Coptotermes gestroi (Isoptera: Rhinotermitidae) in Brazil: possible origins inferred by mitochondrial cytochrome oxidase II gene sequences

The Asian subterranean termite, Coptotermes gestroi, originally from northeast India through Burma, Thailand, Malaysia, and the Indonesian archipelago, is a major termite pest introduced in several countries around the world, including Brazil. We sequenced the mitochondrial COII gene from individuals representing 23 populations. Phylogenetic analysis of COII gene sequences from this and other studies resulted in two main groups: (1) populations of Cleveland (USA) and four populations of Malaysia and (2) populations of Brazil, four populations of Malaysia, and one population from each of Thailand, Puerto Rico, and Key West (USA). Three new localities are reported here, considerably enlarging the distribution of C. gestroi in Brazil: Campo Grande (state of Mato Grosso do Sul), Itajai (state of Santa Catarina), and Porto Alegre (state of Rio Grande do Sul).

Haplotype characterization of the COI mitochondrial gene in Chrysoperla externa (Neuroptera: Chrysopidae) from different environments in Jaboticabal, state of São Paulo, southeastern Brazil

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

Mitochondrial genotype segregation and effects during mammalian development: Applications to biotechnology

Mitochondria are endosymbiotic organelles responsible for energy production in practically every eukaryotic cell. Their uniparental fashion of inheritance, maternally inherited in mammals, and the homogeneity of mitochondrial DNA (mtDNA) within individuals and matrilineages, are biological phenomena that remain unexplained. This paper reviews some of the recent findings on mitochondrial influences on the manner in which embryos develop and how their genotypes are inherited in mammals, with particular emphasis on the genetic bottleneck effect. Animal models carrying a mix of mtDNAs (heteroplasmic) have been produced by karyoplast and cytoplast transplantation to analyze the segregation patterns at different stages during embryogenesis, in fetuses and offspring. Comparisons performed between murine and bovine reveal interesting changes in segregation and replication of transplanted mtDNAs. We have recently obtained Bos indicus and Bos taurus fetuses and calves from embryos reconstructed using enucleated polymorphic oocytes of Bos taurus origin. These and other findings on mitochondrial biology will have important implications in determining the cytoplasmic genotype of clones and in the preservation of endangered breeds and species. (C) 1999 by Elsevier B.V.

Effects of discontinuous Percoll gradient centrifugation on the quality of bovine spermatozoa evaluated with computer-assisted semen analysis and fluorescent probes association

The objective of this study was to evaluate the quality of bovine frozen-thawed sperm cells after Percoll gradient centrifugation. Frozen semen doses were obtained from six bulls of different breeds, including three taurine and three Zebu animals. Four ejaculates per bull were evaluated before and after discontinuous Percoll gradient centrifugation. Sperm motility was assessed by computer-assisted semen analysis and the integrity of the plasma and acrosomal membranes, as well as mitochondrial function, were evaluated using a combination of fluorescent probes propidium iodide, fluorescein isothiocyanate-conjugated Pisum sativum agglutinin and 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolcarbocyanine iodide. The procedure of Percoll gradient centrifugation increased the percentage of total and progressive sperm motility, beat frequency, rectilinear motility, linearity and rapidly moving cells. In addition, the percentage of cells with intact plasma membrane and mitochondrial membrane potential was increased in post-centrifugation samples. However, the percentage of sperm cells with intact acrosomal membrane was markedly reduced. The method used selected the motile cells with intact plasma membrane and higher mitochondrial functionality in frozen-thawed bull semen, but processing, centrifugation and/or the Percoll medium caused damage to the acrosomal membrane.

African-Derived mitochondria in South American native cattle breeds (Bos taurus): Evidence of a new taurine mitochondrial lineage

This article reports the nucleotide diversity within the control region of 42 mitochondrial chromosomes belonging to five South American native cattle breeds (Bos taurus). Analysis of these data in conjunction with B. taurus and B. indicus sequences from Africa, Europe, the Near East, India, and Japan allowed the recognition of eight new mitochondrial haplotypes and their relative positions in a phylogenetic network. The structure of genetic variation among different hypothetical groupings was tested through the molecular variance decomposition, which was best explained by haplotype group components. Haplotypes surveyed were classified as European-related and African-related. Unexpectedly, two haplotypes within the African cluster were more divergent from the African consensus than the latter from the European consensus. A neighbor-joining tree shows the position of two haplotypes compared to European/African mitochondrial lineage splitting. This different and putatively ancestral mitochondrial lineage (AA) is supported by the calibration of sequence divergence based on the Bos-Bison separation. The European/African mitochondria divergence might be subsequent (67,100 years before present) to that between AA and Africans (84,700 years before present), also preceding domestication times. These genetic data could reflect the haplotype distribution of Iberian cattle five centuries ago.

Comparison of the properties of compacted and porous lamellar chitosan-xanthan membranes as dressings and scaffolds for the treatment of skin lesions

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

On the release of metronidazole from natural rubber latex membranes

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

Evaluation of thermal behavior of latex membranes from genetically improved rubber tree (Hevea brasiliensis)

Thermal stability, thermal decomposition process, residual mass, temperature of glass transition (T-g) and temperature dependence of storage modulus (E'), were determined for latex membranes prepared from six clones of Hevea brasiliensis: IAC 331, IAC 332, IAC 333 and IAC 334 grown at experimental plantations of Instituto Agronomico de Campinas (IAC) in Votuporanga, São Paulo State, Brazil. Latex membranes from GT1 and RRIM 600 Asian matrix clones were used as references. The thermal behavior of latex membranes from genetically improved rubber trees was characterized using thermogravimetry/derivative thermogravimetry (TG/DTG), differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). The thermal behavior of latex from clones studied in the present work showed similar features of the clones previously reported (IAC 40, IAC 300, IAC 301, IAC 328, IAC 329 and IAC 330), with mass loss in four consecutive steps, except IAC 333, which showed an additional mass loss step. (c) 2006 Elsevier B.V. All rights reserved.

The influence of natural rubber/Au nanoparticle membranes on the physiology of Leishmania brasiliensis

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

Phylogeny of Triatoma sherlocki (Hemiptera: Reduviidae: Triatominae) Inferred from Two Mitochondrial Genes Suggests Its Location Within the Triatoma brasiliensis Complex

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

Effects of isocoumarins isolated from Paepalanthus bromelioides on mitochondria: Uncoupling, and induction/inhibition of mitochondrial permeability transition

Isolated mitochondria may undergo uncoupling, and in presence of Ca2+ at different conditions, a mitochondrial permeability transition (MPT) linked to protein,thiol oxidation, and demonstrated by CsA-sensitive mitochondrial swelling; these processes may cause cell death either by necrosis or by apoptosis. Isocoumarins isolated from the Brazilian plant Paepalanthus bromelioides (Eriocaulaceae) paepalantine (9,10-dihydroxy-5,7-dimethoxy-1H-naptho(2,3c)pyran-1-one), 8,8'-paepalantine dimer, and vioxanthin were assayed at 1-50 mu M on isolated rat liver mitochondria, for respiration, MPT, protein thiol oxidation, and interaction with the mitochondrial membrane using 1,6-diphenyl-1,3,5-hexatriene (DPH). The isocoumarins did not significantly affect state 3 respiration of succinate-energized mitochondria; they did however, stimulate 4 respiration, indicating mitochondrial uncoupling. Induction of MPT and protein thiol oxidation were assessed in succinate-energized mitochondria exposed to 10 mu M Ca2+; inhibition of these processes was assessed in non-energized organelles in the presence of 300 mu M t-butyl hydroperoxide plus 500 mu M Ca2+. Only paepalantine was an effective MPT/protein thiol oxidation inducer, also releasing cytochrome c from mitochondria; the protein thiol oxidation, unlike mitochondrial swelling, was neither inhibited by CsA nor dependent on the presence of Ca2+. Vioxanthin was an effective inhibitor of MPT/protein thiol oxidation. All isocoumarins inserted deeply into the mitochondrial membrane, but only paepalantine dimer and vioxantin decreased the membrane's fluidity. A direct reaction with mitochondrial membrane protein thiols, involving an oxidation of these groups, is proposed to account for MPT induction by paepalantine, while a restriction of oxidation of these same thiol groups imposed by the decrease of membrane fluidity, is proposed to account for MPT inhibition by vioxanthin. (c) 2006 Published by Elsevier B.V..

Heteroplasmy in Hair: Study of Mitochondrial DNA Third Hypervariable Region in Hair and Blood Samples

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

No relationship found between point heteroplasmy in mitochondrial DNA control region and age range, sex and haplogroup in human hairs

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

Pancreatic islets from dexamethasone-treated rats show alterations in global gene expression and mitochondrial pathways

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