Calmodulin was purified to apparent homogeneity from sea urchin spermatozoa by heat-treatment at 85 degrees C, ammonium sulphate precipitation at pH 4.2, DEAE-Sephacel chromatography and gel filtration on Sephadex G-100. Approximately 8.3 micrograms calmodulin were recovered per 10(10) sperm cells. The sperm calmodulin had an apparent molecular weight of 17 800. The purified calmodulin activate...

A cDNA for fascin, an actin-bundling protein in echinoderms, has been cloned, sequenced, and expressed. The predicted mass of the protein is approximately 55 kDa, similar to that observed for fascin purified from sea urchin eggs. Bacterially expressed fascin reacts with antibodies prepared against sea urchin egg fascin. Fascin has a strong sequence similarity to the singed gene (sn) product in ...

Characterisation of a sea urchin (P. lividus) homeobox gene PIHbox 9 is reported. The homeodomain of PIHbox9 is 95% identical to the homeodomain of the human HB9 gene, indicating that the two genes are highly related. Temporal expression analysis during sea urchin embryogenesis showed an absence of transcripts at early cleavage stages. At late gastrula stage, transcripts were barely detectable ...

Endo16 is a lineage-specific protein expressed during embryogenesis in the sea urchin, Strongylocentrotus purpuratus. We have examined the effects of various concentrations of lithium chloride, a well-known vegetalizing agent, on Endo16 expression in whole sea urchin embryos. Our results show that treatment with LiCl causes increased steady-state levels of Endo16 transcripts. An increase in the...

Bioassay-guided fractionation of the methanolic extract of Tamarindus indica fruits led to the isolation of L-(-)-di-n-butyl malate which exhibited a pronounced cytotoxic activity against sea urchin embryo cells. In order to study structure-activity relationships, close-structure relatives of di-n-butyl malate were synthesized using D-(+)- and L-(-)-malic acid as starting materials, and their c...

Using probes specific for several oncogenes/proto-oncogenes we have performed gel blot hybridization analyses of genomic DNA isolated from the sea urchin Strongylocentrotus droebachiensis. Probes prepared from v-erbB, v-myc, c-myb and v-fps were found to hybridize with discrete fragments of HindIII digested genomic DNA. In contrast, probes prepared from v-abl, v-fos, v-sis, v-src, and v-mos eit...

Sea urchin feeding fronts are a striking example of spatial pattern formation in an ecological system. If it is assumed that urchins are asocial, and that they move randomly, then the formation of these dense fronts is an apparent paradox. The key lies in observations that urchins move further in areas where their algal food is less plentiful. This naturally leads to the accumulation of urchins...

We have used enriched chicken histone cDNA to select genomal clones from a chicken library. Because the cDNA probe also contained other sequences, a further screening of positive plagues with negative probes eliminated most non-histone gene clones. One 'positively-selected' genomal clone, lambda CH-01, hybridised with cloned sea-urchin histone genes and also detected histone genes in EcoRI-dige...

Messenger RNA was prepared from developing sea urchin gastrulae by puromycin release from polyribosomes. Approximately 60% of the total mRNA radioactivity of the postnuclear supernatant was recovered and shown to be free of any other labeled RNA species such as ribosomal and nuclear RNA. The mRNA was examined by hybridization to DNA present in great excess. The mRNA hybridizes almost exclusivel...

THE UTILIZATION dur ing starvation of the nutrient reserves in the gut of a temperate water sea urchin , Strongylocentrotus purpuratus, was measured by Lawrence et al. (1966) . There have been no investigations of the utilization of reserves in the gut of tropical urchins, although the level of reserves in the gut of several tropical species has been reported (Giese et al., 1964; Lawrence, 1967...