l60 as inferred from CAIs and other high temperature condensates.

Evidence for nucleosynthetic enrichment of the protosolar molecular cloud core by multiple supernova events.

PubMed

Schiller, Martin; Paton, Chad; Bizzarro, Martin

2015-01-15

The presence of isotope heterogeneity of nucleosynthetic origin amongst meteorites and their components provides a record of the diverse stars that contributed matter to the protosolar molecular cloud core. Understanding how and when the solar system's nucleosynthetic heterogeneity was established and preserved within the solar protoplanetary disk is critical for unraveling the earliest formative stages of the solar system. Here, we report calcium and magnesium isotope measurements of primitive and differentiated meteorites as well as various types of refractory inclusions, including refractory inclusions (CAIs) formed with the canonical 26 Al/ 27 Al of ~5 × 10 -5 ( 26 Al decays to 26 Mg with a half-life of ~0.73 Ma) and CAIs that show fractionated and unidentified nuclear effects (FUN-CAIs) to understand the origin of the solar system's nucleosynthetic heterogeneity. Bulk analyses of primitive and differentiated meteorites along with canonical and FUN-CAIs define correlated, mass-independent variations in 43 Ca, 46 Ca and 48 Ca. Moreover, sequential dissolution experiments of the Ivuna carbonaceous chondrite aimed at identifying the nature and number of presolar carriers of isotope anomalies within primitive meteorites have detected the presence of multiple carriers of the short-lived 26 Al nuclide as well as carriers of anomalous and uncorrelated 43 Ca, 46 Ca and 48 Ca compositions, which requires input from multiple and recent supernovae sources. We infer that the solar system's correlated nucleosynthetic variability reflects unmixing of old, galactically-inherited homogeneous dust from a new, supernovae-derived dust component formed shortly prior to or during the evolution of the giant molecular cloud parental to the protosolar molecular cloud core. This implies that similarly to 43 Ca, 46 Ca and 48 Ca, the short-lived 26 Al nuclide was heterogeneously distributed in the inner solar system at the time of CAI formation.

Fossil Fishes from China Provide First Evidence of Dermal Pelvic Girdles in Osteichthyans

PubMed Central

Zhu, Min; Yu, Xiaobo; Choo, Brian; Qu, Qingming; Jia, Liantao; Zhao, Wenjin; Qiao, Tuo; Lu, Jing

2012-01-01

Background The pectoral and pelvic girdles support paired fins and limbs, and have transformed significantly in the diversification of gnathostomes or jawed vertebrates (including osteichthyans, chondrichthyans, acanthodians and placoderms). For instance, changes in the pectoral and pelvic girdles accompanied the transition of fins to limbs as some osteichthyans (a clade that contains the vast majority of vertebrates – bony fishes and tetrapods) ventured from aquatic to terrestrial environments. The fossil record shows that the pectoral girdles of early osteichthyans (e.g., Lophosteus, Andreolepis, Psarolepis and Guiyu) retained part of the primitive gnathostome pectoral girdle condition with spines and/or other dermal components. However, very little is known about the condition of the pelvic girdle in the earliest osteichthyans. Living osteichthyans, like chondrichthyans (cartilaginous fishes), have exclusively endoskeletal pelvic girdles, while dermal pelvic girdle components (plates and/or spines) have so far been found only in some extinct placoderms and acanthodians. Consequently, whether the pectoral and pelvic girdles are primitively similar in osteichthyans cannot be adequately evaluated, and phylogeny-based inferences regarding the primitive pelvic girdle condition in osteichthyans cannot be tested against available fossil evidence. Methodology/Principal Findings Here we report the first discovery of spine-bearing dermal pelvic girdles in early osteichthyans, based on a new articulated specimen of Guiyu oneiros from the Late Ludlow (Silurian) Kuanti Formation, Yunnan, as well as a re-examination of the previously described holotype. We also describe disarticulated pelvic girdles of Psarolepis romeri from the Lochkovian (Early Devonian) Xitun Formation, Yunnan, which resemble the previously reported pectoral girdles in having integrated dermal and endoskeletal components with polybasal fin articulation. Conclusions/Significance The new findings reveal hitherto unknown similarity in pectoral and pelvic girdles among early osteichthyans, and provide critical information for studying the evolution of pelvic girdles in osteichthyans and other gnathostomes. PMID:22509388

Generation of felsic crust in the Archean: a geodynamic modeling perspective

NASA Astrophysics Data System (ADS)

Sizova, Elena; Gerya, Taras; Stüwe, Kurt; Brown, Michael

2015-04-01

The relevance of contemporary tectonics to the formation of the Archean terrains is a matter of vigorous debate. Higher mantle temperatures and higher radiogenic heat production in the past would have impacted on the thickness and composition of the oceanic and continental crust. As a consequence of secular cooling, there is generally no modern analog to assist in understanding the tectonic style that may have operated in the Archean. For this reason, well-constrained numerical modeling, based on the fragmentary evidence preserved in the geological record, is the most appropriate tool to evaluate hypotheses of Archean crust formation. The main lithology of Archean terrains is the sodic tonalite-trondhjemite-granodiorite (TTG) suite. Melting of hydrated basalt at garnet-amphibolite to eclogite facies conditions is considered to be the dominant process for the generation of the Archean TTG crust. Taking into account geochemical signatures of possible mantle contributions to some TTGs, models proposed for the formation of Archean crust include subduction, melting at the bottom of thickened continental crust and fractional crystallization of mantle-derived melts under water-saturated conditions. We evaluated these hypotheses using a 2D coupled petrological-thermomechanical numerical model with initial conditions appropriate to the Eoarchean-Mesoarchean. As a result, we identified three tectonic settings in which intermediate to felsic melts are generated by melting of hydrated primitive basaltic crust: 1) delamination and dripping of the lower primitive basaltic crust into the mantle; 2) local thickening of the primitive basaltic crust; and, 3) small-scale crustal overturns. In addition, we consider remelting of the fractionated products derived from underplated dry basalts as an alternative mechanism for the formation of some Archean granitoids. In the context of a stagnant lid tectonic regime which is intermittently terminated by short-lived subduction, we identified two distinct types of continent crust. The first type is a pristine granite-greenstone-like crust with dome-and-keel geometry formed over delaminating-upwelling mantle which is mostly subjected to vertical tectonics processes. By contrast, the second type is a reworked (accreted) crust comprising strongly deformed granite-greenstone and subduction-related sequences and subjected to both strong horizontal compression and vertical tectonics processes. Thus, our study has identified a possible spatial and temporal transition from the lower-grade granite-greenstone terrains to higher-grade gneiss terrains in the Archean as each tectonic cycle is terminated by short-lived subduction. We suggest that the contemporaneity of the proposed mechanisms for the generation of TTGs explains the variety and complexity of the Archean geological record.

A constraint on impact theories of chondrule formation

NASA Technical Reports Server (NTRS)

Kerridge, J. F.; Kieffer, S. W.

1977-01-01

The association between agglutinates and chondrule-like spherules, which characterizes the assemblage of impact-derived melt products in lunar regolith samples and some gas-rich achondrites, is not found in primitive chondrites. This observation suggests that impacts into a parent-body regolith are unlikely to have produced the chondrules. We believe that if chondrules were formed from impact melt, it was probably generated by jetting during particle-to-particle collisions, presumably in the nebula.

Histone posttranslational modifications and cell fate determination: lens induction requires the lysine acetyltransferases CBP and p300

PubMed Central

Wolf, Louise; Harrison, Wilbur; Huang, Jie; Xie, Qing; Xiao, Ningna; Sun, Jian; Kong, Lingkun; Lachke, Salil A.; Kuracha, Murali R.; Govindarajan, Venkatesh; Brindle, Paul K.; Ashery-Padan, Ruth; Beebe, David C.; Overbeek, Paul A.; Cvekl, Ales

2013-01-01

Lens induction is a classical embryologic model to study cell fate determination. It has been proposed earlier that specific changes in core histone modifications accompany the process of cell fate specification and determination. The lysine acetyltransferases CBP and p300 function as principal enzymes that modify core histones to facilitate specific gene expression. Herein, we performed conditional inactivation of both CBP and p300 in the ectodermal cells that give rise to the lens placode. Inactivation of both CBP and p300 resulted in the dramatic discontinuation of all aspects of lens specification and organogenesis, resulting in aphakia. The CBP/p300−/− ectodermal cells are viable and not prone to apoptosis. These cells showed reduced expression of Six3 and Sox2, while expression of Pax6 was not upregulated, indicating discontinuation of lens induction. Consequently, expression of αB- and αA-crystallins was not initiated. Mutant ectoderm exhibited markedly reduced levels of histone H3 K18 and K27 acetylation, subtly increased H3 K27me3 and unaltered overall levels of H3 K9ac and H3 K4me3. Our data demonstrate that CBP and p300 are required to establish lens cell-type identity during lens induction, and suggest that posttranslational histone modifications are integral to normal cell fate determination in the mammalian lens. PMID:24038357

BK virus encephalopathy and sclerosing vasculopathy in a patient with hypohidrotic ectodermal dysplasia and immunodeficiency.

PubMed

Darbinyan, Armine; Major, Eugene O; Morgello, Susan; Holland, Steven; Ryschkewitsch, Caroline; Monaco, Maria Chiara; Naidich, Thomas P; Bederson, Joshua; Malaczynska, Joanna; Ye, Fei; Gordon, Ronald; Cunningham-Rundles, Charlotte; Fowkes, Mary; Tsankova, Nadejda M

2016-07-13

Human BK polyomavirus (BKV) is reactivated under conditions of immunosuppression leading most commonly to nephropathy or cystitis; its tropism for the brain is rare and poorly understood. We present a unique case of BKV-associated encephalopathy in a man with hypohidrotic ectodermal dysplasia and immunodeficiency (HED-ID) due to IKK-gamma (NEMO) mutation, who developed progressive neurological symptoms. Brain biopsy demonstrated polyomavirus infection of gray and white matter, with predominant involvement of cortex and distinct neuronal tropism, in addition to limited demyelination and oligodendroglial inclusions. Immunohistochemistry demonstrated polyoma T-antigen in neurons and glia, but expression of VP1 capsid protein only in glia. PCR analysis on both brain biopsy tissue and cerebrospinal fluid detected high levels of BKV DNA. Sequencing studies further identified novel BKV variant and disclosed unique rearrangements in the noncoding control region of the viral DNA (BKVN NCCR). Neuropathological analysis also demonstrated an unusual form of obliterative fibrosing vasculopathy in the subcortical white matter with abnormal lysosomal accumulations, possibly related to the patient's underlying ectodermal dysplasia. Our report provides the first neuropathological description of HED-ID due to NEMO mutation, and expands the diversity of neurological presentations of BKV infection in brain, underscoring the importance of its consideration in immunodeficient patients with unexplained encephalopathy. We also document novel BKVN NCCR rearrangements that may be associated with the unique neuronal tropism in this patient.

Novel EDA mutation in X-linked hypohidrotic ectodermal dysplasia and genotype-phenotype correlation.

PubMed

Zeng, B; Lu, H; Xiao, X; Zhou, L; Lu, J; Zhu, L; Yu, D; Zhao, W

2015-11-01

X-linked hypohidrotic ectodermal dysplasia (XLHED) is characterized by abnormalities of hair, teeth, and sweat glands, while non-syndromic hypodontia (NSH) affects only teeth. Mutations in Ectodysplasin A (EDA) underlie both XLHED and NSH. This study investigated the genetic causes of six hypohidrotic ectodermal dysplasia (HED) patients and genotype-phenotype correlation. The EDA gene of six patients with HED was sequenced. Bioinformatics analysis and structural modeling for the mutations were performed. The records of 134 patients with XLHED and EDA-related NSH regarding numbers of missing permanent teeth from this study and 20 articles were reviewed. Nonparametric tests were used to analyze genotype-phenotype correlations. In four of the six patients, we identified a novel mutation c.852T>G (p.Phe284Leu) and three reported mutations: c.467G>A (p.Arg156His), c.776C>A (p.Ala259Glu), and c.871G>A (p.Gly291Arg). They were predicted to be pathogenic by bioinformatics analysis and structural modeling. Genotype-phenotype correlation analysis revealed that truncating mutations were associated with more missing teeth. Missense mutations and the mutations affecting the TNF homology domain were correlated with fewer missing teeth. This study extended the mutation spectrum of XLHED and revealed the relationship between genotype and the number of missing permanent teeth. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A novel mutation in homeobox DNA binding domain of HOXC13 gene underlies pure hair and nail ectodermal dysplasia (ECTD9) in a Pakistani family.

PubMed

Khan, Anwar Kamal; Muhammad, Noor; Aziz, Abdul; Khan, Sher Alam; Shah, Khadim; Nasir, Abdul; Khan, Muzammil Ahmad; Khan, Saadullah

2017-04-12

Pure hair and nail ectodermal dysplasia (PHNED) is a congenital disorder of hair abnormalities and nail dysplasia. Both autosomal recessive and dominant inheritance fashion of PHNED occurs. In literature, to date, five different forms of PHNED have been reported at molecular level, having three genes known and two loci with no gene yet. In this study, a four generations consanguineous family of Pakistani origin with autosomal recessive PHNED was investigated. Affected members exhibited PHNED phenotypes with involvement of complete hair loss and nail dysplasia. To screen for mutation in the genes (HOXC13, KRT74, KRT85), its coding exons and exons-intron boundaries were sequenced. The 3D models of normal and mutated HOXC13 were predicted by using homology modeling. Through investigating the family to known loci, the family was mapped to ectodermal dysplasia 9 (ECTD9) loci with genetic address of 12q13.13. Mutation screening revealed a novel missense mutation (c.929A > C; p.Asn310Thr) in homeobox DNA binding domain of HOXC13 gene in affected members of the family. Due to mutation, loss of hydrogen bonding and difference in potential energy occurs, which may resulting in alteration of protein function. This is the first mutation reported in homeodomain, while 5 th mutation reported in HOXC13 gene causing PHNED.

Clinical outcomes of implant therapy in ectodermal dysplasia patients: a systematic review.

PubMed

Wang, Y; He, J; Decker, A M; Hu, J C; Zou, D

2016-08-01

The purpose of this review was to determine the outcome of oral function reconstruction in ectodermal dysplasia (ED) patients who have received dental implant therapy. A search was made of the PubMed and Web of Science databases; key words used were "(ectodermal dysplasia) AND (implant OR implants)", with supplementary retrieval key words "dental implant", "zygomatic implant", "anodontia", and "edentulous". Patient age, use of bone graft, implant site, type of implant, and survival rate of the implants were included in the subsequent data analysis. Forty-five articles published between 1988 and October 2015 were included in this analysis. The cases of a total of 96 patients were retrieved (22 children and 74 adults); these patients received a total of 701 implants. Fourteen implants were removed during a median follow-up time of 24 months. The 24-month implant survival rate was 97.9% in adult subjects and 98.6% in children. Sixty-eight percent of adult patients underwent bone augmentation prior to implant placement. Based on this review, dental implants are commonly used in the oral reconstruction of ED patients. However, long-term data on bone augmentation and implant success are needed, as well as additional clinical evidence on bone resorption, the esthetic outcomes of implant therapy, and physiological considerations in ED patients. Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Wnt ligands from the embryonic surface ectoderm regulate ‘bimetallic strip’ optic cup morphogenesis in mouse

PubMed Central

Carpenter, April C.; Smith, April N.; Wagner, Heidi; Cohen-Tayar, Yamit; Rao, Sujata; Wallace, Valerie; Ashery-Padan, Ruth; Lang, Richard A.

2015-01-01

The Wnt/β-catenin response pathway is central to many developmental processes. Here, we assessed the role of Wnt signaling in early eye development using the mouse as a model system. We showed that the surface ectoderm region that includes the lens placode expressed 12 out of 19 possible Wnt ligands. When these activities were suppressed by conditional deletion of wntless (Le-cre; Wlsfl/fl) there were dramatic consequences that included a saucer-shaped optic cup, ventral coloboma, and a deficiency of periocular mesenchyme. This phenotype shared features with that produced when the Wnt/β-catenin pathway co-receptor Lrp6 is mutated or when retinoic acid (RA) signaling in the eye is compromised. Consistent with this, microarray and cell fate marker analysis identified a series of expression changes in genes known to be regulated by RA or by the Wnt/β-catenin pathway. Using pathway reporters, we showed that Wnt ligands from the surface ectoderm directly or indirectly elicit a Wnt/β-catenin response in retinal pigment epithelium (RPE) progenitors near the optic cup rim. In Le-cre; Wlsfl/fl mice, the numbers of RPE cells are reduced and this can explain, using the principle of the bimetallic strip, the curvature of the optic cup. These data thus establish a novel hypothesis to explain how differential cell numbers in a bilayered epithelium can lead to shape change. PMID:25715397

Removable partial dentures vs overdentures in children with ectodermal dysplasia: two case reports.

PubMed

Maroulakos, G; Artopoulou, I I; Angelopoulou, M V; Emmanouil, D

2016-06-01

Ectodermal dysplasia (ED) represents a disorder group characterised by abnormal development of the ectodermal derivatives. Removable partial dentures (RPD), complete dentures (CD) or overdentures (OD) are most often the treatment of choice for young affected patients. Prosthetic intervention is of utmost importance in the management of ED patients, as it resolves problems associated with functional, aesthetic, and psychological issues, and improves a patient's quality of life. However, few studies present the principles and guidelines that can assist in the decision-making process of the most appropriate removable prosthesis. The purpose of this study was to suggest a simple treatment decision-making algorithm for selecting an effective and individualised rehabilitative treatment plan, considering different parameters. The cases and treatment of two young ED patients are described and each one was treated with either RPDs or ODs. Periodic recalls were employed to manage problems, and monitor the changes associated with occlusion and fit of the prostheses in relation to each patient's growth. Both patients were followed up for more than 2 years and reported significant improvement in their appearance, masticatory function, and social behaviour as a result of the prosthetic rehabilitation. The main factors guiding the decision process towards the choice of an RPD or an OD are the presence of posterior natural teeth, facial aesthetics, lip support, number and size of existing natural teeth, and the occlusal vertical dimension.

Neural transcription factors bias cleavage stage blastomeres to give rise to neural ectoderm

PubMed Central

Gaur, Shailly; Mandelbaum, Max; Herold, Mona; Majumdar, Himani Datta; Neilson, Karen M.; Maynard, Thomas M.; Mood, Kathy; Daar, Ira O.; Moody, Sally A.

2016-01-01

The decision by embryonic ectoderm to give rise to epidermal versus neural derivatives is the result of signaling events during blastula and gastrula stages. However, there also is evidence in Xenopus that cleavage stage blastomeres contain maternally derived molecules that bias them toward a neural fate. We used a blastomere explant culture assay to test whether maternally deposited transcription factors bias 16-cell blastomere precursors of epidermal or neural ectoderm to express early zygotic neural genes in the absence of gastrulation interactions or exogenously supplied signaling factors. We found that Foxd4l1, Zic2, Gmnn and Sox11 each induced explants made from ventral, epidermis-producing blastomeres to express early neural genes, and that at least some of the Foxd4l1 and Zic2 activity is required at cleavage stages. Similarly, providing extra Foxd4l1 or Zic2 to explants made from dorsal, neural plate-producing blastomeres significantly increased expression of early neural genes, whereas knocking down either significantly reduced them. These results show that maternally delivered transcription factors bias cleavage stage blastomeres to a neural fate. We demonstrate that mouse and human homologues of Foxd4l1 have similar functional domains compared to the frog protein, as well as conserved transcriptional activities when expressed in Xenopus embryos and blastomere explants. PMID:27092474

Spontaneous encapsulation and concentration of biological macromolecules in liposomes: an intriguing phenomenon and its relevance in origins of life.

PubMed

de Souza, Tereza Pereira; Fahr, Alfred; Luisi, Pier Luigi; Stano, Pasquale

2014-12-01

One of the main open questions in origin of life research focuses on the formation, by self-organization, of primitive cells composed by macromolecular compounds enclosed within a semi-permeable membrane. A successful experimental strategy for studying the emergence and the properties of primitive cells relies on a synthetic biology approach, consisting in the laboratory assembly of cell models of minimal complexity (semi-synthetic minimal cells). Despite the recent advancements in the construction and characterization of synthetic cells, an important physical aspect related to their formation is still not well known, namely, the mechanism of solute entrapment inside liposomes (in particular, the entrapment of macromolecules). In the past years, we have investigated this phenomenon and here we shortly review our experimental results. We show how the detailed cryo-transmission electron microscopy analyses of liposome populations created in the presence of ferritin (taken as model protein) or ribosomes have revealed that a small fraction of liposomes contains a high number of solutes, against statistical expectations. The local (intra-liposomal) macromolecule concentration in these liposomes largely exceeds the bulk concentration. A similar behaviour is observed when multi-molecular reaction mixtures are used, whereby the reactions occur effectively only inside those liposomes that have entrapped high number of molecules. If similar mechanisms operated in early times, these intriguing results support a scenario whereby the formation of lipid compartments plays an important role in concentrating the components of proto-metabolic systems-in addition to their well-known functions of confinement and protection.

Synergistic Activities of Near-Earth Object Exploration

NASA Technical Reports Server (NTRS)

Abell, Paul

2011-01-01

U.S. President Obama stated on April 15, 2010 that the next goal for human spaceflight will be to send human beings to near-Earth asteroids by 2025. Missions to NEOs would undoubtedly provide a great deal of technical and engineering data on spacecraft operations for future human space exploration while conducting in-depth scientific examinations of these primitive objects. Information obtained from a human investigation of a NEO, together with ground-based observations and prior spacecraft investigations of asteroids and comets, will also provide a real measure of ground truth to data obtained from terrestrial meteorite collections. Major advances in the areas of geochemistry, impact history, thermal history, isotope analyses, mineralogy, space weathering, formation ages, thermal inertias, volatile content, source regions, solar system formation, etc. can be expected from human NEO missions. Samples directly returned from a primitive body would lead to the same kind of breakthroughs for understanding NEOs that the Apollo samples provided for understanding the Earth-Moon system and its formation history. In addition, robotic precursor and human exploration missions to NEOs would allow the NASA and its international partners to gain operational experience in performing complex tasks (e.g., sample collection, deployment of payloads, retrieval of payloads, etc.) with crew, robots, and spacecraft under microgravity conditions at or near the surface of a small body. This would provide an important synergy between the worldwide Science and Exploration communities, which will be crucial for development of future international deep space exploration architectures and has potential benefits for future exploration of other destinations beyond low-Earth orbit.

Constraining the Compositional Heterogeneity in CO-Dominated Comet C/2016 R2 (PanSTARRS)

NASA Astrophysics Data System (ADS)

McKay, Adam; Kelley, Michael; DiSanti, Michael; Womack, Maria; Wierzchos, Kacper; Biver, Nicolas; de Val-Borro, Miguel; Cordiner, Martin; Dello Russo, Neil; Feaga, Lori; Bauer, James; Cochran, Anita; Harrington Pinto, Olga

2018-05-01

Comets exhibit a primitive volatile composition, making them invaluable tools for understanding the formation of the Solar System. Constraining the compositional heterogeneity of cometary nuclei is vital for interpreting cometary composition in terms of the physical conditions operating in the protosolar disk at the time of planet formation. Some comets exhibit variability in observed coma composition over the course of their orbit. This could be indicative of a heterogeneous nucleus consisting of cometesimals formed in different parts of the protosolar nebula under differing conditions. Alternatively, the observed heterogeneity could be post-formation evolution. We propose to use Spitzer IRAC observations of CO2 in the atypically CO-rich comet C/2016 R2 (PanSTARRS) to better understand the compositional heterogeneity of cometary nuclei.

Ectodermal dysplasia

MedlinePlus

... fever, because the skin cannot sweat and control temperature properly. Affected adults are unable to tolerate a ... need special measures to keep a normal body temperature. Depending on which genes are affected, other symptoms ...

Bioelectric signalling via potassium channels: a mechanism for craniofacial dysmorphogenesis in KCNJ2‐associated Andersen–Tawil Syndrome

PubMed Central

Adams, Dany Spencer; Uzel, Sebastien G. M.; Akagi, Jin; Wlodkowic, Donald; Andreeva, Viktoria; Yelick, Pamela Crotty; Devitt‐Lee, Adrian; Pare, Jean‐Francois; Levin, Michael

2016-01-01

Key points Xenopus laevis craniofacial development is a good system for the study of Andersen–Tawil Syndrome (ATS)‐associated craniofacial anomalies (CFAs) because (1) Kcnj2 is expressed in the nascent face; (2) molecular‐genetic and biophysical techniques are available for the study of ion‐dependent signalling during craniofacial morphogenesis; (3) as in humans, expression of variant Kcnj2 forms in embryos causes a muscle phenotype; and (4) variant forms of Kcnj2 found in human patients, when injected into frog embryos, cause CFAs in the same cell lineages.Forced expression of WT or variant Kcnj2 changes the normal pattern of V mem (resting potential) regionalization found in the ectoderm of neurulating embryos, and changes the normal pattern of expression of ten different genetic regulators of craniofacial development, including markers of cranial neural crest and of placodes.Expression of other potassium channels and two different light‐activated channels, all of which have an effect on V mem, causes CFAs like those induced by injection of Kcnj2 variants. In contrast, expression of Slc9A (NHE3), an electroneutral ion channel, and of GlyR, an inactive Cl− channel, do not cause CFAs, demonstrating that correct craniofacial development depends on a pattern of bioelectric states, not on ion‐ or channel‐specific signalling.Using optogenetics to control both the location and the timing of ion flux in developing embryos, we show that affecting V mem of the ectoderm and no other cell layers is sufficient to cause CFAs, but only during early neurula stages. Changes in V mem induced late in neurulation do not affect craniofacial development.We interpret these data as strong evidence, consistent with our hypothesis, that ATS‐associated CFAs are caused by the effect of variant Kcnj2 on the V mem of ectodermal cells of the developing face. We predict that the critical time is early during neurulation, and the critical cells are the ectodermal cranial neural crest and placode lineages. This points to the potential utility of extant, ion flux‐modifying drugs as treatments to prevent CFAs associated with channelopathies such as ATS. Abstract Variants in potassium channel KCNJ2 cause Andersen–Tawil Syndrome (ATS); the induced craniofacial anomalies (CFAs) are entirely unexplained. We show that KCNJ2 is expressed in Xenopus and mouse during the earliest stages of craniofacial development. Misexpression in Xenopus of KCNJ2 carrying ATS‐associated mutations causes CFAs in the same structures affected in humans, changes the normal pattern of membrane voltage potential regionalization in the developing face and disrupts expression of important craniofacial patterning genes, revealing the endogenous control of craniofacial patterning by bioelectric cell states. By altering cells’ resting potentials using other ion translocators, we show that a change in ectodermal voltage, not tied to a specific protein or ion, is sufficient to cause CFAs. By adapting optogenetics for use in non‐neural cells in embryos, we show that developmentally patterned K+ flux is required for correct regionalization of the resting potentials and for establishment of endogenous early gene expression domains in the anterior ectoderm, and that variants in KCNJ2 disrupt this regionalization, leading to the CFAs seen in ATS patients. PMID:26864374

Mutual amino acid catalysis in salt-induced peptide formation supports this mechanism's role in prebiotic peptide evolution.

PubMed

Suwannachot, Y; Rode, B M

1999-10-01

The presence of some amino acids and dipeptides under the conditions of the salt-induced peptide formation reaction (aqueous solution at 85 degrees C, Cu(II) and NaCl) has been found to catalyze the formation of homopeptides of other amino acids, which are otherwise produced only in traces or not at all by this reaction. The condensation of Val, Leu and Lys to form their homodipeptides can occur to a considerable extent due to catalytic effects of other amino acids and related compounds, among which glycine, histidine, diglycine and diketopiperazine exhibit the most remarkable activity. These findings also lead to a modification of the table of amino acid sequences preferentially formed by the salt-induced peptide formation (SIPF) reaction, previously used for a comparison with the sequence preferences in membrane proteins of primitive organisms.

Mutual Amino Acid Catalysis in Salt-Induced Peptide Formation Supports this Mechanism's Role in Prebiotic Peptide Evolution

NASA Astrophysics Data System (ADS)

Suwannachot, Yuttana; Rode, Bernd M.

1999-10-01

The presence of some amino acids and dipeptides under the conditions of the salt-induced peptide formation reaction (aqueous solution at 85 °C, Cu(II) and NaCl) has been found to catalyze the formation of homopeptides of other amino acids, which are otherwise produced only in traces or not at all by this reaction. The condensation of Val, Leu and Lys to form their homodipeptides can occur to a considerable extent due to catalytic effects of other amino acids and related compounds, among which glycine, histidine, diglycine and diketopiperazine exhibit the most remarkable activity. These findings also lead to a modification of the table of amino acid sequences preferentially formed by the salt-induced peptide formation (SIPF) reaction, previously used for a comparison with the sequence preferences in membrane proteins of primitive organisms

Some issues associated with the formation of the Saturnian system

NASA Technical Reports Server (NTRS)

Lunine, Jonathan I.

1992-01-01

Three of the current issues associated with the formation of the Saturn system which involve significant controversy and uncertainty and which bear on the formation of Titan itself are outlined: the notion that the formation of Jupiter and Saturn are well constrained is challenged by recent internal models, which suggest possible significant differences in the composition of planetesimals which formed the two bodies; the composition of volatile ices which was the source of the Saturnian satellites was likely a complex mix of relatively pristine solids from the collapsing interstellar cloud, gas and solid material processed in the solar nebula and material chemically processed in a nebula around Saturn or in the primitive Saturn atmosphere itself; the deuterium enhancement in Titan's atmosphere, which initially appeared to be sufficiently large that it must be a signature of pristine interstellar material, could in fact be largely due to photochemical evolution of Titan's atmosphere.

Crystallinity of Fe-Ni Sulfides in Carbonaceous Chondrites

NASA Technical Reports Server (NTRS)

Zolensky, Michael E.; Ohsumi, Kazumasa; Mikouchi, Takashi; Hagiya, Kenji; Le, Loan

2008-01-01

The main long-term goal of this research is to understand the physical conditions in the early solar nebula through the detailed characterization of a key class of mineral present in all primitive materials: Fe-Ni sulfides [1&2]. Fe-Ni sulfides can take dozens of structures, depending on the temperature of formation, as well as other physico-chemical factors which are imperfectly understood. Add to this the additional varying factor of Ni content, and we have a potentially sensitive cosmothermometer [3]. Unfortunately, this tool requires exact knowledge of the crystal structure of each grain being considered, and there have been few (none?) studies of the detailed structures of sulfides in chondritic materials. We report here on coordinated compositional and crystallographic investigation of Fe-Ni sulfides in diverse carbonaceous chondrites, initially Acfer 094 (the most primitive CM2 [4]) Tagish Lake (a unique type C2 [5]), a C1 lithology in Kaidun [6], Bali (oxidized CV3 [7]), and Efremovka (reduced CV3 [7]).

The Composition and Organization of Cytoplasm in Prebiotic Cells

PubMed Central

Trevors, Jack T.

2011-01-01

This article discusses the hypothesized composition and organization of cytoplasm in prebiotic cells from a theoretical perspective and also based upon what is currently known about bacterial cytoplasm. It is unknown if the first prebiotic, microscopic scale, cytoplasm was initially contained within a primitive, continuous, semipermeable membrane, or was an uncontained gel substance, that later became enclosed by a continuous membrane. Another possibility is that the first cytoplasm in prebiotic cells and a primitive membrane organized at the same time, permitting a rapid transition to the first cell(s) capable of growth and division, thus assisting with the emergence of life on Earth less than a billion years after the formation of the Earth. It is hypothesized that the organization and composition of cytoplasm progressed initially from an unstructured, microscopic hydrogel to a more complex cytoplasm, that may have been in the volume magnitude of about 0.1–0.2 μm3 (possibly less if a nanocell) prior to the first cell division. PMID:21673913

A network of epigenetic regulators guides developmental haematopoiesis in vivo.

PubMed

Huang, Hsuan-Ting; Kathrein, Katie L; Barton, Abby; Gitlin, Zachary; Huang, Yue-Hua; Ward, Thomas P; Hofmann, Oliver; Dibiase, Anthony; Song, Anhua; Tyekucheva, Svitlana; Hide, Winston; Zhou, Yi; Zon, Leonard I

2013-12-01

The initiation of cellular programs is orchestrated by key transcription factors and chromatin regulators that activate or inhibit target gene expression. To generate a compendium of chromatin factors that establish the epigenetic code during developmental haematopoiesis, a large-scale reverse genetic screen was conducted targeting orthologues of 425 human chromatin factors in zebrafish. A set of chromatin regulators was identified that target different stages of primitive and definitive blood formation, including factors not previously implicated in haematopoiesis. We identified 15 factors that regulate development of primitive erythroid progenitors and 29 factors that regulate development of definitive haematopoietic stem and progenitor cells. These chromatin factors are associated with SWI/SNF and ISWI chromatin remodelling, SET1 methyltransferase, CBP-p300-HBO1-NuA4 acetyltransferase, HDAC-NuRD deacetylase, and Polycomb repressive complexes. Our work provides a comprehensive view of how specific chromatin factors and their associated complexes play a major role in the establishment of haematopoietic cells in vivo.

Ar-Ar and I-Xe Ages of Caddo County and Thermal History of IAB Iron Meteorites

NASA Technical Reports Server (NTRS)

Bogard, Donald D.; Garrison, Daniel H.; Takeda, Hiroshi

2005-01-01

Inclusions in IAB iron meteorites include non-chondritic silicate and those with more primitive chondritic silicate composition. Coarse-grained gabbroic material rich in plagioclase and diopside occurs in the Caddo County IAB iron meteorite and represents a new type of chemically differentiated, extra-terrestrial, andesitic silicate. Other parts of Caddo contain mostly andesitic material. Caddo thus exhibits petrologic characteristics of parent body metamorphism of a chondrite-like parent and inhomogeneous segregation of melts. Proposed IAB formation models include parent body partial melting and fractional crystallization or incomplete differentiation due to internal heat sources, and impact/induced melting and mixing. Benedix et al. prefer a hybrid model whereby the IAB parent body largely melted, then underwent collisional breakup, partial mixing of phases, and reassembly. Most reported 129I- Xe-129 ages of IABs are greater than 4.56 Gyr and a few are greater than or = 4.567 Gyr. These oldest ages exceed the 4.567 Gyr Pb-Pb age of Ca, Al-rich inclusions in primitive meteorites,

Significance of solvated electrons (e(aq)-) as promoters of life on earth.

PubMed

Getoff, Nikola

2014-01-01

Based on the present state of knowledge a new hypothesis concerning the origin of life on Earth is presented, and emphasizes the particular significance of solvated electrons (e(aq)(-)). Solvated electrons are produced in seawater, mainly by (40)K radiation and in atmospheric moisture by VUV light, electrical discharges and cosmic ray. Solvated electrons are involved in primary chemical processes and in biological processes. The conversion of aqueous CO2 and CO into simple organic substances, the generation of ammonia from N2 and water, the formation of amines, amino acids and simple proteins under the action of e(aq)(-) has been experimentally proven. Furthermore, it is supposed that the generation of the primitive cell and equilibria of primitive enzymes are also realized due to the strong reducing property of e(aq)(-). The presented hypothesis is mainly founded on recently obtained experimental results. The involvement of e(aq)(-) in such mechanisms, as well as their action as an initiator of life is also briefly discussed.

High-level expression of podoplanin in benign and malignant soft tissue tumors: immunohistochemical and quantitative real-time RT-PCR analysis.

PubMed

Xu, Yongjun; Ogose, Akira; Kawashima, Hiroyuki; Hotta, Tetsuo; Ariizumi, Takashi; Li, Guidong; Umezu, Hajime; Endo, Naoto

2011-03-01

Podoplanin is a 38 kDa mucin-type transmembrane glycoprotein that was first identified in rat glomerular epithelial cells (podocytes). It is expressed in normal lymphatic endothelium, but is absent from vascular endothelial cells. D2-40 is a commercially available mouse monoclonal antibody which binds to an epitope on human podoplanin. D2-40 immunoreactivity is therefore highly sensitive and specific for lymphatic endothelium. Recent investigations have shown widespread applications of immunohistochemical staining with D2-40 in evaluating podoplanin expression as an immunohistochemical marker for diagnosis and prognosis in various tumors. To determine whether the podoplanin (D2-40) antibody may be useful for the diagnosis of soft tissue tumors, 125 cases, including 4 kinds of benign tumors, 15 kinds of malignant tumors and 3 kinds of tumor-like lesions were immunostained using the D2-40 antibody. Total RNA was extracted from frozen tumor tissue obtained from 41 corresponding soft tissue tumor patients and 12 kinds of soft tissue tumor cell lines. Quantitative real-time PCR reactions were performed. Immunohistochemical and quantitative real-time RT-PCR analyses demonstrated the expression of the podoplanin protein and mRNA in the majority of benign and malignant soft tissue tumors and tumor-like lesions examined, with the exception of alveolar soft part sarcoma, embryonal and alveolar rhabdomyosarcoma, extraskeletal Ewing's sarcoma/peripheral primitive neuro-ectodermal tumor and lipoma, which were completely negative for podoplanin. Since it is widely and highly expressed in nearly all kinds of soft tissue tumors, especially in spindle cell sarcoma, myxoid type soft tissue tumors and soft tissue tumors of the nervous system, podoplanin is considered to have little value in the differential diagnosis of soft tissue tumors.

The case for DNA methylation based molecular profiling to improve diagnostic accuracy for central nervous system embryonal tumors (not otherwise specified) in adults.

PubMed

Halliday, Gail C; Junckerstorff, Reimar C; Bentel, Jacqueline M; Miles, Andrew; Jones, David T W; Hovestadt, Volker; Capper, David; Endersby, Raelene; Cole, Catherine H; van Hagen, Tom; Gottardo, Nicholas G

2018-01-01

Central nervous system primitive neuro-ectodermal tumors (CNS-PNETs), have recently been re-classified in the most recent 2016 WHO Classification into a standby catch all category, "CNS Embryonal Tumor, not otherwise specified" (CNS embryonal tumor, NOS) based on epigenetic, biologic and histopathologic criteria. CNS embryonal tumors (NOS) are a rare, histologically and molecularly heterogeneous group of tumors that predominantly affect children, and occasionally adults. Diagnosis of this entity continues to be challenging and the ramifications of misdiagnosis of this aggressive class of brain tumors are significant. We report the case of a 45-year-old woman who was diagnosed with a central nervous system embryonal tumor (NOS) based on immunohistochemical analysis of the patient's tumor at diagnosis. However, later genome-wide methylation profiling of the diagnostic tumor undertaken to guide treatment, revealed characteristics most consistent with IDH-mutant astrocytoma. DNA sequencing and immunohistochemistry confirmed the presence of IDH1 and ATRX mutations resulting in a revised diagnosis of high-grade small cell astrocytoma, and the implementation of a less aggressive treatment regime tailored more appropriately to the patient's tumor type. This case highlights the inadequacy of histology alone for the diagnosis of brain tumours and the utility of methylation profiling and integrated genomic analysis for the diagnostic verification of adults with suspected CNS embryonal tumor (NOS), and is consistent with the increasing realization in the field that a combined diagnostic approach based on clinical, histopathological and molecular data is required to more accurately distinguish brain tumor subtypes and inform more effective therapy. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

18F-FLT Positron Emission Tomography and Diffusion-Weighted Magnetic Resonance Imaging in Planning Surgery and Radiation Therapy and Measuring Response in Patients With Newly Diagnosed Ewing Sarcoma

ClinicalTrials.gov

2017-11-16

Adult Supratentorial Primitive Neuroectodermal Tumor (PNET); Ewing Sarcoma of Bone; Extraosseous Ewing Sarcoma; Localized Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Untreated Childhood Supratentorial Primitive Neuroectodermal Tumor

Ablation of Coactivator Med1 Switches the Cell Fate of Dental Epithelia to That Generating Hair

PubMed Central

Nguyen, Thai; Sakai, Kiyoshi; He, Bing; Fong, Chak; Oda, Yuko

2014-01-01

Cell fates are determined by specific transcriptional programs. Here we provide evidence that the transcriptional coactivator, Mediator 1 (Med1), is essential for the cell fate determination of ectodermal epithelia. Conditional deletion of Med1 in vivo converted dental epithelia into epidermal epithelia, causing defects in enamel organ development while promoting hair formation in the incisors. We identified multiple processes by which hairs are generated in Med1 deficient incisors: 1) dental epithelial stem cells lacking Med 1 fail to commit to the dental lineage, 2) Sox2-expressing stem cells extend into the differentiation zone and remain multi-potent due to reduced Notch1 signaling, and 3) epidermal fate is induced by calcium as demonstrated in dental epithelial cell cultures. These results demonstrate that Med1 is a master regulator in adult stem cells to govern epithelial cell fate. PMID:24949995

Development, Regeneration, and Evolution of Feathers

PubMed Central

Chen, Chih-Feng; Foley, John; Tang, Pin-Chi; Li, Ang; Jiang, Ting Xin; Wu, Ping; Widelitz, Randall B.; Chuong, Cheng Ming

2017-01-01

The feather is a complex ectodermal organ with hierarchical branching patterns. It provides functions in endothermy, communication, and flight. Studies of feather growth, cycling, and health are of fundamental importance to avian biology and poultry science. In addition, feathers are an excellent model for morphogenesis studies because of their accessibility, and their distinct patterns can be used to assay the roles of specific molecular pathways. Here we review the progress in aspects of development, regeneration, and evolution during the past three decades. We cover the development of feather buds in chicken embryos, regenerative cycling of feather follicle stem cells, formation of barb branching patterns, emergence of intrafeather pigmentation patterns, interplay of hormones and feather growth, and the genetic identification of several feather variants. The discovery of feathered dinosaurs redefines the relationship between feathers and birds. Inspiration from biomaterials and flight research further fuels biomimetic potential of feathers as a multidisciplinary research focal point. PMID:25387232

Embryonic development of pleuropodia of the cicada, Magicicada cassini

PubMed Central

Strauß, Johannes; Lakes-Harlan, Reinhard

2006-01-01

In many insects the first abdominal segment possesses embryonic appendages called pleuropodia. Here we show the embryogenesis of pleuropodial cells of the periodical cicada, Magicicada cassini (Fisher 1851) (Insecta, Homoptera, Cicadidae). An antibody, anti-horseradish perioxidase (HRP), that is usually neuron-specific strongly marked the pleuropodial anlagen and revealed their ectodermal origin shortly after limb bud formation. Thereafter the cells sank into the epidermis and their apical parts enlarged. A globular part protruded from the body wall. Filamentous structures were marked at the stem region and into the apical dilation. In later embryonic stages the pleuropodia degenerated. Despite the binding of anti-HRP the cells had no morphological neuronal characters and cannot be regarded as neurons. The binding indicates that glycosylated cell surface molecules contribute to the adhesion between the presumably glandular pleuropodial cells. In comparison, anti-HRP does not mark the pleuropodia of Orthoptera. PMID:19537987

Formation and hematopoietic differentiation of human embryoid bodies by suspension and hanging drop cultures.

PubMed

Cerdan, Chantal; Hong, Seok Ho; Bhatia, Mickie

2007-10-01

The in vitro aggregation of human embryonic stem cells (hESCs) into clusters termed embryoid bodies (EBs) allows for the spontaneous differentiation of cells representing endoderm, mesoderm, and ectoderm lineages. This stochastic process results however, in the generation of low numbers of differentiated cells, and can be enhanced to some extent by the addition of exogenous growth factors or overexpression of regulatory genes. In the authors' laboratory, the use of hematopoietic cytokines in combination with the mesoderm inducer bone morphogenetic protein-4 (BMP-4) was able to generate up to 90% of CD45(+) hematopoietic cells with colony-forming unit (CFU) activity. This unit describes two protocols that have been successfully applied in the authors' laboratory for the generation of EBs in (1) suspension and (2) hanging drop (HD) cultures from enzymatically digested clumps of undifferentiated hESC colonies.

Ras Signaling Regulates Stem Cells and Amelogenesis in the Mouse Incisor.

PubMed

Zheng, X; Goodwin, A F; Tian, H; Jheon, A H; Klein, O D

2017-11-01

The role of Ras signaling during tooth development is poorly understood. Ras proteins-which are activated by many upstream pathways, including receptor tyrosine kinase cascades-signal through multiple effectors, such as the mitogen-activated protein kinase (MAPK) and PI3K pathways. Here, we utilized the mouse incisor as a model to study how the MAPK and PI3K pathways regulate dental epithelial stem cells and amelogenesis. The rodent incisor-which grows continuously throughout the life of the animal due to the presence of epithelial and mesenchymal stem cells-provides a model for the study of ectodermal organ renewal and regeneration. Utilizing models of Ras dysregulation as well as inhibitors of the MAPK and PI3K pathways, we found that MAPK and PI3K regulate dental epithelial stem cell activity, transit-amplifying cell proliferation, and enamel formation in the mouse incisor.

Diagnostic Study of Tumor Characteristics in Patients With Ewing's Sarcoma

ClinicalTrials.gov

2013-06-20

Localized Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor

Ectodermal Influx and Cell Hypertrophy Provide Early Growth for All Murine Mammary Rudiments, and Are Differentially Regulated among Them by Gli3

PubMed Central

Lee, May Yin; Racine, Victor; Jagadpramana, Peter; Sun, Li; Yu, Weimiao; Du, Tiehua; Spencer-Dene, Bradley; Rubin, Nicole; Le, Lendy; Ndiaye, Delphine; Bellusci, Saverio; Kratochwil, Klaus; Veltmaat, Jacqueline M.

2011-01-01

Mammary gland development starts in utero with one or several pairs of mammary rudiments (MRs) budding from the surface ectodermal component of the mammalian embryonic skin. Mice develop five pairs, numbered MR1 to MR5 from pectoral to inguinal position. We have previously shown that Gli3Xt-J/Xt-J mutant embryos, which lack the transcription factor Gli3, do not form MR3 and MR5. We show here that two days after the MRs emerge, Gli3Xt-J/Xt-J MR1 is 20% smaller, and Gli3Xt-J/Xt-J MR2 and MR4 are 50% smaller than their wild type (wt) counterparts. Moreover, while wt MRs sink into the underlying dermis, Gli3Xt-J/Xt-J MR4 and MR2 protrude outwardly, to different extents. To understand why each of these five pairs of functionally identical organs has its own, distinct response to the absence of Gli3, we determined which cellular mechanisms regulate growth of the individual MRs, and whether and how Gli3 regulates these mechanisms. We found a 5.5 to 10.7-fold lower cell proliferation rate in wt MRs compared to their adjacent surface ectoderm, indicating that MRs do not emerge or grow via locally enhanced cell proliferation. Cell-tracing experiments showed that surface ectodermal cells are recruited toward the positions where MRs emerge, and contribute to MR growth during at least two days. During the second day of MR development, peripheral cells within the MRs undergo hypertrophy, which also contributes to MR growth. Limited apoptotic cell death counterbalances MR growth. The relative contribution of each of these processes varies among the five MRs. Furthermore, each of these processes is impaired in the absence of Gli3, but to different extents in each MR. This differential involvement of Gli3 explains the variation in phenotype among Gli3Xt-J/Xt-J MRs, and may help to understand the variation in numbers and positions of mammary glands among mammals. PMID:22046263

The evolution of Msx gene function: expression and regulation of a sea urchin Msx class homeobox gene.

PubMed

Dobias, S L; Ma, L; Wu, H; Bell, J R; Maxson, R

1997-01-01

Msx- class homeobox genes, characterized by a distinct and highly conserved homeodomain, have been identified in a wide variety of metazoans from vertebrates to coelenterates. Although there is evidence that they participate in inductive tissue interactions that underlie vertebrate organogenesis, including those that pattern the neural crest, there is little information about their function in simple deuterostomes. Both to learn more about the ancient function of Msx genes, and to shed light on the evolution of developmental mechanisms within the lineage that gave rise to vertebrates, we have isolated and characterized Msx genes from ascidians and echinoderms. Here we describe the sequence and expression of a sea urchin (Strongylocentrotus purpouratus) Msx gene whose homeodomain is very similar to that of vertebrate Msx2. This gene, designated SpMsx, is first expressed in blastula stage embryos, apparently in a non-localized manner. Subsequently, during the early phases of gastrulation, SpMsx transcripts are expressed intensely in the invaginating archenteron and secondary mesenchyme, and at reduced levels in the ectoderm. In the latter part of gastrulation, SpMsx transcripts are concentrated in the oral ectoderm and gut, and continue to be expressed at those sites through the remainder of embryonic development. That vertebrate Msx genes are regulated by inductive tissue interactions and growth factors suggested to us that the restriction of SpMsx gene expression to the oral ectoderm and derivatives of the vegetal plate might similarly be regulated by the series of signaling events that pattern these embryonic territories. As a first test of this hypothesis, we examined the influence of exogastrulation and cell-dissociation on SpMsx gene expression. In experimentally-induced exogastrulae, SpMsx transcripts were distributed normally in the oral ectoderm, evaginated gut, and secondary mesenchyme. However, when embryos were dissociated into their component cells, SpMsx transcripts failed to accumulate. These data show that the localization of SpMsx transcripts in gastrulae does not depend on interactions between germ layers, yet the activation and maintenance of SpMsx expression does require cell-cell or cell-matrix interactions.

Collecting and Storing Biological Samples From Patients With Ewing Sarcoma

ClinicalTrials.gov

2017-12-11

Askin Tumor; Localized Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor

Otoconial formation in the fetal rat

NASA Technical Reports Server (NTRS)

Salamat, M. S.; Ross, M. D.; Peacor, D. R.

1980-01-01

Otoconial formation in the fetal rat is examined by scanning and transmission electron microscopy, and by X-ray elemental analysis. The primitive otoconia appear highly organic, but are trigonal in cross section, indicating that they already possess a three-fold axis of symmetry and a complement of calcite. These otoconia develop into spindle-shaped and, subsequently, dumbbell-shaped units. Transmission electron microscopy of dumbbell-shaped otoconia not exposed to fluids during embedment showed that calcite deposits mimicked the arrangement of the organic material. X-ray elemental analysis demonstrated that calcium was present in lower quantities in the central core than peripherally. It is concluded that organic material is essential to otoconial seeding and directs otoconial growth.

A numerical investigation of the President's Day storm of February 18-19, 1979

NASA Technical Reports Server (NTRS)

Nappi, A. J.; Warner, T. T.

1983-01-01

The reported investigation is based on the use of a three-dimensional, primitive equation model. The President's Day storm, formed in the Gulf of Mexico as a massive anticyclone, affected the northern states with record-breaking cold temperatures. Attention is given to the physical processes relevant to storm formation, the forecast model, a description of experiments and model forecasts, and model results. An attempt is made to determine the important dynamic processes at work during the evolution of the storm. The jet streak interactions which occurred in the cyclogenetic environment, the effects of cold air damming, and the formation of a strong mesoscale coastal front are found to be of particular interest.

Calcium transport into the cells of the sea urchin larva in relation to spicule formation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vidavsky, Netta; Addadi, Sefi; Schertel, Andreas

We investigated the manner in which the sea urchin larva takes up calcium from its body cavity into the primary mesenchymal cells (PMCs) that are responsible for spicule formation. We used the membrane-impermeable fluorescent dye calcein and alexa-dextran, with or without a calcium channel inhibitor, and imaged the larvae in vivo with selective-plane illumination microscopy. Both fluorescent molecules are taken up from the body cavity into the PMCs and ectoderm cells, where the two labels are predominantly colocalized in particles, whereas the calcium-binding calcein label is mainly excluded from the endoderm and is concentrated in the spicules. The presence ofmore » vesicles and vacuoles inside the PMCs that have openings through the plasma membrane directly to the body cavity was documented using high-resolution cryo-focused ion beam-SEM serial imaging. Some of the vesicles and vacuoles are interconnected to form large networks. We suggest that these vacuolar networks are involved in direct sea water uptake. We conclude that the calcium pathway from the body cavity into cells involves nonspecific endocytosis of sea water with its calcium.« less

Calcium transport into the cells of the sea urchin larva in relation to spicule formation

DOE PAGES

Vidavsky, Netta; Addadi, Sefi; Schertel, Andreas; ...

2016-10-24

We investigated the manner in which the sea urchin larva takes up calcium from its body cavity into the primary mesenchymal cells (PMCs) that are responsible for spicule formation. We used the membrane-impermeable fluorescent dye calcein and alexa-dextran, with or without a calcium channel inhibitor, and imaged the larvae in vivo with selective-plane illumination microscopy. Both fluorescent molecules are taken up from the body cavity into the PMCs and ectoderm cells, where the two labels are predominantly colocalized in particles, whereas the calcium-binding calcein label is mainly excluded from the endoderm and is concentrated in the spicules. The presence ofmore » vesicles and vacuoles inside the PMCs that have openings through the plasma membrane directly to the body cavity was documented using high-resolution cryo-focused ion beam-SEM serial imaging. Some of the vesicles and vacuoles are interconnected to form large networks. We suggest that these vacuolar networks are involved in direct sea water uptake. We conclude that the calcium pathway from the body cavity into cells involves nonspecific endocytosis of sea water with its calcium.« less

Evaluating structural pattern recognition for handwritten math via primitive label graphs

NASA Astrophysics Data System (ADS)

Zanibbi, Richard; Mouchère, Harold; Viard-Gaudin, Christian

2013-01-01

Currently, structural pattern recognizer evaluations compare graphs of detected structure to target structures (i.e. ground truth) using recognition rates, recall and precision for object segmentation, classification and relationships. In document recognition, these target objects (e.g. symbols) are frequently comprised of multiple primitives (e.g. connected components, or strokes for online handwritten data), but current metrics do not characterize errors at the primitive level, from which object-level structure is obtained. Primitive label graphs are directed graphs defined over primitives and primitive pairs. We define new metrics obtained by Hamming distances over label graphs, which allow classification, segmentation and parsing errors to be characterized separately, or using a single measure. Recall and precision for detected objects may also be computed directly from label graphs. We illustrate the new metrics by comparing a new primitive-level evaluation to the symbol-level evaluation performed for the CROHME 2012 handwritten math recognition competition. A Python-based set of utilities for evaluating, visualizing and translating label graphs is publicly available.

Primitive Magnesian Andesites at Mt. Shasta, California: A Real Mix-up

NASA Astrophysics Data System (ADS)

Barr, J. A.; Grove, T. L.; Carlson, R. W.; Krawczynski, M. J.

2009-12-01

Until recently, the only described occurrence of primitive magnesian andesite (PMA) at Mt. Shasta was a cinder-pit in the saddle between Whaleback and Deer Mtns. (Location S-17 of Anderson, 1974), north of the main edifice of the volcano. We have reinvestigated PMA occurrence and collected samples from other nearby vents and associated lava flows to provide better constraints on the magmatic processes that led to the formation of this important magma type. The petrology of the PMA samples from S-17 and the newly recognized PMA occurrences nearby, point to a mixing scenario, in which a PMA is the dominant component in the mixed magma. This stands in contrast to other suggestions in which the PMA is created by mixing melts that differ strongly in composition from the PMA. This idea is not new, and previous researchers (e.g. Grove et al., 2005) have shown that crustal-level fractionation products of PMA lavas are one of the major mixing components in the Mt. Shasta plumbing system. The addition of new samples of PMA indicate that the erupted magma was a multi-component mix of two primitive magmas, the PMA and a primitive basaltic andesite (BA) as well as a minor component of evolved andesite or dacite lava. Mineral compositional data, major and trace element systematics, and Sr, Nd and Re/Os isotopic data on the expanded PMA data set provides additional constraints on the mantle melting, crustal level fractional crystallization and magma mixing processing at work underneath Mt. Shasta. The compositional evidence from surrounding lava flows better constrains the composition of the PMA end member involved in the magma mixing at ~ 57.5 wt. % SiO2 at 10.5 wt. % MgO. Petrologic and isotopic data also firmly rule out the possibility suggested by Streck et al. (2007) that the Shasta PMA was formed by mixing an evolved Shasta dacite and Trinity peridotite.

Rosetta/VIRTIS-M spectral data: Comet 67P/CG compared to other primitive small bodies.

NASA Astrophysics Data System (ADS)

De Sanctis, M. C.; Capaccioni, F.; Filacchione, G.; Erard, S.; Tosi, F.; Ciarniello, M.; Raponi, A.; Piccioni, G.; Leyrat, C.; Bockelée-Morvan, D.; Drossart, P.; Fornasier, S.

2014-12-01

VIRTIS-M, the Visible InfraRed Thermal Imaging Spectrometer, onboard the Rosetta Mission orbiter (Coradini et al., 2007) acquired data of the comet 67P/Churyumov-Gerasimenko in the 0.25-5.1 µm spectral range. The initial data, obtained during the first mission phases to the comet, allow us to derive albedo and global spectral properties of the comet nucleus as well as spectra of different areas on the nucleus. The characterization of cometary nuclei surfaces and their comparison with those of related populations such as extinct comet candidates, Centaurs, near-Earth asteroids (NEAs), trans-Neptunian objects (TNOs), and primitive asteroids is critical to understanding the origin and evolution of small solar system bodies. The acquired VIRTIS data are used to compare the global spectral properties of comet 67P/CG to published spectra of other cometary nuclei observed from ground or visited by space mission. Moreover, the spectra of 67P/Churyumov-Gerasimenko are also compared to those of primitive asteroids and centaurs. The comparison can give us clues on the possible common formation and evolutionary environment for primitive asteroids, centaurs and Jupiter-family comets. Authors acknowledge the funding from Italian and French Space Agencies. References: Coradini, A., Capaccioni, F., Drossart, P., Arnold, G., Ammannito, E., Angrilli, F., Barucci, A., Bellucci, G., Benkhoff, J., Bianchini, G., Bibring, J. P., Blecka, M., Bockelee-Morvan, D., Capria, M. T., Carlson, R., Carsenty, U., Cerroni, P., Colangeli, L., Combes, M., Combi, M., Crovisier, J., De Sanctis, M. C., Encrenaz, E. T., Erard, S., Federico, C., Filacchione, G., Fink, U., Fonti, S., Formisano, V., Ip, W. H., Jaumann, R., Kuehrt, E., Langevin, Y., Magni, G., McCord, T., Mennella, V., Mottola, S., Neukum, G., Palumbo, P., Piccioni, G., Rauer, H., Saggin, B., Schmitt, B., Tiphene, D., Tozzi, G., Space Science Reviews, Volume 128, Issue 1-4, 529-559, 2007.

Teloplasm formation in a leech, Helobdella triserialis, is a microtubule-dependent process.

PubMed

Astrow, S H; Holton, B; Weisblat, D A

1989-10-01

Fertilized eggs of the leech Helobdella triserialis undergo a cytoplasmic reorganization which generates domains of nonyolky cytoplasm, called teloplasm, at the animal and vegetal poles. The segregation of teloplasm to one cell of the eight-cell embryo is responsible for a unique developmental fate of that cell, i.e., to give rise to segmental ectoderm and mesoderm. We have studied the cytoplasmic movements that generate teloplasm using time-lapse video microscopy; the formation and migration of rings of nonyolky cytoplasm were visualized using transmitted light, while the movements of mitochondria into these rings were monitored with epifluorescence after labeling embryos with rhodamine 123, a fluorescent mitochondrial dye. To examine the likelihood that cytoskeletal elements play a role in the mechanism of teloplasm formation in Helobdella, we examined the distribution of microtubules and microfilaments during the first cell cycle by indirect immunofluorescence and rhodamine-phalloidin labeling, respectively. The cortex of the early embryo contained a network of microtubules many of which were oriented parallel to the cell surface. As teloplasm formation ensued, microtubule networks became concentrated in the animal and the vegetal cortex relative to the equatorial cortex. More extensive microtubule arrays were found within the rings of teloplasm. Actin filaments appeared in the form of narrow rings in the cortex, but these varied apparently randomly from embryo to embryo in terms of number, size, and position. The role of microtubules and microfilaments in teloplasm formation was tested using depolymerizing agents. Teloplasm formation was blocked by microtubule inhibitors, but not by microfilament inhibitors. These results differ significantly from those obtained in embryos of the oligochaete Tubifex hattai, suggesting that the presumably homologous cytoplasmic reorganizations seen in these two annelids have different cytoskeletal dependencies.

Planetesimals Born Big by Clustering Instability?

NASA Technical Reports Server (NTRS)

Cuzzi, Jeffrey N.; Hartlep, Thomas; Simon, Justin I.; Estrada, Paul R.

2017-01-01

Roughly 100km diameter primitive bodies (today's asteroids and TNOs; [1]) are thought to be the end product of so-called "primary accretion". They dominated the initial mass function of planetesimals, and precipitated the onset of a subsequent stage, characterized by runaway gravitational effects, which proceeded onwards to planetary mass objects, some of which accreted massive gas envelopes. Asteroids are the parents of primitive meteorites; meteorite data suggest that asteroids initially formed directly from freelyfloating nebula particles in the mm-size range. Unfortunately, the process by which these primary 100km diameter planetesimals formed remains problematic. We review the most diagnostic primitive parent body observations, highlight critical aspects of the nebula context, and describe the issues facing various primary accretion models. We suggest a path forward that combines current scenarios of "turbulent concentration" (TC) and "streaming instabilities" (SI) into a triggered formation process we call clustering instability (CI). Under expected conditions of nebula turbulence, the success of these processes at forming terrestrial region (mostly silicate) planetesimals requires growth by sticking into aggregates in the several cm size range, at least, which is orders of magnitude more massive than allowed by current growth-by-sticking models using current experimental sticking parameters [2-4]. The situation is not as dire in the ice-rich outer solar system; however, growth outside of the snowline has important effects on growth inside of it [4] and at least one aspect of outer solar system planetesimals (high binary fraction) supports some kind of clustering instability.

Planetesimals Born Big by Clustering Instability?

NASA Technical Reports Server (NTRS)

Cuzzi, Jeffrey N.; Hartlep, Thomas; Simon, Justin I.; Estrada, Paul R.

2017-01-01

Roughly 100km diameter primitive bodies (today's asteroids and TNOs; [1]) are thought to be the end product of so-called "primary accretion". They dominated the initial mass function of planetesimals, and precipitated the onset of a subsequent stage, characterized by runaway gravitational effects, which proceeded onwards to planetary mass objects, some of which accreted massive gas envelopes. Asteroids are the parents of primitive meteorites; meteorite data suggest that asteroids initially formed directly from freelyfloating nebula particles in the mm-size range. Unfortunately, the process by which these primary 100km diameter planetesimals formed remains problematic. We review the most diagnostic primitive parent body observations, highlight critical aspects of the nebula context, and describe the issues facing various primary accretion models. We suggest a path forward that combines current scenarios of "turbulent concentration" (TC) and "streaming instabilities" (SI) into a triggered formation process we call clustering instability (CI). Under expected conditions of nebula turbulence, the success of these processes at forming terrestrial region (mostly silicate) planetesimals requires growth by sticking into aggregates in the several cm size range, at least, which is orders of magnitude more massive than allowed by current growth-by-sticking models using current experimental sticking parameters [2-4]. The situation is not as dire in the ice-rich outer solar system; however, growth outside of the snowline has important effects on growth inside of it [4] and at least one aspect of outer solar system planetesimals (high binary fraction) supports some kind of clustering instability

The ECM moves during primitive streak formation--computation of ECM versus cellular motion.

PubMed

Zamir, Evan A; Rongish, Brenda J; Little, Charles D

2008-10-14

Galileo described the concept of motion relativity--motion with respect to a reference frame--in 1632. He noted that a person below deck would be unable to discern whether the boat was moving. Embryologists, while recognizing that embryonic tissues undergo large-scale deformations, have failed to account for relative motion when analyzing cell motility data. A century of scientific articles has advanced the concept that embryonic cells move ("migrate") in an autonomous fashion such that, as time progresses, the cells and their progeny assemble an embryo. In sharp contrast, the motion of the surrounding extracellular matrix scaffold has been largely ignored/overlooked. We developed computational/optical methods that measure the extent embryonic cells move relative to the extracellular matrix. Our time-lapse data show that epiblastic cells largely move in concert with a sub-epiblastic extracellular matrix during stages 2 and 3 in primitive streak quail embryos. In other words, there is little cellular motion relative to the extracellular matrix scaffold--both components move together as a tissue. The extracellular matrix displacements exhibit bilateral vortical motion, convergence to the midline, and extension along the presumptive vertebral axis--all patterns previously attributed solely to cellular "migration." Our time-resolved data pose new challenges for understanding how extracellular chemical (morphogen) gradients, widely hypothesized to guide cellular trajectories at early gastrulation stages, are maintained in this dynamic extracellular environment. We conclude that models describing primitive streak cellular guidance mechanisms must be able to account for sub-epiblastic extracellular matrix displacements.

Genetics Home Reference: hypohidrotic ectodermal dysplasia

MedlinePlus

... chromosome , one of the two sex chromosomes . In males (who have only one X chromosome ), one altered ... copies of the gene to cause the disorder. Males are affected by X-linked recessive disorders much ...

Expression of Wise in chick embryos.

PubMed

Shigetani, Y; Itasaki, N

2007-08-01

We have performed in situ hybridization to study the expression of Wise in early chick embryos. Wise expression is first detectable in the ectoderm at posterior levels of late neurula. As development proceeds, Wise expression is seen in specific patterns in the ectoderm of the trunk region, pharyngeal arches, limb buds, and feather buds. In addition to these areas, particular cartilages such as the ones in the maxillary process and limbs start to express Wise at the late pharyngula stage, and the expression in these cartilages becomes stronger than that in epidermal components at later stages. Importantly, Wise is expressed in regions where other signaling molecules such as Wnt, Bmp, and Shh are known to function in morphogenesis and differentiation. Direct comparisons of the expression of Wise and these genes are also demonstrated. (c) 2007 Wiley-Liss, Inc.

Patterning of mammalian somites by surface ectoderm and notochord: evidence for sclerotome induction by a hedgehog homolog.

PubMed

Fan, C M; Tessier-Lavigne, M

1994-12-30

An early step in the development of vertebrae, ribs, muscle, and dermis is the differentiation of the somitic mesoderm into dermomyotome dorsally and sclerotome ventrally. To analyze this process, we have developed an in vitro assay for somitic mesoderm differentiation. We show that sclerotomal markers can be induced by a diffusible factor secreted by notochord and floor plate and that heterologous cells expressing Sonic hedgehog (shh/vhh-1) mimic this effect. In contrast, expression of dermomyotomal markers can be caused by a contact-dependent signal from surface ectoderm and a diffusible signal from dorsal neural tube. Our results extend previous studies by suggesting that dorsoventral patterning of somites involves the coordinate action of multiple dorsalizing and ventralizing signals and that a diffusible form of Shh/Vhh-1 mediates sclerotome induction.

p38α MAPK Is Required for Tooth Morphogenesis and Enamel Secretion*

PubMed Central

Greenblatt, Matthew B.; Kim, Jung-Min; Oh, Hwanhee; Park, Kwang Hwan; Choo, Min-Kyung; Sano, Yasuyo; Tye, Coralee E.; Skobe, Ziedonis; Davis, Roger J.; Park, Jin Mo; Bei, Marianna; Glimcher, Laurie H.; Shim, Jae-Hyuck

2015-01-01

An improved understanding of the molecular pathways that drive tooth morphogenesis and enamel secretion is needed to generate teeth from organ cultures for therapeutic implantation or to determine the pathogenesis of primary disorders of dentition (Abdollah, S., Macias-Silva, M., Tsukazaki, T., Hayashi, H., Attisano, L., and Wrana, J. L. (1997) J. Biol. Chem. 272, 27678–27685). Here we present a novel ectodermal dysplasia phenotype associated with conditional deletion of p38α MAPK in ectodermal appendages using K14-cre mice (p38αK14 mice). These mice display impaired patterning of dental cusps and a profound defect in the production and biomechanical strength of dental enamel because of defects in ameloblast differentiation and activity. In the absence of p38α, expression of amelogenin and β4-integrin in ameloblasts and p21 in the enamel knot was significantly reduced. Mice lacking the MAP2K MKK6, but not mice lacking MAP2K MKK3, also show the enamel defects, implying that MKK6 functions as an upstream kinase of p38α in ectodermal appendages. Lastly, stimulation with BMP2/7 in both explant culture and an ameloblast cell line confirm that p38α functions downstream of BMPs in this context. Thus, BMP-induced activation of the p38α MAPK pathway is critical for the morphogenesis of tooth cusps and the secretion of dental enamel. PMID:25406311

cis-Regulatory control of the initial neurogenic pattern of onecut gene expression in the sea urchin embryo.

PubMed

Barsi, Julius C; Davidson, Eric H

2016-01-01

Specification of the ciliated band (CB) of echinoid embryos executes three spatial functions essential for postgastrular organization. These are establishment of a band about 5 cells wide which delimits and bounds other embryonic territories; definition of a neurogenic domain within this band; and generation within it of arrays of ciliary cells that bear the special long cilia from which the structure derives its name. In Strongylocentrotus purpuratus the spatial coordinates of the future ciliated band are initially and exactly determined by the disposition of a ring of cells that transcriptionally activate the onecut homeodomain regulatory gene, beginning in blastula stage, long before the appearance of the CB per se. Thus the cis-regulatory apparatus that governs onecut expression in the blastula directly reveals the genomic sequence code by which these aspects of the spatial organization of the embryo are initially determined. We screened the entire onecut locus and its flanking region for transcriptionally active cis-regulatory elements, and by means of BAC recombineered deletions identified three separated and required cis-regulatory modules that execute different functions. The operating logic of the crucial spatial control module accounting for the spectacularly precise and beautiful early onecut expression domain depends on spatial repression. Previously predicted oral ectoderm and aboral ectoderm repressors were identified by cis-regulatory mutation as the products of goosecoid and irxa genes respectively, while the pan-ectodermal activator SoxB1 supplies a transcriptional driver function. Copyright © 2015. Published by Elsevier Inc.

[Association of folate metabolism genes MTRR and MTHFR with complex congenital abnormalities among Chinese population in Shanxi Province, China].

PubMed

Zhang, Qin; Bai, Bao-Ling; Liu, Xiao-Zhen; Miao, Chun-Yue; Li, Hui-Li

2014-08-01

To explore the association of polymorphisms in folate metabolism genes, methionine synthase reductase (MTRR) gene and 5,10-methylenetetrahydrofolate reductase (MTHFR) gene, with complex congenital abnormalities and to further investigate its association with complex congenital abnormalities derived from three germ layers. A total of 250 cases of birth defects (with complex congenital abnormalities including congenital heart disease, neural tube defects, and craniofacial anomalies) in Shanxi Province, China were included in the study. MTRR single nucleotide polymorphism (SNP) (rs1801394) and MTHFR SNP (rs1801133) were genotyped by the SNaPshot method, and the genotyping results were compared with those of controls (n=420). SNPs rs1801394 and rs1801133 were associated with multiple birth defects. For the recessive model, individuals with GG genotype at rs1801394 and CC genotype at rs1801133 had a relatively low risk of developing birth defects, so the two genotypes were protective factors against birth defects. The homozygous recessive genotype at rs1801133, which served as a protective factor, was associated with ectoderm- or endoderm-derived complex congenital abnormalities, while the homozygous recessive genotype at rs1801394, which served as a protective factor, was associated with ectoderm-, mesoderm- or endoderm-derived complex congenital abnormalities. Among the Chinese population in Shanxi Province, the SNPs in folate metabolism genes (MTRR and MTHFR) are associated with complex congenital abnormalities and related to ectoderm, mesoderm or endoderm development.

Scanning Electron Microscopic Hair Shaft Analysis in Ectodermal Dysplasia Syndromes.

PubMed

Hirano-Ali, Stefanie A; Reed, Ashley M; Rowan, Brandon J; Sorrells, Timothy; Williams, Judith V; Pariser, David M; Hood, Antoinette F; Salkey, Kimberly

2015-01-01

The objective of the current study was to catalog hair shaft abnormalities in individuals with ectodermal dysplasia (ED) syndromes using scanning electron microscopy (SEM) and to compare the findings with those in unaffected controls. This is the second of a two-part study, the first of which used light microscopy as the modality and was previously published. Scanning electron microscopy was performed in a blinded manner on hair shafts from 65 subjects with seven types of ED syndromes and 41 unaffected control subjects. Assessment was performed along the length of the shaft and in cross section. Hair donations were collected at the 28th Annual National Family Conference held by the National Foundation for Ectodermal Dysplasia. Control subjects were recruited from a private dermatology practice and an academic children's hospital outpatient dermatology clinic. SEM identified various pathologic hair shaft abnormalities in each type of ED and in control patients. When hairs with all types of ED were grouped together and compared with those of control patients, the difference in the presence of small diameter and shallow and deep grooves was statistically significant (p < 0.05). When the EDs were separated according to subtype, statistically significant findings were also seen. SEM is a possible adjuvant tool in the diagnosis of ED syndromes. There are significant differences, with high specificity, between the hairs of individuals with ED and those of control subjects and between subtypes. © 2015 Wiley Periodicals, Inc.

Eight Mutations of Three Genes (EDA, EDAR, and WNT10A) Identified in Seven Hypohidrotic Ectodermal Dysplasia Patients.

PubMed

Zeng, Binghui; Xiao, Xue; Li, Sijie; Lu, Hui; Lu, Jiaxuan; Zhu, Ling; Yu, Dongsheng; Zhao, Wei

2016-09-19

Hypohidrotic ectodermal dysplasia (HED) is characterized by abnormal development of the teeth, hair, and sweat glands. Ectodysplasin A (EDA), Ectodysplasin A receptor (EDAR), and EDAR-associated death domain (EDARADD) are candidate genes for HED, but the relationship between WNT10A and HED has not yet been validated. In this study, we included patients who presented at least two of the three ectodermal dysplasia features. The four genes were analyzed in seven HED patients by PCR and Sanger sequencing. Five EDA and one EDAR heterozygous mutations were identified in families 1-6. Two WNT10A heterozygous mutations were identified in family 7 as a compound heterozygote. c.662G>A (p.Gly221Asp) in EDA and c.354T>G (p.Tyr118*) in WNT10A are novel mutations. Bioinformatics analyses results confirmed the pathogenicity of the two novel mutations. In family 7, we also identified two single-nucleotide polymorphisms (SNPs) that were predicted to affect the splicing of EDAR. Analysis of the patient's total RNA revealed normal splicing of EDAR. This ascertained that the compound heterozygous WNT10A mutations are the genetic defects that led to the onset of HED. Our data revealed the genetic basis of seven HED patients and expended the mutational spectrum. Interestingly, we confirmed WNT10A as a candidate gene of HED and we propose WNT10A to be tested in EDA-negative HED patients.

Prosthetic rehabilitation of patients with hypohidrotic ectodermal dysplasia: A systematic review.

PubMed

Schnabl, D; Grunert, I; Schmuth, M; Kapferer-Seebacher, I

2018-04-21

Hypohidrotic ectodermal dysplasia (HED) comprises a large group of inherited disorders of ectodermal structures, characterised by hypo- or anhidrosis, hypotrichosis and hypo- or oligo- or anodontia. We aimed to systematically assess the spectrum of prosthodontic approaches with regard to the patients' age and to provide clinical implications for practicing dentists. An electronic and manual search was conducted in four databases (Medline, LIVIVO, Cochrane Library, Web of Science Core Collection). Publications of multiple study designs written in English or German without data restrictions, reporting on prosthodontic treatment of patients diagnosed with HED and afflicted with oligo- or anodontia, were included. In total, 75 articles on 146 patients were analysed according to the patients' age. In children aged 2-17 years, removable full or partial (over)dentures represented standard treatment. In the mandible, implant-supported removable dentures on two interforaminal implants presented an alternative, already in young childhood. In cases with more than six teeth per jaw, also fixed (resin) bridges were used, frequently after orthodontic treatment. In adults, fixed or removable reconstructions with the help of up to eight implants per jaw, usually placed after bone augmentation procedures, were standard. Ten case reports/series with long-term follow-up illustrated the need for consistent maintenance including denture renewals. Prosthodontic rehabilitation should start in early childhood and needs to be revised in accordance with the patients' growth. Treatment should be carried out by a multidisciplinary team addressing variable demands in different age groups. © 2018 John Wiley & Sons Ltd.

2008 International Conference on Ectodermal Dysplasias Classification Conference Report

PubMed Central

Salinas, Carlos F.; Jorgenson, Ronald J.; Wright, J. Timothy; DiGiovanna, John J.; Fete, Mary D.

2009-01-01

There are many ways to classify ectodermal dysplasia syndromes. Clinicians in practice use a list of syndromes from which to choose a potential diagnosis, paging through a volume, such as Freire-Maia and Pinheiro's corpus, matching their patient's findings to listed syndromes. Medical researchers may want a list of syndromes that share one (monothetic system) or several (polythetic system) traits in order to focus research on a narrowly defined group. Special interest groups may want a list from which they can choose constituencies, and insurance companies and government agencies may want a list to determine for whom to provide (or deny) health care coverage. Furthermore, various molecular biologists are now promoting classification systems based on gene mutation (e.g. TP63 associated syndromes) or common molecular pathways. The challenge will be to balance comprehensiveness within the classification with usability and accessibility so that the benefits truly serve the needs of researchers, health care providers and ultimately the individuals and families directly affected by ectodermal dysplasias. It is also recognized that a new classification approach is an ongoing process and will require periodical reviews or updates. Whatever scheme is developed, however, will have far-reaching application for other groups of disorders for which classification is complicated by the number of interested parties and advances in diagnostic acumen. Consensus among interested parties is necessary for optimizing communication among the diverse groups whether it be for equitable distribution of funds, correctness of diagnosis and treatment, or focusing research efforts. PMID:19681152

Exogenous retinoic acid induces digit reduction in opossums (Monodelphis domestica) by disrupting cell death and proliferation, and apical ectodermal ridge and zone of polarizing activity function.

PubMed

Molineaux, Anna C; Maier, Jennifer A; Schecker, Teresa; Sears, Karen E

2015-03-01

Retinoic acid (RA) is a vitamin A derivative. Exposure to exogenous RA generates congenital limb malformations (CLMs) in species from frogs to humans. These CLMs include but are not limited to oligodactyly and long-bone hypoplasia. The processes by which exogenous RA induces CLMs in mammals have been best studied in mouse, but as of yet remain unresolved. We investigated the impact of exogenous RA on the cellular and molecular development of the limbs of a nonrodent model mammal, the opossum Monodelphis domestica. Opossums exposed to exogenous retinoic acid display CLMs including oligodactly, and results are consistent with opossum development being more susceptible to RA-induced disruptions than mouse development. Exposure of developing opossums to exogenous RA leads to an increase in cell death in the limb mesenchyme that is most pronounced in the zone of polarizing activity, and a reduction in cell proliferation throughout the limb mesenchyme. Exogenous RA also disrupts the expression of Shh in the zone of polarizing activity, and Fgf8 in the apical ectodermal ridge, and other genes with roles in the regulation of limb development and cell death. Results are consistent with RA inducing CLMs in opossum limbs by disrupting the functions of the apical ectodermal ridge and zone of polarizing activity, and driving an increase in cell death and reduction of cell proliferation in the mesenchyme of the developing limb. © 2015 Wiley Periodicals, Inc.

Catalase characterization and implication in bleaching of a symbiotic sea anemone.

PubMed

Merle, Pierre-Laurent; Sabourault, Cécile; Richier, Sophie; Allemand, Denis; Furla, Paola

2007-01-15

Symbiotic cnidarians are marine invertebrates harboring photosynthesizing microalgae (named zooxanthellae), which produce great amounts of oxygen and free radicals upon illumination. Studying antioxidative balance is then crucial to understanding how symbiotic cnidarians cope with ROS production. In particular, it is suspected that oxidative stress triggers cnidarian bleaching, i.e., the expulsion of zooxanthellae from the animal host, responsible for symbiotic cnidarian mass mortality worldwide. This study therefore investigates catalase antioxidant enzymes and their role in bleaching of the temperate symbiotic sea anemone Anemonia viridis. Using specific separation of animal tissues (ectoderm and endoderm) from the symbionts (zooxanthellae), spectrophotometric assays and native PAGE revealed both tissue-specific and activity pattern distribution of two catalase electrophoretypes, E1 and E2. E1, expressed in all three tissues, presents high sensitivity to the catalase inhibitor aminotriazole (ATZ) and elevated temperatures. The ectodermal E1 form is responsible for 67% of total catalase activity. The E2 form, expressed only within zooxanthellae and their host endodermal cells, displays low sensitivity to ATZ and relative thermostability. We further cloned an ectodermal catalase, which shares 68% identity with mammalian monofunctional catalases. Last, 6 days of exposure of whole sea anemones to ATZ (0.5 mM) led to effective catalase inhibition and initiated symbiont expulsion. This demonstrates the crucial role of this enzyme in cnidarian bleaching, a phenomenon responsible for worldwide climate-change-induced mass mortalities, with catastrophic consequences for marine biodiversity.

Star Formation and the Solar System

NASA Technical Reports Server (NTRS)

Bally, John; Boss, Alan; Papanastassiou, Dimitri; Sandford, Scott; Sargent, Anneila

1988-01-01

We have seen that studies of nearby star-forming regions are beginning to reveal the first signs of protoplanetary disks. Studies of interstellar and interplanetary grains are starting to provide clues about the processing and incorporation of matter into the Solar System. Studies of meteorites have yielded isotopic anomalies which indicate that some of the grains and inclusions in these bodies are very primitive. Although we have not yet detected a true interstellar grain, some of these materials have not been extensively modified since their removal from the ISM. We are indeed close to seeing our interstellar heritage. The overlap between astronomical and Solar System studies is in its infancy. What future experiments, observations, and missions can be performed in the near future that will greatly enhance our understanding of star formation and the formation of the Solar System?

Exploration of Near-Earth Asteroids

NASA Technical Reports Server (NTRS)

Abell, Paul

2013-01-01

A major goal for NASA's human spaceflight program is to send astronauts to near-Earth asteroids (NEAs) in the coming decades. Missions to NEAs would undoubtedly provide a great deal of technical and engineering data on spacecraft operations for future human space exploration while conducting in-depth scientific examinations of these primitive objects. However, prior to sending human explorers to NEAs, robotic investigations of these bodies would be required in order to maximize operational efficiency and reduce mission risk. These precursor missions to NEAs would fill crucial strategic knowledge gaps concerning their physical characteristics that are relevant for human exploration of these relatively unknown destinations. Information obtained from a human investigation of a NEA, together with ground-based observations and prior spacecraft investigations of asteroids and comets, will also provide a real measure of ground truth to data obtained from terrestrial meteorite collections. Major advances in the areas of geochemistry, impact history, thermal history, isotope analyses, mineralogy, space weathering, formation ages, thermal inertias, volatile content, source regions, solar system formation, etc. can be expected from human NEA missions. Samples directly returned from a primitive body would lead to the same kind of breakthroughs for understanding NEAs that the Apollo samples provided for understanding the Earth-Moon system and its formation history. In addition, robotic precursor and human exploration missions to NEAs would allow the NASA and its international partners to gain operational experience in performing complex tasks (e.g., sample collection, deployment of payloads, retrieval of payloads, etc.) with crew, robots, and spacecraft under microgravity conditions at or near the surface of a small body. This would provide an important synergy between the worldwide Science and Exploration communities, which will be crucial for development of future international deep space exploration architectures and has potential benefits for future exploration of other destinations beyond low-Earth orbit.

A study of the adequacy of quasi-geostrophic dynamics for modeling the effect of frontal cyclones on the larger scale flow

NASA Technical Reports Server (NTRS)

Mudrick, S.

1985-01-01

The validity of quasi-geostrophic (QG) dynamics were tested on compared to primitive equation (PE) dynamics, for modeling the effect of cyclone waves on the larger scale flow. The formation of frontal cyclones and the dynamics of occluded frontogenesis were studied. Surface friction runs with the PE model and the wavelength of maximum instability is described. Also fine resolution PE simulation of a polar low is described.

Experimental constraints on Earth's core formation

NASA Astrophysics Data System (ADS)

Bouhifd, Mohamed Ali

2017-04-01

The Earth contains a Fe-rich metallic core that segregated from the primitive silicate mantle very early in its 4.5 billion year history. One major consequence of this segregation is the depletion of the Earth's mantle from the siderophile elements "high core affinity" relative to primitive solar system abundances. The way in which siderophile elements partition between metal and silicate depends strongly on pressure (P), temperature (T), oxygen fugacity (fO2) and chemical compositions of both metal and silicate phases. In the present presentation, I will discuss the experimental results of metal-silicate partitioning of Ni and Co that show a marked change with increasing pressure (e.g. Bouhifd and Jephcoat, 2011; Siebert et al., 2012; Fischer et al., 2015 for the most recent studies). This behavior coincides with a change in the coordination of silicon (in a basaltic melt composition) from 4-fold coordination under ambient conditions to 6-fold coordination at about 35 GPa, indicating that melt compressibility may controls siderophile-element partitioning (Sanloup et al., 2013). I will also discuss the impact of Earth's core formation on "lithophile" elements such as Sm, Nd, Ta and Nb (e.g. Bouhifd et al. 2015; Cartier et al., 2014), as well as the impact of sulphur on the behavior of various elements during core formation (e.g. Boujibar et al., 2014; Wohlers and Wood, 2015). By combining the metal-silicate partitioning data from siderophile, lithophile and chalcophile elements I will present and discuss the most plausible conditions for Earth's core formation. References Bouhifd and Jephcoat (2011) EPSL, 307, 341-348. Bouhifd et al. (2015) EPSL 413, 158-166. Boujibar et al. (2014) EPSL 391, 42-54. Cartier et al. (2014) Nature Geoscience, 7, 573-576. Fischer et al. (2015) GCA 167, 177-194. Sanloup et al. (2013) Nature, 503, 104-107. Siebert et al. (2012) EPSL 321-322, 189-197. Wohlers and Wood (2015) Nature 520, 337-340.

Use of Optical Storage Devices as Shared Resources in Local Area Networks

DTIC Science & Technology

1989-09-01

13 3. SERVICE CALLS FOR MS-DOS CD-ROM EXTENSIONS . 14 4. MS-DOS PRIMITIVE GROUPS ....................... 15 5. RAM USAGE FOR VARIOUS LAN...17 2. Service Call Translation to DOS Primitives ............. 19 3. MS-DOS Device Drivers ............................. 21 4. MS-DOS/ROM...directed to I/O devices will be referred to as primitive instruction groups). These primitive instruction groups include keyboard, video, disk, serial

On the ab initio calculation of vibrational formation entropy of point defect: the case of the silicon vacancy

NASA Astrophysics Data System (ADS)

Seeberger, Pia; Vidal, Julien

2017-08-01

Formation entropy of point defects is one of the last crucial elements required to fully describe the temperature dependence of point defect formation. However, while many attempts have been made to compute them for very complicated systems, very few works have been carried out such as to assess the different effects of finite size effects and precision on such quantity. Large discrepancies can be found in the literature for a system as primitive as the silicon vacancy. In this work, we have proposed a systematic study of formation entropy for silicon vacancy in its 3 stable charge states: neutral, +2 and -2 for supercells with size not below 432 atoms. Rationalization of the formation entropy is presented, highlighting importance of finite size error and the difficulty to compute such quantities due to high numerical requirement. It is proposed that the direct calculation of formation entropy of VSi using first principles methods will be plagued by very high computational workload (or large numerical errors) and finite size dependent results.

Method for concurrent execution of primitive operations by dynamically assigning operations based upon computational marked graph and availability of data

NASA Technical Reports Server (NTRS)

Mielke, Roland V. (Inventor); Stoughton, John W. (Inventor)

1990-01-01

Computationally complex primitive operations of an algorithm are executed concurrently in a plurality of functional units under the control of an assignment manager. The algorithm is preferably defined as a computationally marked graph contianing data status edges (paths) corresponding to each of the data flow edges. The assignment manager assigns primitive operations to the functional units and monitors completion of the primitive operations to determine data availability using the computational marked graph of the algorithm. All data accessing of the primitive operations is performed by the functional units independently of the assignment manager.

Genetics Home Reference: focal dermal hypoplasia

MedlinePlus

... in people with focal dermal hypoplasia is an omphalocele , which is an opening in the wall of ... Dermal Hypoplasia MedlinePlus Encyclopedia: Ectodermal dysplasia MedlinePlus Encyclopedia: Omphalocele General Information from MedlinePlus (5 links) Diagnostic Tests ...

How to Spot a Primitive Black Hole

NASA Image and Video Library

2010-03-17

These two data plots from NASA Spitzer Space Telescope show a primitive supermassive black hole top compared to a typical one; usually, dust tori are missing and only gas disks are observed in primitive black holes.

Primitive erythrocytes are generated from hemogenic endothelial cells.

PubMed

Stefanska, Monika; Batta, Kiran; Patel, Rahima; Florkowska, Magdalena; Kouskoff, Valerie; Lacaud, Georges

2017-07-25

Primitive erythroblasts are the first blood cells generated during embryonic hematopoiesis. Tracking their emergence both in vivo and in vitro has remained challenging due to the lack of specific cell surface markers. To selectively investigate primitive erythropoiesis, we have engineered a new transgenic embryonic stem (ES) cell line, where eGFP expression is driven by the regulatory sequences of the embryonic βH1 hemoglobin gene expressed specifically in primitive erythroid cells. Using this ES cell line, we observed that the first primitive erythroblasts are detected in vitro around day 1.5 of blast colony differentiation, within the cell population positive for the early hematopoietic progenitor marker CD41. Moreover, we establish that these eGFP + cells emerge from a hemogenic endothelial cell population similarly to their definitive hematopoietic counterparts. We further generated a corresponding βH1-eGFP transgenic mouse model and demonstrated the presence of a primitive erythroid primed hemogenic endothelial cell population in the developing embryo. Taken together, our findings demonstrate that both in vivo and in vitro primitive erythrocytes are generated from hemogenic endothelial cells.

A key heterogeneous structure of fractal networks based on inverse renormalization scheme

NASA Astrophysics Data System (ADS)

Bai, Yanan; Huang, Ning; Sun, Lina

2018-06-01

Self-similarity property of complex networks was found by the application of renormalization group theory. Based on this theory, network topologies can be classified into universality classes in the space of configurations. In return, through inverse renormalization scheme, a given primitive structure can grow into a pure fractal network, then adding different types of shortcuts, it exhibits different characteristics of complex networks. However, the effect of primitive structure on networks structural property has received less attention. In this paper, we introduce a degree variance index to measure the dispersion of nodes degree in the primitive structure, and investigate the effect of the primitive structure on network structural property quantified by network efficiency. Numerical simulations and theoretical analysis show a primitive structure is a key heterogeneous structure of generated networks based on inverse renormalization scheme, whether or not adding shortcuts, and the network efficiency is positively correlated with degree variance of the primitive structure.

Discovery of survival factor for primitive chronic myeloid leukemia cells using induced pluripotent stem cells

PubMed Central

Suknuntha, Kran; Ishii, Yuki; Tao, Lihong; Hu, Kejin; McIntosh, Brian E.; Yang, David; Swanson, Scott; Stewart, Ron; Wang, Jean Y.J.; Thomson, James; Slukvin, Igor

2016-01-01

A definitive cure for chronic myeloid leukemia (CML) requires identifying novel therapeutic targets to eradicate leukemia stem cells (LSCs). However, the rarity of LSCs within the primitive hematopoietic cell compartment remains a major limiting factor for their study in humans. Here we show that primitive hematopoietic cells with typical LSC features, including adhesion defect, increased long-term survival and proliferation, and innate resistance to tyrosine kinase inhibitor (TKI) imatinib, can be generated de novo from reprogrammed primary CML cells. Using CML iPSC-derived primitive leukemia cells, we discovered olfactomedin 4 (OLFM4) as a novel factor that contributes to survival and growth of somatic lin−CD34+ cells from bone marrow of patients with CML in chronic phase, but not primitive hematopoietic cells from normal bone marrow. Overall, this study shows the feasibility and advantages of using reprogramming technology to develop strategies for targeting primitive leukemia cells. PMID:26561938

Analysis of organic grain coatings in primitive interplanetary dust particles: Implications for the origin of Solar System organic matter

NASA Astrophysics Data System (ADS)

Flynn, George

Analysis of organic grain coatings in primitive interplanetary dust particles: Implications for the origin of Solar System organic matter Chondritic, porous interplanetary dust particles (CP IDPs), the most primitive samples of extraterrestrial material available for laboratory analysis [1], are unequilibrated aggregates of mostly submicron, anhydrous grains of a diverse mineralogy. They contain organic matter not produced by parent body aqueous processing [2], some carrying H and N isotopic anomalies consistent with molecular cloud or outer Solar System material [3]. Scanning Transmission X-Ray Microscope (STXM) imaging at the C K-edge shows the individual grains in 10 micron aggregate CP IDPs are coated by a layer of carbonaceous material 100 nm thick. This structure implies a three-step formation sequence. First, individual grains condensed from the cooling nebular gas. Then complex, refractory organic molecules covered the surfaces of the grains either by deposition, formation in-situ, or a combination of both processes. Finally, the grains collided and stuck together forming the first dust-size material in the Solar System. Ultramicrotome sections, 70 to 100 nm thick were cut from several CP IDPs, embedded in elemental S to avoid exposure to C-based embedding media. X-ray Absorption Near Edge Structure (XANES) spectra were derived from image stacks obtained using a STXM. "Cluster analysis" was used to compare the C-XANES spectra from each of the pixels in an image stack and identify pixels exhibiting similar spectra. When applied to a CP IDP, cluster analysis identifies most carbonaceous grain coatings in a particle as having similar C-XANES spectra. Two processes are commonly suggested in the literature for production of organic grain coatings. The similarity in thickness and C-XANES spectra of the coatings on different minerals in the same IDP indicates the first, mineral specific catalysis, was not the process that produced these organic rims. Our results are consistent with this primitive organic matter being produced by the alternative process of condensation of C-bearing ices onto the grain surfaces and production of refractory organic matter by UV or other ionizing radiation bombardment of the ices [4]. The processes by which primitive grains aggregate to form the first dust of our Solar System are not well understood. Collision experiments indicate that bare rocky grains bounce apart at collision speeds ¡30 to 50 m/s and shatter at larger speeds [5]. However, experiments indicate grains coated with organic matter stick quite easily, even at speeds up to 5 m/s -an order of magnitude higher than the speed at which silicate grains accrete [6]. Thus the organic grain coatings we identified likely played a critical role in dust aggregation in the early Solar System. References: [1] Ishii, H. et al. Science 2009. [2] Flynn, G. J. et al. (2003) Geochim. Cosmochim. Acta, 67, 4791-4806. [3] Keller L. P. et al. GCA (2004) Geochim. Cosmochim. Acta, 68, 2577-2589. [4] Bernstein, M. P. et al. (1995) Astrophys. J., 454, 327-344. [5] Hartmann, W. K. (1978) Icarus, 33, 50-61. [6] Kudo, T. et al. (2002) Meteoritics Planet. Sci., 37, 1975-1983.

A mutli-technique search for the most primitive CO chondrites

NASA Astrophysics Data System (ADS)

Alexander, C. M. O'D.; Greenwood, R. C.; Bowden, R.; Gibson, J. M.; Howard, K. T.; Franchi, I. A.

2018-01-01

As part of a study to identify the most primitive COs and to look for weakly altered CMs amongst the COs, we have conducted a multi-technique study of 16 Antarctic meteorites that had been classified as primitive COs. For this study, we have determined: (1) the bulk H, C and N abundances and isotopes, (2) bulk O isotopic compositions, (3) bulk modal mineralogies, and (4) for some selected samples the abundances and compositions of their insoluble organic matter (IOM). Two of the 16 meteorites do appear to be CMs - BUC 10943 seems to be a fairly typical CM, while MIL 090073 has probably been heated. Of the COs, DOM 08006 appears to be the most primitive CO identified to date and is quite distinct from the other members of its pairing group. The other COs fall into two groups that are less primitive than DOM 08006 and ALH 77307, the previously most primitive CO. The first group is composed of members of the DOM 08004 pairing group, except DOM 08006. The second group is composed of meteorites belonging to the MIL 03377 and MIL 07099 pairing groups. These two pairing groups should probably be combined. There is a dichotomy in the bulk O isotopes between the primitive (all Antarctic finds) and the more metamorphosed COs (mostly falls). This dichotomy can only partly be explained by the terrestrial weathering experienced by the primitive Antarctic samples. It seems that the more equilibrated samples interacted to a greater extent with 16O-poor material, probably water, than the more primitive meteorites.