Population dynamics of rhesus macaques and associated foamy virus in Bangladesh.

Foamy viruses are complex retroviruses that have been shown to be transmitted from nonhuman primates to humans. In Bangladesh, infection with simian foamy virus (SFV) is ubiquitous among rhesus macaques, which come into contact with humans in diverse locations and contexts throughout the country. We analyzed microsatellite DNA from 126 macaques at six sites in Bangladesh in order to characterize geographic patterns of macaque population structure. We also included in this study 38 macaques owned by nomadic people who train them to perform for audiences. PCR was used to analyze a portion of the proviral gag gene from all SFV-positive macaques, and multiple clones were sequenced. Phylogenetic analysis was used to infer long-term patterns of viral transmission. Analyses of SFV gag gene sequences indicated that macaque populations from different areas harbor genetically distinct strains of SFV, suggesting that geographic features such as forest cover play a role in determining the dispersal of macaques and SFV. We also found evidence suggesting that humans traveling the region with performing macaques likely play a role in the translocation of macaques and SFV. Our studies found that individual animals can harbor more than one strain of SFV and that presence of more than one SFV strain is more common among older animals. Some macaques are infected with SFV that appears to be recombinant. These findings paint a more detailed picture of how geographic and sociocultural factors influence the spectrum of simian-borne retroviruses

Human migration and the spread of malaria parasites to the New World

We examined the mitogenomes of a large global collection of human malaria parasites to explore how and when Plasmodium falciparum and P. vivax entered the Americas. We found evidence of a significant contribution of African and South Asian lineages to present-day New World malaria parasites with additional P. vivax lineages appearing to originate from Melanesia that were putatively carried by the Australasian peoples who contributed genes to Native Americans. Importantly, mitochondrial lineages of the P. vivax-like species P. simium are shared by platyrrhine monkeys and humans in the Atlantic Forest ecosystem, but not across the Amazon, which most likely resulted from one or a few recent human-to-monkey transfers. While enslaved Africans were likely the main carriers of P. falciparum mitochondrial lineages into the Americas after the conquest, additional parasites carried by Australasian peoples in pre-Columbian times may have contributed to the extensive diversity of extant local populations of P. vivax

Nitrógeno dietario como un nutriente limitante en aves frugívoras Dietary nitrogen as a limiting nutrient in frugivorous birds

La pulpa de las frutas es considerada un alimento inadecuado para las aves frugívoras debido a su bajo contenido de proteína. Por lo tanto, se espera que los frugívoros minimicen sus pérdidas de nitrógeno como una adaptación a la frugivoría. En esta revisión examinamos las propiedades de las frutas y los rasgos fisiológicos de los frugívoros que afectan su capacidad para subsistir en base a una dieta de frutas. La mayoría de las frutas tropicales y templadas parecen contener suficiente nitrógeno para satisfacer los requerimientos de los pájaros, si su ingesta de alimento estuviera ajustada para compensar el gasto energético. Los requerimientos, sin embargo, dependen del tamaño corporal. Las aves más grandes deberían requerir alimentos con una relación de nitrógeno a energía más elevada que las aves pequeñas. No obstante, el nitrógeno digerible puede de hecho ser limitante ya que las pulpas de las frutas parecen contener cantidades considerables de nitrógeno no-proteico y una composición de aminoácidos diferente a la requerida por las aves. Ambas características de las frutas conducen a un aumento de las pérdidas de nitrógeno en aves frugívoras al consumir dietas naturales. En términos de sus adaptaciones fisiológicas, esperaríamos que los frugívoros posean una elevada capacidad de extracción de nitrógeno de la dieta y esbozamos la posibilidad de que las bajas pérdidas urinarias de nitrógeno de los frugívoros pudieran estar relacionadas con una baja tasa metabólica. La minimización de las pérdidas endógenas fecales podría ser la adaptación más importante de los frugívoros para subsistir con base en dietas pobres en nitrógeno. No es evidente como los frugívoros especializados pueden tener requerimientos de nitrógeno más bajos que los esperados en comparación a aves de otros grupos dietarios. Finalmente, sugerimos varios tópicos de investigación que conducirían a mejorar nuestra comprensión de las complejas interacciones involucradas en la regulación de las necesidades proteicas de las aves frugívoras<br>Fruit pulp is considered nutritionally inadequate for frugivorous birds because of its low protein content. Consequently, frugivores are expected to minimize their nitrogen losses as an adaptation to frugivory . In this review we examine properties of fruit and physiological traits of frugivores that affect their ability to subsist on fruit diets. Most tropical and temperate fruit seem to contain enough nitrogen to satisfy bird’s requirements if their food intake was adjusted to meet their energy needs, but requirements depend on body mass. Birds of larger body size should require foods having a higher ratio of nitrogen to energy than smaller species. However, digestible nitrogen may in fact be limiting because fruit pulp seems to contain considerable amounts of nonproteinaceous nitrogen and an amino acid composition that deviates from that required by birds. Both of these characteristics of fruit pulps should augment nitrogen losses of frugivores and consequently their needs when consuming natural diets. In terms of their physiology, we expect frugivores to maximize their nitrogen extraction efficiency from the diet and hint the possibility that low urinary nitrogen losses of frugivores might be related to a low metabolic rate. Minimization of endogenous fecal losses could be the most important adaptation of frugivores to subsist on nitrogen poor diets. It is not evident how specialized frugivores can have lower than expected nitrogen requirements when compared to birds of other dietary groups. We suggest several areas of research that should improve our understanding of the complex interactions involved in the regulation of protein needs of frugivorous bird

Morphometric and molecular characterization of an unpigmented haemosporidian parasite in the Neotropical turnip-tailed gecko (Thecadactylus rapicauda)

Morphological traits from blood stages have been the gold standard for determining haemosporidian parasite species. However, the status of some taxa and the value of such traits in parasites from reptiles remain contentious. The scarce sampling of these species worsens the situation, and several taxa lack molecular data. A survey was performed in the Magdalena Department in Colombia, where 16 species of reptiles were captured. A peculiar haemosporidian parasite was found in the Turnip-tailed gecko Thecadactylus rapicauda. This haemosporidian does not show malarial pigment in blood stages under light microscopy; thus, it fits the Garnia genus's characters belonging to the Garniidae. However, the phylogenetic analyses using a partial sequence of cytochrome b and the mitochondrial DNA placed it within the Plasmodium clade. Our findings suggest that many putative Garnia species belong to the genus Plasmodium, like the one reported here. This study either shows that visible malarial pigment in blood stages is not a diagnostic trait of the genus Plasmodium or malarial pigment might be present in an undetectable form under a light microscope. In any case, the current taxonomy of haemosporidian parasites in reptiles requires revision. This study highlights the importance of using molecular and morphological traits to address taxonomic questions at the species and genus levels in haemosporidian parasites from reptiles

Malaria molecular epidemiology : lessons from the International Centers of Excellence for Malaria Research Network

Molecular epidemiology leverages genetic information to study the risk factors that affect the frequency and distribution of malaria cases. This article describes molecular epidemiologic investigations currently being carried out by the International Centers of Excellence for Malaria Research (ICEMR) network in a variety of malaria-endemic settings. First, we discuss various novel approaches to understand malaria incidence and gametocytemia, focusing on Plasmodium falciparum and Plasmodium vivax. Second, we describe and compare different parasite genotyping methods commonly used in malaria epidemiology and population genetics. Finally, we discuss potential applications of molecular epidemiological tools and methods toward malaria control and elimination efforts

On the diversity of malaria parasites in African apes and the origin of Plasmodium falciparum from Bonobos

The origin of Plasmodium falciparum, the etiological agent of the most dangerous forms of human malaria, remains controversial. Although investigations of homologous parasites in African Apes are crucial to resolve this issue, studies have been restricted to a chimpanzee parasite related to P. falciparum, P. reichenowi, for which a single isolate was available until very recently. Using PCR amplification, we detected Plasmodium parasites in blood samples from 18 of 91 individuals of the genus Pan, including six chimpanzees (three Pan troglodytes troglodytes, three Pan t. schweinfurthii) and twelve bonobos (Pan paniscus). We obtained sequences of the parasites' mitochondrial genomes and/or from two nuclear genes from 14 samples. In addition to P. reichenowi, three other hitherto unknown lineages were found in the chimpanzees. One is related to P. vivax and two to P. falciparum that are likely to belong to distinct species. In the bonobos we found P. falciparum parasites whose mitochondrial genomes indicated that they were distinct from those present in humans, and another parasite lineage related to P. malariae. Phylogenetic analyses based on this diverse set of Plasmodium parasites in African Apes shed new light on the evolutionary history of P. falciparum. The data suggested that P. falciparum did not originate from P. reichenowi of chimpanzees (Pan troglodytes), but rather evolved in bonobos (Pan paniscus), from which it subsequently colonized humans by a host-switch. Finally, our data and that of others indicated that chimpanzees and bonobos maintain malaria parasites, to which humans are susceptible, a factor of some relevance to the renewed efforts to eradicate malaria

Population dynamics of rhesus macaques and associated foamy virus in Bangladesh.

Foamy viruses are complex retroviruses that have been shown to be transmitted from nonhuman primates to humans. In Bangladesh, infection with simian foamy virus (SFV) is ubiquitous among rhesus macaques, which come into contact with humans in diverse locations and contexts throughout the country. We analyzed microsatellite DNA from 126 macaques at six sites in Bangladesh in order to characterize geographic patterns of macaque population structure. We also included in this study 38 macaques owned by nomadic people who train them to perform for audiences. PCR was used to analyze a portion of the proviral gag gene from all SFV-positive macaques, and multiple clones were sequenced. Phylogenetic analysis was used to infer long-term patterns of viral transmission. Analyses of SFV gag gene sequences indicated that macaque populations from different areas harbor genetically distinct strains of SFV, suggesting that geographic features such as forest cover play a role in determining the dispersal of macaques and SFV. We also found evidence suggesting that humans traveling the region with performing macaques likely play a role in the translocation of macaques and SFV. Our studies found that individual animals can harbor more than one strain of SFV and that presence of more than one SFV strain is more common among older animals. Some macaques are infected with SFV that appears to be recombinant. These findings paint a more detailed picture of how geographic and sociocultural factors influence the spectrum of simian-borne retroviruses