5 research outputs found

    Genetic and phenotypic analysis of Tunisian Theileria annulata clones

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    Many parasite species are known to show high levels of genetic diversity, yet the consequences of this diversity for host-parasite interactions are not well understood. Variation in phenotypic traits such as growth rates and the ability to form transmission stages are raw material for natural and artificial selection to act upon with consequences for the evolution of the parasite species and disease control. In order to study genetic and phenotypic diversity amongst Theileria annulata parasites, a collection of 52 parasite clones was generated from cattle isolates and tick material recently collected in Tunisia. Genetic diversity was assessed using PCR-RFLP and monoclonal antibody markers, and genetically distinct clones selected for further study. Clones varied significantly in their growth rates in culture at 37 degreesC, their viability after a period of culture at 41 degreesC and their differentiation rates into transmission stages after culturing at 41 degreesC. The viability of a clone after culturing at 41 degreesC could not be predicted from its growth rate at 37 degreesC, but across clones, differentiation rates were positively correlated with growth rates at 37 degreesC. All 3 in vitro measures are likely to have relevance to parasite-host interactions in animals with clinical theileriosis, and should be acted on by within-host and between-host selection

    USO DE DILUENTES E TEMPERATURAS ALTERNATIVAS NA CONSERVAÇÃO PROLONGADA DO SÊMEN DO VARRÃO

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    The use of appropriate extenders is important for the success of an artificial insemination program. The objective of this study was to evaluate the efficiency of alternative extenders for swine semen at different temperatures (17 to 10 °C). The following extenders were used: Beltsville Thawing Solution (BTS), powdered coconut water (ACP-103®), and skimmed milk powder (LPD). The 50 ejaculates were analyzed daily, in natura and after dilution, during the 5-day period of semen preservation (D0 to D4), regarding spermatic vigor and motility. Acrosome integrity and sperm viability were evaluated on D0 and D4. Data were analyzed using Mann-Whitney, Students, Tukey and chi-square tests (p<0.05). The LPD extender at 10 °C presented higher motility and sperm vigor compared to BTS and ACP until D2, and to treatments stored at 17 °C. Acrosome vitality and integrity remained higher (p<0.001) with LPD at 10 °C on D0 and D4. LPD showed to be a good extender for the swine semen at lower temperature (10 °C). Furthermore, it provided better protection to sperm cells, by allowing greater integrity and vitality of the acrosome
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