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Search Results: 1 - 10 of 8271 matches for " Maurício Bacci "
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The Mitochondrial Genome of the Leaf-Cutter Ant Atta laevigata: A Mitogenome with a Large Number of Intergenic Spacers
Cynara de Melo Rodovalho, Mariana Lúcio Lyra, Milene Ferro, Maurício Bacci
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0097117
Abstract: In this paper we describe the nearly complete mitochondrial genome of the leaf-cutter ant Atta laevigata, assembled using transcriptomic libraries from Sanger and Illumina next generation sequencing (NGS), and PCR products. This mitogenome was found to be very large (18,729 bp), given the presence of 30 non-coding intergenic spacers (IGS) spanning 3,808 bp. A portion of the putative control region remained unsequenced. The gene content and organization correspond to that inferred for the ancestral pancrustacea, except for two tRNA gene rearrangements that have been described previously in other ants. The IGS were highly variable in length and dispersed through the mitogenome. This pattern was also found for the other hymenopterans in particular for the monophyletic Apocrita. These spacers with unknown function may be valuable for characterizing genome evolution and distinguishing closely related species and individuals. NGS provided better coverage than Sanger sequencing, especially for tRNA and ribosomal subunit genes, thus facilitating efforts to fill in sequence gaps. The results obtained showed that data from transcriptomic libraries contain valuable information for assembling mitogenomes. The present data also provide a source of molecular markers that will be very important for improving our understanding of genomic evolutionary processes and phylogenetic relationships among hymenopterans.
Plant or fungal sequences? An alternative optimized PCR protocol to avoid ITS (nrDNA) misamplification
Miranda, Vitor Fernandes Oliveira de;Martins, Vanderlei Geraldo;Furlan, Antonio;Bacci Jr., Maurício;
Brazilian Archives of Biology and Technology , 2010, DOI: 10.1590/S1516-89132010000100018
Abstract: the nuclear ribosomal dna internal transcribed spacers (its1 and its2) from leaves of drosera (droseraceae) were amplified using "universal" primers. the analysis of the products demonstrated most samples were a molecular mixture as a result of unsuccessful and non-specific amplifications. among the obtained sequences, two were from basidiomycota fungi. homologous sequences of basidiomycota were obtained from genbank database and added to a data set with sequences from drosera leaves. parsimony analysis demonstrated that one sequence was amplified from an ustilaginomycetes fungus, and another from a heterobasidiomycetes. possibly these fungi were associated to leaves of drosera, and not because of samples contamination. in order to provide optimization and a better specificity of pcr (polymerase chain reaction), a very successful method was demonstrated using dimethyl sulfoxide (dmso) and bovine serum albumin (bsa) in reactions.
Thelytokous Parthenogenesis in the Fungus-Gardening Ant Mycocepurus smithii (Hymenoptera: Formicidae)
Christian Rabeling, José Lino-Neto, Simone C. Cappellari, Iracenir A. Dos-Santos, Ulrich G. Mueller, Maurício Bacci
PLOS ONE , 2009, DOI: 10.1371/journal.pone.0006781
Abstract: The general prevalence of sexual reproduction over asexual reproduction among organisms testifies to the evolutionary benefits of recombination, such as accelerated adaptation to changing environments and elimination of deleterious mutations. Documented instances of asexual reproduction in groups otherwise dominated by sexual reproduction challenge evolutionary biologists to understand the special circumstances that might confer an advantage to asexual reproductive strategies. Here we report one such instance of asexual reproduction in the ants. We present evidence for obligate thelytoky in the asexual fungus-gardening ant, Mycocepurus smithii, in which queens produce female offspring from unfertilized eggs, workers are sterile, and males appear to be completely absent. Obligate thelytoky is implicated by reproductive physiology of queens, lack of males, absence of mating behavior, and natural history observations. An obligate thelytoky hypothesis is further supported by the absence of evidence indicating sexual reproduction or genetic recombination across the species' extensive distribution range (Mexico-Argentina). Potential conflicting evidence for sexual reproduction in this species derives from three Mycocepurus males reported in the literature, previously regarded as possible males of M. smithii. However, we show here that these specimens represent males of the congeneric species M. obsoletus, and not males of M. smithii. Mycocepurus smithii is unique among ants and among eusocial Hymenoptera, in that males seem to be completely absent and only queens (and not workers) produce diploid offspring via thelytoky. Because colonies consisting only of females can be propagated consecutively in the laboratory, M. smithii could be an adequate study organism a) to test hypotheses of the population-genetic advantages and disadvantages of asexual reproduction in a social organism and b) inform kin conflict theory. For a Portuguese translation of the abstract, please see S1.
Occurrence of Winged Forms of Atta sexdens rubropilosa Forel (Hymenoptera: Formicidae) in Laboratory Colonies
BUENO, ODAIR C.;HEBLING, MARIA J.A.;SCHNEIDER, MARCELO O.;PAGNOCCA, FERNANDO C.;BACCI JR, MAURíCIO;
Neotropical Entomology , 2002, DOI: 10.1590/S1519-566X2002000300019
Abstract: the production of hundreds of reproductive forms of atta sexdens rubropilosa forel in nests maintained in laboratory was observed for the first time in brazil. last instar male larvae were found on august 5, 2000 in a six-year-old colony with approximately 110 l of fungus garden distributed in 21 pots. thirty to forty days later, queen larvae started to be seen. the adult sexual forms were comparable in size with those found in the field. two apparent failed attempts of a nuptial flight were observed during the last week of october, followed by the appearance of dead males and females in the garbage piles of the colony.
Phylogenetic relationships in genus Arachis based on ITS and 5.8S rDNA sequences
Marcelo D Bechara, Márcio C Moretzsohn, Darío A Palmieri, Jomar P Monteiro, Maurício Bacci, Joaquim Martins, José FM Valls, Catalina R Lopes, Marcos A Gimenes
BMC Plant Biology , 2010, DOI: 10.1186/1471-2229-10-255
Abstract: Intraspecific variation was detected, but in general it was not enough to place accessions of the same species in different clades. Our data support the view that Arachis is a monophyletic group and suggested Heteranthae as the most primitive section of genus Arachis. The results confirmed the circumscriptions of some sections (Caulorrhizae, Extranervosae), but raised questions about others. Sections Erectoides, Trierectoides and Procumbentes were not well defined, while sections Arachis and Rhizomatosae seem to include species that could be moved to different sections. The division of section Arachis into A and B genome species was also observed in the phylogenetic tree and these two groups of species may not have a monophyletic origin. The 2n = 2x = 18 species of section Arachis (A. praecox, A. palustris and A. decora) were all placed in the same clade, indicating they are closely related to each other, and their genomes are more related to B genome than to the A genome. Data also allowed insights on the origin of tetraploid A. glabrata, suggesting rhizome appeared twice within the genus and raising questions about the placement of that species in section Rhizomatosae.The main clades established in this study in general agreed with many other studies that have used other types of evidences and sets of species, being some of them included in our study and some not. Thus, the relationships established can be a useful framework for future systematic reviews of genus Arachis and for the selection of species to pre-breeding programs.The genus Arachis originated in South America, where all the cultivated and wild species are found, and includes 80 described species [1,2]. Groundnut, the allotetraploid species A. hypogaea (genome formula AABB), is the most important species of the genus because it is cultivated as an oilseed crop and as a direct source of human food. The genus also includes species such as A. glabrata (section Rhizomatosae) and A. pintoi (section Caulorr
Expressed sequence tags from Atta laevigata and identification of candidate genes for the control of pest leaf-cutting ants
Cynara M Rodovalho, Milene Ferro, Fernando PP Fonseca, Erik A Antonio, Ivan R Guilherme, Flávio Henrique-Silva, Maurício Bacci
BMC Research Notes , 2011, DOI: 10.1186/1756-0500-4-203
Abstract: The analysis of the expressed sequence tags allowed us to characterize 2,006 unique sequences in Atta laevigata. Sixteen of these genes had a high number of transcripts and are likely positively selected for high level of gene expression, being responsible for three basic biological functions: energy conservation through redox reactions in mitochondria; cytoskeleton and muscle structuring; regulation of gene expression and metabolism. Based on leafcutters lifestyle and reports of genes involved in key processes of other social insects, we identified 146 sequences potential targets for controlling pest leafcutters. The targets are responsible for antixenobiosis, development and longevity, immunity, resistance to pathogens, pheromone function, cell signaling, behavior, polysaccharide metabolism and arginine kynase activity.The generation and analysis of expressed sequence tags from Atta laevigata have provided important genetic basis for future studies on the biology of leaf-cutting ants and may contribute to the development of a more specific and environmentally friendly method for the control of agricultural pest leafcutters.The tribe Attini comprises over 200 ant species [1] which culture mutualistic fungi for their feeding [2]. The most evolutionary derived attines are the leaf-cutting ants in the genera Atta and Acromyrmex which are considered major herbivores in the tropics [3].Some Atta species contributes to nutrient cycling, aeration and drainage of water in the soil [4], as well as maintenance of plant diversity [5,6]. Their nests were also found to host arthropods [7-9], reptiles and amphibians [4], and microorganisms [10-14].However, despite of these ecological roles, many leafcutter species are considered agricultural pests which impose severe economic damages to agriculture [15,16]. Some of the characteristics contributing to the pest status of leafcutters are their ability of exploiting a great variety of plant species [17], reaching high population den
Isolation and maintenance of symbiotic fungi of ants in the tribe Attini (Hymenoptera: Formicidae)
Silva-Pinhati, Ana C.O.;Bacci Jr., Maurício;Siqueira, Célia G.;Silva, Aline;Pagnocca, Fernando C.;Bueno, Odair C.;Hebling, Maria J.A.;
Neotropical Entomology , 2005, DOI: 10.1590/S1519-566X2005000100001
Abstract: the isolation and maintenance of symbiotic basidiomycete fungi living in association with ants of the tribe attini has been hindered by the slow growth rate of these fungi and the presence of other microorganisms on the surface of the material which the ants maintain inside their nests to provide a growth substrate for their symbiont. in this paper we describe a method which increases the efficiency of isolation of these fungal symbionts by over seven fold as compared to traditional isolation procedures. underground nests of attine ants of the genera atta, acromyrmex, trachymyrmex and mycetarotes were located, from which samples containing the fungal symbiont and ants were collected and transported to the laboratory where the ants were able to clean the fungal culture and stimulate its growth. as the symbiotic fungus grew, portions of its mycelium were collected and transferred to solid yeast nitrogen base culture medium containing glucose and chloramphenicol. to facilitate the maintenance of the isolates in laboratory cultures, several nutrients were tested to formulate a complex culture medium for fast fungal growth and long-term storage. we successfully applied this methodology to the fungal symbionts of all the ant genera studied, thus producing a useful tool for the creation and maintenance of a comprehensive collection of fungi symbiotic of ants in the tribe attini.
Identification and frequency of transposable elements in Eucalyptus
Bacci Jr., Maurício;Soares, Rafael B.S.;Tajara, Eloíza;Ambar, Guilherme;Fischer, Carlos N.;Guilherme, Ivan R.;Costa, Eduardo P.;Miranda, Vitor F.O.;
Genetics and Molecular Biology , 2005, DOI: 10.1590/S1415-47572005000400019
Abstract: transposable elements (te) are major components of eukaryotic genomes and involved in cell regulation and organism evolution. we have analyzed 123,889 expressed sequence tags of the eucalyptus genome project database and found 124 sequences representing 76 te in 9 groups, of which copia, mudr and far1 groups were the most abundant. the low amount of sequences of te may reflect the high efficiency of repression of these elements, a process that is called te silencing. frequency of groups of te in eucalyptus libraries which were prepared with different tissues or physiologic conditions from seedlings or adult plants indicated that developing plants experience the expression of a much wider spectrum of te groups than that seen in adult plants. these are preliminary results that identify the most relevant te groups involved with eucalyptus development, which is important for industrial wood production.
Cyatta abscondita: Taxonomy, Evolution, and Natural History of a New Fungus-Farming Ant Genus from Brazil
Jeffrey Sosa-Calvo, Ted R. Schultz, Carlos R. F. Brand?o, Christiana Klingenberg, Rodrigo M. Feitosa, Christian Rabeling, Maurício Bacci, Cauê T. Lopes, Heraldo L. Vasconcelos
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0080498
Abstract: Cyatta abscondita, a new genus and species of fungus-farming ant from Brazil, is described based on morphological study of more than 20 workers, two dealate gynes, one male, and two larvae. Ecological field data are summarized, including natural history, nest architecture, and foraging behavior. Phylogenetic analyses of DNA sequence data from four nuclear genes indicate that Cyatta abscondita is the distant sister taxon of the genus Kalathomyrmex, and that together they comprise the sister group of the remaining neoattine ants, an informal clade that includes the conspicuous and well-known leaf-cutter ants. Morphologically, Cyatta abscondita shares very few obvious character states with Kalathomyrmex. It does, however, possess a number of striking morphological features unique within the fungus-farming tribe Attini. It also shares morphological character states with taxa that span the ancestral node of the Attini. The morphology, behavior, and other biological characters of Cyatta abscondita are potentially informative about plesiomorphic character states within the fungus-farming ants and about the early evolution of ant agriculture.
Organic Monadology in Maupertuis  [PDF]
Maurício de Carvalho Ramos
Advances in Historical Studies (AHS) , 2015, DOI: 10.4236/ahs.2015.41003
Abstract: The present paper aims to define the seminal parts in the generation theory in Pierre-Louis Moreau de Maupertuis’s System of nature as Leibnizian physical monads of a special type, organic monads, whose main characteristics are: 1) uniting, within the same explanatory system, epigenesis and preformation, following from an interpretation where initial conditions for epigenesis are a homogenous, non-organic seminal matter; 2) having psychic properties which give them a preformational character, allowing seminal parts to display a combination of material and representational morphologies, elaborated from a distinction between the substantial and relational character of chemical affinities proposed by Fran?ois-Geoffroy; 3) bringing, through the previous two characteristics, the System of nature to intelligibly express preexistence, a concept present in Maupertuis’ conjectures on the origins of the first organisms, where to a strongly naturalistic scenario, a supernatural cause is added—one consistent, within limits, with the natural indestructibility of the physical monad within a panspermic reading of the original Leibnizian monadology. Together, these characteristics allow us to define Maupertuis’s generation theory as an organic monadology, capable of expressing itself in other components of the modern sciences of life and the organic, revealing a historical continuity for the heuristics of Leibniz’s natural philosophy.
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