A new lineage nomenclature to aid genomic surveillance of dengue virus.

Dengue virus (DENV) is currently causing epidemics of unprecedented scope in endemic settings and expanding to new geographical areas. It is therefore critical to track this virus using genomic surveillance. However, the complex patterns of viral genomic diversity make it challenging to use the existing genotype classification system. Here, we propose adding 2 sub-genotypic levels of virus classification, named major and minor lineages. These lineages have high thresholds for phylogenetic distance and clade size, rendering them stable between phylogenetic studies. We present assignment tools to show that the proposed lineages are useful for regional, national, and subnational discussions of relevant DENV diversity. Moreover, the proposed lineages are robust to classification using partial genome sequences. We provide a standardized neutral descriptor of DENV diversity with which we can identify and track lineages of potential epidemiological and/or clinical importance. Information about our lineage system, including methods to assign lineages to sequence data and propose new lineages, can be found at: dengue-lineages.org.

Phylogenetics and an updated taxonomic status of the Tamarins (Callitrichinae, Cebidae).

Traditionally, Saguinus has been organized into six taxonomic groups: bicolor, inustus, midas, mystax, nigricollis, and oedipus. After recent revisions, taxonomic reclassifications were proposed, including (1) the recognition of Leontocebus as a new genus, and (2) the subdivision of Saguinus into three subgenera. Nonetheless, the contradictory nature of these results reinforces the inconsistency concerning the monophyletic status of tamarins and its interspecific phylogeny. Therefore, in this study, we carried out phylogenetic inferences of Saguinus based on 44 molecular markers, of which 37 were from nuclear DNA and seven from mitochondrial DNA. A final dataset of 24,202 base pairs (bp) was obtained from 60 specimens of all recognized species of Saguinus and, also representatives of two main lineages of Leontocebus. Phylogenetic hypothesis was obtained from Maximum Likelihood (ML) and Bayesian inference (BI) methods. We also construct a Species Tree and a fossil-calibrated multi-locus phylogeny to estimate the time of divergence of Tamarins. Our phylogenetic results validated Leontocebus, or nigricollis group, as monophyletic, and recovered additionally three main clades within Saguinus. Same topology was obtained by the Species Tree. These clades correspond to (1) inustus + mystax groups, (2) oedipus group and (3) bicolor + midas group. Our results show support for a 10.5-million-year-old split between Leontocebus and the remaining Saguinus, followed by two other cladogenetic events, around 9.3 and 7.2 mya, which lead to the rise of the main clades of Saguinus. These phylogenetic data, in concert with the consistent morphological, ecological behavior and biogeographic evidence suggest a new classification for the Amazonian and trans-Andean tamarins. Therefore, we support the validation of Leontocebus as genus and recommend the split of Saguinus into three genera: (1) Tamarinus (inustus and mystax groups), (2) Oedipomidas (oedipus group), and (3) Saguinus (bicolor and midas groups).

Vastly underestimated species richness of Amazonian salamanders (Plethodontidae: Bolitoglossa) and implications about plethodontid diversification.

We present data showing that the number of salamander species in Amazonia is vastly underestimated. We used DNA sequences of up to five genes (3 mitochondrial and 2 nuclear) of 366 specimens, 189 corresponding to 89 non-Amazonian nominal species and 177 Amazonian specimens, including types or topotypes, of eight of the nine recognized species in the region. By including representatives of all known species of Amazonian Bolitoglossa, except for one, and 73% of the currently 132 recognized species of the genus, our dataset represents the broadest sample of Bolitoglossa species, specimens, and geographic localities studied to date. We performed phylogenetic analyses using parsimony with tree-alignment and maximum likelihood (ML) with similarity alignment, with indels as binary characters. Our optimal topologies were used to delimit lineages that we assigned to nominal species and candidate new species following criteria that maximize the consilience of the current species taxonomy, monophyly, gaps in branch lengths, genetic distances, and geographic distribution. We contrasted the results of our species-delimitation protocol with those of Automated Barcode Gap Discovery (ABGD) and multi-rate Poisson Tree Processes (mPTP). Finally, we inferred the historical biogeography of South American salamanders by dating the trees and using dispersal-vicariance analysis (DIVA). Our results revealed a clade including almost all Amazonian salamanders, with a topology incompatible with just the currently recognized nine species. Following our species-delimitation criteria, we identified 44 putative species in Amazonia. Both ABGD and mPTP inferred more species than currently recognized, but their numbers (23-49) and limits vary. Our biogeographic analysis suggested a stepping-stone colonization of the Amazonian lowlands from Central America through the Chocó and the Andes, with several late dispersals from Amazonia back into the Andes. These biogeographic events are temporally concordant with an early land bridge between Central and South America (~10-15 MYA) and major landscape changes in Amazonia during the late Miocene and Pliocene, such as the drainage of the Pebas system, the establishment of the Amazon River, and the major orogeny of the northern Andes.

Taxonomy and distribution of the salamander genus Bolitoglossa Duméril, Bibron & Duméril, 1854 (Amphibia, Caudata, Plethodontidae) in Brazilian Amazonia.

For nearly 40 years Bolitoglossa paraensis has been synonymized with Bolitoglossa altamazonica. This fact has been mainly related to taxonomic ambiguities arising from the morphological similarities between these species and the scarcity of material deposited in collections. However, during the past 30 years new material of Bolitoglossa has been collected in many places throughout the Brazilian Amazonia, including the type locality of B. paraensis, Santa Isabel do Pará. In this article we designate the neotype of B. paraensis based on new material from the type locality, correct misinterpretations about this name. We determined how many species of the genus Bolitoglossa occur in Brazilian Amazonia, described three new species, B. caldwellae sp. nov., B. madeira sp. nov., and B. tapajonica sp. nov., provide a key for identifying Brazilian salamanders. Were analyzed two hundred and seventy eight specimens of Bolitoglossa from the Brazilian states of Acre, Amapá, Amazonas, Pará, and Rondonia; morphological data ofB. altamazonica from Colombia were used for comparison purposes. We confirm the presence of B. altamazonica in extreme western Brazil, and expand the number of species occurring in Brazilian Amazonia to five.

Taxonomic status of the Neotropical salamanders Bolitoglossa altamazonica and Bolitoglossa peruviana (Amphibia: Caudata: Plethodontidae), with the description of a new species from Northern Peru.

We examine the phylogenetic relationships among salamanders of the genus Bolitoglossa (Eladinea) distributed in the Amazonian basin of northern Peru and southern Ecuador and assess species diversity based on morphological and phylogenetic analyses. We infer a molecular phylogeny using sequences from two mitochondrial (Cytb, 16S) and two nuclear genes (RAG-1, POMC). We find two well-supported subclades, one including [B. altamazonica + B. peruviana] + B. awajun sp. n., and the other including Bolitoglossa sp. Ituxi + Bolitoglossa sp. Jurúa. Ecuadorian lineages form divergent clades from the Peruvian lineages. Accordingly, Ecuadorian populations previously assigned to Bolitoglossa peruviana sensu lato are treated as members of a Bolitoglossa equatoriana species complex. A newly defined Bolitoglossa altamazonica species complex contains only populations from the Amazonian rainforest of Peru. Maximum likelihood and Bayesian Inference analyses confirm the phylogenetic placement of B. altamazonica and B. peruviana, and support recognition of a related new species of Bolitoglossa. The uncorrected genetic distances between the new species and B. altamazonica are 6.5% for Cytb and 4.9% for 16S; and the uncorrected genetic distances between the new species and B. peruviana are 8.0% for Cytb and 3.9% for 16S. Additionally, analyses of nuclear gene sequences show no haplotype sharing between the new species and closely related species. The new species is distinguished from its congeners by a combination of the following morphological characters: (1) Standard length mean 37.7 mm in males (range 32.0-42.2; n=5) and 41.4 mm in females (range 34.9-48.2; n=6); (2) in life, dorsal coloration uniformly brown with a dark brown triangular marking between the eyes or some irregular light cream spots or patches on the head, back and flanks; (3) iris pale golden; (4) in preservative, dark brown venter with cream mottlings or moderate-sized blotches on the gular region, belly, cloacal region and tail; (5) tips of third finger and third toe protuberant and pointed with nearly complete webbing on the hands and feet; (6) 11-26 maxillary teeth and 8-24 vomerine teeth. Given that the syntypes of B. altamazonica are lost, we designate a neotype for B. altamazonica from Allpahuayo Mishana National Reserve, Loreto department, Peru. Newly collected specimens from ~30 km NE from Moyobamba (type locality of B. peruviana) provide a better understanding of B. peruviana and enable us to show that it is the sister taxon of B. altamazonica. The new species is known from pre-montane forests in Cordillera Escalera Regional Conservation Area, Cordillera Azul National Park and Shucshuyacu, San Martin department, Peru at 485-1311 m elevation,  ~75 km SE from Moyobamba. Bolitoglossa awajun sp. n. is the fourth endemic species of salamander from Peru.