Developmental toxicity of pre-production plastic pellets affects a large swathe of invertebrate taxa.

Microplastics pose risks to marine organisms through ingestion, entanglement, and as carriers of toxic additives and environmental pollutants. Plastic pre-production pellet leachates have been shown to affect the development of sea urchins and, to some extent, mussels. The extent of those developmental effects on other animal phyla remains unknown.

Reaping the benefits of liquid handlers for high-throughput gene expression profiling in a marine model invertebrate.

Background: Modern high-throughput technologies enable the processing of a large number of samples simultaneously, while also providing rapid and accurate procedures. In recent years, automated liquid handling workstations have emerged as an established technology for reproducible sample preparation. They offer flexibility, making them suitable for an expanding range of applications.

A broad-taxa approach as an important concept in ecotoxicological studies and pollution monitoring.

Aquatic invertebrates play a pivotal role in (eco)toxicological assessments because they offer ethical, cost-effective and repeatable testing options. Additionally, their significance in the food chain and their ability to represent diverse aquatic ecosystems make them valuable subjects for (eco)toxicological studies. To ensure consistency and comparability across studies, international (eco)toxicology guidelines have been used to establish standardised methods and protocols for data collection, analysis and interpretation.

Transcriptional and proteomic analysis of the innate immune response to microbial stimuli in a model invertebrate chordate.

Inflammatory response triggered by innate immunity can act to protect against microorganisms that behave as pathogens, with the aim to restore the homeostatic state between host and beneficial microbes. As a filter-feeder organism, the ascidian is continuously exposed to external microbes that may be harmful under some conditions. In this work, we used transcriptional and proteomic approaches to investigate the inflammatory response induced by stimuli of bacterial (lipopolysaccharide -LPS- and diacylated lipopeptide - Pam2CSK4) and fungal (zymosan) origin, in juveniles at stage 4 of metamorphosis.

Application of transcriptome profiling to inquire into the mechanism of nanoplastics toxicity during Ciona robusta embryogenesis.

The growing concern on nanoplastics (<1 μm) impact on marine life has stimulated a significant amount of studies aiming to address ecotoxicity and disclose their mechanisms of action. Here, we applied an integrative approach to develop an Adverse Outcome Pathway (AOP) upon acute exposure to amino-modified polystyrene nanoparticles (PS-NH NPs, 50 nm), as proxy for nanoplastics, during the embryogenesis of the chordate Ciona robusta. Genes related to glutathione metabolism, immune defense, nervous system, transport by aquaporins and energy metabolism were affected by either concentration tested of 10 or 15 μg mL of PS-NH.

Short-Term Exposure to Nanoplastics Does Not Affect Bisphenol A Embryotoxicity to Marine Ascidian .

Plastic pollution is recognized as a global environmental threat and concern is increasing regarding the potential interactions of the smallest fragments, nanoplastics (1 µm), with either physical and chemical entities encountered in the natural environment, including toxic pollutants. The smallest size of nanoplastics (<100nm) rebounds to their safety associated with remarkable biological, chemical and physical reactivity that allow them to interact with cellular machinery by crossing biological barriers and causing damage to living beings. Recent findings on nanoplastic occurrence in marine coastal waters, including the Mediterranean Sea, leave open the question on their ability to act as a vector of other contaminants of emerging concerns (CECs) concomitantly released by wastewater treatment plants and reaching marine coastal waters.

A pan-metazoan concept for adult stem cells: the wobbling Penrose landscape.

Adult stem cells (ASCs) in vertebrates and model invertebrates (e.g. Drosophila melanogaster) are typically long-lived, lineage-restricted, clonogenic and quiescent cells with somatic descendants and tissue/organ-restricted activities.

Brain Sensory Organs of the Ascidian : Structure, Function and Developmental Mechanisms.

During evolution, new characters are designed by modifying pre-existing structures already present in ancient organisms. In this perspective, the Central Nervous System (CNS) of ascidian larva offers a good opportunity to analyze a complex phenomenon with a simplified approach. As sister group of vertebrates, ascidian tadpole larva exhibits a dorsal CNS, made up of only about 330 cells distributed into the anterior sensory brain vesicle (BV), connected to the motor ganglion (MG) and a caudal nerve cord (CNC) in the tail.

Stem cells of aquatic invertebrates as an advanced tool for assessing ecotoxicological impacts.

Environmental stressors are assessed through methods that quantify their impacts on a wide range of metrics including species density, growth rates, reproduction, behaviour and physiology, as on host-pathogen interactions and immunocompetence. Environmental stress may induce additional sublethal effects, like mutations and epigenetic signatures affecting offspring via germline mediated transgenerational inheritance, shaping phenotypic plasticity, increasing disease susceptibility, tissue pathologies, changes in social behaviour and biological invasions. The growing diversity of pollutants released into aquatic environments requires the development of a reliable, standardised and 3R (replacement, reduction and refinement of animals in research) compliant in vitro toolbox.

Toxicity of nanoplastics during the embryogenesis of the ascidian Ciona robusta (Phylum Chordata).

Nanoplastics are considered contaminants of emerging concern at the global scale. The recent evidence of their occurrence in seawater from the Mediterranean Sea calls for a thorough evaluation of their impact on marine life and in particular on vulnerable life stages such as planktonic embryos. Here, we investigated the impact of increasing nominal concentrations of 50 nm amino-modified (PS-NH) and 60 nm carboxy-modified (PS-COOH) polystyrene nanoparticles (PS NPs) on the embryonic development of the ascidian (phylum Chordata), a common benthic invertebrate living in Mediterranean coastal areas with the peculiarity of being an early chordate developmental model.

New approaches on the use of tunicates (Ciona robusta) for toxicity assessments.

After the accidental release of crude oil in marine environment, dispersants are applied on sea surface transferring oil into the water column where it can be broken down by biodegradation, thereby reducing potential pollution to coastal areas. Before they can be used in the wild, the ecotoxicity of such dispersants is usually evaluated with toxicity assays using algae, crustacean and fishes. Nowadays, there is a need to find alternative species to reduce the use of vertebrates both for ethical considerations and for reducing the cost of bioassays.

Sea as a color palette: the ecology and evolution of fluorescence.

Fluorescence and luminescence are widespread optical phenomena exhibited by organisms living in terrestrial and aquatic environments. While many underlying mechanistic features have been identified and characterized at the molecular and cellular levels, much less is known about the ecology and evolution of these forms of bioluminescence. In this review, we summarize recent findings in the evolutionary history and ecological functions of fluorescent proteins (FP) and pigments.

An indoor study of the combined effect of industrial pollution and turbulence events on the gut environment in a marine invertebrate.

Natural storms are able to determine reworking of seabed up to considerable depths and favour suspension of sediment-associated chemicals. Yet, a direct link between exposure to resuspended contaminants and the biological effects on marine organisms have to be fully established. We exposed adults of a suspension feeder, the ascidian Ciona robusta, to polluted sediment (e.

Transcriptional regulation of the Ciona Gsx gene in the neural plate.

The ascidian neural plate consists of a defined number of identifiable cells organized in a grid of rows and columns, representing a useful model to investigate the molecular mechanisms controlling neural patterning in chordates. Distinct anterior brain lineages are specified via unique combinatorial inputs of signalling pathways with Nodal and Delta-Notch signals patterning along the medial-lateral axis and FGF/MEK/ERK signals patterning along the anterior-posterior axis of the neural plate. The Ciona Gsx gene is specifically expressed in the a9.

Detection of long non-coding RNA homology, a comparative study on alignment and alignment-free metrics.

Background: Long non-coding RNAs (lncRNAs) represent a novel class of non-coding RNAs having a crucial role in many biological processes. The identification of long non-coding homologs among different species is essential to investigate such roles in model organisms as homologous genes tend to retain similar molecular and biological functions. Alignment-based metrics are able to effectively capture the conservation of transcribed coding sequences and then the homology of protein coding genes.

A comprehensive analysis of neurotrophins and neurotrophin tyrosine kinase receptors expression during development of zebrafish.

Neurotrophins (NTF) are a family of secreted nerve growth factors with affinity for tyrosine kinase (Ntrk) and p75 receptors. To fully understand the variety of developmental roles played by NTFs, it is critical to know when and where genes encoding individual ligands and receptors are transcribed. Identification of ntf and ntrk transcripts in zebrafish development remains to be fully characterized for further uncovering the potential function(s) of the NTF signal transduction pathway.

Evolutionary recruitment of flexible Esrp-dependent splicing programs into diverse embryonic morphogenetic processes.

Epithelial-mesenchymal interactions are crucial for the development of numerous animal structures. Thus, unraveling how molecular tools are recruited in different lineages to control interplays between these tissues is key to understanding morphogenetic evolution. Here, we study Esrp genes, which regulate extensive splicing programs and are essential for mammalian organogenesis.

Identification of long non-coding transcripts with feature selection: a comparative study.

Background: The unveiling of long non-coding RNAs as important gene regulators in many biological contexts has increased the demand for efficient and robust computational methods to identify novel long non-coding RNAs from transcripts assembled with high throughput RNA-seq data. Several classes of sequence-based features have been proposed to distinguish between coding and non-coding transcripts. Among them, open reading frame, conservation scores, nucleotide arrangements, and RNA secondary structure have been used with success in literature to recognize intergenic long non-coding RNAs, a particular subclass of non-coding RNAs.

Patterning of brain precursors in ascidian embryos.

In terms of their embryonic origins, the anterior and posterior parts of the ascidian central nervous system (CNS) are associated with distinct germ layers. The anterior part of the sensory vesicle, or brain, originates from ectoderm lineages following a neuro-epidermal binary fate decision. In contrast, a large part of the remaining posterior CNS is generated following neuro-mesodermal binary fate decisions.

A Rapid and Cheap Methodology for CRISPR/Cas9 Zebrafish Mutant Screening.

The introduction of new genome editing tools such as ZFNs, TALENs and, more recently, the CRISPR/Cas9 system, has greatly expanded the ability to knock-out genes in different animal models, including zebrafish. However, time and costs required for the screening of a huge number of animals, aimed to identify first founder fishes (F0), and then carriers (F1) are still a bottleneck. Currently, high-resolution melting (HRM) analysis is the most efficient technology for large-scale InDels detection, but the very expensive equipment demanded for its application may represent a limitation for research laboratories.

Ciona intestinalis as a marine model system to study some key developmental genes targeted by the diatom-derived aldehyde decadienal.

The anti-proliferative effects of diatoms, described for the first time in copepods, have also been demonstrated in benthic invertebrates such as polychaetes, sea urchins and tunicates. In these organisms PUAs (polyunsaturated aldehydes) induce the disruption of gametogenesis, gamete functionality, fertilization, embryonic mitosis, and larval fitness and competence. These inhibitory effects are due to the PUAs, produced by diatoms in response to physical damage as occurs during copepod grazing.

Mutation studies in ascidians: a review.

Historically, mutations have had a significant impact on the study of developmental processes and phenotypic evolution. Lesions in DNA are created by artificial methods or detected by natural genetic variation. Random mutations are then ascribed to genetic change by direct sequencing or positional cloning.

New insights into the evolution of metazoan tyrosinase gene family.

Tyrosinases, widely distributed among animals, plants and fungi, are involved in the biosynthesis of melanin, a pigment that has been exploited, in the course of evolution, to serve different functions. We conducted a deep evolutionary analysis of tyrosinase family amongst metazoa, thanks to the availability of new sequenced genomes, assessing that tyrosinases (tyr) represent a distinctive feature of all the organisms included in our study and, interestingly, they show an independent expansion in most of the analyzed phyla. Tyrosinase-related proteins (tyrp), which derive from tyr but show distinct key residues in the catalytic domain, constitute an invention of chordate lineage.