Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| hybrids of oenothera biennis and oenothera franciscana in the first and second generations. | 1916 | 17245857 | |
| the cytology and genetics of a haploid sport from oenothera franciscana. | 1930 | 17246592 | |
| the genetics and cytology of a tetraploid from oenothera franciscana bartlett. | 1933 | 17246693 | |
| the appearance of a balanced lethal situation in the oenothera heterozygote gaudens. franciscana following severe heat treatment of seeds. | 1947 | 17247239 | |
| the gonads of the south american dolphins, inia geoffrensis, pontoporia blainvillei, and sotalia fluviatilis. | 1971 | 5581374 | |
| enzyme differentiation and phylogeny in clarkia franciscana, c. rubicunda and c. amoena. | 1973 | 28564780 | |
| gene duplication and fixed heterozygosity for alcohol dehydrogenase in the diploid plant clarkia franciscana. | all individuals of the diploid plant clarkia franciscana, an annual species native to california, have duplicated genes for the dimeric enzyme alcohol dehydrogenase. since each gene specifies a polypeptide with a distinct charge, the species has a fixed heterozygous phenotype consisting of three isozyme variants. the enzyme is coded by a single gene in closely related species. clarkia franciscana is highly self-pollinated and monomorphic at all but one of its loci that have been examined. conseq ... | 1974 | 4525465 |
| some notes on the pancreas of franciscana (la plata dolphin), pontoporia blainvillei. | 1975 | 1161261 | |
| digestive tract of la plata dolphin, pontoporia blainvillei. ii. small and large intestines. | 1975 | 1161260 | |
| the liver of franciscana (la plata dolphin), pontoporia blainvillei. | 1976 | 1272551 | |
| extrahepatic bile-passage of franciscana (la plata dolphin), pontoporia blainvillei. | 1976 | 995349 | |
| the tongue of franciscana (la plata dolphin), pontoporia blainvillei. | 1976 | 995350 | |
| lungs of franciscana (pontoporia blainvillei), with special references to their external aspects, weights and bronchial ramifications. | 1977 | 859712 | |
| identification of 4,6-o-(1-carboxyethylidene)-d-galactose by combined gas chromatography mass spectrometry. | combined gas chromatography mass spectrometry was used to separate and identify a carrageenan component suspected of being the acid ketal 4,6-o-(1-carboxyethylidene)-d-galactose. the mass spectral fragmentation pattern is presented as evidence of the presence of this component in the carrageenan from petrocelis middendorfii (p. franciscana). | 1978 | 747739 |
| myology of the shoulder of pontoporia blainvillei, including a review of the literature on shoulder morphology in the cetacea. | the purpose of this paper is to describe in detail the shoulder myology of the la plata river dolphin, pontoporia blainvillei, and to review the literature on cetacean shoulder myology. three fetal and one adult animal were used for the collection of morphological information. pontoporia is less specialized in its shoulder anatomy that most delphinid cetaceans, and shares several characteristics with some mysticetes. the omohyoid and anterior serratus anterior muscles are found in both pontopori ... | 1978 | 677058 |
| the axial musculature of pontoporia blainvillei, with comments on the organization of this system and its effect on fluke-stroke dynamics in the cetacea. | the axial muscular system of pontoporia blainvillei is described and compared with published reports of this system in other cetaceans. a comprehensive system for classification of axial muscles is presented, based on the studies of slijper. a discrete obliquus capitis inferior is described for the first time in cetacea, and it is suggested that its absence in previous descriptions may have been due partly to dissection error. the major axial muscle-masses are organized in a similar way in most ... | 1980 | 7405862 |
| control of colonial hydroid macrofouling by free-field ultrasonic radiation. | free-field ultrasonic radiation inhibited the feeding of the macrofouling hydroid garveia franciscana by causing tentacle contraction at the sonic degasification threshold. within the frequency range of 250 to 2000 kilohertz, the threshold sound intensity (sonic degasification threshold) that caused tentacle contraction was directly proportional to frequency, with the minimum observed being 0.6 watt per square centimeter at 250 kilohertz. a pulse length of 0.2 second and interpulse period of 102 ... | 1984 | 17746053 |
| quantitative neuroanatomy of the brain of the la plata dolphin, pontoporia blainvillei. | the brain of the la plata dolphin, pontoporia blainvillei, was studied with methods of quantitative morphology. the volumes and the progression indices of the main brain structures were determined and compared with corresponding data of other cetacea, insectivora and primates. in pontoporia, encephalization and neocorticalization are clearly greater than in primitive ("basal") insectivora. the indices are in the lower part of the range for simian monkeys. the paleocortex is regressive in accorda ... | 1984 | 6433744 |
| enamel structure in odontocete whales. | with regard to the enamel structure of mammals, a large number of studies have been reported in the past. of them, however, the enamel structure of odontocetes has not yet been sufficiently elucidated. the author therefore observed the enamel structure of 11 species in 7 families of living odontocetes. a clear prism structure in the enamel is noted in delphinids and pontoporia blainvillei. neophocaena phocaenoides has a very simple-structured prism, but even this structure is obvious only in the ... | 1987 | 3659855 |
| cell-specific endopolyploidy in developing artemia. | cells in developing artemia franciscana sfb demonstrated tissue-specific differences in dna content, as determined by fluorescence intensity of bisbenzimide-stained nuclei and by nuclear area. the general epidermis comprised proliferating diploid (2c) cells. the setal cells had 4c-8c dna content and did not divide during the first two instars. salt gland cells were polyploid (>8c) and also did not undergo mitosis. neural cells in the brain were diploid and were replicating. cells in the thorax r ... | 1988 | 28305474 |
| sequence-directed curvature of repetitive alui dna in constitutive heterochromatin of artemia franciscana. | an alu i family of repeated dna sequence 113 bp in length was found to be the major component of the heterochromatin in artemia franciscana. on the basis of the analysis of cloned oligomeric (monomer to examer) heterchromatic fragments we predicted that the sequence could produce a stable curvature in chromosomal dna. this prediction was confirmed by polyacrylamide gel electrophoresis analysis and by electron microscope observations. the anomalous mobility of these fragments is reversed when the ... | 1989 | 2813062 |
| a binding protein (p82 protein) recognizes specifically the curved heterochromatic dna in artemia franciscana. | dna bending has been suggested to play a role in the regulation of gene expression, initiation of dna replication, site specific recombination and dna packaging. in artemia franciscana (phillopoda anostraca) cells we have revealed that an alui dna family of repeats, 113-bp in length, is the major component of the constitutive heterochromatin found in the species. by analysis of cloned oligomeric (monomer to hexamer) heterochromatic fragments and electrophoretic experiments we verified that the r ... | 1990 | 2258053 |
| arrest of cytochrome-c oxidase synthesis coordinated with catabolic arrest in dormant artemia embryos. | we have examined cytochrome-c oxidase (cox) biosynthesis in brine shrimp (artemia franciscana) embryos during preemergence development (ped), as well as its inhibition under anaerobic dormancy, to determine whether transitions in intracellular ph (phi) have a regulatory influence on anabolic processes. under control aerobic conditions (embryo phi greater than or equal to 7.9), incorporation of radiolabeled amino acids shows that substantial biosynthesis of cox occurs during 12 h of ped (500% inc ... | 1990 | 2159729 |
| heat dissipation during long-term anoxia in artemia franciscana embryos: identification and fate of metabolic fuels. | microcalorimetric measurements of brine shrimp embryos during 6 days of anoxia indicated that heat dissipation was rapidly suppressed to 2.7% of control (aerobic) values over the first 9 h. energy flow continued to decline slowly to 31 microw.g dry mass-1 (0.4% of control) during the subsequent 5.5 days. within 2 h after returning anoxic embryos to aerobic conditions, heat dissipation rose to 77% of control rates. the calorimetric/respirometric (cr) ratio across this 2-h recovery period increase ... | 1990 | 2292613 |
| liquid chromatographic determination of efficacy of incorporation of trimethoprim and sulfamethoxazole in brine shrimp (artemia spp.) used for prophylactic chemotherapy of fish. | the brine shrimp artemia, an excellent live food source in aquaculture, has been studied as a carrier to deliver selected chemotherapeutic agents to fish for prophylactic treatment of infectious diseases. to monitor the efficiency of incorporation of trimethoprim and sulfamethoxazole in artemia franciscana, a sensitive and specific analytical method was developed. it is based on homogenization of artemia nauplii in methanol, extraction of lipids with hexane, solid-phase cleanup on c18 cartridges ... | 1991 | 1810182 |
| highly repetitive dna sequence in parthenogenetic artemia. | the study of the structural organization of the eukaryotic genome is one of the most important tools for disclosing the evolutionary relationships between species. artemia (crustacea, phyllopoda) offers a very interesting model for speciation studies. the genus, distributed all over the world, comprises both bisexual sibling species and parthenogenetic populations, exhibiting different chromosome numbers (diploidy, polyploidy, and heteroploidy). digestion of genomic dna of the parthenogenetic ar ... | 1991 | 1901366 |
| cloning of a cdna encoding an artemia franciscana na/k atpase alpha-subunit. | clones of cdna that code for an isoform of the artemia franciscana na/k atpase alpha subunit (naka alpha) have been isolated. the sequence of the longest of these clones (paratna136) is 3595 nucleotides; it codes for a 1004-amino acid protein whose sequence is identical to that of two previously sequenced artemia naka alpha peptides. the encoded protein is over 73% identical to drosophila melanogaster and vertebrate naka alpha s, and 73.8% identical to another artemia naka alpha isoform previous ... | 1991 | 1657719 |
| nucleotide variation and molecular structure of the heterochromatic repetitive alui dna in the brine shrimp artemia franciscana. | it has been suggested that dna bending could play a role in the regulation of gene expression, chromosome segregation, specific recombination and/or dna packaging. we have previously demonstrated that an alui dna family of repeats is the major component of constitutive heterochromatin in the brine shrimp a. franciscana. by the analysis of cloned oligomeric (monomer to hexamer) heterochromatic fragments we verified that the repetitive alui dna shows a stable curvature that determines a solenoidal ... | 1992 | 1474602 |
| aerobic heat shock activates trehalose synthesis in embryos of artemia franciscana. | encysted embryos (cysts) of the brine shrimp, artemia franciscana, contain large amounts of trehalose which they use as a major substrate for energy metabolism and biosynthesis for development under aerobic conditions at 25 degrees c. when cysts are placed at 42 degrees c (heat shock) these pathways stop, and the cysts re-synthesize the trehalose that was utilized during the previous incubation at 25 degrees c. glycogen and glycerol, produced from trehalose at 25 degrees c, appear to be substrat ... | 1992 | 1592115 |
| comparison of messenger rna pools in active and dormant artemia franciscana embryos: evidence for translational control. | in response to environmental anoxia, embryos of the brine shrimp artemia franciscana enter a dormant state during which energy metabolism and development are arrested. the intracellular acidification that correlates with this transition into anaerobic dormancy has been linked to the inhibition of protein synthesis in quiescent embryos. in this study, we have addressed the level of control at which a mechanism mediated by intracellular ph might operate to arrest protein synthesis. two independent ... | 1992 | 1349912 |
| purification and characterization of a proteolytic active fragment of dna topoisomerase i from the brine shrimp artemia franciscana (crustacea anostraca). | the atp-independent type i topoisomerase from the crustacean artemia franciscana was purified to near-homogeneity. its activity was measured by an assay that uses the formation of an enzyme-cleaved dna complex in the presence of the specific inhibitor camptothecin. the purification procedure is reported. purified topoisomerase is a single-subunit enzyme with a molecular mass of 63 kda. immunoblot performed on the different steps of purification shows that the purified 63 kda peptide is a proteol ... | 1992 | 1311554 |
| food-web modification by an invertebrate predator in the great salt lake (usa). | during unusually wet years the salinity of the great salt lake (utah) decreased from above 100 g/l to 50 g/l. this allowed the predaceous insect trichocorixa verticalis to invade the pelagic region of the lake and reach a mean summer density of 52/m(3). concurrent changes in the pelagic ecosystem were: a decrease in the dry biomass of the previously dominant filter-feeding brine shrimp artemia franciscana from 720 to 2 mg/m(3), the invasion of three other zooplankton taxa, a 10 × decrease in com ... | 1992 | 28312870 |
| genomic organization and developmental pattern of expression of the engrailed gene from the brine shrimp artemia. | we report the isolation and characterization of an engrailed gene in the crustacean artemia franciscana. the artemia gene spans a genomic region of 15 kilobases and the coding sequence is interrupted by two introns. it appears to be the only gene of the engrailed family present in the artemia genome. the predicted engrailed-like protein is 349 amino acids long and contains several domains including the homeodomain, well conserved when compared to other proteins of the engrailed family. based on ... | 1993 | 7903633 |
| similar alternative splicing events generate two sarcoplasmic or endoplasmic reticulum ca-atpase isoforms in the crustacean artemia franciscana and in vertebrates. | a second isoform of the artemia franciscana sarcoplasmic or endoplasmic reticulum ca-atpase has been identified through the isolation of cdna clones. this isoform differs from the previously identified one only at the c-terminal end of the protein. the last 6 amino acids of the former isoform change to 30 hydrophobic amino acids in the newly identified isoform that have the potentiality of being an additional transmembrane domain. the two a. franciscana isoforms are highly homologous to the two ... | 1993 | 8314776 |
| hom/hox genes of artemia: implications for the origin of insect and crustacean body plans. | insects and crustaceans are generally assumed to derive from a segmented common ancestor that had a distinct head but uniform, undifferentiated trunk segments. the subdivision of the body into functionally distinct regions (e.g. thorax and abdomen) is thought to have evolved independently in these two lineages. in insects, the differences between segments in the trunk are controlled by the antennapedia-like genes of the homeotic gene clusters. study of these genes in crustaceans should provide a ... | 1993 | 15335797 |
| extension of enzyme half-life during quiescence in artemia embryos. | encysted gastrulae of artemia franciscana are known to enter a reversible state of quiescence in which biosynthetic and catabolic pathways are markedly suppressed. given that these embryos can survive months of anoxia, we investigated their ability to extend the half-life of cytochrome-c oxidase (cox), a key metabolic enzyme, during anoxia. we calculate that the half-life of cox is extended to 101 days under anoxia, an estimated 77-fold increase compared with aerobic values. during conditions of ... | 1993 | 8381619 |
| regulatory features of protein synthesis in isolated mitochondria from artemia embryos. | optimal conditions were developed for measuring rates of protein synthesis in isolated mitochondria from encysted embryos of artemia franciscana to 1) identify the required chemical constituents, 2) assess the influence of extramitochondrial ph on protein synthesis, and 3) investigate potential mechanisms coordinating nuclear and mitochondrial gene expression. isolation procedures resulted in intact, highly coupled mitochondria [respiratory control ratio = 6.48 +/- 0.43 (se), n = 21]. requiremen ... | 1993 | 8285263 |
| structure of artemia franciscana sarco/endoplasmic reticulum ca-atpase gene. | genomic clones coding for the artemia franciscana sarco(endo)plasmic reticulum ca-atpase have been isolated. the restriction map of the overlapping clones covers a region of 65 kilobases of dna. nucleotide sequence of mrna coding regions shows that the gene is divided into 18 exons separated by 17 introns. compared with the structure of the rabbit sarco(endo)plasmic reticulum ca-atpase 1 gene, 12 of the introns are in the same position, 8 introns present in the rabbit gene are absent from a. fra ... | 1994 | 8175720 |
| speciation in the artemia genus: mitochondrial dna analysis of bisexual and parthenogenetic brine shrimps. | from the cloned mitochondrial dnas (mtdnas) isolated from two bisexual species, one mediterranean, artemia salina, and one american, artemia franciscana, and two parthenogenetic (diploid and tetraploid) strains of artemia parthenogenetica collected in spain, physical maps have been constructed and compared. they are extremely different among themselves, much more than the differences between drosophila melanogaster and d. yakuba and in the same range of different mammalian species such as mouse/ ... | 1994 | 8169960 |
| environmental contamination and marine mammals in coastal waters from argentina: an overview. | environmental contamination become an increasing global problem. different scientific strategies have been developed in order to assess the impact of pollutants on marine ecosystems. the distribution of toxic contaminants in tissues of different marine mammal species--both cetaceans and pinnipeds--has been studied in many ecosystems, as well as several related ecological processes, like pollutant accumulation or transfer through the food web. a research program directed towards evaluating the oc ... | 1994 | 7973603 |
| the complete mitochondrial dna sequence of the crustacean artemia franciscana. | the complete mitochondrial dna (mtdna) sequence of the brine shrimp artemia franciscana has been determined. it extends the present knowledge of mitochondrial genomes to the crustacean class and supplies molecular markers for future comparative studies in this large branch of the arthropod phylum. artemia mtdna is 15,822 nucleotides long, and when compared with its drosophila counterpart, it shows very few gene rearrangements, merely affecting two trnas placed 3' downstream of the nd 2 gene. in ... | 1994 | 7966370 |
| embryogenesis, hatching and larval development of artemia during orbital spaceflight. | developmental biology studies, using gastrula-arrested cysts of the brine shrimp artemia franciscana, were conducted during two flights of the space shuttle atlantis (missions sts-37 and sts-43) in 1991. dehydrated cysts were activated, on orbit, by addition of salt water to the cysts, and then development was terminated by the addition of fixative. development took place in 5 ml syringes, connected by tubing to activation syringes, containing salt water, and termination syringes, containing fix ... | 1994 | 11537922 |
| structure and expression of a polyubiquitin gene from the crustacean artemia. | we have characterized two polyubiquitin genes from the crustacean artemia franciscana. one of them, ubi1, has nine ubiquitin units and an intron of a minimum size of 3.5 kb that ends 7 bp before the initiator atg. the 5' end of the transcript from this gene has been identified by anchored pcr. the existence of the other gene (ubi2) was inferred from several cdna clones that differ from ubi1 in the c-terminal extension and in the 3' untranslated region as well as in the nucleotide sequence of the ... | 1994 | 7841785 |
| acute blockage of the ubiquitin-mediated proteolytic pathway during invertebrate quiescence. | many organisms withstand adverse environmental conditions by entering a reversible state of quiescence that may last for months or years. in this report we provide evidence that the reduction in adenylate energy status and the associated intracellular acidosis occurring during anoxia-induced quiescence combine to inhibit, directly or indirectly, the initial step in the ubiquitin-mediated proteolytic pathway in embryos of the brine shrimp artemia franciscana. the levels of ubiquitin-conjugated pr ... | 1994 | 7943430 |
| extensive intracellular translocations of a major protein accompany anoxia in embryos of artemia franciscana. | cells of encysted gastrula embryos of the crustacean artemia franciscana exhibit extraordinary stability during prolonged anoxia. we find that they contain an abundant protein (referred to as "26-kda protein") that undergoes translocation to the nucleus during anoxia. the reverse translocation rapidly occurs when anoxic embryos are returned to aerobic conditions. a similar translocation appears to take place in embryos exposed to 42 degrees c aerobic heat shock and prolonged exposure to low temp ... | 1994 | 8174644 |
| global arrest of translation during invertebrate quiescence. | comparing the translational capacities of cell-free systems from aerobically developing embryos of the brine shrimp artemia franciscana vs. quiescent embryos has revealed a global arrest of protein synthesis. incorporation rates of [3h]leucine by lysates from 4-h anoxic embryos were 8% of those from aerobic (control) embryos, when assayed at the respective ph values measured for each treatment in vivo. exposure of embryos to 4 h of aerobic acidosis (elevated co2 in the presence of oxygen) suppre ... | 1994 | 8078909 |
| topoisomerase i action on the heterochromatic dna from the brine shrimp artemia franciscana: studies in vivo and in vitro. | the genomes of higher eukaryotes contain various amounts of tandem repeated dna sequences (satellite dna) typically located in the constitutive heterochromatin, the most highly condensed region of interphase chromosomes. we have previously demonstrated that an alui dna family of repeats is the major component of constitutive heterochromatin in the brine shrimp artemia franciscana. the analysis of cloned heterochromatic fragments revealed that this repetitive dna shows a stable curvature conferri ... | 1994 | 8192650 |
| ontogeny of cardiac function in the brine shrimp artemia franciscana kellogg 1906 (branchiopoda: anostraca). | in newly hatched brine shrimp (artemia franciscana) cardiac organogenesis and function could only take place with the onset of segmentation. consequently differences in age, body size and temperature (in the range 22-34 degrees c) affected the ontogeny of cardiac activity only indirectly, through their influence on developmental stage. once present the frequency of cardiac activity (heart beat) increased with increasing body size and concomitant differentiation of cardiac tissue. at least initia ... | 1994 | 7798869 |
| identification of an artemia franciscana retropseudogene containing part of the last exons of the sarco/endoplasmic reticulum ca-atpase-encoding serca gene. | a genomic clone has been isolated which contains sequences highly homologous to part of exon 14 and exons 15, 16 and 17 of the artemia franciscana sarco-endoplasmic reticulum ca-atpase(serca)-encoding gene, but none of the introns. the homologous region extends to the 3' end of the mrna, although the poly(a) tail is not present. the structure of this clone suggests that it represents a 5'-end-truncated retropseudogene (r psi). | 1994 | 7959022 |
| tissue-specific alternative promoters regulate the expression of the two sarco/endoplasmic reticulum ca-atpase isoforms from artemia franciscana. | the sarco/endoplasmic reticulum ca-atpase gene from artemia franciscana is transcribed into two mrnas of 4.5 and 5.2 kb that code for protein isoforms differing at their carboxyl terminus. northern blot assays and anchored polymerase chain reaction (pcr) experiments have shown that these two mrnas also differ at the initial part of their 5' untranslated region. the 5.2-kb mrna-specific 5' untranslated region is present as an independent exon whose transcription is regulated by a promoter differe ... | 1995 | 7546295 |
| hox genes and the diversification of insect and crustacean body plans. | crustaceans and insects share a common origin of segmentation, but the specialization of trunk segments appears to have arisen independently in insects and various crustacean subgroups. such macroevolutionary changes in body architecture may be investigated by comparative studies of conserved genetic markers. the hox genes are well suited for this purpose, as they determine positional identity along the body axis in a wide range of animals. here we examine the expression of four hox genes in the ... | 1995 | 7630416 |
| phylogenetic study of bisexual artemia using random amplified polymorphic dna. | study of polymorphisms in the eukaryotic genome is an important way to discover the evolutionary relationships between species. artemia (crustacea, anostraca) offers a very interesting model for evolutionary studies. in fact the genus, distributed all over the world in hundreds of known biotopes, comprises both bisexual sibling species and parthenogenetic populations easily available from the artemia reference center of ghent. in spite of great interest in it and its extensive use in aquaculture ... | 1995 | 7666444 |
| effect of microgravity and hypergravity on embryo axis alignment during postencystment embryogenesis in artemia franciscana (anostraca). | cysts of brine shrimp attached with a liquid adhesive to 12-mm diameter glass coverslips in a syringe-type fluid processing apparatus were flown aboard the nasa space shuttle discovery, flight sts-60, from 3-11 february 1994, and were allowed to undergo postencystment embryogenesis and to hatch in microgravity. the shuttle flight and the ground-based control coverslips with attached cysts were parallel to the earth's surface during incubation in salt water. based on the position of the cyst shel ... | 1995 | 11539283 |
| potential role in development of the major cysteine protease in larvae of the brine shrimp artemia franciscana. | encysted embryos and larvae of the brine shrimp artemia franciscana contain a cysteine protease which represents over 90% of the protease activity in these organisms. we have used immunocytochemical methods to determine the localization and potential role of the cysteine protease in development of young larvae. in prenauplius larvae, there is intense staining for the protease on the basal side of the epidermal layer in the posterior region and diffuse staining for the protease throughout the emb ... | 1995 | 8581922 |
| nuclear-cytoplasmic translocations of protein p26 during aerobic-anoxic transitions in embryos of artemia franciscana. | embryos of the crustacean artemia franciscana survive continuous anoxia for periods of years, during which their metabolism comes to a reversible stand-still. a question of some interest concerns the maintenance of cellular integrity in the absence of biosynthesis and an ongoing energy metabolism. the present paper continues previous work on an abundant protein (p26) that undergoes extensive intracellular translocation during aerobic-anoxic transitions, exhibits several characteristics of stress ... | 1995 | 7628526 |
| in situ hybridization analyses of na, k-atpase alpha-subunit expression during early larval development of artemia franciscana. | the spatial pattern of expression of the mrna encoded by the na,k-atpase alpha-subunit cdna clone paratna136 was determined by in situ hybridization of first, second, and third instar artemia franciscana larvae. this mrna was expressed at high levels in the salt gland, the antennal gland, and the end of the midgut, which are the three main osmoregulatory organs in artemia at these stages of development. the pattern of expression was similar at the three stages of development analyzed, although t ... | 1995 | 7897181 |
| reactivation of ubiquitination in artemia franciscana embryos during recovery from anoxia-induced quiescence | encysted gastrulae of artemia franciscana are known to enter a reversible state of quiescence promoted by anoxia, during which the half-life of cytochrome oxidase is prolonged up to 77-fold. this observation suggests that proteolytic pathways within mitochondria are inhibited, and indeed the suppression of the initial step in ubiquitin-mediated proteolysis under anoxia has been reported. given that active embryos require efficient degradation of macromolecules, we investigated the reactivation o ... | 1995 | 9319173 |
| the sequence, organization, and evolution of the locusta migratoria mitochondrial genome. | the sequencing of the cloned locusta migratoria mitochondrial genome has been completed. the sequence is 15,722 bp in length and contains 75.3% a+t, the lowest value in any of the five insect mitochondrial sequences so far determined. the protein coding genes have a similar a+t content (74.1%) but are distinguished by a high cytosine content at the third codon position. the gene content and organization are the same as in drosophila yakuba except for a rearrangement of the two trna genes trnalys ... | 1995 | 8587138 |
| actin gene structure in two artemia species, a. franciscana and a. parthenogenetica. | genomic clones coding for actin have been isolated from two species of the crustacean artemia, a. parthenogenetica and a. franciscana. the act211 isoform gene was isolated from a. parthenogenetica, and the two other isoform genes, act302 and act403, were isolated from a. franciscana. the comparison of the nucleotide sequence of genomic and cdna clones showed an interspecific divergence of 4% in translated and 6.1% in untranslated regions. however, the establishment of the partial structure of th ... | 1996 | 8703088 |
| accumulation of trimethoprim, sulfamethoxazole, and n-acetylsulfamethoxazole in fish and shrimp fed medicated artemia franciscana. | in a previous paper (h.j. nelis, p. léger, p. sorgeloos, and a. p. de leenheer, antimicrob. agents chemother. 35:2486-2489, 1991) it was reported that two selected antibacterial agents, i.e., trimethoprim and sulfamethoxazole, can be efficiently bioencapsulated in nauplii of the brine shrimp artemia franciscana for administration to fish. this follow-up study showed that larvae of the sea bass and the turbot as well as postlarvae of the white shrimp accumulate the therapeutic agents in high quan ... | 1996 | 8807056 |
| partial sequence of the shrimp penaeus notialis mitochondrial genome. | about half of the mitochondrial dna of the shrimp penaeus notialis (crustacea: decapoda) has been cloned (in 2 overlapping fragments of 7.9 kb and 1 kb) and partially sequenced. the gene content and arrangement are identical to that of the homologous domain in drosophila yakuba. intergenic nucleotides are scarce and a 982 bp non-coding sequence exhibit features similar to that of mtdna control regions. the gene organization and the trna structures differentiate the penaeus notialis mitochondrial ... | 1996 | 8881281 |
| acute depression of mitochondrial protein synthesis during anoxia: contributions of oxygen sensing, matrix acidification, and redox state. | mitochondrial protein synthesis is acutely depressed during anoxia-induced quiescence in embryos of artemia franciscana. oxygen deprivation is accompanied in vivo by a dramatic drop in extramitochondrial ph, and both of these alterations strongly inhibit protein synthesis in isolated mitochondria. here we show that the oxygen dependence is not explained simply by blockage of the electron transport chain or by the increased redox state. whereas oxygen deprivation substantially depressed protein s ... | 1996 | 8631750 |
| mitochondrial differentiation during the early development of the brine shrimp artemia franciscana. | during the early development of artemia there is an increase in mitochondrial enzyme activities of about one order of magnitude, whereas the activities of two cytoplasmic enzymes tested as controls remain unaltered. the mitochondrial enzyme activation correlates with (i) large changes in mitochondrial morphology, (ii) a 5-fold increase in the amount of the h+-atp synthase beta-subunit and (iii) a dramatic increase in the steady-state level of mitochondrial mrnas, whereas mitochondrial rrna conce ... | 1996 | 8670064 |
| transcriptional regulation during the activation and development of artemia franciscana encysted embryos. | 1996 | 9087711 | |
| oxygen and ph regulation of protein synthesis in mitochondria from artemia franciscana embryos. | to identify factors responsible for the down-regulation of mitochondrial biosynthetic processes during anoxia in encysted artemia franciscana embryos, the effects of oxygen limitation and ph on protein synthesis were investigated in isolated mitochondria. at the optimal ph of 7.5, exposure of mitochondria to anoxia decreases the protein synthesis rate by 79%. rates were suppressed by a further 10% at ph 6.8, the intracellular ph (phi) measured under anoxia in vivo. matrix ph, measured under iden ... | 1996 | 8546685 |
| segmentation in the crustacean artemia: engrailed staining studied with an antibody raised against the artemia protein. | we have studied the process of post-embryonic segmentation in the anostracan crustacean artemia franciscana using a specific antibody raised against the engrailed protein of this organism. three cephalic segments are specified during embryonic development, before larval hatching, whilst trunk (thoracic) segmentation begins after the first stage free-swimming nauplius larva has emerged from the dormant cyst. thus, cephalic and trunk segmentation seem to be at least in part independent and superim ... | 1996 | 28306093 |
| tissue-specific expression of two artemia franciscana sarco/endoplasmic reticulum ca-atpase isoforms. | the sarco/endoplasmic reticulum ca-atpase (serca) gene from artemia franciscana is transcribed into two mrnas that code for two different enzyme isoforms. we investigated the tissue-specific expression of each mrna by in situ hybridization of larval tissue sections. one of the isoforms is expressed in the muscle fibers of the appendages. the other isoform is generally expressed throughout all tissues of the larvae. the tissue distribution of these two isoforms is very similar to the one describe ... | 1996 | 8601691 |
| profiles of nuclear and mitochondrial encoded mrnas in developing and quiescent embryos of artemia franciscana. | embryos of the brine shrimp artemia franciscana are able to withstand long bouts of environmental anoxia by entering a quiescent state during which metabolism is greatly depressed. recent evidence supports a global arrest of protein synthesis during quiescence. in this study we measured the amounts of mrna for a mitochondrial-encoded subunit of cytochrome c oxidase (cox i) and for nuclear-encoded actin during aerobic development, anaerobiosis, and aerobic acidosis (artificial quiescence imposed ... | 1996 | 8817476 |
| protein kinases in mitochondria of the invertebrate artemia franciscana. | the information concerning protein kinases in animal mitochondria is scarce and related only to mammals. no data are available for invertebrates. we demonstrate here the presence of casein kinase ii (ck ii) and camp-dependent protein kinase (pka) in the purified mitochondria of the crustacean artemia franciscana. whereas the mitochondrial ck ii showed the same characteristics of the cytosolic enzyme, mitochondrial pka had an apparent km for its substrate kemptide 1 order of magnitude lower than ... | 1997 | 9056227 |
| ontogenetic habitat selection by hadwenius pontoporiae (digenea: campulidae) in the intestine of franciscanas (cetacea). | the linear habitat selection of 4 sequential maturity stages (1, 2, 3, and 4) of the trematode hadwenius pontoporiae in the intestines of 26 south american dolphins pontoporia blanvillei was investigated. the franciscana is a suitable host for h. pontoporiae because all 26 hosts were infected, the infrapopulations being composed mostly of gravid (stage 4) worms. most trematodes were found in the first third of the intestine. the niches of the maturity stages decreased from stage 1 to 4. gravid w ... | 1997 | 9057690 |
| embryos of artemia franciscana survive four years of continuous anoxia: the case for complete metabolic rate depression | encysted gastrula embryos of the crustacean artemia franciscana have acquired an array of adaptations that enable them to survive a wide variety of environmental extremes.the present paper shows that at least 60 % survive 4 years of continuous anoxia at physiological temperatures (20­23 °c) when fully hydrated. although these embryos appear to carry on a metabolism during the first day of anoxia, no evidence for a continuing metabolism throughout the subsequent 4 years was obtained. duri ... | 1997 | 9318130 |
| oxygen, phi and arrest of biosynthesis in brine shrimp embryos. | embryos of the brine shrimp artemia franciscana are able to withstand bouts of environmental anoxia for several years by entering a quiescent state, during which time metabolism is greatly depressed. within minutes of oxygen removal, intracellular ph (phi) drops at least 1.0 unit. this acidification has been strongly implicated in the arrest of both catabolic and anabolic processes in the cytoplasm. a global arrest of cytoplasmic translation accompanies the transition into anoxia or into aerobic ... | 1997 | 9429663 |
| mitochondrial transcription initiation in the crustacean artemia franciscana. | mitochondrial transcription has been studied in several vertebrate organisms, but so far no report on mitochondrial transcription initiation in invertebrates has been published. here we present an analysis of transcription initiation sites using in vivo-synthesized transcripts in the crustacean artemia franciscana. the mitochondrial genome of artemia has the same coding capacity as most animal mitochondrial genomes, and its overall organization is almost identical to that of drosophila. using in ... | 1997 | 9428705 |
| effect of anaerobiosis on cysteine protease regulation during the embryonic-larval transition in | hydrated encysted embryos of the brine shrimp artemia franciscana have the ability to withstand years in anaerobic sea water using metabolic strategies that enable them to inactivate all cell metabolic activities and then to resume development when placed in aerobic sea water. however, this unique characteristic of artemia franciscana embryos is lost during a very short period, at the embryonic­larval transition period of development, coincident with the appearance of prenauplius larvae. thu ... | 1997 | 9318685 |
| satellite dna from the brine shrimp artemia affects the expression of a flanking gene in yeast. | we have previously revealed that in the brine shrimp artemia franciscana an alui dna family of repeats, 113 bp in length, is the major component of the constitutive heterochromatin and that this repetitive dna shows a stable curvature that confers a solenoidal geometry on the double helix in vitro. it was suggested that this particular structure may play a relevant role in determining the condensation of the heterochromatin. in this report we have cloned hexamers of highly-repetitive sequence (a ... | 1997 | 9161405 |
| polymorphism and structure of the gene coding for the alpha 1 subunit of the artemia franciscana na/k-atpase. | genomic clones coding for one of the two identified artemia franciscana na/k-atpase alpha subunits, the alpha 1 subunit, have been isolated. several overlapping clones were obtained, although their restriction maps showed a large heterogeneity. sequencing of their exons showed that they differ in up to 3.46% of their nucleotides in translated regions and 8.18% in untranslated regions. southern blot analysis of dna purified from different lots of a. franciscana cysts and from isolated individuals ... | 1997 | 9020888 |
| partial sequence of the mitochondrial genome of the crustacean daphnia pulex. | a 4062-nucleotide (nt) fragment of the mitochondrial genome of the crustacean daphnia pulex was sequenced and found to contain the complete genes for eight trnas and five proteins (atp6, atp8, coii, coiii, nd3) and the partial sequence of coi. in combination with data described previously, approximately 50% of the d. pulex mitochondrial genome has been sequenced. the gene order in this half of the genome is identical to that of drosophila yakuba which differs from that of the other completely se ... | 1997 | 9000380 |
| characterization of gamma-tubulin in artemia: isoform composition and spatial distribution in polarized cells of the larval epidermis. | microtubule arrangement is influenced by gamma-tubulin, a soluble protein of the eukaryotic cell cytosol and a component of microtubule-organizing centers. in this study, affinity purified antibodies to gamma-tubulin were prepared and their specificity demonstrated by immunostaining of western blots and in competitive elisas. when employed to label mouse fibroblasts, one or two brightly stained dots appeared in each cell, a pattern characteristic of centrosomes. antibody 9, raised to a conserved ... | 1998 | 9712263 |
| bioencapsulation of two different vibrio species in nauplii of the brine shrimp (artemia franciscana) | two groups of nauplii from the brine shrimp (artemia franciscana) were enriched with different bacteria, and the dynamics of bacterial uptake by the nauplii were observed. this study showed that the efficiency of artemia nauplii in bioencapsulating bacteria strongly depends on the type of bacteria used, time of exposure, and status (live or dead) of the bacteria. | 1998 | 9603861 |
| quiescence in artemia franciscana embryos: reversible arrest of metabolism and gene expression at low oxygen levels. | depression of the production and consumption of cellular energy appears to be a prerequisite for the survival of prolonged bouts of anoxia. a correlation exists between the degree of metabolic depression under anoxia and the duration of anoxia tolerance. in the case of brine shrimp (artemia franciscana) embryos, oxygen deprivation induces a reversible quiescent state that can be tolerated for several years with substantial survivorship. a global arrest of cytoplasmic translation accompanies the ... | 1998 | 9510534 |
| cloning and sequencing of an alpha-tubulin cdna from artemia franciscana: evidence for translational regulation of alpha-tubulin synthesis. | the brine shrimp, artemia franciscana, exhibits a limited number of tubulin isotypes which change little during early postgastrula growth. in order to better understand the synthesis of alpha-tubulins during artemia development, a cdna termed alphaat1 was cloned and sequenced. alignment analyses revealed that the polypeptide encoded by alphaat1 is similar to alpha-tubulins from other species. hybridization of alphaat1 to restriction-digested dna on southern blots produced a simple banding patter ... | 1998 | 9805005 |
| identification of a mitochondrial rna polymerase in the crustacean artemia franciscana. | mitochondrial rna polymerase activity has been isolated from the crustacean artemia franciscana at two stages of development, dormant embryo and developing larva. the preparations were obtained from purified mitochondria and the polymerase activity was purified by heparin-sepharose chromatography. the presumed polymerase has a molecular mass of about 120 kda and a 7.4 s sedimentation coefficient. the biochemical characterization of the enzymatic reaction identified our rna polymerase preparation ... | 1998 | 9606962 |
| intestinal uptake of lipovitellin from brine shrimp (artemia franciscana) by larval inland silversides (menidia beryllina) and striped bass (morone saxatilis). | intestinal uptake of lipovitellin (lv) from brine shrimp (artemia franciscana) in larval inland silversides (menidia beryllina) and striped bass (morone saxatilis) was described using immunocytochemistry. polyclonal antisera were raised against two subunits of lv (lv68 and lv190). when tested by immunocytochemistry, anti-lv68 showed cross-reactivity with some of the pancreatic cells especially in inland silversides. therefore anti-lv190 was used to localize immunoreactive lv. inland silversides ... | 1998 | 11253815 |
| the synthesis of a small heat shock/alpha-crystallin protein in artemia and its relationship to stress tolerance during development. | fertilized oocytes of the brine shrimp artemia franciscana undergo either ovoviviparous or oviparous development, yielding free-swimming larvae (nauplii) or encysted gastrulae (cysts), respectively. encystment is followed by diapause, wherein metabolism is greatly reduced; the resulting cysts are very resistant to extreme stress, including desiccation and long-term anoxia. the synthesis of p26, a small heat shock/alpha-crystallin protein produced only in oviparously developing artemia, is shown ... | 1999 | 10068475 |
| experimental studies of extinction dynamics | extinction of populations occurs naturally, but global extinction rates are accelerating, making understanding extinction a high priority for conservation. extinction in experimental populations of brine shrimp (artemia franciscana) was measured to assess hypothesized extinction processes. greater initial population size, greater maximum population size supported by the environment, and lower variation in environmental conditions reduced the likelihood of extinction, as hypothesized. however, in ... | 1999 | 10550058 |
| hypoxia accelerates the development of respiratory regulation in brine shrimp - but at a cost | the ability to regulate o(2) uptake during exposure to acutely declining o(2) tensions developed early (stage 6) in the brine shrimp artemia franciscana and co-occurred with the appearance of a functional heart and gills. culture under chronic hypoxia (p(o2)=10 kpa) resulted in this regulation being brought forward both in development (to stage 3) and in time (hypoxia stimulated early growth), but still before heart and gill formation took place. consequently, it was suggested that the hypoxia-r ... | 1999 | 10574741 |
| regulatory features of transcription in isolated mitochondria from artemia franciscana embryos. | optimal conditions were developed for an in organello transcriptional run-on assay using mitochondria isolated from artemia franciscana embryos to investigate potential regulatory features of rna synthesis under conditions of anoxia-induced quiescence. transcription is not dependent on oxidative phosphorylation for maximal activity when exogenous atp is available. bona fide transcription products, as assessed by hybridization with specific mitochondrial cdnas from a. franciscana, are produced in ... | 1999 | 10600903 |
| reexamination of hemocytes in brine shrimp (crustacea, branchiopoda). | in 1941, a single type of hemocyte was described in the blood of the brine shrimp artemia salina using light microscopy. this condition is unusual because most crustaceans examined using morphological, cytochemical, and functional methods have at least two types of hemoctyes. upon examining a. franciscana, we found a single type of disk-shaped hemocyte, with a centrally located nucleus and about 15 large (6 microm diameter) granules. the granules stain for the presence of acid phosphatase and re ... | 1999 | 10580266 |
| formation of a covalent nepsilon2-guanylylhistidyl reaction intermediate by the gtp:gtp guanylyltransferase from the brine shrimp artemia. | the chemical nature of the enzyme-nucleotide phosphoramidate reaction intermediate employed by the unique gtp:gtp guanylyltransferase from yolk platelets of artemia franciscana cysts to synthesize diguanosine tetraphosphate (gp4g) has been investigated. labeling of the enzyme with [alpha-32p]gtp followed by isolation of the labeled phosphoamino acid by periodate treatment and alkaline hydrolysis and comparison of the product with phosphoamino acid standards by thin-layer and ion-exchange chromat ... | 1999 | 9882433 |
| mitochondrial genes collectively suggest the paraphyly of crustacea with respect to insecta. | complete sequences of seven protein coding genes from penaeus notialis mitochondrial dna were compared in base composition and codon usage with homologous genes from artemia franciscana and four insects. the crustacean genes are significantly less a + t-rich than their counterpart in insects and the pattern of codon usage (ratio of g + c-rich versus a + t-rich codon) is less biased. a phylogenetic analysis using amino acid sequences of the seven corresponding polypeptides supports a sister-taxon ... | 1999 | 10368442 |
| interactions of the ccaat-binding trimer nf-y with nucleosomes. | nf-y is a sequence-specific evolutionary conserved activator binding to ccaat boxes with high affinity and specificity. it is a trimer formed by nf-ya and two putative histone-like subunits, nf-yb and nf-yc, showing similarity to histones h2b and h2a, respectively. we investigated the relationships between nf-y and chromatin using an artemia franciscana chromatin assembly system with plasmids containing the major histocompatibility complex class ii ea promoter. the nf-y trimer, but not single su ... | 1999 | 9880503 |
| aph-1, a pou homeobox gene expressed in the salt gland of the crustacean artemia franciscana. | we characterized the first pou-homeoprotein in a crustacean (designated aph-1 for artemia pou-homeoprotein, embl y15070). the amino acid sequence of the aph-1 pou-domain is identical, except for two residues, to that of the two class iii pou proteins cf1-a (drosophila) and pou-m1 (bombyx mori). southern blot analysis suggests that crustaceans have only one class iii pou gene. rt-pcr and whole-mount in situ hybridization show that aph-1 mrna is present in larvae specifically in the salt gland, an ... | 1999 | 10495289 |
| isolation and characterization of the gene coding for artemia franciscana tata-binding protein: expression in cryptobiotic and developing embryos. | genomic and cdna clones coding for the artemia franciscana homolog of the tata box-binding protein (tbp) were isolated. the c-terminal region of the predicted protein displays up to 92% sequence identity with the conserved c-terminal regions of tbps from other species. the gene is divided in seven exons that expand over a region of 33 kb. the position of the four introns located in the conserved c-terminal region has been compared with those of other species. two of these introns have been gener ... | 1999 | 10366711 |
| high dna sequence variability at the alpha 1 na/k-atpase locus of artemia franciscana (brine shrimp): polymorphism in a gene for salt-resistance in a salt-resistant organism. | we previously reported that the na/k-atpase alpha 1 subunit coding gene showed signs of being a very polymorphic locus in artemia franciscana. this species is adapted to highly saline waters, and the na/k-atpase alpha 1 isoform presumably plays a key role in this adaptation. therefore, we were interested in further study of the alpha 1 na/k-atpase polymorphisms to examine whether they might be due to an adaptation to salt resistance driven by natural selection. using coding sequences from 10 gen ... | 2000 | 10677846 |
| cloning and characterization of sarco/endoplasmic reticulum ca(2+)-atpase (serca) from crayfish axial muscle. sarco/endoplasmic reticulum ca(2+)-atpase. | the discontinuous pattern of muscle growth during the moulting cycle of a freshwater crustacean (the crayfish procambarus clarkii) was used as a model system to examine the regulation of the expression of sarco/endoplasmic reticulum ca(2+)-atpase (serca). we describe the cloning, sequencing and characterization of a novel serca cdna (3856 bp) obtained from crayfish axial abdominal muscle by reverse transcription/polymerase chain reaction (rt-pcr) followed by rapid amplification of cdna ends (rac ... | 2000 | 11044380 |
| a serum response factor homologue is expressed in ectodermal tissues during development of the crustacean artemia franciscana. | complementary dna clones have been isolated from the crustacean artemia franciscana coding for a serum response factor (srf)-homologue that is more than 96% identical to human and drosophila melanogaster srfs in their mads boxes. the srf homologue is expressed in ectodermal tissues, as determined by in situ hybridization experiments. a srf-binding site has been identified in the promoter region of the actin403 gene that is also expressed in ectodermal tissues, in accordance with its transcriptio ... | 2000 | 10960789 |
| relationship between dental morphology, sex, body length and age in pontoporia blainvillei and sotalia fluviatilis (cetacea) in northern rio de janeiro, brazil. | the relationship between dental morphology, sex, body length and age of small cetaceans can be used to determine ontogeny, sexual dimorphism and geographical variation. the objective of this study was to determine the relationship between dental morphology, sex, body size and age. a total of 91 specimens of p. blainvillei and 80 specimens of s. fluviatilis accidentally captured in fisheries or stranded in northern rio de janeiro (21 masculine37'-22 masculine25's), from september 1988 to november ... | 2000 | 10959112 |
| a novel heparan sulphate with high degree of n-sulphation and high heparin cofactor-ii activity from the brine shrimp artemia franciscana. | with the aid of heparinase and heparitinases from flavobacterium heparinum and 13c and ih nmr spectroscopy it was shown that the heparan sulphate isolated from the brine shrimp artemia franciscana exhibits structural features intermediate between those of mammalian heparins and heparan sulphates. these include an unusually high degree of n-sulphation (with corresponding very low degree of n-acetylation), a relatively high content of iduronic acid residues (both unsulphated and 2-o-sulphated) and ... | 2000 | 10704986 |
| characterization of atp-dependent proteolysis in embryos of the brine shrimp, artemia franciscana. | under anoxia, embryos of artemia franciscana enter a state of quiescence. during this time protein synthesis is depressed, and continued degradation of proteins could jeopardize the ability to recover from quiescence upon return to favorable conditions. in this study, we developed an assay for monitoring atp/ ubiquitin-dependent proteolysis in order to establish the presence of this degradation mechanism in a. franciscana embryos, and to describe some characteristics that may regulate its functi ... | 2000 | 10791572 |
| depression of nuclear transcription and extension of mrna half-life under anoxia in artemia franciscana embryos. | transcriptional activity, as assessed by nuclear run-on assays, was constant during 10 h of normoxic development for embryos of the brine shrimp artemia franciscana. exposure of embryos to only 4 h of anoxia resulted in a 79.3+/-1 % decrease in levels of in-vivo-initiated transcripts, and transcription was depressed by 88. 2+/-0.7 % compared with normoxic controls after 24 h of anoxia (means +/- s.e.m., n=3). initiation of transcription was fully restored after 1 h of normoxic recovery. artifici ... | 2000 | 10708633 |