Study by evolution of nucleic acid content of prepuberal growth in the shrimp Crangon vulgaris

Regnault, Michèle; Luquet, P.

doi:10.1007/bf00404971

Cited by 39 publications

(23 citation statements)

References 25 publications

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“…T h e amount of DNA, t h e carrier of genetic information, is quasi-constant in somatic tissues a n d tissue concentrations therefore reflect cell numbers (Regnault & Luquet 1974, Dortch e t al. 1983.…”

Section: Introductionmentioning

confidence: 99%

Improvements in the fluorimetric determination of the RNA and DNA content of individual marine fish larvae

Clemmesen¹

1993

Mar. Ecol. Prog. Ser.

125

108

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The RNA/DNA ratio is a useful indicator of the nutritional condition of fish larvae. The presented analytical procedure is an improvement of Clemmesen's (Meeresforschung 32: 134-143, 1988) methodology which involves purification of fish larvae tissue homogenates and subsequent fluorescence-photometric measurements using specific nucleic acid dyes. The modifications concern the homogenization and nucleic acid extraction procedures. A 'shaking mill' was compared to a potter Elvehjem microhomogenizer and a reduction in the washing and purification steps was achieved. Treatment of samples with ribonuclease A and subsequent fluorescence measurement using ethidium bromide was given preference compared to the DNA-bisbenzimidazole determinations due to problems arising from high self-fluorescence of the samples and the influence of 'quenching' substances disturbing the DNA-bisbenzmidazole determinations. Different RNase concentrations and their influences on RNA and DNA were checked. Recovery rates of standard RNA and DNA 'spikes' were determined. Fish larvae samples were analysed with the previous and the improved modified procedure and a correction factor to compare results measured with the 2 procedures was calculated. With the presented method the physiological condition of individual larvae and the amount of variabhty can be determined.

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Section: Introductionmentioning

confidence: 99%

Improvements in the fluorimetric determination of the RNA and DNA content of individual marine fish larvae

Clemmesen¹

1993

Mar. Ecol. Prog. Ser.

125

108

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“…The ratio of RNA to DNA present in tissues has been used as an index of growth rate in fish, crabs, and zooplankton (Sutcliffe 1965, Leick 1968, Regnault & Luguet 1974, Sulkin et al 1975, Buckley 1979, 1980, 1982, 1984 but the application of this technique to bivalve molluscs has been limited. RNA serves as the machinery required for protein synthesis and the amounts of RNA present have been shown to be directly related to the rate of protein synthesis (Munro & Fleck 1966, Kayes 1979.…”

Section: Of the University Of Maryland Center For Environmental And Ementioning

confidence: 99%

Use of RNA: DNA ratios as an indicator of nutritional stress in the American oyster Crassostrea virginica

Da¹,

Hetzel²

1985

Mar. Ecol. Prog. Ser.

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Hatchery spawned oysters approximately 1% yr old were subjected to starvation stress by exposing them to 1 wm filtered seawater over an 8 wk period. Control (fed) oysters were exposed to unfiltered flowing seawater. RNA:DNA ratios in mantle tissue from fed and starved oysters were monitored throughout, together with shell length, width, height, whole specimen displacement and shell displacement. Wet welght was estimated from whole weight determinations made before and at the end of the experiment. From Day -4 (before the start of the experiment) to Day 52, there was a 32 % increase in mean weight of fed animals and a 12.6 % loss in wet weight of starved animals. Rate of wet weight growth was significantly less in starved oysters than in fed oysters after Day 3. Shell height increased in fed oysters, but remained more constant in starved specimens. Shell lengths were significantly different from Day 42. Condition index, defined as ratio of wet tissue weight to cavity volume, decreased rapidly in starved oysters and became significantly less than in fed oysters. Two sample t-tests between treatments showed that there was a significant difference in RNA:DNA ratio between treatments on all sampling days except Day 0. By Day 55, starved oysters had 36.5 % lower ratios than fed oysters. Over the 55 day experimental period the RNA:DNA ratio correlated highly with cond~tion index, but was lower in response to starvation than in reported studies on vertebrates.

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“…Cellular DNA varies within a narrow range during the cell division cycle (twofold, in the case of eukaryotic cells), and is highly stable under changing environmental situations (Holm-Hansen et al, 1968;Dortch et al, 1983;Bulow, 1987). Consequently, DNA is a biomass proxy (Holm-Hansen et al, 1968;Regnault and Luquet, 1974), and RNA/DNA ratio is an indicator for the physiological or nutritional status (Bulow, 1970;Sutcliffe, 1970). This conceptual model has advanced our understanding of physiological state in bacteria (e.g.…”

Section: Introductionmentioning

confidence: 99%

Quantifying RNA and DNA in planktonic organisms with SYBR Green II and nucleases. Part A. Optimisation of the assay

Berdalet¹,

Roldán²,

Olivar³

et al. 2005

Sci. Mar.

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SUMMARY: Assay protocols for RNA and DNA in crude plankton extracts using the fluorochrome SYBR Green II are developed here. The method is based on the fluorescence in 3 aliquots: the first measures RNA after DNA digestion; the second measures DNA after RNA digestion; and the third measures residual fluorescence after digestion of both DNA and RNA. This residual fluorescence measurement is critical for accurate calculations of the nucleic acids. Optimisation of the assay conditions are described: fluorochrome concentration, buffer composition, fluorescence stability, temperature and duration of nuclease incubation. In the optimised procedure, the assays are performed in 5 mM Tris buffer (containing 0.9 mM CaCl 2 ·2H 2 O and 0.9 mM MgCl 2 ·6H 2 O, pH 8.0); DNase and RNase incubations are conducted at 37ºC for 20 min; the fluorochrome is added to all assays at a final concentration of 3.5x10 -4 and readings are done within the 10-60 min period following the SYBR Green II addition. The study evidenced the importance of the residual fluorescence after nuclease digestion, which is especially taken into account in the calculation of the nucleic acid concentrations. Finally, the variability of the fluorescent response to different RNA and DNA standards is examined; from the performed tests, calculations are based on rRNA from calf liver and DNA from calf thymus standards. The accompanying paper (Berdalet et al., 2005) describes the development of the extraction protocol, as well as the application of both protocols in measuring RNA/DNA ratios in natural plankton samples, and a comparison with ethidium bromide based methods.Key words: SYBR Green II, DNase, RNase, RNA/DNA ratios, plankton. RESUMEN: CUANTIFICACIÓN DE ARN Y ADN EN ORGANISMOS PLANCTÓNICOS MARINOS MEDIANTE SYBR GREEN II Y NUCLE-ASES. PARTE A. OPTIMIZACIÓN DEL ENSAYO. -En este trabajo se desarrollan los protocolos para la cuantificación de ARN y ADN en extractos no purificados de plancton utilizando SYBR Green II. El método se basa en la fluorescencia de 3 alícuo-tas: la primera mide el ARN tras la digestión del ADN; la segunda mide el ADN tras la digestión del ARN y la tercera mide la fluorescencia residual tras la digestión tanto del ARN como del ADN. La medida de esta fluorescencia residual es críti-ca para obtener una buena estimación de los ácidos nucleicos. Se describen las condiciones de optimización del ensayo: concentración de fluorocromo, composición del tampón, estabilidad de la fluorescencia, temperatura y duración de la incubación con nucleasas. En el procedimiento optimizado los ensayos se realizan en tampón Tris 5 mM (0.9 mM CaCl 2 ·2H 2 O y 0.9 mM MgCl 2 ·6H 2 O, pH 8); las incubaciones con nucleasas se llevan a cabo a 37°C durante 20 min; el fluorocromo se añade a todos los ensayos a una concentración final de 3.5X10 -4 y las lecturas se realizan en los 10-60 min posteriores a la adición de SYBR Green II. Este estudio evidencia la importancia de la fluorescencia residual después de la digestión con nucleasas, la cual es especialmente incluída...

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Study by evolution of nucleic acid content of prepuberal growth in the shrimp Crangon vulgaris

Cited by 39 publications

References 25 publications

Improvements in the fluorimetric determination of the RNA and DNA content of individual marine fish larvae

Improvements in the fluorimetric determination of the RNA and DNA content of individual marine fish larvae

Use of RNA: DNA ratios as an indicator of nutritional stress in the American oyster Crassostrea virginica

Quantifying RNA and DNA in planktonic organisms with SYBR Green II and nucleases. Part A. Optimisation of the assay

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