Translational regulation of histone synthesis in the sea urchin strongylocentrotus purpuratus (original) (raw)
Related papers
Developmental Biology, 1981
The rates of synthesis of the mRNA molecules coding for histones of sea urchin embryos were determined. At different stages during the early development of the sea urchin, Stmn&ocmtrotus purpuratus, embryos were labeled for brief periods with a radioactive nucleoside. The specific activity of the precursor nucleoside triphosphate pool was measured, and the accumulation of radioactivity into histone mRNA molecules was monitored by separation of the RNA on polyacrylamide gels. The rate of histone mRNA synthesis was found to increase dramatically after the 16cell stage, reaching a value of 80 X lo-i5 g/min/embryo at about the 128-cell stage and gradually declining to a value of 12 X lo-i5 g/min/embryo at the 300-cell stage. The maximal accumulation rates require that histone genes be transcribed at least once per minute.
Roux’s Archives of Developmental Biology, 1986
The ability to specifically delete the store of maternal e-subtype histone mRNAs stored in the egg pronucleus has allowed us to examine the role of this major fraction of the maternal mRNA in the early development of the sea urchin Strongylocentrotuspurpuratus. The egg nucleus was removed by centrifugation, and the resulting enucleate half eggs were fertilized. These haploid anda'omerogones lacked any stored e-subtype histone mRNAs. However, when grown in parallel with control embryos, they showed identical cleavage cycles, cell numbers, and patterns of cell differentiation. Measurements of the amount of ehistone mRNA in these andromerogones showed that there was no premature synthesis of e-histone mRNAs to compensate for the deleted maternal pool. Instead embryonic synthesis was normal in timing of initiation and duration. The ability of these embryos to develop into highly differentiated larvae without their maternal e-subtype histone mRNA pool suggests that this pool is not a critical component of early development per se. This suggestion is strengthened by the observation that the primitive sea urchin Eucidaris tribuloides naturally lacks this maternal histone mRNA store. Evolutionary implications are discussed.
Developmental Biology, 1987
The sea urchin synthesizes distinct classes of histone mRNAs at different stages of development. "Early" embryonic histone mRNAs are synthesized in large amount in cleavage and blastula stage embryos. "Late" embryonic histone mRNAs are the predominant forms in postblastula embryos. To learn more about how early and late histone genes are regulated during the life cycle of the sea urchin and to search for additional classes of developmentally regulated histone mRNAs, we examined histone mRNAs in sea urchin adult tissues. Using methods of primer extension and Sl nuclease protection, we found that tube foot, intestine, testis, and ovary contain a subset of the several H2b mRNA species synthesized by the embryo. We detected early H2b mRNA in ovary, but not. in other tissues. Three late H2b mRNA species were present in all tissues tested, while a fourth late H2b was not detected. Using a probe that hybridized specifically with transcripts of a single-copy late H2b gene, we found that this gene was transcribed in both embryos and adults. Interestingly, its level of expression relative to other late H2b genes varied among tissues. Finally, we identified two H2b mRNA species that were distinct from early and late embryonic forms and were synthesized only in adult tissues. 0 1987 Academic PWSS. I~C.
Nucleic Acids Research, 1979
Histone mRNAs at different stages of development were purified by hybridization with the cloned homologous histone genes. The electrophoretic patterns of oocytes, 2-4 blastomeres, 64 cells and morula histone mRNAs was found to be identical, whereas the electrophoretic pattern of mesenchyme blastula histone mRNA was aseddebr different. The cloned histone DNA of P.lividus was hybridized with the RNA of each stage. The Tm was 74°C in all cases except for the mesenchyme histone mRNAs whose Tm was 59°C, thus suggesting that at least two different clusters of histone genes are active in the course of the sea urchin development.
Accumulation of histone repeat transcripts in the sea urchin egg pronucleus
Cell, 1981
RNA transcripts complementary to a genomic histone repeat are found in high concentration in sea urchin egg pronuclei. In situ hybridizations with the recombinant plasmid pCO2 indicate that the nuclear concentration is at least 25 to 50 fold higher than that in the cytoplasm. If nuclear transcripts are predominantly histone mRNAs, they comprise about 12% of the histone mRNA in eggs, or about 0.36 pg. After fertilization these molecules persist through pronuclear fusion but disappear from nuclei by mid 2-cell stage. A similar high nuclear concentration is not observed for polyadenylated mRNAs or for two individual abundant maternal mRNAs. The high steady-state concentration of nuclear histone repeat transcripts suggests that they have an unusually long lifetime in pronuclei of unfertilized sea urchin eggs.
Histone phosphorylation during sea urchin development
Seminars in Cell Biology, 1995
Studies on histone phosphorylation during transitions in chromatin structure occurring in vivo during spermatogenesis and early embryogenesis in sea urchins are reviewed and evaluated in the light of recent studies on histone phosphorylation occurring during chromatin synthesis in frog egg extracts in vitro and evidence that protein kinases and phosphatases play direct roles in the regulation of cellular structure. Sperm-specific histone variants Sp H1 and Sp H2B are maintained as phosphorylated derivatives N and O/P throughout spermatogenesis and early embryogenesis and egg specific histone variants CS H1 and CS H2A are phosphorylated during early embryogenesis. These developmental correlations provide clues about the roles of histone phosphorylation in control of chromatin structure in vivo and provide a basis for the interpretation of data obtained from in-vitro sperm chromatin remodeling in egg extracts and from biochemical studies on the effects of histone phosphorylation on DNA binding. The potential consequences for chromatin structure of the various histone phosphorylation events observed in sea urchins and frog egg extracts are discussed.
Molecular and cellular biology, 1981
We have examined histone gene expression during the early stages of sea urchin embryogenesis. The five histone genes expressed at that time are contained in tandem repetitive segments. It has been suggested that adjacent coding regions and their intervening spacer sequences are transcribed into large polycistronic messenger ribonucleic acid (RNA) precursors. We have subcloned into pBR322 deoxyribonucleic acid (DNA) sequences mapping either in the coding region, the 5' spacer, or the 3' spacer of the H2B histone gene. These clones were used to produce radioiodinated hybridization probes. We measured the steady-state quantity of H2B messenger RNA as well as spacer-specific RNA in the total RNA from embryos taken at various stages of development from fertilization to hatching of blastulae (0 to 22 h post-fertilization). Small amounts of RNA hybridizing to both spacer probes could be found. However, we show that these RNAs form mismatched hybrids with the spacer DNA and therefor...
Synthesis of histones during sea urchin oogenesis
Biochimica et Biophysica Acta (BBA) - Nucleic Acids and Protein Synthesis, 1974
Oocytes at the stage of vitellogenesis were isolated from sea urchin gonads and incubated in vitro with labelled lysine. The synthesis of arginine-rich and some other histone fraction was detected by column chromatography and electrophoresis.