Differences in genetic structuring of populations of the Argentine hemorrhagic fever reservoir, the rodent Calomys musculinus, from endemic and non endemic zones

Chiappero, M.B., Piacenza, M.F., Gardenal, C.N., Calderón, G., Provensal, C., Polop, J.J

Genetic Evidence of Expansion by Passive Transport of Aedes (Stegomyia) aegypti in Eastern Argentina

Aedes (Stegomyia) aegypti (Linnaeus) (Diptera: Culicidae) is the principal vector of the yellow fever virus, the five dengue virus serotypes (DENV-1 to DENV-5), chikungunya virus, Zika virus, and several types of encephalitis [1–3]. The behavior of this species is synanthropic and anthropophilic, being the culicid most closely associated with human populations [4]. The incidence of dengue has increased 30-fold over the last 50 years; according to the World Health Organization, up to 50–100 million infections occur each year in over 100 endemic countries, and at least one half of the world’s population has risk of being infected with dengue virus [5]. Chikungunya virus has been responsible for over 2 million human infections during the past decade and is currently moving to subtropical latitudes as well as to the western hemisphere. Up until April 2015, there have been 1,379,788 suspected cases of this disease in the Caribbean islands, Latin America, and the United States. This expansion into novel habitats brings unique risks associated with further spread of the virus and the disease it causes [6]. On the other hand, there are about 200,000 cases of yellow fever each year worldwide responsible for about 30,000 deaths, most of them from Africa. Zika virus is an emerging mosquito-borne virus, with outbreaks in Africa, Asia, and the Pacific between 2007 and 2014. Since 2015, there has been an increase in reports of ZIKV infection in the Americas, with Brazil being the most affected country, with 534 confirmed cases and 72,062 suspected cases between 2015 and 2016 [7]. All these viruses and the mosquito vector A. aegypti present in the Americas represent a serious risk. So far, in 2016, 39,926 dengue cases produced by DENV-1 and DENV-4 serotypes and 319 autochthonous cases of chikungunya fever have been reported in Argentina. According to the last census, Argentina has approximately 40 million people (National Institute of Statistics and Censuses of Argentina [INDEC], Census 2010), and over 38 million live in areas suitable for the transmission of dengue and chikungunya viruses [8]. Moreover, although there were 22 imported cases of Zika and 24 autochthonous cases confirmed in Argentina, there is a high incidence of cases in Brazil, and besides that, there is an internal circulation of the virus in the neighboring countries Brazil, Paraguay, and Bolivia [7,8], in addition to the constant expansion of the mosquito vector.Facultad de Ciencias Naturales y Muse

Genetic Evidence of Expansion by Passive Transport of Aedes (Stegomyia) aegypti in Eastern Argentina

Aedes (Stegomyia) aegypti (Linnaeus) (Diptera: Culicidae) is the principal vector of the yellow fever virus, the five dengue virus serotypes (DENV-1 to DENV-5), chikungunya virus, Zika virus, and several types of encephalitis [1–3]. The behavior of this species is synanthropic and anthropophilic, being the culicid most closely associated with human populations [4]. The incidence of dengue has increased 30-fold over the last 50 years; according to the World Health Organization, up to 50–100 million infections occur each year in over 100 endemic countries, and at least one half of the world’s population has risk of being infected with dengue virus [5]. Chikungunya virus has been responsible for over 2 million human infections during the past decade and is currently moving to subtropical latitudes as well as to the western hemisphere. Up until April 2015, there have been 1,379,788 suspected cases of this disease in the Caribbean islands, Latin America, and the United States. This expansion into novel habitats brings unique risks associated with further spread of the virus and the disease it causes [6]. On the other hand, there are about 200,000 cases of yellow fever each year worldwide responsible for about 30,000 deaths, most of them from Africa. Zika virus is an emerging mosquito-borne virus, with outbreaks in Africa, Asia, and the Pacific between 2007 and 2014. Since 2015, there has been an increase in reports of ZIKV infection in the Americas, with Brazil being the most affected country, with 534 confirmed cases and 72,062 suspected cases between 2015 and 2016 [7]. All these viruses and the mosquito vector A. aegypti present in the Americas represent a serious risk. So far, in 2016, 39,926 dengue cases produced by DENV-1 and DENV-4 serotypes and 319 autochthonous cases of chikungunya fever have been reported in Argentina. According to the last census, Argentina has approximately 40 million people (National Institute of Statistics and Censuses of Argentina [INDEC], Census 2010), and over 38 million live in areas suitable for the transmission of dengue and chikungunya viruses [8]. Moreover, although there were 22 imported cases of Zika and 24 autochthonous cases confirmed in Argentina, there is a high incidence of cases in Brazil, and besides that, there is an internal circulation of the virus in the neighboring countries Brazil, Paraguay, and Bolivia [7,8], in addition to the constant expansion of the mosquito vector.Facultad de Ciencias Naturales y Muse

Global genetic diversity of Aedes aegypti

Mosquitoes, especially Aedes aegypti, are becoming important models for studying invasion biology. We characterized genetic variation at 12 microsatellite loci in 79 populations of Ae. aegypti from 30 countries in six continents, and used them to infer historical and modern patterns of invasion. Our results support the two subspecies Ae. aegypti formosus and Ae. aegypti aegypti as genetically distinct units. Ae. aegypti aegypti populations outside Africa are derived from ancestral African populations and are monophyletic. The two subspecies co-occur in both East Africa (Kenya) and West Africa (Senegal). In rural/forest settings (Rabai District of Kenya), the two subspecies remain genetically distinct, whereas in urban settings, they introgress freely. Populations outside Africa are highly genetically structured likely due to a combination of recent founder effects, discrete discontinuous habitats and low migration rates. Ancestral populations in sub-Saharan Africa are less genetically structured, as are the populations in Asia. Introduction of Ae. aegypti to the New World coinciding with trans-Atlantic shipping in the 16th to 18th centuries was followed by its introduction to Asia in the late 19th century from the New World or from now extinct populations in the Mediterranean Basin. Aedes mascarensis is a genetically distinct sister species to Ae. aegypti s.l. This study provides a reference database of genetic diversity that can be used to determine the likely origin of new introductions that occur regularly for this invasive species. The genetic uniqueness of many populations and regions has important implications for attempts to control Ae. aegypti, especially for the methods using genetic modification of populations.Centro de Estudios Parasitológicos y de Vectore

Global genetic diversity of Aedes aegypti

Mosquitoes, especially Aedes aegypti, are becoming important models for studying invasion biology. We characterized genetic variation at 12 microsatellite loci in 79 populations of Ae. aegypti from 30 countries in six continents, and used them to infer historical and modern patterns of invasion. Our results support the two subspecies Ae. aegypti formosus and Ae. aegypti aegypti as genetically distinct units. Ae. aegypti aegypti populations outside Africa are derived from ancestral African populations and are monophyletic. The two subspecies co-occur in both East Africa (Kenya) and West Africa (Senegal). In rural/forest settings (Rabai District of Kenya), the two subspecies remain genetically distinct, whereas in urban settings, they introgress freely. Populations outside Africa are highly genetically structured likely due to a combination of recent founder effects, discrete discontinuous habitats and low migration rates. Ancestral populations in sub-Saharan Africa are less genetically structured, as are the populations in Asia. Introduction of Ae. aegypti to the New World coinciding with trans-Atlantic shipping in the 16th to 18th centuries was followed by its introduction to Asia in the late 19th century from the New World or from now extinct populations in the Mediterranean Basin. Aedes mascarensis is a genetically distinct sister species to Ae. aegypti s.l. This study provides a reference database of genetic diversity that can be used to determine the likely origin of new introductions that occur regularly for this invasive species. The genetic uniqueness of many populations and regions has important implications for attempts to control Ae. aegypti, especially for the methods using genetic modification of populations.Centro de Estudios Parasitológicos y de Vectore

Choosing Dimensions: The Capability Approach and Multidimensional Poverty

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Phylogeography of screaming hairy armadillo Chaetophractus vellerosus: Successive disjunctions and extinctions due to cyclical climatic changes in southern South America.

Little is known about phylogeography of armadillo species native to southern South America. In this study we describe the phylogeography of the screaming hairy armadillo Chaetophractus vellerosus, discuss previous hypothesis about the origin of its disjunct distribution and propose an alternative one, based on novel information on genetic variability. Variation of partial sequences of mitochondrial DNA Control Region (CR) from 73 individuals from 23 localities were analyzed to carry out a phylogeographic analysis using neutrality tests, mismatch distribution, median-joining (MJ) network and paleontological records. We found 17 polymorphic sites resulting in 15 haplotypes. Two new geographic records that expand known distribution of the species are presented; one of them links the distributions of recently synonimized species C. nationi and C. vellerosus. Screaming hairy armadillo phylogeographic pattern can be addressed as category V of Avise: common widespread linages plus closely related lineages confined to one or a few nearby locales each. The older linages are distributed in the north-central area of the species distribution range in Argentina (i.e. ancestral area of distribution). C. vellerosus seems to be a low vagility species that expanded, and probably is expanding, its distribution range while presents signs of genetic structuring in central areas. To explain the disjunct distribution, a hypothesis of extinction of the species in intermediate areas due to quaternary climatic shift to more humid conditions was proposed. We offer an alternative explanation: long distance colonization, based on null genetic variability, paleontological record and evidence of alternance of cold/arid and temperate/humid climatic periods during the last million years in southern South America