| the role of cleavage in the localization of developmental potential in the ctenophore mnemiopsis leidyi. | | 1976 | 943342 |
| the development of bioluminescence in the ctenophore mnemiopsis leidyi. | | 1973 | 4150750 |
| calcium-sensitive action potential of long duration in the fertilized egg of the ctenophore mnemiopsis leidyi. | the membrane properties of fertilized eggs of the ctenophore mnemiopsis leidyi were studied using standard microelectrode techniques. the resting potential was approximately -80 mv, and was dependent on the extracellular k concentration. depolarizing current injections elicited an action potential with an initial peak amplitude of +20 to +40 mv (duration about 5 sec) and a long lasting (duration 3 to 10 min) plateau phase. the depolarizing phase and the plateau phase appeared to have different i ... | 1984 | 6147288 |
| visualization of calcium transients controlling orientation of ciliary beat. | to image changes in intraciliary ca controlling ciliary motility, we microinjected ca green dextran, a visible wavelength fluorescent ca indicator, into eggs or two cell stages of the ctenophore mnemiopsis leidyi. the embryos developed normally into free-swimming, approximately 0.5 mm cydippid larvae with cells and ciliary comb plates (approximately 100 microns long) loaded with the dye. comb plates of larvae, like those of adult ctenophores, undergo spontaneous or electrically stimulated revers ... | 1994 | 8195294 |
| reassessing embryogenesis in the ctenophora: the inductive role of e1 micromeres in organizing ctene row formation in the 'mosaic' embryo, mnemiopsis leidyi. | ctenophores are a phylum of diploblastic marine animals displaying biradial symmetry organized along an oral-aboral axis. one of the apomorphic sets of adult structures in ctenophores are the eight external comb rows, which run along the oral-aboral axis. comb rows consist of serial arrays of individual comb plates of cilia, which beat in a coordinated fashion for locomotory behavior. classical cell lineage experiments using chalk particles indicated that comb rows are derived exclusively from t ... | 1997 | 9169846 |
| the role of ca2+ in deflection-induced excitation of motile, mechanoresponsive balancer cilia in the ctenophore statocyst. | motile, mechanoresponsive cilia (balancers) in ctenophore statocysts, like vertebrate hair cells, are excited or inhibited depending upon the direction in which they are deflected. balancers, however, may become either excited (beat rapidly) or inhibited (beat slowly) by deflection in the same direction, depending on the sign of ctenophore geotaxis (positive or negative). the beat frequency of many cilia is controlled by concentrations of ca2+, membrane potential and neural input. how these fact ... | 1997 | 9202448 |
| the ctenophore mnemiopsis leidyi has a flow-through system for digestion with three consecutive phases of extracellular digestion. | the ctenophore (comb jelly) mnemiopsis leidyi is a periodically abundant and voracious predator in u.s. coastal waters. mnemiopsis leidyi is especially competitive at high prey concentrations because of its very efficient extracellular digestion. we investigated the functional basis for these outstanding digestion capabilities. extracellular digestion takes place in the pharynx and consists of three distinct and consecutive phases. the three phases take place in different regions of the pharynx ... | 1997 | 9231370 |
| intracellular fate mapping in a basal metazoan, the ctenophore mnemiopsis leidyi, reveals the origins of mesoderm and the existence of indeterminate cell lineages. | ctenophores are marine invertebrates that develop rapidly and directly into juvenile adults. they are likely to be the simplest metazoans possessing definitive muscle cells and are possibly the sister group to the bilateria. all ctenophore embryos display a highly stereotyped, phylum-specific pattern of development in which every cell can be identified by its lineage history. we generated a cell lineage fate map for mnemiopsis leidyi by injecting fluorescent lineage tracers into individual blast ... | 1999 | 10525332 |
| [study of the new settler beroe ovata in the black sea]. | primary data on population, size, and distribution of a new settler--comb jelly beroe ovata--in the black sea are presented. we studied certain aspects of its nutrition, consumed organisms, and digestion time. comb jellies mnemiopsis leidyi and pleurobachia pileus were established as the nutritional targets of b. ovata. mnemiopsis proved to be more accessible and assimilable. preliminary data on metabolic level and threshold oxygen content in b. ovata were obtained; proportions of dry and wet we ... | 2000 | 10780118 |
| regulation and regeneration in the ctenophore mnemiopsis leidyi. | lobate ctenophores (tentaculates) generally exhibit a remarkable ability to regenerate missing structures as adults. on the other hand, their embryos exhibit a highly mosaic behavior when cut into halves or when specific cells are ablated. these deficient embryos do not exhibit embryonic regulation, and generate incomplete adult body plans. under certain conditions, however, these deficient animals are subsequently able to replace the missing structures during the adult phase in a process referr ... | 2000 | 11071786 |
| multiple inductive signals are involved in the development of the ctenophore mnemiopsis leidyi. | ctenophores possess eight longitudinally arrayed rows of comb plate cilia. previous intracellular cell lineage analysis has shown that these comb rows are derived from two embryonic lineages, both daughters of the four e(1) micromeres (e(11) and e(12)) and a single daughter of the four m(1) micromeres (the m(12) micromeres). although isolated e(1) micromeres will spontaneously generate comb plates, cell deletion experiments have shown that no comb plates appear during embryogenesis following the ... | 2001 | 11783992 |
| [new settlers comb jellies mnemiopsis leidyi (a. agassiz) and beroe ovata mayer 1912 and their influence on the pelagic ecosystem of the northeastern part of the black sea]. | we analyzed the condition of pelagic ecosystem of northeastern black sea influenced by expansion of a new settler beroe ovata in 1999-2001. expansion of b. ovata considerably decreased the population of another new settler mnemiopsis leidyi that deformed the black sea ecosystem for over a decade. reduction of m. leidyi population limited its influence on the ecosystem and, consequently, we observed reestablishment of the main components of the black sea pelagic ecosystem--zooplankton and fish, t ... | 2003 | 12712584 |
| analysis of the luminescent response of the ctenophore, mnemiopsis leidyi, to stimulation. | | 1954 | 13233291 |
| inductive interactions and embryonic equivalence groups in a basal metazoan, the ctenophore mnemiopsis leidyi. | ctenophores undergo locomotion via the metachronal beating of eight longitudinally arrayed rows of comb plate cilia. these cilia are normally derived from two embryonic lineages, which include both daughters of the four e1 micromeres (e11 and e12) and a single daughter of the four m1 micromeres (the m12 micromeres). although the e1 lineage is established autonomously, the m1 lineage requires an inductive interaction from the e1 lineage to contribute to comb plate formation. successive removal of ... | 2004 | 15108814 |
| the regeneration of plate rows in mnemiopsis leidyi, agassiz. | | 1937 | 16588140 |
| surprisingly complex t-box gene complement in diploblastic metazoans. | ctenophores and cnidarians are two metazoan groups that evolved at least 600 ma, predating the cambrian explosion. although both groups are commonly categorized as diploblastic animals without derivatives of the mesodermal germ layer, ctenophores possess definitive contractile "muscle" cells. t-box family transcription factors are an evolutionarily ancient gene family, arising in the common ancestor of metazoans, and have been divided into eight groups in five distinct subfamilies, many of which ... | 2007 | 17501746 |
| trophic cascades triggered by overfishing reveal possible mechanisms of ecosystem regime shifts. | large-scale transitions between alternative states in ecosystems are known as regime shifts. once described as healthy and dominated by various marine predators, the black sea ecosystem by the late 20th century had experienced anthropogenic impacts such as heavy fishing, cultural eutrophication, and invasions by alien species. we studied changes related to these "natural experiments" to reveal the mechanisms of regime shifts. two major shifts were detected, the first related to a depletion of ma ... | 2007 | 17548831 |
| density and sound speed of two gelatinous zooplankton: ctenophore (mnemiopsis leidyi) and lion's mane jellyfish (cyanea capillata). | the density and sound speed of two coastal, gelatinous zooplankton, mnemiopsis leidyi (a ctenophore) and cyanea capillata (lion's mane jellyfish), were measured. these parameters are important inputs to acoustic scattering models. two different methods were used to measure the density of individual animals: one used a balance and graduated cylinder to determine the mass and displacement volume of the animal, the other varied the density of the solution the animal was immersed in. when the same a ... | 2007 | 17614513 |
| ecological and developmental dynamics of a host-parasite system involving a sea anemone and two ctenophores. | the lined sea anemone edwardsiella lineata has evolved a derived parasitic life history that includes a novel body plan adapted for life inside its ctenophore hosts. reputedly its sole host is the sea walnut, mnemiopsis leidyi, a voracious planktivore and a seasonally abundant member of many pelagic ecosystems. however, we have observed substantially higher e. lineata prevalence in a second ctenophore species, the ctenophore predator beroë ovata. the interplay among these 3 species has important ... | 2007 | 18314686 |
| developmental expression of homeobox genes in the ctenophore mnemiopsis leidyi. | homeobox genes are a large family of genes that encode helix-turn-helix transcription factors that play fundamental roles in such developmental processes including body axis formation and cell specification. they have been found in a wide variety of organisms, from fungi to plants and animals, with some classes being specific to the metazoa. while it was once thought that organismal complexity was tied to gene complexity, sequencing of genomes from a cnidarian, poriferan, and placozoan have show ... | 2008 | 18504608 |
| comparative anatomy and histology of developmental and parasitic stages in the life cycle of the lined sea anemone edwardsiella lineata. | the evolution of parasitism is often accompanied by profound changes to the developmental program. however, relatively few studies have directly examined the developmental evolution of parasitic species from free-living ancestors. the lined sea anemone edwardsiella lineata is a relatively recently evolved parasite for which closely related free-living outgroups are known, including the starlet sea anemone nematostella vectensis. the larva of e. lineata parasitizes the ctenophore mnemiopsis leidy ... | 2009 | 18656992 |
| microsatellites reveal origin and genetic diversity of eurasian invasions by one of the world's most notorious marine invader, mnemiopsis leidyi (ctenophora). | marine invasions are taking place at an increasing rate. when occurring in blooms, zooplanktivorous comb jellies of the genus mnemiopsis are able to cause pelagic regime shifts in coastal areas and may cause the collapse of commercially important fish populations. using microsatellites, developed for the first time in the phylum ctenophora, we show that mnemiopsis leidyi has colonized eurasia from two source regions. our preliminary data set included four sites within the putative source region ... | 2010 | 20561193 |
| stealth predation and the predatory success of the invasive ctenophore mnemiopsis leidyi. | in contrast to higher metazoans such as copepods and fish, ctenophores are a basal metazoan lineage possessing a relatively narrow set of sensory-motor capabilities. yet lobate ctenophores can capture prey at rates comparable to sophisticated predatory copepods and fish, and they are capable of altering the composition of coastal planktonic communities. here, we demonstrate that the predatory success of the lobate ctenophore mnemiopsis leidyi lies in its use of cilia to generate a feeding curren ... | 2010 | 20855619 |
| the homeodomain complement of the ctenophore mnemiopsis leidyi suggests that ctenophora and porifera diverged prior to the parahoxozoa. | abstract: | 2010 | 20920347 |
| genomic insights into wnt signaling in an early diverging metazoan, the ctenophore mnemiopsis leidyi. | abstract: | 2010 | 20920349 |
| expression and phylogenetic analysis of the zic gene family in the evolution and development of metazoans. | abstract: | 2010 | 21054859 |
| developmental expression of coe across the metazoa supports a conserved role in neuronal cell-type specification and mesodermal development. | the transcription factor coe (collier/olfactory-1/early b cell factor) is an unusual basic helix-loop-helix transcription factor as it lacks a basic domain and is maintained as a single copy gene in the genomes of all currently analysed non-vertebrate metazoan genomes. given the unique features of the coe gene, its proposed ancestral role in the specification of chemosensory neurons and the wealth of functional data from vertebrates and drosophila, the evolutionary history of the coe gene can be ... | 2010 | 21069538 |
| nuclear receptors from the ctenophore mnemiopsis leidyi lack a zinc-finger dna-binding domain: lineage-specific loss or ancestral condition in the emergence of the nuclear receptor superfamily? | | 2011 | 21291545 |
| mnemiopsis leidyi spawning and embryo collection. | introductionctenophores, or comb jellies, are a group of marine animals whose unique biological features and phylogenetic placement make them a key taxon for understanding animal evolution. because of its large size, fecundity, abundance in coastal areas, and recent introduction to european waters, mnemiopsis leidyi (commonly called "sea walnuts") is the most highly studied ctenophore. under optimal conditions, these self-fertile hermaphrodites are capable of reproduction at 2 wk of age and can ... | 2008 | 21356725 |
| Regeneration of ciliary comb plates in the ctenophore Mnemiopsis leidyi. i. morphology. | Regeneration of missing body parts in model organisms provides information on the mechanisms underlying the regeneration process. The aim here is to use ctenophores to investigate regeneration of their giant ciliary swimming plates. When part of a row of comb plates on Mnemiopsis is excised, the wound closes and heals, greatly increasing the distance between comb plates near the former cut edges. Video differential interference contrast (DIC) microscopy of the regeneration of new comb plates bet ... | 2012 | 21987455 |
| a unique ef-hand motif in mnemiopsin photoprotein from mnemiopsis leidyi: implication for its low calcium sensitivity. | up to now, all reported ca(2+)-regulated photoproteins, except for mnemiopsin, have been cloned and expressed in escherichia coli. in this study, the cdna for an isotype of mnemiopsin, from the ctenophore mnemiopsis leidyi, has been cloned, sequenced, and functionally expressed. the full length cdna encoding mnemiopsin of m. leidyi was 624 bp open reading frame encoding a protein of 207 amino acid residues with calculated molecular mass of ∼24 kda. the deduced amino acid sequence showed 90% and ... | 2011 | 21871870 |
| Salinity gradient of the Baltic Sea limits the reproduction and population expansion of the newly invaded comb jelly Mnemiopsis leidyi. | The recent invasion of the comb jelly Mnemiopsis leidyi into northern European waters is of major public and scientific concern. One of the key features making M. leidyi a successful invader is its high fecundity combined with fast growth rates. However, little is known about physiological limitations to its reproduction and consequent possible abiotic restrictions to its dispersal. To evaluate the invasion potential of M. leidyi into the brackish Baltic Sea we studied in situ egg production rat ... | 2011 | 21887373 |
| extreme mitochondrial evolution in the ctenophore mnemiopsis leidyi: insight from mtdna and the nuclear genome. | recent advances in sequencing technology have led to a rapid accumulation of mitochondrial dna (mtdna) sequences, which now represent the wide spectrum of animal diversity. however, one animal phylum--ctenophora--has, to date, remained completely unsampled. ctenophores, a small group of marine animals, are of interest due to their unusual biology, controversial phylogenetic position, and devastating impact as invasive species. using data from the mnemiopsis leidyi genome sequencing project, we p ... | 2011 | 21985407 |
| Evolution of the TGF-ß signaling pathway and its potential role in the ctenophore, Mnemiopsis leidyi. | The TGF-ß signaling pathway is a metazoan-specific intercellular signaling pathway known to be important in many developmental and cellular processes in a wide variety of animals. We investigated the complexity and possible functions of this pathway in a member of one of the earliest branching metazoan phyla, the ctenophore Mnemiopsis leidyi. A search of the recently sequenced Mnemiopsis genome revealed an inventory of genes encoding ligands and the rest of the components of the TGF-ß superfamil ... | 2011 | 21931657 |
| Cloning, sequencing, expression and structural investigation of mnemiopsin from Mnemiopsis leidyi: an attempt toward understanding Ca2+-regulated photoproteins. | A comparison of the two most famous groups of calcium-regulated photoproteins, cnidarians and ctenophores, showed unexpectedly high degree of structural similarity regardless of their low sequence identity. It was suggested these photoproteins can play an important role in understanding the structural basis of bioluminescence activity. Based on this postulate, in this study the cDNA of mnemiopsin from luminous ctenophore Mnemiopsis leidyi was cloned, expressed, purified a ... | 2011 | 21987124 |
| lim homeobox genes in the ctenophore mnemiopsis leidyi: the evolution of neural cell type specification. | abstract: background: nervous systems are thought to be important to the evolutionary success and diversification of metazoans, yet little is known about the origin of simple nervous systems at the base of the animal tree. recent data suggest that ctenophores, a group of macroscopic pelagic marine invertebrates, are the most ancient group of animals that possess a definitive nervous system consisting of a distributed nerve net and an apical statocyst. this study reports on details of the evol ... | 2012 | 22239757 |