Forschung

Kliniken/Institute:
Institut für Zoologie

Projektdetails:
Many animals use colorations in antipredator strategies. Cryptic coloration conceals the animal on its natural substrate while bright aposematic coloration is paired with unpalatability, for example conveyed by toxins, and functions as warning signal. Geographic variation in coloration shades or patterns have been interpreted as local adaptations to the prevailing local substrates and predator classes. Yellow bellied toads are particularly exciting study objects since they present a cryptic grey-brown coloration in their dorsum, but a highly contrasting yellow-black pattern on their bellies. The toads also possess highly poisonous bombinatoxins in their skin and use a deimatic display, the so-called Unkenreflex, when a predator is close. We studied variation in the cryptic and aposematic coloration in three local populations in Southern Lower Saxony. We found the toads to be most cryptic dorsally on their local substrates, while the internal aposematic contrast on the belly remained constant. Furthermore we investigate whether the toads are able to change their dorsal coloration when placed on substrates of different colorations (darker and brighter substrates). In the next steps, we will analyze whether toads from different localities and substrates differ in their capacities of coloration plasticity and which genes show differential expression (e.g. genes involved in the production of melanin) while the animals adapt their cryptic coloration to their current substrate. Finally we will carry out predation experiments with clay model toads in the field to find out whether the adaptation of cryptic coloration to the local substrate helps to decrease the attack risk by predators.

Resultate:

Preißler KP, Rodríguez A, Pröhl H (2021) Evidence for coloration plasticity in the yellow-bellied toad, Bombina variegata. Ecology and Evolution, 11: 17557-17567. https://doi.org/10.1002/ece3.8391

Kooperationspartner:

Kathleen Preißler, TU Braunschweig

Drittmittelprojekt: DFG, 199.050 EUR

Kliniken/Institute:
Institut für Zoologie

Projektdetails:
The role of NMDA receptors in neuronal plasticity is well established. However, their role in intracellular voltage-signaling and sensory processing is less well characterized, yet they are implicated in amplifying action potential firing rates. To understand the cellular basis for this NMDA dependent amplification of firing rate, its influence on sensory processing and the carried sensory information we will perform in vivo and in vitro recordings of neurons in the dorsal nucleus of the lateral lemniscus (DNLL) - an auditory brainstem structure important for binaural hearing. We will determine the synaptic interactions of excitation and inhibition with NMDA receptor conductances to understand their contributions to intracellular voltage-signaling in vitro. Using in vivo pharmacology we will answer what impact NMDA receptors have on sound driven firing rates. Thereby, the DNLL serves on the one hand as a read out nucleus where the impact of NMDA receptors on relaying binaural information will be quantified. On the other hand we will assay in vivo the direct binaural interactions at the level of the DNLL to understand the influence of NMDA receptors on interactions between inhibition and excitation. We hypothesize that these interactions might be crucial in terminating a long lasting inhibition that is regarded as a cellular correlate for the suppression of sound sources during echoes.

Resultate:

Felmy F.: The nuclei of the lateral lemniscus. The Oxford Handbook of auditory brainstem. Edited by Karl Kandler. 2019

 

Kladisios N., Fischer L., Felmy F.: Minimal Number of Required Inputs for Temporally Precise Action Potential Generation in Auditory Brainstem Nuclei. Front Cell Neurosci. 2020 Nov 5;14:592213

 

Siveke I., Lingner A., Ammer J.J., Gleiss S.A., Grothe B., Felmy F.: A Temporal Filter for Binaural Hearing Is Dynamically Adjusted by Sound Pressure Level. Front Neural Circuits. 2019 Feb 13; 13:8.

 

Siveke I., Ammer J.J., Gleiss S.A., Grothe B., Leibold C., Felmy F.: Electrogenic N-methyl-D-aspartate receptor signaling enhances binaural responses in the adult brainstem. European Journal of Neuroscience, 2018, 47, 858-865

Drittmittelprojekt: Alexander von Humboldt Stiftung Mohammed Bin Zayed Species Conservation

Kliniken/Institute:
Institut für Zoologie

Projektdetails:
The genus Eleutherodactylus, with over 194 known species and a distribution centered in the Caribbean West Indian islands, is the most speciose lineage of the Eleutherodactylidae family. These frogs represent over 80% of the Caribbean amphibian diversity with most of the species being single-island endemics. With the aid of multiple collaborators, this long term research project seeks to: 1) uncover cryptic diversity and define the species limits in the genus Eleutherodactylus by integrating genomic and phenotypic information; 2) elucidate the phylogenetic relationships among the species and related taxa; 3) compare the phenotypes, geographic distributions and evolutionary history across species to identify the factors responsible for the evolutionary diversification of amphibians in an insular scenario; and 4) generalize the results towards the long term conservation of these species.

Kooperationspartner:

Dr. Roberto Alonso Bosch, University of Havana, Cuba

MSc. Manuel Iturriaga Monsibay, Institute of Ecology and Systematics, Cuba

Prof. Dr. Miguel Vences, Technische Universität Braunschweig, Germany

Dr. Carles Vilà, Estación Biológica de Doñana, CSIC, Spain

Dr. Alejandro Gonzalez Voyer, Instituto de Ecología, UNAM, Mexico

Álvaro Dugo Cota, Estación Biológica de Doñana, CSIC, Spain