| in situ hybridization of "nick-translated" 3h-ribosomal dna to chromosomes from salamanders. | a technique is described for preparation of 3h-labelled dna by nick-translation employing deoxyribonuclease i and dna polymerase i. the labelled dna can be obtained in high yield with specific activities of 10(6) cpm/mug or more. ribosomal dna, isolated from ovaries of young xenopus laevis, and whole dna from plethodon cinereus were labelled in this way. the rdna was used for in situ hybridization to meiotic chromosomes from p. cinereus, p. vehiculum and p. dunni. autoradiographs of in situ hybr ... | 1976 | 1248332 |
| the dark brown integumentary pigment of a barnacle (balanus eburneus). a comparative study. | a histochemical analysis involving tinctorial and solubility tests was pursued in conjunction with electron microscopy for the purpose of identifying the dark brown epidermal pigment of a barnacle (balanus eburneus) as melanin and/or ommochrome. histochemically, comparisons were made with other brown pigments located in the subcarapal epidermis of another crustacean, the fiddler crab (uca pugilator), the dorsal skin of the red-backed salamander (plethodon cinereus), the liver and testis of a sli ... | 1983 | 6874419 |
| sperm storage in the spermatheca of the red-back salamander, plethodon cinereus (amphibia: plethodontidae). | in northern indiana, the mating season of plethodon cinereus occurs after hibernation from march until june, when oviposition begins. during the mating season, a female stores sperm in its spermatheca, a compound tubular gland in the roof of the cloaca. the apical cytoplasm of the spermathecal epithelium is filled with large secretory vacuoles whose product is released while sperm are stored. females induced to oviposit in june and july by injections of human chorionic gonadotropin (hcg) still r ... | 1997 | 9360318 |
| description of the postcloacal glands of plethodon cinereus, the red-backed salamander, during bouts of scent marking. | plethodon cinereus, the red-backed salamander, is a small territorial vertebrate that defends refugia located on the forest floor. as a component of territorial defense, these animals use scent marks to advertise their refugia. behavioral evidence indicates that scent marks are produced by the postcloacal glands located on the ventral surface of the tail just posterior to the cloaca. we placed animals on unmarked substrates and recorded changes in serous acini from the postcloacal and shoulder r ... | 1999 | 10580264 |
| antibacterial and hemolytic activity of the skin of the terrestrial salamander, plethodon cinereus. | as resistance increases against fungal antibiotics, antimicrobial peptides are receiving attention as possible replacements. the dermal glands of frogs secrete, among other things, antimicrobial peptides. as part of the innate immune system, stressors may affect the production of antimicrobial peptides by dermal glands. the dermal secretions of some salamanders have been examined for their toxic secretions, but little attention has been given to salamander antimicrobial peptides. this study exam ... | 2000 | 10980492 |
| salamanders ( plethodon cinereus) go for more: rudiments of number in an amphibian. | techniques traditionally used in developmental research with infants have been widely used with nonhuman primates in the investigation of comparative cognitive abilities. recently, researchers have shown that human infants and monkeys select the larger of two numerosities in a spontaneous forced-choice discrimination task. here we adopt the same method to assess in a series of experiments spontaneous choice of the larger of two numerosities in a species of amphibian, red-backed salamanders ( ple ... | 2003 | 12709845 |
| the identification of 2,4-diacetylphloroglucinol as an antifungal metabolite produced by cutaneous bacteria of the salamander plethodon cinereus. | beneficial bacteria that live on salamander skins have the ability to inhibit pathogenic fungi. our study aimed to identify the specific chemical agent(s) of this process and asked if any of the antifungal compounds known to operate in analogous plant-bacteria-fungi systems were present. crude extracts of bacteria isolated from salamander skin were exposed to hplc, uv-vis, gc-ms, and hr-ms analyses. these investigations show that 2,4-diacetylphloroglucinol is produced by the bacteria isolate lys ... | 2008 | 18058176 |
| diversity of cutaneous bacteria with antifungal activity isolated from female four-toed salamanders. | among the microbiota of amphibian skin are bacteria that produce antifungal compounds. we isolated cutaneous bacteria from the skins of three populations of the nest-attending plethodontid salamander hemidactylium scutatum and subsequently tested the bacterial isolates against two different fungi (related to mariannaea elegans and rhizomucor variabilis) that were obtained from dead salamander eggs. the culturable antifungal bacteria were phylogenetically characterized based on 16s rrna phylogeny ... | 2008 | 18079731 |
| amphibian chemical defense: antifungal metabolites of the microsymbiont janthinobacterium lividum on the salamander plethodon cinereus. | disease has spurred declines in global amphibian populations. in particular, the fungal pathogen batrachochytrium dendrobatidis has decimated amphibian diversity in some areas unaffected by habitat loss. however, there is little evidence to explain how some amphibian species persist despite infection or even clear the pathogen beyond detection. one hypothesis is that certain bacterial symbionts on the skin of amphibians inhibit the growth of the pathogen. an antifungal strain of janthinobacteriu ... | 2008 | 18949519 |
| addition of antifungal skin bacteria to salamanders ameliorates the effects of chytridiomycosis. | chytridiomycosis, caused by the skin fungus batrachochytrium dendrobatidis (bd), has caused population declines of many amphibians in remote protected habitats. progress has been made in understanding the pathogen's life cycle, documenting its devastating effects on individual amphibians and on populations, and understanding how and why disease outbreaks occur. no research has directly addressed the critical question of how to prevent declines and extinctions caused by outbreaks of the disease. ... | 2009 | 19301631 |
| the bacterially produced metabolite violacein is associated with survival of amphibians infected with a lethal fungus. | the disease chytridiomycosis, which is caused by the chytrid fungus batrachochytrium dendrobatidis, is associated with recent declines in amphibian populations. susceptibility to this disease varies among amphibian populations and species, and resistance appears to be attributable in part to the presence of antifungal microbial species associated with the skin of amphibians. the betaproteobacterium janthinobacterium lividum has been isolated from the skins of several amphibian species and produc ... | 2009 | 19717627 |
| new findings from an old pathogen: intraerythrocytic bacteria (family anaplasmatacea) in red-backed salamanders plethodon cinereus. | during a recent study of red-backed salamanders (plethodon cinereus), we discovered an intraerythrocytic organism typified by violet-staining, intracellular inclusions, consistent with descriptions of cytamoeba or aegyptianella (bacteria). here we characterize its taxonomic status using molecular techniques and ask basic questions about its nature. blood smears from 102 salamanders were examined from pennsylvania, new york, and virginia to determine prevalence, and whole blood from several infec ... | 2009 | 19908097 |
| toxicity of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (hmx) in three vertebrate species. | the explosive, octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine or high-melting explosive (hmx), has been found in soils in areas used for testing and training by the military. many of these areas contain habitat for valued wildlife species. in an effort to better understand the environmental consequences from exposure, a reptilian (western fence lizard [sceloporus occidentalis]), an amphibian (red-backed salamander [plethodon cinereus]), and a mammalian species (rabbit [oryctolagus cuniculus]) ... | 2010 | 20012743 |
| intraerythrocytic rickettsial inclusions in ocoee salamanders (desmognathus ocoee): prevalence, morphology, and comparisons with inclusions of plethodon cinereus. | reports of an unusual intraerythrocytic pathogen in amphibian blood have been made for decades; these pathogens appear as membrane-bound vacuoles within erythrocytes. it is now understood that the pathogen is a rickettsia bacteria, which are obligate intracellular parasites, and most are transmitted by arthropod vectors. in an effort to further understand the host range and characteristics of this pathogen, we examined 20 ocoee salamanders (desmognathus ocoee) from a site in southwest north caro ... | 2010 | 20422220 |
| 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 |
| the nucleolar organizer of plethodon cinereus cinereus (green). i. location of the nucleolar organizer by in situ nucleic acid hybridization. | | 2016 | 4730559 |
| the nucleolar organizer of plethodon cinereus cinereus (green). ii. the lampbrush nucleolar organizer. | | 2016 | 4730560 |
| adaptive linkage disequilibrium between two esterase loci of a salamander. | in some populations of the salamander plethodon cinereus, two polymorphic esterase loci are in linkage disequilibrium. short-term stability of the linkage disequilibrium is demonstrated by an age class analysis. long, perhaps very long, term stability is suggested by its distribution. this stability and concordant geographic variation in allelic frequencies imply selective origin and maintenance. data on the frequencies of two color morphs suggest that formation of the linkage disequilibrium is ... | 2015 | 4515614 |
| interactions between amphibians' symbiotic bacteria cause the production of emergent anti-fungal metabolites. | amphibians possess beneficial skin bacteria that protect against the disease chytridiomycosis by producing secondary metabolites that inhibit the pathogen batrachochytrium dendrobatidis (bd). metabolite production may be a mechanism of competition between bacterial species that results in host protection as a by-product. we expect that some co-cultures of bacterial species or strains will result in greater bd inhibition than mono-cultures. to test this, we cultured four bacterial isolates (bacil ... | 2014 | 25191317 |
| microbial community dynamics and effect of environmental microbial reservoirs on red-backed salamanders (plethodon cinereus). | beneficial cutaneous bacteria on amphibians can protect against the lethal disease chytridiomycosis, which has devastated many amphibian species and is caused by the fungus batrachochytrium dendrobatidis. we describe the diversity of bacteria on red-backed salamanders (plethodon cinereus) in the wild and the stability of these communities through time in captivity using culture-independent illumina 16s rrna gene sequencing. after field sampling, salamanders were housed with soil from the field o ... | 2013 | 24335825 |
| amelogenin evolution and tetrapod enamel structure. | amelogenins are the major proteins involved in tooth enamel formation. in the present study, we have cloned and sequenced four novel amelogenins from three amphibian species in order to analyze similarities and differences between mammalian and non-mammalian amelogenins. the newly sequenced amphibian amelogenin sequences were from a red-eyed tree frog (litoria chloris) and a mexican axolotl (ambystoma mexicanum). we identified two amelogenin isoforms in the eastern red-backed salamander (plethod ... | 2009 | 19828974 |
| vertebrate hosts as islands: dynamics of selection, immigration, loss, persistence, and potential function of bacteria on salamander skin. | skin bacterial communities can protect amphibians from a fungal pathogen; however, little is known about how these communities are maintained. we used a neutral model of community ecology to identify bacteria that are maintained on salamanders by selection or by dispersal from a bacterial reservoir (soil) and ecological drift. we found that 75% (9/12) of bacteria that were consistent with positive selection, <1% of bacteria that were consistent with random dispersal and none of the bacteria that ... | 2016 | 27014249 |
| salamanders increase their feeding activity when infected with the pathogenic chytrid fungus batrachochytrium dendrobatidis. | immune function is a costly line of defense against parasitism. when infected with a parasite, hosts frequently lose mass due to these costs. however, some infected hosts (e.g. highly resistant individuals) can clear infections with seemingly little fitness losses, but few studies have tested how resistant hosts mitigate these costly immune defenses. we explored this topic using eastern red-backed salamanders plethodon cinereus and the fungal pathogen batrachochytrium dendrobatidis (bd). bd is g ... | 2015 | 26503775 |
| calibrating abundance indices with population size estimators of red back salamanders (plethodon cinereus) in a new england forest. | herpetologists and conservation biologists frequently use convenient and cost-effective, but less accurate, abundance indices (e.g., number of individuals collected under artificial cover boards or during natural objects surveys) in lieu of more accurate, but costly and destructive, population size estimators to detect and monitor size, state, and trends of amphibian populations. although there are advantages and disadvantages to each approach, reliable use of abundance indices requires that the ... | 2015 | 26020008 |
| bioaccumulation and maternal transfer of mercury and selenium in amphibians. | amphibian population declines have been documented worldwide and environmental contaminants are believed to contribute to some declines. maternal transfer of bioaccumulated contaminants to offspring may be an important and overlooked mechanism of impaired reproductive success that affects amphibian populations. mercury (hg) is of particular concern due to its ubiquity in the environment, known toxicity to other wildlife, and complex relationships with other elements, such as selenium (se). the o ... | 2010 | 20821530 |
| mercury accumulation along a contamination gradient and nondestructive indices of bioaccumulation in amphibians. | mercury (hg) is an important environmental contaminant due to its global distribution, tendency to bioaccumulate, and toxicity in wildlife. however, hg has received little attention in amphibians compared to other vertebrates. amphibians vary widely in life history strategies and feeding ecologies, which could influence hg exposure and accumulation. to determine whether species and life stage affects hg bioaccumulation, adults from three species (plethodon cinereus, eurycea bislineata, and bufo ... | 2010 | 20821529 |
| freeze tolerance and intolerance as strategies of winter survival in terrestrially-hibernating amphibians. | the ability to tolerate extracellular freezing as an adaptation for winter survival was tested in seven species of terrestrially-hibernating amphibians found in eastern canada. all species had only moderate supercooling abilities, with whole animal supercooling points of -1.5 to -3 degrees c. two salamander species, plethodon cinereus and ambystoma laterale, and the toad, bufo americanus, were freezing intolerant and were killed when frozen for 24 hr at temperatures just below their supercooling ... | 1986 | 2870854 |
| blood parasites of amphibians from algonquin park, ontario. | during a 5 wk period beginning may 25, 1983, 329 amphibians, which included specimens of rana catesbeiana shaw, rana clamitans latreille, rana septentrionalis baird, rana sylvatica leconte, hyla crucifer wied, bufo americanus holbrook, and plethodon cinereus green, from lake sasajewun, algonquin park, ontario, canada were examined for blood parasites. the prevalences of species of trypanosoma, haemogregarina, lankesterella, babesiasoma, and thrombocytozoons in these amphibians were determined. t ... | 1984 | 6492319 |
| toxicological responses of red-backed salamander (plethodon cinereus) exposed to aged and amended soils containing lead. | the use of lead in military and civilian small arms projectiles is widely acknowledged to have resulted in high soil lead concentrations at many small arms ranges. these ranges are often adjacent to wildlife habitat or have become habitat when no longer used. to assess the potential toxicity of lead to terrestrial amphibians in contaminated areas, we exposed 100 red-backed salamanders (plethodon cinereus) to either a control soil or one of four soil treatments amended with lead acetate for 28 da ... | 2010 | 20135309 |
| toxicological responses of red-backed salamanders (plethodon cinereus) to soil exposures of copper. | copper (cu) has widespread military use in munitions and small arms, particularly as a protective jacket for lead projectiles. the distribution of cu at many us military sites is substantial and sites of contamination include habitats in and around military storage facilities, manufacturing, load and packing plants, open burning/open detonation areas, and firing ranges. some of these areas include habitat for amphibian species, which generally lack toxicity data for risk assessment purposes. in ... | 2009 | 18825446 |
| toxicological responses of red-backed salamanders (plethodon cinereus) to subchronic soil exposures of 2,4,6-trinitrotoluene. | since world war i, trinitrotoluene (tnt) has been the most commonly used explosive. environmental contamination associated with synthesis, manufacture of weapons, and use during training exercises has been extensive, with soil concentrations reaching 145,000 mg/kg. some of these areas include habitats for amphibian species. earlier studies have shown that salamanders dermally absorb tnt from soil. to ascertain what soil concentrations of tnt are toxic to amphibians, red-backed salamanders (pleth ... | 2008 | 18481903 |
| prey detection by vomeronasal chemoreception in a plethodontid salamander. | while chemoreception is involved in a wide variety of salamander behaviors, the chemosensory system that mediates specific behaviors is rarely known. we investigated the role of the vomeronasal system (vns) in foraging behavior of the red-backed salamander (plethodon cinereus) by manipulating salamanders' abilities to detect nonvolatile chemical cues emitted by potential prey. subjects received one of three treatments: (1) impaired vomeronasal system, (2) sham manipulation, and (3) no manipulati ... | 2002 | 12049224 |
| endoparasites of plethodontid salamanders from paradise brook, new hampshire. | totals of 52 dusky salamanders desmognathus fuscus, 51 two-lined salamanders eurycea bislineata, 54 red-backed salamanders plethodon cinereus, and 3 spring salamanders gyrinophilus porphyriticus (plethodontidae) collected in june and august 1995 from paradise brook, a tributary to hubbard brook, new hampshire, were examined for parasites. parasites found were brachycoelium storeriae, brachycoelium sp., bothriocephalus rarus, falcaustra sp., omeia sp., batracholandros magnavulvaris, and cepediett ... | 1997 | 9406804 |
| effects of host species and environment on the skin microbiome of plethodontid salamanders. | the amphibian skin microbiome is recognized for its role in defence against pathogens, including the deadly fungal pathogen batrachochytrium dendrobatidis (bd). yet, we have little understanding of evolutionary and ecological processes that structure these communities, especially for salamanders and closely related species. we investigated patterns in the distribution of bacterial communities on plethodon salamander skin across host species and environments. quantifying salamander skin microbiom ... | 2017 | 28682480 |
| acclimation to constant and variable temperatures in plethodontid salamanders--i. rates of oxygen consumption. | in preliminary experiments, salamanders of three species (desmognathus ochrophaeus, plethodon cinereus and plethodon jordani) required 5-11 days to complete metabolic acclimation to a constant warm temperature; the rate of oxygen consumption (vo2) decreased 16-28% during acclimation. unfed animals of each species underwent cyclic exposure to 5 and 21 degrees c at three different cycle periods (12 hr, 4-5 days, 51 days), or constant exposure to 14 degrees c for 102 days. the experimental treatmen ... | 1985 | 2863058 |
| differential avoidance of mimetic salamanders by free-ranging birds. | members of a free-ranging avian community avoided the mimetic morph of the salamander plethodon cinereus significantly more often than a nonmimetic morph when offered with the model eft stage of notophthalmus viridescens and the palatable salamander desmognathus ochrophaeus. this is apparently the first demonstration of the efficacy of mimetic coloration of salamanders to uncaged birds. | 1980 | 17745538 |
| tongue and taste organ development in the ontogeny of direct-developing salamander plethodon cinereus (lissamphibia: plethodontidae). | the latest research on direct developing caecilian and anuran species indicate presence of only one generation of taste organs during their ontogeny. this is distinct from indirect developing batrachians studied thus far, which possess taste buds in larvae and anatomically distinct taste discs in metamorphs. this study is a description of the tongue and taste organ morphology and development in direct developing salamander plethodon cinereus (plethodontidae) using histology and electron microsco ... | 2016 | 27087010 |
| batesian mimics influence the evolution of conspicuousness in an aposematic salamander. | conspicuousness, or having high contrast relative to the surrounding background, is a common feature of unpalatable species. several hypotheses have been proposed to explain the occurrence of conspicuousness, and while most involve the role of conspicuousness as a direct signal of unpalatability to potential predators, one hypothesis suggests that exaggerated conspicuousness may evolve in unpalatable species to reduce predator confusion with palatable species (potential batesian mimics). this hy ... | 2015 | 25786622 |
| predator perception of batesian mimicry and conspicuousness in a salamander. | in batesian mimicry a palatable mimic deceives predators by resembling an unpalatable model. the evolution of batesian mimicry relies on the visual capabilities of the potential predators, as prey detection provides the selective force driving evolutionary change. we compared the visual capabilities of several potential predators to test predictions stemming from the hypothesis of batesian mimicry between two salamanders: the model species notophthalmus viridescens, and polymorphic mimic, pletho ... | 2014 | 24274647 |
| assessment of intra and interregional genetic variation in the eastern red-backed salamander, plethodon cinereus, via analysis of novel microsatellite markers. | the red-backed salamander (plethodon cinereus) has long-served as a model system in ecology, evolution, and behavior, and studies surveying molecular variation in this species have become increasingly common over the past decade. however, difficulties are commonly encountered when extending microsatellite markers to populations that are unstudied from a genetic perspective due to high levels of genetic differentiation across this species' range. to ameliorate this issue, we used 454 pyrosequenci ... | 2017 | 29053730 |
| evolutionary response to global change: climate and land use interact to shape color polymorphism in a woodland salamander. | evolutionary change has been demonstrated to occur rapidly in human-modified systems, yet understanding how multiple components of global change interact to affect adaptive evolution remains a critical knowledge gap. climate change is predicted to impose directional selection on traits to reduce thermal stress, but the strength of directional selection may be mediated by changes in the thermal environment driven by land use. we examined how regional climatic conditions and land use interact to a ... | 2017 | 28770079 |
| color-biased dispersal inferred by fine-scale genetic spatial autocorrelation in a color polymorphic salamander. | behavioral traits can be influenced by predation rates of color morphs, potentially leading to reduced boldness or increased escape behaviors in one color morph. the red-backed salamander, plethodon cinereus, is a small terrestrial salamander whose color morphs have different diets and select different microhabitats, but little is known about potential differences in dispersal behaviors. we used fine-scale genetic spatial autocorrelation to examine 122 p. cinereus in a color-polymorphic populati ... | 2017 | 28459986 |
| methodological considerations for detection of terrestrial small-body salamander edna and implications for biodiversity conservation. | environmental dna (edna) can be used as an assessment tool to detect populations of threatened species and provide fine-scale data required to make management decisions. the objectives of this project were to use quantitative pcr (qpcr) to: (i) detect spiked salamander dna in soil, (ii) quantify edna degradation over time, (iii) determine detectability of salamander edna in a terrestrial environment using soil, faeces, and skin swabs, (iv) detect salamander edna in a mesocosm experiment. salaman ... | 2017 | 28296353 |
| evaluating within-population variability in behavior and demography for the adaptive potential of a dispersal-limited species to climate change. | multiple pathways exist for species to respond to changing climates. however, responses of dispersal-limited species will be more strongly tied to ability to adapt within existing populations as rates of environmental change will likely exceed movement rates. here, we assess adaptive capacity in plethodon cinereus, a dispersal-limited woodland salamander. we quantify plasticity in behavior and variation in demography to observed variation in environmental variables over a 5-year period. we found ... | 2016 | 28035265 |
| invasive asian earthworms negatively impact keystone terrestrial salamanders. | asian pheretimoid earthworms (e.g. amynthas and metaphire spp.) are invading north american forests and consuming the vital detrital layer that forest floor biota [including the keystone species plethodon cinereus (eastern red-backed salamander)], rely on for protection, food, and habitat. plethodon cinereus population declines have been associated with leaf litter loss following the invasion of several exotic earthworm species, but there have been few studies on the specific interactions betwee ... | 2016 | 27144403 |
| is geographic variation within species related to macroevolutionary patterns between species? | the relationship between microevolution and macroevolution is a central topic in evolutionary biology. an aspect of this relationship that remains very poorly studied in modern evolutionary biology is the relationship between within-species geographic variation and among-species patterns of trait variation. here, we tested the relationship between climate and morphology among and within species in the salamander genus plethodon. we focus on a discrete colour polymorphism (presence and absence of ... | 2015 | 26079479 |
| partitioning detectability components in populations subject to within-season temporary emigration using binomial mixture models. | detectability of individual animals is highly variable and nearly always < 1; imperfect detection must be accounted for to reliably estimate population sizes and trends. hierarchical models can simultaneously estimate abundance and effective detection probability, but there are several different mechanisms that cause variation in detectability. neglecting temporary emigration can lead to biased population estimates because availability and conditional detection probability are confounded. in thi ... | 2015 | 25775182 |
| effects of timber harvests and silvicultural edges on terrestrial salamanders. | balancing timber production and conservation in forest management requires an understanding of how timber harvests affect wildlife species. terrestrial salamanders are useful indicators of mature forest ecosystem health due to their importance to ecosystem processes and sensitivity to environmental change. however, the effects of timber harvests on salamanders, though often researched, are still not well understood. to further this understanding, we used artificial cover objects to monitor the r ... | 2014 | 25517409 |
| a metagenomics-based approach to the top-down effect on the detritivore food web: a salamanders influence on fungal communities within a deciduous forest. | the flow of energy within an ecosystem can be considered either top-down, where predators influence consumers, or bottom-up, where producers influence consumers. plethodon cinereus (red-backed salamander) is a terrestrial keystone predator who feeds on invertebrates within the ecosystem. we investigated the impact of the removal of p. cinereus on the detritivore food web in an upland deciduous forest in northwest ohio, u.s.a. a total of eight aluminum enclosures, each containing a single p. cine ... | 2014 | 25505537 |
| histology and ultrastructure of the caudal courtship glands of the red-backed salamander, plethodon cinereus (amphibia: plethodontidae). | caudal courtship glands (ccgs) are sexually dimorphic glands described in the skin of the dorsal tail base of some male salamanders in the genera desmognathus, eurycea, and plethodon in the family plethodontidae. these glands are believed to deliver pheromones to females during courtship, when the female rests her chin on the dorsal tail base during the stereotypic tail straddling walk unique to plethodontids. although ccgs have been studied histologically, no investigations of their ultrastruct ... | 2015 | 25393050 |
| questioning the use of an amphibian colour morph as an indicator of climate change. | the effects of recent climate changes on earth ecosystems are likely among the most important ecological concerns in human history. good bioindicators are essential to properly assess the magnitude of these changes. in the last decades, studies have suggested that the morph proportion of the eastern red-backed salamander (plethodon cinereus), one of the most widely distributed and abundant vertebrate species in forests of eastern north america, could be used as a proxy for monitoring climate cha ... | 2015 | 25230362 |
| proteomic analyses of courtship pheromones in the redback salamander, plethodon cinereus. | the evolutionary success of plethodontid salamanders for ~100 my is due partly to the use of courtship pheromones that regulate female receptivity. in ~90 % of plethodontid species, males deliver pheromones by "scratching" a female's dorsum, where pheromones diffuse transdermally into the bloodstream. however, in a single clade, representing ~10 % of plethodon spp., males apply pheromones to the female's nares for olfactory delivery. molecular studies have identified three major pheromone famili ... | 2014 | 25179396 |
| effects of red-backed salamanders on ecosystem functions. | ecosystems provide a vast array of services for human societies, but understanding how various organisms contribute to the functions that maintain these services remains an important ecological challenge. predators can affect ecosystem functions through a combination of top-down trophic cascades and bottom-up effects on nutrient dynamics. as the most abundant vertebrate predator in many eastern us forests, woodland salamanders (plethodon spp.) likely affect ecosystems functions. we examined the ... | 2014 | 24466269 |
| avian, salamander, and forest floor mercury concentrations increase with elevation in a terrestrial ecosystem. | high-elevation ecosystems of the northeastern united states are vulnerable to deposition and environmental accumulation of atmospheric pollutants, yet little work has been done to assess mercury (hg) concentrations in organisms occupying montane ecosystems. the authors present data on hg concentrations in ground-foraging insectivorous songbirds, a terrestrial salamander, and forest floor horizons sampled along a forested elevational gradient from 185 m to 1273 m in the catskill mountains, new yo ... | 2014 | 24302165 |
| parapatric divergence of sympatric morphs in a salamander: incipient speciation on long island? | speciation is often categorized based on geographic modes (allopatric, parapatric or sympatric). although it is widely accepted that species can arise in allopatry and then later become sympatrically or parapatrically distributed, patterns in the opposite direction are also theoretically possible (e.g. sympatric lineages or ecotypes becoming parapatric), but such patterns have not been shown at a macrogeographic scale. here, we analyse genetic, climatic, ecological and morphological data and sho ... | 2013 | 23909857 |
| responses of eastern red-backed salamanders (plethodon cinereus) to chemical cues of prey presented in soluble and volatile forms. | terrestrial salamanders are able to detect prey items using chemical cues, but the nature of the cues involved is uncertain. this study aimed to tease apart the roles of the soluble and volatile components of prey cues detected by eastern red-backed salamanders (plethodon cinereus), assuming the likelihood that these different components are respectively detected by the vomeronasal (accessory) and main olfactory organs. wild-caught salamanders were exposed to control or soluble and volatile cric ... | 2013 | 23499768 |
| comparison of direct, indirect, and ecosystem engineering effects of an earthworm on the red-backed salamander. | in addition to creating or modifying habitat, ecosystem engineers interact with other species as predators, prey, or competitors. the earthworm, lumbricus terrestris, interacts with the common woodland salamander, plethodon cinereus, via: (1) ecosystem engineering, by providing burrows that are used as a refuge, (2) direct effects as a prey item, and (3) indirectly, by competing with microinvertebrates, another prey item for p. cinereus. using enclosures in the forest, i examined the relative st ... | 2012 | 23185881 |
| concurrent speciation in the eastern woodland salamanders (genus plethodon): dna sequences of the complete albumin nuclear and partial mitochondrial 12s genes. | salamanders of the north american plethodontid genus plethodon are important model organisms in a variety of studies that depend on a phylogenetic framework (e.g., chemical communication, ecological competition, life histories, hybridization, and speciation), and consequently their systematics has been intensively investigated over several decades. nevertheless, we lack a synthesis of relationships among the species. in the analyses reported here we use new dna sequence data from the complete nu ... | 2012 | 22230029 |
| do larval traits re-evolve? evidence from the embryogenesis of a direct-developing salamander, plethodon cinereus. | recent molecular phylogenies suggest the surprising reacquisition of posthatching metamorphosis within an otherwise direct-developing clade of lungless salamanders (family plethodontidae). metamorphosis was long regarded as plesiomorphic for plethodontids, yet the genus desmognathus, which primarily includes metamorphosing species, is now nested within a much larger clade of direct-developing species. the extent to which the putative reacquisition of metamorphosis in desmognathus represents a tr ... | 2012 | 22220879 |
| embryonic staging table for a direct-developing salamander, plethodon cinereus (plethodontidae). | this work presents a refined staging table for the direct-developing red-backed salamander plethodon cinereus, which is based on the incomplete staging system of james norman dent (j morphol 1942; 71:577-601). this common species from eastern north america is a member of the species-rich lungless salamander family plethodontidae. the staging table presented here covers several stages omitted by dent and reveals novel developmental features of p. cinereus embryos. these include putative leydig ce ... | 2011 | 21965144 |
| spinal cord regeneration in a tail autotomizing urodele. | adult urodele amphibians possess extensive regenerative abilities, including lens, jaws, limbs, and tails. in this study, we examined the cellular events and time course of spinal cord regeneration in a species, plethodon cinereus, that has the ability to autotomize its tail as an antipredator strategy. we propose that this species may have enhanced regenerative abilities as further coadaptations with this antipredator strategy. we examined the expression of nestin, vimentin, and glial fibrillar ... | 2012 | 21956379 |
| female philopatry and male-biased dispersal in a direct-developing salamander, plethodon cinereus. | the local resource competition hypothesis and the local mate competition hypothesis were developed based on avian and mammalian systems to explain sex-biased dispersal. most avian species show a female bias in dispersal, ostensibly due to resource defence, and most mammals show a male bias, ostensibly due to male-male competition. these findings confound phylogeny with mating strategy; little is known about sex-biased dispersal in other taxa. resource defence and male-male competition are both i ... | 2011 | 21134012 |
| earthworms, as ecosystem engineers, influence multiple aspects of a salamander's ecology. | ecosystem engineers create habitat that can be used by other species in multiple ways, such as refugees from predators, places to breed, or areas with increased prey resources. i conducted a series of enclosure experiments to: (1) determine if salamanders use earthworm burrows, and (2) examine the potential influence of earthworm burrow use and indirect effects on salamander intra- and interspecific competition, predator avoidance, and seasonal performance. i found that one species of woodland s ... | 2011 | 20848134 |
| ecological separation in a polymorphic terrestrial salamander. | 1. when studying speciation, researchers commonly examine reproductive isolation in recently diverged populations. polymorphic species provide an opportunity to examine the role of reproductive isolation in populations that may be in the process of divergence. 2. we examined a polymorphic population of plethodon cinereus (red-backed salamanders) for evidence of sympatric ecological separation by colour morphology. recent studies have correlated temperature and climate with colour morphology in t ... | 2008 | 18479343 |
| location-specific sympatric morphological divergence as a possible response to species interactions in west virginia plethodon salamander communities. | 1. the competitive interactions of closely related species have long been considered important determinants of community composition and a major cause of phenotypic diversification. however, while patterns such as character displacement are well documented, less is known about how local adaptation influences diversifying selection from interspecific competition. 2. we examined body size and head shape variation among allopatric and sympatric populations of two salamander species, the widespread ... | 2007 | 17302836 |
| toxicological responses of red-backed salamanders (plethodon cinereus) to subchronic soil exposures of 2,4-dinitrotoluene. | dinitrotoluenes are used as propellants and in explosives by the military and as such have been found at relatively high concentrations in the soil. to determine whether concentrations of 2,4-dinitrotoluene (2,4-dnt) in soil are toxic to amphibians, 100 red-backed salamanders (plethodon cinereus) were exposed to either 1500, 800, 200, 75 or 0mg 2,4-dnt/kg soil for 28 days and evaluated for indicators of toxicity. concentrations of 2,4-dnt were less than targets and varied with time. most salaman ... | 2007 | 17137690 |
| multiple paternity in a salamander with socially monogamous behaviour. | in the majority of birds and mammals, social monogamy is not congruent with genetic monogamy. no research to date has compared social and genetic monogamy in amphibians. we analysed paternity in clutches of red-backed salamanders (plethodon cinereus), a species in which social monogamy has been demonstrated in the laboratory, and 28% of individuals in the forest are found in male-female pairs in the noncourtship season. we collected 16 clutches of eggs of p. cinereus in the southern appalachian ... | 2006 | 17054509 |
| fine-scale population differentiation and gene flow in a terrestrial salamander (plethodon cinereus) living in continuous habitat. | several recent studies have shown that amphibian populations may exhibit high genetic subdivision in areas with recent fragmentation and urban development. less is known about the potential for genetic differentiation in continuous habitats. we studied genetic differentiation of red-backed salamanders (plethodon cinereus) across a 2-km transect through continuous forest in virginia, usa. mark-recapture studies suggest very little dispersal for this species, whereas homing experiments and post-pl ... | 2007 | 17006531 |
| effects of warming conditions in eastern north american forests on red-backed salamander morphology. | several studies have reported climate-associated changes in phenotypically plastic traits of amphibians, yet it remains unknown whether amphibians can manifest an evolutionary response to global climate change at the rate and magnitude that it is occurring. to assess this issue, we examined temporal change in the morphology of the red-backed salamander (plethodon cinereus), a small, abundant woodland salamander distributed widely in eastern north america with two distinct morphotypes: striped in ... | 2006 | 16909583 |
| the role of thermal niche selection in maintenance of a colour polymorphism in redback salamanders (plethodon cinereus). | in eastern north america two common colour morphs exist in most populations of redback salamanders (plethodon cinereus). previous studies have indicated that the different morphs may be adapted to different thermal niches and the morphological variation has been linked to standard metabolic rate at 15 degrees c in one population of p. cinereus. it has therefore been hypothesized that a correlated response to selection on metabolic rate across thermal niches maintains the colour polymorphism in p ... | 2006 | 16822305 |
| cell birth and survival following seasonal periods of cell proliferation in the chemosensory epithelia of red-backed salamanders, plethodon cinereus. | in addition to the continuous low levels of neurogenesis typical of adult vertebrates to replace damaged chemoreceptor cells, red-backed salamanders (plethodon cinereus) experience an up-regulation of chemoreceptor epithelial cell proliferation on a seasonal basis. significantly more cell division occurs in late spring than at any other time of the year, and we investigated the fate and life span of these newly generated cells. we used 5-bromo-2'-deoxyuridine (brdu) immunocytochemical cell birth ... | 2006 | 16567929 |
| toxicologic and histopathologic response of the terrestrial salamander plethodon cinereus to soil exposures of 1,3,5-trinitrohexahydro-1,3,5-triazine. | red-backed salamanders (plethodon cinereus) were exposed to four different concentrations of 1,3,5-trinitrohexahydro-1,3,5-triazine (rdx) in soil under controlled laboratory conditions for 28 days. wild-caught p. cinereus (n = 20/treatment) were exposed to target concentrations of 5,000, 1000, 100, 10, and 0 mg rdx/kg soil (dry wt) using a microcosm design. animals were fed 5 to 10 uncontaminated mutant drosophila flies every 3 days and monitored daily. animals were weighed 1 day before being pl ... | 2004 | 15499500 |
| mothers influence offspring body size through post-oviposition maternal effects in the redbacked salamander, plethodon cinereus. | in the terrestrial salamander (plethodon cinereus), previous work has shown that mother's body size is positively correlated to offspring size at the time of hatching even after controlling for the effects of egg size. this study was designed to determine whether maternal body size affects offspring size via pre-oviposition factors (e.g., yolk quality, jelly coat composition, or maternal genes) or post-oviposition factors (e.g., parental care behaviors, parental modification of environment). gra ... | 2004 | 14593524 |
| a complex, cross-taxon, chemical releaser of antipredator behavior in amphibians. | prey species show diverse antipredator responses to chemical cues signaling predation threat. among terrestrial vertebrates, the red-backed salamander, plethodon cinereus, is an important species in the study of these chemical defenses. during the day and early evening, this species avoids rinses from garter snakes, thamnophis sirtalis, independent of snake diet, but late at night. avoids only those rinses from garter snakes that have recently eaten p. cinereus. we tested whether the selective, ... | 2002 | 12523567 |
| effects of predator chemical cues and behavioral biorhythms on foraging activity of terrestrial salamanders. | red-backed salamanders, plethodon cinereus, show a variety of alarm responses to chemical cues from eastern garter snakes, thamnophis sirtalis. we measured the foraging activity of red-backed salamanders exposed to water soiled by a garter snake (fed p. cinereus) or to unsoiled water. salamanders exposed to snake-soiled water showed less foraging activity than salamanders exposed to unsoiled water; therefore, predators could have nonlethal effects on salamander populations. our results also show ... | 2001 | 11504031 |
| seasonal cell proliferation in the chemosensory epithelium and brain of red-backed salamanders, plethodon cinereus. | the chemosensory epithelium of vertebrates retains the ability to produce new receptor neurons throughout life, presumably as a mechanism to replace aging or damaged receptors. we examined cell division in the main olfactory and vomeronasal epithelia of red-backed salamanders (plethodon cinereus) because previous studies had shown that the volume of sensory epithelia changes seasonally. cell division was compared throughout the year by injecting salamanders once with 5-bromo-2'-deoxyuridine (brd ... | 2000 | 11025340 |
| social monogamy in a territorial salamander. | social monogamy, which does not necessarily imply mating or genetic monogamy, is important in the formation of male-female pair associations. we operationally define social monogamy as occurring when two heterosexual adults, exclusive of kin-directed behaviour, direct significantly less aggression and significantly more submission towards each other, and/or spend significantly more time associating with each other relative to other adult heterosexual conspecifics. long-term pair associations (i. ... | 2000 | 10877904 |
| ecological character displacement in plethodon: biomechanical differences found from a geometric morphometric study. | ecological character displacement describes a pattern where morphological differences between sympatric species are enhanced through interspecific competition. although widely considered a pervasive force in evolutionary ecology, few clear-cut examples have been documented. here we report a case of ecological character displacement between two salamander species, plethodon cinereus and plethodon hoffmani. morphology was quantified by using linear measurements and landmark-based geometric morphom ... | 2000 | 10760280 |
| perceived predation risk as a function of predator dietary cues in terrestrial salamanders. | prey often avoid predator chemical cues, and in aquatic systems, prey may even appraise predation risk via cues associated with the predator's diet. however, this relationship has not been shown for terrestrial predator-prey systems, where the proximity of predators and prey, and the intensity of predator chemical cues in the environment, may be less than in aquatic systems. in the laboratory, we tested behavioural responses (avoidance, habituation and activity) of terrestrial red-backed salaman ... | 1999 | 10053069 |
| the influence of tail autotomy on agonistic behaviour in a territorial salamander. | assessment of potentially asymmetrical characters (such as fighting ability and resident advantage) is often important in determining the outcome of agonistic interactions. loss of body parts, a predator defence mechanism used by many animals, may lead to a reduction in fighting ability and may be easily assessed by competitors. we investigated the influence of tail loss on the expression of agonistic behaviour in the territorial red-backed salamander, plethodon cinereus. residents and intruders ... | 1998 | 9642013 |
| courtship behaviour in male red-backed salamanders: the ess dating game | social interactions in red-backed salamanders, plethodon cinereusare complex and often depend upon the sex and reproductive status of individuals. in the population at mountain lake biological station, virginia, adult males outnumber sexually active (gravid) females by approximately 2:1, because males court annually while females accept mates only biennially. field observations of male p. cinereus suggest that males maintain feeding territories and allow non-gravid (not sexually active) females ... | 1997 | 9299055 |
| sexual and seasonal differences in the vomeronasal epithelium of the red-backed salamander (plethodon cinereus). | sexually dimorphic behaviors often are associated with sexually dimorphic neural structures. perinatal hormonal levels influence structural sexual dimorphism, and seasonal structural changes also can be the result of seasonal hormonal fluctuations. we compared the volume of vomeronasal organs of male and female red-backed salamanders (plethodon cinereus) throughout the year. odorants are delivered to vomeronasal receptors through nasolabial grooves when salamanders touch the bases of these groov ... | 1995 | 7499536 |
| effects of temperature on muscle phi and phosphate metabolites in newts and lungless salamanders. | the effect of acute alterations in body temperature (bt) on intracellular ph (phi) and phosphate metabolites was assessed in white skeletal muscle of intact newts and lungless red-backed salamanders using 31p-nuclear magnetic resonance spectroscopy. phi decreased with increasing bt in the tail muscle of both newts and lungless red-backed salamanders. the change in ph with change in temperature from 10 to 30 degrees c was -0.018 u/degrees c in newts and -0.041 u/degrees c in red backs. the calcul ... | 1993 | 8238619 |
| retinal pigment epithelial fine structure in the red-backed salamander (plethodon cinereus). | the retinal pigment epithelium (rpe) of the red-backed salamander (plethodon cinerus) consists of a single layer of large squamous shaped cells. the rpe cells are but minimally infolded basally (sclerally) but show many large apical (vitreal) processes interdigitating with the rod outer segments. these epithelial cells are joined laterally by prominent tight junctions located in the mid region of the cells. internally smooth endoplasmic reticulum is very plentiful while rough endoplasmic reticul ... | 1992 | 1504468 |
| retinal photoreceptor fine structure in the red-backed salamander (plethodon cinereus). | the retinal photoreceptors of the red-backed salamander (plethodon cinerus) have been studied by light and electron microscopy. rods and single cones are present in this duplex retina in a ratio of about 25:1. the photoreceptors in this amphibian species are much larger than is reported for most vertebrates. in the light-adapted state, rods reach deep into the retinal epithelial (rpe) layer. the rod outer segment is composed of discs of uniform diameter displaying several very deep incisors. the ... | 1992 | 1504467 |
| territories of male and female terrestrial salamanders: costs, benefits, and intersexual spatial associations. | i used a mark-recapture study to estimate home areas for 107 red-backed salamanders (plethodon cinereus) in a natural forest habitat. both males and females of this species defend feeding territories, but i presume that some individuals in this relatively highdensity population (approximately 2.8 salamanders per m2) are nonterritorial floaters. although territorial salamanders exhibited greater numbers of tail autotomies, they had significantly longer relative tail lengths. this difference sugge ... | 1991 | 28312933 |
| native variant limb skeletal patterns in the red-backed salamander, plethodon cinereus, are not regenerated. | species of the salamander genus plethodon have a characteristically uniform morphology. morphological conservation at the level of interspecific comparisons, however, is not always reflected within species. perhaps the most extreme example of intraspecific variation is the recent description of extensive variability in limb-skeletal patterning both within and between populations of the widespread species p. cinereus. we utilized limb regeneration following experimental amputation as a tool to ex ... | 1986 | 3795274 |
| acetazolamide does not disrupt limb regenerate morphogenesis in the salamander, plethodon cinereus. | acetazolamide, a potent and highly specific inhibitor of carbonic anhydrase, is teratogenic in mammalian embryos and when administered during early limb development causes unique limb defects in a time- and dose-dependent manner. the regenerating urodele limb is often considered to be a good experimental analog of limb development and, if it employs the same mechanisms of tissue interactions during pattern formation, should be susceptible to teratogens which selectively disrupt developmental lim ... | 1986 | 3738812 |
| linkage disequilibrium and a contact zone in plethodon cinereus on the del-mar-va peninsula. | a contact zone between two electrophoretically differentiated forms of plethodon cinereus extends across the del-mar-va peninsula. based on the presumed nature of regional climates during the late pleistocene, it is suggested that the climate was inhospitable for p. cinereus on the del-mar-va peninsula at the wisconsin maximum. it is postulated that, after the laurentide ice sheet receded about 14,000 years bp, the peninsula was invaded by populations of p. cinereus from the north and south. whe ... | 1986 | 28564124 |
| the effect of tail skin on the morphology and morphogenesis of limb regenerates in the red-backed salamander, plethodon cinereus. | tail skin cuffs have been grafted to the upper forelimb of red-backed salamanders in either normal or 180 degrees-rotated dorsoventral orientation. subsequent amputation through the graft region resulted in arrested regeneration, distally deficient or typical four-digit regenerates. distribution was not substantially influenced by graft orientation nor were there any supernumerary limbs induced by the axially dislocated tail skin on the limb stumps. furthermore, regenerates bore no indication of ... | 1982 | 6759604 |
| morphogenetic effect of rotated skin cuffs on tail regeneration in plethodon cinereus. | as an epimorphic system, the urodele tail has much in common with the urodele limb, relative to tissue components. in an effort to elucidate potentially similar functions of the skin during regeneration, two procedures which have been shown to be highly disruptive of limb morphogenesis were performed on the tail. in the first, cuffs of tail skin were rotated 180 degrees about the long axis of tails in plethodon cinereus. subsequent amputation through the rotated cuffs produced regenerates at a n ... | 1981 | 7276889 |
| on the environmental control of oocyte maturation in a plethodontid salamander. | the relationship between condition and oocyte maturation was experimentally studied in plethodon cinereus. gravid females with immature oocytes were collected in september and maintained on different feeding regimes for 180 days. an index of salamander condition was derived. there was no significant relationship between the number of maturing oocytes and condition of the salamander at the end of the experiment, but oocyte size was signifiantly related to condition. a significant regression relat ... | 1980 | 28310036 |
| morphogenetic control during tail regeneration in plethodon cinereus: the role of skeletal muscle. | | 1979 | 510787 |
| the time course of male meiosis in the red-backed salamander, plethodon cinereus. | tritiated-thymidine autoradiography was used to follow the progress of cells through meiosis in male p. cinereus at 20 degrees c. spermatocytes spend 7 days in leptotene, 5 days in zygotene and 3 days in pachytene before entering the diffuse stage. diffuse lasts for 8 days and is followed by a diplotene of 2 days. first and second meiotic metaphase occur a total of 26 days after the end of premeiotic s. considering the information for p. cinereus together with that for 3 other species, it appear ... | 1979 | 521470 |
| fluctuations in prey availability and food limitation for a terrestrial salamander. | a virginia population of the forest-dwelling salamander plethodon cinereus was repeatedly sampled over four years to determine volume and number of prey ingested under varying conditions of moisture and temperature. the proportion of the population on a daily negative energy budget was estimated by comparing actual foraging success with laboratory determined values of energetic requirements at various temperatures.prey became "limited" in availability during rainless periods, apparently because ... | 1979 | 28310289 |
| intra-population variability in energy parameters of the salamander plethodon cinereus. | mean values of energetic parameters are used in ecosystem studies because only crude estimates are possible when dealing with a large scope. however, when the focus is at the population level, finer resolution is possible and thus potential ontogenetic differences should be examined. analysis of energetic parameters of a population of terrestrial salamander, plethodon cinereus, was undertaken in order to determine ontogenetic differences.digestive efficiency does not differ significantly between ... | 1979 | 28309485 |
| an investigation of some problems concerning nucleolus organizers in salamanders. | observed differences in the sizes of lampbrush nucleolus organizers in plethodon cinereus have been shown by in situ hybridization to reflect true molecular differences in the numbers of ribosomal cistrons located at these organizers. likewise, from in situ hybridization experiments on lampbrush and spermatocyte chromosomes it has been shown that animals may be, and indeed usually are, heterozygous with respect to the numbers of ribosomal cistrons on each half of the nucleolus bivalent. filter h ... | 1977 | 837805 |
| tail regeneration in the plethodontid salamander, plethodon cinereus: induced autotomy versus surgical amputation. | regeneration of the tail in the plethodontid salamander, plethodon cinereus, occurs following either surgical amputation or induced autotomy. autotomy may occur along any one of the caudal myosepta which form natural cleavage planes. the distally attached myofibers break away from the myoseptum which then becomes part of the stump surface remaining intact during subsequent regeneration of the distal segments. under these conditions, therefore, muscle fibers do not normally participate in tail re ... | 1977 | 845576 |
| interspecific "common" repetitive dna sequences in salamanders of the genus plethodon. | intermediate repetitive sequences of plethodon cinereus which comprised about 30% of the genomic dna were isolated and iodinated with 125i. about 5% of the 125i-repetitive fraction hybridized with a large excess of dna from p. dunni at cot 20. about half of the 125i-dna in the hybrids was resistant to extensive digestion with s-1 nuclease. the average molecular size of the s-1 nuclease-resistant fraction was about 100 nucleotide pairs. the melting temperature of the s-1 nuclease-resistant fracti ... | 1976 | 1001148 |
| geographic protein variation and divergence in populations of the salamander plethodon cinereus. | | 1976 | 28565041 |