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1.
Curr Zool ; 70(2): 150-162, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38726254

RESUMEN

Influenced by rapid changes in climate and landscape features since the Miocene, widely distributed species provide suitable models to study the environmental impact on their evolution and current genetic diversity. The dice snake Natrix tessellata, widely distributed in the Western Palearctic is one such species. We aimed to resolve a detailed phylogeography of N. tessellata with a focus on the Central Asian clade with 4 and the Anatolia clade with 3 mitochondrial lineages, trace their origin, and correlate the environmental changes that affected their distribution through time. The expected time of divergence of both clades began at 3.7 Mya in the Pliocene, reaching lineage differentiation approximately 1 million years later. The genetic diversity in both clades is rich, suggesting different ancestral areas, glacial refugia, demographic changes, and colonization routes. The Caspian lineage is the most widespread lineage in Central Asia, distributed around the Caspian Sea and reaching the foothills of the Hindu Kush Mountains in Afghanistan, and Eastern European lowlands in the west. Its distribution is limited by deserts, mountains, and cold steppe environments. Similarly, Kazakhstan and Uzbekistan lineages followed the Amu Darya and the Syr Darya water systems in Central Asia, with ranges delimited by the large Kyzylkum and Karakum deserts. On the western side, there are several lineages within the Anatolia clade that converged in the central part of the peninsula with 2 being endemic to Western Asia. The distribution of both main clades was affected by expansion from their Pleistocene glacial refugia around the Caspian Sea and in the valleys of Central Asia as well as by environmental changes, mostly through aridification.

2.
Sci Rep ; 13(1): 13272, 2023 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-37582802

RESUMEN

The timing, sequence, and scale of uplift of the Himalayan-Tibetan Orogen (HTO) are controversially debated. Many geoscientific studies assume paleoelevations close to present-day elevations and the existence of alpine environments across the HTO already in the late Paleogene, contradicting fossil data. Using molecular genetic data of ground beetles, we aim to reconstruct the paleoenvironmental history of the HTO, focusing on its southern margin (Himalayas, South Tibet). Based on a comprehensive sampling of extratropical Carabus, and ~ 10,000 bp of mitochondrial and nuclear DNA we applied Bayesian and Maximum likelihood methods to infer the phylogenetic relationships. We show that Carabus arrived in the HTO at the Oligocene-Miocene boundary. During the early Miocene, five lineages diversified in different parts of the HTO, initially in its southern center and on its eastern margin. Evolution of alpine taxa occurred during the late Miocene. There were apparently no habitats for Carabus before the late Oligocene. Until the Late Oligocene elevations must have been low throughout the HTO. Temperate forests emerged in South Tibet in the late Oligocene at the earliest. Alpine environments developed in the HTO from the late Miocene and, in large scale, during the Pliocene-Quaternary. Findings are consistent with fossil records but contrast with uplift models recovered from stable isotope paleoaltimetry.


Asunto(s)
Evolución Biológica , Escarabajos , Filogenia , Escarabajos/clasificación , Escarabajos/genética , Ecosistema , Paleontología , Asia , Fósiles
3.
Genes (Basel) ; 12(9)2021 09 16.
Artículo en Inglés | MEDLINE | ID: mdl-34573405

RESUMEN

The Himalayan Arc is recognized as a global biodiversity hotspot. Among its numerous cryptic and undiscovered organisms, this composite high-mountain ecosystem harbors many taxa with adaptations to life in high elevations. However, evolutionary patterns and genomic features have been relatively rarely studied in Himalayan vertebrates. Here, we provide the first well-annotated transcriptome of a Greater Himalayan reptile species, the Ladakh Ground skink Asymblepharus ladacensis (Squamata: Scincidae). Based on tissues from the brain, an embryonic disc, and pooled organ material, using pair-end Illumina NextSeq 500 RNAseq, we assembled ~77,000 transcripts, which were annotated using seven functional databases. We tested ~1600 genes, known to be under positive selection in anurans and reptiles adapted to high elevations, and potentially detected positive selection for 114 of these genes in Asymblepharus. Even though the strength of these results is limited due to the single-animal approach, our transcriptome resource may be valuable data for further studies on squamate reptile evolution in the Himalayas as a hotspot of biodiversity.


Asunto(s)
Adaptación Fisiológica/genética , Altitud , Lagartos/genética , Transcriptoma , Aclimatación/genética , Animales , Secuenciación de Nucleótidos de Alto Rendimiento , Lagartos/clasificación , Anotación de Secuencia Molecular , Nepal , RNA-Seq , Análisis de Secuencia de ADN/veterinaria
4.
PLoS One ; 16(9): e0256679, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34550988

RESUMEN

Molecular clocks have become powerful tools given increasing sequencing and fossil resources. However, calibration analyses outcomes depend on the choice of priors. Here, we revisited the seminal dating study published by Andújar and coworkers of the genus Carabus proposing that prior choices need re-evaluation. We hypothesized that reflecting fossil evidence and the Gondwanan split properly significantly rewinds the molecular clock. We re-used the dataset including five mitochondrial and four nuclear DNA fragments with a total length of 7888 nt. Fossil evidence for Oligocene occurrence of Calosoma was considered. Root age was set based on the fossil evidence of Harpalinae ground beetles in the Upper Cretaceous. Paleogene divergence of the outgroup taxa Ceroglossini and Pamborini is introduced as a new prior based on current paleontological and geological literature. The ultrametric time-calibrated tree of the extended nd5 dataset resulted in a median TMRCA Carabus of 53.92 Ma (HPD 95% 45.01-63.18 Ma), roughly 30 Ma older than in the Andújar study. The splits among C. rugosus and C. morbillosus (A), C. riffensis from the European Mesocarabus (B), and Eurycarabus and Nesaeocarabus (C) were dated to 17.58 (12.87-22.85), 24.14 (18.02-30.58), and 21.6 (16.44-27.43) Ma. They were decidedly older than those previously reported (7.48, 10.93, and 9.51 Ma). These changes were driven almost entirely by constraining the Carabidae time-tree root with a Harpalinae amber fossil at ~99 Ma. Utilizing the nd5 dating results of three well-supported Carabus clades as secondary calibration points for the complete MIT-NUC dataset led to a TMRCA of Carabus of 44.72 (37.54-52.22) Ma, compared with 25.16 Ma (18.41-33.04 Ma) in the previous study. Considering fossil evidence for Oligocene Calosoma and Late Cretaceous Harpalini together with the Gondwanan split as a new prior, our new approach supports the origin of genus Carabus in the Eocene. Our results are preliminary because of the heavy reliance on the nd5 gene, and thus will have to be tested with a sufficient set of nuclear markers. Additionally, uncertainties due to dating root age of the tree based on a single fossil and outgroup taxon affect the results. Improvement of the fossil database, particularly in the supertribe Carabitae, is needed to reduce these uncertainties in dating Carabus phylogeny.


Asunto(s)
Escarabajos/genética , ADN Mitocondrial/genética , Complejo I de Transporte de Electrón/genética , Proteínas de Insectos/genética , Filogenia , Animales , Escarabajos/clasificación , ADN Mitocondrial/historia , Complejo I de Transporte de Electrón/historia , Fósiles , Expresión Génica , Especiación Genética , Historia Antigua , Proteínas de Insectos/historia , Paleontología/métodos
5.
Zookeys ; 1049: 67-77, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34385880

RESUMEN

Little is known about the life history, ecology, and distribution of the genus Allopaa (Dicroglossidae) and far less recent data are available about the larvae of this taxon. Here, we provide data on the larval stage of Allopaa hazarensis (Dubois & Khan, 1979) from northern Pakistan based on the examination of three tadpoles. Specimens were obtained from two sites in Buner, Khyber Pakhtunkhwa province, Pakistan. Morphological and genetic analysis (mtDNA and nDNA) confirmed the identity of the tadpoles as A. hazarensis. Tadpole characterizations were illustrated by detailed imagery. Basic measurements and details on oral apparatus provide relevant taxonomic characteristics to distinguish the tadpoles of this species from other spiny frogs. The illustration and description of the tadpole of A. hazarensis should facilitate the identification of this species in the field.

6.
PeerJ ; 9: e11793, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34316409

RESUMEN

BACKGROUND: The Himalaya-Tibet orogen (HTO) presents an outstanding geologically active formation that contributed to, and fostered, modern Asian biodiversity. However, our concepts of the historical biogeography of its biota are far from conclusive, as are uplift scenarios for the different parts of the HTO. Here, we revisited our previously published data set of the tribe Paini extending it with sequence data from the most western Himalayan spiny frogs Allopaa and Chrysopaa and using them as an indirect indicator for the potential paleoecological development of Tibet. METHODS: We obtained sequence data of two mitochondrial loci (16S rRNA, COI) and one nuclear marker (Rag1) from Allopaa samples from Kashmir Himalaya as well as Chrysopaa sequence data from the Hindu Kush available from GenBank to complement our previous data set. A Maximum likelihood and dated Bayesian gene tree were generated based on the concatenated data set. To resolve the inconsistent placement of Allopaa, we performed different topology tests. RESULTS: Consistent with previous results, the Southeast Asian genus Quasipaa is sister to all other spiny frogs. The results further reveal a basal placement of Chrysopaa relative to Allopaa and Nanorana with an estimated age of ca. 26 Mya. Based on the topology tests, the phylogenetic position of Allopaa as a sister clade to Chaparana seems to be most likely, resulting in a paraphyletic genus Nanorana and a separation from the latter clade around 20 Mya, although a basal position of Allopaa to the genus Nanorana cannot be entirely excluded. Both, the placements of Chrysopaa and Allopaa support the presence of basal Paini lineages in the far northwestern part of the HTO, which is diametrically opposite end of the HTO with respect to the ancestral area of spiny frogs in Southeast Asia. These striking distributional patterns can be most parsimoniously explained by trans-Tibet dispersal during the late Oligocene (subtropical Chrysopaa) respectively early Miocene (warm temperate Allopaa). Within spiny frogs, only members of the monophyletic Nanorana+Paa clade are adapted to the colder temperate climates, indicating that high-altitude environments did not dominate in the HTO before ca. 15 Mya. Our results are consistent with fossil records suggesting that large parts of Tibet were characterized by subtropical to warm temperate climates at least until the early Miocene. They contradict prevalent geological models of a highly uplifted late Paleogene proto-Plateau.

7.
Ecol Evol ; 10(11): 4531-4561, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32551042

RESUMEN

Reproductive mode, ancestry, and climate are hypothesized to determine body size variation in reptiles but their effects have rarely been estimated simultaneously, especially at the intraspecific level. The common lizard (Zootoca vivipara) occupies almost the entire Northern Eurasia and includes viviparous and oviparous lineages, thus representing an excellent model for such studies. Using body length data for >10,000 individuals from 72 geographically distinct populations over the species' range, we analyzed how sex-specific adult body size and sexual size dimorphism (SSD) is associated with reproductive mode, lineage identity, and several climatic variables. Variation in male size was low and poorly explained by our predictors. In contrast, female size and SSD varied considerably, demonstrating significant effects of reproductive mode and particularly seasonality. Populations of the western oviparous lineage (northern Spain, south-western France) exhibited a smaller female size and less female-biased SSD than those of the western viviparous (France to Eastern Europe) and the eastern viviparous (Eastern Europe to Far East) lineages; this pattern persisted even after controlling for climatic effects. The phenotypic response to seasonality was complex: across the lineages, as well as within the eastern viviparous lineage, female size and SSD increase with increasing seasonality, whereas the western viviparous lineage followed the opposing trends. Altogether, viviparous populations seem to follow a saw-tooth geographic cline, which might reflect the nonmonotonic relationship of body size at maturity in females with the length of activity season. This relationship is predicted to arise in perennial ectotherms as a response to environmental constraints caused by seasonality of growth and reproduction. The SSD allometry followed the converse of Rensch's rule, a rare pattern for amniotes. Our results provide the first evidence of opposing body size-climate relationships in intraspecific units.

8.
Genes (Basel) ; 10(11)2019 10 31.
Artículo en Inglés | MEDLINE | ID: mdl-31683620

RESUMEN

The Himalayas are one of earth's hotspots of biodiversity. Among its many cryptic and undiscovered organisms, including vertebrates, this complex high-mountain ecosystem is expected to harbour many species with adaptations to life in high altitudes. However, modern evolutionary genomic studies in Himalayan vertebrates are still at the beginning. Moreover, in organisms, like most amphibians with relatively high DNA content, whole genome sequencing remains bioinformatically challenging and no complete nuclear genomes are available for Himalayan amphibians. Here, we present the first well-annotated multi-tissue transcriptome of a Greater Himalayan species, the lazy toad Scutiger cf. sikimmensis (Anura: Megophryidae). Applying Illumina NextSeq 500 RNAseq to six tissues, we obtained 41.32 Gb of sequences, assembled to ~111,000 unigenes, translating into 54362 known genes as annotated in seven functional databases. We tested 19 genes, known to play roles in anuran and reptile adaptation to high elevations, and potentially detected diversifying selection for two (TGS1, SENP5) in Scutiger. Of a list of 37 genes, we also identify 27 candidate genes for sex determination or sexual development, all of which providing the first such data for this non-model megophryid species. These transcriptomes will serve as a valuable resource for further studies on amphibian evolution in the Greater Himalaya as a biodiversity hotspot.


Asunto(s)
Adaptación Fisiológica/genética , Anuros/genética , Procesos de Determinación del Sexo/genética , Transcriptoma , Altitud , Animales , Anuros/fisiología , Femenino , Masculino
9.
Ecol Evol ; 9(24): 14498-14511, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31938536

RESUMEN

Recent advances in the understanding of the evolution of the Asian continent challenge the long-held belief of a faunal immigration into the Himalaya. Spiny frogs of the genus Nanorana are a characteristic faunal group of the Himalaya-Tibet orogen (HTO). We examine the phylogeny of these frogs to explore alternative biogeographic scenarios for their origin in the Greater Himalaya, namely, immigration, South Tibetan origin, strict vicariance. We sequenced 150 Nanorana samples from 62 localities for three mitochondrial (1,524 bp) and three nuclear markers (2,043 bp) and complemented the data with sequence data available from GenBank. We reconstructed a gene tree, phylogenetic networks, and ancestral areas. Based on the nuDNA, we also generated a time-calibrated species tree. The results revealed two major clades (Nanorana and Quasipaa), which originated in the Lower Miocene from eastern China and subsequently spread into the HTO (Nanorana). Five well-supported subclades are found within Nanorana: from the East, Central, and Northwest Himalaya, the Tibetan Plateau, and the southeastern Plateau margin. The latter subclade represents the most basal group (subgenus Chaparana), the Plateau group (Nanorana) represents the sister clade to all species of the Greater Himalaya (Paa). We found no evidence for an east-west range expansion of Paa along the Himalaya, nor clear support for a strict vicariance model. Diversification in each of the three Himalayan subclades has probably occurred in distinct areas. Specimens from the NW Himalaya are placed basally relative to the highly diverse Central Himalayan group, while the lineage from the Tibetan Plateau is placed within a more terminal clade. Our data indicate a Tibetan origin of Himalayan Nanorana and support a previous hypothesis, which implies that a significant part of the Himalayan biodiversity results from primary diversification of the species groups in South Tibet before this part of the HTO was uplifted to its recent heights.

10.
Zootaxa ; 4471(1): 137-153, 2018 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-30313421

RESUMEN

Based on morphological characteristics, two subspecies of the Transcaucasian rat snake (Zamenis hohenackeri) are currently recognized, namely Z. h. tauricus and Z. h. hohenackeri. Both subspecies are repeatedly considered to be conspecific colour morphs, or have even been confused with Z. situla. Although, few studies involved the Transcaucasian rat snake in a phylogenetic approach, none has so far led to any taxonomic changes. We assessed the intraspecific morphological variation and phylogeographic relationships among specimens from different locations across its updated distribution. Our molecular (1191 bp mtDNA, 565 bp nuDNA) and morphological data provide sufficient evidence to support three distinct lineages within the Z. hohenackeri complex with a different arrangement compared to a previous study. These represent the subspecies Z. h. hohenackeri, Z. h. tauricus, and a lineage from southwestern Turkey which is described as a new subspecies. Aspects of historical biogeography and conservation status are briefly discussed.


Asunto(s)
Colubridae , Filogenia , Animales , ADN Mitocondrial , Filogeografía , Turquía
11.
Proc Biol Sci ; 285(1872)2018 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-29436499

RESUMEN

The evolutionary causes and consequences of allopolyploidization, an exceptional pathway to instant hybrid speciation, are poorly investigated in animals. In particular, when and why hybrid polyploids versus diploids are produced, and constraints on sources of paternal and maternal ancestors, remain underexplored. Using the Palearctic green toad radiation (including bisexually reproducing species of three ploidy levels) as model, we generate a range-wide multi-locus phylogeny of 15 taxa and present four new insights: (i) at least five (up to seven) distinct allotriploid and allotetraploid taxa have evolved in the Pleistocene; (ii) all maternal and paternal ancestors of hybrid polyploids stem from two deeply diverged nuclear clades (6 Mya, 3.1-9.6 Mya), with distinctly greater divergence than the parental species of diploid hybrids found at secondary contact zones; (iii) allotriploid taxa possess two conspecific genomes and a deeply diverged allospecific one, suggesting that genomic imbalance and divergence are causal for their partly clonal reproductive mode; (iv) maternal versus paternal genome contributions exhibit asymmetry, with the maternal nuclear (and mitochondrial) genome of polyploids always coming from the same clade, and the paternal genome from the other. We compare our findings with similar patterns in diploid/polyploid vertebrates, and suggest deep ancestral divergence as a precondition for successful allopolyploidization.


Asunto(s)
Bufonidae/genética , Especiación Genética , Variación Genética , Hibridación Genética , Poliploidía , Proteínas Anfibias/genética , Proteínas Anfibias/metabolismo , Animales , Núcleo Celular/genética , ADN Mitocondrial/genética , Genoma , Tipificación de Secuencias Multilocus , Filogenia , Análisis de Secuencia de ADN
12.
Eur Respir J ; 50(6)2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29242257

RESUMEN

Sarcoidosis is a granulomatous disease that mainly affects the lung. A role of microbial factors in disease pathogenesis is assumed, but has not been investigated systematically in a large cohort.This cross-sectional study compared the lung microbiota of 71 patients with sarcoidosis, 15 patients with idiopathic pulmonary fibrosis (non-infectious controls) and 10 healthy controls (HCs). Next-generation sequencing of 16S DNA was used on bronchoalveolar lavage samples to characterise the microbial composition, which was analysed for diversity and indicator species. Host genotypes for 13 known sarcoidosis risk variants were determined and correlated with microbial parameters.The microbial composition differed significantly between sarcoidosis and HC samples (redundancy analysis ANOVA, p=0.025) and between radiographic Scadding types. Atopobium spp. was detected in 68% of sarcoidosis samples, but not in HC samples. Fusobacterium spp. was significantly more abundant in sarcoidosis samples compared with those from HCs. Mycobacteria were found in two of 71 sarcoidosis samples. Host-genotype analysis revealed an association of the rs2076530 (BTNL2) risk allele with a decrease in bacterial burden (p=0.002).Our results indicate Scadding type-dependent microbiota in sarcoidosis BAL samples. Atopobium spp. and Fusobacterium spp. were identified as sarcoidosis-associated bacteria, which may enable new insights into the pathogenesis and treatment of the disease.


Asunto(s)
Actinobacteria/aislamiento & purificación , Fusobacterium/aislamiento & purificación , Pulmón/microbiología , Microbiota , Sarcoidosis/microbiología , Actinobacteria/genética , Adulto , Anciano , Anciano de 80 o más Años , Alelos , Líquido del Lavado Bronquioalveolar/microbiología , Butirofilinas/genética , Estudios de Casos y Controles , Estudios Transversales , Femenino , Fusobacterium/genética , Alemania , Humanos , Masculino , Persona de Mediana Edad , ARN Ribosómico 16S/genética , Sarcoidosis/genética , Adulto Joven
13.
PLoS One ; 12(10): e0185591, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28973006

RESUMEN

Assessing species richness and diversity on the basis of standardised field sampling effort represents a cost- and time-consuming method. Satellite remote sensing (RS) can help overcome these limitations because it facilitates the collection of larger amounts of spatial data using cost-effective techniques. RS information is hence increasingly analysed to model biodiversity across space and time. Here, we focus on image texture measures as a proxy for spatial habitat heterogeneity, which has been recognized as an important determinant of species distributions and diversity. Using bee monitoring data of four years (2010-2013) from six 4 × 4 km field sites across Central Germany and a multimodel inference approach we test the ability of texture features derived from Landsat-TM imagery to model local pollinator biodiversity. Textures were shown to reflect patterns of bee diversity and species richness to some extent, with the first-order entropy texture and terrain roughness being the most relevant indicators. However, the texture measurements accounted for only 3-5% of up to 60% of the variability that was explained by our final models, although the results are largely consistent across different species groups (bumble bees, solitary bees). While our findings provide indications in support of the applicability of satellite imagery textures for modeling patterns of bee biodiversity, they are inconsistent with the high predictive power of texture metrics reported in previous studies for avian biodiversity. We assume that our texture data captured mainly heterogeneity resulting from landscape configuration, which might be functionally less important for wild bees than compositional diversity of plant communities. Our study also highlights the substantial variability among taxa in the applicability of texture metrics for modelling biodiversity.


Asunto(s)
Biodiversidad , Insectos/fisiología , Polinización , Tecnología de Sensores Remotos , Animales , Ecosistema , Alemania , Insectos/clasificación
14.
Sci Rep ; 7(1): 3308, 2017 06 12.
Artículo en Inglés | MEDLINE | ID: mdl-28607415

RESUMEN

The Himalaya presents an outstanding geologically active orogen and biodiversity hotspot. However, our understanding of the historical biogeography of its fauna is far from comprehensive. Many taxa are commonly assumed to have originated from China-Indochina and dispersed westward along the Himalayan chain. Alternatively, the "Tibetan-origin hypothesis" suggests primary diversification of lineages in Paleo-Tibet, and secondary diversification along the slopes of the later uplifted Greater Himalaya. We test these hypotheses in high-mountain megophryid anurans (Scutiger). Extensive sampling from High Asia, and analyses of mitochondrial (2839 bp) and nuclear DNA (2208 bp), using Bayesian and Maximum likelihood phylogenetics, suggest that the Himalayan species form a distinct clade, possibly older than those from the eastern Himalaya-Tibet orogen. While immigration from China-Indochina cannot be excluded, our data may indicate that Himalayan Scutiger originated to the north of the Himalaya by colonization from Paleo-Tibet and then date back to the Oligocene. High intraspecific diversity of Scutiger implies limited migration across mountains and drainages along the Himalaya. While our study strengthens support for a "Tibetan-origin hypothesis", current sampling (10/22 species; 1 revalidated: S. occidentalis) remains insufficient to draw final conclusions on Scutiger but urges comparative phylogeographers to test alternative, geologically supported hypotheses for a true future understanding of Himalayan biogeography.


Asunto(s)
Anuros/clasificación , Filogenia , Animales , Calibración , Núcleo Celular/genética , ADN Mitocondrial/genética , Complejo IV de Transporte de Electrones/genética , Marcadores Genéticos , Geografía , Mitocondrias/genética , Tibet , Factores de Tiempo
15.
Zootaxa ; 4028(1): 102-20, 2015 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-26624298

RESUMEN

The genus Thermophis includes the two species, T. baileyi and T. zhaoermii, which differ morphologically, geographically and molecularly. Recently, a third Thermophis species was described from Shangri-La, northern Yunnan Province, China, and named T. shangrila. The new species was based on morphological and genetic data derived from three specimens. However, the morphological features used to delimit this species seem vague, because they may fall within the range of intraspecific variation of T. zhaoermii. Furthermore, the reported genetic differences in nuclear data are questionable. They likely resulted from a misinterpretation probably due to alignment/analytical flaws or sample/sequence mix-up. Here, we used partial sequences of three mitochondrial (CO1, ND4, cytb) genes and one nuclear (c-mos) gene to analyse the genetic variation between and within species of Thermophis. We inferred the phylogeny using Bayesian Inference and Maximum Likelihood approaches and present additional morphological data that contribute to the knowledge on intraspecific variation in the genus. Our results indicate lacking robustness in the distinguishing morphological features and in the genetic differentiation of T. shangrila and highlight the need for more detailed morphological and molecular studies from a substantially larger sample.


Asunto(s)
Colubridae/clasificación , Colubridae/genética , Distribución Animal , Estructuras Animales/anatomía & histología , Estructuras Animales/crecimiento & desarrollo , Animales , Tamaño Corporal , China , Colubridae/anatomía & histología , Colubridae/crecimiento & desarrollo , ADN Mitocondrial/genética , Femenino , Flujo Genético , Variación Genética , Masculino , Datos de Secuencia Molecular , Tamaño de los Órganos , Filogenia
17.
PLoS One ; 10(7): e0133465, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26197066

RESUMEN

The analysis of structural variants, in particular of copy-number variations (CNVs), has proven valuable in unraveling the genetic basis of human diseases. Hence, a large number of algorithms have been developed for the detection of CNVs in SNP array signal intensity data. Using the European and African HapMap trio data, we undertook a comparative evaluation of six commonly used CNV detection software tools, namely Affymetrix Power Tools (APT), QuantiSNP, PennCNV, GLAD, R-gada and VEGA, and assessed their level of pair-wise prediction concordance. The tool-specific CNV prediction accuracy was assessed in silico by way of intra-familial validation. Software tools differed greatly in terms of the number and length of the CNVs predicted as well as the number of markers included in a CNV. All software tools predicted substantially more deletions than duplications. Intra-familial validation revealed consistently low levels of prediction accuracy as measured by the proportion of validated CNVs (34-60%). Moreover, up to 20% of apparent family-based validations were found to be due to chance alone. Software using Hidden Markov models (HMM) showed a trend to predict fewer CNVs than segmentation-based algorithms albeit with greater validity. PennCNV yielded the highest prediction accuracy (60.9%). Finally, the pairwise concordance of CNV prediction was found to vary widely with the software tools involved. We recommend HMM-based software, in particular PennCNV, rather than segmentation-based algorithms when validity is the primary concern of CNV detection. QuantiSNP may be used as an additional tool to detect sets of CNVs not detectable by the other tools. Our study also reemphasizes the need for laboratory-based validation, such as qPCR, of CNVs predicted in silico.


Asunto(s)
Benchmarking/métodos , Biología Computacional/métodos , Variaciones en el Número de Copia de ADN/genética , Polimorfismo de Nucleótido Simple , Programas Informáticos , Algoritmos , Simulación por Computador , Genoma Humano/genética , Estudio de Asociación del Genoma Completo/métodos , Genotipo , Humanos , Reacción en Cadena de la Polimerasa/métodos , Reproducibilidad de los Resultados , Validación de Programas de Computación
18.
Am J Respir Crit Care Med ; 192(6): 727-36, 2015 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-26051272

RESUMEN

RATIONALE: Genetic variation plays a significant role in the etiology of sarcoidosis. However, only a small fraction of its heritability has been explained so far. OBJECTIVES: To define further genetic risk loci for sarcoidosis, we used the Immunochip for a candidate gene association study of immune-associated loci. METHODS: Altogether the study population comprised over 19,000 individuals. In a two-stage design, 1,726 German sarcoidosis cases and 5,482 control subjects were genotyped for 128,705 single-nucleotide polymorphisms using the Illumina Immunochip for the screening step. The remaining 3,955 cases, 7,514 control subjects, and 684 parents of affected offspring were used for validation and replication of 44 candidate and two established risk single-nucleotide polymorphisms. MEASUREMENTS AND MAIN RESULTS: Four novel susceptibility loci were identified with genome-wide significance in the European case-control populations, located on chromosomes 12q24.12 (rs653178; ATXN2/SH2B3), 5q33.3 (rs4921492; IL12B), 4q24 (rs223498; MANBA/NFKB1), and 2q33.2 (rs6748088; FAM117B). We further defined three independent association signals in the HLA region with genome-wide significance, peaking in the BTNL2 promoter region (rs5007259), at HLA-B (rs4143332/HLA-B*0801) and at HLA-DPB1 (rs9277542), and found another novel independent signal near IL23R (rs12069782) on chromosome 1p31.3. CONCLUSIONS: Functional predictions and protein network analyses suggest a prominent role of the drug-targetable IL23/Th17 signaling pathway in the genetic etiology of sarcoidosis. Our findings reveal a substantial genetic overlap of sarcoidosis with diverse immune-mediated inflammatory disorders, which could be of relevance for the clinical application of modern therapeutics.


Asunto(s)
Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Polimorfismo de Nucleótido Simple , Sarcoidosis/genética , Adulto , Negro o Afroamericano/genética , Anciano , Estudios de Casos y Controles , Europa (Continente) , Femenino , Marcadores Genéticos , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Sarcoidosis/etnología , Sarcoidosis/inmunología , Población Blanca/genética
19.
Evol Biol ; 40: 420-438, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23950617

RESUMEN

The European common lizard, Zootoca vivipara, is the most widespread terrestrial reptile in the world. It occupies almost the entire Northern Eurasia and includes four viviparous and two oviparous lineages. We analysed how female snout-vent length (SVL), clutch size (CS), hatchling mass (HM), and relative clutch mass (RCM) is associated with the reproductive mode and climate throughout the species range and across the evolutionary lineages within Z. vivipara. The studied variables were scored for 1,280 females and over 3,000 hatchlings from 44 geographically distinct study samples. Across the species range, SVL of reproductive females tends to decrease in less continental climates, whereas CS corrected for female SVL and RCM tend to decrease in climates with cool summer. Both relationships are likely to indicate direct phenotypic responses to climate. For viviparous lineages, the pattern of co-variation between female SVL, CS and HM among populations is similar to that between individual females within populations. Consistent with the hypothesis that female reproductive output is constrained by her body volume, the oviparous clade with shortest retention of eggs in utero showed highest HM, the oviparous clade with longer egg retention showed lower HM, and clades with the longest egg retention (viviparous forms) had lowest HM. Viviparous populations exhibited distinctly lower HM than the other European lacertids of similar female SVL, many of them also displaying unusually high RCM. This pattern is consistent with Winkler and Wallin's model predicting a negative evolutionary link between the total reproductive investment and allocation to individual offspring.

20.
Eur Respir J ; 41(4): 888-900, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22936702

RESUMEN

Sarcoidosis is a systemic inflammatory disease of unknown aetiology, influenced by genetic and environmental factors. However, the loci so far identified for sarcoidosis explain only a part of its assumed heritability. To identify further susceptibility loci, we performed a genome-wide association analysis using the Affymetrix 6.0 Human GeneChip followed by validation and replication stages. After quality control, 637 cases, 1233 controls and 677 619 single-nucleotide polymorphisms (SNPs) were available for an initial screening. 99 SNPs were selected for validation in an independent study panel (1664 patients, 2932 controls). SNP rs1050045 was significantly associated with sarcoidosis (corrected p=0.0215) in the validation panel and yielded a p-value of 9.22 × 10(-8) (OR 1.24) in the meta-analysis of the screening and validation stage. A meta-analysis of three populations from Germany, the Czech Republic and Sweden confirmed this finding (p = 0.024; OR 1.14). Fine-mapping and mRNA expression studies pointed to osteosarcoma amplified 9 (OS9) as the most likely candidate for the underlying risk factor. The OS9 protein plays an important role in endoplasmic reticulum-associated protein degradation and acts during Toll-like receptor induced activation of myeloid cells. Expression analyses of OS9 mRNA provide evidence for a functional mechanism underlying the detected association signal.


Asunto(s)
Cromosomas Humanos Par 12 , Estudio de Asociación del Genoma Completo , Enfermedades Pulmonares/genética , Sarcoidosis/genética , Estudios de Casos y Controles , Mapeo Cromosómico/métodos , Enfermedad Crónica , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Enfermedades Pulmonares/diagnóstico , Polimorfismo de Nucleótido Simple , ARN Mensajero/metabolismo , Factores de Riesgo , Sarcoidosis/diagnóstico , Análisis de Secuencia de ADN
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