Os loricariíneos são Siluriformes altamente derivados e contabilizam cerca de 210 espécies, apresentando uma irradiação adaptativa bem sucedida, tendo representantes na Costa Rica, no Panamá e em toda a América do Sul, e ocorrendo também em ambos os lados dos Andes. Discussões taxonômicas conflituosas são encontradas sobre esta subfamília, envolvendo muitos de seus gêneros, principalmente os mais numerosos, como é o caso de Rineloricaria. O elevado número de espécies (64), a ampla distribuição geográfica e a presença de características diagnósticas válidas para todos os gêneros da subfamília, levam à discussão a proposta de uma subdivisão no gênero Rineloricaria, além de indicar as dificuldades de identificação apresentadas pelo gênero. Em relação às características citogenéticas, Loricariinae apresenta-se como uma subfamília heterogênea e diversificada, com o número diplóide variando de 2n=36 cromossomos a 2n=74 cromossomos. O gênero Rineloricaria contribui intensamente para essa variação, com números cromossômicos variando de 2n=36 a 2n=70 cromossomos. A participação de rearranjos Robertsonianos na evolução cariotípica de Rineloricaria é algo claro, mas evidências que confirmem a ordenação desses eventos não existem. No presente trabalho, técnicas citogenéticas e moleculares foram utilizadas com a finalidade de estabelecer relações evolutivas entre os integrantes da subfamília Loricariinae, em especial do gênero Rineloricaria, entender a evolução cariotípica dessa subfamília e identificar marcadores citogenéticos e moleculares úteis na identificação e descrição de espécies de Rineloricaria. Foram analisados os cromossomos de doze espécies de Loricariinae, pertencentes aos gêneros Harttia, Loricariia, Loricariichthys e Rineloricaria, coletadas na Bacia do Alto Paraná e nas drenagens do Leste brasileiro. Três regiões do genoma mitocondrial (ATPase 6 e 8, Citocromo b e Citocromo c Oxidase I) foram investigadas nessas espécies no presente trabalho. As análises filogenéticas recuperaram o gênero Rineloricaria como um grupo monofilético. Os dados citogenéticos permitiram o estabelecimento de tendências de evolução cromossômica em Loricariinae e no gênero Rineloricaria. O presente trabalho reforça a importância da utilização de diferentes abordagens na realização de estudos taxonômicos e evolutivos, sugerindo uma nova revisão do gênero Rineloricaria que leve em consideração os dados genéticos obtidos. / Loricariinae are Siluriformes highly derivative and account for about 210 species, with a successful adaptive radiation and representatives can be seen in Costa Rica, Panama and throughout South America, and also occurring on both sides of the Andes. Conflicting taxonomic discussions are found on this subfamily, involving many of its genera, especially the most numerous, as Rineloricaria. The high number of species (64), the wide geographic distribution and the presence of valid diagnostic features for all genera of the subfamily, leads to a discussion of a proposed subdivision in the genus Rineloricaria, besides indicating the difficulties of identification presented by the genus. With respect to cytogenetic characteristics, Loricariinae is presented as a heterogeneous and diverse subfamily, varying diploid number of 2n = 36 chromosomes to 2n = 74 chromosomes. The genus Rineloricaria contributes strongly to this variation, with chromosome numbers ranging from 2n = 36 to 2n = 70 chromosomes. The involvement of Robertsonian rearrangements in the karyotype evolution of Rineloricaria is something unclear, but evidences that confirm the ordination of these events does not exist. In this study, cytogenetic and molecular techniques were used in order to establish evolutionary relationships among members of the subfamily Loricariinae, especially the genus Rineloricaria, and also to understand the karyotype evolution of this subfamily and to identify cytogenetic and molecular markers useful in identifying and describing species of Rineloricaria. We analyzed the chromosomes of twelve species of Loricariinae from genera Harttia, Loricariia, Loricariichthys Rineloricaria from the Upper Paraná Basin and the drainages of eastern Brazil. Three regions of the mitochondrial genome (ATPase 6 and 8, Cytochrome b and Cytochrome c Oxidase I) were investigated in these species of this study. The phylogenetic analysis recovered the genus Rineloricaria as a monophyletic group. The cytogenetic data allowed us to establish trends in chromosomal evolution in Loricariinae and in the genus Rineloricaria. The present study underscores the importance of using different approaches in carrying out taxonomic and evolutionary studies, suggesting a further revision of the genus Rineloricaria that takes into account the genetic data obtained.

No description available.

To enhance the scientific utility and practical application of the honey bee genome and assign the linkage groups to specific chromosomes, I identified chromosomes and characterized the karyotype of the sequenced strain DH4 of the honey bee. The primary analysis of the karyotype and ideogram construction was based on banding and Fluorescence In Situ Hybridization (FISH) for rDNA detection. FISH confirmed two locations for the NOR on telomeric regions of chromosomes 6 and 12 plus an additional less frequent signal on chromosome 1, all three of which were confirmed with silver staining (AgNO3). 4’6-diamidino-2phenylindole (DAPI), and CBanding methods were used to construct the primary ideograms that served as a basis to further identify the chromosomes and locate important structures. The primary map was compared with Giemsa banding, AgNO3-banding, Trypsin banding, and R-banding. The karyotype of the honey bee was established as two metacentric chromosomes (1 and 10), two submetacentric with ribosomal organizer (6 and 12), four submetacentric heterochromatic chromosomes (16, 15, 4 and 13), four euchromatic subtelocentric chromosomes (2, 8, 11 and 14) and four acrocentric chromosomes (3, 5, 7 and 9). In situ nick-translation banding methods were used to verify the heterochromatin distribution. The cytogenetic maps of the honey bee karyotype represented in the ideograms were subsequently used to place 35 mapped BACs (Solignac et. al. 2004) of Solignac’s BAC library. As the BACs hybridized to multiple sites, the mapping was based on strength and frequency of the signals. Location and position of the BACs was compared with those published in the different version of Map Viewer of the NCBI and BeeBase web sites. 10 BACs were confirmed with the last version of Map Viewer V4, 12 BACs were mapped based on high frequency and agreement with the earlier version of Map Viewer. 14 BACs were mapped as confirmed based on moderate frequency of the signal and agreement with the last version of MVV, most of these BACs hits as a secondary signal.

The genus Salvia L. is significantly important with regard to both its worldwide distribution and usage areas including food, medical and perfumary industries. In this current study, it is targeted to address the chromosome numbers and karyomorphology of the ten species and one variety of the genus Salvia. All of the eleven taxa examined in this study are economically significant and nine of these are endemic to Turkey. To define the chromosome numbers and karyomorphology of these eleven taxa somatic chromosomes of the each were examined. Mitotic metaphase chromosomes were obtained from root meristems of germinating seeds, which were pre-treated in &amp / #945 / -bromonaphtalene at 4&ordm / C for 16 h, then fixed in Carnoy solution (3 parts of ethanol: 1 parts of glacial acetic acid) at 4&ordm / C for 24h and stored in 70 % ethanol. Fixed root tips were stained in 2 % aceto-orcein and squashed in a drop of 45 % acetic acid. Long arm, short arm, total length of the each chromosomes were measured / relative length, arm ratio, centromeric index of the each chromosome were calculated. Karyogram and haploid idiograms were drawn by computer-aided analysis programme (Bs200pro). A cluster analysis of the karyotype data was carried out to examine karyotype similarity among taxa. Somatic chromosome numbers have been counted as 2n=2x=14 for the endemic taxa S. divaricata Montbret &amp / Aucher, S. euphratica Montbret &amp / Aucher ex Bentham (var. leiocalycina (Rech. fil.) Hedge) and S. recognita Fisch. &amp / Mey. / 2n=2x=14-1B for Salvia rosifolia Sm. / 2n=20 for S. longipedicellata Hedge, S. vermifolia Hedge &amp / Hub.-Mor. and S. yosgadensis Freyn &amp / Bornm. / 2n=2x=22 for S. aethiopis L., S. cilicica Boiss. &amp / Kotschy, S. hypargeia Fisch. &amp / Mey. and 2n=2x=32 for S. napifolia Jacq. respectively. In general, the chromosomes are short with median and submedian centromeres. The current study is essential for being the first report about chromosome numbers and karyomorphology of the six endemic taxa, namely S. divaricata, S. euphratica var. leiocalycina, S. longipedicellata, S. rosifolia, S. vermifolia and S. yosgadensis. Moreover, in spite of the chromosome numbers of S. aethiopis, S. cilicica, S. hypargeia and S. recognita are known, this research is the first study for their karyomorphologies.

The freshwater snail Biomphalaria glabrata is an intermediate host for Schistosoma mansoni parasites, causing one of the most prevalent parasitic infections in mammals, known as schistosomiasis (Bilharzia). Due to its importance in the spread of the disease B. glabrata has been selected for whole genome sequencing and is now a molluscan model organism. In order to aid the sequencing project and to understand the structure and organisation of B. glabrata’s genome at the chromosomal level, a G-banded karyotype has been established. Unlike in any other previous reports, two heteromorphic chromosomes have been identified in the genome of B. glabrata and for the first time snail ideograms have been produced. In addition to characterising the snail chromosomes, a methodology for mapping single copy B. glabrata genes onto these chromosomes has also been established, and 4 genes have successfully been mapped using fluorescence in situ hybridisation. In the relationship between a parasite and a host organism, it is of fundamental importance to understand the basic biology and interfere with the life cycle to reveal how the parasite controls and elicits host gene expression for its own benefit. This study is also directly addressing this aspect of host – parasite interactions by investigating the effects of schistosome infection on the genome and cell nuclei of the host snail B. glabrata. Upon infection with S. mansoni miracidia, genes known to be involved in the host response to the parasite are dramatically relocated within the interphase snail nuclei. These events are in conjunction with the up-regulation of gene expression, indicating a parasite induced nuclear event. Moreover, a differential response between the schistosome-resistant and schistosome-susceptible snails is also reported. This is the first time this has been described in a host – pathogen relationship. The precise organisation of the genome is critical for its correct functioning. The genome is non-randomly organised and this level of organisation is very much influenced by the nuclear architecture. Being a molluscan model organism with the availability of a unique cell line, B. glabrata is a remarkable organism for the studies of nuclear and genome biology. For this reason, in this thesis the snail nuclear architecture was also investigated. For the first time PML bodies, transcription factories, and nuclear myosin 1 beta have been visualised in the snail nuclei. A heat shock system was also developed to study the role of these structures in the snail. Upon heat stimuli gene loci were found to reposition and co-localise with transcription factories, which was in parallel with the up-regulation of gene expression. The mechanism of this genome reorganisation was explored by investigating nuclear motor structures in the snail. By using a motor inhibitor on snail cells, gene repositioning and subsequent expression after heat shock was blocked. This is the first time this has been shown in any organism. Thus, due to the ease of use of the snails with respect to maintenance, handling, and treatments, B. glabrata is making a very useful new model organism to study spatial genomic events.

Submitted by FLAVIA MARCORIN DE OLIVEIRA null (flaviamarcorindeoliveira@gmail.com) on 2016-06-30T18:11:11Z No. of bitstreams: 1 Flávia Marcorin versão final.pdf: 2914788 bytes, checksum: da4eb36add8e9d52d25649b86df175e1 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-07-04T18:08:05Z (GMT) No. of bitstreams: 1 oliveira_fm_me_rcla.pdf: 2914788 bytes, checksum: da4eb36add8e9d52d25649b86df175e1 (MD5) / Made available in DSpace on 2016-07-04T18:08:05Z (GMT). No. of bitstreams: 1 oliveira_fm_me_rcla.pdf: 2914788 bytes, checksum: da4eb36add8e9d52d25649b86df175e1 (MD5) Previous issue date: 2016-06-16 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A família Loricariidae é uma das mais diversificadas da ordem Siluriformes, com espécies distribuídas entre sete subfamílias: Hypoptopomatinae, Loricariinae, Hypostominae, Neoplecostominae, Lithogeninae, Delturinae e Ancistrinae. As espécies do gênero Ancistrus Kner, 1854, pertencem à subfamília Ancistrinae, têm mostrado grande variação cariotípica, além de características interessantes do ponto de vista citogenético como a presença de cromossomos sexuais e polimorfismos cromossômicos. Desta forma o objetivo do presente trabalho foi caracterizar os cromossomos de quatro espécies do gênero Ancistrus (Ancistrus sp. 1 “cupim”, Ancistrus sp. 2 “cupim”, Ancistrus sp. “mutuca” e Ancistrus sp. “soberbo”) pertencentes à bacia do Paraguai utilizando técnicas de citogenética clássica e molecular para melhor compreensão da evolução cariotípica dessas espécies. As espécies estudadas apresentaram número diploide variando de 2n=42 a 2n=54, NOR localizadas em regiões pericentroméricas e terminais, além de heteromorfismo de tamanho dessas regiões (NOR) em um dos homólogos nas quatro espécies estudadas. O bandamento C mostrou presença de pouca heterocromatina com exceção das espécies Ancistrus sp. 2 “cupim” e Ancistrus sp. “soberbo” que apresentaram dois blocos grandes de heterocromatina em um par de cromossomos, tanto nos machos quanto nas fêmeas. Um exemplar fêmea da espécie Ancistrus sp. 1 “cupim” também apresentou um bloco grande de heterocromatina em um dos homólogos do par 7, sendo esses resultados indicativos de provável relação entre esses blocos de heterocromatina e a diferenciação de cromossomos sexuais. Os resultados obtidos pela técnica de FISH utilizando sondas de DNAr 18S e 5S mostraram que o DNAr 18S está localizado na mesma região da NOR, o DNAr 5S está distribuído em quatro e cinco pares cromossômicos e o double FISH não mostrou co-localização desses genes. No entanto as espécies Ancistrus sp. 2 “cupim” e Ancistrus sp. “soberbo” mostraram variação nos resultados com marcações de DNAr em blocos de heterocromatina. O uso de sonda telomérica mostrou marcações nos telômeros dos cromossomos das quatro espécies estudadas e marcação pericentromérica em um par de cromossomos da espécie Ancistrus sp. 2 “cupim”. Nossos resultados evidenciam possíveis rearranjos cromossômicos do tipo fusão cêntrica, contribuindo com a redução do número diploide e inversões pericêntricas e paracêntricas resultando na localização dos sítios de DNAr. / The Loricariidae family is one of the most diversified of the Siluriformes order, with species distributed in seven subfamilies: Hypoptopomatinae, Loricariinae, Hypostominae, Neoplecostominae, Lithogeninae, Delturinae and Ancistrinae. The species of the genus Ancistrus Kner, 1854, belong to the subfamily Ancistrinae, have shown great karyotype variation, and interesting features of the cytogenetic point of view as the presence of sex chromosomes and chromosome polymorphisms. Thus the aim of this study was to characterize the chromosomes of four species of Ancistrus genus (Ancistrus sp. 1 "cupim", Ancistrus sp. 2 "cupim", Ancistrus sp. "mutuca" and Ancistrus sp. "soberbo") belonging to Paraguay basin using techniques of classical and molecular cytogenetics to better understand the karyotype evolution of these species. The species showed diploid number ranging from 2n = 42 to 2n = 54, NOR located in pericentomeric and terminal regions, and these regions size heteromorphism (NOR) in one of the homologous in the four species. The C-banding showed the presence of few heterochromatin with the exception of species Ancistrus sp. 2 "cupim" and Ancistrus sp. "soberbo" that had two large blocks of heterochromatin in a pair of chromosomes in both males and females. An exemplary female of the species Ancistrus sp. 1 "cupim" also presented a large block of heterochromatin in one of the pair of 7 homologous, and these results indicating probable relationship between these heterochromatin blocks and differentiation of sex chromosomes. The results obtained by FISH technique using probes 18S rDNA and 5S showed that the 18S rDNA is located in the same region of NOR, the 5S rDNA is distributed in four and five chromosome pairs and double FISH showed colocalization of these genes. However of Ancistrus species sp. 2 "cupim" and Ancistrus sp. "soberbo" showed variation in results with rDNA markings in heterochromatin blocks. The use of telomeric probe showed markings on the telomeres of the chromosomes of four species studied and pericentromeric marking on a pair of chromosomes of the species Ancistrus sp. 2 "cupim". Our results indicate possible chromosomal rearrangements type fusion centric, contributing to the reduction of the diploid number and pericentric inversions and paracentric resulting in the location of rDNA sites. / FAPESP: 2015/05993-3

Submitted by Liliane Ferreira (ljuvencia30@gmail.com) on 2018-11-30T13:53:38Z No. of bitstreams: 2 Dissertação - Daniella Mota Silva - 2012.pdf: 3271983 bytes, checksum: 99a6d63c282c21b5c3ced5fe6efe4944 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Rejected by Luciana Ferreira (lucgeral@gmail.com), reason: O resumo em português está cortado, olhe no formulário de metadados se está completo. on 2018-12-03T13:12:51Z (GMT) / Submitted by Liliane Ferreira (ljuvencia30@gmail.com) on 2018-12-04T13:07:29Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Daniella Mota Silva - 2012.pdf: 3271983 bytes, checksum: 99a6d63c282c21b5c3ced5fe6efe4944 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-12-05T09:55:21Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Daniella Mota Silva - 2012.pdf: 3271983 bytes, checksum: 99a6d63c282c21b5c3ced5fe6efe4944 (MD5) / Made available in DSpace on 2018-12-05T09:55:21Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Daniella Mota Silva - 2012.pdf: 3271983 bytes, checksum: 99a6d63c282c21b5c3ced5fe6efe4944 (MD5) Previous issue date: 2012-10-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / CyrtopodiumsaintlegerianumRchb. f is an epiphytic species typical of the Midwest, especially in distributed Brazilian Central Plateau, and has a wide geographical distribution in Brazil. It is usually found in the trunks of palm trees, forming large clumps. It has good features for ornamentation, for the beauty and size of its inflorescence, however, are not found in the literature about its conservation, methods for its spread or that could be used in floriculture and landscaping. Thus, this study aimed to establishing protocols for germination asymbiotic effects of phytohormones and acclimatization and characterization of chromosomal species. In 2010, the establishment of micropropagation protocols, capsules were collected in a pasture area in the municipality of Mossâmedes, GO, then the part previously sterilized seeds were separated and tested in a 1% tetrazolium dye.. For cultivation was tested asymbiotic different culture media and then tested after different concentrations and combinations in treatments BAP 16 / ANA, to finally evaluate the acclimatization substrates combined and fertilized with chemical fertilizers and organic. For the karyotype of the species, the plant material is derived from plants grown in vitro in culture medium. We tested four protocols, with differences in enzyme solution for softening the roots, dyes, anti-mitotic concentration of the solution and hydrolysis, and the use of growth regulators for root induction in vitro. All protocols were in common roots pretreated with anti-mitotic 8-hydroxyquinoline (0.002 M) in refrigerator for 24 hours. Then protocols roots were fixed in Carnoy 3:1 for 18 hours the first and second and third and fourth protocol for 24 hours at room temperature. After stored at -20 º C in the same fixative for further analysis (only the fourth protocol). The roots of the protocols were stained with different dyes: hematoxylin, Schiff, acetic orcein and Giemsarespectively.The results of germination was satisfactory in all culture media. For medium supplemented with auxin / cytokinin combined the best concentrations for variable height were 0.2 mg L-1 NAA and BAP without adding control without addition of regulators. The best means to induce large numbers of shoots were 4 mg L-1 BAP and 4 mg L-1 BAP / 0.2 mg L-1 NAA. The number of leaves was rated best in the concentrations of BAP without NAA at concentrations of 1.0, 2.0 and 4.0 mg L-1. The treatments with the highest number of roots were control without added growth regulators at doses of 0.2, 0.5, 1.0 mg L-1 NAA without addition of BAP, as well as the length of roots was favored by the same treatments. The largest number occurred in callus treatment with concentrations of 1.0 mg L-1 BAP without adding ANA. ForcytogeneticsC. saintlegerianum the best protocol was evaluated with the regulator which was obtained metaphases, however chromosomes were condensed, and the number of chromosomes was found to be 2n = 48. cides. / CyrtopodiumsaintlegerianumRchb. f é espécie epífita da região Centro-Oeste, distribuída no Planalto Central brasileiro, e tem ampla distribuição geográfica no Brasil. É encontrada em de troncos de palmeiras, formando grandes touceiras. Possui características para ornamentação, pela beleza de sua inflorescência, contudo não são encontrados na literatura estudos sobre sua conservação ou propagação. Assim, esse trabalho teve como objetivo o estabelecimento de protocolos para germinação assimbiótica, efeitos de fitohormônios, aclimatização e a caracterização cromossômica da espécie. Em 2010, para o estabelecimento de protocolos para a micropropagação, cápsulas foram coletadas em uma área de pastagem no município de Mossâmedes, GO, foram previamente desifestadas em seguida parte das sementes foram separadas e testadas em corante tetrazólio a 1%. Para o cultivo assimbiótico, foram testados diferentes meios de cultura e diferentes concentrações e combinações de BAP/ANA em 16 tratamentos. Foram testados substratos combinados e adubação com fertilizante químico e orgânico para a aclimatização das plântulas. Para o cariótipo da espécie, o material vegetal foi proveniente de plantas cultivadas in vitro em meio de cultura. Foram testados quatro protocolos, com diferenças quanto a solução enzimática para o amolecimento das raízes, os corantes, concentração do antimitótico e solução de hidrólise, e o uso de regulador de crescimento para indução de raízes in vitro. Todos os protocolos tiveram em comum raízespré-tratadas com anti-mitótico 8- hidroxiquinoleína (0,002M) em geladeira durante 24 horas. Em seguida nos protocolos as raízes foram fixadas em Carnoy 3:1 por 18 horas o primeiro e o segundo protocolo e o terceiro e o quarto por 24 horas em temperatura ambiente. Depois estocados a -20ºC no próprio fixador, para posterior análise (apenas o quarto protocolo). As raízes dos protocolos foram coradas com diferentes corantes: hematoxilina, reativo de Schiff, orceína acética e Giemsa respectivamente. A germinação foi satisfatória em todos os meios de cultura. Para o meio suplementado com auxina/citocinina combinadas as melhores concentrações para a variável altura foi 0,2 mg L-1 de ANA sem adição de BAP e o controle sem adição de reguladores. Os melhores meios que induziram grande número de brotações foram 4 mg L-1 de BAP e 4 mg L-1 de BAP / 0,2 mg L-1 de ANA. O número de folhas foi melhor avaliado nas concentrações de BAP sem ANA nas concentrações 1,0; 2,0 e 4,0 mg L-1. Os tratamentos com maior número de raízes foram o controle sem adição de reguladores de crescimento, e nas dosagens de 0,2, 0,5, 1,0 mg L-1 de ANA sem adição de BAP, assim como o comprimento da maior raiz foi favorecido pelos mesmos tratamentos. O maior número de calos se deu no tratamento com concentrações de 1,0 BAP mg L-1 sem adição de ANA. Para a citogenética de C. saintlegerianumo melhor protocolo avaliado foi com regulador no qual foi obtido metáfases, no entanto os cromossomos se encontravam condensados, e o numero de cromossomos encontrado foi de 2n=48.

Os loricariíneos são Siluriformes altamente derivados e contabilizam cerca de 210 espécies, apresentando uma irradiação adaptativa bem sucedida, tendo representantes na Costa Rica, no Panamá e em toda a América do Sul, e ocorrendo também em ambos os lados dos Andes. Discussões taxonômicas conflituosas são encontradas sobre esta subfamília, envolvendo muitos de seus gêneros, principalmente os mais numerosos, como é o caso de Rineloricaria. O elevado número de espécies (64), a ampla distribuição geográfica e a presença de características diagnósticas válidas para todos os gêneros da subfamília, levam à discussão a proposta de uma subdivisão no gênero Rineloricaria, além de indicar as dificuldades de identificação apresentadas pelo gênero. Em relação às características citogenéticas, Loricariinae apresenta-se como uma subfamília heterogênea e diversificada, com o número diplóide variando de 2n=36 cromossomos a 2n=74 cromossomos. O gênero Rineloricaria contribui intensamente para essa variação, com números cromossômicos variando de 2n=36 a 2n=70 cromossomos. A participação de rearranjos Robertsonianos na evolução cariotípica de Rineloricaria é algo claro, mas evidências que confirmem a ordenação desses eventos não existem. No presente trabalho, técnicas citogenéticas e moleculares foram utilizadas com a finalidade de estabelecer relações evolutivas entre os integrantes da subfamília Loricariinae, em especial do gênero Rineloricaria, entender a evolução cariotípica dessa subfamília e identificar marcadores citogenéticos e moleculares úteis na identificação e descrição de espécies de Rineloricaria. Foram analisados os cromossomos de doze espécies de Loricariinae, pertencentes aos gêneros Harttia, Loricariia, Loricariichthys e Rineloricaria, coletadas na Bacia do Alto Paraná e nas drenagens do Leste brasileiro. Três regiões do genoma mitocondrial (ATPase 6 e 8, Citocromo b e Citocromo c Oxidase I) foram investigadas nessas espécies no presente trabalho. As análises filogenéticas recuperaram o gênero Rineloricaria como um grupo monofilético. Os dados citogenéticos permitiram o estabelecimento de tendências de evolução cromossômica em Loricariinae e no gênero Rineloricaria. O presente trabalho reforça a importância da utilização de diferentes abordagens na realização de estudos taxonômicos e evolutivos, sugerindo uma nova revisão do gênero Rineloricaria que leve em consideração os dados genéticos obtidos. / Loricariinae are Siluriformes highly derivative and account for about 210 species, with a successful adaptive radiation and representatives can be seen in Costa Rica, Panama and throughout South America, and also occurring on both sides of the Andes. Conflicting taxonomic discussions are found on this subfamily, involving many of its genera, especially the most numerous, as Rineloricaria. The high number of species (64), the wide geographic distribution and the presence of valid diagnostic features for all genera of the subfamily, leads to a discussion of a proposed subdivision in the genus Rineloricaria, besides indicating the difficulties of identification presented by the genus. With respect to cytogenetic characteristics, Loricariinae is presented as a heterogeneous and diverse subfamily, varying diploid number of 2n = 36 chromosomes to 2n = 74 chromosomes. The genus Rineloricaria contributes strongly to this variation, with chromosome numbers ranging from 2n = 36 to 2n = 70 chromosomes. The involvement of Robertsonian rearrangements in the karyotype evolution of Rineloricaria is something unclear, but evidences that confirm the ordination of these events does not exist. In this study, cytogenetic and molecular techniques were used in order to establish evolutionary relationships among members of the subfamily Loricariinae, especially the genus Rineloricaria, and also to understand the karyotype evolution of this subfamily and to identify cytogenetic and molecular markers useful in identifying and describing species of Rineloricaria. We analyzed the chromosomes of twelve species of Loricariinae from genera Harttia, Loricariia, Loricariichthys Rineloricaria from the Upper Paraná Basin and the drainages of eastern Brazil. Three regions of the mitochondrial genome (ATPase 6 and 8, Cytochrome b and Cytochrome c Oxidase I) were investigated in these species of this study. The phylogenetic analysis recovered the genus Rineloricaria as a monophyletic group. The cytogenetic data allowed us to establish trends in chromosomal evolution in Loricariinae and in the genus Rineloricaria. The present study underscores the importance of using different approaches in carrying out taxonomic and evolutionary studies, suggesting a further revision of the genus Rineloricaria that takes into account the genetic data obtained.

Evolution of sex chromosomes and karyotypes in iguanas (Squamata: Pleurodonta) PhD Thesis Marie Altmanová Abstract This PhD thesis is composed of five published articles and one manuscript, and is focused on the evolution of the sex chromosomes and karyotype of the iguanas (Pleurodonta). Based on our primary research of available data, only male heterogamety (XX/XY) with ancestral karyotype 2n = 36 chromosomes was recorded in iguanas. However, in many species sex chromosomes have not been uncovered by classical cytogenetics, probably due to their homomorphy. The partially-known X chromosome content of Anolis carolinensis allowed us to compare the relative gene doses of X-specific genes between male and female of representatives of all iguana families, and to reveal homologous and well-differentiated sex chromosomes across all iguanas, with the exception of basilisks. Thus, due to the comparable age with sex chromosomes of mammals and birds, the results put into question the importance of endothermy for the formation of stable sex chromosomes. The striking feature of the iguanas is the relatively frequent occurrence of multiple sex chromosomes in their karyotypes. Using the ancestral state analysis of the type of sex chromosomes, it has been found that these multiple sex chromosomes developed at least twelve...

Tetraploidy – the presence of four copies of the haploid chromosome complement – is common in cancer. There is evidence that ~40% of tumors pass through a tetraploid stage at some point during their development, and tetraploid cells injected in mice are more tumorigenic than their diploid counterparts. However, the reason for this increased tumorigenicity of tetraploid cells is not well established. Most routes by which cells may become tetraploid also confer cells with double the number of centrosomes, the small membraneless organelle that organizes the cell's microtubule cytoskeleton and mitotic spindle apparatus. Centrosome number homeostasis is crucial for health, and recent studies have shown inducing extra centrosomes in cells can induce tumor formation in mice. This has led some researchers to propose that the extra centrosomes that arise together with tetraploidy may be the reason that tetraploid cells are more tumorigenic. However, several anecdotal reports have found that tetraploid clones generated and grown in vitro appear to lose their extra centrosomes. Here, I investigate the population dynamics of the loss of extra centrosomes in newly formed tetraploid cells generated via cytokinesis failure. I uncover the mechanism driving the process and build a mathematical model that captures the experimentally observed dynamics. Next, I investigate karyotypic heterogeneity in newly formed tetraploid cells and their counterparts that are grown for 12 days under standard culture conditions and find that karyotypic heterogeneity has increased after 12 days of growth after tetraploidization. The day 12 'evolved' population with increased heterogeneity formed larger colonies in soft agar than newly formed tetraploid cells or diploid parental precursors and karyotype analysis of the largest soft agar colonies revealed recurrent aneuploidies shared by a subset of colonies. Finally, I investigate the effects of different culture conditions - meant to mimic various conditions in the tumor microenvironment - on the evolution of centrosome and chromosome number in newly formed tetraploid cells and identify a small subset of conditions that altered centrosome homeostasis or the fitness of tetraploid cells. / Doctor of Philosophy / The genetic information in cancer cells is often drastically altered compared to normal cells in the body. As one important example of this, the number and structure of chromosomes - the DNA structures that hold the genetic information - is often abnormal in cancer cells. Abnormal chromosome number is closely linked with cancer development, but the details of why this leads to more cancer are not clear. One important kind of chromosome number change is when a cell undergoes incomplete cell division, and the resulting cell acquires double the number of chromosomes compared to a normal cell (known as tetraploidy). Tetraploidy occurs in close to 40% of cancers and is linked with the most aggressive cases. The abnormal cell divisions that cause tetraploidy also lead to other cellular changes. One important change is that tetraploid cells also acquire double the number of the structures that organizes cell division (centrosomes). The centrosome organizes the mitotic spindle, the major apparatus that is responsible for equally distributing chromosomes to two daughter cells during the cell division process. Extra centrosomes in cells are closely linked with cancer and can lead to additionally chromosome number changes. Researchers have believed that the extra centrosomes that are acquired with doubled chromosome number may be the major reason that tetraploid cells are linked to more aggressive cancer. However, recent studies have suggested that tetraploid cells may lose their extra centrosomes, calling into question the details of the relationship between tetraploidy and tumor formation. Here, I use human cells grown in culture to understand how extra centrosomes are lost from tetraploid cells. I find that extra centrosomes in newly formed tetraploid cells promote abnormal 'multipolar' cell divisions, in which chromosomes are segregated unevenly to three or more partitions. Such divisions are often fatal to daughter cells. In some cases, the extra centrosomes can cluster to form bipolar spindles that segregate chromosomes into two equal partitions (as is normal). When forming bipolar spindles, extra centrosomes can cluster asymmetrically (three centrosomes at one pole, one at the other) or symmetrically (two centrosomes at each pole). Tetraploid cells with a normal number of centrosomes emerge when extra centrosomes cluster asymmetrically in a bipolar spindle, yielding one tetraploid daughter cell with a normal number of centrosomes. Such cells have a fitness advantage over cells with extra centrosomes, which over time are very likely to undergo fatal multipolar divisions. Thus, cells with a normal centrosome number 'take over' the population. Next, I investigate the cancer-like properties of tetraploid cells without their extra centrosomes and find that they display increased tumor-like behavior even in the absence of extra centrosomes. Finally, I investigate whether changing the conditions in which cells are grown (in ways meant to mimic different conditions that may be experienced in the body) affects whether tetraploid cells lose their extra centrosomes. We identify a small number of conditions that do influence loss of extra centrosomes. Together, these studies illuminate important details of the relationship between tetraploidy and tumor formation. This work lays the foundation to further explore and understand the relative roles of tetraploidy, extra centrosomes, and tissue environment in cancer.