| helminths of two native frog species (rana chiricahuensis, rana yavapaiensis) and one introduced frog species (rana catesbeiana) (ranidae) from arizona. | the gastrointestinal tracts, lungs, urinary bladders, and body cavities of rana catesbeiana (n = 25), rana chiricahuensis (n = 25), and rana yavapaiensis (n = 37) from arizona were examined for helminths. helminths representing 9 species of trematodes: cephalogonimus brevicirrus, glypthelmins quieta, gorgoderina attenuata, haematoloechus complexus, haematoloechus langiplexus, megalodiscus temperatus, alaria sp., clinostomum sp., and an unidentified strigeid; and 4 species of nematodes: falcaustr ... | 1998 | 9488361 |
| chytridiomycosis in native arizona frogs. | twenty-seven adult/sub-adult lowland leopard frogs (rana yavapaiensis), two larval lowland leopard frogs, two adult chirichahua leopard frogs (rana chiricahuensis), and two adult canyon tree frogs (hyla arenicolor) collected from populations experiencing mortality events at eight sites were found to have characteristic lesions of chytrid fungus infection (batrachochytrium dendrobatidis). the mortalities occurred during december 1992 and between october and february in 1997-98 and december and fe ... | 2002 | 11838218 |
| peptides with potent cytolytic activity from the skin secretions of the north american leopard frogs, lithobates blairi and lithobates yavapaiensis. | six structurally similar and strongly cationic peptides belonging to the brevinin-1 family were isolated from skin secretions of the plains leopard frog lithobates blairi and the lowland leopard frog lithobates yavapaiensis on the basis of their antimicrobial activities. brevinin-1blc (flpiiagiaakflpkifctiskkc) from l. blairi represented the most potent peptide (mic=25microm escherichia coli, mic=1.5microm staphylococcus aureus, mic=3microm candida albicans, lc(50)=9microm human erythrocytes and ... | 2009 | 19254736 |
| primary structures of skin antimicrobial peptides indicate a close, but not conspecific, phylogenetic relationship between the leopard frogs lithobates onca and lithobates yavapaiensis (ranidae). | the phylogenetic relationship between the relict leopard frog lithobates (rana) onca (cope, 1875) and the lowland leopard frog lithobates (rana) yavapaiensis (platz and frost, 1984) is unclear. chromatographic analysis of norepinephrine-stimulated skin secretions from l. onca led to the identification of six peptides with antimicrobial activity. determination of their primary structures indicated that four of the peptides were identical to brevinin-1ya, brevinin-1yb, brevinin-1yc and ranatuerin- ... | 2010 | 20044030 |
| nothing a hot bath won't cure: infection rates of amphibian chytrid fungus correlate negatively with water temperature under natural field settings. | dramatic declines and extinctions of amphibian populations throughout the world have been associated with chytridiomycosis, an infectious disease caused by the pathogenic chytrid fungus batrachochytrium dendrobatidis (bd). previous studies indicated that bd prevalence correlates with cooler temperatures in the field, and laboratory experiments have demonstrated that bd ceases growth at temperatures above 28°c. here we investigate how small-scale variations in water temperature correlate with bd ... | 2011 | 22205950 |
| reduced immune function predicts disease susceptibility in frogs infected with a deadly fungal pathogen. | the relationship between amphibian immune function and disease susceptibility is of primary concern given current worldwide declines linked to the pathogenic fungus batrachochytrium dendrobatidis (bd). we experimentally infected lowland leopard frogs (lithobates yavapaiensis) with bd to test the hypothesis that infection causes physiological stress and stimulates humoral and cell-mediated immune function in the blood. we measured body mass, the ratio of circulating neutrophils to lymphocytes (a ... | 2016 | 27293759 |
| seasonal and ontogenetic variation of skin microbial communities and relationships to natural disease dynamics in declining amphibians. | recently, microbiologists have focused on characterizing the probiotic role of skin bacteria for amphibians threatened by the fungal disease chytridiomycosis. however, the specific characteristics of microbial diversity required to maintain health or trigger disease are still not well understood in natural populations. we hypothesized that seasonal and developmental transitions affecting susceptibility to chytridiomycosis could also alter the stability of microbial assemblages. to test our hypot ... | 2015 | 26587253 |
| linking genetic and environmental factors in amphibian disease risk. | a central question in evolutionary biology is how interactions between organisms and the environment shape genetic differentiation. the pathogen batrachochytrium dendrobatidis (bd) has caused variable population declines in the lowland leopard frog (lithobates yavapaiensis); thus, disease has potentially shaped, or been shaped by, host genetic diversity. environmental factors can also influence both amphibian immunity and bd virulence, confounding our ability to assess the genetic effects on dis ... | 2015 | 26136822 |
| hydrologic variability governs population dynamics of a vulnerable amphibian in an arid environment. | dynamics of many amphibian populations are governed by the distribution and availability of water. therefore, understanding the hydrological mechanisms that explain spatial and temporal variation in occupancy and abundance will improve our ability to conserve and recover populations of vulnerable amphibians. we used 16 years of survey data from intermittent mountain streams in the sonoran desert to evaluate how availability of surface water affected survival and adult recruitment of a threatened ... | 2015 | 26030825 |
| isolation and characterization of microsatellite markers in the lowland leopard frog (rana yavapaiensis) and the relict leopard frog (r. onca), two declining frogs of the north american desert southwest. | we characterized 15 microsatellite loci for the lowland leopard frog (rana yavapaiensis) and the relict leopard frog (r. onca) for future studies of population genetic structure and relatedness. analysis of 20 individuals from single populations of each species showed that all markers were polymorphic in at least one species. observed and expected heterozygosities ranged from 0 to 0.94 and from 0.11 to 0.85, respectively, and there were three to 11 alleles per locus. no loci were in linkage dise ... | 2009 | 21564602 |
| conservation and divergence in the frog immunome: pyrosequencing and de novo assembly of immune tissue transcriptomes. | frogs are a diverse group of vertebrates for which limited genomic resources are available. natural frog populations face a multitude of threats, including habitat degradation, infectious disease, and environmental change. characterizing the functional genomics of anuran tissues in general - and the immune system in particular - will enhance our knowledge of genetic and epigenetic responses to environmental threats and inform conservation and recovery efforts. | 2014 | 24680726 |
| host defense peptides from lithobates forreri, hylarana luctuosa, and hylarana signata (ranidae): phylogenetic relationships inferred from primary structures of ranatuerin-2 and brevinin-2 peptides. | the primary structures of host-defense peptides present in frog skin secretions constitute useful molecular markers for establishing taxonomic classifications and investigating phylogenetic relationships between species within a particular genus. peptidomic analysis has led to the characterization of multiple host-defense peptides in norepinephrine-stimulated skin secretions of three species of frogs from the family ranidae: lithobates forreri (boulenger, 1883), hylarana luctuosa (peters, 1871), ... | 2014 | 24463457 |
| drought-mediated extinction of an arid-land amphibian: insights from a spatially explicit dynamic occupancy model. | understanding how natural and anthropogenic processes affect population dynamics of species with patchy distributions is critical to predicting their responses to environmental changes. despite considerable evidence that demographic rates and dispersal patterns vary temporally in response to an array of biotic and abiotic processes, few applications of metapopulation theory have sought to explore factors that explain spatiotemporal variation in extinction or colonization rates. to facilitate exp ... | 2019 | 30680832 |
| sustained immune activation is associated with susceptibility to the amphibian chytrid fungus. | the disease chytridiomycosis caused by the fungus bd has devastated amphibian populations worldwide. functional genomic contributions to host susceptibility remain enigmatic and vary between species and populations. we conducted experimental bd infections in rana yavapaiensis, a species with intraspecific variation in chytridiomycosis susceptibility, to assess the skin and spleen transcriptomic response to infection over time. we predicted that increased immune gene expression would be associate ... | 2020 | 32700351 |