High molecular weight RNA containing histone messenger in the sea urchin Paracentrotus lividus (original) (raw)
Related papers
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.
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...
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.
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.
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.
Most early-variant histone mRNA is contained in the pronucleus of sea urchin eggs
Developmental Biology, 1983
Previous studies demonstrated that the pronucleus of the unfertilized sea urchin egg contains a high concentration of transcripts complementary to the early histone repeat unit (D. L. Venezky, L. M. Angerer, and R. C. Angerer (1981). Cell 24, 385-391.) In this paper, in situ hybridization techniques of improved sensitivity are used to show that these nuclear RNAs include authentic histone mRNA but not spacer-complementary sequences. It is estimated that most early-variant histone mRNA contained in the egg is, in fact, restricted to the pronucleus. These mRNAs are released to the cytoplasm at the time of nuclear breakdown of first cleavage and rapidly distribute throughout the cytoplasm.
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.
Message-specific sequestration of maternal histone mRNA in the sea urchin egg
Proceedings of the National Academy of Sciences, 1982
Nucleate and anucleate fragments of sea urchin eggs were prepared by centrifugation on sucrose step gradients. The amount of total RNA, poly(A)+ RNA, histone mRNA, actin mRNA, alpha-tubulin mRNA, and mitochondrial rRNA was determined for each fragment. Total RNA, poly(A)+ RNA, actin mRNA, and alpha-tubulin mRNA all distributed in the same ratio as the volume of the fragments. In contrast, the mitochondrial rRNA was found preferentially distributed in the anucleate fragments, coinciding with the distribution of the mitochondria. Histone mRNAs did not follow the fragment volume ratios, but rather were always found associated with the fragment containing the nucleus. To distinguish between nuclear association and possible artifacts associated with centrifugation, eggs were manually cut into nucleate and anucleate fragments and the amount of histone mRNA was determined for each set. Again only the fragments containing the nucleus had detectable amounts of histone mRNA. Although histone ...
Transcription of sea urchin histone genes in HeLa cells
Nucleic Acids Research, 1983
HeLa cells were transfected with recombinant DNAs containing the embryonic histone gene repeat of P.miliaris (h22) inserted in either orientation into a pBR-SV4O vector. After 2 to 3 days cytoplasmic RNA was analyzed for authentic sea urchin histone gene transcripts. The correct 5 1 termini of all five histone genes were detected, three (H2B, H2A and H3) at relatively high levels. In contrast, termination was largely aberrant with the correct 3' terminus of only the H2B mRNA found in significant amounts. The levels of histone gene transcription were dependent on the presence, but not the orientation, of SV4O DNA in the recombinant plasmid. The efficiency of initiation of transcription of the individual sea urchin histone genes in HeLa cells was very similar to that previously observed in Xenopus oocytes. The termination pattern, however, was quite different in that oocytes, all but the H3 gene terminate efficiently. The idiosyncrasies in termination efficiencies for these two heterologous transcription systems may reflect the presence of termination factors which are relatively species or even tissue specific and only some of which recognize the sea urchin "terminators" correctly.
A histone H1 protein in sea urchins is encoded by a poly(A)+ mRNA
Proceedings of the National Academy of Sciences, 1988
Typical histone genes lack intervening sequences and encode small mRNAs (400-800 nucleotides) with short leader and trailer regions. Most histone mRNAs are not polyadenylylated but rather terminate in a highly conserved stem and loop structure. The early, late, and testis-specific histone genes of sea urchins, described to date, have this typical histone gene structure. We have identified an unusual Hi gene, H1-8, in sea urchins that encodes a poly(A)+ mRNA. This mRNA is one of a group of polyadenylylated transcripts homologous with Hi gene probes. The sequence of H1-b has been determined. H1-b encodes a different Hi protein. Although the temporal expression of H1-b mRNA is similar to that of other late Hi ((3 and y) mRNAs, its spatial distribution at the time of maximal accumulation is distinct and confirms that H1-b is regulated differently than other Hi genes.