Glaciation Effects on the Phylogeographic Structure of Oligoryzomys longicaudatus (Rodentia: Sigmodontinae) in the Southern Andes

The long-tailed pygmy rice rat Oligoryzomys longicaudatus (Sigmodontinae), the major reservoir of Hantavirus in Chile and Patagonian Argentina, is widely distributed in the Mediterranean, Temperate and Patagonian Forests of Chile, as well as in adjacent areas in southern Argentina. We used molecular data to evaluate the effects of the last glacial event on the phylogeographic structure of this species. We examined if historical Pleistocene events had affected genetic variation and spatial distribution of this species along its distributional range. We sampled 223 individuals representing 47 localities along the species range, and sequenced the hypervariable domain I of the mtDNA control region. Aligned sequences were analyzed using haplotype network, Bayesian population structure and demographic analyses. Analysis of population structure and the haplotype network inferred three genetic clusters along the distribution of O. longicaudatus that mostly agreed with the three major ecogeographic regions in Chile: Mediterranean, Temperate Forests and Patagonian Forests. Bayesian Skyline Plots showed constant population sizes through time in all three clusters followed by an increase after and during the Last Glacial Maximum (LGM; between 26,000–13,000 years ago). Neutrality tests and the “g” parameter also suggest that populations of O. longicaudatus experienced demographic expansion across the species entire range. Past climate shifts have influenced population structure and lineage variation of O. longicaudatus. This species remained in refugia areas during Pleistocene times in southern Temperate Forests (and adjacent areas in Patagonia). From these refugia, O. longicaudatus experienced demographic expansions into Patagonian Forests and central Mediterranean Chile using glacial retreats

Cholera in Oceania

For approximately 200 years, cholera has been feared globally as a disease that can cause rapid-onset epidemics. The causative organisms, Vibrio cholerae O1 and O139 serogroups, are endemic to Southern Asia, but appear to spread globally in waves resulting in seven recognised pandemics to date. The current seventh pandemic has seen the introduction of V. cholerae O1 El Tor into the Oceania region. Since 1962 there have been five large outbreaks at a frequency of approximately one per decade. There have also been regular small outbreaks and clusters of disease throughout the region during the seventh pandemic. The most recent outbreak of cholera in the region occurred in Papua New Guinea in 2009–2011, and this was the largest outbreak to occur in the region to date. In Oceania the majority of people live in high-income settings (Australia and New Zealand) so the risk of cholera transmission is low. Despite this, an estimated 6.5 million people living in the region are at risk of cholera. The most important risk factors are inadequate access to safe water and lack of appropriate sanitation and hygiene measures. However, many other factors may contribute to cholera transmission risk, and people living in Pacific Island countries may be at increased risk in the future due to climate change. Strengthening health delivery services in the region will ensure countries are better equipped to handle future cholera outbreaks; and further understanding the epidemiology of cholera and the causative agent in the region could help prevent future transmission

Diversification and evolutionary histories of patagonian steppe lizards

During the last two decades, regional exploration coupled with dense geographic sampling, new molecular techniques, and phylogeographic approaches have led to the discovery of unexpected hidden diversity. These data have expanded inferences about evolutionary and demographic processes to explain patterns of geographic genetic distribution, phylogenetic history, and morphological characteristics. This chapter summarizes current knowledge of species boundaries and possible underlying processes, highlighting the extent of hybridization and its possible role for the lack of strongly supported phylogenetic relationships within several species groups.Fil: Morando, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; ArgentinaFil: Medina, Cintia Débora. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Centro Nacional Patagonico. Unidad de Administracion Territorial.; ArgentinaFil: Minoli, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; ArgentinaFil: Perez, Cristian Hernan Fulvio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Confluencia. Unidad de Administración Territorial; ArgentinaFil: Sites, Jack W.. University Brigham Young; Estados UnidosFil: Avila, Luciano Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; Argentin