Press releases

FRANKFURT. A particular neuronal circuit in the brains of bats controls their vocalisations. This was recently discovered by biologists at Goethe University Frankfurt. Based on the rhythm with which the circuit oscillated, the Frankfurt researchers were able to predict the kind of sounds the bats were about to make. These research results could contribute to a better understanding of human diseases in which language is impaired such as Parkinson's or Tourette syndrome.

Bats are famous for their sonar-based navigation. They use their extremely sensitive hearing for orientation, emitting ultrasound noises and receiving an image of their surroundings based on the echo. Seba's short-tailed bat (Carollia perspicillata), for example, finds the fruits that are its preferred food using this echolocation system. At the same time, bats also use their voices in a somewhat deeper frequency range to communicate with other members of their species. Seba's short-tailed bats employ a vocal range for this purpose that is otherwise only found among songbirds and humans. Like humans, they produce sound through the larynx.

Together with his team, neuroscientist Julio C. Hechavarria from the Institute for Cell Biology and Neuroscience at Goethe University investigated brain activity preceding vocalisation in Seba's short-tailed bats. The scientists were able to identify a group of nerve cells that create a circuitry from the frontal lobe to the corpus striatum in the interior of the brain. When this neural circuit fires off rhythmic signals, the bat emits a vocalisation about half a second later. The type of rhythm seemed to determine whether the bats were about to utter echolocation or communication vocalisations.

Since it is nearly impossible to make a prediction within half a second, the Frankfurt researchers trained a computer to test their hypothesis: The computer analysed the recorded sounds and the neural rhythm separately and attempted to make prognoses using the various rhythms. The result: in its predictions of echolocation versus communication vocalisations, the computer was correct about 80 percent of the time. Predictions were particularly accurate when considering signals from the frontal lobe, an area that in humans has been linked to action planning, among other functions.    

The Frankfurt scientists argue that the rhythms they observed in the bat brain are similar to neural rhythms often recorded from the human scalp, and concluded that brain rhythms could be linked to sound production in mammals in general.
Julio Hechavarria: “For over 50 years, bats have served as an animal model for studying how the brain processes auditory stimuli and how human language develops. For the first time, we were able to show how distant brain regions in bats communicate with each other during vocalization. At the same time, we know that the corresponding brain networks are impaired in individuals who, for example, stutter as a result of Parkinson's disease or emit involuntary noises due to Tourette syndrome. We therefore hope that by continuing to study vocal behaviour in bats, we can contribute to a better understanding of these human diseases."

Publication: Fronto-striatal oscillations predict vocal output in bats.
Kristin Weineck, Francisco García-Rosales, Julio C. Hechavarria; PLOS Biology DOI 10.1371/journal.pbio.3000658
https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3000658

Images may be downloaded here: http://www.uni-frankfurt.de/86729013

Caption: The image shows that different vocalization-related neural signals occurring across frontal cortex laminae (left) precede the two types of sounds (right) uttered by bats (species: Carollia perspicillata). The sounds are shown as color-coded time-frequency representations. One example social call is shown in the top right and one example echolocation call in the bottom right. Copyright: Julio C. Hechavarria, Goethe University Frankfurt

Further information: Julio C. Hechavarria, Ph.D., Auditory Computations Group (group leader), Institut of Cell Biology and Neuroscience, Goethe University Frankfurt, Phone +49 (0)69 798-42050, E-Mail: Hechavarria@bio.uni-frankfurt.de, https://www.julio-hechavarria.com/.

The formation of gametes and the first cell divisions of the fertilized egg in mammals are prone to errors. Sometimes the wrong number of chromosomes is passed on to the offspring, or the first division leads to two nuclei instead of one in the two-cell embryo. In most cases, these errors result in miscarriages. Judith Reichmann has shown what leads to these errors in mouse embryos.

FRANKFURT am MAIN. Today, Dr. Judith Reichmann is receiving the €60,000 Paul Ehrlich and Ludwig Darmstaedter Prize for Young Researchers 2020. Dr. Reichmann, who works at the European Molecular Biology Laboratory (EMBL) in Heidelberg, researches the sources of chromosomal abnormalities in eggs and embryos of mice and their potential contribution to miscarriages. Mice synthesize a protein called Tex19.1, which maintains chromosome cohesion during the formation of oocytes and protects sperm cells from genetic damage. Without this protein, many mouse embryos have the wrong number of chromosomes and die after a few cell divisions. Errors also occur when the fertilized egg splits into two daughter cells. Reichmann was able to show that the paternal and maternal chromosome sets are not passed on via one but two mitotic spindles. As a result, the two sets of chromosomes sometimes drift apart during the cell division process so that the two-cell embryo ends up with two haploid cell nuclei instead of one diploid cell nucleus.

Reichmann discovered the dual spindle formation using light-sheet microscopy, which she developed further for this purpose. Mouse embryos do not tolerate continuous light exposure and therefore cannot be examined with a conventional microscope in high spatiotemporal resolution. This has precluded detailed live-imaging analyses in the past. In light-sheet microscopy, illumination occurs only in the plane that is actually being observed, while other parts of the embryo remain in the dark. "Judith Reichmann has shown how mice make sure that their offspring have the correct number of chromosomes, and only one cell nucleus. If this process fails, reproduction is compromised," the Scientific Council´s statement reads. "Reichmann's research may one day contribute to reducing the rate of miscarriages in women - provided that the sources of error identified in mice also apply to human reproduction".

Reichmann discovered that the Tex19.1 protein indirectly stabilizes the chromosomes during meiosis. This process ensures that the gametes enter fertilization with a single set of chromosomes, for without this process the number of chromosomes would double with each generation. In oocytes, stabilization of the chromosomes is needed because meiosis is interrupted for a long time and is only completed upon fertilization. When Tex19.1 is missing, the chromosomes drift apart in the egg. As a result, many embryos among the offspring do not inherit the correct number of chromosomes.

Reichmann's discovery of the dual spindles during the first cell division of the fertilized egg has toppled a textbook statement. Up to now, it had been assumed that the parental chromosomes merge in the fertilized egg and are distributed to the two daughter cells via a single spindle apparatus. Reichmann was able to show that the paternal and maternal chromosomes are grouped separately from each other in two spindles and are then distributed to the poles. Even in the nucleus of the two-cell embryo, maternal and paternal chromosomes initially remain in different hemispheres before they finally mix during subsequent cell divisions.

If Reichmann´s findings in mice also hold for human embryogenesis, and the human paternal and maternal chromosomes only merge in the two-cell embryo as well, a central assumption of the German Embryo Protection Act may have to be reconsidered. It states that human life begins when maternal and paternal chromosomes join; by this definition, the two-cell embryo rather than the zygote would take centre stage.

The Paul Ehrlich and Ludwig Darmstaedter Prize for Young Researchers has been awarded since 2006 in recognition of outstanding achievements in biomedical research.

Short biography of Dr. Judith Reichmann
Judith Reichmann (35) studied applied biology at the University of Applied Sciences Bonn-Rhein-Sieg. At the end of her studies, she moved to the University of Aberdeen in Scotland where she pursued a bachelor's degree in genetics. At the University of Edinburgh, she completed her doctorate on the development of oocyte and sperm cells. Reichmann came to EMBL as a postdoctoral fellow in 2012 to investigate cell division at the beginning of life using the latest microscopy techniques. She has been working as a research scientist at EMBL since 2017. Reichmann is married and has two children.

Paul Ehrlich and Ludwig Darmstaedter Prize for Young Researchers
The Paul Ehrlich and Ludwig Darmstaedter Prize for Young Researchers, awarded for the first time in 2006, is conferred once a year by the Paul Ehrlich Foundation on a young investigator working in Germany for his or her outstanding achievements in the field of biomedical research. The prize money must be used for research purposes. University faculty members and leading scientists at German research institutions are eligible for nomination. The selection of the prizewinner is made by the Scientific Council on a proposal by the eight-person selection committee.

The Paul Ehrlich Foundation
The Paul Ehrlich Foundation is a legally dependent foundation which is managed in a fiduciary capacity by the Association of Friends and Sponsors of the Goethe University, Frankfurt. The Honorary Chairman of the Foundation, which was established by Hedwig Ehrlich in 1929, is Professor Dr. Katja Becker, president of the German Research Foundation, who also appoints the elected members of the Scientific Council and the Board of Trustees. The Chairman of the Scientific Council is Professor Thomas Boehm, Managing Director at the Max Planck Institute of Immunobiology and Epigenetics in Freiburg, the Chair of the Board of Trustees is Professor Dr. Jochen Maas, Head of Research and Development and Member of the Management Board, Sanofi-Aventis Deutschland GmbH. Professor Wilhelm Bender, in his function as Chair of the Association of Friends and Sponsors of the Goethe University, is Member of the Scientific Council. The President of the Goethe University is at the same time a member of the Board of Trustees.

Further information
You can obtain selected publications, the list of publications and a photograph of the prizewinner from Dr. Hildegard Kaulen, phone: +49 (0) 6122/52718, e-mail: h.k@kaulen-wissenschaft.de and at www.paul-ehrlich-stiftung.de.

Attack or peacekeeping? Immune cells answer this question countless times a day. If they regularly missed the mark, it would have serious consequences for human health. The regulatory T cells discovered by Shimon Sakaguchi help the immune system to distinguish between friend and foe and are instrumental for achieving self-tolerance. Strengthening or weakening this peacekeeping force gives the immune system a kick or a damper. Both strategies can be harnessed to develop new treatments for human diseases.

FRANKFURT am MAIN. Tomorrow, Shimon Sakaguchi, professor of Experimental Immunology at Osaka University (Japan) will receive the 2020 Paul Ehrlich and Ludwig Darmstaedter Prize for his pioneering discoveries of regulatory T cells and their role in self-tolerance. These cells have the potential to become the new heroes of medicine. They keep the immune system in balance and ensure that it doesn´t run amok or becomes inattentive. "Without regulatory T cells, the immune system would not be able to correct errors in distinguishing between friend and foe with the necessary precision," explained the Scientific Council of the Paul Ehrlich Foundation when presenting the award. "The immune system needs such regulatory control, because overreaction leads to autoimmune diseases such as rheumatoid arthritis and type 1 diabetes, whereas reduced activity gives cancer cells the opportunity to evade immune attack and eventually establish metastases. Therefore, Sakaguchi's discovery offers great potential for the development of new treatments."

Early on in his studies, Sakaguchi was convinced that an immunological peacekeeping force must exist in order to establish immune homeostasis. The difficulty he faced was that there was no molecular marker that would allow him to identify and isolate these cells. Therefore, Sakaguchi set out to search for such a telltale feature. After many years of painstaking work, he demonstrated that the surface protein CD25 is a reliable marker for these cells. "The discovery of CD25 was a watershed in immunological research. It proved the existence of regulatory T-cells and pointed a way forward to isolate and characterize them in greater detail," said Professor Thomas Boehm, Director at the Max Planck Institute of Immunobiology and Epigenetics in Freiburg, and Chairman of the Scientific Council. "This seminal discovery has given the field of immune regulation an enormous boost. Suddenly, many scientists became interested in the biology and use of regulatory T cells."

Subsequently, Sakaguchi was able to show that Foxp3 is the central on/off switch of regulatory T cells, a finding that was quickly confirmed by others. This discovery established an unexpected connection between regulatory T cells and a rare congenital syndrome known as IPEX, which had been shown to be due to the lack of Foxp3. IPEX patients develop severe autoimmune diseases shortly after birth, often leading to early death. Thus, the medical relevance of Sakaguchi´s earlier discovery of regulatory T cells became obvious: patients with IPEX syndrome suffered from lack of an immunological peacekeeping force.

Because of their fundamental importance for the immune system, the manipulation of regulatory T cells offers new forms of treatment for a wide range of conditions. In the case of autoimmune diseases such as rheumatoid arthritis, type 1 diabetes and multiple sclerosis, their activity must be strengthened so that they can take more decisive action against inappropriate attacks on the body's own tissue. In cancer, the activity of regulatory T cells needs to be attenuated. Although they no longer adhere to their normal cellular program, cancer cells are often not considered foreign by the immune system. Hence, the protection of tumor cells by regulatory T cells is unfortunate, as this prevents them from being eliminated. Therefore, to eliminate the tumor´s camouflage, regulatory T cells, which are disproportionately abundant in tumors, must be either reduced in number or their activity diminished to allow an efficient attack on the tumor.

Attenuation of regulatory T cell activity, however, needs to be very precisely controlled, both in space and in time, for they are needed elsewhere in the body to maintain immune homeostasis. "The challenge is to manipulate regulatory T cells only at the site of the tumor," Thomas Boehm explains. "In one approach, Sakaguchi is attempting to convert tumor resident regulatory T cells into conventional T-cells, which then switch sides and participate in attack. If this strategy is successful, an essential component of the body´s peacekeeping force will be converted into an aggressor directed at the malignant tissue ".

At present, various strategies for the treatment of autoimmune diseases and cancer based on the manipulation of regulatory T cells are being evaluated, although these approaches are still in an early phase of clinical development. As with many groundbreaking ideas, therapeutic application requires a long period of painstaking work before they can be offered to patients.

Short biography of Professor Shimon Sakaguchi
Professor Shimon Sakaguchi, M.D. (69) is a medical doctor. He studied medicine at Kyoto University in Japan, then moved to Johns Hopkins University in Baltimore as a post-doctoral fellow and then to Stanford University in California. In 1989 he became an "Assistant Professor" at the Scripps Research Institute in La Jolla. In 1991, Sakaguchi returned to Japan and worked at the Tokyo Metropolitan Institute of Gerontology and later at the Institute for Frontier Medical Sciences at Kyoto University, where he was temporarily director. Since 2011, he has been working at Osaka University. In 2012 he became a Foreign Member of the American National Academy of Sciences and in 2017 the Japanese government appointed him "Person of Cultural Merit". Sakaguchi has received many awards, including the William B. Coley Award from the Cancer Research Institute, the Keio Medical Science Prize, the Canada Gairdner International Award and the Crafoord Prize. Last year he was awarded the "German Immunology Prize 2019".

The Paul Ehrlich and Ludwig Darmstaedter Prize
The Paul Ehrlich and Ludwig Darmstaedter Prize is traditionally awarded on Paul Ehrlich's birthday, March 14, in the Paulskirche, Frankfurt. It honors scientists who have made significant contributions in Paul Ehrlich's field of research, in particular immunology, cancer research, microbiology, and chemotherapy. The Prize, which has been awarded since 1952, is financed by the German Federal Ministry of Health, the German association of research-based pharmaceutical company vfa e.V. and specially earmarked donations from the following companies, foundations and organizations: Christa Verhein Stiftung, Else Kröner-Fresenius-Stiftung, Sanofi-Aventis Deutschland GmbH, C.H. Boehringer Sohn AG & Co. KG, Biotest AG, Hans und Wolfgang Schleussner-Stiftung, Fresenius SE & Co. KGaA, F. Hoffmann-LaRoche Ltd., Grünenthal Group, Janssen-Cilag GmbH, Merck KGaA, Bayer AG, Holtzbrinck Publishing Group, AbbVie Deutschland GmbH & Co. KG, die Baden-Württembergische Bank, B. Metzler seel. Sohn & Co. and Goethe-Universität. The prizewinner is selected by the Scientific Council of the Paul Ehrlich Foundation.

The Paul Ehrlich Foundation
The Paul Ehrlich Foundation is a legally dependent foundation which is managed in a fiduciary capacity by the Association of Friends and Sponsors of the Goethe University, Frankfurt. The Honorary Chairman of the Foundation, which was established by Hedwig Ehrlich in 1929, is Professor Dr. Katja Becker, president of the German Research Foundation, who also appoints the elected members of the Scientific Council and the Board of Trustees. The Chairman of the Scientific Council is Professor Thomas Boehm, Managing Director at the Max Planck Institute of Immunobiology and Epigenetics in Freiburg, the Chair of the Board of Trustees is Professor Dr. Jochen Maas, Head of Research and Development and Member of the Management Board, Sanofi-Aventis Deutschland GmbH. Professor Wilhelm Bender, in his function as Chair of the Association of Friends and Sponsors of the Goethe University, is Member of the Scientific Council. The President of the Goethe University is at the same time a member of the Board of Trustees.

Further information
You can obtain selected publications, the list of publications and a photograph of the laureate from Dr. Hildegard Kaulen, phone: +49 (0)6122/52718, email: h.k@kaulen-wissenschaft.de and at www.paul-ehrlich-stiftung.de

FRANKFURT. Strengthening basic research in African countries – this is the goal of the new postgraduate academy in the Mali city of Bamako – in particular in the humanities and social sciences. The academy, which was financed by the Gerda Henkel Foundation and conceived by scientists from Frankfurt and Mali, was ceremonially opened on 2nd March.

Despite great progress, the francophone African countries still receive scant consideration in the global production of knowledge.  Especially in the humanities and social sciences, there is greater focus on the need for problem solving in politics and development industries – to the detriment of the potential for developing these fields. Professor Elisio Macamo from the University of Basel, one of the two founding directors, described the situation during the opening ceremony: “In politically-oriented discourses, science sees itself as obligated to provide solutions for human problems, and practical utility becomes the benchmark for determining the validity of knowledge." In fact, the debate about the extent to which science is required to produce relevant knowledge leads to a dilemma that has made the discussion very difficult. “Scientists, especially in Africa, are caught between communicating useful knowledge while simultaneously watering down scientific standards on the one hand, and maintaining scientific standards while simultaneously risking irrelevance on the other," says Macamo.

In a context which in public opinion is particularly characterised by “seemingly obvious problem areas" which are to be solved with the help of the scientific repertoire learned at universities, what role does basic research play in the humanities and social sciences? This is a question also asked by Professor Mamadou Diawara from the Institute for Ethnology at Goethe University, who founded the new academy together with Macamo and scientists in Mali. The conceptual and methodical development of the disciplines themselves are often neglected in the process. It is of more importance, however, to understand the problems thoroughly and formulate the right questions. Unfortunately, this is far from being a given. According to the scientists, the excess of “applied research" in the service of development politics leads to Africa increasingly falling behind in the production of global knowledge, a phenomenon particularly evident in francophone Africa, which is the focus of the project.

The “Pilote African Postgraduate Academy (PAPA)“ developed by Goethe University, the University of Basel and the research centre Point Sud in Bamako explicitly does not see itself as decolonial project. “We're not looking for an African science that does everything differently than the so-called European science. On the contrary, we want to free scientific vocabulary from these kinds of intellectual corsets," Macamo explained. PAPA intends to strengthen basic research in the humanities and social sciences. Fifteen early career scientists from eight countries began their work in research following the opening of the academy. Professors Mamadou Diawara and Elisio Macamo are responsible for the scientific leadership. The academy's training programme is designed to encourage scholarship recipients to engage in a critical dialogue with their discipline, area studies, and their identity as scientists to address fundamental epistemological questions. After concluding the three-year PAPA cycle, the carefully selected junior researchers will return to their native institutions to teach and research at a different level. Twice a year, the fifteen selected early career researchers and up to four established scientists in Bamako will take part in two-week workshops in Bamako. A mentoring programme will connect high-level researchers and award winners at their native institutions. In addition, a strong network is to be created for scientists and teachers from francophone African countries who live both inside and outside of Africa to exchange ideas and develop joint projects. The project will be funded by the Gerda Henkel Foundation for its first three years.

The event was ceremoniously opened by the Mali Minister for Education and Research, Professor Mamadou Famanta, and the German ambassador in Mali, Dr Dietrich Fritz Reinhold Pohl. The renowned Senegalese philosophy professor, Soulyemane Bachir Diagne from Columbia University, New York gave a lecture entitled „La question de l'Universel et les Etudes Postcoloniales“. Diagne also spoke in opposition to the radicalism of post- and decolonialists: “Of course we don't want to burn down the colonial libraries – we want to use and criticise them." He also spoke in opposition to “experience science," in which research on certain segments of the population can only be carried out by its own members, since all others are supposedly unable to understand their life reality. “The idea that the everyday problems of black women can only be studied by black women is absurd. This approach would quickly put an end to science," says Diagne. The opening ceremony ended with his brilliant lecture and a discussion with the fellows that lasted for over an hour.

The event continued in the afternoon at the research centre Point Sud which has been financed by Goethe University since 2012 as part of a DFG-programme. There, participants met the early career researchers who work at the centre. In the evening, the launch of the project was celebrated to traditional kora music.

Images may be downloaded here: https://uni-frankfurt.de/86320819

Captions:

PAPA0001: Professor Mamadou Diawara (left) and the Minister for Education and Research, Professor Mamadou Famanta, at the opening in Bamako. (credit: Stefan Schmid)

PAPA0002: Presentation of the research centre Point Sud by Vice Director Professor Tiéman Diarra. (credit: Stefan Schmid)

PAPA0003: Group picture with fellows and mentors. (credit: Stefan Schmid)

PAPA004: The fellows of the new postgraduate academy. (credit: Stefan Schmid)

Further information: s.schmid@em.uni-frankfurt.de; You can find further information on the PAPA project and the selected scholarship recipients on the Point Sud website: http://pointsud.org/pilot-african-postgraduate-academy-papa/?lang=en , on the Goethe University website (https://aktuelles.uni-frankfurt.de/forschung/staerkung-fuer-grundlagenforschung-in-afrika/ ) and the website of the Gerda Henkel Foundation (https://www.gerda-henkel-stiftung.de/pressemitteilung?page_id=120413#top

FRANKFURT. Pet owners have been sure of this for long time, and scientific research provides confirmation: animals, too, have personalities. A study originating at Goethe University documents that even with regard to fish, their own personality traits and that of their potential partner is critical when selecting a “groom”.

Individual animals, from vertebrates to crabs and spiders, exhibit consistent behaviour tendencies that distinguish them from other members of their species. The most thoroughly researched personality trait in the animal world is propensity for risk-taking. A wide range of individuals, from very shy to quite courageous, can be found among the small freshwater fish Poecilia mexicana, which live primarily in the rivers of Mexico. Both traits can be of advantage: while shy fish have a lower risk of being eaten by predatory fish and birds, bold ones are often more efficient at finding food.

Risk-taking males also have advantages when it comes to choosing a partner, as shown in a study by Dr. Carolin Sommer-Trembo and other scientists at Goethe University. Using behaviour tests, males and females were first classified on a scale from shy to bold. A partner selection test followed, in which females were allowed to choose between two males with different risk-taking propensities. To prevent the females from being too strongly affected by other criteria, the males were selected so that they were almost identical in their external characteristics such as body shape, colouration and size.

The results seemed clear: bold males were preferred. But at second glance, the risk appetite of the females also played a role in the decision. Bold females exhibited the strongest preference for bold males, while this preference was weaker among shy females. Are courageous males more attractive to all females, or do less courageous males also have chance, since “birds of a feather flock together”? The study shows that these two mechanisms are intertwined and, as is so often the case, the truth is not a case of “either/or” but of “both/as well as”.

Publication: Sommer-Trembo C, Schreier M, Plath M (2020) Different preference functions act in unison: mate choice and risk-taking behaviour in the Atlantic molly (Poecilia mexicana). Journal of Ethology, DOI: 10.1007/s10164-020-00643-5

Images may be downloaded at: http://www.uni-frankfurt.de/86091187

Caption: The female Atlantic molly is not very colourful, while the tail fins of the male glow in various shades of yellow and orange (Credits: Claudia Earp (Fishes1 and 2) / Martin Plath (Fishes3))

Further information:  Carolin Sommer-Trembo, Postdoc, Zoological Institute of the University of Basel, Vesalgasse 1, 4051 Basel, Telefon: +41 (0) 783079999, Email: sommer-trembo@gmx.de