As células-tronco hematopoéticas (CTHs) e estromais mesenquimais multipotentes (CTMs) isoladas da medula óssea vêm sendo utilizadas como fonte autóloga no tratamento de doenças autoimunes, como a esclerose múltipla (EM). As CTHs dão origem a todas as células dos sistemas hematopoético e imunológico e as CTMs possuem propriedades imunomoduladoras pela liberação de fatores solúveis e interação célula-célula. Existem trabalhos que sugerem que as doenças autoimunes sejam provenientes de defeitos intrínsecos nas células-tronco precursoras da medula óssea. Com o intuito de avaliar se as CTHs e CTMs de pacientes com EM possuem alterações intrínsecas, o objetivo geral deste trabalho foi avaliar o perfil de expressão gênica diferencial por microarrays de CTHs e CTMs de pacientes com EM, além de avaliar o perfil de expressão gênica de CTMs após o transplante autólogo de CTHs e a capacidade imunomoduladora in vitro das CTMs de pacientes. As CTHs e CTMs foram isoladas da medula óssea de pacientes com EM e doadores saudáveis, após consentimento informado. As CTHs foram isoladas por colunas imunomagnéticas e as CTMs foram isoladas por gradiente de densidade e submetidas à caracterização morfológica, imunofenotípica e capacidade de diferenciação em adipócitos e osteócitos. O RNA das CTHs e CTMs foi extraído e purificado e o perfil de expressão gênica foi avaliado por microarrays, utilizando hibridações em lâminas contendo 44.000 sondas. A capacidade imunomoduladora das CTMs de pacientes e controles foi avaliada por ensaios de cocultivo com linfócitos alogênicos e as citocinas foram quantificadas no sobrenadante por CBA flex e ELISA. Este estudo foi aprovado pelo comitê de ética do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto. Os resultados mostraram que as CTHs de pacientes possuem perfis de expressão gênica diferentes dos controles, com 2.722 genes diferencialmente expressos, envolvidos em vias de sinalização importantes para manutenção/proliferação das CTHs e diferenciação em linhagens específicas durante a hematopoese. Dentre essas sinalizações estão incluídas as vias da apoptose, Wnt, Notch, mTOR, PI3K/Akt e Ca/NFAT, sugerindo que as CTHs de pacientes com EM possuam alterações intrínsecas que podem estar relacionadas com a patogenia da doença autoimune. As CTMs isoladas de pacientes com EM exibiram aparência senescente e reduzida expressão de marcadores imunofenotípicos. Com relação à expressão gênica, as CTMs de pacientes possuem perfil diferente das CTMs controle, sendo detectados 618 genes diferencialmente expressos, incluindo genes relacionados à sinalização FGF, HGF, sinalização de moléculas de adesão e moléculas envolvidas nos processos de imunorregulação, como IL10, IL6, TGFB1, IFNGR1, IFNGR2 e HGF. O perfil de expressão gênica das CTMs de pacientes pós-transplante assemelhou-se ao perfil das CTMs pré-transplante. Ensaios de cocultivo de CTMs com linfócitos alogênicos mostraram que as CTMs de pacientes possuem capacidade antiproliferativa reduzida em relação às CTMs controle, e ainda, secreção reduzida de TGF- e IL-10 no sobrenadante das coculturas. Esses dados sugerem que as CTMs isoladas de pacientes com EM possuam alterações fenotípicas, transcricionais e funcionais. Embasados nesses achados, concluímos que as CTHs e as CTMs de pacientes com EM possuem alterações intrínsecas que podem estar relacionadas com a patogenia da doença. Uma vez que as CTMs sejam células com grande potencial terapêutico para controle da EM em pacientes refratários aos tratamentos convencionais, as alterações encontradas sugerem que CTMs de doadores saudáveis sejam mais adequadas em aplicações clínicas. / Bone marrow hematopoietic stem cells (HSCs) and mesenchymal stromal cells (MSCs) have been used as an autologous source to treat autoimmune diseases, such as multiple sclerosis (MS). HSC give rise to all hematopoietic and immune system cells, and MSCs exhibit immunomodulatory properties by releasing soluble factors and by cell-cell interactions. Evidence indicates that bone marrow stem cells obtained from patients with autoimmune diseases may present intrinsic defects. To assess whether or not HSC and MSC of MS patients have intrinsic defects, the main objective of this study was to evaluate the differential gene expression profiles of HSC and MSC from MS patients before and after autologous HSC transplantation, and additionally, to evaluate the in vitro immunomodulatory ability of patient MSCs. Bone marrow HSC and MSCs were isolated from MS patients and healthy donors. HSCs were isolated by immunomagnetic columns and MSCs were isolated by gradient density and cultured until the third passage. MSCs were characterized according to morphology, immunophenotypic markers and cell differentiation into adipocytes and osteocytes. HSC and MSCs mRNAs were extracted, purified, and the gene expression profile was evaluated by microarray hybridizations, using a platform containing 44.000 probes. The immunomodulatory activity of patient and control MSCs was assessed by coculture assays with allogeneic lymphocytes. Cytokines were quantified in coculture supernatants by ELISA and CBA flex. This study was approved by the Ethics Committee of the University Hospital of the School of Medicine of Ribeirão Preto. The results showed that the patient HSCs exhibited a distinctive gene expression profile when compared to healthy HSCs, yielding 2.722 differentially expressed genes, involved in essential HSC signaling pathways for maintenance, proliferation and differentiation into specific lineages during hematopoiesis. Among these signaling pathways were included, apoptosis, Wnt, Notch, mTOR, PI3K/Akt and Ca/NFAT, suggesting that patient HSCs have significant intrinsic transcriptional alterations that may be associated with MS pathogenesis. Regarding MSCs isolated from MS patients, they exhibited senescence appearance, decreased expression of immunophenotypic markers, and also exhibited a distinctive gene expression profile in relation to healthy MSCs, yielding 618 genes differentially expressed genes, included in FGF and HGF signaling pathways, adhesion molecules, and genes involved in immunoregulation processes, such as IL-10, IL-6, TGFB1, IFNGR1, IFNGR2 and HGF. Coculture assays of control or patient MSCs with allogeneic lymphocytes showed that patient cells exhibited reduced antiproliferative activity as compared with controls, and also exhibited reduced secretion of TGF- and IL-10 cytokines in coculture supernatants. These data suggest that MSCs isolated from MS patients have phenotypic, functional and transcriptional defects, highlighting genes related to MSC maintenance, adhesion and immunomodulatory effects. According to these results, we concluded that patient HSCs and MSCs have intrinsic defects that may be associated with the disease per se. Considering that MSCs exhibit great therapeutic potential to control MS patients refractory to conventional treatment, the major MSCs alterations observed in this study indicate that healthy MSCs may be more suitable for MS cell therapy.

No description available.

As células-tronco hematopoéticas (CTHs) e estromais mesenquimais multipotentes (CTMs) isoladas da medula óssea vêm sendo utilizadas como fonte autóloga no tratamento de doenças autoimunes, como a esclerose múltipla (EM). As CTHs dão origem a todas as células dos sistemas hematopoético e imunológico e as CTMs possuem propriedades imunomoduladoras pela liberação de fatores solúveis e interação célula-célula. Existem trabalhos que sugerem que as doenças autoimunes sejam provenientes de defeitos intrínsecos nas células-tronco precursoras da medula óssea. Com o intuito de avaliar se as CTHs e CTMs de pacientes com EM possuem alterações intrínsecas, o objetivo geral deste trabalho foi avaliar o perfil de expressão gênica diferencial por microarrays de CTHs e CTMs de pacientes com EM, além de avaliar o perfil de expressão gênica de CTMs após o transplante autólogo de CTHs e a capacidade imunomoduladora in vitro das CTMs de pacientes. As CTHs e CTMs foram isoladas da medula óssea de pacientes com EM e doadores saudáveis, após consentimento informado. As CTHs foram isoladas por colunas imunomagnéticas e as CTMs foram isoladas por gradiente de densidade e submetidas à caracterização morfológica, imunofenotípica e capacidade de diferenciação em adipócitos e osteócitos. O RNA das CTHs e CTMs foi extraído e purificado e o perfil de expressão gênica foi avaliado por microarrays, utilizando hibridações em lâminas contendo 44.000 sondas. A capacidade imunomoduladora das CTMs de pacientes e controles foi avaliada por ensaios de cocultivo com linfócitos alogênicos e as citocinas foram quantificadas no sobrenadante por CBA flex e ELISA. Este estudo foi aprovado pelo comitê de ética do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto. Os resultados mostraram que as CTHs de pacientes possuem perfis de expressão gênica diferentes dos controles, com 2.722 genes diferencialmente expressos, envolvidos em vias de sinalização importantes para manutenção/proliferação das CTHs e diferenciação em linhagens específicas durante a hematopoese. Dentre essas sinalizações estão incluídas as vias da apoptose, Wnt, Notch, mTOR, PI3K/Akt e Ca/NFAT, sugerindo que as CTHs de pacientes com EM possuam alterações intrínsecas que podem estar relacionadas com a patogenia da doença autoimune. As CTMs isoladas de pacientes com EM exibiram aparência senescente e reduzida expressão de marcadores imunofenotípicos. Com relação à expressão gênica, as CTMs de pacientes possuem perfil diferente das CTMs controle, sendo detectados 618 genes diferencialmente expressos, incluindo genes relacionados à sinalização FGF, HGF, sinalização de moléculas de adesão e moléculas envolvidas nos processos de imunorregulação, como IL10, IL6, TGFB1, IFNGR1, IFNGR2 e HGF. O perfil de expressão gênica das CTMs de pacientes pós-transplante assemelhou-se ao perfil das CTMs pré-transplante. Ensaios de cocultivo de CTMs com linfócitos alogênicos mostraram que as CTMs de pacientes possuem capacidade antiproliferativa reduzida em relação às CTMs controle, e ainda, secreção reduzida de TGF- e IL-10 no sobrenadante das coculturas. Esses dados sugerem que as CTMs isoladas de pacientes com EM possuam alterações fenotípicas, transcricionais e funcionais. Embasados nesses achados, concluímos que as CTHs e as CTMs de pacientes com EM possuem alterações intrínsecas que podem estar relacionadas com a patogenia da doença. Uma vez que as CTMs sejam células com grande potencial terapêutico para controle da EM em pacientes refratários aos tratamentos convencionais, as alterações encontradas sugerem que CTMs de doadores saudáveis sejam mais adequadas em aplicações clínicas. / Bone marrow hematopoietic stem cells (HSCs) and mesenchymal stromal cells (MSCs) have been used as an autologous source to treat autoimmune diseases, such as multiple sclerosis (MS). HSC give rise to all hematopoietic and immune system cells, and MSCs exhibit immunomodulatory properties by releasing soluble factors and by cell-cell interactions. Evidence indicates that bone marrow stem cells obtained from patients with autoimmune diseases may present intrinsic defects. To assess whether or not HSC and MSC of MS patients have intrinsic defects, the main objective of this study was to evaluate the differential gene expression profiles of HSC and MSC from MS patients before and after autologous HSC transplantation, and additionally, to evaluate the in vitro immunomodulatory ability of patient MSCs. Bone marrow HSC and MSCs were isolated from MS patients and healthy donors. HSCs were isolated by immunomagnetic columns and MSCs were isolated by gradient density and cultured until the third passage. MSCs were characterized according to morphology, immunophenotypic markers and cell differentiation into adipocytes and osteocytes. HSC and MSCs mRNAs were extracted, purified, and the gene expression profile was evaluated by microarray hybridizations, using a platform containing 44.000 probes. The immunomodulatory activity of patient and control MSCs was assessed by coculture assays with allogeneic lymphocytes. Cytokines were quantified in coculture supernatants by ELISA and CBA flex. This study was approved by the Ethics Committee of the University Hospital of the School of Medicine of Ribeirão Preto. The results showed that the patient HSCs exhibited a distinctive gene expression profile when compared to healthy HSCs, yielding 2.722 differentially expressed genes, involved in essential HSC signaling pathways for maintenance, proliferation and differentiation into specific lineages during hematopoiesis. Among these signaling pathways were included, apoptosis, Wnt, Notch, mTOR, PI3K/Akt and Ca/NFAT, suggesting that patient HSCs have significant intrinsic transcriptional alterations that may be associated with MS pathogenesis. Regarding MSCs isolated from MS patients, they exhibited senescence appearance, decreased expression of immunophenotypic markers, and also exhibited a distinctive gene expression profile in relation to healthy MSCs, yielding 618 genes differentially expressed genes, included in FGF and HGF signaling pathways, adhesion molecules, and genes involved in immunoregulation processes, such as IL-10, IL-6, TGFB1, IFNGR1, IFNGR2 and HGF. Coculture assays of control or patient MSCs with allogeneic lymphocytes showed that patient cells exhibited reduced antiproliferative activity as compared with controls, and also exhibited reduced secretion of TGF- and IL-10 cytokines in coculture supernatants. These data suggest that MSCs isolated from MS patients have phenotypic, functional and transcriptional defects, highlighting genes related to MSC maintenance, adhesion and immunomodulatory effects. According to these results, we concluded that patient HSCs and MSCs have intrinsic defects that may be associated with the disease per se. Considering that MSCs exhibit great therapeutic potential to control MS patients refractory to conventional treatment, the major MSCs alterations observed in this study indicate that healthy MSCs may be more suitable for MS cell therapy.

A citricultura destaca-se dentro do agronegócio brasileiro gerando dividendos diretos com exportações e empregos, e indiretos com arrecadação de impostos. No entanto, ainda padece com problemas fitossanitários, com destaque para o HLB (Huanglongbing, HLB, ex-greening), que nos últimos dez anos tem dizimado pomares e provocado o abandono da cultura por muitos produtores. Causada no Brasil pelas bactérias Candidatus Liberibacter asiaticus e Ca. Liberibacter americanus, é uma doença sistêmica, restrita aos vasos do floema, e induz ao aparecimento de sintomas semelhantes àqueles causados por deficiência de nutrientes em folhas e ramos, frutos com tamanhos reduzidos e assimétricos e coloração amarelada das plantas, tornando-as economicamente inviáveis. A transmissão da doença acontece naturalmente pelo inseto Diaphorina citri, e artificialmente por meio de borbulhas contaminadas. Todas as variedades de citros e rutáceas próximas são comprovadamente suscetíveis ao HLB; entretanto, há diferenças marcantes entre níveis de suscetibilidade entre os genótipos, como Poncirus trifoliata, que apresenta certa resistência ou tolerância à doença. Os mecanismos de patogenicidade de Ca. Liberibacter spp. e a resposta molecular da planta à infecção ainda não estão bem definidos e o estudo da ativação dos mecanismos de defesa da planta induzidos por hormônios vegetais é um importante foco na elucidação deste complexo patossistema. Diante deste panorama, este estudo propôs avaliar o perfil de expressão de genes associados às vias do jasmonato e do etileno em plantas de Citrus sinensis L. Osb. (suscetível) e Poncirus trifoliata (L.) Raf. (resistente ou tolerante) em resposta à infecção pelas duas espécies de bactérias causadoras do HLB no Brasil, separadamente. Os perfis transcricionais dos genes avaliados não foram estatisticamente distintos, mas mereceram destaque os genes de biossíntese e metabolismo de jasmonato LOX2, AOC3 e JMT, os genes sinalizadores da via de jasmonato JAZ2 e MYC2, o gene de biossíntese de etileno SAM1, os receptores de etileno ETR1, ERS1 e EIN4, o regulador negativo de etileno CTR1, o regulador positivo da sinalização de etileno EIN2, os fatores de transcrição EIN3, EIL1, ERF1, ERF2, ERF/AP2, uma MAPkinase MAPK6 e uma proteína PR PR-4. Estes resultados mostram que as vias sinalizadas por jasmonato e etileno são modificadas pelas bactérias Ca. Liberibacter spp. No entanto, não foi possível comprovar a importância destas vias na resposta diferencial de genótipos suscetível e resistente/ tolerante de citros ao HLB. / The citrus industry stands out in the Brazilian agribusiness generating direct and indirect jobs and significant revenues. However, the citrus crop faces several diseases, especially the HLB (Huanglongbing, ex-greening), which, in the last ten years, have caused severe losses to growers. In Brazil, HLB is caused by the bacteria Candidatus Liberibacter asiaticus and Ca. Liberibacter americanus, which are restricted to the phloem and induce symptoms similar to those caused by nutrient deficiency in citrus leaves and branches. Fruits are of reduced size and asymmetrical, and the plants tend to show overall yellowing. These symptoms altogether lead to the economical death of the plant. Transmission of the pathogens occurs naturally by the Asian citrus psyllid Diaphorina citri, or by contaminated buds. All citrus varieties and relatives are considered susceptible to HLB; however, there are clear differences in levels of susceptibility among genotypes. Poncirus trifoliata, for instance, exhibits some resistance or tolerance to the disease. The mechanisms involved in the pathogenesis of Ca. Liberibacter spp. and the molecular responses of the hosts to the infection are still unknown, but emphasis has been given to the defense mechanisms induced by plant hormones in order to try to elucidate the interactions of such complex pathosystem. Based on this scenario, this study aimed to evaluate the expression profile of Citrus sinensis (L.) Osb. (susceptible) and Poncirus trifoliata (L.) Raf. (resistant or tolerant) genes associated with the jasmonate and ethylene pathways in response to infection by both species of Ca. Liberibacter spp. causing HLB in Brazil, separately. The transcriptional profiles did not differ statistically, for the evaluated genes, including those in the jasmonate biosynthesis and metabolism (LOX2, AOC3 and JMT), signaling pathway (JAZ2 and MYC2), biosynthesis of ethylene (SAM1), ethylene receptors (ETR1, ERS1 and EIN4), negative regulator of ethylene (CTR1), positive regulator of ethylene signaling (EIN2), transcription factors (EIN3, EIL1, ERF1, ERF2, ERF/AP2), a MAPkinase (MAPK6) and a PR protein (PR-4). These results suggest that the jasmonate and ethylene pathways exhibit some modulation caused by the bacteria Ca Liberibacter spp. However, it does not seem that these pathways are relevant for the differential response of susceptibility or resistance/ tolerance of the citrus genotypes to HLB.

O câncer é a segunda maior causa de morte no mundo, sendo responsável por aproximadamente 7,6 milhões de óbitos. Entretanto, pesquisadores alertam para uma associação inversa entre o consumo de frutas e hortaliças e o desenvolvimento de neoplasias, desta forma a organização mundial da saúde sugere, dentre outras medidas para controle do câncer, o aumento do consumo de frutas e hortaliças. Nesse contexto o objetivo deste trabalho foi avaliar os eventuais efeitos quimiopreventivos das hortaliças Brassicas, couve (C) e repolho (R). Realizaram-se dois experimentos sendo o primeiro, o modelo de hepatocacinogênese de Ito, onde as hortaliças foram fornecidas durante 8 semanas na água de beber (10% p/v), animais que receberam apenas água foram utilizados como controle. Nesse experimento não houve inibição (P>0,05) de lesões pré-neoplásicas hepáticas positivas para glutationa S-transferase forma placental e não houve indução (P>0,05) da apoptose nos grupos tratados com C ou R. Contudo, observou-se redução (P<0,05) de danos em DNA hepático e aumento (P<0,05) da concentração hepática de luteína de ratos tratados com C e R, quando comparados a ratos controle. No segundo experimento as hortaliças foram fornecidas durante 8 semanas na água de beber (20% p/v), e os animais foram submetidos a aplicação do carcinogênico hepático 24h antes da eutanásia. Não houve redução (P>0,05) de danos em DNA, contudo a concentração do aduto de DNA 8-hidroxi-2-deoxiguanosina (8-OHdG) e foi elevada (P<0,05) em animais tratados com R quando comparados a tratados com C e controles. Com relação à expressão diferencial de genes, 29 genes foram diferencialmente expressos em fígado, dentre eles o gene da 8-oxoguanina-DNA-glicosilase (enzima de reparo do DNA), foi hipoexpressa no grupo tratado com R, o que pode explicar o aumentado valor de adutos no mesmo grupo. O cólon apresentou 31 genes com diferença de expressão, onde 5 genes estão relacionados ao metabolismo de xenobióticos. / Cancer is the major cause of death in the world, being responsible for approximately 7.6 million deaths. However, there is a hypothesis of an inverse association between fruit and vegetable consumption and the development of cancer. Therefore, the World Health Organization suggests, among other actions for controlling cancer, the increase in vegetable and fruit consumption. The aim of this work was to evaluate eventual chemopreventive effects of Brassicas vegetables, kale (K) and cabbage (C). Two experiments were done: the first one was Ito´s hepatocarcinogenesis model, where vegetables were provided during 8 weeks in the rats´ drinking water (10% w/v). Animals that received only water were considered control. In this experiment, there was no inhibition (P<0,05) of glutathione S-transferase placental form positive preneoplastic lesions and, also, there was no induction (P<0,05) of apoptosis in the groups treated with K or C However, it was observed a reduction (P<0,05) in hepatic DNA damages and an increase (P<0,05) in lutein hepatic concentration of rats treated with K or C, when compared to the control. In the second experiment, the vegetables were provided during 8 weeks in the rats´ drinking water (20% w/v), and animals were submitted to carcinogenic application 24h before euthanasia. There was no reduction (P<0,05) in DNA damages, however there was an increase (P<0,05) in the concentration of 8-hydroxy-2-deoxyguanosine (8-OHdG) DNA in animals treated with C when compared to the ones treated with K and control. In relation to the differential gene expression, 29 genes were differently expressed in the liver, such as the 8-oxoguanine-DNA-glycosylase gene, which was downregulated in the group treated with C. This might explain the increased value of adducts in the same group. Colon presented 31 genes with difference in expression, whereas 5 genes are related to xenobiotic metabolism.

Vysoce výkonné sekvenční technologie produkují obrovské množství dat, která mohou odhalit nové geny, identifikovat splice varianty a kvantifikovat genovou expresi v celém genomu. Objem a složitost dat z RNA-seq experimentů vyžadují škálovatelné metody matematické analýzy založené na robustníchstatistických modelech. Je náročné navrhnout integrované pracovní postupy, které zahrnují různé postupy analýzy. Konkrétně jsou to srovnávací testy transkriptů, které jsou komplikovány několika zdroji variability měření a představují řadu statistických problémů. V tomto výzkumu byla sestavena integrovaná transkripční profilová pipeline k produkci nových reprodukovatelných kódů pro získání biologicky interpretovovatelných výsledků. Počínaje anotací údajů RNA-seq a hodnocení kvality je navržen soubor kódů, který slouží pro vizualizaci hodnocení kvality, potřebné pro zajištění RNA-Seq experimentu s analýzou dat. Dále je provedena komplexní diferenciální analýza genových expresí, která poskytuje popisné metody pro testované RNA-Seq data. Pro implementaci analýzy alternativního sestřihu a diferenciálních exonů jsme zlepšili výkon DEXSeq definováním otevřeného čtecího rámce exonového regionu, který se používá alternativně. Dále je popsána nová metodologie pro analýzu diferenciálně exprimované dlouhé nekódující RNA nalezením funkční korelace této RNA se sousedícími diferenciálně exprimovanými geny kódujícími proteiny. Takto je získán jasnější pohled na regulační mechanismus a poskytnuta hypotéza o úloze dlouhé nekódující RNA v regulaci genové exprese.

No description available.

Text in English / Corridor disease is an economically important tick-borne disease of cattle in southern Africa. The disease is caused by Theileria parva and transmitted by the vectors, Rhipicephalus appendiculatus and R. zambeziensis. There is currently no vaccine to protect cattle against T. parva that is permitted in South Africa. To develop recombinant anti-tick vaccines against Corridor disease, comprehensive databases of genes expressed in the tick’s salivary glands are required. Therefore, in Chapters 2 and 3, mRNA from the salivary glands of R. appendiculatus and R. zambeziensis was sequenced and assembled using next generation sequencing technologies. Respectively, 12 761 and 13 584 non-redundant protein sequences were predicted from the sialotranscriptomes of R. appendiculatus and R. zambeziensis and uploaded to public sequence domains. This greatly expanded the number of sequences available for the two vectors, which will be invaluable resources for the selection of vaccine candidates in future. Further, in Chapter 3, differential gene expression analysis in R. zambeziensis revealed dynamic expression of secretory protein transcripts during feeding, suggestive of stringent transcriptional regulation of these proteins. Knowledge of these intricate expression profiles will further assist vaccine development in future. In Chapter 4, comparative sialotranscriptomic analyses were performed between R. appendiculatus and R. zambeziensis. The ticks have previously shown varying vector competence for T. parva and this chapter presents the search for correlates of this variance. Phylogenetic analyses were performed using these and other publically available tick transcriptomes, which indicated that R. appendiculatus and R. zambeziensis are closely related but distinct species. However, significant expression differences were observed between the two ticks, specifically of genes involved in tick immunity or pathogen transmission, signifying potential bioinformatic signatures of vector competence. Furthermore, nearly four thousand putative long non-coding RNAs (lncRNAs) were predicted in each of the two ticks. A large number of these showed differential expression and suggested a potential transcriptional regulatory function of lncRNA in tick blood feeding. LncRNAs are completely unexplored in ticks. Finally, in Chapter 5, concluding remarks are given on the potential impact the R. appendiculatus and R. zambeziensis sialotranscriptomes may have on future vaccine developments and some future research endeavours are discussed. / Life and Consumer Sciences / Ph. D. (Life Sciences)