Eugene Bell Center for Regenerative Biology and Tissue Engineering

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https://hdl.handle.net/1912/4819

The ability of many animals to spontaneously regenerate their body parts has intrigued scientific observers for centuries. Although humans share the same basic genes and pathways, we have somehow lost these regenerative capacities, which leads to significant health costs. An understanding of tissue and organ regeneration in lower animals holds great promise for translating to medical treatments for serious human conditions, including spinal cord injury, diabetes, organ failure, and degenerative neural diseases such as Alzheimer’s.

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Browsing Eugene Bell Center for Regenerative Biology and Tissue Engineering by Subject "Annelida"
  • Article
    The Nereid on the rise: Platynereis as a model system
    (BMC, 2021-09-27) Ozpolat, B. Duygu ; Randel, Nadine ; Williams, Elizabeth A. ; Bezares-Calderón, Luis Alberto ; Andreatta, Gabriele ; Balavoine, Guillaume ; Bertucci, Paola Y. ; Ferrier, David E. K. ; Gambi, Maria Cristina ; Gazave, Eve ; Handberg-Thorsager, Mette ; Hardege, Jörg ; Hird, Cameron ; Hsieh, Yu-Wen ; Hui, Jerome ; Mutemi, Kevin Nzumbi ; Schneider, Stephan Q. ; Simakov, Oleg ; Vergara, Hernando M. ; Vervoort, Michel ; Jékely, Gáspár ; Tessmar-Raible, Kristin ; Raible, Florian ; Arendt, Detlev
    The Nereid Platynereis dumerilii (Audouin and Milne Edwards (Annales des Sciences Naturelles 1:195–269, 1833) is a marine annelid that belongs to the Nereididae, a family of errant polychaete worms. The Nereid shows a pelago-benthic life cycle: as a general characteristic for the superphylum of Lophotrochozoa/Spiralia, it has spirally cleaving embryos developing into swimming trochophore larvae. The larvae then metamorphose into benthic worms living in self-spun tubes on macroalgae. Platynereis is used as a model for genetics, regeneration, reproduction biology, development, evolution, chronobiology, neurobiology, ecology, ecotoxicology, and most recently also for connectomics and single-cell genomics. Research on the Nereid started with studies on eye development and spiralian embryogenesis in the nineteenth and early twentieth centuries. Transitioning into the molecular era, Platynereis research focused on posterior growth and regeneration, neuroendocrinology, circadian and lunar cycles, fertilization, and oocyte maturation. Other work covered segmentation, photoreceptors and other sensory cells, nephridia, and population dynamics. Most recently, the unique advantages of the Nereid young worm for whole-body volume electron microscopy and single-cell sequencing became apparent, enabling the tracing of all neurons in its rope-ladder-like central nervous system, and the construction of multimodal cellular atlases. Here, we provide an overview of current topics and methodologies for P. dumerilii, with the aim of stimulating further interest into our unique model and expanding the active and vibrant Platynereis community.
  • Article
    Segment number threshold determines juvenile onset of germline cluster expansion in Platynereis dumerilii
    (Wiley, 2021-11-18) Kuehn, Emily ; Clausen, David S. ; Null, Ryan W. ; Metzger, Bria M. ; Willis, Amy D. ; Ozpolat, B. Duygu
    Development of sexual characters and generation of gametes are tightly coupled with growth. Platynereis dumerilii is a marine annelid that has been used to study germline development and gametogenesis. P. dumerilii has germ cell clusters found across the body in the juvenile worms, and the clusters eventually form the gametes. Like other segmented worms, P. dumerilii grows by adding new segments at its posterior end. The number of segments reflect the growth state of the worms and therefore is a useful and measurable growth state metric to study the growth-reproduction crosstalk. To understand how growth correlates with progression of gametogenesis, we investigated germline development across several developmental stages. We discovered a distinct transition period when worms increase the number of germline clusters at a particular segment number threshold. Additionally, we found that keeping worms short in segment number, by manipulating environmental conditions or via amputations, supported a segment number threshold requirement for germline development. Finally, we asked if these clusters in P. dumerilii play a role in regeneration (as similar free-roaming cells are observed in Hydra and planarian regeneration) and found that the clusters were not required for regeneration in P. dumerilii, suggesting a strictly germline nature. Overall, these molecular analyses suggest a previously unidentified developmental transition dependent on the growth state of juvenile P. dumerilii leading to substantially increased germline expansion.