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1.
Science ; 382(6676): 1303-1308, 2023 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-38096292

RESUMEN

Ancestral Coast Salish societies in the Pacific Northwest kept long-haired "woolly dogs" that were bred and cared for over millennia. However, the dog wool-weaving tradition declined during the 19th century, and the population was lost. In this study, we analyzed genomic and isotopic data from a preserved woolly dog pelt from "Mutton," collected in 1859. Mutton is the only known example of an Indigenous North American dog with dominant precolonial ancestry postdating the onset of settler colonialism. We identified candidate genetic variants potentially linked with their distinct woolly phenotype. We integrated these data with interviews from Coast Salish Elders, Knowledge Keepers, and weavers about shared traditional knowledge and memories surrounding woolly dogs, their importance within Coast Salish societies, and how colonial policies led directly to their disappearance.


Asunto(s)
Perros , Selección Genética , Lana , Animales , Perros/anatomía & histología , Perros/clasificación , Perros/genética , Genómica , Noroeste de Estados Unidos , Cruzamiento
2.
Sci Total Environ ; 895: 165087, 2023 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-37379924

RESUMEN

Despite the importance of earthworms for soil formation, more is needed to know about how Pre-Columbian modifications to soils and the landscape. Gaining a deeper understanding is essential for comprehending the historical drivers of earthworm communities and the development of effective conservation strategies in the Amazon rainforest. Human disturbance can significantly impact earthworm diversity, especially in rainforest soils, and in the particular case of the Amazonian rainforest, both recent and ancient anthropic practices may be important. Amazonian Dark Earths (ADEs) are fertile soils found throughout the Amazon Basin, created by sedentary habits and intensification patterns of pre-Colombian societies primarily developed in the second part of the Holocene period. We have sampled earthworm communities in three Brazilian Amazonian (ADEs) and adjacent reference soils (REF) under old and young forests and monocultures. To better assess taxonomic richness, we used morphology and the barcode region of the COI gene to identify juveniles and cocoons and delimit Molecular Operational Taxonomic Units (MOTUs). Here we suggest using Integrated Operational Taxonomical units (IOTUs) which combine both morphological and molecular data and provide a more comprehensive assessment of diversity, while MOTUs only rely on molecular data. A total of 970 individuals were collected, resulting in 51 taxonomic units (IOTUs, MOTUs, and morphospecies combined). From this total, 24 taxonomic units were unique to REF soils, 17 to ADEs, and ten were shared between both soils. The highest richness was found in old forest sites for ADEs (12 taxonomic units) and REFs (21 taxonomic units). The beta-diversity calculations reveal a high species turnover between ADEs and REF soils, providing evidence that ADEs and REFs possess distinct soil biota. Furthermore, results suggest that ADE sites, formed by Pre-Columbian human activities, conserve a high number of native species in the landscape and maintain a high abundance, despite their long-term nature.


Asunto(s)
Oligoquetos , Animales , Humanos , Biodiversidad , Bosques , Suelo , Agricultura
3.
Nature ; 607(7918): 313-320, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35768506

RESUMEN

The grey wolf (Canis lupus) was the first species to give rise to a domestic population, and they remained widespread throughout the last Ice Age when many other large mammal species went extinct. Little is known, however, about the history and possible extinction of past wolf populations or when and where the wolf progenitors of the present-day dog lineage (Canis familiaris) lived1-8. Here we analysed 72 ancient wolf genomes spanning the last 100,000 years from Europe, Siberia and North America. We found that wolf populations were highly connected throughout the Late Pleistocene, with levels of differentiation an order of magnitude lower than they are today. This population connectivity allowed us to detect natural selection across the time series, including rapid fixation of mutations in the gene IFT88 40,000-30,000 years ago. We show that dogs are overall more closely related to ancient wolves from eastern Eurasia than to those from western Eurasia, suggesting a domestication process in the east. However, we also found that dogs in the Near East and Africa derive up to half of their ancestry from a distinct population related to modern southwest Eurasian wolves, reflecting either an independent domestication process or admixture from local wolves. None of the analysed ancient wolf genomes is a direct match for either of these dog ancestries, meaning that the exact progenitor populations remain to be located.


Asunto(s)
Perros , Genoma , Genómica , Filogenia , Lobos , África , Animales , ADN Antiguo/análisis , Perros/genética , Domesticación , Europa (Continente) , Genoma/genética , Historia Antigua , Medio Oriente , Mutación , América del Norte , Selección Genética , Siberia , Proteínas Supresoras de Tumor/genética , Lobos/clasificación , Lobos/genética
4.
BMC Bioinformatics ; 23(1): 228, 2022 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-35698034

RESUMEN

BACKGROUND: Many wild species have suffered drastic population size declines over the past centuries, which have led to 'genomic erosion' processes characterized by reduced genetic diversity, increased inbreeding, and accumulation of harmful mutations. Yet, genomic erosion estimates of modern-day populations often lack concordance with dwindling population sizes and conservation status of threatened species. One way to directly quantify the genomic consequences of population declines is to compare genome-wide data from pre-decline museum samples and modern samples. However, doing so requires computational data processing and analysis tools specifically adapted to comparative analyses of degraded, ancient or historical, DNA data with modern DNA data as well as personnel trained to perform such analyses. RESULTS: Here, we present a highly flexible, scalable, and modular pipeline to compare patterns of genomic erosion using samples from disparate time periods. The GenErode pipeline uses state-of-the-art bioinformatics tools to simultaneously process whole-genome re-sequencing data from ancient/historical and modern samples, and to produce comparable estimates of several genomic erosion indices. No programming knowledge is required to run the pipeline and all bioinformatic steps are well-documented, making the pipeline accessible to users with different backgrounds. GenErode is written in Snakemake and Python3 and uses Conda and Singularity containers to achieve reproducibility on high-performance compute clusters. The source code is freely available on GitHub ( https://github.com/NBISweden/GenErode ). CONCLUSIONS: GenErode is a user-friendly and reproducible pipeline that enables the standardization of genomic erosion indices from temporally sampled whole genome re-sequencing data.


Asunto(s)
Biología Computacional , Genoma , Animales , Especies en Peligro de Extinción , Genómica , Reproducibilidad de los Resultados , Programas Informáticos
5.
Glob Chang Biol ; 27(19): 4575-4591, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34118093

RESUMEN

Amazonian rainforests, once thought to be pristine wilderness, are increasingly known to have been widely inhabited, modified, and managed prior to European arrival, by human populations with diverse cultural backgrounds. Amazonian Dark Earths (ADEs) are fertile soils found throughout the Amazon Basin, created by pre-Columbian societies with sedentary habits. Much is known about the chemistry of these soils, yet their zoology has been neglected. Hence, we characterized soil fertility, macroinvertebrate communities, and their activity at nine archeological sites in three Amazonian regions in ADEs and adjacent reference soils under native forest (young and old) and agricultural systems. We found 673 morphospecies and, despite similar richness in ADEs (385 spp.) and reference soils (399 spp.), we identified a tenacious pre-Columbian footprint, with 49% of morphospecies found exclusively in ADEs. Termite and total macroinvertebrate abundance were higher in reference soils, while soil fertility and macroinvertebrate activity were higher in the ADEs, and associated with larger earthworm quantities and biomass. We show that ADE habitats have a unique pool of species, but that modern land use of ADEs decreases their populations, diversity, and contributions to soil functioning. These findings support the idea that humans created and sustained high-fertility ecosystems that persist today, altering biodiversity patterns in Amazonia.


Asunto(s)
Ecosistema , Suelo , Agricultura , Biodiversidad , Humanos , Microbiología del Suelo
6.
Curr Biol ; 30(19): 3871-3879.e7, 2020 10 05.
Artículo en Inglés | MEDLINE | ID: mdl-32795436

RESUMEN

Ancient DNA has significantly improved our understanding of the evolution and population history of extinct megafauna. However, few studies have used complete ancient genomes to examine species responses to climate change prior to extinction. The woolly rhinoceros (Coelodonta antiquitatis) was a cold-adapted megaherbivore widely distributed across northern Eurasia during the Late Pleistocene and became extinct approximately 14 thousand years before present (ka BP). While humans and climate change have been proposed as potential causes of extinction [1-3], knowledge is limited on how the woolly rhinoceros was impacted by human arrival and climatic fluctuations [2]. Here, we use one complete nuclear genome and 14 mitogenomes to investigate the demographic history of woolly rhinoceros leading up to its extinction. Unlike other northern megafauna, the effective population size of woolly rhinoceros likely increased at 29.7 ka BP and subsequently remained stable until close to the species' extinction. Analysis of the nuclear genome from a ∼18.5-ka-old specimen did not indicate any increased inbreeding or reduced genetic diversity, suggesting that the population size remained steady for more than 13 ka following the arrival of humans [4]. The population contraction leading to extinction of the woolly rhinoceros may have thus been sudden and mostly driven by rapid warming in the Bølling-Allerød interstadial. Furthermore, we identify woolly rhinoceros-specific adaptations to arctic climate, similar to those of the woolly mammoth. This study highlights how species respond differently to climatic fluctuations and further illustrates the potential of palaeogenomics to study the evolutionary history of extinct species.


Asunto(s)
Arqueología/métodos , ADN Antiguo/análisis , Perisodáctilos/genética , Animales , Cambio Climático , Extinción Biológica , Fósiles , Genoma/genética , Genómica/métodos , Densidad de Población , Dinámica Poblacional
7.
Sci Rep ; 10(1): 12621, 2020 07 28.
Artículo en Inglés | MEDLINE | ID: mdl-32724178

RESUMEN

The cave lion is an extinct felid that was widespread across the Holarctic throughout the Late Pleistocene. Its closest extant relative is the lion (Panthera leo), but the timing of the divergence between these two taxa, as well as their taxonomic ranking are contentious. In this study we analyse 31 mitochondrial genome sequences from cave lion individuals that, through a combination of 14C and genetic tip dating, are estimated to be from dates extending well into the mid-Pleistocene. We identified two deeply diverged and well-supported reciprocally monophyletic mitogenome clades in the cave lion, and an additional third distinct lineage represented by a single individual. One of these clades was restricted to Beringia while the other was prevalent across western Eurasia. These observed clade distributions are in line with previous observations that Beringian and European cave lions were morphologically distinct. The divergence dates for these lineages are estimated to be far older than those between extant lions subspecies. By combining our radiocarbon tip-dates with a split time prior that takes into account the most up-to-date fossil stem calibrations, we estimated the mitochondrial DNA divergence between cave lions and lions to be 1.85 Million ya (95% 0.52- 2.91 Mya). Taken together, these results support previous hypotheses that cave lions existed as at least two subspecies during the Pleistocene, and that lions and cave lions were distinct species.


Asunto(s)
Biodiversidad , Cuevas , Leones/genética , Animales , Genoma Mitocondrial , Geografía , Filogenia , Especificidad de la Especie , Manejo de Especímenes , Factores de Tiempo
8.
Commun Biol ; 3(1): 84, 2020 02 21.
Artículo en Inglés | MEDLINE | ID: mdl-32081985

RESUMEN

Ancient remains found in permafrost represent a rare opportunity to study past ecosystems. Here, we present an exceptionally well-preserved ancient bird carcass found in the Siberian permafrost, along with a radiocarbon date and a reconstruction of its complete mitochondrial genome. The carcass was radiocarbon dated to approximately 44-49 ka BP, and was genetically identified as a female horned lark. This is a species that usually inhabits open habitat, such as the steppe environment that existed in Siberia at the time. This near-intact carcass highlights the potential of permafrost remains for evolutionary studies that combine both morphology and ancient nucleic acids.


Asunto(s)
Aves , Huesos/metabolismo , Fósiles , Técnicas Genéticas , Determinación de la Edad por el Esqueleto/métodos , Determinación de la Edad por el Esqueleto/veterinaria , Animales , Aves/clasificación , Aves/genética , Huesos/anatomía & histología , Huesos/química , Ecosistema , Femenino , Fósiles/anatomía & histología , Fósiles/patología , Técnicas Genéticas/veterinaria , Genética de Población , Sedimentos Geológicos/análisis , Historia Antigua , Masculino , Paleontología , Hielos Perennes , Filogenia , Datación Radiométrica , Análisis para Determinación del Sexo/métodos , Análisis para Determinación del Sexo/veterinaria , Siberia
9.
Philos Trans R Soc Lond B Biol Sci ; 374(1788): 20190212, 2019 12 23.
Artículo en Inglés | MEDLINE | ID: mdl-31679495

RESUMEN

Ancient DNA provides a powerful means to investigate the timing, rate and extent of population declines caused by extrinsic factors, such as past climate change and human activities. One species probably affected by both these factors is the arctic fox, which had a large distribution during the last glaciation that subsequently contracted at the start of the Holocene. More recently, the arctic fox population in Scandinavia went through a demographic bottleneck owing to human persecution. To investigate the consequences of these processes, we generated mitogenome sequences from a temporal dataset comprising Pleistocene, historical and modern arctic fox samples. We found no evidence that Pleistocene populations in mid-latitude Europe or Russia contributed to the present-day gene pool of the Scandinavian population, suggesting that postglacial climate warming led to local population extinctions. Furthermore, during the twentieth-century bottleneck in Scandinavia, at least half of the mitogenome haplotypes were lost, consistent with a 20-fold reduction in female effective population size. In conclusion, these results suggest that the arctic fox in mainland Western Europe has lost genetic diversity as a result of both past climate change and human persecution. Consequently, it might be particularly vulnerable to the future challenges posed by climate change. This article is part of a discussion meeting issue 'The past is a foreign country: how much can the fossil record actually inform conservation?'


Asunto(s)
Distribución Animal , Cambio Climático , Zorros/fisiología , Variación Genética , Actividades Humanas , Animales , ADN Antiguo/análisis , Fósiles , Zorros/genética , Genoma Mitocondrial , Dinámica Poblacional , Países Escandinavos y Nórdicos
10.
Zootaxa ; 4545(1): 124-132, 2019 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-30647239

RESUMEN

Following many decades of work on the taxonomy, biology and ecology of the globally-distributed tropical earthworm Pontoscolex corethrurus (Müller, 1857), morphological and molecular data have shown that the stability and effectiveness of nomenclature depends on the designation of a neotype from the type locality. We do that, with all the required justifications, and provide sufficient information to permit the correct identification of this species.


Asunto(s)
Oligoquetos , Animales , Ecología
11.
Zookeys ; (688): 1-13, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29118589

RESUMEN

Pontoscolex corethrurus (Müller, 1857) plays an important role in tropical soil ecosystems and has been widely used as an animal model for a large variety of ecological studies in particular due to its common presence and generally high abundance in human-disturbed tropical soils. In this study we describe the complete mitochondrial genome of the peregrine earthworm P. corethrurus. This is the first record of a mitochondrial genome within the Rhinodrilidae family. Its mitochondrial genome is 14 835 bp in length containing 37 genes (13 protein-coding genes (PCG) 2 rRNA genes and 22 tRNA genes). It has the same gene content and structure as in other sequenced earthworms but unusual among invertebrates it hasseveral overlapping open reading frames. All genes are encoded on the same strand. Most of the PCGs use ATG as the start codon except for ND3 which uses GTG as the start codon. The A+T content of the mitochondrial genome is 59.9% (31.8% A 28.1% T 14.6% G and 25.6% for C). The annotated genome sequence has been deposited in GenBank under the accession number KT988053.

12.
Proc Biol Sci ; 283(1828)2016 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-27053752

RESUMEN

Red deer (Cervus elaphus) have played a key role in human societies throughout history, with important cultural significance and as a source of food and materials. This relationship can be traced back to the earliest human cultures and continues to the present day. Humans are thought to be responsible for the movement of a considerable number of deer throughout history, although the majority of these movements are poorly described or understood. Studying such translocations allows us to better understand ancient human-wildlife interactions, and in the case of island colonizations, informs us about ancient human maritime practices. This study uses DNA sequences to characterise red deer genetic diversity across the Scottish islands (Inner and Outer Hebrides and Orkney) and mainland using ancient deer samples, and attempts to infer historical colonization events. We show that deer from the Outer Hebrides and Orkney are unlikely to have originated from mainland Scotland, implying that humans introduced red deer from a greater distance. Our results are also inconsistent with an origin from Ireland or Norway, suggesting long-distance maritime travel by Neolithic people to the outer Scottish Isles from an unknown source. Common haplotypes and low genetic differentiation between the Outer Hebrides and Orkney imply common ancestry and/or gene flow across these islands. Close genetic proximity between the Inner Hebrides and Ireland, however, corroborates previous studies identifying mainland Britain as a source for red deer introductions into Ireland. This study provides important information on the processes that led to the current distribution of the largest surviving indigenous land mammal in the British Isles.


Asunto(s)
Distribución Animal , Ciervos/fisiología , Variación Genética , Animales , Ciervos/genética , Flujo Génico , Haplotipos , Islas , Escocia , Análisis de Secuencia de ADN
13.
Parasitol Int ; 65(3): 258-67, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26794684

RESUMEN

Metorchis spp. are flukes (Platyhelminthes: Digenea) that infect vertebrates, including humans, dogs, cats, poultry and wild game, with cyprinid freshwater fish serving as typical second intermediate hosts. In their definitive hosts, the Metorchis spp. are difficult to identify to species. We provide and analyze sequences of two nuclear (18S rDNA and ITS2) and two mitochondrial (CO1 and ND1) DNA loci of four morphologically identified European species of the Metorchis, namely Metorchis albidus, Metorchis bilis, Metorchis crassiusculus and Metorchis xanthosomus, and of another opisthorchiid, Euamphimerus pancreaticus. DNA analysis suggests that the Metorchis specimens identified morphologically as M. albidus (from Lutra lutra), M. bilis (from Phalacrocorax carbo) and M. crassiusculus (from Aquila heliaca and Buteo rufinus) represent a single species. Thus, M. albidus (Braun, 1893) Loos, 1899 and M. crassiusculus (Rudolphi, 1809) Looss, 1899 are recognized as junior subjective synonyms of M. bilis (Braun, 1790) Odening, 1962. We also provide comparative measurements of the Central European Metorchis spp., and address their tissue specificity and prevalence based on the examination of extensive bird cohort from 1962 to 2015. M. bilis and M. xanthosomus can be morphologically diagnosed by measuring the extent of genitalia relative to body length and by the size ratio of their suckers. They also differ in their core definitive hosts, with ducks (Anas, Aythya) and coots (Fulica) hosting M. xanthosomus, and cormorants (Phalacrocorax), the birds of prey (Buteo, Aquila, etc.), piscivorous mammals (Lutra, Vulpes, Ursus, etc.) and humans hosting M. bilis. Previous reports on the Metorchis spp. contain numerous suspected misidentifications.


Asunto(s)
Opisthorchidae/clasificación , Infecciones por Trematodos/parasitología , Animales , Aves , ADN Ribosómico/genética , Humanos , Mamíferos , Opisthorchidae/citología , Opisthorchidae/genética , Opisthorchidae/aislamiento & purificación , Filogenia , ARN Ribosómico 18S/genética , Análisis de Secuencia de ADN , Especificidad de la Especie
14.
Parasitol Int ; 65(2): 163-70, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26620805

RESUMEN

The recent identification of Pseudamphistomum truncatum, (Rudolphi, 1819) (Trematoda: Opisthorchiidae) and Metorchis bilis (Braun, 1790) Odening, 1962 (synonymous with Metorchis albidus (Braun, 1893) Loos, 1899 and Metorchis crassiusculus (Rudolphi, 1809) Looss, 1899 (Trematoda: Opisthorchiidae)) in otters from Britain caused concern because of associated biliary damage, coupled with speculation over their alien status. Here, we investigate the presence, intensity and phylogeny of these trematodes in mustelids (principally otters) across Europe (Czech Republic, Denmark, France, Germany, Norway, Poland and Sweden and Britain). The trematodes were identified to species using the internal transcribed spacer II (ITS2) locus. Both parasites were found across Europe but at unequal frequency. In the German state of Saxony, eight out of eleven (73%) otters examined were infected with P. truncatum whilst this parasite was not found in either mink from Scotland (n=40) or otters from Norway (n=21). Differences in the phylogenies between the two species suggest divergent demographic histories possibly reflecting contrasting host diet or competitive exclusion, with M. bilis exhibiting greater mitochondrial diversity than P. truncatum. Shared haplotypes within the ranges of both parasite species probably reflect relatively unrestricted movements (both natural and anthropogenic) of intermediate and definitive hosts across Europe.


Asunto(s)
Visón/parasitología , Nutrias/parasitología , Trematodos/genética , Trematodos/aislamiento & purificación , Infecciones por Trematodos/veterinaria , Animales , Europa (Continente)/epidemiología , Francia/epidemiología , Flujo Génico , Alemania/epidemiología , Haplotipos , Especies Introducidas , Mitocondrias/genética , Filogenia , Polonia/epidemiología , Trematodos/clasificación , Infecciones por Trematodos/epidemiología , Infecciones por Trematodos/parasitología , Reino Unido
15.
PLoS One ; 9(7): e101081, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25007188

RESUMEN

The okapi is an endangered, evolutionarily distinctive even-toed ungulate classified within the giraffidae family that is endemic to the Democratic Republic of Congo. The okapi is currently under major anthropogenic threat, yet to date nothing is known about its genetic structure and evolutionary history, information important for conservation management given the species' current plight. The distribution of the okapi, being confined to the Congo Basin and yet spanning the Congo River, also makes it an important species for testing general biogeographic hypotheses for Congo Basin fauna, a currently understudied area of research. Here we describe the evolutionary history and genetic structure of okapi, in the context of other African ungulates including the giraffe, and use this information to shed light on the biogeographic history of Congo Basin fauna in general. Using nuclear and mitochondrial DNA sequence analysis of mainly non-invasively collected samples, we show that the okapi is both highly genetically distinct and highly genetically diverse, an unusual combination of genetic traits for an endangered species, and feature a complex evolutionary history. Genetic data are consistent with repeated climatic cycles leading to multiple Plio-Pleistocene refugia in isolated forests in the Congo catchment but also imply historic gene flow across the Congo River.


Asunto(s)
Especies en Peligro de Extinción , Rumiantes/genética , Migración Animal , Animales , ADN Mitocondrial/genética , República Democrática del Congo , Evolución Molecular , Flujo Génico , Especiación Genética , Variación Genética , Filogenia , Filogeografía , Ríos , Análisis de Secuencia de ADN
16.
Environ Toxicol Chem ; 33(6): 1315-23, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24648128

RESUMEN

Avian studies of endocrine disruption traditionally have focused on reproductive impairment, given that many environmental contaminants affect sex steroid hormones. There is also increasing interest in altered thyroid function, and associated early development, particularly in altricial species with extended developmental windows. Both types of effect are relevant under the complex pollutant conditions created in streams draining urban areas, but case studies are scarce. Therefore, the authors measured breeding performance, as well as nestling growth, condition, and plasma thyroid hormones, in 87 Eurasian dipper (Cinclus cinclus) nests on 36 urban and rural streams in south and mid-Wales (UK); invertebrate prey data were also collected. The objective of the present study was to evaluate whether urban stream pollution or food scarcity might affect reproduction or development in this specialized aquatic songbird. Clutch sizes and egg fertility were similar on rural and urban streams, whereas nest success was actually higher at urban sites and food abundance was not significantly reduced. However, subtle but important differences were apparent. Urban nestlings were significantly lighter than rural nestlings for their body size (condition index), and brood sex ratios were increasingly male biased with increasing urbanization. The nestling thyroid hormone profile closely reflected urban land use, whereas depressed triiodothyronine (T3) hormones and poorer body condition were associated with higher exposure to polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) at urbanized sites. These data suggest that PCBs, PBDEs, and/or accompanying contaminants in urban streams could be affecting dipper nestling development, with potential consequences for the birds' fitness.


Asunto(s)
Ciudades , Ecotoxicología , Passeriformes/crecimiento & desarrollo , Ríos/química , Contaminantes Químicos del Agua/toxicidad , Animales , Femenino , Masculino , Comportamiento de Nidificación , Passeriformes/metabolismo , Passeriformes/fisiología , Reproducción/efectos de los fármacos , Hormonas Tiroideas/metabolismo , Triyodotironina/metabolismo
17.
Environ Sci Technol ; 47(15): 8931-9, 2013 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-23819781

RESUMEN

Many urban European streams are recovering from industrial, mining, and sewage pollution during the 20th century. However, associated recolonization by clean water organisms can potentially result in exposure to legacy or novel toxic pollutants that persist in the environment. Between 2008 and 2010, we sampled eggs of a river passerine, the Eurasian dipper (Cinclus cinclus), from 33 rivers in South Wales and the English borders (UK) which varied in catchment land use from rural to highly urbanized. Dipper egg δ(15)N and δ(13)C stable isotopes were enriched from urban rivers while δ(34)S was strongly depleted, effectively discriminating their urban or rural origins at thresholds of 10% urban land cover or 1000 people/km(2). Concentrations of total polychlorinated biphenyls (PCBs) and polybrominated biphenyl ethers (PBDEs) were positively related to urban land cover and human population density while legacy organochlorine pesticides such as p,p'-DDE, lindane, and hexachlorobenzene were found in higher concentrations at rural sites. Levels of PBDEs in urban dipper eggs (range of 136-9299 ng/g lw) were among the highest ever reported in passerines, and some egg contaminants were at or approaching levels sufficient for adverse effects on avian development. With the exception of dieldrin, our data shows PCBs and other organochlorine pesticides have remained stable or increased in the past 20 years in dipper eggs, despite discontinued use.


Asunto(s)
Huevos/análisis , Agua Dulce/química , Halógenos/análisis , Compuestos Orgánicos/análisis , Contaminantes Químicos del Agua/análisis , Animales , Asia , Aves , Europa (Continente) , Ríos
18.
Ecology ; 94(11): 2518-28, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24400503

RESUMEN

The relative contribution of top-down and bottom-up processes regulating primary decomposers can influence the strength of the link between the soil animal community and ecosystem functioning. Although soil bacterial communities are regulated by bottom-up and top-down processes, the latter are considered to be less important in structuring the diversity and functioning of fungal-dominated ecosystems. Despite the huge diversity of mycophagous (fungal-feeding) soil fauna, and their potential to reverse the outcomes of competitive fungal interactions, top-down grazing effects have never been found to translate to community-level changes. We constructed soil mesocosms to investigate the potential of isopods grazing on cord-forming basidiomycete fungi to influence the community composition and functioning of a complex woodland soil microbial community. Using metagenomic sequencing we provide conclusive evidence of direct top-down control at the community scale in fungal-dominated woodland soil. By suppressing the dominant cord-forming basidiomycete fungi, isopods prevented the competitive exclusion of surrounding litter fungi, increasing diversity in a community containing several hundred fungal species. This isopod-induced modification of community composition drove a shift in the soil enzyme profile, and led to a restructuring of the wider mycophagous invertebrate community. We highlight characteristics of different soil ecosystems that will give rise to such top-down control. Given the ubiquity of isopods and basidiomycete fungi in temperate and boreal woodland ecosystems, such top-down community control could be of widespread significance for global carbon and nutrient cycling.


Asunto(s)
Hongos/enzimología , Isópodos/fisiología , Microbiología del Suelo , Suelo/química , Animales , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Hongos/clasificación , Hongos/fisiología , Regulación Enzimológica de la Expresión Génica , Regulación Fúngica de la Expresión Génica
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