45 research outputs found

    Determination of fipronil LD50 for the brazilian bee Melipona scutellaris

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    To better understand the sensitivity of the models represented by Apis mellifera L., 1758 in toxicology studies of insecticides to bees, the aim of this study was to determine the LD50 of fipronil by topical application on the stingless bees Melipona scutellaris Latreille, 1811. Foraging bees were collected at the nest entrance and in laboratory anesthetized with CO2 for applying 1.0 μL of fipronil solution on the pronotum. Each group of treatments was made with thirteen bees divided in three cages, while in the control treatments the bees received only acetone. During the assay, the behavior and the number of dead bees were registered. The results showed that the insecticide fipronil applied topically was harmful to M. scutellaris and for A. mellifera, where the LD50 for 48 hours was 0.41 ng a.i./bee or 4.1 ng a.i./ g of bee. Comparing the LD50 values here obtained with the stingless bee M. scutellaris and those of A. mellifera in literature, we can conclude that the native bees are more sensitive to fipronil than the allochtonous bee, suggesting that further studies should be accomplished to determine the real hazard of pesticides to natives bees. Keywords: stingless bees, pesticides, phenylpyrazole, toxicity, LD5

    Interaction between ASIP and MC1R in Black and Brown Alpaca

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    Animal fibres from South American camelids and other fibre or wool bearing species provide important products for use by the human population. The contemporary context includes the competition with petrocarbon-based artificial fibres and concern about excessive persistence of these in the natural environment. Animal fibres present highly valuable characteristics for sustainable production and processing as they are both natural and renewable. On the other hand, their use is recognised to depend on availability of appropriate quality and quantity, the production of which is underpinned by a range of sciences and processes which support development to meet market requirements. This collection of papers combines international experience from South and North America, China and Europe. The focus lies on domestic South American camelids (alpacas, llamas) and also includes research on sheep and goats. It considers latest advances in sustainable development under climate change, breeding and genetics, reproduction and pathology, nutrition, meat and fibre production and fibre metrology. Publication of this book is supported by the Animal Fibre Working Group of the European Federation of Animal Science (EAAP). ‘Advances in Fibre Production Science in South American Camelids and other Fibre Animals’ addresses issues of importance to scientists and animal breeders, textile processors and manufacturers, specialised governmental policy makers and students studying veterinary, animal and applied biological sciences

    Interaction of ASP and MC1R in black and brown alpaca.

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    Alpaca coat colour is a relevant feature both for breeders than textile industries. Agouti (ASP) and Extension (MC1R) are genes known to be involved in coat colour through pigmentation pathways by regulating type, amount and distribution of eumelanin and pheomelanin pigments in melanocytes. In alpaca genotype of ASP and MC1R genes have already been analysed distinctly, but their epistatic interaction have not been evaluated. In this study have been assessed their segregation more insights on black and brown phenotypes. In several mammals MC1R is epistatic over ASP, id est recessive allele in Agouti (a) and dominant allele in Extension locus (E) produces black phenotype. That is confirmed in alpaca where black coat has aH/aΔ57 and aH/ahT genotype on agouti and E/E or E/e genotype on MC1R locus. Otherwise ASP and MC1R in Brown/Red Brown, have a dominant profile at least in one allele as A/A, A/ahT on Agouti and E/e on Extension. Genotype and phenotype comparison clears that receptor and ligand are in concordance to produce pheomelanin and eumelanin in alpaca. Segregation analysis of 12 alpaca families genotyped by coat color, confirm the dominance of brown over black and could be helpful for coat colour classification and genotyping
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