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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
621

Study on activation of Oct4 using engineered TALE and Cas9 transcription factors: 人工TALE和Cas9轉錄因子在激活Oct4基因中的研究 / 人工TALE和Cas9轉錄因子在激活Oct4基因中的研究 / CUHK electronic theses & dissertations collection / Study on activation of Oct4 using engineered TALE and Cas9 transcription factors: ren gong TALE he Cas9 zhuan lu yin zi zai ji huo Oct4 ji yin zhong de yan jiu / Ren gong TALE he Cas9 zhuan lu yin zi zai ji huo Oct4 ji yin zhong de yan jiu

January 2014 (has links)
Regulation of gene expression in a spatiotemporal manner specifies cellular identity. Transcription factors (TFs) bind to DNA regulatory elements to remodel chromosome structure, to recruit transcription machinery to initiate gene transcription or to prevent the assembly of such machinery to repress gene transcription, thus they lie at the heart of gene regulation. Given important roles of TFs in gene regulation, numerous attentions have been attracted for engineered transcription factors (eTFs). The recent advance of generating customized DNA-sequence specific binding domains, including transcription activator-like effectors (TALEs) and RNA-guided clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) gene Cas9, has greatly accelerated the study and application of eTFs. The eTFs with these new binding domains offer a powerful and precise approach for modulating gene expression. / Oct4 is an important TF and it plays essential roles in the formation of inner cell mass during embryogenesis, and the maintenance of embryonic stem cells in culture as well as the reinstatement of cellular pluripotency from somatic cells. / In this study, we systematically investigated the potential of TALE-TFs and CRISPR/Cas9-TFs in activating Oct4. We designed a number of TALEs and small guide RNAs (sgRNAs) targeting various regions in the mouse and human Oct4 promoters. Using luciferase assays, we found that the most efficient TALE-VP64s bound on the region −120 to −80 bp upstream of transcription start site (TSS), while highly effective sgRNAs targeted −147 to −89 bp upstream of TSS to induce high activity of luciferase reporters. This positional effect can serve as a simple guideline for designing eTFs for activating transcription from a reporter system. Next, we examined the potential of TALE-VP64 and sgRNAs to activate endogenous Oct4 transcription. We found that the positional effect was less obvious as individual eTFs exhibited marginal activity to up-regulate endogenous gene expression. Interestingly, we found that when multiple eTFs were applied simultaneously, Oct4 could be induced significantly and synergistically. This phenomenon was well supported by activation of human SOX2, KLF4, cMYC, CDH1 and NANOG by TALE-VP64s. / Using optimized combinations of TALE-VP64s, we successfully enhanced endogenous Oct4 transcription up to 30-fold in mouse NIH3T3 cells and 20-fold in human HEK293T cells. More importantly, the enhancement of OCT4 transcription ultimately generated OCT4 proteins. Furthermore, examination of different epigenetic modifiers showed that histone acetyltransferase p300 could enhance both TALE-VP64- and sgRNA/dCas9-VP64-induced transcription of endogenous OCT4. Taken together, this study demonstrated that engineered TALE-TFs and dCas9-TFs are useful tools for modulating gene expression in mammalian cells. / 基因表達調控是決定細胞命運的關鍵。轉錄因子可以結合到DNA調控序列上,以重塑染色體的結構;而且可以募集轉錄機器,以起始轉錄, 或者幹擾轉錄機器的組裝,從而抑制基因轉錄;因此,在基因表達調控過程中轉錄因子處於核心地位。由于轉錄因子在基因調控方面的重要作用,研究者們越來越多的關注人工轉錄因子的研究。DNA 序列特異性結合域的發現與發展很大程度上促進了人工轉錄因子的研究與應用。最近從TALE和CRISPR/Cas9衍生而來的人工轉錄因子給我們提供了一個強大而且精確的調控基因表達的方法。Oct4是一個重要的轉錄因子,對胚胎發育過程中內細胞團的形成,和體外培養的胚胎幹細胞的維持,以及細胞多能性的重塑等多方面都至關重要。 / 在本研究中,我們系統性地探討了TALE和CRISPR/Cas9衍生而來的人工轉錄因子在激活Oct4基因方面的潛能。我們針對小鼠和人的Oct4的啓動子設計了一序列的TALEs和sgRNAs。通過熒光素酶實驗,我們發現結合到轉錄起始位點上遊120‐80bp位置的TALE‐VP64s,或者結合到147‐89bp位置的sgRNAs可以最有效地誘導熒光素酶報告基因的表達。在激活報告基因方面,這種位置效應可以作爲一條設計人工轉錄因子的簡單原則。然後,我們進一步檢測了這些人工轉錄因子在激活內源性Oct4轉錄方面的效果。結果顯示上述觀察到的位置效應並不明顯,因爲每一單個的人工轉錄因子都幾乎不能上調內源性基因的表達。但是,當同時導入多個人工轉錄因子時,我們可以顯著地激活Oct4的表達,而且可以觀察到明顯的疊加效應。利用人工轉錄因子激活SOX2, KLF4, cMYC, CDH1和NANOG,我們進一步證明了這種疊加效應。 / 通過篩查不同的人工轉錄因子組合,我們在小鼠NIH3T3細胞系把Oct4基因的表達提供到了原來水平的30多倍,而在人的HEK293T中,提高了20多倍。更重要的是,我們可以檢測到蛋白質表達水平的提高。通過檢測不同的表觀調控因子,我們發現組蛋白乙酰化轉移酶p300可以進一步提升這些人工轉錄因子誘導的Oct4基因表達。因此,本研究表明這些人工轉錄因子是調節哺乳動物細胞內基因表達的有效工具。 / Hu, Jiabiao. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2014.y066 / Includes bibliographical references (leaves 132-157). / Abstracts also in Chinese. / Title from PDF title page (viewed on 13, December, 2016). / Hu, Jiabiao. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only.
622

Analysis of the relationship of age and topographic distribution of lipofuscin concentration in the retinal pigment epithelium.

January 1993 (has links)
by Hiu-ming Li. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves 81-88). / SUMMARY --- p.1 / Chapter CHAPTER 1. --- INTRODUCTION --- p.3 / Chapter CHAPTER 2. --- LITERATURE REVIEW --- p.7 / Chapter 2.1. --- Retinal pigment epithelium --- p.7 / Chapter 2.1.1. --- Embryology / Chapter 2.1.2. --- Anatomy and histology / Chapter 2.1.3. --- Growth and aging / Chapter 2.1.4. --- Macular region / Chapter 2.2. --- The photoreceptor outer segment --- p.12 / Chapter 2.3. --- Lipofuscin --- p.13 / Chapter 2.4. --- Lipofuscin in retinal pigment epithelium and retinal photoreceptor disc shedding --- p.14 / Chapter 2.5. --- Possible mechanism for lipofuscin formation in the RPE --- p.22 / Chapter 2.6. --- Age-related lipofuscin accumulation in the RPE --- p.22 / Chapter 2.7. --- Racial difference of RPE lipofuscin concentration --- p.25 / Chapter 2.8. --- RPE lipofuscin and age-related macular degeneration --- p.26 / Chapter CHAPTER 3. --- MATERIALS AND METHODS --- p.28 / Chapter 3.1. --- Histologic Specimens --- p.28 / Chapter 3.2. --- Measuring equipment --- p.28 / Chapter 3.3. --- Software of measurements --- p.31 / Chapter 3.4. --- Light source and filters --- p.31 / Chapter 3.5. --- Control --- p.31 / Chapter 3.6. --- Measurement of autofluorescent Intensity --- p.32 / Chapter 3.7. --- Bleaching (oxidation) of melanin --- p.39 / Chapter CHAPTER 4. --- RESULTS --- p.42 / Chapter 4.1. --- Bleaching test --- p.42 / Chapter 4.2. --- RPE autofluorescence observation in different age --- p.43 / Chapter 4.3. --- RPE autofluorescence observation within individual eyes --- p.45 / Chapter 4.4. --- Topographic distribution of lipofuscin --- p.49 / Chapter 4.5. --- Lipofuscin content at the Foveola --- p.50 / Chapter 4.6. --- The relationship of age and lipofuscin content in total RPE --- p.51 / Chapter 4.7. --- The relationship of age and lipofuscin content in the macular RPE --- p.57 / Chapter 4.8. --- Relationship of age and lipofuscin content in the posterior pole of RPE --- p.59 / Chapter 4.9. --- Relationship of age and lipofuscin content in the temporal RPE --- p.61 / Chapter 4.10. --- Relationship of age and lipofuscin content in the nasal RPE --- p.63 / Chapter 4.11. --- Age related topographic changes --- p.65 / Chapter 4.12. --- The relationship of age and lipofuscin content in the RPE of male --- p.66 / Chapter 4.13. --- The relationship of age and lipofuscin content in the RPE of female --- p.68 / Chapter 4.14. --- Relationship of lipofuscin content in different sex --- p.70 / Chapter CHAPTER 5. --- DISCUSSION --- p.71 / Chapter 5.1. --- Evaluation of method --- p.71 / Chapter 5.2. --- RPE lipofuscin content in different age --- p.71 / Chapter 5.3. --- Topographic distribution of lipofuscin --- p.74 / Chapter 5.4. --- Lipofuscin and age-related macular degeneration in Chinese --- p.78 / REFERENCES --- p.81
623

Studies of the control of VEGF expression in testicular cell lines and in the testis.

January 1999 (has links)
Sy Chun Choi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 123-160). / Abstracts in English and Chinese. / ABSTRACT --- p.i / 摘要 --- p.iv / ACKNOWLEDGEMENT --- p.vi / Chapter 1. --- Introduction / Chapter 1.1 --- General review of the testis --- p.1 / Chapter 1.1.1 --- Structure and function of the testis --- p.1 / Chapter 1.1.2 --- Testicular vasculature --- p.2 / Chapter 1.1.3 --- Testicular angiogenesis --- p.3 / Chapter 1.2 --- Vascular endothelial growth factor (VEGF) --- p.4 / Chapter 1.2.1 --- Discovery of VEGF --- p.4 / Chapter 1.2.2 --- Organization of VEGF --- p.4 / Chapter 1.2.3 --- Properties of the VEGF isoforms --- p.5 / Chapter 1.2.4 --- VEGF receptors --- p.6 / Chapter 1.2.5 --- Functions of VEGF --- p.8 / Chapter 1.3 --- VEGF in the testis --- p.10 / Chapter 1.3.1 --- Localization of VEGF and VEGF receptors in the testis --- p.10 / Chapter 1.3.2 --- Postulated functions of VEGF in the testis --- p.11 / Chapter 1.4 --- Regulation of VEGF --- p.11 / Chapter 1.4.1 --- "VEGF, hypoxia and the testis" --- p.11 / Chapter 1.4.2 --- "VEGF, nitric oxide and the testis" --- p.14 / Chapter 1.4.3 --- Cadmium-induced testicular toxicity --- p.16 / Chapter 1.4.4 --- "VEGF, glucocorticoids and the testis" --- p.17 / Chapter 1.4.5 --- Hormonal regulation of VEGF expression 226}0ؤimportance of LH --- p.19 / Chapter 1.4.6 --- VEGF and Leydig cell - macrophage interaction --- p.21 / Chapter 1.5 --- Aims of the present study --- p.24 / Chapter 2. --- Materials and methods / Chapter 2.1 --- Animals --- p.26 / Chapter 2.1.1 --- Spermatic cord torsion --- p.26 / Chapter 2.1.2 --- Cadmium chloride treatment --- p.27 / Chapter 2.1.3 --- Leydig cell depletion and cadmium chloride treatment --- p.28 / Chapter 2.1.4 --- Dexamethasone pretreatment and cadmium chloride injection --- p.28 / Chapter 2.1.5 --- hCG injection --- p.29 / Chapter 2.2 --- Immunohistochemistry --- p.29 / Chapter 2.2.1 --- Perfusion fixation of the testes --- p.29 / Chapter 2.2.2 --- Processing of the testes for histological section --- p.29 / Chapter 2.2.3 --- Immunohistochemical staining for VEGF --- p.30 / Chapter 2.2.4 --- Photomicrograph --- p.32 / Chapter 2.3 --- Cell cultures --- p.32 / Chapter 2.3.1 --- Cell lines of mouse TM3 Leydig cells and TM4 Sertoli cells --- p.32 / Chapter 2.3.2 --- Tumour cell line of mouse MLTC-1 Leydig cells --- p.33 / Chapter 2.4 --- Cell treatments --- p.33 / Chapter 2.4.1 --- Hypoxic treatment --- p.34 / Chapter 2.4.2 --- Cadmium chloride treatment --- p.36 / Chapter 2.4.3 --- hCG treatment --- p.37 / Chapter 2.4.4 --- Activators of second messenger systems --- p.37 / Chapter 2.4.5 --- Effect of pro-inflammatory cytokines and angiogenic growth factors --- p.38 / Chapter 2.5 --- Preparation of cDNA probes --- p.39 / Chapter 2.5.1 --- VEGF cDNA probe preparation --- p.39 / Chapter 2.5.2 --- P-actin cDNA probe preparation --- p.42 / Chapter 2.5.3 --- Purification of PCR products --- p.44 / Chapter 2.5.4 --- Confirmation of PCR products --- p.45 / Chapter 2.5.5 --- cDNA probe labeling --- p.46 / Chapter 2.6 --- RNA extraction --- p.46 / Chapter 2.6.1 --- Extraction of total RNA from testicular cell lines --- p.46 / Chapter 2.6.2 --- Extraction total RNA from testicular tissues --- p.50 / Chapter 2.7 --- Northern blot analysis --- p.51 / Chapter 2.7.1 --- Measurement of total RNA concentration --- p.51 / Chapter 2.7.2 --- RNA gel electrophoresis --- p.52 / Chapter 2.7.3 --- Transfer of RNA to membrane --- p.53 / Chapter 2.7.4 --- Hybridization with [α-32P]dCTP-labelled probes --- p.53 / Chapter 2.7.5 --- Autoradiography and densitometric quantification --- p.54 / Chapter 2.8 --- Data and statistical analysis --- p.55 / Chapter 3. --- Results / Chapter 3.1 --- Effects of hypoxia and cobalt chloride treatment on VEGF expression in TM3 and TM4 cells --- p.57 / Chapter 3.2 --- Effects of testicular torsion on VEGF expression in adult rat testes --- p.61 / Chapter 3.3 --- Antagonism of hypoxic induction of VEGF expression in TM3 cells by nitric oxide --- p.66 / Chapter 3.4 --- Effect of cadmium on VEGF expression in TM3 and TM4 cells --- p.66 / Chapter 3.5 --- Effect of dexamethasone on Cd-induced increase in VEGF expression in TM3 cells --- p.73 / Chapter 3.6 --- Effect of cadmium treatment on VEGF expression in the adult rat testes --- p.73 / Chapter 3.7 --- Effect of Leydig cell depletion on basal and Cd-induced expression of VEGF in adult rat testes --- p.76 / Chapter 3.8 --- Effect of dexamethasone on basal and Cd-induced expression of VEGF in adult rat testes --- p.76 / Chapter 3.9 --- "Effects of hCG,forskolin and phorbol ester on VEGF expression in TM3 and TM4 cells" --- p.79 / Chapter 3.10 --- Effect of hCG on VEGF expression in MLTC-1 cells --- p.92 / Chapter 3.11 --- "Effect of EL-lα, IL-1β, IL-6, TNF- α and TNF- β on VEGF expression in TM3 cells" --- p.92 / Chapter 3.12 --- Effect of bFGF and TGF- β1 on VEGF expression in TM3 cells --- p.102 / Chapter 4. --- Discussion / Chapter 4.1 --- Upregulation of VEGF expression in TM3 and TM4 cells by hypoxia and cobalt chloride --- p.108 / Chapter 4.2 --- Effect of testicular torsion on VEGF expression in adult rat testes --- p.110 / Chapter 4.3 --- Antagonism of hypoxic induction of VEGF expression in TM3 cells by nitric oxide --- p.111 / Chapter 4.4 --- "Effect of cadmium on VEGF mRNA levels in TM3 and TM4 cells, and in adult rat testes" --- p.113 / Chapter 4.5 --- "Effect of hCG,forskolin and phorbol ester on VEGF expression in TM3 and TM4 cells" --- p.116 / Chapter 4.6 --- Effect of cytokines and growth factors on VEGF expression in TM3 cells --- p.119 / Chapter 5. --- References --- p.123
624

Transcriptional Control of Photoreceptor Axon Growth and Targeting in Drosophila melanogaster

Kniss, Jonathan, Kniss, Jonathan January 2012 (has links)
The nervous system is required for human cognition, motor function, and sensory interaction. A complex network of neuronal connections, or synapses, carries out these behaviors, and defects in neural connectivity can result in developmental and degenerative diseases. In vertebrate nervous systems, synapses most commonly occur at axon terminals. Upon reaching their synaptic targets, growth cones lose their motility and become boutons specialized for neurotransmitter release. I am studying this process in R7 photoreceptors in the
625

Molecular Mechanisms for the Evolution of DNA Specificity in a Transcription Factor Family

McKeown, Alesia 14 January 2015 (has links)
Transcription factors (TFs) bind to specific DNA sequences near target genes to precisely coordinate their regulation. Despite the central role of transcription factors in development and homeostasis, the mechanisms by which TFs have evolved to bind and regulate distinct DNA sequences are poorly understood. This dissertation details the highly collaborative work to determine the genetic, biochemical and biophysical mechanisms by which distinct DNA-binding specificities evolved in the steroid receptor (SR) family of transcription factors. Using ancestral protein reconstruction, we resurrected and functionally characterized the historical transition in DNA-binding specificity between ancient SR proteins. We found that DNA-binding specificity evolved by changes in the energetic components of binding; interactions at the protein-DNA interface were weakened while inter-protein cooperativity was greatly improved. We identified a group of fourteen historical substitutions that were sufficient to recapitulate the derived protein's binding function. Three of these substitutions, which we defined as function-switching, were sufficient to change DNA specificity; however, their introduction greatly decreased binding affinity and was deleterious for protein function. A group of eleven permissive substitutions, which had no effect on DNA specificity, allowed for the protein to tolerate the deleterious effects of the function-switching substitutions. They non-specifically increased binding affinity by improving interactions at the protein-DNA interface and increasing inter-protein cooperativity. We then dissected the functional role of individual substitutions in both the function-switching and permissive groups. We first determined the binding affinity of all possible combinations of function-switching substitutions for a library of DNA sequences. This allowed for us to functionally characterize the sequence space that separated the ancestral and derived DNA-binding specificities as well as identify the genetic determinants for DNA specificity. Lastly, we dissected the effects of the permissive substitutions on the energetics of DNA binding to determine the mechanisms by which they exerted their permissive effect. Together, this work provides insight into the molecular determinants of DNA specificity and identifies the molecular mechanisms by which these interactions changed during the evolution of novel specificity in an important transcription factor family. This dissertation includes previously published and unpublished co-authored material. / 2016-01-14
626

Role of WT1 in Ischaemic Angiogenesis

Ogley, Robert James January 2018 (has links)
Ischaemia causes irreversible tissue damage in cardiovascular disease. Since regenerative angiogenesis fails to consistently induce sufficient reperfusion to facilitate repair, targeted manipulation of angiogenesis is clinically desirable. The Wilms' tumour suppressor (Wt1) is a transcription factor which regulates numerous genes and cellular processes, including many intrinsic to angiogenesis. We hypothesise that WT1 in the endothelium influences the angiogenic function of endothelial cells. WT1 was identified in endothelial and non-endothelial cells comprising vessel outgrowths generated by cultured aortic rings from WT1-GFP reporter mice. Inducible deletion of WT1 from the endothelium (VE-Wt1 KO) significantly delayed angiogenesis in this assay (p < 0.05 relative to controls). In vivo, WT1 expression was evident in vascular endothelial and perivascular cells of the hindlimb as early as 3 days following femoral artery ligation to induce ischaemia, often in cells expressing epithelial and mesenchymal markers simultaneously. However, VE-Wt1 KO had no effect on hindlimb reperfusion (laser Doppler; days 0-28) or on vessel density (day 28). Similarly, VE-Wt1 KO had no effect on vessel density or expression of angiogenic factors (qRT-PCR) in sponges inserted subcutaneously in mice (20 days). To further understand the role of WT1 in angiogenesis, transcriptomic RNA expression analysis was performed in WT1+ and WT1- cells isolated (FACs) from sponges after implantation in WT1-GFP mice. WT1+ cells exhibited higher expression of genes involved in a number of processes relevant to tissue repair, including angiogenesis (p=3.11x10-8), wound healing (p=3.45x10-7) and epithelial-to-mesenchymal transition (EMT) (p=5.86x10-4). These results shed new light on the role of WT1 in ischaemic angiogenesis. In concurrence with previously published work, we show that deletion of endothelial WT1 can delay angiogenesis however, WT1 is not just instrumental in endothelial cells in this context. WT1 has a broader role in tissue repair in ischaemia, in part through regulation of cell transition (EMT). This work has improved our understanding of the regulatory role of WT1 in angiogenesis and repair, while revealing a number of novel insights into the function of WT1. This highlights WT1 as a potentially beneficial therapeutic target to facilitate regeneration in cardiovascular disease.
627

Promoter analysis and identification of transcription factors in edible mushroom Lentinula edodes.

January 2006 (has links)
by Sham Lok To. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 143-171). / Abstracts in English and Chinese. / Abstract --- p.i / 摘要 --- p.iii / Acknowledgement --- p.iv / Abbreviations --- p.v / Table of contents --- p.vi / List of figures --- p.ix / List of tables --- p.xi / Chapter Chapter One --- Literature Review --- p.1 / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.1.1 --- About L. edodes --- p.3 / Chapter 1.1.2 --- Nutritional and medicinal values of L. edodes --- p.4 / Chapter 1.1.3 --- Life cycle of L. edodes --- p.6 / Chapter 1.1.4 --- Environmental factors affecting fruiting body formation in L. edodes --- p.6 / Chapter 1.2 --- Molecular mechanisms of fruiting body development in L. edodes --- p.8 / Chapter 1.2.1 --- Expression profiling and identification of differentially expressed genes during fruiting --- p.8 / Chapter 1.2.2 --- Changing in membrane structure --- p.11 / Chapter 1.2.3 --- The signal transduction cascade --- p.12 / Chapter 1.3 --- Transformation in L. edodes and in other fungi --- p.14 / Chapter 1.3.1 --- Transformation of L. edodes --- p.14 / Chapter 1.3.2 --- Transformation in other fungi --- p.17 / Chapter 1.4 --- Bioinformatics tools for comparative promoter analysis --- p.22 / Chapter 1.5 --- Objectives and significance --- p.26 / Chapter Chapter Two --- Promoter analysis of differentially expressed genes (DEGs) in the fruiting body development in L. edodes --- p.27 / Chapter 2.1 --- Introduction --- p.27 / Chapter 2.2 --- Materials and methods --- p.29 / Chapter 2.2.1 --- Strains and cultivation conditions --- p.29 / Chapter 2.2.2 --- Genome walking of the 5' flanking region of the DEGs --- p.29 / Chapter 2.2.3 --- Annealing Control Primed (ACP) PCR --- p.31 / Chapter 2.2.4 --- Construction of genomic DNA library --- p.36 / Chapter 2.2.5 --- Nested PCR to amplify the target sequences --- p.37 / Chapter 2.2.6 --- Cloning and sequencing of the 5' flanking region --- p.38 / Chapter 2.2.7 --- Determination of transcription start site by the Neural Network algorithm --- p.39 / Chapter 2.2.8 --- Identification of putative transcription factor binding sites --- p.40 / Chapter 2.3 --- Results --- p.41 / Chapter 2.3.1 --- Construction of adaptor linked template for genome walking --- p.41 / Chapter 2.3.2 --- Sequence analysis and quality control --- p.41 / Chapter 2.3.3 --- Comparison of various methods in genome walking --- p.42 / Chapter 2.3.4 --- Promoter analysis --- p.42 / Chapter 2.4 --- Discussion --- p.58 / Chapter Chapter Three --- In-silico analysis of transcription factor binding sites and identification transcription factors expressed in L. edodes --- p.64 / Chapter 3.1 --- Introduction --- p.64 / Chapter 3.2 --- Material and methods --- p.67 / Chapter 3.2.1 --- Sequence manipulation and extraction of homologous ESTs from C. cinereus --- p.67 / Chapter 3.2.2 --- Extraction of 5' flanking region of the corresponding ESTs and promoter prediction --- p.67 / Chapter 3.2.3 --- Positional cloning of mating type factor A --- p.68 / Chapter 3.3 --- Results --- p.70 / Chapter 3.3.1 --- Sequence extraction and manipulation --- p.70 / Chapter 3.3.2 --- In-silico analysis of transcription factor binding sites in C. cinereus . --- p.70 / Chapter 3.3.3 --- Comparison of putative TFBS between L. edodes and C. cinereus --- p.71 / Chapter 3.3.4 --- Identification of transcription factors in L. edodes by positional cloning --- p.71 / Chapter 3.4 --- Discussion --- p.85 / Chapter Chapter Four --- Identification,expression profiling and promoter analysis of hydrophobin genes --- p.91 / Chapter 4.1 --- Introduction --- p.91 / Chapter 4.2 --- Material and methods --- p.92 / Chapter 4.2.1 --- Clustering and grouping of the hydrophobin ESTs --- p.92 / Chapter 4.2.2 --- Identification of the consensus sequences of the hydrophobin groups --- p.93 / Chapter 4.2.3 --- RNA Sources and Preparation --- p.93 / Chapter 4.2.4 --- Expression profiling of hydrophobin genes by RT-PCR --- p.95 / Chapter 4.2.5 --- Promoter cloning and analysis of hydrophobin genes --- p.95 / Chapter 4.3 --- Results --- p.97 / Chapter 4.3.1 --- Isolation and characterization of four newly found hydrophobin genes --- p.97 / Chapter 4.3.2 --- Expression levels of hydrophobins --- p.100 / Chapter 4.3.3 --- Promoter sequencing of the hydrophobins --- p.103 / Chapter 4.4 --- Discussion --- p.103 / Chapter Chapter Five --- Transformation of L. edodes --- p.110 / Chapter 5.1 --- Introduction --- p.110 / Chapter 5.2 --- Materials and methods --- p.112 / Chapter 5.2.1 --- Vectors and primers design --- p.112 / Chapter 5.2.2 --- Maxi-preparation of plasmids --- p.112 / Chapter 5.2.3 --- Cultural condition and optimization of protoplasts release --- p.114 / Chapter 5.2.4 --- PEG mediated transformation --- p.115 / Chapter 5.2.5 --- Electroporation mediated transformation --- p.116 / Chapter 5.2.6 --- PCR screening of regenerated transformant --- p.116 / Chapter 5.2.7 --- Particle bombardment --- p.117 / Chapter 5.3 --- Results --- p.121 / Chapter 5.4 --- Discussion --- p.128 / Chapter Chapter Six --- General discussions --- p.132 / References --- p.143
628

Risk factors for injury in elite rugby union : a series of longitudinal analyses

Williams, Sean January 2015 (has links)
The contacts and collisions that are inherent to elite Rugby Union, alongside changes to players’ physical characteristics and match activities, have raised concerns regarding the level of injury burden associated with the professional game. This programme of research was therefore undertaken to investigate injury risk in this setting. The first study of this thesis (Chapter 3) presents a meta-analytic review of injury data relating to senior men’s professional Rugby Union, which shows an overall match incidence rate of 81 per 1000 player hours; this value is high in comparison with other popular team sports. In Chapter 4, the importance of injuries in the context of performance is demonstrated by showing a substantial negative association exists between injury burden and team success measures. Chapter 5 investigates subsequent injury patterns in this population and identifies injury diagnoses with a high risk of early recurrence, whilst also demonstrating that subsequent injuries are not more severe than their associated index injury. Playing professional Rugby Union on an artificial playing surface does not influence overall acute injury risk in comparison with natural grass surfaces (Chapter 6). Chapters 7 and 8 identify intrinsic risk factors for injury (previous injury, match and training loads) for the first time in this setting, and may be used to inform policies on these pertinent issues. Finally, predictive modelling techniques show some potential for predicting the occurrence and severity of injuries, but require further refinement before they can be implemented within elite Rugby Union teams. Overall, this programme of work highlights the importance of injury prevention for all professional Rugby Union stakeholders, addresses the need to use appropriate statistical techniques to account for the dynamic and clustered nature of sport injury data, and demonstrates approaches through which the injury burden associated with elite Rugby Union may be reduced.
629

Expression of Class I Histone Deacetylases in Insect Cells

Bryan, Erin E 30 May 2006 (has links)
"Histone deacetylases (HDACs) have become one of the leading areas of research for cancer, neurodegenerative diseases, diabetes, obesity, and inflammation. Although HDACs are currently expressible in mammalian cultures and yeast, it is important to explore other cost effective options. Here it is shown that class I HDACs are expressible in insect cells. As well as expressing full length domains for class I HDACs, predicted active domains have also been expressed. This information can be utilized in many areas for future research including identifying unique sites to allow development of specific inhibitors for each HDAC, and developing a better understanding of the specific role of each HDAC. "
630

Form factors and scattering amplitudes in supersymmetric gauge theories

Jones, Martyna Maria January 2018 (has links)
The study of scattering amplitudes in the maximally supersymmetric Yang-Mills theory (N = 4 SYM) is a thriving field of research. Since the reformulation of perturbative gauge theory as a twistor string theory by Witten, this area has witnessed a flurry of activity, leading to the discovery of a multitude of novel techniques, such as recursion relations and MHV diagrams, collectively referred to as on-shell methods. In parallel, many previously hidden properties and rich mathematical structures have been found, a powerful example of such being the dual superconformal symmetry. It is natural to ask whether this understanding can be extended to phenomenologically relevant theories as well as other quantities. The goal of the present work is to apply the modern on-shell methods to calculations of form factors, with particular focus on those which are relevant for describing Higgs production in QCD from the point of view of an effective field theory. Specifically, our analysis will be carried out in supersymmetric gauge theories at two-loop level and will consist of several steps. We focus first on operators in the SU(2j3) closed subsector of N = 4 SYM, in particular two non-protected, dimension-three operators. We then move on to consider the trilinear operator Tr(F3) and a related descendant of the Konishi operator which contains Tr(F3), also in N =4 SYM. Finally, we concentrate on two-loop form factors of these two operators in theories with less-than-maximal supersymmetry. The result of our investigation shows an emergence of a small number of universal building blocks, ultimately related to the two-loop form factor of a trilinear half-BPS operator. This finding suggests that the most complicated, maximally transcendental part of Higgs plus multi-gluon amplitudes in QCD can be equivalently computed in a remarkably simple way by considering form factors of half-BPS operators in N =4 SYM.

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