In Vitro Production of Metacyclic Forms of Trypanosoma musculi and Their Infectivity in CBA Mice1

ABSTRACT. Bloodstream forms of Trypanosoma musculi, cultured in Schneider's drosophila medium at room temperature, multiply and differentiate through a series of developmental stages into infective metacyclic trypomastigotes in 10 days. Oral inoculation with these culture forms into CBA mice produced a parasitemia similar to that produced by intraperitoneal infection with bloodstream forms except for a three-day longer prepatent period. Attempts to induce parasitemia with bloodstream forms given orally were unsuccessful.     

Comparison of Atrazine-Resistant and -Susceptible Biotypes of Senecio vulgaris L.: Effects of High and Low Temperatures on the in vivo Photosynthetic Electron Transfer in Intact Leaves

The effects of temperature on the yield of in vivo modulatedchlorophyll fluorescence were measured in intact leaves of atrazineresistantand -susceptible biotypes of the weed Senecio vulgaris L. At25 ?C, the photochemical quenching (q_Q of steady-state chlorophyllfluorescence was reduced by around 30% in the atrazine-resistantmutant as compared to the susceptible wild type, indicatinga higher reduction state of the primary electron acceptor Q_Aof photosystem II in the former biotype. Moderately elevatedtemperatures (above 30 ?C) further increased the steady-stateconcentration of reduced in the mutant. Analysis of the temperature dependence of both the photochemicalquenching q_Q and the initial fluorescence level F_o clearly indicateda drastically enhanced heat-sensitivity of the photochemicalapparatus in the atrazine-resistant Senecio leaves. The heat-inducedchanges in F₀ and q_Q were closely correlated, suggesting thatthe phenomenon responsible for the rise in F₀ was also involvedin the inhibition of the photosynthetic electron flux. Low temperaturesalso affected reoxidation but, in contrast to heating, no apparent differences were observed in the behaviourof the two biotypes exposed to chilling stress. Key words: Atrazine-resistance, chlorophyll fluorescence, heat stress, Senecio vulgaris     

Taxonomy of the Houbara Bustard Chlamydotis undulata subspecies considered on the basis of sexual display and genetic divergence

The Houbara Bustard Chlamydotis undulata is a polytypic species with three subspecies classified according size, colour and distribution: C. u. undulata, C. u. fuertaventurae and C. u. macqueenii. A comparative study of the male display behaviour of these three subspecies has shown similarities between C. u. undulata and C. u. fuertaventurae , whereas appreciable differences exist in the visual and auditory aspects of the display between C. u. undulata and C. u. macqueenii. These observations make the current taxonomy of Houbara Bustard questionable, particularly in view of the major importance of the sexual display in bird speciation processes. Furthermore, DNA analysis of the cytochrome b gene indicates the existence of a significant differentiation between the C. u. undulata and C. u. macqueenii populations. These findings indicate the need for a revision of the taxonomy of genus Chlamydotis which should separate the macqueenii and undulata populations at species rank. Until further investigations are completed, C. u. fuertaventurae should be kept as a subspecies of undulata since the courtship display is alike in both populations.     

In Vitro Culture of Phytomonas Sp. Isolated from Euphorbia characias. Metabolic Studies by 1H NMR

ABSTRACT. We describe the in vitro culture of Phytomonas species isolated from Euphorbia characias . The best choice between tested media was SDM-79, in which promastigotes, after 6 days of culture, reached cell densities as high as 4 × 10⁷ cells/ml. Cells growing in LIT or MTL medium showed longer division times and lower cell densities. We succeeded in obtaining Phytomonas sp. amastigote and spheromastigote forms in modified GRACE's medium, yielding transformation rates of up to 70%. Electron microscopy studies were performed in order to characterize the ultrastructural features of these forms obtained in vitro. On the other hand, metabolic studies based on qualitative (nuclear magnetic resonance spectroscopy) and quantitative metabolic methods (enzymatic assays) showed that promastigote forms secreted mainly ethanol, acetate, glycine, glycerol, piruvate and succinate in SDM-79 medium, whereas the major metabolites found after transformation in modified Grace's medium were ethanol, acetate, glycine, piruvate and smaller amounts of glycerol.     

Adult movements between populations in the specialist butterfly Proclossiana eunomia (Lepidoptera, Nymphalidae)

Abstract.

• 1 The structure of local populations of a monophagous butterfly, the bog fritillary Proclossiana eunomia, was studied in a complex of suitable habitat patches separated by spruce plantations or fertilized pasture.
• 2 An unexpected high level of adult movements between habitat patches was detected by a mark—release—recapture technique. Local populations were connected by adult movements across unsuitable habitats, leading to a meta-population structure.
• 3 This evidence of the metapopulation structure of a specialist butterfly challenges the supposed relationship between habitat specialization and closed, isolated populations.
• 4 Males and females of P.eunomia exhibited different spatial behaviours; females were more likely to emigrate and dispersed further than males. These differences in spatial behaviour are related to the mating system.