Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 70
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Dairy Sci ; 102(2): 1832-1846, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30580949

RESUMO

Canadian dairy producers have an increasing interest in recycled manure solids (RMS) as bedding material because of reduced availability of traditional bedding resources. Information regarding methods to obtain RMS and composition of RMS is very limited. Hence, a 2-part investigation was developed to compare the performances of 3 mechanical solid-liquid manure separators (part I) and 4 composting methods (part II; companion paper in this issue) for the production of high quality RMS. In this first study, a roller press, a screw press, and a decanter centrifuge were tested for the separation of slurry manure from a commercial dairy farm. During the experiment, the quantity of slurry manure processed and the volume and mass of the liquid and solid fractions were measured. The energy consumption of each separator was recorded, and samples of the slurry, liquid, and solid effluents were collected for analysis. The type of separator did not significantly influence the chemical and bacteriological composition of RMS produced. The choice of a separator for Canadian dairy producers should thus be based on the equipment cost and its capacity, targeted solids dry matter (DM) content and structure, and fertilizing quality of the separated liquid. The decanter centrifuge produced the solid phase with the highest DM and best separation efficiencies for DM, N, and P. However, its low production capacity (1.5 m3/h vs. 9.1-20.3 m3/h) combined with its high acquisition cost (Can$145,000 vs. Can$75,000) and energy consumption (4.99 kWh/m3 vs. 0.10-0.35 kWh/m3) reduce its technical and profitability values. Besides, the centrifuge produced fine structured RMS and a low-quality liquid fraction, not suitable as dairy cow bedding and fertilizer, respectively. Both presses reached acceptable production capacity at a minimal operation cost. However, the poor performance in terms of DM (25%) of the model of screw press used in this study produced RMS unsuitable for immediate use without further processing. The model of roller press used in this study had the advantages of almost reaching the recommended DM content in RMS (>34%), being flexible in terms of inputs, and producing fluffy RMS. Nevertheless, its compression process seemed to allow greater passage of solids into the liquid fraction compared with the screw press. Part II of this work explores different composting methods to reduce the health risks associated with screw-pressed RMS before their use as bedding.


Assuntos
Criação de Animais Domésticos/métodos , Roupas de Cama, Mesa e Banho/veterinária , Bovinos/fisiologia , Esterco/análise , Reciclagem/métodos , Criação de Animais Domésticos/instrumentação , Animais , Canadá , Fazendas , Feminino , Masculino
2.
Psychol Med ; 46(12): 2605-15, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27353541

RESUMO

BACKGROUND: Language use is of increasing interest in the study of mental illness. Analytical approaches range from phenomenological and qualitative to formal computational quantitative methods. Practically, the approach may have utility in predicting clinical outcomes. We harnessed a real-world sample (blog entries) from groups with psychosis, strong beliefs, odd beliefs, illness, mental illness and/or social isolation to validate and extend laboratory findings about lexical differences between psychosis and control subjects. METHOD: We describe the results of two experiments using Linguistic Inquiry and Word Count software to assess word category frequencies. In experiment 1, we compared word use in psychosis and control subjects in the laboratory (23 per group), and related results to subject symptoms. In experiment 2, we examined lexical patterns in blog entries written by people with psychosis and eight comparison groups. In addition to between-group comparisons, we used factor analysis followed by clustering to discern the contributions of strong belief, odd belief and illness identity to lexical patterns. RESULTS: Consistent with others' work, we found that first-person pronouns, biological process words and negative emotion words were more frequent in psychosis language. We tested lexical differences between bloggers with psychosis and multiple relevant comparison groups. Clustering analysis revealed that word use frequencies did not group individuals with strong or odd beliefs, but instead grouped individuals with any illness (mental or physical). CONCLUSIONS: Pairing of laboratory and real-world samples reveals that lexical markers previously identified as specific language changes in depression and psychosis are probably markers of illness in general.


Assuntos
Narrativas Pessoais como Assunto , Transtornos Psicóticos/fisiopatologia , Transtornos Psicóticos/psicologia , Esquizofrenia/fisiopatologia , Psicologia do Esquizofrênico , Comportamento Verbal , Adulto , Depressão/fisiopatologia , Depressão/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
3.
Curr Oncol ; 22(2): 156-63, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25908914

RESUMO

Across Canada, introduction of the Pap test for cervical cancer screening, followed by mammography for breast cancer screening and, more recently, the fecal occult blood test for colorectal cancer screening, has contributed to a reduction in cancer mortality. However, another contribution of screening has been disparities in cancer mortality between certain populations. Here, we explore the disparities associated with breast and cervical cancer screening and preliminary data concerning disparities in colorectal cancer screening. Although some disparities in screening utilization have been successfully reduced over time (for example, mammography and Pap test screening in rural and remote populations), screening utilization data for other populations (for example, low-income groups) clearly indicate that disparities have existed and continue to exist across Canada. Organized screening programs in Canada have been able to successfully engage 80% of women for regular cervical cancer screening and 70% of women for regular mammography screening, but of the women who remain to be reached or engaged in regular screening, those with the least resources, those who are the most isolated, and those who are least culturally integrated into Canadian society as a whole are over-represented. Population differences are also observed for utilization of colorectal cancer screening services. The research literature on interventions to promote screening utilization provides some evidence about what can be done to increase participation in organized screening by vulnerable populations. Adaption and adoption of evidence-based screening promotion interventions can increase the utilization of available screening services by populations that have experienced the greatest burden of disease with the least access to screening services.

4.
Ann Bot ; 111(2): 207-14, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23235696

RESUMO

BACKGROUND AND AIMS: Three ecological relationships are possible between co-flowering plant species; they may have no effect on one another, compete for pollination services, or facilitate one another by attracting more pollinators to the area. In this study, the pollinator-mediated relationship between two mangrove species with overlapping flowering phenologies was investigated in one south Florida community. METHODS: Pollinator observations were recorded between 0900 h and 1700 h during June and July, 2008-2010. Insect visitation rates to Avicennia germinans and Laguncularia racemosa were estimated from 522 observation intervals of 10 min during three phenological time periods, when each species flowered alone and when they co-flowered. The number of timed intervals varied between years due to differences in flowering phenology, from four to 42 for A. germinans and from nine to 94 for L. racemosa. KEY RESULTS: Avicennia germinans began flowering first in all years, and insect visitation rates were significantly greater to A. germinans than to L. racemosa (P<0·001). Flowers of both species received visits from bees, wasps, flies and butterflies; Apis mellifera was the most common floral visitor to both species. Visitation rates to L. racemosa increased significantly when A. germinans stopped flowering (P<0·001). However, there was no significant change in visitation rates to A. germinans after L. racemosa began flowering (P=0·628). CONCLUSIONS: When they co-flowered, A. germinans outcompeted L. racemosa for pollinators. Laguncularia racemosa hermaphrodites self-pollinate autogamously when not visited by insects, so reduced visitation to L. racemosa flowers reduced the frequency of outcrossing and increased the frequency of selfing. Reduced outcrossing limits male reproductive success in this androdioecious species, which could lead to changes in the breeding system. The degree of overlap in flowering phenologies varied between years, so the effect on the mating and breeding system may differ between years.


Assuntos
Avicennia/fisiologia , Avicennia/parasitologia , Abelhas/fisiologia , Combretaceae/fisiologia , Combretaceae/parasitologia , Animais , Cruzamento , Comportamento Alimentar , Florida , Flores/parasitologia , Flores/fisiologia , Insetos/fisiologia , Polinização , Reprodução , Especificidade da Espécie
5.
6.
Nat Commun ; 12(1): 3126, 2021 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-34035259

RESUMO

Hybridization and polyploidization are powerful mechanisms of speciation. Hybrid speciation often coincides with whole-genome duplication (WGD) in eukaryotes. This suggests that WGD may allow hybrids to thrive by increasing fitness, restoring fertility and/or increasing access to adaptive mutations. Alternatively, it has been suggested that hybridization itself may trigger WGD. Testing these models requires quantifying the rate of WGD in hybrids without the confounding effect of natural selection. Here we show, by measuring the spontaneous rate of WGD of more than 1300 yeast crosses evolved under relaxed selection, that some genotypes or combinations of genotypes are more prone to WGD, including some hybrids between closely related species. We also find that higher WGD rate correlates with higher genomic instability and that WGD increases fertility and genetic variability. These results provide evidence that hybridization itself can promote WGD, which in turn facilitates the evolution of hybrids.


Assuntos
Duplicação Gênica , Genoma Fúngico/genética , Hibridização Genética , Saccharomyces/genética , Adaptação Fisiológica/genética , Diploide , Evolução Molecular , Variação Genética/genética , Instabilidade Genômica/genética , Taxa de Mutação , Filogenia , Poliploidia , Saccharomyces/classificação , Saccharomyces cerevisiae/genética , Especificidade da Espécie
7.
J Exp Med ; 193(10): 1189-98, 2001 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-11369790

RESUMO

We show that cytotoxic T lymphocytes (CTLs) infiltrating a kidney tumor recognize a peptide encoded by an alternative open reading frame (ORF) of the macrophage colony-stimulating factor (M-CSF) gene. Remarkably, this alternative ORF, which is translated in many tumors concurrently with the major ORF, is also translated in some tissues that do not produce M-CSF, such as liver and kidney. Such a dissociation of the translation of two overlapping ORFs from the same gene is unexpected. The antigenic peptide encoded by the alternative ORF is presented by human histocompatibility leukocyte antigen (HLA)-B*3501 and has a length of 14 residues. Peptide elution indicated that tumor cells naturally present this 14 mer, which is the longest peptide known to be recognized by CTLs. Binding studies of peptide analogues suggest that it binds by its two extremities and bulges out of the HLA groove to compensate for its length.


Assuntos
Antígenos de Neoplasias/genética , Linfócitos do Interstício Tumoral/imunologia , Fator Estimulador de Colônias de Macrófagos/genética , Fases de Leitura Aberta , Peptídeos/genética , Linfócitos T Citotóxicos/imunologia , Sequência de Aminoácidos , Antígenos de Neoplasias/imunologia , Sequência de Bases , Carcinoma de Células Renais/imunologia , Citotoxicidade Imunológica , Antígeno HLA-B35 , Humanos , Neoplasias Renais , Fator Estimulador de Colônias de Macrófagos/imunologia , Dados de Sequência Molecular , Peptídeos/imunologia , Biossíntese de Proteínas
8.
Sci Total Environ ; 726: 138515, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32481216

RESUMO

Since the mid-1990s, the decline of the yellow perch population of Lake Saint-Pierre (hereinafter LSP) in Quebec, Canada has been the subject of several research programs. The combined effect of habitat deterioration, the presence of invasive species, and poor water quality negatively affected the yellow perch population in this lake. In 2013, we sampled yellow perch (larvae, juveniles and adults) at six sites along the St. Lawrence River representing a gradient of increasing human influences from upstream to downstream and measured several biomarkers including retinoid compounds (vitamin A). In the most contaminated sites (LSP, north and south shores), we found that retinoid stores were decreased in all three stages of development. To corroborate these results and to test other biomarkers, we once again sampled yellow perch (adults only) from the same sites. Results from our 2014 and 2015 samplings confirmed that LSP yellow perch appeared to be at a disadvantage compared to fish from upstream populations. Individuals from LSP have lower acetylcholinesterase (AChE) activity as well as lower retinoid levels in liver and plasma. These fish were also marked by lower levels of antioxidants such as lycopene and vitamin E. A discriminant analysis of this set of results confirmed that the yellow perch of the LSP could be easily discriminated from those of the other sites (2014 and 2015) on the basis of liver retinoid and, to a lesser extent, of the liver tocopherol and protein concentration of the muscle, as well as AChE activity and DROH (all-trans-3,4-dehydroretinol) measured in plasma.


Assuntos
Percas , Poluentes Químicos da Água/análise , Animais , Biomarcadores , Canadá , Nível de Saúde , Humanos , Quebeque
9.
Science ; 260(5114): 1653-5, 1993 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-17810208

RESUMO

Polycrystalline samples of the chalcopyrites CulnS(2), CulnSe(2), and CulnSSe were Prepared from stoichiometric mixtures of the pure elements by microwave irradiation. The reactions were performed in sealed quartz tubes in as few as 3 minutes. The products were analyzed by x-ray diffraction, scanning electron microscopy, energy dispersive x-ray analysis, and x-ray photoelectron spectroscopy. The surface morphology and shape of the particles produced by this method suggest that the products are formed from liquid melts. This method could be applied to the production of bulk chalcopyrite as sources for thin film growth.

10.
Science ; 157(3790): 808-9, 1967 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-17842784

RESUMO

Ultrasensitive radars and uninstrumented jet aircraft in concert have probed regions of the clear atmosphere in search of clear-air turbulence. All sources of clear-air radar echoes above 6 kilometers that were probed simultaneously by the aircraft were found to be turbulent.

11.
Leukemia ; 31(1): 136-142, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27560108

RESUMO

Stem cell transplantation (SCT), an effective therapy for amyloid light chain (AL) amyloidosis patients, is associated with low treatment-related mortality (TRM) with appropriate patient selection and risk-adapted dosing of melphalan (RA-SCT). Consolidation after SCT increases hematologic complete response (CR) rates and may improve overall survival (OS) for patients with

Assuntos
Amiloidose/tratamento farmacológico , Amiloidose/mortalidade , Melfalan/administração & dosagem , Amiloidose/terapia , Bortezomib/uso terapêutico , Quimioterapia de Consolidação/métodos , Intervalo Livre de Doença , Seguimentos , Humanos , Cadeias Leves de Imunoglobulina , Pessoa de Meia-Idade , Indução de Remissão , Estudos Retrospectivos , Risco Ajustado , Transplante de Células-Tronco , Taxa de Sobrevida
12.
Neuroscience ; 139(4): 1435-48, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16517089

RESUMO

Gene expression profiling of suprachiasmatic nucleus, ventrolateral preoptic area and the lateral hypothalamus was used to identify genes regulated diurnally in the hypothalamus of Mus musculus. The putative transcription regulator, cysteine and histidine-rich domain-containing, zinc binding protein 1, which had not been previously described in brain, was found to cycle diurnally in hypothalamus and forebrain with peak levels of mRNA expression during the dark phase. mRNA for the brain-type fatty acid binding protein 7 was found to change rhythmically in hypothalamic and extra-hypothalamic brain regions reaching peak levels early in the light phase suggesting that lipid metabolism is under circadian regulation in astrocytes. Rhythmically expressed genes in suprachiasmatic nucleus identified here were compared with previous reports in a meta-analysis. Genes held in common included fabp7, and the period gene, Per2. Also identified were genes implicated in guanosine-mediated signaling pathways that included dexamethasone-induced ras-related protein one (dexras1), regulator of G-protein signaling (rgs) 16, and ras-like family member 11b. Northern blotting confirmed diurnal changes in mRNA expression in the hypothalamus for these genes. Ras-like family member 11b was examined in more detail using in situ hybridization and antiphase diurnal changes in expression in suprachiasmatic nucleus and arcuate nucleus were identified implicating the gene in circadian-related, guanosine-mediated signaling. The transcription transactivator protein, CBP/p300-interacting transactivators with glutamic acid/aspartic acid-rich carboxyl-terminal domain, which had not been previously identified in brain, was enriched in suprachiasmatic nucleus and discrete regions of the hypothalamus and forebrain. The potential regulatory role of CBP/p300-interacting transactivators with glutamic acid/aspartic acid-rich carboxyl-terminal domain in the transcription of genes like TGF-alpha implicates the protein in diurnal activity rhythms. These results demonstrate the ability of gene expression profiling to identify potential candidates important in circadian or homeostatic processes.


Assuntos
Proteínas de Transporte/metabolismo , Ritmo Circadiano/fisiologia , Proteínas de Ligação a Ácido Graxo/metabolismo , GTP Fosfo-Hidrolases/metabolismo , Regulação da Expressão Gênica/fisiologia , Hipotálamo/metabolismo , Proteínas Imediatamente Precoces/metabolismo , Proteínas Repressoras/metabolismo , Animais , Northern Blotting/métodos , Hibridização In Situ/métodos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Análise de Sequência com Séries de Oligonucleotídeos/métodos
13.
Cancer Res ; 57(18): 4098-104, 1997 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-9307299

RESUMO

We examined the expression of glial- and neuronal-specific mRNAs within human gliomas using in situ hybridization. We found that low-grade astrocytomas contained a high number of proteolipid protein (PLP) mRNA-positive cells and that the number of PLP-stained cells decreased markedly with increasing tumor grade. Interestingly, the ratio of PLP mRNA-stained cells:myelin basic protein (MBP) mRNA-stained cells in normal white matter and low-grade astrocytoma was about 2:1 but approached 1:1 with increasing tumor grade. This parameter appeared to be a good indicator of tumor infiltration in astrocytomas, so we tested this in the analysis of other gliomas. Unlike astrocytomas, oligodendrogliomas were found consistently to contain few PLP mRNA- or MBP mRNA-expressing cells. In contrast, gemistocytic astrocytomas, typically highly invasive tumors, contained high numbers of PLP-positive cells and a ratio of PLP mRNA:MBP mRNA-stained cells of about 1.5:1, similar to low-grade astrocytomas. Nonradioactive in situ hybridization also enabled the morphological identification of specific cells. For example, gemistocytic astrocytes, which were found to be strongly vimentin mRNA positive, contained little glial fibrillary acidic protein mRNA and did not stain for PLP or MBP mRNAs. Neuronal mRNAs, such as neurofilament 68, were observed in small numbers of entrapped neurons within gliomas but were uninformative with respect to predicting tumor grade. Our results suggest that oligodendrocytes survive low-grade tumor infiltration and that glial tumor cells, unlike cell lines derived from them, do not express oligodendrocyte or neuronal mRNAs. In addition, the expression of mRNAs for the two major myelin protein genes, PLP and MBP, could be used to predict the grade and extent of tumor infiltration in astrocytomas.


Assuntos
Astrocitoma/genética , Neoplasias Encefálicas/genética , Regulação Neoplásica da Expressão Gênica , Glioma/genética , Neuroglia/fisiologia , Oligodendroglia/fisiologia , Proteína Glial Fibrilar Ácida/genética , Humanos , Hibridização In Situ , Queratinas/genética , Proteína Básica da Mielina/genética , Proteína Proteolipídica de Mielina/genética , Proteínas de Neurofilamentos/genética , Neurônios/fisiologia , Oligodendroglioma/genética , RNA Mensageiro/genética , RNA Neoplásico/genética , Vimentina/genética
14.
J Neurosci ; 22(20): 8981-91, 2002 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-12388605

RESUMO

Transgenic mice were generated to permit the targeted ablation of cortical preplate cells at the time they are born. In these mice, the 1.3 kb golli promoter of the myelin basic protein gene was used to drive the herpes simplex virus thymidine kinase (TK) transgene in cortical preplate cells. Heterozygous transgenic pairs were bred, and pregnant dams were treated with ganciclovir at embryonic days 11-12 to ablate preplate cells at the time the preplate was forming. This paradigm exposed control (TK-) and experimental (TK+) littermates to exactly the same conditions. Embryological ablation of preplate cells led to an early disruption of the radial glial framework and subplate structure in the developing cortex and dramatically altered the cellular lamination and connectivity of the cortical plate. The disturbed radial glial network contributed to an impaired radial migration of neurons into the cortical plate from the ventricular zone. The cortical plate became dyslaminated, and there was a substantial reduction in short- and long-range cortical projections within the cortex and to subcortical regions. Cell death within the cortical plate and the proliferative zones was substantially increased in the ablated animals. After birth, a cortical lesion developed, which became exacerbated with the secondary onset of hydrocephaly in the second postnatal week. The results underscore the critical importance of the preplate in cortex formation, mediated through its guidance of the formation of radial glial scaffolding, subsequent neuronal migration into the incipient cortical plate, and the final arrangement of its vertical organization and cellular connectivity.


Assuntos
Córtex Cerebral/embriologia , Estruturas Embrionárias/embriologia , Neurônios/efeitos dos fármacos , Animais , Bromodesoxiuridina , Morte Celular/efeitos dos fármacos , Morte Celular/genética , Movimento Celular/efeitos dos fármacos , Córtex Cerebral/citologia , Córtex Cerebral/efeitos dos fármacos , Estruturas Embrionárias/citologia , Estruturas Embrionárias/efeitos dos fármacos , Ganciclovir/farmacologia , Hidrocefalia/induzido quimicamente , Hidrocefalia/genética , Hidrocefalia/patologia , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Camundongos , Camundongos Transgênicos , Modelos Animais , Proteína Básica da Mielina/genética , Malformações do Sistema Nervoso/induzido quimicamente , Malformações do Sistema Nervoso/genética , Malformações do Sistema Nervoso/patologia , Neuroglia/citologia , Neuroglia/efeitos dos fármacos , Neurônios/citologia , Regiões Promotoras Genéticas/genética , Simplexvirus/genética , Timidina Quinase/biossíntese , Timidina Quinase/genética
15.
Neuroscience ; 135(1): 285-97, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16084664

RESUMO

Relatively little attention has been focused on mechanisms related to neural plasticity and drug abuse in adolescence, compared with abundant research using adult animal models. As smoking is typically initiated in adolescence, an important question to address is whether the adolescent brain responds differently to nicotine compared with the adult. To investigate this question, we examined the expression of a number of early response genes (arc, c-fos and NGFI-B) that have been implicated in synaptic plasticity and addiction, following acute nicotine in adolescent and adult rats. Baseline expression of arc and c-fos was higher in adolescent brains compared with adults. Following acute nicotine treatment (0.1, 0.4mg/kg), we found a marked induction of arc mRNA in the prefrontal cortex of nicotine-treated adolescents compared with a less pronounced increase of arc in the adult. c-fos and NGFI-B were also upregulated by nicotine, but not in an age-related manner. In contrast, nicotine induced less arc, c-fos, and NGFI-B expression in the somatosensory cortex of adolescents compared with adults. A fourth gene, quinoid dihydropteridine reductase was expressed at lower levels in white matter of the adolescent forebrain compared with the adult, but was not affected by nicotine. These results suggest that in adolescence, the activity of specific early response genes is higher in brain regions critical for emotional regulation and decision-making. Further, nicotine affects key plasticity molecules in these areas in a manner different from the adult. Thus, adolescence may represent a neurobiologically vulnerable period with regard to nicotine exposure.


Assuntos
Proteínas Imediatamente Precoces/biossíntese , Proteínas do Tecido Nervoso/biossíntese , Plasticidade Neuronal/genética , Nicotina/farmacologia , Prosencéfalo/fisiologia , RNA Mensageiro/biossíntese , Envelhecimento/fisiologia , Animais , Proteínas do Citoesqueleto , Primers do DNA , Hibridização In Situ , Masculino , Córtex Pré-Frontal/fisiologia , Prosencéfalo/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Sinapses/fisiologia , Regulação para Cima/genética
16.
Mech Dev ; 87(1-2): 207-12, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10495289

RESUMO

We characterized the first POU-homeoprotein in a crustacean (designated APH-1 for Artemia POU-Homeoprotein, EMBL Y15070). The amino acid sequence of the APH-1 POU-domain is identical, except for two residues, to that of the two class III POU proteins Cf1-a (Drosophila) and POU-M1 (Bombyx mori). Southern blot analysis suggests that crustaceans have only one class III POU gene. RT-PCR and whole-mount in situ hybridization show that APH-1 mRNA is present in larvae specifically in the salt gland, an organ which is involved in osmoregulation, and disappears in the adult.


Assuntos
Artemia/genética , Proteínas de Caenorhabditis elegans , Expressão Gênica , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Glândula de Sal/metabolismo , Sequência de Aminoácidos , Animais , Artemia/metabolismo , Sequência de Bases , Southern Blotting , Enzimas de Restrição do DNA/metabolismo , Hibridização In Situ , Dados de Sequência Molecular , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo
17.
J Comp Neurol ; 391(1): 87-98, 1998 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-9527544

RESUMO

The cellular localization of the dopaminergic D2 receptor (D2R) mRNA and protein was determined during postnatal development, from birth to 35 days, in the rat neostriatum by in situ hybridization histochemistry and immunohistochemistry. To localize and identify more precisely the morphology of cells expressing the D2R mRNA, nonradioactive, digoxigenin in situ hybridization was performed. Throughout this period of development, D2R mRNA and protein were widely expressed by neostriatal cells, adjoining forebrain cells and small cellular processes. Within morphologically identifiable neurons, the expression of the D2 receptor appeared to occur after cell division ceased. D2R gene expression appeared during neuronal migration and followed the developmental pattern of neuronal settling within the neostriatum. Both D2R mRNA and protein appeared to colocalize in neostriatal cells and the labeling of both appeared to accumulate within the cells progressively with age. The structural phenotypes of neostriatal neurons bearing D2R mRNA and protein were diverse throughout postnatal development. The most frequently stained cells were a heterogeneous group of medium spiny and aspiny neurons. Large cells corresponding to aspiny neurons were less frequently stained. Both phenotypes exhibited considerable postnatal growth of their cell bodies. In addition to neurons, other cell types were also observed to express the D2R mRNA and protein over the developmental period studied. These other cells included patches of ciliated ependymal cells lining the lateral ventricles and many interfascicular oligodendroglia of forebrain fiber tracts. These results demonstrate the unexpected expression of the dopaminergic D2 receptor in non-neuronal cells within the brain. They provide a novel morphologic suggestion that the dopaminergic D2 receptor may support unrecognized, nonsynaptic functions in specific non-neuronal cell populations in the nervous system.


Assuntos
Neostriado/química , Prosencéfalo/química , Receptores de Dopamina D2/genética , Animais , Epêndima/citologia , Epêndima/metabolismo , Feminino , Histocitoquímica , Imuno-Histoquímica , Hibridização In Situ , Masculino , Morfogênese , Neostriado/embriologia , Neostriado/crescimento & desenvolvimento , Neurônios/metabolismo , Oligodendroglia/metabolismo , Prosencéfalo/embriologia , Prosencéfalo/crescimento & desenvolvimento , RNA Mensageiro/biossíntese , Ratos , Ratos Sprague-Dawley
18.
J Comp Neurol ; 374(3): 342-53, 1996 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-8906503

RESUMO

The myelin basic protein (MBP) gene locus is composed of two overlapping transcription units that share all of the MBP exons. One of these transcription units expresses the MBPs and the other expresses a family of proteins structurally related to the MBPs. This second transcription unit is called the Golli gene, and the entire complex is called the Golli-mbp gene. In this study, the expression of the Golli gene was examined in the human fetal central nervous system (CNS). By using reverse transcriptase-polymerase chain reaction cloning we have identified eight new members of the Golli gene family of transcripts expressed in the human CNS. Golli gene expression was examined by in situ hybridization and immunohistochemistry, and surprisingly, Golli products were found to be expressed in neurons as well as oligodendrocytes. Furthermore, the subcellular distribution of Golli immunoreactivity in fetal spinal cord interneurons shifted between the various laminae. Golli protein was localized within the nuclei of interneurons in the posterior horn, but was found in the cell bodies and processes of interneurons in the anterior horn. Within oligodendrocytes, Golli protein was detected in the cell bodies and processes, including processes which were wrapping axonal segments. Golli mRNA expression was also observed in neurons within the cerebral cortex between 18 and 20 weeks postconception, prior to myelination of this brain region. During this period, there was a striking developmental increase in the numbers and in the locations of neurons expressing Golli mRNAs within the cortical plate. The diverse distribution of Golli proteins within neurons and oligodendrocytes indicates that their function is quite different from that of the MBPs to which they are closely related.


Assuntos
Sistema Nervoso Central/embriologia , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Proteína Básica da Mielina/biossíntese , Proteína Básica da Mielina/genética , Neurônios/fisiologia , Oligodendroglia/fisiologia , Anticorpos/análise , Northern Blotting , Sistema Nervoso Central/citologia , Sistema Nervoso Central/fisiologia , Córtex Cerebral/citologia , Córtex Cerebral/embriologia , Córtex Cerebral/fisiologia , Cromatografia de Afinidade , Sondas de DNA , Feminino , Humanos , Imuno-Histoquímica , Hibridização In Situ , Reação em Cadeia da Polimerase , Gravidez , RNA Mensageiro/biossíntese , Proteínas Recombinantes/biossíntese
19.
Proc Biol Sci ; 268(1473): 1279-85, 2001 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-11410155

RESUMO

According to the theory of mate choice based on heterozygosity, mates should choose each other in order to increase the heterozygosity of their offspring. In this study, we tested the 'good genes as heterozygosity' hypothesis of mate choice by documenting the mating patterns of wild Atlantic salmon (Salmo salar) using both major histocompatibility complex (MHC) and microsatellite loci. Specifically, we tested the null hypotheses that mate choice in Atlantic salmon is not dependent on the relatedness between potential partners or on the MHC similarity between mates. Three parameters were assessed: (i) the number of shared alleles between partners (x and y) at the MHC (M(xy)), (ii) the MHC amino-acid genotypic distance between mates' genotypes (AA(xy)), and (iii) genetic relatedness between mates (r(xy)). We found that Atlantic salmon choose their mates in order to increase the heterozygosity of their offspring at the MHC and, more specifically, at the peptide-binding region, presumably in order to provide them with better defence against parasites and pathogens. This was supported by a significant difference between the observed and expected AA(xy) (p = 0.0486). Furthermore, mate choice was not a mechanism of overall inbreeding avoidance as genetic relatedness supported a random mating scheme (p = 0.445). This study provides the first evidence that MHC genes influence mate choice in fish.


Assuntos
Complexo Principal de Histocompatibilidade , Salmo salar/genética , Salmo salar/imunologia , Comportamento Sexual Animal , Alelos , Animais , Feminino , Heterozigoto , Endogamia , Masculino , Repetições de Microssatélites , Modelos Biológicos , Polimorfismo Genético , Salmo salar/fisiologia
20.
Proc Biol Sci ; 270(1526): 1839-47, 2003 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-12964987

RESUMO

The rich species diversity of the marine Indo-West Pacific (IWP) has been explained largely on the basis of historical observation of large-scale diversity gradients. Careful study of divergence among closely related species can reveal important new information about the pace and mechanisms of their formation, and can illuminate the genesis of biogeographic patterns. Young species inhabiting the IWP include urchins of the genus Echinometra, which diverged over the past 1-5 Myr. Here, we report the most recent divergence of two cryptic species of Echinometra inhabiting this region. Mitochondrial cytochrome oxidase 1 (CO1) sequence data show that in Echinometra oblonga, species-level divergence in sperm morphology, gamete recognition proteins and gamete compatibility arose between central and western Pacific populations in the past 250 000 years. Divergence in sperm attachment proteins suggests rapid evolution of the fertilization system. Divergence of sperm morphology may be a common feature of free-spawning animals, and offers opportunities to simultaneously understand genetic divergence, changes in protein expression patterns and morphological evolution in traits directly related to reproductive isolation.


Assuntos
Filogenia , Ouriços-do-Mar/anatomia & histologia , Ouriços-do-Mar/genética , Espermatozoides/ultraestrutura , Animais , Sequência de Bases , Análise por Conglomerados , DNA Mitocondrial/genética , Fertilidade , Geografia , Oceano Índico , Masculino , Dados de Sequência Molecular , Oceano Pacífico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA