Phyllomedusa Species Research Articles

Stable individual variation in ventral spotting patterns in Phyllomedusa trinitatis (Anura: Phyllomedusidae) and other Phyllomedusa species: a minimally invasive method for recognizing individuals

Stable individual variation in ventral spotting patterns in Phyllomedusa trinitatis (Anura: Phyllomedusidae) and other Phyllomedusa species: a minimally invasive method for recognizing individuals. We describe a distinctive pattern of individually variable white ‘islands’ and dots on the ventral surfaces of the throat and forearm regions of male and female Phyllomedusa trinitatis. Crucially, we report from captive-reared individuals that these patterns are ontogenetically stable. We have used these patterns to recognize individual frogs in populations of 60 and more. Examination of the ventral surfaces of other Phyllomedusa species in museum specimens and from published accounts suggests that use of these patterns provides a generally useful, minimally invasive recognition method in this genus. We fnd that species previously classed as Phyllomedusa but now regarded as belonging to different genera lack these patterns.

Advertisement and release calls of Phyllomedusa ayeaye (Anura: Hylidae) with comments on the social context of emission

Male calls play different roles in anuran social organization, such as spacing, territoriality and female attraction. However, calls and associated behaviors remain poorly described for many anuran species. Here we describe the advertisement and release calls of the tree frog Phyllomedusa ayeaye (Lutz, 1966) and report on the social context of emissions and a physical combat. Approximately 35 minutes of digital recordings were obtained from 34 hours of observations at one breeding site in the state of Minas Gerais, southeastern Brazil. Bioacoustic analysis showed that males emitted two types of advertisement calls: 1) simple call (a sequence of short pulsed notes) and 2) composite call (a sequence of short pulsed notes followed by a long pulsed note). Composite calls were emitted more frequently during more intense chorus activity, with various active males at the breeding site. The release call was also composed by short pulsed notes, with a wider spectrum of frequencies and emitted more rapidly than the advertisement calls. Our results suggest that the composite call of P. ayeaye may represent a mixed advertisement call. Long notes might be the aggressive part directed to males, whereas short notes directed to females. Our description of call types, their functions, and male physical interactions will be useful for studies investigating the systematics and behavior of Phyllomedusa species.

The chains of the heterodimeric amphibian skin antimicrobial peptide, distinctin, are encoded by separate messenger RNAs

Using a primer to a conserved nucleotide sequence of previously cloned skin peptides of Phyllomedusa species, two distinct cDNAs were "shotgun" cloned from a skin secretion-derived cDNA library of the frog, Phyllomedusa burmeisteri. The two ORFs separately encode chains A and B of an analog of the previously reported heterodimeric peptide, distinctin. LC-MS/MS analysis of native versus dithiotreitol reduced crude venom, confirmed the predicted primary sequences as well as the cystine link between the two monomers. Distinctin predominantly exists in the venom as a heterodimer (A-B), neither of the constituent peptides were detected as monomer, whereas of the two possible homodimers (A-A or B-B), only B-B was detected in comparatively low quantity. In vitro dimerization of synthetic replicates of the monomers demonstrated that besides heterodimer, both homodimers are also formed in considerable amounts. Distinctin is the first example of an amphibian skin dimeric peptide that is formed by covalent linkage of two chains that are the products of different mRNAs. How this phenomenon occurs in vivo, to exclude significant homodimer formation, is unclear at present but a "favored steric state" type of interaction between chains is most likely.

Antimicrobial peptides from Phyllomedusa frogs: from biomolecular diversity to potential nanotechnologic medical applications

Screening for new bioactive peptides in South American anurans has been pioneered in frogs of the genus Phyllomedusa. All frogs of this genus have venomous skin secretions, i.e., a complex mixture of bioactive peptides against potential predators and pathogens that presumably evolved in a scenario of predator-prey interaction and defense against microbial invasion. For every new anuran species studied new peptides are found, with homologies to hormones, neurotransmitters, antimicrobials, and several other peptides with unknown biological activity. From Vittorio Erspamer findings, this genus has been reported as a "treasure store" of bioactive peptides, and several groups focus their research on these species. From 1966 to 2009, more than 200 peptide sequences from different Phyllomedusa species were deposited in UniProt and other databases. During the last decade, the emergence of high-throughput molecular technologies involving de novo peptide sequencing via tandem mass spectrometry, cDNA cloning, pharmacological screening, and surface plasmon resonance applied to peptide discovery, led to fast structural data acquisition and the generation of peptide molecular libraries. Research groups on bioactive peptides in Brazil using these new technologies, accounted for the exponential increase of new molecules described in the last decade, much higher than in any previous decades. Recently, these secretions were also reported as a rich source of multiple antimicrobial peptides effective against multidrug resistant strains of bacteria, fungi, protozoa, and virus, providing instructive lessons for the development of new and more efficient nanotechnological-based therapies for infectious diseases treatment. Therefore, novel drugs arising from the identification and analysis of bioactive peptides from South American anuran biodiversity have a promising future role on nanobiotechnology.

Predation on the Arboreal Eggs of Three Species of Phyllomedusa in Central Amazônia

Abstract We investigated the aspects of the reproductive characteristics of three species of Phyllomedusa, identified the main embryo predators, and quantified the impact of different predators on clutches of each Phyllomedusa species in Central Amazonia, Brazil. Clutches of Phyllomedusa tarsius had the lowest proportion of attack by predators (29%), 59% of Phyllomedusa tomopterna clutches were attacked by predators, and 61% of Phyllomedusa bicolor clutches were attacked by predators. Staphilynid beetles and phorid flies were the main causes of clutch loss (18 and 17 clutches, respectively), followed by mammals (6), and unidentified (13) predators. Our field observations showed that egg mortality per clutch resulting from phorid flies and staphilynid beetles predation that varied from 67% in P. tomopterna to 77% in P. tarsius. Mammal predation was registered only in P. bicolor clutches, and it was 100%. High clutch attacked rates and within-clutch mortality suggest that predation plays an important role i...

Tachykinins and Other Biologically Active Peptides From the Skin of the Costa Rican Phyllomedusid Frog Agalychnis callidryas

Mignogna, G., C. Severini, G. Falconieri Erspamer, R. Siciliano, G. Kreil and D. Barra. Tachykinins and other biologically active peptides from the skin of the Costa Rican Phyllomedusid frog Agalychnis callidryas. Peptides 18(3) 367–372, 1997.—Peptides present in a methanol extract prepared from skin of the Costa Rican frog Agalychnis callidryas of the Phyllomedusinae subfamily were studied by sequence analysis and pharmacological tests. Members of five different peptide families - tachykinins, bradykinins, caerulein, opioid peptides and sauvagine - were found. In particular, the extract contained a number of tachykinins with the following sequences: Gly-Pro-Pro-Asp-Pro-Asn-Lys-Phe-Ile-Gly-Leu-Met-NH2, Gly-Pro-Pro-Asp-Pro-Asp-Arg(Lys)-Phe-Tyr-Pro-Gly-Met-NH2, pGlu-Pro-Asp-Pro-Asp-Arg-Phe-Tyr-Pro-Gly-Met-NH2, Gly-Pro-Pro-Asp-Pro-Asn-Lys-Phe-Tyr-Pro-Val-Met. The latter three peptides have the unusual C-terminal sequence Pro-Gly(or Val)-Met-NH2 rather than Gly-Leu-Met-NH2 found in many other members of the tachykinin family. The observed amino acid substitutions may be the reason for the marked decrease in the biological activity observed in all in vitro and in vivo tests, even though the spectrum of tachykinin activities was retained. A kassinin-like peptide, with the sequence Gly-Pro-Pro-Asp-Pro-Asn-Lys-Phe-Ile-Gly-Leu-Met-NH2, was also found in the A. callidryas skin. While kassinin has a much higher affinity for NK-3 than for NK-1 receptors, the opposite is true for this A. callidryas peptide. The extract from A. callidryas skin also contained a new caerulein (pGlu-Asp-Tyr(HSO3)-Lys-Gly-Trp-Met-Asp-Phe-NH2) and a phyllokinin (Arg-Pro-Hyp-Gly-Phe-Ser-Pro-Phe-Arg-Ile-Tyr), as well as the opioid peptides dermorphin and [Hyp6]dermorphin, both previously isolated from different Phyllomedusa species

Litorin-like peptides in the skin of five Phyllomedusa species other than [formula omitted] and [formula omitted

Methanol extracts of the skin of five Phyllomedusa species, other than Phyll.sauvagei and Phyll.rohdei , were esamined to check their content in litorin-like peptides. Extracts of Phyll.bicolor and Pachymedusa dacnicolor did not contain appreciable amounts of litorin-like activity. However, extracts of Phyll. burmeisteri presented a typical phyllolitiroin-like activity and extracts of Phyll.hypochondrialis an activity mimiking that of rohdei-litorin. A particular position is taken by extracts of Phyll.trinitatis , which displayed a litorin-like activity differing, in parallel bioassay, from that of all known natural litorins.

Enzymatic correlates and ontogeny of uricotelism in tree frogs of the genus Phyllomedusa

AbstractActivities of arginase, xanthine dehydrogenase, and uricase were measured in liver and kidney of adult Phyllomedusa sauvagei and P. hypochondrialis to examine the enzymatic basis of their unusual ability to excrete uric acid. Comparable values were obtained for two species of ureotelic anurans and a uricotelic lizard. Both Phyllomedusa species exhibited high hepatic and renal levels of xanthine dehydrogenase, whereas this enzyme was not detected in the livers of the ureotelic frogs or the lizard. Hepatic xanthine dehydrogenase was significantly higher in P. sauvagei, which excretes urate predominantly, than in P. hypochondrialis, which excretes 20% of its nitrogen as urate. Hepatic arginase was much lower in both Phyllomedusa species than in the ureotelic frogs, but higher than in the lizard. Reduced levels of uricase were also associated with uricotelism in this genus.Xanthine dehydrogenase was present in livers of larval P. sauvagei well in advance of the onset of uric acid excretion late in metamorphosis. Premetamorphic larvae excreted over 50% of their nitrogen waste as urea and the balance as ammonia.

Sauvagine, a new polypeptide from Phyllomedusa sauvagei skin. Occurrence in various Phyllomedusa species and pharmacological actions on rat blood pressure and diuresis.

1. The occurrence of sauvagine, a new polypeptide from amphibian skin, and its actions on rat blood pressure and diuresis were studied. 2. Sauvagine was found to be present in the skin of all the 10 Phyllomedusa species so far studied, amounts ranging from a few micrograms to 240 micrograms per g fresh skin. 3. The polypeptide displayed in the rat an intense, long-lasting hypotensive action accompanied by tachycardia. Hypotension was not modified by either atropine or propranolol, excluding the participation of the autonomic nervous system in its production. Tachycardia, on the contrary, was partially inhibited by propranolol. 4. Hypotension is probably the main cause of the intense antidiuresis seen in hydrated rats following sauvagine administration. Reduction in urina volume was accompanied by a decrease in GFR and an increase in tubular NA+ reabsorption.

Evaporative water loss, nitrogen excretion and osmoregulation in phyllomedusine frogs

1. Minimal rates of evaporative water loss in tree frogs of genusPhyllomedusa (P. pailona, P. iherengi, P. hypochondrialis) were only 5–10% those of representatives of two related genera,Agalychnis annae andPachymedusa dacnicolor (Table 1). 2. Phyllomedusa species,A. annae andP. dacnicolor all took up water rapidly (25–45% standard wt·hr−1) across the skin following prolonged water deprivation (Table 2). 3. When fed mealworms (Tenebrio larvae) and deprived of additional water, body fluid concentrations increased more slowly inPhyllomedusa species than in representatives of three other genera (Agalychnis, Pachymedusa andHyla) tested. Of thePhyllomedusa species,P. sauvagei showed by far the lowest rate of increase (Table 4). 4. The osmoregulatory ability of thePhyllomedusa species is primarily attributable to their ability to excrete urate. The fraction of total waste nitrogen production excreted as urate was 80% inP. sauvagei, ca. 45% inP. pailona andP. iherengi, and 24% inP. hypochondrialis. Urate excretion inAgalychnis, Pachymedusa andHyla was negligible (Tables 5 and 9). 5. Increased water intake did not alter the rate of urate production in the three species tested (P. sauvagei, P. hypochondrialis andA. annae) (Table 6). 6. Additional osmoregulatory benefit is derived byPhyllomedusa species from the binding of Na+, K+, and NH4+ to precipitated urate (Tables 5 and 7). 7. On a diet of mealworms, energy losses via the feces and nitrogen wastes ranged from 14 to 18% of intake in the four species ofPhyllomedusa and inP. dacnicolor, and were about equally divided between the two avenues (Tables 8 and 9). 8. These results suggest thatP. sauvagei could remain in water balance in nature on a diet of insects with little or no additional water intake.

Structure and pharmacological actions of phyllocaerulein, a caerulein-like nonapeptide: its occurrence in extracts of the skin of Phyllomedusa sauvagei and related Phyllomedusa species.

1. The South American amphibian Phyllomedusa sauvagei contains in its skin large amounts of a polypeptide closely resembling caerulein in its pharmacological actions. This polypeptide, called phyllocaerulein, was obtained in a pure form, and upon acid hydrolysis, enzymic digestion and end-group determination experiments it proved to be a nonapeptide of the following composition Pyr-Glu-Tyr(SO(3)H)-Thr-Gly-Trp-Met-Asp-Phe-NH(2)It may be seen that caerulein and phyllocaerulein have in common the C-terminal heptapeptide and the N-terminal pyroglutamyl residue.2. Phyllocaerulein is indistinguishable from caerulein even in parallel bioassay. However, the former polypeptide seems to be somewhat more potent than the latter on all the preparations tested.3. In different batches of Phyllomedusa sauvagei skin the phyllocaerulein content ranged between 150 and 600 mug/g of fresh tissue.Phyllocaerulein or similar polypeptides occur also in the skin of several other Phyllomedusa species, among which are Phyll. burmeisteri, Phyll. dachnicolor, Phyll, helenae, Phyll. annae, Phyll. callidryas and Phyll. bicolor.4. The qualitative identification and quantitative estimation of caerulein-like polypeptides in crude skin extracts may be complicated by the concomitant occurrence of other active polypeptides. These, however, are poorly effective on some test preparations which seem to respond selectively to caerulein.5. Like that of caerulein, the biological significance of phyllocaerulein is completely obscure.