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ELife Oct 2023The larvae of an annelid worm use nitric oxide signalling to activate the neural pathways needed to swim away from the harmful ultraviolet light of the sun.
The larvae of an annelid worm use nitric oxide signalling to activate the neural pathways needed to swim away from the harmful ultraviolet light of the sun.
Topics: Animals; Polychaeta; Ultraviolet Rays; Annelida; Larva; Signal Transduction
PubMed: 37850625
DOI: 10.7554/eLife.92535 -
Biology Jul 2023The annelid genus occurs in all major oceans but is best represented in the shallow depths of warmer waters, where it lives in elaborately decorated tubes. This paper... (Review)
Review
The annelid genus occurs in all major oceans but is best represented in the shallow depths of warmer waters, where it lives in elaborately decorated tubes. This paper provides an introduction to the animals, discussing their history and diversity. We describe and illustrate its morphology and geographic distribution. While they were thought to be predominantly gonochoristic, recent reproductive studies show that several species are protandric simultaneous hermaphrodites. Development is by broadcast spawning with a brief pelagic stage or direct development in the parental tube or egg mass attached to it. is a key ecosystem engineer, altering water flow and deposition and increasing the availability of refugia. We also discuss its harvesting as fishing bait, its role as an alien or introduced species, its capacity to regenerate, its therapeutic potential, and its applications as a bioindicator species for climate change, geographic distribution changes, and dispersal.
PubMed: 37508456
DOI: 10.3390/biology12071027 -
General and Comparative Endocrinology Aug 2024Estrogen receptors (ERs) are thought to be the ancestor of all steroid receptors and are present in most lophotrochozoans studied to date, including molluscs, annelids,... (Review)
Review
Estrogen receptors (ERs) are thought to be the ancestor of all steroid receptors and are present in most lophotrochozoans studied to date, including molluscs, annelids, and rotifers. A number of studies have investigated the functional role of estrogen receptors in invertebrate species, although most are in molluscs, where the receptor is constitutively active. In vitro experiments provided evidence for ligand-activated estrogen receptors in annelids, raising important questions about the role of estrogen signalling in lophotrochozoan lineages. Here, we review the concordant and discordant evidence of estradiol receptor signalling in lophotrochozoans, with a focus on annelids and rotifers. We explore the de novo synthesis of estrogens, the evolution and expression of estrogen receptors, and physiological responses to activation of estrogen receptors in the lophotrochozoan phyla Annelida and Rotifera. Key data are missing to determine if de novo biosynthesis of estradiol in non-molluscan lophotrochozoans is likely. For example, an ortholog for the CYP11 gene is present, but confirmation of substrate conversion and measured tissue products is lacking. Orthologs CYP17 and CYP19 are lacking, yet intermediates or products (e.g. estradiol) in tissues have been measured. Estrogen receptors are present in multiple species, and for a limited number, in vitro data show agonist binding of estradiol and/or transcriptional activation. The expression patterns of the lophotrochozoan ERs suggest developmental, reproductive, and digestive roles but are highly species dependent. E exposures suggest that lophotrochozoan ERs may play a role in reproduction, but no strong dose-response relationship has been established. Therefore, we expect most lophotrochozoan species, outside of perhaps platyhelminths, to have an ER but their physiological role remains elusive. Mining genomes for orthologs gene families responsible for steroidogenesis, coupled with in vitro and in vivo studies of the steroid pathway are needed to better assess whether lophotrochozoans are capable of estradiol biosynthesis. One major challenge is that much of the data are divided across a diversity of species. We propose that the polychaetes Capitella teleta or Platyneris dumerilii, and rotifer Brachionus manjavacas may be strong species choices for studies of estrogen receptor signalling, because of available genomic data, established laboratory culture techniques, and gene knockout potential.
Topics: Animals; Signal Transduction; Receptors, Estradiol; Annelida; Receptors, Estrogen; Rotifera; Estradiol
PubMed: 38677339
DOI: 10.1016/j.ygcen.2024.114519 -
Nature Communications Sep 2023Earthworms are critical soil ecosystem engineers that support plant growth in numerous ways; however, their contribution to global agricultural production has not been...
Earthworms are critical soil ecosystem engineers that support plant growth in numerous ways; however, their contribution to global agricultural production has not been quantified. We estimate the impacts of earthworms on global production of key crops by analyzing maps of earthworm abundance, soil properties, and crop yields together with earthworm-yield responses from the literature. Our findings indicate that earthworms contribute to roughly 6.5% of global grain (maize, rice, wheat, barley) production and 2.3% of legume production, equivalent to over 140 million metric tons annually. The earthworm contribution is especially notable in the global South, where earthworms contribute 10% of total grain production in Sub-Saharan Africa and 8% in Latin America and the Caribbean. Our findings suggest that earthworms are important drivers of global food production and that investment in agroecological policies and practices to support earthworm populations and overall soil biodiversity could contribute greatly to sustainable agricultural goals.
Topics: Animals; Oligochaeta; Ecosystem; Investments; Vegetables; Crops, Agricultural; Edible Grain
PubMed: 37752110
DOI: 10.1038/s41467-023-41286-7 -
Molecular Phylogenetics and Evolution Aug 2023Polynoidae is the most diverse radiation of Aphroditiformia and one of the most successful groups of all Annelida in terms of diversity and habitats colonized. With such...
Polynoidae is the most diverse radiation of Aphroditiformia and one of the most successful groups of all Annelida in terms of diversity and habitats colonized. With such an unmatched diversity, phylogenetic investigations have struggled to understand their evolutionary relationships. Previous phylogenetic analyses have slowly increased taxon sampling and employed methodologies, but despite their diversity and biological importance, large genomic sampling is limited. To investigate the internal relationships within Polynoidae, we conducted the first phylogenomic analyses of the group based on 12 transcriptomes collected from species inhabiting a broad array of habitats, including shallow and deep waters, as well as hydrothermal vents, anchialine caves and the midwater. Our phylogenomic analyses of Polynoidae recovered congruent tree topologies representing the clades Polynoinae, Macellicephalinae and Lepidonotopodinae. Members of Polynoinae and Macellicephalinae clustered in well-supported and independent clades. In contrast, Lepidonotopodinae taxa were always recovered nested within Macellicephalinae. Though our sampling only covers a small proportion of the species known for Polynoidae, our results provide a robust phylogenomic framework to build from, emphasizing previously hypothesized relationships between Macellicephalinae and Lepidonotopodinae taxa, while providing new insights on the origin of enigmatic cave and pelagic lineages.
Topics: Animals; Phylogeny; Transcriptome; Annelida; Polychaeta; Biological Evolution
PubMed: 37169231
DOI: 10.1016/j.ympev.2023.107811 -
Trends in Neurosciences Sep 2023Leeches display robust motor patterns and exhibit a relatively simple nervous system where neurons are unambiguously identified. This brief article focuses on Hirudo...
Leeches display robust motor patterns and exhibit a relatively simple nervous system where neurons are unambiguously identified. This brief article focuses on Hirudo verbana and summarizes how research in this organism has contributed to insights in the field of motor control, where networks have been studied from population down to individual neuron perspectives.
Topics: Humans; Animals; Leeches; Neurons; Nervous System; Neural Networks, Computer
PubMed: 37422418
DOI: 10.1016/j.tins.2023.06.002 -
International Journal of Molecular... Jul 2023When attacks its prey, the prey bleeds profusely but feels little pain. We and other research teams have identified several anticoagulant molecules in the saliva of ,...
When attacks its prey, the prey bleeds profusely but feels little pain. We and other research teams have identified several anticoagulant molecules in the saliva of , but the substance that produces the paralyzing effect in is not known. In this study, we successfully isolated, purified, and identified a serine protease inhibitor containing an antistasin-like domain from the salivary secretions of . This peptide (named poeciguamerin) significantly inhibited elastase activity and slightly inhibited FXIIa and kallikrein activity, but had no effect on FXa, trypsin, or thrombin activity. Furthermore, poeciguamerin exhibited analgesic activity in the foot-licking and tail-withdrawal mouse models and anticoagulant activity in the FeCl-induced carotid artery thrombosis mouse model. In this study, poeciguamerin was found to be a promising elastase inhibitor with potent analgesic and antithrombotic activity for the inhibition of pain and thrombosis after surgery or in inflammatory conditions.
Topics: Animals; Mice; Leeches; Serine Proteinase Inhibitors; Serpins; Anticoagulants; Thrombosis; Pancreatic Elastase; Analgesics; Pain
PubMed: 37446275
DOI: 10.3390/ijms241311097 -
Advanced Science (Weinheim,... Jun 2024Earthworms are fascinating animals capable of crawling and burrowing through various terrains using peristaltic motion and the directional friction response of their...
Earthworms are fascinating animals capable of crawling and burrowing through various terrains using peristaltic motion and the directional friction response of their epidermis. Anisotropic anchoring governed by tiny appendages on their skin called setae is known to enhance the earthworm's locomotion. A multi-material fabrication technique is employed to produce soft skins with bristles inspired by the earthworm epidermis and their setae. The effect of bristles arranged in triangular and square grids at two spatial densities on the locomotion capability of a simple soft crawling robot comprised of an extending soft actuator covered by the soft skin is investigated experimentally. The results suggest that the presence of bristles results in a rostral to caudal friction ratio of µ/µ > 1 with some variations across bristle arrangements and applied elongations. Doubling the number of bristles increases the robot's speed by a factor of 1.78 for the triangular grid while it is less pronounced for the rectangular grid with a small factor of 1.06. Additionally, it is observed that increasing the actuation stroke for the skin with the high-density triangular grid, from 15% to 30%, elevates the speed from 0.5 to 0.9 mm s, but further increases in stroke to 45% may compromise the durability of the actuators with less gains in speed (1 mm s). Finally, it is demonstrated that a crawling robot equipped with soft skin can traverse both a linear and a curved channel.
Topics: Oligochaeta; Robotics; Animals; Locomotion; Equipment Design
PubMed: 38622890
DOI: 10.1002/advs.202400012 -
Advanced Materials (Deerfield Beach,... Sep 2023Natural earthworm with the ability to loosen soils that favors sustainable agriculture has inspired worldwide interest in the design of intelligent actuators. Given the...
Natural earthworm with the ability to loosen soils that favors sustainable agriculture has inspired worldwide interest in the design of intelligent actuators. Given the inability to carry heavy loads and uncontrolled deformation, the vast majority of actuators can only perform simple tasks by bending, contraction, or elongation. Herein, a degradable actuator with the ability to deform in desired ways is presented, which successfully mimics the burrowing activities of earthworms to loosen soils with increased soil porosity by digging, grabbing, and lifting the soil when it receives rains. Such a scarifying actuator is made of degradable cellulose acetate and uncrosslinked polyacrylamide via the swelling-photopolymerizing method. The water absorption of polyacrylamide in moisture conditions causes rapid and remarkable bending. Such mechanical bending can be controlled in specific areas of the cellulose acetate film if polyacrylamide is polymerized in a patterned way, so as to generate complicated deformations of the whole cellulose acetate. Patterning polyacrylamide within cellulose acetate is achieved based on reversible surface protection by means of pen writing, rather than the traditional masking techniques. The water-induced deformation of programmable cellulose-based actuators is well preserved in soil, which is appropriate for promoting rain diffusion as well as root breath.
Topics: Animals; Oligochaeta; Water; Polymerization; Soil
PubMed: 37226690
DOI: 10.1002/adma.202303805 -
Zoology (Jena, Germany) Oct 2023Ovaries in earthworms belonging to the family Megascolecidae are paired structures attached to the septum in the anterior part of the XIII segment. They are fan to...
Ovaries in earthworms belonging to the family Megascolecidae are paired structures attached to the septum in the anterior part of the XIII segment. They are fan to rosette shaped with numerous rows of growing oocytes, known as egg strings, radiating from the ovary center towards the segmental cavity. The histological and ultrastructural ovary organization in megascolecids and the course of oogenesis remain unknown. The paper presents the results of light and electron microscopy analyses of ovaries in six megascolecid species, three from the genus Amynthas and three from Metaphire. Both parthenogenetic and sexually reproducing species were included in the study. The organization and ultrastructure of ovaries in all studied species are broadly similar. Considering the histological organization of ovaries, they could be divided into two zones. Zone I (proximal, close to the connection with the septum) is tightly packed with germline and somatic cells. Germ cells are interconnected via intercellular bridges and thin strands of the central cytoplasm (known as cytophore) and form syncytial cysts. Cysts unite oogonia, early meiotic cells (till diplotene), and clustering cells develop synchronously. During diplotene, interconnected cells lose developmental synchrony; most probably, one cell per cyst grows faster than others, detaches from the cysts, and becomes an oocyte. The remaining cells grow slightly and are still interconnected via the thin and reticular cytophore; these cells are considered nurse cells. Zone II has a form of egg strings where growing oocytes are isolated one from another by thin somatic cells and form short cords. We present the ultrastructural details of germline and somatic cells. We propose the term "Amynthas" type of ovaries for this ovary organization. We suppose that such ovaries are characteristic of other megascolecids and related families.
Topics: Humans; Female; Animals; Ovary; Oligochaeta; Oocytes; Oogenesis; Germ Cells
PubMed: 37586295
DOI: 10.1016/j.zool.2023.126109