RESUMO
According to the RNA world theory, RNAs which stored genetic information and catalyzed chemical reactions had their contribution in the formation of current living organisms. In recent years, researchers studied this molecule diversity, i.a. focusing on small non-coding regulatory RNAs. Among them, of particular interest is evolutionarily ancient, 19-24 nt molecule of microRNA (miRNA). It has been already recognized as a regulator of gene expression in eukaryotes. In plants, miRNA plays a key role in the response to stress conditions and it participates in the process of growth and development. MicroRNAs originate from primary transcripts (pri-miRNA) encoded in the nuclear genome. They are processed from single-stranded stem-loop RNA precursors containing hairpin structures. While the mechanism of mature miRNA production in animals is better understood, its biogenesis in plants remains less clear. Herein, we present the results of bioinformatics analysis aimed at discovering how plant microRNAs are recognized within their precursors (pre-miRNAs). The study has been focused on sequential and structural motif identification in the neighbourhood of microRNA.
Assuntos
Biologia Computacional/métodos , MicroRNAs/química , Plantas/genética , Precursores de RNA/química , RNA de Plantas/química , Sequência de Bases , MicroRNAs/genética , Conformação de Ácido Nucleico , Nucleotídeos/genética , Precursores de RNA/genética , RNA de Plantas/genéticaRESUMO
We performed qualitative and quantitative amino acids analysis of lymphocytes from normal and leukemic cattle (infected with bovine leukemia virus) to determine cellular cholesterol levels. Leukemic lymphocytes exhibited quantitative differences in the levels of some "glycogenic", "ketogenic" and "glyco-ketogenic" amino acids. These differences may reflect the disturbances of Krebs cycle. Evidence was produced that increased cholesterol content in the above lymphocytes was associated with disorders in beta-oxidation processes of leukemic cells.
