A fine-scale chimpanzee genetic map from population sequencing     

Auton A  Fledel-Alon A  Pfeifer S  Venn O  Ségurel L  Street T  Leffler EM  Bowden R  Aneas I  Broxholme J  Humburg P  Iqbal Z  Lunter G  Maller J  Hernandez RD  Melton C  Venkat A  Nobrega MA  Bontrop R  Myers S  Donnelly P  Przeworski M  McVean G 《Science (New York, N.Y.)》2012,336(6078):193-198

To study the evolution of recombination rates in apes, we developed methodology to construct a fine-scale genetic map from high-throughput sequence data from 10 Western chimpanzees, Pan troglodytes verus. Compared to the human genetic map, broad-scale recombination rates tend to be conserved, but with exceptions, particularly in regions of chromosomal rearrangements and around the site of ancestral fusion in human chromosome 2. At fine scales, chimpanzee recombination is dominated by hotspots, which show no overlap with those of humans even though rates are similarly elevated around CpG islands and decreased within genes. The hotspot-specifying protein PRDM9 shows extensive variation among Western chimpanzees, and there is little evidence that any sequence motifs are enriched in hotspots. The contrasting locations of hotspots provide a natural experiment, which demonstrates the impact of recombination on base composition.  相似文献   

Tritrichomonas foetus isolates from cats and cattle show minor genetic differences in unrelated loci ITS-2 and EF-1α     

Reinmann K  Müller N  Kuhnert P  Campero CM  Leitsch D  Hess M  Henning K  Fort M  Müller J  Gottstein B  Frey CF 《Veterinary parasitology》2012,185(2-4):138-144

The protozoan parasite Tritrichomonas foetus is well known as an important causative agent of infertility and abortion in cattle (bovine trichomonosis). This World Organisation for Animal Health (O.I.E.) notifiable disease is thought to be under control in many countries including Switzerland. In recent studies, however, T. foetus has also been identified as an intestinal parasite that causes chronic large-bowel diarrhoea in cats. Since the feline isolates were considered indistinguishable from bovine isolates, the possibility and risk of parasite transmission from cats to cattle and vice versa has been intensively discussed in current literature. Therefore, we investigated if cat and cattle isolates are genetically distinct from each other or in fact represent identical genotypes. For this purpose, two independent genetic loci were selected that turned out to be well-suited for a PCR sequencing-based genotyping of trichomonad isolates: (i) previously published internal transcribed spacer region 2 (ITS-2) and (ii) a semi-conserved sequence stretch of the elongation factor-1 alpha (EF-1α) gene used for the first time in the present study. Respective comparative analyses revealed that both loci were sufficiently variable to allow unambiguous genetic discrimination between different trichomonad species. Comparison of both genetic loci confirmed that T. suis and T. mobilensis are phylogenetically very close to T. foetus. Moreover, these two genetic markers were suited to define host-specific genotypes of T. foetus. Both loci showed single base differences between cat and cattle isolates but showed full sequence identity within strains from either cat or cattle isolates. Furthermore, an additional PCR with a forward primer designed to specifically amplify the bovine sequence of EF-1α was able to discriminate bovine isolates of T. foetus from feline isolates and also from other trichomonads. The implications these minor genetic differences may have on the biological properties of the distinct isolates remain to be investigated.  相似文献   

Experimental infection of rabbits (Oryctolagus cuniculus) with Brucella suis biovar 1 isolated from wild hares (Lepus europaeus)     

Fort M  Baldone V  Fuchs L  Giménez H  Rojas M  Breccia JD  Oyhenart J 《Veterinary microbiology》2012,156(3-4):439-442

Brucella suis biovar 1 is the causative agent of brucellosis in several domestic and wild animals and it is a common agent of human brucellosis. European hares (Lepus europaeus) have been shown to be infected by B. suis biovar 1 and the transmission to other animals has been suggested. In this work, experimental rabbits (Cuniculus orictolagus) were infected with B. suis biovar 1 isolated from wild hares. Infected rabbits showed high serological response in 2 weeks after discharge and typical granulomatous lesions (2mm diameter) were found in liver, spleen and kidneys after 50 days. B. suis biovar 1 was cultured from the lesion of the organs mentioned above as well as from urine, placenta and fetuses. These data suggest that hares are a potential source for horizontal transmission of B. suis biovar 1 to other mammalians.  相似文献   

Pathogen translocation and histopathological lesions in an experimental model of Salmonella Dublin infection in calves receiving lactic acid bacteria and lactose supplements     

Laureano S. Frizzo  Mar��a V. Zbrun  Lorena P. Soto  Ezequiel Bertozzi  Gabriel J. Sequeira  Luis E. Marti  Marcelo L. Signorini  Roberto Rodr��guez Armesto  Marcelo R. Rosmini 《Journal of veterinary science (Suw?n-si, Korea)》2012,13(3):261-270

The purpose of this study was to evaluate the capacity of a lactic acid bacteria (LAB) inoculum to protect calves with or without lactose supplements against Salmonella Dublin infection by evaluating histopathological lesions and pathogen translocation. Fifteen calves were divided into three groups [control group (C-G), a group inoculated with LAB (LAB-G), and a group inoculated with LAB and given lactose supplements (L-LAB-G)] with five, six, and four animals, respectively. The inoculum, composed of Lactobacillus (L.) casei DSPV 318T, L. salivarius DSPV 315T, and Pediococcus acidilactici DSPV 006T, was administered with milk replacer. The LAB-G and L-LAB-G received a daily dose of 10⁹ CFU/kg body weight of each strain throughout the experiment. Lactose was provided to the L-LAB-G in doses of 100 g/day. Salmonella Dublin (2 × 10¹⁰ CFU) was orally administered to all animals on day 11 of the experiment. The microscopic lesion index values in target organs were 83%, 70%, and 64.3% (p < 0.05) for the C-G, LAB-G, and L-LAB-G, respectively. Administration of the probiotic inoculum was not fully effective against infection caused by Salmonella. Although probiotic treatment was unable to delay the arrival of pathogen to target organs, it was evident that the inoculum altered the response of animals against pathogen infection.  相似文献   

Genetic organization and preferential distribution of putative pilus gene clusters in Streptococcus suis     

Daisuke Takamatsu  Hiroto Nishino  Tomono Ishiji  Jun Ishii  Makoto Osaki  Nahuel Fittipaldi  Marcelo Gottschalk  Prasit Tharavichitkul  Shinji Takai  Tsutomu Sekizaki   《Veterinary microbiology》2009,138(1-2):132-139

Recent analyses of Streptococcus suis isolates using multilocus sequence typing (MLST) suggested the importance of sequence type (ST) 1 and ST27 complexes for animal hygiene and public health. In this study, to investigate whether pilus-associated genes in S. suis can be used as novel genetic markers for important clonal groups, we examined the correlation between STs and putative pilus-associated gene profiles in S. suis. Genomic searches using sequenced genomes and sequence data determined in several isolates revealed the presence of at least four distinct putative pilus gene clusters in S. suis (srtBCD, srtE, srtF, and srtG clusters). On the basis of the presence or absence of genes in the four clusters, 108 S. suis isolates from various origins were classified into 12 genotypes (genotypes A–L). Genotypes A and B, which possessed srtBCD plus srtF clusters and srtF plus srtG clusters, respectively, were the most common in isolates from diseased pigs and humans, and 29.9% and 59.8% of the isolates belonged to genotypes A and B, respectively. In contrast, only 4.8% and 28.6% of isolates from healthy carriers were genotypes A and B, respectively. MLST analysis showed the associations of genotypes A and B with ST1 and ST27 complexes, respectively. In addition, srtBCD and srtG clusters were preferentially distributed to ST1 and ST27 complex members, respectively. These results suggest that profiling of selected pilus-associated genes could be used as an easy screening method to monitor isolates important for S. suis infection.  相似文献   

Probability Method Used in Predicting Contaminant Risk in Groundwater Adjacent to Airport     

Pengxin Zhang  Per Aagaard  Lars Gottschalk 《Water, air, and soil pollution》2010,211(1-4):323-339

A reliability approach, first-order reliability method, is used to develop a probabilistic modeling of reactive transport in porous media. The approach is potentially attractive because it can provide both a probability estimate and probabilistic sensitivity measures. In this work, we extend the application of the reliability methods to the probabilistic assessment of contaminant concentration exceeding critical groundwater contamination levels in airport areas following both continuous release and instantaneous injection scenarios. Failure probability is predicted for “no-information” and “partial-information” about the leakage, and compared with deterministic calculations. Sensitivity analysis demonstrates the main sources of uncertainty by importance factors, and their changing trends with distance from the leakage were presented.  相似文献   

How the Organization of Milk Producers in a Network of Companies Improved the Productivity     

Marcelo Tsuguio  Okano Oduvaldo  Vendrametto Osmildo  Sobral dos  Santos 《农业科学与技术》2012,(2):228-236

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Development of a mathematical model to study the impacts of production and management policies on the herd dynamics and profitability of dairy goats     

Vinícius Pereira Guimares  Luis Orlindo Tedeschi  Marcelo Teixeira Rodrigues 《Agricultural Systems》2009,101(3):186-196

The reduction in goat milk production and the competitiveness of more profitable activities have increased the adoption of measures to enhance goat milk and meat around the world. A simulation model was built to evaluate the dynamics of a dairy goat herd under different scenarios of production. A System Dynamics approach was used to identify management policies that could affect the behaviour of the herd over 10 years of simulation using data from a dairy goat herd in Brazil. The impact of reproductive and mortality rates, one or two annual reproductive cycles on production, and economic health of dairy goats on changes in the herd dynamics were evaluated. Simulations indicated that small changes in reproduction and mortality rates and milk price can considerably affect the dynamics of the herd as well as the financial health of the production system. The interferences created to visualize the effects were not immediately realized because of intrinsic delays in the system. The comparison of models with one or two breeding seasons indicated that the latter was considerably more profitable and had a faster turnover. It was also found that the two breeding season had a greater capacity to support reduction in milk price that could generate financial instability in the production system. It was concluded that mathematical models can be used to predict impacts in management policies on herd dynamics and sensitivity to support the dairy goat activity showing its viability as an agricultural activity that can contribute to the production and incomes in small farms.  相似文献   

Biochemical analysis, cpn60 and 16S rDNA sequence data indicate that Streptococcus suis serotypes 32 and 34, isolated from pigs, are Streptococcus orisratti     

Hill JE  Gottschalk M  Brousseau R  Harel J  Hemmingsen SM  Goh SH 《Veterinary microbiology》2005,107(1-2):63-69

Streptococcus suis serotypes have traditionally been identified by morphology, biochemical profiling and serotyping. Analysis of the sequences of 16S rRNA and cpn60 genes of the 35 characterized serotypes of S. suis led to the observation that two serotypes 32 and 34, are significantly distinct from other S. suis serotypes and may represent a distinct species. Here we present DNA sequence data and biochemical profiles which indicate that S. suis serotypes 32 and 34, isolated from pigs, are clustered with Streptococcus orisratti, a Voges-Proskauer negative, alpha-haemolytic, aesculin-hydrolytic, Lancefield group A streptococcus isolated from the teeth of rats.  相似文献   

Hereditary equine regional dermal asthenia in three related Quarter horses in Brazil     

Borges AS  Conceição LG  Alves AL  Fabris VE  Pessoa MA 《Veterinary dermatology》2005,16(2):125-130

Hereditary equine regional dermal asthenia belongs to a group of inherited, congenital connective tissue dysplasias usually described as hyperelastosis cutis, cutaneous asthenia, dermatosparaxis, or Ehlers-Danlos-like syndrome. This report presents the clinical and histological features of three related Quarter horses affected with regional dermal asthenia. These horses had bilateral asymmetric lesions of the trunk and lumbar regions, where the skin was hyperextensible. Handling of the skin elicited a painful response and superficial trauma led to skin wounds. The skin was thinner than normal in the affected areas, with thickened borders and harder fibrotic masses (pseudotumours). The histopathological findings included thinner and smaller collagen fibrils, and a loose arrangement of collagen fibres in the middle, adventitial and deep dermis. Masson's trichrome and Calleja stains did not reveal any abnormality of collagen and elastic fibres. Electron microscopy showed no abnormalities. As in human patients, pseudotumour histopathological findings included fibroplasia and neovascularization. The pedigree chart of these animals supports an autosomal recessive type of inheritance, which has been suggested by other studies. This is the first report of this disease in Brazil. Its clinical and histological features resemble those described in horses affected with this condition in the United States.  相似文献