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1.
Front Microbiol ; 13: 1074382, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36713167

RESUMO

Due to immunosuppressive cancer therapies, cancer patients diagnosed with COVID-19 have a higher chance of developing severe symptoms and present a higher mortality rate in comparison to the general population. Here we show a comparative analysis of the microbiome from naso-oropharyngeal samples of breast cancer patients with respect to SARS-CoV-2 status and identified bacteria associated with symptom severity. Total DNA of naso-oropharyngeal swabs from 74 women with or without breast cancer, positive or negative for SARS-CoV-2 were PCR-amplified for 16S-rDNA V3 and V4 regions and submitted to massive parallel sequencing. Sequencing data were analyzed with QIIME2 and taxonomic identification was performed using the q2-feature-classifier QIIME2 plugin, the Greengenes Database, and amplicon sequence variants (ASV) analysis. A total of 486 different bacteria were identified. No difference was found in taxa diversity between sample groups. Cluster analysis did not group the samples concerning SARS-CoV-2 status, breast cancer diagnosis, or symptom severity. Three taxa (Pseudomonas, Moraxella, and Klebsiella,) showed to be overrepresented in women with breast cancer and positive for SARS-CoV-2 when compared to the other women groups, and five bacterial groups were associated with COVID-19 severity among breast cancer patients: Staphylococcus, Staphylococcus epidermidis, Scardovia, Parasegitibacter luogiensis, and Thermomonas. The presence of Staphylococcus in COVID-19 breast cancer patients may possibly be a consequence of nosocomial infection.

2.
Front Genet ; 11: 831, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32849820

RESUMO

The southern muriqui (Brachyteles arachnoides) is the largest neotropical primate. This species is endemic to Brazil and is currently critically endangered due to its habitat destruction. The genetic basis underlying adaptive traits of New World monkeys has been a subject of interest to several investigators, with significant concern about genes related to the immune system. In the absence of a reference genome, RNA-seq and de novo transcriptome assembly have proved to be valuable genetic procedures for accessing gene sequences and testing evolutionary hypotheses. We present here a first report on the sequencing, assembly, annotation and adaptive selection analysis for thousands of transcripts of B. arachnoides from two different samples, corresponding to 13 different blood cells and fibroblasts. We assembled 284,283 transcripts with N50 of 2,940 bp, with a high rate of complete transcripts, with a median high scoring pair coverage of 88.2%, including low expressed transcripts, accounting for 72.3% of complete BUSCOs. We could predict and extract 81,400 coding sequences with 79.8% of significant BLAST hit against the Euarchontoglires SwissProt dataset. Of these 64,929 sequences, 34,084 were considered homologous to Supraprimate proteins, and of the remaining sequences (30,845), 94% were associated with a protein domain or a KEGG Orthology group, indicating potentially novel or specific protein-coding genes of B. arachnoides. We use the predicted protein sequences to perform a comparative analysis with 10 other primates. This analysis revealed, for the first time in an Atelid species, an expansion of APOBEC3G, extending this knowledge to all NWM families. Using a branch-site model, we searched for evidence of positive selection in 4,533 orthologous sets. This evolutionary analysis revealed 132 amino acid sites in 30 genes potentially evolving under positive selection, shedding light on primate genome evolution. These genes belonged to a wide variety of categories, including those encoding the innate immune system proteins (APOBEC3G, OAS2, and CEACAM1) among others related to the immune response. This work generated a set of thousands of complete sequences that can be used in other studies on molecular evolution and may help to unveil the evolution of primate genes. Still, further functional studies are required to provide an understanding of the underlying evolutionary forces modeling the primate genome.

3.
Int J Cancer ; 146(3): 731-738, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30963559

RESUMO

HPV73 is classified as possibly oncogenic. It is neither routinely evaluated in HPV screening, nor covered by any of the prophylactic vaccines. We sought to investigate the carcinogenic characteristics of HPV73. Molecular studies were performed on eight cervix cancer biopsy specimens containing HPV73 from a cross-sectional cancer cohort of 590 women referred to the National Cancer Institute in Rio de Janeiro, Brazil. Transcriptional activity of HPV73 was evaluated by detection of spliced transcripts of E6/E6* and E1^E4 in cDNA created from RNA isolated from fresh tissue. Disruption of viral E1 and E2 genes in the tumor DNA was assessed by overlapping PCR amplification. Evaluation of viral integration was performed using a customized capture panel and next-generation sequencing, and an in-house bioinformatic pipeline. HPV73 E6/E6* transcripts were found in 7/7 specimens with available RNA, and three also had HPV73 E1^E4 transcripts. Disruption of E1 and E2 genes was observed in 4/8 specimens. Integration of HPV73 sequences into the cancer cell genomes was identified in all cervix cancer tissues. These results provide evidence that HPV73 is an oncogenic virus that can cause invasive cervix cancer. With current molecular screening and HPV vaccination, not all cervix cancers will be prevented.


Assuntos
Infecções por Papillomavirus/complicações , Neoplasias do Colo do Útero/etiologia , Neoplasias do Colo do Útero/virologia , Adulto , Idoso , Brasil , Estudos Transversais , DNA de Neoplasias/genética , Feminino , Humanos , Pessoa de Meia-Idade , Proteínas Oncogênicas Virais/genética , Papillomaviridae/genética , Reação em Cadeia da Polimerase/métodos , RNA Viral/genética , Integração Viral/genética
4.
Genomics ; 111(6): 1853-1861, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-30552977

RESUMO

Scarce data are available on the expression of papillomavirus genome and the frequency of alternatively spliced E6E7 mRNAs in invasive cervical cancer. We carried out a comprehensive characterization of HPV expression by RNA-Seq analysis in 22 invasive cervical cancer with HPV16 or HPV18, characterizing the presence of integrated/episomal viral DNA, the integration sites in human genome and the proportion of alternative splicing products of E6 and E7 genes. The expression patterns suggested the presence of episomal and/or integrated viral DNA, with integration detected in most tumors, frequently occurring within human genes in HPV18+ and in intergenic regions in HPV16+ tumors. Alternative splicing of E6E7 transcripts showed E6*I as the most frequent isoform for both viral types, followed by E6*II and E6/E7 (unspliced) transcripts in HPV16+, and by E6/E7 in HPV18+ tumors. Previously described E6*VI and E6*V transcript isoforms for HPV16, and E6*X for HPV18, were rare or not detected.


Assuntos
Proteínas de Ligação a DNA , Regulação Neoplásica da Expressão Gênica , Regulação Viral da Expressão Gênica , Papillomavirus Humano 16 , Papillomavirus Humano 18 , Proteínas Oncogênicas Virais , Proteínas E7 de Papillomavirus , RNA-Seq , Proteínas Repressoras , Neoplasias do Colo do Útero , Integração Viral , Processamento Alternativo , Proteínas de Ligação a DNA/biossíntese , Proteínas de Ligação a DNA/genética , Feminino , Papillomavirus Humano 16/genética , Papillomavirus Humano 16/metabolismo , Papillomavirus Humano 18/genética , Papillomavirus Humano 18/metabolismo , Humanos , Proteínas Oncogênicas Virais/biossíntese , Proteínas Oncogênicas Virais/genética , Proteínas E7 de Papillomavirus/biossíntese , Proteínas E7 de Papillomavirus/genética , Proteínas Repressoras/biossíntese , Proteínas Repressoras/genética , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologia
5.
Eur J Oral Sci ; 123(5): 381-384, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26331285

RESUMO

The etiology of cleft lip with or without cleft palate (CL±P) is complex and heterogeneous, and multiple genetic and environmental factors are involved. Some candidate genes reported to be associated with oral clefts are located on the X chromosome. At least three genes causing X-linked syndromes [midline 1 (MID1), oral-facial-digital syndrome 1 (OFD1), and dystrophin (DMD)] were previously found to be associated with isolated CL±P. We attempted to confirm the role of X-linked genes in the etiology of isolated CL±P in a South American population through a family-based genome-wide scan. We studied 27 affected children and their mothers, from 26 families, in a Patagonian population with a high prevalence of CL±P. We conducted an exploratory analysis of the X chromosome to identify candidate regions associated with CL±P. Four genomic segments were identified, two of which showed a statistically significant association with CL±P. One is an 11-kb region of Xp21.1 containing the DMD gene, and the other is an intergenic region (8.7 kb; Xp11.4). Our results are consistent with recent data on the involvement of the DMD gene in the etiology of CL±P. The MID1 and OFD1 genes were not included in the four potential CL±P-associated X-chromosome genomic segments.

6.
World J Gastroenterol ; 20(24): 7665-74, 2014 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-24976704

RESUMO

The hepatitis B virus (HBV) is a cosmopolitan infectious agent currently affecting over 350 million people worldwide, presently accounting for more than two billion infections. In addition to man, other hepatitis virus strains infect species of several mammalian families of the Primates, Rodentia and Chiroptera orders, in addition to birds. The mounting evidence of HBV infection in African, Asian and neotropical primates draws attention to the potential cross-species, zoonotic transmission of these viruses to man. Moreover, recent evidence also suggests the humans may also function as a source of viral infection to other mammals, particularly to domestic animals like poultry and swine. In this review, we list all evidence of HBV and HBV-like infection of nonhuman mammals and discuss their potential roles as donors or recipients of these viruses to humans and to other closely-related species.


Assuntos
Vetores de Doenças , Vírus da Hepatite B/patogenicidade , Hepatite B/transmissão , Hepatite B/virologia , Zoonoses , Animais , Genótipo , Hepatite B/epidemiologia , Vírus da Hepatite B/genética , Humanos , Fenótipo
7.
Mol Biol Rep ; 41(1): 489-95, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24293149

RESUMO

We analyzed wild-type (WT) and four sequence variants of the BRCA1 promoter region-found in patients selected for hereditary breast and ovarian cancer syndrome-in respect to their influence on transcription and translation efficiencies in transient transfection assays in the presence or absence of estrogen. Five types of plasmids containing the EGFP reporter gene proceeded by WT 5'UTR-a, WT 5'UTR-b, and the three 5'UTR-b variants were constructed to evaluate their influence on translation. Plasmids containing the firefly luciferase reporter gene were constructed with the WT BRCA1 promoter region (containing promoter α, 5'UTR-a, promoter ß, and 5'UTR-b) and with the four promoter variants for evaluating their influence on transcription and translation. All constructs were transfected in MCF7 cells maintained with and without estrogen. Expression of EGFP plasmids with WT 5'UTR-a was six to sevenfold higher than of plasmids with WT 5'UTR-b, expression of WT and the three variant 5'UTR-b plasmids showed slight differences in EGFP expression, and the presence or absence of estrogen result in non-significant changes in expression. Promoter's constructs that carry the variants WT or g.3988C showed a higher firefly luciferase activity when estrogen is present; conversely, no significant differences were found in the transcription efficiency of the reporter gene indicating that estrogen affect the translation rather than transcription. The presence or absence of estrogen did not affect the activity of firefly luciferase for constructs with the other promoter variants, being the transcription efficiencies equivalent in both conditions.


Assuntos
Proteína BRCA1/genética , Estrogênios/fisiologia , Regiões Promotoras Genéticas , Biossíntese de Proteínas , Transcrição Gênica , Regiões 5' não Traduzidas , Proteína BRCA1/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Genes Reporter , Proteínas de Fluorescência Verde/biossíntese , Proteínas de Fluorescência Verde/genética , Síndrome Hereditária de Câncer de Mama e Ovário/genética , Humanos , Luciferases de Vaga-Lume/biossíntese , Luciferases de Vaga-Lume/genética , Células MCF-7 , Polimorfismo de Nucleotídeo Único
8.
PLoS One ; 8(7): e67568, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23844033

RESUMO

Foamy viruses naturally infect a wide range of mammals, including Old World (OWP) and New World primates (NWP), which are collectively called simian foamy viruses (SFV). While NWP species in Central and South America are highly diverse, only SFV from captive marmoset, spider monkey, and squirrel monkey have been genetically characterized and the molecular epidemiology of SFV infection in NWPs remains unknown. We tested a large collection of genomic DNA (n = 332) comprising 14 genera of NWP species for the presence of SFV polymerase (pol) sequences using generic PCR primers. Further molecular characterization of positive samples was carried out by LTR-gag and larger pol sequence analysis. We identified novel SFVs infecting nine NWP genera. Prevalence rates varied between 14-30% in different species for which at least 10 specimens were tested. High SFV genetic diversity among NWP up to 50% in LTR-gag and 40% in pol was revealed by intragenus and intrafamilial comparisons. Two different SFV strains infecting two captive yellow-breasted capuchins did not group in species-specific lineages but rather clustered with SFVs from marmoset and spider monkeys, indicating independent cross-species transmission events. We describe the first SFV epidemiology study of NWP, and the first evidence of SFV infection in wild NWPs. We also document a wide distribution of distinct SFVs in 14 NWP genera, including two novel co-speciating SFVs in capuchins and howler monkeys, suggestive of an ancient evolutionary history in NWPs for at least 28 million years. A high SFV genetic diversity was seen among NWP, yet these viruses seem able to jump between NWP species and even genera. Our results raise concerns for the risk of zoonotic transmission of NWP SFV to humans as these primates are regularly hunted for food or kept as pets in forest regions of South America.


Assuntos
Doenças dos Macacos/epidemiologia , Platirrinos/virologia , Infecções por Retroviridae/veterinária , Vírus Espumoso dos Símios/classificação , Vírus Espumoso dos Símios/genética , Animais , Brasil/epidemiologia , Evolução Molecular , Genes Virais , Variação Genética , Geografia Médica , Interações Hospedeiro-Patógeno , Humanos , Dados de Sequência Molecular , Doenças dos Macacos/transmissão , Doenças dos Macacos/virologia , Filogenia , Prevalência , Vírus Espumoso dos Símios/isolamento & purificação
9.
PLoS One ; 7(12): e51699, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23272145

RESUMO

The evolution of Neotropical Primates (NP) is permeated by factors associated with the pattern of diversification and the biogeography of the major lineages. These questions can be better understood by providing a robust estimate of the chronological scenario of NP evolution, a reason why molecular dating methods have been widely applied. One aspect of especial interest is the timing of diversification of the major NP lineages (pitheciids, atelids and cebids), which may have resulted from rapid episodes of adaptive radiation, a question that requires NP divergence time estimates with accurate statistical certainty. In this study, we evaluated the primate timescale focused on the age of nodes of NP radiation. We investigated the performance of complete primate mitochondrial genomes as traditional molecular markers of primate evolution and further including original mitochondrial data from the endangered muriqui, Brachyteles arachnoides (Accession No. JX262672). Comparisons of the age estimates at NP nodes based on mitochondrial genomes with those obtained from a nuclear supermatrix showed similar degrees of uncertainty. Further molecular data and more informative calibration priors are required for a more precise understanding of the early NP diversification.


Assuntos
Atelinae/genética , Evolução Molecular , Genoma Mitocondrial , Filogenia , Animais , Atelinae/classificação , Teorema de Bayes , Masculino
10.
Fam Cancer ; 11(4): 657-60, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22829013

RESUMO

We have screened BRCA2 c.156_157insAlu founder mutation in a cohort of 168 women with diagnosis of breast cancer referred for genetic counseling because of risk of being carriers of hereditary breast and ovarian cancer syndrome. Portuguese founder mutation BRCA2 c.156_157insAlu was identified in three unrelated breast cancer probands. Genotyping identified a common haplotype between markers D13S260 and D13S171, and allele sizes were compatible to those described in the Portuguese families. Allele sizes of marker D13S1246, however, were concordant in two families, suggesting that the haplotype may be larger in a subset of families. Tumor phenotypes in Brazilian families seem to reinforce the high prevalence of breast cancer among affected males. However, an apparent excess of gastrointestinal and tongue neoplasias were also observed in these families. Although these tumors are not part of the phenotypic spectrum of hereditary breast and ovarian cancer syndrome, they might be accounted for by other risk alleles contained in the founder haplotype region.


Assuntos
Proteína BRCA2/genética , Neoplasias da Mama/complicações , Efeito Fundador , Neoplasias Gastrointestinais/etiologia , Mutação em Linhagem Germinativa/genética , Neoplasias Ovarianas/complicações , Neoplasias da Língua/etiologia , Adulto , Idoso , Proteína BRCA1/genética , Sequência de Bases , Brasil/epidemiologia , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/genética , DNA/análise , DNA/genética , Feminino , Neoplasias Gastrointestinais/epidemiologia , Predisposição Genética para Doença , Testes Genéticos , Heterozigoto , Humanos , Pessoa de Meia-Idade , Dados de Sequência Molecular , Neoplasias Ovarianas/epidemiologia , Neoplasias Ovarianas/genética , Linhagem , Fenótipo , Reação em Cadeia da Polimerase , Prognóstico , Neoplasias da Língua/epidemiologia
11.
PLoS Genet ; 7(3): e1001342, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21436896

RESUMO

Comparative genomic analyses of primates offer considerable potential to define and understand the processes that mold, shape, and transform the human genome. However, primate taxonomy is both complex and controversial, with marginal unifying consensus of the evolutionary hierarchy of extant primate species. Here we provide new genomic sequence (~8 Mb) from 186 primates representing 61 (~90%) of the described genera, and we include outgroup species from Dermoptera, Scandentia, and Lagomorpha. The resultant phylogeny is exceptionally robust and illuminates events in primate evolution from ancient to recent, clarifying numerous taxonomic controversies and providing new data on human evolution. Ongoing speciation, reticulate evolution, ancient relic lineages, unequal rates of evolution, and disparate distributions of insertions/deletions among the reconstructed primate lineages are uncovered. Our resolution of the primate phylogeny provides an essential evolutionary framework with far-reaching applications including: human selection and adaptation, global emergence of zoonotic diseases, mammalian comparative genomics, primate taxonomy, and conservation of endangered species.


Assuntos
Filogenia , Primatas/classificação , Primatas/genética , Animais , Biologia Computacional , Feminino , Variação Genética , Genoma/genética , Masculino
12.
Virol J ; 8: 4, 2011 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-21208414

RESUMO

BACKGROUND: Human Papillomavirus (HPV) high-risk (HR) types are the causal factor for cervical cancer and premalignant dysplasia. Data on frequency of HPV types provide a basis to design and evaluate HPV prevention programs. Taking into account the heterogeneity of HPV types across and within populations this study aims to access the HPV frequency in Brazilian women. RESULTS: We identified 24 different types of HPV, including a Betapapillomavirus and a likely new type, previously reported, from 132 women positive for the virus analysed by Hybrid Capture II assay. These women were infected by a single or multiple HPV types and 142 HPV strains were identified. HR types were found in 75% of women and HPV types 16, 18, 45, 58, and 66 had the highest frequency. Significant differences in frequency of HR HPV types were found for presence of cervical lesions, and for different HPV species and women age. CONCLUSIONS: Compared with previous studies in Brazil, our data indicated differences in frequency and HPV type diversity, a significant association of other HR-types but HPV16 and 18 and cervical lesions, and a trend for distinct distribution of HPV types by age.


Assuntos
Colo do Útero/patologia , Colo do Útero/virologia , Papillomaviridae/genética , Infecções por Papillomavirus/virologia , Adulto , Brasil , Estudos de Casos e Controles , Feminino , Variação Genética , Humanos , Pessoa de Meia-Idade , Dados de Sequência Molecular , Papillomaviridae/classificação , Infecções por Papillomavirus/patologia , Gravidez , Fatores Socioeconômicos , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologia , Displasia do Colo do Útero/patologia , Displasia do Colo do Útero/virologia
13.
Infect Genet Evol ; 10(2): 246-53, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19931648

RESUMO

The tripartite motif 5 protein (TRIM5) has been extensively studied in view of its ability to restrict retroviruses in mammalian hosts. The B30.2 domain, encoded by exon 8 of TRIM5, contains the major restriction determinants. We have analyzed the genetic diversity of the TRIM5 B30.2 domain in a wide range of New World primates (NWP). The TRIM5 region encoding the B30.2 domain of 35 animals, representing all NWP families and 10 genera, was PCR-amplified, sequenced and analyzed at the amino acid level. Comparisons were carried out with available GenBank data; analyses were carried out with a dataset of 44 representative sequences of 32 NWP species and 15 genera, with a human B30.2 sequence as outgroup. A high genetic diversity was observed, both with respect to length and amino acid substitutions, mainly at the three variable regions of this domain associated with the restriction phenotype. Phylogenetic reconstructions based on B30.2 DNA differed from the consensus NWP topology due to positive selection along different lineages and definite codon positions, with robust evidence either with a complete or a pruned dataset. This was especially evident in codons 406 and 496, consistently demonstrated with all methods. Positive selection was virtually absent in all NWP species when analyzing intra-specific polymorphisms except for Saguinus labiatus. Our findings indicated that NWP TRIM5 proteins have been subjected to selection, probably by retroviruses and/or retroelements. We anticipate that the diversity of NWP TRIM5 is indicative of disparate retroviral restriction phenotypes representing a plentiful source of factors countering HIV infection.


Assuntos
Proteínas de Transporte/genética , Evolução Molecular , Platirrinos/genética , Estrutura Terciária de Proteína/genética , Sequência de Aminoácidos , Animais , Fatores de Restrição Antivirais , Catarrinos/genética , Humanos , Dados de Sequência Molecular , Filogenia , Alinhamento de Sequência , Proteínas com Motivo Tripartido , Ubiquitina-Proteína Ligases
15.
Birth Defects Res A Clin Mol Teratol ; 79(8): 573-80, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17584896

RESUMO

BACKGROUND: Single median maxillary central incisor (SMMCI) is a rare anomaly that may occur alone or associated with other conditions, frequently as part of the holoprosencephaly (HPE) spectrum. However, it has been suggested that SMMCI alone, or associated with some midline defects, may be considered a different entity from HPE (OMIM: 147250). Families with SMMCI, without HPE cases, are difficult to counsel for the risk of HPE in future generations because the same midline defects described as part of the "SMMCI syndrome" can also be part of the HPE spectrum. METHODS: We screened five cases of SMMCI for mutations in three HPE genes, SHH, TGIF, and SIX3. RESULTS: A missense mutation c.686C>T was found in the gene SIX3 of one patient, which did not differ from the accepted 20% of known HPE gene mutations among all HPE cases. Our results and an extensive literature review of gene mutations in patients with SMMCI showed that 27/28 of them were in HPE genes: SHH (n = 21), SIX3 (n = 3), TGIF (n = 1), GLI2 (n = 1), and PTCH (n = 1), and only one in the SALL4 gene. CONCLUSIONS: The clinical findings in patients with SMMCI without HPE in families with mutations in HPE genes cannot be distinguished from the findings reported in the SMMCI syndrome. Therefore, persons with SMMCI and their relatives should be carefully investigated for related midline disorders, especially of the HPE spectrum, and all known HPE genes screened.


Assuntos
Anormalidades Múltiplas/genética , Proteínas do Olho/genética , Proteínas de Homeodomínio/genética , Incisivo/anormalidades , Mutação de Sentido Incorreto , Proteínas do Tecido Nervoso/genética , Mutação Puntual , Anormalidades Múltiplas/patologia , Adolescente , Criança , Análise Mutacional de DNA , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Recém-Nascido , Masculino , Reação em Cadeia da Polimerase , Proteína Homeobox SIX3
16.
Genet. mol. biol ; 28(4): 693-699, Dec. 2005. mapas, tab
Artigo em Inglês | LILACS | ID: lil-451010

RESUMO

Seven microsatellite loci were used to investigate the genetic variability and structure of six mainland and two island populations of the Neotropical water rat Nectomys squamipes, a South American semi-aquatic rodent species with a wide distribution. High levels of variability were found within mainland populations while island populations were less variable but the more differentiated in respect to allele number and frequency. The time of biological divergence between mainland and island populations coincided with geological data. A significant geographic structure was found in mainland populations (q = 0.099; r = 0.086) although the degree of differentiation was relatively low in respect to the distance between surveyed localities (24 to 740 km). Genetic and geographic distances were not positively correlated as previously found with random amplified polymorphic DNA (RAPD) markers. Significant but low genetic differentiation in the mainland and lack of isolation by distance can be explained by large population size and/or recent population expansion. Additionally, the agreement between the age of geologic events (sea level fluctuations) and divergence times for insular populations points to a good reference for molecular clock calibration to associate recent environmental changes and the distribution pattern of small mammals in the Brazilian Atlantic Forest


Assuntos
Animais , Variação Genética , Ratos/genética , Repetições de Microssatélites , Roedores/genética
17.
J Virol ; 79(23): 14998-5003, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16282502

RESUMO

Host cell factors modulate retroviral infections. Among those, cyclophilin A (CypA) promotes virus infectivity by facilitating virus uncoating or capsid unfolding or by preventing retroviral capsid interaction with cellular restriction factors. In Aotus species, a retrotransposed copy of CypA inserted into the tripartite motif 5 (TRIM5) gene encodes a fusion protein which may block human immunodeficiency virus type 1 by targeting the incoming virus to ubiquitin-ligated degradation or by interfering with normal uncoating of the incoming particle, rendering those monkeys resistant to infection. In this study, we have extensively analyzed representative specimens from all New World primate genera and shown that the retrotransposed CypA copy is only present in Aotus. We have shown that this inserted copy diverged from its original counterpart and that this occurred prior to Aotus radiation, although no positive selection was observed. Finally, our data underscores the need for a precise taxonomic identification of primate species used as models for retroviral infections and novel antiviral approaches.


Assuntos
Ciclofilina A/genética , Infecções por HIV/genética , Primatas/fisiologia , Proteínas/genética , Retroelementos/genética , Animais , Ciclofilina A/metabolismo , Evolução Molecular , Infecções por HIV/virologia , HIV-1/fisiologia , Humanos , Proteínas/metabolismo , Ubiquitina-Proteína Ligases
18.
Genet. mol. biol ; 27(4): 500-504, Dec. 2004. tab
Artigo em Inglês | LILACS | ID: lil-391220

RESUMO

BRCA1 mutations are known to be responsible for the majority of hereditary breast and ovarian cancers in women with early onset and a family history of the disease. In this paper we present a mutational survey conducted in 47 Brazilian patients with breast/ovarian cancer, selected based on age at diagnosis, family history, tumor laterality, and presence of breast cancer in male patients. All 22 coding exons and intron-exon junctions were sequenced. Constitutional mutations were found in seven families, consisting of one insertion (insC5382) in exon 20 (four patients), one four base-pair deletion (3450-3453delCAAG) in exon 11 resulting in a premature stop codon (one patient), one transition (IVS17+2T> C) in intron 17 affecting a mRNA splicing site (one patient), and a C> T transition resulting in a stop-codon (Q1135X) in exon 11 (one patient). The identification of these mutations which are associated to hereditary breast and ovarian cancers will contribute to the characterization of the mutational spectrum of BRCA1 and to the improvement of genetic counseling for familial breast/ovarian cancer patients in Brazil.


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Neoplasias da Mama , Mutação , Neoplasias Ovarianas , Brasil , Genes BRCA1 , Aconselhamento Genético , Mutação em Linhagem Germinativa
19.
Genomics ; 84(3): 511-23, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15498458

RESUMO

Sonic Hedgehog (SHH) plays a fundamental role in numerous developmental processes including morphogenesis of limbs, nervous system, and teeth. Using a Bayesian alignment algorithm for phylogenetic footprinting we analyzed approximately 28 kb of noncoding DNA in the SHH locus of human and mouse. This showed that the length of conserved noncoding sequences (4196 nt) shared by these species was approximately 3 times larger than the SHH coding sequence (1386 nt). Most segments were located in introns (53%) or within 2-kb regions upstream (16%) or downstream (20%) of the first and last SHH codon. Even though regions more than 2 kb upstream or downstream of the first and last SHH codon represented 57% (16 kb) of the sequence compared, they accounted for only 11% (494 nt) of the total length of conserved noncoding segments. One region of 650 nt downstream of SHH was identified as a putative scaffold/matrix attachment region (SMAR). Human-mouse analysis was complemented by sequencing in apes, monkeys, rodents, and bats, thus further confirming the evolutionary conservation of some segments. Gel-shift assays indicated that conserved segments are targeted by nuclear proteins and showed differences between two cell types that expressed different levels of SHH, namely human endothelial cells and breast cancer cells. The relevance of these findings with respect to regulation of SHH expression during normal and pathologic development is discussed.


Assuntos
DNA Intergênico/genética , Genes Reguladores/genética , Mamíferos/genética , Filogenia , Transativadores/genética , Animais , Sequência de Bases , Teorema de Bayes , Sítios de Ligação , Sequência Conservada/genética , Pegada de DNA , Primers do DNA , Ensaio de Desvio de Mobilidade Eletroforética , Proteínas Hedgehog , Humanos , Dados de Sequência Molecular , Alinhamento de Sequência , Análise de Sequência de DNA , Fatores de Transcrição/metabolismo
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