scholarly journals Alkaloid avoidance in poison frog tadpoles

2022 ◽  
Author(s):  
Eugenia Sanchez ◽  
Travis Ramirez ◽  
Lauren A O'Connell
Keyword(s):  
Locomotor Activity ◽  
Secondary Metabolites ◽  
Feeding Behavior ◽  
Chemical Defense ◽  
Poison Frog ◽  
Poison Frogs ◽  
Frog Tadpoles ◽  
Ranitomeya Imitator

Animals show a spectrum of avoidance-tolerance to foods containing toxic secondary metabolites. However, this spectrum has not been evaluated in animals that may actively seek out these compounds as a chemical defense. Poison frogs sequester toxic and unpalatable alkaloids from their diet, and in some species, tadpoles are exposed to these toxins before the development of their skin granular glands, which are used for toxin compartmentalization. Here, we examined the effects of the alkaloid decahydroquinoline (DHQ) in tadpoles of the Mimetic poison frog, Ranitomeya imitator, using alkaloid supplemented food. We found that although their survival is lowered by the alkaloid, their development is only mildly affected, with no evident effects on their growth. Furthermore, locomotor activity and feeding behavior was altered in the first week of DHQ treatment, probably in part through nicotinic blockade. However, after two weeks, tadpoles learned to avoid the alkaloid by visiting the food area only when necessary to eat. Our results suggest that poison frogs navigate the avoidance-tolerance spectrum during the development of their sequestration machinery.

Who cares for the eggs? Analysis of egg attendance behaviour in Ranitomeya imitator, a poison frog with biparental care

Behaviour ◽  
2021 ◽  
pp. 1-12
Author(s):  
Lisa M. Schulte ◽  
Kyle Summers
Keyword(s):  
Parental Care ◽  
Biparental Care ◽  
Poison Frog ◽  
Poison Frogs ◽  
Different Types ◽  
Ranitomeya Imitator ◽  
Males And Females ◽  
General Care

Abstract Dendrobatid poison frogs are known for their diverse parental care behaviours, including terrestrial egg attendance. While usually this behaviour is conducted by males, this study compared the pre-hatching investment of males and females in Ranitomeya imitator, a species with biparental care. Although males tended to spend more time with their eggs overall, there was no difference between sexes when comparing different types of care behaviour. Furthermore, both sexes increased general care behaviour when caring for more than one clutch. The finding that the sexes are relatively equal in their contribution to basic parental care forms provides a basis to understand why biparental care is stable in this species.

In the search for new secondary metabolites with biopesticidal properties

2015 ◽  
Vol 62 (4) ◽  
pp. 216-228 ◽  
Author(s):  
Carlos L. Céspedes ◽  
Julio E. Alarcon ◽  
Pedro Aqueveque ◽  
David S. Seigler ◽  
Isao Kubo
Keyword(s):  
Secondary Metabolites ◽  
Chemical Defense ◽  
Insect Pests ◽  
Sesquiterpene Lactones ◽  
Antibacterial Activities ◽  
Natural Compounds ◽  
Insect Growth Regulator ◽  
Bacterial Strains ◽  
Plant Chemical Defense ◽  
Insect Growth

Secondary metabolites are involved in diverse functions in plants, including defense and protective processes. Information concerning the biosynthesis of secondary metabolites in plants points at a constitutive or induced chemical defense, generated for protection against a variety of phytopathogenic attacks. Our phytochemical studies are aimed at finding biopesticides of botanical origin. Some plant taxa of American distribution are toxic to selected insects, fungi and bacterial strains, and their effect has been associated with the presence of phenolics, phenylpropanoids and terpenes. We have isolated some diterpenes, triterpenes, sesquiterpene lactones, flavonoids, and phenylpropanoids from members of the plant families Araucariaceae, Asteraceae, Calceolariaceae, Celastraceae, and Rhamnaceae. In addition, we have identified a number of chemical derivatives of these compound classes from the plants. A major finding indicates that compounds or their derivatives that possess antioxidant, antifungal, insect growth regulator or insecticidal activity and enzymatic inhibitors are natural compounds. Insecticidal activities were assayed against strains of lepidopteran, dipteran, and coleopteran insect pests that affect many crops. Antifungal and antibacterial activities were assayed against phytopathogenic species of filamentous fungi and bacterial strains that are pests on many crops. Our results indicate that the plant-derived compounds obtained from the abovementioned plants have excellent insect growth regulatory activity and a good potency as antifungal agents. However, little is known about the effects of these natural compounds and their derivatives on insect pests. The natural compounds that we have isolated represent a valuable resource for future studies of plant chemical defense and the role of these substances in chemical ecology.

Central and Peripheral Clock Control of Circadian Feeding Rhythms

2021 ◽  
pp. 074873042110458
Author(s):  
Carson V. Fulgham ◽  
Austin P. Dreyer ◽  
Anita Nasseri ◽  
Asia N. Miller ◽  
Jacob Love ◽  
...  
Keyword(s):  
Locomotor Activity ◽  
Circadian Clock ◽  
Feeding Behavior ◽  
Molecular Clock ◽  
Fat Body ◽  
Molecular Clocks ◽  
Central Brain ◽  
Feeding Rhythms ◽  
Free Running ◽  
The Brain

Many behaviors exhibit ~24-h oscillations under control of an endogenous circadian timing system that tracks time of day via a molecular circadian clock. In the fruit fly, Drosophila melanogaster, most circadian research has focused on the generation of locomotor activity rhythms, but a fundamental question is how the circadian clock orchestrates multiple distinct behavioral outputs. Here, we have investigated the cells and circuits mediating circadian control of feeding behavior. Using an array of genetic tools, we show that, as is the case for locomotor activity rhythms, the presence of feeding rhythms requires molecular clock function in the ventrolateral clock neurons of the central brain. We further demonstrate that the speed of molecular clock oscillations in these neurons dictates the free-running period length of feeding rhythms. In contrast to the effects observed with central clock cell manipulations, we show that genetic abrogation of the molecular clock in the fat body, a peripheral metabolic tissue, is without effect on feeding behavior. Interestingly, we find that molecular clocks in the brain and fat body of control flies gradually grow out of phase with one another under free-running conditions, likely due to a long endogenous period of the fat body clock. Under these conditions, the period of feeding rhythms tracks with molecular oscillations in central brain clock cells, consistent with a primary role of the brain clock in dictating the timing of feeding behavior. Finally, despite a lack of effect of fat body selective manipulations, we find that flies with simultaneous disruption of molecular clocks in multiple peripheral tissues (but with intact central clocks) exhibit decreased feeding rhythm strength and reduced overall food intake. We conclude that both central and peripheral clocks contribute to the regulation of feeding rhythms, with a particularly dominant, pacemaker role for specific populations of central brain clock cells.

scholarly journals Effects of photoperiod on daily locomotor activity, energy expenditure, and feeding behavior in a seasonal mammal

2010 ◽  
Vol 298 (5) ◽  
pp. R1409-R1416 ◽  
Author(s):  
Amy Warner ◽  
Preeti H. Jethwa ◽  
Catherine A. Wyse ◽  
Helen I'Anson ◽  
John M. Brameld ◽  
...  
Keyword(s):  
Body Weight ◽  
Locomotor Activity ◽  
Energy Expenditure ◽  
Feeding Behavior ◽  
Heat Production ◽  
Prolonged Exposure ◽  
Dark Phase ◽  
Daily Rhythms ◽  
Dark Cycle ◽  
Activity Energy

The objective of this study was to determine whether the previously observed effects of photoperiod on body weight in Siberian hamsters were due to changes in the daily patterns of locomotor activity, energy expenditure, and/or feeding behavior. Adult males were monitored through a seasonal cycle using an automated comprehensive laboratory animal monitoring system (CLAMS). Exposure to a short-day photoperiod (SD; 8:16-h light-dark cycle) induced a significant decline in body weight, and oxygen consumption (V̇o2), carbon dioxide production (V̇co2), and heat production all decreased reaching a nadir by 16 wk of SD. Clear daily rhythms in locomotor activity, V̇o2, and V̇co2 were observed at the start of the study, but these all progressively diminished after prolonged exposure to SD. Rhythms in feeding behavior were also detected initially, reflecting an increase in meal frequency but not duration during the dark phase. This rhythm was lost by 8 wk of SD exposure such that food intake was relatively constant across dark and light phases. After 18 wk in SD, hamsters were transferred to a long-day photoperiod (LD; 16:8-h light-dark cycle), which induced significant weight gain. This was associated with an increase in energy intake within 2 wk, while V̇o2, V̇co2, and heat production all increased back to basal levels. Rhythmicity was reestablished within 4 wk of reexposure to long days. These results demonstrate that photoperiod impacts on body weight via complex changes in locomotor activity, energy expenditure, and feeding behavior, with a striking loss of daily rhythms during SD exposure.

Mimetic Divergence and the Speciation Continuum in the Mimic Poison Frog Ranitomeya imitator

2016 ◽  
Vol 187 (2) ◽  
pp. 205-224 ◽  
Author(s):  
Evan Twomey ◽  
Jacob S. Vestergaard ◽  
Pablo J. Venegas ◽  
Kyle Summers
Keyword(s):  
Poison Frog ◽  
Ranitomeya Imitator ◽  
Speciation Continuum

scholarly journals Tactical reproductive parasitism via larval cannibalism in Peruvian poison frogs

2008 ◽  
Vol 5 (2) ◽  
pp. 148-151 ◽  
Author(s):  
Jason L Brown ◽  
Victor Morales ◽  
Kyle Summers
Keyword(s):  
Choice Experiment ◽  
Genetic Analyses ◽  
Poison Frog ◽  
Poison Frogs ◽  
Reproductive Parasitism

We report an unusual example of reproductive parasitism in amphibians. Dendrobates variabilis , an Amazonian poison frog, oviposits at the surface of the water in small pools in plants and deposits tadpoles within the pools. Tadpoles are highly cannibalistic and consume young tadpoles if they are accessible. Deposition of embryos and tadpoles in the same pool is common. Genetic analyses indicate that tadpoles are frequently unrelated to embryos in the same pool. A pool choice experiment in the field demonstrated that males carrying tadpoles prefer to place them in pools with embryos, facilitating reproductive parasitism via cannibalism.

scholarly journals Evidence that toxin resistance in poison birds and frogs is not rooted in sodium channel mutations and may rely on “toxin sponge” proteins

2021 ◽  
Vol 153 (9) ◽  
Author(s):  
Fayal Abderemane-Ali ◽  
Nathan D. Rossen ◽  
Megan E. Kobiela ◽  
Robert A. Craig ◽  
Catherine E. Garrison ◽  
...  
Keyword(s):  
Ion Channel ◽  
Sodium Channel ◽  
Small Molecule ◽  
Resistance Mechanism ◽  
Poison Frog ◽  
Poison Frogs ◽  
Toxin Resistance ◽  
Voltage Gated ◽  
Primary Driver ◽  
Toxin Sequestration

Many poisonous organisms carry small-molecule toxins that alter voltage-gated sodium channel (NaV) function. Among these, batrachotoxin (BTX) from Pitohui poison birds and Phyllobates poison frogs stands out because of its lethality and unusual effects on NaV function. How these toxin-bearing organisms avoid autointoxication remains poorly understood. In poison frogs, a NaV DIVS6 pore-forming helix N-to-T mutation has been proposed as the BTX resistance mechanism. Here, we show that this variant is absent from Pitohui and poison frog NaVs, incurs a strong cost compromising channel function, and fails to produce BTX-resistant channels in poison frog NaVs. We also show that captivity-raised poison frogs are resistant to two NaV-directed toxins, BTX and saxitoxin (STX), even though they bear NaVs sensitive to both. Moreover, we demonstrate that the amphibian STX “toxin sponge” protein saxiphilin is able to protect and rescue NaVs from block by STX. Taken together, our data contradict the hypothesis that BTX autoresistance is rooted in the DIVS6 N→T mutation, challenge the idea that ion channel mutations are a primary driver of toxin resistance, and suggest the possibility that toxin sequestration mechanisms may be key for protecting poisonous species from the action of small-molecule toxins.

scholarly journals Bitki Sekonder Maddelerinin Herbivor Böceklere Etkileri

2017 ◽  
Vol 5 (2) ◽  
pp. 153
Author(s):  
Oğuzhan Yanar ◽  
Elif Fatma Topkara
Keyword(s):  
Secondary Metabolites ◽  
Chemical Defense ◽  
Host Plant ◽  
Secondary Compounds ◽  
The Other ◽  
Herbivorous Insects ◽  
Interspecies Competition ◽  
Secondary Chemistry ◽  
Defense Strategies ◽  
And Behavior

Plants have developed mechanical and chemical defense strategies that are effective against herbivores. Plants contain chemicals that are known as secondary metabolites (allelochemical) and these chemicals do not directly involve in organisms’ reproduction and growth, on the other hand, they affect survival, growth and behavior of species. These compounds usually take ecological tasks and plants use these compounds against diseases, parasites, and predators for interspecies competition. It is known through the observations on feeding of herbivorous insects that these compounds act as deterrent chemicals or they are toxic against them. Feeding is one of the most fundamental and the most important behaviors for herbivorous insects. Even though host plant preference of herbivores is partially depend on nutrients, this behavior greatly depends on secondary chemistry of plants. Effects of secondary compounds on herbivorous insects can be positive or negative.

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