Assuntos
Estágio Clínico/organização & administração , Currículo/normas , Violência Doméstica/prevenção & controle , Educação de Pós-Graduação em Medicina/organização & administração , Capacitação em Serviço/organização & administração , Internato e Residência , Programas de Rastreamento/métodos , Corpo Clínico Hospitalar/educação , Corpo Clínico Hospitalar/psicologia , Estudantes de Medicina/psicologia , Atitude do Pessoal de Saúde , Competência Clínica/normas , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Avaliação das Necessidades , Valor Preditivo dos Testes , Análise de Regressão , Fatores de Risco , Inquéritos e Questionários/normasRESUMO
Metazoans use diverse and rapidly evolving mechanisms to determine sex. In Drosophila melanogaster an X-chromosome-counting mechanism determines the sex of an individual by regulating the master switch gene, Sex-lethal (Sxl). The X-chromosome dose is communicated to Sxl by a set of X-linked signal elements (XSEs), which activate transcription of Sxl through its 'establishment' promoter, SxlPe. Here we describe a new XSE called sisterlessC (sisC) whose mode of action differs from that of previously characterized XSEs, all of which encode transcription factors that activate SxlPe directly. In contrast, sisC encodes a secreted ligand for the Drosophila Janus kinase (JAK) and 'signal transducer and activator of transcription' (STAT) signal transduction pathway and is allelic to outstretched (os, also called unpaired). We conclude that sisC works indirectly on Sxl through this signalling pathway because mutations in sisC or in the genes encoding Drosophila JAK or STAT reduce expression of SxlPe similarly. The involvement of os in sex determination confirms that secreted ligands can function in cell-autonomous processes. Unlike sex signals for other organisms, sisC has acquired its sex-specific function while maintaining non-sex-specific roles in development, a characteristic that it shares with all other Drosophila XSEs.
Assuntos
Proteínas de Drosophila , Drosophila/genética , Glicoproteínas/genética , Proteínas Tirosina Quinases/metabolismo , Proteínas de Ligação a RNA/genética , Processos de Determinação Sexual , Transdução de Sinais , Fatores de Transcrição/metabolismo , Animais , Animais Geneticamente Modificados , Drosophila/enzimologia , Drosophila/fisiologia , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Genes de Insetos , Glicoproteínas/metabolismo , Glicoproteínas/fisiologia , Masculino , Dados de Sequência Molecular , Sequências Reguladoras de Ácido Nucleico , Transcrição Gênica , Cromossomo XRESUMO
The inhibitory glycine receptor is a ligand-gated ion channel protein that occurs in different developmentally regulated isoforms in the mammalian central nervous system. Here, we have analyzed genomic clones covering the coding regions of the murine glycine receptor alpha 1 and alpha 2 subunit genes. Both genes contain eight intronic regions with precisely conserved boundaries. The same structure was also found for seven exons of a third homologous gene, alpha 4, identified during screening. The predicted alpha 4 polypeptide displays very high homology to the alpha 2 subunit. Like the alpha 2 gene, the alpha 4 gene maps to the mouse X chromosome. Our data indicate that the genomic organization of glycine receptor alpha subunit genes is conserved during evolution.
Assuntos
Mapeamento Cromossômico , DNA/química , Variação Genética , Canais Iônicos/genética , Camundongos Endogâmicos C57BL/genética , Receptores de Glicina/genética , Cromossomo X , Sequência de Aminoácidos , Animais , Sequência de Bases , Evolução Biológica , Galinhas/genética , Clonagem Molecular , Sequência Conservada , DNA/metabolismo , DNA Complementar , Drosophila melanogaster/genética , Éxons , Biblioteca Genômica , Hominidae/genética , Humanos , Substâncias Macromoleculares , Camundongos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase/métodos , Mapeamento por Restrição , Homologia de Sequência de Aminoácidos , Transcrição GênicaRESUMO
The same genetic principles are common to all animals, plants and microorganisms. One consequence of the generality of genetic principles is that methods developed in one organism can often be used in other species. Recent advances in mammalian molecular genetics, genome analysis, and gene mapping have been found to be directly applicable to other animals and even plants. This is facilitating the rapid construction of detailed genetic maps in a wide variety of species. Similar advances are being made in the development of manipulation techniques, which allow the genomic deletion and addition of specific genes as well as more subtle alterations. Armed with detailed maps and precise manipulation techniques it is possible to associate genes with phenotypes, test the function of genes and to unravel complex traits that depend on the interaction of different genes.
Assuntos
Mapeamento Cromossômico , Animais , Mapeamento Cromossômico/métodos , Ligação Genética , Marcadores Genéticos , Genoma Humano , Humanos , Mamíferos/genética , Camundongos , Plantas/genéticaAssuntos
Mapeamento Cromossômico , Marcadores Genéticos , Camundongos/genética , Cromossomo X , Animais , Sequência de Bases , Centrômero , Cruzamentos Genéticos , Primers do DNA , Ligação Genética , Genoma Humano , Humanos , Camundongos Endogâmicos/genética , Dados de Sequência Molecular , Muridae/genética , Polimorfismo Genético , Especificidade da EspécieRESUMO
The introduction of new technology and increased effort from around the world is driving the completion of the human gene map. In parallel with the creation of the map, we are beginning to see the bio-medical benefits that are a direct consequence of learning more about our own genome.
Assuntos
Genoma Humano , Projeto Genoma Humano , Animais , Mapeamento Cromossômico , Bases de Dados Bibliográficas , HumanosRESUMO
The introduction of new technology and increased effort from around the world is driving the completion of the human gene map. In parallel with the creation of the map, we are beginning to see the biomedical benefits that are a direct consequence of learning more about our own genome.
Assuntos
Mapeamento Cromossômico , Genoma Humano , Sequência de Bases , Clonagem Molecular , Projeto Genoma Humano , Humanos , Meiose , Dados de Sequência Molecular , Mapeamento por RestriçãoRESUMO
The irradiation and fusion gene transfer (IFGT) procedure provides a means of isolating subchromosomal fragments for use in the mapping of loci and for cloning probes from a particular area of a chromosome. Using this procedure, two large panels of somatic cell hybrids that contain mouse X Chromosome (Chr) fragments have been generated. These hybrid panels were generated by irradiating the monochromosomal mouse-hamster hybrid HYBX, which retains the mouse X Chr, with either 10 K or 50 K rads of X-irradiation followed by fusion with a recipient Chinese hamster cell line. IFGT hybrids retaining mouse material were generated at high frequency. These hybrids were used to orient loci in the X-inactivation center region that had not been resolvable in our interspecies backcross panel and also to map, within the terminal region of the X Chr, repeat elements detected by the probe p15-4. These hybrids not only complement existing interspecies meiotic mapping panels for the detailed analysis of specific regions of particular chromosomes, but also provide a potential source of material for chromosome-specific probe isolation.
Assuntos
Mecanismo Genético de Compensação de Dose , Transfecção , Cromossomo X , Animais , Sequência de Bases , Southern Blotting , Mapeamento Cromossômico , Clonagem Molecular , DNA , Células Híbridas , Camundongos , Dados de Sequência Molecular , Reação em Cadeia da PolimeraseRESUMO
We have generated somatic cell hybrids containing fragments of human chromosome arm 9q by an irradiation and fusion technique. No selection for human material was imposed, but of 23 clones analyzed most contained human DNA sequences and many contained multiple fragments of the human chromosome arm. A hybrid that appears to contain only two small fragments of human DNA from the regions of q33 and q34 has been used as a source from which to clone probes specific to those areas of the chromosome.
Assuntos
Cromossomos Humanos Par 9 , Clonagem Molecular/métodos , Transfecção , Animais , Sequência de Bases , Southern Blotting , Linhagem Celular , Cricetinae , Sondas de DNA/genética , Marcadores Genéticos/genética , Humanos , Células Híbridas/efeitos da radiação , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Proteínas Recombinantes de Fusão/genéticaRESUMO
We have used probes from the human genes PI, PIL, and AACT (alpha 1-antitrypsin, alpha 1-antitrypsin-related sequence, and alpha 1-antichymotrypsin) to make a pulsed-field map of the surrounding region of 14q31-32. We have discovered that the PI-PIL gene cluster is only 220 kb away from the AACT gene and that it is orientated in the opposite direction. The comparatively short distance between the genes comes as a surprise given previous estimates of the level of genetic recombination between them.
Assuntos
Proteínas de Bactérias , Cromossomos Humanos Par 14 , Ligação Genética , Família Multigênica , alfa 1-Antiquimotripsina/genética , alfa 1-Antitripsina/genética , Southern Blotting , Linhagem Celular , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Genes , Humanos , Polimorfismo de Fragmento de Restrição , Recombinação Genética , Mapeamento por RestriçãoRESUMO
A liquid chromatographic (LC) method was compared with the AOAC mouse bioassay method (18.086-18.092) for determination of paralytic shellfish toxins in shellfish tissues. Shellfish samples were collected from Massachusetts coastal waters as part of a state surveillance program, and extracts of shellfish meat were analyzed for toxins by using both analytical methods. Overall correlation of the LC and bioassay methods is good (r = 0.943), but for samples with toxicities less than 100 micrograms saxitoxin/100 g shellfish meat, the correlation is significantly less (r = 0.531). Limits of detection are 10 micrograms saxitoxin/100 g shellfish meat and 40 micrograms saxitoxin/100 g shellfish meat for the LC and bioassay methods, respectively. Analytical capacity of the LC method is limited to 12 samples/person-day compared with 30 samples/person-day for the bioassay. Sampling capacity of the LC method could be increased by using a fluorescence detector with a wider response range, which would eliminate the need for dilution of concentrated samples.
