Navegando por Autor "Yotoko, Karla S. C."
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Item Does variation in genome sizes reflect adaptive or neutral processes? New clues from Passiflora(PLOS ONE, 2011-03-28) Yotoko, Karla S. C.; Dornelas, Marcelo C.; Togni, Pakisa D.; Fonseca, Tamara C.; Salzano, Francisco M.; Bonatto, Sandro L.; Freitas, Loreta B.One of the long-standing paradoxes in genomic evolution is the observation that much of the genome is composed of repetitive DNA which has been typically regarded as superfluous to the function of the genome in generating phenotypes. In this work, we used comparative phylogenetic approaches to investigate if the variations in genome sizes (GS) should be considered as adaptive or neutral processes by the comparison between GS and flower diameters (FD) of 50 Passiflora species, more specifically, within its two most species-rich subgenera, Passiflora and Decaloba. For this, we have constructed a phylogenetic tree of these species, estimated GS and FD of them, inferred the tempo and mode of evolution of these traits and their correlations, using both current and phylogenetically independent contrasted values. We found significant correlations among the traits, when considering the complete set of data or only the subgenus Passiflora, whereas no correlations were observed within Decaloba. Herein, we present convincing evidence of adaptive evolution of GS, as well as clues that this pattern is limited by a minimum genome size, which could reduce both the possibilities of changes in GS and the possibility of phenotypic responses to environment changes.Item Nuclear mitochondrial DNA: an Achilles’ heel of molecular systematics, phylogenetics, and phylogeographic studies of stingless bees(Apidologie, 2012-09) Cristiano, Maykon P.; Fernandes-Salomão, Tânia M.; Yotoko, Karla S. C.Mitochondrial-like DNA (numt) has been found in a variety of insect species. In this work, our objective was to create a phylogeographic hypothesis of Melipona capixaba based on the complete COI sequence. However, several inconsistencies were found, such as 1–2-bp-long indels and a stop codon within the putative amino acid sequences. This led us to infer that M. capixaba has numts. A phylogenetic analysis which included COI sequences of several species of Melipona Illiger, 1806 revealed that numts are also common among other species of the genus. Based on our results, we have proposed a checklist to help to identify the most conspicuous numts; however, it does not ensure that all numts will be identified, since not all numts present explicit signals. Therefore, we recommend taking the maximum care in phylogeographic and phylogenetic analysis within Melipona as well as Hymenoptera, since several evidences of numts were found within this order.Item Phylogeography of the cactophilic species Drosophila gouveai: demographic events and divergence timing in dry vegetation enclaves in eastern Brazil(Journal of Biogeography, 2009-11) Moraes, Evandro M.; Yotoko, Karla S. C.; Manfrin, Maura H.; Solferini, Vera N.; Sene, Fábio M.The aim of this study was to assess the causal mechanisms underlying populational subdivision in Drosophila gouveai, a cactophilic species associated with xeric vegetation enclaves in eastern Brazil. A secondary aim was to investigate the genetic effects of Pleistocene climatic fluctuations on these environments. Dry vegetation enclaves within the limits of the Cerrado domain in eastern Brazil. We determined the mitochondrial DNA haplotypes of 55 individuals (representing 12 populations) based on sequence data of a 483‐bp fragment from the cytochrome c oxidase subunit II (COII) gene. Phylogenetic and coalescent analyses were used to test for the occurrence of demographic events and to infer the time of divergence amongst genetically independent groups. Our analyses revealed the existence of two divergent subclades (G1 and G2) plus an introgressed clade restricted to the southernmost range of D. gouveai. Subclades G1 and G2 displayed genetic footprints of range expansion and segregated geographical distributions in south‐eastern and some central highland regions, east and west of the Paraná River valley. Molecular dating indicated that the main demographic and diversification events occurred in the late to middle Pleistocene. The phylogeographical and genetic patterns observed for D. gouveai in this study are consistent with changes in the distribution of dry vegetation in eastern Brazil. All of the estimates obtained by molecular dating indicate that range expansion and isolation pre‐dated the Last Glacial Maximum, occurring during the late to middle Pleistocene, and were probably triggered by climatic changes during the Pleistocene. The current patchy geographical distribution and population subdivision in D. gouveai is apparently closely linked to these past events.Item Pliocene and Pleistocene events shaping the genetic diversity within the central corridor of the Brazilian Atlantic Forest(Biological Journal of the Linnean Society, 2010-11-17) Resende, Helder C.; Yotoko, Karla S. C.; Delabie, Jacques H. C.; Costa, Marco A.; Campiopo, Sofia; Tavares, Mara G.; Campos, Lucio A. O.; Fernandes‐ Salomão, Tânia M.Dinoponera lucida (Formicidae; Ponerinae) is an extinction-threatened species of ant which is endemic in the central corridor of the Atlantic Forest. We used mitochondrial sequences of the Cox1, Cox2 and Cytb genes in order to infer some aspects of the evolutionary history and phylogeography of this ant. High genetic divergence and population structure were observed for the whole species. The current pattern of D. lucida diversity seems to be shaped during different geological times: middle Pliocene, early Pleistocene and mainly late Pleistocene, when the reduction of populations generated a structure pattern of the genetic variation of this species. Our data show that this structure results from the maintenance of populations of D. lucida within very small putative refuges to the south of the central Bahia refugium. We thus argue that, for some Atlantic forest endemic species, especially those resistant to very small fragments of forest, such as D. lucida, the small putative refuges were as important as, or even more important than, larger and stable refuges for the creation and maintenance of diversity, adding another piece to the puzzle of the mechanisms underlying local endemism.