Myeloid leukemias include malignant diseases characterized by clonal expansion of the myeloid cell lineage. While in case of chronic myeloid leukemia (CML), the main cause of the disease has already been identified - t(9;22) and the aktivity of the fusion product of the translocation BCR-ABL, acute myeloid leukemia (AML) has been associated with plenty of different translocations and mutations. The aim of this work was to contribute to the improvement of monitoring of patients with myeloid leukemias via detailed study of the panleukemic marker Wilms tumor gene 1 (wt1) expression. Prognostic value of wt1 expression has been proved for AML patients, however, it has not yet been confirmed for CML patients. Expression of different wt1 variants (more then 36 protein products) is known very poorly in both, AML and CML as well as in normal hematopoiesis. Most of the study is focused on CML, only limited parts are dedicated to AML. In the first part of the work, we clearly proved prognostic value of total wt1 mRNA expression for CML patients. Statistical evaluations revealed critical wt1 values which enable to specify prognosis of patients responding non-optimally to imatinib. Bcr-abl looses much of its prognostic value in these patients. Further, we have designed and optimized PCRs for selected wt1...

Thesis advisor: Matthew S. Rutledge / In the past several decades, saving for retirement has significantly changed, with the large replacement of Defined Contribution for Defined Benefit plans, as well as the unreliability of Social Security given the aging population. This paper analyzes retirement wealth across three generational cohorts—Baby Boomers (1946-1964), Gen Xers (1965-1980), and Millennials (1981-2000)—in order to compare preparedness and determine whether or not younger cohorts have compensated for the future unreliability of other traditional retirement income sources. The results suggest that levels of retirement wealth do not significantly differ across cohorts at all age profiles. Therefore, younger generational cohorts have not increased the amount of personal saving in order to maintain their pre-retirement standards of living throughout retirement. These results indicate that a change in saving structure and policy may be necessary to ensure that younger cohorts retire out of poverty. / Thesis (BA) — Boston College, 2017. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Arts and Sciences Honors Program. / Discipline: Economics.

Thesis advisor: Gabor T. Marth / During the last few years, numerous new sequencing technologies have emerged that require tools that can process large amounts of read data quickly and accurately. Regardless of the downstream methods used, reference-guided aligners are at the heart of all next-generation analysis studies. I have developed a general reference-guided aligner, MOSAIK, to support all current sequencing technologies (Roche 454, Illumina, Applied Biosystems SOLiD, Helicos, and Sanger capillary). The calibrated alignment qualities calculated by MOSAIK allow the user to fine-tune the alignment accuracy for a given study. MOSAIK is a highly configurable and easy-to-use suite of alignment tools that is used in hundreds of labs worldwide. MOSAIK is an integral part of our genetic variant discovery pipeline. From SNP and short-INDEL discovery to structural variation discovery, alignment accuracy is an essential requirement and enables our downstream analyses to provide accurate calls. In this thesis, I present three major studies that were formative during the development of MOSAIK and our analysis pipeline. In addition, I present a novel algorithm that identifies mobile element insertions (non-LTR retrotransposons) in the human genome using split-read alignments in MOSAIK. This algorithm has a low false discovery rate (4.4 %) and enabled our group to be the first to determine the number of mobile elements that differentially occur between any two individuals. / Thesis (PhD) — Boston College, 2010. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Biology.

Made available in DSpace on 2015-04-14T13:55:14Z (GMT). No. of bitstreams: 1 387905.pdf: 630912 bytes, checksum: 5c11a94965c50eee0f374f0f6d6200ff (MD5) Previous issue date: 2007-01-08 / O presente trabalho aborda a quest?o da manipula??o gen?tica, especialmente a clonagem e o Diagn?stico Geral de Pr?-Implementa??o de Embri?es a partir de suas implica??es para a autocompreens?o do ser humano. Para tanto, as perspectivas de Hans Jonas, Jurgen Habermas, Michel Foucault e Giorgio Agamben ser?o consideradas, propondo uma leitura complementar destes autores que indica para um limite da pesquisa biom?dica. Tal limite ser? estabelecido a partir de uma perspectiva antropol?gica, que sustenta na diferencia??o entre a tomada biol?gica do homem, enquanto mero vivente, e na considera??o deste enquanto fen?meno espec?fico que ocorre em uma cesura d a vida nua para uma vida politicamente relevante

Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-05-12T17:02:20Z No. of bitstreams: 1 DIS_JULIA_DWORAKOWSKI_EMERIM_COMPLETO.pdf: 1877908 bytes, checksum: 2a3d9dd67d62d1577dfa5b5e156dff40 (MD5) / Made available in DSpace on 2017-05-12T17:02:20Z (GMT). No. of bitstreams: 1 DIS_JULIA_DWORAKOWSKI_EMERIM_COMPLETO.pdf: 1877908 bytes, checksum: 2a3d9dd67d62d1577dfa5b5e156dff40 (MD5) Previous issue date: 2016-09-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Currently there are seven recognized reproductive stocks (A-G) of humpback whales (Megaptera novaeangliae) in the southern hemisphere. The breeding stock 'A' spreads along the Brazilian coast (between 5 ? and 23 ? S) and the Abrolhos Bank- BA is the main breeding area of the Southwest Atlantic Ocean. During the commercial whaling period (early 20th century) the breeding stock ?A? had reached nearly of 2% of its historical size. Recent researches, using different techniques to study the demographic history, have found different values for recent and historical abundance for this population. The knowledge about population size at specific times and its dynamics during time is very important to draw conservations strategies. Here we sequenced a ddRADseq library of 25 DNA samples extracted from tissues of individuals from the Brazilian humpback whales population. The data suggests absence of population structure in the population. The analysis with 5145 locus with migrate-n estimated the genetic diversity of the population as 0.00237 in per site, indicating an effective size of approximately 40,000 and a census size ~140,000. The ABC approach (Approximate Bayesian Computation), used to test different demographic scenarios related to the commercial whaling period, supported a constant population scenario (<10 generations) (against scenarios with population changes in this period) corroborating previous studies using microsatellites and a few nuclear loci. The Ne estimated in the constant scenario was similar to that obtained with the migrate-n method. Finally, the skyline plot obtained with the migrate-n suggests an increase in the effective size of more than an order of magnitude extending for hundreds of thousands of generation in the past. This very long time frame suggests that this estimate may actually reflects the population size of a metapopulation covering the entire Southern Hemisphere or even entire species, a hypothesis that needs to be tested with the addition of other populations and appropriate demographic scenarios. / Atualmente s?o reconhecidos sete estoques reprodutivos (A-G) de baleias jubarte (Megaptera novaeangliae) no hemisf?rio sul. O estoque reprodutivo ?A? estende-se ao longo costa brasileira (entre 5? e 23? S) sendo o Banco de Abrolhos-BA a principal ?rea de reprodu??o do oceano atl?ntico sul para a esp?cie. Durante o per?odo de ca?a baleeira comercial (in?cio do s?culo XX) sugere-se que esse estoque tenha sofrido um grande impacto populacional chegando a aproximadamente 2% do seu tamanho original. Pesquisas recentes, utilizando diferentes t?cnicas para estudo da hist?ria demogr?fica, t?m apresentado controv?rsias acerca dos valores de abund?ncia recente e hist?rico para essa popula??o. Para o delineamento de estrat?gias de conserva??o ? de grande import?ncia o conhecimento a diversidade gen?tica e as poss?veis flutua??es populacionais ao longo do tempo e em determinados per?odos. No presente estudo fez-se o sequenciamento de 25 amostras de DNA extra?das de tecido de indiv?duos da popula??o Brasileira de baleias jubarte, atrav?s da constru??o de bibliotecas de ddRADseq e sequenciamento de nova gera??o. Os dados evidenciam a aus?ncia de estrutura??o populacional na popula??o. A an?lise com 5145 locos com o migrate-n estimou a diversidade gen?tica desta popula??o em 0.00237 por s?tio, que indica um tamanho efetivo de aproximadamente 40.000 e tamanho censit?rio de ~140.000. A abordagem de ABC (Approximate Bayesian Computation), usando ~mil locos nucleares, aplicada para testar diferentes cen?rios demogr?ficos relacionados ao per?odo de ca?a apontou para um cen?rio de popula??o recente (<10 gera??es) constante (contra cen?rios com altera??es populacionais neste per?odo) corroborando estudos pr?vios utilizando microssat?lites e poucos loci nucleares. A estimativa para o Ne no cen?rio constante foi semelhante ao obtido com o migrate-n. Por fim, o skyline plot obtido com o migrate-n sugere um aumento do tamanho efetivo de mais de uma ordem de magnitude se estendendo por centenas de milhares de gera??o, o que sugere que esta estimativa pode na verdade refletir o tamanho populacional de uma da metapopula??o abrangendo todo o hemisf?rio sul ou mesmo toda a esp?cie, hip?tese que precisa ser testada com a adi??o de outras popula??es e cen?rios demogr?ficos apropriados.

Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-05-31T18:59:06Z No. of bitstreams: 1 DIS_TIAGO_DANTAS_GERMANO_PARCIAL.pdf: 3157434 bytes, checksum: e8cb6408a2ef3d19385295feb91a7fad (MD5) / Made available in DSpace on 2017-05-31T18:59:06Z (GMT). No. of bitstreams: 1 DIS_TIAGO_DANTAS_GERMANO_PARCIAL.pdf: 3157434 bytes, checksum: e8cb6408a2ef3d19385295feb91a7fad (MD5) Previous issue date: 2017-01-24 / Conselho Nacional de Pesquisa e Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Esta disertaci?n est? compuesta de dos partes: una novela de ficci?n titulada O que Pesa do Norte, y un ensayo preparado a lo largo de la escrita de la obra, titulado Cartograf?a Ficcional. La novela sigue la trayectoria de Ricardo, un personaje que se desplaza desde Jo?o Pessoa hacia S?o Paulo a buscar su hijo Guilherme, que ha desaparecido despu?s de trasladarse a la ciudad con el fin de perseguir el sue?o de ser actor de teatro. La relaci?n entre padre e hijo es presentada desde la revelaci?n de dos ?pocas: el pasado de los personajes, en el que conocemos la convivencia tumultuosa entre los dos, y el presente, en el que el vac?o dejado por el hijo es llenado por el enfrentamiento del padre con una realidad que hasta el momento trat? de evitar. Respecto a la concepci?n y el desarrollo de esta historia, el ensayo registra su itinerario creativo desde la g?nesis de la idea hasta la ejecuci?n, intercalando testimonios del proceso, tales como notas personales y notas de trabajo, reflexiones sobre la literatura y sobre el hacer literario. / Esta disserta??o ? composta por duas partes: um romance de fic??o, intitulado O que Pesa no Norte, e um ensaio elaborado no decorrer da escrita da obra, intitulado Cartografia Ficcional. O romance acompanha a trajet?ria de Ricardo, personagem que viaja de Jo?o Pessoa para S?o Paulo em busca do filho Guilherme, que desapareceu ap?s se mudar para a cidade com o objetivo de perseguir o sonho de ser ator de teatro. A rela??o entre pai e filho se d? a ver a partir do desvelamento de duas temporalidades: o passado dos personagens, no qual conhecemos a conviv?ncia tumultuada entre os dois, e o presente, no qual o vazio deixado pelo filho ? preenchido pelo confrontamento do pai com uma realidade que at? ent?o procurou evitar. Relativo ? concep??o e ao desenvolvimento desta hist?ria, o ensaio registra o seu percurso criativo da g?nese da ideia at? a execu??o, entremeando testemunhos do processo, como notas pessoais e notas de trabalho, a reflex?es sobre a literatura e sobre o fazer liter?rio.

Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-06-30T17:57:27Z No. of bitstreams: 1 TES_ODI_ALEXANDER_ROCHA_DA_SILVA_COMPLETO.pdf: 9409951 bytes, checksum: 7c765ba030fac89b12a17ed9e49a6948 (MD5) / Made available in DSpace on 2017-06-30T17:57:27Z (GMT). No. of bitstreams: 1 TES_ODI_ALEXANDER_ROCHA_DA_SILVA_COMPLETO.pdf: 9409951 bytes, checksum: 7c765ba030fac89b12a17ed9e49a6948 (MD5) Previous issue date: 2017-03-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / This work is dedicated to the study of handwritten notes for classes by Donaldo Sch?ler. The content of these notes focuses on issues related to the plot of the Iliad, especially those related to Song IX of that work. The interest of this study is to reveal the role that these notes for classes had in the making of the published work of Sch?ler Aspectos Estruturais na Il?ada. These notes are part of one of the binders, entitled Iliad II, which features handwritten notes for classes on Homer and his works. These notes were made by Sch?ler when he was a professor at the Federal University of Rio Grande do Sul. From this binder, we chose three pieces as a clipping for analysis. These three pieces belong to the set of discussions corresponding to Song IX of the Iliad. To make easy the reference, the pieces are numbered and classified as follows: Piece 1, which discusses the psychology of the ancient man, Piece 2, which presents a summary of Song IX for didactic purposes and Piece 3, which outlines some reflections on the Phoenix character. The contents of these pieces demonstrate just from their outline the presence of an essayistic thought, marked by questioning, restlessness and reflection. Such thinking, unfolding in more complex reflections such as a thesis and a published essay, reveals through material evidence that, parallel to the classroom, the teacher develops his own essayistic thought, characterized by critical reflections on what he researches and teaches, which is reflected in his scientific production. / Este trabalho dedica-se ao estudo de notas manuscritas para aulas de Donaldo Sch?ler. O conte?do destas notas enfoca quest?es ligadas ao enredo da Il?ada, em especial as relacionadas ao Canto IX da referida obra. O interesse dessa tese consiste em revelar o papel que essas notas para aulas tiveram na feitura da obra Aspectos Estruturais na Il?ada. Essas notas fazem parte de um dos fich?rios, intitulado Il?ada II, que apresenta notas manuscritas para aulas sobre Homero e suas obras. Essas notas foram feitas por Sch?ler quando era docente na Universidade Federal do Rio Grande do Sul. Deste fich?rio, escolhemos tr?s fichas como recorte para an?lise. Tais fichas pertencem ao conjunto de discuss?es correspondentes ao Canto IX da Il?ada?. Para facilitar a refer?ncia, as fichas se apresentam numeradas e classificadas da seguinte maneira: ficha 1, que discute a psicologia do homem antigo, ficha 2, que apresenta um resumo do Canto IX para fins did?ticos e ficha 3, que esbo?a algumas reflex?es sobre o personagem F?nix. O conte?do destas fichas demonstra j? a partir de seu esbo?o a presen?a de um pensamento ensa?stico, marcado por interroga??o, inquieta??o e reflex?o. Tal pensamento, desdobrando- se em reflex?es mais complexas como uma tese e um ensaio publicado, revelam por meio de evid?ncias materiais que, em paralelo ? sala de aula o professor desenvolve um pensamento ensa?stico pr?prio, caracterizado por reflex?es cr?ticas a respeito do que pesquisa e ensina e que se reflete em sua produ??o cient?fica.

Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-06-30T18:31:20Z No. of bitstreams: 1 TES_ANDRE_ZORATTO_GASTALDO_COMPLETO.pdf: 1361129 bytes, checksum: dbc7c8c4f5ab004118129ecf678044b8 (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-06-30T18:31:27Z (GMT) No. of bitstreams: 1 TES_ANDRE_ZORATTO_GASTALDO_COMPLETO.pdf: 1361129 bytes, checksum: dbc7c8c4f5ab004118129ecf678044b8 (MD5) / Made available in DSpace on 2017-06-30T18:31:34Z (GMT). No. of bitstreams: 1 TES_ANDRE_ZORATTO_GASTALDO_COMPLETO.pdf: 1361129 bytes, checksum: dbc7c8c4f5ab004118129ecf678044b8 (MD5) Previous issue date: 2017-03-21 / The evolution in human identification through the study of genetic markers STR (Short Tandem Repeats) induced and propitiated the growth also of animal genetic identification. However, contrary to what occurs in the human domain, animal molecular identification still lacks validation of analysis systems and population studies to be considered reliable to the degree required. Only recently the International Society for Animal Genetics (ISAG) has recommended STR markers suitable for individual discrimination in domestic animal species. Accurate animal genetic identification is sought to provide entities, associations, breeders and owners in general with assurances that their animals are in fact derived from reliable breeders. Only reliable and authentic genealogical records will ensure, for example, efficiency in genetic breeding processes. Even though it is a promising area, there are currently only two options in the market for commercial kits for animal genotyping. But its use has been deferred by specialized laboratories in the field, which end up preparing their own identification panels, using the recommended genetic markers to meet their local demands more specifically. However, if the frequencies of the alleles present in these genetic markers in the study population are not known and the real power of discrimination that they provide is not estimated, the analyzes performed and the results obtained may generate misleading or imprecise interpretations. In the present study, three panels of STR genetic markers were used with all loci recommended by ISAG, capable of identifying equine, bovine and canine individuals. Allelic frequencies and other parameters such as heterozygosity, polymorphism information content, power of exclusion and power of discrimination were obtained from significant samples in breeds present in Rio Grande do Sul (Southern Brazil), Uruguay and Paraguay, to be used in the practice of animal genetics for identification purposes. In addition, comparative population studies within and among breeds were also carried out, in order to evaluate the genetic diversity of the animal populations studied. / O avan?o da identifica??o molecular humana pelo estudo dos marcadores gen?ticos STR (Short Tandem Repeats) induziu e propiciou o crescimento tamb?m da identifica??o gen?tica animal. Contudo, ao contr?rio da ?rea humana, a identifica??o molecular animal ainda carece de valida??es dos sistemas de an?lise e de estudos populacionais para que seja considerada fidedigna no grau que se necessita. Apenas recentemente a ISAG (International Society for Animal Genetics) recomendou marcadores STR adequados para discrimina??o individual em esp?cies de animais dom?sticos. A identifica??o gen?tica animal exata e precisa ? buscada para fornecer, a entidades, associa??es, criadores e propriet?rios em geral, garantias de que seus animais s?o, de fato, oriundos de reprodutores confi?veis. Apenas registros geneal?gicos fidedignos e aut?nticos garantir?o, por exemplo, efici?ncia nos processos de melhoramento gen?tico. Mesmo sendo uma ?rea promissora, neste momento h? somente duas op??es no mercado de kits comerciais para genotipagem animal. Mas seu uso tem sido preterido por laborat?rios do ramo, os quais acabam preparando seus pr?prios pain?is (in house) de identifica??o, utilizando os marcadores gen?ticos recomendados para atender suas demandas locais de forma customizada. Contudo, se n?o forem conhecidas as frequ?ncias dos alelos presentes nestes marcadores gen?ticos na popula??o em estudo e n?o for estimado o real poder de discrimina??o que estes fornecem, as an?lises realizadas e os resultados obtidos poder?o gerar interpreta??es equivocadas ou imprecisas. No presente trabalho, foram utilizados tr?s pain?is de marcadores gen?ticos STR com todos os loci recomendados pela ISAG, capazes de identificar indiv?duos equinos, bovinos e caninos. Frequ?ncias al?licas e outros par?metros como heterozigosidade, conte?do de informa??o de polimorfismo, poder de exclus?o e de discrimina??o foram obtidos a partir de amostras significativas em ra?as presentes no Rio Grande do Sul/Brasil, no Uruguai e no Paraguai, para que sejam usados na pr?tica da gen?tica animal com fins de identifica??o. Al?m disso, estudos populacionais comparativos dentro e entre ra?as tamb?m foram realizados, com o intuito de avaliar a diversidade gen?tica das popula??es animais estudadas.

Submitted by PPG Letras (letraspg@pucrs.br) on 2018-02-06T11:39:42Z No. of bitstreams: 1 Tese_NadjaVoss.pdf: 3725438 bytes, checksum: bfafd5360bdd935c77abbcbb31e2889a (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2018-02-07T13:19:51Z (GMT) No. of bitstreams: 1 Tese_NadjaVoss.pdf: 3725438 bytes, checksum: bfafd5360bdd935c77abbcbb31e2889a (MD5) / Made available in DSpace on 2018-02-07T13:24:31Z (GMT). No. of bitstreams: 1 Tese_NadjaVoss.pdf: 3725438 bytes, checksum: bfafd5360bdd935c77abbcbb31e2889a (MD5) Previous issue date: 2018-01-17 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / This essay, which is the second volume of the thesis, deals with the analysis of the documents of process of the novel Dentro, by my authorship. It is a hybrid novel between literature and visual arts, inscribed in Liberature, a Polish movement where the wholeness of the book is fundamental. No longer is the author's role only the literary text, but all of the questions relating to the object book. In Liberature, images, typography, cover, bookbinding, etc., have as much authorial meaning as the linguistic and, for such, they should be taken care of by the author. This essay also includes the mapping of the Primordial Image ? a concept that I have being theorizing since 2012 ?, a fractal and rhizomatic gear, that is denominator of creation, within this hybrid work. Thus, the process of creating a hybrid, liberatic work that leads to the extreme of Liberature?s concept, encompassing the whole process under a singe person is analyzed. As so how this Primordial Image drives the creation, mainly in a liberatic creation which, as such, does not end with the linguistic, but extendsand unfolds in each gesture. / Este ensaio, segundo volume da tese, traz a an?lise dos documentos de processo da novela Dentro, de autoria pr?pria. Uma novela h?brida entre literatura e artes visuais, inscrita na Libertura, movimento polon?s onde a integralidade do livro ? fundamental. N?o ? mais papel do autor apenas o texto liter?rio, mas sim todas as quest?es acerca do objeto livro. Na Liberatura, imagens, tipografia, capa, formas de encaderna??o, etc., possuem tanta significa??o autoral quanto o lingu?stico e, por tal, devem ficar a encargo do autor. Este ensaio traz ainda o mapeamento da Imagem Primordial ? conceito que venho teorizando desde 2012 ?, uma engrenagem fractal e rizom?tica, denominadora da cria??o, no seio dessa obra h?brida. Assim, ? analisado aqui o processo de cria??o de uma obra h?brida, liber?tica, que leva ao extremo o conceito de Liberatura, abarcando absolutamente todo o processo sob uma ?nica pessoa. E, como essa Imagem Primordial conduz a cria??o, principalmente uma cria??o liber?tica que, por tal, n?o finda com o lingu?stico, mas se estende e descortina em cada gesto.

Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2018-01-31T21:20:36Z No. of bitstreams: 1 Disserta??o_B?rbara_Vers?o Final.pdf: 5176075 bytes, checksum: 01d1c376e06ac1b74f5e854ac3136513 (MD5) / Made available in DSpace on 2018-01-31T21:20:36Z (GMT). No. of bitstreams: 1 Disserta??o_B?rbara_Vers?o Final.pdf: 5176075 bytes, checksum: 01d1c376e06ac1b74f5e854ac3136513 (MD5) Previous issue date: 2017-01-19 / The present work consists in the specific delimitation study of Croton muscicapa M?ll. Arg. and Croton longibracteatus Mart. Gord. & de Luna, belonging to Croton L., one of the biggest genus of Euphorbiaceae. It was analyzed the differentiation and the relations between these two species and associated morphotypes occurring along Espinha?o Range and adjacent areas in Brazil. For this purpose, samples of two species from herbarium were previously analyzed and 11 populations were collected, which correspond to five morphological groups, being used different methods of analysis. Morphotypes were tested by traditional uni and multivariated morphometrics involving 37 vegetative and floral variables. In addition, analyses of structuring and genetic variability using ISSR markers were realized, selecting the eight most variable primers and obtained 116 polymorphic loci. Foliar anatomy and micromorphology data was obtained from representatives of the 11 populations by optical and scanning electronic microscopy, respectively. Based on analyzed samples, it was observed that vegetative characters are much more variable than reproductive ones and are less taxonomically informative in this group. From the genetic point of view, the populations demonstrated high structuring and low variability. These different lines of evidence confirmed four distinct groups, two corresponding to C. muscicapa and C. longibracteatus, restricted to Chapada Diamantina and adjacent areas in Bahia, Brazil. Two new species are proposed (C. aemulus Barbosa & Carn.-Torres and C. graomogolensis Barbosa & Carn.-Torres), endemic to North of Minas Gerais. These species can be separated principally by limb indumentum, quantity and length of glands in the limb margin, length of pistillate and staminate flowers and amount of stamens. Croton aemulus corresponds to a natural hybrid, confirmed by the genetic pool shared between C. longibracteatus and C. graomogolensis. It is presented a recircumscription for C. muscicapa and C. longibracteatus, besides descriptions, key for identification, illustrations, photos, distribution maps and general comments for all species. The four species share anatomical and micromorphological characters, however, differs by the position of stamens, petiole surface, length of glands in the limb margin and quantity of secondary compounds. The two new species are considered as endangered, according to IUCN criteria. / O presente trabalho consiste no estudo de delimita??o espec?fica de Croton muscicapa M?ll. Arg. e Croton longibracteatus Mart. Gord. & de Luna, pertencentes ao g?nero Croton L., um dos maiores de Euphorbiaceae. Foi analisada a diferencia??o e as rela??es entre essas duas esp?cies e morfotipos associados ocorrentes ao longo da Cadeia do Espinha?o e ?reas adjacentes no Brasil. Para isso, foram previamente analisadas amostras das duas esp?cies em herb?rio e coletadas 11 popula??es que correspondem a cinco grupos morfol?gicos, sendo aplicados diferentes m?todos de an?lise. Os morfotipos foram inicialmente testados atrav?s de morfometria tradicional uni e multivariada, envolvendo 37 vari?veis vegetativas e florais. Tamb?m foram realizadas an?lises de estrutura??o e variabilidade gen?tica a partir de marcadores moleculares ISSR, e sendo selecionados os oito primers mais vari?veis e obtidas 116 loci polim?rficos. Dados de anatomia e micromorfologia foliar tamb?m foram obtidos para representantes das 11 popula??es, atrav?s de microscopia ?ptica e microscopia elet?nica de varredura, respectivamente. A partir das amostras analisadas, observou-se que os caracteres vegetativos s?o muito mais vari?veis que os reprodutivos e menos informativos para fins taxon?micos nesse grupo. Do ponto de vista gen?tico, as popula??es demonstraram alta estrutura??o e baixa variabilidade. Atrav?s dessas diferentes linhas de evid?ncia, foram confirmados quatro grupos bastante distintos, dois deles correspondendo a C. muscicapa e C. longibracteatus, restritas ? Chapada Diamantina e ?reas adjacentes, no estado da Bahia, Brasil. Duas novas esp?cies s?o propostas (C. aemulus Barbosa & Carn.-Torres e C. graomogolensis Barbosa & Carn.-Torres), end?micas da regi?o norte de Minas Gerais. Estas esp?cies podem ser separadas especialmente por indumento no limbo, quantidade e comprimento de gl?ndulas na margem do limbo, comprimenro das flores pistiladas e estaminadas e quantidade de estames. Croton aemulus corresponde a um h?brido natural, confirmado pelo pool g?nico compartilhado entre C. longibracteatus e C. graomogolensis. ? apresentada uma recircunscri??o para C. muscicapa e C. longibracteatus, al?m de descri??es, chaves para identifica??o, ilustra??es, fotografias, mapas de distribui??o e coment?rios gerais para todas as esp?cies. Com base nos caracteres anat?micos e micromorfol?gicos, essas quatro esp?cies apresentam alguns caracteres compartilhados, mas diferem pela posi??o dos est?matos, superf?cie do pec?olo, comprimento das gl?ndulas da margem do limbo e a quantidade de compostos secund?rios. As duas novas esp?cies s?o consideradas amea?adas de extin??o, de acordo com os crit?rios da IUCN.