Caring about the future

Gregor Christa

Gregor Christa

Post-Doctoral Research Fellow

  • Author Name : Christa G.

  • Researcher ID: I-6808-2015
  • ORCID: 0000-0002-9454-7351
  • Ciencia ID:
  • Department: Biology
  • Research Group: Coastal and Deep-Ocean Ecology & Conservation (CDEC)
  • ISI Web of KnowledgeSM search factor: Christa Gregor


Research interests

Evolution of photosymbioses in animals
Phylogeny of Heterobranchia
Photophysiology of kleptoplasts in Sacoglossa
Genome evolution of molluscs, especially Nudibranchia and Sacoglossa

Academic degrees

2014 PhD in Evolutionary Biology, University of Bonn, Germany
2010 Diploma in Biology, University of Bonn, Germany

Scientific activities

Postdoctoral Fellowship (BPD): 01.09.2016 - 31.01.2019

Associate editor for Frontiers in Ecology and Evolution | Coevolution

Publications

Projects

Scientific Supervision

Master (Main Supervisor): Quirin Luppa (not a CESAM member)

Master (Main Supervisor): Jenny Melo (not a CESAM member)

Bachelor (Main Supervisor): Corinna Sickinger (not a CESAM member)

Bachelor (Main Supervisor): Laura Pütz (not a CESAM member)

Teaching

WS/2017 „Photosynthetic symbiosis in animals“ seminar for Master students, Rheinische Friedrich-Wilhelms-Universität, Bonn


WS/2016 „Photosynthetic symbiosis in animals“ seminar for Master students, Rheinische Friedrich-Wilhelms-Universität, Bonn


SS/2016 „Physiologie und Biochemie der Pflanzen - Photosynthese (Bio 280)“, Bachelor course, Heinrich-Heine-Universität, Düsseldorf


SS/2014 „Biology and ecology of the mediterranean littoral“,  Masters course, Zoologisches Forschungsmuseum Alexander Koenig, Bonn


SS/2011 „Biology and ecology of the mediterranean littoral“,  Masters course, Zoologisches Forschungsmuseum Alexander Koenig, Bonn


SS/2010 „Biology and ecology of the mediterranean littoral“,  Masters course, Zoologisches Forschungsmuseum Alexander Koenig, Bonn 


WS/2009„Morphologie und Evolution der Tiere (BP02)“, Bachelor course, Rheinische Friedrich-Wilhelms-Universität, Bonn

Curriculum vitea

since 09/2016 PostDoctoral Researcher, Center for Environmental and Marine Studies (CESAM), Universidade Aveiro, Portugal, Prof. João Serôdio


since 2016 visiting Professor at the Zoological Research Museum Alexander Koenig, Bonn, Germany


07/2014 - 08/2016 PostDoctoral Researcher, Institute for Molekular Evolution, Prof. William Martin, Heinrich-Heine-Universität Düsseldorf


07/2011 – 06/2014 PhD student, Zoologisches Forschungsmuseum Alexander Koenig, Bonn, Prof. Heike Wägele. Thesis: „Evolution of chloroplast sequestration in Sacoglossa (Mollusca, Gastropoda)“


05/2010 – 06/2011 Research Assistant, Institute for Molekular Evolution, Prof. William Martin, Heinrich-Heine-Universität Düsseldorf


09/2009 - 05/2010 Diploma student, Zoologisches Forschungsmuseum Alexander Koenig, Bonn, Prof. Heike Wägele. Thesis: „Identifikation von Nahrungsalgen in Sacoglossa (Mollusca, Gastropoda)”


0/2004 - 04/2009 Studies of Biology, Rheinische Friedrich-Wilhelms-Universität, Bonn


 

Photosymbioses in animals

Genome adaptions to evolve photosymbioses


Photoautotrophy is restricted to bacteria, algae and plants; animals are heterotrophs. Yet, several animals establish a symbiosis with cyanobacteria or unicellular algae, the so-called photosymbiosis. The animals may thus benefit from the phototrophs mainly by receiving fixed carbon, the symbiont is sheltered and supplied with sufficient inorganic compounds. A functional unique system of photosymbiosis is found among Sacoglossa sea slugs. Numerous members of this small group of marine herbivores incorporate photosynthetic active plastids of their algae food source in cells of their own digestive glands. The ‚stolen plastids‘ (then referred to as kleptoplasts) are even kept active during weeks to months of starvation. Little is known about the mechanisms involved in plastid/symbiont recognition and maintenance, but research on corals revealed some promising insights. My research focuses on marine sea slugs of the Nudibranchia and the Sacoglossa. In particular, we want to understand


 


1.) Which genome adaptations evolved in photosymbiotic species that are absent in non-photosymbiotic ones?


2.) Are the genome adaptations in photosymbiotic Nudibranchia and Sacoglossa the same or evolved this convergent?


3.) Are the genome adaptations similar to those in other symbiotic animals, such as corals, sponges, flatworms or ascidia?


 


To address these question we are currently sequencing and assembling the genomes of Elysia viridis (Sacoglossa) and Berghia stephaniaea (Nudibranchia) using the Oxford Nanopore technique. In physiological studies we want to understand if the potential factors that we identify are indeed involved in the recognition and maintenance of photosymbiosis.


 


Elysia viridis - more than just a slimy slug


Elysia viridis is a polyphaous speices belonging to the Sacogloss and widely distributed along the Portuguese coast. Depending on the food source, the plastids are either functionally integrated into the slugs or not, while the morphology of the radula is adapted to the according food source (Rauch et al. 2018). Using E. viridis, we want to understand


1.) If and how fast plastid are replaced upon a food switch


2.) How and how fast the radula morphology changes


3.) If E. viridis is a monotypic species along the Portuguese coast


 


 


CESAM Funding: UIDP/50017/2020 + UIDB/50017/2020 + LA/P/0094/2020