Research

Funding: DFG Ra 50/23-1, 2, Houston Zoo, 344.938 EUR

Project Details:
Drivers of speciation are diverse and complex, ranging from large-scale geomorphological processes like the formation of mountains or rivers to small-scale mechanisms like intra-specific ecological plasticity, divergent habitat choice or colonization potential. Due to the lack of appropriate model regions and species, previous studies typically focused on single or dual factor approaches without investigating interactions between drivers. We propose a highly suitable model region in eastern Madagascar to better explore the principal evolutionary processes driving species diversification and their interactions. The proposed study region is traversed by several large rivers that differ greatly in age. The geology and vegetation is rather uniform with similar macro-habitats ranging from tropical lowland to highland rain forest along an elevational east-west gradient. The area harbors an outstanding lemur species richness of which three genera are chosen as models for this project. Thirteen model species belong to two exceptionally speciose genera, Lepilemur and Microcebus, in contrast to the less speciose but ecologically plastic genus of woolly lemurs (Avahi). Rivers and mountains are assumed to have played a crucial role during speciation of lemurs, providing refugia during Pleistocene glaciation events which supposedly facilitated speciation. We propose that river chronology is an additional major co-variate shaping diversification processes, colonization pathways and phylogeographic history of species. We aim to combine geomorphological reconstructions of relative river ages, (micro-)habitat characterizations, ecological niche modeling techniques and RADseq-based phylogeographic reconstructions of colonization routes to investigate the role and interactions of various drivers of speciation including chronology of riverine barriers, vagility, altitudinal tolerance, body size, and ecological plasticity. This interdisciplinary project will thereby illuminate the relative importance of various extrinsic (e.g., geomorphology, habitat) and intrinsic factors (e.g., ecological plasticity, vagility) for the evolutionary diversification of animal populations.

Results:

Tiley, G.P.*; van Elst, T.*; Teixeira, H.; Schüßler, D.; Salmona, J.; Blanco, M.B.; Ralison, J.M.; Randrianambinina, B.; Rasoloarison, R.M.; Stahlke, A.R.; Hohenlohe, P.A.; Chikhi, L.; Louis, E.E.; Radespiel, U.; Yoder, A.D. (2022): Population genomic structure in Goodman?s mouse lemur reveals long-standing separation of Madagascar?s Central Highlands and eastern rainforests. Mol. Ecol., 31, 4901-4918. https://doi.org/10.1111/mec.16632 (*: shared first authors)

 

Schüßler, D.#; Blanco, M.B.#; Salmona, J.; Poelstra, J.; Andriambeloson, J.B.; Miller, A.; Randrianambinina, B.; Rasolofoson, D.W.; Mantilla-Contreras, J.; Chikhi, L.; Louis, E.E. Jr., Yoder, A.D.; Radespiel, U. (2020): Ecology and morphology of mouse lemurs (Microcebus spp.) in a hotspot of microendemism in northeastern Madagascar, with the description of a new species. Am. J. of Primatol., e23180. https://doi.org/10.1002/ajp.23180 (#: joint first authors)

 

Poelstra, J.#; Salmona, J. #; Tiley, G.P. #; Schüßler, D.; Blanco, M.B.; Andriambeloson, J.B.; Manzi, S.; Campbell, C.R.; Bouchez, O.; Etter, P.D.; Iribar, A.; Hohenlohe, P.A.; Hunnicutt, K.E.; Johnson, E.A.; Kappeler P.M.; Larsen, P.A.; Ralison, J.M.; Randrianambinina, B.; Rasoloarison, R.M.; Rasolofoson, D.W.; Stahlke, A.R.; Weisrock, D.; Williams, R.C.; Chikhi, L.; Louis Jr., E.E.; Radespiel, U.* Yoder, A.D.*; (2020): Cryptic patterns of speciation in cryptic primates: microendemic mouse lemurs and the multispecies coalescent. Systematic Biology, syaa053. https://doi.org/10.1093/sysbio/syaa053 (#: joint first authors, *: joint senior authors)

Cooperation Partners:

Prof. Dr. M. Sauerwein, Universität Hildesheim

Dr. Jordi Salmona, Universität Toulouse, Frankreich

Dr. Lounès Chikhi, IGC, Oeiras, Portugal

Pr. Dr. Jonah Ratsimbazafy, Universität Antananarivo, Madagaskar

Pr. Dr. Solofonirina Rasoloharijaona, Universität Mahajanga, Madagaskar

Dr. Romule Rakotondravony, Universität Mahajanga, Madagaskar

Dominik Schüßler, Apl.Prof. Dr. Jasmin Mantilla-Contreras, Universität Hildesheim

Funding: DFG, 466.350 EUR

Project Details:
The objective of this research work is to evaluate the genetic architecture of body size using a pig model in a multi-omics approach. It particularly aims at in-depth investigations of interrelations of size determining variants, transcriptional variation among miniature and large size as well as the identification of topologically associated domains (TADs) and putative enhancers involved in body size determination. This study is particularly focusing on the elucidation of the regulatory landscape in pigs and its essential role in the determination of body size.Initial analyses of whole genome sequencing data of miniature versus standard sized breeds/populations are supposed to identify potential signatures of selection reflecting high selection pressures in both directions- miniature and large size- harboring variants causative for the miniaturization across-breeds. Subsequently, I aim at detecting chromatin interactions defined as TADs and putative enhancer elements in the region of these variants involved in size-determination by targeting high intensity peaks of chromatin interactions from Hi-C analysis as well as high histone modification levels associated with active enhancers (H3K27ac and H3K4me1) from ChIP-seq in the growth plates of the long bones. These marks of active DNA sequences will then be linked to transcriptional variation in-between miniature and large pigs. An in vitro model will be established for further functional validation.This will be the first study investigating genomic and functional effects on body size specifically targeting growth plates in pigs. Based on these data, we aim at increasing the knowledge of biological processes in mammals regulating growth and determining the size of a body. This profound understanding of body size development will not only be of high importance for livestock breeding but will also provide better understanding of growth biology, developmental genetics and disturbances in growth processes.

Results:

https://link.springer.com/article/10.1186/s12864-022-08801-4

Cooperation Partners:

Prof. Stefan Mundlos, Max-Planck-Institut für Molekulare Genetik, Berlin

Funding: F. Hoffmann-La Roche Ltd, 236.600 EUR

Project Details:
exploratory research project

Funding: Gesellschaft der Freunde der Tierärztlichen Hochschule Hannover e.V. (GdF), 15.600 EUR

Project Details:
Growing evidence indicates that exercise has the potential to reduce components of Parkinson's disease (PD)-related pathology. PD progression starts early before onset of the cardinal motor signs and subtle motor and non-motor dysfunctions are evident even in the early prodromal stage before clinical disease diagnosis (Berg et al. 2021 Nat Rev Neurol). We therefore examine whether and to which degree exercise affects disease pathology and progression in young mice that overexpress human wildtype alpha-synuclein under the Thy-1 promotor (Thy1-aSyn mice) and replicate PD hallmarks by developing, among others, robust fine motor deficits at two months of age (Chesselet, Richter et al. 2012 Neurotherapeutics). We hypothesize that early intervention by exercise has a disease-modifying effect during prodromal phase in Thy1-aSyn mice and can be applied as a non-pharmacological preventive strategy for early-stage PD (Schäffer et al. 2020 Neurology). Next, we will administer a substance to the animal model, which shows increased levels under exercise and neuroprotective properties in other neurodegenerative diseases.

Cooperation Partners:

Prof Dr. Daniela Berg (Neurologie, Christian-Albrechts Universität Kiel), Prof. Dr. Christiane Wrann (Harvard Medical School)

Funding: DFG (Heisenberg), 256.200 EUR

Project Details:
The objective of this research work is to evaluate the genetic architecture of body size using a pig model in a multi-omics approach. It particularly aims at in-depth investigations of interrelations of size determining variants, transcriptional variation among miniature and large size as well as the identification of topologically associated domains (TADs) and putative enhancers involved in body size determination. This study is particularly focusing on the elucidation of the regulatory landscape in pigs and its essential role in the determination of body size.Initial analyses of whole genome sequencing data of miniature versus standard sized breeds/populations are supposed to identify potential signatures of selection reflecting high selection pressures in both directions- miniature and large size- harboring variants causative for the miniaturization across-breeds. Subsequently, I aim at detecting chromatin interactions defined as TADs and putative enhancer elements in the region of these variants involved in size-determination by targeting high intensity peaks of chromatin interactions from Hi-C analysis as well as high histone modification levels associated with active enhancers (H3K27ac and H3K4me1) from ChIP-seq in the growth plates of the long bones. These marks of active DNA sequences will then be linked to transcriptional variation in-between miniature and large pigs. An in vitro model will be established for further functional validation.This will be the first study investigating genomic and functional effects on body size specifically targeting growth plates in pigs. Based on these data, we aim at increasing the knowledge of biological processes in mammals regulating growth and determining the size of a body. This profound understanding of body size development will not only be of high importance for livestock breeding but will also provide better understanding of growth biology, developmental genetics and disturbances in growth processes.

Results:

https://link.springer.com/article/10.1186/s12864-022-08801-4

Cooperation Partners:

Prof. Dr. Stefan Mundlos, Max-Planck-Institut für Molekulare Genetik, Berlin

Project Details:
Das Projekt untersucht die Pathogenese der Rifttalfieberenzephalitis im Mausmodell. Rifttalfieber ist eine virale Zoonose, die in seltenen, aber schweren, teils fatalen Fällen zu einer Enzephalitis in Humanpatienten führt. Wichtige Details zu deren Pathogenese, insbesondere der Infektionsweg, die intrazerebrale Virusausbreitung und die Rolle der (intrazerebralen) Immunantwort sind bisher nicht vollständig geklärt. Das Projekt erforscht den Verlauf der Rifttalfieberenzephalitis nach intranasaler Infektion bei verschiedenen immundefizienten Knockoutmäusen im Vergleich mit immunkompetenten Wildtypmäusen, um die genaue Rolle verschiedener Immunzellen in der Pathogenese zu charakterisieren.

Results:

https://pubmed.ncbi.nlm.nih.gov/36293352/ (2022 Oct 18)

Funding: Deutscher Akadademischer Austausch Dienst (DAAD-PROCOPE), 9.108 EUR

Project Details:
Nonverbal vocal communication in humans contains information about the emotional state of the sender which can be used by the receiver. Comparing the acoustic structure and the context of production of these vocalizations across mammalian species revealed cross-taxa similarities suggesting a pre-human origin in encoding emotional information acoustically (e.g., Davila Ross et al., 2009, Newman, 1985, Zimmermann et al., 2013). In contrast to human laughter and cries, our knowledge on other nonverbal sounds such as the Sigh is limited. Therefore, the current study investigated whether vocalizations comparable to the human sigh can be found in nonhuman mammals and whether these vocalizations can be related to emotional states of the sender as well as to the quality of social interaction.
In the order Perissodactyla, horses and rhinoceros are known to produce noisy vocalizations at a high call rate (e.g. Policht et al., 2008, Yeon et al., 2011). The Snort is one of this noisy vocalizations, characterized as an explosive more or less pulsed breathing sound produced by nostril vibrations while expulsing the air. The function of this call type is not yet clear. First, it was proposed that this call type might have a hygienic function rather than a communicative function (e.g., Yeon et al., 2011, Linn et al., 2018). Second, it was proposed that the Snort might be an indicator of positive emotions or at least a relaxed state in horses. In the rhinoceros infant Snorts occurred also during affiliative interactions supporting to function as an indicator of the positive emotional state (Linn et al., 2018). This suggests that either the Snort has a communicative function to signal socially acceptance to group members or express an internal relaxed state of the sender which might affect group members via an emotional contagion mechanism.
To clarify the function of Snorts and to investigate to which extent there are cross-taxa similarities at least in the order Perissodactyla, we aim to compare Snort production between horses and rhinoceros.

Cooperation Partners:

Idu Azogu-Sepe, Serengeti Park Hodenhagen

Prof. Alban Lemasson, Rennes 1 University, France

Prof. Martine Hausberger, Rennes 1 University, France

Dr. Mathilde Stomp, Rennes 1 University, France

Planét Sauvage, Frankreich

Project Details:
Part A.) Warmblood horses without back pain are trained three times per week up to 30 minutes on a water treadmill. The remaining days the horses are in ridden training as usual. Back dimensions are objectively assessed at week 0, 3, 6 and 9 by using a flexible curved ruler. The cross-sectional areas of the deep muscles (Mm. multifidi) are determined by ultrasound examination.

Part B.) Warmblood riding horses with clinical signs of back pain are randomized into three groups to participate in a 6-week water treadmill, lunge training or dry treadmill training program at otherwise same conditions. A structured clinical examination of the thoracic and lumbar back region is performed independently by two clinicians at 3 time points (baseline, week 3, 6). Mechanical nociceptive thresholds (MNT) are determined with pressure algometry.

Results:

Rogge, L., Geiger, T., Delarocque, J., Geburek, F. Water treadmill training causes a significant increase in back dimensions at the level of Th10 in warmblood riding horses without a history of back pain. In: Proceedings of the 4th Scientific Meeting of the European College of Veterinary Sports Medicine and Rehabilitation, ECVSMR; Maisons-Alfort, Paris, France, July 22-23, 2023; ECVSMR, p. 59, ISSN: 2510-8093

 

Geiger, T., Rogge, L., Delarocque, J., Geburek, F. Comparative effect of water treadmill training, lunging and treadmill training during rehabilitation of horses with back pain. In: Proceedings of the 4th Scientific Meeting of the European College of Veterinary Sports Medicine and Rehabilitation, ECVSMR; Maisons-Alfort, Paris, France, July 22-23, 2023; ECVSMR, ISSN: 2510-8093, p. 64

Project Details:
Kniegelenkserkrankungen kommen bei Pferden regelmäßig vor. Bei der ultrasonographischen Untersichung ihrer Menisken entstehen akustische Artefakte, die mit krankhaften Befunden verwechselt werden können. In dieser Studie sollen ultrasonographische Befunde an Menisken von Pferden ohne Kniegelenkserkrankung mit anatomischen und feingeweblichen Befunden verglichen werden, um eine bessere Abgrenzung zwischen normalen Ultraschall-Befunden mit den üblichen akustischen Artefakten einerseits und pathologischen Veränderungen andererseits zu ermöglichen. Durch eine Einteilung der Präparate in verschiedene Lebensaltersgruppen wird zudem eine Einordnung alterungsbedingter morphologischer Veränderungen am Meniskus erwartet.

Results:

Geburek, F., Bodem, L., Staszyk, C.

Tears or Artifacts? Comparison between normal ultrasound and macro-anatomy of the medial femorotibial meniscus.

In: Scientific Abstracts of the 29th Annual Scientific Meeting of the ECVS. Vet. Surg. 2020, 49(S2), p. O195

https://doi.org/10.1111/vsu.13478

Cooperation Partners:

Prof. Dr. C. Staszyk, Institut für Veterinär-Anatomie, -Histologie und -Embryologie, Fachbereich Veterinärmedizin, Justus-Liebig-Universität Gießen

Funding: Pharmaceutical sector, 230.000 EUR

Project Details:
therapy development for neurodegenerative diseases