Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2020 ( 2 )

2019 ( 203 )

2018 ( 253 )

2017 ( 259 )

Custom range...

Search Results: 1 - 10 of 156512 matches for " Marcelo B Cioffi "
All listed articles are free for downloading (OA Articles)
Page 1 /156512
Display every page Item
Chromosome spreading of associated transposable elements and ribosomal DNA in the fish Erythrinus erythrinus. Implications for genome change and karyoevolution in fish
Marcelo B Cioffi, Cesar Martins, Luiz AC Bertollo
BMC Evolutionary Biology , 2010, DOI: 10.1186/1471-2148-10-271
Abstract: Conspicuous differences in the distribution of the 5S rDNA and Rex3 non-LTR retrotransposon were found between the two karyomorphs, while no changes in the heterochromatin and 18S rDNA patterns were found between them. Rex3 was interstitially dispersed in most chromosomes. It had a compartmentalized distribution in the centromeric regions of only two acrocentric chromosomes in karyomorph A. In comparison, in karyomorph D, Rex3 was found in 22 acrocentric chromosomes in females and 21 in males. All 5S rDNA sites co-localized with Rex3, suggesting that these are associated in the genome. In addition, the origin of the large metacentric Y chromosome in karyomorph D by centric fusion was highlighted by the presence of internal telomeric sites and 5S rDNA/Rex3 sites on this chromosome.We demonstrated that some repetitive DNAs (5S rDNA, Rex3 retroelement and (TTAGGG)n telomeric repeats) were crucial for the evolutionary divergence inside E. erythrinus. These elements were strongly associated with the karyomorphic evolution of this species. Our results indicate that chromosomal rearrangements and genomic modifications were significant events during the course of evolution of this fish. We detected centric fusions that were associated with the differentiation of the multiple sex chromosomes in karyomorph D, as well as a surprising increase of associated 5S rDNA/Rex3 loci, in contrast to karyomorph A. In this sense, E. erythrinus emerges as an excellent model system for better understanding the evolutionary mechanisms underlying the huge genome diversity in fish. This organism can also contribute to understanding vertebrate genome evolution as a whole.Repetitive DNA sequences include tandemly-arrayed satellites, as well as minisatellites, microsatellites and dispersed repeats such as transposable elements (TEs) [1]. Satellite DNAs are organized as long arrays of head-to-tail linked repeats. TEs are DNA segments capable of integrating into new locations in the genome, and the
Comparative chromosome mapping of repetitive sequences. Implications for genomic evolution in the fish, Hoplias malabaricus
Marcelo B Cioffi, Cesar Martins, Luiz AC Bertollo
BMC Genetics , 2009, DOI: 10.1186/1471-2156-10-34
Abstract: The results showed that several chromosomal markers had conserved location in the four karyomorphs. In addition, some other markers were only conserved in corresponding chromosomes of karyomorphs A-B and C-D. These data therefore reinforced and confirmed the proposed grouping of karyomorphs A-D in Group I and highlight a closer relationship between karyomorphs A-B and C-D. Moreover, the mapping pattern of some markers on some autosomes and on the chromosomes of the XY and X1X2Y systems provided new evidence concerning the possible origin of the sex chromosomes.The in situ investigation of repetitive DNA sequences adds new informative characters useful in comparative genomics at chromosomal level and provides insights into the evolutionary relationships among Hoplias malabaricus karyomorphs.Although usually reported as a single taxonomic entity, Hoplias malabaricus (Characiformes, Erythrinidae) has significant karyotypic diversity and well-defined population differences concerning the diploid number, morphology of chromosomes and sex chromosome systems. Such intraspecific diversity enabled the characterization of seven main karyomorphs (A-G), in which those without differentiated sex chromosome systems (A, C, E and F) show a wider geographical distribution compared to those that have such systems (B, D and G), which highlights the derivative character of the latter [1]. Despite differences in diploid chromosome number and in the presence or absence of differentiated sex chromosome systems, the seven karyomorphs were subdivided into two major groups (I and II) based on general karyotype similarity [1]. Thus, Group I included karyomorphs A-D, while Group II included karyomorphs E-G (Table 1).The karyotype diversity in H. malabaricus indicates the probable occurrence of distinct species, which is reinforced by the sympatry between some karyomorphs, without evidence of gene flow between them [1]. Specifically for karyomorphs A and C, and for karyomorphs A and D, the resu
The Unique Karyotype of Henochilus wheatlandii, a Critically Endangered Fish Living in a Fast-Developing Region in Minas Gerais State, Brazil
Priscilla C. Silva, Udson Santos, Natália M. Travenzoli, Jose C. Zanuncio, Marcelo de B. Cioffi, Jorge A. Dergam
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0042278
Abstract: Henochilus wheatlandii, the only species of this genus, is critically endangered and was considered extinct for over a century. The rediscovery of this fish in 1996 made it possible to study its phylogenetic relationships with other species in the subfamily Bryconinae. The aim of this study was to characterise the karyotype of H. wheatlandii. Standard staining, C-positive heterochromatin and nucleolar organiser region (NOR) banding, chromomycin A3 staining, and fluorescent in situ hybridisation (FISH) using 5S rDNA and 18S rDNA probes were conducted on nineteen specimens collected in the Santo Antonio River, a sub-basin of the Doce River in Ferros municipality, Minas Gerais State, Brazil. Henochilus wheatlandii shared the same diploid number and chromosome morphology as other species of Bryconinae. However, its heterochromatin distribution patterns, NOR localisation, and FISH patterns revealed a cytogenetic profile unique among Neotropical Bryconinae, emphasizing the evolutionary uniqueness of this threatened species.
Cross-species chromosome painting tracks the independent origin of multiple sex chromosomes in two cofamiliar Erythrinidae fishes
Marcelo B Cioffi, Antonio Sánchez, Juan A Marchal, Nadezda Kosyakova, Thomas Liehr, Vladimir Trifonov, Luiz AC Bertollo
BMC Evolutionary Biology , 2011, DOI: 10.1186/1471-2148-11-186
Abstract: Our results yield valuable information regarding the origin and evolution of these sex chromosome systems. Our data indicate that these sex chromosomes evolved independently in these two closed related Erythrinidae species. Different autosomes were first converted into a poorly differentiated XY sex pair in each species, and additional chromosomal rearrangements produced both X1X2Y sex systems that are currently present.Our data provide new insights into the origin and evolution of sex chromosomes, which increases our knowledge about fish sex chromosome evolution.Fluorescence in situ hybridization (FISH) using whole chromosome-specific probes (wcp) is an important cytogenetic tool to study the origin and evolution of sex chromosomes in several organisms [1-8]. The diversity of sex-determining mechanisms, as well as the absence of heteromorphic sex chromosomes in many fish species make this group a useful model to study the evolution of vertebrate sex chromosomes [9,10]. However, research involving chromosome painting in fish is rarely performed because it is difficult to obtain the necessary probes. The few available studies are focused on karyotypic [11,12] and sex chromosome evolution [2,5,7,13-15]. The current literature suggests that a variety of sex-determining mechanisms and sex chromosomes may have evolved independently in different fish species.Erythrinidae is a Neotropical fish family that is characterized by species that have a wide variety of chromosomal forms, as well as a wide range of distinct sex chromosomes. The red wolf fish Erythrinus erythrinus (EER) is karyotypically diverse among different populations, with four currently identified karyomorphs (A to D) [16]. Karyomorph A is characterized by 2n = 54 chromosomes that have very similar karyotypic structures and the absence of heteromorphic sex chromosomes. Karyomorphs B, C and D share an X1X1X2X2/X1X2Y sex chromosome system, but they can differ in the diploid number and chromosomal morphology. Kar
Correction: The key role of repeated DNAs in sex chromosome evolution in two fish species with ZW sex chromosome system
Cioffi Marcelo de Bello,Kejnovsky Eduard,Marquioni Vinicius,Poltronieri Juliana
Molecular Cytogenetics , 2012, DOI: 10.1186/1755-8166-5-42
Sindicalismo brasileiro: história, ideologias, legitimidade e direito
Leandro Cioffi
Espa?o Jurídico : Journal of Law , 2010,
Abstract: Estudo histórico e jurídico sobre a forma o e as transforma es institucionais no sindicalismo brasileiro, com o objetivo de verificar basicamente suas conseqüências no direito sindical, tendo como período em quest o a partir da “República Velha”, passando para o período da “Era Vargas”, o da fase democrática, iniciada na década de 1940, o da ditadura militar a partir da década de 1960, o da Constitui o Federal de 1988, e o período da atual situa o jurídica sobre tendências de reforma sindical e de recentes mudan as legislativas. Palavras-chave: Sindicalismo brasileiro. Legitimidade. Direito do trabalho.
The key role of repeated DNAs in sex chromosome evolution in two fish species with ZW sex chromosome system
Marcelo de Bello Cioffi, Eduard Kejnovsky, Vinicius Marquioni, Juliana Poltronieri, Wagner Franco Molina, Débora Diniz, Luiz Antonio Carlos Bertollo
Molecular Cytogenetics , 2012, DOI: 10.1186/1755-8166-5-28
Chromosomal Mapping of Repetitive DNAs in Triportheus trifurcatus (Characidae, Characiformes): Insights into the Differentiation of the Z and W Chromosomes
Cassia Fernanda Yano, Juliana Poltronieri, Luiz Antonio Carlos Bertollo, Roberto Ferreira Artoni, Thomas Liehr, Marcelo de Bello Cioffi
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0090946
Abstract: Repetitive DNA sequences play an important role in the structural and functional organization of chromosomes, especially in sex chromosome differentiation. The genus Triportheus represents an interesting model for such studies because all of its species analyzed so far contain a ZZ/ZW sex chromosome system. A close relationship has been found between the differentiation of the W chromosome and heterochromatinization, with the involvement of different types of repetitive DNA in this process. This study investigated several aspects of this association in the W chromosome of Triportheus trifurcatus (2n = 52 chromosomes), including the cytogenetic mapping of repetitive DNAs such as telomeric sequences (TTAGGG)n, microsatellites and retrotransposons. A remarkable heterochromatic segment on the W chromosome was observed with a preferential accumulation of (CAC)10, (CAG)10, (CGG)10, (GAA)10 and (TA)15. The retrotransposons Rex1 and Rex3 showed a general distribution pattern in the chromosomes, and Rex6 showed a different distribution on the W chromosome. The telomeric repeat (TTAGGG)n was highly evident in both telomeres of all chromosomes without the occurrence of ITS. Thus, the differentiation of the W chromosome of T. trifurcatus is clearly associated with the formation of heterochromatin and different types of repetitive DNA, suggesting that these elements had a prominent role in this evolutionary process.
Hemominas: aplica??o e impacto do instrumento de auto-avalia??o de 250 pontos do Gespública
Rodrigues, Daniela O. W.;Proietti, Anna B. F. C.;Cioffi, Junia G. M.;
Revista Brasileira de Hematologia e Hemoterapia , 2008, DOI: 10.1590/S1516-84842008000200006
Abstract: the experience of an administration model in hematology and blood transfusion, which transforms administration practices excessively focused on procedures, norms and strategy into approaches based on results that determine the citizens' satisfaction, presents a challenge. the great difficulty in the quality of administration of a public service is to obtain effective results by decreasing or eliminating problems, or by adding benefits and values expected by society. hemominas, aware of the importance of its role as a service provider in a critical and vital area, elaborated strategies to meet a management system based on constitutional and institutional public values and quality principles with defined goals accompanied by a appraisal system. the hemominas foundation works as a network, with administration and technical coordination located in belo horizonte. it has 23 regional units throughout the state of minas gerais. in an effort to obtain a modern a management model focused on results, the hemominas foundation quality control program (pqfh) implemented self-evaluation criteria of excellence in seven of its transfusion units. the 250 score self-evaluation tool was utilized, with external validation and posterior certification and recognition in regards of adequate practices, by the federal ministry of planning and management.
Ultra-som na Avalia o da Doen a Nodular da Tireóide: Experiência de Um Grupo Multidisciplinar
Fonseca Bernardo L.C.,Ferreira Jader B.,Ribeiro Carlos A.,Cioffi Ant?nio Carlos
Arquivos Brasileiros de Endocrinologia & Metabologia , 2002,
Abstract: O objetivo do trabalho foi correlacionar as características ecográficas dos nódulos tireóideos aos achados citológicos, para determinar a importancia da ultra-sonografia na doen a nodular da tireóide. Foram realizadas pun es aspirativas por agulha fina orientadas por ultra-som, após avalia o e classifica o ecográfica de 436 nódulos. Obteve-se celularidade adequada para análise em 401 nódulos (92%), procedendo-se à correla o ecográfico/citológica. A classifica o utilizada permitiu distribuir as características ecográficas de acordo com o risco de malignidade, identificando nódulos Grau III císticos com foco sólido (citologia positiva em 23,8%) e sólidos hipoecóicos (40%) como suspeitos e os Grau IV (95,2%) como altamente suspeitos. Os nódulos Grau II sólidos iso e hiperecóicos (5%) e mistos (1,9%), em acordo com a literatura, foram considerados provavelmente benignos. O ultra-som forneceu auxílio importante à avalia o clínica e determina o da conduta a ser tomada, devendo fazer parte dos protocolos para avalia o inicial e acompanhamento da doen a nodular da tireóide.
Page 1 /156512
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.