Whole genome sequencing (WGS) projects for model mammalian organisms exposed the magnitude to which transposable elements (TEs) have contributed to DNA content, but led to inferences on repeat composition and activity patterns which do not capture the true diversity within Mammalia. Understanding of the evolutionary importance of TEs and the development of TEs for biological applications are hindered when considering only the data gathered from a limited sampling of model organisms. The research presented here begins with analysis of a mouse lemur WGS dataset, revealing an exception in the primate lineage to the generalizations garnered from model organisms. A recently active TE was uncovered with evidence of horizontal transfer involving a primate and another mammal; this discovery may lead to a useful transfection vector with known efficacy in mammalian cells. Furthermore, an opportunity to observe atypical patterns of TE diversification within a mammalian family was achieved through survey sequencing and comparative analyses of five vespertilionid taxa and a phyllostomid outgroup. A potential inverse relationship between the two classes of TEs was tentatively described, and further explored by an in-depth analysis of the dominant TE family from each class in a species with WGS data available. The interplay of the two classes could not previously be investigated in mammals, due to ~40 million years of Class II TE inactivity in model organisms. Through exploration of activity patterns of both classes, this study provides insight on the relationship between TEs and their host.

Doctor of Philosophy / Department of Entomology / James F. Campbell / Kun Yan Zhu / Aerosol applications of reduced risk insecticides such as synergized pyrethrin and insect growth regulators (IGR) are part of food industry integrated pest management programs. Since aerosols cannot penetrate into hidden areas exploited by pests such as the red flour beetle, Tribolium castaneum, the potential for these insecticides to effect beetle populations was evaluated. Because IGRs do not cause immediate mortality, the potential of horizontal transfer for an IGR from treated to untreated individuals was also examined. Results showed that when untreated T. castaneum, larvae or pupae, were added to flour containing methoprene, IGR, treated larvae, pupae or adults, the untreated individuals exhibited evidence of methoprene exposure (external deformities and reduced survival). Evaluation of the different mechanisms of transfer indicated that contact with methoprene treated individuals or flour that had been in contact with treated individuals may be the primary method of methoprene transfer. Since aerosols are often applied as a combination of IGR and pyrethrin with a carrier, the effect of these components was evaluated. Applications of synergized pyrethrin caused knockdown of adults but affected adults recovered and progeny production was not effected. Exposure of eggs to these insecticides reduced egg hatch. Food material accumulations inside food facilities can potentially increase or reduce insecticide efficacy. Evaluation of different flour residue levels, representing different sanitation levels, revealed that sanitation alone reduced immature development. As flour residue depths increased more individuals developed into adults but very few developed in the insecticide treatments. Food facilities that use aerosol insecticides apply them at regular intervals, so the cumulative effects of these treatments were considered. Experiments evaluating repeated insecticide exposures indicated that the direct morality from synergized pyrethrin not the horizontal transfer of methoprene was the primary factor in population reduction. Overall findings suggested that methoprene is highly mobile between different surfaces. Exposure of untreated individual beetle larvae to treated larvae or pupae or to flour that has been in contact with exposed beetles can have detrimental effects on development or survival, but these effects may be highly variable and even in cumulative exposures the overall level of population suppression is limited.

A soja (Glycine max) é uma das culturas mais importantes do mundo, os seus grãos servem tanto para a alimentação quanto para a extração de óleo para a fabricação do biodiesel. O vírus do mosaico do pepino (CMV, do inglês, “Cucumber mosaic virus”) é um vírus de RNA, patogênico a diversas plantas. O RNA de interferência é um sistema de silenciamento de RNA presente na maioria dos eucariotos no qual precursores de RNA de dupla fita (dsRNA) são processados em pequenos RNAs (sRNAs) de 21-24 nucleotídeos (nt), que podem regular a atividade de genes, elementos genéticos e vírus de uma maneira sequência específica. A integração de vírus de DNA e de retrovírus no genoma do hospedeiro já é bem conhecida tanto para sistemas eucarióticos quanto para procarióticos. Mais recentemente, foi observada a integração de vírus de RNA não retrovirais (NIRVs) em mamíferos. O presente trabalho é o primeiro a demonstrar tal evento no genoma de plantas. A partir das sequências dos sRNAs de 19-24 nt de 15 bibliotecas de sRNAs sequenciados de amostras de tecidos de soja, foram montadas sequências contíguas (“contigs”) pelo programa SOAP, algumas das quais apresentaram homologia de sequência ao RNA 1 do CMV. Por montagem de novo desses contigs foi obtida uma sequência de 3.092 nt do RNA 1 do CMV, presente em todas as bibliotecas pesquisadas de pelo menos cinco cultivares diferentes de soja. A presença dessa sequência foi confirmada em outras sete cultivares, exceto em "Willians". Foi observada uma maior presença de sRNAs derivados do CMV senso do que anti-senso nas 15 bibliotecas sequenciadas. Os sRNAs de 22-nt foram os mais abundantes. Para o vírus da mancha da vagem do feijoeiro (BPMV, do inglês “Bean pod mottle virus”) presente em uma das bibliotecas, os sRNAs de 21-nt e 22-nt representaram em torno de 80% do total de sRNAs. Foram encontrados sRNAs que variaram sob estresse biótico (Phakospora pachyrhizi) e abiótico (seca) e entre diferentes cultivares. A expressão do RNA 1 aumentou nas plantas sob estresse. Provavelmente o evento de integração ocorreu via recombinação à um retrotransposon. / The Soybean (Glycine max) is one of the world's most important crops, its seeds are used both as food and for the extraction of oil to manufacture biodiesel. The Cucumber mosaic virus (CMV) is a pathogenic RNA virus of plants. The RNA interference is a system of RNA silencing present in most eukaryotes in which precursors of double-stranded RNA (dsRNA) are processed into small RNAs (sRNAs) of 21-24 nucleotides (nt), which can regulate the activity of genes, genetic elements and virus in a sequence-specific manner. The integration of DNA virus and retrovirus into the host genome is well known both for prokaryotic and eukaryotic systems. The integration of non-retroviral RNA virus (NIRVs) in mammals was previously observed, but the present work is the first to demonstrate such an event in a plant genome. The sequences of the sRNAs ranging from 19 to 24 nt, in 15 libraries of sRNAs sequenced from samples of soybean tissues, were assembled in contigs by the program SOAP, with some preentering sequence homology to the RNA 1 of CMV. By de novo assembling of these contigs it was obtained a sequence of 3,092 nt of the CMV RNA 1, present in all libraries surveyed in at least five different varieties of soybeans. The presence of this sequence was confirmed by PCR in seven other cultivars, but in "Williams". We observed a greater presence of sRNAs derived from CMV of sense orientation than antisense in the 15 libraries sequenced. The 22-nt sRNAs were the most abundant. For the Bean pod mottle virus (BPMV), present in one of the libraries, the 21 and 22 nt sRNAs were represented by around 80% of all sRNAs. The sRNAs were found varying under biotic stress (Phakospora pachyrhizi) and abiotic (drought) and among different cultivars. RNA 1 expression increased in plants under stress. Probably the integration event occurred via recombination of a retrotransposon.

Organisations are often faced with many challenges when they attempt to implement an entire workforce to a technologically advanced and complex platform that will alter the skill-set requirements for performance. Training can be ä very effective intervention strategy to implement this organisational change. However, theorists have proposed that training can also enhance organisational effectiveness, and it is believed that individual outcomes from training that emerge upward to achieve organisational objectives vertical transfer would strengthen the link between training effectiveness and organisational effectiveness. Using these theories as a foundation, this case study examined the effectiveness of an organisation's training to achieve performance objectives. Expansion from these theories was possible as this case study presented the multiple influences involved during successive interdependent team training to support the performance of safety-critical operations for a new working platform. In achieving interdependent team vertical transfer in emergency management during this training, results have revealed that training must first focus on individual level skill proficiency and collective enabling process skills horizontal transfer as they are a critical antecedent to ensure cohesion in interdependent team performance. Findings have further identified that the training content and methods must both support and determine the achievement of individual required skills. While simulation training that reflected the working platform benefits both learning and performance. Conclusions can also be drawn from this exploratory case study that the efforts by individuals upward through to teams and across teams has enhanced training performance outcomes. This empirical case study has shown that a multitude of factors and cumulative events that occurred prior to training and during training influenced the effectiveness of team training from multiple levels. Thus, this case study has been able to verify and expand current postulated models to provide foundation support for the design and delivery of interdependent training.

A soja (Glycine max) é uma das culturas mais importantes do mundo, os seus grãos servem tanto para a alimentação quanto para a extração de óleo para a fabricação do biodiesel. O vírus do mosaico do pepino (CMV, do inglês, “Cucumber mosaic virus”) é um vírus de RNA, patogênico a diversas plantas. O RNA de interferência é um sistema de silenciamento de RNA presente na maioria dos eucariotos no qual precursores de RNA de dupla fita (dsRNA) são processados em pequenos RNAs (sRNAs) de 21-24 nucleotídeos (nt), que podem regular a atividade de genes, elementos genéticos e vírus de uma maneira sequência específica. A integração de vírus de DNA e de retrovírus no genoma do hospedeiro já é bem conhecida tanto para sistemas eucarióticos quanto para procarióticos. Mais recentemente, foi observada a integração de vírus de RNA não retrovirais (NIRVs) em mamíferos. O presente trabalho é o primeiro a demonstrar tal evento no genoma de plantas. A partir das sequências dos sRNAs de 19-24 nt de 15 bibliotecas de sRNAs sequenciados de amostras de tecidos de soja, foram montadas sequências contíguas (“contigs”) pelo programa SOAP, algumas das quais apresentaram homologia de sequência ao RNA 1 do CMV. Por montagem de novo desses contigs foi obtida uma sequência de 3.092 nt do RNA 1 do CMV, presente em todas as bibliotecas pesquisadas de pelo menos cinco cultivares diferentes de soja. A presença dessa sequência foi confirmada em outras sete cultivares, exceto em "Willians". Foi observada uma maior presença de sRNAs derivados do CMV senso do que anti-senso nas 15 bibliotecas sequenciadas. Os sRNAs de 22-nt foram os mais abundantes. Para o vírus da mancha da vagem do feijoeiro (BPMV, do inglês “Bean pod mottle virus”) presente em uma das bibliotecas, os sRNAs de 21-nt e 22-nt representaram em torno de 80% do total de sRNAs. Foram encontrados sRNAs que variaram sob estresse biótico (Phakospora pachyrhizi) e abiótico (seca) e entre diferentes cultivares. A expressão do RNA 1 aumentou nas plantas sob estresse. Provavelmente o evento de integração ocorreu via recombinação à um retrotransposon. / The Soybean (Glycine max) is one of the world's most important crops, its seeds are used both as food and for the extraction of oil to manufacture biodiesel. The Cucumber mosaic virus (CMV) is a pathogenic RNA virus of plants. The RNA interference is a system of RNA silencing present in most eukaryotes in which precursors of double-stranded RNA (dsRNA) are processed into small RNAs (sRNAs) of 21-24 nucleotides (nt), which can regulate the activity of genes, genetic elements and virus in a sequence-specific manner. The integration of DNA virus and retrovirus into the host genome is well known both for prokaryotic and eukaryotic systems. The integration of non-retroviral RNA virus (NIRVs) in mammals was previously observed, but the present work is the first to demonstrate such an event in a plant genome. The sequences of the sRNAs ranging from 19 to 24 nt, in 15 libraries of sRNAs sequenced from samples of soybean tissues, were assembled in contigs by the program SOAP, with some preentering sequence homology to the RNA 1 of CMV. By de novo assembling of these contigs it was obtained a sequence of 3,092 nt of the CMV RNA 1, present in all libraries surveyed in at least five different varieties of soybeans. The presence of this sequence was confirmed by PCR in seven other cultivars, but in "Williams". We observed a greater presence of sRNAs derived from CMV of sense orientation than antisense in the 15 libraries sequenced. The 22-nt sRNAs were the most abundant. For the Bean pod mottle virus (BPMV), present in one of the libraries, the 21 and 22 nt sRNAs were represented by around 80% of all sRNAs. The sRNAs were found varying under biotic stress (Phakospora pachyrhizi) and abiotic (drought) and among different cultivars. RNA 1 expression increased in plants under stress. Probably the integration event occurred via recombination of a retrotransposon.

Made available in DSpace on 2014-12-17T15:18:09Z (GMT). No. of bitstreams: 1 UaskaBS.pdf: 2080120 bytes, checksum: b16b535c47ed35cd6d738822bec1281d (MD5) Previous issue date: 2008-03-31 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The phylogeny is one of the main activities of the modern taxonomists and a way to reconstruct the history of the life through comparative analysis of these sequences stored in their genomes aimed find any justification for the origin or evolution of them. Among the sequences with a high level of conservation are the genes of repair because it is important for the conservation and maintenance of genetic stability. Hence, variations in repair genes, as the genes of the nucleotide excision repair (NER), may indicate a possible gene transfer between species. This study aimed to examine the evolutionary history of the components of the NER. For this, sequences of UVRA, UVRB, UVRC and XPB were obtained from GenBank by Blast-p, considering 10-15 as cutoff to create a database. Phylogenetic studies were done using algorithms in PAUP programs, BAYES and PHYLIP package. Phylogenetic trees were build with protein sequences and with sequences of 16S ribosomal RNA for comparative analysis by the methods of parsimony, likelihood and Bayesian. The XPB tree shows that archaeal?s XPB helicases are similar to eukaryotic helicases. According to this data, we infer that the eukaryote nucleotide excision repair system had appeared in Archaea. At UVRA, UVRB and UVRC trees was found a monophyletic group formed by three species of epsilonproteobacterias class, three species of mollicutes class and archaeabacterias of Methanobacteria and Methanococci classes. This information is supported by a tree obtained with the proteins, UVRA, UVRB and UVRC concatenated. Thus, although there are arguments in the literature defending the horizontal transfer of the system uvrABC of bacteria to archaeabacterias, the analysis made in this study suggests that occurred a vertical transfer, from archaeabacteria, of both the NER genes: uvrABC and XPs. According the parsimony, this is the best way because of the occurrence of monophyletic groups, the time of divergence of classes and number of archaeabacterias species with uvrABC system / A filogen?mica estuda os organismos atrav?s de an?lises comparativas das seq??ncias conservadas presentes em seus genomas visando encontrar alguma justificativa para a origem ou a evolu??o dos mesmos. Dentre as seq??ncias com elevado n?vel de conserva??o encontram-se os genes de reparo, pois s?o importantes para a conserva??o e manuten??o da estabilidade gen?tica. Por isso, varia??es em genes de reparo, como os da via de excis?o de nucleot?deos (REN), podem indicar uma poss?vel transfer?ncia g?nica entre esp?cies. O presente trabalho teve o objetivo de analisar a hist?ria evolutiva dos componentes do REN. Para isso, seq??ncias de UVRA, UVRB, UVRC e XPB foram obtidas a partir do GenBank por Blast-p, considerando-se 10-15 como limiar, com o fim de criar um banco de dados. Estudos filogen?ticos foram feitos utilizando algoritmos presentes nos programas PAUP, BAYES e no pacote PHYLIP. Foram constru?das ?rvores com seq??ncias prot?icas e com seq??ncias de RNA riboss?mico 16S para an?lises comparativas atrav?s dos m?todos de parcim?nia, verossimilhan?a e bayesiano. De acordo com a ?rvore de XPB, as helicases dos eucariotos s?o similares as das arqueobact?rias e apresentam comportamento semelhante ao longo da evolu??o, ou seja, compartilham um mesmo ancestral. Nas filogenias feitas para cada prote?na do sistema uvrABC, foram encontradas tr?s esp?cies da classe epsilonproteobacterias, tr?s esp?cies da classe mollicutes e arqueobacterias das classes Methanobacteria e Methanococci formando um grupo monofil?tico. Esse dado ? fortalecido atrav?s de uma ?rvore obtida com as prote?nas, UVRA, UVRB e UVRC concatenadas. Assim, embora existam argumentos, na literatura, defendendo a transfer?ncia horizontal do sistema uvrABC de bact?rias para arqueobact?rias, a an?lise feita neste estudo sugere que a transfer?ncia vertical, tendo arquebacterias como origem, tanto do sistema uvrABC quanto dos genes XP, seja o caminho mais parcimonioso, considerando a ocorr?ncia de grupos monofil?ticos, o tempo de diverg?ncia das classes e o n?mero de esp?cies e arqueobact?rias portadoras dos genes do sistema uvrABC

A soja (Glycine max) é uma das culturas mais importantes do mundo, os seus grãos servem tanto para a alimentação quanto para a extração de óleo para a fabricação do biodiesel. O vírus do mosaico do pepino (CMV, do inglês, “Cucumber mosaic virus”) é um vírus de RNA, patogênico a diversas plantas. O RNA de interferência é um sistema de silenciamento de RNA presente na maioria dos eucariotos no qual precursores de RNA de dupla fita (dsRNA) são processados em pequenos RNAs (sRNAs) de 21-24 nucleotídeos (nt), que podem regular a atividade de genes, elementos genéticos e vírus de uma maneira sequência específica. A integração de vírus de DNA e de retrovírus no genoma do hospedeiro já é bem conhecida tanto para sistemas eucarióticos quanto para procarióticos. Mais recentemente, foi observada a integração de vírus de RNA não retrovirais (NIRVs) em mamíferos. O presente trabalho é o primeiro a demonstrar tal evento no genoma de plantas. A partir das sequências dos sRNAs de 19-24 nt de 15 bibliotecas de sRNAs sequenciados de amostras de tecidos de soja, foram montadas sequências contíguas (“contigs”) pelo programa SOAP, algumas das quais apresentaram homologia de sequência ao RNA 1 do CMV. Por montagem de novo desses contigs foi obtida uma sequência de 3.092 nt do RNA 1 do CMV, presente em todas as bibliotecas pesquisadas de pelo menos cinco cultivares diferentes de soja. A presença dessa sequência foi confirmada em outras sete cultivares, exceto em "Willians". Foi observada uma maior presença de sRNAs derivados do CMV senso do que anti-senso nas 15 bibliotecas sequenciadas. Os sRNAs de 22-nt foram os mais abundantes. Para o vírus da mancha da vagem do feijoeiro (BPMV, do inglês “Bean pod mottle virus”) presente em uma das bibliotecas, os sRNAs de 21-nt e 22-nt representaram em torno de 80% do total de sRNAs. Foram encontrados sRNAs que variaram sob estresse biótico (Phakospora pachyrhizi) e abiótico (seca) e entre diferentes cultivares. A expressão do RNA 1 aumentou nas plantas sob estresse. Provavelmente o evento de integração ocorreu via recombinação à um retrotransposon. / The Soybean (Glycine max) is one of the world's most important crops, its seeds are used both as food and for the extraction of oil to manufacture biodiesel. The Cucumber mosaic virus (CMV) is a pathogenic RNA virus of plants. The RNA interference is a system of RNA silencing present in most eukaryotes in which precursors of double-stranded RNA (dsRNA) are processed into small RNAs (sRNAs) of 21-24 nucleotides (nt), which can regulate the activity of genes, genetic elements and virus in a sequence-specific manner. The integration of DNA virus and retrovirus into the host genome is well known both for prokaryotic and eukaryotic systems. The integration of non-retroviral RNA virus (NIRVs) in mammals was previously observed, but the present work is the first to demonstrate such an event in a plant genome. The sequences of the sRNAs ranging from 19 to 24 nt, in 15 libraries of sRNAs sequenced from samples of soybean tissues, were assembled in contigs by the program SOAP, with some preentering sequence homology to the RNA 1 of CMV. By de novo assembling of these contigs it was obtained a sequence of 3,092 nt of the CMV RNA 1, present in all libraries surveyed in at least five different varieties of soybeans. The presence of this sequence was confirmed by PCR in seven other cultivars, but in "Williams". We observed a greater presence of sRNAs derived from CMV of sense orientation than antisense in the 15 libraries sequenced. The 22-nt sRNAs were the most abundant. For the Bean pod mottle virus (BPMV), present in one of the libraries, the 21 and 22 nt sRNAs were represented by around 80% of all sRNAs. The sRNAs were found varying under biotic stress (Phakospora pachyrhizi) and abiotic (drought) and among different cultivars. RNA 1 expression increased in plants under stress. Probably the integration event occurred via recombination of a retrotransposon.

Les bactéries pectinolytiques appartenant aux genres Pectobacterium et Dickeya spp. sont des agents pathogènes chez Solanum tuberosum. Ces bactéries sont responsables de la maladie de la jambe noire et de la pourriture molle lors de la culture et du stockage des tubercules. Ce travail de thèse est divisé en deux axes: 1) Etude dela diversité d'une population du pathogène D. solani par approche de génomique comparée afin de mieux comprendre la structure génomique de cette espèce émergente. 2) L'assemblage du génome et la caractérisation génomique des facteurs de virulence chez Pectobacterium wasabiae RNS 08421A.L'analyse des génomes de 20 isolats de D. solani issus d’environnements différents, par une approche de génomique comparative associée à des analyses fonctionnelles, a révélé une forte homogénéité génétique au sein de la majorité des souches (16/20). De plus, cette analyse a permis de caractériser un nouveau sous-groupe au sein de l'espèce D. solani, représenté par la souche 0512 (1/20). En revanche, d’autres isolats (3/20) montrent des variations de quelques centaines à quelques milliers de SNPs/InDels qui sont regroupés dans des îlots génomiques. Leur analyse phylogénétique révèle qu’ils proviennent d’autres pathogènes par transferts horizontaux. Par ailleurs, l’analyse des fonctions affectées par les SNPs/InDels a permis de prédire, puis de vérifier sur pomme de terre, qu’un des isolats était faiblement virulent.La deuxième partie de mon travail porte sur l'assemblage, la caractérisation et l'analyse du génome de la souche RNS 08.42.1A de P. wasabiae, qui a été isolée en France. La génomique comparative avec 3 autres souches de P. wasabiae d'origines géographiques différentes, a révélé à la fois une forte similitude au niveau de la séquence génomique (ANI> 99%) et une synténie conservée des gènes de virulence. En outre, notre analyse a mis en évidence une nette distinction entre ces quatre souches de P. wasabiae (isolées de S. tuberosum) et la souche type japonaise P. wasabiae CFBP 3304T (isolée du raifort). Dans P. wasabiae RNS 08.42.1A, les gènes de synthèse et de perception du quorum sensing, expI/expR, présentent une plus forte homologie avec leurs orthologues chez P. atrosepticum et P. carotovurm (90%) qu'avec leurs homologues chez P. wasabiae (70%). Ceci suggère une acquisition de ces gènes par transfert horizontal au sein d'une population de pathogènes infectant la même plante hôte. / The pectolytic bacteria Pectobacterium and Dickeya species cause important diseases on Solanum tuberosum and other arable and horticultural crops. These bacteria are responsible for blackleg in the field and tuber soft rots in storage and in transit as well as in the field worldwide. The main objectives of this thesis are: 1) To study the diversity of a D. solani population using comparative genomics approaches in order to understand the genomic structure and evolution of this emerging species. 2) Characterization and genomic analysis of virulence factors in Pectobacterium wasabiae RNS 08421A.Using comparative genomics approach combined with functional assays, the analysis of the genomes of 20 isolates of D. solani from different environments, revealed a strong genetic homogeneity within the majority of strains (16/20). Moreover, this analysis allowed to characterize a new subgroup within D. solani species, represented by the 0512 strain (1/20). In contrast, some strains (3/20) showed variations from hundreds to a few thousand of SNPs/Indels which are grouped in genomic islands (GIs). Phylogenetic analysis of these GIs shows that they were acquired from other pathogens by horizontal transfer. Furthermore, the analysis of the functions affected by SNPs/Indels allowed to predict, then check on potatoes, that one of these strain was less virulent.The second part of my work involves assembly, characterization and analysis of the genome of the strain P. wasabiae RNS 08.42.1A, which was isolated in France. Comparative genomics with three other P. wasabiae strains from different geographical origins, revealed a strong similarity in the genome sequence (ANI> 99%) and conserved synteny of virulence genes. In addition, our analysis showed a clear distinction between the strains of P. wasabiae isolated from S. tuberosum and the type strain P. wasabiae CFBP 3304T (isolated from horseradish). In P. wasabiae RNS 08.42.1A, the complex system for synthesis and perception of quorum sensing signal expI/expR, exhibit higher homology with their orthologs in P. atrosepticum and P. carotovurm (90%) than their homologs in P. wasabiae (70%). This suggests acquisition of these genes by horizontal gene transfer within a population of pathogens infecting the same host plant.

Transposable elements (TEs) are mobile genetic elements capable of replicating and spreading within, and in some cases, between genomes. I describe a whole-genome analysis of DD34E TEs, which belong to the IS630-Tc1-mariner superfamily of DNA transposable elements, in the African malaria mosquito, Anopheles gambiae. Twenty-six new transposons as well as a new family, gambol, were identified. The gambol family shares the DD34E catalytic motif with Tc1-DD34E transposons, but is distinct from these elements in their phylogenetic relationships. Although gambol appears to be related to a few DD34E transposons from cyanobacteria and fungi, no gambol elements have been reported in any other insects or animals thus far. This discovery expands the already expansive diversity of the IS630-Tc1-mariner TEs, and raises interesting questions as to the origin of gambol elements and their apparent diversity in An. gambiae. Several DD34E transposons discovered in An. gambiae possess characteristics that are associated with recent transposition, such as high sequence identity between copies, and intact terminal-inverted repeats and open reading frames. One such element, AgTango, was also found in a distantly related mosquito species, Aedes aegypti, at high amino acid sequence identity (79.9%). It was discovered that Tango transposons have patchy distribution among twelve mosquito species surveyed using PCR as well as genomic searches, suggesting a possible case for horizontal transfer. Additionally, it was discovered that in some mosquito genomes, there are several Tango transposons. These observations suggest differential evolutionary scenarios and/or TE-host interaction of Tango elements between mosquito species. This strengthened the case that AgTango may be a functional transposase, and I sought to test its potential activity in a cell culture-based inter-plasmid transposition assay using the Herves plasmids as a positive control (Arensburger et al., 2005). AgTango constructs were successfully constructed; however, no transposition events were detected for Tango or Herves. Because the positive control failed to work, no assessment can be made concerning Tango's transposase. Possible causes and solutions for these results, alternative means to detect transposition, as well as future directions with Tango are discussed. / Ph. D.

No description available.