| Expression of Vomeronasal Receptors and Related Signaling Molecules in the Nasal Cavity of a Caudate Amphibian (Plethodon shermani). | G-protein-coupled receptors are responsible for binding to chemosensory cues and initiating responses in vertebrate olfactory neurons. We investigated the genetic diversity and expression of one family of G-protein-coupled receptors in a terrestrial caudate amphibian (the red-legged salamander, Plethodon shermani). We used degenerate RT-PCR to isolate vomeronasal type 2 receptors (V2Rs)-including full-length sequences-and compared them with other vertebrate V2Rs with phylogenetic analyses. We al ... | 2011 | 22104031 |
| effects of corticosterone on infection and disease in salamanders exposed to the amphibian fungal pathogen batrachochytrium dendrobatidis. | although it is well established that glucocorticoid hormones (gcs) alter immune function and disease resistance in humans and laboratory animal models, fewer studies have linked elevated gcs to altered immune function and disease resistance in wild animals. the chytrid fungal pathogen batrachochytrium dendrobatidis (bd) infects amphibians and can cause the disease chytridiomycosis, which is responsible for worldwide amphibian declines. it is hypothesized that long-term exposure to environmental ... | 2017 | 28262636 |
| evolutionary shifts in courtship pheromone composition revealed by est analysis of plethodontid salamander mental glands. | courtship behavior in salamanders of the family plethodontidae can last more than an hour. during courtship, males use stereotyped behaviors to repeatedly deliver a variety of proteinaceous pheromones to the female. these pheromones are produced and released from a specialized gland on the male's chin (the mental gland). several pheromone components are well characterized and represented by high frequency transcripts in cdna pools derived from plethodontid mental glands. however, evolutionary tr ... | 2009 | 19084057 |
| salamanders on the bench - a biocompatibility study of salamander skin secretions in cell cultures. | salamanders have evolved a wide variety of antipredator mechanisms and behavior patterns, including toxins and noxious or adhesive skin secretions. the high bonding strength of the natural bioadhesives makes these substances interesting for biomimetic research and applications in industrial and medical sectors. secretions of toxic species may help to understand the direct effect of harmful substances on the cellular level. in the present study, the biocompatibility of adhesive secretions from fo ... | 2017 | 28551363 |
| phylogeographic analysis of mitochondrial gene flow and introgression in the salamander, plethodon shermani. | plethodon shermani comprises a series of geographically disjunct populations occupying high-elevation mountain isolates. these populations hybridize at their borders with salamanders of the plethodon glutinosus species complex, and past range expansions inferred from pleistocene climatic cycles may have increased the possible genetic interactions between p. shermani and species of the p. glutinosus complex. because mitochondrial dna haplotypes often show introgression across species borders, we ... | 2005 | 15813784 |
| neuroanatomical distribution of vasotocin and mesotocin in two urodele amphibians (plethodon shermani and taricha granulosa) based on in situ hybridization histochemistry. | previous research suggests that considerable species-specific variation exists in the neuroanatomical distributions of arginine vasotocin (avt) and mesotocin (mst), non-mammalian homologues of vasopressin and oxytocin. an earlier study in rough-skinned newts (taricha granulosa) indicated that the neuroanatomical distribution of cells labeled for avt-immunoreactivity (ir) was greater in this urodele amphibian than in any other species. it was unknown whether the widespread distribution of avt-ir ... | 2005 | 15713271 |
| trpc2 is expressed in two olfactory subsystems, the main and the vomeronasal system of larval xenopus laevis. | complete segregation of the main olfactory epithelium (moe) and the vomeronasal epithelium is first observed in amphibians. in contrast, teleost fishes possess a single olfactory surface, in which genetic components of the main and vomeronasal olfactory systems are intermingled. the transient receptor potential channel trpc2, a marker of vomeronasal neurons, is present in the single fish sensory surface, but is already restricted to the vomeronasal epithelium in a terrestrial amphibian, the red- ... | 2014 | 24737764 |
| an annual cycle of gene regulation in the red-legged salamander mental gland: from hypertrophy to expression of rapidly evolving pheromones. | cell differentiation is mediated by synchronized waves of coordinated expression for hundreds to thousands of genes, and must be regulated to produce complex tissues and phenotypes. for many animal species, sexual selection has driven the development of elaborate male ornaments, requiring sex-specific differentiation pathways. one such male ornament is the pheromone-producing mental gland of the red-legged salamander (plethodon shermani). mental gland development follows an annual cycle of extre ... | 2019 | 31029098 |
| chemical characterization of the adhesive secretions of the salamander plethodon shermani (caudata, plethodontidae). | salamanders have developed a wide variety of antipredator mechanisms, including tail autotomy, colour patterns, and noxious skin secretions. as an addition to these tactics, the red-legged salamander (plethodon shermani) uses adhesive secretions as part of its defensive strategy. the high bonding strength, the fast-curing nature, and the composition of the biobased materials makes salamander adhesives interesting for practical applications in the medical sector. to understand the adhesive secret ... | 2017 | 28751633 |
| olfactory effects of a hypervariable multicomponent pheromone in the red-legged salamander, plethodon shermani. | chemical communication via chemosensory signaling is an essential process for promoting and modifying reproductive behavior in many species. during courtship in plethodontid salamanders, males deliver a mixture of non-volatile proteinaceous pheromones that activate chemosensory neurons in the vomeronasal epithelium (vne) and increase female receptivity. one component of this mixture, plethodontid modulating factor (pmf), is a hypervariable pheromone expressed as more than 30 unique isoforms that ... | 2017 | 28358844 |
| lesions of the dorsal striatum impair orienting behaviour of salamanders without affecting visual processing in the tectum. | in amphibians, visual information in the midbrain tectum is relayed via the thalamus to telencephalic centres. lesions of the dorsal thalamus of the salamander plethodon shermani result in impairment of orienting behaviour and in modulation of spike pattern of tectal neurons. these effects may be induced by an interruption of a tectum-thalamus-telencephalon-tectum feedback loop enabling spatial attention and selection of visual objects. the striatum is a potential candidate for involvement in th ... | 2016 | 27545109 |
| morphological characterization of the glandular system in the salamander plethodon shermani (caudata, plethodontidae). | amphibians have evolved a wide variety of mechanisms that provide a certain degree of protection against predators, including camouflage, tail autonomy, encounter behavior and noxious or toxic skin secretions. in addition to these strategies, some amphibians release a glue-like secretion onto the surface of their skin when threatened. while some information regarding the origin and production of these adhesive secretions is available for frogs such as notaden bennetti, these aspects are only par ... | 2015 | 26163863 |
| structural insights into the evolution of a sexy protein: novel topology and restricted backbone flexibility in a hypervariable pheromone from the red-legged salamander, plethodon shermani. | in response to pervasive sexual selection, protein sex pheromones often display rapid mutation and accelerated evolution of corresponding gene sequences. for proteins, the general dogma is that structure is maintained even as sequence or function may rapidly change. this phenomenon is well exemplified by the three-finger protein (tfp) superfamily: a diverse class of vertebrate proteins co-opted for many biological functions - such as components of snake venoms, regulators of the complement syste ... | 2014 | 24849290 |
| life history as a predictor of salamander recovery rate from timber harvest in southern appalachian forests, usa. | forest management often represents a balance between social, economic, and ecological objectives. in the eastern united states, numerous studies have established that terrestrial salamander populations initially decline in abundance following timber harvest, yet the large-scale and long-term consequences are relatively unknown. we used count data from terrestrial survey points to examine the relation between salamander abundance and historic timber harvest while accounting for imperfect detectio ... | 2013 | 24033390 |
| the role of the dorsal thalamus in visual processing and object selection: a case of an attentional system in amphibians. | in amphibians, the midbrain tectum is regarded as the visual centre for object recognition but the functional role of forebrain centres in visual information processing is less clear. in order to address this question, the dorsal thalamus was lesioned in the salamander plethodon shermani, and the effects on orienting behaviour or on visual processing in the tectum were investigated. in a two-alternative-choice task, the average number of orienting responses toward one of two competing prey or si ... | 2012 | 22934985 |
| elevated plasma corticosterone increases metabolic rate in a terrestrial salamander. | plasma glucocorticoid hormones (gcs) increase intermediary metabolism, which may be reflected in whole-animal metabolic rate. studies in fish, birds, and reptiles have shown that gcs may alter whole-animal energy expenditure, but results are conflicting and often involve gc levels that are not physiologically relevant. a previous study in red-legged salamanders found that male courtship pheromone increased plasma corticosterone (cort; the primary gc in amphibians) concentrations in males, which ... | 2012 | 22047668 |
| characterization of two putative cytokine receptors, gp130 and ciliary neurotrophic factor receptor, from terrestrial salamanders. | cytokines of the gp130 family are fundamental regulators of immune responses and signal through multimeric receptors to initiate intracellular second-messenger cascades. here, we provide the first characterization of two full-length gp130 cytokine receptors from the cdna of the red-legged salamander (plethodon shermani). the first, gp130 (2745 bp), is a common signaling receptor for several multi-functional cytokines in vertebrates. we also isolated the full-length (1104 bp) sequence of the cili ... | 2011 | 21670553 |
| high convergence of olfactory and vomeronasal influence in the telencephalon of the terrestrial salamander plethodon shermani. | previous work suggested that the telencephalic pathways of the main olfactory and vomeronasal systems of vertebrates are mostly isolated from each other, with the possible exception of convergence of the two systems into a small part of the olfactory amygdala. we tested the hypothesis of convergence between the main olfactory and vomeronasal systems by investigating the physiology of telencephalic olfactory responses in an in vitro brain preparation of the salamander plethodon shermani. this ani ... | 2011 | 21182902 |
| exposure to pheromones increases plasma corticosterone concentrations in a terrestrial salamander. | sensory cues involved in social interactions can influence plasma steroid hormone concentrations. although pheromonal communication is common in amphibians, it is unknown whether pheromones can alter hormone levels in amphibians as they do in mammals. we tested whether courtship pheromones would alter steroid hormone concentrations in male and female terrestrial salamanders (plethodon shermani). plasma corticosterone concentrations were elevated in male salamanders exposed to mental gland courts ... | 2009 | 19523389 |
| cytoarchitecture of the accessory olfactory bulb in the salamander plethodon shermani. | plethodontid terrestrial salamanders are emerging models in the study of the evolution of chemical communication in vertebrates. their vomeronasal system is well defined. it comprises sensory neurons in the epithelium of the vomeronasal organ, whose axons form the vomeronasal nerve projecting to the accessory olfactory bulb (aob), which in turn projects to the vomeronasal amygdala through the accessory olfactory tract. a detailed description of the cellular elements of the urodele aob is lacking ... | 2008 | 18538312 |
| a recombinant courtship pheromone affects sexual receptivity in a plethodontid salamander. | pheromones are important chemical signals for many vertebrates, particularly during reproductive interactions. in the terrestrial salamander plethodon shermani, a male delivers proteinaceous pheromones to the female as part of their ritualistic courtship behavior. these pheromones increase the female's receptivity to mating, as shown by a reduction in courtship duration. one pheromone component in particular is plethodontid receptivity factor (prf), a 22-kda protein with multiple isoforms. this ... | 2008 | 18534996 |
| the effects of sex on chemosensory communication in a terrestrial salamander (plethodon shermani). | although much evidence reveals sexually dimorphic processing of chemosensory cues by the brain, potential sex differences at more peripheral levels of chemoreception are understudied. in plethodontid salamanders, the volume of the vomeronasal organ (vno) is almost twice as large in males as compared to females, both in absolute and relative size. to determine whether the structural sexual dimorphism in vno volume is associated with sex differences in other peripheral aspects of chemosensation, w ... | 2008 | 18460406 |
| courtship pheromone-induced c-fos-like immunolabeling in the female salamander brain. | plethodontid salamanders display intricate courtship behaviors. proteinaceous courtship pheromones were recently discovered in the submandibular (mental) gland of the male plethodon shermani, the red-legged salamander. behavioral studies showed that these male pheromones are delivered by direct contact to the female snout and modulate her receptivity during courtship. previous reports demonstrated that experimental application of courtship pheromones activates vomeronasal sensory neurons in p. s ... | 2008 | 18082970 |
| plethodontid modulating factor, a hypervariable salamander courtship pheromone in the three-finger protein superfamily. | the soluble members of the three-finger protein superfamily all share a relatively simple 'three-finger' structure, yet perform radically different functions. plethodontid modulating factor (pmf), a pheromone protein produced by the lungless salamander, plethodon shermani, is a new and unusual member of this group. it affects female receptivity when delivered to the female's nares during courtship. as with other plethodontid pheromone genes, pmf is hyperexpressed in a specialized male mental (ch ... | 2007 | 17419731 |
| sex steroid hormones and sexual dimorphism of chemosensory structures in a terrestrial salamander (plethodon shermani). | the volume of the vomeronasal organ (vno) in the terrestrial salamander plethodon shermani was approximately 1.7 times larger in adult males compared to adult females, even though male body size was, on average, slightly smaller than female body size. vno cell density, however, was the same in adult males and females. the sex difference in vno volume was found in sexually immature animals as well, indicating that the increase of plasma androgens that occurs at sexual maturity does not produce th ... | 2007 | 17276418 |
| in situ localization of plethodontid courtship pheromone mrna in formalin-fixed tissue. | male plethodontid salamanders produce courtship pheromones that increase female receptivity. three protein components of the courtship pheromone cocktail have been characterized in the mental gland of plethodon shermani, the red-legged salamander: plethodontid receptivity factor (prf), plethodontid modulating factor (pmf), and sodefrin precursor-like factor (spf). in this study, a streamlined in situ hybridization (ish) protocol, employing a biotinylated oligonucleotide probe, is used to visuali ... | 2007 | 17188687 |
| effects of androgens on behavioral and vomeronasal responses to chemosensory cues in male terrestrial salamanders (plethodon shermani). | chemosensory stimuli and sex steroid hormones are both required for the full expression of social behaviors in many species. the terrestrial salamander, plethodon shermani, is an emerging nonmammalian system for investigating the nature and evolution of pheromonal communication, yet little is known regarding the role of sex steroid hormones. we hypothesized that increased circulating androgen levels in male p. shermani enhance chemoreception through morphological, behavioral, and physiological m ... | 2006 | 16860800 |
| male pheromone protein components activate female vomeronasal neurons in the salamander plethodon shermani. | the mental gland pheromone of male plethodon salamanders contains two main protein components: a 22 kda protein named plethodon receptivity factor (prf) and a 7 kda protein named plethodon modulating factor (pmf), respectively. each protein component individually has opposing effects on female courtship behavior, with prf shortening and pmf lengthening courtship. in this study, we test the hypothesis that prf or pmf individually activate vomeronasal neurons. the agmatine-uptake technique was use ... | 2006 | 16553953 |
| dynamic response properties of visual neurons and context-dependent surround effects on receptive fields in the tectum of the salamander plethodon shermani. | neuronal responses to complex prey-like stimuli and rectangles were investigated in the tectum of the salamander plethodon shermani using extracellular single-cell recording. cricket dummies differing in size, contrast or movement pattern or a rectangle were moved singly through the excitatory receptive field of a neuron. paired presentations were performed, in which a reference stimulus was moved inside and the different cricket dummies or the rectangle outside the excitatory receptive field. v ... | 2005 | 15975725 |
| connectivity and cytoarchitecture of the ventral telencephalon in the salamander plethodon shermani. | the cytoarchitecture and axonal connection pattern of centers in the ventral telencephalon of the salamander plethodon shermani were studied using biocytin for anterograde and retrograde labeling of cell groups, as well as by intracellular injections. application of biocytin to the main and accessory olfactory bulbs identified the olfactory pallial regions and the vomeronasal portion of the amygdala, respectively. according to our results, the amygdala of plethodon is divided into (1) a rostral ... | 2005 | 15611991 |
| pheromonal activation of vomeronasal neurons in plethodontid salamanders. | pheromones from the mental glands of male plethodontid salamanders increase sexual receptivity in conspecific females. the pheromone enters the vomeronasal organ during courtship to produce this effect. vomeronasal neurons from female plethodon shermani were examined following exposure to male pheromone or saline placed on the nares. agmatine was used in conjunction with the pheromone to enable immunocytochemical visualization of chemosensory neurons that were activated by the pheromone. olfacto ... | 2002 | 12376197 |