Identification of bluetongue virus serotype 2 (Corsican strain) by reverse-transcriptase PCR reaction analysis of segment 2 of the genome

In October 2000, bluetongue virus was detected on the French island of Corsica. The disease was also reported in Sardinia, Calabria, Sicily and on the Spanish islands of Majorca and Minorca. This paper describes the use of molecular techniques for a rapid identification and serotype determination of serotype 2 of the virus. The nucleotide sequences of segments 2 and 7 of the genome of the Corsican strain were determined and its phylogenetic relationships are described.     

The interaction among age,thermal acclimation and growth rate in determining muscle metabolic capacities and tissue masses in the threespine stickleback,Gasterosteus aculeatus

Thermal acclimation may directly modify muscle metabolic capacities, or may modify them indirectly via effects upon physiological processes such as growth, reproduction or senescence. To evaluate these interacting effects, we examined the influence of thermal acclimation and acclimatization upon muscle metabolic capacities and tissue masses in 1 + stickleback, Gasterosteus aculeatus, in which confounding interactions between temperature and senescense should be absent. Furthermore, we examined the influence of thermal acclimation upon individual growth rate, muscle enzyme levels and tissue masses in 2 + stickleback sampled at the beginning of their final reproductive season. For 1 + stickleback, cold acclimation more than doubles mitochondrial enzyme levels in the axial muscle. Thermal acclimation did not change the condition of 1 + stickleback at feeding levels which could not maintain the condition of 2+ stickleback. Compensatory metabolic responses to temperature were not apparent in field acclimatized 1 + stickleback. The growth rate of 2 + stickleback was markedly affected by temperature: warm-acclimated fish generally lost mass even at very high levels of feeding (up to 78 enchytraid worms per day) while cold-acclimated fish gained mass. This suggests that warm temperatures accelerate the senescence of 2 + stickleback. Generally, muscle enzyme activities increased with growth rate. In axial muscle, the relationships between CS activity and growth rate differed with acclimation temperature. Independent of the influence of growth rate, CS activities were consistently higher in cold- than warm-acclimated 2 + stickleback, suggesting compensatory increases of CS activity with cold acclimation. Corresponding author; This paper is dedicated to the memory of Gerry J. FitzGerald who passed away on March 14, 1994.     

The conservation status of Sabellaria alveolata (L.) (Polychaeta: Sabellariidae) reefs in the Bay of Mont‐Saint‐Michel

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Variation for plant characters and for performance of softwood cuttings of Rosa canina ‘Inermis’ seedlings

Summary Thirty, one-season-old Rosa canina Inermis seedlings (8–12 mm in diameter) were grown in the greenhouse. After 5 months, single-node softwood cuttings were made of each plant. Analysis of variance demonstrated marked differences between the internode length, number of leaflets per leaf and the leaf area of the original seedling, and between the time of axillary bud-break, axillary sprout length and weight of adventitious roots of their 23-day-old cuttings. Clonal root weight of cuttings was highly significantly correlated with: number of leaflets per leaf (r=–0.65), leaf area (r=+0.65), and days to axillary bud-break (r=+0.62). The origin of heterogeneity among Inermis seedling rootstocks, its probable effect on the flower production of cut roses and its possible use in the selection for clonal rootstocks are discussed.     

Identification on commercialized products of AFLP markers able to discriminate slow- from fast-growing chicken strains

The European chicken meat market is characterized by numerous quality marks: "Label de Qualité Wallon" in Belgium, "Label Rouge" in France, denominations of geographical origin, organic agriculture, etc. Most of those certified productions have specifications requiring the use of slow-growing chicken strains. The amplified fragment length polymorphism (AFLP) technique has been used to search molecular markers able to discriminate slow-growing chicken strains from fast-growing ones and to authenticate certified products. Two pairs of restriction enzymes (EcoRI/MseI and EcoRI/TaqI) and 121 selective primer combinations were tested on individual DNA samples from chicken products essentially in carcass form that were ascribed as belonging to either slow- or fast-growing strains. Within the resulting fingerprints, two fragments were identified as type-strains specific markers. One primer combination gives a band (333 bp) that is specific for slow-growing chickens, and another primer pair generates a band (372 bp) that was found to be characteristic of fast-growing chickens. The two markers were isolated, cloned, and sequenced. The effectiveness and the specificity of the two interesting determinants were assessed on individuals of two well-known strains (ISA 657 and Cobb 500) and on commercialized products coming from various origins.     

Interaction of temperature and light on growth and development of hybrid tea-rose seedlings,with reference to breeding for low-energy requirements

As a basis for a breeding-programme of glasshouse roses adapted to low-energy conditions (low temperature and low light intensity), growth and development of Hybrid Tearose seedlings were studied in 9 controlled environments (16, 20 or 24°C combined with 8, 16 or 24 Wm^?2 for 8 h). The percentage of flowering seedlings increased with increasing light intensity independent of temperature, rapidity of flowering was promoted by increasing both light intensity and temperature, stem length at anthesis was promoted by increasing light intensity but shortened by increasing temperature. The possibility of selecting seedlings, and consequently cultivars, adapted to low-energy conditions was discussed.     

Uptake and Fate of Lead in the Common Asteroid Asterias Rubens (Echinodermata)

Lead uptake kinetics in the body compartments of Asterias rubens individuals exposed through sea water to different concentrations (5, 20, 50 µg Pb l-¹) were studied during 30 days. Uptake kinetics were always best described by linear regressions. In every compartment, uptake rate increased significantly with the contaminating concentration. At a given concentration, the uptake rate of the central digestive tract was always significantly higher than that of the other compartments. After short-term exposures (50 µg Pb l-¹, 8 days), fate of accumulated Pb was followed in asteroids kept in non-contaminated water during 20 days. The central digestive tract and the pyloric caeca lost Pb according to an inverse exponential trend and concentrations returned to initial values after 4 to 8 days. Pb concentrations in the body wall decreased linearly. Pb concentrations in the skeleton did not vary significantly. In the gonads, Pb concentrations kept on rising while exogenous Pb was no more supplied. Pb loss from the body wall and the digestive compartments could account for such endogenous source to the gonads. It is suggested that Pb accumulated in the gonads is expulsed later through spawning. According to the parameters of uptake and loss kinetics, the central digestive tract and the skeleton are proposed as complementary temporal bioindicators of Pb contamination.