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A list of the species and taxa of some pelagic animals from a tropical upwelling region, based on collections made off the coast of Costa Rica is presented. The list includes a total of 224 species, 53 genera and 11 subspecific forms in Cnidaria, Annelida, Mollusca, Artropoda (Crustacea), Chaetognatha and Pisces.
Nexuses have been demonstrated between glial cell processes in the earthworm ventral nerve cord. The nexuses have been demonstrated by freeze-cleavage to be A-type neuxuses, thus demonstrating for the first time the type of nexus present in the Annelida. If the nexal cleavage pattern has physiological significance then the results suggest that physiologically the nexuses of the earthworm may be similar to those of vertebrates.
We describe the embryonic development of the soil-living oligochaete Enchytraeus coronatus (Enchytraeidae, Oligochaeta, Annelida). Enchytraeus coronatus is a direct developer. It follows the typical spiral cleavage mode of development that is highly conserved among annelids and a large number of other lophotrochozoan taxa that are collectively named "Spiralia." Scanning electron microscopy (SEM) was combined with light microscopic analysis of wholemounted and sectioned embryos, differentially processed through histological stainings, to reconstruct and document cellular movements and organogenesis from early cleavage stages until hatching. With the help of these data we have established a scheme of morphologically defined stages in order to facilitate future studies on the molecular and histological level that will allow a detailed cross-species comparison among annelids and other phyla.
Although some species of Annelida have an enormous capacity to regenerate, it is not yet known whether reestablishment of lost body parts is performed by stem cells, depends on preceding dedifferentiation of somatic cells, or is a combination of both. In order to clarify how, in the case of epimorphic regeneration, the blastemas are formed, we applied the thymidine analog 5'-bromo-2'-deoxyuridine (BrdU) in the dorvilleid polychaete Dorvillea bermudensis to identify cells in the S-phase of the cell cycle. Regeneration pulse-chase experiments were carried out to determine onset and dynamics of the proliferation process, and BrdU pulse-chase experiments were undertaken to follow cell fate. We found irregularly distributed S-phase cells throughout the body of adult specimens. Subsequent to amputation, these cells do not migrate from the amputee towards the wound site, where proliferation activity was documented no earlier than 16 h after fragmentation. In the initial phase, the proliferation rate at the anterior end exceeds the rate at the posterior end. Observance of identity could be demonstrated for the ectoderm and can be assumed for the two other germ layers. The anterior blastema transforms into the head, while the posterior forms the pygidium and persists as a proliferation zone; four or numerous segments are formed by intercalation between the former anterior or posterior blastema and the amputee.
In order to evaluate the differences in the cleavage patterns of the glossiphoniid leeches Glossiphonia complanata and Theromyzon tessulatum, previously studied by Müller ('32) and Schmidt ('17, '41), the cleavage of Theromyzon tessulatum was reexamined. For the period of the first 29 hours of development embryos were observed, photographed, and serially sectioned for light microscopy at each developmental stage. The exact cell lineage until completion of teloblast formation is reported. Besides some other not previously reported features, we show that the mesoteloblast precursor cell in the glossiphoniid leeches, as probably in most Annelida, is not the cell 3D, but cell 4d formed by an additional division of cell 3D. The results further indicate that all glossiphoniid leeches likely share a common cleavage pattern, and that major differences between Glossiphonia complanata and Theromyzon tessulatum do not exist. A comparison between the cleavage patterns of some Oligochaeta and Hirudinea is made, and plesiomorphic characters in the cleavage of a clitellate ancestor species and their deviations in present day species are discussed.
The mature sperm of Dina lineata is of the modified type. The sperm are 48 micron long and 0.3 micron wide. The sperm are filiform and helicoidal cells with a distinct head, a midpiece, and a tail. There are two distinct regions in the head: the acrosome and the posterior acrosome, each with its own characteristic morphology. The midpiece is the mitochondrial region and has a single mitochondrion. Two distinct portions can be observed in the tail: the axonematic region and the terminal piece. In the process of spermatogenesis the early spermatogonia divide to form a poliplast of 512 spermatic cells. In the spermiogenesis the following sequential stages can be distinguished: elongation of the flagellum; reciprocal migration of mitochondria and Golgi complex; condensation of chromatin and formation of the posterior acrosome; spiralization of nuclear and mitochondrial regions; and, finally, formation of the anterior acrosome. The extreme morphological complexity of the Dina spermatozoon is related to the peculiar hypodermal fertilization which characterizes the erpobdellid family. Correlation between sperm morphology and fertilization biology in the Annelida is revised.
Regionalization and segmentation of the leech body plan have been examined by numerous approaches over the years. A wealth of knowledge has accumulated regarding the normally invariant cell lineages of the leech and the degree of developmental plasticity that is possible in each cell line in early development and in neurogenesis. Homologues of genes that control regionalization and segmentation in Drosophila have been cloned from the leech and the expression patterns reveal conserved features with those in Drosophila and other organisms. Possible developmental functions of the en-class proteins in spatial and temporal modes of segment formation are discussed in light of leech and Drosophila development. Annelida and Arthropoda cell lineages of engrailed-class gene expression are compared in leech blast cell clones and crustacean parasegments. In addition, future directions for molecular analysis of segmentation of the leech are summarized.
Joint toxic effects of copper and zinc were studied in the terrestrial worm Enchytraeus crypticus (Westheide and Graefe) (Oligochaeta, Annelida). Animals were exposed in OECD artificial soil. Sublethal toxicity was judged by effects on reproduction. Metals were applied singly or in binary mixtures. Observed effects were compared with effects expected from simple similar action (concentration addition), by recalculation of metal concentrations in toxic units. Exposure of the worms was quantified with body concentrations and with external concentrations (total, extractable, soluble). The observed joint effect was similar to concentration additive when judged by external concentrations and less than concentration additive for body concentrations. This difference is attributable to interactions among metals during sorption to soil and during uptake. Copper reduced the sorption of zinc to soil, but copper sorption was inert for zinc addition. Zinc uptake from the soil solution was stimulated by copper, but copper uptake was not stimulated by zinc. Joint effects of toxicants to soil biota are partly determined by interactions outside the organism, as a result of dissimilarity between total and bioavailable concentrations. The design of joint toxicity studies in terrestrial systems is discussed with special reference to metal sorption in soils, experimental methodology, and laboratory practice. The joint toxic effect of copper and zinc for E. crypticus was of similar magnitude as found in studies with aquatic species exposed to metal mixtures.
Monoclonal antibodies (mAb) directed against Schistosoma mansoni tropomyosin isoform, SMTM (Xu et al. Experimental Parasitology 69, 373-392, 1989), were used to test for cross-reactivity with Biomphalaria glabrata antigens. One mAb (1F10) recognized antigens of 39, 41, and 80 kDa in a snail head/foot antigen preparation but not a hepatopancreas antigen preparation. Another mAb (1C1) cross-reacted with a 39-kDa antigen in the head/foot extract but not in the hepatopancreas extract. Epitope mapping revealed the 1F10 epitope to be between amino acids 135 and 188 of both Bg39 (Dissous et al. Molecular and Biochemical Parasitology 43, 245-256, 1990) and BgTMII (Weston and Kemp, Experimental Parasitology 76, 358-370, 1993), while the 1C1 epitope was located between amino acids 189 and 213 of BgTMII. Various invertebrate species, including members from Trematoda, Pulmonata, Annelida, and Arthropoda, were tested for cross-reactivity with the monoclonal antibodies. While the 1F10 mAb displayed broad invertebrate cross-reactivity, the 1C1 mAb cross-reactivity was restricted to schistosomes, F. hepatica, and the pulmonate snails B. glabrata and Physa sp.
Of the six phosphagen kinases found in animals, the primary structure is known only for creatine kinase. Here we report three cDNA-derived or chemically determined amino acid sequences of two kinds of phosphagen kinases: a glycocyamine kinase from the polychaete Neanthes diversicolor (Annelida) and arginine kinase from the abalone Nordotis madaka (Mollusca) and the shrimp Penaeus japonicus (Arthropoda). Like vertebrate creatine kinases are monomers. These enzymes consist of 350 to 390 amino acid residues, and have a calculated molecular mass of 39,900 to 44,500 Da. Neanthes glycocyamine kinase shows 50 to 58% sequence similarity with vertebrate and invertebrate creatine kinases, having the greatest similarity (57 to 58%) with vertebrate mitochondrial creatine kinase isoform. It shows lower, but significant similarity (37 to 39%) with invertebrate arginine kinases. The sequence similarity between Nordotis and Penaeus arginine kinases is 51%. A phylogenetic tree constructed from 14 amino acid sequences of phosphagen kinases showed that they can be separated into three major clusters corresponding to creatine kinase, glycocyamine kinase and arginine kinase. The cluster of glycocyamine kinase is apparently closer to that of creatine kinase than arginine kinase. The cluster of creatine kinase is composed of several subclusters, each corresponding to three vertebrate isoforms and the invertebrate enzyme.
Metallothionein (MT) and the related metal-binding proteins in tissues of lower vertebrates and invertebrates were isolated by gel filtration chromatography (conventional liquid and high performance liquid chromatography). The metal-binding proteins including MT were detected by determining the metals bound to the proteins by atomic absorption spectrophotometry. This analytical procedure was recommendable as the first step to characterize unknown metal-binding proteins in diverse living bodies. As MT in the lower vertebrates, avian (Japanese quail), reptilian (tortoise), amphibian (8 species of frogs and 2 species of tailed amphibians) and fish MTs were isolated and characterized. The number of isoMTs was different among animals belonging not only to different classes but also to different species in the same family. One of the isoMTs in the avian, reptilian and amphibian MTs was shown to contain one histidinyl residue. Cadmium(Cd)-binding proteins were induced in three species of insect (Insecta, Arthropoda) larvae (midge, fleshfly and silkworm) by loading of Cd. Distribution of Cd in insect tissues was different among the three species though the alimentary canal was commonly the most important tissue for the storage of Cd in all species. Further, Cd in the soluble fractions was bound to inducible proteins of different molecular sizes in the three species. Cd-binding protein was also detected in the waterflea (Crustacea, Arthropoda) after loading of Cd. Cd-binding proteins induced in the earthworm (Oligochaeta, Annelida) by loading of Cd were a mixture of proteins with three different molecular sizes. One of the Cd-binding proteins with an apparent molecular size of 7,000 was shown to have characteristics of MT.
The development of the egg envelope and its incorporation into the larval cuticle of the polychaete Phragmatopoma lapidosa, was studied by correlative scanning and transmission electron microscopy. The mature egg possesses an envelope composed of five zones including an outer granular zone formed by the tips of the egg microvilli. The formation of the granules is described and their functions are discussed. The entire egg envelope is retained as the larval cuticle up to the 16 h trochophore stage. From this stage to about the 60 h larval stage, the envelope is gradually lost and replaced by a cuticle consisting of branching microvilli. The cuticle of the 20 day larva is composed of highly branching microvilli penetrating a homogeneous electron opaque cuticle. The possible functions of the cuticle among the Annelida are discussed.
Protein kinases play important roles in various cellular interactions underlying metazoan development. To complement existing analyses of protein kinase function in the development of members of the three phyla, Chordata, Arthropoda, and Nematoda, we have begun to examine the cell- and tissue-specific localization of protein kinases in another metazoan phylum, the Annelida. For this purpose, we used the polymerase chain reaction to amplify putative protein kinase catalytic domain cDNAs from the medicinal leech, Hirudo medicinalis. This strategy allowed us to identify 11 cytoplasmic and receptor tyrosine kinase catalytic domains, and 2 cytoplasmic serine/threonine kinase catalytic domains. Using these cDNAs as probes for nonradioactive whole-mount in situ hybridization, we examined the embryonic expression pattern of each of the corresponding putative kinase mRNAs. As has been found in other species, most of the Hirudo protein kinase mRNAs were expressed in a highly specific manner in certain embryonic cells and tissues. We found both neuron- and glia-specific kinases within the nervous system, as well as kinases expressed in non-nervous tissues, such as the haemocoelomic, muscular, and excretory systems. These kinase cDNAs encode proteins likely to be critical for proper development, and can be used as cell- and tissue-specific histological probes for the analysis of Hirudo embryogenesis.
This review of the invasion of the human brain by tumors is based upon a comparative approach. The taxonomic distribution of a structure of the CNS to be considered a brain is present in the following taxonomic groups: Mollusca (Cephalopoda, Pulmonata) Sipunculida, Echiurida, Annelida, Arthropoda and Vertebrata (fishes, amphibians, reptiles, birds and mammals). The comparative approach (inter-, and intraspecies specific) provides a more informative, indicative, understanding of invasion of the human brain; especially in view of the morphological and functional heterogeneity of structures playing a role in the neoplastic invasion to and from the brain. It can be distinguished among primary invasiveness (as cancer in situ) and local recurrence on the one hand and remote spreading, such as metastasis, on the other. A review of the recent literature arranged according to tumor types is provided and comparative conclusions elucidated, especially to underline the tumor specificity of the invasion of brain tumors, especially the second or intra-species specific approach is therapeutically important. This is set forth against a background of epidemiology and species specificity. Due to the lack of bony skull capsule an extensive knowledge of the brain of cephalopod molluscs with its functional and morphological similarity to the human eye, and also that of the pulmonate Helix pomatia, the vineyard snail, could well serve as excellent oncologic models. Some conclusions can be drawn dealing with the theoretical possibility of first appearance of the different and heterogeneous components of the complicated structure known as brain including its supporting accessory organs during phylogeny.
The Ento- and Ectoprocta are sometimes placed together in the Bryozoa, which have variously been regarded as proto- or deuterostomes. However, Entoprocta have also been allied to the pseudocoelomates, while Ectoprocta are often united with the Brachiopoda and Phoronida in the (super)phylum Lophophorata. Hence, the phylogenetic relationships of these taxa are still much debated. We determined complete 18S rRNA sequences of two entoprocts, an ectoproct, an inarticulate brachiopod, a phoronid, two annelids, and a platyhelminth. Phylogenetic analyses of these data show that (1) entoprocts and lophophorates have spiralian, protostomous affinities, (2) Ento- and Ectoprocta are not sister taxa, (3) phoronids and brachiopods form a monophyletic clade, and (4) neither Ectoprocta or Annelida appear to be monophyletic. Both deuterostomous and pseudocoelomate features may have arisen at least two times in evolutionary history. These results advocate a Spiralia-Radialia-based classification rather than one based on the Protostomia-Deuterostomia concept.
Parenteral administration of foreign proteins results in earthworms in significantly increased levels of the antigen-binding protein (ABP). The earthworms (Lumbricus terrestris and Eisenia foetida; Oligochaeta, Annelida) were stimulated with different proteins and the ABP response was followed with an anti-ABP monoclonal antibody and in ligand assay with biotin conjugates of all proteins used for stimulation. ABP levels are increased after the stimulation with different proteins irrespective of the size and extent of glycosylation. Molar mass of the ABP molecules was always the same, 56 kDa in L. terrestris and 60 kDa in E. foetida. The level of the specificity is considerably lower in comparison with immunoglobulins since ABP reacts not only with the protein used for stimulation but also, though to lesser extent, with related proteins.
In contrast to the malacostracan crustaceans that use hemocyanin as the oxygen carrier, a number of branchiopod crustaceans, such as the water flea Daphnia magna, utilize hemoglobin (Hb) as the respiratory protein. By means of in situ hybridization (ISH) techniques with subsequent signal amplification using catalyzed reporter deposition, sites of Hb synthesis were localized in Daphnia magna. Based on a previously reported Hb-cDNA sequence, a specific ISH probe was designed and hybridized with the Hb-mRNA in histological sections of adult D. magna. The detection of Hb-mRNA was tissue specific and revealed that Hb is synthesized in fat cells, which play a role in fat and glycogen metabolism, and in epithelial cells of the epipodites, which are involved in osmoregulation. Sites of Hb synthesis have been identified in several invertebrate phyla, including Annelida and Nematoda. However, this is the first example in the class Crustacea, and only the second in the phylum Arthropoda.
We previously reported the sequence of a 9260-bp fragment of mitochondrial (mt) DNA of the cephalopod Loligo bleekeri [J. Sasuga et al. (1999) J. Mol. Evol. 48:692-702]. To clarify further the characteristics of Loligo mtDNA, we have sequenced an 8148-bp fragment to reveal the complete mt genome sequence. Loligo mtDNA is 17,211 bp long and possesses a standard set of metazoan mt genes. Its gene arrangement is not identical to any other metazoan mt gene arrangement reported so far. Three of the 19 noncoding regions longer than 10 bp are 515, 507, and 509 bp long, and their sequences are nearly identical, suggesting that multiplication of these noncoding regions occurred in an ancestral Loligo mt genome. Comparison of the gene arrangements of Loligo, Katharina tunicata, and Littorina saxatilis mt genomes revealed that 17 tRNA genes of the Loligo mt genome are adjacent to noncoding regions. A majority (15 tRNA genes) of their counterparts is found in two tRNA gene clusters of the Katharina mt genome. Therefore, the Loligo mt genome (17 tRNA genes) may have spread over the genome, and this may have been coupled with the multiplication of the noncoding regions. Maximum likelihood analysis of mt protein genes supports the clade Mollusca + Annelida + Brachiopoda but fails to infer the relationships among Katharina, Loligo, and three gastropod species.