Estudo biotecnológico, citogenético e molecular em espécies de orquídeas endêmicas da flora brasileira

Pós-graduação em Biociências - FCLAS

Seleção recorrente em abobrinha 'piramoita' (Cucurbita moschata Duch.)

Seleção recorrente é um dos métodos mais eficientes para o melhoramento de espécies alógamas, especialmente quando progênies S1 são utilizadas. Considerando-se que abobrinha geralmente não apresenta perda de vigor pela endogamia, este método pode ser adequado para o melhoramento desta espécie. Neste trabalho foram realizados experimentos com o objetivo de avaliar a eficiência da seleção recorrente em abobrinha 'Piramoita'. Foram realizados três ciclos de seleção recorrente a partir da cultivar Piramoita (população P0), com avaliação e seleção de progênies S1. Novas populações foram obtidas com a recombinação de plantas das progênies selecionadas, utilizando-se sementes remanescentes. No primeiro ciclo foram avaliadas 74 progênies e selecionadas 14, no segundo foram avaliadas 60 e selecionadas 10 progênies e no terceiro ciclo foram avaliadas 77 e selecionadas 12 progênies. Foram obtidas populações melhoradas após um (PI), dois (PII) e três (PIII) ciclos de seleção recorrente. Quatro populações (P0, PI, PII e PIII) foram avaliadas em um delineamento em blocos ao acaso, com oito repetições e cinco plantas por parcela. Em todos os experimentos foram avaliadas as seguintes características: número de frutos total e comercial por planta, % de frutos comerciais, produção, em massa, de frutos total e comercial por planta e a massa média de fruto comercial. Foram observados aumentos de produção lineares significativos ao longo dos ciclos de seleção. Para número de frutos total e comercial e produção, em massa, total e comercial foram obtidos aumentos com a população PIII, comparativamente a população inicial, de 32, 63, 24 e 57%, respectivamente. A massa média de fruto comercial não foi afetada pela seleção recorrente. Conclui-se que a seleção recorrente foi eficiente para melhorar a abobrinha 'Piramoita'... (Resumo completo, clicar acesso eletrônico abaixo)

Telomere and Telomerase Biology

Telomeres are the physical ends of eukaryotic linear chromosomes. Telomeres form special structures that cap chromosome ends to prevent degradation by nucleolytic attack and to distinguish chromosome termini from DNA double-strand breaks. With few exceptions, telomeres are composed primarily of repetitive DNA associated with proteins that interact specifically with double- or single-stranded telomeric DNA or with each other, forming highly ordered and dynamic complexes involved in telomere maintenance and length regulation. In proliferative cells and unicellular organisms, telomeric DNA is replicated by the actions of telomerase, a specialized reverse transcriptase. In the absence of telomerase, some cells employ a recombination-based DNA replication pathway known as alternative lengthening of telomeres. However, mammalian somatic cells that naturally lack telomerase activity show telomere shortening with increasing age leading to cell cycle arrest and senescence. In another way, mutations or deletions of telomerase components can lead to inherited genetic disorders, and the depletion of telomeric proteins can elicit the action of distinct kinases-dependent DNA damage response, culminating in chromosomal abnormalities that are incompatible with life. In addition to the intricate network formed by the interrelationships among telomeric proteins, long noncoding RNAs that arise from subtelomeric regions, named telomeric repeat-containing RNA, are also implicated in telomerase regulation and telomere maintenance. The goal for the next years is to increase our knowledge about the mechanisms that regulate telomere homeostasis and the means by which their absence or defect can elicit telomere dysfunction, which generally results in gross genomic instability and genetic diseases.

Combined photoelectrocatalytic/electro-Fenton process using a Pt/TiO2NTs photoanode for enhanced degradation of an azo dye: A mechanistic study

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Investigation of Bulk and DTMOS triple-gate devices under 60 MeV proton irradiation

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Photoluminescence activity of Ba1-xCaxTiO3: dependence on particle size and morphology

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Origin and Evolution of B Chromosomes in the Cichlid Fish Astatotilapia latifasciata Based on Integrated Genomic Analyses

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Homomorphic Sex Chromosomes and the Intriguing Y Chromosome of Ctenomys Rodent Species (Rodentia, Ctenomyidae)

Unlike the X chromosome, the mammalian Y chromosome undergoes evolutionary decay resulting in small size. This sex chromosomal heteromorphism, observed in most species of the fossorial rodent Ctenomys, contrasts with the medium-sized, homomorphic acrocentric sex chromosomes of closely related C. maulinus and C. sp. To characterize the sequence composition of these chromosomes, fluorescent banding, self-genomic in situ hybridization, and fluorescent in situ hybridization with an X painting probe were performed on mitotic and meiotic plates. High molecular homology between the sex chromosomes was detected on mitotic material as well as on meiotic plates immunodetected with anti-SYCP3 and anti-gamma H2AX. The Y chromosome is euchromatic, poor in repetitive sequences and differs from the X by the loss of a block of pericentromeric chromatin. Inferred from the G-banding pattern, an inversion and the concomitant prevention of recombination in a large asynaptic region seems to be crucial for meiotic X chromosome inactivation. These peculiar findings together with the homomorphism of Ctenomys sex chromosomes are discussed in the light of the regular purge that counteracts Muller's ratchet and the probable mechanisms accounting for their origin and molecular homology. (C) 2014 S. Karger AG, Basel

Paracoccidioides lutzii sp nov.: biological and clinical implications

Paracoccidioides lutzii, formerly known as 'Pb01-like' strains in the P. brasiliensis complex, is proposed as a new species based on phylogenetic and comparative genomics data, recombination analysis, and morphological characteristics. Conidia of P. lutzii are elongated, different from those of P. brasiliensis. P. lutzii occurs in the central and northern regions of Brazil. Studies comparing P. brasiliensis and P. lutzii may have significant clinical consequences for the diagnosis and treatment of paracoccidioidomycosis.

Hepatitis C virus molecular evolution: Transmission, disease progression and antiviral therapy

Hepatitis C virus (HCV) infection represents an important public health problem worldwide. Reduction of HCV morbidity and mortality is a current challenge owned to several viral and host factors. Virus molecular evolution plays an important role in HCV transmission, disease progression and therapy outcome. The high degree of genetic heterogeneity characteristic of HCV is a key element for the rapid adaptation of the intrahost viral population to different selection pressures (e.g., host immune responses and antiviral therapy). HCV molecular evolution is shaped by different mechanisms including a high mutation rate, genetic bottlenecks, genetic drift, recombination, temporal variations and compartmentalization. These evolutionary processes constantly rearrange the composition of the HCV intrahost population in a staging manner. Remarkable advances in the understanding of the molecular mechanism controlling HCV replication have facilitated the development of a plethora of direct-acting antiviral agents against HCV. As a result, superior sustained viral responses have been attained. The rapidly evolving field of anti-HCV therapy is expected to broad its landscape even further with newer, more potent antivirals, bringing us one step closer to the interferon-free era. (C) 2014 Baishideng Publishing Group Inc. All rights reserved.

Estimativa da frequência da inversão SWBinv-1 entre pais de portadores ds síndrome de Williams-Beuren e pais de filhos normais do Brasil

Pós-graduação em Ciências Biológicas (Genética) - IBB

Phyllosticta citricarpa: diversidade genética temporal em pomares de citrus sinensis e sensibilidade a fungicidas

Pós-graduação em Agronomia (Genética e Melhoramento de Plantas) - FCAV

Desempenho de híbridos intraespecíficos de Brachiaria decumbens desenvolvidos por seleção recorrente recíproca

Pós-graduação em Agronomia (Genética e Melhoramento de Plantas) - FCAV

Cultura digital e educação para a mídia: análise do programa Mídias na educação

Pós-graduação em Comunicação - FAAC

Molecular study on endemic cattleya species from brazilian flora

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)