No description available.

This article advocates the reanalysis of historical data on extinct languages in the view of our current knowledge on the grammatical characteristics of possibly related languages.The example given here is a corpus of eight Arawakan languages of Bolivia, of which four are already extinct (Apolista, Joaquiniano, Paikoneka, Saraveka). Even though there are only wordlists available for these extinct languages, it is possible to analyze the data in the light of Arawakan grammar.Those aspects that can be excerpted from all data are taken as typological features in a questionnaire used for phylogenetic analyses. The graphs that result from the feature analysis deliver evidence for certain relations between the languages and those that are still spoken today, which again gives us some idea about the migration of the Arawakan languages, in general.

Thesis (PhD)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Potato virus Y (PVY) is responsible for considerable yield losses in the South African potato industry. The incidence of this virus has greatly increased over the past 20 years. In previous studies nonrecombinant strains of PVY, PVY N and PVY O, were detected in South African potatoes. In a recent study the occurrence of non-recombinant strains of PVY in South African potatoes was shown to have decreased while infection by more virulent recombinant strains, PVY NTN and PVY N-W, had increased dramatically. Infection of potato plants with PVY may cause stunted growth and mosaic or necrotic leaf symptoms which in turn can lead to a significant reduction in yield. Highly virulent recombinant PVY isolates as well as some of the non-recombinant strains may cause potato tuber necrotic ringspot disease (PTNRD) which may result in losses of 10% to total crop failure. For this reason investigation of infection by local recombinant isolates on local cultivars was important. To this end a representative number of isolates were selected for whole genome sequencing based on the relative occurrence of the various isolates in South Africa. A number of these sequenced isolates were subsequently used to infect local cultivars of potato in order to investigate the influence of genetic variation within the viral genome on symptom expression. In this study 27 South African isolates of PVY were sequenced through overlapping RT-PCR fragments. Seven of these isolates, six PVY NTN and one PVY N-W, were used to mechanically infect four local cultivars of potatoes under greenhouse conditions. The infected plants were monitored to establish the rate of systemic spread using a highly sensitive qRT-PCR and resulting tubers were visually screened for PTNRD. Highly variable recombinant isolates appear to be less virulent than the more conserved recombinant isolates possibly indicating molecular determinants for pathogenicity. For this reason the amino acid sequences of the South African isolates were compared to those of international isolates and scrutinized for variation and substitutions. Some South African isolates displayed amino acid substitutions unique to the specific isolate, making them unlike those found internationally. Substitution rates throughout the amino acid sequences differed greatly, with some isolates displaying hardly any changes whilst others varied a great deal from overseas isolates. Certain regions, many of which had specific functions, were more conserved than others. This study further investigated the recombination events within the PVY genome using reticulate phylogenetic analysis, molecular dating and network construction techniques. Unlike existing approaches, the one described in this study neither assumes an underlying strictly bifurcating species tree nor assumes prior knowledge of processes underlying deviations between individual gene trees. Through the use of the resulting robust time calibrated phylogeny, the patterns of diversification and recombination in PVY may be placed in the historical context of human cultivation of potatoes. Through the use of these techniques the study aimed to test whether diversification of the major strains of PVY and recombination between them occurred within the time frame of the domestication and modern cultivation of potatoes. From these analyses it can be deduced that recombinant strains of PVY were imported into South Africa. / AFRIKAANSE OPSOMMING: Aartappel virus Y (PVY) is verantwoordelik vir aansienlike opbrengs verliese in die Suid-Afrikaanse aartappelbedryf. Die voorkoms van die virus het grootliks toegeneem oor die afgelope 20 jaar. In vorige studies is nie-rekombinante rasse van PVY, PVY N en PVY O, gedokumenteer in Suid-Afrikaanse aartappels. 'n Onlangse studie het gevind dat die voorkoms van nie-rekombinante rasse van PVY in Suid- Afrikaanse aartappels aansienlik gedaal het terwyl infeksie deur virulente rekombinante rasse, PVY NTN en PVY N-W, dramaties toegeneem het. Infeksie van aartappelplante met PVY kan vertraagde groei en mosaïek- of nekrotiese blaarsimptome veroorsaak wat kan lei tot aansienlike vermindering in opbrengs. Hoogs virulente rekombinante PVY isolate, sowel as sommige nie-rekombinante rasse, kan aartappel nekrotiese ring simptome (PTNRD) veroorsaak wat verliese van 10% tot totale misoes tot gevolg kan hê. Om hierdie rede was die ondersoek van infeksie deur plaaslike rekombinante isolate op plaaslike kultivare belangrik. Vir hierdie doel is 'n verteenwoordigende aantal isolate gekies, gebaseer op die relatiewe voorkoms daarvan in Suid-Afrika, vir heelgenoom-volgordebepaling. Van die isolate is vervolgens gebruik om plaaslike kultivare te besmet ten einde die invloed van genetiese variasie binne die virale genoom op simptoom uitdrukking te ondersoek. In hierdie studie is 27 heelgenoomvolgordes van Suid-Afrikaanse PVY isolate bepaal deur oorvleuelende RT-PCR fragmente. Sewe van hierdie isolate, ses PVY NTN en een PVY N-W, is gebruik om vier plaaslike aartappel kultivare, gegroei onder kweekhuis kondisies, meganies te infekteer. Die geïnfekteerde plante is gemonitor om die tempo van sistemiese verspreiding vas te stel deur middel van 'n hoogs sensitiewe qRTPCR en knolle is visueel inspekteer vir PTNRD. Hoogs variante rekombinante isolate blyk om minder virulent te wees as die meer bewaarde rekombinante isolate wat dui op molekulêre determinante van patogenisiteit. Om hierdie rede is die aminosuurvolgordes van die Suid-Afrikaanse isolate vergelyk met die van internasionale isolate en ondersoek vir variasie en substitusies. Sommige Suid-Afrikaanse isolate vertoon aminosuur substitusies wat uniek is tot die spesifieke isolaat en maak hul dus anders as internasionale isolate. Die aantal aminosuursubstitusies in die volgordes verskil grootliks. In vergelyking met internasionale isolate toon sommige isolate skaars enige veranderinge terwyl ander ‘n aantal verskille toon. Sekere gebiede, waarvan baie spesifieke funksies het, was meer gekonserveerd as ander. Hierdie studie ondersoek ook rekombinasie gebeure binne die PVY genoom deur retikulêre filogenetiese analise, molekulêre datering en netwerk konstruksie tegnieke. In teenstelling met bestaande benaderinge, aanvaar die tegniek wat hier beskryf word nie ‘n streng bifurkeerende filogenie, wat onderliggende verdeel, of enige voorafgaande kennis van die prosesse onderliggend aan afwykings tussen individuele filogenieë nie. ‘n Robuuste, tyd gekalibreer filogenie kan diversifikasie patrone en rekombinasie van PVY plaas in die historiese konteks van menslike verbouing van aartappels. Deur gebruik te maak van hierdie tegnieke poog die studie om te toets of diversifikasie en rekombinasie van PVY rasse plaasgevind het binne die tydsbestek van die inburgering en moderne verbouing van aartappels. Van hierdie ontledinge word afgelei dat rekombinante rasse van PVY wat in Suid-Afrika voorkom, ingevoer is.

Thesis (PhD)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Background: Human immunodeficiency virus type 1 (HIV-1) viral protein R (Vpr) is an accessory protein that interacts with a number of host cellular and other viral proteins. Vpr exerts several functions such as induction of apoptosis, induction of cell cycle G2 arrest, modulation of gene expression, and suppression of immune activation. The functionality of subtype C Vpr, especially South African strains, has not been studied. The aim of this study was to describe the diversity of South African HIV-1 subtype C vpr genes and to investigate selected functions of these Vpr proteins. Methodology: The HIV-1 vpr region of 58 strains was amplified, sequenced, and subtyped using phylogenetic analysis. Fragments containing natural mutations were cloned in mammalian expression vectors. A consensus subtype C vpr gene was constructed and site-directed mutagenesis was used to induce mutations in postions in which no natural mutations have been described. The functionality of all constructs was compared with the wild-type subtype B Vpr, by transfecting human 293T cell line to investigate subcellular localization, induction of apoptosis and cell cycle G2 arrest. The modulation of genes expressed in the induction of apoptosis using TaqMan Low density arrays (TLDA) was also investigated. Results: Phylogenetic analysis characterized 54 strains as HIV-1 subtype C and 4 strains as HIV-1 subtype B. The overall amino acid sequence of Vpr was conserved including motifs FPRPWL and TYGDTW, but the C-terminal was more variable. The following mutations were constructed using site-directed mutagenesis: P14I, W18C, Y47N, Q65H and Q88S. Subtype B and all natural mutants of subtype C Vpr localized to the nucleus but the W18C mutation disturbed the nuclear localization of Vpr. The cell cycle G2 arrest activity of all the mutants, as well as consensus-C, was lower than that of subtype B Vpr. All the natural mutants of subtype C Vpr induced cell cycle G2 arrest in 54.0-66.3% of the cells, while subtype B Vpr induced cell cycle G2 arrest in 71.5% of the cells. Subtype B and the natural mutant Vpr proteins induced apoptosis in a similar manner, ranging from 95.3-98.6% of transfected cells. However, an artificially designed Vpr protein containing the consensus sequences of subtype C Vpr indicated a reduced ability to induce apoptosis. While consensus-C Vpr induced apoptosis in only 82.0% of the transfected cells, the artificial mutants of Vpr induced apoptosis in 88.4 to 96.2% of the cells. The induction of apoptosis associated gene expression was similar for all constructs, indicated that apoptosis was efficiently induced through the intrinsic pathway by the mutants. Conclusion: This study indicated that both HIV-1 subtype B and C Vpr display a similar ability for nuclear localization and apoptosis induction. The induction of cell cycle G2 arrest by HIV-1 subtype B Vpr may be more robust than many subtype C Vpr proteins. The natural mutations studied in the isolates did not disturb the functions of subtype C Vpr and in some cases even potentiated the protein to induce apoptosis. Naturally occurring mutations in HIV-1 Vpr cannot be regarded as defective, since enhanced functionality would be more indicative of an adaptive role. The increased potency of the mutated Vpr proteins suggests that Vpr may increase the pathogenicity of HIV-1 by adapting apoptotic enhancing mutations. / AFRIKAANSE OPSOMMING: Agtergrond: Die virus protein R (Vpr) van Menslike Immuungebrek Virus tipe 1 (MIV-1) is ‘n bykomstige protein wat met ‘n aantal sellulêre proteine van die gasheer en ander virus proteine in wisselwerking tree. Vpr het 'n invloed op verskeie funksies onder andere die induksie van apoptose, die induksie van selsiklus G2 staking, modulering van geen uitdrukking en onderdrukking van immuun aktivering. Die funksionaliteit van subtipe C Vpr, en veral die van Suid-Afrikaanse stamme, is nie beskryf nie. Die doelwit van die studie was om die diversiteit van Suid Afrikaanse MIV-1 subtipe C vpr gene te beskryf en ook om selektiewe funksies van die Vpr proteine te ondersoek Metodiek: Die MIV-1 vpr streek van 58 stamme is vermeerder, die DNA volgordes is bepaal en die stamme is gesubtipeer deur filogenetiese analise. Fragmente met natuurlike mutasies is in ekspressie vektore gekloon. ‘n Konsensus subtipe C Vpr geen is ontwerp en mutasies in posisies waar geen natuurlike mutasies beskryf is nie, is ontwerp deur mutagenese. Die funksionaliteit van die konstrukte is met die wilde tipe subtype B vergelyk deur 293T sellyn te transfekteer en te ondersoek vir subsellulêre lokalisering, induksie van apoptose, en G2 selsiklus stilstand. Die modulering van geen uitdrukking in die induksie van apoptose is deur TLDA ondersoek. Resultate: Filogenetiese analise het 54 stamme as HIV-1 subtipe C geklassifiseer en 4 stamme as subtype B. Die Vpr aminosuur volgordes was konstant insluitend die FPRPWL en TYGDTW motiewe, maar die C-terminaal was meer variëerbaar. Deur mutagenese is die volgende mutasies ontwerp: P14I, W18C, Y47N, Q65H and Q88S. Subtipe B en al die natuurlike mutante van subtipe C het in die selkern gelokaliseer, maar die W18C mutasie het die lokalisasie versteur. Die G2 selsiklus stilstand van alle mutante en konsensus C was laer as die van subtype B. Al die natuurlike subtipe C mutante het G2 selsiklus tot stilstand gebring in 54.0-66.3% van die selle, terwyl subtype B selsiklus tot stilstand gebring het in 71.5% van die selle. Subtipe B en die natuurlike Vpr mutante het apoptose op ‘n soortgelyke wyse geinduseer, wat wissel tussen 95.3-98.6% van getransfekteerde selle. Die protein met die kunsmatig ontwerpte konsensus C volgorde het egter ‘n verlaagde vermoë gehad om apoptose te induseer. Die konsensus subtipe C het apoptose in 82.0% van getransfekteerde selle geinduseer en die kunsmatige mutante in 88.4 – 96.2% van die selle. Die induksie van die apoptose verwante geen ekspressie deur die mutante was soortgelyk as die van konsensus C en subtipe B Vpr wat ’n aangeduiding is dat apoptose effektief veroorsaak is deur die intrinsieke roete. Gevolgtrekking: Hierdie studie het aangetoon dat kern lokalisering en apoptose op ‘n soortgelyke wyse by beide MIV-1 subtipe B en C Vpr plaasvind. Die induksie van selsiklus G2 stilstand deur MIV-1 subtipe B Vpr is egter meer robuust as baie van die subtipe C Vpr proteïene. Natuurlike mutasies in MIV-1 Vpr kan nie as gebrekkig beskou word nie, aangesien beter funksionaliteit 'n aanduiding is vandie aanpasbare rol. Die verhoogde krag van die gemuteerde Vpr proteïen dui daarop dat Vpr die patogenisiteit van MIV-1 kan verbeter deur die aanpassing van mutasies.

The research presented in this dissertation integrates data and theory to examine three important topics in biology. In the first chapter, I investigate genetic variation at two loci involved in a genetic incompatibility in the genus Xiphophorus. In this genus, hybrids develop a fatal melanoma due to the interaction of an oncogene and its repressor. Using the genetic variation data from each locus, I fit evolutionary models to test for coevolution between the oncogene and the repressor. The results of this study suggest that the evolutionary trajectory of a microsatellite element in the proximal promoter of the repressor locus is affected by the presence of the oncogene. This study significantly advances our understanding of how loci involved in both a genetic incompatibility and a genetically determined cancer evolve. Chapter two addresses the role polyploidy, or whole genome duplication, has played in generating flowering plant diversity. The question of whether polyploidy events facilitate diversification has received considerable attention among plant and evolutionary biologists. To address this question, I estimated the speciation and genome duplication rates for 60 genera of flowering plants. The results suggest that diploids, as opposed to polyploids, generate more species diversity. This study represents the broadest comparative analysis to date of the effect of polyploidy on flowering plant diversity. In the final chapter, I develop a computational method for designing disease surveillance networks. The method is a data-driven, geographic optimization of surveillance sites. Networks constructed using this method are predicted to significantly outperform existing networks, in terms of information quality, efficiency, and robustness. This work involved the coordinated efforts of researchers in biology, epidemiology, and operations research with public health decision makers. Together, the results of this dissertation demonstrate the utility of applying quantitative theory and statistical methods to data in order to address complex, biological processes. / text

Chez les eucaryotes, la voie de protéolyse Ub/ protéasome 26S est responsable de la dégradation sélective de la plupart des protéines intracellulaires. Cette dégradation par le protéasome 26S est initiée par une polyubiquitination de la protéine réalisée grâce à l’action d’une cascade enzymatique impliquant 3 types d'enzymes nommées « ubiquitin-activating enzyme » (E1), « ubiquitin-conjugating enzyme » (E2) et « ubiquitin-protein ligase » (E3). Il existe différentes classes d’ubiquitines ligases (E3), parmi lesquelles la plus connue est le complexe SCF (Skp1-Cullin-F-box). La protéine SKP1 fixe à la fois la Culline et la F-box qui va reconnaitre spécifiquement la protéine cible. Contrairement aux protistes, les champignons et certains vertébrés qui possèdent un unique gène SKP1 fonctionnel, de nombreux animaux et espèces de plantes présentent plusieurs SKP1 homologues. Vingt et un et trente deux gènes SKP1 ont été décrits respectivement chez Arabidopsis thaliana et Oryza sativa. En dépit de l’importance du complexe SCF, chez le riz, peu de travaux décrivent les interactions entre les dizaines de protéines « SKP1-like » et les centaines de protéines F-box. Dans un premier temps, nous avons collecté et analysé les séquences de 288 gènes « SKP1-like » appartenant à 17 espèces, dont la mousse Physcomitrella patens, cinq monocotylédones et 11 eudicotylédones. Les analyses structurales et phylogénétiques de ces gènes indiquent qu’ils peuvent être divisés en différentes sous-familles. Nos analyses ont montré qu’OSK1 et OSK20 chez le riz constituent une classe de gènes SKP1 à intron unique conservé. Dans un deuxième temps, nous avons étudié le profil d’expression des gènes « SKP1-like » chez le riz. Notre investigation sur le nombre d’EST a montré que les gènes OSK1 et OSK20 sont les plus largement représentés dans les bases de données EST publiques. La méta-analyse de l’expression des gènes « SKP1-like » chez le riz, indique que les gènes OSK présentent des profils d'expression hétérogènes selon les tissus et les conditions physiologiques. Les résultats des intearctions protéine-protéine en double hybride ont révélé que les protéines OSK présentent différentes capacités d’interactions avec les protéines F-box. Cependant, OSK1 et OSK20 semblent interagir avec la plupart des protéines F-box testées. Les études de localisation subcellulaire ont indiqué que OSK1 et OSK20 sont des protéines nucléaires et cytosoliques. En se basant sur les divers résultats obtenus dans ce travail, nous pouvons suggérer que chez le riz, les gènes OSK1 et OSK20 sont fonctionnellement équivalents aux gènes ASK1 et ASK2 chez Arabidopsis thaliana. Nous pouvons également proposer les équivalents de ces gènes chez les autres espèces végétales dont le génome a été séquencé. / In eukaryotes, the ubiquitin Ub/26S proteasome pathway is responsible for the selective degradation of most intracellular proteins. This cellular process is initiated by protein polyubiquitination mediated by a three-step cascade involving: an ubiquitin-activating enzyme (E1), an ubiquitin-conjugating enzyme (E2) and an ubiquitin-protein ligase (E3). The E3 ubiquitin ligases contain several classes, among which the best-known are Skp1-Cullin-F-box (SCF) complexes. The SKP1 protein binds both Cullin and F-box which recognizes specifically the target proteins. Whereas protists, fungi and some vertebrates have a single functional SKP1 gene, many animal and plant species possess multiple SKP1 homologues. Twenty one and thirty-two SKP1-related genes have been described respectively in the Arabidopsis and Oryza sativa genome. Despite the importance of the SCF complex, there have been a few reports of systematic surveys of interactions between the dozens of SKP1-like proteins and the hundreds of F-box proteins in rice. In a first step, we retrieved and analyzed 288 SKP1-like genes belonging to 17 species including the moss Physcomitrella patens, five monocots and 11 eudicots. Structural and phylogenetic analysis of rice OSK genes and other plant SKP1-like genes have indicated that the different members of the plant SKP1 can be split into different subfamily. Our analyses indicated that OSK1 and OSK20 belong to a class of SKP1 genes that contain one intron at a conserved position. In a second step, we studied expression profiles of the rice Skp1-like genes. Our EST survey indicated that OSK1 and OSK20 are the most widely represented genes in public EST databases. Meta-analysis of the expression of rice SKP1-like genes indicated that OSK genes exhibit an expression profile that was heterogeneous in terms of tissues, conditions and overall intensity. Yeast two-hybrid results revealed that OSK proteins display a differing ability to interact with F-box proteins. However, OSK1 and OSK20 seemed to interact with most F-box proteins tested. Subcellular localization studies indicated that OSK1 and OSK20 are nuclear and cytosolic proteins. Based on the results obtained in this study, we can suggest that rice OSK1 and OSK20 are likely to have similar functions as do the Arabidopsis ASK1 and ASK2 genes. Similarly, we suggest a list of functional equivalent in the other sequenced plant genomes.

Dans le cadre de cette thèse nous nous sommes intéressés à l'étude de l'évolution et de la variabilité génétique de la famille des butyrophilines (BTN), des récepteurs de la superfamille des immunoglobulines impliqués dans la régulation de la réponse immunitaire. Par une étude phylogénétique approfondie nous avons caractérisé chez les mammifères 14 groupes phylogénétiques résultant d'une série de duplications à partir de huit gènes ancestraux à la base des thériens. Par la suite, nous avons étudié l'évolution des BTN de la région CMH chez les primates et leur variabilité génétique dans les populations humaines par une analyse minutieuse des données de séquençage générées du projet 1000 Genomes pour plus de 1600 individus à travers le monde. Nous avons montré que l'évolution du gène BTNL2 est marquée par une pression de sélection positive diversifiante chez les mammifères qui est accompagnée chez les hominoïdes d'un niveau de polymorphisme élevé induisant la formation de variants tronqués de BTNL2. Chez l'homme, quatre lignages d'allèles ont été identifiés. Ils ont été maintenus à des fréquences intermédiaires par une forte sélection balancée. D'autre part, l'analyse phylogénétique détaillée du groupe BTN3 (BTN3A1, 3A2 et 3A3) a montré la présence d'une évolution concertée, caractérisée par une homogénéisation forte et récurrente de la région codant pour le peptide signale et le domaine IgV chez les hominoïdes, au cours de laquelle les séquences de 3A1 et 3A3 sont remplacées par la séquence de 3A2. Chez l'homme, ces gènes sont polymorphismes important avec plus de 46 allèles chacun, mais avec la présence d'une homogénéisation extrême des séquences du domaine IgV / In this thesis we were interested in studying the evolution and the genetic variability of the butyrophilin family (BTN), a family of immune receptors belonging to the immunoglobulin superfamily implicated in the regulation of immune response. Through a thorough phylogenetic study of the family we characterized 14 phylogenetic groups in mammals resulting from a series of duplications from eight ancestral genes at the base of therian. Thereafter, we studied the evolution of the BTN of the MHC region and their genetic variability in human populations by a careful analysis of sequencing data generated by the consortium 1000 Genomes for more than 1,600 individuals representing 26 populations worldwide. We have shown that the evolution of BTNL2 gene is marked by a positive diversifying selection in placental mammals. This selection pressure is accompanied in hominoids of a high level of polymorphism inducing the formation of truncated BTNL2 variants. In humans this high level of polymorphism results in the presence of four ancient allele lineages that are maintained at intermediate frequencies by a strong balancing selection. On the other hand, a detailed phylogenetic analysis of BTN3 group (BTN3A1, 3A2 and 3A3) showed that these genes evolve in hominoids in a concerted manner characterized by a strong and recurrent homogenization of the regions encoding for the peptide signal and the IgV domain in which the 3A1 and 3A3 sequences are replaced by the 3A2 sequence. In humans these genes are polymorphic with over 46 alleles each, but with the presence of extreme homogenization of IgV domain sequences

A comparação de genomas, genes ou até sequências de nucleotídeos não condificantes é uma importante tarefa na qual a bioinformática pode ser aplicada, uma vez que ela auxiliar em diversas atividades, por exemplo, análises filogenéticas. Análise filogenética, por sua vez, busca analisar a relação evolutiva de cada espécie, considerando suas características genéticas. Esses processos e as técnicas que os implementam se baseiam em sequências de nucleotídeos sequenciadas e armazenadas em bancos de dados de genomas públicos. Com análise filogenética também é possível identificar possíveis origens de um gene. Essa tarefa é de grande importância, pois auxilia na identificação da origem de genes patogênicos, podendo auxiliar no combate e prevenção do surgimento de doenças. Um problema potencial dessas sequências é a possibilidade de haver erros nas anotações (marcações de sequências como genes). Esses erros são pouco explorados por pesquisadores atualmente. Outro tema pouco explorado é a análise filogenética de genes exclusivos, que são genes que se manifestam em apenas uma espécie, considerando um grupo de espécies próximas. A identificação de genes exclusivos de alguma espécie pode servir para a correta identificação de, por exemplo, a espécie que causa uma doença, de forma a permitir o uso do tratamento mais específico e adequado. A importância da descoberta de filogenias de genes exclusivos e a dificuldade de garantir a consistência nas anotações genéticas motivaram este trabalho, que teve como objetivo implementar ferramentas para interpretar dados de comparação genética, identificando potenciais erros em anotação de genes exclusivos e criando estratégias para identificar a origem desses genes. As origens de genes exclusivos exploradas neste trabalho envolvem a possibilidade dos genes exclusivos terem derivado de outras famílias de genes do próprio organismo, ou, os genes exclusivos se diferenciaram muito dos genes ancestrais. Essas hipóteses, juntamente com a hipótese da existência de erros de anotação, foram exploradas em experimentos utilizando as ferramentas desenvolvidas. Os experimentos visaram a analisar a aplicabilidade da estratégia desenvolvida. Foram utilizados genomas de bactérias do gênero Xanthomonas, que contém um grande grupo de bactérias que causam doenças em plantas. Os resultados obtidos demonstram que existe uma quantidade considerável de potenciais erros de anotação nos genomas considerados, provando a hipótese de que a inconsistência nas anotações genômicas possui grande influência para a dificuldade na identificação de filogenias (tanto de genes exclusivos como para não exclusivos). Os resultados também demonstraram que boa parte dos genes exclusivos possivelmente se originaram de outras famílias de genes do próprio genoma. Ou ainda, que esses genes sofreram modificações em relação aos genes ancestrais, mas ainda possuem certas semelhanças com sequências de nucleotídeos que não codificam genes em outras espécies mais distantes. Por fim, a estratégia desenvolvida se mostrou útil na análise filogenética das bactérias estudadas, sendo este um forte indício de que a mesma abordagem pode ser utilizada para problemas similares com outras espécies de seres vivos / Comparison of genomes, genes or even non-coding nucleotide sequences is an important task in which bioinformatics can be applied, since it allows the application of phylogenetic analyses. Phylogenetic analysis, in its turn, seeks to analyze the evolutionary relation of each species, considering its genetic characteristics. These processes and the techniques that implement them are based on nucleotide sequences sequenced and stores in databases of public genomes. With phylogenetic analysis it is also possible to identify possible origins of a gene. This task has a great importance, because it allows the identification of the origin of pathogenic genes, which may help to combat or prevent deseases. A potencial problem of these sequences is the possibility of having annotation errors (sequences marking as genes). These errors are little explored by researchers nowadays. Another unexplored topic is the phylogenetic analysis of exclusive genes, which are genes thaht manifest in only one species, considering a group of nearby species. The identification of exclusive genes of a species may serve to correctly identify, for example, a desease, in order to allow the use of a more especific and appropriate treatment. The importance of discovering phylogenies of exclusive genes and the difficulty of guaranteeing the consistency of genetic annotations motivated this work, whose objective was to implement tools to interpret data of genetic comparison, identifying annotation errors in exclusive genes and creating strategies to identify the origin of these genes.The origins of exclusive genes explored in this work involve the possibility of the exclusive genes have derived of other gene families of the organism itself, or, the exclusive genes differed a lot from the ancestral genes. Theses hypotheses, with the hypotesis of the existance of annotation errors, were explored in experiments using the developed tools. The experiments aimed to analyse the applicability of the developed strategy. Genomes of bacteria of the genus Xanthomonas were used, which contains a large group of bacteria that cause diseases in plants. The results show that there is a considerable amount of annotation errors on the genomes, proving the hypothesis that the inconsistency in genomic annotations has a great influence on the difficulty in identifying phylogenies (both exclusive and non-exclusive genes). The results also show that much of exclusive genes possibly originated from other gene families of the genome itself. Furthermore, these genes may have sufferedmodifications in relation to the ancestral genes, but still have certain similarities with nucleotide sequences that don\'t encode genes in other more distant species. Finally, the strategy developed proved useful on phylogenetic analysis of the studied bacteria, which is a strong indication that the same approach can be used for similar problems with other species of living beings

O gênero Persephona Leach, 1817 é restrito a América e é constituído por dez espécies com ocorrência no Atlântico Ocidental e Pacífico Oriental, estando inserido na subfamília Ebaliinae, a qual não se encontra taxonomicamente bem estabelecida. Ao longo dos anos, este gênero foi alocado em diferentes subfamílias e sua classificação é mal definida. Além disso, existem chaves de identificação que não permitem a correta identificação das espécies dentro do gênero. Estas infomações são indicativos de uma forte necessidade de estudos enfocando Persephona, os quais podem fornecer uma melhor compreensão sobre a história evolutiva do gênero. Neste contexto, o presente estudo pretendeu realizar uma ampla revisão taxonômica do gênero Persephona, incluindo caracteres que possuem grande variabilidade dentro do gênero (número e tamanho dos espinhos, quelípodos, etc), caracteres tradicionalmente utilizados na diagnose das espécies, além de outros selecionados a partir do presente estudo (gonópodos, coloração, etc), além de incluir pela primeira vez para o gênero, análises de dados moleculares. Dois genes mitocondriais, o 16S rRNA e o Citocromo Oxidase I (COI) foram utilizados como marcadores. As análises morfológicas revelaram uma ausência de diferenças entre algumas espécies propostas para o gênero Persephona, as quais foram corroboradas pelas análises moleculares. Desta forma, são propostas modificações a respeito da taxonomia de Persephona: P. finneganae é um sinônimo júnior de P. lichtensteinii. O nome P. crinita é valido apenas para os espécimes de ocorrência no Golfo do México; os espécimes de P. mediterranea com ocorrência no Golfo do México, correspondem a P. aquilonaris e aqueles com ocorrência no Caribe e Atlântico Sul, correspondem a P. mediterranea e além do exposto, Iliacantha hancocki é um sinônimo júnior de P. subovata. / The genus Persephona Leach, 1817 is restricted to America and consists of ten species occurring in the Western Atlantic and Eastern Pacific. It belongs to the subfamily Ebaliinae, which is not taxonomically well established. Over the years, Persephona was placed in different subfamilies and its classification is still poorly defined. Also, existing identification keys do not allow a correct classification of the species within the genus. These informations are indicatives of a strong need of studies focusing on Persephona, which can provide a better understanding concerning its evolutionary history. In this context, the present study intends to undertake a broad taxonomic revision of the genus Persephona, including characters possessing great variability within the genus (number and size of the spines, cheliped, etc.), characters traditionally used in the diagnosis of the species, and others selected from the present study (gonopod, coloration, etc.), including for the first time for the genus, analyses of molecular data. As guides for the molecular analyses, two mitochondrial genes, the 16S rRNA and the Cytochrome Oxidase I (COI) were used as markers. The morphological analyses revealed an absence of differences among some species proposed for the genus Persephona, wich were corroborated by molecular and phylogenetic analysis. In this way, is propose modifications regarding Persephona taxonomy: P. finneganae is a junior synonym of P. lichtensteinii: the name P. crinita is valid only for specimens occurring in the Gulf of Mexico; the specimens of P. mediterranea with occurence in the Gulf of Mexico, correspond to P. aquilonaris and those with occurence in the Caribbean and South Atlantic correspond to P. mediterranea, moreover I. hancocki is a junior synonym of P. subovata.

Este trabalho avaliou as relações de parentesco entre as abelhas corbiculadas (Apini) utilizando a evidência total disponível: dados morfométricos tradicionais, dados de morfometria geométrica, dados morfológicos, dados comportamentais e dados moleculares. Fontes que historicamente se mostraram incongruentes. Os problemas metodológicos que cada fonte de caracteres oferece foram investigados e corrigidos na análise filogenética de evidencia total. Todos os dados foram analisados com métodos de parcimônia. Vinte e quatro espécies de Apini e quatro espécies dos grupos externos foram analisadas. As análises filogenéticas de onze medidas corporais tradicionais sugeriram grande interferência do tamanho corporal das espécies nos resultados. Ao corrigir esse efeito do tamanho, os dados morfométricos puderam ser utilizados como caracteres filogenéticos confiáveis. O caráter obtido a partir da morfometria geométrica foi altamente convergente na análise filogenética, apesar da relação entre a forma da asa e do tamanho do corpo das espécies aparentemente terem uma restrição filogenética. As análises dos dados moleculares sugeriram a interferência da escolha dos grupos externos nos resultados, diferentes hipóteses filogenéticas surgiram quando se incluiram duas especies mais distantes de Apini nos grupos externos. Com os grupos externos mais distantes, o suporte dos clados se mostrou constante e maior para os clados mais abrangentes. Porém, os dados moleculares se mantiveram incongruentes com os caracteres morfológicos, morfométricos tradicionais e comportamentais analisados. Em contraste, os dados morfológicos e comportamentais não foram afetados pela escolha dos grupos externos, Euglossina se manteve como um grupo parafiletico segundo esses caracteres. Finalmente, a hipótese filogenética proposta nesse trabalho para o grupo das abelhas corbiculadas apoia a monofilia da tribo Apini, assim como das subtribos Euglossina, Apina, Bombina e Meliponina. A hipótese (Euglossina + (Bombina + (Apina + Meliponina))) é revalidada. Em consequência, a origem única da eussocialidade dentro de Apini é sustentada. / This work evaluated the relationship between corbiculate Apidae using the total evidence available: traditional morphometric data, geometric morphometric data, morphological data, behavioral data and molecular data. These characters historically were incongruent. Methodological problems of each source of character were investigated and corrected in the phylogenetic analysis of the total evidence. The methodological problems were searched for each source of characters. All data are analyzed with parsimony methods. Twenty- four species of Apini and four outgroup species were analyzed. Phylogenetic analysis of eleven traditional body measurements suggested significant interference with body size of the species in the results, to correct this size effect morphometric data can be used as reliable phylogenetic characters. The character obtained from geometric morphometric was highly convergent in the phylogenetic analysis, despite the apparent phylogenetic constraint observed on relationship between the wing shape and body size of the species. Analyses of molecular data suggested the interference of the choice of outgroup in the results, different phylogenetic hypotheses emerged when include two species more distant of Apini in the outgroup. With the most distant outgroup, the support of the clades showed constant and higher for most comprehensive clades. However, the molecular data remained incongruent with traditional morphological and behavioral, morphometric characters analyzed. In contrast, morphological and behavioral data were not affected by the choice of outgroup, Euglossina remained as a paraphyletic group according to these characters. Finally, the phylogenetic hypothesis proposed for the corbiculate Apidae supports the monophyly of the tribe Apini, Euglossina Apina, Bombina and Meliponina. The hypothesis (Euglossina + (Bombina + (Apina + Meliponina))) is revalidated. Consequently, a single origin of eussocialidade within Apini is sustained.