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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 -
Developmental Cell Sep 2004The three major taxa with metameric segmentation (annelids, arthropods, and chordates) appear to use three very different molecular strategies to generate segments.... (Review)
Review
The three major taxa with metameric segmentation (annelids, arthropods, and chordates) appear to use three very different molecular strategies to generate segments. However, unexpected similarities are starting to emerge from characterization of pair-rule patterning and segmental border formation. Moreover, the existence of an ancestral segmentation clock based on Notch signaling has become likely. An old concept of comparative anatomy, the enterocoele theory, is compatible with a single origin of segmentation mechanisms and could therefore provide a conceptual framework for assessing these molecular similarities.
Topics: Animals; Annelida; Body Patterning; Chickens; Chordata, Nonvertebrate; Drosophila; Embryo, Nonmammalian; Gene Expression Regulation, Developmental; Leeches; Models, Biological
PubMed: 15363406
DOI: 10.1016/j.devcel.2004.08.008 -
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 -
Molecular Biology of the Cell Mar 2019Climate change has accentuated the importance of understanding how organisms respond to stresses imposed by changes to their environment, like water availability....
Climate change has accentuated the importance of understanding how organisms respond to stresses imposed by changes to their environment, like water availability. Unusual organisms, called anhydrobiotes, can survive loss of almost all intracellular water. Desiccation tolerance of anhydrobiotes provides an unusual window to study the stresses and stress response imposed by water loss. Because of the myriad of stresses that could be induced by water loss, desiccation tolerance seemed likely to require many established stress effectors. The sugar trehalose and hydrophilins (small intrinsically disordered proteins) had also been proposed as stress effectors against desiccation because they were found in nearly all anhydrobiotes, and could mitigate desiccation-induced damage to model proteins and membranes in vitro. Here, we summarize in vivo studies of desiccation tolerance in worms, yeast, and tardigrades. These studies demonstrate the remarkable potency of trehalose and a subset of hydrophilins as the major stress effectors of desiccation tolerance. They act, at least in part, by limiting in vivo protein aggregation and loss of membrane integrity. The apparent specialization of individual hydrophilins for desiccation tolerance suggests that other hydrophilins may have distinct roles in mitigating additional cellular stresses, thereby defining a potentially new functionally diverse set of stress effectors.
Topics: Adaptation, Physiological; Animals; Annelida; Climate Change; Desiccation; Droughts; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Stress, Physiological; Tardigrada; Trehalose; Water
PubMed: 30870092
DOI: 10.1091/mbc.E17-04-0257 -
Journal of Oleo Science 2022Earthworm, a ubiquitous (but neglected) macro-invertebrate, is found in terrestrial vicinity of Pakistan. Moreover, the occurrence of earthworms is often diverse with... (Review)
Review
Earthworm, a ubiquitous (but neglected) macro-invertebrate, is found in terrestrial vicinity of Pakistan. Moreover, the occurrence of earthworms is often diverse with fluctuating quantity depending upon abiotic factors and land usage patterns. The aim of this study was to summarize all the reported information related to earthworm diversity in different areas of Pakistan. Almost all the data published from year 2001 to 2021 were collected. Following data organization, total 42 earthworm's species including five families (Acanthodrilidae, Lumbricidae, Moniligastridae, Octochaetidae and Megascolecidae) were reported from various researchers. Among five families, family Acanthodrilidae was found to have only one specie (Ramiella bishambari), Lumbricidae consist of 10 species (Apporactodea rosea, Allolobophora trapezoids, Allolobophora chloroticaa, Aporrectodea longa, A. caliginosa, Bimastus parvus, Eisenia fetida, Helodrilus foetidus, Lumbricus terrestris and L. rubillus), Moniligastridae has two species (Drawida nepalensis and D. pellucida) while Octochaetidae possess only one specie (Eutyphoeus incommodus). The most abundant and diverse family Megascolecidae consist of 28 earthworm species in all habitats of different regions of Pakistan. Among geographical areas, Faisalabad was found as the richest territory with most reported earthworm species (i.e. 28). The current study suggests further in depth research to explore the unidentified and/ missing species of earthworms in Pakistan.
Topics: Animals; Humans; Oligochaeta; Pakistan
PubMed: 35661065
DOI: 10.5650/jos.ess22018 -
Methods in Molecular Biology (Clifton,... 2022Regeneration, the ability to restore body parts after an injury or an amputation, is a widespread property in the animal kingdom. This chapter describes methods used to...
Regeneration, the ability to restore body parts after an injury or an amputation, is a widespread property in the animal kingdom. This chapter describes methods used to study this fascinating process in the annelid Platynereis dumerilii. During most of its life, this segmented worm is able to regenerate upon amputation the posterior part of its body, including its pygidium (terminal non-segmented body region bearing the anus) and a subterminal posterior growth zone which contains stem cells required for the formation of new segments. Detailed description of Platynereis worm culture and how to obtain large quantity of regenerating worms is provided. We also describe the staging system that we established and three important methods to study regeneration: whole mount in situ hybridization to study gene expression, 5-ethynyl-2'-deoxyuridine (EdU) labeling to characterize cell proliferation, and use of pharmacological treatments to establish putative roles of defined signaling pathways and processes.
Topics: Animals; Annelida; Cell Proliferation; Polychaeta; Signal Transduction; Stem Cells
PubMed: 35359310
DOI: 10.1007/978-1-0716-2172-1_11 -
Genes Jul 2021The question of why animals vary in their ability to regenerate remains one of the most intriguing questions in biology. Annelids are a large and diverse phylum, many... (Comparative Study)
Comparative Study Review
The question of why animals vary in their ability to regenerate remains one of the most intriguing questions in biology. Annelids are a large and diverse phylum, many members of which are capable of extensive regeneration such as regrowth of a complete head or tail and whole-body regeneration, even from few segments. On the other hand, some representatives of both of the two major annelid clades show very limited tissue regeneration and are completely incapable of segmental regeneration. Here we review experimental and descriptive data on annelid regeneration, obtained at different levels of organization, from data on organs and tissues to intracellular and transcriptomic data. Understanding the variety of the cellular and molecular basis of regeneration in annelids can help one to address important questions about the role of stem/dedifferentiated cells and "molecular morphallaxis" in annelid regeneration as well as the evolution of regeneration in general.
Topics: Animals; Annelida; Head; Regeneration; Tail
PubMed: 34440322
DOI: 10.3390/genes12081148 -
The International Journal of... 2014
Topics: Animals; Annelida; Bryozoa; Developmental Biology; Embryo, Nonmammalian; Mollusca; Platyhelminths
PubMed: 25690956
DOI: 10.1387/ijdb.140289jh -
Nature Jan 2018It has been hypothesized that a condensed nervous system with a medial ventral nerve cord is an ancestral character of Bilateria. The presence of similar dorsoventral...
It has been hypothesized that a condensed nervous system with a medial ventral nerve cord is an ancestral character of Bilateria. The presence of similar dorsoventral molecular patterns along the nerve cords of vertebrates, flies, and an annelid has been interpreted as support for this scenario. Whether these similarities are generally found across the diversity of bilaterian neuroanatomies is unclear, and thus the evolutionary history of the nervous system is still contentious. Here we study representatives of Xenacoelomorpha, Rotifera, Nemertea, Brachiopoda, and Annelida to assess the conservation of the dorsoventral nerve cord patterning. None of the studied species show a conserved dorsoventral molecular regionalization of their nerve cords, not even the annelid Owenia fusiformis, whose trunk neuroanatomy parallels that of vertebrates and flies. Our findings restrict the use of molecular patterns to explain nervous system evolution, and suggest that the similarities in dorsoventral patterning and trunk neuroanatomies evolved independently in Bilateria.
Topics: Animals; Annelida; Biological Evolution; Body Patterning; Central Nervous System; Invertebrates; Nerve Net; Neural Plate; Phylogeny; Rotifera
PubMed: 29236686
DOI: 10.1038/nature25030 -
Scientific Reports May 2021Across Annelida, accessing the water column drives morphological and lifestyle modifications-yet in the primarily "benthic" scale worms, the ecological significance of...
Across Annelida, accessing the water column drives morphological and lifestyle modifications-yet in the primarily "benthic" scale worms, the ecological significance of swimming has largely been ignored. We investigated genetic, morphological and behavioural adaptations associated with swimming across Polynoidae, using mitogenomics and comparative methods. Mitochondrial genomes from cave and pelagic polynoids were highly similar, with non-significant rearrangements only present in cave Gesiella. Gene orders of the new mitogenomes were highly similar to shallow water species, suggestive of an underlying polynoid ground pattern. Being the first phylogenetic analyses to include the holopelagic Drieschia, we recovered this species nested among shallow water terminals, suggesting a shallow water ancestry. Based on these results, our phylogenetic reconstructions showed that swimming evolved independently three times in Polynoidae, involving convergent adaptations in morphology and motility patterns across the deep sea (Branchipolynoe), midwater (Drieschia) and anchialine caves (Pelagomacellicephala and Gesiella). Phylogenetic generalized least-squares (PGLS) analyses showed that holopelagic and anchialine cave species exhibit hypertrophy of the dorsal cirri, yet, these morphological modifications are achieved along different evolutionary pathways, i.e., elongation of the cirrophore versus style. Together, these findings suggest that a water column lifestyle elicits similar morphological adaptations, favouring bodies designed for drifting and sensing.
Topics: Adaptation, Biological; Animals; Biological Evolution; Caves; Genome, Mitochondrial; Genomics; Phenotype; Phylogeny; Polychaeta
PubMed: 34021174
DOI: 10.1038/s41598-021-89459-y