JOLI · Using the jellyfish Clytia hemisphaerica to explore the first steps of meiosis by live-imaging.
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2019-05-01 → 2021-04-30
- EU contribution
- €196,708
- Participants
- 1
- Scheme
- MSCA-IF-EF-RI
Lines connect the coordinator with its partners.
Results in brief
Using the jellyfish Clytia hemisphaerica to explore the first steps of meiosis by live-imaging.
Meiosis is a fundamental biological process, producing viable high quality gametes is essential for the sexual propagation of most eukaryotic species. Basic research in the field of meiosis enables us to understand how gametes are made, and in turn to understand how and why disruptions in this process can lead to possible infertility, aneuploidy, and also developmental defects. Genetic recombination is a source of variation upon which evolutionary forces can act, but additionally meiosis itself is subject to evolutionary forces. While the progression of meiosis and many of the core components are highly conserved, there is considerable variation among species and even sexes within the same species. As with many other fields, current meiosis knowledge focuses predominantly on classical model systems, however by investigating these processes in new and diverse species, we are able to understand both the diversity of meiotic processes and also gain new insight into the genes and mechanisms that regulate these processes. Our research on Clytia hemisphaerica meiosis provides a crucial evolutionary comparative insight into meiosis in a non-bilaterian animal. The overall objective of this project was to provide a framework for investigating meiosis during oogenesis in Clytia by development of specific molecular tools and approaches to establish a spatiotemporal cartography of early meiotic events within the developing gonad. More specifically the aims were 1) To develop and deploy a variety of tools and methods to characterize early meiosis (in-situ hybridization for gene expression analysis and telomere detection, Clytia specific antibodies for key molecular actors of synapsis to allow their tracking by immunohistochemistry, vital dyes for live imaging), 2) To conduct pilot studies to explore possibilities live imaging of the Clytia gonad, and 3) to study of the function of spo11 in Clytia meiosis via the generation of CRISPR mutants.
Data: CORDIS, © European Union
Project objective
Oocyte production is a key feature of animal development, comprising a series of carefully regulated events. This project will exploit a new experimental model, the hydrozoan Clytia hemisphaerica, to analyse by live imaging approaches the entire process of oogenesis in isolated female gonads from stem cell to oocyte for the first time. Analyses will focus on early events largely inaccessible in existing animal models, covering the transition from mitotic proliferation of germ cell precursors to meiotic entry. Key events include homologous chromosome pairing, synaptonemal complex formation, and meiotic double strand break formation. Clytia gonads are optically clear, simply organised and maintain oocyte production for several days ex-vivo. The three specific project objectives are 1) to define the spatiotemporal progression of early oogenesis through molecular cartography of the different precursor pools and cell morphology characterisation; 2) to establish conditions for long term imaging, including development of fluorescent markers; 3) to address the function of the key enzyme Spo11 by combining live imaging with CRISPR-mediated gene knockout, monitoring the movements of homologous chromosomes during pairing and identifying the sites of synaptonemal complex polymerisation. This multifaceted project represents a thematic shift for the applicant and involves a new collaboration between expert labs with complementary strengths in developmental, molecular, and cellular biology. Two-way transfer of knowledge will enable the candidate to develop new skills (microscopy, live imaging, transgenics) whilst introducing her existing expertise with cnidarian biology and bioinformatics to the host labs. The project will improve understanding of the cellular and molecular dynamics of meiosis, establish a new experimental model for oogenesis studies, and provide the candidate with a solid foundation of complementary experience to fulfill her long term career objectives.
Original text from CORDIS.
Participants
- COLLEGE DE FRANCE · PARISCoordinatorFrance
Links
Data: CORDIS, © European Union