Charlotte Helfrich-Förster

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Charlotte Helfrich-Förster (born August 30, 1957 in Heilbronn - Sontheim) is a German zoologist and neurobiologist as well as a university professor at the University of Würzburg. Förster is particularly known for her research into the functioning of the internal clock in insects.

Life

Charlotte Helfrich-Förster studied biology from 1976 at the University of Stuttgart and the University of Tübingen . She graduated with a diploma in 1981 and did her doctorate in 1985 on the subject of investigations into the circadian system of flies . As a post-doctoral student , she was at the Max Planck Institute for Biological Cybernetics in Tübingen from 1994 . In 2000 she completed her habilitation in zoology and in 2001 became a substitute professor and then professor of zoology at the University of Regensburg . Since 2009 she has held the chair for neurobiology and genetics at the University of Würzburg . In 2012 she established the DFG Collaborative Research Center Insect timing: mechanisms, plasticity and interactions .

Scientific contribution

Förster's main interest is to understand the functioning of internal clocks on a molecular and neural level and to explain how internal clocks are synchronized to the cyclical changes in the environment and how they control behavior. Since the function of internal clocks in the animal kingdom is highly conserved, the fruit fly Drosophila melanogaster is best suited to investigate most of these questions due to its genetic accessibility. Förster succeeded in elucidating the neural clock network in the fruit fly's brain in detail. Furthermore, Förster was able to show that special neuropeptidergic neurons in this clock network are of particular importance for the rhythmic activity of the fly. These are neurons that express the neuropeptide “Pigment-Dispersing Factor” (PDF). The PDF neurons are essential for maintaining rhythmic activity in the absence of external timers such as light and temperature cycles. In the normal 24-hour day, the PDF neurons are important for normal morning activity and at the same time determine the time of evening activity for the animals. However, other clock neurons are essential for evening activity per se. a. those that express the neuropeptide "Ion Transport Peptide" (ITP). Together with the results of other working groups, Charlotte Helfrich-Förster's investigations led to a generally applicable model of activity control using morning and evening oscillators.

Förster's second scientific focus lies in the clarification of the synchronization of the internal clock by external timers, in particular by light-dark cycles. In her doctoral thesis, she was able to show that the rhythm of activity of eyeless fruit flies can still be synchronized with light-dark cycles, which speaks for the existence of extraocular photoreceptors . Such were also found in the form of an extra-retinal eye and in the form of the blue light pigment cryptochrome. In numerous works and in national and international collaboration with many scientists, Förster largely clarified the importance and role of all photoreceptor organs and photopigments of the fruit fly for the synchronization of the fruit fly. The role of a seventh rhodopsin , Rh7, is still unknown , but there is increasing evidence that this too is involved in synchronizing the internal clock with light. It is also unclear why the fly needs so many photoreceptors for its internal clock. This may have to do with the fact that the spectral changes during twilight, which allow the most precise time determination, must be perceived. Similar mechanisms have also been considered for mammals. Among the various photopigments, cryptochrome is particularly interesting because it also appears to act as a magnetic receptor in addition to light perception.

In comparative studies, Förster and her research group are also examining the neural network of the internal clock of other insects, especially that of northern Drosophila species. These flies are particularly interesting because they are exposed to completely different environmental conditions than the southern species and differ in both activity patterns and the neural clock network of Drosophila melanogaster. This suggests that the internal clock has evolved to adapt to the environment.

Research projects (selection)

Förster also conducts her research with the help of third-party funds.

  • As part of the EU-funded project "FP7-People-2012-ITN: INsecTIME" from 2012 to March 31, 2017, she investigates the photoperiodic control of diapause in various organisms ( fire bug , olive fly , Drosophila melanogaster , Drosophila melanogaster, Drosophila ezoana and Chymomyza costata (fly larvae)). The timely adaptation to the coming winter is vital for all animals - if they start too late to store fat reserves and stop reproducing, they and their offspring will hardly survive the winter. The falling temperatures in autumn are only partially suitable for anticipating winter, as cold days also occur in summer and autumn is quite warm in some years. A reliable indicator of the upcoming winter is the decreasing day length ( photoperiod ). Insects usually start hibernating when the photoperiod drops below a critical value and temperatures are low. It is commonly believed that the circadian clock is responsible for measuring the length of day, but the way in which this happens is largely unknown. It is also unclear how the day length information is passed on to the hormonal centers in the brain that ultimately trigger the diapause.
  • The Collaborative Research Center 1047 Insect timing: mechanisms, plasticity and interactions will be funded by the DFG from January 1, 2013 to December 31, 2016 . Förster is involved here with two of its own projects. The first sub-project deals with the circadian clock networks of selected insects. An important prerequisite for understanding the daily “timing” of insects is the functional characterization of the neural clock network in the brain. Förster contributes to this understanding by not only clarifying the clock network of different Drosophila species with sequenced genomes and with different habitats, but also that of social insects such as bees and ants in collaboration with other researchers. Bees and ants have a well-developed time memory and are capable of orienting the sun compass. To do this, they need an internal clock that works with the neural structures that are responsible for learning, memory and navigation in space. The second sub-project deals with the role of photoreceptors in synchronizing the internal clock of Drosophila and other insects with natural conditions.

Publications

Research Gate publication list

honors and awards

  • 2014: Karl-Ritter-von-Frisch-Medal
  • 2012: Chaire Joliot at the Laboratoire de Neurobiologie, ESPCI ParisTech
  • 2011: Ariens-Kappers Medallion of the "European Biological Rhythms Society"
  • 2008: SRBR Member (Society of Biological Rhythm Research) at Large
  • 2005: Aschoff-Honma Prize from the Japanese “Honma Foundation of Life Science” in recognition of an outstanding contribution to the scientific field of biological rhythm
  • 2003: Awarded the Aschoff's Ruler Prize
  • 2000: Research grant from the German Research Foundation
  • 1998: Margarete von Wrangell habilitation grant
  • 1996: Research grant from the German Research Foundation
  • 1986: Attempto Prize from the University of Tübingen for neurobiological research

Web links

References and comments

  1. ↑ a b c Chair for Neurobiology and Genetics, University of Würzburg
  2. ↑ CV Charlotte Helfrich-Förster ( Memento of the original from October 8, 2016 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / www.neurogenetics.biozentrum.uni-wuerzburg.de
  3. ↑ a b Timing in Insects: Mechanisms, Plasticity, and Consequences of Fitness. Julius Maximilians University of Würzburg (2013–2016)
  4. ↑ Helfrich-Förster, C. (2004). The circadian clock in the brain: a structural and functional comparison between mammals and insects. Journal of Comparative Physiology. A, Neuroethology, Sensory, Neural, and Behavioral Physiology, 190 (8), 601-613. doi: 10.1007 / s00359-004-0527-2
  5. ↑ Helfrich-Förster, C. (2005). Neurobiology of the fruit fly's circadian clock. Genes, Brain and Behavior, 4 (2), 65-76. doi: 10.1111 / j.1601-183X.2004.00092.x
  6. ↑ Helfrich-Förster, C., Shafer, OT, Wülbeck, C., Grieshaber, E., Rieger, D., & Taghert, P. (2007). Development and morphology of the clock-gene-expressing lateral neurons of Drosophila melanogaster. The Journal of Comparative Neurology, 500 (1), 47-70. doi: 10.1002 / cne.21146
  7. ↑ Helfrich-Förster, C., Yoshii, T., Wülbeck, C., Grieshaber, E., Rieger, D., Bachleitner, W., ... Rouyer, F. (2007). The lateral and dorsal neurons of Drosophila melanogaster: new insights about their morphology and function. Cold Spring Harbor Symposia on Quantitative Biology, 72, 517-525. doi: 10.1101 / sqb.2007.72.063
  8. ^ Hermann-Luibl, C., & Helfrich-Förster, C. (2015). Clock network in Drosophila. Current Opinion in Insect Science, 7, 65-70. doi: 10.1016 / j.cois.2014.11.003
  9. ↑ Helfrich-Förster C, Homberg U (1993) Pigment-dispersing hormone-immunoreactive neurons in the nervous system of wild-type Drosophila melanogaster and of several mutants with altered circadian rhythmicity. J Comp Neurol 337, 177-190.
  10. ↑ Helfrich-Förster, C. (1995). The period clock gene is expressed in central nervous system neurons which also produce a neuropeptide that reveals the projections of circadian pacemaker cells within the brain of Drosophila melanogaster. Proceedings of the National Academy of Sciences , 92 (2), 612-616.
  11. ↑ Helfrich-Förster, C. (1998). Robust circadian rhythmicity of Drosophila melanogaster requires the presence of lateral neurons: a brain-behavioral study of disconnected mutants. Journal of Comparative Physiology A, 182 (4), 435-453. doi: 10.1007 / s003590050192
  12. ↑ Helfrich-Förster, C., Täuber, M., Park, JH, Mühlig-Versen, M., Schneuwly, S., & Hofbauer, A. (2000). Ectopic expression of the neuropeptide pigment-dispersing factor alters behavioral rhythms in Drosophila melanogaster. The Journal of Neuroscience: The Official Journal of the Society for Neuroscience, 20 (9), 3339-3353.
  13. ↑ Yoshii, T., Wülbeck, C., Sehadova, H., Veleri, S., Bichler, D., Stanewsky, R., & Helfrich-Förster, C. (2009). The neuropeptide pigment-dispersing factor adjusts period and phase of Drosophila's clock. The Journal of Neuroscience: The Official Journal of the Society for Neuroscience, 29 (8), 2597-2610. doi: 10.1523 / JNEUROSCI.5439-08.2009
  14. ↑ Hermann-Luibl, C., Yoshii, T., Senthilan, PR, Dircksen, H., & Helfrich-Förster, C. (2014). The ion transport peptide is a new functional clock neuropeptide in the fruit fly Drosophila melanogaster. The Journal of Neuroscience: The Official Journal of the Society for Neuroscience, 34 (29), 9522-9536. doi: 10.1523 / JNEUROSCI.0111-14.2014
  15. ↑ The activity rhythm of Drosophila melanogaster is controlled by a dual oscillator. (no year). Retrieved April 4, 2017, from https://www.researchgate.net/publication/223763985_The_activity_rhythm_of_Drosophila_melanogaster_is_controlled_by_a_dual_oscillator .
  16. ↑ Rieger, D., Shafer, OT, Tomioka, K., & Helfrich-Förster, C. (2006). Functional analysis of circadian pacemaker neurons in Drosophila melanogaster. The Journal of Neuroscience: The Official Journal of the Society for Neuroscience, 26 (9), 2531-2543. doi: 10.1523 / JNEUROSCI.1234-05.2006
  17. ↑ Helfrich-Förster, C. (2009). Does the Morning and Evening Oscillator Model Fit Better for Flies or Mice? Journal of Biological Rhythms, 24 (4), 259-270. doi: 10.1177 / 0748730409339614
  18. ^ Yoshii, T., Rieger, D., & Helfrich-Förster, C. (2012). Two clocks in the brain: an update of the morning and evening oscillator model in Drosophila. Progress in Brain Research, 199, 59-82. doi: 10.1016 / B978-0-444-59427-3.00027-7
  19. ↑ Helfrich-Förster, C. (2014). From Neurogenetic Studies in the Fly Brain to a Concept in Circadian Biology. Journal of Neurogenetics, 28 (3-4), 329-347. doi: 10.3109 / 01677063.2014.905556
  20. ↑ Helfrich, C., & Engelmann, W. (1983). Circadian rhythm of the locomotor activity in Drosophila melanogaster and its mutants 'sine oculis' and 'small optic lobes'. Physiological Entomology, 8 (3), 257-272. doi: 10.1111 / j.1365-3032.1983.tb00358.x
  21. ↑ Emery, P., Stanewsky, R., Helfrich-Förster, C., Emery-Le, M., Hall, JC, & Rosbash, M. (2000). Drosophila CRY is a deep brain circadian photoreceptor. Neuron, 26 (2), 493-504.
  22. ↑ Veleri, S., Rieger, D., Helfrich-Forster, C., & Stanewsky, R. (2007). Hofbauer-Buchner Eyelet Affects Circadian Photosensitivity and Coordinates TIM and PER Expression in Drosophila Clock Neurons. Journal of Biological Rhythms, 22 (1), 29-42. doi: 10.1177 / 0748730406295754
  23. ↑ Rieger D., Stanewsky R. Helfrich-Förster C. (2003). Cryptochrome, compound eyes, Hofbauer-Buchner eyelets, and ocelli play different roles in the entrainment and masking pathway of the locomotor activity rhythm in the fruit fly Drosophila melanogaster. J Biol Rhythms 18, 377-391.
  24. ^ Yoshii T., Todo T., Wülbeck C., Stanewsky R., Helfrich-Förster C. (2008). Cryptochrome operates in the compound eyes and a subset of Drosophila's clock neurons. J Comp Neurol 508, 952-966.
  25. ^ Yoshii T., Vanin S., Costa R., Helfrich-Förster C. (2009). Synergic entrainment of Drosophila's circadian clock by light and temperature. J Biol Rhythms 24,452-464.
  26. ↑ Mazotta G., Rossi A., Leonardi E., Mason M., Bertolucci C., Caccin L., Spolaore B., Martin AJM, Schlichting M., Grebler R., Helfrich-Förster C., Mammi S., Costa R., Tosatto SCE. (2013). Fly cryptochrome and the visual system, Proc Natl Acad Sci USA 110 (15), 6163-6168.
  27. ↑ Schlichting M., Grebler R., Peschel N., T. Yoshii, Helfrich Ranger C. (2014). Moonlight detection by Drosophila's endogenous clock depends on multiple photopigments in the compound eyes. J Biol Rhythms 29, 75-86.
  28. ^ Yoshii T., Hermann-Luibl C., Kistenpfennig C., Tomioka K., Helfrich-Förster C. (2015). Cryptochrome dependent and independent circadian entrainment circuits in Drosophila. J Neurosci 35 (15), 6131-6141.
  29. ^ Yoshii T., Hermann-Luibl C., Helfrich-Förster C. (2016). Circadian light-input pathways in Drosophila. Communicative & Integrative Biol 9 (1), e1102805. doi: 10.1080 / 19420889.2015.1102805.
  30. ↑ Senthilan, PR, & Helfrich-Förster, C. (2016). Rhodopsin 7 – The unusual Rhodopsin in Drosophila. PeerJ, 4, e2427. doi: 10.7717 / peerj.2427
  31. ^ Foster, RG, & Helfrich-Förster, C. (2001). The regulation of circadian clocks by light in fruit flies and mice. Philosophical Transactions of the Royal Society of London. Series B, 356 (1415), 1779-1789. doi: 10.1098 / rstb.2001.0962
  32. ^ Yoshii, T., Ahmad, M., & Helfrich-Förster, C. (2009). Cryptochrome Mediates Light-Dependent Magnetosensitivity of Drosophila's Circadian Clock. PLOS Biology, 7 (4), e1000086. doi: 10.1371 / journal.pbio.1000086
  33. ↑ Kauranen H., Menegazzi P., Costa R., Helfrich-Förster C., Kankainen A., Hoikkala A (2012). Flies in the North: Locomotor behavior and clock neuron organization of Drosophila montana. J Biol Rhythms 27, 377-387.
  34. ^ Hermann C., Saccon R., Senthilan P., Domnik L., Dircksen H., Yoshii T., Helfrich-Förster C. (2013). The circadian clock network in the brain of different Drosophila species. J Comp Neurol 521 (2), 367-388.
  35. ↑ Menegazzi P., Dalla Benetta E., Beauchamp M., Schlichting M., Steffan-Dewenter I., Helfrich-Förster C. (2017). Adaptation of circadian neuronal network to photoperiod in high-latitude European Drosophilids. Curr Biol 27, 1-7.
  36. ↑ a b Projects AG Förster, Homepage Biozentrum Universität Würzburg
  37. ↑ KM Vaze, C. Helfrich-Förster: Drosophila ezoana uses an hour-glass or highly damped circadian clock for measuring night length and inducing diapause. In: Physiological Entomology. 41, 4, 2016, pp. 378-389.
  38. ↑ The circadian clock network of selected insects. Biozentrum University of Würzburg
  39. ↑ The role of photoreceptors in synchronizing Drosophila's clock to natural conditions. Biozentrum University of Würzburg
  40. ↑ Science Prize of the DZG: Karl-Ritter-von-Frisch-Medal 2014 goes to the neurobiologist Charlotte Helfrich-Förster ( Memento of the original from September 15, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.dzg-ev.de
  41. ↑ SRBR Committee
personal data
SURNAME Helfrich-Förster, Charlotte
BRIEF DESCRIPTION German neurobiologist
DATE OF BIRTH August 30, 1957
PLACE OF BIRTH Heilbronn