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Investigating Patterns of Mitochondrial DNA Inheritance Using New Zealand Chinook Salmon (Oncorhynchus tshawytscha) as a Model OrganismWolff, Jonci Nikolai January 2008 (has links)
The laws for the inheritance of animal mitochondrial DNA differ from those revealed for nuclear DNA. In contrast to nuclear genes, animal mitochondrial DNA (mtDNA) is predominantly inherited through the maternal line and is typically assumed to be nonrecombining. The absence of both paternal transmission (hereafter: paternal leakage) and heterologous recombination of mtDNA are assumed to be key characteristics of mitochondrial DNA inheritance, which has enabled evolutionary models to be much simpler than those needed for the interpretation of nuclear DNA. However, recent revelations of paternal leakage in the animal kingdom challenge our current knowledge about mtDNA inheritance and the utility of mtDNA as a molecular marker. The occurrence of paternal leakage potentially introduces new haplotypes into populations and therefore impacts on the interpretation of mtDNA analysis. To date, it is unclear whether the documented cases of paternal leakage are exceptions to the general rule or if these events occur more frequently than so far believed. If this event occurred at a measurable frequency, it is vital to implement such data into models of mtDNA evolution to improve the accuracy at which evolutionary relationships and times of divergence are estimated. In this thesis, I aimed to provide an insight into the broader patterns of mtDNA inheritance using chinook salmon as a model organism. I first sought to delimit the frequency of paternal leakage in chinook salmon and further investigated two major mechanisms which are believed to limit paternal leakage: The many-fold dilution of paternal mtDNA by maternal mtDNA upon fertilization and the genetic bottleneck mtDNA is believed to be exposed to during early developmental stages. A screen of roughly 10.000 offspring did not reveal the presence of paternal mtDNA within these samples delimiting the maximum frequency of paternal leakage in this system to 0.18% (power of 0.95) and 0.27% (power of 0.99), suggesting that the occurrence of paternal leakage is most likely an exception to the general rule. To infer the dilution of paternal mtDNA upon fertilization, I employed real-time PCR and determined the mtDNA content of salmon spermatozoa and oocytes to be 5.73 ± 2.28 and 3.15x109 ± 9.98x108 molecules per gamete, respectively. Accordingly, the estimated ratio of paternal to maternal mtDNA in zygotes is 1:7.35x108 ± 4.67x108. This estimate is 3 to 5 orders of magnitude smaller than the ratio revealed for mammals. Consequently, and if the dilution acts as an efficient barrier against the transmission of paternal mtDNA, paternal inheritance of mtDNA per offspring will be much less likely in this system than in mammals. To estimate at what probability the diminutive contribution of paternal mtDNA in zygotes is potentially inherited to offspring, I determined the size of the bottleneck acting on mtDNA during both embryogenesis and oogensis by examining the transmission of mtDNA variants to offspring and oocytes within a pedigree of heteroplasmic individuals. The number of segregating units (mtDNAs) between a mother’s somatic tissue and oocytes was estimated to be 109.3 (median = 109.3; 62.4 < NeOog < 189.6; 95% confidence interval) and from a mother’s soma to offspring’s soma 105.4 (median = 105.4; 70.3 < NeEmb < 153.1; 95% confidence interval). Detected variances in allele frequency among oocytes were not significantly different from those in offspring, strongly suggesting that segregation of mtDNA occurs during oogenesis with its completion before oocyte maturation. However, considering a ratio of roughly 1:7.35x108 for paternal to maternal mtDNA in zygotes and that approximately 109.3 (NeOog) of the mitochondrial genomes present in zygotes are ultimately inherited to offspring, the probability for paternal mtDNA to be transmitted to offspring is in round terms 1.0x10-11/paternal mtDNA molecule. In summary, the results presented in this thesis document the presence of efficient barriers to prohibit the inheritance of minor allele contributions, such as paternal mtDNA, to offspring. These results strongly suggest that paternal leakage is an exception to the general rule. Furthermore, in comparison to studies undertaken in mammals, my results indicate that mechanisms in place to prevent paternal leakage may be unequally efficient among different animal taxa, reflecting differences in life traits, such as gamete morphology, gamete investment and reproductive strategies. Nonetheless, by the means of the dilution effect in zygotes and the genetic bottleneck during oogenesis, the occurrence of paternal leakage might be simply a quantitative phenomenon and cannot be excluded per se. The increasing number of documented cases of paternal leakage clarifies that its occurrence must be considered when applying mtDNA as a genetic marker. Furthermore, for species in which mtDNA inheritance can be confirmed to be purely random, theoretical frequencies of paternal leakage can be inferred and potentially implemented into models of mtDNA evolution.
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Experimentelle Gingivitis in verschiedenen Altersgruppen klinische und mikrobiologische Untersuchung mittels quantitativer real-time PCRWerner, Daniel. Unknown Date (has links)
Univ., Diss., 2010--Marburg.
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Molecular identification of Bartonella bacilliformis in ticks collected from two species of wild mammals in Madre de Dios: Perudel Valle-Mendoza, Juana, Rojas-Jaimes, Jesús, Vásquez-Achaya, Fernando, Aguilar-Luis, Miguel Angel, Correa-Nuñez, Germán, Silva-Caso, Wilmer, Lescano, Andrés G., Song, Xiuping, Liu, Qiyong, Li, Dongmei 06 1900 (has links)
Objective: To study the presence of Bartonella bacilliformis in ticks collected from two wild mammals in Madre de Dios, Peru. Results: A total of 110 ticks were collected. Among the 43 Amblyomma spp. extracted from the 3 Tapirus terrestris only 3 were positive for B. bacilliformis. In addition, 12 out of the 67 Rhipicephalus (Boophilus) microplus obtained from the 3 Pecari tajacu were positive for B. bacilliformis. For the first time B. bacilliformis have been detected in arthropods other than Lutzomyia spp. Further studies are required to elucidate the possible role of ticks in the spread of South American Bartonellosis. / This work was supported by Cienciativa of CONCYTEC Peru, under the contract N° 164‑2016‑FONDECYT. Dr. Lescano is sponsored by the training grant D43 TW007393 awared by the Fogarty International Center of the US National Institutes of Health. / Revisión por pares / Revisión por pares
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Výskyt hlístic rodu Trichuris u přežvýkavců v České republice. / Trichurids in ruminants from Czech Republic.Antošová, Tereza January 2016 (has links)
The goal of this paper was to determine rate of presence of whipworms of genus
Trichuris in bodies of selected ruminants (sheep, roe deer) in certain areas and to morphologically state different species of whipworms using molecular revision and professional literature on samples found during helmitological dissections of selected ruminants. Two hypotheses were stated: H1: species that are found in highest volume in case of roe deer and sheep are whipworms Trichuris discolor and Trichuris ovis H2: these whipworms can not be positively distinguished when using morphometrical methods.
Material needed for the study, i.e. the intestines of examined ruminants, was recovered in different areas of Czech Republic. Later were the intestines dissected in a laboratory using standardized procedure and hereby collected samples were analysed.
Based on selected methods it was determined that in roe deer the rate of occurence of Trichuris discolor is much higher compared to that of Trichuris ovis. With sheep the difference between rates of presence is smaller. These results confirm the first hypothesis by showing high rate of presence of whipworms in these hosts. Collected females of genus Trichurids were morphometrically differentiated by their sex and in 4 morphotypes. Following this differentiation, the most present were the females of morphotype M2, those with a vulval opening without an everted vagina. The second hypothesis was also confirmed.
Multihosting species Trichuris discolor and Trichuris ovis are prevalent in the bodies of roe deer and sheep. Thus we can say the roe deer are a potential source of whipworm contamination to sheep breeding. It can not be excluded that sheep are infected by roe deer and vice versa. Molecular determination is a necessary tool for correct assessment of whipworm species, considering the fact that morphological methods may lead to incorrect results.
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Diagnóstico e caracterização molecular do vírus da anemia infecciosa equina na Bahia Brasil.Tigre, Dellane Martins 27 January 2017 (has links)
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tese Dellane Martins Tigre 75folhas 2017.pdf: 1616856 bytes, checksum: a34a008544e31d63c94fa0cf795cc2ff (MD5) / O vírus da Anemia Infecciosa Equina (EIAV), membro da família Retroviridae, gênero Lentivirus, causa uma doença de curso crônico e latente em equídeos. A infecção é limitada a equinos, asininos e muares e caracteriza-se por episódios febris, perda de peso, debilidade progressiva, mucosas ictéricas, edemas subcutâneos e anemia. A AIE não tem tratamento nem vacina eficaz. O diagnóstico clínico é difícil pelo fato que os sinais da doença não são específicos, além disso, após a fase aguda da infecção a maioria dos animais se torna portador assintomático do vírus. Neste estudo nós detectamos e caracterizamos filogeneticamente o vírus isolado na Bahia, Brasil. A partir de amostras de sangue e soro de animais de diferentes municípios do estado utilizamos a técnica de referência pela Organização Mundial para Sanidade Animal (OIE), a prova sorológica de IDGA, e as técnicas moleculares de nested-PCR e nested-RT-PCR. No total 82 animais foram examinados neste estudo por IDGA e PCR. Primers para o gene gag foram utilizados para amplificar o DNA proviral/RNA do EIAV, nos ensaios de nested-PCR e nested-RT-PCR respectivamente. Amplicons de 15 amostras positivas por nested-PCR foram submetidas ao sequenciamento e análise filogenética. As sequencias de EIAV analisadas neste estudo formam um clado com as cepas WSU5, EIAVUK e EIAVwyoming, todas dos EUA. 51 amostras (62,2%) foram positivas por nested-PCR, enquanto apenas 31 amostras (37,8%) foram positivas por IDGA. No presente estudo utilizando técnicas moleculares foi possível demonstrar que animais portadores assintomáticos do EIAV, com diferentes status sorológico apresentam vírus e/ou DNA proviral detectável por PCR, em PBMC e plasma, demonstrando que o vírus se replica mesmo na presença de mecanismos de defesa imunológicos do hospedeiro, sendo o animal portador assintomático e sorologicamente negativo, importante reservatório do vírus no plantel, e sugerindo que o controle da AIE baseado apenas no IDGA precisa ser revisto pelos órgãos fiscalizadores no Brasil. / The Equine Infectious Anemia Virus (EIAV), a member of the family Retroviridae, genus Lentivirus, causes a disease of chronic and latent course in equidae. Infection is limited to horses, asinines and mules and is characterized by febrile episodes, weight loss, progressive weakness, icteric mucous, subcutaneous edema and anemia. The equine infectious anemia (EIA) has no effective treatment or vaccine. The clinical diagnosis is difficult due to the fact that the signs of the disease are not specific; moreover, after the acute phase of infection, most animals become asymptomatic carriers of the virus. In this study we detected and characterized phylogenetically the virus isolated in Bahia, Brazil. We used the reference technique from the World Organization for Animal Health (OIE), the serological test of AGID, and the molecular techniques of nested-PCR and nested-RT-PCR from blood and serum samples from different municipalities of the state. In total, 82 animals were examined in this study by AGID and PCR. Primers for the gag gene were used to amplify the EIAV proviral DNA/RNA in the nested-PCR and nested-RT-PCR assays, respectively. Amplicons of 15 samples positive by nested-PCR were submitted to sequencing and phylogenetic analysis. The EIAV sequences analyzed in this study form a clade with strains WSU5, EIAVUK and EIAVwyoming, all from the USA. 51 samples (62.2%) were positive by nested-PCR, whereas only 31 samples (37.8%) were positive by AGID. In the present study using molecular techniques, it was possible to demonstrate that asymptomatic carriers of EIAV, with different serological status, have virus and/or DNA proviral detectable by PCR, in PBMC and plasma, demonstrating that the virus replicates even in the presence of immunological defense mechanisms of the host, being the asymptomatic and serologically negative carrier animal, an important reservoir of the virus in the establishment, and suggesting that the control of the EIA based only on the AGID test needs to be reviewed by the inspection agencies in Brazil.
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Diagnóstico molecular e caracterização dos genes de virulência de infecção por Escherichia coli enteropatogênica em crianças no Semiárido Brasileiro / Molecular diagnosis and characterization of virulence genes of enteropathogenic Escherichia coli infection in children in the Brazilian Semi-aridSantos, Ana Karolina Silva dos 13 July 2015 (has links)
SANTOS, A. K. S. Diagnóstico molecular e caracterização dos genes de virulência de infecção por Escherichia coli enteropatogênica em crianças no Semiárido Brasileiro. 2015. 110 f. Dissertação (Mestrado em Microbiologia Médica) - Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, 2015. / Submitted by Carolinda Oliveira (ppgmm@ufc.br) on 2017-07-11T12:40:12Z
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Previous issue date: 2015-07-13 / The Escherichia coli diarrheagenic (DEC) are important pathogens associated with intestinal infections. Among these, Escherichia coli (EPEC) is one of the most important etiological agents for the diagnosis of diarrhea in infantos. However, the epidemiology of infections by these pathogens remain poorly elucidated in much of the world, so this study aimed to evaluate the impact of EPEC infection in children with and without diarrhea 2-36 months of life of the Brazilian semiarid, study type observational case-control, which also examined the presence or absence of diarrhea in children participating. The study population consisted of 365 cases and 365 controls, and the cases, children with diarrhea history in the 14 days before you check for the study. Socioeconomic parameters were evaluated through epidemiological questionnaire. The diagnosis of EPEC was carried out by xMAP (Bioplex 200) based on the eaeA genes (chromosomal) and bfpA (plasmid). Samples identified as EPEC were analyzed for five Polymerase Chain Reactions (PCR) of the Multiplex type for 19 EPEC virulence factors widely investigated in literature: espB, espD, tir, espC, espZ, espL, Ler, Map, espG, espH, nleE, nleF, nleB, paa, nleC, nleD, espJ, cesT and espP. Among the 730 children, EPEC was diagnosed in 118 children. The typical EPEC proved in 1.7% of cases (6/365) and 0.6% of controls (2/635). While atypical EPEC was detected in 13.7% of cases (50/365) and 16.4% of controls (60/365). And all samples isolated EPEC genes read, cest, and espB were the most prevalent (67.7%; 58.4%; 54.2% and 52.5%) respectively. These are associated with the global regulation of pathogenicity island bacteria, as well as the secretion and translocation various effector proteins into the host cell, and microtubule destruction and disruption tight junctions. In contrast, the lowest prevalence of the tir gene was (4,2% - 5/118), an important component of bacterial adhesion to host cell. The prevalence of the espD gene, associated with liposaccharide membrane pore translocation protein, was significantly associated with cases (p = 0.0354) as compared to controls. In the hierarchical combination analysis of the virulence genes the data suggest that three groups of genes were important and associated with the cases compared to the controls. The presence of the Paa gene, related to the protein associated with enterocyte adhesion injury, but in the absence of other virulence genes such as espH, espJ and espG, related to actin polymerization, inhibition of phagocytosis and effector translocation blocker T3SS , Respectively, are associated with cases compared to controls. A set of virulence genes, the presence of espJ and in the absence of nleF. And another set of virulence genes, with presence of espC, and in the absence of espP. The data also showed that in the hierarchical combinations of the virulence genes, such as the presence of espP and in the absence of nleF, as well as the presence of espG and in the absence of tir were associated with protection in the controls compared to the cases. The data suggest that the prevalence of EPEC is relatively high in this child population in the Brazilian semi-arid region. / As cepas Escherichia coli diarreiogênicas (DEC) são importantes patógenos associados às infecções intestinais. Dentre estes, a Escherichia coli enteropatogênica (EPEC) é um dos agentes etiológicos mais relevantes para o diagnóstico de diarreias em infantos. Contudo a epidemiologia das infecções por esses patógenos permanecem pouco elucidadas em grande parte do mundo. Este trabalho objetivou avaliar o impacto da infecção por EPEC em crianças com e sem diarreia de 2-36 meses de vida no Semiárido Brasileiro, em estudo do tipo observacional caso-controle, que também examinou a presença ou ausência de diarreia nas crianças participantes. A população estudada consistiu em 730 crianças, 365 casos e 365 controles, sendo os casos, crianças com histórico de diarreia nos 14 dias antes à seleção para o estudo. Foram avaliados parâmetros socioeconômicos através de questionário epidemiológico. O diagnóstico de EPEC foi realizado pela técnica de xMAP (Bioplex 200) com base nos genes eaeA (cromossomal) e bfpA (plasmidial). As amostras identificadas como EPEC foram analisadas por cinco Reações em Cadeia da Polimerase (PCR) do tipo Multiplex para 19 fatores de virulência de EPEC amplamente investigados na literatura: espB, espD, tir, espC, espZ, espL, Ler, Map, espG, espH, nleE, nleF, nleB, paa, nleC, nleD, espJ, cesT e espP. Entre as 730 crianças, a EPEC foi diagnosticada em 118 crianças. A EPEC típica mostrou-se em 1,7% dos casos (6/365) e em 0,6% dos controles (2/635). Enquanto a EPEC atípica foi detectado em 13,7% dos casos (50/365) e 16,4% dos controles (60/365). E de todas as amostras de EPEC isoladas, os genes ler, cesT, espB e espG foram os mais prevalentes (67,7%; 58,4%; 54,2%; e 52,5%), respectivamente. Estes estão associados com a regulação global da ilha de patogenicidade da bactéria, assim como a secreção e a translocação de diversas proteínas efetoras para dentro da célula do hospedeiro, e a destruição de micro túbulos e ruptura das junções firmes entre as células intestinais. Em contrapartida, o gene de menor prevalência foi o tir (4,2% - 5/118), importante componente para a aderência bacteriana a célula do hospedeiro. A prevalência do gene espD, associado com a proteína de translocação dos poros da membrana de lipossacarídeo, foi significativamente associado com os casos (p=0,0354) quando comparados com os controles. Na análise de combinação hierárquica dos genes de virulência os dados sugerem que três grupos de genes que foram importantes e associados com os casos comparados com os controles. A presença do gene Paa, relacionado com a proteína associado a lesão de aderência do enterócito, mas na ausência de outros genes de virulência como o espH, espJ e espG, relacionados com polimerização de actina, inibição de fagocitose e bloqueador de translocação de efetor T3SS, respectivamente, estão associados com os casos comparados com os controles. Um conjunto de genes de virulência, a presença de espJ e na ausência de nleF. E outro conjunto de genes de virulência, com presença de espC, e na ausência de espP. Os dados mostraram também que nas combinações hierárquicas dos genes de virulência, tais como a presença de espJ e na ausência de nleF, bem como a presença de espG e na ausência de tir foram associados com proteção nos controles comparados com os casos. Os dados sugerem que a prevalência de EPEC é relativamente alta nesta população infantil no semiárido brasileiro.
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Druhová identifikace zástupců rodu Enterococcus a testování jejich probiotických vlastnostíVolná, Lucie January 2009 (has links)
No description available.
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Diagnosis and control of foot rot pathogens of wheatLees, Alison Kathryn January 1995 (has links)
Foot rot disease of wheat is caused by the pathogens Fusarium cuImorum, F.avenaceum and Microdochium nivale. Symptoms of foot rot are a general browning of the stem base and leaf sheath. There is a discrepancy between the ability of fungicides to control these pathogens in vivo and in vitro, and no relationship between disease symptom severity and yield loss has been established in wheat. The identification of the causal agents of foot rot disease is not possible from examination of disease symptoms alone. This work showed that the azole fungicides flusilazole and prochloraz inhibited the germination of conidia and mycelial growth of F. culmonon, F. avenaceum and M. nivale in vitro to a varying extent. However, no consistent control of these pathogens in wheat was observed in the field using the same fungicides. Further studies employing a semicontrolled outdoor experiment showed a relationship between density and timing of inoculum application, disease symptom severity and yield loss in wheat artificially inoculated with F. culmorum and M. nivale. Molecular marker systems were used to address the problem of pathogen detection and identification. A Random Amplified Polymorphic DNA (RAPD) assay was developed to differentiate F.culmorum, F.avenaceum and two types of M.nivale (M.nivale var.nivale and M. nivale var .majus) in vitro. Selected RAPD products were cloned and sequenced and species specific primers constructed from this sequence infonnation. These primers were used in the polymerase chain reaction (peR) and were shown to detect the pathogens in host tissue. This technique was adapted by addition of a competitor fragment to the peR reaction resulting in a quantifiable competitive peR assay. Using this method the fungal biomass of each pathogen present in the host tissue could be estimated. The development of these techniques for the identification, detection and quantification of F. cuimorum, F.avenaceum, M.nivale var.nivale and M.nivale var.majus in plant tissue will allow more extensive studies of the epidemiology of these species, the competition between species and the effect of fungicides on these pathogens can be carried out.
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Detekce patogenních mikroorganismů v kravském mléce pomocí real - time PCRGrussmannová, Alena January 2013 (has links)
No description available.
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Germination ecology in orchids / Germination ecology in orchidsTĚŠITELOVÁ, Tamara January 2009 (has links)
Germination ecology of four Epipactis species (E. albensis, E. atrorubens, E. helleborine, E. purpurata) was studied. Habitat preferences of adult plants were analyzed using phytosociological relevés from the Czech Phytosociological Database. A field experiment was carried out to determine course of germination of Epipactis seeds sown in different habitat types. Relationship between ecological preferences and germination ecology, and spatial aspects of seed dispersal and seedling recruitment are discussed.
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