Origens dos cromossomos B em espécies de Characidium (Characiformes, Crenuchidae) baseada em pintura cromossômica, sequências de rDNA e histonas

Pós-graduação em Ciências Biológicas (Genética) - IBB

Contribuições a elucidação da estrutura, origem e evolução de neo-sistemas cromossômicos de determinação sexual em gafanhotos utilizando como modelo espécies dos gêneros Chlorus, Dichromatos e Eurotettix (Melanoplinae; Acrididae)

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

Delimiting the Origin of a B Chromosome by FISH Mapping, Chromosome Painting and DNA Sequence Analysis in Astyanax paranae (Teleostei, Characiformes)

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

Participação das NETs (neutrophil extracellular traps) na atividade fungicida de neutrófilos humanos contra o Paracoccidioides brasiliensis

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

Kinome profiling of osteoblasts on hydroxyapatite opens new avenues on biomaterial cell signaling

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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

Mapeamento citogenético de sequências histônicas e ribossomais revelam conservação e divergência cromossômica em populações de peixes da espécie Astyanax bockmanni (Teleostei, Characidae)

In the present work we performed molecular cytogenetic studies in two different populations of Astyanax bockmanni from streams of Botucatu, SP: one from Capivara river, on Tietê river basin and one from Água da Madalena river, on Paranapanema river basin. The results showed that the population of Astyanax bockmanni from Capivara river have a diploid number of 50 chromosomes, with karyotype consisting of 8 methacentric, 14 submethacentric, 12 subtelocentric and 16 acrocentric, while the individuals of the population from Água da Madalena river have 50 diploid chromosomes but with karyotype organized in 8 metacentric, 14 submetacentric, 16 subtelocentric and 12 acrocentric. Also, the rDNA 18s sequences are widely dispersed throughout the genome of two populations, with intra and interindividual variations. On the other hand, the sequences for rDNA 5S and Histone H1 remained chromosomally conserved in these two samples and sites located in pairs 2 and 19 (rDNA 5S) and the pairs 2 and 15 (Histone H1). The low dispersion of structural genes and a functional dynamic independence between sequences of rDNA 5S and rDNA 18S may be related to the process of karyotype maintenance and differentiation in these populations of Astyanax bockmanni

New ligands of the cellular retinoic acid-binding protein 2 (CRABP2) suggest a role for this protein in chromatin remodeling

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

Identificação de Neutrophil Extracellular Traps em lesões tegumentares de pacientes com Paracoccidiodomicose e análise da formação de NETs in vitro por neutrófilos humanos desafiados com Paracoccidioides brasiliensis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Descrição cariótica e novas ocorrências de cromossomos supranuméricos em Moenkhausia Eigenmann, 1903 (Characiformes: Characidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Tuberculosis: challenges to improve the treatment

Tuberculosis is one of the leading causes of morbidity and mortality worldwide. Current treatment has several challenges including multi-drug resistance, extensively drug-resistance and HIV co-infection. Problems related to patients, treatment and health care system also contributes negatively to this panel. This review summarizes the main obstacles to treat tuberculosis and discuss several strategies to improve the treatment.

Neo-sex chromosomes of Ronderosia bergi: insight into the evolution of sex chromosomes in grasshoppers

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

Participation of dectin-1 receptor on NETs release against Paracoccidioides brasiliensis: role on extracellular killing

Paracoccidioides brasiliensis is a dimorphic fungus from the Paracoccidioides genus, which is the causative agent of paracoccidioidomycosis, a chronic, subacute or acute mycosis, with visceral and cutaneous involvement. This disease that is acquired through inhalation primarily attacks the lungs but, can spread to other organs. Phagocytic cells as neutrophils play an important role during innate immune response against this fungus, but studies on antifungal activities of these cells are scarce. In addition to their ability to eliminate pathogens by phagocytosis and antimicrobial secretions, neutrophils can trap and kill microorganisms by release of extracellular structures composed by DNA and antimicrobial proteins, called neutrophil extracellular traps (NETs). Here, we provide evidence that P. brasiliensis virulent strain (P. brasiliensis 18) induces NETs release. These structures were well evidenced by scanning electron microscopy, and specific NETs compounds such as histone, elastase and DNA were shown by confocal microscopy. In addition, we have shown that dectin-1 receptor is the main PRR to which fungus binds to induce NETS release. Fungi were ensnared by NETs, denoting the role of these structures in confining the fungus, avoiding dissemination. NETs were also shown to be involved in fungus killing, since fungicidal activity detected before and mainly after neutrophils activation with TNF-α, IFN-γ and GM-CSF was significantly inhibited by cocultures treatment with DNAse.

ROBO1 deletion as a novel germline alteration in breast and colorectal cancer patients

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

Physiological Studies on Candida albicans

Candida albicans is a common opportunistic, dimorphic human fungal pathogen. One of its virulence factors is the morphological switch between yeasts and hyphal or pseudohyphal forms, which can invade tissues and cause damage. Our studies focus on factors regulating pseudohyphae and epigenetic modifications of C. albicans. Regulating factors of pseudohyphae are aromatic alcohols and high phosphate. At low concentrations, exogenous aromatic alcohols induced pseudohyphae, as did high phosphate. For addressing the pathways involved in inducing pseudohyphae by aromatic alcohols or high phosphate, we used mutants defective in cAMP dependent PKA pathway (efg1/efg1), MAP kinase pathway (cph1/cph1), or both (cph1/cph1/efg1/efg1). These mutants failed to produce either hyphae or pseudohyphae in the presence of aromatic alcohols; but high phosphate still stimulated pseudohyphae. Gcn4, a transcription activator of more than 500 amino acid related genes, is turned-on in response to amino acid starvation. The accumulation of aromatic alcohols sends nitrogen starvation signals, which inhibit eIF2B, which in turn derepresses Gcn4p. High phosphate also induces pseudohyphae by derepressing Gcn4p, although the pathways involved are still unknown. In sum, aromatic alcohols and high phosphate induce pseudohyphae by derepressing Gcn4. In this study we found a novel posttranslational histone modification in C. albicans, which is biotinylation. Western blot and Mass spectrometry techniques were used to find that Histones H2B and H4 were biotinylated at every condition tested such as yeast vs. hyphae, aerobic growth vs. anaerobic growth, rich medium vs. defined medium. In C. albicans lysines K8, K11 in histone H4 and lysines K17, K18, K31 in histone H2B are biotin attachment sites as found using mass spectrometry. Biotin was also found to enhance the germ tube formation of C. albicans. Germ tube formation assays with biotin-starved cells as inoculum showed low percent of germ tubes (1-5%). Addition of biotin to the media showed 100% germ tubes. Biotinylation of histones were not detected from biotin-starved cells. Appendix-A details work related to Farnesol quantification assays in several strains of C.albicans and Ceratocystis ulmi, and growth studies of class E VPS strains of Saccharomyces Cerevisiae. Adviser: Kenneth W. Nickerson