| synthesis, conformational analysis and biological properties of a dicarba derivative of the antimicrobial peptide, brevinin-1bya. | brevinin-1bya (flpilaslaakfgpklfclvtkkc), first isolated from skin secretions of the frog rana boylii, displays broad-spectrum antimicrobial activity and potent haemolytic activity. this study investigates the effects on conformation and biological activity of replacement of the intramolecular disulphide bridge in the peptide by a non-reducible dicarba bond. dicarba-brevinin-1bya was prepared by microwave irradiation of [agl(18),agl(24)]-brevinin-1bya (agl = allylglycine) in the presence of a se ... | 2011 | 21312033 |
| projecting invasion risk of non-native watersnakes (nerodia fasciata and nerodia sipedon) in the western united states. | species distribution models (sdms) are increasingly used to project the potential distribution of introduced species outside their native range. such studies rarely explicitly evaluate potential conflicts with native species should the range of introduced species expand. two snake species native to eastern north america, nerodia fasciata and nerodia sipedon, have been introduced to california where they represent a new stressor to declining native amphibians, fish, and reptiles. to project the p ... | 2014 | 24964204 |
| cliff swallows petrochelidon pyrrhonota as bioindicators of environmental mercury, cache creek watershed, california. | to evaluate mercury (hg) and other element exposure in cliff swallows (petrochelidon pyrrhonota), eggs were collected from 16 sites within the mining-impacted cache creek watershed, colusa, lake, and yolo counties, california, usa, in 1997-1998. nestlings were collected from seven sites in 1998. geometric mean total hg (thg) concentrations ranged from 0.013 to 0.208 microg/g wet weight (ww) in cliff swallow eggs and from 0.047 to 0.347 microg/g ww in nestlings. mercury detected in eggs generally ... | 2008 | 18166988 |
| the description of haemogregarina boyli n. sp. from the yellow-legged frog rana boyli boyli. | | 1959 | 13642174 |
| evidence from peptidomic analysis of skin secretions that the red-legged frogs, rana aurora draytonii and rana aurora aurora, are distinct species. | the northern red-legged frog rana aurora aurora and the california red-legged frog rana aurora draytonii are traditionally classified together in the same species group. ten peptides with antimicrobial activity were isolated from norepinephrine-stimulated skin secretions of r. aurora draytonii and purified to near homogeneity. the peptides were identified as belonging to the ranatuerin-2 family (two peptides), brevinin-1 family (four peptides), temporin family (three peptides), and a novel pepti ... | 2006 | 16307827 |
| pesticides are involved with population declines of amphibians in the california sierra nevadas. | several species of frogs and toads are in serious decline in the sierra nevada mountains of california. these species include the threatened red-legged frog ( rana aurora ), foothill yellow-legged frog ( r. boylii ), mountain yellow-legged frog ( r. muscosa ), cascades frog ( rana cascadae ), western toad ( bufo boreas ) and yosemite toad ( b. canorus ). for many of these species current distributions are down to 10% of historical ranges. several factors including introduced predators, habitat l ... | 2001 | 12805670 |
| pathophysiology in mountain yellow-legged frogs (rana muscosa) during a chytridiomycosis outbreak. | the disease chytridiomycosis is responsible for declines and extirpations of amphibians worldwide. chytridiomycosis is caused by a fungal pathogen (batrachochytrium dendrobatidis) that infects amphibian skin. although we have a basic understanding of the pathophysiology from laboratory experiments, many mechanistic details remain unresolved and it is unknown if disease development is similar in wild amphibian populations. to gain a better understanding of chytridiomycosis pathophysiology in wild ... | 2012 | 22558145 |
| getting under—and through—the skin: ecological genomics of chytridiomycosis infection in frogs. | amphibian species around the world are currently becoming endangered or lost at a rate that outstrips other vertebrates—victims of a combination of habitat loss, climate change and susceptibility to emerging infectious disease (stuart et al. 2004). one of the most devastating such diseases is caused by the chytrid fungus batrachochytrium dendrobatidis (bd), which infects hundreds of amphibian species on multiple continents. while bd itself has been characterized for some time, we still know litt ... | 2012 | 22916344 |
| mountain yellow-legged frogs (rana muscosa) did not produce detectable antibodies in immunization experiments with batrachochytrium dendrobatidis. | chytridiomycosis is a devastating infectious disease of amphibians caused by the fungal pathogen batrachochytrium dendrobatidis (bd). a growing number of studies have examined the role of amphibian adaptive immunity in response to this pathogen, with varying degrees of immune activation reported. here we present immunologic data for the mountain yellow-legged frog, rana muscosa, and the sierra nevada yellow-legged frog, rana sierrae, which are two endangered and ecologically important species ex ... | 2016 | 26540180 |
| citizen scientists monitor a deadly fungus threatening amphibian communities in northern coastal california, usa. | ecoclub youth and supervising family members conducted citizen science to assess regional prevalence and distribution of batrachochytrium dendrobatidis (bd) among amphibians at humboldt bay national wildlife refuge (refuge) and redwood national and state parks (parks), humboldt county, california, us, may 2013 through december 2014. using quantitative real-time pcr, 26 (17%) of 155 samples were positive for bd. positive samples occurred in four frog and toad species: foothill yellow-legged frog ... | 2016 | 27195681 |
| integral projection models for host-parasite systems with an application to amphibian chytrid fungus. | host parasite models are typically constructed under either a microparasite or macroparasite paradigm. however, this has long been recognized as a false dichotomy because many infectious disease agents, including most fungal pathogens, have attributes of both microparasites and macroparasites.we illustrate how integral projection models (ipm)s provide a novel, elegant modeling framework to represent both types of pathogens. we build a simple host-parasite ipm that tracks both the number of susce ... | 2016 | 28239442 |
| host defense peptides in skin secretions of the oregon spotted frog rana pretiosa: implications for species resistance to chytridiomycosis. | population declines due to chytridiomycosis among frogs belonging to the amerana (rana boylii) species group from western north america have been particularly severe. norepinephrine-stimulated skin secretions from the oregon spotted frog rana pretiosa baird and girard, 1853 were collected from individuals that had been previously infected with the causative agent batrachochytrium dendrobatidis but had proved resistant to developing chytridiomycosis. these secretions contained a more diverse arra ... | 2011 | 21295070 |
| cutaneous bacteria of the redback salamander prevent morbidity associated with a lethal disease. | chytridiomycosis, caused by the fungal pathogen batrachochytrium dendrobatidis (bd), is an infectious disease that causes population declines of many amphibians. cutaneous bacteria isolated from redback salamanders, plethodon cinereus, and mountain yellow-legged frogs, rana muscosa, inhibit the growth of bd in vitro. in this study, the bacterial community present on the skin of p. cinereus individuals was investigated to determine if it provides protection to salamanders from the lethal and sub- ... | 2010 | 20532032 |
| dynamics of an emerging disease drive large-scale amphibian population extinctions. | epidemiological theory generally suggests that pathogens will not cause host extinctions because the pathogen should fade out when the host population is driven below some threshold density. an emerging infectious disease, chytridiomycosis, caused by the fungal pathogen batrachochytrium dendrobatidis (bd) is directly linked to the recent extinction or serious decline of hundreds of amphibian species. despite continued spread of this pathogen into uninfected areas, the dynamics of the host-pathog ... | 2010 | 20457913 |
| immunization is ineffective at preventing infection and mortality due to the amphibian chytrid fungus batrachochytrium dendrobatidis. | the fungal pathogen batrachochytrium dendrobatidis (bd), the causative agent of chytridiomycosis, has been implicated in amphibian declines worldwide. it has been hypothesized that low inherent immunogenicity in bd may be related to the high rates of morbidity and mortality that are associated with bd-infected anuran populations. to test this idea, juvenile rana muscosa (mountain yellow-legged frogs) were immunized with adjuvants in combination with a formalin-killed bd culture to determine if i ... | 2010 | 20090019 |
| effect of temperature on host response to batrachochytrium dendrobatidis infection in the mountain yellow-legged frog (rana muscosa). | the pathogenic chytrid fungus batrachochytrium dendrobatidis, which causes the disease chytridiomycosis, has been implicated in declines of amphibian populations throughout the world, including declines and extinctions of local populations of mountain yellow-legged frogs, rana muscosa, in the california sierra nevada. previous studies have shown b. dendrobatidis achieves its maximum growth rate in culture in the temperature range of 17-25 c, and exposure to very high temperatures can clear frogs ... | 2008 | 18689660 |
| quantifying the disease transmission function: effects of density on batrachochytrium dendrobatidis transmission in the mountain yellow-legged frog rana muscosa. | 1. chytridiomycosis is an emerging infectious disease of amphibians, caused by the fungal pathogen batrachochytrium dendrobatidis, which has been implicated recently in population declines and possible extinctions throughout the world. 2. the transmission rate of this pathogen was quantified in the mountain yellow-legged frog rana muscosa through laboratory and field experiments, and a maximum likelihood approach was used to determine the form of the transmission function that was best supported ... | 2007 | 17584377 |
| peptide defenses of the cascades frog rana cascadae: implications for the evolutionary history of frogs of the amerana species group. | the cascades frog rana cascadae belongs to the amerana (or rana boylii) group that includes six additional species from western north america (r. aurora, r. boylii, r. draytonii, r. luteiventris, r. muscosa, and r. pretiosa). r. cascadae is particularly susceptible to pathogenic microorganisms in the environment and populations have declined precipitously in parts of its range so that the protection afforded by dermal antimicrobial peptides may be crucial to survival of the species. peptidomic a ... | 2007 | 17451843 |
| effects of chytrid and carbaryl exposure on survival, growth and skin peptide defenses in foothill yellow-legged frogs. | environmental contaminants and disease may synergistically contribute to amphibian population declines. sub-lethal levels of contaminants can suppress amphibian immune defenses and, thereby, may facilitate disease outbreaks. we conducted laboratory experiments on newly metamorphosed foothill yellow-legged frogs (rana boylii) to determine whether sublethal exposure to the pesticide carbaryl would increase susceptibility to the pathogenic chytrid fungus batrachochytrium dendrobatidis that is widel ... | 2007 | 17396672 |
| removal of nonnative fish results in population expansion of a declining amphibian (mountain yellow-legged frog, rana muscosa). | the mountain yellow-legged frog (rana muscosa) was once a common inhabitant of the sierra nevada (california, usa), but has declined precipitously during the past century due in part to the introduction of nonnative fish into naturally fishless habitats. the objectives of the current study were to describe (1) the effect of fish removal from three lakes (located in two watersheds) on the small, remnant r. muscosa populations inhabiting those lakes, and (2) the initial development of metapopulati ... | 2007 | 17396156 |
| emerging infectious disease as a proximate cause of amphibian mass mortality. | a newly discovered infectious disease of amphibians, chytridiomycosis, caused by the fungal pathogen batrachochytrium dendrobatidis, is implicated in population declines and possible extinctions throughout the world. the purpose of our study was to examine the effects of b. dendrobatidis on the mountain yellow-legged frog (rana muscosa) in the sierra nevada of california (usa). we (1) quantified the prevalence and incidence of b. dendrobatidis through repeat surveys of several hundred r. muscosa ... | 2006 | 16922318 |
| brevinin-1bya: a naturally occurring peptide from frog skin with broad-spectrum antibacterial and antifungal properties. | brevinin-1bya (flpilaslaakfgpklfclvtkkc) is a cationic alpha-helical peptide containing an intramolecular disulphide bridge that is present in skin secretions of the foothill yellow-legged frog rana boylii. a synthetic replicate of the peptide showed growth inhibitory activity against a range of reference strains of gram-positive and gram-negative bacteria, against clinical isolates of methicillin-resistant staphylococcus aureus (mrsa) (minimum inhibitory concentration (mic)=2.5 microm), and aga ... | 2006 | 16713189 |
| antimicrobial peptide defenses of the mountain yellow-legged frog (rana muscosa). | the mountain yellow-legged frog (rana muscosa) inhabits high elevation lakes in california that are largely undisturbed by human activities. in spite of this habitation in remote sites, populations continue to decline. although predation by non-native fish is one cause for declines, some isolated populations in fishless lakes are suffering new declines. one possible cause of the current wave of declines is the introduction of the pathogenic chytrid fungus (batrachochytrium dendrobatidis) which i ... | 2006 | 16330099 |
| transmission of batrachochytrium dendrobatidis within and between amphibian life stages. | chytridiomycosis is an emerging infectious disease caused by the chytrid fungus batrachochytrium dendrobatidis, which has been implicated in amphibian declines worldwide. the mountain yellow-legged frog rana muscosa is a declining amphibian species that can be infected by b. dendrobatidis; however, transmission between conspecifics has not been documented. here, we present experimental evidence that r. muscosa tadpoles can be infected by fungal zoospores and that they can transmit infection to e ... | 2004 | 15584413 |
| host-defense peptides isolated from the skin secretions of the northern red-legged frog rana aurora aurora. | antimicrobial peptides in the skin secretions of anurans constitute a component of the innate immunity that protects the organism against invading pathogens. four peptides with antimicrobial activity were isolated in high yield from norepinephrine-stimulated skin secretions of the northern red-legged frog rana aurora aurora and their primary structures determined. ranatuerin-2aua (gilssfkgvakgvaknlagklldelkckitgc) showed potent growth-inhibitory activity against a range of gram-positive and gram ... | 2005 | 15325526 |
| isolation of peptides of the brevinin-1 family with potent candidacidal activity from the skin secretions of the frog rana boylii. | the emergence of strains of the human pathogen candida albicans with resistance to commonly used antibiotics has necessitated a search for new types of antifungal agents. six peptides with antimicrobial activity were isolated from norepinephrine-stimulated skin secretions from the foothill yellow-legged frog rana boylii. brevinin-1bya (flpilaslaa10kfgpklf clv20tkkc) was particularly potent against c. albicans [minimal inhibitory concentration (mic) = 3 microm] and also active against escherichia ... | 2003 | 14531844 |
| expression analysis and identification of antimicrobial peptide transcripts from six north american frog species. | frogs secrete antimicrobial peptides onto their skin. we describe an assay to preserve and analyze antimicrobial peptide transcripts from field-collected skin secretions that will complement existing methods for peptide analysis. we collected skin secretions from 4 north american species in the field in california and 2 species in the laboratory. most frogs appeared healthy after release; however, rana boylii in the sierra nevada foothills, but not the coast range, showed signs of morbidity and ... | 2013 | 23759560 |
| mercury contamination in three species of anuran amphibians from the cache creek watershed, california, usa. | fish and wildlife may bioaccumulate mercury (hg) to levels that adversely affect reproduction, growth, and survival. sources of hg within the cache creek watershed in northern california have been identified, and concentrations of hg in invertebrates and fish have been documented. however, bioaccumulation of hg by amphibians has not been evaluated. in this study, adult and juvenile american bullfrogs (lithobates catesbeianus) and foothill yellow-legged frogs (rana boylii), adult northern pacific ... | 2010 | 19353298 |
| toxicity of two insecticides to california, usa, anurans and its relevance to declining amphibian populations. | contaminants have been associated with population declines of several amphibian species in california (usa). pesticides from the central valley of california are transported by winds into the sierra nevada mountains and precipitate into wet meadows where amphibians breed. the present study examined the chronic toxicity of two of the insecticides most commonly used in the central valley and found in the mountains, chlorpyrifos and endosulfan, to larval pacific treefrogs (pseudacris regilla) and f ... | 2009 | 19290680 |
| effects of flow regimes altered by dams on survival, population declines, and range-wide losses of california river-breeding frogs. | widespread alteration of natural hydrologic patterns by large dams combined with peak demands for power and water delivery during summer months have resulted in frequent aseasonal flow pulses in rivers of western north america. native species in these ecosystems have evolved with predictable annual flood-drought cycles; thus, their likelihood of persistence may decrease in response to disruption of the seasonal synchrony between stable low-flow conditions and reproduction. we evaluated whether a ... | 2012 | 22594596 |
| using environmental dna for early detection of amphibian chytrid fungus batrachochytrium dendrobatidis prior to a ranid die-off. | amphibian chytridiomycosis caused by the fungus batrachochytrium dendrobatidis (bd) is an emerging infectious disease that has been associated with mass mortality and extinctions of amphibians worldwide. environmental dna (edna) techniques have been used to detect the presence of bd in the environment, but not to detect bd prior to an amphibian die-off. we collected edna using filtered water samples from 13 lakes across sequoia kings canyon national park. seven of those sites had populations of ... | 2017 | 29256431 |
| rapid extirpation of a north american frog coincides with an increase in fungal pathogen prevalence: historical analysis and implications for reintroduction. | as extinctions continue across the globe, conservation biologists are turning to species reintroduction programs as one optimistic tool for addressing the biodiversity crisis. for repatriation to become a viable strategy, fundamental prerequisites include determining the causes of declines and assessing whether the causes persist in the environment. invasive species-especially pathogens-are an increasingly significant factor contributing to biodiversity loss. we hypothesized that batrachochytriu ... | 2017 | 29238549 |
| large-scale recovery of an endangered amphibian despite ongoing exposure to multiple stressors. | amphibians are one of the most threatened animal groups, with 32% of species at risk for extinction. given this imperiled status, is the disappearance of a large fraction of the earth's amphibians inevitable, or are some declining species more resilient than is generally assumed? we address this question in a species that is emblematic of many declining amphibians, the endangered sierra nevada yellow-legged frog (rana sierrae). based on >7,000 frog surveys conducted across yosemite national park ... | 2016 | 27698128 |
| introduced trout sever trophic connections in watersheds: consequences for a declining amphibian. | trophic linkages between terrestrial and aquatic ecosystems are increasingly recognized as important yet poorly known features of food webs. here we describe research to understand the dynamics of lake food webs in relation to a native riparian amphibian and its interaction with introduced trout. the mountain yellow-legged frog rana muscosa is endemic to alpine watersheds of the sierra nevada mountains and the transverse ranges of california, but it has declined to a small fraction of its histor ... | 2007 | 17918397 |
| reversing introduced species effects: experimental removal of introduced fish leads to rapid recovery of a declining frog. | amphibian population declines and extinctions are occurring even in the world's least impacted areas. the introduction and spread of nonnative predators is one of many proposed causes of amphibian declines. correlational studies have shown a negative relationship between introduced fishes and declining amphibians, but little direct experimental evidence is available. this study experimentally manipulated the presence and absence of widely introduced salmonids rainbow trout (oncorhynchus mykiss) ... | 2004 | 15136741 |
| multiple stressors and amphibian declines: dual impacts of pesticides and fish on yellow-legged frogs. | more than 40% of earth's 5700+ amphibian species have undergone recent declines. despite the likely involvement of multiple factors in driving these declines, most studies continue to focus on single stressors. in california (usa), separate studies have implicated either introduced fish or pesticides as causal agents. to date, however, no study has simultaneously evaluated the respective roles of these two potential stressors nor attempted to assess their relative importance, information critica ... | 2007 | 17489262 |
| comparative toxicity of chlorpyrifos, diazinon, malathion and their oxon derivatives to larval rana boylii. | organophosphorus pesticides (ops) are ubiquitous in the environment and are highly toxic to amphibians. they deactivate cholinesterase, resulting in neurological dysfunction. most chemicals in this group require oxidative desulfuration to achieve their greatest cholinesterase-inhibiting potencies. oxon derivatives are formed within liver cells but also by bacterial decay of parental pesticides. this study examines the toxicity of chlorpyrifos, malathion and diazinon and their oxons on the foothi ... | 2007 | 17218044 |
| pesticides in mountain yellow-legged frogs (rana muscosa) from the sierra nevada mountains of california, usa. | in 1997, pesticide concentrations were measured in mountain yellow-legged frogs (rana muscosa) from two areas in the sierra nevada mountains of california, usa. one area (sixty lakes basin, kings canyon national park) had large, apparently healthy populations of frogs. a second area (tablelands, sequoia national park) once had large populations, but the species had been extirpated from this area by the early 1980s. the tablelands is exposed directly to prevailing winds from agricultural regions ... | 2004 | 15378994 |
| molecular phylogenetics of western north american frogs of the rana boylii species group. | phylogenetic relationships among frogs of the genus rana from western north america are investigated using 2013 aligned bases of mitochondrial dna sequence from the genes encoding nd1 (subunit one of nadh dehydrogenase), trna(ile), trna(gln), trna(met), nd2, trna(trp), trna(ala), trna(asn), trna(cys), trna(tyr), and coi (subunit i of cytochrome c oxidase), plus the origin for light-strand replication (o(l)) between the trna(asn) and trna(cys) genes. the aligned sequences contain 401 phylogenetic ... | 2001 | 11286498 |
| amphibian orientation: an unexpected observation. | the study of homing movements of displaced newts (taricha rivularis) revealed unexpected features of the migratory behavior of amphibians. newts leaving the breeding stream in the spring move not directly uphill but at an angle carrying them upstream. when they emerge after summer estivation this tendency is not evident in captures made during the autumn and winter. during the latter period, however, newly metamorphosed frogs (rana boylii) show the same pronounced upstream migration that charact ... | 1967 | 17792064 |
| probiotics modulate a novel amphibian skin defense peptide that is antifungal and facilitates growth of antifungal bacteria. | probiotics can ameliorate diseases of humans and wildlife, but the mechanisms remain unclear. host responses to interventions that change their microbiota are largely uncharacterized. we applied a consortium of four natural antifungal bacteria to the skin of endangered sierra nevada yellow-legged frogs, rana sierrae, before experimental exposure to the pathogenic fungus batrachochytrium dendrobatidis (bd). the probiotic microbes did not persist, nor did they protect hosts, and skin peptide sampl ... | 2020 | 31093727 |
| opening the file drawer: unexpected insights from a chytrid infection experiment. | infection experiments are critical for understanding wildlife disease dynamics. although infection experiments are typically designed to reduce complexity, disease outcomes still result from complex interactions between host, pathogen, and environmental factors. cryptic variation across factors can lead to decreased repeatability of infection experiments within and between research groups and hinder research progress. furthermore, studies with unexpected results are often relegated to the "file ... | 2018 | 29742111 |
| structural and positional studies of the antimicrobial peptide brevinin-1bya in membrane-mimetic environments. | brevinin-1bya (flpilaslaakfgpklfclvtkkc), first isolated from skin secretions of the foothill yellow-legged frog rana boylii, shows broad-spectrum activity, being particularly effective against opportunistic yeast pathogens. the structure of brevinin-1bya was investigated in various solution and membrane-mimicking environments by proton nuclear magnetic resonance (1 h-nmr) spectroscopy and molecular modelling. the peptide does not possess a secondary structure in aqueous solution. in a 33% 2,2,2 ... | 2019 | 31721374 |
| insights into conformation and membrane interactions of the acyclic and dicarba-bridged brevinin-1bya antimicrobial peptides. | brevinin-1bya is a 24-amino acid residue host-defense peptide, first isolated from skin secretions of the foothill yellow-legged frog rana boylii. the peptide is of interest, as it shows broad-spectrum antimicrobial activity, and is particularly effective against opportunistic yeast pathogens. its potential for clinical use, however, is hindered by its latent haemolytic activity. the structures of two analogues, the less haemolytic [c18s,c24s]brevinin-1bya and the more potent cis-dicarba-brevini ... | 2019 | 31515575 |
| hybridization between two parapatric ranid frog species in the northern sierra nevada, california, usa. | contact zones between species provide a unique opportunity to test whether taxa can hybridize or not. cross-breeding or hybridization between closely related taxa can promote gene flow (introgression) between species, adaptation, or even speciation. though hybridization events may be short-lived and difficult to detect in the field, genetic data can provide information about the level of introgression between closely related taxa. hybridization can promote introgression between species, which ma ... | 2019 | 31495012 |
| an empirical pipeline for choosing the optimal clustering threshold in radseq studies. | genomic data are increasingly used for high resolution population genetic studies including those at the forefront of biological conservation. a key methodological challenge is determining sequence similarity clustering thresholds for radseq data when no reference genome is available. these thresholds define the maximum permitted divergence among allelic variants and the minimum divergence among putative paralogues and are central to downstream population genomic analyses. here we develop a nove ... | 2019 | 31058458 |
| stepping into the past to conserve the future: archived skin swabs from extant and extirpated populations inform genetic management of an endangered amphibian. | moving animals on a landscape through translocations and reintroductions is an important management tool used in the recovery of endangered species, particularly for the maintenance of population genetic diversity and structure. management of imperiled amphibian species rely heavily on translocations and reintroductions, especially for species that have been brought to the brink of extinction by habitat loss, introduced species, and disease. one striking example of amphibian declines and associa ... | 2020 | 32573039 |
| spatial and temporal patterns of environmental dna detection to inform sampling protocols in lentic and lotic systems. | the development of efficient sampling protocols for the capture of environmental dna (edna) could greatly help improve accuracy of occupancy monitoring for species that are difficult to detect. however, the process of developing a protocol in situ is complicated for rare species by the fact that animal locations are often unknown. we tested sampling designs in lake and stream systems to determine the most effective edna sampling protocols for two rare species: the sierra nevada yellow-legged fro ... | 2020 | 32076537 |
| reduced skin bacterial diversity correlates with increased pathogen infection intensity in an endangered amphibian host. | the fungal pathogen batrachochytrium dendrobatidis (bd) infects the skin of amphibians and has caused severe declines and extinctions of amphibians globally. in this study, we investigate the interaction between bd and the bacterial skin microbiome of the endangered sierra nevada yellow-legged frog, rana sierrae, using both culture-dependent and culture-independent methods. samples were collected from two populations of r. sierrae that likely underwent bd epizootics in the past, but that continu ... | 2019 | 30506592 |
| population genomic data reveal extreme geographic subdivision and novel conservation actions for the declining foothill yellow-legged frog. | genomic data have the potential to inform high resolution landscape genetic and biological conservation studies that go far beyond recent mitochondrial and microsatellite analyses. we characterize the relationships of populations of the foothill yellow-legged frog, rana boylii, a declining, "sentinel" species for stream ecosystems throughout its range in california and oregon. we generated radseq data and applied phylogenetic methods, hierarchical bayesian clustering, pca and population differen ... | 2018 | 29941996 |