Browsing by Author "González Acuña, Daniel"

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    A comprehensive overview of the genetic diversity in Thylamys elegans (Didelphimorphia : Didelphidae) : establishing the phylogeographic determinants
    (2021) Boric Bargetto, Dusan Vladimir; Zúñiga Reinoso, Álvaro; Inostroza Michel, Óscar; Rodríguez Serrano, Enrique Alfonso; González Acuña, Daniel; Palma Vásquez, Ramón Eduardo; Hernández, Cristián E.
    Background: For the genus Thylamys, the rivers have been reported as barriers to dispersal, limiting current and historical distribution of its lineages. We hypothesized that the Maipo river has affected the genetic structure of northern and southern lineages of Thylamys elegans, recovering a phylogenetic relationships with reciprocally monophyletic sister groups on opposite river banks. We evaluated the role of other rivers in the Mediterranean zone of Chile as historical and recent modulators of the biogeographic processes of this species. Methods: We applied a phylogeographic approach, using the cytochrome-b mitochondrial gene for 93 individuals of T. elegans, from 37 localities in a latitudinal gradient between 21°25’ and 35˚56’S, encompassing a geographic area between the Atacama Desert and most of the Mediterranean Chilean zone. Results: The phylogenetics results recovered six lineages within T. elegans: Thylamys elegans elegans, Thylamys elegans coquimbensis, the Loa lineage and three other lineages not described previously (Aconcagua, South 1 and South 2). We suggest that following rivers play a role like primary barrier: the Maipo river in the genetic differentiation of northern and southern ancestral lineages, and the Mataquito river and its tributary Teno river for the South 1 and South 2 lineages. On the other hand, the Quilimarí river preserve the genetic divergence in T. e. coquimbensis and Aconcagua lineage and the Aconcagua river in Aconcagua lineage and T. e. elegans acting like secondary barriers. Conclusions: We concluded that the genetic diversity and biogeographic history of T. elegans was shaped by mountain glaciers, changes in river water levels during the Pleistocene glaciations and hyperaridity, promoting the differentiation and persistance of the T. elegans lineages.
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    Comparative genome-wide polymorphic microsatellite markers in Antarctic penguins through next generation sequencing
    (2017) Abreu Vianna, Juliana de; Noll, Daly; Mura Jornet, Isidora; Valenzuela Guerra, Paulina; González Acuña, Daniel; Navarro, Cristel; Loyola, David E.; Dantas, Gisele P. M.
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    Cryptic speciation in gentoo penguins is driven by geographic isolation and regional marine conditions: Unforeseen vulnerabilities to global change
    (2020) Pertierra, Luis R.; Segovia, Nicolás I.; Noll, Daly; Martínez, Pablo A.; Pliscoff, Patricio; Barbosa, Andrés; Vianna, Juliana; Aragón, Pedro; Raya Rey, Andrea; Pistorius, Pierre; Trathan, Phil; Polanowski, Andrea; Bonadonna, Francesco; Le Bohec, Célin; Bi, Ke; Wang-Claypool, Cynthia Y.; González Acuña, Daniel; Dantas, Gisele P. M.; Bowie, Rauri C. K.; Poulin, Elie
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    Geographic morphological variation of Gentoo penguin (Pygoscelis papua) and sex identification: using morphometric characters and molecular markers
    (2013) Valenzuela Guerra, Paulina; Morales Moraga, David Alejandro; González Acuña, Daniel; De Abreu, Vianna Juliana
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    Landscape genomics: natural selection drives the evolution of mitogenome in penguins
    (2018) Ramos, Barbara.; Miranda, Marcelo; Vianna, Juliana; González Acuña, Daniel; Loyola, David E.; Johnson, Warren E.; Parker, Patricia G.; Massaro, Melanie.; Dantas, Gisele P.M.
    Abstract Background Mitochondria play a key role in the balance of energy and heat production, and therefore the mitochondrial genome is under natural selection by environmental temperature and food availability, since starvation can generate more efficient coupling of energy production. However, selection over mitochondrial DNA (mtDNA) genes has usually been evaluated at the population level. We sequenced by NGS 12 mitogenomes and with four published genomes, assessed genetic variation in ten penguin species distributed from the equator to Antarctica. Signatures of selection of 13 mitochondrial protein-coding genes were evaluated by comparing among species within and among genera (Spheniscus, Pygoscelis, Eudyptula, Eudyptes and Aptenodytes). The genetic data were correlated with environmental data obtained through remote sensing (sea surface temperature [SST], chlorophyll levels [Chl] and a combination of SST and Chl [COM]) through the distribution of these species. Results We identified the complete mtDNA genomes of several penguin species, including ND6 and 8 tRNAs on the light strand and 12 protein coding genes, 14 tRNAs and two rRNAs positioned on the heavy strand. The highest diversity was found in NADH dehydrogenase genes and the lowest in COX genes. The lowest evolutionary divergence among species was between Humboldt (Spheniscus humboldti) and Galapagos (S. mendiculus) penguins (0.004), while the highest was observed between little penguin (Eudyptula minor) and Adélie penguin (Pygoscelis adeliae) (0.097). We identified a signature of purifying selection (Ka/Ks < 1) across the mitochondrial genome, which is consistent with the hypothesis that purifying selection is constraining mitogenome evolution to maintain Oxidative phosphorylation (OXPHOS) proteins and functionality. Pairwise species maximum-likelihood analyses of selection at codon sites suggest positive selection has occurred on ATP8 (Fixed-Effects Likelihood, FEL) and ND4 (Single Likelihood Ancestral Counting, SLAC) in all penguins. In contrast, COX1 had a signature of strong negative selection. ND4 Ka/Ks ratios were highly correlated with SST (Mantel, p-value: 0.0001; GLM, p-value: 0.00001) and thus may be related to climate adaptation throughout penguin speciation. Conclusions These results identify mtDNA candidate genes under selection which could be involved in broad-scale adaptations of penguins to their environment. Such knowledge may be particularly useful for developing predictive models of how these species may respond to severe climatic changes in the future.
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    Mercury exposure in humboldt (Spheniscus humboldti) and chinstrap (pygoscelis antarcticus) penguins throughout the chilean coast and Antarctica
    (2018) Álvarez Varas, Rocío; Morales Moraga, David Alejandro; González Acuña, Daniel; Klarian, Sebastián A.; De Abreu, Vianna Juliana
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    Novel Avulaviruses in Penguins, Antarctica
    (2017) Neira, Víctor; Tapia, Rodrigo; Verdugo, Claudio; Barriga, Gonzalo; Mor, Sunil; Fei Fan Ng, Terry; García, Victoria; Del Río, José; Rodríguez, Pedro; Medina, Rafael; Briceño, Cristóbal; González Acuña, Daniel
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    Phylogenetic evaluation of taxonomic definition of didelphid mouse opossum of the genus Thylamys from valleys of Coquimbo region, Chile.
    (2016) Boric Bargetto, Dusan Vladimir; Zúñiga Reinoso, Alvaro; Cancino, Ricardo A.; González Acuña, Daniel; Rodríguez Serrano, Enrique; Palma Vásquez, Ramón Eduardo; Hernández Ulloa, Cristián Esteban
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    Record of an alleged extinct rodent: molecular analyses of the endemic Octodon pacificus from Chile
    (2017) Abreu Vianna, Juliana de; Noll, Daly; Moreno, Lucila; Silva, Carolina; Muñoz Leal, Sebastián; Najle, María; González Acuña, Daniel