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RNA Content (rna + content)
Selected AbstractsUtility of reticulocyte maturation parameters in the differential diagnosis of macrocytic anemiasINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 5 2003A. Torres Gomez Summary The aim of this study was to test the clinical utility of reticulocyte maturation parameters in the differential diagnosis of macrocytic anemias. Using an automated reticulocyte counter, we analyzed immature reticulocyte fraction (IRF), mean reticulocyte volume (MRV) and mean fluorescence index (MFI) in peripheral blood samples from healthy donors (n = 30), patients diagnosed with myelodysplastic syndromes (MDS, n = 35), with megaloblastic anemia (MA, n = 10) and with non-megaloblastic macrocytic anemias (NMMA, n = 30). Macrocytic anemias due to ineffective erythropoiesis (MA and MDS) showed reticulocytes skewed to a more immature fraction. Therefore, they have a larger volume and a greater RNA content than healthy controls. Interestingly, reticulocytes in both low and high risk MDS are significantly larger (127.3 vs. 118.3 fl, P < 0.01) and have a greater RNA content (MFI 20.5 vs. 12.9, P < 0.01 and IRF 22.5 vs. 9.1%, P < 0.01) than NMMA patients. We conclude that measurement of reticulocyte maturation parameters may be a very useful tool in the differential diagnosis of macrocytic anemia. The presence of extremely high values of IRF (>16%), MFI (>18) and MRV (>129 fl), makes the diagnosis of NMMA very unlikely. An underlying MDS should, therefore, be sought. [source] Properties of Human Mitochondrial RibosomesIUBMB LIFE, Issue 9 2003Thomas W. O'Brien Abstract Mammalian mitochondrial ribosomes (55S) differ unexpectedly from bacterial (70S) and cytoplasmic ribosomes (80S), as well as other kinds of mitochondrial ribosomes. Typical of mammalian mitochondrial ribosomes, the bovine mitochondrial ribosome has been developed as a model system for the study of human mitochondrial ribosomes, to address several questions related to the structure, function, biosynthesis and evolution of these interesting ribosomes. Bovine mitochondrial ribosomal proteins (MRPs) from each subunit have been identified and characterized with respect to individuality and electrophoretic properties, amino acid sequence, topographic disposition, RNA binding properties, evolutionary relationships and reaction with affinity probes of ribosomal functional domains. Several distinctive properties of these ribosomes are being elucidated, including their antibiotic susceptibility and composition. Human mitochondrial ribosomes lack several of the major RNA stem structures of bacterial ribosomes but they contain a correspondingly higher protein content (as many as 80 proteins), suggesting a model where proteins have replaced RNA structural elements during the evolution of these ribosomes. Despite their lower RNA content they are physically larger than bacterial ribosomes, because of the 'extra' proteins they contain. The extra proteins in mitochondrial ribosomes are 'new' in the sense that they are not homologous to proteins in bacterial or cytoplasmic ribosomes. Some of the new proteins appear to be bifunctional. All of the mammalian MRPs are encoded in nuclear genes (a separate set from those encoding cytoplasmic ribosomal proteins) which are evolving more rapidly than those encoding cytoplasmic ribosomal proteins. The MRPs are imported into mitochondria where they assemble coordinately with mitochondrially transcribed rRNAs into ribosomes that are responsible for translating the 13 mRNAs for essential proteins of the oxidative phosphorylation system. IUBMB Life, 55: 505-513, 2003 [source] Developmental change in RNA: DNA ratios of fed and starved laboratory-reared Japanese flounder larvae and juveniles, and its application to assessment of nutritional condition for wild fishJOURNAL OF FISH BIOLOGY, Issue 4 2001W. S. Gwak Starved Japanese flounder Paralichthys olivaceus larvae were characterized by relatively lower levels of RNA content throughout their early life stages. Significant differences in the RNA: DNA ratios were found between fed and starved fish, and appeared to increase as starvation proceeded. Ontogenetic changes in RNA: DNA ratios were clearly observed during metamorphosis, especially decreasing during the period from the late-metamorphic to postmetamorphic stages. The criteria established from these laboratory experiments, were applied to the nutritional condition of wild larvae and juveniles collected in Wakasa Bay, Sea of Japan in 1994 and 1995 by measuring RNA and DNA content. Starved fish were mainly found in stage I (settling stage) fish during the late season of settlement in 1995. This suggests that starvation could be associated with settlement in Japanese flounder. [source] The dynamics of gene products fluctuation during bovine pre-hatching developmentMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 8 2009Isabelle Gilbert Early embryonic development, spanning fertilization to blastocyst hatching, is a very dynamic developmental window that is characterized, especially in large mammals, by a period of transcriptional incompetence that ends during the maternal to embryonic transition (MET). Prior to the MET, the first cell cycles are supported by stored RNA and proteins pools accumulated during oogenesis. Therefore, RNA and protein content are different between developmental stages. It is also known that the stability of the stored mRNA and the mechanisms for translation recruitment are partly controlled by the length of the poly(A) tail. To date, little is known about RNA and protein content fluctuations during the pre-hatching period. In this report we present measurements of total RNA, mRNA, poly(A) bearing mRNA and protein contents, as well as estimations of the proportions of both mRNA fractions to total RNA contents within these developmental stages. We found that while the ontogenic profiles of the different transcript contents were expected, their amounts were considerably lower than the reported values. Additionally, low 28S rRNA abundance and a tendency for diminishing protein content prior to the MET, suggest a limited potential for ribosomal turnover and translation. We consider the overall fluctuations in RNA and protein contents to be reference points that are essential for downstream interpretation of gene expression data across stages whether it be through candidates or high throughput approaches. Mol. Reprod. Dev. 76: 762,772, 2009. © 2009 Wiley-Liss, Inc. [source] RNA/DNA ratio of crabs as an indicator of mangrove habitat qualityAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue S1 2009Valter Amaral Abstract 1.Pollution of mangrove ecosystems puts their future and that of local communities at risk. Only the use of informed and integrative approaches will successfully maintain and restore these valuable ecosystems. 2.Biochemical indicators of organism physiological condition have been widely used to evaluate habitat quality and for early detection of the impact of stressors. Mangrove crabs may be useful bioindicators of the quality of mangrove habitats, as they are characteristic and ecologically important organisms in mangrove environments. 3.The physiological condition (evaluated by the RNA/DNA ratio) of Perisesarma guttatum (Grapsidae) and Uca annulipes (Ocypodidae) was assessed to determine its potential as an indicator of habitat quality in one polluted and two relatively unpolluted Mozambican mangroves, during the rainy and dry seasons. 4.Both species showed seasonal effects on RNA/DNA ratio, but only U. annulipes was significantly affected by pollution. RNA/DNA ratio of U. annulipes may thus be a useful indicator of pollution and seasonality in mangrove habitats. There was a synergistic negative effect of the rainy season and pollution on the RNA/DNA ratio of U. annulipes. Due to higher DNA, rather than lower RNA contents, the RNA/DNA ratio of P. guttatum was always significantly lower than that of U. annulipes. 5.The knowledge gathered in this study can be used in integrative strategies, policies and programmes aiming to sustain, maintain and restore mangrove areas, and for the evaluation of mangrove habitat quality. Copyright © 2009 John Wiley & Sons, Ltd. [source] | ||||||||||