Assessment of Needs of Adults with Developmental Disabilities in Skilled Nursing and Intermediate Care Facilities in Illinois.

ERIC Educational Resources Information Center

Uehara, Edwina S.; And Others

1991-01-01

This study evaluated 2,815 adults with developmental disabilities in 328 Illinois intermediate care and skilled nursing facilities. Only 10 percent were determined to be appropriately placed in medical settings; 27 percent were enrolled in day training programs; and many individuals recommended for alternative residential settings had medical and…

Evaluation of biological effects of intermediate frequency magnetic field on differentiation of embryonic stem cell.

PubMed

Yoshie, Sachiko; Ogasawara, Yuki; Ikehata, Masateru; Ishii, Kazuyuki; Suzuki, Yukihisa; Wada, Keiji; Wake, Kanako; Nakasono, Satoshi; Taki, Masao; Ohkubo, Chiyoji

2016-01-01

The embryotoxic effect of intermediate frequency (IF) magnetic field (MF) was evaluated using murine embryonic stem (ES) cells and fibroblast cells based on the embryonic stem cell test (EST). The cells were exposed to 21 kHz IF-MF up to magnetic flux density of 3.9 mT during the cell proliferation process (7 days) or the cell differentiation process (10 days) during which an embryonic body differentiated into myocardial cells. As a result, there was no significant difference in the cell proliferation between sham- and IF-MF-exposed cells for both ES and fibroblast cells. Similarly, the ratio of the number of ES-derived cell aggregates differentiated to myocardial cells to total number of cell aggregates was not changed by IF-MF exposure. In addition, the expressions of a cardiomyocytes-specific gene, Myl2 , and an early developmental gene, Hba-x , in the exposed cell aggregate were not altered. Since the magnetic flux density adopted in this study is much higher than that generated by an inverter of the electrical railway, an induction heating (IH) cooktop, etc . in our daily lives, these results suggested that IF-MF in which the public is exposed to in general living environment would not have embryotoxic effect.

Further studies on cortical tangential migration in wild type and Pax-6 mutant mice.

PubMed

Jiménez, D; López-Mascaraque, L; de Carlos, J A; Valverde, F

2002-01-01

In this study we present new data concerning the tangential migration from the medial and lateral ganglionic eminences (MGE and LGE) to the cerebral cortex during development. We have used Calbindin as a useful marker to follow the itinerary of tangential migratory cells during early developmental stages in wild-type and Pax-6 homozygous mutant mice. In the wild-type mice, at early developmental stages, migrating cells advance through the intermediate zone (IZ) and preplate (PP). At more advanced stages, migrating cells were present in the subplate (SP) and cortical plate (CP) to reach the entire developing cerebral cortex. We found that, in the homozygous mutant mice (Pax-6(Sey-Neu)/Pax-6(Sey-Neu)), this tangential migration is severely affected at early developmental stages: migrating cells were absent in the IZ, which were only found some days later, suggesting that in the mutant mice, there is a temporal delay in tangential migration. We have also defined some possible mechanisms to explain certain migratory routes from the basal telencephalon to the cerebral cortex. We describe the existence of two factors, which we consider to be essential for the normal migration; the first one is the cell adhesion molecule PSA-NCAM, whose role in other migratory systems is well known. The second factor is Robo-2, whose expression delimits a channel for the passage of migratory cells from the basal telencephalon to the cerebral cortex.

The making of a lymphocyte: the choice among disparate cell fates and the IKAROS enigma.

PubMed

Georgopoulos, Katia

2017-03-01

Lymphocyte differentiation is set to produce myriad immune effector cells with the ability to respond to multitudinous foreign substances. The uniqueness of this developmental system lies in not only the great diversity of cellular functions that it can generate but also the ability of its differentiation intermediates and mature effector cells to expand upon demand, thereby providing lifelong immunity. Surprisingly, the goals of this developmental system are met by a relatively small group of DNA-binding transcription factors that work in concert to control the timing and magnitude of gene expression and fulfill the demands for cellular specialization, expansion, and maintenance. The cellular and molecular mechanisms through which these lineage-promoting transcription factors operate have been a focus of basic research in immunology. The mechanisms of development discerned in this effort are guiding clinical research on disorders with an immune cell base. Here, I focus on IKAROS, one of the earliest regulators of lymphoid lineage identity and a guardian of lymphocyte homeostasis. © 2017 Georgopoulos; Published by Cold Spring Harbor Laboratory Press.

RELATIONSHIP OF GERMINAL CENTERS IN LYMPHOID TISSUE TO IMMUNOLOGICAL MEMORY

PubMed Central

Wakefield, J. D.; Thorbecke, G. J.

1968-01-01

The fate, proliferation, and developmental potentialities of cell suspensions made from white pulp containing large germinal centers have been studied in the mouse by transfer of cells labeled with thymidine-3H to lethally irradiated, syngeneic recipients. Radioautographic analyses were made using both smears and sections of a variety of tissues. Thymidine-3H-labeling patterns of white pulp showed that, initially, labeling occurred in a majority of blast and "intermediate cells" but in very few or no small lymphocytes. After intravenous transfer, most of the labeled cells localized in the lymphoid tissues of spleen, lymph nodes, and Peyer's patches. Few cells migrated to the thymus, lung, liver, and intestinal mucosa. Both after intravenous and after intraperitoneal transfer there was a rapid increase in the incidence of labeled small lymphocytes and a decrease of labeled blasts and intermediate cells. This was accompanied by an increase in the grain count of the small lymphocytes and a progressive decrease in the grain counts of the blast cells. Exposure of nonlabeled donor cells to thymidine-3H at various time intervals after transfer indicated that dividing cells were present early after transfer but that their incidence progressively decreased. Between 24 and 48 hr, very little cell division was detectable. PMID:5662013

Differential expression of the intermediate filament protein nestin during renal development and its localization in adult podocytes.

PubMed

Chen, Jing; Boyle, Scott; Zhao, Min; Su, Wei; Takahashi, Keiko; Davis, Linda; Decaestecker, Mark; Takahashi, Takamune; Breyer, Matthew D; Hao, Chuan-Ming

2006-05-01

Nestin, an intermediate filament protein, is widely used as stem cell marker. Nestin has been shown to interact with other cytoskeleton proteins, suggesting a role in regulating cellular cytoskeletal structure. These studies examined renal nestin localization and developmental expression in mice. In developing kidney, anti-nestin antibody revealed strong immunoreactivity in vascular cleft of the S-shaped body and vascular tuft of capillary loop-stage glomerulus. The nestin-positive structures also were labeled by endothelial cell markers FLK1 and CD31 in immature glomeruli. Nestin was not detected in epithelial cells of immature glomeruli. In contrast, in mature glomerular, nestin immunoreactivity was observed only outside laminin-positive glomerular basement membrane, and co-localized with nephrin, consistent with podocyte nestin expression. In adult kidney, podocytes were the only cells that exhibited persistent nestin expression. Nestin was not detected in ureteric bud and its derivatives throughout renal development. Cell lineage studies, using a nestin promoter-driven Cre mouse and a ROSA26 reporter mouse, showed a strong beta-galactosidase activity in intermediate mesoderm in an embryonic day 10 embryo and all of the structures except those that were derived from ureteric bud in embryonic kidney through adult kidney. These studies show that nestin is expressed in progenitors of glomerular endothelial cells and renal progenitors that are derived from metanephric mesenchyme. In the adult kidney, nestin expression is restricted to differentiated podocytes, suggesting that nestin could play an important role in maintaining the structural integrity of the podocytes.

Human natural killer cell development in secondary lymphoid tissues

PubMed Central

Freud, Aharon G.; Yu, Jianhua; Caligiuri, Michael A.

2014-01-01

For nearly a decade it has been appreciated that critical steps in human natural killer (NK) cell development likely occur outside of the bone marrow and potentially necessitate distinct microenvironments within extramedullary tissues. The latter include the liver and gravid uterus as well as secondary lymphoid tissues such as tonsils and lymph nodes. For as yet unknown reasons these tissues are naturally enriched with NK cell developmental intermediates (NKDI) that span a maturation continuum starting from an oligopotent CD34+CD45RA+ hematopoietic precursor cell to a cytolytic mature NK cell. Indeed despite the detection of NKDI within the aforementioned tissues, relatively little is known about how, why, and when these tissues may be most suited to support NK cell maturation and how this process fits in with other components of the human immune system. With the discovery of other innate lymphoid subsets whose immunophenotypes overlap with those of NKDI, there is also need to revisit and potentially re-characterize the basic immunophenotypes of the stages of the human NK cell developmental pathway in vivo. In this review, we provide an overview of human NK cell development in secondary lymphoid tissues and discuss the many questions that remain to be answered in this exciting field. PMID:24661538

Directed differentiation of embryonic stem cells using a bead-based combinatorial screening method.

PubMed

Tarunina, Marina; Hernandez, Diana; Johnson, Christopher J; Rybtsov, Stanislav; Ramathas, Vidya; Jeyakumar, Mylvaganam; Watson, Thomas; Hook, Lilian; Medvinsky, Alexander; Mason, Chris; Choo, Yen

2014-01-01

We have developed a rapid, bead-based combinatorial screening method to determine optimal combinations of variables that direct stem cell differentiation to produce known or novel cell types having pre-determined characteristics. Here we describe three experiments comprising stepwise exposure of mouse or human embryonic cells to 10,000 combinations of serum-free differentiation media, through which we discovered multiple novel, efficient and robust protocols to generate a number of specific hematopoietic and neural lineages. We further demonstrate that the technology can be used to optimize existing protocols in order to substitute costly growth factors with bioactive small molecules and/or increase cell yield, and to identify in vitro conditions for the production of rare developmental intermediates such as an embryonic lymphoid progenitor cell that has not previously been reported.

The Broad Spectrum of Human Natural Killer Cell Diversity.

PubMed

Freud, Aharon G; Mundy-Bosse, Bethany L; Yu, Jianhua; Caligiuri, Michael A

2017-11-21

Natural killer (NK) cells provide protection against infectious pathogens and cancer. For decades it has been appreciated that two major NK cell subsets (CD56 bright and CD56 dim ) exist in humans and have distinct anatomical localization patterns, phenotypes, and functions in immunity. In light of this traditional NK cell dichotomy, it is now clear that the spectrum of human NK cell diversity is much broader than originally appreciated as a result of variegated surface receptor, intracellular signaling molecule, and transcription factor expression; tissue-specific imprinting; and foreign antigen exposure. The recent discoveries of tissue-resident NK cell developmental intermediates, non-NK innate lymphoid cells, and the capacity for NK cells to adapt and differentiate into long-lived memory cells has added further complexity to this field. Here we review our current understanding of the breadth and generation of human NK cell diversity. Copyright © 2017 Elsevier Inc. All rights reserved.

Factors Associated with Living in Developmental Centers in California

ERIC Educational Resources Information Center

Harrington, Charlene; Kang, Taewoon; Chang, Jamie

2009-01-01

This study examined need, predisposing, market, and regional factors that predicted the likelihood of individuals with developmental disabilities living in state developmental centers (DCs) compared with living at home, in community care, or in intermediate care (ICFs) and other facilities. Secondary data analysis using logistic regression models…

The unique structural and biochemical development of single cell C4 photosynthesis along longitudinal leaf gradients in Bienertia sinuspersici and Suaeda aralocaspica (Chenopodiaceae)

PubMed Central

Koteyeva, Nuria K.; Voznesenskaya, Elena V.; Berry, James O.; Cousins, Asaph B.; Edwards, Gerald E.

2016-01-01

Temporal and spatial patterns of photosynthetic enzyme expression and structural maturation of chlorenchyma cells along longitudinal developmental gradients were characterized in young leaves of two single cell C4 species, Bienertia sinuspersici and Suaeda aralocaspica. Both species partition photosynthetic functions between distinct intracellular domains. In the C4-C domain, C4 acids are formed in the C4 cycle during capture of atmospheric CO2 by phosphoenolpyruvate carboxylase. In the C4-D domain, CO2 released in the C4 cycle via mitochondrial NAD-malic enzyme is refixed by Rubisco. Despite striking differences in origin and intracellular positioning of domains, these species show strong convergence in C4 developmental patterns. Both progress through a gradual developmental transition towards full C4 photosynthesis, with an associated increase in levels of photosynthetic enzymes. Analysis of longitudinal sections showed undeveloped domains at the leaf base, with Rubisco rbcL mRNA and protein contained within all chloroplasts. The two domains were first distinguishable in chlorenchyma cells at the leaf mid-regions, but still contained structurally similar chloroplasts with equivalent amounts of rbcL mRNA and protein; while mitochondria had become confined to just one domain (proto-C4-D). The C4 state was fully formed towards the leaf tips, Rubisco transcripts and protein were compartmentalized specifically to structurally distinct chloroplasts in the C4-D domains indicating selective regulation of Rubisco expression may occur by control of transcription or stability of rbcL mRNA. Determination of CO2 compensation points showed young leaves were not functionally C4, consistent with cytological observations of the developmental progression from C3 default to intermediate to C4 photosynthesis. PMID:26957565

Comparison of Gene Expression in Human Embryonic Stem Cells, hESC-Derived Mesenchymal Stem Cells and Human Mesenchymal Stem Cells.

PubMed

Barbet, Romain; Peiffer, Isabelle; Hatzfeld, Antoinette; Charbord, Pierre; Hatzfeld, Jacques A

2011-01-01

We present a strategy to identify developmental/differentiation and plasma membrane marker genes of the most primitive human Mesenchymal Stem Cells (hMSCs). Using sensitive and quantitative TaqMan Low Density Arrays (TLDA) methodology, we compared the expression of 381 genes in human Embryonic Stem Cells (hESCs), hESC-derived MSCs (hES-MSCs), and hMSCs. Analysis of differentiation genes indicated that hES-MSCs express the sarcomeric muscle lineage in addition to the classical mesenchymal lineages, suggesting they are more primitive than hMSCs. Transcript analysis of membrane antigens suggests that IL1R1(low), BMPR1B(low), FLT4(low), LRRC32(low), and CD34 may be good candidates for the detection and isolation of the most primitive hMSCs. The expression in hMSCs of cytokine genes, such as IL6, IL8, or FLT3LG, without expression of the corresponding receptor, suggests a role for these cytokines in the paracrine control of stem cell niches. Our database may be shared with other laboratories in order to explore the considerable clinical potential of hES-MSCs, which appear to represent an intermediate developmental stage between hESCs and hMSCs.

Directed Differentiation of Embryonic Stem Cells Using a Bead-Based Combinatorial Screening Method

PubMed Central

Tarunina, Marina; Hernandez, Diana; Johnson, Christopher J.; Rybtsov, Stanislav; Ramathas, Vidya; Jeyakumar, Mylvaganam; Watson, Thomas; Hook, Lilian; Medvinsky, Alexander; Mason, Chris; Choo, Yen

2014-01-01

We have developed a rapid, bead-based combinatorial screening method to determine optimal combinations of variables that direct stem cell differentiation to produce known or novel cell types having pre-determined characteristics. Here we describe three experiments comprising stepwise exposure of mouse or human embryonic cells to 10,000 combinations of serum-free differentiation media, through which we discovered multiple novel, efficient and robust protocols to generate a number of specific hematopoietic and neural lineages. We further demonstrate that the technology can be used to optimize existing protocols in order to substitute costly growth factors with bioactive small molecules and/or increase cell yield, and to identify in vitro conditions for the production of rare developmental intermediates such as an embryonic lymphoid progenitor cell that has not previously been reported. PMID:25251366

Phenotypic Checkpoints Regulate Neuronal Development

PubMed Central

Ben-Ari, Yehezkel; Spitzer, Nicholas C.

2010-01-01

Nervous system development proceeds by sequential gene expression mediated by cascades of transcription factors in parallel with sequences of patterned network activity driven by receptors and ion channels. These sequences are cell type- and developmental stage-dependent and modulated by paracrine actions of substances released by neurons and glia. How and to what extent these sequences interact to enable neuronal network development is not understood. Recent evidence demonstrates that CNS development requires intermediate stages of differentiation providing functional feedback that influences gene expression. We suggest that embryonic neuronal functions constitute a series of phenotypic checkpoint signatures; neurons failing to express these functions are delayed or developmentally arrested. Such checkpoints are likely to be a general feature of neuronal development and may constitute presymptomatic signatures of neurological disorders when they go awry. PMID:20864191

An in vitro model of intestinal infection reveals a developmentally regulated transcriptome of Toxoplasma sporozoites and a NF-κB-like signature in infected host cells

PubMed Central

Sagawa, Janelle M.; Fritz, Heather M.; Boothroyd, John C.

2017-01-01

Toxoplasmosis is a zoonotic infection affecting approximately 30% of the world’s human population. After sexual reproduction in the definitive feline host, Toxoplasma oocysts, each containing 8 sporozoites, are shed into the environment where they can go on to infect humans and other warm-blooded intermediate hosts. Here, we use an in vitro model to assess host transcriptomic changes that occur in the earliest stages of such infections. We show that infection of rat intestinal epithelial cells with mature sporozoites primarily results in higher expression of genes associated with Tumor Necrosis Factor alpha (TNFα) signaling via NF-κB. Furthermore, we find that, consistent with their biology, these mature, invaded sporozoites display a transcriptome intermediate between the previously reported day 10 oocysts and that of their tachyzoite counterparts. Thus, this study uncovers novel host and pathogen factors that may be critical for the establishment of a successful intracellular niche following sporozoite-initiated infection. PMID:28362800

24 CFR 891.505 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-04-01

... reservation. Except for intermediate care facilities for the mentally retarded and individuals with related conditions, this term does not include nursing homes, hospitals, intermediate care facilities, or... designed for the physically disabled, developmentally disabled, or chronically mentally ill depending upon...

24 CFR 891.505 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-04-01

... reservation. Except for intermediate care facilities for the mentally retarded and individuals with related conditions, this term does not include nursing homes, hospitals, intermediate care facilities, or... designed for the physically disabled, developmentally disabled, or chronically mentally ill depending upon...

24 CFR 891.505 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-04-01

... reservation. Except for intermediate care facilities for the mentally retarded and individuals with related conditions, this term does not include nursing homes, hospitals, intermediate care facilities, or... designed for the physically disabled, developmentally disabled, or chronically mentally ill depending upon...

24 CFR 891.505 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-04-01

... reservation. Except for intermediate care facilities for the mentally retarded and individuals with related conditions, this term does not include nursing homes, hospitals, intermediate care facilities, or... designed for the physically disabled, developmentally disabled, or chronically mentally ill depending upon...

24 CFR 891.505 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-04-01

... reservation. Except for intermediate care facilities for the mentally retarded and individuals with related conditions, this term does not include nursing homes, hospitals, intermediate care facilities, or... designed for the physically disabled, developmentally disabled, or chronically mentally ill depending upon...

Computational Modeling and Simulation of Genital Tubercle ...

EPA Pesticide Factsheets

Hypospadias is a developmental defect of urethral tube closure that has a complex etiology. Here, we describe a multicellular agent-based model of genital tubercle development that simulates urethrogenesis from the urethral plate stage to urethral tube closure in differentiating male embryos. The model, constructed in CompuCell3D, implemented spatially dynamic signals from SHH, FGF10, and androgen signaling pathways. These signals modulated stochastic cell behaviors, such as differential adhesion, cell motility, proliferation, and apoptosis. Urethral tube closure was an emergent property of the model that was quantitatively dependent on SHH and FGF10 induced effects on mesenchymal proliferation and endodermal apoptosis, ultimately linked to androgen signaling. In the absence of androgenization, simulated genital tubercle development defaulted to the female condition. Intermediate phenotypes associated with partial androgen deficiency resulted in incomplete closure. Using this computer model, complex relationships between urethral tube closure defects and disruption of underlying signaling pathways could be probed theoretically in multiplex disturbance scenarios and modeled into probabilistic predictions for individual risk for hypospadias and potentially other developmental defects of the male genital tubercle. We identify the minimal molecular network that determines the outcome of male genital tubercle development in mice.

Functional genomic characterization of neoblast-like stem cells in larval Schistosoma mansoni

PubMed Central

Wang, Bo; Collins, James J; Newmark, Phillip A

2013-01-01

Schistosomes infect hundreds of millions of people in the developing world. Transmission of these parasites relies on a stem cell-driven, clonal expansion of larvae inside a molluscan intermediate host. How this novel asexual reproductive strategy relates to current models of stem cell maintenance and germline specification is unclear. Here, we demonstrate that this proliferative larval cell population (germinal cells) shares some molecular signatures with stem cells from diverse organisms, in particular neoblasts of planarians (free-living relatives of schistosomes). We identify two distinct germinal cell lineages that differ in their proliferation kinetics and expression of a nanos ortholog. We show that a vasa/PL10 homolog is required for proliferation and maintenance of both populations, whereas argonaute2 and a fibroblast growth factor receptor-encoding gene are required only for nanos-negative cells. Our results suggest that an ancient stem cell-based developmental program may have enabled the evolution of the complex life cycle of parasitic flatworms. DOI: http://dx.doi.org/10.7554/eLife.00768.001 PMID:23908765

Ultrastructure of the developing fibrocartilage of the os penis of rat.

PubMed

Izumi, K; Yamaoka, I; Murakami, R

2000-02-01

Development of the fibrocartilage of the os penis of rat was studied by transmission electron microscopy. Prepubertal (0-4 weeks of development) and pubertal (4-8 weeks of development) males were examined. Effects of castration on the development of the fibrocartilage were also examined. During the first 0-4 weeks of development, cells in the primordium of the fibrocartilage became large and the cytoplasm had well-developed rough endoplasmic reticulum (rER) and many intermediate filaments. Collagen fibers increased markedly in amount in the extracellular matrix (ECM) during the period. For 4-6 weeks, when gonadal secretion of androgens increases, the cells developed into mature chondrocytes with lacunae. Collagenous bundles were pushed away from the lacunae, resulting in a characteristic appearance of this fibrocartilage. The cytoplasm of the mature chondrocytes of the fibrocartilage was characterized by many intermediate filaments, oil droplets, glycogen granules, and well-developed rER. At 6 weeks, calcification started on the cell membrane of the mature chondrocytes. At 8 weeks, a large part of the cartilage matrix was calcified. Matrix vesicles that originate from degenerated chondrocytes were found in the ECM of decalcified samples. In castrated males, cells of the primordium of the fibrocartilage ceased further development after castration. Intermediate filaments were still abundant in the cytoplasm and collagen fibers increased even after castration, but mature chondrocytes never differentiated. There were no signs of matrix vesicle formation, calcification, or cell degeneration in the fibrocartilage primordium. The developmental process of the fibrocartilage can be subdivided into two phases: collagenous matrix formation during the prepubertal period (0-4 weeks), and maturation of chondrocytes and calcification after puberty (4-8 weeks). Copyright 2000 Wiley-Liss, Inc.

Generation of functional podocytes from human induced pluripotent stem cells.

PubMed

Ciampi, Osele; Iacone, Roberto; Longaretti, Lorena; Benedetti, Valentina; Graf, Martin; Magnone, Maria Chiara; Patsch, Christoph; Xinaris, Christodoulos; Remuzzi, Giuseppe; Benigni, Ariela; Tomasoni, Susanna

2016-07-01

Generating human podocytes in vitro could offer a unique opportunity to study human diseases. Here, we describe a simple and efficient protocol for obtaining functional podocytes in vitro from human induced pluripotent stem cells. Cells were exposed to a three-step protocol, which induced their differentiation into intermediate mesoderm, then into nephron progenitors and, finally, into mature podocytes. After differentiation, cells expressed the main podocyte markers, such as synaptopodin, WT1, α-Actinin-4, P-cadherin and nephrin at the protein and mRNA level, and showed the low proliferation rate typical of mature podocytes. Exposure to Angiotensin II significantly decreased the expression of podocyte genes and cells underwent cytoskeleton rearrangement. Cells were able to internalize albumin and self-assembled into chimeric 3D structures in combination with dissociated embryonic mouse kidney cells. Overall, these findings demonstrate the establishment of a robust protocol that, mimicking developmental stages, makes it possible to derive functional podocytes in vitro. Copyright © 2016. Published by Elsevier B.V.

A Concurrent Support Course for Intermediate Algebra

ERIC Educational Resources Information Center

Cooper, Cameron I.

2011-01-01

This article summarizes the creation and implementation of a concurrent support class for TRS 92--Intermediate Algebra, a developmental mathematics course at Fort Lewis College in Durango, Colorado. The concurrent course outlined in this article demonstrates a statistically significant increase in student success rates since its inception.…

Which visual functions depend on intermediate visual regions? Insights from a case of developmental visual form agnosia.

PubMed

Gilaie-Dotan, Sharon

2016-03-01

A key question in visual neuroscience is the causal link between specific brain areas and perceptual functions; which regions are necessary for which visual functions? While the contribution of primary visual cortex and high-level visual regions to visual perception has been extensively investigated, the contribution of intermediate visual areas (e.g. V2/V3) to visual processes remains unclear. Here I review more than 20 visual functions (early, mid, and high-level) of LG, a developmental visual agnosic and prosopagnosic young adult, whose intermediate visual regions function in a significantly abnormal fashion as revealed through extensive fMRI and ERP investigations. While expectedly, some of LG's visual functions are significantly impaired, some of his visual functions are surprisingly normal (e.g. stereopsis, color, reading, biological motion). During the period of eight-year testing described here, LG trained on a perceptual learning paradigm that was successful in improving some but not all of his visual functions. Following LG's visual performance and taking into account additional findings in the field, I propose a framework for how different visual areas contribute to different visual functions, with an emphasis on intermediate visual regions. Thus, although rewiring and plasticity in the brain can occur during development to overcome and compensate for hindering developmental factors, LG's case seems to indicate that some visual functions are much less dependent on strict hierarchical flow than others, and can develop normally in spite of abnormal mid-level visual areas, thereby probably less dependent on intermediate visual regions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Classical Conditioning of Profoundly Retarded, Multiply Handicapped Children.

ERIC Educational Resources Information Center

Hogg, J.; And Others

1979-01-01

Conditioning was established for the two most developmentally advanced Ss, and the intermediate pair showed different patterns of orienting response to the conditioned stimulus but no evidence of conditioning. The fifth and most developmentally delayed child did not respond to the stimuli. Journal Availability: J. B. Lippincott Co., East…

Developmental stages of fish blood flukes, Cardicola forsteri and Cardicola opisthorchis (Trematoda: Aporocotylidae), in their polychaete intermediate hosts collected at Pacific bluefin tuna culture sites in Japan.

PubMed

Ogawa, Kazuo; Shirakashi, Sho; Tani, Kazuki; Shin, Sang Phil; Ishimaru, Katsuya; Honryo, Tomoki; Sugihara, Yukitaka; Uchida, Hiro'omi

2017-02-01

Farming of Pacific bluefin tuna (PBT), Thunnus orientalis, is a rapidly growing industry in Japan. Aporocotylid blood flukes of the genus Cardicola comprising C. orientalis, C. opisthorchis and C. forsteri are parasites of economic importance for PBT farming. Recently, terebellid polychaetes have been identified as the intermediate hosts for all these parasites. We collected infected polychaetes, Terebella sp., the intermediate host of C. opisthorchis, from ropes and floats attached to tuna cages in Tsushima, Nagasaki Prefecture, Japan. Also, Neoamphitrite vigintipes (formerly as Amphitrite sp. sensu Shirakashi et al., 2016), the intermediate host of C. forsteri, were collected from culture cages in Kushimoto, Wakayama Prefecture, Japan. The terebellid intermediate hosts harbored the sporocysts and cercariae in their body cavity. Developmental stages of these blood flukes were molecularly identified using species specific PCR primers. In this paper, we describe the cercaria and sporocyst stages of C. opisthorchis and C. forsteri and compare their morphological characteristics among three Cardicola blood flukes infecting PBT. We also discuss phylogenetic relations of the six genera of the terebellid intermediate hosts (Artacama, Lanassa, Longicarpus, Terebella, Nicolea and Neoamphitrite) of blood flukes infecting marine fishes, based on their morphological characters. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Expression of a Rho guanine nucleotide exchange factor, Ect2, in the developing mouse pituitary.

PubMed

Islam, M S; Tsuji, T; Higashida, C; Takahashi, M; Higashida, H; Koizumi, K

2010-05-01

The pituitary gland is a highly mitotically active tissue after birth. Various cell types are known to undergo proliferation in the anterior pituitary. However, little is known about the mechanisms regulating mitotic activity in this tissue. When searching for genes specifically expressed in the pituitary gland among those that we previously screened in Drosophila, we found epithelial cell-transforming gene 2 (Ect2). Ect2 is a guanine nucleotide exchange factor for Rho GTPases, which is known to play an essential role in cytokinesis. Although there have been many cellular studies regarding the function of Ect2, the temporal and spatial expression patterns of Ect2 in vivo have not been determined. In the present study, we examined the postnatal developmental expression of Ect2 in the mouse pituitary. Enhanced Ect2 expression was detected in the mouse pituitary gland during the first 3 weeks after birth, which coincided well with the period of rapid pituitary expansion associated with increased growth rate. Immunostaining analysis showed that Ect2-expressing cells were distributed in the anterior and intermediate lobes, but not the posterior lobe, of the pituitary. These Ect2-expressing cells frequently incorporated the thymidine analogue, EdU (5-ethynyl-2'-deoxyuridine), indicating that these cells were mitotically active. Taken together, the results demonstrate the functional role of Ect2 in postnatal proliferating cells in the two lobes of the pituitary, thereby suggesting roles in developmental growth of the mammalian pituitary.

Retinal Determination genes function along with cell-cell signals to regulate Drosophila eye development: examples of multi-layered regulation by Master Regulators

PubMed Central

Baker, Nicholas E.; Firth, Lucy C.

2015-01-01

It is thought that Retinal Determination gene products define the response made to cell-cell signals within the eye developmental field by binding to enhancers of genes that are also regulated by cell-cell signaling pathways. In Drosophila, Retinal Determination genes including Eyeless, teashirt, eyes absent, dachsous and sine oculis, are required for normal eye development and can induce ectopic eyes when mis-expressed. Characterization of the enhancers responsible for eye expression of the hedgehog, shaven, and atonal genes, as well as the dynamics of Retinal Determination gene expression themselves, now suggest a multilayered network whereby transcriptional regulation by either Retinal Determination genes or cell-cell signaling pathways can sometimes be indirect and mediated by other transcription factor intermediates. In this updated view of the interaction between extracellular information and cell intrinsic programs during development, regulation of individual genes might sometimes be several steps removed from either the Retinal Determination genes or cell-cell signaling pathways that nevertheless govern their expression. PMID:21607995

Using e-Learning Platforms for Mastery Learning in Developmental Mathematics Courses

ERIC Educational Resources Information Center

Boggs, Stacey; Shore, Mark; Shore, JoAnna

2004-01-01

Many colleges and universities have adopted e-learning platforms to utilize computers as an instructional tool in developmental (i.e., beginning and intermediate algebra) mathematics courses. An e-learning platform is a computer program used to enhance course instruction via computers and the Internet. Allegany College of Maryland is currently…

Costs of Epilepsy in an Intermediate Care Facility for Persons with Mental Retardation.

ERIC Educational Resources Information Center

Burke, Thomas A.; McKee, Jerry R.; Pathak, Dev S.; Donahue, Rafe M. J.; Parasuraman, T. V.; Batenhorst, Alice S.

1999-01-01

A study compared the cost of caring for 50 institutionalized persons with developmental disabilities and epilepsy with 50 individuals with developmental disabilities. Costs attributable to epilepsy were found to be approximately $825.00 and $918.00 per person over a six-month period. Personnel, drugs, hospitalization, and laboratories/procures…

Pluripotent stem cell-derived radial glia-like cells as stable intermediate for efficient generation of human oligodendrocytes.

PubMed

Gorris, Raphaela; Fischer, Julia; Erwes, Kim Lina; Kesavan, Jaideep; Peterson, Daniel A; Alexander, Michael; Nöthen, Markus M; Peitz, Michael; Quandel, Tamara; Karus, Michael; Brüstle, Oliver

2015-12-01

Neural precursor cells (NPCs) derived from human pluripotent stem cells (hPSCs) represent an attractive tool for the in vitro generation of various neural cell types. However, the developmentally early NPCs emerging during hPSC differentiation typically show a strong propensity for neuronal differentiation, with more limited potential for generating astrocytes and, in particular, for generating oligodendrocytes. This phenomenon corresponds well to the consecutive and protracted generation of neurons and GLIA during normal human development. To obtain a more gliogenic NPC type, we combined growth factor-mediated expansion with pre-exposure to the differentiation-inducing agent retinoic acid and subsequent immunoisolation of CD133-positive cells. This protocol yields an adherent and self-renewing population of hindbrain/spinal cord radial glia (RG)-like neural precursor cells (RGL-NPCs) expressing typical neural stem cell markers such as nestin, ASCL1, SOX2, and PAX6 as well as RG markers BLBP, GLAST, vimentin, and GFAP. While RGL-NPCs maintain the ability for tripotential differentiation into neurons, astrocytes, and oligodendrocytes, they exhibit greatly enhanced propensity for oligodendrocyte generation. Under defined differentiation conditions promoting the expression of the major oligodendrocyte fate-determinants OLIG1/2, NKX6.2, NKX2.2, and SOX10, RGL-NPCs efficiently convert into NG2-positive oligodendroglial progenitor cells (OPCs) and are subsequently capable of in vivo myelination. Representing a stable intermediate between PSCs and OPCs, RGL-NPCs expedite the generation of PSC-derived oligodendrocytes with O4-, 4860-, and myelin basic protein (MBP)-positive cells that already appear within 7 weeks following growth factor withdrawal-induced differentiation. Thus, RGL-NPCs may serve as robust tool for time-efficient generation of human oligodendrocytes from embryonic and induced pluripotent stem cells. © 2015 Wiley Periodicals, Inc.

Single-cell RNA-seq analysis unveils a prevalent epithelial/mesenchymal hybrid state during mouse organogenesis.

PubMed

Dong, Ji; Hu, Yuqiong; Fan, Xiaoying; Wu, Xinglong; Mao, Yunuo; Hu, Boqiang; Guo, Hongshan; Wen, Lu; Tang, Fuchou

2018-03-14

Organogenesis is crucial for proper organ formation during mammalian embryonic development. However, the similarities and shared features between different organs and the cellular heterogeneity during this process at single-cell resolution remain elusive. We perform single-cell RNA sequencing analysis of 1916 individual cells from eight organs and tissues of E9.5 to E11.5 mouse embryos, namely, the forebrain, hindbrain, skin, heart, somite, lung, liver, and intestine. Based on the regulatory activities rather than the expression patterns, all cells analyzed can be well classified into four major groups with epithelial, mesodermal, hematopoietic, and neuronal identities. For different organs within the same group, the similarities and differences of their features and developmental paths are revealed and reconstructed. We identify mutual interactions between epithelial and mesenchymal cells and detect epithelial cells with prevalent mesenchymal features during organogenesis, which are similar to the features of intermediate epithelial/mesenchymal cells during tumorigenesis. The comprehensive transcriptome at single-cell resolution profiled in our study paves the way for future mechanistic studies of the gene-regulatory networks governing mammalian organogenesis.

Development and Stem Cells of the Esophagus

PubMed Central

Zhang, Yongchun; Jiang, Ming; Kim, Eugene; Lin, Sijie; Liu, Kuancan; Lan, Xiaopeng; Que, Jianwen

2017-01-01

The esophagus is derived from the anterior portion of the developmental intermediate foregut, a structure that also gives rise to other organs including the trachea, lung, and stomach. Genetic studies have shown that multiple signaling pathways (e.g. Bmp) and transcription factors (e.g. SOX2) are required for the separation of the esophagus from the neighboring respiratory system. Notably, some of these signaling pathways and transcription factors continue to play essential roles in the subsequent morphogenesis of the esophageal epithelium which undergoes a simple columnar-to-stratified squamous conversion. Reactivation of the relevant signaling pathways has also been associated with pathogenesis of esophageal diseases that affect the epithelium and its stem cells in adults. In this review we will summarize these findings. We will also discuss new data regarding the cell-of-origin for the striated and smooth muscles surrounding the esophagus and how they are differentiated from the mesenchyme during development. PMID:28007661

Effectiveness of a Caregiver Education Program on Providing Oral Care to Individuals with Intellectual and Developmental Disabilities

ERIC Educational Resources Information Center

Fickert, Nancy A.; Ross, Diana

2012-01-01

Caregivers who work in community living arrangements or intermediate care facilities are responsible for the oral hygiene of individuals with intellectual and developmental disabilities. Oral hygiene training programs do not exist in many organizations, despite concerns about the oral care of this population. The purpose of this study was to…

78 FR 78731 - Indoxacarb; Pesticide Tolerances

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-27

.../kg/day Chronic RfD = 0.02 Weight of evidence approach was UFA = 10x mg/kg/day. used from four studies..... Weight of evidence approach was 30 days), intermediate-term (1 UFA = 10x used from four studies: to 6..., one developmental toxicity study in rats with DPX-MP062 and DPX-KN128, one developmental toxicity...

Developmental Patterns of Past-Tense Acquisition among Foreign Language Learners of French.

ERIC Educational Resources Information Center

Kaplan, Marsha A.

The patterns of acquisition of the passe compose and imperfect tenses in French among 16 adult beginning and intermediate students were studied. Based on 15-minute speech samples in which both verb tenses were elicited by seeded questions and cues for descriptive and narrative monologues, the intermediate learners had greater success with the…

DNA intermediates and telomere addition during genome reorganization in Euplotes crassus.

PubMed

Roth, M; Prescott, D M

1985-06-01

Three gene-sized molecules cloned intact from macronuclear DNA served as hybridization probes to study excision of these molecules from chromosomes and their processing during macronuclear development in the hypotrich Euplotes crassus. These molecules occur in integrated forms within polytene chromosomal DNA during macronuclear developmental. After transection of the polytene chromosomes, the three molecules occur in intermediate forms. One of the three molecules first appeared in a large intermediate that was subsequently replaced by a second intermediate, approximately 140 bp larger than the final molecule. The other two macronuclear molecules were detected only in intermediates approximately 140 bp larger than the mature form. These penultimate intermediates are larger by virtue of oversized telomeres, which are pared to yield the mature gene-sized molecules.

Nuclear Lamins

PubMed Central

Dechat, Thomas; Adam, Stephen A.; Taimen, Pekka; Shimi, Takeshi; Goldman, Robert D.

2010-01-01

The nuclear lamins are type V intermediate filament proteins that are critically important for the structural properties of the nucleus. In addition, they are involved in the regulation of numerous nuclear processes, including DNA replication, transcription and chromatin organization. The developmentally regulated expression of lamins suggests that they are involved in cellular differentiation. Their assembly dynamic properties throughout the cell cycle, particularly in mitosis, are influenced by posttranslational modifications. Lamins may regulate nuclear functions by direct interactions with chromatin and determining the spatial organization of chromosomes within the nuclear space. They may also regulate chromatin functions by interacting with factors that epigenetically modify the chromatin or directly regulate replication or transcription. PMID:20826548

Early therapy-related myeloid sarcoma and deletion of 9q22.32 to q31.1.

PubMed

Brickler, Molly M; Basel, Donald G; Gheorghe, Gabriela; Margolis, David M; Kelly, Michael E; Ehrhardt, Matthew J

2014-09-01

Survival following childhood neuroblastoma is improving with low rates of secondary myeloid neoplasms. We describe a 13-month-old male with intermediate risk neuroblastoma who developed an isolated scalp therapy-related myeloid sarcoma (t-MS). Developmental delays and two distinct malignancies prompted constitutional evaluation. Chromosomal microarray identified a 7.3 Mb deletion of 9q22.32 to 9q31.1. He remains in remission 11 months following hematopoietic cell transplant. Unusual presentations of rare diseases necessitate a multidisciplinary approach and adaptation of standardized protocols to accommodate increased risks imposed by genetic variants. © 2014 Wiley Periodicals, Inc.

Transcriptomic Responses During Early Development Following Arsenic Exposure in Western Clawed Frogs, Silurana tropicalis.

PubMed

Zhang, Jing; Koch, Iris; Gibson, Laura A; Loughery, Jennifer R; Martyniuk, Christopher J; Button, Mark; Caumette, Guilhem; Reimer, Kenneth J; Cullen, William R; Langlois, Valerie S

2015-12-01

Arsenic compounds are widespread environmental contaminants and exposure elicits serious health issues, including early developmental anomalies. Depending on the oxidation state, the intermediates of arsenic metabolism interfere with a range of subcellular events, but the fundamental molecular events that lead to speciation-dependent arsenic toxicity are not fully elucidated. This study therefore assesses the impact of arsenic exposure on early development by measuring speciation and gene expression profiles in the developing Western clawed frog (Silurana tropicalis) larvae following the environmental relevant 0.5 and 1 ppm arsenate exposure. Using HPLC-ICP-MS, arsenate, dimethylarsenic acid, arsenobetaine, arsenocholine, and tetramethylarsonium ion were detected. Microarray and pathway analyses were utilized to characterize the comprehensive transcriptomic responses to arsenic exposure. Clustering analysis of expression data showed distinct gene expression patterns in arsenate treated groups when compared with the control. Pathway enrichment revealed common biological themes enriched in both treatments, including cell signal transduction, cell survival, and developmental pathways. Moreover, the 0.5 ppm exposure led to the enrichment of pathways and biological processes involved in arsenic intake or efflux, as well as histone remodeling. These compensatory responses are hypothesized to be responsible for maintaining an in-body arsenic level comparable to control animals. With no appreciable changes observed in malformation and mortality between control and exposed larvae, this is the first study to suggest that the underlying transcriptomic regulations related to signal transduction, cell survival, developmental pathways, and histone remodeling may contribute to maintaining ongoing development while coping with the potential arsenic toxicity in S. tropicalis during early development. © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Epigenetic and in vivo comparison of diverse MSC sources reveals an endochondral signature for human hematopoietic niche formation.

PubMed

Reinisch, Andreas; Etchart, Nathalie; Thomas, Daniel; Hofmann, Nicole A; Fruehwirth, Margareta; Sinha, Subarna; Chan, Charles K; Senarath-Yapa, Kshemendra; Seo, Eun-Young; Wearda, Taylor; Hartwig, Udo F; Beham-Schmid, Christine; Trajanoski, Slave; Lin, Qiong; Wagner, Wolfgang; Dullin, Christian; Alves, Frauke; Andreeff, Michael; Weissman, Irving L; Longaker, Michael T; Schallmoser, Katharina; Majeti, Ravindra; Strunk, Dirk

2015-01-08

In the last decade there has been a rapid expansion in clinical trials using mesenchymal stromal cells (MSCs) from a variety of tissues. However, despite similarities in morphology, immunophenotype, and differentiation behavior in vitro, MSCs sourced from distinct tissues do not necessarily have equivalent biological properties. We performed a genome-wide methylation, transcription, and in vivo evaluation of MSCs from human bone marrow (BM), white adipose tissue, umbilical cord, and skin cultured in humanized media. Surprisingly, only BM-derived MSCs spontaneously formed a BM cavity through a vascularized cartilage intermediate in vivo that was progressively replaced by hematopoietic tissue and bone. Only BM-derived MSCs exhibited a chondrogenic transcriptional program with hypomethylation and increased expression of RUNX3, RUNX2, BGLAP, MMP13, and ITGA10 consistent with a latent and primed skeletal developmental potential. The humanized MSC-derived microenvironment permitted homing and maintenance of long-term murine SLAM(+) hematopoietic stem cells (HSCs), as well as human CD34(+)/CD38(-)/CD90(+)/CD45RA(+) HSCs after cord blood transplantation. These studies underscore the profound differences in developmental potential between MSC sources independent of donor age, with implications for their clinical use. We also demonstrate a tractable human niche model for studying homing and engraftment of human hematopoietic cells in normal and neoplastic states. © 2015 by The American Society of Hematology.

Meiotic competence of equine oocytes and pronucleus formation after intracytoplasmic sperm injection (ICSI) as related to granulosa cell apoptosis.

PubMed

Dell'Aquila, Maria Elena; Albrizio, Maria; Maritato, Filippo; Minoia, Paolo; Hinrichs, Katrin

2003-06-01

Follicle atresia and granulosa cell apoptosis may be related to oocyte meiotic and developmental competence. We analyzed the relationships among granulosa cell apoptosis, initial cumulus morphology, oocyte nuclear maturation in vitro, and pronucleus formation after intracytoplasmic sperm injection (ICSI) in the horse. For each follicle, the size was measured and granulosa cells were used for DNA laddering analysis. Oocytes were evaluated for cumulus morphology, cultured for in vitro maturation, and submitted to ICSI. Apoptosis was categorized as absent, intermediate, or advanced according to the relative concentrations of two DNA fragments at 900 and 360 base pairs (bp). In 98 oocyte-follicle pairs, 52 oocytes were classified as expanded (Exp), 39 as compact (Cp), and 7 as having a partial (P) cumulus. Advanced apoptosis was detected in 55% (54/98) of follicles; 37% (36/98) of follicles showed an intermediate level of apoptosis; and 8 follicles (8%) were nonapoptotic. Follicle size was not significantly correlated with granulosa cell apoptosis (P > 0.05). Significantly more Exp than Cp oocytes originated from follicles with advanced apoptosis (P < 0.001). The proportion of oocytes maturing in vitro was significantly higher in oocytes issuing from apoptotic follicles than in oocytes issuing from healthy follicles (P < 0.05). The proportion of normally (two pronuclei) or abnormally fertilized oocytes (one or greater than two pronuclei, or partially decondensed sperm) did not differ in relation to granulosa cell apoptosis. We conclude that, in the mare, granulosa cell apoptosis is related to cumulus expansion and an increase in oocyte meiotic competence but has no effect on the proportion of meiotically competent oocytes that activate after ICSI. These results provide selection criteria for horse oocytes used in assisted reproductive techniques so that embryo production may be maximized.

The Effect of a Math Emporium Course Redesign in Developmental and Introductory Mathematics Courses on Student Achievement and Students' Attitudes toward Mathematics at a Two-Year College

ERIC Educational Resources Information Center

Bishop, Amy Renee

2010-01-01

The purpose of this research was to determine the effect of computer-based instruction on student mathematics achievement and students' attitudes toward mathematics in developmental and introductory mathematics courses, namely Elementary Algebra, Intermediate Algebra, and College Algebra, at a community college. The researcher also examined the…

Perceived Needs of Developmentally Disabled Skilled Care Facility and Intermediate Care Facility Residents as Compared to Their Non-institutionalized Peers.

ERIC Educational Resources Information Center

Loughman, Sharon

The Center for Independent Living of Greater Bridgeport and its operating agencies conducted a survey of 32 people, the majority of whom were developmentally disabled and residents of institutional or community settings, in both rural and urban areas. The aim of the survey was to determine the perceived needs and levels of independence experienced…

Eya1 Interacts with Six2 and Myc to Regulate Expansion of the Nephron Progenitor Pool during Nephrogenesis

PubMed Central

Xu, Jinshu; Wong, Elaine Y.M.; Cheng, Chunming; Li, Jun; Sharkar, Mohammad T.K.; Xu, Chelsea Y.; Chen, Binglai; Sun, Jianbo; Jing, Dongzhu; Xu, Pin-Xian

2014-01-01

SUMMARY Self-renewal and proliferation of nephron progenitor cells and the decision to initiate nephrogenesis are crucial events directing kidney development. Despite recent advancements in defining lineage and regulators for the progenitors, fundamental questions about mechanisms driving expansion of the progenitors remain unanswered. Here we show that Eya1 interacts with Six2 and Myc to control self-renewing cell activity. Cell fate tracing reveals a developmental restriction of the Eya1+ population within the intermediate mesoderm to nephron-forming cell fates and a common origin shared between caudal mesonephric and metanephric nephrons. Conditional inactivation of Eya1 leads to loss of Six2 expression and premature epithelialization of the progenitors. Six2 mediates translocation of Eya1 to the nucleus, where Eya1 uses its threonine phosphatase activity to control Myc phosphorylation/dephosphorylation and function in the progenitor cells. Our results reveal a functional link between Eya1, Six2, and Myc in driving the expansion and maintenance of the multipotent progenitors during nephrogenesis. PMID:25458011

Eya1 interacts with Six2 and Myc to regulate expansion of the nephron progenitor pool during nephrogenesis.

PubMed

Xu, Jinshu; Wong, Elaine Y M; Cheng, Chunming; Li, Jun; Sharkar, Mohammad T K; Xu, Chelsea Y; Chen, Binglai; Sun, Jianbo; Jing, Dongzhu; Xu, Pin-Xian

2014-11-24

Self-renewal and proliferation of nephron progenitor cells and the decision to initiate nephrogenesis are crucial events directing kidney development. Despite recent advancements in defining lineage and regulators for the progenitors, fundamental questions about mechanisms driving expansion of the progenitors remain unanswered. Here we show that Eya1 interacts with Six2 and Myc to control self-renewing cell activity. Cell fate tracing reveals a developmental restriction of the Eya1(+) population within the intermediate mesoderm to nephron-forming cell fates and a common origin shared between caudal mesonephric and metanephric nephrons. Conditional inactivation of Eya1 leads to loss of Six2 expression and premature epithelialization of the progenitors. Six2 mediates translocation of Eya1 to the nucleus, where Eya1 uses its threonine phosphatase activity to control Myc phosphorylation/dephosphorylation and function in the progenitor cells. Our results reveal a functional link between Eya1, Six2, and Myc in driving the expansion and maintenance of the multipotent progenitors during nephrogenesis. Copyright © 2014 Elsevier Inc. All rights reserved.

Stage 3 immature human natural killer cells found in secondary lymphoid tissue constitutively and selectively express the TH17 cytokine interleukin-22

PubMed Central

Hughes, Tiffany; Becknell, Brian; McClory, Susan; Briercheck, Edward; Freud, Aharon G.; Zhang, Xiaoli; Mao, Hsiaoyin; Nuovo, Gerard; Yu, Jianhua

2009-01-01

Considerable functional heterogeneity within human natural killer (NK) cells has been revealed through the characterization of distinct NK-cell subsets. Accordingly, a small subset of CD56+NKp44+NK cells, termed NK-22 cells, was recently described within secondary lymphoid tissue (SLT) as IL-22− when resting, with a minor fraction of this population becoming IL-22+ when activated. Here we discover that the vast majority of stage 3 immature NK (iNK) cells in SLT constitutively and selectively express IL-22, a TH17 cytokine important for mucosal immunity, whereas earlier and later stages of NK developmental intermediates do not express IL-22. These iNK cells have a surface phenotype of CD34−CD117+CD161+CD94−, largely lack expression of NKp44 and CD56, and do not produce IFN-γ or possess cytolytic activity. In summary, stage 3 iNK cells are highly enriched for IL-22 and IL-26 messenger RNA, and IL-22 protein production, but do not express IL-17A or IL-17F. PMID:19244159

F.O.O.D. for Thought: Focus on Optimal Development of the Child: Intermediate Level. Teaching Activities in Nutrition, Physical and Mental Health, and Learning Abilities.

ERIC Educational Resources Information Center

Durham City Schools, NC.

The booklet suggests 32 classroom and teaching activities for intermediate teachers, grades 4-6, in the four areas of nutrition, physical health, mental health, and developmental skills. The project was developed to show how nutritionists, physical and mental health workers, and learning specialists could assist children and classroom teachers in…

Factors Associated with Expenditures for Medicaid Home and Community Based Services (HCBS) and Intermediate Care Facilities for Persons with Mental Retardation (ICF/MR) Services for Persons with Intellectual and Developmental Disabilities

ERIC Educational Resources Information Center

Lakin, K. Charlie; Doljanac, Robert; Byun, Soo-Yong; Stancliffe, Roger J.; Taub, Sarah; Chiri, Giuseppina

2008-01-01

This article examines expenditures for a random sample of 1,421 adult Home and Community Based Services (HCBS) and Intermediate Care Facility/Mental Retardation (ICF/MR) recipients in 4 states. The article documents variations in expenditures for individuals with different characteristics and service needs and, controlling for individual…

State transitions of actin cortices in vitro and in vivo

NASA Astrophysics Data System (ADS)

Tan, Tzer Han; Keren, Kinneret; Mackintosh, Fred; Schmidt, Christoph; Fakhri, Nikta

Most animal cells are enveloped by a thin layer of actin cortex which governs the cell mechanics. A functional cortex must be rigid to provide mechanical support while being flexible to allow for rapid restructuring events such as cell division. To satisfy these requirements, the actin cortex is highly dynamic with fast actin turnover and myosin-driven contractility. The regulatory mechanism responsible for the transition between a mechanically stable state and a restructuring state is not well understood. Here, we develop a technique to map the dynamics of reconstituted actin cortices in emulsion droplets using IR fluorescent single-walled carbon nanotubes (SWNTs). By increasing crosslinker concentration, we find that a homogeneous cortex transitions to an intermediate state with broken rotational symmetry and a globally contractile state which further breaks translational symmetry. We apply this new dynamic mapping technique to cortices of live starfish oocytes in various developmental stages. To identify the regulatory mechanism for steady state transitions, we subject the oocytes to actin and myosin disrupting drugs.

A small molecule-based strategy for endothelial differentiation and three-dimensional morphogenesis from human embryonic stem cells.

PubMed

Geng, Yijie; Feng, Bradley

2016-07-01

The emerging models of human embryonic stem cell (hESC) self-organizing organoids provide a valuable in vitro platform for studying self-organizing processes that presumably mimic in vivo human developmental events. Here we report that through a chemical screen, we identified two novel and structurally similar small molecules BIR1 and BIR2 which robustly induced the self-organization of a balloon-shaped three-dimensional structure when applied to two-dimensional adherent hESC cultures in the absence of growth factors. Gene expression analyses and functional assays demonstrated an endothelial identity of this balloon-like structure, while cell surface marker analyses revealed a VE-cadherin(+)CD31(+)CD34(+)KDR(+)CD43(-) putative endothelial progenitor population. Furthermore, molecular marker labeling and morphological examinations characterized several other distinct DiI-Ac-LDL(+) multi-cellular modules and a VEGFR3(+) sprouting structure in the balloon cultures that likely represented intermediate structures of balloon-formation.

Activins and inhibins: Novel regulators of thymocyte development

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

Licona-Limon, Paula; Aleman-Muench, German; Chimal-Monroy, Jesus

2009-04-03

Activins and inhibins are members of the transforming growth factor-{beta} superfamily that act on different cell types and regulate a broad range of cellular processes including proliferation, differentiation, and apoptosis. Here, we provide the first evidence that activins and inhibins regulate specific checkpoints during thymocyte development. We demonstrate that both activin A and inhibin A promote the DN3-DN4 transition in vitro, although they differentially control the transition to the DP stage. Whereas activin A induces the accumulation of a CD8{sup +}CD24{sup hi}TCR{beta}{sup lo} intermediate subpopulation, inhibin A promotes the differentiation of DN4 to DP. In addition, both activin A andmore » inhibin A appear to promote CD8{sup +}SP differentiation. Moreover, inhibin {alpha} null mice have delayed in vitro T cell development, showing both a decrease in the DN-DP transition and reduced thymocyte numbers, further supporting a role for inhibins in the control of developmental signals taking place during T cell differentiation in vivo.« less

Hoxd11 specifies a program of metanephric kidney development within the intermediate mesoderm of the mouse embryo.

PubMed

Mugford, Joshua W; Sipilä, Petra; Kobayashi, Akio; Behringer, Richard R; McMahon, Andrew P

2008-07-15

The mammalian kidney consists of an array of tubules connected to a ductal system that collectively function to control water/salt balance and to remove waste from the organisms' circulatory system. During mammalian embryogenesis, three kidney structures form within the intermediate mesoderm. The two most anterior structures, the pronephros and the mesonephros, are transitory and largely non-functional, while the most posterior, the metanephros, persists as the adult kidney. We have explored the mechanisms underlying regional specific differentiation of the kidney forming mesoderm. Previous studies have shown a requirement for Hox11 paralogs (Hoxa11, Hoxc11 and Hoxd11) in metanephric development. Mice lacking all Hox11 activity fail to form metanephric kidney structures. We demonstrate that the Hox11 paralog expression is restricted in the intermediate mesoderm to the posterior, metanephric level. When Hoxd11 is ectopically activated in the anterior mesonephros, we observe a partial transformation to a metanephric program of development. Anterior Hoxd11(+) cells activate Six2, a transcription factor required for the maintenance of metanephric tubule progenitors. Additionally, Hoxd11(+) mesonephric tubules exhibit an altered morphology and activate several metanephric specific markers normally confined to distal portions of the functional nephron. Collectively, our data support a model where Hox11 paralogs specify a metanephric developmental program in responsive intermediate mesoderm. This program maintains tubule forming progenitors and instructs a metanephric specific pattern of nephron differentiation.

24 CFR 891.105 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-04-01

..., subpart F of subtitle A of this title. In the case of an individual residing in an intermediate care facility for the developmentally disabled that is assisted under title XIX of the Social Security Act and...

Androgens trigger different growth responses in genetically identical human hair follicles in organ culture that reflect their epigenetic diversity in life.

PubMed

Miranda, Benjamin H; Charlesworth, Matthew R; Tobin, Desmond J; Sharpe, David T; Randall, Valerie A

2018-02-01

Male sex hormones-androgens-regulate male physique development. Without androgen signaling, genetic males appear female. During puberty, increasing androgens harness the hair follicle's unique regenerative ability to replace many tiny vellus hairs with larger, darker terminal hairs ( e.g., beard). Follicle response is epigenetically varied: some remain unaffected ( e.g., eyelashes) or are inhibited, causing balding. How sex steroid hormones alter such developmental processes is unclear, despite high incidences of hormone-driven cancer, hirsutism, and alopecia. Unfortunately, existing development models are not androgen sensitive. Here, we use hair follicles to establish an androgen-responsive human organ culture model. We show that women's intermediate facial follicles respond to men's higher androgen levels by synthesizing more hair over several days, unlike donor-matched, androgen-insensitive, terminal follicles. We demonstrate that androgen receptors-androgen-activated gene transcription regulators-are required and are present in vivo within these follicles. This is the first human organ that involves multiple cell types that responds appropriately to hormones in prolonged culture, in a way which mirrors its natural behavior. Thus, intermediate hair follicles offer a hormone-switchable human model with exceptional, unique availability of genetically identical, but epigenetically hormone-insensitive, terminal follicles. This should enable advances in understanding sex steroid hormone signaling, gene regulation, and developmental and regenerative systems and facilitate better therapies for hormone-dependent disorders.-Miranda, B. H., Charlesworth, M. R., Tobin, D. J., Sharpe, D. T., Randall, V. A. Androgens trigger different growth responses in genetically identical human hair follicles in organ culture that reflect their epigenetic diversity in life.

Accurate Prediction of Drug-Induced Liver Injury Using Stem Cell-Derived Populations

PubMed Central

Szkolnicka, Dagmara; Farnworth, Sarah L.; Lucendo-Villarin, Baltasar; Storck, Christopher; Zhou, Wenli; Iredale, John P.; Flint, Oliver

2014-01-01

Despite major progress in the knowledge and management of human liver injury, there are millions of people suffering from chronic liver disease. Currently, the only cure for end-stage liver disease is orthotopic liver transplantation; however, this approach is severely limited by organ donation. Alternative approaches to restoring liver function have therefore been pursued, including the use of somatic and stem cell populations. Although such approaches are essential in developing scalable treatments, there is also an imperative to develop predictive human systems that more effectively study and/or prevent the onset of liver disease and decompensated organ function. We used a renewable human stem cell resource, from defined genetic backgrounds, and drove them through developmental intermediates to yield highly active, drug-inducible, and predictive human hepatocyte populations. Most importantly, stem cell-derived hepatocytes displayed equivalence to primary adult hepatocytes, following incubation with known hepatotoxins. In summary, we have developed a serum-free, scalable, and shippable cell-based model that faithfully predicts the potential for human liver injury. Such a resource has direct application in human modeling and, in the future, could play an important role in developing renewable cell-based therapies. PMID:24375539

A Population of Progenitor Cells in the Basal and Intermediate Layers of the Murine Bladder Urothelium Contributes to Urothelial Development and Regeneration

PubMed Central

Colopy, Sara A.; Bjorling, Dale E.; Mulligan, William A.; Bushman, Wade

2014-01-01

Background Homeostatic maintenance and repair of the bladder urothelium has been attributed to proliferation of keratin 5-expressing basal cells (K5-BC) with subsequent differentiation into superficial cells. Recent evidence, however, suggests that the intermediate cell layer harbors a population of progenitor cells. We use label-retaining cell (LRC) methodology in conjunction with a clinically relevant model of uropathogenic Escherichia coli (UPEC)-induced injury to characterize urothelial ontogeny during development and in response to diffuse urothelial injury. Results In the developing urothelium, proliferating cells were dispersed throughout the K5-BC and intermediate cells layers, becoming progressively concentrated in the K5-BC layer with age. When 5-bromo-2-deoxyuridine (BrdU) was administered during urothelial development, LRCs in the adult were found within the K5-BC, intermediate, and superficial cell layers, the location dependent upon time of labeling. UPEC inoculation resulted in loss of the superficial cell layer followed by robust proliferation of K5-BCs and intermediate cells. LRCs within the K5-BC and intermediate cell layers proliferated in response to injury. Conclusions Urothelial development and regeneration following injury relies on proliferation of K5-BC and intermediate cells. The existence and proliferation of LRCs within both the K5-BC and intermediate cell layers suggests the presence of two populations of urothelial progenitor cells. PMID:24796293

Expertise under the microscope: processing histopathological slides.

PubMed

Jaarsma, Thomas; Jarodzka, Halszka; Nap, Marius; van Merrienboer, Jeroen J G; Boshuizen, Henny P A

2014-03-01

Although the obvious goal of training in clinical pathology is to bring forth capable diagnosticians, developmental stages and their characteristics are unknown. This study therefore aims to find expertise-related differences in the processing of histopathological slides using a combination of eye tracking data and verbal data. Participants in this study were 13 clinical pathologists (experts), 12 pathology residents (intermediates) and 13 medical students (novices). They diagnosed 10 microscopic images of colon tissue for 2 seconds. Eye movements, the given diagnoses, and the vocabulary used in post hoc verbal explanations were registered. Eye movements were analysed according to changes over trial time and the processing of diagnostically relevant areas. The content analysis of verbal data was based on a categorisation system developed from the literature. Although experts and intermediates showed equal levels of diagnostic accuracy, their visual and cognitive processing differed. Whereas experts relied on their first findings and checked the image further for other abnormalities, intermediates tended to double-check their first findings. In their explanations, experts focused on the typicality of the tissue, whereas intermediates mainly mentioned many specific pathologies. Novices looked less often at the relevant areas and were incomplete, incorrect and inconclusive in their explanations. Their diagnostic accuracy was correspondingly poor. This study indicates that in the case of intermediates and experts, different visual and cognitive strategies can result in equal levels of diagnostic accuracy. Lessons for training underline the relevance of the distinction between normal and abnormal tissue for novices, especially when the mental rotation of 2-D images is required. Intermediates need to be trained to see deviations in abnormalities. Feedback and an educational design that is specific to these developmental stages might improve training. © 2014 John Wiley & Sons Ltd.

Circular RNAs: analysis, expression and potential functions

PubMed Central

Salzman, Julia

2016-01-01

Just a few years ago, it had been assumed that the dominant RNA isoforms produced from eukaryotic genes were variants of messenger RNA, functioning as intermediates in gene expression. In early 2012, however, a surprising discovery was made: circular RNA (circRNA) was shown to be a transcriptional product in thousands of human and mouse genes and in hundreds of cases constituted the dominant RNA isoform. Subsequent studies revealed that the expression of circRNAs is developmentally regulated, tissue and cell-type specific, and shared across the eukaryotic tree of life. These features suggest important functions for these molecules. Here, we describe major advances in the field of circRNA biology, focusing on the regulation of and functional roles played by these molecules. PMID:27246710

Two waves of anisotropic growth generate enlarged follicles in the spiny mouse

PubMed Central

2014-01-01

Background Mammals exhibit a remarkable variety of phenotypes and comparative studies using novel model species are needed to uncover the evolutionary developmental mechanisms generating this diversity. Here, we undertake a developmental biology and numerical modeling approach to investigate the development of skin appendages in the spiny mouse, Acomys dimidiatus. Results We demonstrate that Acomys spines, possibly involved in display and protection, are enlarged awl hairs with a concave morphology. The Acomys spines originate from enlarged placodes that are characterized by a rapid downwards growth which results in voluminous follicles. The dermal condensation (dermal papilla) at the core of the follicle is very large and exhibits a curved geometry. Given its off-centered position, the dermal papilla generates two waves of anisotropic proliferation, first of the posterior matrix, then of the anterior inner root sheath (IRS). Higher in the follicle, the posterior and anterior cortex cross-section areas substantially decrease due to cortex cell elongation and accumulation of keratin intermediate filaments. Milder keratinization in the medulla gives rise to a foamy material that eventually collapses under the combined compression of the anterior IRS and elongation of the cortex cells. Simulations, using linear elasticity theory and the finite-element method, indicate that these processes are sufficient to replicate the time evolution of the Acomys spine layers and the final shape of the emerging spine shaft. Conclusions Our analyses reveal how hair follicle morphogenesis has been altered during the evolution of the Acomys lineage, resulting in a shift from ancestral awl follicles to enlarged asymmetrical spines. This study contributes to a better understanding of the evolutionary developmental mechanisms that generated the great diversity of skin appendage phenotypes observed in mammals. PMID:25705371

Nuclear magnetic resonance relaxation characterisation of water status of developing grains of maize (Zea mays L.) grown at different nitrogen levels.

PubMed

Krishnan, Prameela; Chopra, Usha Kiran; Verma, Ajay Pal Singh; Joshi, Devendra Kumar; Chand, Ishwar

2014-04-01

Changes in water status of developing grains of maize (Zea mays L.) grown under different nitrogen levels were characterized by nuclear magnetic resonance (NMR) spectroscopy. There were distinct changes in water status of grains due to the application of different levels of nitrogen (0, 120 and 180 kg N ha(-1)). A comparison of the grain developmental characteristics, composition and physical properties indicated that, not only the developmental characteristics like grain weight, grain number/ear, and rate of grain filling increased, but also bound water characterized by the T2 component of NMR relaxation increased with nitrogen application (50-70%) and developmental stages leading to maturation (10-60%). The consistency in the patterns of responses to free water and intermediate water to increasing levels of nitrogen application and grain maturity suggested that nitrogen application resulted in more proportion of water to both bound- and intermediate states and less in free state. These changes are further corroborated by the concomitant increases in protein and starch contents in grains from higher nitrogen treatments as macromolecules like protein and starch retain more amount of water in the bound state. The results of the changes in T2 showed that water status during grain development was not only affected by developmental processes but also by nitrogen supply to plants. This study strongly indicated a clear nutrient and developmental stage dependence of grain tissue water status in maize. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Increased Rate of NAD Metabolism Shortens Plant Longevity by Accelerating Developmental Senescence in Arabidopsis.

PubMed

Hashida, Shin-Nosuke; Itami, Taketo; Takahara, Kentaro; Hirabayashi, Takayuki; Uchimiya, Hirofumi; Kawai-Yamada, Maki

2016-11-01

NAD is a well-known co-enzyme that mediates hundreds of redox reactions and is the basis of various processes regulating cell responses to different environmental and developmental cues. The regulatory mechanism that determines the amount of cellular NAD and the rate of NAD metabolism remains unclear. We created Arabidopsis thaliana plants overexpressing the NAD synthase (NADS) gene that participates in the final step of NAD biosynthesis. NADS overexpression enhanced the activity of NAD biosynthesis but not the amounts of NAD + , NADH, NADP + or NADPH. However, the amounts of some intermediates were elevated, suggesting that NAD metabolism increased. The NAD redox state was greatly facilitated by an imbalance between NAD generation and degradation in response to bolting. Metabolite profiling and transcriptional analysis revealed that the drastic modulation of NAD redox homeostasis increased tricarboxylic acid flux, causing the ectopic generation of reactive oxygen species. Vascular bundles suffered from oxidative stress, leading to a malfunction in amino acid and organic acid transportation that caused early wilting of the flower stalk and shortened plant longevity, probably due to malnutrition. We concluded that the mechanism regulating the balance between NAD synthesis and degradation is important in the systemic plant response to developmental cues during the growth-phase transition. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Developmental biology, the stem cell of biological disciplines.

PubMed

Gilbert, Scott F

2017-12-01

Developmental biology (including embryology) is proposed as "the stem cell of biological disciplines." Genetics, cell biology, oncology, immunology, evolutionary mechanisms, neurobiology, and systems biology each has its ancestry in developmental biology. Moreover, developmental biology continues to roll on, budding off more disciplines, while retaining its own identity. While its descendant disciplines differentiate into sciences with a restricted set of paradigms, examples, and techniques, developmental biology remains vigorous, pluripotent, and relatively undifferentiated. In many disciplines, especially in evolutionary biology and oncology, the developmental perspective is being reasserted as an important research program.

Imaging molecular dynamics in vivo--from cell biology to animal models.

PubMed

Timpson, Paul; McGhee, Ewan J; Anderson, Kurt I

2011-09-01

Advances in fluorescence microscopy have enabled the study of membrane diffusion, cell adhesion and signal transduction at the molecular level in living cells grown in culture. By contrast, imaging in living organisms has primarily been restricted to the localization and dynamics of cells in tissues. Now, imaging of molecular dynamics is on the cusp of progressing from cell culture to living tissue. This transition has been driven by the understanding that the microenvironment critically determines many developmental and pathological processes. Here, we review recent progress in fluorescent protein imaging in vivo by drawing primarily on cancer-related studies in mice. We emphasize the need for techniques that can be easily combined with genetic models and complement fluorescent protein imaging by providing contextual information about the cellular environment. In this Commentary we will consider differences between in vitro and in vivo experimental design and argue for an approach to in vivo imaging that is built upon the use of intermediate systems, such as 3-D and explant culture models, which offer flexibility and control that is not always available in vivo. Collectively, these methods present a paradigm shift towards the molecular-level investigation of disease and therapy in animal models of disease.

A rare case of os odontoideum from an Early Intermediate period tomb at the Huacas de Moche, Peru.

PubMed

Titelbaum, A R; Castillo, S Uceda

2015-12-01

Os odontoideum is an uncommon vertebral anomaly where there is a smoothly corticated ossicle independent from a shortened odontoid peg. An example of os odontoideum was observed in an Early Intermediate period skeleton excavated from the Huacas de Moche (Moche IV, AD 400-700), Peru. The affected individual is a middle adult male who presents additional minor developmental anomalies of the axial skeleton. This individual was interred with a middle adult female who also has developmental anomalies of the axial skeleton, including block cervical vertebra (Klippel-Feil). Os odontoideum is infrequently reported in the medical literature and there continues to be debate about whether it is acquired or congenital. Unlike clinical cases, archaeological cases present an opportunity to examine the entirety of the skeleton. In the present case, there does not appear to be macroscopic or radiographic evidence for a healed fracture, and since the individual has multiple minor axial developmental anomalies, a congenital etiology is plausible. This case is the first to be described from the archaeological context of South America and one of few paleopathological examples worldwide. Copyright © 2015 Elsevier Inc. All rights reserved.

Diffractive intermediate layer enables broadband light trapping for high efficiency ultrathin c-Si tandem cells

NASA Astrophysics Data System (ADS)

Li, Guijun; Ho, Jacob Y. L.; Li, He; Kwok, Hoi-Sing

2014-06-01

Light management through the intermediate reflector in the tandem cell configuration is of great practical importance for achieving high stable efficiency and also low cost production. So far, however, the intermediate reflectors employed currently are mainly focused on the light absorption enhancement of the top cell. Here, we present a diffractive intermediate layer that allows for light trapping over a broadband wavelength for the ultrathin c-Si tandem solar cell. Compared with the standard intermediate reflector, this nanoscale architectural intermediate layer results in a 35% and 21% remarkable enhancement of the light absorption in the top (400-800 nm) and bottom (800-1100 nm) cells simultaneously, and ultrathin c-Si tandem cells with impressive conversion efficiency of 13.3% are made on the glass substrate.

Temporal genetic structure in a poecilogonous polychaete: the interplay of developmental mode and environmental stochasticity

PubMed Central

2014-01-01

Background Temporal variation in the genetic structure of populations can be caused by multiple factors, including natural selection, stochastic environmental variation, migration, or genetic drift. In benthic marine species, the developmental mode of larvae may indicate a possibility for temporal genetic variation: species with dispersive planktonic larvae are expected to be more likely to show temporal genetic variation than species with benthic or brooded non-dispersive larvae, due to differences in larval mortality and dispersal ability. We examined temporal genetic structure in populations of Pygospio elegans, a poecilogonous polychaete with within-species variation in developmental mode. P. elegans produces either planktonic, benthic, or intermediate larvae, varying both among and within populations, providing a within-species test of the generality of a relationship between temporal genetic variation and larval developmental mode. Results In contrast to our expectations, our microsatellite analyses of P. elegans revealed temporal genetic stability in the UK population with planktonic larvae, whereas there was variation indicative of drift in temporal samples of the populations from the Baltic Sea, which have predominantly benthic and intermediate larvae. We also detected temporal variation in relatedness within these populations. A large temporal shift in genetic structure was detected in a population from the Netherlands, having multiple developmental modes. This shift could have been caused by local extiction due to extreme environmental conditions and (re)colonization by planktonic larvae from neighboring populations. Conclusions In our study of P. elegans, temporal genetic variation appears to be due to not only larval developmental mode, but also the stochastic environment of adults. Large temporal genetic shifts may be more likely in marine intertidal habitats (e.g. North Sea and Wadden Sea) which are more prone to environmental stochasticity than the sub-tidal Baltic habitats. Sub-tidal and/or brackish (less saline) habitats may support smaller P. elegans populations and these may be more susceptible to the effects of random genetic drift. Moreover, higher frequencies of asexual reproduction and the benthic larval developmental mode in these populations leads to higher relatedness and contributes to drift. Our results indicate that a general relationship between larval developmental mode and temporal genetic variation may not exist. PMID:24447386

Temporal genetic structure in a poecilogonous polychaete: the interplay of developmental mode and environmental stochasticity.

PubMed

Kesäniemi, Jenni E; Mustonen, Marina; Boström, Christoffer; Hansen, Benni W; Knott, K Emily

2014-01-22

Temporal variation in the genetic structure of populations can be caused by multiple factors, including natural selection, stochastic environmental variation, migration, or genetic drift. In benthic marine species, the developmental mode of larvae may indicate a possibility for temporal genetic variation: species with dispersive planktonic larvae are expected to be more likely to show temporal genetic variation than species with benthic or brooded non-dispersive larvae, due to differences in larval mortality and dispersal ability. We examined temporal genetic structure in populations of Pygospio elegans, a poecilogonous polychaete with within-species variation in developmental mode. P. elegans produces either planktonic, benthic, or intermediate larvae, varying both among and within populations, providing a within-species test of the generality of a relationship between temporal genetic variation and larval developmental mode. In contrast to our expectations, our microsatellite analyses of P. elegans revealed temporal genetic stability in the UK population with planktonic larvae, whereas there was variation indicative of drift in temporal samples of the populations from the Baltic Sea, which have predominantly benthic and intermediate larvae. We also detected temporal variation in relatedness within these populations. A large temporal shift in genetic structure was detected in a population from the Netherlands, having multiple developmental modes. This shift could have been caused by local extiction due to extreme environmental conditions and (re)colonization by planktonic larvae from neighboring populations. In our study of P. elegans, temporal genetic variation appears to be due to not only larval developmental mode, but also the stochastic environment of adults. Large temporal genetic shifts may be more likely in marine intertidal habitats (e.g. North Sea and Wadden Sea) which are more prone to environmental stochasticity than the sub-tidal Baltic habitats. Sub-tidal and/or brackish (less saline) habitats may support smaller P. elegans populations and these may be more susceptible to the effects of random genetic drift. Moreover, higher frequencies of asexual reproduction and the benthic larval developmental mode in these populations leads to higher relatedness and contributes to drift. Our results indicate that a general relationship between larval developmental mode and temporal genetic variation may not exist.

Germinal zones in the developing cerebral cortex of ferret: ontogeny, cell cycle kinetics, and diversity of progenitors.

PubMed

Reillo, Isabel; Borrell, Víctor

2012-09-01

Expansion and folding of the cerebral cortex are landmark features of mammalian brain evolution. This is recapitulated during embryonic development, and specialized progenitor cell populations known as intermediate radial glia cells (IRGCs) are believed to play central roles. Because developmental mechanisms involved in cortical expansion and folding are likely conserved across phylogeny, it is crucial to identify features specific for gyrencephaly from those unique to primate brain development. Here, we studied multiple features of cortical development in ferret, a gyrencephalic carnivore, in comparison with primates. Analyzing the combinatorial expression of transcription factors, cytoskeletal proteins, and cell cycle parameters, we identified a combination of traits that distinguish in ferret similar germinal layers as in primates. Transcription factor analysis indicated that inner subventricular zone (ISVZ) and outer subventricular zone (OSVZ) may contain an identical mixture of progenitor cell subpopulations in ferret. However, we found that these layers emerge at different time points, differ in IRGC abundance, and progenitors have different cell cycle kinetics and self-renewal dynamics. Thus, ISVZ and OSVZ are likely distinguished by genetic differences regulating progenitor cell behavior and dynamics. Our findings demonstrate that some, but not all, features of primate cortical development are shared by the ferret, suggesting a conserved role in the evolutionary emergence of gyrencephaly.

Revving up Natural Killer Cells and Cytokine-Induced Killer Cells Against Hematological Malignancies.

PubMed

Pittari, Gianfranco; Filippini, Perla; Gentilcore, Giusy; Grivel, Jean-Charles; Rutella, Sergio

2015-01-01

Natural killer (NK) cells belong to innate immunity and exhibit cytolytic activity against infectious pathogens and tumor cells. NK-cell function is finely tuned by receptors that transduce inhibitory or activating signals, such as killer immunoglobulin-like receptors, NK Group 2 member D (NKG2D), NKG2A/CD94, NKp46, and others, and recognize both foreign and self-antigens expressed by NK-susceptible targets. Recent insights into NK-cell developmental intermediates have translated into a more accurate definition of culture conditions for the in vitro generation and propagation of human NK cells. In this respect, interleukin (IL)-15 and IL-21 are instrumental in driving NK-cell differentiation and maturation, and hold great promise for the design of optimal NK-cell culture protocols. Cytokine-induced killer (CIK) cells possess phenotypic and functional hallmarks of both T cells and NK cells. Similar to T cells, they express CD3 and are expandable in culture, while not requiring functional priming for in vivo activity, like NK cells. CIK cells may offer some advantages over other cell therapy products, including ease of in vitro propagation and no need for exogenous administration of IL-2 for in vivo priming. NK cells and CIK cells can be expanded using a variety of clinical-grade approaches, before their infusion into patients with cancer. Herein, we discuss GMP-compliant strategies to isolate and expand human NK and CIK cells for immunotherapy purposes, focusing on clinical trials of adoptive transfer to patients with hematological malignancies.

Cell Migration Analysis: A Low-Cost Laboratory Experiment for Cell and Developmental Biology Courses Using Keratocytes from Fish Scales

ERIC Educational Resources Information Center

Prieto, Daniel; Aparicio, Gonzalo; Sotelo-Silveira, Jose R.

2017-01-01

Cell and developmental processes are complex, and profoundly dependent on spatial relationships that change over time. Innovative educational or teaching strategies are always needed to foster deep comprehension of these processes and their dynamic features. However, laboratory exercises in cell and developmental biology at the undergraduate level…

Myxococcus xanthus Developmental Cell Fate Production: Heterogeneous Accumulation of Developmental Regulatory Proteins and Reexamination of the Role of MazF in Developmental Lysis

PubMed Central

Lee, Bongsoo; Holkenbrink, Carina; Treuner-Lange, Anke

2012-01-01

Myxococcus xanthus undergoes a starvation-induced multicellular developmental program during which cells partition into three known fates: (i) aggregation into fruiting bodies followed by differentiation into spores, (ii) lysis, or (iii) differentiation into nonaggregating persister-like cells, termed peripheral rods. As a first step to characterize cell fate segregation, we enumerated total, aggregating, and nonaggregating cells throughout the developmental program. We demonstrate that both cell lysis and cell aggregation begin with similar timing at approximately 24 h after induction of development. Examination of several known regulatory proteins in the separated aggregated and nonaggregated cell fractions revealed previously unknown heterogeneity in the accumulation patterns of proteins involved in type IV pilus (T4P)-mediated motility (PilC and PilA) and regulation of development (MrpC, FruA, and C-signal). As part of our characterization of the cell lysis fate, we set out to investigate the unorthodox MazF-MrpC toxin-antitoxin system which was previously proposed to induce programmed cell death (PCD). We demonstrate that deletion of mazF in two different wild-type M. xanthus laboratory strains does not significantly reduce developmental cell lysis, suggesting that MazF's role in promoting PCD is an adaption to the mutant background strain used previously. PMID:22493014

On the interrelation of multiplication and division in secondary school children.

PubMed

Huber, Stefan; Fischer, Ursula; Moeller, Korbinian; Nuerk, Hans-Christoph

2013-01-01

Each division problem can be transformed into as a multiplication problem and vice versa. Recent research has indicated strong developmental parallels between multiplication and division in primary school children. In this study, we were interested in (i) whether these developmental parallels persist into secondary school, (ii) whether similar developmental parallels can be observed for simple and complex problems, (iii) whether skill level modulates this relationship, and (iv) whether the correlations are specific and not driven by general cognitive or arithmetic abilities. Therefore, we assessed performance of 5th and 6th graders attending two secondary school types of the German educational system in simple and complex multiplication as well as division while controlling for non-verbal intelligence, short-term memory, and other arithmetic abilities. Accordingly, we collected data from students differing in skills levels due to either age (5th < 6th grade) or school type (general < intermediate secondary school). We observed moderate to strong bivariate and partial correlations between multiplication and division with correlations being higher for simple tasks but nevertheless reliable for complex tasks. Moreover, the association between simple multiplication and division depended on students' skill levels as reflected by school types, but not by age. Partial correlations were higher for intermediate than for general secondary school children. In sum, these findings emphasize the importance of the inverse relationship between multiplication and division which persists into later developmental stages. However, evidence for skill-related differences in the relationship between multiplication and division was restricted to the differences for school types.

Signaling networks in joint development

PubMed Central

Salva, Joanna E.; Merrill, Amy E.

2016-01-01

Here we review studies identifying regulatory networks responsible for synovial, cartilaginous, and fibrous joint development. Synovial joints, characterized by the fluid-filled synovial space between the bones, are found in high-mobility regions and are the most common type of joint. Cartilaginous joints unite adjacent bones through either a hyaline cartilage or fibrocartilage intermediate. Fibrous joints, which include the cranial sutures, form a direct union between bones through fibrous connective tissue. We describe how the distinct morphologic and histogenic characteristics of these joint classes are established during embryonic development. Collectively, these studies reveal that despite the heterogeneity of joint strength and mobility, joint development throughout the skeleton utilizes common signaling networks via long-range morphogen gradients and direct cell-cell contact. This suggests that different joint types represent specialized variants of homologous developmental modules. Identifying the unifying aspects of the signaling networks between joint classes allows a more complete understanding of the signaling code for joint formation, which is critical to improving strategies for joint regeneration and repair. PMID:27859991

The NOTCH1-autophagy interaction: Regulating self-eating for survival.

PubMed

Sarin, Apurva; Marcel, Nimi

2017-02-01

T-cell subsets in the mammalian immune system use varied mechanisms for survival, a demand imposed by the diverse and dynamic niches that they function in. In a recent study, we showed that survival of natural T-regulatory cells (Tregs) was determined by spatially regulated NOTCH1 activity signaling leading to the activation of macroautophagy/autophagy. While this interaction was revealed in experimental conditions of limited nutrient availability in vitro, the consequences of this interaction were confirmed in the context of immune physiology. Consistently, disrupting NOTCH signaling or the autophagy cascade was deleterious to Tregs. At the molecular level, ligand-activated NOTCH1, which is enriched outside the nucleus in Tregs, was detected in complexes that included specific molecular intermediates controlling the progression of autophagy. Mitochondria were a prominent cellular target, with organelle remodeling and function dependent on NOTCH1 signaling to autophagy. It is tempting to speculate that the link between autophagy and the developmental regulator NOTCH1 identified in this work may be conserved in other biological contexts.

Metabolomics of human brain aging and age-related neurodegenerative diseases.

PubMed

Jové, Mariona; Portero-Otín, Manuel; Naudí, Alba; Ferrer, Isidre; Pamplona, Reinald

2014-07-01

Neurons in the mature human central nervous system (CNS) perform a wide range of motor, sensory, regulatory, behavioral, and cognitive functions. Such diverse functional output requires a great diversity of CNS neuronal and non-neuronal populations. Metabolomics encompasses the study of the complete set of metabolites/low-molecular-weight intermediates (metabolome), which are context-dependent and vary according to the physiology, developmental state, or pathologic state of the cell, tissue, organ, or organism. Therefore, the use of metabolomics can help to unravel the diversity-and to disclose the specificity-of metabolic traits and their alterations in the brain and in fluids such as cerebrospinal fluid and plasma, thus helping to uncover potential biomarkers of aging and neurodegenerative diseases. Here, we review the current applications of metabolomics in studies of CNS aging and certain age-related neurodegenerative diseases such as Alzheimer disease, Parkinson disease, and amyotrophic lateral sclerosis. Neurometabolomics will increase knowledge of the physiologic and pathologic functions of neural cells and will place the concept of selective neuronal vulnerability in a metabolic context.

Mechanisms and consequences of paternally transmitted chromosomal abnormalities

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

Marchetti, F; Wyrobek, A J

Paternally transmitted chromosomal damage has been associated with pregnancy loss, developmental and morphological defects, infant mortality, infertility, and genetic diseases in the offspring including cancer. There is epidemiological evidence linking paternal exposure to occupational or environmental agents with an increased risk of abnormal reproductive outcomes. There is also a large body of literature on germ cell mutagenesis in rodents showing that treatment of male germ cells with mutagens has dramatic consequences on reproduction producing effects such as those observed in human epidemiological studies. However, we know very little about the etiology, transmission and early embryonic consequences of paternally-derived chromosomal abnormalities.more » The available evidence suggests that: (1) there are distinct patterns of germ cell-stage differences in the sensitivity of induction of transmissible genetic damage with male postmeiotic cells being the most sensitive; (2) cytogenetic abnormalities at first metaphase after fertilization are critical intermediates between paternal exposure and abnormal reproductive outcomes; and, (3) there are maternally susceptibility factors that may have profound effects on the amount of sperm DNA damage that is converted into chromosomal aberrations in the zygote and directly affect the risk for abnormal reproductive outcomes.« less

Intermediate band solar cell with extreme broadband spectrum quantum efficiency.

PubMed

Datas, A; López, E; Ramiro, I; Antolín, E; Martí, A; Luque, A; Tamaki, R; Shoji, Y; Sogabe, T; Okada, Y

2015-04-17

We report, for the first time, about an intermediate band solar cell implemented with InAs/AlGaAs quantum dots whose photoresponse expands from 250 to ∼6000  nm. To our knowledge, this is the broadest quantum efficiency reported to date for a solar cell and demonstrates that the intermediate band solar cell is capable of producing photocurrent when illuminated with photons whose energy equals the energy of the lowest band gap. We show experimental evidence indicating that this result is in agreement with the theory of the intermediate band solar cell, according to which the generation recombination between the intermediate band and the valence band makes this photocurrent detectable.

Developmental conditioning of endothelium-derived hyperpolarizing factor-mediated vasorelaxation

PubMed Central

Stead, Rebecca; Musa, Moji G.; Bryant, Claire L.; Lanham, Stuart A.; Johnston, David A.; Reynolds, Richard; Torrens, Christopher; Fraser, Paul A.; Clough, Geraldine F.

2016-01-01

Objectives: The endothelium maintains vascular homeostasis through the release of endothelium-derived relaxing factors (EDRF) and endothelium-derived hyperpolarization (EDH). The balance in EDH : EDRF is disturbed in cardiovascular disease and may also be susceptible to developmental conditioning through exposure to an adverse uterine environment to predispose to later risk of hypertension and vascular disease. Methods: Developmentally conditioned changes in EDH : EDRF signalling pathways were investigated in cremaster arterioles (18–32 μm diameter) and third-order mesenteric arteries of adult male mice offspring of dams fed either a fat-rich (high fat, HF, 45% energy from fat) or control (C, 10% energy from fat) diet. After weaning, offspring either continued on high fat or were placed on control diets to give four dietary groups (C/C, HF/C, C/HF, and HF/HF) and studied at 15 weeks of age. Results: EDH via intermediate (IKCa) and small (SKca) conductance calcium-activated potassium channels contributed less than 10% to arteriolar acetylcholine-induced relaxation in in-situ conditioned HF/C offspring compared with ∼60% in C/C (P < 0.01). The conditioned reduction in EDH signalling in HF/C offspring was reversed in offspring exposed to a high-fat diet both before and after weaning (HF/HF, 55%, P < 0.01 vs. HF/C). EDH signalling was unaffected in arterioles from C/HF offspring. The changes in EDH : EDRF were associated with altered endothelial cell expression and localization of IKCa channels. Conclusion: This is the first evidence that EDH-mediated microvascular relaxation is susceptible to an adverse developmental environment through down-regulation of the IKCa signalling pathway. Conditioned offspring exposed to a ‘second hit’ (HF/HF) exhibit adaptive vascular mechanisms to preserve dilator function. PMID:26682783

Developmental conditioning of endothelium-derived hyperpolarizing factor-mediated vasorelaxation.

PubMed

Stead, Rebecca; Musa, Moji G; Bryant, Claire L; Lanham, Stuart A; Johnston, David A; Reynolds, Richard; Torrens, Christopher; Fraser, Paul A; Clough, Geraldine F

2016-03-01

The endothelium maintains vascular homeostasis through the release of endothelium-derived relaxing factors (EDRF) and endothelium-derived hyperpolarization (EDH). The balance in EDH : EDRF is disturbed in cardiovascular disease and may also be susceptible to developmental conditioning through exposure to an adverse uterine environment to predispose to later risk of hypertension and vascular disease. Developmentally conditioned changes in EDH : EDRF signalling pathways were investigated in cremaster arterioles (18-32  μm diameter) and third-order mesenteric arteries of adult male mice offspring of dams fed either a fat-rich (high fat, HF, 45% energy from fat) or control (C, 10% energy from fat) diet. After weaning, offspring either continued on high fat or were placed on control diets to give four dietary groups (C/C, HF/C, C/HF, and HF/HF) and studied at 15 weeks of age. EDH via intermediate (IKCa) and small (SKca) conductance calcium-activated potassium channels contributed less than 10% to arteriolar acetylcholine-induced relaxation in in-situ conditioned HF/C offspring compared with ∼60% in C/C (P < 0.01). The conditioned reduction in EDH signalling in HF/C offspring was reversed in offspring exposed to a high-fat diet both before and after weaning (HF/HF, 55%, P < 0.01 vs. HF/C). EDH signalling was unaffected in arterioles from C/HF offspring. The changes in EDH : EDRF were associated with altered endothelial cell expression and localization of IKCa channels. This is the first evidence that EDH-mediated microvascular relaxation is susceptible to an adverse developmental environment through down-regulation of the IKCa signalling pathway. Conditioned offspring exposed to a 'second hit' (HF/HF) exhibit adaptive vascular mechanisms to preserve dilator function.

Production of photocurrent due to intermediate-to-conduction-band transitions: a demonstration of a key operating principle of the intermediate-band solar cell.

PubMed

Martí, A; Antolín, E; Stanley, C R; Farmer, C D; López, N; Díaz, P; Cánovas, E; Linares, P G; Luque, A

2006-12-15

We present intermediate-band solar cells manufactured using quantum dot technology that show for the first time the production of photocurrent when two sub-band-gap energy photons are absorbed simultaneously. One photon produces an optical transition from the intermediate-band to the conduction band while the second pumps an electron from the valence band to the intermediate-band. The detection of this two-photon absorption process is essential to verify the principles of operation of the intermediate-band solar cell. The phenomenon is the cornerstone physical principle that ultimately allows the production of photocurrent in a solar cell by below band gap photon absorption, without degradation of its output voltage.

D-2-hydroxyglutaric aciduria: a case with an intermediate phenotype and prenatal diagnosis of two affected fetuses.

PubMed

Clarke, Nigel F; Andrews, Ian; Carpenter, Kevin; Jakobs, Cornelis; van der Knaap, Marjo S; Kirk, Edwin P

2003-08-01

D-2-hydroxyglutaric aciduria (D2HGA) is a rare autosomal recessive disorder with variable clinical expression. The biochemical defect is unknown at present. Previously reported cases have either followed a severe clinical course characterized by neonatal epileptic encephalopathy, cortical blindness, and profound developmental delay, or a mild course characterized by mild developmental delay, manageable epilepsy, and mild hypotonia. To date there has been a clear distinction between these two groups. We report the second case of a child with D2HGA who has followed an intermediate course. She presented in infancy with hypotonia, manageable epilepsy and developed moderate to severe developmental delay, and cortical visual impairment. The proposita had a coarse facial appearance, flat face, broad nasal bridge, up-turned nose, and simple, anteverted ears. These facial anomalies have been noted in other children with D2HGA and this case strengthens the proposed association between this facial phenotype and D2HGA. We also report the third and fourth instances of prenatal diagnosis for D2HGA. At each prenatal diagnosis, an affected fetus was diagnosed on the basis of markedly increased levels of D-2-hydroxyglutaric acid in amniotic fluid. Copyright 2003 Wiley-Liss, Inc.

Safe-Site Effects on Rhizosphere Bacterial Communities in a High-Altitude Alpine Environment

PubMed Central

Zerbe, Stefan

2014-01-01

The rhizosphere effect on bacterial communities associated with three floristic communities (RW, FI, and M sites) which differed for the developmental stages was studied in a high-altitude alpine ecosystem. RW site was an early developmental stage, FI was an intermediate stage, M was a later more matured stage. The N and C contents in the soils confirmed a different developmental stage with a kind of gradient from the unvegetated bare soil (BS) site through RW, FI up to M site. The floristic communities were composed of 21 pioneer plants belonging to 14 species. Automated ribosomal intergenic spacer analysis showed different bacterial genetic structures per each floristic consortium which differed also from the BS site. When plants of the same species occurred within the same site, almost all their bacterial communities clustered together exhibiting a plant species effect. Unifrac significance value (P < 0.05) on 16S rRNA gene diversity revealed significant differences (P < 0.05) between BS site and the vegetated sites with a weak similarity to the RW site. The intermediate plant colonization stage FI did not differ significantly from the RW and the M vegetated sites. These results pointed out the effect of different floristic communities rhizospheres on their soil bacterial communities. PMID:24995302

Understanding development and stem cells using single cell-based analyses of gene expression

PubMed Central

Kumar, Pavithra; Tan, Yuqi

2017-01-01

In recent years, genome-wide profiling approaches have begun to uncover the molecular programs that drive developmental processes. In particular, technical advances that enable genome-wide profiling of thousands of individual cells have provided the tantalizing prospect of cataloging cell type diversity and developmental dynamics in a quantitative and comprehensive manner. Here, we review how single-cell RNA sequencing has provided key insights into mammalian developmental and stem cell biology, emphasizing the analytical approaches that are specific to studying gene expression in single cells. PMID:28049689

Curriculum for the Intellectually Disabled Trainable.

ERIC Educational Resources Information Center

Magnolia Special Education Center, Orlando, FL.

The curriculum guide presents a developmental sequence of learning activities to achieve specific goals for primary, intermediate, and secondary age level trainable mentally retarded students. Six major areas of learning are covered: self care (bathroom, grooming, food, clothing, safety), body usage (gross motor, health, fitness, eye-hand…

Curriculum for the Special Education Early Childhood Center.

ERIC Educational Resources Information Center

Taulbee, Dianne R.; And Others

This document presents Jackson County (Michigan) Intermediate School District's Special Education Early Childhood Center's 1988 curriculum. Sections focus on: (1) the center's program; (2) play observation; (3) eligibility; (4) classroom structure and function; (5) the importance of play; (6) developmental milestones; (7) planning and teaching…

The Paradox of Regulations: A Commentary.

ERIC Educational Resources Information Center

Taylor, Steven J.

1992-01-01

This response to previous symposium papers (EC 604 155-161) concerning regulations and quality assurance in Intermediate Care Facilities for the Mentally Retarded (ICF/MR) sees regulations as the bureaucratization of values, identifies paradoxes implicit in regulatory controls, and urges reform of the current developmental disability service…

Students' Reflections on Mathematics Homework Feedback

ERIC Educational Resources Information Center

Landers, Mara; Reinholz, Daniel

2015-01-01

Homework is considered an important aspect of learning mathematics, but little research has considered how students utilize feedback as part of the homework process. This mixed methods, quasi-experimental study examines how community college students in a developmental intermediate algebra course participated in a feedback reflection activity…

Improved method for in vitro secondary amastigogenesis of Trypanosoma cruzi: morphometrical and molecular analysis of intermediate developmental forms.

PubMed

Hernández-Osorio, L A; Márquez-Dueñas, C; Florencio-Martínez, L E; Ballesteros-Rodea, G; Martínez-Calvillo, S; Manning-Cela, R G

2010-01-01

Trypanosoma cruzi undergoes a biphasic life cycle that consists of four alternate developmental stages. In vitro conditions to obtain a synchronic transformation and efficient rates of pure intermediate forms (IFs), which are indispensable for further biochemical, biological, and molecular studies, have not been reported. In the present study, we established an improved method to obtain IFs from secondary amastigogenesis. During the transformation kinetics, we observed progressive decreases in the size of the parasite body, undulating membrane and flagellum that were concomitant with nucleus remodeling and kinetoplast displacement. In addition, a gradual reduction in parasite movement and acquisition of the amastigote-specific Ssp4 antigen were observed. Therefore, our results showed that the in vitro conditions used obtained large quantities of highly synchronous and pure IFs that were clearly distinguished by morphometrical and molecular analyses. Obtaining these IFs represents the first step towards an understanding of the molecular mechanisms involved in amastigogenesis.

(Eco)toxicological effects of 2,4,7,9-tetramethyl-5-decyne-4,7-diol (TMDD) in zebrafish (Danio rerio) and permanent fish cell cultures.

PubMed

Vincze, Krisztina; Gehring, Martin; Braunbeck, Thomas

2014-01-01

2,4,7,9-tetramethyl-5-decyne-4,7-diol (TMDD) is a high-production volume chemical used in paper, ink, pesticide, and adhesive industries as a wetting and anti-foaming agent. The physicochemical properties and slow biodegradation rate of TMDD indicate a low bioaccumulation potential but a high prevalence in the environment. As a consequence, TMDD has been detected in several European rivers in the nanogram per liter and lower microgram per liter range; however, its environmental risk to aquatic organisms is considered low. Recent studies almost exclusively focused on acute effects by TMDD, little is known about cytotoxic and genotoxic effects, reproduction and developmental toxicity, endocrine disruption, and any kind of long-term toxicity and carcinogenicity so far. The present study aims to provide more specific baseline information on the ecotoxicological effects of TMDD in fish. For this end, cyto- and genotoxicity assays were carried out in vitro with the permanent fish cell line RTL-W1; in addition, in vivo studies were conducted with the early life stages of zebrafish (Danio rerio) in order to fill the data gaps in developmental toxicity and endocrine disruption. TMDD showed a cytotoxic and slight genotoxic potential in fish cell lines; moreover, various sublethal and lethal effects could be detected in developing zebrafish embryos. There was no evidence of endocrine-disrupting effects by TMDD; however, mortality following prolonged exposure to TMDD during fish sexual development test was clearly higher than mortality in the fish embryo test after 96-h exposure. Our results thus confirmed previous findings of laboratory screening tests, suggesting short-term toxic effects of TMDD in the intermediate, and long-term effects in the lower milligram per liter range.

Identification, characterization and isolation of a common progenitor for osteoclasts, macrophages and dendritic cells from murine bone marrow and periphery

PubMed Central

Jacome-Galarza, Christian E.; Lee, Sun-Kyeong; Lorenzo, Joseph A.; LeonardoAguila, Hector

2012-01-01

Osteoclasts are specialized bone resorbing cells that derive from monocyte precursors. We have identified three populations of cells with high osteoclastogenic potential in murine bone marrow, which expressed the phenotype: B220−CD3−CD11b−/low CD115+ and either CD117hi, CD117intermediate or CD117low. We have evaluated these populations for their ability to also generate macrophages and dendritic cells. At a single cell level, the population expressing higher CD117 levels was able to generate bone-resorbing osteoclasts, phagocytic macrophages and antigen-presenting dendritic cells in vitro with efficiencies of over 90 percent, indicating that there exists a common developmental pathway for these cell types. Cells with osteoclastogenic potential also exist in blood and peripheral hematopoietic organs. Their functional meaning and/or their relationship with bone marrow progenitors is not well established. Hence, we characterized murine peripheral cell populations for their ability to form osteoclasts, macrophages and dendritic cells in vitro. The spleen and peripheral blood monocyte progenitors share phenotypic markers with bone marrow progenitors, but differ in their expression of CD11b, which was low in bone marrow but high in periphery. We propose that circulating monocyte progenitors are derived from a common bone marrow osteoclasts/macrophage/dendritic cell progenitor (OcMDC), which we have now characterized at a clonal level. However, the lineage relationship between the bone marrow and peripheral monocyte progenitors has yet to be defined. PMID:23165930

On the interrelation of multiplication and division in secondary school children

PubMed Central

Huber, Stefan; Fischer, Ursula; Moeller, Korbinian; Nuerk, Hans-Christoph

2013-01-01

Multiplication and division are conceptually inversely related: Each division problem can be transformed into as a multiplication problem and vice versa. Recent research has indicated strong developmental parallels between multiplication and division in primary school children. In this study, we were interested in (i) whether these developmental parallels persist into secondary school, (ii) whether similar developmental parallels can be observed for simple and complex problems, (iii) whether skill level modulates this relationship, and (iv) whether the correlations are specific and not driven by general cognitive or arithmetic abilities. Therefore, we assessed performance of 5th and 6th graders attending two secondary school types of the German educational system in simple and complex multiplication as well as division while controlling for non-verbal intelligence, short-term memory, and other arithmetic abilities. Accordingly, we collected data from students differing in skills levels due to either age (5th < 6th grade) or school type (general < intermediate secondary school). We observed moderate to strong bivariate and partial correlations between multiplication and division with correlations being higher for simple tasks but nevertheless reliable for complex tasks. Moreover, the association between simple multiplication and division depended on students' skill levels as reflected by school types, but not by age. Partial correlations were higher for intermediate than for general secondary school children. In sum, these findings emphasize the importance of the inverse relationship between multiplication and division which persists into later developmental stages. However, evidence for skill-related differences in the relationship between multiplication and division was restricted to the differences for school types. PMID:24133476

Three cell recognition changes accompany the ingression of sea urchin primary mesenchyme cells.

PubMed

Fink, R D; McClay, D R

1985-01-01

At gastrulation the primary mesenchyme cells of sea urchin embryos lose contact with the extracellular hyaline layer and with neighboring blastomeres as they pass through the basal lamina and enter the blastocoel. This delamination process was examined using a cell-binding assay to follow changes in affinities between mesenchyme cells and their three substrates: hyalin, early gastrula cells, and basal lamina. Sixteen-cell-stage micromeres (the precursors of primary mesenchyme cells), and mesenchyme cells obtained from mesenchyme-blastula-stage embryos were used in conjunction with micromeres raised in culture to intermediate ages. The micromeres exhibited an affinity for hyalin, but the affinity was lost at the time of mesenchyme ingression in vivo. Similarly, micromeres had an affinity for monolayers of gastrula cells but the older mesenchyme cells lost much of their cell-to-cell affinity. Presumptive ectoderm and endoderm cells tested against the gastrula monolayers showed no decrease in binding over the same time interval. When micromeres and primary mesenchyme cells were tested against basal lamina preparations, there was an increase in affinity that was associated with developmental time. Presumptive ectoderm and endoderm cells showed no change in affinity over the same interval. Binding measurements using isolated basal laminar components identified fibronectin as one molecule for which the wandering primary mesenchyme cells acquired a specific affinity. The data indicate that as the presumptive mesenchyme cells leave the vegetal plate of the embryo they lose affinities for hyalin and for neighboring cells, and gain an affinity for fibronectin associated with the basal lamina and extracellular matrix that lines the blastocoel.

EMR Behavioral Curriculum and Student Record.

ERIC Educational Resources Information Center

Hartnett, John J.

Intended for use as a curriculum guide, a source for objectives for the individualized educational plan, and an evaluation instrument to measure handicapped students' learning, the guide lists sequences of developmental tasks. Tasks are outlined for primary, intermediate, and secondary levels in the following areas (sample subskills in…

Isolation, Culture and Cryopreservation of Sarcocystis species

USDA-ARS?s Scientific Manuscript database

More than 200 valid Sarcocystis species have been described in the parasitological literature. The developmental life cycle in the intermediate host and definitive host has only been described for a few species. The majority of species have been identified based solely on the presence of the sarcocy...

Understanding development and stem cells using single cell-based analyses of gene expression.

PubMed

Kumar, Pavithra; Tan, Yuqi; Cahan, Patrick

2017-01-01

In recent years, genome-wide profiling approaches have begun to uncover the molecular programs that drive developmental processes. In particular, technical advances that enable genome-wide profiling of thousands of individual cells have provided the tantalizing prospect of cataloging cell type diversity and developmental dynamics in a quantitative and comprehensive manner. Here, we review how single-cell RNA sequencing has provided key insights into mammalian developmental and stem cell biology, emphasizing the analytical approaches that are specific to studying gene expression in single cells. © 2017. Published by The Company of Biologists Ltd.

Insulin-secreting non-islet cells are resistant to autoimmune destruction.

PubMed Central

Lipes, M A; Cooper, E M; Skelly, R; Rhodes, C J; Boschetti, E; Weir, G C; Davalli, A M

1996-01-01

Transgenic nonobese diabetic mice were created in which insulin expression was targeted to proopiomelanocortin-expressing pituitary cells. Proopiomelanocortin-expressing intermediate lobe pituitary cells efficiently secrete fully processed, mature insulin via a regulated secretory pathway, similar to islet beta cells. However, in contrast to the insulin-producing islet beta cells, the insulin-producing intermediate lobe pituitaries are not targeted or destroyed by cells of the immune system. Transplantation of the transgenic intermediate lobe tissues into diabetic nonobese diabetic mice resulted in the restoration of near-normoglycemia and the reversal of diabetic symptoms. The absence of autoimmunity in intermediate lobe pituitary cells engineered to secrete bona fide insulin raises the potential of these cell types for beta-cell replacement therapy for the treatment of insulin-dependent diabetes mellitus. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:8710916

Developmental origins of epigenetic transgenerational inheritance

PubMed Central

Hanson, Mark A.; Skinner, Michael K.

2016-01-01

Abstract Environmental factors can induce epigenetic alterations in the germ cells that can potentially be transmitted transgenerationally. This non-genetic form of inheritance is termed epigenetic transgenerational inheritance and has been shown in a variety of species including plants, flies, worms, fish, rodents, pigs, and humans. This phenomenon operates during specific critical windows of exposure, linked to the developmental biology of the germ cells (sperm and eggs). Therefore, concepts of the developmental origins of transgenerational inheritance of phenotypic variation and subsequent disease risk need to include epigenetic processes affecting the developmental biology of the germ cell. These developmental impacts on epigenetic transgenerational inheritance, in contrast to multigenerational exposures, are the focus of this Perspective. PMID:27390622

Comparison of a teratogenic transcriptome-based predictive test based on human embryonic versus inducible pluripotent stem cells.

PubMed

Shinde, Vaibhav; Perumal Srinivasan, Sureshkumar; Henry, Margit; Rotshteyn, Tamara; Hescheler, Jürgen; Rahnenführer, Jörg; Grinberg, Marianna; Meisig, Johannes; Blüthgen, Nils; Waldmann, Tanja; Leist, Marcel; Hengstler, Jan Georg; Sachinidis, Agapios

2016-12-30

Human embryonic stem cells (hESCs) partially recapitulate early embryonic three germ layer development, allowing testing of potential teratogenic hazards. Because use of hESCs is ethically debated, we investigated the potential for human induced pluripotent stem cells (hiPSCs) to replace hESCs in such tests. Three cell lines, comprising hiPSCs (foreskin and IMR90) and hESCs (H9) were differentiated for 14 days. Their transcriptome profiles were obtained on day 0 and day 14 and analyzed by comprehensive bioinformatics tools. The transcriptomes on day 14 showed that more than 70% of the "developmental genes" (regulated genes with > 2-fold change on day 14 compared to day 0) exhibited variability among cell lines. The developmental genes belonging to all three cell lines captured biological processes and KEGG pathways related to all three germ layer embryonic development. In addition, transcriptome profiles were obtained after 14 days of exposure to teratogenic valproic acid (VPA) during differentiation. Although the differentially regulated genes between treated and untreated samples showed more than 90% variability among cell lines, VPA clearly antagonized the expression of developmental genes in all cell lines: suppressing upregulated developmental genes, while inducing downregulated ones. To quantify VPA-disturbed development based on developmental genes, we estimated the "developmental potency" (D p ) and "developmental index" (D i ). Despite differences in genes deregulated by VPA, uniform D i values were obtained for all three cell lines. Given that the D i values for VPA were similar for hESCs and hiPSCs, D i can be used for robust hazard identification, irrespective of whether hESCs or hiPSCs are used in the test systems.

75 FR 29901 - Boscalid; Pesticide Tolerances

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-28

... level of concern for boscalid is a MOE of 100 or below, these MOEs are not of concern. 4. Intermediate... dogs resulted in increases in alkaline phosphatase levels as well as hepatic weights. In subchronic and... in rats and in the rat developmental neurotoxicity (DNT) study at a level that did not induce...

Grades 4-6: Arkansas Public School Course Content Guide.

ERIC Educational Resources Information Center

Arkansas State Dept. of Education, Little Rock.

Provided as a framework for use in curriculum development are Arkansas' course content guides for the intermediate elementary grades four, five, and six. At each grade level, language arts, mathematics, reading, social studies, and science skills have been identified at three instructional levels: basic, developmental, and extensional. Basic…

Developing Compressed Beginning and Intermediate Algebra Courses

ERIC Educational Resources Information Center

Walker, Sylvia E.

2017-01-01

The purpose of this project was two-fold. First, it would provide an opportunity for students to complete the developmental math course sequence more quickly, thereby enabling students to proceed to a college-level mathematics course sooner. To accomplish this, the classroom was designed with computer-assisted homework courses that blended…

Developmental stage related patterns of codon usage and genomic GC content: searching for evolutionary fingerprints with models of stem cell differentiation

PubMed Central

2007-01-01

Background The usage of synonymous codons shows considerable variation among mammalian genes. How and why this usage is non-random are fundamental biological questions and remain controversial. It is also important to explore whether mammalian genes that are selectively expressed at different developmental stages bear different molecular features. Results In two models of mouse stem cell differentiation, we established correlations between codon usage and the patterns of gene expression. We found that the optimal codons exhibited variation (AT- or GC-ending codons) in different cell types within the developmental hierarchy. We also found that genes that were enriched (developmental-pivotal genes) or specifically expressed (developmental-specific genes) at different developmental stages had different patterns of codon usage and local genomic GC (GCg) content. Moreover, at the same developmental stage, developmental-specific genes generally used more GC-ending codons and had higher GCg content compared with developmental-pivotal genes. Further analyses suggest that the model of translational selection might be consistent with the developmental stage-related patterns of codon usage, especially for the AT-ending optimal codons. In addition, our data show that after human-mouse divergence, the influence of selective constraints is still detectable. Conclusion Our findings suggest that developmental stage-related patterns of gene expression are correlated with codon usage (GC3) and GCg content in stem cell hierarchies. Moreover, this paper provides evidence for the influence of natural selection at synonymous sites in the mouse genome and novel clues for linking the molecular features of genes to their patterns of expression during mammalian ontogenesis. PMID:17349061

Deciphering the roles of acyl-CoA-binding proteins in plant cells.

PubMed

Lung, Shiu-Cheung; Chye, Mee-Len

2016-09-01

Lipid trafficking is vital for metabolite exchange and signal communications between organelles and endomembranes. Acyl-CoA-binding proteins (ACBPs) are involved in the intracellular transport, protection, and pool formation of acyl-CoA esters, which are important intermediates and regulators in lipid metabolism and cellular signaling. In this review, we highlight recent advances in our understanding of plant ACBP families from a cellular and developmental perspective. Plant ACBPs have been extensively studied in Arabidopsis thaliana (a dicot) and to a lesser extent in Oryza sativa (a monocot). Thus far, they have been detected in the plasma membrane, vesicles, endoplasmic reticulum, Golgi apparatus, apoplast, cytosol, nuclear periphery, and peroxisomes. In combination with biochemical and molecular genetic tools, the widespread subcellular distribution of respective ACBP members has been explicitly linked to their functions in lipid metabolism during development and in response to stresses. At the cellular level, strong expression of specific ACBP homologs in specialized cells, such as embryos, stem epidermis, guard cells, male gametophytes, and phloem sap, is of relevance to their corresponding distinct roles in organ development and stress responses. Other interesting patterns in their subcellular localization and spatial expression that prompt new directions in future investigations are discussed.

Sterols in spermatogenesis and sperm maturation

PubMed Central

Keber, Rok; Rozman, Damjana; Horvat, Simon

2013-01-01

Mammalian spermatogenesis is a complex developmental program in which a diploid progenitor germ cell transforms into highly specialized spermatozoa. One intriguing aspect of sperm production is the dynamic change in membrane lipid composition that occurs throughout spermatogenesis. Cholesterol content, as well as its intermediates, differs vastly between the male reproductive system and nongonadal tissues. Accumulation of cholesterol precursors such as testis meiosis-activating sterol and desmosterol is observed in testes and spermatozoa from several mammalian species. Moreover, cholesterogenic genes, especially meiosis-activating sterol-producing enzyme cytochrome P450 lanosterol 14α-demethylase, display stage-specific expression patterns during spermatogenesis. Discrepancies in gene expression patterns suggest a complex temporal and cell-type specific regulation of sterol compounds during spermatogenesis, which also involves dynamic interactions between germ and Sertoli cells. The functional importance of sterol compounds in sperm production is further supported by the modulation of sterol composition in spermatozoal membranes during epididymal transit and in the female reproductive tract, which is a prerequisite for successful fertilization. However, the exact role of sterols in male reproduction is unknown. This review discusses sterol dynamics in sperm maturation and describes recent methodological advances that will help to illuminate the complexity of sperm formation and function. PMID:23093550

Electrochemical cells and methods of manufacturing the same

DOEpatents

Bazzarella, Ricardo; Slocum, Alexander H; Doherty, Tristan; Cross, III, James C

2015-11-03

Electrochemical cells and methods of making electrochemical cells are described herein. In some embodiments, an apparatus includes a multi-layer sheet for encasing an electrode material for an electrochemical cell. The multi-layer sheet including an outer layer, an intermediate layer that includes a conductive substrate, and an inner layer disposed on a portion of the conductive substrate. The intermediate layer is disposed between the outer layer and the inner layer. The inner layer defines an opening through which a conductive region of the intermediate layer is exposed such that the electrode material can be electrically connected to the conductive region. Thus, the intermediate layer can serve as a current collector for the electrochemical cell.

Medical and developmental impact of transition from subcutaneous insulin to oral glyburide in a 15-yr-old boy with neonatal diabetes mellitus and intermediate DEND syndrome: extending the age of KCNJ11 mutation testing in neonatal DM.

PubMed

Mohamadi, Ali; Clark, Loretta M; Lipkin, Paul H; Mahone, E Mark; Wodka, Ericka L; Plotnick, Leslie P

2010-05-01

Mutations in the KCNJ11 gene, which encodes the Kir6.2 subunit of the ATP-sensitive potassium channel, often result in neonatal diabetes. Patients with this mutation have been successfully transitioned from insulin to sulfonylurea (SU) therapy without compromise in their glycemic control. Among patients with neonatal diabetes due to KCNJ11 mutations, approximately 25% have neurological findings including developmental delay, motor dysfunction, and epilepsy, known as DEND syndrome. There have been rare cases of juvenile patients with intermediate DEND syndrome (iDEND) reporting variable improvement in neurological function following transition from insulin to SU treatment. We describe the response to glyburide in a 15-yr-old boy with severe global developmental delays resulting from the KCNJ11 mutation V59M. The patient was discovered to have diabetes mellitus at 11.5 months of age, making this the oldest age at diagnosis of a KCNJ11 mutation-related case of neonatal diabetes. Because consensus has been to screen patients for this mutation only if younger than 6 months at the time of diagnosis, we suggest that all patients under the age of 12 months at diagnosis should receive genetic testing for monogenic causes of diabetes.

Neural basis of imprinting behavior in chicks.

PubMed

Nakamori, Tomoharu; Maekawa, Fumihiko; Sato, Katsushige; Tanaka, Kohichi; Ohki-Hamazaki, Hiroko

2013-01-01

Newly hatched chicks memorize the characteristics of the first moving object they encounter, and subsequently show a preference for it. This "imprinting" behavior is an example of infant learning and is elicited by visual and/or auditory cues. Visual information of imprinting stimuli in chicks is first processed in the visual Wulst (VW), a telencephalic area corresponding to the mammalian visual cortex, congregates in the core region of the hyperpallium densocellulare (HDCo) cells, and transmitted to the intermediate medial mesopallium (IMM), a region similar to the mammalian association cortex. The imprinting memory is stored in the IMM, and activities of IMM neurons are altered by imprinting. Imprinting also induces functional and structural plastic changes of neurons in the circuit that links the VW and the IMM. Of these neurons, the activity of the HDCo cells is strongly influenced by imprinting. Expression and modulation of NR2B subunit-containing N-methyl-D-aspartate (NMDA) receptors in the HDCo cells are crucial for plastic changes in this circuit as well as the process of visual imprinting. Thus, elucidation of cellular and molecular mechanisms underlying the plastic changes that occurred in the HDCo cells may provide useful knowledge about infant learning. © 2012 The Authors Development, Growth & Differentiation © 2012 Japanese Society of Developmental Biologists.

Development and maintenance of the brain's immune toolkit: Microglia and non-parenchymal brain macrophages.

PubMed

Lopez-Atalaya, Jose P; Askew, Katharine E; Sierra, Amanda; Gomez-Nicola, Diego

2018-06-01

Microglia and non-parenchymal macrophages located in the perivascular space, the meninges and the choroid plexus are independent immune populations that play vital roles in brain development, homeostasis, and tissue healing. Resident macrophages account for a significant proportion of cells in the brain and their density remains stable throughout the lifespan thanks to constant turnover. Microglia develop from yolk sac progenitors, later evolving through intermediate progenitors in a fine-tuned process in which intrinsic factors and external stimuli combine to progressively sculpt their cell type-specific transcriptional profiles. Recent evidence demonstrates that non-parenchymal macrophages are also generated during early embryonic development. In recent years, the development of powerful fate mapping approaches combined with novel genomic and transcriptomic methodologies have greatly expanded our understanding of how brain macrophages develop and acquire specialized functions, and how cell population dynamics are regulated. Here, we review the transcription factors, epigenetic remodeling, and signaling pathways orchestrating the embryonic development of microglia and non-parenchymal macrophages. Next, we describe the dynamics of the macrophage populations of the brain and discuss the role of progenitor cells, to gain a better understanding of their functions in the healthy and diseased brain. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 78: 561-579, 2018. © 2017 The Authors Developmental Neurobiology Published by Wiley Periodicals, Inc.

Developmental diversity in free-living flatworms

PubMed Central

2012-01-01

Flatworm embryology has attracted attention since the early beginnings of comparative evolutionary biology. Considered for a long time the most basal bilaterians, the Platyhelminthes (excluding Acoelomorpha) are now robustly placed within the Spiralia. Despite having lost their relevance to explain the transition from radially to bilaterally symmetrical animals, the study of flatworm embryology is still of great importance to understand the diversification of bilaterians and of developmental mechanisms. Flatworms are acoelomate organisms generally with a simple centralized nervous system, a blind gut, and lacking a circulatory organ, a skeleton and a respiratory system other than the epidermis. Regeneration and asexual reproduction, based on a totipotent neoblast stem cell system, are broadly present among different groups of flatworms. While some more basally branching groups - such as polyclad flatworms - retain the ancestral quartet spiral cleavage pattern, most flatworms have significantly diverged from this pattern and exhibit unique strategies to specify the common adult body plan. Most free-living flatworms (i.e. Platyhelminthes excluding the parasitic Neodermata) are directly developing, whereas in polyclads, also indirect developers with an intermediate free-living larval stage and subsequent metamorphosis are found. A comparative study of developmental diversity may help understanding major questions in evolutionary biology, such as the evolution of cleavage patterns, gastrulation and axial specification, the evolution of larval types, and the diversification and specialization of organ systems. In this review, we present a thorough overview of the embryonic development of the different groups of free-living (turbellarian) platyhelminths, including the Catenulida, Macrostomorpha, Polycladida, Lecithoepitheliata, Proseriata, Bothrioplanida, Rhabdocoela, Fecampiida, Prolecithophora and Tricladida, and discuss their main features under a consensus phylogeny of the phylum. PMID:22429930

Cellular level robotic surgery: Nanodissection of intermediate filaments in live keratinocytes.

PubMed

Yang, Ruiguo; Song, Bo; Sun, Zhiyong; Lai, King Wai Chiu; Fung, Carmen Kar Man; Patterson, Kevin C; Seiffert-Sinha, Kristina; Sinha, Animesh A; Xi, Ning

2015-01-01

We present the nanosurgery on the cytoskeleton of live cells using AFM based nanorobotics to achieve adhesiolysis and mimic the effect of pathophysiological modulation of intercellular adhesion. Nanosurgery successfully severs the intermediate filament bundles and disrupts cell-cell adhesion similar to the desmosomal protein disassembly in autoimmune disease, or the cationic modulation of desmosome formation. Our nanomechanical analysis revealed that adhesion loss results in a decrease in cellular stiffness in both cases of biochemical modulation of the desmosome junctions and mechanical disruption of intercellular adhesion, supporting the notion that intercellular adhesion through intermediate filaments anchors the cell structure as focal adhesion does and that intermediate filaments are integral components in cell mechanical integrity. The surgical process could potentially help reveal the mechanism of autoimmune pathology-induced cell-cell adhesion loss as well as its related pathways that lead to cell apoptosis. Copyright © 2015 Elsevier Inc. All rights reserved.

Chromosome nondisjunction during bipolar mitoses of binucleated intermediates promote aneuploidy formation along with multipolar mitoses rather than chromosome loss in micronuclei induced by asbestos

PubMed Central

Zhang, Tianwei; Lv, Lei; Huang, Yun; Ren, Xiaohui; Shi, Qinghua

2017-01-01

Asbestos is a well-known occupational carcinogen that can cause aneuploidy during the early stages of neoplastic development. To explore the origins of asbestos-induced aneuploidy, we performed long-term live-cell imaging followed by fluorescence in situ hybridization of chromosomes 8 and 12 in human bronchial epithelial (HBEC) and mesothelial (MeT5A) cells. We demonstrate that asbestos induces aneuploidy via binucleated intermediates resulting from cytokinesis failure. On the one hand, asbestos increases chromosome nondisjunction during bipolar divisions of binucleated intermediates and produces near-tetraploidy. On the other hand, asbestos increases multipolar divisions of binucleated intermediates to produce aneuploidy. Surprisingly, chromosomes in asbestos-induced micronucleated cells are not truly lost by the cells, and do not contribute to aneuploid cell formation in either cell type. These results clarify the cellular source of asbestos-induced aneuploidy. In particular, they show the asbestos-induced disruption of bipolar chromosomal segregation in tetraploid cells, thereby demonstrating the causality between binucleated intermediates and aneuploidy evolution, rather than chromosome loss in micronuclei. PMID:28038458

Chromosome nondisjunction during bipolar mitoses of binucleated intermediates promote aneuploidy formation along with multipolar mitoses rather than chromosome loss in micronuclei induced by asbestos.

PubMed

Zhang, Tianwei; Lv, Lei; Huang, Yun; Ren, Xiaohui; Shi, Qinghua

2017-02-14

Asbestos is a well-known occupational carcinogen that can cause aneuploidy during the early stages of neoplastic development. To explore the origins of asbestos-induced aneuploidy, we performed long-term live-cell imaging followed by fluorescence in situ hybridization of chromosomes 8 and 12 in human bronchial epithelial (HBEC) and mesothelial (MeT5A) cells. We demonstrate that asbestos induces aneuploidy via binucleated intermediates resulting from cytokinesis failure. On the one hand, asbestos increases chromosome nondisjunction during bipolar divisions of binucleated intermediates and produces near-tetraploidy. On the other hand, asbestos increases multipolar divisions of binucleated intermediates to produce aneuploidy. Surprisingly, chromosomes in asbestos-induced micronucleated cells are not truly lost by the cells, and do not contribute to aneuploid cell formation in either cell type. These results clarify the cellular source of asbestos-induced aneuploidy. In particular, they show the asbestos-induced disruption of bipolar chromosomal segregation in tetraploid cells, thereby demonstrating the causality between binucleated intermediates and aneuploidy evolution, rather than chromosome loss in micronuclei.

Electrochemical cells and methods of manufacturing the same

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

Bazzarella, Ricardo; Slocum, Alexander H.; Doherty, Tristan

2016-07-26

Electrochemical cells and methods of making electrochemical cells are described herein. In some embodiments, an apparatus includes a multi-layer sheet for encasing an electrode material for an electrochemical cell. The multi-layer sheet including an outer layer, an intermediate layer that includes a conductive substrate, and an inner layer disposed on a portion of the conductive substrate. The intermediate layer is disposed between the outer layer and the inner layer. The inner layer defines an opening through which a conductive region of the intermediate layer is exposed such that the electrode material can be electrically connected to the conductive region. Thus,more » the intermediate layer can serve as a current collector for the electrochemical cell.« less

Anatomical and Molecular Properties of Long Descending Propriospinal Neurons in Mice

PubMed Central

Flynn, Jamie R.; Conn, Victoria L.; Boyle, Kieran A.; Hughes, David I.; Watanabe, Masahiko; Velasquez, Tomoko; Goulding, Martyn D.; Callister, Robert J.; Graham, Brett A.

2017-01-01

Long descending propriospinal neurons (LDPNs) are interneurons that form direct connections between cervical and lumbar spinal circuits. LDPNs are involved in interlimb coordination and are important mediators of functional recovery after spinal cord injury (SCI). Much of what we know about LDPNs comes from a range of species, however, the increased use of transgenic mouse lines to better define neuronal populations calls for a more complete characterisation of LDPNs in mice. In this study, we examined the cell body location, inhibitory neurotransmitter phenotype, developmental provenance, morphology and synaptic inputs of mouse LDPNs throughout the cervical and upper thoracic spinal cord. LDPNs were retrogradely labelled from the lumbar spinal cord to map cell body locations throughout the cervical and upper thoracic segments. Ipsilateral LDPNs were distributed throughout the dorsal, intermediate and ventral grey matter as well as the lateral spinal nucleus and lateral cervical nucleus. In contrast, contralateral LDPNs were more densely concentrated in the ventromedial grey matter. Retrograde labelling in GlyT2GFP and GAD67GFP mice showed the majority of inhibitory LDPNs project either ipsilaterally or adjacent to the midline. Additionally, we used several transgenic mouse lines to define the developmental provenance of LDPNs and found that V2b positive neurons form a subset of ipsilaterally projecting LDPNs. Finally, a population of Neurobiotin (NB) labelled LDPNs were assessed in detail to examine morphology and plot the spatial distribution of contacts from a variety of neurochemically distinct axon terminals. These results provide important baseline data in mice for future work on their role in locomotion and recovery from SCI. PMID:28220062

The Biological Role of Nestin(+)-Cells in Physiological and Pathological Cardiovascular Remodeling

PubMed Central

Calderone, Angelino

2018-01-01

The intermediate filament protein nestin was identified in diverse populations of cells implicated in cardiovascular remodeling. Cardiac resident neural progenitor/stem cells constitutively express nestin and following an ischemic insult migrate to the infarct region and participate in angiogenesis and neurogenesis. A modest number of normal adult ventricular fibroblasts express nestin and the intermediate filament protein is upregulated during the progression of reparative and reactive fibrosis. Nestin depletion attenuates cell cycle re-entry suggesting that increased expression of the intermediate filament protein in ventricular fibroblasts may represent an activated phenotype accelerating the biological impact during fibrosis. Nestin immunoreactivity is absent in normal adult rodent ventricular cardiomyocytes. Following ischemic damage, the intermediate filament protein is induced in a modest population of pre-existing adult ventricular cardiomyocytes bordering the peri-infarct/infarct region and nestin(+)-ventricular cardiomyocytes were identified in the infarcted human heart. The appearance of nestin(+)-ventricular cardiomyocytes post-myocardial infarction (MI) recapitulates an embryonic phenotype and depletion of the intermediate filament protein inhibits cell cycle re-entry. Recruitment of the serine/threonine kinase p38 MAPK secondary to an overt inflammatory response after an ischemic insult may represent a seminal event limiting the appearance of nestin(+)-ventricular cardiomyocytes and concomitantly suppressing cell cycle re-entry. Endothelial and vascular smooth muscle cells (VSMCs) express nestin and upregulation of the intermediate filament protein may directly contribute to vascular remodeling. This review will highlight the biological role of nestin(+)-cells during physiological and pathological remodeling of the heart and vasculature and discuss the phenotypic advantage attributed to the intermediate filament protein. PMID:29492403

Farm-Life Skills Training of Autistic Adults at Bittersweet Farms.

ERIC Educational Resources Information Center

Giddan, Jane J.

A farmstead community in Northwest Ohio, called Bittersweet Farms, serves as a habilitation program for autistic adults, involving 20 residents ranging from profoundly retarded to high functioning and 15 developmentally delayed adults who are part of an agricultural day program. The community is designated as an Intermediate Care Facility for the…

Choice-Making among Medicaid HCBS and ICF/MR Recipients in Six States

ERIC Educational Resources Information Center

Lakin, K. Charlie; Doljanac, Robert; Byun, Soo-Yong; Stancliffe, Roger; Taub, Sarah; Chiri, Giuseppina

2008-01-01

Choice in everyday decisions and in support-related decisions was addressed among 2,398 adults with intellectual and developmental disabilities receiving Medicaid Home and Community Based Services (HCBS) and Intermediate Care Facility (ICF/MR) services and living in nonfamily settings in six states. Everyday choice in daily life and in…

Promoting Community-Based Services: Implications for Program Design, Implementation, and Public Policy.

ERIC Educational Resources Information Center

Powers, Michael D.

1986-01-01

Program design, implementation, and public policy issues are discussed for five urban community-based programs for the developmentally disabled: (1) direct services in intermediate care facilities; (2) a High Risk Infant project; (3) group home consultative services; (4) training for support services to adoptive families; (5) a national…

A Sorting-to-Matching Method to Teach Compound Matching to Sample

ERIC Educational Resources Information Center

Farber, Rachel S.; Dube, William V.; Dickson, Chata A.

2016-01-01

Individuals with developmental disabilities may fail to attend to multiple features in compound stimuli (e.g., arrays of pictures, letters within words) with detrimental effects on learning. Participants were 5 children with autism spectrum disorder who had low to intermediate accuracy scores (35% to 84%) on a computer-presented compound matching…

Overexplicit Referent Tracking in L2 English: Strategy, Avoidance, or Myth?

ERIC Educational Resources Information Center

Ryan, Jonathon

2015-01-01

The tendency of intermediate and advanced second language speakers to underuse pronouns and zero anaphora has been characterized as a developmental stage of overexplicitness, yet little consideration has been given to whether learners create sufficient contexts for their use. This study analyzed references across eight degrees of accessibility,…

Evidence for a stepwise program of extrathymic T cell development within the human tonsil

PubMed Central

McClory, Susan; Hughes, Tiffany; Freud, Aharon G.; Briercheck, Edward L.; Martin, Chelsea; Trimboli, Anthony J.; Yu, Jianhua; Zhang, Xiaoli; Leone, Gustavo; Nuovo, Gerard; Caligiuri, Michael A.

2012-01-01

The development of a broad repertoire of T cells, which is essential for effective immune function, occurs in the thymus. Although some data suggest that T cell development can occur extrathymically, many researchers remain skeptical that extrathymic T cell development has an important role in generating the T cell repertoire in healthy individuals. However, it may be important in the setting of poor thymic function or congenital deficit and in the context of autoimmunity, cancer, or regenerative medicine. Here, we report evidence that a stepwise program of T cell development occurs within the human tonsil. We identified 5 tonsillar T cell developmental intermediates: (a) CD34+CD38dimLin– cells, which resemble multipotent progenitors in the bone marrow and thymus; (b) more mature CD34+CD38brightLin– cells; (c) CD34+CD1a+CD11c– cells, which resemble committed T cell lineage precursors in the thymus; (d) CD34–CD1a+CD3–CD11c– cells, which resemble CD4+CD8+ double-positive T cells in the thymus; and (e) CD34–CD1a+CD3+CD11c– cells. The phenotype of each subset closely resembled that of its thymic counterpart. The last 4 populations expressed RAG1 and PTCRA, genes required for TCR rearrangement, and all 5 subsets were capable of ex vivo T cell differentiation. TdT+ cells found within the tonsillar fibrous scaffold expressed CD34 and/or CD1a, indicating that this distinct anatomic region contributes to pre–T cell development, as does the subcapsular region of the thymus. Thus, we provide evidence of a role for the human tonsil in a comprehensive program of extrathymic T cell development. PMID:22378041

Interconversion of large packets and small groups of cells of Micrococcus rubens: dependence upon magnesium and phosphate.

PubMed Central

Yamada, M; Koyama, T; Matsuhashi, M

1977-01-01

Micrococcus rubens, a gram-positive occus, usually forms large, cubic packets of more than 500 cells that are regularly arranged in three-dimensional cell groups. In medium with extremely low concentration of Mg2+ and phosphate, in which the cells can only grow on a agar surface, it formed small groups of 2 to 20 cells. Irregularly arraged cell groups of intermediated size were obtained in culture media containing intermediated concentrations of Mg2+ and phosphate. Mutants that formed irregular cell groups of intermediate size under normal culture conditions were also obtained. Images PMID:845123

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

Bazzarella, Ricardo; Slocum, Alexander H.; Doherty, Tristan

Electrochemical cells and methods of making electrochemical cells are described herein. In some embodiments, an apparatus includes a multi-layer sheet for encasing an electrode material for an electrochemical cell. The multi-layer sheet including an outer layer, an intermediate layer that includes a conductive substrate, and an inner layer disposed on a portion of the conductive substrate. The intermediate layer is disposed between the outer layer and the inner layer. The inner layer defines an opening through which a conductive region of the intermediate layer is exposed such that the electrode material can be electrically connected to the conductive region. Thus,more » the intermediate layer can serve as a current collector for the electrochemical cell.« less

Analysis of gene expression and Ig transcription in PU.1/Spi-B-deficient progenitor B cell lines.

PubMed

Schweitzer, Brock L; DeKoter, Rodney P

2004-01-01

A number of presumptive target genes for the Ets-family transcription factor PU.1 have been identified in the B cell lineage. However, the precise function of PU.1 in B cells has not been studied because targeted null mutation of the PU.1 gene results in a block to lymphomyeloid development at an early developmental stage. In this study, we take advantage of recently developed PU.1(-/-)Spi-B(-/-) IL-7 and stromal cell-dependent progenitor B (pro-B) cell lines to analyze the function of PU.1 and Spi-B in B cell development. We show that contrary to previously published expectations, PU.1 and/or Spi-B are not required for Ig H chain (IgH) gene transcription in pro-B cells. In fact, PU.1(-/-)Spi-B(-/-) pro-B cells have increased levels of IgH transcription compared with wild-type pro-B cells. In addition, high levels of Igkappa transcription are induced after IL-7 withdrawal of wild-type or PU.1(-/-)Spi-B(-/-) pro-B cells. In contrast, we found that Iglambda transcription is reduced in PU.1(-/-)Spi-B(-/-) pro-B cells relative to wild-type pro-B cells after IL-7 withdrawal. These results suggest that Iglambda, but not IgH or Igkappa, transcription, is dependent on PU.1 and/or Spi-B. The PU.1(-/-)Spi-B(-/-) pro-B cells have other phenotypic changes relative to wild-type pro-B cells including increased proliferation, increased CD25 expression, decreased c-Kit expression, and decreased RAG-1 expression. Taken together, our observations suggest that reduction of PU.1 and/or Spi-B activity in pro-B cells promotes their differentiation to a stage intermediate between late pro-B cells and large pre-B cells.

Extended evaluation on the ES-D3 cell differentiation assay combined with the BeWo transport model, to predict relative developmental toxicity of triazole compounds.

PubMed

Li, Hequn; Flick, Burkhard; Rietjens, Ivonne M C M; Louisse, Jochem; Schneider, Steffen; van Ravenzwaay, Bennard

2016-05-01

The mouse embryonic stem D3 (ES-D3) cell differentiation assay is based on the morphometric measurement of cardiomyocyte differentiation and is a promising tool to detect developmental toxicity of compounds. The BeWo transport model, consisting of BeWo b30 cells grown on transwell inserts and mimicking the placental barrier, is useful to determine relative placental transport velocities of compounds. We have previously demonstrated the usefulness of the ES-D3 cell differentiation assay in combination with the in vitro BeWo transport model to predict the relative in vivo developmental toxicity potencies of a set of reference azole compounds. To further evaluate this combined in vitro toxicokinetic and toxicodynamic approach, we combined ES-D3 cell differentiation data of six novel triazoles with relative transport rates obtained from the BeWo model and compared the obtained ranking to the developmental toxicity ranking as derived from in vivo data. The data show that the combined in vitro approach provided a correct prediction for in vivo developmental toxicity, whereas the ES-D3 cell differentiation assay as stand-alone did not. In conclusion, we have validated the combined in vitro approach for developmental toxicity, which we have previously developed with a set of reference azoles, for a set of six novel triazoles. We suggest that this combined model, which takes both toxicodynamic and toxicokinetic aspects into account, should be further validated for other chemical classes of developmental toxicants.

Developmental imaging: the avian embryo hatches to the challenge.

PubMed

Kulesa, Paul M; McKinney, Mary C; McLennan, Rebecca

2013-06-01

The avian embryo provides a multifaceted model to study developmental mechanisms because of its accessibility to microsurgery, fluorescence cell labeling, in vivo imaging, and molecular manipulation. Early two-dimensional planar growth of the avian embryo mimics human development and provides unique access to complex cell migration patterns using light microscopy. Later developmental events continue to permit access to both light and other imaging modalities, making the avian embryo an excellent model for developmental imaging. For example, significant insights into cell and tissue behaviors within the primitive streak, craniofacial region, and cardiovascular and peripheral nervous systems have come from avian embryo studies. In this review, we provide an update to recent advances in embryo and tissue slice culture and imaging, fluorescence cell labeling, and gene profiling. We focus on how technical advances in the chick and quail provide a clearer understanding of how embryonic cell dynamics are beautifully choreographed in space and time to sculpt cells into functioning structures. We summarize how these technical advances help us to better understand basic developmental mechanisms that may lead to clinical research into human birth defects and tissue repair. Copyright © 2013 Wiley Periodicals, Inc.

Computational Tools for Stem Cell Biology

PubMed Central

Bian, Qin; Cahan, Patrick

2016-01-01

For over half a century, the field of developmental biology has leveraged computation to explore mechanisms of developmental processes. More recently, computational approaches have been critical in the translation of high throughput data into knowledge of both developmental and stem cell biology. In the last several years, a new sub-discipline of computational stem cell biology has emerged that synthesizes the modeling of systems-level aspects of stem cells with high-throughput molecular data. In this review, we provide an overview of this new field and pay particular attention to the impact that single-cell transcriptomics is expected to have on our understanding of development and our ability to engineer cell fate. PMID:27318512

Computational Tools for Stem Cell Biology.

PubMed

Bian, Qin; Cahan, Patrick

2016-12-01

For over half a century, the field of developmental biology has leveraged computation to explore mechanisms of developmental processes. More recently, computational approaches have been critical in the translation of high throughput data into knowledge of both developmental and stem cell biology. In the past several years, a new subdiscipline of computational stem cell biology has emerged that synthesizes the modeling of systems-level aspects of stem cells with high-throughput molecular data. In this review, we provide an overview of this new field and pay particular attention to the impact that single cell transcriptomics is expected to have on our understanding of development and our ability to engineer cell fate. Copyright © 2016 Elsevier Ltd. All rights reserved.

Differential Immunotoxicity Induced by Two Different Windows of Developmental Trichloroethylene Exposure

PubMed Central

Gilbert, Kathleen M.; Woodruff, William; Blossom, Sarah J.

2014-01-01

Developmental exposure to environmental toxicants may induce immune system alterations that contribute to adult stage autoimmune disease. We have shown that continuous exposure of MRL+/+ mice to trichloroethylene (TCE) from gestational day (GD) 0 to postnatal day (PND) 49 alters several aspects of CD4+ T cell function. This window of exposure corresponds to conception-adolescence/young adulthood in humans. More narrowly defining the window of TCE developmental exposure causes immunotoxicity that would establish the stage at which avoidance and/or intervention would be most effective. The current study divided continuous TCE exposure into two separate windows, namely, gestation only (GD0 to birth (PND0)) and early-life only (PND0-PND49). The mice were examined for specific alterations in CD4+ T cell function at PND49. One potentially long-lasting effect of developmental exposure, alterations in retrotransposon expression indicative of epigenetic alterations, was found in peripheral CD4+ T cells from both sets of developmentally exposed mice. Interestingly, certain other effects, such as alterations in thymus cellularity, were only found in mice exposed to TCE during gestation. In contrast, expansion of memory/activation cell subset of peripheral CD4+ T cells were only found in mice exposed to TCE during early life. Different windows of developmental TCE exposure can have different functional consequences. PMID:24696780

Causes of death of patients in an institution for the developmentally disabled.

PubMed

Blisard, K S; Martin, C; Brown, G W; Smialek, J E; Davis, L E; McFeeley, P J

1988-11-01

The causes of death of 53 severely to profoundly developmentally disabled patients who died in an intermediate care facility were reviewed. Respiratory disease, predominantly pneumonia and aspiration, accounted for 72% of deaths. Seven patients died of nonrespiratory causes, and in 8 patients, no cause of death could be determined, even after a complete autopsy or investigation. The median age at death was 20 years. The weights of these patients' organs at autopsy were lower than those for normal individuals of the same age. The lifespan of these severely impaired individuals continues to be significantly shortened, even with improved methods of care.

Epigenetic stress responses induce muscle stem-cell ageing by Hoxa9 developmental signals.

PubMed

Schwörer, Simon; Becker, Friedrich; Feller, Christian; Baig, Ali H; Köber, Ute; Henze, Henriette; Kraus, Johann M; Xin, Beibei; Lechel, André; Lipka, Daniel B; Varghese, Christy S; Schmidt, Manuel; Rohs, Remo; Aebersold, Ruedi; Medina, Kay L; Kestler, Hans A; Neri, Francesco; von Maltzahn, Julia; Tümpel, Stefan; Rudolph, K Lenhard

2016-12-15

The functionality of stem cells declines during ageing, and this decline contributes to ageing-associated impairments in tissue regeneration and function. Alterations in developmental pathways have been associated with declines in stem-cell function during ageing, but the nature of this process remains poorly understood. Hox genes are key regulators of stem cells and tissue patterning during embryogenesis with an unknown role in ageing. Here we show that the epigenetic stress response in muscle stem cells (also known as satellite cells) differs between aged and young mice. The alteration includes aberrant global and site-specific induction of active chromatin marks in activated satellite cells from aged mice, resulting in the specific induction of Hoxa9 but not other Hox genes. Hoxa9 in turn activates several developmental pathways and represents a decisive factor that separates satellite cell gene expression in aged mice from that in young mice. The activated pathways include most of the currently known inhibitors of satellite cell function in ageing muscle, including Wnt, TGFβ, JAK/STAT and senescence signalling. Inhibition of aberrant chromatin activation or deletion of Hoxa9 improves satellite cell function and muscle regeneration in aged mice, whereas overexpression of Hoxa9 mimics ageing-associated defects in satellite cells from young mice, which can be rescued by the inhibition of Hoxa9-targeted developmental pathways. Together, these data delineate an altered epigenetic stress response in activated satellite cells from aged mice, which limits satellite cell function and muscle regeneration by Hoxa9-dependent activation of developmental pathways.

Developmental control of transcriptional and proliferative potency during the evolutionary emergence of animals

PubMed Central

Arenas-Mena, Cesar; Coffman, James A.

2016-01-01

Summary It is proposed that the evolution of complex animals required repressive genetic mechanisms for controlling the transcriptional and proliferative potency of cells. Unicellular organisms are transcriptionally potent, able to express their full genetic complement as the need arises through their life cycle, whereas differentiated cells of multicellular organisms can only express a fraction of their genomic potential. Likewise, whereas cell proliferation in unicellular organisms is primarily limited by nutrient availability, cell proliferation in multicellular organisms is developmentally regulated. Repressive genetic controls limiting the potency of cells at the end of ontogeny would have stabilized the gene expression states of differentiated cells and prevented disruptive proliferation, allowing the emergence of diverse cell types and functional shapes. We propose that distal cis-regulatory elements represent the primary innovations that set the stage for the evolution of developmental gene regulatory networks and the repressive control of key multipotency and cell-cycle control genes. The testable prediction of this model is that the genomes of extant animals, unlike those of our unicellular relatives, encode gene regulatory circuits dedicated to the developmental control of transcriptional and proliferative potency. PMID:26173445

Modeling activity and target-dependent developmental cell death of mouse retinal ganglion cells ex vivo.

PubMed

Voyatzis, Sylvie; Muzerelle, Aude; Gaspar, Patricia; Nicol, Xavier

2012-01-01

Programmed cell death is widespread during the development of the central nervous system and serves multiple purposes including the establishment of neural connections. In the mouse retina a substantial reduction of retinal ganglion cells (RGCs) occurs during the first postnatal week, coinciding with the formation of retinotopic maps in the superior colliculus (SC). We previously established a retino-collicular culture preparation which recapitulates the progressive topographic ordering of RGC projections during early post-natal life. Here, we questioned whether this model could also be suitable to examine the mechanisms underlying developmental cell death of RGCs. Brn3a was used as a marker of the RGCs. A developmental decline in the number of Brn3a-immunolabelled neurons was found in the retinal explant with a timing that paralleled that observed in vivo. In contrast, the density of photoreceptors or of starburst amacrine cells increased, mimicking the evolution of these cell populations in vivo. Blockade of neural activity with tetrodotoxin increased the number of surviving Brn3a-labelled neurons in the retinal explant, as did the increase in target availability when one retinal explant was confronted with 2 or 4 collicular slices. Thus, this ex vivo model reproduces the developmental reduction of RGCs and recapitulates its regulation by neural activity and target availability. It therefore offers a simple way to analyze developmental cell death in this classic system. Using this model, we show that ephrin-A signaling does not participate to the regulation of the Brn3a population size in the retina, indicating that eprhin-A-mediated elimination of exuberant projections does not involve developmental cell death.

Pattern and process in the evolution of the sole dioecious member of Brassicaceae.

PubMed

Soza, Valerie L; Le Huynh, Vietnam; Di Stilio, Verónica S

2014-01-01

Lepidium sisymbrioides, a polyploid New Zealand endemic, is the sole dioecious species in Brassicaceae and therefore the closest dioecious relative of the model plant Arabidopsis thaliana. The attractiveness of developing this system for future studies on the genetics of sex determination prompted us to investigate historical and developmental factors surrounding the evolution of its unisexual flowers. Our goal was to determine the evolutionary pattern of polyploidization of L. sisymbrioides and the timing and process of flower reproductive organ abortion. To that end, we used a combination of phylogenetics to place this species within the complex history of polyploidization events in Lepidium and histology to compare its floral ontogeny to that of its closest hermaphroditic relatives and to A. thaliana. Using a nuclear locus (PISTILLATA), we reconstructed the gene tree among Lepidium taxa and applied a phylogenetic network analysis to identify ancestral genomes that contributed to the evolution of L. sisymbrioides. Combining this phylogenetic framework with cytological and genome size data, we estimated L. sisymbrioides as an allo-octoploid resulting from three hybridization events. Our investigations of flower development showed that unisexual flowers appear to abort reproductive organs by programmed cell death in female flowers and by developmental arrest in male flowers. This selective abortion occurs at the same floral developmental stage in both males and females, corresponding to Arabidopsis stage nine. Dioecy in Brassicaceae evolved once in L. sisymbrioides following several allopolyploidization events, by a process of selective abortion of reproductive organs at intermediate stages of flower development. Different developmental processes, but similar timing of abortions, affect male versus female flower development. An increased understanding of how and when reproductive organs abort in this species, combined with our estimates of ancestral genome contributions, ploidy and genome size, lay the foundation for future efforts to examine the genetic mechanisms involved in the evolution of unisexual flowers in the closest dioecious relative of the best studied model plant.

The history of the development of the rectenna

NASA Technical Reports Server (NTRS)

Brown, W. C.

1980-01-01

The history of the development of the rectenna is first reviewed through its early conceptual and developmental phases in which the Air Force and Raytheon Company were primarily involved. The intermediate period of development which involved NASA, Jet Propulsion Laboratory, and Raytheon is then reviewed. Some selective aspects of the current SPS rectenna development are examined.

[Life cycle of the trematode Echinochasmus spinosus Odhner, 1911 (Echinostomatidae) in the natural conditions of Primorye].

PubMed

Besprozvannykh, V V

2011-01-01

Life cycle and developmental stages of the trematode Echinochasmus spinosus Odhner, 1911 are described. As it was established experimentally, in the conditions of Primorsky Krai circulation of the trematode involves first intermediate host, mollusk Parafossarulus spiridonovi, and the second one, freshwater fishes. Adult worms were reared in chicken.

Fiscal Year 2001 Medicaid Home and Community-Based Services Expenditures Exceed Those of ICFs/MR.

ERIC Educational Resources Information Center

Lakin, K. Charlie; Prouty, Robert; Smith, Jerra; Polister, Barb; Smith, Gary

2002-01-01

This article reports that in 2001, for the first time since its creation 20 years earlier, Medicaid Home and Community-Based Services (HCBS) Waiver programs for persons with intellectual and developmental disabilities had Federal and state expenditures that exceeded those for Medicaid Intermediate Care Facilities for Persons with Mental…

Role of Intermediate Filaments in Vesicular Traffic.

PubMed

Margiotta, Azzurra; Bucci, Cecilia

2016-04-25

Intermediate filaments are an important component of the cellular cytoskeleton. The first established role attributed to intermediate filaments was the mechanical support to cells. However, it is now clear that intermediate filaments have many different roles affecting a variety of other biological functions, such as the organization of microtubules and microfilaments, the regulation of nuclear structure and activity, the control of cell cycle and the regulation of signal transduction pathways. Furthermore, a number of intermediate filament proteins have been involved in the acquisition of tumorigenic properties. Over the last years, a strong involvement of intermediate filament proteins in the regulation of several aspects of intracellular trafficking has strongly emerged. Here, we review the functions of intermediate filaments proteins focusing mainly on the recent knowledge gained from the discovery that intermediate filaments associate with key proteins of the vesicular membrane transport machinery. In particular, we analyze the current understanding of the contribution of intermediate filaments to the endocytic pathway.

The chromaffin cell: paradigm in cell, developmental and growth factor biology.

PubMed Central

Unsicker, K

1993-01-01

This article reviews the chromaffin cell in relation to studies that have elucidated fundamental phenomena in cell biology (the molecular anatomy of exocytosis) and developmental neuroscience (the principle of neuropoiesis in the development of the sympathoadrenal cell lineage). A final section addresses growth factor synthesis and storage in chromaffin cells and their implications for the treatment of neurological disorders, such as Parkinson's disease. Images Fig. 3 PMID:8300412

EVALUATION OF HUMAN NEURAL PROGENITOR CELLS FOR DEVELOPMENTAL NEUROTOXICITY SCREENING: TIME COURSE OF EFFECTS ON CELL PROLIFERATION AND VIABILITY.

EPA Science Inventory

Current testing methods for developmental neurotoxicity (DNT) make evaluation of the effects of large numbers of chemicals impractical and prohibitively expensive. As such, we are evaluating human neural progenitor cells (NPCs) as a screen for DNT. ReNcell CX (ReN CX) cells are a...

Applied Developmental Biology: Making Human Pancreatic Beta Cells for Diabetics.

PubMed

Melton, Douglas A

2016-01-01

Understanding the genes and signaling pathways that determine the differentiation and fate of a cell is a central goal of developmental biology. Using that information to gain mastery over the fates of cells presents new approaches to cell transplantation and drug discovery for human diseases including diabetes. © 2016 Elsevier Inc. All rights reserved.

Cellular and Molecular Dynamics of Th17 Differentiation and its Developmental Plasticity in the Intestinal Immune Response

PubMed Central

Bhaumik, Suniti; Basu, Rajatava

2017-01-01

After emerging from the thymus, naive CD4 T cells circulate through secondary lymphoid tissues, including gut-associated lymphoid tissue of the intestine. The activation of naïve CD4 T cells by antigen-presenting cells offering cognate antigen initiate differentiation programs that lead to the development of highly specialized T helper (Th) cell lineages. Although initially believed that developmental programing of effector T cells such as T helper 1 (Th1) or T helper 2 (Th2) resulted in irreversible commitment to a fixed fate, subsequent studies have demonstrated greater flexibility, or plasticity, in effector T cell stability than originally conceived. This is particularly so for the Th17 subset, differentiation of which is a highly dynamic process with overlapping developmental axes with inducible regulatory T (iTreg), T helper 22 (Th22), and Th1 cells. Accordingly, intermediary stages of Th17 cells are found in various tissues, which co-express lineage-specific transcription factor(s) or cytokine(s) of developmentally related CD4 T cell subsets. A highly specialized tissue like that of the intestine, which harbors the largest immune compartment of the body, adds several layers of complexity to the intricate process of Th differentiation. Due to constant exposure to millions of commensal microbes and periodic exposure to pathogens, the intestinal mucosa maintains a delicate balance between regulatory and effector T cells. It is becoming increasingly clear that equilibrium between tolerogenic and inflammatory axes is maintained in the intestine by shuttling the flexible genetic programming of a developing CD4 T cell along the developmental axis of iTreg, Th17, Th22, and Th1 subsets. Currently, Th17 plasticity remains an unresolved concern in the field of clinical research as targeting Th17 cells to cure immune-mediated disease might also target its related subsets. In this review, we discuss the expanding sphere of Th17 plasticity through its shared developmental axes with related cellular subsets such as Th22, Th1, and iTreg in the context of intestinal inflammation and also examine the molecular and epigenetic features of Th17 cells that mediate these overlapping developmental programs. PMID:28408906

Zscan4 restores the developmental potency of embryonic stem cells

PubMed Central

Amano, Tomokazu; Hirata, Tetsuya; Falco, Geppino; Monti, Manuela; Sharova, Lioudmila V.; Amano, Misa; Sheer, Sarah; Hoang, Hien G.; Piao, Yulan; Stagg, Carole A.; Yamamizu, Kohei; Akiyama, Tomohiko; Ko, Minoru S.H.

2013-01-01

The developmental potency of mouse embryonic stem (ES) cells, which is the ability to contribute to a whole embryo is known to deteriorate during long-term cell culture. Previously we have shown that ES cells oscillate between Zscan4- and Zscan4+ states, and the transient activation of Zscan4 is required for the maintenance of telomeres and genome stability of ES cells. Here we show that increasing the frequency of Zscan4 activation in mouse ES cells restores and maintains their developmental potency in long-term cell culture. Injection of a single ES cell with such increased potency into a tetraploid blastocyst gives rise to an entire embryo with a higher success rate. These results not only provide a means to rejuvenate ES cells by manipulating Zscan4 expression, but also indicate the active roles of Zscan4 in the long-term maintenance of ES cell potency. PMID:23739662

Developmental Localization and Methylesterification of Pectin Epitopes during Somatic Embryogenesis of Banana (Musa spp. AAA)

PubMed Central

Xu, Chunxiang; Zhao, Lu; Pan, Xiao; Šamaj, Jozef

2011-01-01

Background The plant cell walls play an important role in somatic embryogenesis and plant development. Pectins are major chemical components of primary cell walls while homogalacturonan (HG) is the most abundant pectin polysaccharide. Developmental regulation of HG methyl-esterification degree is important for cell adhesion, division and expansion, and in general for proper organ and plant development. Methodology/Principal Findings Developmental localization of pectic homogalacturonan (HG) epitopes and the (1→4)-β-D-galactan epitope of rhamnogalacturonan I (RG-I) and degree of pectin methyl-esterification (DM) were studied during somatic embryogenesis of banana (Musa spp. AAA). Histological analysis documented all major developmental stages including embryogenic cells (ECs), pre-globular, globular, pear-shaped and cotyledonary somatic embryos. Histochemical staining of extracellularly secreted pectins with ruthenium red showed the most intense staining at the surface of pre-globular, globular and pear-shaped somatic embryos. Biochemical analysis revealed developmental regulation of galacturonic acid content and DM in diverse embryogenic stages. Immunodots and immunolabeling on tissue sections revealed developmental regulation of highly methyl-esterified HG epitopes recognized by JIM7 and LM20 antibodies during somatic embryogenesis. Cell walls of pre-globular/globular and late-stage embryos contained both low methyl-esterified HG epitopes as well as partially and highly methyl-esterified ones. Extracellular matrix which covered surface of early developing embryos contained pectin epitopes recognized by 2F4, LM18, JIM5, JIM7 and LM5 antibodies. De-esterification of cell wall pectins by NaOH caused a decrease or an elimination of immunolabeling in the case of highly methyl-esterified HG epitopes. However, immunolabeling of some low methyl-esterified epitopes appeared stronger after this base treatment. Conclusions/Significance These data suggest that both low- and highly-methyl-esterified HG epitopes are developmentally regulated in diverse embryogenic stages during somatic embryogenesis. This study provides new information about pectin composition, HG methyl-esterification and developmental localization of pectin epitopes during somatic embryogenesis of banana. PMID:21826225

Receptor tyrosine kinase mutations in developmental syndromes and cancer: two sides of the same coin

PubMed Central

McDonell, Laura M.; Kernohan, Kristin D.; Boycott, Kym M.; Sawyer, Sarah L.

2015-01-01

Receptor tyrosine kinases (RTKs) are a family of ligand-binding cell surface receptors that regulate a wide range of essential cellular activities, including proliferation, differentiation, cell-cycle progression, survival and apoptosis. As such, these proteins play an important role during development and throughout life; germline mutations in genes encoding RTKs cause several developmental syndromes, while somatic alterations contribute to the pathogenesis of many aggressive cancers. This creates an interesting paradigm in which mutation timing, type and location in a gene leads to different cell signaling and biological responses, and ultimately phenotypic outcomes. In this review, we highlight the roles of RTKs in developmental disorders and cancer. The multifaceted roles of these receptors, their genetic signatures and their signaling during developmental morphogenesis and oncogenesis are discussed. Additionally, we propose that comparative analysis of RTK mutations responsible for developmental syndromes may shed light on those driving tumorigenesis. PMID:26152202

Developmentally arrested structures preceding cerebellar tumors in von Hippel–Lindau disease

PubMed Central

Shively, Sharon B; Falke, Eric A; Li, Jie; Tran, Maxine G B; Thompson, Eli R; Maxwell, Patrick H; Roessler, Erich; Oldfield, Edward H; Lonser, Russell R; Vortmeyer, Alexander O

2011-01-01

There is increasing evidence that suggests that knockout of tumor-suppressor gene function causes developmental arrest and protraction of cellular differentiation. In the peripheral nervous system of patients with the tumor-suppressor gene disorder, von Hippel–Lindau disease, we have demonstrated developmentally arrested structural elements composed of hemangioblast progenitor cells. Some developmentally arrested structural elements progress to a frank tumor, hemangioblastoma. However, in von Hippel–Lindau disease, hemangioblastomas are frequently observed in the cerebellum, suggesting an origin in the central nervous system. We performed a structural and topographic analysis of cerebellar tissues obtained from von Hippel–Lindau disease patients to identify and characterize developmentally arrested structural elements in the central nervous system. We examined the entire cerebella of five tumor-free von Hippel–Lindau disease patients and of three non-von Hippel–Lindau disease controls. In all, 9 cerebellar developmentally arrested structural elements were detected and topographically mapped in 385 blocks of von Hippel–Lindau disease cerebella. No developmentally arrested structural elements were seen in 214 blocks from control cerebella. Developmentally arrested structural elements are composed of poorly differentiated cells that express hypoxia-inducible factor (HIF)2α, but not HIF1α or brachyury, and preferentially involve the molecular layer of the dorsum cerebelli. For the first time, we identify and characterize developmentally arrested structural elements in the central nervous system of von Hippel–Lindau patients. We provide evidence that developmentally arrested structural elements in the cerebellum are composed of developmentally arrested hemangioblast progenitor cells in the molecular layer of the dorsum cerebelli. PMID:21499240

Amyloid Precursor Protein 96–110 and β-Amyloid 1–42 Elicit Developmental Anomalies in Sea Urchin Embryos and Larvae that are Alleviated by Neurotransmitter Analogs for Acetylcholine, Serotonin and Cannabinoids

PubMed Central

Buznikov, Gennady A.; Nikitina, Lyudmila A.; Seidler, Frederic J.; Slotkin, Theodore A.; Bezuglov, Vladimir V.; Milošević, Ivan; Lazarević, Lidija; Rogač, Ljubica; Ruzdijić, Sabera; Rakić, Ljubiša M.

2008-01-01

Amyloid precursor protein (APP) is overexpressed in the developing brain and portions of its extracellular domain, especially amino acid residues 96–110, play an important role in neurite outgrowth and neural cell differentiation. In the current study, we evaluated the developmental abnormalities caused by administration of exogenous APP96–110 in sea urchin embryos and larvae, which, like the developing mammalian brain, utilize acetylcholine and other neurotransmitters as morphogens; effects were compared to those of β-amyloid 1–42 (Aβ42), the neurotoxic APP fragment contained within neurodegenerative plaques in Alzheimer’s Disease. Although both peptides elicited dysmorphogenesis, Aβ42 was far more potent; in addition, whereas Aβ42 produced abnormalities at developmental stages ranging from early cleavage divisions to the late pluteus, APP96–110 effects were restricted to the intermediate, mid-blastula stage. For both agents, anomalies were prevented or reduced by addition of lipid-permeable analogs of acetylcholine, serotonin or cannabinoids; physostigmine, a carbamate-derived cholinesterase inhibitor, was also effective. In contrast, agents that act on NMDA receptors (memantine) or α-adrenergic receptors (nicergoline), and that are therapeutic in Alzheimer’s Disease, were themselves embryotoxic, as was tacrine, a cholinesterase inhibitor from a different chemical class than physostigmine. Protection was also provided by agents acting downstream from receptor-mediated events: increasing cyclic AMP with caffeine or isobutylmethylxanthine, or administering the antioxidant, α-tocopherol, were all partially effective. Our findings reinforce a role for APP in development and point to specific interactions with neurotransmitter systems that act as morphogens in developing sea urchins as well as in the mammalian brain. PMID:18565728

Glycine decarboxylase is confined to the bundle-sheath cells of leaves of C3-C 4 intermediate species.

PubMed

Hylton, C M; Rawsthorne, S; Smith, A M; Jones, D A; Woolhouse, H W

1988-10-01

Immunogold labelling has been used to determine the cellular distribution of glycine decarboxylase in leaves of C3, C3-C4 intermediate and C4 species in the genera Moricandia, Panicum, Flaveria and Mollugo. In the C3 species Moricandia foleyi and Panicum laxum, glycine decarboxylase was present in the mitochondria of both mesophyll and bundle-sheath cells. However, in all the C3-C4 intermediate (M. arvensis var. garamatum, M. nitens, M. sinaica, M. spinosa, M. suffruticosa, P. milioides, Flaveria floridana, F. linearis, Mollugo verticillata) and C4 (P. prionitis, F. trinervia) species studied glycine decarboxylase was present in the mitochondria of only the bundle-sheath cells. The bundle-sheath cells of all the C3-C4 intermediate species have on their centripetal faces numerous mitochondria which are larger in profile area than those in mesophyll cells and are in close association with chloroplasts and peroxisomes. Confinement of glycine decarboxylase to the bundle-sheath cells is likely to improve the potential for recapture of photorespired CO2 via the Calvin cycle and could account for the low rate of photorespiration in all C3-C4 intermediate species.

Lifetime enhancement for multiphoton absorption in intermediate band solar cells

NASA Astrophysics Data System (ADS)

Bezerra, Anibal T.; Studart, Nelson

2017-08-01

A semiconductor structure consisting of two coupled quantum wells embedded into the intrinsic region of a p-i-n junction is proposed as an intermediate band solar cell with a photon ratchet state, which would lead to increasing the cell efficiency. The conduction subband of the right-hand side quantum well works as the intermediated band, whereas the excited conduction subband of the left-hand side quantum well operates as the ratchet state. The photoelectrons in the intermediate band are scattered through the thin wells barrier and accumulated into the ratchet subband. A rate equation model for describing the charge transport properties is presented. The efficiency of the current generation is analyzed by studying the occupation of the wells subbands, taking into account the charge dynamic behavior provided by the electrical contacts connected to the cell. The current generation efficiency depends essentially from the relations between the generation, recombination rates and the scattering rate to the ratchet state. The inclusion of the ratchet states led to both an increase and a decrease in the cell current depending on the transition rates. This suggests that the coupling between the intermediate band and the ratchet state is a key point in developing an efficient solar cell.

Regulated expression of telomerase activity in human T lymphocyte development and activation

PubMed Central

1996-01-01

Telomerase, a ribonucleoprotein that is capable of synthesizing telomeric repeats, is expressed in germline and malignant cells, and is absent in most normal human somatic cells. The selective expression of telomerase has thus been proposed to be a basis for the immortality of the germline and of malignant cells. In the present study, telomerase activity was analyzed in normal human T lymphocytes. It was found that telomerase is expressed at a high level in thymocyte subpopulations, at an intermediate level in tonsil T lymphocytes, and at a low to undetectable level in peripheral blood T lymphocytes. Moreover, telomerase activity is highly inducible in peripheral T lymphocytes by activation through CD3 with or without CD28 costimulation, or by stimulation with phorbol myristate acetate (PMA)/ionomycin. The induction of telomerase by anti-CD3 plus anti-CD28 (anti-CD3/CD28) stimulation required RNA and protein synthesis, and was blocked by herbimycin A, an inhibitor of S pi protein tyrosine kinases. The immunosuppressive drug cyclosporin A selectively inhibited telomerase induction by PMA/ionomycin and by anti-CD3, but not by anti-CD3/CD28. Although telomerase activity in peripheral T lymphocytes was activation dependent and correlated with cell proliferation, it was not cell cycle phase restricted. These results indicate that the expression of telomerase in normal human T lymphocytes is both developmentally regulated and activation induced. Telomerase may thus play a permissive role in T cell development and in determining the capacity of lymphoid cells for cell division and clonal expansion. PMID:8676067

IT-25DEVELOPMENTALLY REGULATED ANTIGENS FOR IMMUNOLOGIC TARGETING OF MEDULLOBLASTOMA SUBTYPES

PubMed Central

Pham, Christina; Flores, Catherine; Pei, Yanxin; Wechsler-Reya, Robert; Mitchell, Duane

2014-01-01

INTRODUCTION: Medulloblastoma (MB) remains incurable in one third of patients despite aggressive multi-modality standard therapies. Immunotherapy presents a promising alternative by specifically targeting cancer cells. To date, there have been no successful immunologic applications targeting MB. Emerging evidence from integrated genomic studies has suggested MB variants arise from deregulation of pathways affecting proliferation of progenitor cell populations within the developing cerebellum. Using total embryonic RNA as a source of tumor rejection antigens is attractive because it can be delivered as a single vaccine, target both known and unknown fetal proteins, and can be refined to preferentially treat distinct MB subtypes. METHODS: We have created two transplantable, syngeneic animal MB models recapitulating human SHH and Group 3 variants to investigate the immunologic targeting of different MB subtypes. We generated T cells specific to the developing mouse cerebellum (P5) and tested their reactivity to target cells pulsed with total RNA from two MB subtypes and the normal brain. Immune responses were evaluated by measuring cytokine secretion following re-stimulation of activated T cells with both normal and tumor cell targets. In vivo antitumor efficacy was also tested in survival studies of intracranial tumor-bearing animals. RESULTS: We generated T cells specific to the developing cerebellum in vitro, confirming the immunogenicity of developmentally regulated antigens. Additionally, we have shown that developmental antigen-specific T cells produce high levels of Th1-type cytokines in response to tumor cells of two immunologically distinct subtypes of MB. Interestingly, developmental antigen specific T cells do not show cross reactivity with the normal brain or subsequent stages of the developing brain after P5. Targeting developmental antigens also conferred a significant survival benefit in a treatment model of Group 3 tumor bearing animals. CONCLUSIONS: Developmental antigens can safely target multiple MB subtypes with equal effectiveness compared to previously established total tumor strategies.

odd skipped related1 reveals a novel role for endoderm in regulating kidney vs. vascular cell fate

PubMed Central

Mudumana, Sudha P.; Hentschel, Dirk; Liu, Yan; Vasilyev, Aleksandr; Drummond, Iain A.

2009-01-01

Summary The kidney and vasculature are intimately linked functionally and during development, where nephric and blood/vascular progenitor cells occupy adjacent bands of mesoderm in zebrafish and frog embryos. Developmental mechanisms underlying the differentiation of kidney vs. blood/vascular lineages remain unknown. The odd skipped related1 (osr1) gene encodes a zinc finger transcription factor that is expressed in the germ ring mesendoderm and subsequently in the endoderm and intermediate mesoderm, prior to the expression of definitive kidney or blood/vascular markers. Knockdown of osr1 in zebrafish embryos resulted in a complete, segment-specific loss of anterior kidney progenitors and a compensatory increase in the number of angioblast cells in the same trunk region. Histology revealed a subsequent absence of kidney tubules, enlarged cardinal vein, and expansion of the posterior venous plexus. Altered kidney vs. vascular development correlated with expanded endoderm development in osr1 knockdowns. Combined osr1 loss of function and blockade of endoderm development by knockdown of sox32/casanova rescued anterior kidney development. The results indicate that osr1 activity is required to limit endoderm differentiation from mesendoderm and, in the absence of osr1, excess endoderm alters mesoderm differentiation, shifting the balance from kidney toward vascular development. PMID:18787069

Fine-Tuning of Neurogenesis is Essential for the Evolutionary Expansion of the Cerebral Cortex

PubMed Central

Poluch, Sylvie; Juliano, Sharon L.

2015-01-01

We used several animal models to study global and regional cortical surface expansion: The lissencephalic mouse, gyrencephalic normal ferrets, in which the parietal cortex expands more than the temporal cortex, and moderately lissencephalic ferrets, showing a similar degree of temporal and parietal expansion. We found that overall cortical surface expansion is achieved when specific events occur prior to surpragranular layer formation. (1) The subventricular zone (SVZ) shows substantial growth, (2) the inner SVZ contains an increased number of outer radial glia and intermediate progenitor cells expressing Pax6, and (3) the outer SVZ contains a progenitor cell composition similar to the combined VZ and inner SVZ. A greater parietal expansion is also achieved by eliminating the latero-dorsal neurogenic gradient, so that neurogenesis displays a similar developmental degree between parietal and temporal regions. In contrast, mice or lissencephalic ferrets show more advanced neurogenesis in the temporal region. In conclusion, we propose that global and regional cortical surface expansion rely on similar strategies consisting in altering the timing of neurogenic events prior to the surpragranular layer formation, so that more progenitor cells, and ultimately more neurons, are produced. This hypothesis is supported by findings from a ferret model of lissencephaly obtained by transiently blocking neurogenesis during the formation of layer IV. PMID:23968831

Maternal and developmental toxicity of ayahuasca in Wistar rats.

PubMed

Oliveira, Carolina Dizioli Rodrigues; Moreira, Camila Queiroz; de Sá, Lilian Rose Marques; Spinosa, Helenice de Souza; Yonamine, Mauricio

2010-06-01

Ayahuasca is a psychotropic plant beverage initially used by shamans throughout the Amazon region during traditional religious cult. In recent years, ayahuasca has also been used in ceremonies of a number of modern syncretic religious groups, including pregnant women. However, no documented study has been performed to evaluate the risk of developmental toxicity of ayahuasca. In the present work, maternal and developmental toxicity was evaluated in Wistar rats. Ayahuasca was administered to pregnant rats in three different doses [the equivalent typical dose (TD) administered to humans, five-fold TD and 10-fold TD] during the gestational period (6-20 days). Dams treated with the highest ayahuasca dose showed maternal toxicity with decrease of weight gain and food intake. Visceral fetal findings were observed in all treatment groups. Skeletal findings were observed in the intermediate- and high-dose groups. The fetuses deriving from the highest dose group also presented a decrease in body weight. From these results, it is possible to conclude that there is a risk of maternal and developmental toxicity following ayahuasca exposure and that the level of toxicity appears to be dose-dependent.

Identification and Targeting of Candidate Preexisting Lurker Cells That Give Rise to Castration-Resistant Prostate Cancer

DTIC Science & Technology

2016-10-01

cells as the pre-existing “lurker” cells in primary prostate tumors, to evaluate potential therapeutic targets in intermediate luminal progenitor cells...intermediate luminal progenitor cells as the pre-existing “lurker” cells in primary prostate tumors, to evaluate potential therapeutic targets in...candidate target expressed in CD38-lo cells and evaluated the role of CD38 in cell proliferation. No prior Hormonal *** No prior therapy

A DNA damage checkpoint pathway coordinates the division of dikaryotic cells in the ink cap mushroom Coprinopsis cinerea.

PubMed

de Sena-Tomás, Carmen; Navarro-González, Mónica; Kües, Ursula; Pérez-Martín, José

2013-09-01

The fungal fruiting body or mushroom is a multicellular structure essential for sexual reproduction. It is composed of dikaryotic cells that contain one haploid nucleus from each mating partner sharing the same cytoplasm without undergoing nuclear fusion. In the mushroom, the pileus bears the hymenium, a layer of cells that includes the specialized basidia in which nuclear fusion, meiosis, and sporulation occur. Coprinopsis cinerea is a well-known model fungus used to study developmental processes associated with the formation of the fruiting body. Here we describe that knocking down the expression of Atr1 and Chk1, two kinases shown to be involved in the response to DNA damage in a number of eukaryotic organisms, dramatically impairs the ability to develop fruiting bodies in C. cinerea, as well as other developmental decisions such as sclerotia formation. These developmental defects correlated with the impairment in silenced strains to sustain an appropriated dikaryotic cell cycle. Dikaryotic cells in which chk1 or atr1 genes were silenced displayed a higher level of asynchronous mitosis and as a consequence aberrant cells carrying an unbalanced dose of nuclei. Since fruiting body initiation is dependent on the balanced mating-type regulator doses present in the dikaryon, we believe that the observed developmental defects were a consequence of the impaired cell cycle in the dikaryon. Our results suggest a connection between the DNA damage response cascade, cell cycle regulation, and developmental processes in this fungus.

Systems Modeling in Developmental Toxicity

EPA Science Inventory

An individual starts off as a single cell, the progeny of which form complex structures that are themselves integrated into progressively larger systems. Developmental biology is concerned with how this cellular complexity and patterning arises through orchestration of cell divi...

Pluripotent stem cell-derived organoids: using principles of developmental biology to grow human tissues in a dish.

PubMed

McCauley, Heather A; Wells, James M

2017-03-15

Pluripotent stem cell (PSC)-derived organoids are miniature, three-dimensional human tissues generated by the application of developmental biological principles to PSCs in vitro The approach to generate organoids uses a combination of directed differentiation, morphogenetic processes, and the intrinsically driven self-assembly of cells that mimics organogenesis in the developing embryo. The resulting organoids have remarkable cell type complexity, architecture and function similar to their in vivo counterparts. In the past five years, human PSC-derived organoids with components of all three germ layers have been generated, resulting in the establishment of a new human model system. Here, and in the accompanying poster, we provide an overview of how principles of developmental biology have been essential for generating human organoids in vitro , and how organoids are now being used as a primary research tool to investigate human developmental biology. © 2017. Published by The Company of Biologists Ltd.

FBXL19 recruits CDK-Mediator to CpG islands of developmental genes priming them for activation during lineage commitment

PubMed Central

Dimitrova, Emilia; Nakayama, Manabu; Koseki, Yoko; Konietzny, Rebecca; Kessler, Benedikt M; Koseki, Haruhiko

2018-01-01

CpG islands are gene regulatory elements associated with the majority of mammalian promoters, yet how they regulate gene expression remains poorly understood. Here, we identify FBXL19 as a CpG island-binding protein in mouse embryonic stem (ES) cells and show that it associates with the CDK-Mediator complex. We discover that FBXL19 recruits CDK-Mediator to CpG island-associated promoters of non-transcribed developmental genes to prime these genes for activation during cell lineage commitment. We further show that recognition of CpG islands by FBXL19 is essential for mouse development. Together this reveals a new CpG island-centric mechanism for CDK-Mediator recruitment to developmental gene promoters in ES cells and a requirement for CDK-Mediator in priming these developmental genes for activation during cell lineage commitment. PMID:29809150

Nanostructured Materials Developed for Solar Cells

NASA Technical Reports Server (NTRS)

Bailey, Sheila G.; Castro, Stephanie L.; Raffaelle, Ryne P.; Fahey, Stephen D.; Gennett, Thomas; Tin, Padetha

2004-01-01

There has been considerable investigation recently regarding the potential for the use of nanomaterials and nanostructures to increase the efficiency of photovoltaic devices. Efforts at the NASA Glenn Research Center have involved the development and use of quantum dots and carbon nanotubes to enhance inorganic and organic cell efficiencies. Theoretical results have shown that a photovoltaic device with a single intermediate band of states resulting from the introduction of quantum dots offers a potential efficiency of 63.2 percent. A recent publication extended the intermediate band theory to two intermediate bands and calculated a limiting efficiency of 71.7 percent. The enhanced efficiency results from converting photons of energy less than the band gap of the cell by an intermediate band. The intermediate band provides a mechanism for low-energy photons to excite carriers across the energy gap by a two-step process.

Effects of nuclear transfer procedures on ES cell cloning efficiency in the mouse.

PubMed

Yabuuchi, Akiko; Yasuda, Yoshiko; Kato, Yoko; Tsunoda, Yukio

2004-04-01

Enucleated oocytes receiving mouse embryonic stem (ES) cells develop into fertile young. The developmental potential to young is low, however, and the rate of postnatal death is high. We examined the effect of various nuclear transfer procedures on the in vitro and in vivo developmental potential of nuclear-transferred oocytes. The potential of oocytes receiving ES cells at M phase to develop into blastocysts after fusion by Sendai virus was high compared with that after direct injection (67% vs. 30%). The developmental potential of oocytes receiving ES cells at the M phase is higher than that of oocytes receiving ES cells at the G(1) phase (30-67% vs. 2-5%). Developmental ability to live young was low in all groups (0-4%). Different activation protocols affected the potential to develop into blastocysts to a different extent (27-62%), but did not affect the potential to develop into live young (0-3%). The present study demonstrated that the various conditions examined did not affect the potential of nuclear-transferred oocytes receiving ES cells to develop into live young or the incidence of postnatal death.

A Drosophila LexA Enhancer-Trap Resource for Developmental Biology and Neuroendocrine Research

PubMed Central

Kockel, Lutz; Huq, Lutfi M.; Ayyar, Anika; Herold, Emma; MacAlpine, Elle; Logan, Madeline; Savvides, Christina; Kim, Grace E. S.; Chen, Jiapei; Clark, Theresa; Duong, Trang; Fazel-Rezai, Vahid; Havey, Deanna; Han, Samuel; Jagadeesan, Ravi; Kim, Eun Soo Jackie; Lee, Diane; Lombardo, Kaelina; Piyale, Ida; Shi, Hansen; Stahr, Lydia; Tung, Dana; Tayvah, Uriel; Wang, Flora; Wang, Ja-Hon; Xiao, Sarah; Topper, Sydni M.; Park, Sangbin; Rotondo, Cheryl; Rankin, Anne E.; Chisholm, Townley W.; Kim, Seung K.

2016-01-01

Novel binary gene expression tools like the LexA-LexAop system could powerfully enhance studies of metabolism, development, and neurobiology in Drosophila. However, specific LexA drivers for neuroendocrine cells and many other developmentally relevant systems remain limited. In a unique high school biology course, we generated a LexA-based enhancer trap collection by transposon mobilization. The initial collection provides a source of novel LexA-based elements that permit targeted gene expression in the corpora cardiaca, cells central for metabolic homeostasis, and other neuroendocrine cell types. The collection further contains specific LexA drivers for stem cells and other enteric cells in the gut, and other developmentally relevant tissue types. We provide detailed analysis of nearly 100 new LexA lines, including molecular mapping of insertions, description of enhancer-driven reporter expression in larval tissues, and adult neuroendocrine cells, comparison with established enhancer trap collections and tissue specific RNAseq. Generation of this open-resource LexA collection facilitates neuroendocrine and developmental biology investigations, and shows how empowering secondary school science can achieve research and educational goals. PMID:27527793

A Drosophila LexA Enhancer-Trap Resource for Developmental Biology and Neuroendocrine Research.

PubMed

Kockel, Lutz; Huq, Lutfi M; Ayyar, Anika; Herold, Emma; MacAlpine, Elle; Logan, Madeline; Savvides, Christina; Kim, Grace E S; Chen, Jiapei; Clark, Theresa; Duong, Trang; Fazel-Rezai, Vahid; Havey, Deanna; Han, Samuel; Jagadeesan, Ravi; Kim, Eun Soo Jackie; Lee, Diane; Lombardo, Kaelina; Piyale, Ida; Shi, Hansen; Stahr, Lydia; Tung, Dana; Tayvah, Uriel; Wang, Flora; Wang, Ja-Hon; Xiao, Sarah; Topper, Sydni M; Park, Sangbin; Rotondo, Cheryl; Rankin, Anne E; Chisholm, Townley W; Kim, Seung K

2016-10-13

Novel binary gene expression tools like the LexA-LexAop system could powerfully enhance studies of metabolism, development, and neurobiology in Drosophila However, specific LexA drivers for neuroendocrine cells and many other developmentally relevant systems remain limited. In a unique high school biology course, we generated a LexA-based enhancer trap collection by transposon mobilization. The initial collection provides a source of novel LexA-based elements that permit targeted gene expression in the corpora cardiaca, cells central for metabolic homeostasis, and other neuroendocrine cell types. The collection further contains specific LexA drivers for stem cells and other enteric cells in the gut, and other developmentally relevant tissue types. We provide detailed analysis of nearly 100 new LexA lines, including molecular mapping of insertions, description of enhancer-driven reporter expression in larval tissues, and adult neuroendocrine cells, comparison with established enhancer trap collections and tissue specific RNAseq. Generation of this open-resource LexA collection facilitates neuroendocrine and developmental biology investigations, and shows how empowering secondary school science can achieve research and educational goals. Copyright © 2016 Kockel et al.

Using Comic Books and Graphic Novels to Improve and Facilitate Community College Students' Literacy Development

ERIC Educational Resources Information Center

Burke, Brian Patrick

2012-01-01

This study evaluated how comic books and graphic novels enhanced the reading comprehension of the students enrolled in the intermediate reading course at Western Pennsylvania Community College. The three research questions are: (1) How can a developmental reading course make use of comics as a learning tool? (2) What impact does reading comics…

Satisfaction and Sense of Well Being among Medicaid ICF/MR and HCBS Recipients in Six States

ERIC Educational Resources Information Center

Stancliffe, Roger J.; Lakin, K. Charlie; Taub, Sarah; Chiri, Giuseppina; Byun, Soo-yong

2009-01-01

Self-reported satisfaction and sense of well-being were assessed in a sample of 1,885 adults with intellectual and developmental disabilities receiving Medicaid Home and Community Based Services (HCBS) and Intermediate Care Facility (ICF/MR) services in 6 states. Questions dealt with such topics as loneliness, feeling afraid at home and in one's…

Mouse model of chromosome mosaicism reveals lineage-specific depletion of aneuploid cells and normal developmental potential.

PubMed

Bolton, Helen; Graham, Sarah J L; Van der Aa, Niels; Kumar, Parveen; Theunis, Koen; Fernandez Gallardo, Elia; Voet, Thierry; Zernicka-Goetz, Magdalena

2016-03-29

Most human pre-implantation embryos are mosaics of euploid and aneuploid cells. To determine the fate of aneuploid cells and the developmental potential of mosaic embryos, here we generate a mouse model of chromosome mosaicism. By treating embryos with a spindle assembly checkpoint inhibitor during the four- to eight-cell division, we efficiently generate aneuploid cells, resulting in embryo death during peri-implantation development. Live-embryo imaging and single-cell tracking in chimeric embryos, containing aneuploid and euploid cells, reveal that the fate of aneuploid cells depends on lineage: aneuploid cells in the fetal lineage are eliminated by apoptosis, whereas those in the placental lineage show severe proliferative defects. Overall, the proportion of aneuploid cells is progressively depleted from the blastocyst stage onwards. Finally, we show that mosaic embryos have full developmental potential, provided they contain sufficient euploid cells, a finding of significance for the assessment of embryo vitality in the clinic.

Preserved local but disrupted contextual figure-ground influences in an individual with abnormal function of intermediate visual areas

PubMed Central

Brooks, Joseph L.; Gilaie-Dotan, Sharon; Rees, Geraint; Bentin, Shlomo; Driver, Jon

2012-01-01

Visual perception depends not only on local stimulus features but also on their relationship to the surrounding stimulus context, as evident in both local and contextual influences on figure-ground segmentation. Intermediate visual areas may play a role in such contextual influences, as we tested here by examining LG, a rare case of developmental visual agnosia. LG has no evident abnormality of brain structure and functional neuroimaging showed relatively normal V1 function, but his intermediate visual areas (V2/V3) function abnormally. We found that contextual influences on figure-ground organization were selectively disrupted in LG, while local sources of figure-ground influences were preserved. Effects of object knowledge and familiarity on figure-ground organization were also significantly diminished. Our results suggest that the mechanisms mediating contextual and familiarity influences on figure-ground organization are dissociable from those mediating local influences on figure-ground assignment. The disruption of contextual processing in intermediate visual areas may play a role in the substantial object recognition difficulties experienced by LG. PMID:22947116

Prenatal betamethasone does not affect glutamatergic or GABAergic neurogenesis in preterm newborns

PubMed Central

Vose, Linnea R.; Vinukonda, Govindaiah; Diamond, Daniel; Korumilli, Ritesh; Hu, Furong; Zia, Muhammad TK; Hevner, Robert; Ballabh, Praveen

2014-01-01

Prenatal glucocorticoids (GCs) are routinely used for pregnant women in preterm labor to prevent respiratory distress syndrome and intraventricular hemorrhage in premature infants. However, the effect of antenatal GCs on neurogenesis in preterm neonates remains elusive. Herein, we hypothesized that prenatal GCs might suppress both glutamatergic and GABAergic neurogenesis in preterm rabbits and that this treatment would induce distinct changes in the expression of transcription factors regulating these developmental events. To test our hypotheses, we treated pregnant rabbits with betamethasone at E27 and E28, delivered the pups at E29 (term=32d), and assessed neurogenesis at birth and postnatal day 3. We quantified radial glia (Sox2+) and intermediate progenitor cells (Tbr2+) in the dorsal cortical subventricular zone to assess glutamatergic neuronal progenitors, and counted Nkx2.1+ and Dlx2+ cells in the ganglionic eminence to evaluate GABAergic neurogenesis. In addition, we assayed transcription factors regulating neurogenesis. We found that prenatal GCs did not affect the densities of radial glia and intermediate progenitors of glutamatergic or GABAergic neurons. The number of GABA+ interneurons in the ganglionic eminence was similar between the prenatal GC treated pups compared to untreated controls. Moreover, the mRNA expression of transcription factors, including Pax6, Ngn1/2, Emx1/2, Insm1, Dlx1, Nkx2.1, and Gsh2, were comparable between the two groups. However, there was a transient elevation in Mash1 protein in betamethasone treated pups relative to controls at birth. This data suggests that prenatal GC treatment does not significantly impact the balance of glutamatergic and GABAergic neurogenesis in premature infants. PMID:24735821

Virtual Tissue Models in Developmental Toxicity Research

EPA Science Inventory

Prenatal exposure to drugs and chemicals may perturb, directly or indirectly, core developmental processes in the embryo (patterning, morphogenesis, proliferation and apoptosis, and cell differentiation), leading to adverse developmental outcomes. Because embryogenesis entails a...

Genetic alteration of UDP-rhamnose metabolism in Botrytis cinerea leads to the accumulation of UDP-KDG that adversely affects development and pathogenicity.

PubMed

Ma, Liang; Salas, Omar; Bowler, Kyle; Oren-Young, Liat; Bar-Peled, Maor; Sharon, Amir

2017-02-01

Botrytis cinerea is a model plant-pathogenic fungus that causes grey mould and rot diseases in a wide range of agriculturally important crops. A previous study has identified two enzymes and corresponding genes (bcdh, bcer) that are involved in the biochemical transformation of uridine diphosphate (UDP)-glucose, the major fungal wall nucleotide sugar precursor, to UDP-rhamnose. We report here that deletion of bcdh, the first biosynthetic gene in the metabolic pathway, or of bcer, the second gene in the pathway, abolishes the production of rhamnose-containing glycans in these mutant strains. Deletion of bcdh or double deletion of both bcdh and bcer has no apparent effect on fungal development or pathogenicity. Interestingly, deletion of the bcer gene alone adversely affects fungal development, giving rise to altered hyphal growth and morphology, as well as reduced sporulation, sclerotia production and virulence. Treatments with wall stressors suggest the alteration of cell wall integrity. Analysis of nucleotide sugars reveals the accumulation of the UDP-rhamnose pathway intermediate UDP-4-keto-6-deoxy-glucose (UDP-KDG) in hyphae of the Δbcer strain. UDP-KDG could not be detected in hyphae of the wild-type strain, indicating fast conversion to UDP-rhamnose by the BcEr enzyme. The correlation between high UDP-KDG and modified cell wall and developmental defects raises the possibility that high levels of UDP-KDG result in deleterious effects on cell wall composition, and hence on virulence. This is the first report demonstrating that the accumulation of a minor nucleotide sugar intermediate has such a profound and adverse effect on a fungus. The ability to identify molecules that inhibit Er (also known as NRS/ER) enzymes or mimic UDP-KDG may lead to the development of new antifungal drugs. © 2016 BSPP AND JOHN WILEY & SONS LTD.

Brain tumor specifies intermediate progenitor cell identity by attenuating β-catenin/Armadillo activity

PubMed Central

Komori, Hideyuki; Xiao, Qi; McCartney, Brooke M.; Lee, Cheng-Yu

2014-01-01

During asymmetric stem cell division, both the daughter stem cell and the presumptive intermediate progenitor cell inherit cytoplasm from their parental stem cell. Thus, proper specification of intermediate progenitor cell identity requires an efficient mechanism to rapidly extinguish the activity of self-renewal factors, but the mechanisms remain unknown in most stem cell lineages. During asymmetric division of a type II neural stem cell (neuroblast) in the Drosophila larval brain, the Brain tumor (Brat) protein segregates unequally into the immature intermediate neural progenitor (INP), where it specifies INP identity by attenuating the function of the self-renewal factor Klumpfuss (Klu), but the mechanisms are not understood. Here, we report that Brat specifies INP identity through its N-terminal B-boxes via a novel mechanism that is independent of asymmetric protein segregation. Brat-mediated specification of INP identity is critically dependent on the function of the Wnt destruction complex, which attenuates the activity of β-catenin/Armadillo (Arm) in immature INPs. Aberrantly increasing Arm activity in immature INPs further exacerbates the defects in the specification of INP identity and enhances the supernumerary neuroblast mutant phenotype in brat mutant brains. By contrast, reducing Arm activity in immature INPs suppresses supernumerary neuroblast formation in brat mutant brains. Finally, reducing Arm activity also strongly suppresses supernumerary neuroblasts induced by overexpression of klu. Thus, the Brat-dependent mechanism extinguishes the function of the self-renewal factor Klu in the presumptive intermediate progenitor cell by attenuating Arm activity, balancing stem cell maintenance and progenitor cell specification. PMID:24257623

HSF-1 activates the ubiquitin proteasome system to promote non-apoptotic developmental cell death in C. elegans.

PubMed

Kinet, Maxime J; Malin, Jennifer A; Abraham, Mary C; Blum, Elyse S; Silverman, Melanie R; Lu, Yun; Shaham, Shai

2016-03-08

Apoptosis is a prominent metazoan cell death form. Yet, mutations in apoptosis regulators cause only minor defects in vertebrate development, suggesting that another developmental cell death mechanism exists. While some non-apoptotic programs have been molecularly characterized, none appear to control developmental cell culling. Linker-cell-type death (LCD) is a morphologically conserved non-apoptotic cell death process operating in Caenorhabditis elegans and vertebrate development, and is therefore a compelling candidate process complementing apoptosis. However, the details of LCD execution are not known. Here we delineate a molecular-genetic pathway governing LCD in C. elegans. Redundant activities of antagonistic Wnt signals, a temporal control pathway, and mitogen-activated protein kinase kinase signaling control heat shock factor 1 (HSF-1), a conserved stress-activated transcription factor. Rather than protecting cells, HSF-1 promotes their demise by activating components of the ubiquitin proteasome system, including the E2 ligase LET-70/UBE2D2 functioning with E3 components CUL-3, RBX-1, BTBD-2, and SIAH-1. Our studies uncover design similarities between LCD and developmental apoptosis, and provide testable predictions for analyzing LCD in vertebrates.

GHF-1-promoter-targeted immortalization of a somatotropic progenitor cell results in dwarfism in transgenic mice.

PubMed

Lew, D; Brady, H; Klausing, K; Yaginuma, K; Theill, L E; Stauber, C; Karin, M; Mellon, P L

1993-04-01

During pituitary development, the homeo domain protein GHF-1 is required for generation of somatotropes and lactotropes and for growth hormone (GH) and prolactin (PRL) gene expression. GHF-1 mRNA is detectable several days before the emergence of GH- or PRL-expressing cells, suggesting the existence of a somatotropic progenitor cell in which GHF-1 transcription is first activated. We have immortalized this cell type by using the GHF-1 regulatory region to target SV40 T-antigen (Tag) tumorigenesis in transgenic mice. The GHF-Tag transgene caused developmental entrapment of somatotropic progenitor cells that express GHF-1 but not GH or PRL, resulting in dwarfism. Immortalized cell lines derived from a transgenic pituitary tumor maintain the characteristics of the somato/lactotropic progenitor in that they express GHF-1 mRNA and protein yet fail to activate GH or PRL transcription. Using these cells, we identified an enhancer that activates GHF-1 transcription at this early stage of development yet is inactive in cells representing later developmental stages of the somatotropic lineage or in other cell types. These experiments not only demonstrate the potential for immortalization of developmental progenitor cells using the regulatory regions from cell type-specific transcription factor genes but illustrate the power of such model systems in the study of developmental control.

Cadherins in cerebellar development: translation of embryonic patterning into mature functional compartmentalization.

PubMed

Redies, Christoph; Neudert, Franziska; Lin, Juntang

2011-09-01

Cadherins are cell adhesion molecules with multiple morphogenic functions in brain development, for example, in neuroblast migration and aggregation, axon navigation, neural circuit formation, and synaptogenesis. More than 100 members of the cadherin superfamily are expressed in the developing and mature brain. Most of the cadherins investigated, in particular classic cadherins and δ-protocadherins, are expressed in the cerebellum. For several cadherin subtypes, expression begins at early embryonic stages and persists until mature stages of cerebellar development. At intermediate stages, distinct Purkinje cell clusters exhibit unique rostrocaudal and mediolateral expression profiles for each cadherin. In the chicken, mouse, and other species, the Purkinje cell clusters are separated by intervening raphes of migrating granule cells. This pattern of Purkinje cell clusters/raphes is, at least in part, continuous with the parasagittal striping pattern that is apparent in the mature cerebellar cortex, for example, for zebrin II/aldolase C. Moreover, subregions of the deep cerebellar nuclei, vestibular nuclei and the olivary complex also express cadherins differentially. Neuroanatomical evidence suggests that the nuclear subregions and cortical domains that express the same cadherin subtype are connected to each other, to form neural subcircuits of the cerebellar system. Cadherins thus provide a molecular code that specifies not only embryonic structures but also functional cerebellar compartmentalization. By following the implementation of this code, it can be revealed how mature functional architecture emerges from embryonic patterning during cerebellar development. Dysfunction of some cadherins is associated with psychiatric diseases and developmental impairments and may also affect cerebellar function.

Integrated modulation of phorbol ester-induced Raf activation in EL4 lymphoma cells.

PubMed

Han, Shujie; Meier, Kathryn E

2009-05-01

The EL4 murine lymphoma cell line exists in variant phenotypes that differ with respect to responses to the tumor promoter phorbol 12-myristate 13-acetate (PMA1). Previous work showed that "PMA-sensitive" cells, characterized by a high magnitude of PMA-induced Erk activation, express RasGRP, a phorbol ester receptor that directly activates Ras. In "PMA-resistant" and "intermediate" EL4 cell lines, PMA induces Erk activation to lesser extents, but with a greater response in intermediate cells. In the current study, these cell lines were used to examine mechanisms of Raf-1 modulation. Phospho-specific antibodies were utilized to define patterns and kinetics of Raf-1 phosphorylation on several sites. Further studies showed that Akt is constitutively activated to a greater extent in PMA-resistant than in PMA-sensitive cells, and also to a greater extent in resistant than intermediate cells. Akt negatively regulates Raf-1 activation (Ser259), partially explaining the difference between resistant and intermediate cells. Erk activation exerts negative feedback on Raf-1 (Ser289/296/301), thus resulting in earlier termination of the signal in cells with a higher level of Erk activation. RKIP, a Raf inhibitory protein, is expressed at higher levels in resistant cells than in sensitive or intermediate cells. Knockdown of RKIP increases Erk activation and also negative feedback. In conclusion, this study delineates Raf-1 phosphorylation events occurring in response to PMA in cell lines with different extents of Erk activation. Variations in the levels of expression and activation of multiple signaling proteins work in an integrated fashion to modulate the extent and duration of Erk activation.

Human pluripotent stem cells: an emerging model in developmental biology.

PubMed

Zhu, Zengrong; Huangfu, Danwei

2013-02-01

Developmental biology has long benefited from studies of classic model organisms. Recently, human pluripotent stem cells (hPSCs), including human embryonic stem cells and human induced pluripotent stem cells, have emerged as a new model system that offers unique advantages for developmental studies. Here, we discuss how studies of hPSCs can complement classic approaches using model organisms, and how hPSCs can be used to recapitulate aspects of human embryonic development 'in a dish'. We also summarize some of the recently developed genetic tools that greatly facilitate the interrogation of gene function during hPSC differentiation. With the development of high-throughput screening technologies, hPSCs have the potential to revolutionize gene discovery in mammalian development.

Single-Cell Resolution of Temporal Gene Expression during Heart Development.

PubMed

DeLaughter, Daniel M; Bick, Alexander G; Wakimoto, Hiroko; McKean, David; Gorham, Joshua M; Kathiriya, Irfan S; Hinson, John T; Homsy, Jason; Gray, Jesse; Pu, William; Bruneau, Benoit G; Seidman, J G; Seidman, Christine E

2016-11-21

Activation of complex molecular programs in specific cell lineages governs mammalian heart development, from a primordial linear tube to a four-chamber organ. To characterize lineage-specific, spatiotemporal developmental programs, we performed single-cell RNA sequencing of >1,200 murine cells isolated at seven time points spanning embryonic day 9.5 (primordial heart tube) to postnatal day 21 (mature heart). Using unbiased transcriptional data, we classified cardiomyocytes, endothelial cells, and fibroblast-enriched cells, thus identifying markers for temporal and chamber-specific developmental programs. By harnessing these datasets, we defined developmental ages of human and mouse pluripotent stem-cell-derived cardiomyocytes and characterized lineage-specific maturation defects in hearts of mice with heterozygous mutations in Nkx2.5 that cause human heart malformations. This spatiotemporal transcriptome analysis of heart development reveals lineage-specific gene programs underlying normal cardiac development and congenital heart disease. Copyright © 2016 Elsevier Inc. All rights reserved.

Dilute group III-V nitride intermediate band solar cells with contact blocking layers

DOEpatents

Walukiewicz, Wladyslaw; Yu, Kin Man

2015-02-24

An intermediate band solar cell (IBSC) is provided including a p-n junction based on dilute III-V nitride materials and a pair of contact blocking layers positioned on opposite surfaces of the p-n junction for electrically isolating the intermediate band of the p-n junction by blocking the charge transport in the intermediate band without affecting the electron and hole collection efficiency of the p-n junction, thereby increasing open circuit voltage (V.sub.OC) of the IBSC and increasing the photocurrent by utilizing the intermediate band to absorb photons with energy below the band gap of the absorber layers of the IBSC. Hence, the overall power conversion efficiency of a IBSC will be much higher than an conventional single junction solar cell. The p-n junction absorber layers of the IBSC may further have compositionally graded nitrogen concentrations to provide an electric field for more efficient charge collection.

Dilute Group III-V nitride intermediate band solar cells with contact blocking layers

DOEpatents

Walukiewicz, Wladyslaw [Kensington, CA; Yu, Kin Man [Lafayette, CA

2012-07-31

An intermediate band solar cell (IBSC) is provided including a p-n junction based on dilute III-V nitride materials and a pair of contact blocking layers positioned on opposite surfaces of the p-n junction for electrically isolating the intermediate band of the p-n junction by blocking the charge transport in the intermediate band without affecting the electron and hole collection efficiency of the p-n junction, thereby increasing open circuit voltage (V.sub.OC) of the IBSC and increasing the photocurrent by utilizing the intermediate band to absorb photons with energy below the band gap of the absorber layers of the IBSC. Hence, the overall power conversion efficiency of a IBSC will be much higher than an conventional single junction solar cell. The p-n junction absorber layers of the IBSC may further have compositionally graded nitrogen concentrations to provide an electric field for more efficient charge collection.

Homologous recombination and non-homologous end-joining repair pathways in bovine embryos with different developmental competence

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

Henrique Barreta, Marcos; Laboratorio de Biotecnologia e Reproducao Animal-BioRep, Universidade Federal de Santa Maria, Santa Maria, RS; Garziera Gasperin, Bernardo

2012-10-01

This study investigated the expression of genes controlling homologous recombination (HR), and non-homologous end-joining (NHEJ) DNA-repair pathways in bovine embryos of different developmental potential. It also evaluated whether bovine embryos can respond to DNA double-strand breaks (DSBs) induced with ultraviolet irradiation by regulating expression of genes involved in HR and NHEJ repair pathways. Embryos with high, intermediate or low developmental competence were selected based on the cleavage time after in vitro insemination and were removed from in vitro culture before (36 h), during (72 h) and after (96 h) the expected period of embryonic genome activation. All studied genes weremore » expressed before, during and after the genome activation period regardless the developmental competence of the embryos. Higher mRNA expression of 53BP1 and RAD52 was found before genome activation in embryos with low developmental competence. Expression of 53BP1, RAD51 and KU70 was downregulated at 72 h and upregulated at 168 h post-insemination in response to DSBs induced by ultraviolet irradiation. In conclusion, important genes controlling HR and NHEJ DNA-repair pathways are expressed in bovine embryos, however genes participating in these pathways are only regulated after the period of embryo genome activation in response to ultraviolet-induced DSBs.« less

Description of Rhagoletis cerasi (Diptera: Tephritidae) Pupal Developmental Stages: Indications of Prolonged Diapause

PubMed Central

Papanastasiou, Stella A.; Papadopoulos, Nikos T.

2014-01-01

Abstract The European cherry fruit fly, Rhagoletis cerasi (L.) (Diptera: Tephritidae), is the key pest of sweet and sour cherries in many European countries and west Asia. It is a univoltine species of the west Palaearctic zone that undergoes obligatory pupal diapause. In this study, the development of R. cerasi pupae that were brought to an optimum temperature for postdiapause development following a long chilling period is described. The six most representative developmental stages within the puparium are illustrated, and the developmental progression among the stages after the end of the chilling period is quantified. Within 20 d postchilling, there was a gradual progress from stage I to pharate adult. However, ∼30% of the pupae remained at the transitional stage II, after 20 d at 25°C (optimum temperature for development). This suggests that a proportion of pupae remain at an intermediate developmental stage for an extended period of time that goes beyond 20 d postchilling. The pupal stage II might be related to diapause termination and responsiveness to environmental cues. It may also define the time before developmental progress to pharate adult. This finding agrees with previous studies proposing that a number of R. cerasi pupae undergo prolonged diapause, though the morphological characteristics of these pupae have never been described before. PMID:25399427

Effects of early intraoral acesulfame-K stimulation to mice on the adult's sweet preference and the expression of α-gustducin in fungiform papilla.

PubMed

Chen, Meng-Ling; Liu, Si-Si; Zhang, Gen-Hua; Quan, Ying; Zhan, Yue-Hua; Gu, Tian-Yuan; Qin, Yu-Mei; Deng, Shao-Ping

2013-06-01

Exposure to artificial sweetener acesulfame-K (AK) at early development stages may influence the adult sweet preference and the periphery gustatory system. We observed that the intraoral AK stimulation to mice from postnatal day 4 (P4) to weaning decreased the preference thresholds for AK and sucrose solutions in adulthood, with the preference pattern unchanged. The preference scores were increased in the exposure group significantly when compared with the control group at a range of concentrations for AK or sucrose solution. Meanwhile, more α-Gustducin-labeled fungiform taste buds and cells in a single taste bud were induced from week 7 by the early intraoral AK stimulation. However, the growth in the number of α-Gustducin-positive taste bud or positive cell number per taste bud occurred only in the anterior region, the rostral 1-mm part, but not in the intermediate region, the caudal 4-mm part, of the anterior two-third of the tongue containing fungiform papillae. This work extends our previous observations and provides new information about the developmental and regional expression pattern of α-Gustducin in mouse fungiform taste bud under early AK-stimulated conditions.

Vomeronasal versus olfactory epithelium: is there a cellular basis for human vomeronasal perception?

PubMed

Witt, Martin; Hummel, Thomas

2006-01-01

The vomeronasal organ (VNO) constitutes an accessory olfactory organ that receives chemical stimuli, pheromones, which elicit behavioral, reproductive, or neuroendocrine responses among individuals of the same species. In many macrosmatic animals, the morphological substrate constitutes a separate organ system consisting of a vomeronasal duct (ductus vomeronasalis, VND), equipped with chemosensory cells, and a vomeronasal nerve (nervus vomeronasalis, VNN) conducting information into the accessory olfactory bulb (AOB) in the central nervous system (CNS). Recent data require that the long-accepted dual functionality of a main olfactory system and the VNO be reexamined, since all species without a VNO are nevertheless sexually active, and species possessing a VNO also can sense other than "vomeronasal" stimuli via the vomeronasal epithelium (VNE). The human case constitutes a borderline situation, as its embryonic VNO anlage exerts a developmental track common to most macrosmatics, but later typical structures such as the VNN, AOB, and probably most of the chemoreceptor cells within the still existent VND are lost. This review also presents recent information on the VND including immunohistochemical expression of neuronal markers, intermediate filaments, lectins, integrins, caveolin, CD44, and aquaporins. Further, we will address the issue of human pheromone candidates.

Integration of wings and their eyespots in the speckled wood butterfly Pararge aegeria.

PubMed

Breuker, Casper J; Gibbs, Melanie; Van Dyck, Hans; Brakefield, Paul M; Klingenberg, Christian Peter; Van Dongen, Stefan

2007-07-15

We investigated both the phenotypic and developmental integration of eyespots on the fore- and hindwings of speckled wood butterflies Pararge aegeria. Eyespots develop within a framework of wing veins, which may not only separate eyespots developmentally, but may at the same time also integrate them by virtue of being both signalling sources and barriers during eyespot development. We therefore specifically investigated the interaction between wing venation patterns and eyespot integration. Phenotypic covariation among eyespots was very high, but only eyespots in neighbouring wing cells and in homologous wing cells on different wing surfaces were developmentally integrated. This can be explained by the fact that the wing cells of these eyespots share one or more wing veins. The wing venation patterns of fore- and hindwings were highly integrated, both phenotypically and developmentally. This did not affect overall developmental integration of the eyespots. The adaptive significance of integration patterns is discussed and more specifically we stress the need to conduct studies on phenotypic plasticity of integration.

Predictability of spatio-temporal patterns in a lattice of coupled FitzHugh–Nagumo oscillators

PubMed Central

Grace, Miriam; Hütt, Marc-Thorsten

2013-01-01

In many biological systems, variability of the components can be expected to outrank statistical fluctuations in the shaping of self-organized patterns. In pioneering work in the late 1990s, it was hypothesized that a drift of cellular parameters (along a ‘developmental path’), together with differences in cell properties (‘desynchronization’ of cells on the developmental path) can establish self-organized spatio-temporal patterns (in their example, spiral waves of cAMP in a colony of Dictyostelium discoideum cells) starting from a homogeneous state. Here, we embed a generic model of an excitable medium, a lattice of diffusively coupled FitzHugh–Nagumo oscillators, into a developmental-path framework. In this minimal model of spiral wave generation, we can now study the predictability of spatio-temporal patterns from cell properties as a function of desynchronization (or ‘spread’) of cells along the developmental path and the drift speed of cell properties on the path. As a function of drift speed and desynchronization, we observe systematically different routes towards fully established patterns, as well as strikingly different correlations between cell properties and pattern features. We show that the predictability of spatio-temporal patterns from cell properties contains important information on the pattern formation process as well as on the underlying dynamical system. PMID:23349439

Developmental potential of murine germinal vesicle stage cumulus-oocyte complexes following exposure to dimethylsulphoxide or cryopreservation: loss of membrane integrity of cumulus cells after thawing.

PubMed

Ruppert-Lingham, C J; Paynter, S J; Godfrey, J; Fuller, B J; Shaw, R W

2003-02-01

Cumulus cells of the cumulus-oocyte complex (COC) are important in oocyte maturation. Thus, in preserving immature oocytes it is prudent to also preserve their associated cumulus cells. The survival and function of oocytes and their associated cumulus cells was assessed following cryopreservation or exposure to cryoprotectant without freezing. Immature COCs were collected from mice primed with pregnant mare's serum. COCs were either slow-cooled or exposed to 1.5 mol/l dimethylsulphoxide without freezing. Treated and fresh COCs were stained for membrane integrity or, after in-vitro maturation and IVF, were assessed for developmental capability. Development of cumulus-denuded fresh oocytes, as well as denuded and frozen-thawed oocytes co-cultured with fresh cumulus cells, was assessed. Slow-cooled oocytes had significantly reduced coverage by intact cumulus cells compared with fresh COCs. Cumulus cell association and developmental capability were not substantially affected by exposure to cryoprotectant without freezing. Denuded fresh oocytes and cryopreserved COCs had decreased developmental potential that was not overcome by co-culture with fresh cumulus cells. Loss of association between oocyte and cumulus cells was induced by cryopreservation, but not by treatment with cryoprotectant alone. The data indicate that direct physical contact between cumulus cells and the oocyte, throughout maturation, improves subsequent embryo development.

Progranulin regulates neurogenesis in the developing vertebrate retina.

PubMed

Walsh, Caroline E; Hitchcock, Peter F

2017-09-01

We evaluated the expression and function of the microglia-specific growth factor, Progranulin-a (Pgrn-a) during developmental neurogenesis in the embryonic retina of zebrafish. At 24 hpf pgrn-a is expressed throughout the forebrain, but by 48 hpf pgrn-a is exclusively expressed by microglia and/or microglial precursors within the brain and retina. Knockdown of Pgrn-a does not alter the onset of neurogenic programs or increase cell death, however, in its absence, neurogenesis is significantly delayed-retinal progenitors fail to exit the cell cycle at the appropriate developmental time and postmitotic cells do not acquire markers of terminal differentiation, and microglial precursors do not colonize the retina. Given the link between Progranulin and cell cycle regulation in peripheral tissues and transformed cells, we analyzed cell cycle kinetics among retinal progenitors following Pgrn-a knockdown. Depleting Pgrn-a results in a significant lengthening of the cell cycle. These data suggest that Pgrn-a plays a dual role during nervous system development by governing the rate at which progenitors progress through the cell cycle and attracting microglial progenitors into the embryonic brain and retina. Collectively, these data show that Pgrn-a governs neurogenesis by regulating cell cycle kinetics and the transition from proliferation to cell cycle exit and differentiation. © 2017 The Authors. Developmental Neurobiology Published by Wiley Periodicals, Inc. Develop Neurobiol 77: 1114-1129, 2017. © 2017 The Authors. Developmental Neurobiology Published by Wiley Periodicals, Inc.

Solid oxide fuel cell generator

DOEpatents

Draper, Robert; George, Raymond A.; Shockling, Larry A.

1993-01-01

A solid oxide fuel cell generator has a pair of spaced apart tubesheets in a housing. At least two intermediate barrier walls are between the tubesheets and define a generator chamber between two intermediate buffer chambers. An array of fuel cells have tubes with open ends engaging the tubesheets. Tubular, axially elongated electrochemical cells are supported on the tubes in the generator chamber. Fuel gas and oxidant gas are preheated in the intermediate chambers by the gases flowing on the other side of the tubes. Gas leakage around the tubes through the tubesheets is permitted. The buffer chambers reentrain the leaked fuel gas for reintroduction to the generator chamber.

Insights into Host Cell Modulation and Induction of New Cells by the Corn Smut Ustilago maydis.

PubMed

Redkar, Amey; Matei, Alexandra; Doehlemann, Gunther

2017-01-01

Many filamentous fungal pathogens induce drastic modulation of host cells causing abnormal infectious structures such as galls, or tumors that arise as a result of re-programming in the original developmental cell fate of a colonized host cell. Developmental consequences occur predominantly with biotrophic phytopathogens. This suggests that these host structures result as an outcome of efficient defense suppression and intimate fungal-host interaction to suit the pathogen's needs for completion of its infection cycle. This mini-review mainly summarizes host cell re-programming that occurs in the Ustilago maydis - maize interaction, in which the pathogen deploys cell-type specific effector proteins with varying activities. The fungus senses the physiological status and identity of colonized host cells and re-directs the endogenous developmental program of its host. The disturbance of host cell physiology and cell fate leads to novel cell shapes, increased cell size, and/or the number of host cells. We particularly highlight the strategies of U. maydis to induce physiologically varied host organs to form the characteristic tumors in both vegetative and floral parts of maize.

Decoding the Regulatory Network for Blood Development from Single-Cell Gene Expression Measurements

PubMed Central

Haghverdi, Laleh; Lilly, Andrew J.; Tanaka, Yosuke; Wilkinson, Adam C.; Buettner, Florian; Macaulay, Iain C.; Jawaid, Wajid; Diamanti, Evangelia; Nishikawa, Shin-Ichi; Piterman, Nir; Kouskoff, Valerie; Theis, Fabian J.; Fisher, Jasmin; Göttgens, Berthold

2015-01-01

Here we report the use of diffusion maps and network synthesis from state transition graphs to better understand developmental pathways from single cell gene expression profiling. We map the progression of mesoderm towards blood in the mouse by single-cell expression analysis of 3,934 cells, capturing cells with blood-forming potential at four sequential developmental stages. By adapting the diffusion plot methodology for dimensionality reduction to single-cell data, we reconstruct the developmental journey to blood at single-cell resolution. Using transitions between individual cellular states as input, we develop a single-cell network synthesis toolkit to generate a computationally executable transcriptional regulatory network model that recapitulates blood development. Model predictions were validated by showing that Sox7 inhibits primitive erythropoiesis, and that Sox and Hox factors control early expression of Erg. We therefore demonstrate that single-cell analysis of a developing organ coupled with computational approaches can reveal the transcriptional programs that control organogenesis. PMID:25664528

Mechanics of vimentin intermediate filaments

NASA Technical Reports Server (NTRS)

Wang, Ning; Stamenovic, Dimitrijie

2002-01-01

It is increasingly evident that the cytoskeleton of living cells plays important roles in mechanical and biological functions of the cells. Here we focus on the contribution of intermediate filaments (IFs) to the mechanical behaviors of living cells. Vimentin, a major structural component of IFs in many cell types, is shown to play an important role in vital mechanical and biological functions such as cell contractility, migration, stiffness, stiffening, and proliferation.

Bidirectional Interplay between Vimentin Intermediate Filaments and Contractile Actin Stress Fibers.

PubMed

Jiu, Yaming; Lehtimäki, Jaakko; Tojkander, Sari; Cheng, Fang; Jäälinoja, Harri; Liu, Xiaonan; Varjosalo, Markku; Eriksson, John E; Lappalainen, Pekka

2015-06-16

The actin cytoskeleton and cytoplasmic intermediate filaments contribute to cell migration and morphogenesis, but the interplay between these two central cytoskeletal elements has remained elusive. Here, we find that specific actin stress fiber structures, transverse arcs, interact with vimentin intermediate filaments and promote their retrograde flow. Consequently, myosin-II-containing arcs are important for perinuclear localization of the vimentin network in cells. The vimentin network reciprocally restricts retrograde movement of arcs and hence controls the width of flat lamellum at the leading edge of the cell. Depletion of plectin recapitulates the vimentin organization phenotype of arc-deficient cells without affecting the integrity of vimentin filaments or stress fibers, demonstrating that this cytoskeletal cross-linker is required for productive interactions between vimentin and arcs. Collectively, our results reveal that plectin-mediated interplay between contractile actomyosin arcs and vimentin intermediate filaments controls the localization and dynamics of these two cytoskeletal systems and is consequently important for cell morphogenesis. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Generation of an expandable intermediate mesoderm restricted progenitor cell line from human pluripotent stem cells

PubMed Central

Kumar, Nathan; Richter, Jenna; Cutts, Josh; Bush, Kevin T; Trujillo, Cleber; Nigam, Sanjay K; Gaasterland, Terry; Brafman, David; Willert, Karl

2015-01-01

The field of tissue engineering entered a new era with the development of human pluripotent stem cells (hPSCs), which are capable of unlimited expansion whilst retaining the potential to differentiate into all mature cell populations. However, these cells harbor significant risks, including tumor formation upon transplantation. One way to mitigate this risk is to develop expandable progenitor cell populations with restricted differentiation potential. Here, we used a cellular microarray technology to identify a defined and optimized culture condition that supports the derivation and propagation of a cell population with mesodermal properties. This cell population, referred to as intermediate mesodermal progenitor (IMP) cells, is capable of unlimited expansion, lacks tumor formation potential, and, upon appropriate stimulation, readily acquires properties of a sub-population of kidney cells. Interestingly, IMP cells fail to differentiate into other mesodermally-derived tissues, including blood and heart, suggesting that these cells are restricted to an intermediate mesodermal fate. DOI: http://dx.doi.org/10.7554/eLife.08413.001 PMID:26554899

Electronic Warfare for Cyber Warriors

DTIC Science & Technology

2008-06-01

This research paper provides complete course content for the AFIT EENG 509, Electronic Warfare class. It is intended as a replacement for the existing course and designed for Intermediate Developmental Education (IDE) students in the Cyber Warfare degree program. This course provides relevant academic courseware and study material to give cyber warriors an academic and operational perspective on electronic warfare and its integration in the cyber domain.

What It Takes. Air Force Command of Joint Operations

DTIC Science & Technology

2009-01-01

Iraq Assistance Group IDE intermediate developmental education IO international organization ISAF International Security and Assistance Force ISR...Operations Table A.1—Continued Joint Task Force Mission/Operation Start End Service Command Rank JTF–Joint Area Support Group (JASG) Iraqi Freedom...be of interest to a wide group of Air Force personnel involved in the development and func- tion of the service’s command organizations, including

Electron microscopic study of developmental stages of Rickettsiella phytoseiuli in Phytoseiulus persimilis Athias-Henriot (Gamasoidea:Phytoseiidae) mites.

PubMed

Sutáková, G

1988-01-01

Rickettsiella phytoseiuli was found in great amounts in all tissues except of the nervous system of adult Phytoseiulus persimilis mites. Six morphologically different stages (dense, intermediate, bacterial, giant, crystal-forming and small dark particles) of R. phytoseiuli were detected. No rickettsiae were seen in the larvae and in phase 1 and 2 nymphae of these mites.

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

Garige, Mamatha; Walters, Eric, E-mail: ewalters@howard.edu

The molecular basis for nutraceutical properties of the polyphenol curcumin (Curcuma longa, Turmeric) is complex, affecting multiple factors that regulate cell signaling and homeostasis. Here, we report the effect of curcumin on cellular and developmental mechanisms in the eukaryotic model, Dictyostelium discoideum. Dictyostelium proliferation was inhibited in the presence of curcumin, which also suppressed the prestarvation marker, discoidin I, members of the yakA-mediated developmental signaling pathway, and expression of the extracellular matrix/cell adhesion proteins (DdCAD and csA). This resulted in delayed chemotaxis, adhesion, and development of the organism. In contrast to the inhibitory effects on developmental genes, curcumin induced gstAmore » gene expression, overall GST activity, and generated production of reactive oxygen species. These studies expand our knowledge of developmental and biochemical signaling influenced by curcumin, and lends greater consideration of GST enzyme function in eukaryotic cell signaling, development, and differentiation.« less

Ascites-induced shift along epithelial-mesenchymal spectrum in ovarian cancer cells: enhancement of their invasive behavior partly dependant on αv integrins.

PubMed

Carduner, L; Leroy-Dudal, J; Picot, C R; Gallet, O; Carreiras, F; Kellouche, S

2014-08-01

At least one-third of patients with epithelial ovarian cancer (OC) present ascites at diagnosis and almost all have ascites at recurrence. The presence of ascites, which acts as a dynamic reservoir of active molecules and cellular components, correlates with the OC peritoneal metastasis and is associated with poor prognosis. Since epithelial-mesenchymal transition (EMT) is involved in different phases of OC progression, we have investigated the effect of the unique ascitic tumor microenvironment on the EMT status and the behavior of OC cells. The exposure of three OC cell lines to ascites leads to changes in cellular morphologies. Within ascites, OC cells harboring an initial intermediate epithelial phenotype are characterized by marked dislocation of epithelial markers (E-cadherin, ZO-1 staining) while OC cells initially harboring an intermediate mesenchymal phenotype strengthen their mesenchymal markers (N-cadherin, vimentin). Ascites differentially triggers a dissemination phenotype related to the initial cell features by either allowing the proliferation and the formation of spheroids and the extension of colonies for cells that present an initial epithelial intermediate phenotype, or favoring the migration of cells with a mesenchymal intermediate phenotype. In an ascitic microenvironment, a redeployment of αv integrins into cells was observed and the ascites-induced accentuation of the two different invasive phenotypes (i.e. spheroids formation or migration) was shown to involve αv integrins. Thus, ascites induces a shift toward an unstable intermediate state of the epithelial-mesenchymal spectrum and confers a more aggressive cell behavior that takes on a different pathway based on the initial epithelial-mesenchymal cell features.

Intermediate hepatobiliary cells predict an increased risk of hepatocarcinogenesis in patients with hepatitis C virus-related cirrhosis.

PubMed

Ziol, Marianne; Nault, Jean-Charles; Aout, Mounir; Barget, Nathalie; Tepper, Maryline; Martin, Antoine; Trinchet, Jean-Claude; Ganne-Carrié, Nathalie; Vicaut, Eric; Beaugrand, Michel; N'Kontchou, Gisele

2010-07-01

The expression of biliary lineage markers such as cytokeratin (K) 7 by hepatocytes is thought to reflect an altered regeneration pathway recruiting a stem cell compartment, more prone to carcinogenesis. We aimed to investigate the presence of these so-called intermediate hepatobiliary cells (IHC) in liver biopsies of patients with hepatitis C-related cirrhosis and their potential influence on the subsequent occurrence of hepatocellular carcinoma (HCC). From a cohort of patients with hepatitis C-related cirrhosis, prospectively screened for HCC, we retrospectively selected those with a liver biopsy performed for the initial diagnosis of cirrhosis. Presence of IHC was recorded when foci of K7-positive, intermediate-sized hepatocytes were detected. A total of 150 patients were included (87 men; mean age, 57 y; range, 19-84 y; body mass index, 25 kg/m(2)). After a median follow-up period of 4.85 years, HCC was diagnosed in 36 patients (24%). Baseline liver biopsy showed intermediate hepatobiliary cell foci in 61 patients (41%). Intermediate cells co-expressed both hepatocytes markers and the progenitor cell markers Ep-CAM and K19. The presence of intermediate hepatobiliary cells was associated independently with HCC occurrence (Fine and Gray model; hazard ratio, 2.48; 95% confidence interval, 1.24-4.96; P = .01). Other predictors of HCC were diabetes and low platelet count. The HCC annual incidence rate was significantly higher in patients with IHC compared with patients without (8.14% vs 3.12%, Gray's test, P = .003). The aberrant expression of biliary K by hepatocytes in patients with hepatitis C virus-related cirrhosis is related independently to HCC occurrence. Copyright 2010 AGA Institute. Published by Elsevier Inc. All rights reserved.

Characterization of Human Neural Progenitor Cell Models for Developmental Neurotoxicity Screening

EPA Science Inventory

Current testing methods for developmental neurotoxicity (DNT) make evaluation of the effects of large numbers of chemicals impractical and prohibitively expensive. As such, we are evaluating two different human neural progenitor cell (hNPC) models for their utility in screens for...

DNA Replication Control During Drosophila Development: Insights into the Onset of S Phase, Replication Initiation, and Fork Progression

PubMed Central

Hua, Brian L.; Orr-Weaver, Terry L.

2017-01-01

Proper control of DNA replication is critical to ensure genomic integrity during cell proliferation. In addition, differential regulation of the DNA replication program during development can change gene copy number to influence cell size and gene expression. Drosophila melanogaster serves as a powerful organism to study the developmental control of DNA replication in various cell cycle contexts in a variety of differentiated cell and tissue types. Additionally, Drosophila has provided several developmentally regulated replication models to dissect the molecular mechanisms that underlie replication-based copy number changes in the genome, which include differential underreplication and gene amplification. Here, we review key findings and our current understanding of the developmental control of DNA replication in the contexts of the archetypal replication program as well as of underreplication and differential gene amplification. We focus on the use of these latter two replication systems to delineate many of the molecular mechanisms that underlie the developmental control of replication initiation and fork elongation. PMID:28874453

Increase in Peripheral Blood Intermediate Monocytes is Associated with the Development of Recent-Onset Type 1 Diabetes Mellitus in Children.

PubMed

Ren, Xiaoya; Mou, Wenjun; Su, Chang; Chen, Xi; Zhang, Hui; Cao, Bingyan; Li, Xiaoqiao; Wu, Di; Ni, Xin; Gui, Jingang; Gong, Chunxiu

2017-01-01

Monocytes play important roles in antigen presentation and cytokine production to achieve a proper immune response, and are therefore largely implicated in the development and progression of autoimmune diseases. The aim of this study was to analyze the change in the intermediate (CD14+CD16+) monocyte subset in children with recent-onset type 1 diabetes mellitus (T1DM) and its possible association with clinical parameters reflecting islet β-cell dysfunction. Compared with age- and sex-matched healthy controls, intermediate monocytes were expanded in children with T1DM, which was positively associated with hemoglobin A1C and negatively associated with serum insulin and C-peptide. Interestingly, the intermediate monocytes in T1DM patients expressed higher levels of human leukocyte antigen-DR and CD86, suggesting better antigen presentation capability. Further analysis revealed that the frequency of CD45RO+CD4+ memory T cells was increased in the T1DM patients, and the memory T cell content was well correlated with the increase in intermediate monocytes. These results suggest that expanded intermediate monocytes are a predictive factor for the poor residual islet β-cell function in children with recent-onset T1DM.

Prolonged Mek1/2 suppression impairs the developmental potential of embryonic stem cells.

PubMed

Choi, Jiho; Huebner, Aaron J; Clement, Kendell; Walsh, Ryan M; Savol, Andrej; Lin, Kaixuan; Gu, Hongcang; Di Stefano, Bruno; Brumbaugh, Justin; Kim, Sang-Yong; Sharif, Jafar; Rose, Christopher M; Mohammad, Arman; Odajima, Junko; Charron, Jean; Shioda, Toshi; Gnirke, Andreas; Gygi, Steven; Koseki, Haruhiko; Sadreyev, Ruslan I; Xiao, Andrew; Meissner, Alexander; Hochedlinger, Konrad

2017-08-10

Concomitant activation of the Wnt pathway and suppression of Mapk signalling by two small molecule inhibitors (2i) in the presence of leukaemia inhibitory factor (LIF) (hereafter termed 2i/L) induces a naive state in mouse embryonic stem (ES) cells that resembles the inner cell mass (ICM) of the pre-implantation embryo. Since the ICM exists only transiently in vivo, it remains unclear how sustained propagation of naive ES cells in vitro affects their stability and functionality. Here we show that prolonged culture of male mouse ES cells in 2i/L results in irreversible epigenetic and genomic changes that impair their developmental potential. Furthermore, we find that female ES cells cultured in conventional serum plus LIF medium phenocopy male ES cells cultured in 2i/L. Mechanistically, we demonstrate that the inhibition of Mek1/2 is predominantly responsible for these effects, in part through the downregulation of DNA methyltransferases and their cofactors. Finally, we show that replacement of the Mek1/2 inhibitor with a Src inhibitor preserves the epigenetic and genomic integrity as well as the developmental potential of ES cells. Taken together, our data suggest that, although short-term suppression of Mek1/2 in ES cells helps to maintain an ICM-like epigenetic state, prolonged suppression results in irreversible changes that compromise their developmental potential.

Human pluripotent stem cells: an emerging model in developmental biology

PubMed Central

Zhu, Zengrong; Huangfu, Danwei

2013-01-01

Developmental biology has long benefited from studies of classic model organisms. Recently, human pluripotent stem cells (hPSCs), including human embryonic stem cells and human induced pluripotent stem cells, have emerged as a new model system that offers unique advantages for developmental studies. Here, we discuss how studies of hPSCs can complement classic approaches using model organisms, and how hPSCs can be used to recapitulate aspects of human embryonic development ‘in a dish’. We also summarize some of the recently developed genetic tools that greatly facilitate the interrogation of gene function during hPSC differentiation. With the development of high-throughput screening technologies, hPSCs have the potential to revolutionize gene discovery in mammalian development. PMID:23362344

Cancer: Mitochondrial Origins.

PubMed

Stefano, George B; Kream, Richard M

2015-12-01

The primacy of glucose derived from photosynthesis as an existential source of chemical energy across plant and animal phyla is universally accepted as a core principle in the biological sciences. In mammalian cells, initial processing of glucose to triose phosphate intermediates takes place within the cytosolic glycolytic pathway and terminates with temporal transport of reducing equivalents derived from pyruvate metabolism by membrane-associated respiratory complexes in the mitochondrial matrix. The intra-mitochondrial availability of molecular oxygen as the ultimate electron acceptor drives the evolutionary fashioned chemiosmotic production of ATP as a high-efficiency biological process. The mechanistic bases of carcinogenesis have demonstrated profound alteration of normative mitochondrial function, notably dysregulated respiratory processes. Accordingly, the classic Warburg effect functionally links aerobic glycolysis, aberrant production and release of lactate, and metabolic down-regulation of mitochondrial oxidative processes with the carcinogenetic phenotype. We surmise, however, that aerobic fermentation by cancer cells may also represent a developmental re-emergence of an evolutionarily conserved early phenotype, which was "sidelined" with the emergence of mitochondrial oxidative phosphorylation as a primary mechanism for ATP production in normal cells. Regardless of state-dependent physiological status in mixed populations of cancer cells, it has been established that mitochondria are functionally linked to the initiation of cancer and its progression. Biochemical, molecular, and physiological differences in cancer cell mitochondria, notably mtDNA heteroplasmy and allele-specific expression of selected nuclear genes, may represent major focal points for novel targeting and elimination of cancer cells in metastatic disease afflicting human populations. To date, and despite considerable research efforts, the practical realization of advanced mitochondrial targeted therapies has not been forthcoming.

The Developmental Regulator SEEDSTICK Controls Structural and Mechanical Properties of the Arabidopsis Seed Coat

PubMed Central

Beauzamy, Léna; Caporali, Elisabetta; Koroney, Abdoul-Salam

2016-01-01

Although many transcription factors involved in cell wall morphogenesis have been identified and studied, it is still unknown how genetic and molecular regulation of cell wall biosynthesis is integrated into developmental programs. We demonstrate by molecular genetic studies that SEEDSTICK (STK), a transcription factor controlling ovule and seed integument identity, directly regulates PMEI6 and other genes involved in the biogenesis of the cellulose-pectin matrix of the cell wall. Based on atomic force microscopy, immunocytochemistry, and chemical analyses, we propose that structural modifications of the cell wall matrix in the stk mutant contribute to defects in mucilage release and seed germination under water-stress conditions. Our studies reveal a molecular network controlled by STK that regulates cell wall properties of the seed coat, demonstrating that developmental regulators controlling organ identity also coordinate specific aspects of cell wall characteristics. PMID:27624758

Monoclonal antibodies against trophectoderm-specific markers during mouse blastocyst formation.

PubMed Central

Brûlet, P; Babinet, C; Kemler, R; Jacob, F

1980-01-01

Two-dimensional gel electrophoresis has allowed the detection of proteins characteristic of inner cell mass and trophectoderm in mouse blastocyst. Certain of the proteins characterizing trophectoderm copurify with intermediate filaments from trophectoderm and a trophoblastoma cell line. A monoclonal antibody prepared against proteins of these intermediate filaments labels a filament network in trophectoderm but not in inner cell mass cells. Images PMID:6933460

Developmental Changes is Expression of Beta-Adrenergic Receptors in Cultures of C2C12 Skeletal Muscle Cells

NASA Technical Reports Server (NTRS)

Young, Ronald B.; Bridge, K. Y.; Vaughn, J. R.

2000-01-01

beta-Adrenergic receptor (bAR) agonists have been reported to modulate growth in several mammalian and avian species, and bAR agonists presumably exert their physiological action on skeletal muscle cells through this receptor. Because of the importance of bAR regulation on muscle protein metabolism in muscle cells, the objectives of this study were to determine the developmental expression pattern of the bAR population in C2C12 skeletal muscle cells, and to analyze changes in both the quantity and isoform expression of the major muscle protein, myosin. The number of bAR in mononucleated C2C12 cells was approximately 8,000 bAR per cell, which is comparable with the population reported in several other nonmuscle cell types. However, the bar population increased after myoblast fusion to greater than 50,000 bAR per muscle cell equivalent. The reasons for this apparent over-expression of bAR in C2C12 cells is not known. The quantity of myosin also increased after C2C12 myoblast fusion, but the quantity of myosin was less than that reported in primary muscle cell cultures. Finally, at least five different isoforms of myosin heavy chain could be resolved in C2C12 cells, and three of these exhibited either increased or decreased developmental regulation relative to the others. Thus, C2C12 myoblasts undergo developmental regulation of bAR population and myosin heavy chain isoform expression.

DNA replication origins—where do we begin?

PubMed Central

Prioleau, Marie-Noëlle; MacAlpine, David M.

2016-01-01

For more than three decades, investigators have sought to identify the precise locations where DNA replication initiates in mammalian genomes. The development of molecular and biochemical approaches to identify start sites of DNA replication (origins) based on the presence of defining and characteristic replication intermediates at specific loci led to the identification of only a handful of mammalian replication origins. The limited number of identified origins prevented a comprehensive and exhaustive search for conserved genomic features that were capable of specifying origins of DNA replication. More recently, the adaptation of origin-mapping assays to genome-wide approaches has led to the identification of tens of thousands of replication origins throughout mammalian genomes, providing an unprecedented opportunity to identify both genetic and epigenetic features that define and regulate their distribution and utilization. Here we summarize recent advances in our understanding of how primary sequence, chromatin environment, and nuclear architecture contribute to the dynamic selection and activation of replication origins across diverse cell types and developmental stages. PMID:27542827

Rap Phosphatase of Virulence Plasmid pXO1 Inhibits Bacillus anthracis Sporulation†

PubMed Central

Bongiorni, Cristina; Stoessel, Ricarda; Shoemaker, Dorinda; Perego, Marta

2006-01-01

This study shows that the Bacillus anthracis pXO1 virulence plasmid carries a Rap-Phr system, BXA0205, which regulates sporulation initiation in this organism. The BXA0205Rap protein was shown to dephosphorylate the Spo0F response regulator intermediate of the phosphorelay signal transduction system that regulates the initiation of the developmental pathway in response to environmental, metabolic, and cell cycle signals. The activity of the Rap protein was shown to be inhibited by the carboxy-terminal pentapeptide generated through an export-import processing pathway from the associated BXA0205Phr protein. Deregulation of the Rap activity by either overexpression or lack of the Phr pentapeptide resulted in severe inhibition of sporulation. Five additional Rap-Phr encoding systems were identified on the chromosome of B. anthracis, one of which, BA3790-3791, also affected sporulation initiation. The results suggest that the plasmid-borne Rap-Phr system may provide a selective advantage to the virulence of B. anthracis. PMID:16385039

Rap phosphatase of virulence plasmid pXO1 inhibits Bacillus anthracis sporulation.

PubMed

Bongiorni, Cristina; Stoessel, Ricarda; Shoemaker, Dorinda; Perego, Marta

2006-01-01

This study shows that the Bacillus anthracis pXO1 virulence plasmid carries a Rap-Phr system, BXA0205, which regulates sporulation initiation in this organism. The BXA0205Rap protein was shown to dephosphorylate the Spo0F response regulator intermediate of the phosphorelay signal transduction system that regulates the initiation of the developmental pathway in response to environmental, metabolic, and cell cycle signals. The activity of the Rap protein was shown to be inhibited by the carboxy-terminal pentapeptide generated through an export-import processing pathway from the associated BXA0205Phr protein. Deregulation of the Rap activity by either overexpression or lack of the Phr pentapeptide resulted in severe inhibition of sporulation. Five additional Rap-Phr encoding systems were identified on the chromosome of B. anthracis, one of which, BA3790-3791, also affected sporulation initiation. The results suggest that the plasmid-borne Rap-Phr system may provide a selective advantage to the virulence of B. anthracis.

Apoptosis as a possible mechanism of infertility in Echinococcus granulosus hydatid cysts.

PubMed

Paredes, R; Jiménez, V; Cabrera, G; Iragüen, D; Galanti, N

2007-04-01

Echinococcus granulosus is a parasitic cestode causing hydatidosis in intermediate hosts (human and herbivorous). Most symptoms of the disease occur by the pressure exerted on viscera by cysts that are formed upon ingestion of the parasite eggs excreted by definitive hosts (canines). Protoscoleces, the developmental form of the parasite infective to definitive hosts, are formed in the germinal nucleated layer of fertile hydatid cysts. For unknown reasons, some cysts are unable to produce protoscoleces (infertile hydatid cysts). In this study, analysis of DNA fragmentation using TUNEL and agarose gel electrophoresis showed higher levels of apoptosis in infertile cysts as compared to fertile cysts. Additionally, caspase 3 was detected both in fertile and infertile cysts; the activity of this enzyme was found to be higher in infertile cysts. We conclude that apoptosis may be involved in hydatid cyst infertility. This is the first report on the presence of programmed cell death in E. granulosus. c 2006 Wiley-Liss, Inc.

A Conserved Core of Programmed Cell Death Indicator Genes Discriminates Developmentally and Environmentally Induced Programmed Cell Death in Plants.

PubMed

Olvera-Carrillo, Yadira; Van Bel, Michiel; Van Hautegem, Tom; Fendrych, Matyáš; Huysmans, Marlies; Simaskova, Maria; van Durme, Matthias; Buscaill, Pierre; Rivas, Susana; Coll, Nuria S.; Coppens, Frederik; Maere, Steven; Nowack, Moritz K.

2015-12-01

A plethora of diverse programmed cell death (PCD) processes has been described in living organisms. In animals and plants, different forms of PCD play crucial roles in development, immunity, and responses to the environment. While the molecular control of some animal PCD forms such as apoptosis is known in great detail, we still know comparatively little about the regulation of the diverse types of plant PCD. In part, this deficiency in molecular understanding is caused by the lack of reliable reporters to detect PCD processes. Here, we addressed this issue by using a combination of bioinformatics approaches to identify commonly regulated genes during diverse plant PCD processes in Arabidopsis (Arabidopsis thaliana). Our results indicate that the transcriptional signatures of developmentally controlled cell death are largely distinct from the ones associated with environmentally induced cell death. Moreover, different cases of developmental PCD share a set of cell death-associated genes. Most of these genes are evolutionary conserved within the green plant lineage, arguing for an evolutionary conserved core machinery of developmental PCD. Based on this information, we established an array of specific promoter-reporter lines for developmental PCD in Arabidopsis. These PCD indicators represent a powerful resource that can be used in addition to established morphological and biochemical methods to detect and analyze PCD processes in vivo and in planta. © 2015 American Society of Plant Biologists. All Rights Reserved.

Identification of Putative Cardiovascular System Developmental Toxicants using a Classification Model based on Signaling Pathway-Adverse Outcome Pathways

EPA Science Inventory

An important challenge for an integrative approach to developmental systems toxicology is associating putative molecular initiating events (MIEs), cell signaling pathways, cell function and modeled fetal exposure kinetics. We have developed a chemical classification model based o...

Retinoid-signaling in progenitors controls specification and regeneration of the urothelium

PubMed Central

Reiley, Maia; Laufer, Ed; Metzger, Daniel; Liang, Fengxia; Liao, Yi; Sun, Tung-Tien; Aronow, Bruce; Rosen, Roni; Mauney, Josh; Adam, Rosalyn; Rosselot, Carolina; Van Batavia, Jason; McMahon, Andrew; McMahon, Jill; Guo, Jin-Jin; Mendelsohn, Cathy

2013-01-01

The urothelium is a stratified epithelium that prevents exchange of water and toxic substances between the urinary tract and blood. It is composed of Keratin-5-expressing-basal-cells (K5-BCs), intermediate cells and superficial cells specialized for synthesis and transport of uroplakins that assemble into the apical barrier. K5-BCs are considered to be a progenitor cell type in the urothelium and other stratified epithelia. Fate mapping studies however, reveal that P-cells, a transient population, are urothelial progenitors in the embryo, intermediate cells are superficial cell progenitors in the adult regenerating urothelium, and K5-BCs are a distinct lineage. Our studies indicate that retinoids, potent regulators of ES cells and other progenitors, are also required in P-cells and intermediate cells for their specification. These observations have important implications for tissue engineering and repair, and ultimately, may lead to treatments that prevent loss of the urothelial barrier, a major cause of voiding dysfunction and bladder pain syndrome. PMID:23993789

The high mobility group protein Abf2p influences the level of yeast mitochondrial DNA recombination intermediates in vivo.

PubMed

MacAlpine, D M; Perlman, P S; Butow, R A

1998-06-09

Abf2p is a high mobility group (HMG) protein found in yeast mitochondria that is required for the maintenance of wild-type (rho+) mtDNA in cells grown on fermentable carbon sources, and for efficient recombination of mtDNA markers in crosses. Here, we show by two-dimensional gel electrophoresis that Abf2p promotes or stabilizes Holliday recombination junction intermediates in rho+ mtDNA in vivo but does not influence the high levels of recombination intermediates readily detected in the mtDNA of petite mutants (rho-). mtDNA recombination junctions are not observed in rho+ mtDNA of wild-type cells but are elevated to detectable levels in cells with a null allele of the MGT1 gene (Deltamgt1), which codes for a mitochondrial cruciform-cutting endonuclease. The level of recombination intermediates in rho+ mtDNA of Deltamgt1 cells is decreased about 10-fold if those cells contain a null allele of the ABF2 gene. Overproduction of Abf2p by >/= 10-fold in wild-type rho+ cells, which leads to mtDNA instability, results in a dramatic increase in mtDNA recombination intermediates. Specific mutations in the two Abf2p HMG boxes required for DNA binding diminishes these responses. We conclude that Abf2p functions in the recombination of rho+ mtDNA.

Systematically labeling developmental stage-specific genes for the study of pancreatic β-cell differentiation from human embryonic stem cells.

PubMed

Liu, Haisong; Yang, Huan; Zhu, Dicong; Sui, Xin; Li, Juan; Liang, Zhen; Xu, Lei; Chen, Zeyu; Yao, Anzhi; Zhang, Long; Zhang, Xi; Yi, Xing; Liu, Meng; Xu, Shiqing; Zhang, Wenjian; Lin, Hua; Xie, Lan; Lou, Jinning; Zhang, Yong; Xi, Jianzhong; Deng, Hongkui

2014-10-01

The applications of human pluripotent stem cell (hPSC)-derived cells in regenerative medicine has encountered a long-standing challenge: how can we efficiently obtain mature cell types from hPSCs? Attempts to address this problem are hindered by the complexity of controlling cell fate commitment and the lack of sufficient developmental knowledge for guiding hPSC differentiation. Here, we developed a systematic strategy to study hPSC differentiation by labeling sequential developmental genes to encompass the major developmental stages, using the directed differentiation of pancreatic β cells from hPSCs as a model. We therefore generated a large panel of pancreas-specific mono- and dual-reporter cell lines. With this unique platform, we visualized the kinetics of the entire differentiation process in real time for the first time by monitoring the expression dynamics of the reporter genes, identified desired cell populations at each differentiation stage and demonstrated the ability to isolate these cell populations for further characterization. We further revealed the expression profiles of isolated NGN3-eGFP(+) cells by RNA sequencing and identified sushi domain-containing 2 (SUSD2) as a novel surface protein that enriches for pancreatic endocrine progenitors and early endocrine cells both in human embryonic stem cells (hESC)-derived pancreatic cells and in the developing human pancreas. Moreover, we captured a series of cell fate transition events in real time, identified multiple cell subpopulations and unveiled their distinct gene expression profiles, among heterogeneous progenitors for the first time using our dual reporter hESC lines. The exploration of this platform and our new findings will pave the way to obtain mature β cells in vitro.

Regulation of priority carcinogens and reproductive or developmental toxicants

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

Hooper, K.; LaDou, J.; Rosenbaum, J.S.

In California, 370 carcinogens and 112 reproductive/developmental toxicants have been identified as a result of the State's Safe Drinking Water and Toxic Enforcement Act of 1986. They include pesticides, solvents, metals, industrial intermediates, environmental mixtures, and reactive agents. Occupational, environmental, and consumer product exposures that involve these agents are regulated under the Act. At levels of concern, businesses must provide warnings for and limit discharges of those chemicals. The lists of chemicals were compiled following systematic review of published data, including technical reports from the U.S. Public Health Service--National Toxicology Program (NTP), and evaluation of recommendations from authoritative bodies suchmore » as the International Agency for Research on Cancer (IARC) and the U.S. Environmental Protection Agency (USEPA). Given the large number of chemicals that are carcinogens or reproductive/developmental toxicants, regulatory concerns should focus on those that have high potential for human exposure, e.g., widely distributed or easily absorbed solvents, metals, environmental mixtures, or reactive agents. In this paper, we present a list of 33 potential priority carcinogens and reproductive/developmental toxicants, including alcoholic beverages, asbestos, benzene, chlorinated solvents, formaldehyde, glycol ethers, lead, tobacco smoke, and toluene.« less

Regulation of priority carcinogens and reproductive or developmental toxicants.

PubMed

Hooper, K; LaDou, J; Rosenbaum, J S; Book, S A

1992-01-01

In California, 370 carcinogens and 112 reproductive/developmental toxicants have been identified as a result of the State's Safe Drinking Water and Toxic Enforcement Act of 1986. They include pesticides, solvents, metals, industrial intermediates, environmental mixtures, and reactive agents. Occupational, environmental, and consumer product exposures that involve these agents are regulated under the Act. At levels of concern, businesses must provide warnings for and limit discharges of those chemicals. The lists of chemicals were compiled following systematic review of published data, including technical reports from the U.S. Public Health Service--National Toxicology Program (NTP), and evaluation of recommendations from authoritative bodies such as the International Agency for Research on Cancer (IARC) and the U.S. Environmental Protection Agency (USEPA). Given the large number of chemicals that are carcinogens or reproductive/developmental toxicants, regulatory concerns should focus on those that have high potential for human exposure, e.g., widely distributed or easily absorbed solvents, metals, environmental mixtures, or reactive agents. In this paper, we present a list of 33 potential priority carcinogens and reproductive/developmental toxicants, including alcoholic beverages, asbestos, benzene, chlorinated solvents, formaldehyde, glycol ethers, lead, tobacco smoke, and toluene.

Medicaid program; mental retardation--definition of "persons with related conditions"--Health Care Financing Administration. Proposed rule.

PubMed

1983-02-23

We propose to amend the 1978 Medicaid regulations on intermediate care facility services for the mentally retarded and persons with related conditions to correct the definition of "persons with related conditions". This definition, because of an inadvertent error in 1978, is currently tied to the definition of developmental disability in the Developmental Disabilities Assistance and Bill of Rights Act (DDABRA) as amended in 1978. The DDABRA, as amended, covers the mentally ill. The 1978 regulations intended to make "no substantive change" to prior Medicaid regulations which did not cover the mentally ill. The cross-reference to the DDABRA produced the unintended result of incorporating into Medicaid regulations the revision to the definition of the developmentally disabled created by the 1978 amendments to the DDABRA and may tend to cause confusion about the kind of care that is covered by the Medicaid program. Therefore, a correction of this drafting error is necessary. To avoid results of this kind in the future this proposal would establish a Medicaid definition of conditions related to mental retardation that would meet specific needs of the Medicaid program and would be independent of the definition of developmental disability in the DDABRA.

Cytoskeletal changes in actin and microtubules underlie the developing surface mechanical properties of sensory and supporting cells in the mouse cochlea

PubMed Central

Szarama, Katherine B.; Gavara, Núria; Petralia, Ronald S.; Kelley, Matthew W.; Chadwick, Richard S.

2012-01-01

Correct patterning of the inner ear sensory epithelium is essential for the conversion of sound waves into auditory stimuli. Although much is known about the impact of the developing cytoskeleton on cellular growth and cell shape, considerably less is known about the role of cytoskeletal structures on cell surface mechanical properties. In this study, atomic force microscopy (AFM) was combined with fluorescence imaging to show that developing inner ear hair cells and supporting cells have different cell surface mechanical properties with different developmental time courses. We also explored the cytoskeletal organization of developing sensory and non-sensory cells, and used pharmacological modulation of cytoskeletal elements to show that the developmental increase of hair cell stiffness is a direct result of actin filaments, whereas the development of supporting cell surface mechanical properties depends on the extent of microtubule acetylation. Finally, this study found that the fibroblast growth factor signaling pathway is necessary for the developmental time course of cell surface mechanical properties, in part owing to the effects on microtubule structure. PMID:22573615

Role of the immune modulator programmed cell death-1 during development and apoptosis of mouse retinal ganglion cells

PubMed Central

Chen, Ling; Sham, Caroline W.; Chan, Ann M.; Francisco, Loise M.; Wu, Yin; Mareninov, Sergey; Sharpe, Arlene H.; Freeman, Gordon J.; Yang, Xian-Jie; Braun, Jonathan; Gordon, Lynn K.

2011-01-01

PURPOSE Mammalian programmed cell death-1 (PD-1) is a membrane-associated receptor regulating the balance between T cell activation, tolerance and immunopathology, however its role in neurons has not yet been defined. We investigate the hypothesis that PD-1 signaling actively promotes retinal ganglion cell (RGC) death within the developing mouse retina. METHODS Mature retinal cell types expressing PD-1 were identified by immunofluorescence staining of vertical retina sections; developmental expression was localized by immunostaining and quantified by Western analysis. PD-1 involvement in developmental RGC survival was assessed in vitro using retina explants and in vivo using PD-1 knockout mice. PD-1 ligand gene expression was detected by RT-PCR. RESULTS PD-1 is expressed in most adult RGCs, and undergoes dynamic upregulation during the early postnatal window of retinal cell maturation and physiological programmed cell death (PCD). In vitro blockade of PD-1 signaling during this time selectively increases survival of RGCs. Furthermore, PD-1 deficient mice show a selective increase in RGC number in the neonatal retina at the peak of developmental RGC death. Lastly, throughout postnatal retina maturation, we find gene expression of both immune PD-1 ligand genes, PD-L1 and PD-L2. CONCLUSIONS These findings collectively support a novel role for a PD-1-mediated signaling pathway in developmental PCD during postnatal RGC maturation. PMID:19420345

Induced pluripotent stem cell-derived neuron as a human model for testing environmentally induced developmental neurotoxicity

EPA Science Inventory

Induced pluripotent stem cell-derived neurons as a human model for testing environmentally induced developmental neurotoxicity Ingrid L. Druwe1, Timothy J. Shafer2, Kathleen Wallace2, Pablo Valdivia3 ,and William R. Mundy2. 1University of North Carolina, Curriculum in Toxicology...

Markers of murine embryonic and neural stem cells, neurons and astrocytes: reference points for developmental neurotoxicity testing

EPA Science Inventory

Developmental neurotoxicity (DNT) is a significant concern for environmental chemicals, as well as for food and drug constituents. The sensitivity of animal-based DNT models is unclear, and they are expensive and time consuming. Murine embryonic stem cells (mESC) recapitulate sev...

Developing predictions of in vivo developmental toxicity of ToxCast chemicals using mouse embryonic stem cells.

EPA Science Inventory

Developing predictions of in vivo developmental toxicity of ToxCast chemicals using mouse embryonic stem cells S. Hunter, M. Rosen, M. Hoopes, H. Nichols, S. Jeffay, K. Chandler1, Integrated Systems Toxicology Division, National Health and Environmental Effects Research Labor...

Neglected but Exciting Concepts in Developmental and Neurobiological Psychology

ERIC Educational Resources Information Center

Jordan, Evan M.; Thomas, David G.

2017-01-01

This review provides an evaluative overview of five concepts specific to developmental and neurobiological psychology that are found to be largely overlooked in current textbooks. A sample of 19 introductory psychology texts was surveyed to develop a list, including glial cell signaling, grandmother cells, memory reconsolidation, brain plasticity,…

Developmental mechanisms regulating secondary growth in woody plants

Treesearch

Andrew Groover; Marcel Robischon

2006-01-01

Secondary growth results in the radial expansion of woody stems, and requires the coordination of tissue patterning, cell differentiation, and the maintenance of meristematic stem cells within the vascular cambium. Advances are being made towards describing molecular mechanisms that regulate these developmental processes, thanks in part to the application of new...

Effects of developmental variability on the dynamics and self-organization of cell populations

NASA Astrophysics Data System (ADS)

Prabhakara, Kaumudi H.; Gholami, Azam; Zykov, Vladimir S.; Bodenschatz, Eberhard

2017-11-01

We report experimental and theoretical results for spatiotemporal pattern formation in cell populations, where the parameters vary in space and time due to mechanisms intrinsic to the system, namely Dictyostelium discoideum (D.d.) in the starvation phase. We find that different patterns are formed when the populations are initialized at different developmental stages, or when populations at different initial developmental stages are mixed. The experimentally observed patterns can be understood with a modified Kessler-Levine model that takes into account the initial spatial heterogeneity of the cell populations and a developmental path introduced by us, i.e. the time dependence of the various biochemical parameters. The dynamics of the parameters agree with known biochemical studies. Most importantly, the modified model reproduces not only our results, but also the observations of an independent experiment published earlier. This shows that pattern formation can be used to understand and quantify the temporal evolution of the system parameters.

Using Neural Progenitor Cells in High-Throughput Screens for Developmental Neurotoxicants: Triumphs and Tragedies

EPA Science Inventory

Current protocols for developmental neurotoxicity testing are insufficient to test thousands of commercial chemicals. Thus, development of highthroughput screens (HTS) to detect and prioritize chemicals that may cause developmental neurotoxicity is needed to improve protection of...

Virtual Embryo: Cell-Agent Based Modeling of Developmental Processes and Toxicities (CSS BOSC)

EPA Science Inventory

Spatial regulation of cellular dynamics is fundamental to morphological development. As such, chemical disruption of spatial dynamics is a determinant of developmental toxicity. Incorporating spatial dynamics into AOPs for developmental toxicity is desired but constrained by the ...

Elevated temperature tensile properties of P9 steel towards ferritic steel wrapper development for sodium cooled fast reactors

NASA Astrophysics Data System (ADS)

Choudhary, B. K.; Mathew, M. D.; Isaac Samuel, E.; Christopher, J.; Jayakumar, T.

2013-11-01

Tensile deformation and fracture behaviour of the three developmental heats of P9 steel for wrapper applications containing varying silicon in the range 0.24-0.60% have been examined in the temperature range 300-873 K. Yield and ultimate tensile strengths in all the three heats exhibited gradual decrease with increase in temperature from room to intermediate temperatures followed by rapid decrease at high temperatures. A gradual decrease in ductility to a minimum at intermediate temperatures followed by an increase at high temperatures has been observed. The fracture mode remained transgranular ductile. The steel displayed signatures of dynamic strain ageing at intermediate temperatures and dominance of recovery at high temperatures. No significant difference in the strength and ductility values was observed for varying silicon in the range 0.24-0.60% in P9 steel. P9 steel for wrapper application displayed strength and ductility values comparable to those reported in the literature.

Discovering sparse transcription factor codes for cell states and state transitions during development

PubMed Central

Furchtgott, Leon A; Melton, Samuel; Menon, Vilas; Ramanathan, Sharad

2017-01-01

Computational analysis of gene expression to determine both the sequence of lineage choices made by multipotent cells and to identify the genes influencing these decisions is challenging. Here we discover a pattern in the expression levels of a sparse subset of genes among cell types in B- and T-cell developmental lineages that correlates with developmental topologies. We develop a statistical framework using this pattern to simultaneously infer lineage transitions and the genes that determine these relationships. We use this technique to reconstruct the early hematopoietic and intestinal developmental trees. We extend this framework to analyze single-cell RNA-seq data from early human cortical development, inferring a neocortical-hindbrain split in early progenitor cells and the key genes that could control this lineage decision. Our work allows us to simultaneously infer both the identity and lineage of cell types as well as a small set of key genes whose expression patterns reflect these relationships. DOI: http://dx.doi.org/10.7554/eLife.20488.001 PMID:28296636

An incoherent regulatory network architecture that orchestrates B cell diversification in response to antigen signaling

PubMed Central

Sciammas, Roger; Li, Ying; Warmflash, Aryeh; Song, Yiqiang; Dinner, Aaron R; Singh, Harinder

2011-01-01

The B-lymphocyte lineage is a leading system for analyzing gene regulatory networks (GRNs) that orchestrate distinct cell fate transitions. Upon antigen recognition, B cells can diversify their immunoglobulin (Ig) repertoire via somatic hypermutation (SHM) and/or class switch DNA recombination (CSR) before differentiating into antibody-secreting plasma cells. We construct a mathematical model for a GRN underlying this developmental dynamic. The intensity of signaling through the Ig receptor is shown to control the bimodal expression of a pivotal transcription factor, IRF-4, which dictates B cell fate outcomes. Computational modeling coupled with experimental analysis supports a model of ‘kinetic control', in which B cell developmental trajectories pass through an obligate transient state of variable duration that promotes diversification of the antibody repertoire by SHM/CSR in direct response to antigens. More generally, this network motif could be used to translate a morphogen gradient into developmental inductive events of varying time, thereby enabling the specification of distinct cell fates. PMID:21613984

Conservation in the involvement of heterochronic genes and hormones during developmental transitions.

PubMed

Faunes, Fernando; Larraín, Juan

2016-08-01

Developmental transitions include molting in some invertebrates and the metamorphosis of insects and amphibians. While the study of Caenorhabditis elegans larval transitions was crucial to determine the genetic control of these transitions, Drosophila melanogaster and Xenopus laevis have been classic models to study the role of hormones in metamorphosis. Here we review how heterochronic genes (lin-4, let-7, lin-28, lin-41), hormones (dafachronic acid, ecdysone, thyroid hormone) and the environment regulate developmental transitions. Recent evidence suggests that some heterochronic genes also regulate transitions in higher organisms that they are controlled by hormones involved in metamorphosis. We also discuss evidence demonstrating that heterochronic genes and hormones regulate the proliferation and differentiation of embryonic and neural stem cells. We propose the hypothesis that developmental transitions are regulated by an evolutionary conserved mechanism in which heterochronic genes and hormones interact to control stem/progenitor cells proliferation, cell cycle exit, quiescence and differentiation and determine the proper timing of developmental transitions. Finally, we discuss the relevance of these studies to understand post-embryonic development, puberty and regeneration in humans. Copyright © 2016 Elsevier Inc. All rights reserved.

DNA methylation in schizophrenia in different patient-derived cell types.

PubMed

Vitale, Alejandra M; Matigian, Nicholas A; Cristino, Alexandre S; Nones, Katia; Ravishankar, Sugandha; Bellette, Bernadette; Fan, Yongjun; Wood, Stephen A; Wolvetang, Ernst; Mackay-Sim, Alan

2017-01-01

DNA methylation of gene promoter regions represses transcription and is a mechanism via which environmental risk factors could affect cells during development in individuals at risk for schizophrenia. We investigated DNA methylation in patient-derived cells that might shed light on early development in schizophrenia. Induced pluripotent stem cells may reflect a "ground state" upon which developmental and environmental influences would be minimal. Olfactory neurosphere-derived cells are an adult-derived neuro-ectodermal stem cell modified by developmental and environmental influences. Fibroblasts provide a non-neural control for life-long developmental and environmental influences. Genome-wide profiling of DNA methylation and gene expression was done in these three cell types from the same individuals. All cell types had distinct, statistically significant schizophrenia-associated differences in DNA methylation and linked gene expression, with Gene Ontology analysis showing that the differentially affected genes clustered in networks associated with cell growth, proliferation, and movement, functions known to be affected in schizophrenia patient-derived cells. Only five gene loci were differentially methylated in all three cell types. Understanding the role of epigenetics in cell function in the brain in schizophrenia is likely to be complicated by similar cell type differences in intrinsic and environmentally induced epigenetic regulation.

Cellular Immunotherapy Following Chemotherapy in Treating Patients With Recurrent Non-Hodgkin Lymphomas, Chronic Lymphocytic Leukemia or B-Cell Prolymphocytic Leukemia

ClinicalTrials.gov

2018-04-20

Post-transplant Lymphoproliferative Disorder; B-Cell Prolymphocytic Leukemia; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Small Lymphocytic Lymphoma; Refractory Chronic Lymphocytic Leukemia; Refractory Hairy Cell Leukemia; B-Cell Lymphoma, Unclassifiable, With Features Intermediate Between Diffuse Large B-Cell Lymphoma and Burkitt Lymphoma; B-Cell Lymphoma, Unclassifiable, With Features Intermediate Between Diffuse Large B-Cell Lymphoma and Classical Hodgkin Lymphoma; Recurrent Lymphoplasmacytic Lymphoma

The Tlx gene regulates the timing of neurogenesis in the cortex.

PubMed

Roy, Kristine; Kuznicki, Kathleen; Wu, Qiang; Sun, Zhuoxin; Bock, Dagmar; Schutz, Gunther; Vranich, Nancy; Monaghan, A Paula

2004-09-22

The tailless (tlx) gene is a forebrain-restricted transcription factor. Tlx mutant animals exhibit a reduction in the size of the cerebral hemispheres and associated structures (Monaghan et al., 1997). Superficial cortical layers are specifically reduced, whereas deep layers are relatively unaltered (Land and Monaghan, 2003). To determine whether the adult laminar phenotype has a developmental etiology and whether it is associated with a change in proliferation/differentiation decisions, we examined the cell cycle and neurogenesis in the embryonic cortex. We found that there is a temporal and regional requirement for the Tlx protein in progenitor cells (PCs). Neurons prematurely differentiate at all rostrocaudal levels up to mid-neurogenesis in mutant animals. Heterozygote animals have an intermediate phenotype indicating there is a threshold requirement for Tlx in early cortical neurogenesis. Our studies indicate that PCs in the ventricular zone are sensitive to loss of Tlx in caudal regions only; however, PCs in the subventricular zone are altered at all rostrocaudal levels in tlx-deficient animals. Furthermore, we found that the cell cycle is shorter from embryonic day 9.5 in tlx-/- embryos. At mid-neurogenesis, the PC population becomes depleted, and late PCs have a longer cell cycle in tlx-deficient animals. Consequently, later generated structures, such as upper cortical layers, the dentate gyrus, and the olfactory bulbs, are severely reduced. These studies indicate that tlx is an essential intrinsic regulator in the decision to proliferate or differentiate in the developing forebrain.

The Tlx Gene Regulates the Timing of Neurogenesis in the Cortex

PubMed Central

Roy, Kristine; Kuznicki, Kathleen; Wu, Qiang; Sun, Zhuoxin; Bock, Dagmar; Schutz, Gunther; Vranich, Nancy; Monaghan, A. Paula

2009-01-01

The tailless (tlx) gene is a forebrain-restricted transcription factor. Tlx mutant animals exhibit a reduction in the size of the cerebral hemispheres and associated structures (Monaghan et al., 1997). Superficial cortical layers are specifically reduced, whereas deep layers are relatively unaltered (Land and Monaghan, 2003). To determine whether the adult laminar phenotype has a developmental etiology and whether it is associated with a change in proliferation/differentiation decisions, we examined the cell cycle and neurogenesis in the embryonic cortex. We found that there is a temporal and regional requirement for the Tlx protein in progenitor cells (PCs). Neurons prematurely differentiate at all rostrocaudal levels up to mid-neurogenesis in mutant animals. Heterozygote animals have an intermediate phenotype indicating there is a threshold requirement for Tlx in early cortical neurogenesis. Our studies indicate that PCs in the ventricular zone are sensitive to loss of Tlx in caudal regions only; however, PCs in the subventricular zone are altered at all rostrocaudal levels in tlx-deficient animals. Furthermore, we found that the cell cycle is shorter from embryonic day 9.5 in tlx−/− embryos. At mid-neurogenesis, the PC population becomes depleted, and late PCs have a longer cell cycle in tlx-deficient animals. Consequently, later generated structures, such as upper cortical layers, the dentate gyrus, and the olfactory bulbs, are severely reduced. These studies indicate that tlx is an essential intrinsic regulator in the decision to proliferate or differentiate in the developing forebrain. PMID:15385616

Functional high-resolution time-course expression analysis of human embryonic stem cells undergoing cardiac induction.

PubMed

Piccini, Ilaria; Araúzo-Bravo, Marcos; Seebohm, Guiscard; Greber, Boris

2016-12-01

Cardiac induction of human embryonic stem cells (hESCs) is a process bearing increasing medical relevance, yet it is poorly understood from a developmental biology perspective. Anticipated technological progress in deriving stably expandable cardiac precursor cells or in advancing cardiac subtype specification protocols will likely require deeper insights into this fascinating system. Recent improvements in controlling hESC differentiation now enable a near-homogeneous induction of the cardiac lineage. This is based on an optimized initial stimulation of mesoderm-inducing signaling pathways such as Activin and/or FGF, BMP, and WNT, followed by WNT inhibition as a secondary requirement. Here, we describe a comprehensive data set based on varying hESC differentiation conditions in a systematic manner and recording high-resolution differentiation time-courses analyzed by genome-wide expression profiling (GEO accession number GSE67154). As a baseline, hESCs were differentiated into cardiomyocytes under optimal conditions. Moreover, in additional time-series, individual signaling factors were withdrawn from the initial stimulation cocktail to reveal their specific roles via comparison to the standard condition. Hence, this data set presents a rich resource for hypothesis generation in studying human cardiac induction, as we reveal numbers of known as well as uncharacterized genes prominently marking distinct intermediate stages in the process. These data will also be useful for identifying putative cardiac master regulators in the human system as well as for characterizing expandable cardiac stem cells.

Making quantitative morphological variation from basic developmental processes: where are we? The case of the Drosophila wing

PubMed Central

Alexis, Matamoro-Vidal; Isaac, Salazar-Ciudad; David, Houle

2015-01-01

One of the aims of evolutionary developmental biology is to discover the developmental origins of morphological variation. The discipline has mainly focused on qualitative morphological differences (e.g., presence or absence of a structure) between species. Studies addressing subtle, quantitative variation are less common. The Drosophila wing is a model for the study of development and evolution, making it suitable to investigate the developmental mechanisms underlying the subtle quantitative morphological variation observed in nature. Previous reviews have focused on the processes involved in wing differentiation, patterning and growth. Here, we investigate what is known about how the wing achieves its final shape, and what variation in development is capable of generating the variation in wing shape observed in nature. Three major developmental stages need to be considered: larval development, pupariation, and pupal development. The major cellular processes involved in the determination of tissue size and shape are cell proliferation, cell death, oriented cell division and oriented cell intercalation. We review how variation in temporal and spatial distribution of growth and transcription factors affects these cellular mechanisms, which in turn affects wing shape. We then discuss which aspects of the wing morphological variation are predictable on the basis of these mechanisms. PMID:25619644

Stochastic Cell Fate Progression in Embryonic Stem Cells

NASA Astrophysics Data System (ADS)

Zou, Ling-Nan; Doyle, Adele; Jang, Sumin; Ramanathan, Sharad

2013-03-01

Studies on the directed differentiation of embryonic stem (ES) cells suggest that some early developmental decisions may be stochastic in nature. To identify the sources of this stochasticity, we analyzed the heterogeneous expression of key transcription factors in single ES cells as they adopt distinct germ layer fates. We find that under sufficiently stringent signaling conditions, the choice of lineage is unambiguous. ES cells flow into differentiated fates via diverging paths, defined by sequences of transitional states that exhibit characteristic co-expression of multiple transcription factors. These transitional states have distinct responses to morphogenic stimuli; by sequential exposure to multiple signaling conditions, ES cells are steered towards specific fates. However, the rate at which cells travel down a developmental path is stochastic: cells exposed to the same signaling condition for the same amount of time can populate different states along the same path. The heterogeneity of cell states seen in our experiments therefore does not reflect the stochastic selection of germ layer fates, but the stochastic rate of progression along a chosen developmental path. Supported in part by the Jane Coffin Childs Fund

The differentiation of mammalian ovarian granulosa cells – living in the shadow of cellular developmental capacity.

PubMed

Chachuła, A; Kranc, W; Budna, J; Bryja, A; Ciesiólka, S; Wojtanowicz-Markiewicz, K; Piotrowska, H; Bukowska, D; Krajecki, M; Antosik, P; Brüssow, K P; Bruska, M; Nowicki, M; Zabel, M; Kempisty, B

2016-01-01

The mammalian cumulus-oocyte complex (COCs) promotes oocyte growth and development during long stages of folliculogenesis and oogenesis. Before ovulation, the follicle is formed by a variety of fully differentiated cell populations; cumulus cells (CCs) that tightly surround the female gamete, granulosa cells (GCs) and theca cells (TCs) which build the internal and external mass of the follicular wall. It is well documented that CCs surrounding the oocyte are necessary for resumption of meiosis and full maturation of the gamete. However, the role of the granulosa cells in acquisition of MII stage and/or full fertilization ability is not yet entirely known. In this article, we present an overview of mammalian oocytes and their relationship to the surrounding cumulus and granulosa cells. We also describe the processes of GCs differentiation and developmental capacity. Finally, we describe several markers of mammalian GCs, which could be used for positive identification of isolated cells. The developmental capacity of oocytes and surrounding somatic cells – a “fingerprint” of folliculogenesis and oogenesis.

Structural complexity and developmental stage after an intermediate-scale wind disturbance on an upland Quercus stand

Treesearch

Lauren E. Cox; Justin L. Hart; Callie J. Schweitzer; Daniel C. Dey

2017-01-01

Promoting stand structural complexity is an increasingly popular silvicultural objective, as complex structures are hypothesized to be more resistant and resilient to perturbations. On April 20, 2011 in Lawrence County, Alabama, an EF1 tornado tracked 5 km, leaving a patchwork mosaic of disturbed areas. In summer 2014, we established a 100 m × 200 m (2 ha) rectangular...

Irreversible barrier to the reprogramming of donor cells in cloning with mouse embryos and embryonic stem cells.

PubMed

Ono, Yukiko; Kono, Tomohiro

2006-08-01

Somatic cloning does not always result in ontogeny in mammals, and development is often associated with various abnormalities and embryo loss with a high frequency. This is considered to be due to aberrant gene expression resulting from epigenetic reprogramming errors. However, a fundamental question in this context is whether the developmental abnormalities reported to date are specific to somatic cloning. The aim of this study was to determine the stage of nuclear differentiation during development that leads to developmental abnormalities associated with embryo cloning. In order to address this issue, we reconstructed cloned embryos using four- and eight-cell embryos, morula embryos, inner cell mass (ICM) cells, and embryonic stem cells as donor nuclei and determined the occurrence of abnormalities such as developmental arrest and placentomegaly, which are common characteristics of all mouse somatic cell clones. The present analysis revealed that an acute decline in the full-term developmental competence of cloned embryos occurred with the use of four- and eight-cell donor nuclei (22.7% vs. 1.8%) in cases of standard embryo cloning and with morula and ICM donor nuclei (11.4% vs. 6.6%) in serial nuclear transfer. Histological observation showed abnormal differentiation and proliferation of trophoblastic giant cells in the placentae of cloned concepti derived from four-cell to ICM cell donor nuclei. Enlargement of placenta along with excessive proliferation of the spongiotrophoblast layer and glycogen cells was observed in the clones derived from morula embryos and ICM cells. These results revealed that irreversible epigenetic events had already started to occur at the four-cell stage. In addition, the expression of genes involved in placentomegaly is regulated at the blastocyst stage by irreversible epigenetic events, and it could not be reprogrammed by the fusion of nuclei with unfertilized oocytes. Hence, developmental abnormalities such as placentomegaly as well as embryo loss during development may occur even in cloned embryos reconstructed with nuclei from preimplantation-stage embryos, and these abnormalities are not specific to somatic cloning.

Developmental regulation of CYCA2s contributes to tissue-specific proliferation in Arabidopsis

PubMed Central

Vanneste, Steffen; Coppens, Frederik; Lee, EunKyoung; Donner, Tyler J; Xie, Zidian; Van Isterdael, Gert; Dhondt, Stijn; De Winter, Freya; De Rybel, Bert; Vuylsteke, Marnik; De Veylder, Lieven; Friml, Jiří; Inzé, Dirk; Grotewold, Erich; Scarpella, Enrico; Sack, Fred; Beemster, Gerrit T S; Beeckman, Tom

2011-01-01

In multicellular organisms, morphogenesis relies on a strict coordination in time and space of cell proliferation and differentiation. In contrast to animals, plant development displays continuous organ formation and adaptive growth responses during their lifespan relying on a tight coordination of cell proliferation. How developmental signals interact with the plant cell-cycle machinery is largely unknown. Here, we characterize plant A2-type cyclins, a small gene family of mitotic cyclins, and show how they contribute to the fine-tuning of local proliferation during plant development. Moreover, the timely repression of CYCA2;3 expression in newly formed guard cells is shown to require the stomatal transcription factors FOUR LIPS/MYB124 and MYB88, providing a direct link between developmental programming and cell-cycle exit in plants. Thus, transcriptional downregulation of CYCA2s represents a critical mechanism to coordinate proliferation during plant development. PMID:21772250

Embryonic stem cells and the next generation of developmental toxicity testing.

PubMed

Kugler, Josephine; Huhse, Bettina; Tralau, Tewes; Luch, Andreas

2017-08-01

The advent of stem cell technology has seen the establishment of embryonic stem cells (ESCs) as molecular model systems and screening tools. Although ESCs are nowadays widely used in research, regulatory implementation for developmental toxicity testing is pending. Areas Covered: This review evaluates the performance of current ESC, including human (h)ESC testing systems, trying to elucidate their potential for developmental toxicity testing. It shall discuss defining parameters and mechanisms, their relevance and contemplate what can realistically be expected. Crucially this includes the question of how to ascertain the quality of currently employed cell lines and tests based thereon. Finally, the use of hESCs will raise ethical concerns which should be addressed early on. Expert Opinion: While the suitability of (h)ESCs as tools for research and development goes undisputed, any routine use for developmental toxicity testing currently still seems premature. The reasons for this comprise inherent biological deficiencies as well as cell line quality and system validation. Overcoming these issues will require collaboration of scientists, test developers and regulators. Also, validation needs to be made worthwhile for academia. Finally we have to continuously rethink existing strategies, making room for improved testing and innovative approaches.

Description of Rhagoletis cerasi (Diptera: Tephritidae) pupal developmental stages: indications of prolonged diapause.

PubMed

Papanastasiou, Stella A; Papadopoulos, Nikos T

2014-01-01

The European cherry fruit fly, Rhagoletis cerasi (L.) (Diptera: Tephritidae), is the key pest of sweet and sour cherries in many European countries and west Asia. It is a univoltine species of the west Palaearctic zone that undergoes obligatory pupal diapause. In this study, the development of R. cerasi pupae that were brought to an optimum temperature for postdiapause development following a long chilling period is described. The six most representative developmental stages within the puparium are illustrated, and the developmental progression among the stages after the end of the chilling period is quantified. Within 20 d postchilling, there was a gradual progress from stage I to pharate adult. However, ∼30% of the pupae remained at the transitional stage II, after 20 d at 25°C (optimum temperature for development). This suggests that a proportion of pupae remain at an intermediate developmental stage for an extended period of time that goes beyond 20 d postchilling. The pupal stage II might be related to diapause termination and responsiveness to environmental cues. It may also define the time before developmental progress to pharate adult. This finding agrees with previous studies proposing that a number of R. cerasi pupae undergo prolonged diapause, though the morphological characteristics of these pupae have never been described before. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

Computational Modeling and Simulation of Developmental ...

EPA Pesticide Factsheets

SYNOPSIS: The question of how tissues and organs are shaped during development is crucial for understanding human birth defects. Data from high-throughput screening assays on human stem cells may be utilized predict developmental toxicity with reasonable accuracy. Other types of models are necessary, however, for mechanism-specific analysis because embryogenesis requires precise timing and control. Agent-based modeling and simulation (ABMS) is an approach to virtually reconstruct these dynamics, cell-by-cell and interaction-by-interaction. Using ABMS, HTS lesions from ToxCast can be integrated with patterning systems heuristically to propagate key events This presentation to FDA-CFSAN will update progress on the applications of in silico modeling tools and approaches for assessing developmental toxicity.

A Western Blot-based Investigation of the Yeast Secretory Pathway Designed for an Intermediate-Level Undergraduate Cell Biology Laboratory

ERIC Educational Resources Information Center

Hood-DeGrenier, Jennifer K.

2008-01-01

The movement of newly synthesized proteins through the endomembrane system of eukaryotic cells, often referred to generally as the secretory pathway, is a topic covered in most intermediate-level undergraduate cell biology courses. An article previously published in this journal described a laboratory exercise in which yeast mutants defective in…

Develop and test fuel cell powered on-site integrated total energy systems. Phase 3: Full-scale power plant development

NASA Technical Reports Server (NTRS)

Feigenbaum, H.; Kaufman, A.; Wang, C. L.; Werth, J.; Whelan, J. A.

1983-01-01

Operating experience with a 5kW methanol-air integrated system is described. On-going test results for a 24-cell, two-sq ft (4kW) stack are reported. The main activity for this stack is currently the evaluation of developmental non-metalic cooling plates. Single-cell test results are presented for a promising developmental cathode catalyst.

Cell migration analysis: A low-cost laboratory experiment for cell and developmental biology courses using keratocytes from fish scales.

PubMed

Prieto, Daniel; Aparicio, Gonzalo; Sotelo-Silveira, Jose R

2017-11-01

Cell and developmental processes are complex, and profoundly dependent on spatial relationships that change over time. Innovative educational or teaching strategies are always needed to foster deep comprehension of these processes and their dynamic features. However, laboratory exercises in cell and developmental biology at the undergraduate level do not often take into account the time dimension. In this article, we provide a laboratory exercise focused in cell migration, aiming to stimulate thinking in time and space dimensions through a simplification of more complex processes occurring in cell or developmental biology. The use of open-source tools for the analysis, as well as the whole package of raw results (available at http://github.com/danielprieto/keratocyte) make it suitable for its implementation in courses with very diverse budgets. Aiming to facilitate the student's transition from science-students to science-practitioners we propose an exercise of scientific thinking, and an evaluation method. This in turn is communicated here to facilitate the finding of common caveats and weaknesses in the process of producing simple scientific communications describing the results achieved. © 2017 by The International Union of Biochemistry and Molecular Biology, 45(6):475-482, 2017. © 2017 The International Union of Biochemistry and Molecular Biology.

Mechanically based generative laws of morphogenesis

NASA Astrophysics Data System (ADS)

Beloussov, Lev V.

2008-03-01

A deep (although at the first glance naïve) question which may be addressed to embryonic development is why during this process quite definite and accurately reproduced successions of precise and complicated shapes are taking place, or why, in several cases, the result of development is highly precise in spite of an extensive variability of intermediate stages. This problem can be attacked in two different ways. One of them, up to now just slightly employed, is to formulate robust macroscopic generative laws from which the observed successions of shapes could be derived. Another one, which dominates in modern embryology, regards the development as a succession of highly precise 'micropatterns', each of them arising due to the action of specific factors, having, as a rule, nothing in common with each other. We argue that the latter view contradicts a great bulk of firmly established data and gives no satisfactory answers to the main problems of development. Therefore we intend to follow the first way. By doing this, we regard developing embryos as self-organized systems transpierced by feedbacks among which we pay special attention to those linked with mechanical stresses (MS). We formulate a hypothesis of so-called MS hyper-restoration as a common basis for the developmentally important feedback loops. We present a number of examples confirming this hypothesis and use it for reconstructing prolonged chains of developmental events. Finally, we discuss the application of the same set of assumptions to the first steps of egg development and to the internal differentiation of embryonic cells.

Nicotinic acetylcholine receptors in porcine hypophyseal intermediate lobe cells.

PubMed Central

Zhang, Z W; Feltz, P

1990-01-01

1. Acetylcholine (ACh) was found to depolarize isolated porcine intermediate lobe cells maintained in primary cells culture. We investigated the ACh-induced responses in both whole-cell and cell-attached configurations of the patch-clamp technique. 2. From noise analysis of ACh-evoked whole-cell currents, we estimated an elementary conductance of 20 pS and a channel open duration of about 1.7 ms at -60 mV. From single-channel recordings, we obtained a slope conductance of 26 pS and a mean open time of 1.8 ms at membrane potentials between -60 and -80 mV. 3. ACh-evoked responses were blocked by d-tubocurarine (d-TC), hexamethonium and mecamylamine, but were insensitive to alpha-bungarotoxin. These characteristics define a neuronal type of nicotinic receptors. 4. The whole-cell current induced by ACh showed a strong inward rectification with no outward current being obtained. This phenomenon was observed when the intracellular ion is either sodium or caesium, and even when Ca2+ and Mg2+ were totally removed from the intracellular medium. 5. ACh-gated channels in intermediate lobe cells were cation selective and were permeable to Na+ and Cs+. In Ca2(+)-free extracellular solution, single-channel conductances were much larger (46 pS) than in the presence of 2 mM-Ca2+ (26 pS). 6. The possibility of an excitatory cholinergic control of intermediate lobe cells is discussed. PMID:1693685

Developmental exposure to 2,3,7,8 tetrachlorodibenzo-p-dioxin attenuates later-life Notch1-mediated T cell development and leukemogenesis

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

Ahrenhoerster, Lori S.; Leuthner, Tess C.; Tate, Everett R.

2015-03-01

Over half of T cell acute lymphoblastic leukemia (T-ALL) patients have activating mutations in the Notch gene. Moreover, the contaminant 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD) is a known carcinogen that mediates its toxicity through the aryl hydrocarbon receptor (AHR), and crosstalk between activated AHR and Notch signaling pathways has previously been observed. Given the importance of Notch signaling in thymocyte development and T-ALL disease progression, we hypothesized that the activated AHR potentiates disease initiation and progression in an in vivo model of Notch1-induced thymoma. This hypothesis was tested utilizing adult and developmental exposure paradigms to TCDD in mice expressing a constitutively activemore » Notch1 transgene (Notch{sup ICN-TG}). Following exposure of adult Notch{sup ICN-TG} mice to a single high dose of TCDD, we observed a significant increase in the efficiency of CD8 thymocyte generation. We next exposed pregnant mice to 3 μg/kg of TCDD throughout gestation and lactation to elucidate effects of developmental AHR activation on later-life T cell development and T-ALL-like thymoma susceptibility induced by Notch1. We found that the vehicle-exposed Notch{sup ICN-TG} offspring have a peripheral T cell pool heavily biased toward the CD4 lineage, while TCDD-exposed Notch{sup ICN-TG} offspring were biased toward the CD8 lineage. Furthermore, while the vehicle-exposed NotchICN-TG mice showed increased splenomegaly and B to T cell ratios indicative of disease, mice developmentally exposed to TCDD were largely protected from disease. These studies support a model where developmental AHR activation attenuates later-life Notch1-dependent impacts on thymocyte development and disease progression. - Highlights: • Adult mice exposed to 30 μg/kg TCDD have higher efficiency of CD8 thymocyte generation. • Mice carrying a constitutively active Notch transgene were exposed to 3 μg/kg TCDD throughout development. • Progression of Notch-induced thymoma was different in offspring exposed to TCDD developmentally. • Developmental AHR activation attenuates later-life Notch1-dependent impacts on T cell differentiation.« less

Targeting Developmental Pathways: The Achilles Heel of Cancer?

PubMed

Dempke, Wolfram C M; Fenchel, Klaus; Uciechowski, Peter; Chevassut, Timothy

2017-01-01

Developmental pathways (e.g., Notch, Hippo, Hedgehog, Wnt, and TGF-β/BMP/FGF) are networks of genes that act co-ordinately to establish the body plan, and disruptions of genes in one pathway can have effects in related pathways and may result in serious dysmorphogenesis or cancer. Interestingly, all developmental pathways are highly conserved cell signalling systems present in almost all multicellular organisms. In addition, they have a crucial role in cell proliferation, apoptosis, differentiation, and finally in organ development. Of note, almost all of these pathways promote oncogenesis through synergistic associations with the Hippo signalling pathway, and several lines of evidence have also indicated that these pathways (e.g., Wnt/β-catenin) may be implicated in checkpoint inhibitor resistance (e.g., CTLA-4, PD-1, and PD-L1). Since Notch inhibition in vivo results in partial loss of its stemness features such as self-renewal, chemoresistance, invasive and migratory potential, and tumorigenesis, these highly conserved developmental pathways are regarded as being critical for regulation of self-renewal in both embryonic and adult stem cells and hence are likely to be implicated in the maintenance of cancer stem cells. Many small molecules are currently in preclinical and early clinical development, and only two compounds are approved for treatment of advanced or metastatic basal cell carcinoma (vismodegib and sonidegib). Furthermore, therapeutic targeting of cancer stem cells using drugs that disrupt activated developmental pathways may also represent an attractive strategy that is potentially relevant to many types of malignancy, notably blood cancers, where the evidence for leukaemia stem cells is well established. Future work will hopefully pave the way for the development of new strategies for targeting these pervasive oncogenic pathways. © 2017 S. Karger AG, Basel.

Childhood developmental vulnerabilities associated with early life exposure to infectious and noninfectious diseases and maternal mental illness.

PubMed

Green, Melissa J; Kariuki, Maina; Dean, Kimberlie; Laurens, Kristin R; Tzoumakis, Stacy; Harris, Felicity; Carr, Vaughan J

2017-12-26

Fetal exposure to infectious and noninfectious diseases may influence early childhood developmental functioning, on the path to later mental illness. Here, we investigated the effects of in utero exposure to maternal infection and noninfectious diseases during pregnancy on offspring developmental vulnerabilities at age 5 years, in the context of estimated effects for early childhood exposures to infectious and noninfectious diseases and maternal mental illness. We used population data for 66,045 children from an intergenerational record linkage study (the New South Wales Child Development Study), for whom a cross-sectional assessment of five developmental competencies (physical, social, emotional, cognitive, and communication) was obtained at school entry, using the Australian Early Development Census (AEDC). Child and maternal exposures to infectious or noninfectious diseases were determined from the NSW Ministry of Health Admitted Patients Data Collection (APDC) and maternal mental illness exposure was derived from both APDC and Mental Health Ambulatory Data collections. Multinomial logistic regression analyses were used to examine unadjusted and adjusted associations between these physical and mental health exposures and child developmental vulnerabilities at age 5 years. Among the physical disease exposures, maternal infectious diseases during pregnancy and early childhood infection conferred the largest associations with developmental vulnerabilities at age 5 years; maternal noninfectious illness during pregnancy also retained small but significant associations with developmental vulnerabilities even when adjusted for other physical and mental illness exposures and covariates known to be associated with early childhood development (e.g., child's sex, socioeconomic disadvantage, young maternal age, prenatal smoking). Among all exposures examined, maternal mental illness first diagnosed prior to childbirth conferred the greatest odds of developmental vulnerability at age 5 years. Prenatal exposure to infectious or noninfectious diseases appear to influence early childhood physical, social, emotional and cognitive developmental vulnerabilities that may represent intermediate phenotypes for subsequent mental disorders. © 2017 Association for Child and Adolescent Mental Health.

Induced adult stem (iAS) cells and induced transit amplifying progenitor (iTAP) cells-a possible alternative to induced pluripotent stem (iPS) cells?

PubMed

Heng, Boon Chin; Richards, Mark; Ge, Zigang; Shu, Yimin

2010-02-01

The successful derivation of iPSC lines effectively demonstrates that it is possible to reset the 'developmental clock' of somatic cells all the way back to the initial embryonic state. Hence, it is plausible that this clock may instead be turned back half-way to a less immature developmental stage that is more directly applicable to clinical therapeutic applications or for in vitro pharmacology/toxicology screening assays. Such a suitable developmental state is postulated to be either the putative transit amplifying progenitor stage or adult stem cell stage. It is hypothetically possible to reprogram mature and terminally differentiated somatic cells back to the adult stem cell or transit amplifying progenitor stage, in a manner similar to the derivation of iPSC. It is proposed that the terminology 'Induced Adult Stem Cells' (iASC) or 'Induced Transit Amplifying Progenitor Cells' (iTAPC) be used to described such reprogrammed somatic cells. Of particular interest, is the possibility of resetting the developmental clock of mature differentiated somatic cells of the mesenchymal lineage, explanted from adipose tissue, bone marrow and cartilage. The putative adult stem cell sub-population from which these cells are derived, commonly referred to as 'mesenchymal stem cells', are highly versatile and hold much therapeutic promise in regenerative medicine, as attested to by numerous human clinical trials and animal studies. Perhaps it may be appropriate to term such reprogrammed cells as 'Induced Mesenchymal Stem Cells' (iMSC) or as 'Induced Mesenchumal Progenitor Cells' (iMPC). Given that cells from the same organ/tissue will share some commonalities in gene expression, we hypothesize that the generation of iASC or iTAPC would be more efficient as compared to iPSC generation, since a common epigenetic program must exist between the reprogrammed cells, adult stem cell or progenitor cell types and terminally differentiated cell types from the same organ/tissue.

Evaluation of 1066 ToxCast Chemicals in a human stem cell assay for developmental toxicity (SOT)

EPA Science Inventory

To increase the diversity of assays used to assess potential developmental toxicity, the ToxCast chemical library was screened in the Stemina devTOX quickPREDICT assay using human embryonic stem (hES) cells. A model for predicting teratogenicity was based on a training set of 23 ...

Effect of doping on room temperature carrier escape mechanisms in InAs/GaAs quantum dot p-i-n junction photovoltaic cells

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

Sellers, D. G.; Chen, E. Y.; Doty, M. F.

2016-05-21

We investigate the effect of doping on the mechanisms of carrier escape from intermediate states in delta-doped InAs/GaAs intermediate band solar cells. The intermediate states arise from InAs quantum dots embedded in a GaAs p-i-n junction cell. We find that doping the sample increases the number of excited-state carriers participating in a cycle of trapping and carrier escape via thermal, optical, and tunneling mechanisms. However, we find that the efficiency of the optically-driven carrier escape mechanism is independent of doping and remains small.

Phenotypic and functional characterization of a CD4+ CD25high FOXP3high regulatory T-cell population in the dog

PubMed Central

Pinheiro, Dammy; Singh, Yogesh; Grant, Charlotte R; Appleton, Richard C; Sacchini, Flavio; Walker, Kate R L; Chadbourne, Alden H; Palmer, Charlotte A; Armitage-Chan, Elizabeth; Thompson, Ian; Williamson, Lina; Cunningham, Fiona; Garden, Oliver A

2011-01-01

Relatively little is known about regulatory T (Treg) cells and their functional responses in dogs. We have used the cross-reactive anti-mouse/rat Foxp3 antibody clone FJK-16s to identify a population of canine CD4+ FOXP3high T cells in both the peripheral blood (PB) and popliteal lymph node (LN). FOXP3+ cells in both PB and LN yielded positive staining with the newly developed anti-murine/human Helios antibody clone 22F6, consistent with the notion that they were naturally occurring Treg cells. Stimulation of mononuclear cells of LN origin with concanavalin A (Con A) in vitro yielded increased proportions and median fluorescence intensity of FOXP3 expression by both CD4+ and CD8+ T cells. Removal of the Con A and continued culture disclosed a CD4+ FOXP3high population, distinct from the CD4+ FOXP3intermediate T cells; very few CD8+ FOXP3high T cells were observed, though CD8+ FOXP3intermediate cells were present in equal abundance to CD4+ FOXP3intermediate cells. The CD4+ FOXP3high T cells were thought to represent activated Treg cells, in contrast to the FOXP3intermediate cells, which were thought to be a more heterogeneous population comprising predominantly activated conventional T cells. Co-staining with interferon-γ (IFN-γ) supported this notion, because the FOXP3high T cells were almost exclusively IFN-γ−, whereas the FOXP3intermediate cells expressed a more heterogeneous IFN-γ phenotype. Following activation of mononuclear cells with Con A and interleukin-2, the 5% of CD4+ T cells showing the highest CD25 expression (CD4+ CD25high) were enriched in cells expressing FOXP3. These cells were anergic in vitro, in contrast to the 20% of CD4+ T cells with the lowest CD25 expression (CD4+ CD25−), which proliferated readily. The CD4+ CD25high FOXP3high T cells were able to suppress the proliferation of responder CD4+ T cells in vitro, in contrast to the CD4+ CD25− cells, which showed no regulatory properties. PMID:20880379

Wash functions downstream of Rho1 GTPase in a subset of Drosophila immune cell developmental migrations

PubMed Central

Verboon, Jeffrey M.; Rahe, Travis K.; Rodriguez-Mesa, Evelyn; Parkhurst, Susan M.

2015-01-01

Drosophila immune cells, the hemocytes, undergo four stereotypical developmental migrations to populate the embryo, where they provide immune reconnoitering, as well as a number of non–immune-related functions necessary for proper embryogenesis. Here, we describe a role for Rho1 in one of these developmental migrations in which posteriorly located hemocytes migrate toward the head. This migration requires the interaction of Rho1 with its downstream effector Wash, a Wiskott–Aldrich syndrome family protein. Both Wash knockdown and a Rho1 transgene harboring a mutation that prevents Wash binding exhibit the same developmental migratory defect as Rho1 knockdown. Wash activates the Arp2/3 complex, whose activity is needed for this migration, whereas members of the WASH regulatory complex (SWIP, Strumpellin, and CCDC53) are not. Our results suggest a WASH complex–independent signaling pathway to regulate the cytoskeleton during a subset of hemocyte developmental migrations. PMID:25739458

Genome wide assessment of mRNA in astrocyte protrusions by direct RNA sequencing reveals mRNA localization for the intermediate filament protein nestin.

PubMed

Thomsen, Rune; Pallesen, Jonatan; Daugaard, Tina F; Børglum, Anders D; Nielsen, Anders L

2013-11-01

Subcellular RNA localization plays an important role in development, cell differentiation, and cell migration. For a comprehensive description of the population of protrusion localized mRNAs in astrocytes we separated protrusions from cell bodies in a Boyden chamber and performed high-throughput direct RNA sequencing. The mRNAs with localization in astrocyte protrusions encode proteins belonging to a variety of functional groups indicating involvement of RNA localization for a palette of cellular functions. The mRNA encoding the intermediate filament protein Nestin was among the identified mRNAs. By RT-qPCR and RNA FISH analysis we confirmed Nestin mRNA localization in cell protrusions and also protrusion localization of Nestin protein. Nestin mRNA localization was dependent of Fragile X mental retardation syndrome proteins Fmrp and Fxr1, and the Nestin 3'-UTR was sufficient to mediate protrusion mRNA localization. The mRNAs for two other intermediate filament proteins in astrocytes, Gfap and Vimentin, have moderate and no protrusion localization, respectively, showing that individual intermediate filament components have different localization mechanisms. The correlated localization of Nestin mRNA with Nestin protein in cell protrusions indicates the presence of a regulatory mechanism at the mRNA localization level for the Nestin intermediate filament protein with potential importance for astrocyte functions during brain development and maintenance. Copyright © 2013 Wiley Periodicals, Inc.

Modularity in developmental biology and artificial organs: a missing concept in tissue engineering.

PubMed

Lenas, Petros; Luyten, Frank P; Doblare, Manuel; Nicodemou-Lena, Eleni; Lanzara, Andreina Elena

2011-06-01

Tissue engineering is reviving itself, adopting the concept of biomimetics of in vivo tissue development. A basic concept of developmental biology is the modularity of the tissue architecture according to which intermediates in tissue development constitute semiautonomous entities. Both engineering and nature have chosen the modular architecture to optimize the product or organism development and evolution. Bioartificial tissues do not have a modular architecture. On the contrary, artificial organs of modular architecture have been already developed in the field of artificial organs. Therefore the conceptual support of tissue engineering by the field of artificial organs becomes critical in its new endeavor of recapitulating in vitro the in vivo tissue development. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Fracture epidemiology and control in a developmental center.

PubMed Central

Lohiya, G S; Crinella, F M; Tan-Figueroa, L; Caires, S; Lohiya, S

1999-01-01

During 3.5 years, 182 fractures occurred among 994 residents of a developmental center. The fracture rate was 5.2 per 100 person-years (1.7 times greater than the rate in the US population). Fracture rate was significantly greater in residents with: epilepsy, older age, male gender, white race, independent ambulation, osteoporosis, and residence in intermediate care (versus skilled nursing) units; it was not affected by severity of mental retardation. Hand and foot bones were fractured in 58% of cases. Femur fracture occurred in 13 cases (7%). Fracture was caused by a fall in 41 cases (23%); its cause was indeterminable in 105 cases (58%). Fractures, occurring without significant injury, may be an important cause of preventable disability in this population. Control measures are suggested. Images Figure 1. Figure 2. PMID:10344173

Costs of epilepsy in an intermediate care facility for persons with mental retardation.

PubMed

Burke, T A; McKee, J R; Pathak, D S; Donahue, R M; Parasuraman, T V; Batenhorst, A S

1999-03-01

Epilepsy is a significant comorbid condition in institutionalized persons with developmental disabilities and may contribute significant additional costs. This study was conducted to provide an estimate of the costs of epilepsy from the institutional perspective. Costs were measured retrospectively for 50 persons with epilepsy and 50 persons without epilepsy matched by severity of developmental disability. A time and motion study was employed to assign opportunity costs to documented nursing and physician activities. Two separate methods of attribution were used and incremental costs attributable to epilepsy were found to be approximately $825 and $918 per person over a 6-month period. The following categories accounted for costs: personnel (47.0%), drug (39.6%), hospitalization (9.4%), and laboratories/procedures (4.0%). Results are useful for describing the economic burden of epilepsy.

Generation of germ cells in vitro in the era of induced pluripotent stem cells.

PubMed

Imamura, Masanori; Hikabe, Orie; Lin, Zachary Yu-Ching; Okano, Hideyuki

2014-01-01

Induced pluripotent stem cells (iPSCs) are stem cells that can be artificially generated via "cellular reprogramming" using gene transduction in somatic cells. iPSCs have enormous potential in stem-cell biology as they can give rise to numerous cell lineages, including the three germ layers. An evaluation of germ-line competency by blastocyst injection or tetraploid complementation, however, is critical for determining the developmental potential of mouse iPSCs towards germ cells. Recent studies have demonstrated that primordial germ cells obtained by the in vitro differentiation of iPSCs produce functional gametes as well as healthy offspring. These findings illustrate not only that iPSCs are developmentally similar to embryonic stem cells (ESCs), but also that somatic cells from adult tissues can produce gametes in vitro, that is, if they are reprogrammed into iPSCs. In this review, we discuss past and recent advances in the in vitro differentiation of germ cells using pluripotent stem cells, with an emphasis on ESCs and iPSCs. While this field of research is still at a stage of infancy, it holds great promises for investigating the mechanisms of germ-cell development, especially in humans, and for advancing reproductive and developmental engineering technologies in the future. © 2013 Wiley Periodicals, Inc.

Effects of an imprinting procedure on cell proliferation in the chick brain.

PubMed

Komissarova, N V; Anokhin, K V

2008-03-01

We report here studies on the effects of an imprinting procedure on cell proliferation in neonatal chicks in brain structures known to undergo plastic changes in imprinting. Proliferating cells were detected immunohistochemically on brain sections by incorporation of pre-training doses of 5-bromodeoxyuridine (BrdU) into DNA; numbers of new cells were counted in the intermediate medial mesopallium, the intermediate arcopallium, the medial part of the mesopallium and the nidopallium, the dorsocaudal nidopallium, the hippocampus, and the parahippocampal region 24 h and seven days after training. The intermediate medial mesopallium showed an increase in the number of BrdU-positive cells 24 h after training. However, at seven days post-training, the number of BrdU-containing cells decreased in the medial nidopallium and mesopallium, in the dorsocaudal nidopallium, and the right intermediate medial mesopallium. Thus, the imprinting procedure had differently directed transient and long-term influences on the genesis of new cells in the chick brain, inducing the appearance of a large number of cells in the parenchyma of the brain one day after training and decreases in the numbers of cells at later time points. This double effect may be associated with the fact that the imprinting procedure simultaneously initiates two brain processes involving the control of cell proliferation - one related to maturation of a species-specific functional system for tracking individuals of the same species and one related to remembering the characteristics of the actual parent.

Bioinformatics approaches to single-cell analysis in developmental biology.

PubMed

Yalcin, Dicle; Hakguder, Zeynep M; Otu, Hasan H

2016-03-01

Individual cells within the same population show various degrees of heterogeneity, which may be better handled with single-cell analysis to address biological and clinical questions. Single-cell analysis is especially important in developmental biology as subtle spatial and temporal differences in cells have significant associations with cell fate decisions during differentiation and with the description of a particular state of a cell exhibiting an aberrant phenotype. Biotechnological advances, especially in the area of microfluidics, have led to a robust, massively parallel and multi-dimensional capturing, sorting, and lysis of single-cells and amplification of related macromolecules, which have enabled the use of imaging and omics techniques on single cells. There have been improvements in computational single-cell image analysis in developmental biology regarding feature extraction, segmentation, image enhancement and machine learning, handling limitations of optical resolution to gain new perspectives from the raw microscopy images. Omics approaches, such as transcriptomics, genomics and epigenomics, targeting gene and small RNA expression, single nucleotide and structural variations and methylation and histone modifications, rely heavily on high-throughput sequencing technologies. Although there are well-established bioinformatics methods for analysis of sequence data, there are limited bioinformatics approaches which address experimental design, sample size considerations, amplification bias, normalization, differential expression, coverage, clustering and classification issues, specifically applied at the single-cell level. In this review, we summarize biological and technological advancements, discuss challenges faced in the aforementioned data acquisition and analysis issues and present future prospects for application of single-cell analyses to developmental biology. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Reassessing ecdysteroidogenic cells from the cell membrane receptors' perspective.

PubMed

Alexandratos, Alexandros; Moulos, Panagiotis; Nellas, Ioannis; Mavridis, Konstantinos; Dedos, Skarlatos G

2016-02-05

Ecdysteroids secreted by the prothoracic gland (PG) cells of insects control the developmental timing of their immature life stages. These cells have been historically considered as carrying out a single function in insects, namely the biochemical conversion of cholesterol to ecdysteroids and their secretion. A growing body of evidence shows that PG cells receive multiple cues during insect development so we tested the hypothesis that they carry out more than just one function in insects. We characterised the molecular nature and developmental profiles of cell membrane receptors in PG cells of Bombyx mori during the final larval stage and determined what receptors decode nutritional, developmental and physiological signals. Through iterative approaches we identified a complex repertoire of cell membrane receptors that are expressed in intricate patterns and activate previously unidentified signal transduction cascades in PG cells. The expression patterns of some of these receptors explain precisely the mechanisms that are known to control ecdysteroidogenesis. However, the presence of receptors for the notch, hedgehog and wingless signalling pathways and the expression of innate immunity-related receptors such as phagocytosis receptors, receptors for microbial ligands and Toll-like receptors call for a re-evaluation of the role these cells play in insects.

Retinoid signaling in progenitors controls specification and regeneration of the urothelium.

PubMed

Gandhi, Devangini; Molotkov, Andrei; Batourina, Ekatherina; Schneider, Kerry; Dan, Hanbin; Reiley, Maia; Laufer, Ed; Metzger, Daniel; Liang, Fengxia; Liao, Yi; Sun, Tung-Tien; Aronow, Bruce; Rosen, Roni; Mauney, Josh; Adam, Rosalyn; Rosselot, Carolina; Van Batavia, Jason; McMahon, Andrew; McMahon, Jill; Guo, Jin-Jin; Mendelsohn, Cathy

2013-09-16

The urothelium is a multilayered epithelium that serves as a barrier between the urinary tract and blood, preventing the exchange of water and toxic substances. It consists of superficial cells specialized for synthesis and transport of uroplakins that assemble into a tough apical plaque, one or more layers of intermediate cells, and keratin 5-expressing basal cells (K5-BCs), which are considered to be progenitors in the urothelium and other specialized epithelia. Fate mapping, however, reveals that intermediate cells rather than K5-BCs are progenitors in the adult regenerating urothelium, that P cells, a transient population, are progenitors in the embryo, and that retinoids are critical in P cells and intermediate cells, respectively, for their specification during development and regeneration. These observations have important implications for tissue engineering and repair and, ultimately, may lead to treatments that prevent loss of the urothelial barrier, a major cause of voiding dysfunction and bladder pain syndrome. Copyright © 2013 Elsevier Inc. All rights reserved.

Developmental origin and lineage plasticity of endogenous cardiac stem cells

PubMed Central

Santini, Maria Paola; Forte, Elvira; Harvey, Richard P.; Kovacic, Jason C.

2016-01-01

Over the past two decades, several populations of cardiac stem cells have been described in the adult mammalian heart. For the most part, however, their lineage origins and in vivo functions remain largely unexplored. This Review summarizes what is known about different populations of embryonic and adult cardiac stem cells, including KIT+, PDGFRα+, ISL1+ and SCA1+ cells, side population cells, cardiospheres and epicardial cells. We discuss their developmental origins and defining characteristics, and consider their possible contribution to heart organogenesis and regeneration. We also summarize the origin and plasticity of cardiac fibroblasts and circulating endothelial progenitor cells, and consider what role these cells have in contributing to cardiac repair. PMID:27095490

Differential gene expression in notochord and nerve cord fate segregation in the Ciona intestinalis embryo.

PubMed

Kobayashi, Kenji; Yamada, Lixy; Satou, Yutaka; Satoh, Nori

2013-09-01

During early embryogenesis, embryonic cells gradually restrict their developmental potential and are eventually destined to give rise to one type of cells. Molecular mechanisms underlying developmental fate restriction are one of the major research subjects within developmental biology. In this article, this subject was addressed by combining blastomere isolation with microarray analysis. During the 6th cleavage of the Ciona intestinalis embryo, from the 32-cell to the 64-cell stage, four mother cells divide into daughter cells with two distinct fates, one giving rise to notochord precursor cells and the other to nerve cord precursors. Approximately 2,200 each of notochord and nerve cord precursor cells were isolated, and their mRNA expression profiles were compared by microarray. This analysis identified 106 and 68 genes, respectively, that are differentially expressed in notochord and nerve cord precursor cells. These included not only genes for transcription factors and signaling molecules but also those with generalized functions observed in many types of cells. In addition, whole-mount in situ hybridization showed dynamic spatial expression profiles of these genes during segregation of the two fates: partitioning of transcripts present in the mother cells into either type of daughter cells, and initiation of preferential gene expression in either type of cells. Copyright © 2013 Wiley Periodicals, Inc.

Developmental delay in moderately preterm-born children with low socioeconomic status: risks multiply.

PubMed

Potijk, Marieke R; Kerstjens, Jorien M; Bos, Arend F; Reijneveld, Sijmen A; de Winter, Andrea F

2013-11-01

To assess separate and joint effects of low socioeconomic status (SES) and moderate prematurity on preschool developmental delay. Prospective cohort study with a community-based sample of preterm- and term-born children (Longitudinal Preterm Outcome Project). We assessed SES on the basis of education, occupation, and family income. The Ages and Stages Questionnaire was used to assess developmental delay at age 4 years. We determined scores for overall development, and domains fine motor, gross motor, communication, problem-solving, and personal-social of 926 moderately preterm-born (MP) (32-36 weeks gestation) and 544 term-born children. In multivariable logistic regression analyses, we used standardized values for SES and gestational age (GA). Prevalence rates for overall developmental delay were 12.5%, 7.8%, and 5.6% in MP children with low, intermediate, and high SES, respectively, and 7.2%, 4.0%, and 2.8% in term-born children, respectively. The risk for overall developmental delay increased more with decreasing SES than with decreasing GA, but the difference was not statistically significant: OR (95% CI) for a 1 standard deviation decrease were: 1.62 (1.30-2.03) and 1.34 (1.05-1.69), respectively, after adjustment for sex, number of siblings, and maternal age. No interaction was found except for communication, showing that effects of SES and GA are mostly multiplicative. Low SES and moderate prematurity are separate risk factors with multiplicative effects on developmental delay. The double jeopardy of MP children with low SES needs special attention in pediatric care. Copyright © 2013 Mosby, Inc. All rights reserved.

Planning Assembly Of Large Truss Structures In Outer Space

NASA Technical Reports Server (NTRS)

De Mello, Luiz S. Homem; Desai, Rajiv S.

1992-01-01

Report dicusses developmental algorithm used in systematic planning of sequences of operations in which large truss structures assembled in outer space. Assembly sequence represented by directed graph called "assembly graph", in which each arc represents joining of two parts or subassemblies. Algorithm generates assembly graph, working backward from state of complete assembly to initial state, in which all parts disassembled. Working backward more efficient than working forward because it avoids intermediate dead ends.

Development of Fermented Taro as a Food Preservative Ingredient in Intermediate Moisture Products

DTIC Science & Technology

2005-11-01

BACTERIOCINS TARO MOISTURE MICROBIOLOGY NISIN SHELF LIFE FOOD SPOILAGE RATIONS FOOD SAFETY FERMF.l’l TATION 16. SECURITY CLASSIFICATION OF: 17. LIMITATION...Antibacterial Potential of Fermented Taro and its Development as a Food Preservative". This report covers the second part of the microbiology and food ... safety aspects of the project, the development of fermented taro as a food preservative and its incorporation into a developmental military food

Clinical pharmacy services in an intermediate care facility for the mentally retarded.

PubMed

McKee, J R

1994-03-01

The impact of a focused drug regimen review process based on clear objectives and of interdisciplinary team cooperation is described. By shifting from a pharmacy departmental focus, which was primarily on drug distribution activities, to a broader agenda that promotes pharmacists as clinicians, inroads were made in reducing medication doses per resident, decreasing nursing time spent in medication administration, and decreasing pharmacy expenses in this residential facility for the developmentally disabled.

Evaluation of an adherent mouse embryonic stem cell in vitro assay to predict developmental toxicity of ToxCast chemicals.

EPA Science Inventory

The potential for most environmental chemicals to produce developmental toxicity is unknown. Mouse embryonic stem cell (mESC) assays are an alternative in vitro model to assess chemicals. The chemical space evaluated using mESC and compared to in vivo is limited. We used an adher...

Effects Of Haloacetic Acids and their major metabolites in a Mouse Embryonic Stem Cell Adherent Cell Differentiation and Cytotoxicity (ACDC) Assay

EPA Science Inventory

The haloacetic acids (HAAs) are a class of chemicals produced by disinfection of drinking water. Many of the HAAs are developmental toxicants when administered to rodents producing a variety of developmental effects. We have previously shown that the HAAs can produce direct effec...

The role of Drosophila TNF Eiger in developmental and damage-induced neuronal apoptosis.

PubMed

Shklover, Jeny; Levy-Adam, Flonia; Kurant, Estee

2015-04-02

Eiger, the sole Drosophila TNF-alpha homolog, causes ectopic apoptosis through JNK pathway activation. Yet, its role in developmental apoptosis remains unclear. eiger mutant flies are viable and fertile but display compromised elimination of oncogenic cells and extracellular bacteria. Here we show that Eiger, specifically expressed in embryonic neurons and glia, is not involved in developmental neuronal apoptosis or in apoptotic cell clearance. Instead, we provide evidence that Eiger is required for damage-induced apoptosis in the embryonic CNS through regulation of the pro-apoptotic gene hid independently of the JNK pathway. Our study thus reveals a new requirement for Eiger in eliminating damaged cells during development. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Developmental Bisphenol A Exposure Modulates Immune-Related Diseases

PubMed Central

Xu, Joella; Huang, Guannan; Guo, Tai L.

2016-01-01

Bisphenol A (BPA), used in polycarbonate plastics and epoxy resins, has a widespread exposure to humans. BPA is of concern for developmental exposure resulting in immunomodulation and disease development due to its ability to cross the placental barrier and presence in breast milk. BPA can use various mechanisms to modulate the immune system and affect diseases, including agonistic and antagonistic effects on many receptors (e.g., estrogen receptors), epigenetic modifications, acting on cell signaling pathways and, likely, the gut microbiome. Immune cell populations and function from the innate and adaptive immune system are altered by developmental BPA exposure, including decreased T regulatory (Treg) cells and upregulated pro- and anti-inflammatory cytokines and chemokines. Developmental BPA exposure can also contribute to the development of type 2 diabetes mellitus, allergy, asthma and mammary cancer disease by altering immune function. Multiple sclerosis and type 1 diabetes mellitus may also be exacerbated by BPA, although more research is needed. Additionally, BPA analogs, such as bisphenol S (BPS), have been increasing in use, and currently, little is known about their immune effects. Therefore, more studies should be conducted to determine if developmental exposure BPA and its analogs modulate immune responses and lead to immune-related diseases. PMID:29051427

Developmental Bisphenol A Exposure Modulates Immune-Related Diseases.

PubMed

Xu, Joella; Huang, Guannan; Guo, Tai L

2016-09-26

Bisphenol A (BPA), used in polycarbonate plastics and epoxy resins, has a widespread exposure to humans. BPA is of concern for developmental exposure resulting in immunomodulation and disease development due to its ability to cross the placental barrier and presence in breast milk. BPA can use various mechanisms to modulate the immune system and affect diseases, including agonistic and antagonistic effects on many receptors (e.g., estrogen receptors), epigenetic modifications, acting on cell signaling pathways and, likely, the gut microbiome. Immune cell populations and function from the innate and adaptive immune system are altered by developmental BPA exposure, including decreased T regulatory (Treg) cells and upregulated pro- and anti-inflammatory cytokines and chemokines. Developmental BPA exposure can also contribute to the development of type 2 diabetes mellitus, allergy, asthma and mammary cancer disease by altering immune function. Multiple sclerosis and type 1 diabetes mellitus may also be exacerbated by BPA, although more research is needed. Additionally, BPA analogs, such as bisphenol S (BPS), have been increasing in use, and currently, little is known about their immune effects. Therefore, more studies should be conducted to determine if developmental exposure BPA and its analogs modulate immune responses and lead to immune-related diseases.

Asymmetric Distribution of GFAP in Glioma Multipotent Cells

PubMed Central

Guichet, Pierre-Olivier; Guelfi, Sophie; Ripoll, Chantal; Teigell, Marisa; Sabourin, Jean-Charles; Bauchet, Luc; Rigau, Valérie; Rothhut, Bernard; Hugnot, Jean-Philippe

2016-01-01

Asymmetric division (AD) is a fundamental mechanism whereby unequal inheritance of various cellular compounds during mitosis generates unequal fate in the two daughter cells. Unequal repartitions of transcription factors, receptors as well as mRNA have been abundantly described in AD. In contrast, the involvement of intermediate filaments in this process is still largely unknown. AD occurs in stem cells during development but was also recently observed in cancer stem cells. Here, we demonstrate the asymmetric distribution of the main astrocytic intermediate filament, namely the glial fibrillary acid protein (GFAP), in mitotic glioma multipotent cells isolated from glioblastoma (GBM), the most frequent type of brain tumor. Unequal mitotic repartition of GFAP was also observed in mice non-tumoral neural stem cells indicating that this process occurs across species and is not restricted to cancerous cells. Immunofluorescence and videomicroscopy were used to capture these rare and transient events. Considering the role of intermediate filaments in cytoplasm organization and cell signaling, we propose that asymmetric distribution of GFAP could possibly participate in the regulation of normal and cancerous neural stem cell fate. PMID:26953813

Heparan sulfate deficiency leads to Peters anomaly in mice by disturbing neural crest TGF-β2 signaling

PubMed Central

Iwao, Keiichiro; Inatani, Masaru; Matsumoto, Yoshihiro; Ogata-Iwao, Minako; Takihara, Yuji; Irie, Fumitoshi; Yamaguchi, Yu; Okinami, Satoshi; Tanihara, Hidenobu

2009-01-01

During human embryogenesis, neural crest cells migrate to the anterior chamber of the eye and then differentiate into the inner layers of the cornea, the iridocorneal angle, and the anterior portion of the iris. When proper development does not occur, this causes iridocorneal angle dysgenesis and intraocular pressure (IOP) elevation, which ultimately results in developmental glaucoma. Here, we show that heparan sulfate (HS) deficiency in mouse neural crest cells causes anterior chamber dysgenesis, including corneal endothelium defects, corneal stroma hypoplasia, and iridocorneal angle dysgenesis. These dysfunctions are phenotypes of the human developmental glaucoma, Peters anomaly. In the neural crest cells of mice embryos, disruption of the gene encoding exostosin 1 (Ext1), which is an indispensable enzyme for HS synthesis, resulted in disturbed TGF-β2 signaling. This led to reduced phosphorylation of Smad2 and downregulated expression of forkhead box C1 (Foxc1) and paired-like homeodomain transcription factor 2 (Pitx2), transcription factors that have been identified as the causative genes for developmental glaucoma. Furthermore, impaired interactions between HS and TGF-β2 induced developmental glaucoma, which was manifested as an IOP elevation caused by iridocorneal angle dysgenesis. These findings suggest that HS is necessary for neural crest cells to form the anterior chamber via TGF-β2 signaling. Disturbances of HS synthesis might therefore contribute to the pathology of developmental glaucoma. PMID:19509472

Developmentally Programmed 3′ CpG Island Methylation Confers Tissue- and Cell-Type-Specific Transcriptional Activation

PubMed Central

Yu, Da-Hai; Ware, Carol; Waterland, Robert A.; Zhang, Jiexin; Chen, Miao-Hsueh; Gadkari, Manasi; Kunde-Ramamoorthy, Govindarajan; Nosavanh, Lagina M.

2013-01-01

During development, a small but significant number of CpG islands (CGIs) become methylated. The timing of developmentally programmed CGI methylation and associated mechanisms of transcriptional regulation during cellular differentiation, however, remain poorly characterized. Here, we used genome-wide DNA methylation microarrays to identify epigenetic changes during human embryonic stem cell (hESC) differentiation. We discovered a group of CGIs associated with developmental genes that gain methylation after hESCs differentiate. Conversely, erasure of methylation was observed at the identified CGIs during subsequent reprogramming to induced pluripotent stem cells (iPSCs), further supporting a functional role for the CGI methylation. Both global gene expression profiling and quantitative reverse transcription-PCR (RT-PCR) validation indicated opposing effects of CGI methylation in transcriptional regulation during differentiation, with promoter CGI methylation repressing and 3′ CGI methylation activating transcription. By studying diverse human tissues and mouse models, we further confirmed that developmentally programmed 3′ CGI methylation confers tissue- and cell-type-specific gene activation in vivo. Importantly, luciferase reporter assays provided evidence that 3′ CGI methylation regulates transcriptional activation via a CTCF-dependent enhancer-blocking mechanism. These findings expand the classic view of mammalian CGI methylation as a mechanism for transcriptional silencing and indicate a functional role for 3′ CGI methylation in developmental gene regulation. PMID:23459939

Systems Approaches to Predict the Functions of Glycoside Hydrolases during the Life Cycle of Aspergillus niger Using Developmental Mutants ∆brlA and ∆flbA

PubMed Central

van Munster, Jolanda M.; Nitsche, Benjamin M.; Akeroyd, Michiel; Dijkhuizen, Lubbert; van der Maarel, Marc J. E. C.; Ram, Arthur F. J.

2015-01-01

Background The filamentous fungus Aspergillus niger encounters carbon starvation in nature as well as during industrial fermentations. In response, regulatory networks initiate and control autolysis and sporulation. Carbohydrate-active enzymes play an important role in these processes, for example by modifying cell walls during spore cell wall biogenesis or in cell wall degradation connected to autolysis. Results In this study, we used developmental mutants (ΔflbA and ΔbrlA) which are characterized by an aconidial phenotype when grown on a plate, but also in bioreactor-controlled submerged cultivations during carbon starvation. By comparing the transcriptomes, proteomes, enzyme activities and the fungal cell wall compositions of a wild type A. niger strain and these developmental mutants during carbon starvation, a global overview of the function of carbohydrate-active enzymes is provided. Seven genes encoding carbohydrate-active enzymes, including cfcA, were expressed during starvation in all strains; they may encode enzymes involved in cell wall recycling. Genes expressed in the wild-type during starvation, but not in the developmental mutants are likely involved in conidiogenesis. Eighteen of such genes were identified, including characterized sporulation-specific chitinases and An15g02350, member of the recently identified carbohydrate-active enzyme family AA11. Eight of the eighteen genes were also expressed, independent of FlbA or BrlA, in vegetative mycelium, indicating that they also have a role during vegetative growth. The ΔflbA strain had a reduced specific growth rate, an increased chitin content of the cell wall and specific expression of genes that are induced in response to cell wall stress, indicating that integrity of the cell wall of strain ΔflbA is reduced. Conclusion The combination of the developmental mutants ΔflbA and ΔbrlA resulted in the identification of enzymes involved in cell wall recycling and sporulation-specific cell wall modification, which contributes to understanding cell wall remodeling mechanisms during development. PMID:25629352

Transient chondrogenic phase in the intramembranous pathway during normal skeletal development.

PubMed

Nah, H D; Pacifici, M; Gerstenfeld, L C; Adams, S L; Kirsch, T

2000-03-01

Calvarial and facial bones form by intramembranous ossification, in which bone cells arise directly from mesenchyme without an intermediate cartilage anlage. However, a number of studies have reported the emergence of chondrocytes from in vitro calvarial cell or organ cultures and the expression of type II collagen, a cartilage-characteristic marker, in developing calvarial bones. Based on these findings we hypothesized that a covert chondrogenic phase may be an integral part of the normal intramembranous pathway. To test this hypothesis, we analyzed the temporal and spatial expression patterns of cartilage characteristic genes in normal membranous bones from chick embryos at various developmental stages (days 12, 15 and 19). Northern and RNAse protection analyses revealed that embryonic frontal bones expressed not only the type I collagen gene but also a subset of cartilage characteristic genes, types IIA and XI collagen and aggrecan, thus resembling a phenotype of prechondrogenic-condensing mesenchyme. The expression of cartilage-characteristic genes decreased with the progression of bone maturation. Immunohistochemical analyses of developing embryonic chick heads indicated that type II collagen and aggrecan were produced by alkaline phosphatase activity positive cells engaged in early stages of osteogenic differentiation, such as cells in preosteogenic-condensing mesenchyme, the cambium layer of periosteum, the advancing osteogenic front, and osteoid bone. Type IIB and X collagen messenger RNAs (mRNA), markers for mature chondrocytes, were also detected at low levels in calvarial bone but not until late embryonic stages (day 19), indicating that some calvarial cells may undergo overt chondrogenesis. On the basis of our findings, we propose that the normal intramembranous pathway in chicks includes a previously unrecognized transient chondrogenic phase similar to prechondrogenic mesenchyme, and that the cells in this phase retain chondrogenic potential that can be expressed in specific in vitro and in vivo microenvironments.

Intermediate band formation in a δ-doped like QW superlattices of GaAs/AlxGa1-xAs for solar cell design

NASA Astrophysics Data System (ADS)

Del Río-De Santiago, A.; Martínez-Orozco, J. C.; Rodríguez-Magdaleno, K. A.; Contreras-Solorio, D. A.; Rodríguez-Vargas, I.; Ungan, F.

2018-03-01

It is reported a numerical computation of the local density of states for a δ-doped like QW superlattices of AlxGa1-xAs, as a possible heterostructure that, being integrated into a solar cell device design, can provide an intermediate band of allowed states to assist the absorption of photons with lower energies than that of the energy gap of the solar-cell constituent materials. This work was performed using the nearest neighbors sp3s* tight-binding model including spin. The confining potential caused by the ionized donor impurities in δ-doped impurities seeding that was obtained analytically within the lines of the Thomas-Fermi approximation was reproduced here by the Al concentration x variation. This potential is considered as an external perturbation in the tight-binding methodology and it is included in the diagonal terms of the tight-binding Hamiltonian. Special attention is paid to the width of the intermediate band caused by the change in the considered aluminium concentration x, the inter-well distance between δ-doped like QW wells and the number of them in the superlattice. In general we can conclude that this kind of superlattices can be suitable for intermediate band formation for possible intermediate-band solar cell design.

Lenalidomide and Blinatumomab in Treating Patients With Relapsed Non-Hodgkin Lymphoma

ClinicalTrials.gov

2018-06-11

CD19 Positive; Mediastinal Lymphoma; Recurrent B-Cell Lymphoma, Unclassifiable, With Features Intermediate Between Diffuse Large B-Cell Lymphoma and Classic Hodgkin Lymphoma; Recurrent Burkitt Lymphoma; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Non-Hodgkin Lymphoma; Recurrent Small Lymphocytic Lymphoma; Refractory B-Cell Lymphoma, Unclassifiable, With Features Intermediate Between Diffuse Large B-Cell Lymphoma and Classic Hodgkin Lymphoma; Refractory Burkitt Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Follicular Lymphoma; Refractory Mantle Cell Lymphoma; Refractory Small Lymphocytic Lymphoma

Reactive Oxygen Species (ROS): Beneficial Companions of Plants’ Developmental Processes

PubMed Central

Singh, Rachana; Singh, Samiksha; Parihar, Parul; Mishra, Rohit K.; Tripathi, Durgesh K.; Singh, Vijay P.; Chauhan, Devendra K.; Prasad, Sheo M.

2016-01-01

Reactive oxygen species (ROS) are generated inevitably in the redox reactions of plants, including respiration and photosynthesis. In earlier studies, ROS were considered as toxic by-products of aerobic pathways of the metabolism. But in recent years, concept about ROS has changed because they also participate in developmental processes of plants by acting as signaling molecules. In plants, ROS regulate many developmental processes such as cell proliferation and differentiation, programmed cell death, seed germination, gravitropism, root hair growth and pollen tube development, senescence, etc. Despite much progress, a comprehensive update of advances in the understanding of the mechanisms evoked by ROS that mediate in cell proliferation and development are fragmentry and the matter of ROS perception and the signaling cascade remains open. Therefore, keeping in view the above facts, an attempt has been made in this article to summarize the recent findings regarding updates made in the regulatory action of ROS at various plant developmental stages, which are still not well-known. PMID:27729914

High developmental potential in vitro and in vivo of cattle embryos cloned without micromanipulators

PubMed Central

Rodríguez, Lleretny; Navarrete, Felipe I.; Tovar, Heribelt; Cox, José F.

2008-01-01

Purpose In order to simplify cloning, a new method that does not require micromanipulators was used. We aimed to evaluate the developmental potential of two bovine cell lines upon cloning. Materials and methods In vitro matured bovine oocytes, were released from zona pellucida, enucleated, fused to foetal or adult somatic donor cells. The reconstructed embryos were reprogrammed, activated and cultured until blastocyst stage. No micromanipulators were used. Blastocyst rate and quality was scored. Some expanded (d7) blastocysts were transferred to recipient cattle and collected back at d17 to assess elongation. Results High developmental potential in vitro of cloned embryos to expanded (d7) blastocysts was achieved (52.6%). In one cell line, 65.7% of blastocysts was scored. Most blastocysts (87.4%) were graded as excellent. In vivo development to elongation (day-17) in temporary recipient cows also showed a high developmental potential (11/18 transferred blastocysts elongated). Conclusions Hand-made cloning is an efficient alternative for cloning in cattle. PMID:18205035

Cytosolic glyceraldehyde-3-phosphate dehydrogenases play crucial roles in controlling cold-induced sweetening and apical dominance of potato (Solanum tuberosum L.) tubers.

PubMed

Liu, Tengfei; Fang, Hui; Liu, Jun; Reid, Stephen; Hou, Juan; Zhou, Tingting; Tian, Zhendong; Song, Botao; Xie, Conghua

2017-12-01

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is an important enzyme that functions in producing energy and supplying intermediates for cellular metabolism. Recent researches indicate that GAPDHs have multiple functions beside glycolysis. However, little information is available for functions of GAPDHs in potato. Here, we identified 4 putative cytosolic GAPDH genes in potato genome and demonstrated that the StGAPC1, StGAPC2, and StGAPC3, which are constitutively expressed in potato tissues and cold inducible in tubers, encode active cytosolic GAPDHs. Cosuppression of these 3 GAPC genes resulted in low tuber GAPDH activity, consequently the accumulation of reducing sugars in cold stored tubers by altering the tuber metabolite pool sizes favoring the sucrose pathway. Furthermore, GAPCs-silenced tubers exhibited a loss of apical dominance dependent on cell death of tuber apical bud meristem (TAB-meristem). It was also confirmed that StGAPC1, StGAPC2, and StGAPC3 interacted with the autophagy-related protein 3 (ATG3), implying that the occurrence of cell death in TAB-meristem could be induced by ATG3 associated events. Collectively, the present research evidences first that the GAPC genes play crucial roles in diverse physiological and developmental processes in potato tubers. © 2017 John Wiley & Sons Ltd.

Quantification of biofilm structures by the novel computer program COMSTAT.

PubMed

Heydorn, A; Nielsen, A T; Hentzer, M; Sternberg, C; Givskov, M; Ersbøll, B K; Molin, S

2000-10-01

The structural organization of four microbial communities was analysed by a novel computer program, COMSTAT, which comprises ten features for quantifying three-dimensional biofilm image stacks. Monospecies biofilms of each of the four bacteria, Pseudomonas: putida, P. aureofaciens, P. fluorescens and P. aeruginosa, tagged with the green fluorescent protein (GFP) were grown in flow chambers with a defined minimal medium as substrate. Analysis by the COMSTAT program of four variables describing biofilm structure - mean thickness, roughness, substratum coverage and surface to volume ratio - showed that the four Pseudomonas: strains represent different modes of biofilm growth. P. putida had a unique developmental pattern starting with single cells on the substratum growing into micro-colonies, which were eventually succeeded by long filaments and elongated cell clusters. P. aeruginosa colonized the entire substratum, and formed flat, uniform biofilms. P. aureofaciens resembled P. aeruginosa, but had a stronger tendency to form micro-colonies. Finally, the biofilm structures of P. fluorescens had a phenotype intermediate between those of P. putida and P. aureofaciens. Analysis of biofilms of P. aureofaciens growing on 0.03 mM, 0.1 mM or 0.5 mM citrate minimal media showed that mean biofilm thickness increased with increasing citrate concentration. Moreover, biofilm roughness increased with lower citrate concentrations, whereas surface to volume ratio increased with higher citrate concentrations.

Specific subpopulations of hypothalamic leptin receptor-expressing neurons mediate the effects of early developmental leptin receptor deletion on energy balance.

PubMed

Rupp, Alan C; Allison, Margaret B; Jones, Justin C; Patterson, Christa M; Faber, Chelsea L; Bozadjieva, Nadejda; Heisler, Lora K; Seeley, Randy J; Olson, David P; Myers, Martin G

2018-06-06

To date, early developmental ablation of leptin receptor (LepRb) expression from circumscribed populations of hypothalamic neurons (e.g., arcuate nucleus (ARC) Pomc- or Agrp-expressing cells) has only minimally affected energy balance. In contrast, removal of LepRb from at least two large populations (expressing vGat or Nos1) spanning multiple hypothalamic regions produced profound obesity and metabolic dysfunction. Thus, we tested the notion that the total number of leptin-responsive hypothalamic neurons (rather than specific subsets of cells with a particular molecular or anatomical signature) subjected to early LepRb deletion might determine energy balance. We generated new mouse lines deleted for LepRb in ARC Ghrh Cre neurons or in Htr2c Cre neurons (representing roughly half of all hypothalamic LepRb neurons, distributed across many nuclei). We compared the phenotypes of these mice to previously-reported models lacking LepRb in Pomc, Agrp, vGat or Nos1 cells. The early developmental deletion of LepRb from vGat or Nos1 neurons produced dramatic obesity, but deletion of LepRb from Pomc, Agrp, Ghrh, or Htr2c neurons minimally altered energy balance. Although early developmental deletion of LepRb from known populations of ARC neurons fails to substantially alter body weight, the minimal phenotype of mice lacking LepRb in Htr2c cells suggests that the phenotype that results from early developmental LepRb deficiency depends not simply upon the total number of leptin-responsive hypothalamic LepRb cells. Rather, specific populations of LepRb neurons must play particularly important roles in body energy homeostasis; these as yet unidentified LepRb cells likely reside in the DMH. Copyright © 2018 The Authors. Published by Elsevier GmbH.. All rights reserved.

From Early Embryonic to Adult Stage: Comparative Study of Action Potentials of Native and Pluripotent Stem Cell-Derived Cardiomyocytes.

PubMed

Peinkofer, Gabriel; Burkert, Karsten; Urban, Katja; Krausgrill, Benjamin; Hescheler, Jürgen; Saric, Tomo; Halbach, Marcel

2016-10-01

Cardiomyocytes (CMs) derived from induced pluripotent stem cells (iPS-CMs) are promising candidates for cell therapy, drug screening, and developmental studies. It is known that iPS-CMs possess immature electrophysiological properties, but an exact characterization of their developmental stage and subtype differentiation is hampered by a lack of knowledge of electrophysiological properties of native CMs from different developmental stages and origins within the heart. Thus, we sought to systematically investigate action potential (AP) properties of native murine CMs and to establish a database that allows classification of stem cell-derived CMs. Hearts from 129S2PasCrl mice were harvested at days 9-10, 12-14, and 16-18 postcoitum, as well as 1 day, 3-4 days, 1-2 weeks, 3-4 weeks, and 6 weeks postpartum. AP recordings in left and right atria and at apical, medial, and basal left and right ventricles were performed with sharp glass microelectrodes. Measurements revealed significant changes in AP morphology during pre- and postnatal murine development and significant differences between atria and ventricles, enabling a classification of developmental stage and subtype differentiation of stem cell-derived CMs based on their AP properties. For iPS-CMs derived from cell line TiB7.4, a typical ventricular phenotype was demonstrated at later developmental stages, while there were electrophysiological differences from atrial as well as ventricular native CMs at earlier stages. This finding supports that iPS-CMs can develop AP properties similar to native CMs, but points to differences in the maturation process between iPS-CMs and native CMs, which may be explained by dissimilar conditions during in vitro differentiation and in vivo development.

Engineered nanomaterials for solar energy conversion.

PubMed

Mlinar, Vladan

2013-02-01

Understanding how to engineer nanomaterials for targeted solar-cell applications is the key to improving their efficiency and could lead to breakthroughs in their design. Proposed mechanisms for the conversion of solar energy to electricity are those exploiting the particle nature of light in conventional photovoltaic cells, and those using the collective electromagnetic nature, where light is captured by antennas and rectified. In both cases, engineered nanomaterials form the crucial components. Examples include arrays of semiconductor nanostructures as an intermediate band (so called intermediate band solar cells), semiconductor nanocrystals for multiple exciton generation, or, in antenna-rectifier cells, nanomaterials for effective optical frequency rectification. Here, we discuss the state of the art in p-n junction, intermediate band, multiple exciton generation, and antenna-rectifier solar cells. We provide a summary of how engineered nanomaterials have been used in these systems and a discussion of the open questions.

MGOUN1 encodes an Arabidopsis type IB DNA topoisomerase required in stem cell regulation and to maintain developmentally regulated gene silencing.

PubMed

Graf, Philipp; Dolzblasz, Alicja; Würschum, Tobias; Lenhard, Michael; Pfreundt, Ulrike; Laux, Thomas

2010-03-01

Maintenance of stem cells in the Arabidopsis thaliana shoot meristem is regulated by signals from the underlying cells of the organizing center, provided through the transcription factor WUSCHEL (WUS). Here, we report the isolation of several independent mutants of MGOUN1 (MGO1) as genetic suppressors of ectopic WUS activity and enhancers of stem cell defects in hypomorphic wus alleles. mgo1 mutants have previously been reported to result in a delayed progression of meristem cells into differentiating organ primordia (Laufs et al., 1998). Genetic analyses indicate that MGO1 functions together with WUS in stem cell maintenance at all stages of shoot and floral meristems. Synergistic interactions of mgo1 with several chromatin mutants suggest that MGO1 affects gene expression together with chromatin remodeling pathways. In addition, the expression states of developmentally regulated genes are randomly switched in mgo1 in a mitotically inheritable way, indicating that MGO1 stabilizes epigenetic states against stochastically occurring changes. Positional cloning revealed that MGO1 encodes a putative type IB topoisomerase, which in animals and yeast has been shown to be required for regulation of DNA coiling during transcription and replication. The specific developmental defects in mgo1 mutants link topoisomerase IB function in Arabidopsis to stable propagation of developmentally regulated gene expression.

High fat programming of beta cell compensation, exhaustion, death and dysfunction.

PubMed

Cerf, Marlon E

2015-03-01

Programming refers to events during critical developmental windows that shape progeny health outcomes. Fetal programming refers to the effects of intrauterine (in utero) events. Lactational programming refers to the effects of events during suckling (weaning). Developmental programming refers to the effects of events during both fetal and lactational life. Postnatal programming refers to the effects of events either from birth (lactational life) to adolescence or from weaning (end of lactation) to adolescence. Islets are most plastic during the early life course; hence programming during fetal and lactational life is most potent. High fat (HF) programming is the maintenance on a HF diet (HFD) during critical developmental life stages that alters progeny metabolism and physiology. HF programming induces variable diabetogenic phenotypes dependent on the timing and duration of the dietary insult. Maternal obesity reinforces HF programming effects in progeny. HF programming, through acute hyperglycemia, initiates beta cell compensation. However, HF programming eventually leads to chronic hyperglycemia that triggers beta cell exhaustion, death and dysfunction. In HF programming, beta cell dysfunction often co-presents with insulin resistance. Balanced, healthy nutrition during developmental windows is critical for preserving beta cell structure and function. Thus early positive nutritional interventions that coincide with the development of beta cells may reduce the overwhelming burden of diabetes and metabolic disease. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Electron microscopic observations of mouse sperm whole mounts after extraction for nuclear matrix and intermediate filaments.

PubMed

Markova, M D

2001-01-01

Nuclear matrix and intermediate filaments (NM-IF) can be isolated by sequential treatment with non-ionic detergent, high salt. and nuclease. Extracted cells are easily observed by unembedded whole-mount transmission electron microscopy. Different somatic cell types have been subjected to this procedure and retained their essential architecture. To our knowledge, this work describes the first application of NM-IF extraction to sperm. After chemical dissection the general appearance of mouse sperm cells was preserved, except for head-from-neck separation in some cases. The cell membrane, acrosome and mitochondria were not present. The nucleus showed no apparent changes and revealed no details excepting pore complexes in the posterior part. Tissue-specific cytoskeletal elements (perforatorium, postacrosomal sheath, capitulum, segmented columns, outer dense fibers, submitochondrial reticulum, annulus, and fibrous sheath) were retained, which permitted a parallel between them and intermediate filaments of somatic cells. Tail microtubules were also relatively well preserved, showing high intrinsic stability. Cell structures could be observed well, with some details in the tail even better visible than in ultrathin sections. Observation of mouse sperm whole mounts after NM-IF extraction not only revealed intermediate filament-like properties of their cytoskeletal elements but also offered an additional viewpoint to sperm ultrastructure.

Chromatin Switches during Neural Cell Differentiation and Their Dysregulation by Prenatal Alcohol Exposure.

PubMed

Gavin, David P; Grayson, Dennis R; Varghese, Sajoy P; Guizzetti, Marina

2017-05-11

Prenatal alcohol exposure causes persistent neuropsychiatric deficits included under the term fetal alcohol spectrum disorders (FASD). Cellular identity emerges from a cascade of intrinsic and extrinsic (involving cell-cell interactions and signaling) processes that are partially initiated and maintained through changes in chromatin structure. Prenatal alcohol exposure influences neuronal and astrocyte development, permanently altering brain connectivity. Prenatal alcohol exposure also alters chromatin structure through histone and DNA modifications. However, the data linking alcohol-induced differentiation changes with developmental alterations in chromatin structure remain to be elucidated. In the first part of this review, we discuss the sequence of chromatin structural changes involved in neural cell differentiation during normal development. We then discuss the effects of prenatal alcohol on developmental histone modifications and DNA methylation in the context of neurogenesis and astrogliogenesis. We attempt to synthesize the developmental literature with the FASD literature, proposing that alcohol-induced changes to chromatin structure account for altered neurogenesis and astrogliogenesis as well as altered neuron and astrocyte differentiation. Together these changes may contribute to the cognitive and behavioral abnormalities in FASD. Future studies using standardized alcohol exposure paradigms at specific developmental stages will advance the understanding of how chromatin structural changes impact neural cell fate and maturation in FASD.

Chromatin Switches during Neural Cell Differentiation and Their Dysregulation by Prenatal Alcohol Exposure

PubMed Central

Gavin, David P.; Grayson, Dennis R.; Varghese, Sajoy P.; Guizzetti, Marina

2017-01-01

Prenatal alcohol exposure causes persistent neuropsychiatric deficits included under the term fetal alcohol spectrum disorders (FASD). Cellular identity emerges from a cascade of intrinsic and extrinsic (involving cell-cell interactions and signaling) processes that are partially initiated and maintained through changes in chromatin structure. Prenatal alcohol exposure influences neuronal and astrocyte development, permanently altering brain connectivity. Prenatal alcohol exposure also alters chromatin structure through histone and DNA modifications. However, the data linking alcohol-induced differentiation changes with developmental alterations in chromatin structure remain to be elucidated. In the first part of this review, we discuss the sequence of chromatin structural changes involved in neural cell differentiation during normal development. We then discuss the effects of prenatal alcohol on developmental histone modifications and DNA methylation in the context of neurogenesis and astrogliogenesis. We attempt to synthesize the developmental literature with the FASD literature, proposing that alcohol-induced changes to chromatin structure account for altered neurogenesis and astrogliogenesis as well as altered neuron and astrocyte differentiation. Together these changes may contribute to the cognitive and behavioral abnormalities in FASD. Future studies using standardized alcohol exposure paradigms at specific developmental stages will advance the understanding of how chromatin structural changes impact neural cell fate and maturation in FASD. PMID:28492482

Biological adhesion of the flatworm Macrostomum lignano relies on a duo-gland system and is mediated by a cell type-specific intermediate filament protein.

PubMed

Lengerer, Birgit; Pjeta, Robert; Wunderer, Julia; Rodrigues, Marcelo; Arbore, Roberto; Schärer, Lukas; Berezikov, Eugene; Hess, Michael W; Pfaller, Kristian; Egger, Bernhard; Obwegeser, Sabrina; Salvenmoser, Willi; Ladurner, Peter

2014-02-12

Free-living flatworms, in both marine and freshwater environments, are able to adhere to and release from a substrate several times within a second. This reversible adhesion relies on adhesive organs comprised of three cell types: an adhesive gland cell, a releasing gland cell, and an anchor cell, which is a modified epidermal cell responsible for structural support. However, nothing is currently known about the molecules that are involved in this adhesion process. In this study we present the detailed morphology of the adhesive organs of the free-living marine flatworm Macrostomum lignano. About 130 adhesive organs are located in a horse-shoe-shaped arc along the ventral side of the tail plate. Each organ consists of exactly three cells, an adhesive gland cell, a releasing gland cell, and an anchor cell. The necks of the two gland cells penetrate the anchor cell through a common pore. Modified microvilli of the anchor cell form a collar surrounding the necks of the adhesive- and releasing glands, jointly forming the papilla, the outer visible part of the adhesive organs. Next, we identified an intermediate filament (IF) gene, macif1, which is expressed in the anchor cells. RNA interference mediated knock-down resulted in the first experimentally induced non-adhesion phenotype in any marine animal. Specifically, the absence of intermediate filaments in the anchor cells led to papillae with open tips, a reduction of the cytoskeleton network, a decline in hemidesmosomal connections, and to shortened microvilli containing less actin. Our findings reveal an elaborate biological adhesion system in a free-living flatworm, which permits impressively rapid temporary adhesion-release performance in the marine environment. We demonstrate that the structural integrity of the supportive cell, the anchor cell, is essential for this adhesion process: the knock-down of the anchor cell-specific intermediate filament gene resulted in the inability of the animals to adhere. The RNAi mediated changes of the anchor cell morphology are comparable to situations observed in human gut epithelia. Therefore, our current findings and future investigations using this powerful flatworm model system might contribute to a better understanding of the function of intermediate filaments and their associated human diseases.

Origins and implications of pluripotent stem cell variability and heterogeneity

PubMed Central

Cahan, Patrick; Daley, George Q.

2014-01-01

Pluripotent stem cells constitute a platform to model disease and developmental processes and can potentially be used in regenerative medicine. However, not all pluripotent cell lines are equal in their capacity to differentiate into desired cell types in vitro. Genetic and epigenetic variations contribute to functional variability between cell lines and heterogeneity within clones. These genetic and epigenetic variations could ‘lock’ the pluripotency network resulting in residual pluripotent cells or alter the signalling response of developmental pathways leading to lineage bias. The molecular contributors to functional variability and heterogeneity in both embryonic stem (ES) cells and induced pluripotent stem (iPS) cells are only beginning to emerge, yet they are crucial to the future of the stem cell field. PMID:23673969

High-throughput Screening of ToxCast" Phase I Chemicals in an Embryonic Stem Cell Assay Reveals Potential Disruption of a Critical Developmental Signaling Pathway

EPA Science Inventory

Little is known about the developmental toxicity of the expansive chemical landscape in existence today. Significant efforts are being made to apply novel methods to predict developmental activity of chemicals utilizing high-throughput screening (HTS) and high-content screening (...

Zebrafish model systems for developmental neurobehavioral toxicology.

PubMed

Bailey, Jordan; Oliveri, Anthony; Levin, Edward D

2013-03-01

Zebrafish offer many advantages that complement classic mammalian models for the study of normal development as well as for the teratogenic effects of exposure to hazardous compounds. The clear chorion and embryo of the zebrafish allow for continuous visualization of the anatomical changes associated with development, which, along with short maturation times and the capability of complex behavior, makes this model particularly useful for measuring changes to the developing nervous system. Moreover, the rich array of developmental, behavioral, and molecular benefits offered by the zebrafish have contributed to an increasing demand for the use of zebrafish in behavioral teratology. Essential for this endeavor has been the development of a battery of tests to evaluate a spectrum of behavior in zebrafish. Measures of sensorimotor plasticity, emotional function, cognition and social interaction have been used to characterize the persisting adverse effects of developmental exposure to a variety of chemicals including therapeutic drugs, drugs of abuse and environmental toxicants. In this review, we present and discuss such tests and data from a range of developmental neurobehavioral toxicology studies using zebrafish as a model. Zebrafish provide a key intermediate model between high throughput in vitro screens and the classic mammalian models as they have the accessibility of in vitro models and the complex functional capabilities of mammalian models. Copyright © 2013 Wiley Periodicals, Inc.

Zebrafish Model Systems for Developmental Neurobehavioral Toxicology

PubMed Central

Bailey, Jordan; Oliveri, Anthony; Levin, Edward D.

2014-01-01

Zebrafish offer many advantages that complement classic mammalian models for the study of normal development as well as for the teratogenic effects of exposure to hazardous compounds. The clear chorion and embryo of the zebrafish allow for continuous visualization of the anatomical changes associated with development, which, along with short maturation times and the capability of complex behavior, makes this model particularly useful for measuring changes to the developing nervous system. Moreover, the rich array of developmental, behavioral, and molecular benefits offered by the zebrafish have contributed to an increasing demand for the use of zebrafish in behavioral teratology. Essential for this endeavor has been the development of a battery of tests to evaluate a spectrum of behavior in zebrafish. Measures of sensorimotor plasticity, emotional function, cognition and social interaction have been used to characterize the persisting adverse effects of developmental exposure to a variety of chemicals including therapeutic drugs, drugs of abuse and environmental toxicants. In this review, we present and discuss such tests and data from a range of developmental neurobehavioral toxicology studies using zebrafish as a model. Zebrafish provide a key intermediate model between high throughput in vitro screens and the classic mammalian models as they have the accessibility of in vitro models and the complex functional capabilities of mammalian models. PMID:23723169

In Vitro Experimental Model for the Long-Term Analysis of Cellular Dynamics During Bronchial Tree Development from Lung Epithelial Cells

PubMed Central

Maruta, Naomichi; Marumoto, Moegi

2017-01-01

Lung branching morphogenesis has been studied for decades, but the underlying developmental mechanisms are still not fully understood. Cellular movements dynamically change during the branching process, but it is difficult to observe long-term cellular dynamics by in vivo or tissue culture experiments. Therefore, developing an in vitro experimental model of bronchial tree would provide an essential tool for developmental biology, pathology, and systems biology. In this study, we succeeded in reconstructing a bronchial tree in vitro by using primary human bronchial epithelial cells. A high concentration gradient of bronchial epithelial cells was required for branching initiation, whereas homogeneously distributed endothelial cells induced the formation of successive branches. Subsequently, the branches grew in size to the order of millimeter. The developed model contains only two types of cells and it facilitates the analysis of lung branching morphogenesis. By taking advantage of our experimental model, we carried out long-term time-lapse observations, which revealed self-assembly, collective migration with leader cells, rotational motion, and spiral motion of epithelial cells in each developmental event. Mathematical simulation was also carried out to analyze the self-assembly process and it revealed simple rules that govern cellular dynamics. Our experimental model has provided many new insights into lung development and it has the potential to accelerate the study of developmental mechanisms, pattern formation, left–right asymmetry, and disease pathogenesis of the human lung. PMID:28471293

Peptide Signaling in Plant Development

PubMed Central

Katsir, Leron; Davies, Kelli A.; Bergmann, Dominique C.; Laux, Thomas

2011-01-01

Cell-to-cell communication is integral to the evolution of multicellularity. In plant development, peptide signals relay information coordinating cell proliferation and differentiation. These peptides are often encoded by gene families and bind to corresponding families of receptors. The precise spatiotemporal expression of signals and their cognate receptors underlies developmental patterning, and expressional and biochemical changes over evolutionary time have likely contributed to the refinement and complexity of developmental programs. Here, we discuss two major plant peptide families which have central roles in plant development: the CLAVATA3/ENDOSPERM SURROUNDING REGION (CLE) peptide family and the EPIDERMAL PATTERNING FACTOR (EPF) family. We discuss how specialization has enabled the CLE peptides to modulate stem cell differentiation in various tissue types, and how differing activities of EPF peptides precisely regulate the stomatal developmental program, and we examine the contributions of these peptide families to plant development from an evolutionary perspective. PMID:21549958

[Effect of human oviductal embryotrophic factors on gene expression of mouse preimplantation embryos].

PubMed

Yao, Yuan-Qing; Lee, Kai-Fai; Xu, Jia-Seng; Ho, Pak-Chung; Yeung, Shu-Biu

2007-09-01

To investigate the effect of embryotrophic factors (ETF) from human oviductal cells on gene expression of mouse early developmental embryos and discuss the role of fallopian tube in early development of embryos. ETF was isolated from conditioned medium of human oviductal cell line by sequential liquid chromatographic systems. Mouse embryos were treated by ETF in vitro. Using differential display RT-PCR, the gene expression of embryos treated by ETF was compared with embryos without ETF treatment. The differentially expressed genes were separated, re-amplified, cloned and sequenced. Gene expression profiles of embryos with ETF treatment was different from embryos without this treatment. Eight differentially expressed genes were cloned and sequenced. These genes functioned in RNA degradation, synthesis, splicing, protein trafficking, cellular differentiation and embryo development. Embryotrophic factors from human oviductal cells affect gene expression of early developmental embryos. The human oviductal cells play wide roles in early developmental stages of embryos.

Reporter-Based Isolation of Developmental Myogenic Progenitors

PubMed Central

Kheir, Eyemen; Cusella, Gabriella; Messina, Graziella; Cossu, Giulio; Biressi, Stefano

2018-01-01

The formation and activity of mammalian tissues entail finely regulated processes, involving the concerted organization and interaction of multiple cell types. In recent years the prospective isolation of distinct progenitor and stem cell populations has become a powerful tool in the hands of developmental biologists and has rendered the investigation of their intrinsic properties possible. In this protocol, we describe how to purify progenitors with different lineage history and degree of differentiation from embryonic and fetal skeletal muscle by fluorescence-activated cell sorting (FACS). The approach takes advantage of a panel of murine strains expressing fluorescent reporter genes specifically in the myogenic progenitors. We provide a detailed description of the dissection procedures and of the enzymatic dissociation required to maximize the yield of mononucleated cells for subsequent FACS-based purification. The procedure takes ~6–7 h to complete and allows for the isolation and the subsequent molecular and phenotypic characterization of developmental myogenic progenitors. PMID:29674978

INTEGRATED MODULATION OF PHORBOL ESTER-INDUCED RAF ACTIVATION IN EL4 LYMPHOMA CELLS

PubMed Central

Han, Shujie; Meier, Kathryn E.

2009-01-01

The EL4 murine lymphoma cell line exists in variant phenotypes that differ with respect to responses to the tumor promoter phorbol 12-myristate 13-acetate (PMA1). Previous work showed that “PMA-sensitive” cells, characterized by a high magnitude of PMA-induced Erk activation, express RasGRP, a phorbol ester receptor that directly activates Ras. In “PMA-resistant” and “intermediate” EL4 cell lines, PMA induces Erk activation to lesser extents, but with a greater response in intermediate cells. In the current study, these cell lines were used to examine mechanisms of Raf-1 modulation. Phospho-specific antibodies were utilized to define patterns and kinetics of Raf-1 phosphorylation on several sites. Further studies showed that Akt is constitutively activated to a greater extent in PMA-resistant than in PMA-sensitive cells, and also to a greater extent in resistant than intermediate cells. Akt negatively regulates Raf-1 activation (Ser259), partially explaining the difference between resistant and intermediate cells. Erk activation exerts negative feedback on Raf-1 (Ser289/296/301), thus resulting in earlier termination of the signal in cells with a higher level of Erk activation. RKIP, a Raf inhibitory protein, is expressed at higher levels in resistant cells than in sensitive or intermediate cells. Knockdown of RKIP increases Erk activation and also negative feedback. In conclusion, this study delineates Raf-1 phosphorylation events occurring in response to PMA in cell lines with different extents of Erk activation. Variations in the levels of expression and activation of multiple signaling proteins work in an integrated fashion to modulate the extent and duration of Erk activation. PMID:19263515

Intermediate-band dynamics of quantum dots solar cell in concentrator photovoltaic modules

PubMed Central

Sogabe, Tomah; Shoji, Yasushi; Ohba, Mitsuyoshi; Yoshida, Katsuhisa; Tamaki, Ryo; Hong, Hwen-Fen; Wu, Chih-Hung; Kuo, Cherng-Tsong; Tomić, Stanko; Okada, Yoshitaka

2014-01-01

We report for the first time a successful fabrication and operation of an InAs/GaAs quantum dot based intermediate band solar cell concentrator photovoltaic (QD-IBSC-CPV) module to the IEC62108 standard with recorded power conversion efficiency of 15.3%. Combining the measured experimental results at Underwriters Laboratory (UL®) licensed testing laboratory with theoretical simulations, we confirmed that the operational characteristics of the QD-IBSC-CPV module are a consequence of the carrier dynamics via the intermediate-band at room temperature. PMID:24762433

Photon ratchet intermediate band solar cells

NASA Astrophysics Data System (ADS)

Yoshida, M.; Ekins-Daukes, N. J.; Farrell, D. J.; Phillips, C. C.

2012-06-01

In this paper, we propose an innovative concept for solar power conversion—the "photon ratchet" intermediate band solar cell (IBSC)—which may increase the photovoltaic energy conversion efficiency of IBSCs by increasing the lifetime of charge carriers in the intermediate state. The limiting efficiency calculation for this concept shows that the efficiency can be increased by introducing a fast thermal transition of carriers into a non-emissive state. At 1 sun, the introduction of a "ratchet band" results in an increase of efficiency from 46.8% to 48.5%, due to suppression of entropy generation.

IMMU-22. ADOPTIVE CELL THERAPY AGAINST DIPG USING DEVELOPMENTALLY REGULATED ANTIGENS

PubMed Central

Flores, Catherine; Gil, Jorge; Abraham, Rebecca; Pham, Christina; Wildes, Tyler; Moore, Ginger; Drake, Jeffrey; Dyson, Kyle; Mitchell, Duane

2017-01-01

Abstract INTRODUCTION: Diffuse intrinsic pontine glioma (DIPG) survival has remained static over decades and DIPG is now the main cause of brain tumor-related deaths in children. Immunotherapy has emerged as a treatment modality with the highest curative potential in patients with refractory malignancies. Our group has pioneered an adoptive cell therapy platform employing total tumor RNA pulsed dendritic cells to generate large amounts of polyclonal antigen-specific T cells in both human and murine systems. As DIPGs are embryonal tumors, our objective in this proposal is to identify a set of developmentally regulated antigens that are overexpressed during oncogenesis of DIPG in order to cause immunological rejection of this tumor without the need for tumor tissue. METHODS: We employ RNA-pulsed bone marrow-derived dendritic cells to ex vivo activate tumor-reactive T cells for use in adoptive cell therapy. Here we use either total RNA isolated from tumor tissue, (TTRNA) or developmental antigens (DevAg) RNA isolated from postnatal day 4 murine brain stem. Either TTRNA-T cells or DevAg-T cells were used in adoptive cell therapy against a preclinical model of DIPG. RESULTS: Pediatric brain tumors are bland relative to peripheral tumors in terms of high expression of immunogenic antigens. Since DIPG antigens remain largely uncharacterized, we used total RNA isolated from tumor cells to generate tumor-specific T cells to use for our therapeutic approach to first demonstrate that immune responses can be generated against this tumor. We also successfully generated immunity against DIPG in a preclinical model using DevAg-T cells for adoptive cell therapy. CONCLUSION: The region- and age- specific nature of DIPG suggests that the underlying pathophysiology likely involves dysregulation of a postnatal neurodevelopmental process which occurs in embryonal tumors. Here we leverage this and demonstrate that DIPG can be effectively treated using adoptive cell therapy against overexpressed developmentally regulated antigens.

Computational Modeling and Simulation of Developmental ...

EPA Pesticide Factsheets

Standard practice for assessing developmental toxicity is the observation of apical endpoints (intrauterine death, fetal growth retardation, structural malformations) in pregnant rats/rabbits following exposure during organogenesis. EPA’s computational toxicology research program (ToxCast) generated vast in vitro cellular and molecular effects data on >1858 chemicals in >600 high-throughput screening (HTS) assays. The diversity of assays has been increased for developmental toxicity with several HTS platforms, including the devTOX-quickPredict assay from Stemina Biomarker Discovery utilizing the human embryonic stem cell line (H9). Translating these HTS data into higher order-predictions of developmental toxicity is a significant challenge. Here, we address the application of computational systems models that recapitulate the kinematics of dynamical cell signaling networks (e.g., SHH, FGF, BMP, retinoids) in a CompuCell3D.org modeling environment. Examples include angiogenesis (angiodysplasia) and dysmorphogenesis. Being numerically responsive to perturbation, these models are amenable to data integration for systems Toxicology and Adverse Outcome Pathways (AOPs). The AOP simulation outputs predict potential phenotypes based on the in vitro HTS data ToxCast. A heuristic computational intelligence framework that recapitulates the kinematics of dynamical cell signaling networks in the embryo, together with the in vitro profiling data, produce quantitative predic

Signaling molecules involved in the transition of growth to development of Dictyostelium discoideum.

PubMed

Mir, Hina A; Rajawat, Jyotika; Pradhan, Shalmali; Begum, Rasheedunnisa

2007-03-01

The social amoeba Dictyostelium discoideum, a powerful paradigm provides clear insights into the regulation of growth and development. In addition to possessing complex individual cellular functions like a unicellular eukaryote, D. discoideum cells face the challenge of multicellular development. D. discoideum undergoes a relatively simple differentiation process mainly by cAMP mediated pathway. Despite this relative simplicity, the regulatory signaling pathways are as complex as those seen in metazoan development. However, the introduction of restriction-enzyme-mediated integration (REMI) technique to produce developmental gene knockouts has provided novel insights into the discovery of signaling molecules and their role in D. discoideum development. Cell cycle phase is an important aspect for differentiation of D. discoideum, as cells must reach a specific stage to enter into developmental phase and specific cell cycle regulators are involved in arresting growth phase genes and inducing the developmental genes. In this review, we present an overview of the signaling molecules involved in the regulation of growth to differentiation transition (GDT), molecular mechanism of early developmental events leading to generation of cAMP signal and components of cAMP relay system that operate in this paradigm.

Effect of developmental stage of unfed fry on survival and growth of steelhead released in a stream and hatchery ponds (Study sites: Dworshak Hatchery and North Fork Palouse River; Stock: Dworshak hatchery; Year class: 1996): Chapter 6

USGS Publications Warehouse

Rubin, Stephen P.; Reisenbichler, Reginald R.; Wetzel, Lisa A.; Stenberg, Karl D.; Rubin, Stephen P.; Reisenbichler, Reginald R.; Wetzel, Lisa A.; Hayes, Michael C.

2012-01-01

We tested whether differences in developmental stage of unfed fry at release affected subsequent survival and growth of steelhead Oncorhynchus mykiss in a stream and hatchery ponds. Differences in development were created by artificially spawning hatchery steelhead from the Clearwater River, Idaho, and incubating their progeny at three different temperatures (means=10.9, 11.3, and 11.7°C). Time between fertilization and maximum alevin wet weight (MAWW) was predicted from incubation temperature using a model. MAWW is equivalent to the button - up fry stage of development. Developmental stages at release were “underdeveloped” (97.7% of model - predicted time to MAWW, mean weight=0.177 g, proportion yolk=0.087), “intermediate” (102.5%, 0.179 g, 0.044), and “overdeveloped” (107.9%, 0.156 g, 0.030). Neither survival nor growth in the hatchery to near the end of the standard one year rearing period differed among groups. In the stream, frequency of overdeveloped fish relative to the other two groups decreased fro m release in May to September, probably indicating lower survival for the overdeveloped fish during that interval since emigration of sub - yearlings is typically negligible. Length in September was less for overdeveloped than for intermediate fish and was in between for underdeveloped fish, suggesting that growth between May and September was less for overdeveloped fish than for intermediate fish. Although changes in relative frequency and size occurred among fry development groups from September to one ye ar later, those changes may have reflected differences in emigration rate during the interval rather than differential survival or growth. Our results show a cost to survival and growth in a stream, but not in a hatchery, from overdevelopment characterize d by loss of weight and yolk reserves relative to fry closer to MAWW at release. We didn’t find any cost from underdevelopment; however, our underdeveloped fry were closer to MAWW than the overdeveloped fry, and they may have been no farther from MAWW than the intermediate fry based on percentage of model - predicted time to MAWW at release. 

Growth of Myxococcus xanthus in continuous-flow-cell bioreactors as a method for studying development.

PubMed

Smaldone, Gregory T; Jin, Yujie; Whitfield, Damion L; Mu, Andrew Y; Wong, Edward C; Wuertz, Stefan; Singer, Mitchell

2014-04-01

Nutrient sensors and developmental timers are two classes of genes vital to the establishment of early development in the social soil bacterium Myxococcus xanthus. The products of these genes trigger and regulate the earliest events that drive the colony from a vegetative state to aggregates, which ultimately leads to the formation of fruiting bodies and the cellular differentiation of the individual cells. In order to more accurately identify the genes and pathways involved in the initiation of this multicellular developmental program in M. xanthus, we adapted a method of growing vegetative populations within a constant controllable environment by using flow cell bioreactors, or flow cells. By establishing an M. xanthus community within a flow cell, we are able to test developmental responses to changes in the environment with fewer concerns for effects due to nutrient depletion or bacterial waste production. This approach allows for greater sensitivity in investigating communal environmental responses, such as nutrient sensing. To demonstrate the versatility of our growth environment, we carried out time-lapse confocal laser scanning microscopy to visualize M. xanthus biofilm growth and fruiting body development, as well as fluorescence staining of exopolysaccharides deposited by biofilms. We also employed the flow cells in a nutrient titration to determine the minimum concentration required to sustain vegetative growth. Our data show that by using a flow cell, M. xanthus can be held in a vegetative growth state at low nutrient concentrations for long periods, and then, by slightly decreasing the nutrient concentration, cells can be allowed to initiate the developmental program.

Marsupial tammar wallaby delivers milk bioactives to altricial pouch young to support lung development.

PubMed

Modepalli, Vengamanaidu; Hinds, Lyn A; Sharp, Julie A; Lefevre, Christophe; Nicholas, Kevin R

2016-11-01

Our research is exploiting the marsupial as a model to understand the signals required for lung development. Marsupials have a unique reproductive strategy, the mother gives birth to altricial neonate with an immature lung and the changes in milk composition during lactation in marsupials appears to provide bioactives that can regulate diverse aspects of lung development, including branching morphogenesis, cell proliferation and cell differentiation. These effects are seen with milk collected between 25 and 100days postpartum. To better understand the temporal effects of milk composition on postnatal lung development we used a cross-fostering technique to restrict the tammar pouch young to milk composition not extending beyond day 25 for 45days of its early postnatal life. These particular time points were selected as our previous study showed that milk protein collected prior to ~day 25 had no developmental effect on mouse embryonic lungs in culture. The comparative analysis of the foster group and control young at day 45 postpartum demonstrated that foster pouch young had significantly reduced lung size. The lungs in fostered young were comprised of large intermediate tissue, had a reduced size of airway lumen and a higher percentage of parenchymal tissue. In addition, expression of marker genes for lung development (BMP4, WNT11, AQP-4, HOPX and SPB) were significantly reduced in lungs from fostered young. Further, to identify the potential bioactive expressed by mammary gland that may have developmental effect on pouch young lungs, we performed proteomics analysis on tammar milk through mass-spectrometry and listed the potential bioactives (PDGF, IGFBP5, IGFBPL1 and EGFL6) secreted in milk that may be involved in regulating pouch young lung development. The data suggest that postnatal lung development in the tammar young is most likely regulated by maternal signalling factors supplied through milk. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Identification of a Methane Oxidation Intermediate on Solid Oxide Fuel Cell Anode Surfaces with Fourier Transform Infrared Emission.

PubMed

Pomfret, Michael B; Steinhurst, Daniel A; Owrutsky, Jeffrey C

2013-04-18

Fuel interactions on solid oxide fuel cell (SOFC) anodes are studied with in situ Fourier transform infrared emission spectroscopy (FTIRES). SOFCs are operated at 800 °C with CH4 as a representative hydrocarbon fuel. IR signatures of gas-phase oxidation products, CO2(g) and CO(g), are observed while cells are under load. A broad feature at 2295 cm(-1) is assigned to CO2 adsorbed on Ni as a CH4 oxidation intermediate during cell operation and while carbon deposits are electrochemically oxidized after CH4 operation. Electrochemical control provides confirmation of the assignment of adsorbed CO2. FTIRES has been demonstrated as a viable technique for the identification of fuel oxidation intermediates and products in working SOFCs, allowing for the elucidation of the mechanisms of fuel chemistry.

In vitro developmental model of the gastrointestinal tract from mouse embryonic stem cells.

PubMed

Torihashi, Shigeko; Kuwahara, Masaki; Kurahashi, Masaaki

2007-10-01

Mouse embryonic stem (ES) cells are pluripotent and retain their potential to form cells, tissues and organs originated from three embryonic germ layers. Recently, we developed in vitro organ--gut-like structures--from mouse ES cells. They had basically similar morphological features to a mouse gastrointestinal tract in vivo composed of three distinct layers (i.e., epithelium, connective tissue and musculature). Gut-like structures showed spontaneous contractions derived from pacemaker cells (interstitial cells of Cajal) in the musculature. We also examined their formation process and expression pattern of transcription factors crucial for gut organogenesis such as Id2, Sox17, HNF3beta/Foxa2 and GATA4. We found that they mimic the development of embryonic gut in vivo and showed a similar expression pattern of common transcription factors. They also maintain their developmental potential after transplantation to a renal capsule. Therefore, gut-like structures are suitable for in vitro models of gastrointestinal tracts and their development. In addition, we pointed out several unique features different from gut in vivo that provide useful and advantageous tools to investigate the developmental mechanism of the gastrointestinal tract.

Effect of timing of development on total cell number and expression profile of HSP-70.1 and GLUT-1 in buffalo (Bubalus bubalis) oocytes and preimplantation embryos produced in vitro.

PubMed

Rajhans, Rajib; Kumar, G Sai; Dubey, Pawan K; Sharma, G Taru

2010-03-29

The present study was designed to compare the expression profile of two developmentally important genes (HSP-70.1 and GLUT-1) and TCN (total cell number) count in fast (group A) and slow (group B) cleaved buffalo embryos to access their in vitro developmental competence. Buffalo COCs (cumulus oocyte complexes) were collected from local abattoir ovaries and subjected to in vitro maturation in: TCM-199 supplemented with 10% FBS (fetal bovine serum), BSA (3 mg/ml), sodium pyruvate (0.25 mM) and 20 ng/ml EGF (epidermal growth factor) at 38.5 degrees C under 5% CO2. In vitro derived embryos were collected at 4-8, 8-16 cell, morula and blastocyst stages at specific time points for gene expression analysis and total cell count. A semiquantitative RT-PCR (reverse transcriptase-PCR) assay was used to determine the HSP-70.1 and GLUT-1 transcripts. Results showed that developmental competence and TCN count in fast (group A)-cleaving embryos was significantly (P<0.05) higher than in the slow group (group B). The gene transcript of HSP-70.1 and GLUT-1 was expressed in oocytes (immature and mature) and throughout the embryonic developmental stages in the fast group (group A), while in the slow (group B) cleaving embryos, the expression of HSP-70.1 was absent in all the embryonic developmental stages, and expression of GLUT-1 was absent after 8-16 cell stage. In conclusion, TCN count and expression profile of HSP-70.1 and GLUT-1 genes in buffalo embryos are different taking into account the cleavage rate. Quality of such embryos for research purposes, TCN and expression profiling of developmentally important genes should be employed to optimize the in vitro culture system to produce superior quality of embryos.

Critical Thinking Skills of U.S. Air Force Senior and Intermediate Developmental Education Students

DTIC Science & Technology

2016-02-16

SAASS), and Air War College (AWC). T-tests indicated no statistically significant difference in the CT skills of the sample of ACSC and AWC students...hypothesis that there was no statistically significant difference in the CT skills of IDE and SDE students. SAASS, as a more selective advanced studies...potential to develop CT skills, concluding, “students in the experimental group performed at a statistically significantly higher level than students in

PIK3CA-associated developmental disorders exhibit distinct classes of mutations with variable expression and tissue distribution

PubMed Central

Timms, Andrew E.; Conti, Valerio; Girisha, Katta M.; Martin, Beth; Olds, Carissa; Collins, Sarah; Park, Kaylee; Carter, Melissa; Krägeloh-Mann, Inge; Chitayat, David; Parikh, Aditi Shah; Bradshaw, Rachael; Torti, Erin; Braddock, Stephen; Burke, Leah; Ghedia, Sondhya; Stephan, Mark; Stewart, Fiona; Prasad, Chitra; Napier, Melanie; Saitta, Sulagna; Straussberg, Rachel; Gabbett, Michael; O’Connor, Bridget C.; Yin, Lim Jiin; Lai, Angeline Hwei Meeng; Martin, Nicole; McKinnon, Margaret; Addor, Marie-Claude; Schwartz, Charles E.; Lanoel, Agustina; Conway, Robert L.; Devriendt, Koenraad; Tatton-Brown, Katrina; Pierpont, Mary Ella; Painter, Michael; Worgan, Lisa; Reggin, James; Hennekam, Raoul; Pritchard, Colin C.; Aracena, Mariana; Gripp, Karen W.; Cordisco, Maria; Van Esch, Hilde; Garavelli, Livia; Curry, Cynthia; Goriely, Anne; Kayserilli, Hulya; Shendure, Jay; Graham, John; Guerrini, Renzo; Dobyns, William B.

2016-01-01

Mosaicism is increasingly recognized as a cause of developmental disorders with the advent of next-generation sequencing (NGS). Mosaic mutations of PIK3CA have been associated with the widest spectrum of phenotypes associated with overgrowth and vascular malformations. We performed targeted NGS using 2 independent deep-coverage methods that utilize molecular inversion probes and amplicon sequencing in a cohort of 241 samples from 181 individuals with brain and/or body overgrowth. We identified PIK3CA mutations in 60 individuals. Several other individuals (n = 12) were identified separately to have mutations in PIK3CA by clinical targeted-panel testing (n = 6), whole-exome sequencing (n = 5), or Sanger sequencing (n = 1). Based on the clinical and molecular features, this cohort segregated into three distinct groups: (a) severe focal overgrowth due to low-level but highly activating (hotspot) mutations, (b) predominantly brain overgrowth and less severe somatic overgrowth due to less-activating mutations, and (c) intermediate phenotypes (capillary malformations with overgrowth) with intermediately activating mutations. Sixteen of 29 PIK3CA mutations were novel. We also identified constitutional PIK3CA mutations in 10 patients. Our molecular data, combined with review of the literature, show that PIK3CA-related overgrowth disorders comprise a discontinuous spectrum of disorders that correlate with the severity and distribution of mutations. PMID:27631024

The development of expertise in pediatric rehabilitation therapists: changes in approach, self-knowledge, and use of enabling and customizing strategies.

PubMed

King, Gillian; Currie, Melissa; Bartlett, Doreen J; Gilpin, Michelle; Willoughby, Colleen; Tucker, Mary Ann; Strachan, Deborah; Baxter, Donna

2007-01-01

To examine the clinical decision making of novice, intermediate, and expert pediatric rehabilitation therapists from various disciplines. Two qualitative studies were conducted. Thirteen therapists took part in a study using the critical incident interview technique and 11 therapists took part in a study using the 'think aloud' technique. Therapists were classified as novice, intermediate, or expert in developmental level based on a cluster analysis of data collected using a multifaceted battery of assessment tools. Data were analyzed using a grounded theory approach. Expert and intermediate therapists differed from novices with respect to content, self-, and procedural knowledge. With increasing expertise, therapists use a supportive, educational, holistic, functional, and strengths-based approach; have heightened humility yet increased self-confidence; and understand how to facilitate and support client change and adaptation by using principles of engagement, coherence, and manageability. Expert therapists use enabling and customizing strategies to ensure a successful therapeutic session, optimize the child's functioning in the mid-term, and ensure child and family adaptation and accommodation over the longer-term.

Human organomics: a fresh approach to understanding human development using single-cell transcriptomics.

PubMed

Camp, J Gray; Treutlein, Barbara

2017-05-01

Innovative methods designed to recapitulate human organogenesis from pluripotent stem cells provide a means to explore human developmental biology. New technologies to sequence and analyze single-cell transcriptomes can deconstruct these 'organoids' into constituent parts, and reconstruct lineage trajectories during cell differentiation. In this Spotlight article we summarize the different approaches to performing single-cell transcriptomics on organoids, and discuss the opportunities and challenges of applying these techniques to generate organ-level, mechanistic models of human development and disease. Together, these technologies will move past characterization to the prediction of human developmental and disease-related phenomena. © 2017. Published by The Company of Biologists Ltd.

Integrative analysis of genes and miRNA alterations in human embryonic stem cells-derived neural cells after exposure to silver nanoparticles

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

Oh, Jung-Hwa; Department of human and environmental toxicology, University of Science & Technology, Daejeon 34113; Son, Mi-Young

Given the rapid growth of engineered and customer products made of silver nanoparticles (Ag NPs), understanding their biological and toxicological effects on humans is critically important. The molecular developmental neurotoxic effects associated with exposure to Ag NPs were analyzed at the physiological and molecular levels, using an alternative cell model: human embryonic stem cell (hESC)-derived neural stem/progenitor cells (NPCs). In this study, the cytotoxic effects of Ag NPs (10–200 μg/ml) were examined in these hESC-derived NPCs, which have a capacity for neurogenesis in vitro, at 6 and 24 h. The results showed that Ag NPs evoked significant toxicity in hESC-derivedmore » NPCs at 24 h in a dose-dependent manner. In addition, Ag NPs induced cell cycle arrest and apoptosis following a significant increase in oxidative stress in these cells. To further clarify the molecular mechanisms of the toxicological effects of Ag NPs at the transcriptional and post-transcriptional levels, the global expression profiles of genes and miRNAs were analyzed in hESC-derived NPCs after Ag NP exposure. The results showed that Ag NPs induced oxidative stress and dysfunctional neurogenesis at the molecular level in hESC-derived NPCs. Based on this hESC-derived neural cell model, these findings have increased our understanding of the molecular events underlying developmental neurotoxicity induced by Ag NPs in humans. - Highlights: • This system served as a suitable model for developmental neurotoxicity testing. • Ag NPs induce the apoptosis in human neural cells by ROS generation. • Genes for development of neurons were dysregulated in response to Ag NPs. • Molecular events during early developmental neurotoxicity were proposed.« less

Methylation and microRNA-mediated epigenetic regulation of SOCS3

PubMed Central

Boosani, Chandra S.; Agrawal, Devendra K.

2017-01-01

Epigenetic gene silencing of several genes causes different pathological conditions in humans, and DNA methylation has been identified as one of the key mechanisms that underlie this evolutionarily conserved phenomenon associated with developmental and pathological gene regulation. Recent advances in the miRNA technology with high throughput analysis of gene regulation further increased our understanding on the role of miRNAs regulating multiple gene expression. There is increasing evidence supporting that the miRNAs not only regulate gene expression but they also are involved in the hypermethylation of promoter sequences, which cumulatively contributes to the epigenetic gene silencing. Here, we critically evaluated the recent progress on the transcriptional regulation of an important suppressor protein that inhibits cytokine-mediated signaling, SOCS3, whose expression is directly regulated both by promoter methylation and also by microRNAs, affecting its vital cell regulating functions. SOCS3 was identified as a potent inhibitor of Jak/STAT signaling pathway which is frequently upregulated in several pathologies, including cardiovascular disease, cancer, diabetes, viral infections, and the expression of SOCS3 was inhibited or greatly reduced due to hypermethylation of the CpG islands in its promoter region or suppression of its expression by different microRNAs. Additionally, we discuss key intracellular signaling pathways regulated by SOCS3 involving cellular events, including cell proliferation, cell growth, cell migration and apoptosis. Identification of the pathway intermediates as specific targets would not only aid in the development of novel therapeutic drugs, but, would also assist in developing new treatment strategies that could successfully be employed in combination therapy to target multiple signaling pathways. PMID:25682267

Somatic stem cell heterogeneity: diversity in the blood, skin and intestinal stem cell compartments

PubMed Central

Goodell, Margaret A.; Nguyen, Hoang; Shroyer, Noah

2017-01-01

Somatic stem cells replenish many tissues throughout life to repair damage and to maintain tissue homeostasis. Stem cell function is frequently described as following a hierarchical model in which a single master cell undergoes self-renewal and differentiation into multiple cell types and is responsible for most regenerative activity. However, recent data from studies on blood, skin and intestinal epithelium all point to the concomitant action of multiple types of stem cells with distinct everyday roles. Under stress conditions such as acute injury, the surprising developmental flexibility of these stem cells enables them to adapt to diverse roles and to acquire different regeneration capabilities. This paradigm shift raises many new questions about the developmental origins, inter-relationships and molecular regulation of these multiple stem cell types. PMID:25907613

Electrochemical impedance spectroscopy analysis of a thin polymer film-based micro-direct methanol fuel cell

NASA Astrophysics Data System (ADS)

Schulz, Tobias; Weinmüller, Christian; Nabavi, Majid; Poulikakos, Dimos

A single cell micro-direct methanol fuel cell (micro-DMFC) was investigated using electrochemical impedance spectroscopy. The electrodes consisted of thin, flexible polymer (SU8) film microchannel structures fabricated in-house using microfabrication techniques. AC impedance spectroscopy was used to separate contributions to the overall cell polarization from the anode, cathode and membrane. A clear distinction between the different electrochemical phenomena occurring in the micro-DMFC, especially the distinction between double layer charging and Faradaic reactions was shown. The effect of fuel flow rate, temperature, and anode flow channel structure on the impedance of the electrode reactions and membrane/electrode double layer charging were investigated. Analysis of impedance data revealed that the performance of the test cell was largely limited by the presence of intermediate carbon monoxide in the anode reaction. Higher temperatures increase cell performance by enabling intermediate CO to be oxidized at much higher rates. The results also revealed that serpentine anode flow microchannels show a lower tendency to intermediate CO coverage and a more stable cell behavior than parallel microchannels.

Surface Expression of Hsp25 and Hsp72 Differentially Regulates Tumor Growth and Metastasis

PubMed Central

Bausero, María A.; Page, Diana T.; Osinaga, Eduardo; Asea, Alexzander

2006-01-01

The expression of unique surface structures on tumors that allow for recognition and activation of host immunocompetent cells plays an important role in determining tumor growth and/or metastasis. Recent studies have identified an important role for heat shock proteins (Hsp) in antitumor surveillance; however, the exact role of Hsp expressed on the surface of tumors has not been fully addressed. In this study, we show that 4T1 mammary adenocarcinoma cells sorted for high Hsp25 surface expression (Hsp25high) grow significantly faster than cells sorted for intermediate Hsp25 surface expression (Hsp25intermediate) or wild-type 4T1 cells implanted into the abdominal breast gland of female BALB/c mice (p < 0.05). In addition, histological examination of lung tissues revealed that Hsp25high 4T1 cells metastasized to the lungs more aggressively than either Hsp25intermediate or wild-type 4T1 cells (p < 0.05). Exposure of 4T1 cells to nonlethal heat shock (43°C, 30 min) induced the surface expression of Hsp72 and a concomitant reduction in Hsp25 surface expression. The growth and metastastic potential of Hsp72+ 4T1 cells was significantly less than that of Hsp25high, Hsp25intermediate or wild-type 4T1 cells (p < 0.05). Taken together, these studies identify an important role for expression of Hsp25 and Hsp72 during tumor growth and metastatic spread which might be helpful in the design of antimetastatic therapies. PMID:15627887

Surface expression of Hsp25 and Hsp72 differentially regulates tumor growth and metastasis.

PubMed

Bausero, María A; Page, Diana T; Osinaga, Eduardo; Asea, Alexzander

2004-01-01

The expression of unique surface structures on tumors that allow for recognition and activation of host immunocompetent cells plays an important role in determining tumor growth and/or metastasis. Recent studies have identified an important role for heat shock proteins (Hsp) in antitumor surveillance; however, the exact role of Hsp expressed on the surface of tumors has not been fully addressed. In this study, we show that 4T1 mammary adenocarcinoma cells sorted for high Hsp25 surface expression (Hsp25(high)) grow significantly faster than cells sorted for intermediate Hsp25 surface expression (Hsp25(intermediate)) or wild-type 4T1 cells implanted into the abdominal breast gland of female BALB/c mice (p < 0.05). In addition, histological examination of lung tissues revealed that Hsp25(high) 4T1 cells metastasized to the lungs more aggressively than either Hsp25(intermediate) or wild-type 4T1 cells (p < 0.05). Exposure of 4T1 cells to nonlethal heat shock (43 degrees C, 30 min) induced the surface expression of Hsp72 and a concomitant reduction in Hsp25 surface expression. The growth and metastastic potential of Hsp72(+) 4T1 cells was significantly less than that of Hsp25(high), Hsp25(intermediate) or wild-type 4T1 cells (p < 0.05). Taken together, these studies identify an important role for expression of Hsp25 and Hsp72 during tumor growth and metastatic spread which might be helpful in the design of antimetastatic therapies. Copyright 2004 S. Karger AG, Basel.

Investigation of the open-circuit voltage in wide-bandgap InGaP-host InP quantum dot intermediate-band solar cells

NASA Astrophysics Data System (ADS)

Aihara, Taketo; Tayagaki, Takeshi; Nagato, Yuki; Okano, Yoshinobu; Sugaya, Takeyoshi

2018-04-01

To analyze the open-circuit voltage (V oc) in intermediate-band solar cells, we investigated the current-voltage characteristics in wide-bandgap InGaP-based InP quantum dot (QD) solar cells. From the temperature dependence of the current-voltage curves, we show that the V oc in InP QD solar cells increases with decreasing temperature. We use a simple diode model to extract V oc at the zero-temperature limit, V 0, and the temperature coefficient C of the solar cells. Our results show that, while the C of InP QD solar cells is slightly larger than that of the reference InGaP solar cells, V 0 significantly decreases and coincides with the bandgap energy of the InP QDs rather than that of the InGaP host. This V 0 indicates that the V oc reduction in the InP QD solar cells is primarily caused by the breaking of the Fermi energy separation between the QDs and the host semiconductor in intermediate-band solar cells, rather than by enhanced carrier recombination.

AV59M KCNJ11 gene mutation leading to intermediate DEND syndrome in a Chinese child.

PubMed

Sang, Yanmei; Ni, Guichen; Gu, Yi; Liu, Min

2011-01-01

Heterozygous activating mutations in the KCNJ11 gene can cause permanent and transient neonatal diabetes. In the present study, we sequenced the KCNJ11 gene in a Chinese boy diagnosed with permanent neonatal diabetes mellitus (PNDM) and also in his parents. A heterozygous 175G > A (V59M) mutation was identified in the patient, while no KCNJ11 gene mutations were found in his parents, indicating that this mutation is de novo. The patient with the V59M mutation successfully switched from insulin injections to oral glibenclamide; 2 years of follow-up revealed that the patient had intermediate developmental delay, epilepsy and neonatal diabetes (DEND) syndrome. This is the first patient who is reported to have iDEND syndrome due to KCNJ11 V59M mutation in China.

The developmental potential of parthenogenetic and somatic cell nuclear-transferred rat oocytes in vitro.

PubMed

Mizumoto, Shigetoshi; Kato, Yoko; Tsunoda, Yukio

2008-12-01

We examined the optimal conditions for somatic cell nuclear transfer (SCNT) in rat oocytes. First, we compared the effects of two types of inhibitors of spontaneous activation, MG132 and demecolcine, on the developmental potential of parthenogenetic oocytes. The potential of activated oocytes to develop into blastocysts significantly decreased 2 h after oocyte recovery (77% vs. 7%). The developmental potential of oocytes preserved in MG132-supplemented medium for 1 to 4 h was high (62% to 77%), but the potential of those preserved in demecolcine-supplemented medium for 3 and 4 h was low (77% vs. 41% and 37%, respectively). Second, the effect of the duration of parthenogenetic activation on the developmental potential was examined. When oocytes preserved in MG132 for 4 h were treated with 10 mM strontium for 5 or 6 h, the potential of activated oocytes to develop into blastocysts was high (78% and 70%, respectively). Using the optimal conditions for parthenogenetic activation, we examined the potential of rat enucleated oocytes receiving cumulus cells to develop into blastocysts. In contrast to parthenogenotes, the potential of SCNT rat oocytes to develop into blastocysts was low (2%) even if then oocytes were treated with the histone deacetylation inhibitor trichostatin A. The reason for the low developmental potential of rat SCNT oocytes is discussed.

Embryonic stem cells and prospects for their use in regenerative medicine approaches to motor neurone disease.

PubMed

Christou, Y A; Moore, H D; Shaw, P J; Monk, P N

2007-10-01

Human embryonic stem cells are pluripotent cells with the potential to differentiate into any cell type in the presence of appropriate stimulatory factors and environmental cues. Their broad developmental potential has led to valuable insights into the principles of developmental and cell biology and to the proposed use of human embryonic stem cells or their differentiated progeny in regenerative medicine. This review focuses on the prospects for the use of embryonic stem cells in cell-based therapy for motor neurone disease or amyotrophic lateral sclerosis, a progressive neurodegenerative disease that specifically affects upper and lower motor neurones and leads ultimately to death from respiratory failure. Stem cell-derived motor neurones could conceivably be used to replace the degenerated cells, to provide authentic substrates for drug development and screening and for furthering our understanding of disease mechanisms. However, to reliably and accurately culture motor neurones, the complex pathways by which differentiation occurs in vivo must be understood and reiterated in vitro by embryonic stem cells. Here we discuss the need for new therapeutic strategies in the treatment of motor neurone disease, the developmental processes that result in motor neurone formation in vivo, a number of experimental approaches to motor neurone production in vitro and recent progress in the application of stem cells to the treatment and understanding of motor neurone disease.

The developmental programme for genesis of the entire kidney is recapitulated in Wilms tumour.

PubMed

Fukuzawa, Ryuji; Anaka, Matthew R; Morison, Ian M; Reeve, Anthony E

2017-01-01

Wilms tumour (WT) is an embryonal tumour that recapitulates kidney development. The normal kidney is formed from two distinct embryological origins: the metanephric mesenchyme (MM) and the ureteric bud (UB). It is generally accepted that WT arises from precursor cells in the MM; however whether UB-equivalent structures participate in tumorigenesis is uncertain. To address the question of the involvement of UB, we assessed 55 Wilms tumours for the molecular features of MM and UB using gene expression profiling, immunohistochemsitry and immunofluorescence. Expression profiling primarily based on the Genitourinary Molecular Anatomy Project data identified molecular signatures of the UB and collecting duct as well as those of the proximal and distal tubules in the triphasic histology group. We performed immunolabeling for fetal kidneys and WTs. We focused on a central epithelial blastema pattern which is the characteristic of triphasic histology characterized by UB-like epithelial structures surrounded by MM and MM-derived epithelial structures, evoking the induction/aggregation phase of the developing kidney. The UB-like epithelial structures and surrounding MM and epithelial structures resembling early glomerular epithelium, proximal and distal tubules showed similar expression patterns to those of the developing kidney. These observations indicate WTs can arise from a precursor cell capable of generating the entire kidney, such as the cells of the intermediate mesoderm from which both the MM and UB are derived. Moreover, this provides an explanation for the variable histological features of mesenchymal to epithelial differentiation seen in WT.

The developmental programme for genesis of the entire kidney is recapitulated in Wilms tumour

PubMed Central

Anaka, Matthew R.; Morison, Ian M.; Reeve, Anthony E.

2017-01-01

Wilms tumour (WT) is an embryonal tumour that recapitulates kidney development. The normal kidney is formed from two distinct embryological origins: the metanephric mesenchyme (MM) and the ureteric bud (UB). It is generally accepted that WT arises from precursor cells in the MM; however whether UB-equivalent structures participate in tumorigenesis is uncertain. To address the question of the involvement of UB, we assessed 55 Wilms tumours for the molecular features of MM and UB using gene expression profiling, immunohistochemsitry and immunofluorescence. Expression profiling primarily based on the Genitourinary Molecular Anatomy Project data identified molecular signatures of the UB and collecting duct as well as those of the proximal and distal tubules in the triphasic histology group. We performed immunolabeling for fetal kidneys and WTs. We focused on a central epithelial blastema pattern which is the characteristic of triphasic histology characterized by UB-like epithelial structures surrounded by MM and MM-derived epithelial structures, evoking the induction/aggregation phase of the developing kidney. The UB-like epithelial structures and surrounding MM and epithelial structures resembling early glomerular epithelium, proximal and distal tubules showed similar expression patterns to those of the developing kidney. These observations indicate WTs can arise from a precursor cell capable of generating the entire kidney, such as the cells of the intermediate mesoderm from which both the MM and UB are derived. Moreover, this provides an explanation for the variable histological features of mesenchymal to epithelial differentiation seen in WT. PMID:29040332

Assessment of the developmental totipotency of neural cells in the cerebral cortex of mouse embryo by nuclear transfer

PubMed Central

Yamazaki, Yukiko; Makino, Hatsune; Hamaguchi-Hamada, Kayoko; Hamada, Shun; Sugino, Hidehiko; Kawase, Eihachiro; Miyata, Takaki; Ogawa, Masaharu; Yanagimachi, Ryuzo; Yagi, Takeshi

2001-01-01

When neural cells were collected from the entire cerebral cortex of developing mouse fetuses (15.5–17.5 days postcoitum) and their nuclei were transferred into enucleated oocytes, 5.5% of the reconstructed oocytes developed into normal offspring. This success rate was the highest among all previous mouse cloning experiments that used somatic cells. Forty-four percent of live embryos at 10.5 days postcoitum were morphologically normal when premature and early-postmitotic neural cells from the ventricular side of the cortex were used. In contrast, the majority (95%) of embryos were morphologically abnormal (including structural abnormalities in the neural tube) when postmitotic-differentiated neurons from the pial side of the cortex were used for cloning. Whereas 4.3% of embryos cloned with ventricular-side cells developed into healthy offspring, only 0.5% of those cloned with differentiated neurons in the pial side did so. These facts seem to suggest that the nuclei of neural cells in advanced stages of differentiation had lost their developmental totipotency. The underlying mechanism for this developmental limitation could be somatic DNA rearrangements in differentiating neural cells. PMID:11698647

Identifying Developmental Zones in Maize Lateral Root Cell Length Profiles using Multiple Change-Point Models

PubMed Central

Moreno-Ortega, Beatriz; Fort, Guillaume; Muller, Bertrand; Guédon, Yann

2017-01-01

The identification of the limits between the cell division, elongation and mature zones in the root apex is still a matter of controversy when methods based on cellular features, molecular markers or kinematics are compared while methods based on cell length profiles have been comparatively underexplored. Segmentation models were developed to identify developmental zones within a root apex on the basis of epidermal cell length profiles. Heteroscedastic piecewise linear models were estimated for maize lateral roots of various lengths of both wild type and two mutants affected in auxin signaling (rtcs and rum-1). The outputs of these individual root analyses combined with morphological features (first root hair position and root diameter) were then globally analyzed using principal component analysis. Three zones corresponding to the division zone, the elongation zone and the mature zone were identified in most lateral roots while division zone and sometimes elongation zone were missing in arrested roots. Our results are consistent with an auxin-dependent coordination between cell flux, cell elongation and cell differentiation. The proposed segmentation models could extend our knowledge of developmental regulations in longitudinally organized plant organs such as roots, monocot leaves or internodes. PMID:29123533

Many layers of embryonic hematopoiesis: new insights into B-cell ontogeny and the origin of hematopoietic stem cells.

PubMed

Hadland, Brandon; Yoshimoto, Momoko

2018-04-01

In adult hematopoiesis, the hematopoietic stem cell (HSC) sits at the top of a hierarchy of hematopoietic progenitors responsible for generating the diverse repertoire of blood and immune cells. During embryonic development, however, the initial waves of hematopoiesis provide the first functioning blood cells of the developing embryo, such as primitive erythrocytes arising in the yolk sac, independently of HSCs. In the field of developmental immunology, it has been recognized that some components of the immune system, such as B-1a lymphocytes, are uniquely produced during the embryonic and neonatal period, suggesting a "layered" development of immunity. Several recent studies have shed new light on the developmental origin of the layered immune system, suggesting complex and sometimes multiple contributions to unique populations of innate-like immune cells from both fetal HSCs and earlier HSC-independent progenitors. In this review, we will attempt to synthesize these studies to provide an integrated model of developmental hematopoiesis and layered immunity that may offer new insights into the origin of HSCs. Copyright © 2018 ISEH – Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved.

The histone acetyltransferases CBP and Chameau integrate developmental and DNA replication programs in Drosophila ovarian follicle cells

PubMed Central

McConnell, Kristopher H.; Dixon, Michael; Calvi, Brian R.

2012-01-01

DNA replication origin activity changes during development. Chromatin modifications are known to influence the genomic location of origins and the time during S phase that they initiate replication in different cells. However, how chromatin regulates origins in concert with cell differentiation remains poorly understood. Here, we use developmental gene amplification in Drosophila ovarian follicle cells as a model to investigate how chromatin modifiers regulate origins in a developmental context. We find that the histone acetyltransferase (HAT) Chameau (Chm) binds to amplicon origins and is partially required for their function. Depletion of Chm had relatively mild effects on origins during gene amplification and genomic replication compared with previous knockdown of its ortholog HBO1 in human cells, which has severe effects on origin function. We show that another HAT, CBP (Nejire), also binds amplicon origins and is partially required for amplification. Knockdown of Chm and CBP together had a more severe effect on nucleosome acetylation and amplicon origin activity than knockdown of either HAT alone, suggesting that these HATs collaborate in origin regulation. In addition to their local function at the origin, we show that Chm and CBP also globally regulate the developmental transition of follicle cells into the amplification stages of oogenesis. Our results reveal a complexity of origin epigenetic regulation by multiple HATs during development and suggest that chromatin modifiers are a nexus that integrates differentiation and DNA replication programs. PMID:22951641

Evolution of robustness in the signaling network of Pristionchus vulva development

PubMed Central

Zauner, Hans; Sommer, Ralf J.

2007-01-01

Robustness to environmental or genetic perturbation, like any other trait, is affected by evolutionary change. However, direct studies on the interplay of robustness and evolvability are limited and require experimental microevolutionary studies of developmental processes. One system in which such microevolutionary studies can be performed is vulva development in the nematode Pristionchus pacificus. Three vulval precursor cells respond to redundant cell–cell interactions, including signals from the gonad and the epidermal cell P8.p. Interestingly, P. pacificus P8.p is involved in cell fate specification of the future vulva cells by lateral inhibition but is incompetent to respond to the inductive signal from the gonad itself. These functional properties of P8.p are unknown from other nematodes, such as Caenorhabditis elegans. We began an experimental and genetic analysis of the microevolution of P8.p function. We show that vulva misspecification events differ between Pristionchus strains and species. Similarly, lateral inhibition and developmental competence of P8.p evolved within the genus Pristionchus and between natural isolates of P. pacificus. Surprisingly, in some recombinant inbred lines of two distinct P. pacificus isolates, P8.p gained competence to form vulva tissue, a trait that was never observed in P. pacificus isolates. Our results suggest differences in developmental stability between natural isolates, and we hypothesize that the remarkable evolvability of redundant cell–cell interactions allows for adaptive evolution of robustness to developmental noise. PMID:17551021

DNA replication origins-where do we begin?

PubMed

Prioleau, Marie-Noëlle; MacAlpine, David M

2016-08-01

For more than three decades, investigators have sought to identify the precise locations where DNA replication initiates in mammalian genomes. The development of molecular and biochemical approaches to identify start sites of DNA replication (origins) based on the presence of defining and characteristic replication intermediates at specific loci led to the identification of only a handful of mammalian replication origins. The limited number of identified origins prevented a comprehensive and exhaustive search for conserved genomic features that were capable of specifying origins of DNA replication. More recently, the adaptation of origin-mapping assays to genome-wide approaches has led to the identification of tens of thousands of replication origins throughout mammalian genomes, providing an unprecedented opportunity to identify both genetic and epigenetic features that define and regulate their distribution and utilization. Here we summarize recent advances in our understanding of how primary sequence, chromatin environment, and nuclear architecture contribute to the dynamic selection and activation of replication origins across diverse cell types and developmental stages. © 2016 Prioleau and MacAlpine; Published by Cold Spring Harbor Laboratory Press.

The Tbr2 Molecular Network Controls Cortical Neuronal Differentiation Through Complementary Genetic and Epigenetic Pathways.

PubMed

Sessa, Alessandro; Ciabatti, Ernesto; Drechsel, Daniela; Massimino, Luca; Colasante, Gaia; Giannelli, Serena; Satoh, Takashi; Akira, Shizuo; Guillemot, Francois; Broccoli, Vania

2017-06-01

The T-box containing Tbr2 gene encodes for a transcription factor essential for the specification of the intermediate neural progenitors (INPs) originating the excitatory neurons of the cerebral cortex. However, its overall mechanism of action, direct target genes and cofactors remain unknown. Herein, we carried out global gene expression profiling combined with genome-wide binding site identification to determine the molecular pathways regulated by TBR2 in INPs. This analysis led to the identification of novel protein-protein interactions that control multiple features of INPs including cell-type identity, morphology, proliferation and migration dynamics. In particular, NEUROG2 and JMJD3 were found to associate with TBR2 revealing unexplored TBR2-dependent mechanisms. These interactions can explain, at least in part, the role of this transcription factor in the implementation of the molecular program controlling developmental milestones during corticogenesis. These data identify TBR2 as a major determinant of the INP-specific traits by regulating both genetic and epigenetic pathways. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Zebrafish vitamin K epoxide reductases: expression in vivo, along extracellular matrix mineralization and under phylloquinone and warfarin in vitro exposure.

PubMed

Fernández, Ignacio; Vijayakumar, Parameswaran; Marques, Carlos; Cancela, M Leonor; Gavaia, Paulo J; Laizé, Vincent

2015-06-01

Vitamin K (VK) acts as a cofactor driving the biological activation of VK-dependent proteins and conferring calcium-binding properties to them. As a result, VK is converted into VK epoxide, which must be recycled by VK epoxide reductases (Vkors) before it can be reused. Although VK has been shown to play a central role in fish development, particularly during skeletogenesis, pathways underlying VK actions are poorly understood, while good and reliable molecular markers for VK cycle/homeostasis are still lacking in fish. In the present work, expression of 2 zebrafish vkor genes was characterized along larval development and in adult tissues through qPCR analysis. Zebrafish cell line ZFB1 was used to evaluate in vitro regulation of vkors and other VK cycle-related genes during mineralization and upon 24 h exposure to 0.16 and 0.8 µM phylloquinone (VK1), 0.032 µM warfarin, or a combination of both molecules. Results showed that zebrafish vkors are differentially expressed during larval development, in adult tissues, and during cell differentiation/mineralization processes. Further, several VK cycle intermediates were differentially expressed in ZFB1 cells exposed to VK1 and/or warfarin. Present work provides data identifying different developmental stages and adult tissues where VK recycling is probably highly required, and shows how genes involved in VK cycle respond to VK nutritional status in skeletal cells. Expression of vkor genes can represent a reliable indicator to infer VK nutritional status in fish, while ZFB1 cells could represent a suitable in vitro tool to get insights into the mechanisms underlying VK action on fish bone.

Maternally Contributed Folate Receptor 1 Is Expressed in Ovarian Follicles and Contributes to Preimplantation Development

PubMed Central

Strandgaard, Trine; Foder, Solveig; Heuck, Anders; Ernst, Erik; Nielsen, Morten S.; Lykke-Hartmann, Karin

2017-01-01

Folates have been shown to play a crucial role for proper development of the embryo as folate deficiency has been associated with reduced developmental capacity such as increased risk of fetal neural tube defects and spontanous abortion. Transcripts encoding the reduced folate carrier RFC1 (SLC19A1 protein) and the high-affinity folate receptor FOLR1 are expressed in oocytes and preimplantation embryos, respectively. In this study, we observed maternally contributed FOLR1 protein during mouse and human ovarian follicle development, and 2-cell mouse embryos. In mice, FOLR1 was highly enriched in oocytes from primary, secondary and tertiary follicles, and in the surrounding granulosa cells. Interestingly, during human follicle development, we noted a high and specific presence of FOLR1 in oocytes from primary and intermediate follicles, but not in the granulosa cells. The distribution of FOLR1 in follicles was noted as membrane-enriched but also seen in the cytoplasm in oocytes and granulosa cells. In 2-cell embryos, FOLR1-eGFP fusion protein was detected as cytoplasmic and membrane-associated dense structures, resembling the distribution pattern observed in ovarian follicle development. Knock-down of Folr1 mRNA function was accomplished by microinjection of short interference (si)RNA targeting Folr1, into mouse pronuclear zygotes. This revealed a reduced capacity of Folr1 siRNA-treated embryos to develop to blastocyst compared to the siRNA-scrambled control group, indicating that maternally contributed protein and zygotic transcripts sustain embryonic development combined. In summary, maternally contributed FOLR1 protein appears to maintain ovarian functions, and contribute to preimplantation development combined with embryonically synthesized FOLR1. PMID:29034232

T cell infiltrate and outcome following resection of intermediate-grade primary neuroendocrine tumours and liver metastases.

PubMed

Katz, Steven C; Donkor, Charan; Glasgow, Kristen; Pillarisetty, Venu G; Gönen, Mithat; Espat, N Joseph; Klimstra, David S; D'Angelica, Michael I; Allen, Peter J; Jarnagin, William; Dematteo, Ronald P; Brennan, Murray F; Tang, Laura H

2010-12-01

Tumour-infiltrating lymphocytes (TILs) have been shown to predict survival in numerous malignancies. The importance of TILs in primary pancreatic neuroendocrine tumours (NETs) and NET liver metastases (NETLMs) has not been defined. We identified 87 patients with NETs and 39 with NETLMs who had undergone resection. Immunohistochemistry was performed to determine TIL counts. Recurrence-free survival (RFS) and overall survival (OS) were determined using the log-rank test. The median follow-up time was 62 months in NET patients and 48 months in NETLM patients. Vascular invasion and histologic grade were the only independent predictors of outcome for NETs and NETLMs, respectively. Analysis of intermediate-grade NETs indicated that a dense T cell (CD3+) infiltrate was associated with a median RFS of 128 months compared with 61 months for those with low levels of intratumoral T cells (P= 0.05, univariate analysis). Examination of NETLMs revealed that a low level of infiltrating regulatory T cells (Treg, FoxP3+) was a predictor of prolonged survival (P < 0.01, univariate analysis). A robust T cell infiltrate is associated with improved RFS following resection of intermediate-grade NETs, whereas the presence of more Treg correlated with shorter OS after treatment of NETLMs. Further study of the immune response to intermediate-grade NETs and NETLMs is warranted.

Chromatin configurations in the ferret germinal vesicle that reflect developmental competence for in vitro maturation.

PubMed

Sun, X; Li, Z; Yi, Y; Ding, W; Chen, J; Engelhardt, J F; Leno, G H

2009-04-01

In several mammalian species, the configuration of germinal vesicle (GV) chromatin correlates with the developmental competence of oocytes. Yet, no study has been published on the configuration of GV chromatin in ferret, nor is it known whether a specific configuration predicts meiotic competence in this species, in spite of the potential importance of ferret cloning to the study of human disease and to species conservation efforts. Here, we report on an analysis of the chromatin configuration in ferret GV oocytes and on how they correlate with meiotic development. Three distinct configurations were identified based on the degree of chromatin condensation: (1) fibrillar chromatin (FC), featuring strands of intertwined chromatin occupying most of the visible GV region; (2) intermediate condensed chromatin (ICC), characterized by dense, irregular chromatin masses throughout the GV; and (3) condensed chromatin (CC), which is highly compact and centered around the nucleolus. We also found that chromatin configuration was related to the extent of association with cumulus cells in cumulus-oocyte complexes; CC-configured oocytes were most often surrounded by a compact cumulus layer and also a compact corona but FC-configured oocytes were associated with neither. In addition, increasing chromatin condensation corresponded to an increase in oocyte diameter. Finally, following in vitro culture, significantly more CC-configured oocytes underwent maturation to meiotic metaphase II than did FC- or ICC-configured oocytes. We conclude that, in ferret, chromatin condensation is related to the sequential achievement of meiotic competencies during oocyte growth and differentiation, and thus can be used as a predictor of competence.

CHLORPYRIFOS DEVELOPMENTAL NEUROTOXICITY: INTERACTION WITH GLUCOCORTICOIDS IN PC12 CELLS

PubMed Central

Slotkin, Theodore A.; Card, Jennifer; Seidler, Frederic J.

2012-01-01

Prenatal coexposures to glucocorticoids and organophosphate pesticides are widespread. Glucocorticoids are elevated by maternal stress and are commonly given in preterm labor; organophosphate exposures are virtually ubiquitous. We used PC12 cells undergoing neurodifferentiation in order to assess whether dexamethasone enhances the developmental neurotoxicity of chlorpyrifos, focusing on concentrations relevant to human exposures. By themselves, each agent reduced the number of cells and the combined exposure elicited a correspondingly greater effect than with either agent alone. There was no general cytotoxicity, as cell growth was actually enhanced, and again, the combined treatment evoked greater cellular hypertrophy than with the individual compounds. The effects on neurodifferentiation were more complex. Chlorpyrifos alone had a promotional effect on neuri to genesis whereas dexamethasone impaired it; combined treatment showed an overall impairment greater than that seen with dexamethasone alone. The effect of chlorpyrifos on differentiation into specific neurotransmitter phenotypes was shifted by dexamethasone. Either agent alone promoted differentiation into the dopaminergic phenotype at the expense of the cholinergic phenotype. However, in dexamethasone-primed cells, chlorpyrifos actually enhanced cholinergic neurodifferentiation instead of suppressing this phenotype. Our results indicate that developmental exposure to glucocorticoids, either in the context of stress or the therapy of preterm labor, could enhance the developmental neurotoxicity of organophosphates and potentially of other neurotoxicants, as well as producing neurobehavioral outcomes distinct from those seen with either individual agent. PMID:22796634

Control of asgE Expression during Growth and Development of Myxococcus xanthus

PubMed Central

Garza, Anthony G.; Harris, Baruch Z.; Greenberg, Brandon M.; Singer, Mitchell

2000-01-01

One of the earliest events in the Myxococcus xanthus developmental cycle is production of an extracellular cell density signal called A-signal (or A-factor). Previously, we showed that cells carrying an insertion in the asgE gene fail to produce normal levels of this cell-cell signal. In this study we found that expression of asgE is growth phase regulated and developmentally regulated. Several lines of evidence indicate that asgE is cotranscribed with an upstream gene during development. Using primer extension analyses, we identified two 5′ ends for this developmental transcript. The DNA sequence upstream of one 5′ end has similarity to the promoter regions of several genes that are A-signal dependent, whereas sequences located upstream of the second 5′ end show similarity to promoter elements identified for genes that are C-signal dependent. Consistent with this result is our finding that mutants failing to produce A-signal or C-signal are defective for developmental expression of asgE. In contrast to developing cells, the large majority of the asgE transcript found in vegetative cells appears to be monocistronic. This finding suggests that asgE uses different promoters for expression during vegetative growth and development. Growth phase regulation of asgE is abolished in a relA mutant, indicating that this vegetative promoter is induced by starvation. The data presented here, in combination with our previous results, indicate that the level of AsgE in vegetative cells is sufficient for this protein to carry out its function during development. PMID:11073904

Ultraviolet Photolysis of Chlorpyrifos: Developmental Neurotoxicity Modeled in PC12 Cells

PubMed Central

Slotkin, Theodore A.; Seidler, Frederic J.; Wu, Changlong; MacKillop, Emiko A.; Linden, Karl G.

2009-01-01

Background Ultraviolet photodegradation products from pesticides form both in the field and during water treatment. Objectives We evaluated the photolytic breakdown of the organophosphate pesticide chlorpyrifos (CPF) in terms of both the chemical entities generated by low-pressure ultraviolet C irradiation and their potential as developmental neurotoxicants. Methods We separated by-products using high-performance liquid chromatography and characterized them by gas chromatography/mass spectrometry. We assessed neurotoxicity in neuronotypic PC12 cells, both in the undifferentiated state and during differentiation. Results Photodegradation of CPF in methanol solution generated CPF oxon and trichloropyridinol, products known to retain developmental neurotoxicant actions, as well as a series of related organophosphate and phosphorothionate derivatives. Exposure conditions that led to 50% degradation of CPF thus did not reduce developmental neurotoxicity. The degradation mixture inhibited DNA synthesis in undifferentiated cells to the same extent as native CPF. In differentiating cells, the products likewise retained the full ability to elicit shortfalls in cell number and corresponding effects on cell growth and neurite formation. When the exposure was prolonged to the point where 70% of the CPF was degraded, the adverse effects on PC12 cells were no longer evident; however, these conditions were sufficiently severe to generate toxic products from the methanol vehicle. Conclusions Our results indicate that field conditions or remediation treatments that degrade a significant proportion of the CPF do not necessarily produce inactive products and, indeed, may elicit formation of even more toxic chemicals that are more water soluble and thus have greater field mobility than CPF itself. PMID:19337505

Citrinin induces apoptosis via a mitochondria-dependent pathway and inhibition of survival signals in embryonic stem cells, and causes developmental injury in blastocysts

PubMed Central

Chan, Wen-Hsiung

2007-01-01

The mycotoxin CTN (citrinin), a natural contaminant in foodstuffs and animal feeds, has cytotoxic and genotoxic effects on various mammalian cells. CTN is known to cause cell injury, including apoptosis, but the precise regulatory mechanisms of CTN action, particularly in stem cells and embryos, are currently unclear. In the present paper, I report that CTN has cytotoxic effects on mouse embryonic stem cells and blastocysts, and is associated with defects in their subsequent development, both in vitro and in vivo. Experiments in embryonic stem cells (ESC-B5) showed that CTN induces apoptosis via ROS (reactive oxygen species) generation, increased Bax/Bcl-2 ratio, loss of MMP (mitochondrial membrane potential), induction of cytochrome c release, and activation of caspase 3. In this model, CTN triggers cell death via inactivation of the HSP90 [a 90 kDa isoform of the HSP (heat-shock protein) family proteins]/multichaperone complex and subsequent degradation of Ras and Raf-1, further inhibiting anti-apoptotic processes, such as the Ras→ERK (extracellular-signal-regulated kinase) signal transduction pathway. In addition, CTN causes early developmental injury in mouse ESCs and blastocysts in vitro. Lastly, using an in vivo mouse model, I show that consumption of drinking water containing 10 μM CTN results in blastocyst apoptosis and early embryonic developmental injury. Collectively, these findings show for the first time that CTN induces ROS and mitochondria-dependent apoptotic processes, inhibits Ras→ERK survival signalling via inactivation of the HSP90/multichaperone complex, and causes developmental injury in vivo. PMID:17331071

Comparative ultrastructure of fruit plastids in three genetically diverse genotypes of apple (Malus × domestica Borkh.) during development.

PubMed

Schaeffer, Scott M; Christian, Ryan; Castro-Velasquez, Nohely; Hyden, Brennan; Lynch-Holm, Valerie; Dhingra, Amit

2017-10-01

Comparative ultrastructural developmental time-course analysis has identified discrete stages at which the fruit plastids undergo structural and consequently functional transitions to facilitate subsequent development-guided understanding of the complex plastid biology. Plastids are the defining organelle for a plant cell and are critical for myriad metabolic functions. The role of leaf plastid, chloroplast, is extensively documented; however, fruit plastids-chromoplasts-are poorly understood, especially in the context of the diverse metabolic processes operating in these diverse plant organs. Recently, in a comparative study of the predicted plastid-targeted proteomes across seven plant species, we reported that each plant species is predicted to harbor a unique set of plastid-targeted proteins. However, the temporal and developmental context of these processes remains unknown. In this study, an ultrastructural analysis approach was used to characterize fruit plastids in the epidermal and collenchymal cell layers at 11 developmental timepoints in three genotypes of apple (Malus × domestica Borkh.): chlorophyll-predominant 'Granny Smith', carotenoid-predominant 'Golden Delicious', and anthocyanin-predominant 'Top Red Delicious'. Plastids transitioned from a proplastid-like plastid to a chromoplast-like plastid in epidermis cells, while in the collenchyma cells, they transitioned from a chloroplast-like plastid to a chloro-chromo-amyloplast plastid. Plastids in the collenchyma cells of the three genotypes demonstrated a diverse array of structures and features. This study enabled the identification of discrete developmental stages during which specific functions are most likely being performed by the plastids as indicated by accumulation of plastoglobuli, starch granules, and other sub-organeller structures. Information regarding the metabolically active developmental stages is expected to facilitate biologically relevant omics studies to unravel the complex biochemistry of plastids in perennial non-model systems.

Comparative cell cycle transcriptomics reveals synchronization of developmental transcription factor networks in cancer cells

PubMed Central

Johard, Helena; Mahdessian, Diana; Fedr, Radek; Marks, Carolyn; Medalová, Jiřina; Souček, Karel; Lundberg, Emma; Linnarsson, Sten; Bryja, Vítězslav; Sekyrova, Petra; Altun, Mikael; Andäng, Michael

2017-01-01

The cell cycle coordinates core functions such as replication and cell division. However, cell-cycle-regulated transcription in the control of non-core functions, such as cell identity maintenance through specific transcription factors (TFs) and signalling pathways remains unclear. Here, we provide a resource consisting of mapped transcriptomes in unsynchronized HeLa and U2OS cancer cells sorted for cell cycle phase by Fucci reporter expression. We developed a novel algorithm for data analysis that enables efficient visualization and data comparisons and identified cell cycle synchronization of Notch signalling and TFs associated with development. Furthermore, the cell cycle synchronizes with the circadian clock, providing a possible link between developmental transcriptional networks and the cell cycle. In conclusion we find that cell cycle synchronized transcriptional patterns are temporally compartmentalized and more complex than previously anticipated, involving genes, which control cell identity and development. PMID:29228002

Intermediates of Metabolism: From Bystanders to Signalling Molecules.

PubMed

Haas, Robert; Cucchi, Danilo; Smith, Joanne; Pucino, Valentina; Macdougall, Claire Elizabeth; Mauro, Claudio

2016-05-01

The integration of biochemistry into immune cell biology has contributed immensely to our understanding of immune cell function and the associated pathologies. So far, most studies have focused on the regulation of metabolic pathways during an immune response and their contribution to its success. More recently, novel signalling functions of metabolic intermediates are being discovered that might play important roles in the regulation of immunity. Here we describe the three long-known small metabolites lactate, acetyl-CoA, and succinate in the context of immunometabolic signalling. Functions of these ubiquitous molecules are largely dependent on their intra- and extracellular concentrations as well as their subcompartmental localisation. Importantly, the signalling functions of these metabolic intermediates extend beyond self-regulatory roles and include cell-to-cell communication and sensing of microenvironmental conditions to elicit stress responses and cellular adaptation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Nitric oxide functions as a signal in plant disease resistance.

PubMed

Delledonne, M; Xia, Y; Dixon, R A; Lamb, C

1998-08-06

Recognition of an avirulent pathogen triggers the rapid production of the reactive oxygen intermediates superoxide (O2-) and hydrogen peroxide (H2O2). This oxidative burst drives crosslinking of the cell wall, induces several plant genes involved in cellular protection and defence, and is necessary for the initiation of host cell death in the hypersensitive disease-resistance response. However, this burst is not enough to support a strong disease-resistance response. Here we show that nitric oxide, which acts as a signal in the immune, nervous and vascular systems, potentiates the induction of hypersensitive cell death in soybean cells by reactive oxygen intermediates and functions independently of such intermediates to induce genes for the synthesis of protective natural products. Moreover, inhibitors of nitric oxide synthesis compromise the hypersensitive disease-resistance response of Arabidopsis leaves to Pseudomonas syringae, promoting disease and bacterial growth. We conclude that nitric oxide plays a key role in disease resistance in plants.

Distribution and developmental changes of ghrelin-immunopositive cells in the pancreas of African ostrich chicks (Struthio camelus).

PubMed

Wang, J X; Li, P; Zhang, X T; Ye, L X

2017-09-01

Ghrelin, the endogenous ligand for the growth hormone secretagogue receptor (GHS-R), is produced by multiple cell types and affects feeding behavior, metabolic regulation, and energy balance. In the mammalian pancreas, the types of endocrine cells that are immunoreactive to ghrelin vary. However, little was known about its distribution and developmental changes in the pancreas of African ostrich chicks (Struthio camelus). In the present study, the distribution, morphological characteristics, and developmental changes of ghrelin-immunopositive (ghrelin-ip) cells in the pancreas of African ostrich chicks were investigated using immunohistochemistry. Ghrelin-ip cells were found in both the pancreatic islets and acinar cell regions. The greatest number of ghrelin-ip cells were found in the pancreatic islets, and were primarily observed at the periphery of the islets; some ghrelin-ip cells were also located in the central portion of the pancreatic islets. Interestingly, from postnatal d 1 to d 90, there was a steady decrease in the number of ghrelin-ip cells in the pancreatic islets and acinar cell regions. These results clearly demonstrated that ghrelin-ip cells exist and decreased with age in the African ostrich pancreas from postnatal d 1 to d90. Thus, these findings indicated that ghrelin may be involved in the development of the pancreas in the African ostrich. © 2017 Poultry Science Association Inc.

Developmental and Tissue-Specific Structural Alterations of the Cell-Wall Polysaccharides of Arabidopsis thaliana Roots.

PubMed Central

Freshour, G.; Clay, R. P.; Fuller, M. S.; Albersheim, P.; Darvill, A. G.; Hahn, M. G.

1996-01-01

The plant cell wall is a dynamic structure that plays important roles in growth and development and in the interactions of plants with their environment and other organisms. We have used monoclonal antibodies that recognize different carbohydrate epitopes present in plant cell-wall polysaccharides to locate these epitopes in roots of developing Arabidopsis thaliana seedlings. An epitope in the pectic polysaccharide rhamnogalacturonan I is observed in the walls of epidermal and cortical cells in mature parts of the root. This epitope is inserted into the walls in a developmentally regulated manner. Initially, the epitope is observed in atrichoblasts and later appears in trichoblasts and simultaneously in cortical cells. A terminal [alpha]-fucosyl-containing epitope is present in almost all of the cell walls in the root. An arabinosylated (1->6)-[beta]-galactan epitope is also found in all of the cell walls of the root with the exception of lateral root-cap cell walls. It is striking that these three polysaccharide epitopes are not uniformly distributed (or accessible) within the walls of a given cell, nor are these epitopes distributed equally across the two walls laid down by adjacent cells. Our results further suggest that the biosynthesis and differentiation of primary cell walls in plants are precisely regulated in a temporal, spatial, and developmental manner. PMID:12226270

MRCK-1 drives apical constriction in C. elegans by linking developmental patterning to force generation

PubMed Central

Marston, Daniel J.; Higgins, Christopher D.; Peters, Kimberly A.; Cupp, Timothy D.; Dickinson, Daniel J.; Pani, Ariel M.; Moore, Regan P.; Cox, Amanda H.; Kiehart, Daniel P.; Goldstein, Bob

2016-01-01

Summary Apical constriction is a change in cell shape that drives key morphogenetic events including gastrulation and neural tube formation. Apical force-producing actomyosin networks drive apical constriction by contracting while connected to cell-cell junctions. The mechanisms by which developmental patterning regulates these actomyosin networks and associated junctions with spatial precision are not fully understood. Here, we identify a myosin light chain kinase MRCK-1 as a key regulator of C. elegans gastrulation that integrates spatial and developmental patterning information. We show that MRCK-1 is required for activation of contractile actomyosin dynamics and elevated cortical tension in the apical cell cortex of endodermal precursor cells. MRCK-1 is apically localized by active Cdc42 at the external, cell-cell contact-free surfaces of apically constricting cells, downstream of cell fate determination mechanisms. We establish that the junctional components α-catenin, β-catenin, and cadherin become highly enriched at the apical junctions of apically-constricting cells, and that MRCK-1 and myosin activity are required in vivo for this enrichment. Taken together, our results define mechanisms that position a myosin activator to a specific cell surface where it both locally increases cortical tension and locally enriches junctional components to facilitate apical constriction. These results reveal crucial links that can tie spatial information to local force generation to drive morphogenesis. PMID:27451898

Krebs Cycle Intermediates Protective against Oxidative Stress by Modulating the Level of Reactive Oxygen Species in Neuronal HT22 Cells.

PubMed

Sawa, Kenta; Uematsu, Takumi; Korenaga, Yusuke; Hirasawa, Ryuya; Kikuchi, Masatoshi; Murata, Kyohei; Zhang, Jian; Gai, Xiaoqing; Sakamoto, Kazuichi; Koyama, Tomoyuki; Satoh, Takumi

2017-03-16

Krebs cycle intermediates (KCIs) are reported to function as energy substrates in mitochondria and to exert antioxidants effects on the brain. The present study was designed to identify which KCIs are effective neuroprotective compounds against oxidative stress in neuronal cells. Here we found that pyruvate, oxaloacetate, and α-ketoglutarate, but not lactate, citrate, iso-citrate, succinate, fumarate, or malate, protected HT22 cells against hydrogen peroxide-mediated toxicity. These three intermediates reduced the production of hydrogen peroxide-activated reactive oxygen species, measured in terms of 2',7'-dichlorofluorescein diacetate fluorescence. In contrast, none of the KCIs-used at 1 mM-protected against cell death induced by high concentrations of glutamate-another type of oxidative stress-induced neuronal cell death. Because these protective KCIs did not have any toxic effects (at least up to 10 mM), they have potential use for therapeutic intervention against chronic neurodegenerative diseases.

VITRECTOMY FOR INTERMEDIATE AGE-RELATED MACULAR DEGENERATION ASSOCIATED WITH TANGENTIAL VITREOMACULAR TRACTION: A CLINICOPATHOLOGIC CORRELATION.

PubMed

Ziada, Jean; Hagenau, Felix; Compera, Denise; Wolf, Armin; Scheler, Renate; Schaumberger, Markus M; Priglinger, Siegfried G; Schumann, Ricarda G

2018-03-01

To describe the morphologic characteristics of the vitreomacular interface in intermediate age-related macular degeneration associated with tangential traction due to premacular membrane formation and to correlate with optical coherence tomography (OCT) findings and clinical data. Premacular membrane specimens were removed sequentially with the internal limiting membrane from 27 eyes of 26 patients with intermediate age-related macular degeneration during standard vitrectomy. Specimens were processed for immunocytochemical staining of epiretinal cells and extracellular matrix components. Ultrastructural analysis was performed using transmission electron microscopy. Spectral domain optical coherence tomography images and patient charts were evaluated in retrospect. Immunocytochemistry revealed hyalocytes and myofibroblasts as predominant cell types. Ultrastructural analysis demonstrated evidence of vitreoschisis in all eyes. Myofibroblasts with contractile properties were observed to span between folds of the internal limiting membrane and vitreous cortex collagen. Retinal pigment epithelial cells or inflammatory cells were not detected. Mean visual acuity (Snellen) showed significant improvement from 20/72 ± 20/36 to 20/41 ± 20/32 (P < 0.001) after a mean follow-up period of 19 months (median, 17 months). During this period, none of the eyes required anti-vascular endothelial growth factor therapy. Fibrocellular premacular proliferation in intermediate age-related macular degeneration predominantly consists of vitreous collagen, hyalocytes, and myofibroblasts with contractile properties. Vitreoschisis and vitreous-derived cells appear to play an important role in traction formation of this subgroup of eyes. In patients with intermediate age-related macular degeneration and contractile premacular membrane, release of traction by vitrectomy with internal limiting membrane peeling results in significantly functional and anatomical improvement.

Functional Conservation of the Glide/Gcm Regulatory Network Controlling Glia, Hemocyte, and Tendon Cell Differentiation in Drosophila

PubMed Central

Cattenoz, Pierre B.; Popkova, Anna; Southall, Tony D.; Aiello, Giuseppe; Brand, Andrea H.; Giangrande, Angela

2016-01-01

High-throughput screens allow us to understand how transcription factors trigger developmental processes, including cell specification. A major challenge is identification of their binding sites because feedback loops and homeostatic interactions may mask the direct impact of those factors in transcriptome analyses. Moreover, this approach dissects the downstream signaling cascades and facilitates identification of conserved transcriptional programs. Here we show the results and the validation of a DNA adenine methyltransferase identification (DamID) genome-wide screen that identifies the direct targets of Glide/Gcm, a potent transcription factor that controls glia, hemocyte, and tendon cell differentiation in Drosophila. The screen identifies many genes that had not been previously associated with Glide/Gcm and highlights three major signaling pathways interacting with Glide/Gcm: Notch, Hedgehog, and JAK/STAT, which all involve feedback loops. Furthermore, the screen identifies effector molecules that are necessary for cell-cell interactions during late developmental processes and/or in ontogeny. Typically, immunoglobulin (Ig) domain–containing proteins control cell adhesion and axonal navigation. This shows that early and transiently expressed fate determinants not only control other transcription factors that, in turn, implement a specific developmental program but also directly affect late developmental events and cell function. Finally, while the mammalian genome contains two orthologous Gcm genes, their function has been demonstrated in vertebrate-specific tissues, placenta, and parathyroid glands, begging questions on the evolutionary conservation of the Gcm cascade in higher organisms. Here we provide the first evidence for the conservation of Gcm direct targets in humans. In sum, this work uncovers novel aspects of cell specification and sets the basis for further understanding of the role of conserved Gcm gene regulatory cascades. PMID:26567182

Neural crest cells: from developmental biology to clinical interventions.

PubMed

Noisa, Parinya; Raivio, Taneli

2014-09-01

Neural crest cells are multipotent cells, which are specified in embryonic ectoderm in the border of neural plate and epiderm during early development by interconnection of extrinsic stimuli and intrinsic factors. Neural crest cells are capable of differentiating into various somatic cell types, including melanocytes, craniofacial cartilage and bone, smooth muscle, and peripheral nervous cells, which supports their promise for cell therapy. In this work, we provide a comprehensive review of wide aspects of neural crest cells from their developmental biology to applicability in medical research. We provide a simplified model of neural crest cell development and highlight the key external stimuli and intrinsic regulators that determine the neural crest cell fate. Defects of neural crest cell development leading to several human disorders are also mentioned, with the emphasis of using human induced pluripotent stem cells to model neurocristopathic syndromes. © 2014 Wiley Periodicals, Inc.

RETRACTED: Aerobic degradation of 4-nitroaniline (4-NA) via novel degradation intermediates by Rhodococcus sp. strain FK48.

PubMed

Khan, Fazlurrahman; Pandey, Janmejay; Vikram, Surendra; Pal, Deepika; Cameotra, Swaranjit Singh

2013-06-15

An aerobic strain, Rhodococcus sp. strain FK48, capable of growing on 4-nitroaniline (4-NA) as the sole source of carbon, nitrogen, and energy has been isolated from enrichment cultures originating from contaminated soil samples. During growth studies with non- induced cells of FK48 catalyzed sequential denitrification (release of NO₂ substituent) and deamination (release of NH₂ substituent) of 4-NA. However, none of the degradation intermediates could be identified with growth studies. During resting cell studies, 4-NA-induced cells of strain FK48 transformed 4-NA via a previously unknown pathway which involved oxidative hydroxylation leading to formation of 4-aminophenol (4-AP). Subsequent degradation involved oxidated deamination of 4-AP and formation of 1,2,4-benzenetriol (BT) as the major identified terminal aromatic intermediate. Identification of these intermediates was ascertained by HPLC, and GC-MS analyses of the culture supernatants. 4-NA-induced cells of strain FK48 showed positive activity for 1,2,4-benzenetriol dioxygenase in spectrophotometric assay. This is the first conclusive study on aerobic microbial degradation of 4-NA and elucidation of corresponding metabolic pathway. Copyright © 2013 Elsevier B.V. All rights reserved.

Development of Anode-Supported Single Cells and Small Stacks for Intermediate Temperature Sofc at Kepri

NASA Astrophysics Data System (ADS)

Yoo, Y.-S.; Park, J.-W.; Park, J.-K.; Lim, H.-C.; Oh, J.-M.; Bae, J.-M.

Recent results on intermediate temperature-operating solid oxide fuel cells (IT-SOFC) are mainly focused on getting the higher performance of single cell at lower operating temperature, especially using planar type. We have started a project to develop 1 kW-class SOFC system for Residential Power Generation(RPG) application. For a 1 kW-class SOFC stack that can be operated at intermediate temperatures, we have developed anode-supported, planar type SOFC to have advantages for commercialization of SOFCs considering mass production and using cost-effective interconnects such as ferritic stainless steels. At higher temperature, performance of SOFC can be increased due to higher electrochemical activity of electrodes and lower ohmic losses, but the surface of metallic interconnects at cathode side is rapidly oxidized into resistive oxide scale. For efficient operation of SOFC at reduced temperature at, firstly we have developed alternative cathode materials of LSCF instead of LSM to get higher performance of electrodes, and secondly introduced functional-layered structure at anode side. The I-V and AC impedance characteristics of improved single cells and small stacks were evaluated at intermediate temperatures (650°C and 750°C) using hydrogen gas as a fuel.

Recent Insights Into Molecular Mechanisms of Propofol-Induced Developmental Neurotoxicity: Implications for the Protective Strategies.

PubMed

Bosnjak, Zeljko J; Logan, Sarah; Liu, Yanan; Bai, Xiaowen

2016-11-01

Mounting evidence has demonstrated that general anesthetics could induce developmental neurotoxicity, including acute widespread neuronal cell death, followed by long-term memory and learning abnormalities. Propofol is a commonly used intravenous anesthetic agent for the induction and maintenance of anesthesia and procedural and critical care sedation in children. Compared with other anesthetic drugs, little information is available on its potential contributions to neurotoxicity. Growing evidence from multiple experimental models showed a similar neurotoxic effect of propofol as observed in other anesthetic drugs, raising serious concerns regarding pediatric propofol anesthesia. The aim of this review is to summarize the current findings of propofol-induced developmental neurotoxicity. We first present the evidence of neurotoxicity from animal models, animal cell culture, and human stem cell-derived neuron culture studies. We then discuss the mechanism of propofol-induced developmental neurotoxicity, such as increased cell death in neurons and oligodendrocytes, dysregulation of neurogenesis, abnormal dendritic development, and decreases in neurotrophic factor expression. Recent findings of complex mechanisms of propofol action, including alterations in microRNAs and mitochondrial fission, are discussed as well. An understanding of the toxic effect of propofol and the underlying mechanisms may help to develop effective novel protective or therapeutic strategies for avoiding the neurotoxicity in the developing human brain.

Control of DNA replication: a new facet of Hox proteins?

PubMed

Miotto, Benoit; Graba, Yacine

2010-09-01

Hox proteins are well-known as developmental transcription factors controlling cell and tissue identity, but recent findings suggest that they are also part of the cell replication machinery. Hox-mediated control of transcription and replication may ensure coordinated control of cell growth and differentiation, two processes that need to be tightly and precisely coordinated to allow proper organ formation and patterning. In this review we summarize the available data linking Hox proteins to the replication machinery and discuss the developmental and pathological implications of this new facet of Hox protein function.

Markers of Developmentally Regulated Programmed Cell Death and Their Analysis in Cereal Seeds.

PubMed

Domínguez, Fernando; Cejudo, Francisco Javier

2018-01-01

Programmed cell death (PCD) is a key process for the development and differentiation of multicellular organisms, which is characterized by well-defined morphological and biochemical features. These include chromatin condensation, DNA degradation and nuclear fragmentation, with nucleases and proteases playing a relevant function in these processes. In this chapter we describe methods routinely used for the analysis of hallmarks of developmentally regulated PCD in cereal seed tissues, which are based on agarose and polyacrylamide gel electrophoresis, in situ staining of DNA fragmentation, and cell-free assays of relevant enzymatic activities.

The fledging of common and thick-billed murres on Middleton Island, Alaska

USGS Publications Warehouse

Hatch, Scott A.

1983-01-01

Three species of alcids, Common and Thick-billed murres (Uria aalge and U. lomvia) and the Razorbill (Alca torda), have post-hatching developmental patterns intermediate to precocial and semi-precocial modes (Sealy 1973). The young leave their cliff nest sites at about one quarter of adult weight and complete their growth at sea. At departure, an event here loosely referred to as "fledging," neither primary nor secondary flight feathers are grown, but well-developed wing coverts enable limited, descending flight.

TOO MANY MOUTHS promotes cell fate progression in stomatal development of Arabidopsis stems.

PubMed

Bhave, Neela S; Veley, Kira M; Nadeau, Jeanette A; Lucas, Jessica R; Bhave, Sanjay L; Sack, Fred D

2009-01-01

Mutations in TOO MANY MOUTHS (TMM), which encodes a receptor-like protein, cause stomatal patterning defects in Arabidopsis leaves but eliminate stomatal formation in stems. Stomatal development in wild-type and tmm stems was analyzed to define TMM function. Epidermal cells in young tmm stems underwent many asymmetric divisions characteristic of entry into the stomatal pathway. The resulting precursor cells, meristemoids, appropriately expressed cell fate markers such as pTMM:GFP. However, instead of progressing developmentally by forming a guard mother cell, the meristemoids arrested, dedifferentiated, and enlarged. Thus asymmetric divisions are necessary but not sufficient for stomatal formation in stems, and TMM promotes the fate and developmental progression of early precursor cells. Comparable developmental and mature stomatal phenotypes were also found in tmm hypocotyls and in the proximal flower stalk. TMM is also a positive regulator of meristemoid division in leaves suggesting that TMM generally promotes meristemoid activity. Our results are consistent with a model in which TMM interacts with other proteins to modulate precursor cell fate and progression in an organ and domain-specific manner. Finally, the consistent presence of a small number of dedifferentiated meristemoids in mature wild-type stems suggests that precursor cell arrest is a normal feature of Arabidopsis stem development.

Cell fate regulation in early mammalian development

NASA Astrophysics Data System (ADS)

Oron, Efrat; Ivanova, Natalia

2012-08-01

Preimplantation development in mammals encompasses a period from fertilization to implantation and results in formation of a blastocyst composed of three distinct cell lineages: epiblast, trophectoderm and primitive endoderm. The epiblast gives rise to the organism, while the trophectoderm and the primitive endoderm contribute to extraembryonic tissues that support embryo development after implantation. In many vertebrates, such as frog or fish, maternally supplied lineage determinants are partitioned within the egg. Cell cleavage that follows fertilization results in polarization of these factors between the individual blastomeres, which become restricted in their developmental fate. In contrast, the mouse oocyte and zygote lack clear polarity and, until the eight-cell stage, individual blastomeres retain the potential to form all lineages. How are cell lineages specified in the absence of a maternally supplied blueprint? This is a fundamental question in the field of developmental biology. The answer to this question lies in understanding the cell-cell interactions and gene networks involved in embryonic development prior to implantation and using this knowledge to create testable models of the developmental processes that govern cell fates. We provide an overview of classic and contemporary models of early lineage development in the mouse and discuss the emerging body of work that highlights similarities and differences between blastocyst development in the mouse and other mammalian species.

Semaphorin 3A is a retrograde cell death signal in developing sympathetic neurons

PubMed Central

Wehner, Amanda B.; Abdesselem, Houari; Dickendesher, Travis L.; Imai, Fumiyasu; Yoshida, Yutaka; Giger, Roman J.; Pierchala, Brian A.

2016-01-01

ABSTRACT During development of the peripheral nervous system, excess neurons are generated, most of which will be lost by programmed cell death due to a limited supply of neurotrophic factors from their targets. Other environmental factors, such as ‘competition factors' produced by neurons themselves, and axon guidance molecules have also been implicated in developmental cell death. Semaphorin 3A (Sema3A), in addition to its function as a chemorepulsive guidance cue, can also induce death of sensory neurons in vitro. The extent to which Sema3A regulates developmental cell death in vivo, however, is debated. We show that in compartmentalized cultures of rat sympathetic neurons, a Sema3A-initiated apoptosis signal is retrogradely transported from axon terminals to cell bodies to induce cell death. Sema3A-mediated apoptosis utilizes the extrinsic pathway and requires both neuropilin 1 and plexin A3. Sema3A is not retrogradely transported in older, survival factor-independent sympathetic neurons, and is much less effective at inducing apoptosis in these neurons. Importantly, deletion of either neuropilin 1 or plexin A3 significantly reduces developmental cell death in the superior cervical ganglia. Taken together, a Sema3A-initiated apoptotic signaling complex regulates the apoptosis of sympathetic neurons during the period of naturally occurring cell death. PMID:27143756

The role of the parenchyma sheath and PCD during the development of oil cavities in Pterodon pubescens (Leguminosae-Papilionoideae).

PubMed

Rodrigues, Tatiane Maria; Santos, Daniela Carvalho Dos; Machado, Silvia Rodrigues

2011-07-01

Pterodon pubescens cavities are constituted by lumen and uniseriated epithelium surrounded by multiseriate parenchyma sheath. We studied the development of secretory cavities, including the role of parenchyma sheath, using light and transmission electron microscopy. A Tunel assay was performed to verify whether programmed cell death (PCD) occurs during the process. The lumen is formed by schizogeny and lysigeny occur in later developmental stages of the secretory cavities. Ultrastructurally, epithelial cells in later developmental stages become dark and with sinuous walls; the protoplast becomes retracted and the cytoplasm shows low organelle definition. Degenerated cells are released toward the lumen. Our results showed that PCD occurs during later developmental stages of cavities and plays a critical role in functioning of these glands. New cells originated from the parenchyma sheath differentiate into secretory cells and replace those degenerated ones. This fact associated to PCD guarantees epithelium renovation during the secretory cycle and the maintenance of secretory activity of cavities. Copyright © 2011 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Requirements for efficient cell-type proportioning: regulatory timescales, stochasticity and lateral inhibition

NASA Astrophysics Data System (ADS)

Pfeuty, B.; Kaneko, K.

2016-04-01

The proper functioning of multicellular organisms requires the robust establishment of precise proportions between distinct cell types. This developmental differentiation process typically involves intracellular regulatory and stochastic mechanisms to generate cell-fate diversity as well as intercellular signaling mechanisms to coordinate cell-fate decisions at tissue level. We thus surmise that key insights about the developmental regulation of cell-type proportion can be captured by the modeling study of clustering dynamics in population of inhibitory-coupled noisy bistable systems. This general class of dynamical system is shown to exhibit a very stable two-cluster state, but also metastability, collective oscillations or noise-induced state hopping, which can prevent from timely and reliably reaching a robust and well-proportioned clustered state. To circumvent these obstacles or to avoid fine-tuning, we highlight a general strategy based on dual-time positive feedback loops, such as mediated through transcriptional versus epigenetic mechanisms, which improves proportion regulation by coordinating early and flexible lineage priming with late and firm commitment. This result sheds new light on the respective and cooperative roles of multiple regulatory feedback, stochasticity and lateral inhibition in developmental dynamics.

Integrating photonic crystals in thin film silicon photovoltaics

NASA Astrophysics Data System (ADS)

O'Brien, P. G.; Chutinan, A.; Ozin, G. A.; Kherani, N. P.; Zukotynski, S.

2010-06-01

Wave-optics analysis is performed to investigate the benefits of integrating photonic crystals into micromorph cells. Specifically, we theoretically investigate two novel micromorph cells which integrate photonic crystals and compare their optical performance with that of conventional micromorph cells. In the first innovative micromorph cell configuration the intermediate reflector is a selectively transparent and conducting photonic crystal (STCPC). In the second micromorph cell its bottom μc-Si:H cell is structured in the form of an inverted opal. Our results show that with the AM1.5 solar spectrum at normal incidence the current generated in a conventional micromorph cell is increased from 12.1 mA/cm2 to 13.0 mA/cm2 when the bottom μc-Si:H cell is structured in the form of an inverted opal. However, the current generated in the micromorph cell can be increased to as much as 13.7 mA/cm2 when an STCPC is utilized as the intermediate reflector. Furthermore, the thickness of the μc-Si:H opal must be relatively large in order to absorb a sufficient amount of the solar irradiance, which is expected to degrade the electrical performance of the device. In contrast, our results suggest that STCPC intermediate reflectors are a viable technology that could potentially enhance the performance of micromorph cells.

The never-ending story: from pluripotency to plant developmental plasticity

PubMed Central

Gaillochet, Christophe; Lohmann, Jan U.

2015-01-01

Plants are sessile organisms, some of which can live for over a thousand years. Unlike most animals, plants employ a post-embryonic mode of development driven by the continuous activity of pluripotent stem cells. Consequently, plants are able to initiate new organs over extended periods of time, and many species can readily replace lost body structures by de novo organogenesis. Classical studies have also shown that plant tissues have a remarkable capacity to undergo de-differentiation and proliferation in vitro, highlighting the fact that plant cell fate is highly plastic. This suggests that the mechanisms regulating fate transitions must be continuously active in most plant cells and that the control of cellular pluripotency lies at the core of diverse developmental programs. Here, we review how pluripotency is established in plant stem cell systems, how it is maintained during development and growth and re-initiated during regeneration, and how these mechanisms eventually contribute to the amazing developmental plasticity of plants. PMID:26130755

Nutrient-Dependent Endocycling in Steroidogenic Tissue Dictates Timing of Metamorphosis in Drosophila melanogaster

PubMed Central

Ohhara, Yuya; Kobayashi, Satoru

2017-01-01

Many animals have an intrinsic growth checkpoint during juvenile development, after which an irreversible decision is made to upregulate steroidogenesis, triggering the metamorphic juvenile-to-adult transition. However, a molecular process underlying such a critical developmental decision remains obscure. Here we show that nutrient-dependent endocycling in steroidogenic cells provides the machinery necessary for irreversible activation of metamorphosis in Drosophila melanogaster. Endocycle progression in cells of the prothoracic gland (PG) is tightly coupled with the growth checkpoint, and block of endocycle in PG cells causes larval developmental arrest due to reduction in biosynthesis of the steroid hormone ecdysone. Moreover, inhibition of the nutrient sensor target of rapamycin (TOR) in the PG during the checkpoint period causes endocycle inhibition and developmental arrest, which can be rescued by inducing additional rounds of endocycles by Cyclin E. We propose that a TOR-mediated cell cycle checkpoint in steroidogenic tissue provides a systemic growth checkpoint for reproductive maturation. PMID:28121986

Programmed cell senescence during mammalian embryonic development.

PubMed

Muñoz-Espín, Daniel; Cañamero, Marta; Maraver, Antonio; Gómez-López, Gonzalo; Contreras, Julio; Murillo-Cuesta, Silvia; Rodríguez-Baeza, Alfonso; Varela-Nieto, Isabel; Ruberte, Jesús; Collado, Manuel; Serrano, Manuel

2013-11-21

Cellular senescence disables proliferation in damaged cells, and it is relevant for cancer and aging. Here, we show that senescence occurs during mammalian embryonic development at multiple locations, including the mesonephros and the endolymphatic sac of the inner ear, which we have analyzed in detail. Mechanistically, senescence in both structures is strictly dependent on p21, but independent of DNA damage, p53, or other cell-cycle inhibitors, and it is regulated by the TGF-β/SMAD and PI3K/FOXO pathways. Developmentally programmed senescence is followed by macrophage infiltration, clearance of senescent cells, and tissue remodeling. Loss of senescence due to the absence of p21 is partially compensated by apoptosis but still results in detectable developmental abnormalities. Importantly, the mesonephros and endolymphatic sac of human embryos also show evidence of senescence. We conclude that the role of developmentally programmed senescence is to promote tissue remodeling and propose that this is the evolutionary origin of damage-induced senescence. Copyright © 2013 Elsevier Inc. All rights reserved.

Switching of the positive feedback for RAS activation by a concerted function of SOS membrane association domains.

PubMed

Nakamura, Yuki; Hibino, Kayo; Yanagida, Toshio; Sako, Yasushi

2016-01-01

Son of sevenless (SOS) is a guanine nucleotide exchange factor that regulates cell behavior by activating the small GTPase RAS. Recent in vitro studies have suggested that an interaction between SOS and the GTP-bound active form of RAS generates a positive feedback loop that propagates RAS activation. However, it remains unclear how the multiple domains of SOS contribute to the regulation of the feedback loop in living cells. Here, we observed single molecules of SOS in living cells to analyze the kinetics and dynamics of SOS behavior. The results indicate that the histone fold and Grb2-binding domains of SOS concertedly produce an intermediate state of SOS on the cell surface. The fraction of the intermediated state was reduced in positive feedback mutants, suggesting that the feedback loop functions during the intermediate state. Translocation of RAF, recognizing the active form of RAS, to the cell surface was almost abolished in the positive feedback mutants. Thus, the concerted functions of multiple membrane-associating domains of SOS governed the positive feedback loop, which is crucial for cell fate decision regulated by RAS.

Analysis of branched DNA replication and recombination intermediates from prokaryotic cells by two-dimensional (2D) native-native agarose gel electrophoresis.

PubMed

Robinson, Nicholas P

2013-01-01

Branched DNA molecules are generated by the essential processes of replication and recombination. Owing to their distinctive extended shapes, these intermediates migrate differently from linear double-stranded DNA under certain electrophoretic conditions. However, these branched species exist in the cell at much low abundance than the bulk linear DNA. Consequently, branched molecules cannot be visualized by conventional electrophoresis and ethidium bromide staining. Two-dimensional native-native agarose electrophoresis has therefore been developed as a method to facilitate the separation and visualization of branched replication and recombination intermediates. A wide variety of studies have employed this technique to examine branched molecules in eukaryotic, archaeal, and bacterial cells, providing valuable insights into how DNA is duplicated and repaired in all three domains of life.

WormGUIDES: an interactive single cell developmental atlas and tool for collaborative multidimensional data exploration.

PubMed

Santella, Anthony; Catena, Raúl; Kovacevic, Ismar; Shah, Pavak; Yu, Zidong; Marquina-Solis, Javier; Kumar, Abhishek; Wu, Yicong; Schaff, James; Colón-Ramos, Daniel; Shroff, Hari; Mohler, William A; Bao, Zhirong

2015-06-09

Imaging and image analysis advances are yielding increasingly complete and complicated records of cellular events in tissues and whole embryos. The ability to follow hundreds to thousands of cells at the individual level demands a spatio-temporal data infrastructure: tools to assemble and collate knowledge about development spatially in a manner analogous to geographic information systems (GIS). Just as GIS indexes items or events based on their spatio-temporal or 4D location on the Earth these tools would organize knowledge based on location within the tissues or embryos. Developmental processes are highly context-specific, but the complexity of the 4D environment in which they unfold is a barrier to assembling an understanding of any particular process from diverse sources of information. In the same way that GIS aids the understanding and use of geo-located large data sets, software can, with a proper frame of reference, allow large biological data sets to be understood spatially. Intuitive tools are needed to navigate the spatial structure of complex tissue, collate large data sets and existing knowledge with this spatial structure and help users derive hypotheses about developmental mechanisms. Toward this goal we have developed WormGUIDES, a mobile application that presents a 4D developmental atlas for Caenorhabditis elegans. The WormGUIDES mobile app enables users to navigate a 3D model depicting the nuclear positions of all cells in the developing embryo. The identity of each cell can be queried with a tap, and community databases searched for available information about that cell. Information about ancestry, fate and gene expression can be used to label cells and craft customized visualizations that highlight cells as potential players in an event of interest. Scenes are easily saved, shared and published to other WormGUIDES users. The mobile app is available for Android and iOS platforms. WormGUIDES provides an important tool for examining developmental processes and developing mechanistic hypotheses about their control. Critically, it provides the typical end user with an intuitive interface for developing and sharing custom visualizations of developmental processes. Equally important, because users can select cells based on their position and search for information about them, the app also serves as a spatially organized index into the large body of knowledge available to the C. elegans community online. Moreover, the app can be used to create and publish the result of exploration: interactive content that brings other researchers and students directly to the spatio-temporal point of insight. Ultimately the app will incorporate a detailed time lapse record of cell shape, beginning with neurons. This will add the key ability to navigate and understand the developmental events that result in the coordinated and precise emergence of anatomy, particularly the wiring of the nervous system.

The Texas-Indiana Virtual STAR Center: Zebrafish Models for Developmental Toxicity Screening

EPA Pesticide Factsheets

The Texas-Indiana Virtual STAR Center: Zebrafish Models for Developmental Toxicity Screening (Presented by Maria Bondesson Bolin, Ph.D, University of Houston, Center for Nuclear Receptors and Cell Signaling) (3/22/2012)

Acrylamide affects proliferation and differentiation of the neural progenitor cell line C17.2 and the neuroblastoma cell line SH-SY5Y.

PubMed

Attoff, K; Kertika, D; Lundqvist, J; Oredsson, S; Forsby, A

2016-09-01

Acrylamide is a well-known neurotoxic compound and people get exposed to the compound by food consumption and environmental pollutants. Since acrylamide crosses the placenta barrier, the fetus is also being exposed resulting in a risk for developmental neurotoxicity. In this study, the neural progenitor cell line C17.2 and the neuroblastoma cell line SH-SY5Y were used to study proliferation and differentiation as alerting indicators for developmental neurotoxicity. For both cell lines, acrylamide reduced the number of viable cells by reducing proliferation and inducing cell death in undifferentiated cells. Acrylamide concentrations starting at 10fM attenuated the differentiation process in SH-SY5Y cells by sustaining cell proliferation and neurite outgrowth was reduced at concentrations from 10pM. Acrylamide significantly reduced the number of neurons starting at 1μM and altered the ratio between the different phenotypes in differentiating C17.2 cell cultures. Ten micromolar of acrylamide also reduced the expression of the neuronal and astrocyte biomarkers. Although the neurotoxic concentrations in the femtomolar range seem to be specific for the SH-SY5Y cell line, the fact that micromolar concentrations of acrylamide seem to attenuate the differentiation process in both cell lines raises the interest to further investigations on the possible developmental neurotoxicity of acrylamide. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

An intermediate level of BMP signaling directly specifies cranial neural crest progenitor cells in zebrafish.

PubMed

Schumacher, Jennifer A; Hashiguchi, Megumi; Nguyen, Vu H; Mullins, Mary C

2011-01-01

The specification of the neural crest progenitor cell (NCPC) population in the early vertebrate embryo requires an elaborate network of signaling pathways, one of which is the Bone Morphogenetic Protein (BMP) pathway. Based on alterations in neural crest gene expression in zebrafish BMP pathway component mutants, we previously proposed a model in which the gastrula BMP morphogen gradient establishes an intermediate level of BMP activity establishing the future NCPC domain. Here, we tested this model and show that an intermediate level of BMP signaling acts directly to specify the NCPC. We quantified the effects of reducing BMP signaling on the number of neural crest cells and show that neural crest cells are significantly increased when BMP signaling is reduced and that this increase is not due to an increase in cell proliferation. In contrast, when BMP signaling is eliminated, NCPC fail to be specified. We modulated BMP signaling levels in BMP pathway mutants with expanded or no NCPCs to demonstrate that an intermediate level of BMP signaling specifies the NCPC. We further investigated the ability of Smad5 to act in a graded fashion by injecting smad5 antisense morpholinos and show that increasing doses first expand the NCPCs and then cause a loss of NCPCs, consistent with Smad5 acting directly in neural crest progenitor specification. Using Western blot analysis, we show that P-Smad5 levels are dose-dependently reduced in smad5 morphants, consistent with an intermediate level of BMP signaling acting through Smad5 to specify the neural crest progenitors. Finally, we performed chimeric analysis to demonstrate for the first time that BMP signal reception is required directly by NCPCs for their specification. Together these results add substantial evidence to a model in which graded BMP signaling acts as a morphogen to pattern the ectoderm, with an intermediate level acting in neural crest specification.

Mutational Analysis of Cell Types in TSC

DTIC Science & Technology

2008-01-01

disability, and autism . TSC1/TSC2 gene mutations lead to developmental alterations in brain structure known as tubers in over 80% of TSC patients. Loss of...that is associated with epilepsy, cognitive disability, and autism . TSC1/TSC2 gene mutations lead to developmental alterations in brain structure...2000). Comorbid neuropsychological disorders such as autism , mental retardation (MR), pervasive developmental disorder, attention deficit disorder (ADD

Taurine protects methamphetamine-induced developmental angiogenesis defect through antioxidant mechanism

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

Shao, Xue; Hu, Zhengtao; Hu, Chunyan

Investigations have characterized addictive drug-induced developmental cardiovascular malformation in human, non-human primate and rodent. However, the underlying mechanism of malformation caused by drugs during pregnancy is still largely unknown, and preventive and therapeutic measures have been lacking. Using {sup 1}H NMR spectroscopy, we profiled the metabolites from human embryo endothelial cells exposed to methamphetamine (METH) and quantified a total of 226 peaks. We identified 11 metabolites modified robustly and found that taurine markedly increased. We then validated the hypothesis that this dramatic increase in taurine could attribute to its effect in inhibiting METH-induced developmental angiogenesis defect. Taurine supplement showed amore » more significant potential than other metabolites in protecting against METH-induced injury in endothelial cells. Taurine strongly attenuated METH-induced inhibition of proliferation and migration in endothelial cells. Furthermore, death rate and vessel abnormality of zebrafish embryos treated with METH were greatly reversed by taurine. In addition, taurine supplement caused a rapid decrease in reactive oxygen species generation and strongly attenuated the excitable arise of antioxidase activities in the beginning of METH exposure prophase. Dysregulations of NF-κB, p-ERK as well as Bax, which reflect apoptosis, cell cycle arrest and oxidative stress in vascular endothelium, were blocked by taurine. Our results provide the first evidence that taurine prevents METH-caused developmental angiogenesis defect through antioxidant mechanism. Taurine could serve as a potential therapeutic or preventive intervention of developmental vascular malformation for the pregnant women with drug use. Highlights: ► Metabonomics findings. ► Abnormal development. ► Dysregulations of key proteins.« less

Ultrastructural evidence of the ehrlichial developmental cycle in naturally infected Ixodes persulcatus ticks in the course of coinfection with Rickettsia, Borrelia, and a flavivirus.

PubMed

Popov, Vsevolod L; Korenberg, Edward I; Nefedova, Valentina V; Han, Violet C; Wen, Julie W; Kovalevskii, Yurii V; Gorelova, Natalia B; Walker, David H

2007-01-01

Ehrlichiae are small gram-negative obligately intracellular bacteria that multiply within vacuoles of their host cells and are associated for a part of their life cycle with ticks, which serve as vectors for vertebrate hosts. Two morphologically and physiologically different ehrlichial cell types, reticulate cells (RC) and dense-cored cells (DC), are observed during experimental infection of cell cultures, mice, and ticks. Dense-cored cells and reticulate cells in vertebrate cell lines alternate in a developmental cycle. We observed ultrastructure of RC and DC of Ehrlichia muris in morulae in salivary gland cells and coinfection with Borrelia burgdorferi sensu lato (sl), "Candidatus Rickettsia tarasevichiae," and a flavivirus (presumably, tick-borne encephalitis virus [TBEV]) of Ixodes persulcatusticks collected in the Cis-Ural region of Russia. Polymerase chain reaction revealed 326 (81.5%) of 400 ticks carrying at least one infectious agent, and 41.5% (166 ticks) were coinfected with two to four agents. Ehrlichiae and rickettsiae were identified by sequencing of 359 bp of the 16S rRNA gene of E. muris and of 440 bp of the 16S rRNA gene and 385 bp of the gltA gene of "R. tarasevichiae." Different organs of the same tick harbored different microorganisms: TBEV in salivary gland and borreliae in midgut; E. muris in salivary gland; and "R. tarasevichiae" in midgut epithelium. Salivary gland cells contained both RC and DC, a finding that confirmed the developmental cycle in naturally infected ticks. Dense-cored cells in tick salivary glands were denser and of more irregular shape than DC in cell cultures. Ehrlichia-infected salivary gland cells had lysed cytoplasm, suggesting pathogenicity of E. muris for the tick host at the cellular level, as well as potential transmission during feeding. Rickettsiae in the midgut epithelial cells multiplied to significant numbers without altering the host cell ultrastructure. This is the first demonstration of E. muris, "R. tarasevichiae," and the ehrlichial developmental cycle in naturally infected I. persulcatus sticks.

Robust and irreversible development in cell society as a general consequence of intra-inter dynamics

NASA Astrophysics Data System (ADS)

Kaneko, Kunihiko; Furusawa, Chikara

2000-05-01

A dynamical systems scenario for developmental cell biology is proposed, based on numerical studies of a system with interacting units with internal dynamics and reproduction. Diversification, formation of discrete and recursive types, and rules for differentiation are found as a natural consequence of such a system. “Stem cells” that either proliferate or differentiate to different types stochastically are found to appear when intra-cellular dynamics are chaotic. Robustness of the developmental process against microscopic and macroscopic perturbations is shown to be a natural consequence of such intra-inter dynamics, while irreversibility in developmental process is discussed in terms of the gain of stability, loss of diversity and chaotic instability.

Alternation in the gap-junctional intercellular communication capacity during the maturation of osteocytes in the embryonic chick calvaria.

PubMed

Wang, Ziyi; Odagaki, Naoya; Tanaka, Tomoyo; Hashimoto, Mana; Nakamura, Masahiro; Hayano, Satoru; Ishihara, Yoshihito; Kawanabe, Noriaki; Kamioka, Hiroshi

2016-10-01

The intercellular network of cell-cell communication among osteocytes is mediated by gap junctions. Gap junctional intercellular communication (GJIC) is thought to play an important role in the integration and synchronization of bone remodeling. To further understand the mechanism of bone development it is important to quantify the difference in the GJIC capacity of young and developmentally mature osteocytes. We first established an embryonic chick calvaria growth model to show the growth of the calvaria in embryos at 13 to 21days of age. We then applied a fluorescence recovery after photobleaching (FRAP) technique to compare the difference in the GJIC capacity of young osteocytes with that of developmentally mature osteocytes. Finally, we quantified the dye (Calcein) diffusion from the FRAP data using a mathematic model of simple diffusion which was also used to identify simple diffusion GJIC pattern cells (fitted model) and accelerated diffusion GJIC pattern cells (non-fitted model). The relationship between the longest medial-lateral length of the calvaria (frontal bone) and the embryonic age fit a logarithmic growth model: length=5.144×ln(day)-11.340. The morphometric data during osteocyte differentiation showed that the cellular body becomes more spindle-shaped and that the cell body volume decreased by approximately 22% with an increase in the length of the processes between the cells. However, there were no significant differences in the cellular body surface area or in the distance between the mass centres of the cells. The dye-displacement rate in young osteocytes was significantly higher than that in developmentally mature osteocytes: dye displacement only occurred in 26.88% of the developmentally mature osteocytes, while it occurred in 64.38% of the young osteocytes. Additionally, in all recovered osteocytes, 36% of the developmentally mature osteocytes comprised non-fitted model cells while 53.19% of the young osteocytes were the non-fitted model, which indicates the active transduction of dye molecules. However, there were no statistically significant differences between the young and developmentally mature osteocytes with regard to the diffusion coefficient, permeability coefficient, or permeance of the osteocyte processes, which were 3.93±3.77 (×10(-8)cm(2)/s), 5.12±4.56 (×10(-5)cm(2)/s) and 2.99±2.47 (×10(-13)cm(2)/s) (mean±SD), respectively. These experiments comprehensively quantified the GJIC capacity in the embryonic chick calvaria and indicated that the cell-cell communication capacity of the osteocytes in the embryonic chick calvaria was related to their development. Copyright © 2016 Elsevier Inc. All rights reserved.

Longitudinal and Integrative Tests of Family Stress Model Effects on Mexican-Origin Adolescents

PubMed Central

White, Rebecca M. B.; Liu, Yu; Nair, Rajni L.; Tein, Jenn-Yun

2015-01-01

The family stress model represents a common framework through which to examine the effects of environmental stressors on adolescent adjustment. The model suggests that economic and neighborhood stressors influence youth adjustment via disruptions to parenting. Incorporating integrative developmental theory, we examined the degree to which parents’ cultural value orientations mitigated the effects of stressors on parenting disruptions and the degree to which environmental adversity qualified the effect of parenting on adolescent adjustment. We tested the hypothesized Integrative Family Stress Model longitudinally in a sample of mother-youth dyads (N = 749) and father-youth dyads (N = 467) from Mexican origin families, across three times points spanning early to middle adolescence. Providing the first longitudinal evidence of family stress mediated effects, mothers’ perceptions of economic pressure were associated with increases in adolescent externalizing symptoms five years later via intermediate increases in harsh parenting. The remaining findings supported the notion that integrative developmental theory can inform family stress model hypothesis testing that is culturally and contextually relevant for wide range of diverse families and youth. For example, fathers’ perceptions of economic pressure and neighborhood danger had important implications for adolescent internalizing, via reductions in paternal warmth, but only at certain levels of neighborhood adversity. Mothers’ familism value orientations mitigated the effects of economic pressure on maternal warmth, protecting their adolescents from experiencing developmental costs associated with environmental stressors. Results are discussed in terms of identifying how integrative developmental theory intersects with the family stress model to set diverse youth on different developmental pathways. PMID:25751100

Longitudinal and integrative tests of family stress model effects on Mexican origin adolescents.

PubMed

White, Rebecca M B; Liu, Yu; Nair, Rajni L; Tein, Jenn-Yun

2015-05-01

The family stress model represents a common framework through which to examine the effects of environmental stressors on adolescent adjustment. The model suggests that economic and neighborhood stressors influence youth adjustment via disruptions to parenting. Incorporating integrative developmental theory, we examined the degree to which parents' cultural value orientations mitigated the effects of stressors on parenting disruptions and the degree to which environmental adversity qualified the effect of parenting on adolescent adjustment. We tested the hypothesized integrative family stress model longitudinally in a sample of mother-youth dyads (N = 749) and father-youth dyads (N = 467) from Mexican origin families, across 3 times points spanning early to middle adolescence. Providing the first longitudinal evidence of family stress mediated effects, mothers' perceptions of economic pressure were associated with increases in adolescent externalizing symptoms 5 years later via intermediate increases in harsh parenting. The remaining findings supported the notion that integrative developmental theory can inform family stress model hypothesis testing that is culturally and contextually relevant for a wide range of diverse families and youth. For example, fathers' perceptions of economic pressure and neighborhood danger had important implications for adolescent internalizing, via reductions in paternal warmth, but only at certain levels of neighborhood adversity. Mothers' familism value orientations mitigated the effects of economic pressure on maternal warmth, protecting their adolescents from experiencing developmental costs associated with environmental stressors. Results are discussed in terms of identifying how integrative developmental theory intersects with the family stress model to set diverse youth on different developmental pathways. (c) 2015 APA, all rights reserved).

Effects of computerized match-to-sample training on emergent fraction-decimal relations in individuals with fragile X syndrome.

PubMed

Hammond, Jennifer L; Hirt, Melissa; Hall, Scott S

2012-01-01

Individuals diagnosed with fragile X syndrome (FXS), the most common known form of inherited intellectual disability, are reported to exhibit considerable deficits in mathematical skills that are often attributed to brain-based abnormalities associated with the syndrome. We examined whether participants with FXS would display emergent fraction-decimal relations following brief, intensive match-to-sample training on baseline relations. The performance profiles on tests of symmetry and transitivity/equivalence of 11 participants with FXS, aged 10-23 years, following baseline match-to-sample training were compared to those of 11 age- and IQ-matched controls with idiopathic developmental disability. The results showed that both groups of participants showed significant improvements in the baseline (trained) relations, as expected. However, participants with FXS failed to show significant improvements in the (untrained) symmetry and transitivity/equivalence relations compared to those in the control group. A categorical analysis of the data indicated that five participants with FXS and eight controls showed at least "intermediate" emergence of symmetry relations, whereas one individual with FXS and three controls showed at least intermediate emergence of transitivity/equivalence relations. A correlation analysis of the data indicated that improvements in the symmetry relations were significantly associated with improvements in the transitivity/equivalence relations in the control group (r=.69, p=.018), but this was not the case in the FXS group (r=.34, p>.05). Participant IQ was significantly associated with improvements in the symmetry relations in individuals with FXS (r=.60, p=.049), but not in controls (r=.21, p>.05). Taken together, these results suggest that brief, computerized match-to-sample training may produce emergent mathematical relations for a subset of children with FXS and developmental disabilities. However, the ability of individuals with FXS to form transitivity/equivalence relations may be impaired relative to those with idiopathic developmental disabilities, which may be attributed to neurodevelopmental variables associated with the syndrome. Copyright © 2011 Elsevier Ltd. All rights reserved.

Predicting human developmental toxicity of pharmaceuticals using human embryonic stem cells and metabolomics

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

West, Paul R., E-mail: pwest@stemina.co; Weir, April M.; Smith, Alan M.

2010-08-15

Teratogens, substances that may cause fetal abnormalities during development, are responsible for a significant number of birth defects. Animal models used to predict teratogenicity often do not faithfully correlate to human response. Here, we seek to develop a more predictive developmental toxicity model based on an in vitro method that utilizes both human embryonic stem (hES) cells and metabolomics to discover biomarkers of developmental toxicity. We developed a method where hES cells were dosed with several drugs of known teratogenicity then LC-MS analysis was performed to measure changes in abundance levels of small molecules in response to drug dosing. Statisticalmore » analysis was employed to select for specific mass features that can provide a prediction of the developmental toxicity of a substance. These molecules can serve as biomarkers of developmental toxicity, leading to better prediction of teratogenicity. In particular, our work shows a correlation between teratogenicity and changes of greater than 10% in the ratio of arginine to asymmetric dimethylarginine levels. In addition, this study resulted in the establishment of a predictive model based on the most informative mass features. This model was subsequently tested for its predictive accuracy in two blinded studies using eight drugs of known teratogenicity, where it correctly predicted the teratogenicity for seven of the eight drugs. Thus, our initial data shows that this platform is a robust alternative to animal and other in vitro models for the prediction of the developmental toxicity of chemicals that may also provide invaluable information about the underlying biochemical pathways.« less

Cerebellum: links between development, developmental disorders and motor learning

PubMed Central

Manto, Mario U.; Jissendi, Patrice

2012-01-01

The study of the links and interactions between development and motor learning has noticeable implications for the understanding and management of neurodevelopmental disorders. This is particularly relevant for the cerebellum which is critical for sensorimotor learning. The olivocerebellar pathway is a key pathway contributing to learning of motor skills. Its developmental maturation and remodeling are being unraveled. Advances in genetics have led to major improvements in our appraisal of the genes involved in cerebellar development, especially studies in mutant mice. Cerebellar neurogenesis is compartmentalized in relationship with neurotransmitter fate. The Engrailed-2 gene is a major actor of the specification of cerebellar cell types and late embryogenic morphogenesis. Math1, expressed by the rhombic lip, is required for the genesis of glutamatergic neurons. Mutants deficient for the transcription factor Ptf1a display a lack of Purkinje cells and gabaergic interneurons. Rora gene contributes to the developmental signaling between granule cells and Purkinje neurons. The expression profile of sonic hedgehog in postnatal stages determines the final size/shape of the cerebellum. Genes affecting the development impact upon the physiological properties of the cerebellar circuits. For instance, receptors are developmentally regulated and their action interferes directly with developmental processes. Another field of research which is expanding relates to very preterm neonates. They are at risk for cerebellar lesions, which may themselves impair the developmental events. Very preterm neonates often show sensori-motor deficits, highlighting another major link between impaired developments and learning deficiencies. Pathways playing a critical role in cerebellar development are likely to become therapeutical targets for several neurodevelopmental disorders. PMID:22291620

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

Epigenomic Landscape of Human Fetal Brain, Heart, and Liver.

PubMed

Yan, Liying; Guo, Hongshan; Hu, Boqiang; Li, Rong; Yong, Jun; Zhao, Yangyu; Zhi, Xu; Fan, Xiaoying; Guo, Fan; Wang, Xiaoye; Wang, Wei; Wei, Yuan; Wang, Yan; Wen, Lu; Qiao, Jie; Tang, Fuchou

2016-02-26

The epigenetic regulation of spatiotemporal gene expression is crucial for human development. Here, we present whole-genome chromatin immunoprecipitation followed by high throughput DNA sequencing (ChIP-seq) analyses of a wide variety of histone markers in the brain, heart, and liver of early human embryos shortly after their formation. We identified 40,181 active enhancers, with a large portion showing tissue-specific and developmental stage-specific patterns, pointing to their roles in controlling the ordered spatiotemporal expression of the developmental genes in early human embryos. Moreover, using sequential ChIP-seq, we showed that all three organs have hundreds to thousands of bivalent domains that are marked by both H3K4me3 and H3K27me3, probably to keep the progenitor cells in these organs ready for immediate differentiation into diverse cell types during subsequent developmental processes. Our work illustrates the potentially critical roles of tissue-specific and developmental stage-specific epigenomes in regulating the spatiotemporal expression of developmental genes during early human embryonic development. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Individual blastomeres of 16- and 32-cell mouse embryos are able to develop into foetuses and mice.

PubMed

Tarkowski, Andrzej K; Suwińska, Aneta; Czołowska, Renata; Ożdżeński, Wacław

2010-12-15

Cell and developmental studies have clarified how, by the time of implantation, the mouse embryo forms three primary cell lineages: epiblast (EPI), primitive endoderm (PE), and trophectoderm (TE). However, it still remains unknown when cells allocated to these three lineages become determined in their developmental fate. To address this question, we studied the developmental potential of single blastomeres derived from 16- and 32-cell stage embryos and supported by carrier, tetraploid blastomeres. We were able to generate singletons, identical twins, triplets, and quadruplets from individual inner and outer cells of 16-cell embryos and, sporadically, foetuses from single cells of 32-cell embryos. The use of embryos constitutively expressing GFP as the donors of single diploid blastomeres enabled us to identify their cell progeny in the constructed 2n↔4n blastocysts. We showed that the descendants of donor blastomeres were able to locate themselves in all three first cell lineages, i.e., epiblast, primitive endoderm, and trophectoderm. In addition, the application of Cdx2 and Gata4 markers for trophectoderm and primitive endoderm, respectively, showed that the expression of these two genes in the descendants of donor blastomeres was either down- or up-regulated, depending on the cell lineage they happened to occupy. Thus, our results demonstrate that up to the early blastocysts stage, the destiny of at least some blastomeres, although they have begun to express markers of different lineage, is still labile. Copyright © 2010 Elsevier Inc. All rights reserved.

Modeling Glaucoma: Retinal Ganglion Cells Generated from Induced Pluripotent Stem Cells of Patients with SIX6 Risk Allele Show Developmental Abnormalities.

PubMed

Teotia, Pooja; Van Hook, Matthew J; Wichman, Christopher S; Allingham, R Rand; Hauser, Michael A; Ahmad, Iqbal

2017-11-01

Glaucoma represents a group of multifactorial diseases with a unifying pathology of progressive retinal ganglion cell (RGC) degeneration, causing irreversible vision loss. To test the hypothesis that RGCs are intrinsically vulnerable in glaucoma, we have developed an in vitro model using the SIX6 risk allele carrying glaucoma patient-specific induced pluripotent stem cells (iPSCs) for generating functional RGCs. Here, we demonstrate that the efficiency of RGC generation by SIX6 risk allele iPSCs is significantly lower than iPSCs-derived from healthy, age- and sex-matched controls. The decrease in the number of RGC generation is accompanied by repressed developmental expression of RGC regulatory genes. The SIX6 risk allele RGCs display short and simple neurites, reduced expression of guidance molecules, and immature electrophysiological signature. In addition, these cells have higher expression of glaucoma-associated genes, CDKN2A and CDKN2B, suggesting an early onset of the disease phenotype. Consistent with the developmental abnormalities, the SIX6 risk allele RGCs display global dysregulation of genes which map on developmentally relevant biological processes for RGC differentiation and signaling pathways such as mammalian target of rapamycin that integrate diverse functions for differentiation, metabolism, and survival. The results suggest that SIX6 influences different stages of RGC differentiation and their survival; therefore, alteration in SIX6 function due to the risk allele may lead to cellular and molecular abnormalities. These abnormalities, if carried into adulthood, may make RGCs vulnerable in glaucoma. Stem Cells 2017;35:2239-2252. © 2017 AlphaMed Press.

In vitro studies of cellular and molecular developmental toxicity of adjuvants, herbicides, and fungicides commonly used in Red River Valley, Minnesota.

PubMed

Lin, N; Garry, V F

2000-07-28

Recent epidemiologic studies showed increased frequency of birth defects in pesticide applicators and general population of the Red River Valley, Minnesota. These studies further indicated that this crop growing area used more chlorophenoxy herbicides and fungicides than elsewhere in Minnesota. Based on frequency of use and known biology, certain herbicides, pesticide additives, fungicides, and mycotoxins are suspect agents. To define whether these agents affect developmental endpoints in vitro, 16 selected agrochemicals were examined using the MCF-7 breast cancer cell line. In the flow cytometric assay, cell proliferation in this estrogen-responsive cell line indicates xenobiotic-mediated estrogenic effects. Cell viability, morphology, ploidy, and apoptosis were incorporated in this assay. Data showed that the adjuvants X-77 and Activate Plus induced significant cell proliferation at 0.1 and 1 microg/ml. The commercial-grade herbicides 2,4-D LV4 and 2,4-D amine induced cell proliferation at 1 and 10 microg/ml. The reagent-grade 2,4-D products failed to induce proliferation over the same concentration range, suggesting that other ingredients in the commercial products, presumably adjuvants, could be a factor in these results. The fungicides triphenyltin and mancozeb induced apoptosis at concentrations of 4.1 microg/ml (10(-5) M) and 50 microg/ml, respectively. Triphenyltin also induced aneuploidy (C2/M arrest) at 0.41 microg/ml (10(-6) M). Data provide a mechanistic step to understanding human reproductive and developmental effects in populations exposed to these agrochemicals, and initiative to focusing limited resources for future in vivo animal developmental toxicity studies.

A SYSTEMS BIOLOGY APPROACH TO DEVELOPMENTAL TOXICOLOGY

EPA Science Inventory

Abstract
Recent advances in developmental biology have yielded detailed models of gene regulatory networks (GRNs) involved in cell specification and other processes in embryonic differentiation. Such networks form the bedrock on which a systems biology approach to developme...

Light-regulated leaf expansion in two Populus species: dependence on developmentally controlled ion transport.

PubMed

Stiles, Kari A; Van Volkenburgh, Elizabeth

2002-07-01

Leaf growth responses to light have been compared in two species of Populus, P. deltoides and P. trichocarpa. These species differ markedly in morphology, anatomy, and dependence on light during leaf expansion. Light stimulates the growth rate and acidification of cell walls in P. trichocarpa but not in P. deltoides, whereas leaves of P. deltoides maintain growth in the dark. Light-induced growth is promoted in P. deltoides when cells are provided 50-100 mM KCl. In both species, light initially depolarizes, then hyperpolarizes mesophyll plasma membranes. However, in the dark, the resting E(m) of mesophyll cells in P. deltoides, but not in P. trichocarpa, is relatively insensitive to decade changes in external [K+]. Results suggest that light-stimulated leaf growth depends on developmentally regulated cellular mechanisms controlling ion fluxes across the plasma membrane. These developmental differences underlie species-level differences in growth and physiological responses to the photoenvironment.

Polarized Light Microscopy in Reproductive and Developmental Biology

PubMed Central

KOIKE-TANI, MAKI; TANI, TOMOMI; MEHTA, SHALIN B.; VERMA, AMITABH; OLDENBOURG, RUDOLF

2016-01-01

SUMMARY The polarized light microscope reveals orientational order in native molecular structures inside living cells, tissues, and whole organisms. It is a powerful tool used to monitor and analyze the early developmental stages of organisms that lend themselves to microscopic observations. In this article, we briefly discuss the components specific to a traditional polarizing microscope and some historically important observations on: chromosome packing in the sperm head, the first zygote division of the sea urchin, and differentiation initiated by the first asymmetric cell division in the sand dollar. We then introduce the LC-PolScope and describe its use for measuring birefringence and polarized fluorescence in living cells and tissues. Applications range from the enucleation of mouse oocytes to analyzing the polarized fluorescence of the water strider acrosome. We end with new results on the birefringence of the developing chick brain, which we analyzed between developmental stages of days 12–20. PMID:23901032

Identification of chemicals inducing cardiomyocyte proliferation in developmental stage-specific manner with pluripotent stem cells.

PubMed

Uosaki, Hideki; Magadum, Ajit; Seo, Kinya; Fukushima, Hiroyuki; Takeuchi, Ayako; Nakagawa, Yasuaki; Moyes, Kara White; Narazaki, Genta; Kuwahara, Koichiro; Laflamme, Michael; Matsuoka, Satoshi; Nakatsuji, Norio; Nakao, Kazuwa; Kwon, Chulan; Kass, David A; Engel, Felix B; Yamashita, Jun K

2013-12-01

The proliferation of cardiomyocytes is highly restricted after postnatal maturation, limiting heart regeneration. Elucidation of the regulatory machineries for the proliferation and growth arrest of cardiomyocytes is imperative. Chemical biology is efficient to dissect molecular mechanisms of various cellular events and often provides therapeutic potentials. We have been investigating cardiovascular differentiation with pluripotent stem cells. The combination of stem cell and chemical biology can provide novel approaches to investigate the molecular mechanisms and manipulation of cardiomyocyte proliferation. To identify chemicals that regulate cardiomyocyte proliferation, we performed a screening of a defined chemical library based on proliferation of mouse pluripotent stem cell-derived cardiomyocytes and identified 4 chemical compound groups: inhibitors of glycogen synthase kinase-3, p38 mitogen-activated protein kinase, and Ca(2+)/calmodulin-dependent protein kinase II, and activators of extracellular signal-regulated kinase. Several appropriate combinations of chemicals synergistically enhanced proliferation of cardiomyocytes derived from both mouse and human pluripotent stem cells, notably up to a 14-fold increase in mouse cardiomyocytes. We also examined the effects of identified chemicals on cardiomyocytes in various developmental stages and species. Whereas extracellular signal-regulated kinase activators and Ca(2+)/calmodulin-dependent protein kinase II inhibitors showed proliferative effects only on cardiomyocytes in early developmental stages, glycogen synthase kinase-3 and p38 mitogen-activated protein kinase inhibitors substantially and synergistically induced re-entry and progression of cell cycle in neonatal but also as well as adult cardiomyocytes. Our approach successfully uncovered novel molecular targets and mechanisms controlling cardiomyocyte proliferation in distinct developmental stages and offered pluripotent stem cell-derived cardiomyocytes as a potent tool to explore chemical-based cardiac regenerative strategies.

A Model of Evolution of Development Based on Germline Penetration of New “No-Junk” DNA

PubMed Central

Fontana, Alessandro; Wróbel, Borys

2012-01-01

There is a mounting body of evidence that somatic transposition may be involved in normal development of multicellular organisms and in pathology, especially cancer. Epigenetic Tracking (ET) is an abstract model of multicellular development, able to generate complex 3-dimensional structures. Its aim is not to model the development of a particular organism nor to merely summarise mainstream knowledge on genetic regulation of development. Rather, the goal of ET is to provide a theoretical framework to test new postulated genetic mechanisms, not fully established yet in mainstream biology. The first proposal is that development is orchestrated through a subset of cells which we call driver cells. In these cells, the cellular state determines a specific pattern of gene activation which leads to the occurrence of developmental events. The second proposal is that evolution of development is affected by somatic transposition events. We postulate that when the genome of a driver cell does not specify what developmental event should be undertaken when the cell is in a particular cellular state, somatic transposition events can reshape the genome, build new regulatory regions, and lead to a new pattern of gene activation in the cell. Our third hypothesis, not supported yet by direct evidence, but consistent with some experimental observations, is that these new “no-junk” sequences—regulatory regions created by transposable elements at new positions in the genome—can exit the cell and enter the germline, to be incorporated in the genome of the progeny. We call this mechanism germline penetration. This process allows heritable incorporation of novel developmental events in the developmental trajectory. In this paper we will present the model and link these three postulated mechanisms to biological observations. PMID:24704981

Developmental expression of Toll‑like receptors in the guinea pig lung.

PubMed

Ma, Lingjie; Yang, Jiali; Yang, Li; Shi, Juan; Xue, Jing; Li, Yong; Liu, Xiaoming

2017-03-01

The guinea pig is a useful model for investigating infectious and non‑infectious lung diseases due to the sensitivity of its respiratory system and susceptibility to infectious agents. Toll‑like receptors (TLRs) are important components of the innate immune response and are critical for lung immune function. In the present study, the differentiation of epithelial cells in the guinea pig lung was examined during gestation by studying anatomic morphology and the major epithelial cell types using cell type‑specific markers. The developmental expression of all 9 TLRs and the TLR signaling adaptors myeloid differentiation factor 88 (MyD88) and tumor necrosis factor receptor associated factor 6 (TRAF‑6) were investigated by reverse transcription‑quantitative polymerase chain reaction and western blotting analysis. The formation of lung lobes in guinea pigs was observed at 45 days of gestation (dGA), along with the expression of the basal cell marker keratin 14 and the alveolar type II cell marker pro‑surfactant protein. However, the cube cell marker secretoglobin family1A member 1 and ciliated cell marker b‑tubulin IV were only detected in the lungs from 52 dGA onward. The expression levels of all TLRs, MyD88 and TRAF‑6 were determined in lung tissues harvested from embryos, newborn, postnatal and adult animals. The expression levels of all TLR signaling components displayed similar dynamic expression patterns with gestation age and postnatal maturation time, except for TLR‑4 and TLR‑7. mRNA expression levels of TLR components were significantly increased in the lungs at 45 and 52 dGA, compared with later developmental stages. These results suggest that TLR expression in the guinea pig lung is developmentally regulated, enhancing the understanding of lung biology in guinea pig models.

Growth dynamics and cytoskeleton organization during stem maturation and gravity-induced stem bending in Zea mays L

NASA Technical Reports Server (NTRS)

Collings, D. A.; Winter, H.; Wyatt, S. E.; Allen, N. S.; Davies, E. (Principal Investigator)

1998-01-01

Characterization of gravitropic bending in the maize stem pulvinus, a tissue that functions specifically in gravity responses, demonstrates that the pulvinus is an ideal system for studying gravitropism. Gravistimulation during the second of three developmental phases of the pulvinus induces a gradient of cell elongation across the non-growing cells of the pulvinus, with the most elongation occurring on the lower side. This cell elongation is spatially and temporally separated from normal internodal cell elongation. The three characterized growth phases in the pulvinus correspond closely to a specialized developmental sequence in which structural features typical of cells not fully matured are retained while cell maturation occurs in surrounding internodal and nodal tissue. For example, the lignification of supporting tissue and rearrangement of transverse microtubules to oblique that occur in the internode when cell elongation ceases are delayed for up to 10 d in the adjacent cells of the pulvinus, and only occurs as a pulvinus loses its capacity to respond to gravistimulation. Gravistimulation does not modify this developmental sequence. Neither wall lignification nor rearrangement of transverse microtubules occurs in the rapidly elongating lower side or non-responsive upper side of the pulvinus until the pulvinus loses the capacity to bend further. Gravistimulation does, however, lead to the formation of putative pit fields within the expanding cells of the pulvinus.

Fitness variation in response to artificial selection for reduced cell area, cell number and wing area in natural populations of Drosophila melanogaster.

PubMed

Trotta, Vincenzo; Calboli, Federico C F; Ziosi, Marcello; Cavicchi, Sandro

2007-08-16

Genetically based body size differences are naturally occurring in populations of Drosophila melanogaster, with bigger flies in the cold. Despite the cosmopolitan nature of body size clines in more than one Drosophila species, the actual selective mechanisms controlling the genetic basis of body size variation are not fully understood. In particular, it is not clear what the selective value of cell size and cell area variation exactly is. In the present work we determined variation in viability, developmental time and larval competitive ability in response to crowding at two temperatures after artificial selection for reduced cell area, cell number and wing area in four different natural populations of D. melanogaster. No correlated effect of selection on viability or developmental time was observed among all selected populations. An increase in competitive ability in one thermal environment (18 degrees C) under high larval crowding was observed as a correlated response to artificial selection for cell size. Viability and developmental time are not affected by selection for the cellular component of body size, suggesting that these traits only depend on the contingent genetic makeup of a population. The higher larval competitive ability shown by populations selected for reduced cell area seems to confirm the hypothesis that cell area mediated changes have a relationship with fitness, and might be the preferential way to change body size under specific circumstances.

From the cradle to the grave: activities of GATA-3 throughout T cell development and differentiation

PubMed Central

Hosoya, Tomonori; Maillard, Ivan; Engel, James Douglas

2010-01-01

Summary GATA family transcription factors play multiple vital roles in hematopoiesis in many cell lineages, and in particular, T cells require GATA-3 for execution of several developmental steps. Transcriptional activation of the Gata3 gene is observed throughout T-cell development and differentiation in stage-specific fashion. GATA-3 has been described as a master regulator of T-helper 2 (Th2) cell differentiation in mature CD4+ T cells. During T-cell development in the thymus, its roles in the CD4 vs. CD8 lineage choice and at the β-selection checkpoint are the best characterized. In contrast, its importance prior to β-selection has been obscured both by the developmental heterogeneity of double negative (DN) 1 thymocytes and the paucity of early T-lineage progenitors (ETPs), a subpopulation of DN1 cells that contains the most immature thymic progenitors that retain potent T-lineage developmental potential. By examining multiple lines of in vivo evidence procured through the analysis of Gata3 mutant mice, we have recently demonstrated that GATA-3 is additionally required at the earliest stage of thymopoiesis for the development of the ETP population. Here, we review the characterized functions of GATA-3 at each stage of T-cell development and discuss hypothetical molecular pathways that mediate these functions. PMID:20969588

Group I-III-VI.sub.2 semiconductor films for solar cell application

DOEpatents

Basol, Bulent M.; Kapur, Vijay K.

1991-01-01

This invention relates to an improved thin film solar cell with excellent electrical and mechanical integrity. The device comprises a substrate, a Group I-III-VI.sub.2 semiconductor absorber layer and a transparent window layer. The mechanical bond between the substrate and the Group I-III-VI.sub.2 semiconductor layer is enhanced by an intermediate layer between the substrate and the Group I-III-VI.sub.2 semiconductor film being grown. The intermediate layer contains tellurium or substitutes therefor, such as Se, Sn, or Pb. The intermediate layer improves the morphology and electrical characteristics of the Group I-III-VI.sub.2 semiconductor layer.

ETOILE Regulates Developmental Patterning in the Filamentous Brown Alga Ectocarpus siliculosus[W

PubMed Central

Le Bail, Aude; Billoud, Bernard; Le Panse, Sophie; Chenivesse, Sabine; Charrier, Bénédicte

2011-01-01

Brown algae are multicellular marine organisms evolutionarily distant from both metazoans and land plants. The molecular or cellular mechanisms that govern the developmental patterning in brown algae are poorly characterized. Here, we report the first morphogenetic mutant, étoile (etl), produced in the brown algal model Ectocarpus siliculosus. Genetic, cellular, and morphometric analyses showed that a single recessive locus, ETL, regulates cell differentiation: etl cells display thickening of the extracellular matrix (ECM), and the elongated, apical, and actively dividing E cells are underrepresented. As a result of this defect, the overrepresentation of round, branch-initiating R cells in the etl mutant leads to the rapid induction of the branching process at the expense of the uniaxial growth in the primary filament. Computational modeling allowed the simulation of the etl mutant phenotype by including a modified response to the neighborhood information in the division rules used to specify wild-type development. Microarray experiments supported the hypothesis of a defect in cell–cell communication, as primarily Lin-Notch-domain transmembrane proteins, which share similarities with metazoan Notch proteins involved in binary cell differentiation were repressed in etl. Thus, our study highlights the role of the ECM and of novel transmembrane proteins in cell–cell communication during the establishment of the developmental pattern in this brown alga. PMID:21478443

Novel Metrics to Characterize Embryonic Elongation of the Nematode Caenorhabditis elegans.

PubMed

Martin, Emmanuel; Rocheleau-Leclair, Olivier; Jenna, Sarah

2016-03-28

Dissecting the signaling pathways that control the alteration of morphogenic processes during embryonic development requires robust and sensitive metrics. Embryonic elongation of the nematode Caenorhabditis elegans is a late developmental stage consisting of the elongation of the embryo along its longitudinal axis. This developmental stage is controlled by intercellular communication between hypodermal cells and underlying body-wall muscles. These signaling mechanisms control the morphology of hypodermal cells by remodeling the cytoskeleton and the cell-cell junctions. Measurement of embryonic lethality and developmental arrest at larval stages as well as alteration of cytoskeleton and cell-cell adhesion structures in hypodermal and muscle cells are classical phenotypes that have been used for more than 25 years to dissect these signaling pathways. Recent studies required the development of novel metrics specifically targeting either early or late elongation and characterizing morphogenic defects along the antero-posterior axis of the embryo. Here, we provide detailed protocols enabling the accurate measurement of the length and the width of the elongating embryos as well as the length of synchronized larvae. These methods constitute useful tools to identify genes controlling elongation, to assess whether these genes control both early and late phases of this stage and are required evenly along the antero-posterior axis of the embryo.

Macrophage/epithelium cross-talk regulates cell cycle progression and migration in pancreatic progenitors.

PubMed

Mussar, Kristin; Tucker, Andrew; McLennan, Linsey; Gearhart, Addie; Jimenez-Caliani, Antonio J; Cirulli, Vincenzo; Crisa, Laura

2014-01-01

Macrophages populate the mesenchymal compartment of all organs during embryogenesis and have been shown to support tissue organogenesis and regeneration by regulating remodeling of the extracellular microenvironment. Whether this mesenchymal component can also dictate select developmental decisions in epithelia is unknown. Here, using the embryonic pancreatic epithelium as model system, we show that macrophages drive the epithelium to execute two developmentally important choices, i.e. the exit from cell cycle and the acquisition of a migratory phenotype. We demonstrate that these developmental decisions are effectively imparted by macrophages activated toward an M2 fetal-like functional state, and involve modulation of the adhesion receptor NCAM and an uncommon "paired-less" isoform of the transcription factor PAX6 in the epithelium. Over-expression of this PAX6 variant in pancreatic epithelia controls both cell motility and cell cycle progression in a gene-dosage dependent fashion. Importantly, induction of these phenotypes in embryonic pancreatic transplants by M2 macrophages in vivo is associated with an increased frequency of endocrine-committed cells emerging from ductal progenitor pools. These results identify M2 macrophages as key effectors capable of coordinating epithelial cell cycle withdrawal and cell migration, two events critical to pancreatic progenitors' delamination and progression toward their differentiated fates.

Effect of two intermediate electron donors, NADPH and FADH(2), on Spirulina Delta (6)-desaturase co-expressed with two different immediate electron donors, cytochrome b (5) and ferredoxin, in Escherichia coli.

PubMed

Kurdrid, Pavinee; Subudhi, Sanjukta; Cheevadhanarak, Supapon; Tanticharoen, Morakot; Hongsthong, Apiradee

2007-12-01

When the gene desD encoding Spirulina Delta(6)-desaturase was heterologously expressed in E. coli, the enzyme was expressed without the ability to function. However, when this enzyme was co-expressed with an immediate electron donor, i.e. the cytochrome b (5) domain from Mucor rouxii, the results showed the production of GLA (gamma-linolenic acid), the product of the reaction catalyzed by Delta(6)-desaturase. The results revealed that in E. coli cells, where cytochrome b (5) is absent and ferredoxin, a natural electron donor of Delta(6)-desaturase, is present at a very low level, the cytochrome b (5) domain can complement for the function of ferredoxin in the host cells. In the present study, the Spirulina-ferredoxin gene was cloned and co-expressed with the Delta(6)-desaturase in E. coli. In comparison to the co-expression of cytochrome b ( 5 ) with the Delta(6)-desaturase, the co-expression with ferredoxin did not cause any differences in the GLA level. Moreover, the cultures containing the Delta(6)-desaturase co-expressed with cytochrome b (5) and ferredoxin were exogenously supplied with the intermediate electron donors, NADPH (nicotinamide adenine dinucleotide phosphate, reduced form) and FADH(2) (flavin adenine dinucleotide, reduced form), respectively. The GLA level in these host cells increased drastically, by approximately 50%, compared to the cells without the intermediate electron donors. The data indicated that besides the level of immediate electron donors, the level of intermediate electron donors is also critical for GLA production. Therefore, if the pools of the immediate and intermediate electron donors in the cells are manipulated, the GLA production in the heterologous host will be affected.

Leaps and lulls in the developmental transcriptome of Dictyostelium discoideum.

PubMed

Rosengarten, Rafael David; Santhanam, Balaji; Fuller, Danny; Katoh-Kurasawa, Mariko; Loomis, William F; Zupan, Blaz; Shaulsky, Gad

2015-04-13

Development of the soil amoeba Dictyostelium discoideum is triggered by starvation. When placed on a solid substrate, the starving solitary amoebae cease growth, communicate via extracellular cAMP, aggregate by tens of thousands and develop into multicellular organisms. Early phases of the developmental program are often studied in cells starved in suspension while cAMP is provided exogenously. Previous studies revealed massive shifts in the transcriptome under both developmental conditions and a close relationship between gene expression and morphogenesis, but were limited by the sampling frequency and the resolution of the methods. Here, we combine the superior depth and specificity of RNA-seq-based analysis of mRNA abundance with high frequency sampling during filter development and cAMP pulsing in suspension. We found that the developmental transcriptome exhibits mostly gradual changes interspersed by a few instances of large shifts. For each time point we treated the entire transcriptome as single phenotype, and were able to characterize development as groups of similar time points separated by gaps. The grouped time points represented gradual changes in mRNA abundance, or molecular phenotype, and the gaps represented times during which many genes are differentially expressed rapidly, and thus the phenotype changes dramatically. Comparing developmental experiments revealed that gene expression in filter developed cells lagged behind those treated with exogenous cAMP in suspension. The high sampling frequency revealed many genes whose regulation is reproducibly more complex than indicated by previous studies. Gene Ontology enrichment analysis suggested that the transition to multicellularity coincided with rapid accumulation of transcripts associated with DNA processes and mitosis. Later development included the up-regulation of organic signaling molecules and co-factor biosynthesis. Our analysis also demonstrated a high level of synchrony among the developing structures throughout development. Our data describe D. discoideum development as a series of coordinated cellular and multicellular activities. Coordination occurred within fields of aggregating cells and among multicellular bodies, such as mounds or migratory slugs that experience both cell-cell contact and various soluble signaling regimes. These time courses, sampled at the highest temporal resolution to date in this system, provide a comprehensive resource for studies of developmental gene expression.

Embryology of the lamprey and evolution of the vertebrate jaw: insights from molecular and developmental perspectives.

PubMed Central

Kuratani, S; Nobusada, Y; Horigome, N; Shigetani, Y

2001-01-01

Evolution of the vertebrate jaw has been reviewed and discussed based on the developmental pattern of the Japanese marine lamprey, Lampetra japonica. Though it never forms a jointed jaw apparatus, the L. japonica embryo exhibits the typical embryonic structure as well as the conserved regulatory gene expression patterns of vertebrates. The lamprey therefore shares the phylotype of vertebrates, the conserved embryonic pattern that appears at pharyngula stage, rather than representing an intermediate evolutionary state. Both gnathostomes and lampreys exhibit a tripartite configuration of the rostral-most crest-derived ectomesenchyme, each part occupying an anatomically equivalent site. Differentiated oral structure becomes apparent in post-pharyngula development. Due to the solid nasohypophyseal plate, the post-optic ectomesenchyme of the lamprey fails to grow rostromedially to form the medial nasal septum as in gnathostomes, but forms the upper lip instead. The gnathostome jaw may thus have arisen through a process of ontogenetic repatterning, in which a heterotopic shift of mesenchyme-epithelial relationships would have been involved. Further identification of shifts in tissue interaction and expression of regulatory genes are necessary to describe the evolution of the jaw fully from the standpoint of evolutionary developmental biology. PMID:11604127

Effectiveness of a caregiver education program on providing oral care to individuals with intellectual and developmental disabilities.

PubMed

Fickert, Nancy A; Ross, Diana

2012-06-01

Caregivers who work in community living arrangements or intermediate care facilities are responsible for the oral hygiene of individuals with intellectual and developmental disabilities. Oral hygiene training programs do not exist in many organizations, despite concerns about the oral care of this population. The purpose of this study was to determine the effectiveness of a caregiver educational program. This study used a quasi-experimental one-group pretest/posttest design with repeated measures to describe the outcomes of an educational program. Program participants demonstrated oral hygiene skills on each other while being scored by a trained observer, after which they completed an oral hygiene compliance survey. After three months, a follow-up included the same posttest, demonstration of oral hygiene skills, and repeat of the compliance survey. Paired-sample t-tests of oral hygiene knowledge showed a statistically significant improvement from pretest to posttest and from pretest to three-month posttest. Oral hygiene skills and compliance improved. Results demonstrate evidence that caregiver education improves knowledge, skill, and compliance in oral hygiene. Further studies are required to demonstrate the value of providing oral hygiene education and training for caregivers of individuals with intellectual and developmental disabilities.

Systems analysis of a maize leaf developmental gradient redefines the current C4 model and provides candidates for regulation.

PubMed

Pick, Thea R; Bräutigam, Andrea; Schlüter, Urte; Denton, Alisandra K; Colmsee, Christian; Scholz, Uwe; Fahnenstich, Holger; Pieruschka, Roland; Rascher, Uwe; Sonnewald, Uwe; Weber, Andreas P M

2011-12-01

We systematically analyzed a developmental gradient of the third maize (Zea mays) leaf from the point of emergence into the light to the tip in 10 continuous leaf slices to study organ development and physiological and biochemical functions. Transcriptome analysis, oxygen sensitivity of photosynthesis, and photosynthetic rate measurements showed that the maize leaf undergoes a sink-to-source transition without an intermediate phase of C(3) photosynthesis or operation of a photorespiratory carbon pump. Metabolome and transcriptome analysis, chlorophyll and protein measurements, as well as dry weight determination, showed continuous gradients for all analyzed items. The absence of binary on-off switches and regulons pointed to a morphogradient along the leaf as the determining factor of developmental stage. Analysis of transcription factors for differential expression along the leaf gradient defined a list of putative regulators orchestrating the sink-to-source transition and establishment of C(4) photosynthesis. Finally, transcriptome and metabolome analysis, as well as enzyme activity measurements, and absolute quantification of selected metabolites revised the current model of maize C(4) photosynthesis. All data sets are included within the publication to serve as a resource for maize leaf systems biology.

"Intermetamorphic" developmental stages in 150 million-year-old achelatan lobsters--The case of the species tenera Oppel, 1862.

PubMed

Haug, Joachim T; Haug, Carolin

2016-03-01

We re-investigated the fossil species tenera Oppel, 1862, an achelatan lobster (traditionally named Palinurina tenera) found in 150 million years old limestones of southern Germany. All known specimens attributed to this species show a mixture of characters, which in modern forms occur either in larvae or post-larval juveniles. Hence these specimens provide insight into a phase in ontogeny that is no longer present in the developmental sequence of any modern achelatan lobster, as the latter ones skip this phase and replace it by a drastic metamorphosis. Comparable cases have been described earlier, yet did only comprise single stages or two successive ones at most. In the here described case four developmental stages are preserved. The reconstructed ontogeny of tenera therefore represents the currently best known sequence of an early achelatan lobster that covers this specific intermediate phase. The largest known stage most likely still represents an immature of a yet undiscovered adult. These findings support the interpretation that early achelatan lobsters developed in a more gradual ontogenetic sequence than modern forms. It furthermore demonstrates that it was even more gradual than anticipated previously. Copyright © 2015 Elsevier Ltd. All rights reserved.

Systems Analysis of a Maize Leaf Developmental Gradient Redefines the Current C4 Model and Provides Candidates for Regulation[W][OA

PubMed Central

Pick, Thea R.; Bräutigam, Andrea; Schlüter, Urte; Denton, Alisandra K.; Colmsee, Christian; Scholz, Uwe; Fahnenstich, Holger; Pieruschka, Roland; Rascher, Uwe; Sonnewald, Uwe; Weber, Andreas P.M.

2011-01-01

We systematically analyzed a developmental gradient of the third maize (Zea mays) leaf from the point of emergence into the light to the tip in 10 continuous leaf slices to study organ development and physiological and biochemical functions. Transcriptome analysis, oxygen sensitivity of photosynthesis, and photosynthetic rate measurements showed that the maize leaf undergoes a sink-to-source transition without an intermediate phase of C3 photosynthesis or operation of a photorespiratory carbon pump. Metabolome and transcriptome analysis, chlorophyll and protein measurements, as well as dry weight determination, showed continuous gradients for all analyzed items. The absence of binary on–off switches and regulons pointed to a morphogradient along the leaf as the determining factor of developmental stage. Analysis of transcription factors for differential expression along the leaf gradient defined a list of putative regulators orchestrating the sink-to-source transition and establishment of C4 photosynthesis. Finally, transcriptome and metabolome analysis, as well as enzyme activity measurements, and absolute quantification of selected metabolites revised the current model of maize C4 photosynthesis. All data sets are included within the publication to serve as a resource for maize leaf systems biology. PMID:22186372

From the Cover: Cell-replacement therapy for diabetes: Generating functional insulin-producing tissue from adult human liver cells

NASA Astrophysics Data System (ADS)

Sapir, Tamar; Shternhall, Keren; Meivar-Levy, Irit; Blumenfeld, Tamar; Cohen, Hamutal; Skutelsky, Ehud; Eventov-Friedman, Smadar; Barshack, Iris; Goldberg, Iris; Pri-Chen, Sarah; Ben-Dor, Lya; Polak-Charcon, Sylvie; Karasik, Avraham; Shimon, Ilan; Mor, Eytan; Ferber, Sarah

2005-05-01

Shortage in tissue availability from cadaver donors and the need for life-long immunosuppression severely restrict the large-scale application of cell-replacement therapy for diabetic patients. This study suggests the potential use of adult human liver as alternate tissue for autologous beta-cell-replacement therapy. By using pancreatic and duodenal homeobox gene 1 (PDX-1) and soluble factors, we induced a comprehensive developmental shift of adult human liver cells into functional insulin-producing cells. PDX-1-treated human liver cells express insulin, store it in defined granules, and secrete the hormone in a glucose-regulated manner. When transplanted under the renal capsule of diabetic, immunodeficient mice, the cells ameliorated hyperglycemia for prolonged periods of time. Inducing developmental redirection of adult liver offers the potential of a cell-replacement therapy for diabetics by allowing the patient to be the donor of his own insulin-producing tissue. pancreas | transdifferentiation

Single-cell RNA sequencing reveals developmental heterogeneity among early lymphoid progenitors.

PubMed

Alberti-Servera, Llucia; von Muenchow, Lilly; Tsapogas, Panagiotis; Capoferri, Giuseppina; Eschbach, Katja; Beisel, Christian; Ceredig, Rhodri; Ivanek, Robert; Rolink, Antonius

2017-12-15

Single-cell RNA sequencing is a powerful technology for assessing heterogeneity within defined cell populations. Here, we describe the heterogeneity of a B220 + CD117 int CD19 - NK1.1 - uncommitted hematopoietic progenitor having combined lymphoid and myeloid potential. Phenotypic and functional assays revealed four subpopulations within the progenitor with distinct lineage developmental potentials. Among them, the Ly6D + SiglecH - CD11c - fraction was lymphoid-restricted exhibiting strong B-cell potential, whereas the Ly6D - SiglecH - CD11c - fraction showed mixed lympho-myeloid potential. Single-cell RNA sequencing of these subsets revealed that the latter population comprised a mixture of cells with distinct lymphoid and myeloid transcriptional signatures and identified a subgroup as the potential precursor of Ly6D + SiglecH - CD11c - Subsequent functional assays confirmed that B220 + CD117 int CD19 - NK1.1 - single cells are, with rare exceptions, not bipotent for lymphoid and myeloid lineages. A B-cell priming gradient was observed within the Ly6D + SiglecH - CD11c - subset and we propose a herein newly identified subgroup as the direct precursor of the first B-cell committed stage. Therefore, the apparent multipotency of B220 + CD117 int CD19 - NK1.1 - progenitors results from underlying heterogeneity at the single-cell level and highlights the validity of single-cell transcriptomics for resolving cellular heterogeneity and developmental relationships among hematopoietic progenitors. © 2017 The Authors.

Ups and downs in alfalfa: Proteomic and metabolic changes occurring in the growing stem.

PubMed

Printz, Bruno; Guerriero, Gea; Sergeant, Kjell; Renaut, Jenny; Lutts, Stanley; Hausman, Jean-Francois

2015-09-01

The expanding interest for using lignocellulosic biomass in industry spurred the study of the mechanisms underlying plant cell-wall synthesis. Efforts using genetic approaches allowed the disentanglement of major steps governing stem fibre synthesis. Nonetheless, little is known about the relations between the stem maturation and the evolution of its proteome. During Medicago sativa L. maturation, the different internodes grow asynchronously allowing the discrimination of various developmental stages on a same stem. In this study, the proteome of three selected regions of the stem of alfalfa (apical, intermediate and basal) was analyzed and combined with a compositional analysis of the different stem parts. Interestingly, the apical and the median regions share many similarities: high abundance of chloroplast- and mitochondrial-related proteins together with the accumulation of proteins acting in the early steps of fibre production. In the mature basal region, forisomes and stress-related proteins accumulate. The RT-qPCR assessment of the expression of genes coding for members of the cellulose synthase family likewise indicates that fibres and the machinery responsible for the deposition of secondary cell walls are predominantly formed in the apical section. Altogether, this study reflects the metabolic change from the fibre production in the upper stem regions to the acquisition of defence-related functions in the fibrous basal part. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Neutral sphingomyelinase (SMPD3) deficiency disrupts the Golgi secretory pathway and causes growth inhibition

PubMed Central

Stoffel, Wilhelm; Hammels, Ina; Jenke, Bitta; Binczek, Erika; Schmidt-Soltau, Inga; Brodesser, Susanne; Schauss, Astrid; Etich, Julia; Heilig, Juliane; Zaucke, Frank

2016-01-01

Systemic loss of neutral sphingomyelinase (SMPD3) in mice leads to a novel form of systemic, juvenile hypoplasia (dwarfism). SMPD3 deficiency in mainly two growth regulating cell types contributes to the phenotype, in chondrocytes of skeletal growth zones to skeletal malformation and chondrodysplasia, and in hypothalamic neurosecretory neurons to systemic hypothalamus–pituitary–somatotropic hypoplasia. The unbiased smpd3−/− mouse mutant and derived smpd3−/− primary chondrocytes were instrumental in defining the enigmatic role underlying the systemic and cell autonomous role of SMPD3 in the Golgi compartment. Here we describe the unprecedented role of SMPD3. SMPD3 deficiency disrupts homeostasis of sphingomyelin (SM), ceramide (Cer) and diacylglycerol (DAG) in the Golgi SMPD3-SMS1 (SM-synthase1) cycle. Cer and DAG, two fusogenic intermediates, modify the membrane lipid bilayer for the initiation of vesicle formation and transport. Dysproteostasis, unfolded protein response, endoplasmic reticulum stress and apoptosis perturb the Golgi secretory pathway in the smpd3−/− mouse. Secretion of extracellular matrix proteins is arrested in chondrocytes and causes skeletal malformation and chondrodysplasia. Similarly, retarded secretion of proteo-hormones in hypothalamic neurosecretory neurons leads to hypothalamus induced combined pituitary hormone deficiency. SMPD3 in the regulation of the protein vesicular secretory pathway may become a diagnostic target in the etiology of unknown forms of juvenile growth and developmental inhibition. PMID:27882938

Neutral sphingomyelinase (SMPD3) deficiency disrupts the Golgi secretory pathway and causes growth inhibition.

PubMed

Stoffel, Wilhelm; Hammels, Ina; Jenke, Bitta; Binczek, Erika; Schmidt-Soltau, Inga; Brodesser, Susanne; Schauss, Astrid; Etich, Julia; Heilig, Juliane; Zaucke, Frank

2016-11-24

Systemic loss of neutral sphingomyelinase (SMPD3) in mice leads to a novel form of systemic, juvenile hypoplasia (dwarfism). SMPD3 deficiency in mainly two growth regulating cell types contributes to the phenotype, in chondrocytes of skeletal growth zones to skeletal malformation and chondrodysplasia, and in hypothalamic neurosecretory neurons to systemic hypothalamus-pituitary-somatotropic hypoplasia. The unbiased smpd3-/- mouse mutant and derived smpd3-/- primary chondrocytes were instrumental in defining the enigmatic role underlying the systemic and cell autonomous role of SMPD3 in the Golgi compartment. Here we describe the unprecedented role of SMPD3. SMPD3 deficiency disrupts homeostasis of sphingomyelin (SM), ceramide (Cer) and diacylglycerol (DAG) in the Golgi SMPD3-SMS1 (SM-synthase1) cycle. Cer and DAG, two fusogenic intermediates, modify the membrane lipid bilayer for the initiation of vesicle formation and transport. Dysproteostasis, unfolded protein response, endoplasmic reticulum stress and apoptosis perturb the Golgi secretory pathway in the smpd3-/- mouse. Secretion of extracellular matrix proteins is arrested in chondrocytes and causes skeletal malformation and chondrodysplasia. Similarly, retarded secretion of proteo-hormones in hypothalamic neurosecretory neurons leads to hypothalamus induced combined pituitary hormone deficiency. SMPD3 in the regulation of the protein vesicular secretory pathway may become a diagnostic target in the etiology of unknown forms of juvenile growth and developmental inhibition.

Long G2 accumulates recombination intermediates and disturbs chromosome segregation at dysfunction telomere in Schizosaccharomyces pombe

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

Habib, Ahmed G.K.; Masuda, Kenta; Yukawa, Masashi

Protection of telomere (Pot1) is a single-stranded telomere binding protein which is essential for chromosome ends protection. Fission yeast Rqh1 is a member of RecQ helicases family which has essential roles in the maintenance of genomic stability and regulation of homologous recombination. Double mutant between fission yeast pot1Δ and rqh1 helicase dead (rqh1-hd) maintains telomere by homologous recombination. In pot1Δ rqh1-hd double mutant, recombination intermediates accumulate near telomere which disturb chromosome segregation and make cells sensitive to microtubule inhibitors thiabendazole (TBZ). Deletion of chk1{sup +} or mutation of its kinase domain shortens the G2 of pot1Δ rqh1-hd double mutant andmore » suppresses both the accumulation of recombination intermediates and the TBZ sensitivity of that double mutant. In this study, we asked whether the long G2 is the reason for the TBZ sensitivity of pot1Δ rqh1-hd double mutant. We found that shortening the G2 of pot1Δ rqh1-hd double mutant by additional mutations of wee1 and mik1 or gain of function mutation of Cdc2 suppresses both the accumulation of recombination intermediates and the TBZ sensitivity of pot1Δ rqh1-hd double mutant. Our results suggest that long G2 of pot1Δ rqh1-hd double mutant may allow time for the accumulation of recombination intermediates which disturb chromosome segregation and make cells sensitive to TBZ. - Ηighlights: • We show link between long G2 and accumulation of toxic recombination intermediates. • Accumulation of recombination intermediates at telomere results in TBZ sensitivity. • Activation of DNA damage checkpoint worsens cells' viability in presence of TBZ.« less

Baicalin increases developmental competence of mouse embryos in vitro by inhibiting cellular apoptosis and modulating HSP70 and DNMT expression

PubMed Central

QI, Xiaonan; LI, Huatao; CONG, Xia; WANG, Xin; JIANG, Zhongling; CAO, Rongfeng; TIAN, Wenru

2016-01-01

Scutellaria baicalensis has been effectively used in Chinese traditional medicine to prevent miscarriages. However, little information is available on its mechanism of action. This study is designed specifically to reveal how baicalin, the main effective ingredient of S. baicalensis, improves developmental competence of embryos in vitro, using the mouse as a model. Mouse pronuclear embryos were cultured in KSOM medium supplemented with (0, 2, 4 and 8 μg/ml) baicalin. The results demonstrated that in vitro culture conditions significantly decreased the blastocyst developmental rate and blastocyst quality, possibly due to increased cellular stress and apoptosis. Baicalin (4 µg/ml) significantly increased 2- and 4-cell cleavage rates, morula developmental rate, and blastocyst developmental rate and cell number of in vitro-cultured mouse embryos. Moreover, baicalin increased the expression of Gja1, Cdh1, Bcl-2, and Dnmt3a genes, decreased the expression of Dnmt1 gene, and decreased cellular stress and apoptosis as it decreased the expression of HSP70, CASP3, and BAX and increased BCL-2 expression in blastocysts cultured in vitro. In conclusion, baicalin improves developmental competence of in vitro-cultured mouse embryos through inhibition of cellular apoptosis and HSP70 expression, and improvement of DNA methylation. PMID:27478062

Applying Evolutionary Genetics to Developmental Toxicology and Risk Assessment

PubMed Central

Leung, Maxwell C. K.; Procter, Andrew C.; Goldstone, Jared V.; Foox, Jonathan; DeSalle, Robert; Mattingly, Carolyn J.; Siddall, Mark E.; Timme-Laragy, Alicia R.

2018-01-01

Evolutionary thinking continues to challenge our views on health and disease. Yet, there is a communication gap between evolutionary biologists and toxicologists in recognizing the connections among developmental pathways, high-throughput screening, and birth defects in humans. To increase our capability in identifying potential developmental toxicants in humans, we propose to apply evolutionary genetics to improve the experimental design and data interpretation with various in vitro and whole-organism models. We review five molecular systems of stress response and update 18 consensual cell-cell signaling pathways that are the hallmark for early development, organogenesis, and differentiation; and revisit the principles of teratology in light of recent advances in high-throughput screening, big data techniques, and systems toxicology. Multiscale systems modeling plays an integral role in the evolutionary approach to cross-species extrapolation. Phylogenetic analysis and comparative bioinformatics are both valuable tools in identifying and validating the molecular initiating events that account for adverse developmental outcomes in humans. The discordance of susceptibility between test species and humans (ontogeny) reflects their differences in evolutionary history (phylogeny). This synthesis not only can lead to novel applications in developmental toxicity and risk assessment, but also can pave the way for applying an evo-devo perspective to the study of developmental origins of health and disease. PMID:28267574

Solar cells with low cost substrates and process of making same

DOEpatents

Mitchell, Kim W.

1984-01-01

A solar cell having a substrate and an intermediate recrystallized film and a semiconductor material capable of absorbing light with the substrate being selected from one of a synthetic organic resin, graphite, glass and a crystalline material having a grain size less than about 1 micron.sup.2. The intermediate recrystallized film has a grain size in the range of from about 10 microns.sup.2 to about 10,000 microns.sup.2 and a lattice mismatch with the semiconductor material not greater than about 4%. The semiconductor material has a grain size not less than about 10 microns.sup.2. An anti-reflective layer and electrical contact means are provided. Also disclosed is a subcombination of substrate, intermediate recrystallized film and semiconductor material. Also, methods of formulating the solar cell and subcombination are disclosed.

Solar cells with low cost substrates, process of making same and article of manufacture

DOEpatents

Mitchell, K.W.

A solar cell is disclosed having a substrate and an intermediate recrystallized film and a semiconductor material capable of absorbing light with the substrate being selected from one of a synthetic organic resin, graphite, glass and a crystalline material having a grain size less than about 1 micron/sup 2/. The intermediate recrystallized film has a grain size in the range of from about 10 microns/sup 2/ to about 10,000 microns/sup 2/ and a lattice mismatch with the semiconductor material not greater than about 4%. The semiconductor material has a grain size not less than about 10 microns/sup 2/. An anti-reflective layer and electrical contact means are provided. Also disclosed is a subcombination of substrate, intermediate recrystallized film and semiconductor material. Also, methods of formulating the solar cell and subcombination are disclosed.

Developmental Regulation of Effector and Resident Memory T Cell Generation during Pediatric Viral Respiratory Tract Infection.

PubMed

Connors, Thomas J; Baird, J Scott; Yopes, Margot C; Zens, Kyra D; Pethe, Kalpana; Ravindranath, Thyyar M; Ho, Siu-Hong; Farber, Donna L

2018-05-30

Viral respiratory tract infections (VRTI) remain a leading cause of morbidity and mortality among infants and young children. In mice, optimal protection to VRTI is mediated by recruitment of effector T cells to the lungs and respiratory tract, and subsequent establishment of tissue resident memory T cells (Trm), which provide long-term protection. These critical processes of T cell recruitment to the respiratory tract, their role in disease pathogenesis, and establishment of local protective immunity remain undefined in pediatric VRTI. In this study, we investigated T cell responses in the upper respiratory tract (URT) and lower respiratory tract (LRT) of infants and young children with VRTI, revealing developmental regulation of T cell differentiation and Trm generation in situ. We show a direct concurrence between T cell responses in the URT and LRT, including a preponderance of effector CD8 + T cells that was associated with disease severity. During infant VRTI, there was an accumulation of terminally differentiated effector cells (effector memory RA + T cells) in the URT and LRT with reduced Trm in the early neonatal period, and decreased effector memory RA + T cell and increased Trm formation with age during the early years of childhood. Moreover, human infant T cells exhibit increased expression of the transcription factor T-bet compared with adult T cells, suggesting a mechanism for preferential generation of effector over Trm. The developmental regulation of respiratory T cell responses as revealed in the present study is important for diagnosing, monitoring, and treating VRTI in the critical early life stages. Copyright © 2018 by The American Association of Immunologists, Inc.

The development of Neoechinorhynchus buttnerae (Eoacanthocephala: Neoechinorhynchidae) in its intermediate host Cypridopsis vidua in Brazil.

PubMed

Lourenço, Felipe de Sousa; Morey, Germán Augusto Murrieta; Malta, José Celso de Oliveira

2018-06-26

The family Neoechinorhynchidae includes seven species of Neoechinorhynchus from freshwater fishes of Brazil. Although several Neoechinorhynchus species are cited infecting different fish species in Brazil, there is a lack of information concerning to their life cycle and the identification of the intermediate hosts. Thus, the aim of the present study was to describe the development of Neoechinorhynchus buttnerae in its intermediate host collected in a fish farm located in Rio Preto da Eva, Amazonas, Brazil. To verify the presence of N. buttnerae in the fish pond, twenty Colossoma macropomum were captured and analyzed, being corroborated the presence of this parasite species. Samples of plankton were also collected, finding the ostracod Cypridopsis vidua as the intermediate host. For the description of the larvae development, a laboratory experimental procedure was conducted by feeding the collected ostracods with the eggs of the adult specimens taken from the sampled fish. To observe the stages of development an artificial hatch was performed. Every stage of development was photographed, measured, drawn and described. The time of development of the immature stages of N. buttnerae was 29 days, reporting the stages: acanthor, acanthella (with eight developmental changes) and cystacanth. As high infections by N. buttnerae causes morphological damages to the intestine and may compromise the quality of C. macropomum and in consequence the production of fish farmers in the Brazilian Amazon region, the knowledge of its intermediate host and the understanding of its life cycle represents a useful information to prevent and combat infections by this parasite.

Desynchronization of cells on the developmental path triggers the formation of spiral waves of cAMP during Dictyostelium aggregation.

PubMed

Lauzeral, J; Halloy, J; Goldbeter, A

1997-08-19

Whereas it is relatively easy to account for the formation of concentric (target) waves of cAMP in the course of Dictyostelium discoideum aggregation after starvation, the origin of spiral waves remains obscure. We investigate a physiologically plausible mechanism for the spontaneous formation of spiral waves of cAMP in D. discoideum. The scenario relies on the developmental path associated with the continuous changes in the activity of enzymes such as adenylate cyclase and phosphodiesterase observed during the hours that follow starvation. These changes bring the cells successively from a nonexcitable state to an excitable state in which they relay suprathreshold cAMP pulses, and then to autonomous oscillations of cAMP, before the system returns to an excitable state. By analyzing a model for cAMP signaling based on receptor desensitization, we show that the desynchronization of cells on this developmental path triggers the formation of fully developed spirals of cAMP. Developmental paths that do not correspond to the sequence of dynamic transitions no relay-relay-oscillations-relay are less able or fail to give rise to the formation of spirals.

Desynchronization of cells on the developmental path triggers the formation of spiral waves of cAMP during Dictyostelium aggregation

PubMed Central

Lauzeral, Jacques; Halloy, José; Goldbeter, Albert

1997-01-01

Whereas it is relatively easy to account for the formation of concentric (target) waves of cAMP in the course of Dictyostelium discoideum aggregation after starvation, the origin of spiral waves remains obscure. We investigate a physiologically plausible mechanism for the spontaneous formation of spiral waves of cAMP in D. discoideum. The scenario relies on the developmental path associated with the continuous changes in the activity of enzymes such as adenylate cyclase and phosphodiesterase observed during the hours that follow starvation. These changes bring the cells successively from a nonexcitable state to an excitable state in which they relay suprathreshold cAMP pulses, and then to autonomous oscillations of cAMP, before the system returns to an excitable state. By analyzing a model for cAMP signaling based on receptor desensitization, we show that the desynchronization of cells on this developmental path triggers the formation of fully developed spirals of cAMP. Developmental paths that do not correspond to the sequence of dynamic transitions no relay-relay-oscillations-relay are less able or fail to give rise to the formation of spirals. PMID:9256451

Insights in spatio-temporal characterization of human fetal neural stem cells.

PubMed

Martín-Ibáñez, Raquel; Guardia, Inés; Pardo, Mónica; Herranz, Cristina; Zietlow, Rike; Vinh, Ngoc-Nga; Rosser, Anne; Canals, Josep M

2017-05-01

Primary human fetal cells have been used in clinical trials of cell replacement therapy for the treatment of neurodegenerative disorders such as Huntington's disease (HD). However, human fetal primary cells are scarce and difficult to work with and so a renewable source of cells is sought. Human fetal neural stem cells (hfNSCs) can be generated from human fetal tissue, but little is known about the differences between hfNSCs obtained from different developmental stages and brain areas. In the present work we characterized hfNSCs, grown as neurospheres, obtained from three developmental stages: 4-5, 6-7 and 8-9weeks post conception (wpc) and four brain areas: forebrain, cortex, whole ganglionic eminence (WGE) and cerebellum. We observed that, as fetal brain development proceeds, the number of neural precursors is diminished and post-mitotic cells are increased. In turn, primary cells obtained from older embryos are more sensitive to the dissociation process, their viability is diminished and they present lower proliferation ratios compared to younger embryos. However, independently of the developmental stage of derivation proliferation ratios were very low in all cases. Improvements in the expansion rates were achieved by mechanical, instead of enzymatic, dissociation of neurospheres but not by changes in the seeding densities. Regardless of the developmental stage, neurosphere cultures presented large variability in the viability and proliferation rates during the initial 3-4 passages, but stabilized achieving significant expansion rates at passage 5 to 6. This was true also for all brain regions except cerebellar derived cultures that did not expand. Interestingly, the brain region of hfNSC derivation influences the expansion potential, being forebrain, cortex and WGE derived cells the most expandable compared to cerebellar. Short term expansion partially compromised the regional identity of cortical but not WGE cultures. Nevertheless, both expanded cultures were multipotent and kept the ability to differentiate to region specific mature neuronal phenotypes. Copyright © 2017 Elsevier Inc. All rights reserved.

Immunohistochemistry of choriocarcinoma: an aid in differential diagnosis and in elucidating pathogenesis.

PubMed

Mao, Tsui-Lien; Kurman, Robert J; Huang, Chao-Cheng; Lin, Ming-Chieh; Shih, Ie-Ming

2007-11-01

Choriocarcinoma is traditionally described as being composed of cytotrophoblast and syncytiotrophoblast. Microscopically, these 2 types of cells are intimately associated with each other, forming a characteristic biphasic plexiform pattern, however, the nature of these 2 types of trophoblastic cells is not well understood. In this study, we used immunohistochemistry for several trophoblastic markers to analyze the trophoblastic subpopulations in 36 gestational choriocarcinomas. Eighty-one specimens including placenta, complete mole, placental site nodule, epithelioid trophoblastic tumor, and placental site trophoblastic tumor were analyzed. The antibodies included Mel-CAM, HLA-G, MUC-4, and beta-catenin. A semiquantitative assessment of positive cells and the cellular localization of these markers were recorded. We found diffuse strong membranous and cytoplasmic staining for MUC-4 in mononucleate cells in all 36 cases (100%) and a similar pattern of localization in 28 cases (78%) for HLA-G. This distribution was similar to that in normal placentas, where MUC-4 and HLA-G are expressed in the trophoblastic cells of the trophoblastic columns and implantation site. In choriocarcinoma, mononucleate trophoblastic cells showed moderate immunoreactivity for Mel-CAM, a specific marker for implantation site intermediate trophoblast, in 78% of the cases. The MUC-4, HLA-G, and Mel-CAM-positive trophoblastic cells were larger than cytotrophoblastic cells, with more abundant cytoplasm, consistent with the morphology of intermediate trophoblast. In contrast, 31% of the choriocarcinomas contained a very small proportion (<5%) of mononucleate trophoblastic cells compatible with cytotrophoblast that was positive for nuclear beta-catenin, a cytotrophoblast-associated marker. These results suggest that choriocarcinoma is composed predominantly of a mixture of syncytiotrophoblast and intermediate trophoblast with only a small proportion of cytotrophoblast. The presence of nuclear beta-catenin staining in the cytotrophoblast of choriocarcinoma is consistent with the view that choriocarcinoma develops from transformed cytotrophoblastic cells which are presumably the cancer stem cells that differentiate into either intermediate trophoblast or syncytiotrophoblast.

Evidence for heterogeneity of astrocyte de-differentiation in vitro: astrocytes transform into intermediate precursor cells following induction of ACM from scratch-insulted astrocytes.

PubMed

Yang, Hao; Qian, Xin-Hong; Cong, Rui; Li, Jing-wen; Yao, Qin; Jiao, Xi-Ying; Ju, Gong; You, Si-Wei

2010-04-01

Our previous study definitely demonstrated that the mature astrocytes could undergo a de-differentiation process and further transform into pluripotential neural stem cells (NSCs), which might well arise from the effect of diffusible factors released from scratch-insulted astrocytes. However, these neurospheres passaged from one neurosphere-derived from de-differentiated astrocytes possessed a completely distinct characteristic in the differentiation behavior, namely heterogeneity of differentiation. The heterogeneity in cell differentiation has become a crucial but elusive issue. In this study, we show that purified astrocytes could de-differentiate into intermediate precursor cells (IPCs) with addition of scratch-insulted astrocyte-conditioned medium (ACM) to the culture, which can express NG2 and A2B5, the IPCs markers. Apart from the number of NG2(+) and A2B5(+) cells, the percentage of proliferative cells as labeled with BrdU progressively increased with prolonged culture period ranging from 1 to 10 days. Meanwhile, the protein level of A2B5 in cells also increased significantly. These results revealed that not all astrocytes could de-differentiate fully into NSCs directly when induced by ACM, rather they generated intermediate or more restricted precursor cells that might undergo progressive de-differentiation to generate NSCs.

Analysis of stem cell apheresis products using intermediate-dose filgrastim plus large volume apheresis for allogeneic transplantation.

PubMed

Engelhardt, M; Bertz, H; Wäsch, R; Finke, J

2001-04-01

Previously, a dose-dependent influence of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on CD34+ mobilization was demonstrated. In this single-center prospective analysis, 52 healthy donors were investigated to determine the efficacy of intermediate-dose rhG-CSF 2x8 microg/kg donor body weight (bw) and intermediate large volume apheresis (LVA, median 12 l) to mobilize peripheral blood progenitor cells (PBPC) for allogeneic transplantation. The median number of CD34+ cells in apheresis products was 0.45% and 2.2x10(6)/kg recipient bw per single apheresis. A total of 5.4x10(6)/kg CD34+ cells were collected with two (range: one to three) LVA. In the analysis of donor subgroups, higher peripheral blood (PB) and apheresis results were obtained in male vs female donors; however, donor weight significantly differed in both groups. Heavier donors displayed higher PB and apheresis CD34+ counts; however, when CD34+ cells/kg were adjusted to a constant bw, similar harvest results were calculated in males and females, demonstrating that gender per se does not, whereas bw does affect apheresis results. Younger donors had significantly higher PB CD34+ counts, higher CD34+ numbers per single apheresis, increased CFU, more T, B, and CD61+, comparable NK, and less CD14+ cells. A correlation analysis of donor age and apheresis results displayed an age-related decline of 0.46x10(6)/kg CD34 cells per decade of donor aging. Cell subsets in apheresis products were CD14 (49%), CD3 (22%), CD4 (13%), CD8 (7%), CD61 (20%), CD19 (5%), and CD16/56+ (3%) cells, with increasing CD14+ cells and decreasing CD3, CD4, CD8, CD61, CD19, and CD16/56+ cells on subsequent days of apheresis. Compared to our previous analysis using high- (2x12 microg) and low-dose (1x10 microg) rhG-CSF for allogeneic PBPC mobilization, the intermediate-dose showed a similar CD34+ mobilization potential to 1x10 microg rhG-CSF; however, with use of LVA, two instead of three (p<0.05) aphereses were sufficient to mobilize > or =4x10(6)/kg bw CD34+ cells in most donors. Taken together, our results demonstrate that intermediate-dose rhG-CSF sufficiently mobilizes > or =4x10(6)/kg x bw CD34+ cells with use of LVA and that especially younger donors display increased CD34+ cell numbers.

Numerical modelling of high efficiency InAs/GaAs intermediate band solar cell

NASA Astrophysics Data System (ADS)

Imran, Ali; Jiang, Jianliang; Eric, Debora; Yousaf, Muhammad

2018-01-01

Quantum Dots (QDs) intermediate band solar cells (IBSC) are the most attractive candidates for the next generation of photovoltaic applications. In this paper, theoretical model of InAs/GaAs device has been proposed, where we have calculated the effect of variation in the thickness of intrinsic and IB layer on the efficiency of the solar cell using detailed balance theory. IB energies has been optimized for different IB layers thickness. Maximum efficiency 46.6% is calculated for IB material under maximum optical concentration.

Metformin and phenformin deplete tricarboxylic acid cycle and glycolytic intermediates during cell transformation and NTPs in cancer stem cells

PubMed Central

Janzer, Andreas; German, Natalie J.; Gonzalez-Herrera, Karina N.; Asara, John M.; Haigis, Marcia C.; Struhl, Kevin

2014-01-01

Metformin, a first-line diabetes drug linked to cancer prevention in retrospective clinical analyses, inhibits cellular transformation and selectively kills breast cancer stem cells (CSCs). Although a few metabolic effects of metformin and the related biguanide phenformin have been investigated in established cancer cell lines, the global metabolic impact of biguanides during the process of neoplastic transformation and in CSCs is unknown. Here, we use LC/MS/MS metabolomics (>200 metabolites) to assess metabolic changes induced by metformin and phenformin in an Src-inducible model of cellular transformation and in mammosphere-derived breast CSCs. Although phenformin is the more potent biguanide in both systems, the metabolic profiles of these drugs are remarkably similar, although not identical. During the process of cellular transformation, biguanide treatment prevents the boost in glycolytic intermediates at a specific stage of the pathway and coordinately decreases tricarboxylic acid (TCA) cycle intermediates. In contrast, in breast CSCs, biguanides have a modest effect on glycolytic and TCA cycle intermediates, but they strongly deplete nucleotide triphosphates and may impede nucleotide synthesis. These metabolic profiles are consistent with the idea that biguanides inhibit mitochondrial complex 1, but they indicate that their metabolic effects differ depending on the stage of cellular transformation. PMID:25002509

Metformin and phenformin deplete tricarboxylic acid cycle and glycolytic intermediates during cell transformation and NTPs in cancer stem cells.

PubMed

Janzer, Andreas; German, Natalie J; Gonzalez-Herrera, Karina N; Asara, John M; Haigis, Marcia C; Struhl, Kevin

2014-07-22

Metformin, a first-line diabetes drug linked to cancer prevention in retrospective clinical analyses, inhibits cellular transformation and selectively kills breast cancer stem cells (CSCs). Although a few metabolic effects of metformin and the related biguanide phenformin have been investigated in established cancer cell lines, the global metabolic impact of biguanides during the process of neoplastic transformation and in CSCs is unknown. Here, we use LC/MS/MS metabolomics (>200 metabolites) to assess metabolic changes induced by metformin and phenformin in an Src-inducible model of cellular transformation and in mammosphere-derived breast CSCs. Although phenformin is the more potent biguanide in both systems, the metabolic profiles of these drugs are remarkably similar, although not identical. During the process of cellular transformation, biguanide treatment prevents the boost in glycolytic intermediates at a specific stage of the pathway and coordinately decreases tricarboxylic acid (TCA) cycle intermediates. In contrast, in breast CSCs, biguanides have a modest effect on glycolytic and TCA cycle intermediates, but they strongly deplete nucleotide triphosphates and may impede nucleotide synthesis. These metabolic profiles are consistent with the idea that biguanides inhibit mitochondrial complex 1, but they indicate that their metabolic effects differ depending on the stage of cellular transformation.

SOX2 expression levels distinguish between neural progenitor populations of the developing dorsal telencephalon.

PubMed

Hutton, Scott R; Pevny, Larysa H

2011-04-01

The HMG-Box transcription factor SOX2 is expressed in neural progenitor populations throughout the developing and adult central nervous system and is necessary to maintain their progenitor identity. However, it is unclear whether SOX2 levels are uniformly expressed across all neural progenitor populations. In the developing dorsal telencephalon, two distinct populations of neural progenitors, radial glia and intermediate progenitor cells, are responsible for generating a majority of excitatory neurons found in the adult neocortex. Here we demonstrate, using both cellular and molecular analyses, that SOX2 is differentially expressed between radial glial and intermediate progenitor populations. Moreover, utilizing a SOX2(EGFP) mouse line, we show that this differential expression can be used to prospectively isolate distinct, viable populations of radial glia and intermediate cells for in vitro analysis. Given the limited repertoire of cell-surface markers currently available for neural progenitor cells, this provides an invaluable tool for prospectively identifying and isolating distinct classes of neural progenitor cells from the central nervous system. Copyright © 2011 Elsevier Inc. All rights reserved.

[Architectural ultrastructure of the human urinary transitional epithelium].

PubMed

Takayama, H; Konishi, T

1984-07-01

Human urinary bladder mucosa, confirmed to be normal by cystoscopic, histologic and bacteriologic examination, were obtained from four patients at prostatectomy and from two patients at an anti-VUR procedure. The luminal surface and the three dimensional architecture of the bladder mucosa were observed by scanning electron microscopy (SEM) after cryofracture of specimen and by transmission electron microscopy (TEM). The epithelium consists of superficial, intermediate and basal cells, and SEM and TEM showed that it was stratified. Intermediate cells reached the basal lamina by slender cytoplasmic processes but superficial cells were not directly in contact with the basal lamina. No pleomorphic or long microvilli were observed but short microvilli or granular protrusions were sparsely seen on the luminal surface of superficial cells. SEM of cryofractured surfaces revealed that cells from each cell layer were in contact with cellular junctions such as ridges, plicated projections and septum-like walls. Their junctions were more complicated with increasing depth of the cell layer. No pleomorphic or long microvilli were observed on any cell surface of the intermediate or basal cell layer. Under TEM, however, these junctional structures of ridges, plicated projections and septal walls appeared to be microvilli under TEM. Microvilli-like structures on TEM, therefore, have to be carefully distinguished from real microvilli. Careful observation is required when the presence of cells covered with microvilli is described as a sign of malignancy.

Use of Advanced Solar Cells for Commercial Communication Satellites

NASA Technical Reports Server (NTRS)

Bailey, Sheila G.; Landis, Geoffrey A.

1995-01-01

The current generation of communications satellites are located primarily in geosynchronous Earth orbit (GEO). Over the next decade, however, a new generation of communications satellites will be built and launched, designed to provide a world-wide interconnection of portable telephones. For this mission, the satellites must be positioned in lower polar and near-polar orbits. To provide complete coverage, large numbers of satellites will be required. Because the required number of satellites decreases as the orbital altitude is increased, fewer satellites would be required if the orbit chosen were raised from low to intermediate orbit. However, in intermediate orbits, satellites encounter significant radiation due to trapped electrons and protons. Radiation tolerant solar cells may be necessary to make such satellites feasible. We analyze the amount of radiation encountered in low and intermediate polar orbits at altitudes of interest to next-generation communication satellites, calculate the expected degradation for silicon, GaAs, and InP solar cells, and show that the lifetimes can be significantly increased by use of advanced solar cells.

Use of advanced solar cells for commerical communication satellites

NASA Astrophysics Data System (ADS)

Landis, Geoffrey A.; Bailey, Sheila G.

1995-01-01

The current generation of communications satellites are located primarily in geosynchronous Earth orbit (GEO). Over the next decade, however, a new generation of communications satellites will be built and launched, designed to provide a world-wide interconnection of portable telephones. For this mission, the satellites must be positioned in lower polar- and near-polar orbits. To provide complete coverage, large numbers of satellites will be required. Because of the required number of satellites decreases as the orbital altitude is increased, fewer satellites would be required if the orbit chosen were raised from Low to intermediate orbit. However, in intermediate orbits, satellites encounter significant radiation due to trapped electrons and protons. Radiation tolerant solar cells may be necessary to make such satellites feasible. We analyze the amount of radiation encountered in low and intermediate polar orbits at altitudes of interest to next-generation communication satellites, calculate the expected degradation for silicon, GaAs, and InP solar cells, and show that the lifetimes can be significantly increased by use of advanced solar cells.

Use of advanced solar cells for commercial communication satellites

NASA Astrophysics Data System (ADS)

Bailey, Sheila G.; Landis, Geoffrey A.

1995-03-01

The current generation of communications satellites are located primarily in geosynchronous Earth orbit (GEO). Over the next decade, however, a new generation of communications satellites will be built and launched, designed to provide a world-wide interconnection of portable telephones. For this mission, the satellites must be positioned in lower polar and near-polar orbits. To provide complete coverage, large numbers of satellites will be required. Because the required number of satellites decreases as the orbital altitude is increased, fewer satellites would be required if the orbit chosen were raised from low to intermediate orbit. However, in intermediate orbits, satellites encounter significant radiation due to trapped electrons and protons. Radiation tolerant solar cells may be necessary to make such satellites feasible. We analyze the amount of radiation encountered in low and intermediate polar orbits at altitudes of interest to next-generation communication satellites, calculate the expected degradation for silicon, GaAs, and InP solar cells, and show that the lifetimes can be significantly increased by use of advanced solar cells.

A 3-dimensional human embryonic stem cell (hESC)-derived model to detect developmental neurotoxicity of nanoparticles.

PubMed

Hoelting, Lisa; Scheinhardt, Benjamin; Bondarenko, Olesja; Schildknecht, Stefan; Kapitza, Marion; Tanavde, Vivek; Tan, Betty; Lee, Qian Yi; Mecking, Stefan; Leist, Marcel; Kadereit, Suzanne

2013-04-01

Nanoparticles (NPs) have been shown to accumulate in organs, cross the blood-brain barrier and placenta, and have the potential to elicit developmental neurotoxicity (DNT). Here, we developed a human embryonic stem cell (hESC)-derived 3-dimensional (3-D) in vitro model that allows for testing of potential developmental neurotoxicants. Early central nervous system PAX6(+) precursor cells were generated from hESCs and differentiated further within 3-D structures. The 3-D model was characterized for neural marker expression revealing robust differentiation toward neuronal precursor cells, and gene expression profiling suggested a predominantly forebrain-like development. Altered neural gene expression due to exposure to non-cytotoxic concentrations of the known developmental neurotoxicant, methylmercury, indicated that the 3-D model could detect DNT. To test for specific toxicity of NPs, chemically inert polyethylene NPs (PE-NPs) were chosen. They penetrated deep into the 3-D structures and impacted gene expression at non-cytotoxic concentrations. NOTCH pathway genes such as HES5 and NOTCH1 were reduced in expression, as well as downstream neuronal precursor genes such as NEUROD1 and ASCL1. FOXG1, a patterning marker, was also reduced. As loss of function of these genes results in severe nervous system impairments in mice, our data suggest that the 3-D hESC-derived model could be used to test for Nano-DNT.

The telomeric protein SNM1B/Apollo is required for normal cell proliferation and embryonic development.

PubMed

Akhter, Shamima; Lam, Yung C; Chang, Sandy; Legerski, Randy J

2010-12-01

Conserved metallo β-Lactamase and β-CASP (CPSF-Artemis-Snm1-Pso2) domain nuclease family member SNM1B/Apollo is a shelterin-associated protein that localizes to telomeres through its interaction with TRF2. To study its in vivo role, we generated a knockout of SNM1B/Apollo in a mouse model. Snm1B/Apollo homozygous null mice die at birth with developmental delay and defects in multiple organ systems. Cell proliferation defects were observed in Snm1B/Apollo mutant mouse embryonic fibroblasts (MEFs) owing to high levels of telomeric end-to-end fusions. Deficiency of the nonhomologous end-joining (NHEJ) factor Ku70, but not p53, rescued the developmental defects and lethality observed in Snm1B/Apollo mutant mice as well as the impaired proliferation of Snm1B/Apollo-deficient MEFs. These findings demonstrate that SNM1B/Apollo is required to protect telomeres against NHEJ-mediated repair, which results in genomic instability and the consequent multi-organ developmental failure. Although Snm1B/Apollo-deficient MEFs exhibited high levels of apoptosis, abrogation of p53-dependent programmed cell death did not rescue the multi-organ developmental failure in the mice. © 2010 The Authors. Aging Cell © 2010 Blackwell Publishing Ltd/Anatomical Society of Great Britain and Ireland.

Scriptaid and 5-aza-2'deoxycytidine enhanced expression of pluripotent genes and in vitro developmental competence in interspecies Black-footed cat cloned embryos

USGS Publications Warehouse

Gómez, M. C.; Biancardi, M.N.; Jenkins, J.A.; Dumas, C.; Galiguis, J.; Wang, G.; Earle Pope, C.

2012-01-01

Somatic cell nuclear transfer offers the possibility of preserving endangered species including the black-footed cat, which is threatened with extinction. The effectiveness and efficiency of somatic cell nuclear transfer (SCNT) depends on a variety of factors, but 'inappropriate epigenetic reprogramming of the transplanted nucleus is the primary cause of the developmental failure of cloned embryos. Abnormal epigenetic events such as DNA methylation and histone modifications during SCNT perturb the expression of imprinted and pluripotent-related genes that, consequently, may result in foetal and neonatal abnormalities. We have demonstrated that pregnancies can be established after transfer of black-footed cat cloned embryos into domestic cat recipients, but none of the implanted embryos developed to term and the foetal failure has been associated to aberrant reprogramming in cloned embryos. There is growing evidence that modifying the epigenetic pattern of the chromatin template of both donor cells and reconstructed embryos with a combination of inhibitors of histone deacetylases and DNA methyltransferases results in enhanced gene reactivation and improved in vitro and in vivo developmental competence. Epigenetic modifications of the chromatin template of black-footed cat donor cells and reconstructed embryos with epigenetic-modifying compounds enhanced in vitro development, and regulated the expression of pluripotent genes, but these epigenetic modifications did not improve in vivo developmental competence.

A Cascade of Wnt, Eda, and Shh Signaling Is Essential for Touch Dome Merkel Cell Development.

PubMed

Xiao, Ying; Thoresen, Daniel T; Miao, Lingling; Williams, Jonathan S; Wang, Chaochen; Atit, Radhika P; Wong, Sunny Y; Brownell, Isaac

2016-07-01

The Sonic hedgehog (Shh) signaling pathway regulates developmental, homeostatic, and repair processes throughout the body. In the skin, touch domes develop in tandem with primary hair follicles and contain sensory Merkel cells. The developmental signaling requirements for touch dome specification are largely unknown. We found dermal Wnt signaling and subsequent epidermal Eda/Edar signaling promoted Merkel cell morphogenesis by inducing Shh expression in early follicles. Lineage-specific gene deletions revealed intraepithelial Shh signaling was necessary for Merkel cell specification. Additionally, a Shh signaling agonist was sufficient to rescue Merkel cell differentiation in Edar-deficient skin. Moreover, Merkel cells formed in Fgf20 mutant skin where primary hair formation was defective but Shh production was preserved. Although developmentally associated with hair follicles, fate mapping demonstrated Merkel cells primarily originated outside the hair follicle lineage. These findings suggest that touch dome development requires Wnt-dependent mesenchymal signals to establish reciprocal signaling within the developing ectoderm, including Eda signaling to primary hair placodes and ultimately Shh signaling from primary follicles to extrafollicular Merkel cell progenitors. Shh signaling often demonstrates pleiotropic effects within a structure over time. In postnatal skin, Shh is known to regulate the self-renewal, but not the differentiation, of touch dome stem cells. Our findings relate the varied effects of Shh in the touch dome to the ligand source, with locally produced Shh acting as a morphogen essential for lineage specification during development and neural Shh regulating postnatal touch dome stem cell maintenance.

Developmentally regulated expression of APG-1, a member of heat shock protein 110 family in murine male germ cells.

PubMed

Kaneko, Y; Kimura, T; Nishiyama, H; Noda, Y; Fujita, J

1997-04-07

Apg-1 encodes a heat shock protein belonging to the heat shock protein 110 family, and is inducible by a 32 degrees C to 39 degrees C heat shock. Northern blot analysis of the testis from immature and adult mice, and of the purified germ cells revealed the quantitative change of the apg-1 transcripts during germ cell development. By in situ hybridization histochemistry the expressions of the apg-1 transcripts were detected in germ cells at specific stages of development including spermatocytes and spermatids. Although heat-induction of the apg-1 transcripts was observed in W/Wv mutant testis lacking germ cells, it was not detected in wild-type testis nor in the purified germ cells. Thus, the apg-1 expression is not heat-regulated but developmentally regulated in germ cells, suggesting that APG-1 plays a role in normal development of germ cells.

Definition of Drosophila hemocyte subsets by cell-type specific antigens.

PubMed

Kurucz, Eva; Váczi, B; Márkus, R; Laurinyecz, Barbara; Vilmos, P; Zsámboki, J; Csorba, Kinga; Gateff, Elisabeth; Hultmark, D; Andó, I

2007-01-01

We analyzed the heterogeneity of Drosophila hemocytes on the basis of the expression of cell-type specific antigens. The antigens characterize distinct subsets which partially overlap with those defined by morphological criteria. On the basis of the expression or the lack of expression of blood cell antigens the following hemocyte populations have been defined: crystal cells, plasmatocytes, lamellocytes and precursor cells. The expression of the antigens and thus the different cell types are developmentally regulated. The hemocytes are arranged in four main compartments: the circulating blood cells, the sessile tissue, the lymph glands and the posterior hematopoietic tissue. Each hemocyte compartment has a specific and characteristic composition of the various cell types. The described markers represent the first successful attempt to define hemocyte lineages by immunological markers in Drosophila and help to define morphologically, functionally, spatially and developmentally distinct subsets of hemocytes.

Natural Killer T Cells: An Ecological Evolutionary Developmental Biology Perspective

PubMed Central

Kumar, Amrendra; Suryadevara, Naveenchandra; Hill, Timothy M.; Bezbradica, Jelena S.; Van Kaer, Luc; Joyce, Sebastian

2017-01-01

Type I natural killer T (NKT) cells are innate-like T lymphocytes that recognize glycolipid antigens presented by the MHC class I-like protein CD1d. Agonistic activation of NKT cells leads to rapid pro-inflammatory and immune modulatory cytokine and chemokine responses. This property of NKT cells, in conjunction with their interactions with antigen-presenting cells, controls downstream innate and adaptive immune responses against cancers and infectious diseases, as well as in several inflammatory disorders. NKT cell properties are acquired during development in the thymus and by interactions with the host microbial consortium in the gut, the nature of which can be influenced by NKT cells. This latter property, together with the role of the host microbiota in cancer therapy, necessitates a new perspective. Hence, this review provides an initial approach to understanding NKT cells from an ecological evolutionary developmental biology (eco-evo-devo) perspective. PMID:29312339

Natural Killer T Cells: An Ecological Evolutionary Developmental Biology Perspective.

PubMed

Kumar, Amrendra; Suryadevara, Naveenchandra; Hill, Timothy M; Bezbradica, Jelena S; Van Kaer, Luc; Joyce, Sebastian

2017-01-01

Type I natural killer T (NKT) cells are innate-like T lymphocytes that recognize glycolipid antigens presented by the MHC class I-like protein CD1d. Agonistic activation of NKT cells leads to rapid pro-inflammatory and immune modulatory cytokine and chemokine responses. This property of NKT cells, in conjunction with their interactions with antigen-presenting cells, controls downstream innate and adaptive immune responses against cancers and infectious diseases, as well as in several inflammatory disorders. NKT cell properties are acquired during development in the thymus and by interactions with the host microbial consortium in the gut, the nature of which can be influenced by NKT cells. This latter property, together with the role of the host microbiota in cancer therapy, necessitates a new perspective. Hence, this review provides an initial approach to understanding NKT cells from an ecological evolutionary developmental biology (eco-evo-devo) perspective.

Developmental sources of conservation and variation in the evolution of the primate eye.

PubMed

Dyer, Michael A; Martins, Rodrigo; da Silva Filho, Manoel; Muniz, José Augusto P C; Silveira, Luiz Carlos L; Cepko, Constance L; Finlay, Barbara L

2009-06-02

Conserved developmental programs, such as the order of neurogenesis in the mammalian eye, suggest the presence of useful features for evolutionary stability and variability. The owl monkey, Aotus azarae, has developed a fully nocturnal retina in recent evolution. Description and quantification of cell cycle kinetics show that embryonic cytogenesis is extended in Aotus compared with the diurnal New World monkey Cebus apella. Combined with the conserved mammalian pattern of retinal cell specification, this single change in retinal progenitor cell proliferation can produce the multiple alterations of the nocturnal retina, including coordinated reduction in cone and ganglion cell numbers, increase in rod and rod bipolar numbers, and potentially loss of the fovea.

Increased FGF8 signaling promotes chondrogenic rather than osteogenic development in the embryonic skull.

PubMed

Schmidt, Linnea; Taiyab, Aftab; Melvin, Vida Senkus; Jones, Kenneth L; Williams, Trevor

2018-05-10

The bones of the cranial vault are formed directly from mesenchymal cells through intramembranous ossification rather than via a cartilage intermediate. Formation and growth of the skull bones involves the interaction of multiple cell:cell signaling pathways, with Fibroblast Growth Factors (FGFs) and their receptors exerting prominent influence. Mutations within this pathway are the most frequent cause of craniosynostosis, which is a common human craniofacial developmental abnormality characterized by the premature fusion of the cranial sutures. Here, we have developed new mouse models to investigate how different levels of increased Fgf signaling can impact the formation of the calvarial bones and associated sutures. While moderate Fgf8 overexpression resulted in delayed ossification followed by craniosynostosis of the coronal suture, higher Fgf8 levels promoted a loss of ossification and favored cartilage over bone formation across the skull. In contrast, endochondral bones were still able to form and ossify in the presence of increased Fgf8 , though the growth and mineralization of these bones were impacted to varying extents. Expression analysis demonstrated that abnormal skull chondrogenesis was accompanied by changes in genes required for Wnt signaling. Moreover, further analysis indicated that the pathology was associated with decreased Wnt signaling since the reduction in ossification could be partially rescued by halving Axin2 gene dosage. Taken together, these findings indicate that mesenchymal cells of the skull are not fated to form bone but can be forced into a chondrogenic fate via manipulation of FGF8 signaling. These results have implications for evolution of the different methods of ossification as well as for therapeutic intervention in craniosynostosis. © 2018. Published by The Company of Biologists Ltd.

N-Cadherin and Fibroblast Growth Factor Receptors crosstalk in the control of developmental and cancer cell migrations.

PubMed

Nguyen, Thao; Mège, René Marc

2016-11-01

Cell migrations are diverse. They constitutemajor morphogenetic driving forces during embryogenesis, but they contribute also to the loss of tissue homeostasis and cancer growth. Capabilities of cells to migrate as single cells or as collectives are controlled by internal and external signalling, leading to the reorganisation of their cytoskeleton as well as by the rebalancing of cell-matrix and cell-cell adhesions. Among the genes altered in numerous cancers, cadherins and growth factor receptors are of particular interest for cell migration regulation. In particular, cadherins such as N-cadherin and a class of growth factor receptors, namely FGFRs cooperate to regulate embryonic and cancer cell behaviours. In this review, we discuss on reciprocal crosstalk between N-cadherin and FGFRs during cell migration. Finally, we aim at clarifying the synergy between N-cadherin and FGFR signalling that ensure cellular reorganization during cell movements, mainly during cancer cell migration and metastasis but also during developmental processes. Copyright © 2016 Elsevier GmbH. All rights reserved.

Phenotypic screening for developmental neurotoxicity: mechanistic data at the level of the cell

EPA Science Inventory

There are large numbers of environmental chemicals with little or no available information on their toxicity, including developmental neurotoxicity. Because of the resource-intensive nature of traditional animal tests, high-throughput (HTP) methods that can rapidly evaluate chemi...

Demonstration of intermediate cells during human prostate epithelial differentiation in situ and in vitro using triple-staining confocal scanning microscopy.

PubMed

van Leenders, G; Dijkman, H; Hulsbergen-van de Kaa, C; Ruiter, D; Schalken, J

2000-08-01

In human prostate epithelium, morphologically basal and luminal cells can be discriminated. The basal cell layer that putatively contains progenitor cells of the secretory epithelium is characterized by the expression of keratins (K) 5 and 14. Luminal cells represent the secretory compartment of the epithelium and express K8 and 18. We developed a technique for the simultaneous analysis of K5, 14, and 18 to identify intermediate cell stages in the prostate epithelium and to study the dynamic aspects of its differentiation in vitro. Nonmalignant prostate tissue and primary epithelial cultures were immunohistochemically characterized using triple staining with antibodies for K5, K14, and K18. Antibodies for K18 and K5 were conjugated directly with fluorochromes Alexa 488 and 546. K14 was visualized indirectly with streptavidin-Cy5. Keratin expression was analyzed by confocal scanning microscopy. The occurrence of exocrine and neuroendocrine differentiation in culture was determined via antibodies to prostate-specific antigen (PSA), chromogranin A, and serotonin. We found that basal cells expressed either K5(++)/14(++)/18+ or K5(++)/18+. The majority of luminal cells expressed K18(++), but colocalization of K5+/18(++) were recognized. Epithelial monolayer cultures predominantly revealed the basal cell phenotype K5(++)/14(++)/18+, whereas intermediate subpopulations expressing K5+/14+/18(++) and K5+/18(++) were also identified. On confluence, differentiation was induced as multicellular gland-like buds, and extensions became evident on top of the monolayer. These structures were composed of K18(++)- and K5+/18(+)-positive cell clusters surrounded by phenotypically basal cells. Few multicellular structures and cells in the monolayer showed exocrine differentiation (PSA+), but expression of chromogranin A and serotonin was absent. We conclude that simultaneous evaluation of keratin expression is useful for analyzing epithelial differentiation in the prostate. During this process, putative stem cells phenotypically resembling K5(++)/14(++)/18+ differentiate toward luminal cells (K18(++)) via intermediate cell stages, as identified by up-regulation of K18 and down-regulation of K5 and 14.

Switching of the positive feedback for RAS activation by a concerted function of SOS membrane association domains

PubMed Central

Nakamura, Yuki; Hibino, Kayo; Yanagida, Toshio; Sako, Yasushi

2016-01-01

Son of sevenless (SOS) is a guanine nucleotide exchange factor that regulates cell behavior by activating the small GTPase RAS. Recent in vitro studies have suggested that an interaction between SOS and the GTP-bound active form of RAS generates a positive feedback loop that propagates RAS activation. However, it remains unclear how the multiple domains of SOS contribute to the regulation of the feedback loop in living cells. Here, we observed single molecules of SOS in living cells to analyze the kinetics and dynamics of SOS behavior. The results indicate that the histone fold and Grb2-binding domains of SOS concertedly produce an intermediate state of SOS on the cell surface. The fraction of the intermediated state was reduced in positive feedback mutants, suggesting that the feedback loop functions during the intermediate state. Translocation of RAF, recognizing the active form of RAS, to the cell surface was almost abolished in the positive feedback mutants. Thus, the concerted functions of multiple membrane-associating domains of SOS governed the positive feedback loop, which is crucial for cell fate decision regulated by RAS. PMID:27924253

Mas-allatotropin in the developing antennal lobe of the sphinx moth Manduca sexta: distribution, time course, developmental regulation, and colocalization with other neuropeptides.

PubMed

Utz, Sandra; Huetteroth, Wolf; Vömel, Matthias; Schachtner, Joachim

2008-01-01

The paired antennal lobes (ALs) of the sphinx moth Manduca sexta serve as a well-established model for studying development of the primary integration centers for odor information in the brain. To further reveal the role of neuropeptides during AL development, we have analyzed cellular distribution, developmental time course, and regulation of the neuropeptide M. sexta allatotropin (Mas-AT). On the basis of morphology and appearance during AL formation, seven major types of Mas-AT-immunoreactive (ir) cells could be distinguished. Mas-AT-ir cells are identified as local, projection, and centrifugal neurons, which are either persisting larval or newly added adult-specific neurons. Complementary immunostaining with antisera against two other neuropeptide families (A-type allatostatins, RFamides) revealed colocalization within three of the Mas-AT-ir cell types. On the basis of this neurochemistry, the most prominent type of Mas-AT-ir neurons, the local AT neurons (LATn), could be divided in three subpopulations. The appearance of the Mas-AT-ir cell types occurring during metamorphosis parallels the rising titer of the developmental hormone 20-hydroxyecdysone (20E). Artificially shifting the 20E titer to an earlier developmental time point resulted in the precocious occurrence of Mas-AT immunostaining. This result supports the hypothesis that the pupal rise of 20E is causative for Mas-AT expression during AL development. Comparing localization and developmental time course of Mas-AT and other neuropeptides with the time course of AL formation suggests various functions for these neuropeptides during development, including an involvement in the formation of the olfactory glomeruli.

Fibroblast Growth Factor 10 Enhances the Developmental Efficiency of Somatic Cell Nuclear Transfer Embryos by Accelerating the Kinetics of Cleavage During In Vitro Maturation.

PubMed

Son, Yeo-Jin; Lee, Seung-Eun; Park, Yun-Gwi; Jeong, Sang-Gi; Shin, Min-Young; Kim, Eun-Young; Park, Se-Pill

2018-06-01

Somatic cell nuclear transfer (SCNT) is required for the generation of transgenic animals as disease models. During the in vitro development of SCNT embryos, the quality of matured oocytes is one of the major factors regulating the developmental potential of embryos. Time-lapse monitoring systems are new tools that assess the developmental capacity of embryos for use in embryo transfer. In this study, we investigated the effect of fibroblast growth factor 10 (FGF 10) on the developmental potential of SCNT embryos. After the in vitro maturation (IVM) of oocytes in IVM medium containing 10 ng/mL FGF 10 (10 F), the polar body extrusion rate was significantly higher than in the control. However, there was no difference in the percentage of fused embryos between the groups. The cleavage and blastocyst formation rates of embryos were significantly increased in the 10 F compared with the control. In addition, the total cell number was higher and the apoptotic index was lower in the 10 F than control at day 7. The messenger RNA (mRNA) expression of genes involved in apoptosis (baculoviral inhibitor of apoptosis repeat containing 5 [BIRC5] and caspase 3 [CASP3]) and development (octamer-binding transcription factor 4 [POU5F1] and sex determining region Y box 2 [SOX2]) increased after 10 F treatment. Furthermore, the kinetics of the first cleavage was faster and the percentage of embryos at cell block was significantly lower in the 10 F group than in the control. These results demonstrate that exposure of oocytes to FGF 10 during IVM promotes developmental competence.

Shavenbaby Couples Patterning to Epidermal Cell Shape Control

PubMed Central

Fernandes, Isabelle; Roch, Fernando; Payre, François

2006-01-01

It is well established that developmental programs act during embryogenesis to determine animal morphogenesis. How these developmental cues produce specific cell shape during morphogenesis, however, has remained elusive. We addressed this question by studying the morphological differentiation of the Drosophila epidermis, governed by a well-known circuit of regulators leading to a stereotyped pattern of smooth cells and cells forming actin-rich extensions (trichomes). It was shown that the transcription factor Shavenbaby plays a pivotal role in the formation of trichomes and underlies all examined cases of the evolutionary diversification of their pattern. To gain insight into the mechanisms of morphological differentiation, we sought to identify shavenbaby's downstream targets. We show here that Shavenbaby controls epidermal cell shape, through the transcriptional activation of different classes of cellular effectors, directly contributing to the organization of actin filaments, regulation of the extracellular matrix, and modification of the cuticle. Individual inactivation of shavenbaby's targets produces distinct trichome defects and only their simultaneous inactivation prevent trichome formation. Our data show that shavenbaby governs an evolutionarily conserved developmental module consisting of a set of genes collectively responsible for trichome formation, shedding new light on molecular mechanisms acting during morphogenesis and the way they can influence evolution of animal forms. PMID:16933974

The impairment of HCCS leads to MLS syndrome by activating a non-canonical cell death pathway in the brain and eyes

PubMed Central

Indrieri, Alessia; Conte, Ivan; Chesi, Giancarlo; Romano, Alessia; Quartararo, Jade; Tatè, Rosarita; Ghezzi, Daniele; Zeviani, Massimo; Goffrini, Paola; Ferrero, Ileana; Bovolenta, Paola; Franco, Brunella

2013-01-01

Mitochondrial-dependent (intrinsic) programmed cell death (PCD) is an essential homoeostatic mechanism that selects bioenergetically proficient cells suitable for tissue/organ development. However, the link between mitochondrial dysfunction, intrinsic apoptosis and developmental anomalies has not been demonstrated to date. Now we provide the evidence that non-canonical mitochondrial-dependent apoptosis explains the phenotype of microphthalmia with linear skin lesions (MLS), an X-linked developmental disorder caused by mutations in the holo-cytochrome c-type synthase (HCCS) gene. By taking advantage of a medaka model that recapitulates the MLS phenotype we demonstrate that downregulation of hccs, an essential player of the mitochondrial respiratory chain (MRC), causes increased cell death via an apoptosome-independent caspase-9 activation in brain and eyes. We also show that the unconventional activation of caspase-9 occurs in the mitochondria and is triggered by MRC impairment and overproduction of reactive oxygen species (ROS). We thus propose that HCCS plays a key role in central nervous system (CNS) development by modulating a novel non-canonical start-up of cell death and provide the first experimental evidence for a mechanistic link between mitochondrial dysfunction, intrinsic apoptosis and developmental disorders. PMID:23239471

H19, a marker of developmental transition, is reexpressed in human atherosclerotic plaques and is regulated by the insulin family of growth factors in cultured rabbit smooth muscle cells.

PubMed

Han, D K; Khaing, Z Z; Pollock, R A; Haudenschild, C C; Liau, G

1996-03-01

H19 is a developmentally regulated gene with putative tumor suppressor activity, and loss of H19 expression may be involved in Wilms' tumorigenesis. In this report, we have performed in situ hybridization analysis of H19 expression during normal rabbit development and in human atherosclerotic plaques. We have also used cultured smooth muscle cells to identify H19 regulatory factors. Our data indicate that H19 expression in the developing skeletal and smooth muscles correlated with specific differentiation events in these tissues. Expression of H19 in the skeletal muscle correlated with nonproliferative, actin-positive muscle cells. In the prenatal blood vessel, H19 expression was both temporally and spatially regulated with initial loss of expression in the inner smooth muscle layers adjacent to the lumen. We also identified H19-positive cells within the adult atherosclerotic lesion and we suggest that these cells may recapitulate earlier developmental events. These results, along with the identification of the insulin family of growth factors as potent regulatory molecules for H19 expression, provide additional clues toward understanding the physiological regulation and function of H19.

H19, a marker of developmental transition, is reexpressed in human atherosclerotic plaques and is regulated by the insulin family of growth factors in cultured rabbit smooth muscle cells.

PubMed Central

Han, D K; Khaing, Z Z; Pollock, R A; Haudenschild, C C; Liau, G

1996-01-01

H19 is a developmentally regulated gene with putative tumor suppressor activity, and loss of H19 expression may be involved in Wilms' tumorigenesis. In this report, we have performed in situ hybridization analysis of H19 expression during normal rabbit development and in human atherosclerotic plaques. We have also used cultured smooth muscle cells to identify H19 regulatory factors. Our data indicate that H19 expression in the developing skeletal and smooth muscles correlated with specific differentiation events in these tissues. Expression of H19 in the skeletal muscle correlated with nonproliferative, actin-positive muscle cells. In the prenatal blood vessel, H19 expression was both temporally and spatially regulated with initial loss of expression in the inner smooth muscle layers adjacent to the lumen. We also identified H19-positive cells within the adult atherosclerotic lesion and we suggest that these cells may recapitulate earlier developmental events. These results, along with the identification of the insulin family of growth factors as potent regulatory molecules for H19 expression, provide additional clues toward understanding the physiological regulation and function of H19. PMID:8636440

An imbalanced parental genome ratio affects the development of rice zygotes.

PubMed

Toda, Erika; Ohnishi, Yukinosuke; Okamoto, Takashi

2018-04-27

Upon double fertilization, one sperm cell fuses with the egg cell to form a zygote with a 1:1 maternal-to-paternal genome ratio (1m:1p), and another sperm cell fuses with the central cell to form a triploid primary endosperm cell with a 2m:1p ratio, resulting in formation of the embryo and the endosperm, respectively. The endosperm is known to be considerably sensitive to the ratio of the parental genomes. However, the effect of an imbalance of the parental genomes on zygotic development and embryogenesis has not been well studied, because it is difficult to reproduce the parental genome-imbalanced situation in zygotes and to monitor the developmental profile of zygotes without external effects from the endosperm. In this study, we produced polyploid zygotes with an imbalanced parental genome ratio by electro-fusion of isolated rice gametes and observed their developmental profiles. Polyploid zygotes with an excess maternal gamete/genome developed normally, whereas approximately half to three-quarters of polyploid zygotes with a paternal excess showed developmental arrests. These results indicate that paternal and maternal genomes synergistically serve zygote development with distinct functions, and that genes with monoallelic expression play important roles during zygotic development and embryogenesis.

Immunohistochemical localization of anterior pituitary hormones in S-100 protein-positive cells in the rat pituitary gland.

PubMed

Kikuchi, Motoshi; Yatabe, Megumi; Tando, Yukiko; Yashiro, Takashi

2011-09-01

In the anterior and intermediate lobes of the rat pituitary gland, non-hormone-producing cells that express S-100 protein coexist with various types of hormone-producing cells and are believed to function as phagocytes, supporting and paracrine-controlling cells of hormone-producing cells and stem cells, among other functions; however, their cytological characteristics are not yet fully understood. Using a transgenic rat that expresses green fluorescent protein under the promoter of the S100β protein gene, we immunohistochemically detected expression of the luteinizing hormone, thyroid-stimulating hormone, prolactin, growth hormone and proopiomelanocortin by S-100 protein-positive cells located between clusters of hormone-producing cells in the intermediate lobe. These findings lend support to the hypothesis that S-100 protein-positive cells are capable of differentiating into hormone-producing cells in the adult rat pituitary gland.

Establishment of segment polarity in the ectoderm of the leech Helobdella

NASA Technical Reports Server (NTRS)

Seaver, E. C.; Shankland, M.

2001-01-01

The segmented ectoderm and mesoderm of the leech arise via a stereotyped cell lineage from embryonic stem cells called teloblasts. Each teloblast gives rise to a column of primary blast cell daughters, and the blast cells generate descendant clones that serve as the segmental repeats of their particular teloblast lineage. We have examined the mechanism by which the leech primary blast cell clones acquire segment polarity - i.e. a fixed sequence of positional values ordered along the anteroposterior axis of the segmental repeat. In the O and P teloblast lineages, the earliest divisions of the primary blast cell segregate anterior and posterior cell fates along the anteroposterior axis. Using a laser microbeam, we ablated single cells from both o and p blast cell clones at stages when the clone was two to four cells in length. The developmental fate of the remaining cells was characterized with rhodamine-dextran lineage tracer. Twelve different progeny cells were ablated, and in every case the ablation eliminated the normal descendants of the ablated cell while having little or no detectable effect on the developmental fate of the remaining cells. This included experiments in which we specifically ablated those blast cell progeny that are known to express the engrailed gene, or their lineal precursors. These findings confirm and extend a previous study by showing that the establishment of segment polarity in the leech ectoderm is largely independent of cell interactions conveyed along the anteroposterior axis. Both intercellular signaling and engrailed expression play an important role in the segment polarity specification of the Drosophila embryo, and our findings suggest that there may be little or no conservation of this developmental mechanism between those two organisms.

Fullerene surfactants and their use in polymer solar cells

DOEpatents

Jen, Kwan-Yue; Yip, Hin-Lap; Li, Chang-Zhi

2015-12-15

Fullerene surfactant compounds useful as interfacial layer in polymer solar cells to enhance solar cell efficiency. Polymer solar cell including a fullerene surfactant-containing interfacial layer intermediate cathode and active layer.

Calcium-binding proteins and development

NASA Technical Reports Server (NTRS)

Beckingham, K.; Lu, A. Q.; Andruss, B. F.; McIntire, L. V. (Principal Investigator)

1998-01-01

The known roles for calcium-binding proteins in developmental signaling pathways are reviewed. Current information on the calcium-binding characteristics of three classes of cell-surface developmental signaling proteins (EGF-domain proteins, cadherins and integrins) is presented together with an overview of the intracellular pathways downstream of these surface receptors. The developmental roles delineated to date for the universal intracellular calcium sensor, calmodulin, and its targets, and for calcium-binding regulators of the cytoskeleton are also reviewed.

Disruption of Canonical TGFβ-signaling in Murine Coronary Progenitor Cells by Low Level Arsenic

PubMed Central

Allison, Patrick; Huang, Tianfang; Broka, Derrick; Parker, Patti; Barnett, Joey V.; Camenisch, Todd D.

2013-01-01

Exposure to arsenic results in several types of cancers as well as heart disease. A major contributor to ischemic heart pathologies is coronary artery disease, however the influences by environmental arsenic in this disease process are not known. Similarly, the impact of toxicants on blood vessel formation and function during development has not been studied. During embryogenesis, the epicardium undergoes proliferation, migration, and differentiation into several cardiac cell types including smooth muscle cells which contribute to the coronary vessels. The TGFβ family of ligands and receptors are essential for developmental cardiac epithelial to mesenchymal transition (EMT) and differentiation into coronary smooth muscle cells. In this in vitrostudy, 18 hour exposure to 1.34 μMarsenite disrupted developmental EMT programming in murine epicardial cells causing a deficit in cardiac mesenchyme. The expression of EMT genes including TGFβ2, TGFβ receptor-3, Snail, and Has-2 are decreased in a dose-dependent manner following exposure to arsenite. TGFβ2 cell signaling is abrogated as detected by decreases in phosphorylated Smad2/3 when cells are exposed to 1.34 μMarsenite. There is also loss of nuclear accumulation pSmad due to arsenite exposure. These observations coincide with a decrease invimentinpositive mesenchymal cells invading three-dimensional collagen gels. However, arsenite does not block TGFβ2 mediated smooth muscle cell differentiation by epicardial cells. Overall these results show that arsenic exposure blocks developmental EMT gene programming in murine coronary progenitor cells by disrupting TGFβ2 signals and Smad activation, and that smooth muscle cell differentiation is refractory to this arsenic toxicity. PMID:23732083

Transcriptomic analysis of Arabidopsis developing stems: a close-up on cell wall genes

PubMed Central

Minic, Zoran; Jamet, Elisabeth; San-Clemente, Hélène; Pelletier, Sandra; Renou, Jean-Pierre; Rihouey, Christophe; Okinyo, Denis PO; Proux, Caroline; Lerouge, Patrice; Jouanin, Lise

2009-01-01

Background Different strategies (genetics, biochemistry, and proteomics) can be used to study proteins involved in cell biogenesis. The availability of the complete sequences of several plant genomes allowed the development of transcriptomic studies. Although the expression patterns of some Arabidopsis thaliana genes involved in cell wall biogenesis were identified at different physiological stages, detailed microarray analysis of plant cell wall genes has not been performed on any plant tissues. Using transcriptomic and bioinformatic tools, we studied the regulation of cell wall genes in Arabidopsis stems, i.e. genes encoding proteins involved in cell wall biogenesis and genes encoding secreted proteins. Results Transcriptomic analyses of stems were performed at three different developmental stages, i.e., young stems, intermediate stage, and mature stems. Many genes involved in the synthesis of cell wall components such as polysaccharides and monolignols were identified. A total of 345 genes encoding predicted secreted proteins with moderate or high level of transcripts were analyzed in details. The encoded proteins were distributed into 8 classes, based on the presence of predicted functional domains. Proteins acting on carbohydrates and proteins of unknown function constituted the two most abundant classes. Other proteins were proteases, oxido-reductases, proteins with interacting domains, proteins involved in signalling, and structural proteins. Particularly high levels of expression were established for genes encoding pectin methylesterases, germin-like proteins, arabinogalactan proteins, fasciclin-like arabinogalactan proteins, and structural proteins. Finally, the results of this transcriptomic analyses were compared with those obtained through a cell wall proteomic analysis from the same material. Only a small proportion of genes identified by previous proteomic analyses were identified by transcriptomics. Conversely, only a few proteins encoded by genes having moderate or high level of transcripts were identified by proteomics. Conclusion Analysis of the genes predicted to encode cell wall proteins revealed that about 345 genes had moderate or high levels of transcripts. Among them, we identified many new genes possibly involved in cell wall biogenesis. The discrepancies observed between results of this transcriptomic study and a previous proteomic study on the same material revealed post-transcriptional mechanisms of regulation of expression of genes encoding cell wall proteins. PMID:19149885

Lessons from the synthetic chemist nature.

PubMed

Jürjens, Gerrit; Kirschning, Andreas; Candito, David A

2015-05-01

This conceptual review examines the ideal multistep synthesis from the perspective of nature. We suggest that besides step- and redox economies, one other key to efficiency is steady state processing with intermediates that are immediately transformed to the next intermediate when formed. We discuss four of nature's strategies (multicatalysis, domino reactions, iteration and compartmentation) that commonly proceed via short-lived intermediates and show that these strategies are also part of the chemist's portfolio. We particularly focus on compartmentation which in nature is found microscopically within cells (organelles) and between cells and on a molecular level on multiprotein scaffolds (e.g. in polyketide synthases) and demonstrate how compartmentation is manifested in modern multistep flow synthesis.

Clonal type I interferon-producing and dendritic cell precursors are contained in both human lymphoid and myeloid progenitor populations.

PubMed

Chicha, Laurie; Jarrossay, David; Manz, Markus G

2004-12-06

Because of different cytokine responsiveness, surface receptor, and transcription factor expression, human CD11c(-) natural type I interferon-producing cells (IPCs) and CD11c(+) dendritic cells were thought to derive through lymphoid and myeloid hematopoietic developmental pathways, respectively. To directly test this hypothesis, we used an in vitro assay allowing simultaneous IPC, dendritic cell, and B cell development and we tested lymphoid and myeloid committed hematopoietic progenitor cells for their developmental capacity. Lymphoid and common myeloid and granulocyte/macrophage progenitors were capable of developing into both functional IPCs, expressing gene transcripts thought to be associated with lymphoid lineage development, and into dendritic cells. However, clonal progenitors for both populations were about fivefold more frequent within myeloid committed progenitor cells. Thus, in humans as in mice, natural IPC and dendritic cell development robustly segregates with myeloid differentiation. This would fit with natural interferon type I-producing cell and dendritic cell activity in innate immunity, the evolutionary older arm of the cellular immune system.

Introduction to provocative questions in left-right asymmetry.

PubMed

Levin, Michael; Klar, Amar J S; Ramsdell, Ann F

2016-12-19

Left-right asymmetry is a phenomenon that has a broad appeal-to anatomists, developmental biologists and evolutionary biologists-because it is a morphological feature of organisms that spans scales of size and levels of organization, from unicellular protists, to vertebrate organs, to social behaviour. Here, we highlight a number of important aspects of asymmetry that encompass several areas of biology-cell-level, physiological, genetic, anatomical and evolutionary components-and that are based on research conducted in diverse model systems, ranging from single cells to invertebrates to human developmental disorders. Together, the contributions in this issue reveal a heretofore-unsuspected variety in asymmetry mechanisms, including ancient chirality elements that could underlie a much more universal basis to asymmetry development, and provide much fodder for thought with far reaching implications in biomedical, developmental, evolutionary and synthetic biology. The new emerging theme of binary cell-fate choice, promoted by asymmetric cell division of a deterministic cell, has focused on investigating asymmetry mechanisms functioning at the single cell level. These include cytoskeleton and DNA chain asymmetry-mechanisms that are amplified and coordinated with those employed for the determination of the anterior-posterior and dorsal-ventral axes of the embryo.This article is part of the themed issue 'Provocative questions in left-right asymmetry'. © 2016 The Author(s).

Mitochondrial DNA transmission and confounding mitochondrial influences in cloned cattle and pigs.

PubMed

Takeda, Kumiko

2013-04-01

Although somatic cell nuclear transfer (SCNT) is a powerful tool for production of cloned animals, SCNT embryos generally have low developmental competency and many abnormalities. The interaction between the donor nucleus and the enucleated ooplasm plays an important role in early embryonic development, but the underlying mechanisms that negatively impact developmental competency remain unclear. Mitochondria have a broad range of critical functions in cellular energy supply, cell signaling, and programmed cell death; thus, affect embryonic and fetal development. This review focuses on mitochondrial considerations influencing SCNT techniques in farm animals. Donor somatic cell mitochondrial DNA (mtDNA) can be transmitted through what has been considered a "bottleneck" in mitochondrial genetics via the SCNT maternal lineage. This indicates that donor somatic cell mitochondria have a role in the reconstructed cytoplasm. However, foreign somatic cell mitochondria may affect the early development of SCNT embryos. Nuclear-mitochondrial interactions in interspecies/intergeneric SCNT (iSCNT) result in severe problems. A major biological selective pressure exists against survival of exogenous mtDNA in iSCNT. Yet, mtDNA differences in SCNT animals did not reflect transfer of proteomic components following proteomic analysis. Further study of nuclear-cytoplasmic interactions is needed to illuminate key developmental characteristics of SCNT animals associated with mitochondrial biology.

Epigenetic memory via concordant DNA methylation is inversely correlated to developmental potential of mammalian cells

PubMed Central

Goodson, Jamie; Al-Azzawi, Haneen; Allain, Shannon Q.; Simon, Noah; Palasek, Stan; Miller, Daniel G.; Johnson, Winslow C.; Laird, Charles D.

2017-01-01

In storing and transmitting epigenetic information, organisms must balance the need to maintain information about past conditions with the capacity to respond to information in their current and future environments. Some of this information is encoded by DNA methylation, which can be transmitted with variable fidelity from parent to daughter strand. High fidelity confers strong pattern matching between the strands of individual DNA molecules and thus pattern stability over rounds of DNA replication; lower fidelity confers reduced pattern matching, and thus greater flexibility. Here, we present a new conceptual framework, Ratio of Concordance Preference (RCP), that uses double-stranded methylation data to quantify the flexibility and stability of the system that gave rise to a given set of patterns. We find that differentiated mammalian cells operate with high DNA methylation stability, consistent with earlier reports. Stem cells in culture and in embryos, in contrast, operate with reduced, albeit significant, methylation stability. We conclude that preference for concordant DNA methylation is a consistent mode of information transfer, and thus provides epigenetic stability across cell divisions, even in stem cells and those undergoing developmental transitions. Broader application of our RCP framework will permit comparison of epigenetic-information systems across cells, developmental stages, and organisms whose methylation machineries differ substantially or are not yet well understood. PMID:29107996