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Význam a funkce stromálních enzymů v patogenezi keratokonu / The role and function of stromal enzymes in keratoconus pathogenesisĎuďáková, Ľubica January 2015 (has links)
Lubica Dudakova Doctoral Thesis ABSTRACT Keratoconus (KC) is a non-inflammatory disease of the cornea, in which ectasia and thinning occur probably due to defects in the collagen fibers binding. It is one of the most common indications for corneal transplantation. KC is a complex disorder with the involvement of both genetic and environmental factors; however the exact pathogenic mechanisms leading to the disease development have not been elucidated. The main aim of our work was to compare the presence and enzyme activity of cross- linking enzymes lysyl oxidases (LOX and LOX-like enzymes), in control human cornea samples and explanted cornea gained from patients with KC. We also focused on diseases previously described to be associated with KC with the aim to identify common signs among them. Furthermore, we replicated association of single nucleotide polymorphisms (SNPs) in LOX and hepatocyte growth factor (HGF) with KC risk. We attempted to link all pathophysiological disturbances observed in KC into one common pathway. We have used a wide spectrum of methods (cell culturing, immunohisto- and immunocytochemistry, microscopy, fluorimetric enzyme activity measurement, genotyping and direct sequencing, statistical analysis). We demonstrated the presence of entire family of LOX enzymes in control and in KC...
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Význam a funkce stromálních enzymů v patogenezi keratokonu / The role and function of stromal enzymes in keratoconus pathogenesisĎuďáková, Ľubica January 2015 (has links)
Lubica Dudakova Doctoral Thesis ABSTRACT Keratoconus (KC) is a non-inflammatory disease of the cornea, in which ectasia and thinning occur probably due to defects in the collagen fibers binding. It is one of the most common indications for corneal transplantation. KC is a complex disorder with the involvement of both genetic and environmental factors; however the exact pathogenic mechanisms leading to the disease development have not been elucidated. The main aim of our work was to compare the presence and enzyme activity of cross- linking enzymes lysyl oxidases (LOX and LOX-like enzymes), in control human cornea samples and explanted cornea gained from patients with KC. We also focused on diseases previously described to be associated with KC with the aim to identify common signs among them. Furthermore, we replicated association of single nucleotide polymorphisms (SNPs) in LOX and hepatocyte growth factor (HGF) with KC risk. We attempted to link all pathophysiological disturbances observed in KC into one common pathway. We have used a wide spectrum of methods (cell culturing, immunohisto- and immunocytochemistry, microscopy, fluorimetric enzyme activity measurement, genotyping and direct sequencing, statistical analysis). We demonstrated the presence of entire family of LOX enzymes in control and in KC...
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The relationship between single nucleotide polymorphism in taste receptor genes and body composition, energy intake, and macronutrient consumption in young adultsSunbul, Manal Abbas 11 May 2022 (has links) (PDF)
Genetic variations in taste receptor genes play a notable role in human taste perception and food preferences and intake, which may affect nutritional and health status. Understanding how genetic variations in taste receptor genes influence food perception, preferences, and intake can play an important role in designing effective interventions to improve the quality of peoples' nutrition and minimize the risk of diet-related diseases such as obesity. The objective of this study was to investigate single nucleotide polymorphisms (SNPs) of umami taste receptor gene TAS1R1 and GRM4 and sweet taste receptor gene TAS1R3 and percentage of body fat mass (BF%) among young adults. 833 young adults aged 18-31 years old were enrolled in a cross-sectional study. Umami and sweet taste receptor genotypes were determined and analyzed. A strong association was observed between the allele frequencies of sweet taste receptor gene TAS1R3 for SNPs rs307355 and rs35744813 and BMI, and between the same SNPs rs307355 and rs35744813 and BF%. In addition, the allele frequencies of SNP rs2499729 were significantly related to the likelihood of having obesity based on BMI classification. However, there was no association between the allele frequencies of the SNPs of the umami taste receptor genes; TAS1R1 for rs34160967 and BMI or BF%. The results of this study also indicated association in total energy intake and the percentage of energy from carbohydrates, protein, and fat intake between the alleles of the sweet receptor gene TAS1R3 for rs307355 and 35744813. Furthermore, a notable association was also detected in the percentage of energy from fat intake among the alleles of the umami receptors gene TAS1R1 rs34160967, and a significant relation in the percentage of energy from carbohydrates and protein intake between the different genotype polymorphisms of the umami receptor GRM4 gene for rs2499729.
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Associations of Polymorphisms in the Peroxisome Proliferator-Activated Receptor Gamma Coactivator-1 Alpha Gene With Subsequent Coronary Heart Disease: An Individual-Level Meta-AnalysisSchillemans, Tessa, Tragante, Vinicius, Maitusong, Buamina, Gigante, Bruna, Cresci, Sharon, Laguzzi, Federica, Vikström, Max, Richards, Mark, Pilbrow, Anna, Cameron, Vicky, Foco, Luisa, Doughty, Robert N., Kuukasjärvi, Pekka, Allayee, Hooman, Hartiala, Jaana A., Tang, W.H. Wilson, Lyytikäinen, Leo-Pekka, Nikus, Kjell, Laurikka, Jari O., Srinivasan, Sundararajan, Mordi, Ify R., Trompet, Stella, Kraaijeveld, Adriaan, van Setten, Jessica, Gijsberts, Crystel M., Maitland-van der Zee, Anke H., Saely, Christoph H., Gong, Yan, Johnson, Julie A., Cooper-DeHoff, Rhonda M., Pepine, Carl J., Casu, Gavino, Leiherer, Andreas, Drexel, Heinz, Horne, Benjamin D., van der Laan, Sander W., Marziliano, Nicola, Hazen, Stanley L., Sinisalo, Juha, Kähönen, Mika, Lehtimäki, Terho, Lang, Chim C., Burkhardt, Ralph, Scholz, Markus, Jukema, J. Wouter, Eriksson, Niclas, Akerblom, Axel, James, Stefan, Held, Claes, Hagström, Emil, Spertus, John A., Algra, Ale, de Faire, Ulf, Akesson, Agneta, Asselbergs, Folkert W., Patel, Riyaz S., Leander, Karin 26 October 2023 (has links)
Background: The knowledge of factors influencing disease progression in patients with
established coronary heart disease (CHD) is still relatively limited. One potential pathway is
related to peroxisome proliferator–activated receptor gamma coactivator-1 alpha
(PPARGC1A), a transcription factor linked to energy metabolism which may play a role
in the heart function. Thus, its associations with subsequent CHD events remain unclear.
We aimed to investigate the effect of three different SNPs in the PPARGC1A gene on the
risk of subsequent CHD in a population with established CHD.
Methods: We employed an individual-level meta-analysis using 23 studies from the
GENetIcs of sUbSequent Coronary Heart Disease (GENIUS-CHD) consortium, which
included participants (n = 80,900) with either acute coronary syndrome, stable CHD, or a
mixture of both at baseline. Three variants in the PPARGC1A gene (rs8192678, G482S;
rs7672915, intron 2; and rs3755863, T528T) were tested for their associations with
subsequent events during the follow-up using a Cox proportional hazards model adjusted
for age and sex. The primary outcome was subsequent CHD death or myocardial
infarction (CHD death/myocardial infarction). Stratified analyses of the participant or
study characteristics as well as additional analyses for secondary outcomes of specific
cardiovascular disease diagnoses and all-cause death were also performed.
Results: Meta-analysis revealed no significant association between any of the three
variants in the PPARGC1A gene and the primary outcome of CHD death/myocardial
infarction among those with established CHD at baseline: rs8192678, hazard ratio (HR):
1.01, 95% confidence interval (CI) 0.98–1.05 and rs7672915, HR: 0.97, 95% CI
0.94–1.00; rs3755863, HR: 1.02, 95% CI 0.99–1.06. Similarly, no significant
associations were observed for any of the secondary outcomes. The results from
stratified analyses showed null results, except for significant inverse associations
between rs7672915 (intron 2) and the primary outcome among 1) individuals aged
≥65, 2) individuals with renal impairment, and 3) antiplatelet users.
Conclusion: We found no clear associations between polymorphisms in the PPARGC1A
gene and subsequent CHD events in patients with established CHD at baseline.
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Molecular Analysis of Host Resistance and Pathogenicity of Rice Blast in East Africa.Mgonja, Emmanuel Mohamed January 2016 (has links)
No description available.
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Constructing confidence regions for the locations of putative trait loci using data from affected sib-pair designsPapachristou, Charalampos 24 August 2005 (has links)
No description available.
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A Comprehensive Analysis of Rust Disease Resistance in the Bioenergy Plant Switchgrass (Panicum virgatum L.)Frazier, Taylor Price 14 January 2016 (has links)
Switchgrass is a C4 perennial grass that is currently being developed for use as a second generation lignocellulosic biofuel crop. For switchgrass to be fully utilized as a bioenergy crop, large-scale plantings of elite switchgrass germplasm, possibly in monoculture, are likely to occur. This practice may increase the selection pressure on plant pathogens, such as switchgrass rust, which could result in devastating disease epidemics. The identification and deployment of quantitative trait loci (QTLs) and major plant disease resistance genes (R) in switchgrass breeding programs could offer broad spectrum and durable disease resistance in commercial switchgrass cultivars. 'Alamo', a lowland cultivar, is generally resistant to switchgrass rust whereas 'Dacotah', an upland cultivar, is highly susceptible. I hypothesized that major R genes and/or QTLs were contributing to the differences in disease phenotypes of these two cultivars. In this dissertation, bioinformatics and molecular biology approaches were employed to dissect the genetic mechanisms underlying switchgrass rust disease resistance. Novel pseudo-F2 mapping populations were created from a cross derived from 'Alamo' and 'Dacotah'. RNA-sequencing of the pseudo-F2 progenies of 'Alamo' x 'Dacotah' was used to construct a genetic linkage map and to identify potential QTLs correlating with disease resistance. In addition, a homology-based computational method was used to identify 1,011 potential NB-LRR R genes in the switchgrass genome (v 1.1). These potential R genes were characterized for polymorphism and expression differences between 'Alamo' and 'Dacotah'. Moreover, I found that some NB-LRR genes are developmentally regulated in switchgrass. One of the major objectives of switchgrass breeding programs is to develop cultivars with improved feedstock quality; however, changes in the components of the plant cell wall may affect disease resistance. I hypothesized that genetically modified switchgrass plants with altered cell wall components will respond differently than the wild-type to switchgrass rust. Transgenic switchgrass plants overexpressing AtSHN3, a transcription factor with known functions in epicuticular wax accumulation and cell wall deposition, were created. I found that AtSHN3-overexpressing transgenic switchgrass lines were more susceptible than wild-type plants in their response to switchgrass rust. Overall, the results of this dissertation provide a platform for elucidating the molecular mechanisms underlying resistance of switchgrass to switchgrass rust. These findings will help breeders create switchgrass cultivars with improved disease resistance, and will ultimately allow switchgrass to be used for sustainable biomass production. / Ph. D.
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Enemy within the gates : reasons for the invasive success of a guppy population (Poecilia reticulata) in TrinidadSievers, Caya January 2010 (has links)
The invasion of individuals into new habitats can pose a major threat to native species and to biodiversity itself. However, the consequences of invasions for native populations that are not fully reproductively isolated from their invaders are not yet well explored. Here I chose the Trinidadian guppy, Poecilia reticulata, to investigate how different population traits shaped the outcome of Haskins's introduction, a well-documented invasion of Guanapo river guppies into the Turure river. I especially concentrated on the importance of behaviour for invasive success. I investigated if the spread of Guanapo guppies is due to superiority in behaviour, life-history and/or genetics, or if the outcome of this translocation is due to chance. Despite the fact that by today the invasive front has passed the Turure's confluence with the River Quare many kilometres downstream of the introduction site, and the original genotype only survives in small percentages, as was revealed by genetic analysis in this and other studies, no obvious differences between invasive and native populations could be detected in any of the tested behavioural, life-history and genetic traits. When tested for mate choice, neither Guanapo nor Oropuche (Turure) males seemed to be able to distinguish between the population origin of females, but courted and mated at random. At the same time, females did not prefer to school with individuals of the same population over schooling with more distantly related females. The formation of mixed schools after an invasive event is therefore likely. Because female guppies showed a very low willingness to mate, even after having been separated from males for up to six months, sperm transfer through forced copulations will become more important. Taken together, these behaviours could increase the speed of population mixing after an invasion without the need for behavioural superiority of the invasive population. When tested for their schooling abilities, offspring of mixed parentage, in contrast to pure breds, displayed a large amount of variety in the time they spent schooling, a circumstance that can potentially influence survival rates and therefore the direction of gene pool mixing. Guanapo fish did not show reproductive superiority in a mesocosm experiment, where both populations were mixed in different proportions. On the contrary, in two out of three mixed treatments, the amount of Oropuche (Turure) alleles was significantly higher than expected from the proportion of initially stocked fish. The almost complete absence of distinguishable traits other than genetic variation between the examined populations that belong to different drainage systems, opposes the recent split of the guppy into two different species following drainage system borders, as is argued in this thesis. However, the successful invasion of the Turure by Guanapo guppies and the nearly entire disappearance of the original population can be explained in absence of differing population traits. Here I demonstrate how behavioural and genetic interactions between subspecies influence the outcome of biological invasions and second, how factors other than population traits, such as the geographic situation, can produce an advantageous situation for the invader even in the absence of population differences.
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Genetics of litter size and prenatal survival in pigsHernández Velasco, Silvia Clara January 2012 (has links)
Female reproductive performance is a critical component of sustainable pig production systems. There is abundant evidence of genetic variation in these traits among pig breeds. The aims of this study were to identify quantitative trait loci (QTL) affecting reproductive traits and to identify and characterise positional candidate gene(s) underlying the QTL. A Large White - Meishan F2 population was scanned for QTL with effects on reproductive traits. This analysis revealed 13 putative QTLs on seven different chromosomes with effects on five different traits: ovulation rate (OR), teat number (TN), prenatal survival (PS), total born alive (TBA) and litter size (LS). QTL for PS and LS on chromosome 8 were fine mapped and Secreted Phosphoprotein 1 (SPP1) confirmed as a candidate gene. A genome-wide association study was performed on a diverse population of different breeds and crosses lines, for reproductive traits including LS, TBA, number of stillborn piglets, and number of mummified piglets. Fourteen SNPs were found significantly associated with reproductive traits. The functional study of SPP1 examined the hypothesis that differences in foetal growth may be associated with the effectiveness of conceptus attachment, as measured by SPP1 expression. Patterns of SPP1 mRNA and protein expression in placental and uterine tissues supplying the smallest and a normal-sized foetus from the same uterus were examined in Large White-Landrace (LW-LR), Large White (LW) and Meishan (MS) females 40 and 45 of pregnancy. The smallest LW-LR foetuses tended to have a higher level of SPP1 mRNA in endometrium tissue compared to the normal-sized foetuses. However, placenta expression was higher in the normal-sized foetuses compared to the smallest ones. SPP1 protein levels in normal sized foetuses were significantly higher than in the smallest litter mates for all the tissues. Significantly higher levels of SPP1 mRNA and protein were found in MS compared to LW. In both breeds, significant differences between sizes were found in some tissues, with similar expression patterns in respect to size, for both mRNA and protein in endometrial tissues when compared to contemporary LW. In placenta, the direction of the expression differed between breeds, with a higher expression of mRNA and protein in the normal-sized MS foetuses and in the smallest sized LW foetuses. The comparison of SPP1 expression between different foetal sizes and different breeds revealed associations between breed, foetal size, and SPP1 protein, factors implicated in PS and LS. These results together with the genetic evidence indicate that the potential role of SPP1 in placental and foetal development merits further investigation.
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The decline of Fowler's Toad (Bufo fowleri) in southern Louisiana: molecular genetics, field experiments and landscape studiesVogel, Laura Sanders 08 August 2007 (has links)
Two of the most pervasive threats to species biodiversity are invasive species and habitat loss and degradation. Invasive species are often relatively insensitive to disturbance and many expand their range into disturbed and fragmented habitats. This dissertation uses an interdisciplinary approach to investigate how anthropogenic habitat disturbance is precipitating a range expansion in an invasive toad species, Bufo nebulifer, which is driving a decline in its native congener, B. fowleri. I employed a remote sensing and GIS study using historical data to compare changes in the two species distributions and habitat changes, a molecular genetic study to identify interspecific hybrids and their potential effects on the parental species, and an experimental ecology study to look at the effects of competition and predation on the two species. The results of the landscape level analyses of species' distributional changes in different disturbance levels showed that both species' distributions have changed significantly. The distributions of the two species are inversely affected by habitat disturbance; the distribution of B. fowleri in highly degraded habitat has contracted while the expansion of B. nebulifer increased substantially. The molecular genetic study successfully demonstrated the use of nuclear and mitochondrial markers to identify cryptic hybrids and their maternal lineage. Three hybrids were detected using nuclear introns and a morphologically cryptic hybrid was identified using mitochondrial DNA as the progeny of a cross that was previously thought to be inviable. Although relatively few hybrids were currently found, the identification of a cryptic hybrid implies that the rate of historical hybridization may have been drastically underestimated. Ecological studies showed that competition with B. nebulifer tadpoles had a negative effect on both body size measures and survival to metamorphosis for B. fowleri tadpoles. The addition of predators to experiment did not favor the survival of B. fowleri over B. nebulifer. Bufo fowleri's inability to compete with its invasive congener could be a driving mechanism for the decline of B. fowleri and the expansion of B. nebulifer. The methods discussed in this dissertation offer promising and practical new approaches for evaluating and managing changes in the distribution of species of conservation concern.
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