RESUMO
A total of 5450 sequences obtained from the NCBI pig SNP database were consolidated into 465 unique sequences (189 singleton sequences and 276 contigs). These 465 sequences contained 1787 putative SNPs and had strong sequence homology to 433 human protein-coding genes based on blast analyses. These genes were assigned to the pig QTL maps (http://www.animalgenome.org/QTLdb/pig.html) via the human and pig comparative maps established by a pig radiation hybrid (RH) map. The SNP information characterized from this study provides a useful functional gene variation resource to facilitate QTL data mining in the pig genome.
Assuntos
Mapeamento de Sequências Contíguas , Polimorfismo de Nucleotídeo Único , Sus scrofa/genética , Animais , Bases de Dados de Ácidos Nucleicos , Humanos , Locos de Características Quantitativas , Mapeamento de Híbridos Radioativos , Alinhamento de Sequência , Homologia de Sequência do Ácido NucleicoRESUMO
Imprinted genes play important roles in embryo survival and postnatal growth regulation. The DLK1 and MEG3 (previously GTL2) genes are linked and reciprocally imprinted in several mammals, but their imprinting status is still unknown in pigs. In this study, we report polymorphisms, imprinting status and QTL analyses of the porcine DLK1 and MEG3 genes. Muscle and adipose DNA and RNA samples from 30-day-old animals generated with reciprocal crosses between the Korean native pig (KNP) and Yorkshire breeds were used to analyse DLK1 and MEG3 variation and expression. The samples exhibited paternal expression of DLK1 and maternal expression of MEG3 in pigs. These results indicated that the imprinting status of the DLK1 and MEG3 genes is conserved across mammalian species. By linkage analyses, we assigned the DLK1 and MEG3 genes to the telomeric region of SSC7. By QTL analyses, we confirmed a significant polar overdominance (POD) effect in DLK1, which was previously detected for several growth traits in pigs. However, no significant POD effect was found with the MEG3 locus.
Assuntos
Peptídeos e Proteínas de Sinalização Intercelular/genética , Proteínas de Membrana/genética , Suínos/genética , Animais , Composição Corporal/genética , Mapeamento Cromossômico , Cruzamentos Genéticos , Primers do DNA , Feminino , Variação Genética , Crescimento/genética , Masculino , Mamíferos , Locos de Características QuantitativasRESUMO
The tumor suppressor gene p53 is mutated in many human cancers. One of its major roles is as a transcription factor, and its many effector genes control key cellular processes including cell cycle checkpoints and apoptosis. An important role in DNA repair is also emerging for both p53 itself and some of its effector genes. The products of two p53-regulated genes, GADD45a and DDB2, are now known to participate in the global genomic repair (GGR) sub-pathway of nucleotide excision repair (NER). We recently reported the induction of a third GGR gene, XPC, following exposure of normal human peripheral blood lymphocytes to gamma-rays. We now show that XPC is induced in a variety of human cell lines in response to both ionizing and ultra-violet (UV) radiation and alkylating agents, and that this induction requires wild-type p53.
Assuntos
Pareamento Incorreto de Bases , Proteínas de Ciclo Celular , Reparo do DNA/genética , Genes p53/fisiologia , Dano ao DNA , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica , Humanos , Proteínas Nucleares/genética , Células Tumorais CultivadasRESUMO
Since early in the Atomic Age, biological indicators of radiation exposure have been sought, but currently available methods are not entirely satisfactory. Using cDNA microarray hybridization to discover new potential biomarkers, we have identified genes expressed at increased levels in human peripheral blood lymphocytes after ex vivo irradiation. We recently used this technique to identify a large set of ionizing radiation-responsive genes in a human cell line (Oncogene 18, 3666-3672, 1999). The present set of radiation markers in peripheral blood lymphocytes was identified 24 h after treatment, and while the magnitude of mRNA induction generally decreased over time, many markers were still significantly elevated up to 72 h after irradiation. In all donors, the most highly responsive gene identified was DDB2, which codes for the p48 subunit of XPE, a protein known to play a crucial role in repair of ultraviolet (UV) radiation damage in DNA. Induction of DDB2, CDKN1A (also known at C1P1/WAF1) and XPC showed a linear dose-response relationship between 0.2 and 2 Gy at 24 and 48 h after irradiation, with less linearity at earlier or later times. These results suggest that relative levels of gene expressions in peripheral blood cells may provide estimated of environmental radiation exposures.
Assuntos
Reparo do DNA/genética , DNA Complementar/genética , Regulação da Expressão Gênica/efeitos da radiação , Linfócitos/efeitos da radiação , RNA Mensageiro/análise , Adulto , Biomarcadores , Células Cultivadas/efeitos da radiação , Ciclina G , Ciclina G1 , Inibidor de Quinase Dependente de Ciclina p21 , Ciclinas/biossíntese , Ciclinas/genética , Proteínas de Ligação a DNA/biossíntese , Proteínas de Ligação a DNA/genética , Relação Dose-Resposta à Radiação , Raios gama , Perfilação da Expressão Gênica , Humanos , Interleucinas/biossíntese , Interleucinas/genética , Análise de Sequência com Séries de Oligonucleotídeos , Antígeno Nuclear de Célula em Proliferação/biossíntese , Antígeno Nuclear de Célula em Proliferação/genéticaRESUMO
Using cells of a human myeloid tumor cell line (ML-1), we have detected induction of several stress-responsive genes by doses of gamma rays below 50 cGy. We found a linear dose-response relationship for induction of CDKN1A (formerly known as CIP1/WAF1) and GADD45 mRNA levels over the range of 2-50 cGy, with no evidence of a threshold for induction. Although exposures to 2 and 5 cGy did not result in any detectable reduction in cloning efficiency or increased apoptosis in ML-1 cells, these exposures did produce a transient delay of cells in the phases of the cell cycle in addition to the observed up-regulation of CDKN1A and GADD45. The relative induction of genes such as CDKN1A by radiation doses that produce little toxicity indicates that surviving cells do contribute significantly to the observed stress responses. These studies should provide insight into the molecular responses to physiologically relevant doses that cannot necessarily be extrapolated from high-dose studies.
Assuntos
Ciclinas/genética , Raios gama , Regulação Leucêmica da Expressão Gênica/efeitos da radiação , Proteínas Nucleares , Proteínas/genética , Proteínas Proto-Oncogênicas c-bcl-2 , Fatores Ativadores da Transcrição , Apoptose/genética , Apoptose/efeitos da radiação , Proteínas Sanguíneas/biossíntese , Proteínas Sanguíneas/genética , Sobrevivência Celular/genética , Sobrevivência Celular/efeitos da radiação , Inibidor de Quinase Dependente de Ciclina p21 , Ciclinas/biossíntese , Relação Dose-Resposta à Radiação , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Leucemia Mieloide/genética , Leucemia Mieloide/metabolismo , Leucemia Mieloide/patologia , Biossíntese de Proteínas , Proteínas Proto-Oncogênicas/biossíntese , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-mdm2 , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fatores de Transcrição/biossíntese , Fatores de Transcrição/genética , Células Tumorais Cultivadas , Proteína X Associada a bcl-2 , Proteínas GADD45RESUMO
Cytoplasmic dynein contains a series of accessory proteins associated with the motor containing heavy chains.1 These include three distinct classes of light chains (Mr < approximately 22 000). Here we demonstrate that a previously cloned protein termed rp3 is a bona fide Mr 14 000 light chain component of this microtubule motor complex. The rp3 polypeptide is approximately 55% identical to the Tctex1 dynein light chain, and together, these two proteins define one branch of a diverse family of Mr 14 000 light chains associated with both cytoplasmic and flagellar dyneins. The Tctex1 and rp3 light chains are differentially expressed in various tissues: rp3 is most prevalent in liver and brain cytoplasmic dynein, whereas those tissues contain the least amounts of Tctex1. Immunofluorescence analysis was consistent with the tissue-specific distribution of these proteins and revealed that both rp3 and Tctex1 are present in multiple perinuclear punctate particles. Furthermore, in two cell lines, rp3 was found associated with an elongated structure located in the layer of cytoplasm above the nucleus. Electrophoretic/immunological analysis indicates that there are only single isoforms for these proteins in brain and PC-12 cells, suggesting that alterations in the Mr 14 000 light chains of dynein are achieved at the level of the individual proteins and not by posttranslational modification. Dissection of the cytoplasmic dynein complex revealed that Tctex1, an Mr 8000 LC dimer, and IC74 associate to define a basal-located intermediate chain/light chain complex analogous to that found in flagellar outer arm dynein.
