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1.
Diabet Med ; 35(2): 223-231, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29178332

RESUMEN

AIMS: To explore the experiential perspective of people with Type 1 diabetes mellitus and eating disorders and that of the healthcare professionals treating them, and to understand the experience of both sides to inform future development of healthcare services. METHODS: Participants were recruited from Diabetics with Eating Disorders (a national UK charity), and through professional networks. Nine partially/fully recovered individuals with Type 1 diabetes and eating disorders and eight healthcare professionals participated in semi-structured interviews carried out by medically trained researchers. Data were transcribed and coded using a six-stage framework of thematic analysis. RESULTS: Four superordinate themes and several subordinate themes emerged from the Type 1 diabetes and eating disorders dataset: (1) perceptions surrounding service provision; (2) reflections on the recovery process; (3) the experiential perspective of living with Type 1 diabetes and an eating disorder; and (4) support mechanisms. Healthcare professional data elicited three superordinate themes and several subordinate themes: (1) service provision; (2) personal insight and reflection of professional role; and (3) challenges of working with dual diagnoses. CONCLUSION: People with Type 1 diabetes and eating disorders and their healthcare professionals provided insight into healthcare services from the patient and care delivery perspectives. There was general agreement from both groups that a multidisciplinary, collaborative (family inclusive), clinical approach to treatment is important, as well as adequate training opportunities for service providers. These findings may help to inform development strategies for multidisciplinary care approaches to Type 1 diabetes complicated by eating disorders.


Asunto(s)
Diabetes Mellitus Tipo 1/psicología , Trastornos de Alimentación y de la Ingestión de Alimentos/psicología , Adaptación Psicológica , Adolescente , Adulto , Actitud del Personal de Salud , Actitud Frente a la Salud , Diabetes Mellitus Tipo 1/complicaciones , Trastornos de Alimentación y de la Ingestión de Alimentos/complicaciones , Femenino , Humanos , Persona de Mediana Edad , Factores de Riesgo , Apoyo Social , Adulto Joven
2.
Anal Bioanal Chem ; 406(4): 1081-8, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23877174

RESUMEN

An analytical method was developed to characterize puparia cuticular lipids (hydrocarbons, waxes) and to compare the molecular distribution patterns in the extracts from either recent or older puparia. Acid-catalyzed transesterification and solvent extraction and purification, followed by combined gas chromatography coupled to mass spectrometry, were optimized for the determination of hydrocarbons and fatty acid ethyl esters from transesterified waxes, extracted from a single species of a fly scavenger (Hydrotaea aenescens Wiedemann, 1830). Comparison between recent (2012) or older (1997) puparia contents has highlighted significant composition differences, in particular, a general decrease of the chain length in the n-alkane distribution pattern and, on the contrary, an increase of the ester chain length. Both extracts contain traces of three hopane hydrocarbon congeners. Preliminary results evidence the change in puparia lipid composition over time, thus potentially providing new indices for estimating postmortem interval.


Asunto(s)
Cromatografía de Gases y Espectrometría de Masas/métodos , Muscidae/química , Pupa/química , Ceras/química , Animales , Hidrocarburos , Muscidae/crecimiento & desarrollo , Cambios Post Mortem , Pupa/crecimiento & desarrollo , Factores de Tiempo
3.
Development ; 128(20): 3987-94, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11641222

RESUMEN

The transcription factor Pax6 is required for eye morphogenesis in humans, mice and insects, and can induce ectopic eye formation in vertebrate and invertebrate organisms. Although the role of Pax6 has intensively been studied, only a limited number of genes have been identified that depend on Pax6 activity for their expression in the mammalian visual system. Using a large-scale in situ hybridization screen approach, we have identified a novel gene expressed in the mouse optic vesicle. This gene, Necab, encodes a putative cytoplasmic Ca(2+)-binding protein and coincides with Pax6 expression pattern in the neural ectoderm of the optic vesicle and in the forebrain pretectum. Remarkably, Necab expression is absent in both structures in Pax6 mutant embryos. By contrast, the optic vesicle-expressed homeobox genes Rx, Six3, Otx2 and Lhx2 do not exhibit an altered expression pattern. Using gain-of-function experiments, we show that Pax6 can induce ectopic expression of Necab, suggesting that Necab is a direct or indirect transcriptional target of Pax6. In addition, we have found that Necab misexpression can induce ectopic expression of the homeobox gene Chx10, a transcription factor implicated in retina development. Taken together, our results provide evidence that Necab is genetically downstream of Pax6 and that it is a part of a signal transduction pathway in retina development.


Asunto(s)
Proteínas de Unión al Calcio/genética , Proteínas de Unión al Calcio/fisiología , Proteínas del Ojo/genética , Proteínas del Ojo/fisiología , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/fisiología , Retina/embriología , Secuencia de Aminoácidos , Animales , Secuencia de Bases , ADN Complementario/genética , Regulación del Desarrollo de la Expresión Génica , Genes Homeobox , Humanos , Hibridación in Situ , Ratones , Datos de Secuencia Molecular , Familia de Multigenes , Factor de Transcripción PAX6 , Factores de Transcripción Paired Box , Proteínas Represoras , Homología de Secuencia de Aminoácido , Transducción de Señal
4.
Hum Mol Genet ; 10(17): 1819-27, 2001 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-11532991

RESUMEN

Here, we describe a novel spontaneous autosomal recessive mutation in the mouse that is characterized by skeletal and cardiac muscle degeneration. We have named this mutant degenerating muscle (dmu). At birth, mutant mice are indistinguishable from their normal littermates. Thereafter, the disease progresses rapidly and a phenotype is first observed at approximately 11 days after birth; the dmu mice are weak and have great difficulty in moving. The principal cause of the lack of mobility is muscle atrophy and wasting in the hindquarters. Affected mice die at or around the time of weaning of unknown causes. Histopathological observations and ultrastructural analysis revealed muscle degeneration in both skeletal and cardiac muscle, but no abnormalities in sciatic nerves. Using linkage analysis, we have mapped the dmu locus to the distal portion of mouse chromosome 15 in a region syntenic to human chromosome 12q13. Interestingly, scapuloperoneal muscular dystrophy (SPMD) in humans has been linked to this region. SPMD patients with associated cardiomyopathy have also been described in the past. Initial analysis of candidate genes on mouse chromosome 15 reveal that although intact transcripts for Scn8a, the gene encoding the sodium channel 8a subunit, are present in dmu mice, their levels are dramatically reduced. Furthermore, genetic complementation crosses between dmu and med (mutation in Scn8a) mice revealed that they are allelic. Our results suggest that at least a portion of the dmu phenotype is caused by a down-regulation of Scn8a, making dmu a new allele of Scn8a.


Asunto(s)
Ratones Mutantes/genética , Mutación , Proteínas del Tejido Nervioso/genética , Enfermedades Neuromusculares/genética , Canales de Sodio/genética , Alelos , Animales , Mapeo Cromosómico , Cromosomas Humanos Par 12 , Cruzamientos Genéticos , Modelos Animales de Enfermedad , Homocigoto , Humanos , Ratones , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Músculo Esquelético/patología , Miocardio/patología , Canal de Sodio Activado por Voltaje NAV1.6
5.
Plant J ; 24(1): 103-11, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11029708

RESUMEN

In plants of Sinapis alba induced to flower by one long day, the MADS box gene, SaMADS A, is expressed initially in the central corpus (L3 cells) of the shoot apical meristem (SAM), about 1.5-2 days before initiation of the first floral meristem. We have combined a physiological approach by testing the effects of three putative floral signals on SaMADS A expression in the SAM of S. alba plants with a transgenic approach using Arabidopsis thaliana plants. A single application of a low dose of a cytokinin or a gibberellin to the apex of vegetative S. alba plants is capable of mimicking perfectly the initial effect of the long day on SaMADS A transcription. A treatment combining the two hormones causes the same activation but seems to enhance the level of SaMADS A expression. A sucrose application to the apex of vegetative plants is, on the contrary, unable to activate SaMADS A expression. None of these chemicals, alone or combined, is capable of causing the floral shift at the SAM. Since the constitutive expression of SaMADS A leads to precocious flowering in A. thaliana and antisense expression of a fragment of the A. thaliana homologue AGL20 leads to a delay in flowering time, these results are consistent with SaMADS A activation being an intermediate event in a cytokinin- and/or gibberellin-triggered signal transduction pathway that is involved in the regulation of floral transition in S. alba.


Asunto(s)
Citocininas/farmacología , Proteínas de Unión al ADN/genética , Regulación de la Expresión Génica de las Plantas/fisiología , Giberelinas/farmacología , Planta de la Mostaza/genética , Plantas Medicinales , Factores de Transcripción/genética , Agrobacterium tumefaciens/genética , ADN sin Sentido/genética , Proteínas de Unión al ADN/metabolismo , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Hibridación in Situ , Proteínas de Dominio MADS , Meristema/fisiología , Planta de la Mostaza/efectos de los fármacos , Planta de la Mostaza/crecimiento & desarrollo , Fenotipo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Tallos de la Planta/fisiología , Plantas Modificadas Genéticamente , Regiones Promotoras Genéticas , Factores de Transcripción/metabolismo , Transformación Genética
6.
Development ; 127(20): 4325-34, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11003833

RESUMEN

We have studied the molecular basis of the Pax2 and Pax6 function in the establishment of visual system territories. Loss-of-function mutants have revealed crucial roles for Pax2 in the generation of the optic stalk and for Pax6 in the development of the optic cup. Ectopic expression of Pax6 in the optic stalk under control of Pax2 promoter elements resulted in a shift of the optic cup/optic stalk boundary indicated by the presence of retinal pigmented cells on the optic stalk. By studying mouse embryos at early developmental stages we detected an expansion of Pax2 expression domain in the Pax6(-/-) mutant and of Pax6 expression domain in the Pax2(-/-) embryo. These results suggest that the position of the optic cup/optic stalk boundary depends on Pax2 and Pax6 expression, hinting at a possible molecular interaction. Using gel shift experiments, we confirmed the presence of Pax2- and Pax6-binding sites on the retina enhancer of the Pax6 gene and on the Pax2 upstream control region, respectively. Co-transfection experiments revealed a reciprocal inhibition of Pax2 promoter/enhancer activity by Pax6 protein and vice versa. Based on our findings, we propose a model for Pax gene regulation that establishes the proper spatial regionalization of the mammalian visual system.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Ojo/embriología , Proteínas de Homeodominio/metabolismo , Proteínas Represoras/metabolismo , Factores de Transcripción/metabolismo , Animales , Tipificación del Cuerpo , Elementos de Facilitación Genéticos , Proteínas del Ojo/metabolismo , Ratones , Ratones Transgénicos , Modelos Genéticos , Factor de Transcripción PAX2 , Factor de Transcripción PAX6 , Factores de Transcripción Paired Box , Transcripción Genética
7.
Planta ; 211(3): 370-5, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10987555

RESUMEN

The frequency of plasmodesmata increases in the shoot apical meristem of plants of Sinapis alba L. induced to flower by exposure to a single long day. This increase is observed within all cell layers (L1, L2, L3) as well as at the interfaces between these layers, and it occurs in both the central and peripheral zones of the shoot apical meristem. The extra plasmodesmata are formed only transiently, from 28 to 48 h after the start of the long day, and acropetally since they are detectable in L3 4 h before they are seen in L1 and L2. These observations indicate that (i) in the Sinapis shoot apical meristem at floral transition, there is an unfolding of a single field with increased plasmodesmatal connectivity, and (ii) this event is an early effect of the arrival at this meristem of the floral stimulus of leaf origin. Since (i) the wave of increased frequency of plasmodesmata is 12 h later than the wave of increased mitotic frequency (A. Jacqmard et al. 1998, Plant cell proliferation and its regulation in growth and development, pp. 67 78; Wiley), and (ii) the increase in frequency of plasmodesmata is observed in all cell walls, including in walls not deriving from recent divisions (periclinal walls separating the cell layers), it is concluded that the extra plasmodesmata seen at floral transition do not arise in the forming cell plate during mitosis and are thus of secondary origin.


Asunto(s)
Planta de la Mostaza/citología , Planta de la Mostaza/fisiología , Plantas Medicinales , Meristema/citología , Meristema/fisiología , Meristema/ultraestructura , Planta de la Mostaza/ultraestructura , Brotes de la Planta/citología , Brotes de la Planta/fisiología , Brotes de la Planta/ultraestructura , Tallos de la Planta/citología , Tallos de la Planta/fisiología
8.
Dev Dyn ; 219(2): 216-25, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11002341

RESUMEN

Several proteins belonging to the plakin family of cytoskeletal linker proteins have recently been identified, including dystonin/Bpag1 and plectin. These proteins are unique in their abilities to form bridges between different cytoskeletal elements through specialized modular domains. We have previously reported the cloning and partial characterization of Acf7, a novel member of the plakin family. More recently, the full-length cDNA for mouse Acf7 has been reported. Acf7 has a hybrid composition, with extended homology to dystonin/Bpag1 and plectin in the N-terminal half, and to dystrophin in the central and C-terminal half. Recent studies have demonstrated that Acf7 has functional actin and microtubule binding domains. Here, we describe the developmental expression profile for mouse Acf7. RNA in situ hybridization experiments revealed Acf7 transcripts in the dermomyotome and neural fold of day 8.5 mouse embryos. Later in development, Acf7 expression was predominant in neural and muscle tissues and was strongly up-regulated just before birth in type II alveolar cells of the lung. Altogether, our results suggest that Acf7 functions as a versatile cytoskeletal linker protein and plays an important role in neural, muscle, and lung development.


Asunto(s)
Encéfalo/fisiología , Regulación del Desarrollo de la Expresión Génica , Pulmón/fisiología , Proteínas de Microfilamentos/genética , Músculos/fisiología , Médula Espinal/fisiología , Envejecimiento , Animales , Animales Recién Nacidos , Encéfalo/embriología , Encéfalo/crecimiento & desarrollo , Desarrollo Embrionario y Fetal , Pulmón/embriología , Pulmón/crecimiento & desarrollo , Ratones , Ratones Mutantes , Proteínas de Microfilamentos/metabolismo , Microtúbulos/fisiología , Desarrollo de Músculos , Músculos/embriología , Especificidad de Órganos , Polimorfismo de Longitud del Fragmento de Restricción , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Médula Espinal/embriología , Médula Espinal/crecimiento & desarrollo
9.
Acad Med ; 75(6): 595-601, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10875503

RESUMEN

Two dissimilar U.S. medical schools--the University of Pittsburgh School of Medicine and the University of Texas Medical Branch at Galveston-changed their curricula for the first two years of medical education from ones that were lecture-dominated and departmentally run to ones that are centrally governed, multi-modal, goal-oriented, and fully integrated, with mechanisms to continue curricular change into the last two years of medical education. The change at each school was in response to national education philosophy, the recommendations of the Liaison Committee for Medical Education after the most recent site visit, and faculty's and students' concerns and interests. The change process took place over a three- to four-year period at each school, involved students, faculty, and administration, and utilized task forces and retreats as communication vehicles. The barriers encountered (e.g., belief by some that the curriculum needed no change; concern over loss of departments' control) and the processes employed to overcome them and to radically change the curricula (e.g., commitment of the central administration and dean to the change, involvement of all segments of the school in the change process, appointment of department chairs on task forces, and creation of a strong curriculum committee that gave authority to faculty and students) were essentially identical. The resulting curricula were also largely similar in their main characteristics, but there were notable differences, based on the goals and concerns of the two institutions.


Asunto(s)
Curriculum , Facultades de Medicina/normas , Educación Médica/normas , Humanos , Objetivos Organizacionales , Pennsylvania , Facultades de Medicina/organización & administración , Texas
10.
Mech Dev ; 93(1-2): 59-69, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10781940

RESUMEN

During vertebrate eye development, the expression of the homeobox gene Six6 is restricted to the neural retina and is initiated later than Rx and Pax6 in the presumptive retina field. We show here that overexpression of mouse Six6 in Xenopus embryos can induce transformation of competent tissue of the anterior neural plate into retinal tissue. In Six6 injected embryos, the molecular identity of the presumptive midbrain and rostral hindbrain regions was lost, as shown by the absence of XEn-2 and Xpax2 expression, being replaced by the ectopic expression of the retinal markers Xpax6 and Xrx. When allowed to grow further, Six6 injected embryos developed ectopic eye-like structures in the rostral brain and showed a transformation of the midbrain into retina. Similar results were obtained upon overexpression of Six3 or Xsix3, revealing a possible redundance of Six3 and Six6 activities. Taken together, results obtained suggest that during normal retina development, the relatively late expressed Six6 gene becomes part of a network of retinal homeobox genes that are linked together by positive feedback loops. Furthermore, our results demonstrate that the primitive neural ectoderm of the future midbrain and rostral hindbrain is competent to form retinal tissue.


Asunto(s)
Proteínas del Ojo/fisiología , Proteínas de Homeodominio/fisiología , Mesencéfalo/embriología , Retina/embriología , Transactivadores/fisiología , Proteínas de Xenopus , Animales , Sistema Nervioso Central/embriología , Ojo/embriología , Proteínas del Ojo/biosíntesis , Proteínas del Ojo/genética , Expresión Génica , Proteínas de Homeodominio/biosíntesis , Proteínas de Homeodominio/genética , Ratones , Morfogénesis , Proteínas del Tejido Nervioso/genética , ARN , Transactivadores/biosíntesis , Transactivadores/genética , Xenopus , Proteína Homeobox SIX3
11.
Mech Dev ; 84(1-2): 31-40, 1999 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10473118

RESUMEN

We report on the isolation of a murine homeobox-containing gene, Six6 (Optx2), that shows extended identity in its coding region with Six3, the only member of the mammalian Six gene family known to be expressed in the optic primordium. Phylogenetic analysis demonstrates that Six6 and Six3 belong to a separate group of homeobox-genes that are closely related to the recently identified Drosophila optix. Earliest Six6 expression was detected in the floor of the diencephalic portion of the primitive forebrain, a region predicted to give rise to the neurohypophysis and to the hypothalamus. Later on, Six6 mRNA was found in the primordial tissues giving rise to the mature pituitary: the Rathke's pouch and the infundibular recess. In the optic primordium, Six6 demarcates the presumptive ventral optic stalk and the ventral portion of the future neural retina. In the developing eye. Six6 expression was detected in the neural retina, the optic chiasma and optic stalk, but not in the lens. When compared to Six6, Six3 expression pattern was highly similar, but with a generally broader transcripts distribution in the brain and in the visual system. We finally show that Six6 does not require Pax6 for its expression in the optic primordium, suggesting that Six6 acts on a parallel and/or independent pathway with Pax6 in the genetic cascade governing early development of the eye.


Asunto(s)
Proteínas de Homeodominio/genética , Hipotálamo/embriología , Quiasma Óptico/embriología , Hipófisis/embriología , Transactivadores/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Clonación Molecular , Proteínas de Unión al ADN/genética , Proteínas del Ojo/genética , Proteínas del Ojo/metabolismo , Proteínas de Homeodominio/metabolismo , Hipotálamo/metabolismo , Ratones , Ratones Mutantes , Datos de Secuencia Molecular , Mutación , Proteínas del Tejido Nervioso/genética , Quiasma Óptico/metabolismo , Factor de Transcripción PAX6 , Factores de Transcripción Paired Box , Filogenia , Hipófisis/metabolismo , Proteínas Represoras , Retina/embriología , Retina/metabolismo , Homología de Secuencia de Aminoácido , Transactivadores/metabolismo , Corteza Visual/embriología , Corteza Visual/metabolismo , Proteína Homeobox SIX3
12.
Planta ; 207(4): 496-504, 1999 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10093894

RESUMEN

Although endoreduplication is common in plants, little is known about the mechanisms regulating this process. Here, we report the patterns of endoreduplication at the cellular level in the shoot apex of Arabidopsis thaliana L. Heynh. plants grown under short-day conditions. We show that polyploidy is developmentally established in the pith, maturing leaves, and stipules. To investigate the role of the cell cycle genes CDC2aAt, CDC2bAt, CYCB1;1, and CKS1At in the process of endoreduplication, in-situ hybridizations were performed on the vegetative shoot apices. Expression of CDC2aAt, CDC2bAt, and CYCB1;1 was restricted to mitotically dividing cells. In contrast, CKS1At expression was present in both mitotic and endoreduplicating tissues. Our data indicate that CDC2aAt, CDC2bAt, and CYCB1;1 only operate during mitotic divisions, whereas CKS1At may play a role in both the mitotic and endoreduplication cycle.


Asunto(s)
Arabidopsis/genética , Proteínas de Ciclo Celular/genética , Replicación del ADN/fisiología , Mitosis/fisiología , Arabidopsis/citología , Proteínas de Ciclo Celular/fisiología , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Poliploidía
13.
J Gen Intern Med ; 13(11): 768-73, 1998 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9824524

RESUMEN

The confluence of enhanced attention to primary care and palliative care education presents educators with an opportunity to improve both (as well as patient care) through integrated teaching. Improvements in palliative care education will have benefits for dying patients and their families, but will also extend to the care of many other primary care patients, including geriatric patients and those with chronic illnesses, who make up a large proportion of the adult primary care population. In addition, caring for the dying, and teaching others to carry out this task, can be an important vehicle for personal and professional growth and development for both students and their teachers.


Asunto(s)
Educación de Pregrado en Medicina/tendencias , Cuidados Paliativos/tendencias , Atención Primaria de Salud/tendencias , Cuidado Terminal/tendencias , Curriculum , Humanos
14.
Planta ; 206(1): 131-7, 1998 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9715535

RESUMEN

In order to test whether an increased export of carbohydrates by leaves and starch mobilization are critical for floral transition in Arabidopsis thaliana, the Columbia ecotype as well as its starchless mutant pgm and starch-in-excess mutant sex1 were investigated. Induction of flowering was achieved by exposure of plants to either one long day (LD) or one displaced short day (DSD). The following conclusions were drawn: (i) Both the pgm and sex1 mutants have a late-flowering phenotype in days shorter than 16 h. (ii) When inductive treatments cause a large, percentage of induced plants, there is always a large, early and transient increase in carbohydrate export from leaves. By contrast, when an inductive treatment results in only a low percentage of induced plants (pgm plants exposed to one DSD), the export of carbohydrates from leaves is not increased, supporting the idea that phloem carbohydrates have a critical function in floral transition. (iii) Starch mobilization is not required to obtain an increased carbohydrate export when induction is by one LD (extended period of photosynthesis), but is absolutely essential when induction is by one DSD (period of photosynthesis unaffected). (iv) Floral induction apparently increases the capability of the leaf phloem-loading system.


Asunto(s)
Arabidopsis/fisiología , Carbohidratos/fisiología , Almidón/fisiología , Mutagénesis , Fotoperiodo , Hojas de la Planta/metabolismo
15.
Development ; 125(11): 2135-48, 1998 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9570777

RESUMEN

A central role for the Schwann cell cytoskeleton in the process of peripheral nerve myelination has long been suggested. However, there is no genetic or biological evidence as yet to support this assumption. Here we show that dystonia musculorum (dt) mice, which carry mutations in dystonin, a cytoskeletal crosslinker protein, have hypo/amyelinated peripheral nerves. In neonatal dt mice, Schwann cells were arrested at the promyelinating stage and had multiple myelinating lips. Nerve graft experiments and primary cultures of Schwann cells demonstrated that the myelination abnormality in dt mice was autonomous to Schwann cells. In culture, dt Schwann cells showed abnormal polarization and matrix attachment, and had a disorganized cytoskeleton. Finally, we show that the dt mutation was semi-dominant, heterozygous animals presenting hypo- and hyper-myelinated peripheral nerves. Altogether, our results suggest that dt Schwann cells are deficient for basement membrane interaction and demonstrate that dystonin is an essential component of the Schwann cell cytoskeleton at the time of myelination.


Asunto(s)
Proteínas Portadoras , Proteínas del Citoesqueleto/metabolismo , Citoesqueleto/metabolismo , Enfermedades Desmielinizantes/etiología , Distonía/etiología , Vaina de Mielina/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Células de Schwann/metabolismo , Animales , Animales Recién Nacidos , Enfermedades Desmielinizantes/genética , Distonía/genética , Distonina , Heterocigoto , Homocigoto , Ratones , Ratones Mutantes , Proteína P0 de la Mielina/biosíntesis , Proteína P0 de la Mielina/genética , Neuronas Aferentes/patología , Nervios Periféricos/patología , ARN Mensajero/análisis , Células de Schwann/patología , Raíces Nerviosas Espinales/patología
16.
Dev Genet ; 22(2): 160-8, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9581287

RESUMEN

Dystonia musculorum (dt) is a recessive hereditary neuropathy of the mouse. Affected animals display loss of limb coordination and twisting of the trunk. Sensory nerve fibers of these mice are severely reduced in number, and the remaining fibers present numerous axonal swellings. The gene defective in dt, dystonin (Dst), encodes a cytoskeletal linker protein that forms the bridge between F-actin and intermediate filaments. Dst is expressed during embryogenesis, whereas overt phenotype in dt mice only appears during the second week after birth. Here we show that axonal swellings are present in sensory nerve fibers of dt embryos as early as E15.5, before myelination and radial axonal growth have begun. Thus disease progression is gradual in dt mice, having begun during embryogenesis. In dt embryos, microtubule network disorganization and cytoplasmic organelle accumulation within axonal swellings were consistently observed. In addition, a few of the axonal swellings presented intermediate filament accumulation. These results demonstrate that dystonin is required for cytoskeleton organization during axonogenesis. They also suggest that axonal transport defects, through microtubule network perturbation, may be the primary mechanism of neurodegeneration in dt mice.


Asunto(s)
Proteínas Portadoras , Distonía Muscular Deformante/embriología , Distonía Muscular Deformante/patología , Regulación del Desarrollo de la Expresión Génica , Sistema Nervioso/patología , Animales , Proteínas del Citoesqueleto/genética , Citoesqueleto/genética , Citoesqueleto/patología , Distonía Muscular Deformante/genética , Distonina , Ratones , Ratones Mutantes , Mutación , Proteínas del Tejido Nervioso/genética , Sistema Nervioso/embriología
17.
Plant Mol Biol ; 34(4): 573-82, 1997 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9247539

RESUMEN

SaMADS D gene of Sinapis alba was isolated by screening a cDNA library from young inflorescences with a mixture of MADS-box genes of Antirrhinum majus (DEF, GLO, SQUA) as probe. Amino acid sequence comparison showed a high degree of similarity between the SaMADS D and AGL9, DEFH200, TM5, FBP2 and DEFH 72 gene products. Analysis of the SaMADS D gene expression by in situ hybridization reveals a novel expression pattern for a MADS-box gene and suggests a dual function for this gene: first, as a determinant in inflorescence meristem identity since it starts to be expressed directly beneath the inflorescence meristem at the time of initiation of the first floral meristem, is no longer expressed in the inflorescence meristem forced to revert to production of leafy appendages, and is expressed again when the reverted meristem resumes floral meristem initiation, and, second, as an interactor with genes specifying floral organ identity since it is expressed in the floral meristem from the stage of sepal protrusion.


Asunto(s)
Proteínas de Unión al ADN/genética , Genes de Plantas , Meristema/genética , Planta de la Mostaza/genética , Proteínas de Plantas/genética , Plantas Medicinales , Factores de Transcripción/genética , Secuencia de Aminoácidos , Secuencia de Bases , ADN Complementario/genética , Biblioteca de Genes , Hibridación in Situ , Proteínas de Dominio MADS , Meristema/anatomía & histología , Datos de Secuencia Molecular , Morfogénesis/genética , Planta de la Mostaza/crecimiento & desarrollo , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , Distribución Tisular
18.
New Phytol ; 135(1): 59-66, 1997 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33863157

RESUMEN

Unifoliated plants of Lolium temulentum L. ev. Ceres, a qualitative long-day grass, were induced to flower by one 24-h long day (LD) or by one 8-h short day (SD) advanced by 1 2 h in the normal regime, so-called 'displaced short day' (DSD). Standard light for SD and DSD was a mixture of fluorescence and incandescence at 400 µmol m-2 s-1 whereas the extension period of the 24-h LD was solely incandescence at 10-15 µmol m-2 s-1 . The DSD system was first characterized by the timings of floral induction, stimulus translocation and apical development. Carbohydrates in the blade tissues and in leaf exudate were analysed comparatively in vegetative and induced plants. Fructans were not detected in the leaf tissues whereas sucrose and starch were found to be present in similar amounts. In SD, their contents exhibited a diurnal fluctuation and were not in large excess. The common change observed during the two inductive treatments was that starch remained at a high level during the LD extension, even though the lighting was unsuitable for photosynthesis, and increased transiently in DSD. Sucrose was the major sugar contained in the leaf exudate. Its content increased when flowering was induced, but not at the same time in the two systems. In LD, sucrose exudation rose when plants were returned to standard light after the inductive cycle, i.e. after the LD stimulus had left the leaf blade. By contrast, during the DSD, sucrose was transported at the same time as the floral stimulus. Results are discussed together with the methods used to time stimulus translocation and their implications.

19.
Genomics ; 38(1): 19-29, 1996 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-8954775

RESUMEN

We have recently cloned the gene responsible for the mouse neurological disorder dystonia musculorum. The predicted product of this gene, dystonin (Dst), is a neural isoform of bullous pemphigoid antigen 1 (Bpag1) with an N-terminal actin binding domain. Here we report on the cloning and characterization of mouse ACF7. Sequence analysis revealed extended homology of mACF7 with both the actin binding domain (ABD) and the Bpag1 portions of dystonin. Moreover, mACF7 and Dst display similar isoform diversity and encode similar sized transcripts in the nervous system. Phylogenetic analysis of mACF7 and dystonin ABD sequences suggests a recent evolutionary origin and that these proteins form a separate novel subfamily within the beta-spectrin superfamily of actin binding proteins. Given the implication of several actin binding proteins in genetic disorders, it is important to know the pattern of mACF7 expression. mACF7 transcripts are detected principally in lung, brain, spinal cord, skeletal and cardiac muscle, and skin. Intriguingly, mACF7 expression in lung is strongly induced just before birth and is restricted to type II alveolar cells. To determine whether spontaneous mutants that may be defective in mACF7 exist, we have mapped the mACF7 gene to mouse chromosome 4.


Asunto(s)
Proteínas Portadoras , Proteínas del Citoesqueleto/genética , Proteínas de Microfilamentos/genética , Proteínas del Tejido Nervioso/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Mapeo Cromosómico , Clonación Molecular , Proteínas del Citoesqueleto/metabolismo , ADN Complementario , Distonina , Masculino , Ratones , Ratones Endogámicos BALB C , Proteínas de Microfilamentos/metabolismo , Datos de Secuencia Molecular , Proteínas del Tejido Nervioso/metabolismo , ARN Mensajero/genética
20.
Plant J ; 9(6): 947-52, 1996 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8696370

RESUMEN

A system of one-shot induction of flowering in Arabidopsis thaliana, ecotype Columbia, is described. Plants from vernalized seeds are grown for 2 months in 8 h short days at an irradiance of 48 mumol m-2 sec-1 (fluorescent light only). At that age they can be induced to flower by exposure to either a single long day or a single displaced short day. Non-induced plants stay vegetative for at least a further month. Synchrony of induction among the individuals of the population exposed to one long day is of the same order as in the best classical model plants, that is, the fastest individuals are only 6 h ahead of the slowest ones. A further advantage of this system is the large size of plants at the time of induction, allowing easy analysis of changes in leaves, leaf exudate and shoot meristem. The design of such a synchronous system will allow the timings of gene activations and deactivations to be established in the different plant parts, before flowers are initiated.


Asunto(s)
Arabidopsis/fisiología , Arabidopsis/efectos de la radiación , Oscuridad , Luz , Modelos Biológicos , Estaciones del Año , Factores de Tiempo
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