A5046392140- Marine Invertebrate Physiology and Ecology
- Marine Ecology and Invasive Species
- Protist diversity and phylogeny
- Hippo pathway signaling and YAP/TAZ
- Reproductive Biology and Fertility
- Microtubule and mitosis dynamics
- Planarian Biology and Electrostimulation
- Sperm and Testicular Function
- Genetic and Kidney Cyst Diseases
- Neurobiology and Insect Physiology Research
- Genetics, Aging, and Longevity in Model Organisms
- Evolutionary Game Theory and Cooperation
- Single-cell and spatial transcriptomics
- Reproductive biology and impacts on aquatic species
- 3D Printing in Biomedical Research
- Barrier Structure and Function Studies
- Developmental Biology and Gene Regulation
- Zebrafish Biomedical Research Applications
- Parasite Biology and Host Interactions
- Nuclear Structure and Function
Sorbonne Université
2003-2024
Laboratoire de Biologie du Développement de Villefranche-sur-Mer
2009-2024
Centre National de la Recherche Scientifique
2003-2024
Institut de la Mer de Villefranche
2003-2020
Laboratoire d’Océanographie de Villefranche
2003
Abstract Jellyfish (medusae) are a distinctive life-cycle stage of medusozoan cnidarians. They major marine predators, with integrated neurosensory, muscular and organ systems. The genetic foundations this complex form largely unknown. We report the draft genome hydrozoan jellyfish Clytia hemisphaerica use multiple transcriptomes to determine gene across stages. Medusa, planula larva polyp each characterized by distinct transcriptome signatures reflecting abrupt transitions all deploy...
Whole-organism perturbations reveal single-cell responses across the Clytia medusa.
We have used Digital Gene Expression analysis to identify, without bilaterian bias, regulators of cnidarian embryonic patterning. Transcriptome comparison between un-manipulated Clytia early gastrula embryos and ones in which the key polarity regulator Wnt3 was inhibited using morpholino antisense oligonucleotides (Wnt3-MO) identified a set significantly over under-expressed transcripts. These code for candidate Wnt signaling modulators, orthologs other transcription factors, secreted...
The reproductive hormones that trigger oocyte meiotic maturation and release from the ovary vary greatly between animal species. Identification of receptors for these maturation-inducing (MIHs) understanding how they initiate largely conserved process remain important challenges. In hydrozoan cnidarians including jellyfish Clytia hemisphaerica, MIH comprises neuropeptides released somatic cells gonad. We identified receptor (MIHR) in using cell culture–based "deorphanization" candidate...
Jellyfish, with their tetraradial symmetry, offer a novel paradigm for addressing patterning mechanisms during regeneration. Here we show that an interplay between mechanical forces, cell migration and proliferation allows jellyfish fragments to regain shape functionality rapidly, notably by efficient restoration of the central feeding organ (manubrium). Fragmentation first triggers actomyosin-powered remodeling restores body umbrella shape, causing radial smooth muscle fibers converge...
The jellyfish species Clytia hemisphaerica (Cnidaria, Hydrozoa) has emerged as a new experimental model animal in the last decade. Favorable characteristics include fully transparent body suitable for microscopy, daily gamete production and relatively short life cycle. Furthermore, whole genome sequence assembly efficient gene editing techniques using CRISPR/Cas9 have opened possibilities genetic studies. quasi-immortal vegetatively-growing polyp colony stage provides practical means to...
The atypical protein kinase C (aPKC) is part of the conserved aPKC/PAR6/PAR3 complex, which regulates many cell polarity events, including formation a primary cilium at apical surface epithelial cells. Cilia are highly organized, conserved, microtubule-based structures involved in motility, sensory processes, signaling, and polarity. We examined distribution function aPKC sea urchin embryo, forms swimming blastula covered with motile cilia. found that early embryo uniformly cortical becomes...
We have used complementary biochemical and in vivo approaches to study the compartmentalization of M phase-promoting factor (MPF) prophase Xenopus eggs oocytes. first examined distribution MPF (Cdc2/CyclinB2) membranous organelles high-speed extracts made during mitotic prophase. These were found lack mitochondria, Golgi membranes, most endoplasmic reticulum (ER) but contain bulk pre-MPF pool. This could be pelleted by further centrifugation along with components necessary activate it. On...
Poc1 (Protein of Centriole 1) proteins are highly conserved WD40 domain-containing centriole components, well characterized in the alga Chlamydomonas, ciliated protazoan Tetrahymena, insect Drosophila and vertebrate cells including Xenopus zebrafish embryos. Functions localizations related to ciliary axoneme have been demonstrated for a range species. The protein has also reported show an additional association with mitochondria, enrichment specialized "germ plasm" region oocytes. We...
Abstract We present an organism-wide, transcriptomic cell atlas of the hydrozoan medusa Clytia hemisphaerica , and determine how its component types respond to starvation. Utilizing multiplexed scRNA-seq, in which individual animals were indexed pooled from control perturbation conditions into a single sequencing run, we avoid artifacts batch effects are able discern shifts state response organismal perturbations. This work serves as foundation for future studies development, function,...
Jellyfish (medusae) are a distinctive life-cycle stage of medusozoan cnidarians. They major marine predators, with integrated neurosensory, muscular and organ systems. The genetic foundations this complex form largely unknown. We report the draft genome hydrozoan jellyfish Clytia hemisphaerica use multiple transcriptomes to determine gene across stages. Medusa, planula larva polyp each characterised by distinct transcriptome signatures reflecting abrupt life cycle transitions, all deploy...
Abstract The jellyfish species Clytia hemisphaerica (Cnidaria, Hydrozoa) has emerged as a new experimental model animal in the last decade. Favorable characters include fully transparent body suitable for microscopy, daily gamete production and relatively short life cycle. Furthermore, whole genome sequence assembly efficient gene editing techniques using CRISPR/Cas9 have opened possibilities genetic studies. quasi-immortal vegetatively-growing polyp colony stage provides practical means to...
ABSTRACT cAMP-PKA signaling initiates the crucial process of oocyte meiotic maturation in many animals, but inhibits it vertebrates. To address this ‘cAMP paradox’, we exchanged key PKA substrate ARPP19 between representative species, vertebrate Xenopus and cnidarian Clytia, comparing its phosphorylation function. We found that, as Xenopus, Clytia maturing oocytes undergo on a highly conserved Gwl site, which PP2A promotes M-phase entry. In contrast, despite signature motif recognizable...
Abstract The cnidarian “planula” larva shows radial symmetry around a polarized, oral-aboral, body axis and comprises two epithelia cell layers, ectodermal endodermal. This simple plan is set up during gastrulation, process which proceeds by variety of modes amongst the diverse species. In hydrozoan laboratory model Clytia hemisphaerica, gastrulation involves termed unipolar ingression, in endoderm derives from mass ingression individual cells via epithelial-mesenchymal transition (EMT)...
Abstract The reproductive hormones that trigger oocyte meiotic maturation and release from the ovary vary greatly between animal species. Identification of receptors for these Maturation Inducing Hormones (MIHs), understanding how they initiate largely conserved process, remain important challenges. In hydrozoan cnidarians including jellyfish Clytia hemisphaerica , MIH comprises neuropeptides released somatic cells gonad. We identified receptor (MIHR) in using cell culture-based...
Abstract Clytia hemisphaerica jellyfish, with their tetraradial symmetry, offer a novel paradigm for addressing patterning mechanisms during regeneration. Here we show that an interplay between mechanical forces, cell migration and proliferation allows jellyfish fragments to regain shape functionality rapidly, notably by efficient restoration of the central feeding organ (manubrium). Fragmentation first triggers actomyosin-powered remodeling restores body umbrella shape, causing radial...
ABSTRACT In many animal species, elevated cAMP-PKA signaling initiates oocyte meiotic maturation upon hormonal stimulation, whereas in vertebrates, it acts as a negative regulator of this process. To address “cAMP paradox”, we have focused on ARPP19 proteins. Dephosphorylation Xenopus specific PKA site has been identified key step initiating maturation. We first tracked evolution the phosphorylation site, revealing that appeared early during emergence metazoans. This contrasts with strong...