| novel screening procedure for recombinant plasmids. | lysed bacterial colonies containing potential recombinant plasmids were mixed with molten agar and sealed into slots of an agarose gel. after electrophoresis overnight, the gel was stained with ethidium bromide, which clearly reveals recombinant plasmids. xenopus laevis ribosomal dna and histone dna of psammechinus miliaris were ligated into pcri plasmids and screened by this method. | 1977 | 318763 |
| primary structure of histone h2a from gonad of the sea urchin psammechinus miliaris. | the complete amino acid sequence (125 residues) of sea urchin histone h2a has been established by structural studies of peptides derived from tryptic and chymotryptic cleavage of the maleylated protein and from thermolysin cleavage of the intact protein. by comparison with calf homologous histone, the basic amino-terminal and carboxy-terminal parts of the protein show 11 substitutions and 4 deletions. the remainder of the sequence, mostly hydrophobic, is almost completely unchanged. | 1978 | 710427 |
| histone-gene reiteration in the genome of mouse. | histone messenger rna labelled to high specific activity has been isolated and purified from the mouse tissue-culture cell line l929. it had an electrophoretic mobility equivalent to a mean molecular weight of 1.4 x 10(5). the synthesis of this rna was suppressed, but apparently not completely so, by inhibition of cellular dna synthesis to more than 95% by addition of cytosine arabinoside. the synthesis of other rna species remained unaffected by this treatment. poly(a)-containing mrna, represen ... | 1976 | 945162 |
| integration of eukaryotic genes for 5s rna and histone proteins into a phage lambda receptor. | highly purified hindiii restriction fragments of xenopus laevis 5s dna and of psammechinus miliaris histone dna have been covalently inserted into a derivative of phage lambda. this phage, genetically constructed by murray et al. (1), contains only a single target for hindiii in the ci gene. viable hybrid molecules were detected as clear plaque-forming phage after transfection of e. coli, the vast majority of which were shown by hybridization to be recombinants of the desired type. the lambdasam ... | 1976 | 1069257 |
| cis-acting elements of the sea urchin histone h2a modulator bind transcriptional factors. | functional tests, performed by microinjection into xenopus laevis oocytes, show that a dna fragment containing the modulator of the early histone h2a gene of paracentrotus lividus enhances transcription of a reporter gene when located, in the physiological orientation, upstream of the tk basal promoter. gel retardation and dnase i footprinting assays further reveal that the h2a modulator contains at least two binding sites [upstream sequence elements 1 and 2 (use 1 and use 2)] for nuclear factor ... | 1989 | 2762313 |
| polyadenylylation of sea urchin histone rna sequences in transfected cos cells. | the region of psv2neo that encompasses the simian virus 40 early polyadenylylation signal was replaced with a dna fragment that spans the 3' end of a sea urchin (psammechinus miliaris) histone h2a gene. this clone, pmk2.h2a(3'), was used to transfect cos cells. rna analysis revealed that transcripts from pmk2.h2a(3') were polyadenylylated at a site 85 nucleotides downstream from the expected 3' end of mature h2a mrna. nucleotide sequencing showed that the site of poly(a) addition was located 10 ... | 1985 | 2858095 |
| high diadenosine tetraphosphate (ap4a) level in germ cells and embryos of sea urchin and xenopus and its effect on dna synthesis. | ap4a levels in sperms, eggs and different developmental stages of sea urchin (psammechinus miliaris) and (xenopus laevis) were determined by a method based on atp measurement with luciferin/luciferase after splitting diadenosine 5',5'''-p1,p4-tetraphosphate (ap4a) into atp and amp. appreciable storage pools of ap4a were found in unfertilized eggs of psammechinus and xenopus as well as in sea urchin sperms. the actual ap4a concentration of 28 microm in sperm represents the highest ap4a level so f ... | 1985 | 4043245 |
| histone genes from xenopus laevis: molecular cloning and initial characterization. | histone dna sequences, were detected in eco ri fragments of total xenopus laevis dna, by hybridization with 32p-labeled h22-dna, a histone gene repeat unit of the sea urchin psammechinus miliaris. the about 6 kb-size class, which was found to hybridize, was subsequently integrated into the e. coli plasmid pcr1. a clone was isolated that contains a 5.8 kb ecori fragment hybridizing with h22-dna. a physical map was constructed using the restriction endonucleases bamhi, psti, hincii, bglii, xbai, p ... | 1980 | 6254837 |
| subcloning of the histone dna sequences of phage lambda sam 7 h 22 in plasmid pbr 322. | the histone dna sequences of the hind iii cluster of the sea urchin psammechinus miliaris which are carried by the chimeric phage dna of lambda sam 7 h 22 have been subcloned in plasmid p br 322. due to this procedure single segments of the cluster have been separated from each other and are available as gene specific hybridization probes. | 1980 | 6255695 |
| yeast h3 and h4 histone messenger rnas are transcribed from two non-allelic gene sets. | the genes coding for the h3 and h4 histones of saccharomyces cerevisiae have been isolated by recombinant dna cloning. the genes were detected in a bacteriophage lambda library of the yeast genome by hybridization with plasmids containing the cloned psammechinus miliaris sea urchin histone genes (pch7) and the cloned drosophila histone genes (cdm500). two non-allelic sets of the h3 and h4 genes have been isolated. each set consists of one h3 gene and one h4 gene arranged as a divergently transcr ... | 1983 | 6313932 |
| transcription of sea urchin histone genes in escherichia coli. | dna fragments comprising units of the repeated histone genes form the sea urchins psammechinus miliaris and echinus esculentus were placed under the control of bacteriophage lambda promoters by cloning into lambda replacement vectors. although promoter-like regions exist within the cloned fragments, transcription of the histone genes is controlled mainly, but not exclusively, by lambda pl promoter. a transcription map of the cloned p. miliaris histone dna fragment was obtained. the order of hist ... | 1981 | 6458017 |
| delimitation of far upstream sequences required for maximal in vitro transcription of an h2a histone gene. | sea urchin (psammechinus miliaris) h2a histone genes shown to be promoter mutants from oocyte injection experiments were tested for their ability to initiate transcription in vitro. circular templates were transcribed with hela cell extracts, and the transcripts were assayed by mung bean or s1 nuclease mapping of the 5' ends. the transcripts of the h2a mutants produced in vitro were qualitatively similar and, in most cases, identical to those seen in oocyte injection experiments, but quite large ... | 1982 | 6952185 |
| re-evaluation of the structure and physiological function of guanidino kinases in fruitfly (drosophila), sea urchin (psammechinus miliaris) and man. | purification and biophysical characterization of mitochondrial creatine kinase (mi-ck) from sperm of the sea urchin psammechinus miliaris, as well as gel-permeation chromatography of human heart mi-ck demonstrate that these two mi-ck isoenzymes form highly symmetrical octameric molecules with an m(r) of approx. 350,000, a value similar to that found for all other mi-ck isoenzymes investigated so far. the absolute evolutionary conservation of this oligomeric form from sea urchins to mammals point ... | 1995 | 7619066 |
| the five cleavage-stage (cs) histones of the sea urchin are encoded by a maternally expressed family of replacement histone genes: functional equivalence of the cs h1 and frog h1m (b4) proteins. | the cleavage-stage (cs) histones of the sea urchin are known to be maternally expressed in the egg, have been implicated in chromatin remodeling of the male pronucleus following fertilization, and are the only histone variants present in embryonic chromatin up to the four-cell stage. with the help of partial peptide sequence information, we have isolated and identified cs h1, h2a, h2b, h3, and h4 cdnas from egg poly(a)+ mrna of the sea urchin psammechinus miliaris. all five cs proteins correspon ... | 1997 | 9032246 |
| the dawn of gene isolation. | ever since it became clear through the work of watson and crick that the gene is a stretch of double stranded helical dna and is understandable in chemical terms, biochemists have striven to get their hands on isolated genes. the isolation of the ribosomal genes of xenopus laevis in 1966 provided a first instance where a purified dna of known function could be investigated, long before the advent of gene cloning technologies. the second instance was the purification of the lac operon from escher ... | 2002 | 12468080 |
| a toxicity identification evaluation of silty marine harbor sediments to characterize persistent and non-persistent constituents. | sediment toxicity in silty marine harbor sediments is frequently dominated by ammonia or sulfide, leaving the adverse effects of persistent toxic substances unnoticed. to investigate the latter, we subjected interstitial water from three contaminated silty sediments to toxicity identification evaluation (tie) phase i manipulations and tested for toxicity with four bioassays: the amphipod corophium volutator (survival as an endpoint), the sea urchin psammechinus miliaris (fertilization, embryo de ... | 2003 | 12535970 |
| histone genes in macronuclear dna of the ciliate stylonychia mytilus. | dna in the macronucleus of stylonychia mytilus exists as discrete gene-sized fragments which are derived from micronuclear dna through a series of well-defined developmental events. it has been proposed that each of the dna fragments might represent a gene and its controlling elements. we have investigated this possibility using genes which code for the five histone proteins. macronuclear dna fragments were fractionated according to size by agarose gel electrophoresis, the fragments transferred ... | 1998 | 105862 |
| a new metabolite of vitamin d the small sea-urchin psammechinus miliaris [proceedings]. | | 1988 | 202524 |
| exposure to 2,4-decadienal negatively impacts upon marine invertebrate larval fitness. | diatoms liberate volatile, biologically active unsaturated aldehydes following cell damage, which negatively impact upon invertebrate reproductive processes such as fertilization, embryogenesis and larval survival. 2,4-decadienal is frequently identified among the aldehydes produced and is one of the more biologically active. the majority of studies which have examined the toxic effects of diatom aldehydes to invertebrate reproduction have scored egg production and/or hatching success as indicat ... | 2005 | 15603766 |
| echinoderms as bioindicators, bioassays, and impact assessment tools of sediment-associated metals and pcbs in the north sea. | the study assessed the occurrence, possible toxicity, and impact of sediment-associated metals and pcbs in the coastal zone of the southern north sea using echinoderms as representatives of the macrobenthos. metals and pcbs were analyzed in the sediments and in the body compartments of the starfish asterias rubens from 11 stations. the general toxicity of sediment-associated contaminants was assessed by bioassays using embryonic and larval developments of both a. rubens and the sea urchin psamme ... | 2003 | 14565576 |
| inhibition of embryonic development and fertilization in broadcast spawning marine invertebrates by water soluble diatom extracts and the diatom toxin 2-trans,4-trans decadienal. | water soluble diatom extracts and the diatom aldehyde 2-trans,4-trans decadienal were assayed on the gametes and embryos of the broadcast spawning polychaetes arenicola marina and nereis virens and the echinoderms asterias rubens and psammechinus miliaris. both crude cellular extracts and purified aldehyde were found to inhibit fertilization, embryogenesis and hatching success in a dose dependent manner. intact diatom cells had no discernable effect on fertilization or development. extracts of s ... | 2002 | 12204592 |
| escape and aggregation responses of three echinoderms to conspecific stimuli. | in marine invertebrates, waterborne chemical stimuli mediate responses including prey detection and predator avoidance. alarm and flight, in response to damaged conspecifics, have been reported in echinoderms, but the nature of the stimuli involved is not known. the responses of asterias rubens linnaeus, psammechinus miliaris (gmelin), and echinus esculentus linnaeus to conspecifics were tested in a choice chamber against a control of clean seawater (no stimulus). all three species showed statis ... | 2001 | 11687389 |
| localization of sequences coding for histone messenger rna in the chromosomes of drosophila melanogaster. | in situ hybridization of sea urchin (psammechinus miliaris, lytechinus pictus and strongylocentrotus purpuratus) histone messenger rna has been used to map complementary sequences on polytene chromosomes from drosophila melanogaster. the sea urchin rna hybridizes to the polytene regions from 39d3 through 39e1-2, including both of these bands (39d2 may also be included). this region is identical to the one which hybridizes most heavily with non-polyadenylated cytoplasmic rna from d. melanogaster ... | 1977 | 411642 |