About
235
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Introduction
Additional affiliations
January 2012 - present
Aix-Marseille Université, CNRS
Position
- Senior Researcher
January 2007 - December 2011
Aix-Marseille Université
Position
- Researcher
January 1997 - December 2013
Publications
Publications (235)
Niche partitioning studies are essential to understand the mechanisms that allow ecologically similar species to coexist. The Rhone streber (Zingel asper) and the European bullhead
(Cottus gobio) are both benthic riverine fishes that consume macroinvertebrates. Both species are
protected under European legislature. We focused on trophic niche parti...
Actin is a fundamental member of an ancient superfamily of structural intracellular proteins and plays a crucial role in cytoskeleton dynamics, ciliogenesis, phagocytosis, and force generation in both prokaryotes and eukaryotes. It is shown that actin has another function in metazoans: patterning biosilica deposition, a role that has spanned over 5...
Potential for, and limits to, adaptation to environmental changes are critical for resilience and risk mitigation. The Mediterranean basin is a mosaic of biodiversity-rich ecosystems long affected by human influence, whose resilience is now questioned by climate change. After reviewing the different components of biological adaptation, we present t...
Tissues of multicellular animals are maintained due to a tight balance between cell proliferation and programmed cell death. Sponges are early branching metazoans essential to understanding the key mechanisms of tissue homeostasis. This article is dedicated to the comparative analysis of proliferation and apoptosis in intact tissues of two sponges,...
Carnivorous sponges (family Cladorhizidae) lack the aquiferous system and choanocytes and, therefore, their reproduction and in particular spermatogenesis is unusual for Porifera. We studied spermatogenesis in a carnivorous sponge Lycopodina hypogea using confocal microscopy, SEM and TEM. In brief, spermatogenesis in L. hypogea proceeds as follows....
Sponges (phylum Porifera) are early-branching animals, whose outwardly simple body plan is underlain by a complex genetic repertoire. The transition from a mobile larva to an attached filter-feeding organism occurs by metamorphosis, a process accompanied by a radical change of the body plan and cell transdifferentiation. The continuity between larv...
Stem cells (SCs) in vertebrates typically reside in “stem cell niches” (SCNs), morphologically restricted tissue microenvironments that are important for SC survival and proliferation. SCNs are broadly defined by properties including physical location, but in contrast to vertebrates and other “model” organisms, aquatic invertebrate SCs do not have...
Sponges (phylum Porifera) are highly specialized filter-feeding metazoans, pumping and filtering water with a network of canals and chambers, the aquiferous system. Most sponges have a leuconoid aquiferous system, characterized by choanocytes organized in small spherical chambers connected with ambient water by a complex net of canals. Such organiz...
Details of spermatogenesis and sperm organization are often useful for reconstructing the phylogeny of closely related taxa of invertebrates. Here, the spermiogenesis and the ultrastructure of sperm were studied in two marine demosponges, Crellomima imparidens and Hymedesmia irregularis (order Poecilosclerida). In C. imparidens and H. irregularis w...
Sponges (Porifera), basal nonbilaterian metazoans, are well known for their high regenerative capacities ranging from reparation of a lost body wall to whole-body regeneration from a small piece of tissues or even from dissociated cells. Sponges from different clades utilize different cell sources and various morphological processes to complete the...
Although Bonellia viridis is the best studied echiurid species, many features of its anatomy and ultrastructure are still unclear. Detailed data on the organisation of the proboscis may help us to understand the echiurid biology and some aspects of their feeding behaviour. In this study, a detailed description of the proboscis epithelium of females...
Background
Tissues of multicellular animals are maintained due to a tight balance between cell proliferation and programmed cell death. Phylum Porifera is an early branching group of metazoans essential to understanding the key mechanisms of tissue homeostasis. This paper is dedicated to the comparative analysis of proliferation and apoptosis in in...
The morphological investigation of the larval development in a White-Sea sponge, Iophon piceus (Vosmaer, 1882) (the family Myxillidae), was carried out. The differentiation of larval structures begins with the morula stage. The larval surface epithelium develops from the embryo peripheral cells. Numerous folds of epithelium are formed during the la...
Background
The ability to regenerate lost or damaged body parts is an ancient animal characteristic with a wide yet variable distribution across all phyla. Sponges, likely the sister group to all other animals, have remarkable regenerative abilities including whole body regeneration and re-development from dissociated cells. The calcareous sponge S...
The phenomenon of whole-body regeneration means rebuilding of the whole body of an animal from a small fragment or even a group of cells. In this process, the old axial relationships are often lost, and new ones are established. An amazing model for studying this process is sponges, some of which are able to regenerate into a definitive organism af...
Porifera, commonly named sponges, are devoid of head, digestive tract, nervous system, muscles or any other organs. Despite this anatomical and morphological simplicity, they are true animals or metazoans. Sponges are a successful group of mostly marine filter feeders that represent a major life form of several aquatic ecosystems. Efficient water f...
Alexander O. Kowalevsky (1840–1901), a founder of cellular and comparative evolutionary embryology, was one of the most prominent biologists of the nineteenth century. He worked at the intersection of zoology, embryology, and evolution. His studies on the lancelet, tunicates, insects, and germ layer homologies pioneered comparative embryology and c...
While virtually all animals show certain abilities for regeneration after an injury, these abilities vary greatly among metazoans. Porifera (Sponges) is basal metazoans characterized by a wide variety of different regenerative processes, including whole-body regeneration (WBR). Considering phylogenetic position and unique body organization, sponges...
Sponges (Porifera) belong to an ancient metazoan lineage that represents one of the earliest branches of the animal tree. The superficial region of the sponge body is devoid of choanocyte chambers (which are a component of the aquiferous system) and referred to as the ectosome. Sponges from classes Calcarea, Demospongiae, and Homoscleromorpha have...
Dietary studies are critical for understanding foraging strategies and have important applications in conservation and habitat management. We applied a robust metabarcoding protocol to characterize the diet of the critically endangered freshwater fish Zingel asper and conducted modelling and simulation analyses to characterize and identify some of...
Spicules are mineral-based biocomposites skeletal structures that are widely distributed among phylogenetically distant groups of invertebrates (Porifera, Cnidaria, Mollusca, Echinodermata). Subepidermal spicules are formed under the ectodermal epithelium and are characterized for all groups except mollusks (Aplacophora, Polyplacophora, Bivalvia),...
The structure of the kinetid (flagellar or ciliary apparatus) is known to be of phylogenetic significance in sponges (Phylum Porifera) and can provide information about evolutionary relationships. Here, we report on the larval kinetid structure of two closely related species, Oscarella lobularis and O. tuberculata (Homoscleromorpha, Oscarellidae)....
Homoscleromorpha is a recently recognized class within the phylum Porifera. While molecular analyses support monophyly of Homoscleromorpha, morphological data are largely lacking. Here, we investigate and comparatively analyze the detailed morphology of kinetids (flagellar apparatus) in choanocytes of ten Oscarella species. The kinetid is known to...
[Full text here: https://rdcu.be/b7qrv] The kinetid (flagellar/ciliary apparatus) of eukaryotic cells is an important source of phylogenetic information. It was found to be a prospective morphological phylogenetic marker in sponges, since its arrangement in choanocytes is congruent with the topology of the phylogenetic trees. However, investigation...
The comparative study of the four non-bilaterian phyla (Cnidaria, Placozoa, Ctenophora, Porifera) should provide insights into the origin of bilaterian traits. Except for Cnidaria, present knowledge on the cell biology and development of these animals is so far limited. Non-bilaterian models are needed to get further into cell architecture and mole...
Although Arctic communities are very sensitive to global warming, direct evidence of the effects of high temperature on bottom communities is quite rare. We observed a mass mortality event (MME) of sponges by SCUBA diving in July and August 2018 along the coasts of Kandalaksha Bay, White Sea, and sub-Arctic. This event severely affected sponges fro...
Fabrication of biomimetic materials and scaffolds is usually a micro- or even nanoscale process; however, most testing and all manufacturing require larger-scale synthesis of nanoscale features. Here, we propose the utilization of naturally prefabricated three-dimensional (3D) spongin scaffolds that preserve molecular detail across centimeter-scale...
[Full text here: https://rdcu.be/bntId] At larval and adult stage of life cycle, sponges (Porifera) have different flagellated cells that play different roles in their body. The larval epithelium cells serve as locomotion organs, while adult collar cells (choanocytes) have a feeding function. Here, for the first time, we describe detailed structure...
The genus Hemimysis (Malacostraca: Mysida: Mysidae) encompasses near-bottom, demersal and cave-dwelling mysids living in the marine, brackish and freshwater habitats around the European coast, from the Caspian Sea to the Scandinavian Peninsula. We conducted cladistic analysis of 52 morphological characters of all nine species and three subspecies o...
Sponges (Porifera) represent one of the most ancient metazoan lineages. They possess unique anatomical and tissue structure, making them promising models for evolutionary studies. The high plasticity of sponge tissue and cells provide them with outstanding recovery abilities, ranging from wound healing to re-building of a functional body from disso...
The spermatogenesis of Porifera is still relatively poorly understood. In the past, it was accepted that all species presented a primitive-type spermatozoon, lacking special structures and acrosome. Nonetheless, a very peculiar spermatogenesis resulting in a sophisticated V-shaped spermatozoon with an acrosome was found in Poecilosclerida. This fin...
Sponges are a valuable source of natural compounds and biomaterials for many biotechnological applications. Marine sponges belonging to the order Verongiida are known to contain both chitin and biologically active bromotyrosines. Aplysina archeri (Aplysineidae: Verongiida) is well known to contain bromotyrosines with relevant bioactivity against hu...
Cell-to-cell signaling is responsible for regulation of many developmental processes such as proliferation, cell migration, survival, cell fate specification and axis patterning. In this article we discussed the role of signaling in the metamorphosis of sponges with a focus on epithelial–mesenchymal transition (EMT) accompanying this event. Sponges...
Sponges are the most ancient multicellular animals. They demonstrate broad recovery abilities after various wounds, and due to their phylogenetic position, studies of repair processes in sponges are required for understanding the evolution of the regeneration mechanisms in animals. We studied the reparative regeneration in two widely distributed sp...
Porifera represents one of the most diverse taxon of sessile invertebrates with over 9 000 extant species. Calcareous sponges of the genus Leucosolenia are an emerging model object for evolutionary developmental biology studies. However, recent studies on the class Calcarea, and in particular on the subclass Calcaronea, indicates the presence of hi...
Sponges (Porifera) demonstrate prominent regeneration abilities and possess a wide variety of mechanisms, used during this process. In the current study, we combined in vivo observations with histological, immunohistochemical, and ultrastructural technics to elucidate the fine cellular mechanisms of the regeneration in the calcareous sponge Leucoso...
VideoS1. The growth of the regenerative membrane during the oscular regeneration of Leucosolenia cf. variabilis. Stopwatch indicates hours, minutes and seconds. Red arrows mark the position of the regenerative membrane internal rim, white cycle – the moment and position of the regenerative membrane closure.
rm – regenerative membrane; we – wound ed...
Supplemental Figure 1. In vivo images of Leucosolenia cf. variabilis body wall regeneration. A – just after surgical operation. B – 10 hours post operation (hpo). C – regenerative membrane formation (24 hpo). D – beginning of new spicule formation in the regenerative membrane (48 hpo). E – beginning of normal body wall restoration (96 hpo). F – end...
The Mediterranean basin is a region of high biodiversity, marine and terrestrial, with important endemism. This diversity has faced long-lasting, strong and increasing human demographic pressure. The relatively more recent effects of climate change are well visible in the Mediterranean basin, with for example, heat wave and summer-drought related m...
Sponges are the earliest branching metazoans, and as such a key group for understanding of the evolutionary history of animal regeneration mechanisms. Sponges are known to possess remarkable reconstitutive and regenerative abilities. We investigated regeneration of Leucosolenia complicata, an abundant and broadly distributed in White Sea species. W...