A new species of Anadia (Reptilia, Squamata) from the Venezuelan 'Lost World', northern South America

A new gymnophthalmid lizard of the genus Anadia Gray, 1845 is described from the summit of Abakapá-tepui, Bolívar State, Venezuela, between 2200-2242 m elevation. The new species, Anadia mcdiarmidi sp. nov., is endemic to the Chimantá Massif and seemingly also occurs on Amurí-tepui and Murei-tepui. The new taxon is mainly distinguished from all known congeners by the following combination of characters: body fairly robust, dorsal scales small and quadrangular, middorsal scales 53-57, suboculars large, subequal in size, with sometimes one scale slightly protruding downward between 4th and 5th supralabial, nasal entire, without sub-nostril groove, body uniform beige or greyish to bluish brown in life, devoid of any conspicuous pattern in males, venter immaculate golden grey in life, femoral pores 9-10 on each side in males, preanal pores absent, hemipenis globose, weakly bilobed, bordered by numerous fl ounces (>20) bearing comblike rows of minute weakly mineralized spinules. The presence of a species of Anadia, a primarily Andean genus, on the top of tepuis is of considerable interest to the understanding of the Pantepui biogeography

Geographic distribution and habitat use of Lepidoblepharis miyatai (Squamata: Sphaerodactylidae), with comments on the taxonomic status of the genus in northern Colombia

Geographic distribution and habitat use of Lepidoblepharis miyatai (Squamata: Sphaerodactylidae), with comments on the taxonomic status of the genus in northern Colombia. We present some ecological and biogeographic data on Lepidoblepharis miyatai, a small and endangered gecko endemic to the northwestern foothills of the Sierra Nevada de Santa Marta (SNSM), 31 years after its description. Based on museum specimens and feld observations, we recorded four new localities with confrmed presence of L. miyatai. We calculated the extent of occurrence and altitudinal distribution of this species reaching 21.3 km2 and from sea level to 360 m respectively. Lepidoblepharis miyatai inhabits plant formations of scrub thorn and tropical deciduous forest. Based on microhabitat data obtained from 88 individuals observed in “Las Tinajas Village” we can state a differential use of three substrates with predominant use of leaf-litter. We consider L. miyatai an endemic species of the northwestern sector of the SNSM with a distribution range limited to the south-west by the occurrence of L. sanctaemartae, and towards the east by a thus far undetermined Lepidoblepharis species (here called Lepidoblepharis cf. sanctaemartae). We do not register sympatry of L. miyatai with any other congener. Accordingly, we consider that the recent records of this species in the southeast sector of SNSM are erroneous, given that the specimens cited as L. miyatai of this zone correspond to Lepidoblepharis cf. sanctaemartae. Finally, a reevaluation of the conservation status of L. miyatai is needed, including precise information of its distribution.Distribuição geográfca e uso de hábitat de Lepidoblepharis miyatai (Squamata: Sphaerodactylidae) com comentários sobre a taxonomia do gênero no norte da Colômbia. Apresentamos alguns dados ecológicos de Lepidoblepharis miyatai, um pequeno lagarto ameaçado endêmico das encostas norteocidentais da Sierra Nevada de Santa Marta (SNSM) 31 anos após sua descrição. Com base em exemplares depositados em coleções e observações de campo, registramos quatro novas localidades com presença confrmada de L. miyatai. Calculamos a extensão de ocorrência e a distribuição altitudinal dessa espécie com as localidades apresentadas, alcançando uma área de 21.3 km2 e uma variação altitudinal do nível do mar a 360 m. Essa espécie está presente em formações de bosque espinhoso e de foresta tropical decídua. Com informações sobre o uso de micro-hábitats obtidas de 88 indivíduos registrados em “Las Tinajas”, determinamos que essa espécie apresenta uso diferencial dos três tipos de substrato que ocupa, utilizando principalmente a serapilheira. Consideramos esse lagarto como endêmico do setor norte-ocidental de SNSM, com sua distribuição limitada a sudoeste pelo contato com Lepidoblepharis sanctaemartae e a leste com uma espécie indeterminada de Lepidoblepharis (aqui denominada Lepidoblepharis cf. sanctaemartae). Não registramos simpatria de L. miyatai com nenhuma dessas espécies congêneres. Do mesmo modo, consideramos errôneos os registros recentes dessa espécie no setor sul-oriental de SNSM, já que os exemplares citados previamente como L. miyatai nessa zona correspondem a Lepidoblepharis cf. sanctaemartae. Finalmente, se faz necessária uma reavaliação do estado de conservação de L. miyatai que incluam informações mais precisas sobre sua distribuição.Distribución geográfca y uso de hábitat de Lepidoblepharis miyatai (Squamata: Sphaerodactylidae) con comentarios sobre la taxonomía del género en el norte de Colombia. Presentamos algunos datos ecológicos de Lepidoblepharis miyatai, un pequeño y amenazado gecko endémico de las estribaciones noroccidentales de la Sierra Nevada de Santa Marta (SNSM) 31 años después de su descripción. Con base a ejemplares depositados en colecciones y observaciones en campo, registramos cuatro nuevas localidades con presencia confrmada de L. miyatai. Calculamos la extensión de ocurrencia y la distribución altitudinal de esta especie con las localidades presentadas, alcanzando un área de 21.3 km2 y un rango altitudinal entre el nivel del mar y los 360 m. Esta especie está presente en formaciones de matorral espinoso y bosque seco. Con la información de microhábitat obtenida de 88 individuos registrados en “Las Tinajas”, determinamos que esta especie presenta uso diferencial de los tres tipos de sustrato que ocupa, utilizando principalmente la hojarasca. Consideramos a este lagarto como endémico del sector noroccidental de la SNSM, limitando hacia occidente con el rango de distribución de Lepidoblepharis sanctaemartae y hacia oriente con una especie de Lepidoblepharis hasta ahora no determinada (denominada aquí como Lepidoblepharis cf. sanctaemartae). No registramos simpatría de L. miyatai con alguno de estos congéneres. De igual manera, consideramos que los registros recientes de esta especie en el sector suroriental de la SNSM son erróneos, dado a que los ejemplares citados previamente como L. miyatai en esta zona corresponden con Lepidoblepharis cf. sanctaemartae. Finalmente, se hace necesaria una reevaluación del estado de conservación de L. miyatai, donde se incluya la información más precisa de su distribución

Stability and kinetics of G-quadruplex structures

In this review, we give an overview of recent literature on the structure and stability of unimolecular G-rich quadruplex structures that are relevant to drug design and for in vivo function. The unifying theme in this review is energetics. The thermodynamic stability of quadruplexes has not been studied in the same detail as DNA and RNA duplexes, and there are important differences in the balance of forces between these classes of folded oligonucleotides. We provide an overview of the principles of stability and where available the experimental data that report on these principles. Significant gaps in the literature have been identified, that should be filled by a systematic study of well-defined quadruplexes not only to provide the basic understanding of stability both for design purposes, but also as it relates to in vivo occurrence of quadruplexes. Techniques that are commonly applied to the determination of the structure, stability and folding are discussed in terms of information content and limitations. Quadruplex structures fold and unfold comparatively slowly, and DNA unwinding events associated with transcription and replication may be operating far from equilibrium. The kinetics of formation and resolution of quadruplexes, and methodologies are discussed in the context of stability and their possible biological occurrence

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

A new species of &lt;i&gt;Anadia&lt;/i&gt; (Reptilia, Squamata) from the Venezuelan “Lost World”, northern South America

A new gymnophthalmid lizard of the genus Anadia Gray, 1845 is described from the summit of Abakapá-tepui, Bolívar state, Venezuela, between 2200-2242 m elevation. The new species, Anadia mcdiarmidi sp. nov., is endemic to the Chimantá Massif and seemingly also occurs on Amurí-tepui and Murei-tepui. The new taxon is mainly distinguished from all known congeners by the following combination of characters: body fairly robust, tail longer than SVL, dorsal scales small, quadrangular, middorsal scales 53-57, suboculars large, subequal in size, with sometimes one scale slightly protruding downward between 4th and 5th supralabial, nasal entire, without sub-nostril groove, body uniform greyish to bluish brown in life, devoid of any conspicuous pattern in males, venter immaculate golden grey in life, femoral pores not extending onto preanal area, 9-10 on each side in males, preanal pores absent, hemipenis globose, weakly bilobed, bordered by numerous flounces (&gt;20) bearing comblike rows of minute weakly mineralized spinules.</p

The taxonomic status of the Venezuelan snakes Atractus matthewi and A. nororientalis (Serpentes, Colubridae)

Kok, Philippe J. R., Pauwels, Gilson A. Rivas Fuenmayor Olivier S. G. (2007): The taxonomic status of the Venezuelan snakes Atractus matthewi and A. nororientalis (Serpentes, Colubridae). Zootaxa 1493 (1): 66-68, DOI: 10.11646/zootaxa.1493.1.4, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.1493.1.

Five new species of Pristimantis (Anura: Strabomantidae) from the coastal cloud forest of the Península de Paria, Venezuela

Fieldwork in the cloud forest of Venezuela’s remote Península de Paria in 2001 resulted in the collection of several specimens that could unquestionably be classified as members of the genus Pristimantis.  Subsequent analysis of comparative material in museum collections brought the total number of specimens to 44, and these collectively represent five new species. Two of these species, P. geminus sp. nov. and P. nubisilva sp. nov., have phenotypes remarkably similar to the Trinidadian P. urichi, supporting a prediction that Pristimantis from easternmost Venezuela may have given rise to Trinidadian forms. Pristimantis hoogmoedi sp. nov. is easily identified by its large size and red eyes. Two of the species, P. longicorpus sp. nov. and P. pariagnomus sp. nov., are very distinct morphologically but are known only from the holotypes. The former is characterized by an elongate body form supported by relatively short limbs, whereas the latter has very distinctive hand morphology and is likely the smallest Venezuelan frog. Chromosome banding studies of P. nubisilva sp. nov. and P. hoogmoedi sp. nov. revealed chromosome numbers of 2n = 36 and 2n = 26, respectively, with an unusual submetacentric fusion chromosome 11;18 in some males of the former and a unique meiotic pairing of chromosomes in males of the latter.  All five species can be readily distinguished by their osteology, such as by the extent of the sphenethmoid and features on the roof of the mouth, as well as by the shape and rearrangement of mesopodial elements.  The unexpectedly high diversity of Pristimantis in this region, along with high endemism of amphibians and reptiles in general, underscores the position of the Península de Paria as a center for frog biodiversity in Venezuela.  The similarity of these Paria species to Pristimantis from Trinidad, Tobago and the central Cordillera de la Costa represents a tangible piece of evidence for the close biogeographic link of the anuran fauna of these landmasses.</p

Disentangling the Anacondas: Revealing a New Green Species and Rethinking Yellows

Anacondas, genus Eunectes, are a group of aquatic snakes with a wide distribution in South America. The taxonomic status of several species has been uncertain and/or controversial. Using genetic data from four recognized anaconda species across nine countries, this study investigates the phylogenetic relationships within the genus Eunectes. A key finding was the identification of two distinct clades within Eunectes murinus, revealing two species as cryptic yet genetically deeply divergent. This has led to the recognition of the Northern Green Anaconda as a separate species (Eunectes akayima sp. nov), distinct from its southern counterpart (E. murinus), the Southern Green Anaconda. Additionally, our data challenge the current understanding of Yellow Anaconda species by proposing the unification of Eunectes deschauenseei and Eunectes beniensis into a single species with Eunectes notaeus. This reclassification is based on comprehensive genetic and phylogeographic analyses, suggesting closer relationships than previously recognized and the realization that our understanding of their geographic ranges is insufficient to justify its use as a separation criterion. We also present a phylogeographic hypothesis that traces the Miocene diversification of anacondas in western South America. Beyond its academic significance, this study has vital implications for the conservation of these iconic reptile species, highlighting our lack of knowledge about the diversity of the South American fauna and the need for revised strategies to conserve the newly identified and reclassified species

Not withering on the evolutionary vine: Systematic revision of the Brown Vine Snake (Reptilia: Squamata: Oxybelis) from its northern distribution

The genus Oxybelis currently is composed of four taxa despite numerous studies suggesting and describing multiple taxa within the O. aeneus complex. Here, we utilize a multilocus molecular dataset (i.e. cyt b, ND4, 12S, 16S, cmos, PRLR, 3663 bp) to conduct phylogenetic analyses to assess the evolutionary history of Oxybelis. Our molecular analyses find three major lineages of Oxybelis (i.e. O. aeneus complex, O. brevirostris, O. fulgidus complex) with a sister relationship between O. brevirostris and the O. aeneus complex to the exclusion of the O. fulgidus complex. More specifically, O. aeneus appears to harbor at least five taxa currently unrecognized while O. fulgidus was found to be paraphyletic with respect to O. wilsoni, suggesting cryptic diversity and novel taxa in that clade as well. Additionally, we use morphological data in concert with our molecular analyses and the literature to support removing Oxybelis microphthalmus Barbour and Amaral, 1926, Oxybelis potosiensis Taylor, 1941, and Dryophis vittatus Girard, 1854 from the synonymy of O. aeneus. Finally, we describe two new species from Central and northern South America