Isogenic, or inbred, mouse strains are currently the experimental subjects of choice in laboratory studies focused on genetics, pharmacology, and psychological issues. Understanding phenotypic differences in isogenic strains is important in order to interpret experimental results obtained from inbred mouse strains. Four commonly used inbred strains, C57BL/6NHsd (C57), DBA/2NHsd (DBA), 129S2/SvHsd (129), and Balb/cAnHsd (Balb/c), are investigated in this study using four different behavioral tasks that measure locomotor activity and cognitive behavior (Morris Water Maze (MWM), T-maze, and operant autoshaping procedures). In the locomotor activity task 129 mice showed significantly less horizontal ambulation than any other strain, while differences in rearing was seen between all strains, with C57 mice producing the most, and 129 showing the least rearing. Thigmotaxia was seen the most in the 129 strain, less so with the Balb/c and DBA strains, and the least in the C57 mice. In the MWM learning across strains was noted but there was no difference between the strains. In the T-maze the Balb/c strain showed the shortest latency to enter an arm, while the 129 strain showed the longest. As expected they also showed the lowest accuracy and the highest percent time-outs compared to all the other strains. In the autoshaping procedure little difference between the strains was observed. Balb/c mice trended graphically towards higher rates however there was no difference with regard to number of contingent responses or number per strain to reach a criterion of 10 or more contingent reinforcers. Finally, locomotor activity was measured again at the end of the study. The activity results were still similar, although the C57 strain showed a decrease in horizontal ambulation as compared to DBA and Balb/c strains; however, the 129 strain still showed the least activity. These results indicate that there are significant differences in locomotor behavior and cognitive processes in these strains that should be considered when interpreting results from studies using these inbred mouse strains.

The purpose of this investigation is to determine if differences exist between four inbred strains of mice in susceptibility to the drug thalidomide.

Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 109-126).

Thesis (doctoral)--Universität Hamburg, 1979.

Despite drought accounting for over 80% of agricultural losses, little progress has been made towards improving drought tolerance in crops. My approach to identifying traits underlying drought tolerance involved a comparison between two accessions of the crucifer, Eutrema salsugineum, that display differential tolerance to water deficits. The accessions, originating from the semi-arid Yukon, Canada, and a monsoonal region of Shandong, China, were subjected to a two-step, water deficit and recovery protocol to identify physiological characteristics that discern their drought-responsive behaviour. Traits that discriminate between the ecotypes were used to screen recombinant inbred lines (RILs) that were generated by crossing Yukon and Shandong parent plants. Selected physiological measurements were: anthocyanin accumulation, cut rosette water loss (CRWL), solute potential, relative water content (RWC), static leaf water content (SLWC), specific leaf area (SLA), and OJIP fluorescence emission. Of the measurements taken, CRWL measurements and anthocyanin content distinguished the Yukon ecotype from the Shandong ecotype during the first drought exposure whereas SLA and fluorescence responses differentiated these accessions better after plants that experienced the first drought were rewatered and recovering or undergoing a second drought treatment. Sixty-eight RILs were screened using SLA and OJIP fluorescence emission. SLA and OJIP measurements varied among the recombinant inbred lines (RILs) with many lines showing responses to water deficit intermediate to those of the parental lines. Evidence of heritability in SLA and/or OJIP responses to water deficits would make them useful phenotypic markers for identifying quantitative trait loci (QTLs) associated with drought tolerance in future work. / Thesis / Master of Science (MSc)

The majority of genetic differences between species and individuals have been hypothesised to impact on the regulation, rather than the structure, of genes. As the details of genetic variation are uncovered by the various genome sequencing projects, understanding the functional effects on gene regulation will be key to uncovering the molecular mechanisms underying the genesis and inheritance of common phenotypes, such as complex human disease and commercially important traits in plants and animals. Unlike coding sequence polymorphisms, genetic variants affecting gene expression will reside in the transcriptional machinery and its regulatory inputs. As these are largely specific to cell- or tissue-types, we would expect that regulatory variants will also affect final mRNA levels in a tissue specific manner. Genetic variation between individuals may therefore be more complex than the sum total of sequence differences between them. Demonstrating this hypothesis is the main focus of this thesis. We use microarrays to measure mRNA levels of approximately 22,000 transcripts in inbred and recombinant inbred strains of mice, and present compelling evidence that the genetic influences on these levels are tissue-specific in at least 85% of cases. We uncover two loci which apparently influence transcript levels of multiple genes in a tissue-specific manner. We also present evidence that failure of microarray data normalisation may cause spurious linkage of expression phenotypes leading to erroneous biological conclusions, and detail a novel, extensible mathematical framework for performing tailored normalisation which can remove such systematic bias. The wider context of these results is then discussed.

Submitted by Tatiana Oliveira (tsilva@icict.fiocruz.br) on 2012-05-31T16:59:24Z No. of bitstreams: 1 bernardo_as_pereira_ioc_bp_002_2010.pdf: 3428909 bytes, checksum: 68f2b1087a42200dd708a3f10aac479e (MD5) / Made available in DSpace on 2012-05-31T16:59:24Z (GMT). No. of bitstreams: 1 bernardo_as_pereira_ioc_bp_002_2010.pdf: 3428909 bytes, checksum: 68f2b1087a42200dd708a3f10aac479e (MD5) Previous issue date: 2010 / Fundação Oswaldo Cruz.Instituto Oswaldo Cruz. Rio de janeiro, RJ, Brasil / A leishmaniose é uma doença antropozoonose que afeta 88 países, o que denota a importância da realização de estudos que permitem o desenvolvimento de novas estratégias de vacinação ou quimioterapias. Os agentes etiológicos dessa doença são espécies do gênero Leishmania, sendo que, no Brasil, a Leishmania (Leishimania) amazonensis está relacionada à forma tegumentar da leishmaniose e está expandindo sua área de distribuição geográfica. O modelo murino de infecção experimental tem sido largamente empregado nos estudos de leishmanioses, por permitir o controle das características do hospedeiro e a análise de aspectos específicos da doença. O presente estudo tem por objetivo verificar a atuação de fatores de interação parasito-hospedeiro nesse modelo de infecção utilizando linhagens de camundongos comdiferentes graus de susceptibilidade. Para tanto, efetuamos o seqüenciamento da extensão COOH-terminal de um tipo específico de cisteína proteinase (CP) do parasito, a CPB, e, em seguida, o mapeamento in silico de epitopos de MHC classe I nessa seqüência. Os epitopos preditos foram então sintetizados e utilizados em ensaios in vivo (vacinação) e in vitro (indução de blastogênese e de expressão de citocinas e efeitos sobre os linfócitos T CD4+ e CD8+). Alguns desses epitopos preditos demonstraram efeitos antigênicos nos ensaios in vitro, porém sem efeitos perceptíveis nos ensaios in vivo. Os epitopos preditos P4 e P5 induziram a blastogênese em culturas de células de camundongos BALB/c (mais susceptíveis a Leishmania), enquanto P2, P8 e P9 o fizeram em células de células de camundongos CBA (menos suscetíveis). Os epitopos P5, P6 e P8 também promoveram alterações nas porcentagens dos linfócitos CD4+ ou CD8+ em culturas de células de camundongos BALB/c. Quanto à indução da expressão de citocinas, os epitopos P1 e P2 (em BALB/c) e P2 e P3 (em CBA) induziram à expressão de citosinas relacionadas à resposta imune tipo Th1; P6 (em BALB/c) e P8 (em CBA) à expressão de citosinas da resposta Th2; e P4 (em BALB/c) e P9 (em CBA) à expressão de citosinas dos dois tipos de resposta imune. Ensaios de Molecular Doking foram utilizados para auxiliar na compreensão dos fenômenos de interação nos complexos epitoppos/MHC, apontando para padrões de interação associados aos padrões de indução da expressão de citocinas. Adicionalmente, foram efetuados ensaios de PCR em tempo real para se analisar os padrões de expressão de genes de moléculas de MHC do hospedeiro e de CPs do parasito ao longo da infecção, que indicam distinções na expressão de genes de MHC classes I e II entre as linhagens murinas e na expressão de CPs pelo parasito, o que pode estar relacionado às diferentes formas de progressão da infecção nessas linhagens. Os resultados obtidos nesse estudo complementam os dados da literatura sobre as interações parasito-hospedeiro na infecção experimental murina e apontam para novas estratégias de análise dessas interações em leishmaniose / Leishmaniasis is a disease that affects anthropozoonosis 88 countries, demonstrating the importance of studies that allow the development of new strategies for vaccination or chemotherapy. The etiologic agents of this disease are species of the genus Leishmania, and in Brazil, Leishmania (Leishimania) amazonensis is related to the cutaneous form of leishmaniasis and is expanding its geographical distribution. The murine model of experimental infection has been widely used in studies of leishmaniasis by allowing the control of the characteristics of the host and analysis of specific aspects of the disease. The present study aims to verify the performance factors of the host-parasite interaction in this infection model using mice strains comdiferentes degrees of susceptibility. Therefore, we performed by sequencing the COOH-terminal extension of a particular type of cysteine ​​proteinase (CP) of the parasite, CPB, and then, the in silico mapping of epitopes on MHC class I that sequence. The predicted epitopes were then synthesized and used in vivo assays (vaccination) and in vitro (induced blastogenesis and expression of cytokines and effects on T lymphocytes CD4 + and CD8 +). Some of these antigenic epitopes predicted effects demonstrated in vitro assays, but without noticeable effects in vivo assays .. The predicted epitopes P4 and P5 induced blastogenesis in cultured cells of BALB / c (most likely Leishmania), while P2, P8 and P9 cells did cell CBA mice (less likely). The epitopes P5, P6 and P8 also induced variations in the percentages of CD4 + or CD8 + cell cultures of BALB / c mice. The induction of expression of cytokines, the epitopes P1 and P2 (in BALB / c) and P3 and P2 (in CBA) to induce expression of cytokines related to Th1 type immune response, P6 (in BALB / c) and P8 (in CBA) to the expression of Th2 cytokines, and P4 (in BALB / c) and P9 (in CBA) to the expression of cytokines of both types of immune response. Molecular tests Doking were used to assist in understanding the complex interaction phenomena in epitoppos / MHC, pointing to patterns of interaction patterns associated with induction of cytokine expression. Additionally, PCR assays were performed in real time to examine the expression patterns of genes of the host MHC molecules and CPs along the parasite infection, indicating distinctions in the gene expression of MHC class I and II between the strains and expression of murine CPs the parasite, which can be related to different forms of progression of the infection in these strains. The results of this study complement the literature on host-parasite interactions in murine experimental infection and point to new strategies for analysis of these interactions in leishmaniasis

Made available in DSpace on 2014-06-11T19:22:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-07-28Bitstream added on 2014-06-13T18:07:55Z : No. of bitstreams: 1 toppa_evb_me_botfca.pdf: 122921 bytes, checksum: 6b7c30c3b38979411e7c5aebe010b6a3 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Como conseqüência do melhoramento de populações, novas idéias e métodos surgiram, procurando melhorar a eficiência na obtenção de linhagens e híbridos, bem como diminuir o tempo requerido na sua obtenção. Este é o caso do método dos Híbridos Crípticos, que corresponde essencialmente a um teste precoce de combinação através de cruzamentos entre plantas individuais. Apesar da possibilidade do método dos Híbridos Crípticos representar um ganho de tempo na produção de híbridos, pode ser considerado de uso restrito em programas de melhoramento de espécies alógamas, principalmente em decorrência da excessiva perda de vigor das linhagens femininas com a condução de sucessivas autofecundações. No tocante, supõe-se que em programas de melhoramento de espécies que possuem o sistema reprodutivo do tipo misto, o método possa se configurar como uma ferramenta efetiva em razão de que nestas espécies a depressão endogâmica é desprezível. Ao encontro da necessidade de informações que permitam avaliar o real potencial do método dos Híbridos Crípticos em espécies com sistema reprodutivo do tipo misto, objetivou-se neste trabalho analisar comparativamente o comportamento dos híbridos de mamoneira (Ricinus communis L.) produzidos pelo processo convencional, em que as linhagens são extraídas pelo método “Standard”, com os obtidos pelo método dos Híbridos Crípticos. O estudo relata resultados de produtividade de grãos de 24 híbridos interpopulacionais... / As a consequence of population breeding, new ideas and methods have arisen in order to improve the efficiency in obtaining lines and hybrids, as well as to decrease the time required for their production. This is the case of the Cryptic Hybrids method, which corresponds essentially to an early combination test through breeding between individual plants. Although the Cryptic Hybrids method may represent time gain in hybrid production, it can be considered of restrict use in breeding programs of allogamous species, mainly due to excessive vigor loss in female lines with the conduction of successive self-pollinations. In breeding programs of species with mixed reproductive system, the method is supposed to be an effective tool since endogamic depression is negligible in these species. Based on the need of information that allow assessing the real potential of the Cryptic Hybrids method in mixed reproductive system, this study aimed to comparatively analyze the behavior of castor bean (Ricinus communis L.) hybrids produced through the conventional process, in which the lines are extracted by the Standard method, relative to those obtained by the Cryptic Hybrids method. The study reports grain productivity results for 24 interpopulational hybrids, of which 12 were conventionally produced and the other 12 were produced by the Cryptic Hybrids method; all of them were synthesized at the Department of Plant Production of the School of Agronomical Sciences.Experiments to assess the behavior of hybrids were developed in the crop cycles 2006/2007 and 2007/2008, simultaneously in the municipalities Lins and Penápolis, and were all conducted under randomized block design with four replicates. Grain productivity results for castor bean hybrids evidenced that cryptic hybrids are superior to hybrids conventionally... (Complete abstract click electronic access below)

This thesis is an investigation of barrenness and plant-to-plant variability (PPV) in ear development of maize (Zea mays L.). A three-year field experiment was conducted on homogenous plants with similar initial plant size, development and uniform spatial patterns in parental inbred lines CG60, CG102 and their F1 hybrid CG60 × CG102. Physiological processes underlying barrenness were dissected into plant growth through development and dry matter partitioning to the ear at canopy, subpopulation, and primarily, individual plant levels. The growth and development of the ultimately barren individuals were followed from early vegetative stage to physiological maturity (PM) using a non-destructive allometric methodology. Plant-to-plant variability in ear development, related to plant development, was measured destructively from ear initiation to 1 wk after silking and at PM. Results showed that the individual plants exhibited differential responses to their previous growth and development in the two parental inbred lines. No physiological traits in growth and development or dry matter partitioning to the ear during the critical period bracketing silking could characterize individual barren plants. The F1 hybrid was resistant to barrenness even at 160,000 plants ha-1. At 80,000 plants ha-1, the spikelet number per row (SNPR) and spikelet number per ear (SNPE) exhibited less PPV around silking than earlier stages of development. For the three genotypes, PPV in plant morphological traits and ear length was relatively constant throughout development. In addition, the period around the kernel row number (KRN) formation stage was the only time-window that the PPV in stem volume, representing PPV in above-ground plant dry matter (PDM), affected PPV in SNPR and KRN for the three genotypes, with SNPR being more affected. Although the F1 produced greater PDM at silking and 1 wk after silking, it had shorter ear length and less ear dry matter than the two parental inbred lines at the corresponding stages. When the relationships are elucidated among early ear development, plant growth, leaftip development, and dry matter partitioning to the ear, during the vegetative to silking stages and under stress conditions, then the physiological processes underlying barrenness of the tested inbred lines could be further characterized. / Syngenta, the Ontario Research Fund, the Ontario Ministry of Agriculture, Food and Rural Affairs, and the Natural Sciences and Engineering Research Council of Canada

Dissertation (Ph.D.)--University of Toledo, 2006. / "In partial fulfillment of the requirements for the degree of Doctor of Philosophy in Biomedical Sciences." Title from title page of PDF document. Bibliography: p. 89-95, p. 127-131, p. 184-192, p.198-233.