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PubMed1977

The coelomocytes of the earthworm Lumbricus terrestris: morphology and phagocytic properties.

The coelomocytes of Lumbricus terrestris have been classified and described, based on Wright's stained preparations and on living cells. The five major categories consist of basophils, acidophils, neutrophils, granulocytes and chloragogen cells. Both the acidophil and chloragogen cell groups contain two subgroups. Granulocytes also exhibit heterogeneity with respect to staining properties of granules. Some possess acidophilic granules, some basophilic granules, and others contain both types. Granules of acidophils have been observed to be occasionally excreted from the cells. All cell types, with the exception of chloragogen cells, produce pseudopodia and are capable of phagocytosis, a vital component of the earthworm's immune response.

Animals↗
PubMed1982

Electrophysiological correlates of rapid escape reflexes in intact earthworms, Eisenia foetida. I. Functional development of giant nerve fibers during embryonic and postembryonic periods.

Grids of recording electrodes etched onto printed circuit boards were used for noninvasive recording of medial (MGF) and lateral (LGF) giant nerve fiber spikes in developing earthworms, Eisenia foetida. Stereotyped patterns of through-conducted giant fiber spikes, evoked by light tactile stimulation, were first detectable in the normal crawling embryonic stage and continued to be detectable throughout postembryonic development. Giant fiber spiking activity in normal crawling embryos was accompanied by stereotyped muscle activity and rapid escape withdrawal, suggesting that giant fiber reflex pathways are functionally intact before the worm hatches. For both the MGF and LFG, several age-dependent changes were noted, including the following: increases in spike conduction velocity, increases in giant fiber diameter, and decreases in spike duration. The MGF conduction velocity in normal crawling embryos was 1.1-1.6 m s-1 (6-7 micrometers diameter) and increased to 7.0-8.5 m s-1 (20-25 micrograms diameter) by 60 days after hatching. The LGF conduction velocity in normal crawling embryos was 0.7-1.1 m s-1 (2.5-4.0 micrometers diameter) and increased to 4.0-5.5 m s-1 (8-14 micrometers diameter) by 60 days after hatching. During postembryonic development MGF and LGF conduction velocities were linearly related to fiber diameter.

Aging↗
PubMed1982

Electrophysiological correlates of rapid escape reflexes in intact earthworms, Eisenia foetida. II. Effects of food deprivation on the functional development of giant nerve fibers.

Noninvasive electrophysiological recording methods were used to study the effects of prolonged food deprivation on the postembryonic patterns of giant fiber growth, as indicated by age-dependent changes in giant fiber conduction velocity and diameter, in the earthworm, Eisenia foetida. In addition, giant fiber growth was compared to patterns of somatic growth, as indicated by increases in body weight. Within a wide range of food deprivation levels, normal age-dependent increases in conduction velocity and diameter occurred in spite of marked stunting of somatic growth. Stunting of giant fiber velocity and diameter occurred only during severe food deprivation, but giant fiber spikes and associated rapid escape responses were still readily evoked. The stunting effects of prolonged and severe food deprivation upon giant fiber conduction velocity and diameter were readily reversed by replenishing food. The results demonstrate the persistence of rapid escape reflex functioning, as well as the priority of giant fiber growth relative to somatic growth, during severe and prolonged food deprivation. As a consequence of the priority of giant fiber growth during limited food availability, giant fiber conduction velocity appears to be a more reliable predictor of animal age then body size.

Aging↗
PubMed1985

Donor-recipient interconnections between giant nerve fibers in transplanted ventral nerve cords of earthworms.

Twelve segments of ventral nerve cord (VNC) from donor earthworms, Eisenia foetida, were transplanted into recipient worms from which a comparable length of VNC had been removed. Within the first few days after transplantation, bud-like formations, containing outgrowths of the giant nerve fibers, were evident at the ends of transplanted and recipient VNC. Morphological and electrophysiological evidence indicated that by 4-10 days after transplantation, medial (MGF) and lateral (LGF) giant fibers within the transplanted VNC formed cell-specific connections with their counterparts in the recipient VNC. Although the diameters of the giant fiber connections in the transplant-recipient junctions were often larger than normal, spike conduction across the junction was initially slow (approximately 1.0 m/s) but gradually increased over the next 2-3 weeks. Within the transplant, giant fibers were initially normal in appearance, but spike conduction was slow (1-2 m/s). During the next few weeks velocities increased by as much as fourfold and then stabilized for the next several months. However, by 4-5 weeks after transplantation, giant fiber morphology within the transplant was altered significantly, as indicated by the formation of numerous branch-like extensions along the length of each giant fiber. By 9-10 months there were further morphological changes in the transplant, as indicated by decreased branching of the giant fibers and altered neuropile. Despite these morphological changes, through-conduction of giant fiber spikes remained reliable.

Animals↗
PubMed1985

Restoration of sensory and motor function in earthworm escape reflex pathways following ventral nerve cord transplantation.

Twelve segments of earthworm ventral nerve cord (VNC) were excised from either segments 10-22 (i.e., within the MGF sensory field) or segments 75-87 (i.e., within the LGF sensory field) in donor worms and heterotopically, or homotopically, transplanted into recipient animals. Morphological evidence indicated that by four days after transplantation, peripheral connections were formed between the transplanted VNC and the body wall of the recipient, many of these connections involving novel pathways projecting ventrally from the transplant. Restoration of giant fiber touch sensitivity in the transplant occurred from 4-14 days after transplantation. Regardless of the site of transplantation, the restored sensitivity (i.e., MGF versus LGF sensory field) always reflected the origin of the donor VNC. Restoration of MGF-mediated motor activity in the transplant occurred approximately 17-22 days after transplantation. In the case of heterotopic transplants (i.e., anterior VNC into posterior segments), the restored MGF-mediated muscle potentials were facilitating, indicating at least some tendency for persistence of this feature after transplantation. Behavioral observations suggested that reconnections involving other reflex pathways (e.g., those controlling setal movements and peristaltic locomotion) were made within the transplant region and that properties of the restored reflexes reflected those of the donor VNC. The rapid restoration of sensory and motor connections, despite heterotopic placement, indicates a significant capacity for peripheral regeneration by the transplanted VNC. On the other hand, the maintenance of various properties of reflex function, despite heterotopic transplantation, suggests a limited capacity for rearrangement of established central connections in the transplanted VNC.

Afferent Pathways↗
PubMed2006

Linker chains of the gigantic hemoglobin of the earthworm Lumbricus terrestris: primary structures of linkers L2, L3, and L4 and analysis of the connectivity of the disulfide bonds in linker L1.

The extracellular hemoglobin (Hb) of the earthworm, Lumbricus terrestris, has four major kinds of globin chains: a, b, c, and d, present in equimolar proportions, and additional non-heme, non-globin scaffolding chains called linkers that are required for the calcium-dependent assembly of the full-sized molecule. The amino acid sequences of all four of the globin chains and one of the linkers (L1) have previously been determined. The amino acid sequences via cDNA of each of the three remaining linkers, L2, L3, and L4, have been determined so that the sequences of all constituent polypeptides of the hemoglobin are now known. Each linker has a highly conserved cysteine-rich segment of approximately 40 residues that is homologous with the seven ligand-binding repeats of the human low-density lipoprotein receptor (LDLR). Analysis of linker L1 shows that the connectivity of the three disulfide bonds is exactly the same as in the LDLR ligand-binding repeats. The presence of a calcium-binding site comprising one glutamyl and three aspartyl residues in both the LDLR repeats and in the linkers supports the suggestion that calcium is required for the folding and disulfide connectivity of the linkers as in the LDLR repeats. Linker L2 is markedly heterogeneous and contains unusual glycine-rich sequences near the NH2-terminus and a polar zipper-like sequence with imperfect repeats of Asp-Asp-His at the carboxyl terminus. Similar Asp-Asp-His repeats have been found in a protein homologous to superoxide dismutase in the hemolymph of certain mussels. These repeats may function as metal-binding sites.

Amino Acid Sequence↗
PubMed1996

Superoxide dismutase activity in the giant hemoglobin of the earthworm, Lumbricus terrestris.

The giant hemoglobin, which occurs in free solution in the blood of earthworms, contains copper and zinc and exhibits superoxide dismutase activity as assessed by competition assays using cytochrome c or nitroblue tetrazolium. On a molar basis, the activity of this hemoglobin was approximately 10% that of the mammalian copper, zinc superoxide dismutase. The dodecamer, which contains the globin chains but lacks the linker subunits, had very little activity when compared to the complete native molecule. This suggests that the superoxide dismutase activity resides in one of the linker subunits. This is the first report of a superoxide dismutase bound to a respiratory pigment.

Animals↗
PubMed1994

Annetocin: an oxytocin-related peptide isolated from the earthworm, Eisenia foetida.

An oxytocin-vasopressin-related peptide, Cys-Phe-Val-Arg-Asn-Cys-Pro-Thr-Gly-NH2, was isolated from the lumbricid earthworm, Eisenia foetida and termed annectocin. Annetocin potentiated not only spontaneous contractions of the gut but also pulsatory contractions and bladder-shaking movement of the nephridia. Annetocin may be involved in osmoregulation of the animal through nephridial function.

Amino Acid Sequence↗
PubMed1995

Mitochondrial mass and membrane potential in coelomocytes from the earthworm Eisenia foetida: studies with fluorescent probes in single intact cells.

Earthworm coelomocytes exist in two forms, i.e., small (SC) and large (LC) cells, as demonstrated by velocity sedimentation, electron microscopy, and FCM. However, we know little concerning the functional activities of various, important organelles, such as mitochondria. In comparison with SC, LC from Eisenia foetida have a higher number of mitochondria, and, accordingly, showed a greater fluorescence intensity when mitochondrial mass was measured by nonyl acridine orange and FCM. To measure MMP we used both the lipophilic cationic probe JC-1 and Rh123. The intracellular localization of JC-1 in SC and LC was observed by fluorescence microscopy. Using JC-1, MMP was analyzed separately on SC and LC by FCM, and significant percentages of coelomocytes (> 95% of SC and about 90% of LC) displayed a high MMP. Adding 0.1 microM VAL caused most SC to depolarize, while this occurred in only a few LC. Rh123 gave different results: no effects of VAL were observed either in SC or in LC. In coelomocytes there may be several energy-independent Rh123-binding sites whose role must still be elucidated. On the whole, these data indicate that it is possible to analyze mitochondrial parameters by FCM in intact invertebrate coelomocytes, and that the type of cell and the probe used have a critical importance.

Animals↗
PubMed1995

The GGNG peptides: novel myoactive peptides isolated from the gut and the whole body of the earthworms.

Three novel bioactive peptides, which were structurally related to each other, were purified and chemically identified from two species of the earthworms, Eisenia foetida and Pheretima vittata. One peptide was isolated from the gut tissue of E. foetida, and the other two were purified from the whole body of E. foetida and P. vittata, respectively. These peptides consisted of 17 or 18 amino acid residues and were named GGNG peptides after their unique, common structure of the C-termini. These GGNG peptides augmented both tension and frequency of spontaneous contractions of isolated gut preparations of E. foetida, and also elicited contractions of other annelidan tissues such as the polychaete esophagus and the leech vagina. However, they showed no activity on molluscan or arthropodan tissues, suggesting that GGNG peptides may be peculiar to annelids. No peptides homologous to GGNG peptides have been known so far in any living organisms.

Amino Acid Sequence↗
PubMed1996

Earthworm gene as indicator of bioefficacious cadmium.

The expression of a novel Cd-inducible gene encoding a 25 kDa non-metallothionein cysteine-rich protein (CRP) in the earthworm Enchytraeus buchholzi is investigated with respect to Cd-specificity and Cd-sensitivity. The amount of CRP-mRNA correlates with the environmental as well as with the intra-worm Cd-concentration. Even the subtoxic concentration of 100 microgram Cd/1 induces CRP-gene expression. CRP-mRNA is expressed already 2 h after the worms were exposed to Cd. Other heavy metals or stress conditions can induce only little or even no CRP-mRNA. The CRP-gene is switched on long before Cd becomes toxic to worms and can be therefore taken as a warning signal of prospective irreversible Cd-damages at an early, still reversible stage.

Amino Acid Sequence↗
PubMed1996

Cadmium-detoxification in the earthworm Enchytraeus: specific expression of a putative aldehyde dehydrogenase.

The ubiquitous earthworm Enchytraeus buchholzi is provided with a very effective, but still unknown, mechanism of Cadmium (Cd)-detoxification, a central role in which has been ascribed to the Cd-inducible crp-gene encoding a novel cysteine-rich, non-metallothionein 25 kDa protein. This study identifies another Cd-responsive gene by differential screening of a cDNA-library constructed from Cd-exposed E. buchholzi. The isolated cDNA-clone designated Ebaldh encodes a putative aldehyde dehydrogenase. Northern blot analysis shows that the Ebaldh-expression is strongly enhanced by Cd, but remains unaffected by other stressors such as Zn, Hg, and H2O2. This Cd-specificity of Ebaldh suggests that Cd-detoxification in E. buchholzi requires low intracellular concentrations of aldehydes which are known to target sulfhydryl groups thus inactivating the Cd-binding capacity of CRP.

Aldehyde Dehydrogenase↗
PubMed1993

The toxicokinetic behavior of chlorobenzenes in earthworms (Eisenia andrei): experiments in water.

The toxicokinetic behavior of five chlorobenzenes in earthworms (Eisenia andrei) was studied. Because exposure in soil is difficult to control, worms were kept in water. Bioconcentration factors (BCF) were studied in a static test system. The results show that a steady-state concentration in worms is reached within 5 days. BCF values increased with increasing octanol-water partition coefficient (Kow). To determine elimination rate constants (k2), worms were exposed to a mixture of chlorobenzenes for 6 days followed by a depuration period of 21 days. The data of the elimination process are described by one-compartment first order kinetics. Hexachlorobenzene was not eliminated within the observed period. Bioconcentration factors increase and elimination rate constants (k2 values) decrease with increasing log Kow. The resulting BCF and k2 values are comparable with those found in fish studies.

Animals↗
PubMed1995

Dietary uptake of superlipophilic compounds by earthworms (Eisenia andrei).

The uptake and elimination of three superlipophilic compounds (hexabromobenzene, PCB153, and octachloronaphthalene) after dietary uptake was studied in earthworms (Eisenia andrei). All three compounds were taken up from the food, although they did not significantly accumulate despite their hydrophobicity. Both uptake efficiencies (E) and biomagnification factors (BMF) were low. E varied between 0.70 and 7.5%, while BMF values were all below 0.17. The elimination of the compounds was slow, with elimination rate constants k2 varying between 0.04 and 0.09 day-1.

Animals↗
PubMed1995

CO2 production in three earthworm species exposed to terbuthylazine and carbofuran in food.

Studies were conducted in the laboratory to determine the influence of sublethal doses of pesticides on the respiration of earthworms. Three different lumbricids were exposed to different concentrations of terbuthylazine and carbofuran for up to 12 weeks by allowing them to feed on contaminated plant material. After different exposure periods the CO2 output of the worms was determined by gas chromatography. High terbuthylazine concentrations generally increased CO2 production, whereas the low concentration tended to decrease it, especially in two of the three species studied. Low carbofuran concentration increased the CO2 expired in all the species; the high dose negatively affected the respiration in Lumbricus terrestris and L. rubellus after 3 weeks and in Eisenia andrei after 4 weeks of exposure.

Animals↗
PubMed1997

Effect of Cd or Pb addition to Cu-contaminated soil on tissue Cu accumulation in the earthworm, Dendrobaena veneta.

Generally, soil heavy metal contamination consists of a mixture of heavy metals. Soil chemical properties and interaction with other pollutants in soil affect the external heavy metal bioavailability. Moreover, interaction with other pollutants accumulated in organisms may change the toxicity of each pollutant. Therefore, the hypotheses was tested that addition of Cd or Pb to Cu-contaminated soil would lead to an increase in tissue Cu accumulation in the earthworm, Dendrobaena veneta, caused by (i) induction of metallothionein by Cd, or (ii) an increase in Cu concentration in soil solution due to the exchange of adsorbed Cu for Pb. Tissue heavy metal concentrations were determined after exposure in contaminated soils for 3 or 21 days. Considerable amounts of Cu, Cd, and Pb were accumulated, indicating that these heavy metals were available for uptake by D. veneta. Both Cd and Pb, however, did not significantly affect tissue Cu accumulation.

Animals↗
PubMed1999

Effects of low levels of lead on growth and reproduction of the Asian earthworm Perionyx excavatus (Oligochaeta).

The effects of sublethal concentrations of lead nitrate on growth and reproduction of the Asian composting earthworm species Perionyx excavatus was studied experimentally by exposing worms in an organic substrate to lead nitrate-contaminated food over a period of 76 days. The results revealed that growth was affected negatively by the presence of lead while maturation rate and cocoon production was not affected. In agreement with other studies on Eisenia fetida, cocoon viability was affected negatively by lead, making this a sensitive toxicity endpoint. Lead accumulation was of the same order of magnitude as for other previously studied species.

Animals↗
PubMed2001

Toxic effects of benomyl on the ultrastructure during spermatogenesis of the earthworm Eisenia fetida.

The present study has investigated the toxic effect of benomyl on the ultrastructure of the male reproductive system and spermatozoa of the earthworm Eiseniafetida in a laboratory experiment. Three different concentrations of benomyl (8.3, 56, 112 mg/kg dry soil) were applied for one week. These applications caused abnormalities in ultrastructure of the cytophore, the spermatogonia, spermatids, and spermatozoa. The alterations include uncomplete forms of acrosomes, nuclear distortion, and disruption of microtubules. These micromorphological changes should be included in a model for predicting environmental hazards.

Animals↗