RESUMO
RNA leukemia viruses induce T-cell lymphoblastic lymphomas or myeloid leukemias. Infection of cells with Moloney murine leukemia virus (M-MuLV) up-regulates the expression of a number of cellular genes, including those involved in T-lymphocyte activation. Previously, we demonstrated that this up-regulation occurs via the trans-activation activity of the M-MuLV long terminal repeat (LTR) sequences which produce an LTR-encoded transcript. Sequence analysis of the LTR revealed a potential transcription unit for RNA polymerase III (Pol III) within the U3 region that is actively occupied by Pol II factors. Here, we provide the direct evidence of involvement of Pol III in the trans-activation process and demonstrate the precise localization of the intragenic control elements for accurate and active Pol III transcription. Deletions of a copy of the directed repeats and further immediate upstream sequences significantly abrogated the generation of LTR-encoded transcript and abolished the trans-activational activity, whereas the deletion of a copy of directed repeats alone proportionally reduced the transcript size, but still retained moderately high trans-activational activity. In electrophoretic mobility shift assay, the fraction containing a multiple transcription factor TFIIIC complex strongly bound to the LTR-U3 probe containing the essential control elements. The specificity of the DNA-TFIIIC interaction was confirmed by conducting competition assays with DNA fragments containing a genuine Pol III-transcribed gene, VA1, and by vaccinia virus infection which stimulates the expression of Pol III factors. However, a deletion mutant lacking an essential control element bound to the TFIIIC complex poorly, consequently resulting in weak Pol III transcription as assessed by an IRES-GFP reporter system. This correlation strongly supports the possibility that the generation of LTR-encoded transcript is directed by Pol III. Therefore, this finding suggests the involvement of Pol III transcription in the retrovirus-induced activation of cellular genes, potentially contributing to leukemogenesis.
Assuntos
RNA Polimerase III/metabolismo , Retroviridae/genética , Sequências Repetidas Terminais , Células 3T3 , Animais , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Citometria de Fluxo , Deleção de Genes , Regulação da Expressão Gênica , Proteínas de Fluorescência Verde/metabolismo , Células HeLa , Humanos , Células Jurkat , Camundongos , Camundongos Endogâmicos BALB C , Vírus da Leucemia Murina de Moloney , Mutação , Plasmídeos/metabolismo , Transcrição Gênica , Ativação Transcricional , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Livestock manure (LSM) management is emerging as a challenge due to increasing livestock consumption. Owing to the decreased agricultural land area, it is necessary to ensure LSM utilization in non-agricultural fields. LSM can be a valuable resource if managed as a circulating resource. This study discusses research trends based on a literature review and classifies LSM treatments. The analysis of each treatment is presented according to research trends, and implications for the future LSM processing are discussed. "Biological treatment" accounted for the largest portion at 48%, "manure management," which suggests improvement in manure treatment through systematic thinking or LSM management practices, accounted for 16%, and "thermochemical conversion" accounted for 11%. In addition, "life cycle assessment (LCA) research," "solid-liquid separation approach," and "nutrient-recovery/losses" were derived. Studies on biological treatments are increasing. Although anaerobic digestion (AD) is the most used method, it has the disadvantages of long processing time and waste generation after processing. As a key supplement, thermochemical conversion (TCC) technology, which could overcome the disadvantages of AD, was reviewed.
Assuntos
Gado , Esterco , Animais , Esterco/análise , Agricultura , TecnologiaRESUMO
Thiosulfate (S(2)O(3)(2-)) contained in the media for autotrophic Cr (VI) reduction was found to interfere with Cr (VI) measurement following the 1,5-diphenylcarbazide (DPC) method. The interference was confirmed at several abiotic and biotic conditions, and was influenced by S(2)O(3)(2-) concentration, pH, and the media components. At neutral to alkaline pH, 500 mg/L of S(2)O(3)(2-) did not cause interference, while 4 mg/L of S(2)O(3)(2-) resulted in the interference at pH 2.0. Atomic absorption spectrophotometry could be an alternative method when the interference by S(2)O(3)(2-) is expected.