| stimulation of starfish coelomocytes by interleukin-1. | echinoderms have coelomocytes that are capable of non-specific phagocytosis of pathogens and cellular debris. it has been suggested that cytokines, analogous to vertebrate interleukins, are involved in mediating these responses, though how they may function is not known. using a mouse thymocyte proliferation assay we confirm that cytokine activity, which can be blocked with antibodies to mammalian il-1 alpha, can be extracted from coelomic fluid of the starfish pisaster ochraceus. a subset of st ... | 1991 | 1953727 |
| partial purification and some enzymatic properties of proteolytic enzyme fractions isolated from pisaster ochraceus (echinoderm) pyloric caeca. | | 1973 | 4714907 |
| actin genes from the sea star pisaster ochraceus. | genomic and tube foot cdna recombinant libraries have been prepared from the sea star pisaster ochraceus. three major classes of actin-bearing lambda phage clones have been identified on the basis of restriction enzyme mapping and localization of actin coding regions. there are at most six non-allelic actin genes in the sea star genome. southern blots of restriction enzyme-digested genomic dna from individual sea stars probed with actin coding sequences indicate extensive polymorphism in actin g ... | 1984 | 6547058 |
| the design of peptide-based substrates for the cdc2 protein kinase. | the substrate sequence specificity of the cdc2 protein kinase from pisaster ochraceus has been evaluated. the peptide, ac-ser-pro-gly-arg-arg-arg-arg-lys-amide, serves as an efficient cdc2 kinase substrate with a km of 1.50 +/- 0.04 microm and a vmax. of 12.00 +/- 0.18 mumol/min per mg. the amino acid sequence of this peptide is not based on any sequence in a known protein substrate of the cyclin-dependent kinase, but rather was designed from structural attributes that appear to be important in ... | 1995 | 7639712 |
| characterization of fertilization-modulated myelin basic protein kinases from sea star: regulation of mapk. | the myelin basic protein (mbp)-phosphorylating enzymes present during maturation and early embryogenesis of the sea star (pisaster ochraceus) were investigated. the major maturation-activated mbp kinase (p45 mapk) was molecularly cloned based on tryptic sequence information obtained with the purified enzyme and shown to be highly related to human erk1 with 76% amino acid identity. kinase assays and immunoblotting studies revealed that mapk remained highly active until 12 h post-fertilization (pf ... | 1999 | 10502300 |
| conservation of sequence in the internal transcribed spacers and 5.8s ribosomal rna among geographically separated isolates of parasitic scuticociliates (ciliophora, orchitophryidae). | nucleotide sequence from the internal transcribed spacers (its1 and its2) and the 5.8s gene from the ribosomal rna gene cluster of isolates of the scuticociliate orchitophrya stellarum from 4 asteroid hosts were compared. surprisingly, these data (495 bp) were identical for o. stellarum isolated from the testes of asterias amurensis from japan; pisaster ochraceus from british columbia, canada; asterias rubens from the netherlands; and asterias vulgaris from prince edward island, canada. these se ... | 2000 | 10785865 |
| association and distribution of the ciliate orchitophrya stellarum with asteriid sea stars on the west coast of north america. | the association of the scuticociliate orchitophrya stellarum with 3 species of asteriid sea stars from the west coast of north america was studied by flushing the gonopore region with seawater and spawning the sea stars, along a latitudinal gradient of 2549 km between pigeon point, california, and kodiak, alaska. asterias forbesii and a. rubens from the isles of shoals, new hampshire (east coast), were also sampled. the ciliate was found on the aboral surface of both sexes of reproductively ripe ... | 2008 | 18714682 |
| prioritized phenotypic responses to combined predators in a marine snail. | although many species face numerous predators in nature, the combined impact of multiple predators on the inducible defenses of prey has rarely been studied. prey may respond with an intermediate phenotype that balances the risk from several sources or may simply respond to the most dangerous predator. i examined the separate and combined effects of the presence of shell-breaking (crabs, cancer productus) and shell-entry (seastars, pisaster ochraceus) predators fed conspecific snails on the defe ... | 2009 | 19569380 |
| purification and characterization of a maturation-activated myelin basic protein kinase from sea star oocytes. | a meiosis-activated myelin basic protein (mbp) kinase was purified approximately 8700-fold from soluble post-germinal vesicle breakdown extracts from maturing oocytes of the sea star pisaster ochraceus. purification to apparent homogeneity was achieved by sequential chromatography on deae-cellulose, hydroxylapatite, phosphocellulose, phenyl-sepharose, heparin-sepharose, polylysine-sepharose, and mono-q. the final product exhibited an apparent molecular mass of approximately 42 kda by both native ... | 2008 | 2294120 |
| the phylogenetic status of paxillosida (asteroidea) based on complete mitochondrial dna sequences. | one of the most important issues in asteroid phylogeny is the phylogenetic status of paxillosida. this group lacks an anus and suckers on the tube feet in adults and does not develop the brachiolaria stage in early development. two controversial hypotheses have been proposed for the phylogenetic status of paxillosida, i.e., paxillosida is primitive or rather specialized in asteroids. in this study, we determined the complete mitochondrial dna nucleotide sequences from two paxillosidans (astropec ... | 2005 | 15878829 |
| sea otters homogenize mussel beds and reduce habitat provisioning in a rocky intertidal ecosystem. | sea otters (enhydra lutris) are keystone predators that consume a variety of benthic invertebrates, including the intertidal mussel, mytilus californianus. by virtue of their competitive dominance, large size, and longevity, m. californianus are ecosystem engineers that form structurally complex beds that provide habitat for diverse invertebrate communities. we investigated whether otters affect mussel bed characteristics (i.e. mussel length distributions, mussel bed depth, and biomass) and asso ... | 2013 | 23717697 |
| patterns of mass mortality among rocky shore invertebrates across 100 km of northeastern pacific coastline. | mass mortalities in natural populations, particularly those that leave few survivors over large spatial areas, may cause long-term ecological perturbations. yet mass mortalities may remain undocumented or poorly described due to challenges in responding rapidly to unforeseen events, scarcity of baseline data, and difficulties in quantifying rare or patchily distributed species, especially in remote or marine systems. better chronicling the geographic pattern and intensity of mass mortalities is ... | 2015 | 26039349 |