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1.
PLoS Biol ; 20(9): e3001751, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-36125990

RESUMEN

Vocal learning is thought to have evolved in 3 orders of birds (songbirds, parrots, and hummingbirds), with each showing similar brain regions that have comparable gene expression specializations relative to the surrounding forebrain motor circuitry. Here, we searched for signatures of these same gene expression specializations in previously uncharacterized brains of 7 assumed vocal non-learning bird lineages across the early branches of the avian family tree. Our findings using a conserved marker for the song system found little evidence of specializations in these taxa, except for woodpeckers. Instead, woodpeckers possessed forebrain regions that were anatomically similar to the pallial song nuclei of vocal learning birds. Field studies of free-living downy woodpeckers revealed that these brain nuclei showed increased expression of immediate early genes (IEGs) when males produce their iconic drum displays, the elaborate bill-hammering behavior that individuals use to compete for territories, much like birdsong. However, these specialized areas did not show increased IEG expression with vocalization or flight. We further confirmed that other woodpecker species contain these brain nuclei, suggesting that these brain regions are a common feature of the woodpecker brain. We therefore hypothesize that ancient forebrain nuclei for refined motor control may have given rise to not only the song control systems of vocal learning birds, but also the drumming system of woodpeckers.


Asunto(s)
Pájaros Cantores , Animales , Mapeo Encefálico , Núcleo Celular , Masculino , Prosencéfalo , Vocalización Animal
2.
Placenta ; 105: 14-22, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33517149

RESUMEN

INTRODUCTION: Dysregulated genes in glucose transport and metabolize pathways have been found in patients with Gestational diabetes (GDM), but the underlying mechanisms were still unclear. MATERIALS AND METHODS: Placental villous samples were collected from 31 patients with GDM and 20 healthy controls. The expression of GLUT1, GLUT4, GLUT9 and HK2 was examined by immunoblotting and qRT-PCR. The miRNAs have the potential targeting GLUT1 and HK2 were predicted using online bioinformatics tool: TargetScan. The interaction between miRNAs and target genes were confirmed by dual luciferase assay and immunoblotting. The function of miR-9 and miR-22 on glucose metabolism was examined by glucose uptake assay and lactate secretion assay. RESULTS: GLUT1 and HK2 proteins level was found upregulated in patients with GDM, but the mRNA level was not significantly changed. Predicted by using bioinformatics tools and confirmed by dual luciferase assay and immunoblotting, GLUT1 was identified as a target of miR-9 and miR-22, whereas HK2 was identified as a target of miR-9. MiR-9 and miR-22 level was found reduced in the placenta villous and negatively correlated with the expression of GLUT1 and HK2. Functional studies indicated that miR-9 and miR-22 inhibitors upregulated the expression of GLUT1 and HK2, and then increased the glucose uptake, lactate secretion, cell viability and repressed apoptosis in primary syncytiotrophoblasts (STBs) and HTR8/SVneo cells. DISCUSSION: The upregulation of GLUT1 and HK2 in the placenta, which is induced by miR-9 and miR-22 reduction, contributes to the disordered glucose metabolism in patients with GDM.


Asunto(s)
Diabetes Gestacional/metabolismo , Transportador de Glucosa de Tipo 1/metabolismo , Glucosa/metabolismo , Hexoquinasa/metabolismo , MicroARNs/metabolismo , Placenta/metabolismo , Adulto , Apoptosis/fisiología , Diabetes Gestacional/genética , Femenino , Regulación de la Expresión Génica , Transportador de Glucosa de Tipo 1/genética , Hexoquinasa/genética , Humanos , MicroARNs/genética , Embarazo , Trofoblastos/metabolismo , Adulto Joven
3.
Front Psychol ; 11: 849, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32719628

RESUMEN

Higher education, which has the function of cultivating human capital, has already become a key focus of developed countries around the world. From ministries of education to higher education institutions, many bodies are dedicated to enhancing student learning outcomes. However, social and educational problems derived from disadvantaged groups have long been hindering the development of individuals and the whole country. This study examines the learning motivations of economically disadvantaged versus non-disadvantaged college students and evaluates the relationship between learning modes and learning outcomes from a self-determination theory (SDT) perspective. In this study, 817 valid questionnaires were collected to compare the two sample groups in terms of learning path. The results show that non-economically disadvantaged students have superior outcomes compared to disadvantaged students in terms of role identity, academic identity, explorative learning, exploitative learning, and cognitive and non-cognitive gains. In regard to path analysis, economically disadvantaged students are significantly superior to non-disadvantaged students in the face of positive influence of academic identity on different learning modes and positive influence of explorative learning on cognitive and non-cognitive gains. Finally, based on the conclusions, this study proposes some suggestions specific to theoretical mode for future study.

4.
5.
Front Psychol ; 11: 231, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32210865

RESUMEN

This study was conducted from the strategic marketing perspective to test the impact of brand relationship types on brand loyalty. We also test three path effects of brand love and brand trust. Data were collected from three metropolitan customers who use tablet PCs. We obtained 383 valid samples, giving a valid response rate of 89%. Data analysis was performed with SmartPLS2.0 and SPSS 23.0 to test the proposed model. The results indicate that an expressive brand relationship significantly predicts brand trust and brand loyalty. In turn, brand trust has a positive influence on brand love, while brand awareness and brand love influence attitudinal and behavioral loyalty. Expressive brand relationship has two indirect mediating affects via brand trust and brand love, which influence brand loyalty. Finally, we suggest managerial implications and directions for future research.

6.
Artículo en Inglés | MEDLINE | ID: mdl-31340440

RESUMEN

Previous studies of the relationship between job security and job satisfaction were mostly conducted on research samples in Asia from the perspective of oriental culture; however, under the same cultural background, different social systems might lead to different cognition outcomes. Therefore, this study examines the job security and organizational support of Taiwan and mainland China employees from the perspectives of competence enhancement motivation, and investigates the relationship between employability and job satisfaction. Adopting judgmental sampling, a total of 1307 valid questionnaires were collected from Taiwan and mainland China employees. The path relationship of the two groups was examined through structural equation modeling (SEM) by using analysis of moment structure (AMOS). Results show that job security and organizational support are positive for employability and job satisfaction. Employability has a positive influence on job satisfaction. Additionally, employability has a mediating effect of job security and organizational support on job satisfaction.


Asunto(s)
Empleo , Satisfacción en el Trabajo , Adulto , China , Femenino , Humanos , Masculino , Persona de Mediana Edad , Motivación , Encuestas y Cuestionarios , Taiwán , Adulto Joven
7.
Neurochem Res ; 43(9): 1814-1825, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30027364

RESUMEN

Traumatic brain injury (TBI) is one of the major causes of death and disability worldwide. Novel and effective therapy is needed to prevent the secondary spread of damage beyond the initial injury. The aim of this study was to investigate whether berberine has a neuroprotective effect on secondary injury post-TBI, and to explore its potential mechanism in this protection. The mice were randomly divided into Sham-saline, TBI-saline and TBI-Berberine (50 mg/kg). TBI was induced by Feeney's weight-drop technique. Saline or berberine was administered via oral gavage starting 1 h post-TBI and continuously for 21 days. Motor coordination, spatial learning and memory were assessed using beam-walking test and Morris water maze test, respectively. Brain sections were processed for lesion volume assessment, and expression of neuronal nuclei (NeuN), cyclooxygenase 2 (COX-2), inducible nitric oxide synthase (iNOS), 8-hydroxy-2-deoxyguanosine (8-OHdG), ionized calcium-binding adapter molecule 1 (Iba1) and glial fibrillary acidic protein (GFAP) were detected via immunohistochemistry and immunofluorescence. There were statistically significant improvement in motor coordination, spatial learning and memory in the TBI-Berberine group, compared to the TBI-saline group. Treatment with berberine significantly reduced cortical lesion volume, neuronal loss, COX-2, iNOS and 8-OHdG expression in both the cortical lesion border zone (LBZ) and ipsilateral hippocampal CA1 region (CA1), compared to TBI-saline. Berberine treatment also significantly decreased Iba1- and GFAP-positive cell number in both the cortical LBZ and ipsilateral CA1, relative to saline controls. These results indicated that berberine exerted neuroprotective effects on secondary injury in mice with TBI probably through anti-oxidative and anti-inflammatory properties.


Asunto(s)
Antiinflamatorios/farmacología , Antioxidantes/farmacología , Berberina/farmacología , Lesiones Traumáticas del Encéfalo/tratamiento farmacológico , Encéfalo/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Animales , Encéfalo/metabolismo , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Ratones Endogámicos C57BL , Óxido Nítrico Sintasa de Tipo II/metabolismo
8.
Exp Eye Res ; 160: 21-30, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-28434813

RESUMEN

Teleost fish continues to grow their eyes throughout life with the body size. In Astatotilapia burtoni, the fish retina increases by adding new retinal cells at the ciliary marginal zone (CMZ) and in the outer nuclear layer (ONL). Cell proliferation at both sites exhibits a daily rhythm in number of dividing cells. To understand how this diurnal rhythm of new cell production is controlled in retinal progenitor cells, we studied the transcription pattern of clock genes in retina, including clock1a, clock1b, bmal1a (brain and muscle ARNT-Like), and per1b (period1b). We found that these genes have a strong diurnal rhythmic transcription during light-dark cycles but not in constant darkness. An oscillation in pcna transcription was also observed during light-dark cycles, but again not in constant darkness. Our results also indicate an association between Clock proteins and the upstream region of pcna (proliferating cellular nuclear antigen) gene. A luciferase reporter assay conducted in an inducible clock knockdown cell line further demonstrated that the mutation on predicted E-Boxes in pcna promoter region significantly attenuated the transcriptional activation induced by Clock protein. These results suggested that the diurnal rhythmic expression of clock genes in A. burtoni retina could be light dependent and might contribute to the daily regulation of the proliferation of the retina progenitors through key components of cell cycle machinery, for instance, pcna.


Asunto(s)
Proteínas CLOCK/genética , Regulación de la Expresión Génica , Antígeno Nuclear de Célula en Proliferación/genética , ARN/genética , Retina/metabolismo , Animales , Western Blotting , Proteínas CLOCK/biosíntesis , División Celular , Línea Celular , Proliferación Celular , Cíclidos , Ritmo Circadiano/fisiología , Inmunohistoquímica , Hibridación in Situ , Luz , Ratones , Modelos Animales , Fotoperiodo , Antígeno Nuclear de Célula en Proliferación/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Retina/citología , Células Madre/citología , Células Madre/metabolismo , Transcripción Genética
9.
J Comp Neurol ; 523(6): 892-906, 2015 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-25424606

RESUMEN

Only a few distantly related mammals and birds have the trait of complex vocal learning, which is the ability to imitate novel sounds. This ability is critical for speech acquisition and production in humans, and is attributed to specialized forebrain vocal control circuits that have several unique connections relative to adjacent brain circuits. As a result, it has been hypothesized that there could exist convergent changes in genes involved in neural connectivity of vocal learning circuits. In support of this hypothesis, expanding on our related study (Pfenning et al. [2014] Science 346: 1256846), here we show that the forebrain part of this circuit that makes a relatively rare direct connection to brainstem vocal motor neurons in independent lineages of vocal learning birds (songbird, parrot, and hummingbird) has specialized regulation of axon guidance genes from the SLIT-ROBO molecular pathway. The SLIT1 ligand was differentially downregulated in the motor song output nucleus that makes the direct projection, whereas its receptor ROBO1 was developmentally upregulated during critical periods for vocal learning. Vocal nonlearning bird species and male mice, which have much more limited vocal plasticity and associated circuits, did not show comparable specialized regulation of SLIT-ROBO genes in their nonvocal motor cortical regions. These findings are consistent with SLIT and ROBO gene dysfunctions associated with autism, dyslexia, and speech sound language disorders and suggest that convergent evolution of vocal learning was associated with convergent changes in the SLIT-ROBO axon guidance pathway.


Asunto(s)
Axones/fisiología , Encéfalo/anatomía & histología , Regulación de la Expresión Génica/fisiología , Glicoproteínas/metabolismo , Aprendizaje/fisiología , Proteínas del Tejido Nervioso/metabolismo , Receptores Inmunológicos/metabolismo , Vocalización Animal/fisiología , Factores de Edad , Animales , Aves/fisiología , Femenino , Glicoproteínas/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Proteínas del Tejido Nervioso/genética , Neuronas/citología , ARN Mensajero/metabolismo , Receptores Inmunológicos/genética , Proteínas Roundabout
10.
Brain Behav Evol ; 83(1): 1-8, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24603302

RESUMEN

Efforts to understand nervous system structure and function have received new impetus from the federal Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative. Comparative analyses can contribute to this effort by leading to the discovery of general principles of neural circuit design, information processing, and gene-structure-function relationships that are not apparent from studies on single species. We here propose to extend the comparative approach to nervous system 'maps' comprising molecular, anatomical, and physiological data. This research will identify which neural features are likely to generalize across species, and which are unlikely to be broadly conserved. It will also suggest causal relationships between genes, development, adult anatomy, physiology, and, ultimately, behavior. These causal hypotheses can then be tested experimentally. Finally, insights from comparative research can inspire and guide technological development. To promote this research agenda, we recommend that teams of investigators coalesce around specific research questions and select a set of 'reference species' to anchor their comparative analyses. These reference species should be chosen not just for practical advantages, but also with regard for their phylogenetic position, behavioral repertoire, well-annotated genome, or other strategic reasons. We envision that the nervous systems of these reference species will be mapped in more detail than those of other species. The collected data may range from the molecular to the behavioral, depending on the research question. To integrate across levels of analysis and across species, standards for data collection, annotation, archiving, and distribution must be developed and respected. To that end, it will help to form networks or consortia of researchers and centers for science, technology, and education that focus on organized data collection, distribution, and training. These activities could be supported, at least in part, through existing mechanisms at NSF, NIH, and other agencies. It will also be important to develop new integrated software and database systems for cross-species data analyses. Multidisciplinary efforts to develop such analytical tools should be supported financially. Finally, training opportunities should be created to stimulate multidisciplinary, integrative research into brain structure, function, and evolution.


Asunto(s)
Evolución Biológica , Mapeo Encefálico , Encéfalo/anatomía & histología , Encéfalo/fisiología , Anatomía Comparada , Animales , Humanos , Especificidad de la Especie
11.
J Comp Neurol ; 522(7): 1445-53, 2014 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-24596113

RESUMEN

Efforts to understand nervous system structure and function have received new impetus from the federal Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative. Comparative analyses can contribute to this effort by leading to the discovery of general principles of neural circuit design, information processing, and gene-structure-function relationships that are not apparent from studies on single species. We here propose to extend the comparative approach to nervous system 'maps' comprising molecular, anatomical, and physiological data. This research will identify which neural features are likely to generalize across species, and which are unlikely to be broadly conserved. It will also suggest causal relationships between genes, development, adult anatomy, physiology, and, ultimately, behavior. These causal hypotheses can then be tested experimentally. Finally, insights from comparative research can inspire and guide technological development. To promote this research agenda, we recommend that teams of investigators coalesce around specific research questions and select a set of 'reference species' to anchor their comparative analyses. These reference species should be chosen not just for practical advantages, but also with regard for their phylogenetic position, behavioral repertoire, well-annotated genome, or other strategic reasons. We envision that the nervous systems of these reference species will be mapped in more detail than those of other species. The collected data may range from the molecular to the behavioral, depending on the research question. To integrate across levels of analysis and across species, standards for data collection, annotation, archiving, and distribution must be developed and respected. To that end, it will help to form networks or consortia of researchers and centers for science, technology, and education that focus on organized data collection, distribution, and training. These activities could be supported, at least in part, through existing mechanisms at NSF, NIH, and other agencies. It will also be important to develop new integrated software and database systems for cross-species data analyses. Multidisciplinary efforts to develop such analytical tools should be supported financially. Finally, training opportunities should be created to stimulate multidisciplinary, integrative research into brain structure, function, and evolution.


Asunto(s)
Mapeo Encefálico/métodos , Encéfalo/anatomía & histología , Encéfalo/fisiología , Animales , Mapeo Encefálico/normas , Evolución Química , Expresión Génica/fisiología , Humanos , Difusión de la Información/métodos , Vías Nerviosas/anatomía & histología , Vías Nerviosas/fisiología , Especificidad de la Especie
12.
Stem Cells Int ; 2014: 182737, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25610469

RESUMEN

Pluripotent stem cells have the potential to become any cell in the adult body, including neurons and glia. Avian stem cells could be used to study questions, like vocal learning, that would be difficult to examine with traditional mouse models. Induced pluripotent stem cells (iPSCs) are differentiated cells that have been reprogrammed to a pluripotent stem cell state, usually using inducing genes or other molecules. We recently succeeded in generating avian iPSC-like cells using mammalian genes, overcoming a limitation in the generation and use of iPSCs in nonmammalian species (Rosselló et al., 2013). However, there were no established optimal cell culture conditions for avian iPSCs to establish long-term cell lines and thus to study neuronal differentiation in vitro. Here we present an efficient method of maintaining chicken iPSC-like cells and for differentiating them into action potential generating neurons.

13.
Elife ; 2: e00036, 2013 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-24015354

RESUMEN

Cells are fundamental units of life, but little is known about evolution of cell states. Induced pluripotent stem cells (iPSCs) are once differentiated cells that have been re-programmed to an embryonic stem cell-like state, providing a powerful platform for biology and medicine. However, they have been limited to a few mammalian species. Here we found that a set of four mammalian transcription factor genes used to generate iPSCs in mouse and humans can induce a partially reprogrammed pluripotent stem cell (PRPSCs) state in vertebrate and invertebrate model organisms, in mammals, birds, fish, and fly, which span 550 million years from a common ancestor. These findings are one of the first to show cross-lineage stem cell-like induction, and to generate pluripotent-like cells for several of these species with in vivo chimeras. We suggest that the stem-cell state may be highly conserved across a wide phylogenetic range. DOI:http://dx.doi.org/10.7554/eLife.00036.001.


Asunto(s)
Reprogramación Celular , Células Madre Embrionarias/metabolismo , Células Madre Pluripotentes Inducidas/metabolismo , Factores de Transcripción/metabolismo , Animales , Biomarcadores/metabolismo , Linaje de la Célula , Proliferación Celular , Células Cultivadas , Embrión de Pollo , Quimera , Drosophila , Pinzones , Regulación del Desarrollo de la Expresión Génica , Genotipo , Cariotipificación , Factor 4 Similar a Kruppel , Factores de Transcripción de Tipo Kruppel/genética , Factores de Transcripción de Tipo Kruppel/metabolismo , Ratones , Factor 3 de Transcripción de Unión a Octámeros/genética , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Fenotipo , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , Codorniz , Factores de Transcripción SOXB1/genética , Factores de Transcripción SOXB1/metabolismo , Telomerasa/metabolismo , Factores de Transcripción/genética , Transfección , Pez Cebra
14.
J Comp Neurol ; 521(16): 3614-65, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23818122

RESUMEN

Based on quantitative cluster analyses of 52 constitutively expressed or behaviorally regulated genes in 23 brain regions, we present a global view of telencephalic organization of birds. The patterns of constitutively expressed genes revealed a partial mirror image organization of three major cell populations that wrap above, around, and below the ventricle and adjacent lamina through the mesopallium. The patterns of behaviorally regulated genes revealed functional columns of activation across boundaries of these cell populations, reminiscent of columns through layers of the mammalian cortex. The avian functionally regulated columns were of two types: those above the ventricle and associated mesopallial lamina, formed by our revised dorsal mesopallium, hyperpallium, and intercalated hyperpallium; and those below the ventricle, formed by our revised ventral mesopallium, nidopallium, and intercalated nidopallium. Based on these findings and known connectivity, we propose that the avian pallium has four major cell populations similar to those in mammalian cortex and some parts of the amygdala: 1) a primary sensory input population (intercalated pallium); 2) a secondary intrapallial population (nidopallium/hyperpallium); 3) a tertiary intrapallial population (mesopallium); and 4) a quaternary output population (the arcopallium). Each population contributes portions to columns that control different sensory or motor systems. We suggest that this organization of cell groups forms by expansion of contiguous developmental cell domains that wrap around the lateral ventricle and its extension through the middle of the mesopallium. We believe that the position of the lateral ventricle and its associated mesopallium lamina has resulted in a conceptual barrier to recognizing related cell groups across its border, thereby confounding our understanding of homologies with mammals.


Asunto(s)
Aves/anatomía & histología , Cerebro/anatomía & histología , Cerebro/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Animales , Recuento de Células , Expresión Génica , Imagenología Tridimensional , Proteínas del Tejido Nervioso/genética , Neuroimagen , Neuronas/metabolismo , Especificidad de la Especie
15.
J Comp Neurol ; 521(16): 3666-701, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23818174

RESUMEN

In our companion study (Jarvis et al. [2013] J Comp Neurol. doi: 10.1002/cne.23404) we used quantitative brain molecular profiling to discover that distinct subdivisions in the avian pallium above and below the ventricle and the associated mesopallium lamina have similar molecular profiles, leading to a hypothesis that they may form as continuous subdivisions around the lateral ventricle. To explore this hypothesis, here we profiled the expression of 16 genes at eight developmental stages. The genes included those that define brain subdivisions in the adult and some that are also involved in brain development. We found that phyletic hierarchical cluster and linear regression network analyses of gene expression profiles implicated single and mixed ancestry of these brain regions at early embryonic stages. Most gene expression-defined pallial subdivisions began as one ventral or dorsal domain that later formed specific folds around the lateral ventricle. Subsequently a clear ventricle boundary formed, partitioning them into dorsal and ventral pallial subdivisions surrounding the mesopallium lamina. These subdivisions each included two parts of the mesopallium, the nidopallium and hyperpallium, and the arcopallium and hippocampus, respectively. Each subdivision expression profile had a different temporal order of appearance, similar in timing to the order of analogous cell types of the mammalian cortex. Furthermore, like the mammalian pallium, expression in the ventral pallial subdivisions became distinct during prehatch development, whereas the dorsal portions did so during posthatch development. These findings support the continuum hypothesis of avian brain subdivision development around the ventricle and influence hypotheses on homologies of the avian pallium with other vertebrates.


Asunto(s)
Regulación del Desarrollo de la Expresión Génica/fisiología , Expresión Génica/fisiología , Telencéfalo , Factores de Edad , Animales , Animales Recién Nacidos , Recuento de Células , Embrión no Mamífero , Femenino , Redes Reguladoras de Genes/genética , Masculino , Pájaros Cantores , Telencéfalo/embriología , Telencéfalo/crecimiento & desarrollo , Telencéfalo/metabolismo
16.
Chem Asian J ; 8(6): 1076-89, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23606648

RESUMEN

This Review focuses on the development of metal aminoboranes; it discusses their synthesis, structure, chemical characterization, and applications. The lightweight nature of the molecules, the simplified procedures for the synthesis of the target compounds, the reversibility of hydrogen storage and dehydrogenation, and in-depth research on the mechanism of the thermal decomposition are also discussed. A major challenge that still remains is how to combine the advantages of the compounds to produce a material that is not only able to release and absorb hydrogen under atmospheric conditions, but is also lightweight with a stable molecular structure. Finally, some future trends and perspectives in these research areas will be outlined.

17.
PLoS One ; 7(7): e42477, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22860132

RESUMEN

Like humans, birds that exhibit vocal learning have relatively delayed telencephalon maturation, resulting in a disproportionately smaller brain prenatally but enlarged telencephalon in adulthood relative to vocal non-learning birds. To determine if this size difference results from evolutionary changes in cell-autonomous or cell-interdependent developmental processes, we transplanted telencephala from zebra finch donors (a vocal-learning species) into Japanese quail hosts (a vocal non-learning species) during the early neural tube stage (day 2 of incubation), and harvested the chimeras at later embryonic stages (between 9-12 days of incubation). The donor and host tissues fused well with each other, with known major fiber pathways connecting the zebra finch and quail parts of the brain. However, the overall sizes of chimeric finch telencephala were larger than non-transplanted finch telencephala at the same developmental stages, even though the proportional sizes of telencephalic subregions and fiber tracts were similar to normal finches. There were no significant changes in the size of chimeric quail host midbrains, even though they were innervated by the physically smaller zebra finch brain, including the smaller retinae of the finch eyes. Chimeric zebra finch telencephala had a decreased cell density relative to normal finches. However, cell nucleus size differences between each species were maintained as in normal birds. These results suggest that telencephalic size development is partially cell-interdependent, and that the mechanisms controlling the size of different brain regions may be functionally independent.


Asunto(s)
Encéfalo/embriología , Pinzones/embriología , Animales , Encéfalo/fisiología , Inmunohistoquímica
18.
J Vis Exp ; (62)2012 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-22566072

RESUMEN

Knowing the timing, level, cellular localization, and cell type that a gene is expressed in contributes to our understanding of the function of the gene. Each of these features can be accomplished with in situ hybridization to mRNAs within cells. Here we present a radioactive in situ hybridization method modified from Clayton et al. (1988)(1) that has been working successfully in our lab for many years, especially for adult vertebrate brains(2-5). The long complementary RNA (cRNA) probes to the target sequence allows for detection of low abundance transcripts(6,7). Incorporation of radioactive nucleotides into the cRNA probes allows for further detection sensitivity of low abundance transcripts and quantitative analyses, either by light sensitive x-ray film or emulsion coated over the tissue. These detection methods provide a long-term record of target gene expression. Compared with non-radioactive probe methods, such as DIG-labeling, the radioactive probe hybridization method does not require multiple amplification steps using HRP-antibodies and/or TSA kit to detect low abundance transcripts. Therefore, this method provides a linear relation between signal intensity and targeted mRNA amounts for quantitative analysis. It allows processing 100-200 slides simultaneously. It works well for different developmental stages of embryos. Most developmental studies of gene expression use whole embryos and non-radioactive approaches(8,9), in part because embryonic tissue is more fragile than adult tissue, with less cohesion between cells, making it difficult to see boundaries between cell populations with tissue sections. In contrast, our radioactive approach, due to the larger range of sensitivity, is able to obtain higher contrast in resolution of gene expression between tissue regions, making it easier to see boundaries between populations. Using this method, researchers could reveal the possible significance of a newly identified gene, and further predict the function of the gene of interest.


Asunto(s)
Perfilación de la Expresión Génica/métodos , Hibridación in Situ/métodos , Radioisótopos de Azufre/química , Animales , Aves , Embrión no Mamífero , Sondas ARN/química , Sondas ARN/genética , ARN Complementario/química , ARN Complementario/genética
19.
PLoS One ; 6(5): e20313, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21633515

RESUMEN

Social behavior can influence physiological systems dramatically yet the sensory cues responsible are not well understood. Behavior of male African cichlid fish, Astatotilapia burtoni, in their natural habitat suggests that visual cues from conspecifics contribute significantly to regulation of social behavior. Using a novel paradigm, we asked whether visual cues alone from a larger conspecific male could influence behavior, reproductive physiology and the physiological stress response of a smaller male. Here we show that just seeing a larger, threatening male through a clear barrier can suppress dominant behavior of a smaller male for up to 7 days. Smaller dominant males being "attacked" visually by larger dominant males through a clear barrier also showed physiological changes for up to 3 days, including up-regulation of reproductive- and stress-related gene expression levels and lowered plasma 11-ketotestesterone concentrations as compared to control animals. The smaller males modified their appearance to match that of non-dominant males when exposed to a larger male but they maintained a physiological phenotype similar to that of a dominant male. After 7 days, reproductive- and stress- related gene expression, circulating hormone levels, and gonad size in the smaller males showed no difference from the control group suggesting that the smaller male habituated to the visual intruder. However, the smaller male continued to display subordinate behaviors and assumed the appearance of a subordinate male for a full week despite his dominant male physiology. These data suggest that seeing a larger male alone can regulate the behavior of a smaller male but that ongoing reproductive inhibition depends on additional sensory cues. Perhaps, while experiencing visual social stressors, the smaller male uses an opportunistic strategy, acting like a subordinate male while maintaining the physiology of a dominant male.


Asunto(s)
Cíclidos/fisiología , Reproducción/fisiología , Conducta Social , Vías Visuales/fisiología , Análisis de Varianza , Andrógenos/sangre , Animales , Tamaño Corporal , Encéfalo/metabolismo , Proteínas Portadoras/genética , Cíclidos/genética , Hormona Liberadora de Corticotropina/genética , Femenino , Proteínas de Peces/genética , Expresión Génica , Jerarquia Social , Masculino , Receptores de Hormona Liberadora de Corticotropina/genética , Reproducción/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Estrés Fisiológico/genética , Testosterona/análogos & derivados , Testosterona/sangre , Factores de Tiempo
20.
Gen Comp Endocrinol ; 157(2): 148-55, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18501902

RESUMEN

Corticotropin-releasing factor (CRF) is well known for its role in regulating the stress response in vertebrate species by controlling release of glucocorticoids. CRF also influences other physiological processes via two distinct CRF receptors (CRF-Rs) and is co-regulated by a CRF binding protein (CRFBP). Although CRF was first discovered in mammals, it is important for the regulation of the stress response, motor behavior, and appetite in all vertebrates. However, it is unclear how the actions of CRF, CRF-Rs, and CRFBP are coordinated. To approach this problem, we cloned and identified CRF, CRF-Rs, and CRFBP in a teleost fish model system, Astatotilapia burtoni and mapped their expression patterns in the body and brain. We found that CRF, CRFBP, and CRF-Rs gene sequences are highly conserved across vertebrates, suggesting that the CRF system plays an essential role in survival. Members of the CRF system are expressed widely in the brain, retina, gill, spleen, muscle, and kidney, thereby implicating them in a variety of bodily functions, including vision, respiration, digestion, and movement. We also found that following long-term social stress, mRNA expression of CRF in the brain and CRF type 1 receptor in the pituitary decrease whereas CRFBP in the pituitary increases via a homeostatic mechanism.


Asunto(s)
Hormona Liberadora de Corticotropina/genética , Proteínas de Peces/genética , Perfilación de la Expresión Génica , Perciformes/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Proteínas Portadoras/genética , Femenino , Masculino , Datos de Secuencia Molecular , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptores de Hormona Liberadora de Corticotropina/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Alineación de Secuencia
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