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Marine Drugs Dec 2021Peanut worms (Sipunculids) are unsegmented marine worms that usually inhabit shallow waters. Peanut worms are good source of bioactive compounds including peptides and... (Review)
Review
Peanut worms (Sipunculids) are unsegmented marine worms that usually inhabit shallow waters. Peanut worms are good source of bioactive compounds including peptides and polysaccharides. Many recent studies have investigated the bioactive properties of peptides and polysaccharides derived from peanut worms in order to enhance their applications in food and pharmaceutical industries. The peptides and polysaccharides isolated from peanut worms have been reported to possess anti-hypertensive, anti-oxidant, immunomodulatory, anti-inflammatory, anti-cancer, anti-hypoxia and wound healing activities through the modulation of various molecular mechanisms. Most researchers used in vitro, cell culture and animal models for the determination of bioactivities of peanut worm derived compounds. However, studies in humans have not been performed considerably. Therefore, it is important to conduct more human studies for better utilization of marine bioactive compounds (peptides and polysaccharides) derived from peanut worms. This review mainly focuses on the bioactive properties of peptides and polysaccharides of peanut worms and their molecular mechanisms.
Topics: Animals; Annelida; Peptides; Polysaccharides
PubMed: 35049866
DOI: 10.3390/md20010010 -
Genome Biology and Evolution Feb 2022Streblospio benedicti is a common marine annelid that has become an important model for developmental evolution. It is the only known example of poecilogony (where two...
Streblospio benedicti is a common marine annelid that has become an important model for developmental evolution. It is the only known example of poecilogony (where two distinct developmental modes occur within a single species) that is due to a heritable difference in egg size. The dimorphic developmental programs and life-histories exhibited in this species depend on differences within the genome, making it an optimal model for understanding the genomic basis of developmental divergence. Studies using S. benedicti have begun to uncover the genetic and genomic principles that underlie developmental uncoupling, but until now they have been limited by the lack of availability of genomic tools. Here, we present an annotated chromosomal-level genome assembly of S. benedicti generated from a combination of Illumina reads, Nanopore long reads, Chicago and Hi-C chromatin interaction sequencing, and a genetic map from experimental crosses. At 701.4 Mb, the S. benedicti genome is the largest annelid genome to date that has been assembled to chromosomal scaffolds. The complete genome of S. benedicti is valuable for functional genomic analyses of development and evolution, as well as phylogenetic comparison within the annelida and the Lophotrochozoa. Despite having two developmental modes, there is no evidence of genome duplication or substantial gene number expansions. Instead, lineage-specific repeats account for much of the expansion of this genome compared with other annelids.
Topics: Animals; Annelida; Larva; Phylogeny; Polychaeta; Sequence Analysis, DNA
PubMed: 35078222
DOI: 10.1093/gbe/evac008 -
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 -
Science (New York, N.Y.) May 2023Sterols are vital for nearly all eukaryotes. Their distribution differs in plants and animals, with phytosterols commonly found in plants whereas most animals are...
Sterols are vital for nearly all eukaryotes. Their distribution differs in plants and animals, with phytosterols commonly found in plants whereas most animals are dominated by cholesterol. We show that sitosterol, a common sterol of plants, is the most abundant sterol in gutless marine annelids. Using multiomics, metabolite imaging, heterologous gene expression, and enzyme assays, we show that these animals synthesize sitosterol de novo using a noncanonical C-24 sterol methyltransferase (C-SMT). This enzyme is essential for sitosterol synthesis in plants, but not known from most bilaterian animals. Our phylogenetic analyses revealed that C-SMTs are present in representatives of at least five animal phyla, indicating that the synthesis of sterols common to plants is more widespread in animals than currently known.
Topics: Animals; Cholesterol; Phylogeny; Plants; Sitosterols; Annelida
PubMed: 37141360
DOI: 10.1126/science.add7830 -
Journal of Experimental Zoology. Part... Dec 2021The germline is unique and immortal (or at least its genome is). It is able to perform unique jobs (meiosis) and is selected for genetic changes. Part of being this... (Review)
Review
The germline is unique and immortal (or at least its genome is). It is able to perform unique jobs (meiosis) and is selected for genetic changes. Part of being this special also means that entry into the germline club is restricted and cells of the soma are always left out. However, the recent evidence from multiple animals now suggests that somatic cells may join the club and become germline cells in an animal when the original germline is removed. This "violation" may have garnered acceptance by the observation that iPScells, originating experimentally from somatic cells of an adult, can form reproductively successful eggs and sperm, all in vitro. Each of the genes and their functions used to induce pluripotentiality are found normally in the cell and the in vitro conditions to direct germline commitment replicate conditions in vivo. Here, we discuss evidence from three different animals: an ascidian, a segmented worm, and a sea urchin; and that the cells of a somatic cell lineage can convert into the germline in vivo. We discuss the consequences of such transitions and provide thoughts as how this process may have equal precision to the original germline formation of an embryo.
Topics: Animals; Annelida; Cell Lineage; Germ Cells; Meiosis; Sea Urchins; Urochordata
PubMed: 32445519
DOI: 10.1002/jez.b.22952 -
Molecular Ecology Resources Feb 2022Leeches play important roles in food webs due to their abundance, diversity and feeding habits. Studies using invertebrate-derived DNA (iDNA) extracted from leech gut...
Leeches play important roles in food webs due to their abundance, diversity and feeding habits. Studies using invertebrate-derived DNA (iDNA) extracted from leech gut contents to target vertebrate DNA have focused on the Indo-Pacific region and mainly leveraged the leech family Haemadipsidae, composed of bloodfeeding terrestrial leeches, while predatory, fluid/tissue-feeding and aquatic bloodfeeding species have been largely disregarded. While there is some general knowledge regarding the taxonomic groups that leeches prefer to feed on, detailed taxonomic resolution is missing and, therefore, their potential use for monitoring animals is unknown. In this study, 116 leeches from 12 species (six families) and spanning the three feeding habits were collected in Mexico and Canada. We used DNA metabarcoding to investigate their diet and assess their potential use for biodiversity monitoring. We detected vertebrates from five orders including fish, turtles and birds in the diet of aquatic bloodfeeding leeches; eight invertebrate orders of annelids, arthropods and molluscs in leeches that feed on body fluids and tissues; and 10 orders of invertebrates belonging to Arthropoda and Annelida, as well as one vertebrate and one parasitic nematode, in predatory leeches. These results show the potential use of iDNA from aquatic bloodfeeding leeches for retrieving vertebrate taxa, and from predatory and fluid-feeding leeches for invertebrates. Our study provides information about the dietary range of freshwater leeches and one terrestrial leech and contributes proof-of-concept for the use of these leeches for animal monitoring, expanding our knowledge of the use of iDNA from leech gut contents to North America.
Topics: Animals; Annelida; Biodiversity; DNA Barcoding, Taxonomic; Leeches; Vertebrates
PubMed: 34402209
DOI: 10.1111/1755-0998.13486 -
Bioinspiration & Biomimetics Dec 2022Existing soft robots face challenges given the need for an improved flexible robot elongation rate, bending angle and movement flexibility in space target acquisition,...
Existing soft robots face challenges given the need for an improved flexible robot elongation rate, bending angle and movement flexibility in space target acquisition, disaster search and rescue, unknown environment detection and other fields. Yoshimura tubular origami shows good applied performance with regard to the axial elongation ratio. However, due to the characteristics of nonrigid folding and a negative Poisson's ratio, the axial elongation length and bending angle of the Yoshimura tubular origami mechanism are limited. Annelids show highly flexible body movement. By analyzing the main factors limiting the axial elongation rate of the Yoshimura tubular origami mechanism and imitating the morphological characteristics and motion mechanism of annelid somite joints, we proposed a method to achieve high flexibility and large angle bending of a tubular origami mechanism based on local material removal and macroscopic elimination of the negative Poisson's ratio. Combined with a Ni-Ti memory alloy wire segmented driving scheme based on force constraints and geometric constraints a continuous origami robot is designed. The optimal cutting amount of the origami mechanism is determined by experiments, and the maximum elongation ratio and bending angle of the origami mechanism reach 2.5 and 3 times those before material removal, respectively. The paper folding module unit was solved in a kinematic analysis workspace. Finally, a prototype was used to verify the performance and demonstrate the application potential of the robot in an unstructured rescue scene.
Topics: Animals; Robotics; Annelida; Motion; Biomechanical Phenomena; Mechanical Phenomena
PubMed: 36541461
DOI: 10.1088/1748-3190/aca5da -
The Biological Bulletin Feb 2023AbstractThe interstitial environment of marine sediments is a complex network of voids and pores that is inhabited by a diverse and abundant fauna. Animals living within...
AbstractThe interstitial environment of marine sediments is a complex network of voids and pores that is inhabited by a diverse and abundant fauna. Animals living within these interstitial spaces show widespread functional adaptations to this environment and have developed many strategies for moving and navigating through small spaces. Interstitial annelids demonstrate a remarkable level of morphologic diversity, and some possess dexterous, filiform palps (tentacle-like appendages common across Annelida). The function(s) of these palps in interstitial spaces has not been closely examined, and we propose that they serve a sensory role in the navigation of interstitial spaces. We investigated the locomotory function of long, dexterous palps in three families of interstitial annelids to determine their role in interstitial navigation. We observed two species of protodrilids (Protodrilidae), (Saccocirridae), and (Dorvilleidae), as they moved through two transparent sand analogs: cyolite and glass beads. All four species of annelids consistently used their palps to probe the interstitial environment while locomoting, and the distance probed with their palps was greater than the distance traveled with their heads, indicating a sensory form of palp-based navigation. The functionality of palps as sensory organs in the interstitial environment raises interesting questions about interstitial navigation and how fauna without appendages map their surroundings. The discovery of this previously undocumented function was possible only through the direct observation of interstitial behavior and emphasizes the importance of developing new techniques to study these animals in more natural habitats.
Topics: Animals; Annelida; Polychaeta; Ecosystem; Adaptation, Physiological
PubMed: 37167622
DOI: 10.1086/724580 -
PeerJ 2024, a genus of freshwater macrophagous leeches, belongs to Erpobdelliformes (Salifidae: Clitellata: Annelida), and , a well-known leech within this genus, has a worldwide...
BACKGROUND
, a genus of freshwater macrophagous leeches, belongs to Erpobdelliformes (Salifidae: Clitellata: Annelida), and , a well-known leech within this genus, has a worldwide distribution. However, the systematics of have not yet been adequately investigated, primarily due to a few molecular markers, and only 20 sequences available in the GenBank database. This gap significantly limits our understanding of the species identification, as well as the phylogenetic placement of the genus within Salifidae.
METHODS
Next-generation sequencing (NGS) was used to simultaneously capture the entire mitochondrial genome and the full-length 18S/28S rDNA sequences. The species boundary of species was estimated using bGMYC and bPTP methods, based on all available COI sequences. Uncorrected COI p-distance was calculated in MEGA. A molecular data matrix consisting of four loci (COI, 12S, 18S, and 28S rDNA) for outgroups (three leeches) and 49 erpobdellid leeches, representing eight genera within the Suborder Erpobdelliformes was aligned using MAFFT and LocARNA. This matrix was used to reconstruct the phylogenetic relationship of Bayesian inference (BI) and the maximum likelihood (ML) method.
RESULTS
The full lengths of the mitochondrial genome, 18S and 28S rDNAs of . cf. , are 14847 bp, 1876 bp 1876 bp, and 2863 bp, respectively. Both bGMYC and bPTP results based on COI data are generally congruent, suggesting that the previously proposed taxa (, . formosana, and . or ) are synonyms of . . The specimens listed in the group, however, are split into at least two Primary Species Hypotheses (PSHs). The p-distance of the first PSH is less than 1.3% but increased to 4.5% when including the secondary PSH (., . cf. ). In comparison, the interspecific p-distance between the group and the group ranged from 6.4% to 8.7%, and the intraspecific p-distance within the group is less than 0.8%. Considering the species delimitation results and the sufficient large p-distance, the specimen sampled in China is treated as . cf. . The monophyly of the four Erpobdelliformes families Salifidae, Orobdellidae, Gastrostomobdellidae and Erpobdellidae is well supported in ML and BI analysis based on a data of four markers. Within the Salifidae, a well-supported is closely related to a clade containing and , and these three genera are sister to a clade consisted of and . According to the results of this study, the strategy of simultaneous obtaining both whole mitochondria and nuclear markers from extensively sampled Salifids species using NGS is expected to fathom both the species diversity of and the evolutionary relationship of Salifidae.
Topics: Animals; Phylogeny; Genome, Mitochondrial; Leeches; High-Throughput Nucleotide Sequencing; RNA, Ribosomal, 28S
PubMed: 38827288
DOI: 10.7717/peerj.17480 -
The Journal of Experimental Biology Oct 2023Dissolved organic matter is a ubiquitous component of freshwater and marine environments, and includes small nutrient molecules, such as amino acids, which may be...
Dissolved organic matter is a ubiquitous component of freshwater and marine environments, and includes small nutrient molecules, such as amino acids, which may be available for uptake by aquatic biota. Epithelial transporters, including cotransporters, uniporters and antiporters, facilitate the absorption of dissolved amino acids (often against concentration gradients). Although there is a lack of mechanistic and molecular characterization of such transporters, pathways for the direct uptake of amino acids from the water appear to exist in a wide range of marine phyla, including Porifera, Cnidaria, Platyhelminthes, Brachiopoda, Mollusca, Nemertea, Annelida, Echinodermata, Arthropoda and Chordata. In these animals, absorbed amino acids have several putative roles, including osmoregulation, hypoxia tolerance, shell formation and metabolism. Therefore, amino acids dissolved in the water may play an important, but overlooked, role in aquatic animal nutrition.
Topics: Animals; Amino Acids; Invertebrates; Annelida; Cnidaria; Mollusca; Water
PubMed: 37843468
DOI: 10.1242/jeb.245375