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Abstract
In this review, the types of mRNAs found in oocytes and eggs of several animal species, particularly Drosophila, marine invertebrates, frogs, and mice, are described. The roles that proteins derived from these mRNAs play in early development are discussed, and connections between maternally inherited information and embryonic pattern are sought. Comparisons between genetically identified maternally expressed genes in Drosophila and maternal mRNAs biochemically characterized in other species are made when possible. Regulation of the meiotic and early embryonic cell cycles is reviewed, and translational control of maternal mRNA following maturation and/or fertilization is discussed with regard to specific mRNAs.
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Cantatore P, Roberti M, Loguercio Polosa P, Mustich A, Gadaleta MN. Mapping and characterization of Paracentrotus lividus mitochondrial transcripts: multiple and overlapping transcription units. Curr Genet 1990; 17:235-45. [PMID: 1692770 DOI: 10.1007/bf00312615] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
This paper reports the mapping of both mature and precursor Paracentrotus lividus mitochondrial transcripts. Several mtRNAs were found to have 5' and 3' termini which differ from those inferred through DNA sequencing (Cantatore et al. 1989). The 3' ends of the two rRNAs (12S and 16S) overlap with the downstream transcripts (tRNAGlu and CoI mRNA) by 5 and 10 nt respectively. The 132 nt non-coding region is extensively transcribed: in particular it contains a 124 nt RNA and the 5' end of a possible precursor of 13 clustered tRNAs. This latter overlaps by 7 nt with the 3' end of the 124 nt RNA. In addition to the mature RNAs, 32 high molecular weight RNAs, which are probably the precursors of the smaller more abundant mature species, were detected by Northern blotting. The mapping of these transcripts indicates that they are processed at the level of tRNA or tRNA-like sequences and suggests the existence of two transcription initiation sites upstream of the ND1 and the cytochrome b genes respectively. In the light of these results it appears that P. lividus mitochondrial DNA transcription takes place via multiple and probably overlapping transcription units. Moreover, the wide variation in the steady-state levels of the mature mRNAs indicates that sea urchin mitochondrial DNA expression is also regulated at the level of RNA decay.
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Affiliation(s)
- P Cantatore
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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Wessel GM, Goldberg L, Lennarz WJ, Klein WH. Gastrulation in the sea urchin is accompanied by the accumulation of an endoderm-specific mRNA. Dev Biol 1989; 136:526-36. [PMID: 2583374 DOI: 10.1016/0012-1606(89)90278-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Spatial diversification of the endoderm during gastrulation in the sea urchin Lytechinus variegatus was examined with an endoderm-specific cDNA clone. This cDNA clone, LvN1.2, was identified by a differential cDNA screen between the ectoderm and endoderm/mesoderm fractions from prism stage embryos. The LvN 1.2-kb mRNA was first detectable by Northern blots at the mesenchyme blastula stage just prior to gastrulation and then accumulated approximately 15-fold from gastrulation to the pluteus stage. In situ hybridization analysis demonstrated that the mRNA accumulated specifically in endoderm and was restricted to the hindgut-midgut regions. This restricted localization was apparent during gastrulation and predicted the morphological distinction between foregut and midgut eventually seen at prism and pluteus stages. Sequence analysis showed that the 189-amino acid open reading frame represented a novel protein. In vitro translation of synthetically produced LvN1.2 mRNA and Western blot analysis with antibodies to the protein sequence yielded the same 25-kDa polypeptide on SDS-PAGE. The LvN1.2 protein resided within discrete granules of the hindgut and midgut cells. These particles were concentrated to the luminal aspect of the cells, suggesting the LvN1.2 protein participates in the digestive function of this region of the gut.
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Affiliation(s)
- G M Wessel
- Department of Biochemistry and Molecular Biology, University of Texas M. D. Anderson Cancer Center, Houston 77030
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Cantatore P, Flagella Z, Fracasso F, Lezza AM, Gadaleta MN, de Montalvo A. Synthesis and turnover rates of four rat liver mitochondrial RNA species. FEBS Lett 1987; 213:144-8. [PMID: 2435574 DOI: 10.1016/0014-5793(87)81480-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The synthesis and turnover rates of the two 12 S and 16 S mt rRNAs and of the mt mRNAs for subunits I and III of cytochrome oxidase have been determined by measuring the kinetics of incorporation of [3H]uridine in the mtRNA of rat hepatocytes. All the RNA species examined have approximately the same turnover (t1/2 approximately 100 min) and therefore the rate of synthesis, which is about 10-times higher for the rRNAs, seems to be the factor responsible for the different mt rRNA and mRNA steady-state levels.
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Poccia D, Wolff R, Kragh S, Williamson P. RNA synthesis in male pronuclei of the sea urchin. BIOCHIMICA ET BIOPHYSICA ACTA 1985; 824:349-56. [PMID: 2580559 DOI: 10.1016/0167-4781(85)90042-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Transcription in male pronuclei of fertilized sea urchin eggs was measured by comparison of [3H]uridine incorporation into RNA in polyspermic, monospermic and activated eggs under conditions where uptake of the isotope and conversion to UTP were equivalent. RNA accumulation from male pronuclei begins by S phase of the first cell cycle. Initiation of this RNA synthesis does not require DNA synthesis. A major fraction of the newly synthesized transcripts are mRNAs coding for early embryo (alpha-) histones. In addition, several other unidentified transcripts are detected by gel electrophoresis. The pattern of RNA transcription remains constant for at least 4 h post-fertilization. These results demonstrate that specific transcription of male pronuclear sequences is activated in the first cell cycle following fertilization.
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Brandhorst BP. Informational content of the echinoderm egg. DEVELOPMENTAL BIOLOGY (NEW YORK, N.Y. : 1985) 1985; 1:525-76. [PMID: 2481472 DOI: 10.1007/978-1-4615-6814-8_12] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The sea urchin egg contains a store of mRNA synthesized during oogenesis but translated only after fertilization, which accounts for a large, rapid increase in the rate of synthesis of largely the same set of proteins synthesized by eggs. Starfish oocytes contain a population of stored maternal mRNA that becomes actively translated upon GVBD and codes for a set of proteins distinct from that synthesized by oocytes. The sequence complexity of RNA in echinoderm eggs is about 3.5 x 10(8) nucleotides, enough to code for about 12,000 different mRNAs averaging 3 kb in length. About 2-4% of the egg RNA functions as mRNA during early embryonic development; most of the sequences are rare, represented in a few thousand copies per egg, but some are considerably more abundant. Many of the stored RNA sequences accumulate during the period of vitellogenesis, which lasts a few weeks. The mechanisms of storage and translational activation of maternal mRNA are not well understood. Histone mRNAs are sequested in the egg pronucleus until first cleavage, but other mRNAs are widely distributed in the cytoplasm. The population of maternal RNA includes many very large molecules having interspersed repetitive sequence transcripts colinear with single-copy sequences. The structural features of much of the cytoplasmic maternal RNA is thus reminiscent of incompletely processed nuclear precursors of mRNA. The functional role of these strange molecules is not understood, but many interesting possibilities have been considered. For instance, they may be segregated into different cell lineages during cleavage and/or they may become translationally activated by selective processing during development. Maternal mRNA appears to be underloaded with ribosomes when translated, possibly because the coding sequences are short relative to the size of the mRNA. Most abundant and many rare mRNA sequences persist during embryonic development. The rare sequence molecules are replaced by newly synthesized RNA, but some abundant maternal transcripts appear to persist throughout embryonic development. Most of the proteins present in the egg do not change significantly in mass during development, but a few decline or accumulate substantially. Together, these observations indicate that much of the information for embryogenesis is stored in the egg, although substantial changes in gene expression occur during development.
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Affiliation(s)
- B P Brandhorst
- Department of Biology, McGill University, Montreal, Quebec, Canada
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Cantatore P, Gadaleta MN, Saccone C. Determination of some mitochondrial RNAs concentration in adult rat liver. Biochem Biophys Res Commun 1984; 118:284-91. [PMID: 6320827 DOI: 10.1016/0006-291x(84)91098-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A method has been developed to accurately measure steady state concentrations of mitochondrial transcripts in adult rat liver. Total mitochondrial RNA has been hybridized with an excess of labelled mitochondrial DNA fragments coding for a single gene or a piece of it. The results obtained show that each mitochondrion contains 36 molecules of 16S rRNA, 81 of 12S rRNA and about 8 molecules of mRNAs coding for identified and unidentified reading frames. Thus, the rRNA/mRNA ratio in rat liver differs from that reported in HeLa cell mitochondria. These results are discussed in the light of mitochondrial DNA transcription regulation.
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Cabrera CV, Jacobs HT, Posakony JW, Grula JW, Roberts JW, Britten RJ, Davidson EH. Transcripts of three mitochondrial genes in the RNA of sea urchin eggs and embryos. Dev Biol 1983; 97:500-5. [PMID: 6189753 DOI: 10.1016/0012-1606(83)90107-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
cDNA clones representing mitochondrial 16 S rRNA, and mRNAs for cytochrome oxidase I and an unidentified reading frame were used to measure the prevalence and stability of these transcripts in gastrula stage embryos. The 16 S rRNA is the most prevalent embryo poly(A) RNA, and is synthesized about four times more rapidly than is the mRNA for cytochrome oxidase. The relative prevalence of the two mRNAs is largely determined by their turnover rates.
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Duncan R, Humphreys T. Oligo(U) sequences present in sea urchin maternal RNA decrease following fertilization. Dev Biol 1983; 96:258-62. [PMID: 6186552 DOI: 10.1016/0012-1606(83)90326-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Oligo(U) tracts were identified and measured in RNA from sea urchin eggs and embryos using a quantitative assay based on the amount of [3H]poly(A) protected from RNase T2 in duplexes with the oligo(U). The oligo(U) amounted to 0.0035% of egg RNA (0.063 X 10(-12) g/egg) and decreased to 0.0015% (0.027 X 10(-12) g/embryo) by 2 hr after fertilization. The oligo(U) tracts had a maximum size of 15-30 nucleotides and were associated with two size classes of RNA. In eggs about half were in 100 to 200 nucleotide RNA and half in mRNA-sized molecules. After fertilization, the oligo(U) in the population of large-mRNA-sized molecules was greatly reduced.
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Wells DE, Bruskin AM, O'Brochta DA, Raff RA. Prevalent RNA sequences of mitochondrial origin in sea urchin embryos. Dev Biol 1982; 92:557-62. [PMID: 6180946 DOI: 10.1016/0012-1606(82)90202-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Flytzanis CN, Brandhorst BP, Britten RJ, Davidson EH. Developmental patterns of cytoplasmic transcript prevalence in sea urchin embryos. Dev Biol 1982; 91:27-35. [PMID: 7095261 DOI: 10.1016/0012-1606(82)90004-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Brower PT, Gizang E, Boreen SM, Schultz RM. Biochemical studies of mammalian oogenesis: synthesis and stability of various classes of RNA during growth of the mouse oocyte in vitro. Dev Biol 1981; 86:373-83. [PMID: 6169567 DOI: 10.1016/0012-1606(81)90195-0] [Citation(s) in RCA: 83] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Sagata N, Shiokawa K, Yamana K. A study on the steady-state population of poly(A)+RNA during early development of Xenopus laevis. Dev Biol 1980; 77:431-48. [PMID: 6156874 DOI: 10.1016/0012-1606(80)90486-8] [Citation(s) in RCA: 85] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Sevaljević L, Petrović LS, Rickwood D. Isolation and partial characterization of a mitochondrial deoxyribonucleic acid-protein complex from sea urchin embryos. Mol Cell Biochem 1978; 21:139-43. [PMID: 732819 DOI: 10.1007/bf00240132] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Lysis of mitochondria from sea urchin embryos with Triton X-100 led to a complete conversion of DNA-containing mitochondrial residues into protein-DNA complex with a density higher than 1.22 g/cm3 in sucrose solutions. This complex banded isopycnically in metrizamide gradients at a density of 1.26 g/cm3. Exposure to mixtures of Triton X-100 with Tween 80 resulted in progressively less delipitated and disorganized mitochondria over Tween/Triton weight ratios from 1 to 2, with the retention of the starting buoyant density in sucrose of approximately 1.16 g/cm3 at Tween/Triton ratios above 2.5. The DNA-internal protein complex sedimented with the bulk of the surviving mitochondrial structure under all conditions studied. No free DNA could be detected under any conditions of membrane removal.
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Craig SP, Innis MA. Mitochondrial regulation in sea urchins. III. Rapid degradation of mitochondrial RNA in association with a failure to form mitochondrial polyribosomes in eggs activated with ionophore A 23187. Exp Cell Res 1978; 117:145-53. [PMID: 363437 DOI: 10.1016/0014-4827(78)90437-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Innis MA, Craig SP. Mitochondrial regulation in sea urchins. II. Formation of polyribosomes within the mitochondria of 4-8 cell stage embryos of the sea urchin. Exp Cell Res 1978; 111:223-30. [PMID: 627230 DOI: 10.1016/0014-4827(78)90164-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Bresch H. Mitochondrial profile densities and areas in different developmental stages of the sea urchin Sphaerechinus granularis. Exp Cell Res 1978; 111:205-9. [PMID: 620692 DOI: 10.1016/0014-4827(78)90250-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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24
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Kidder GM, Clark J, Gerdes PA. Polyadenylic acid in Ilyanassa: localization and size distribution of newly-synthesized poly(A) in embryonic and larval stages. Differentiation 1977; 9:77-84. [PMID: 590663 DOI: 10.1111/j.1432-0436.1977.tb01521.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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25
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Jeffery WR. Polyadenylation of maternal and newly-synthesized RNA during starfish oocyte maturation. Dev Biol 1977; 57:98-108. [PMID: 863115 DOI: 10.1016/0012-1606(77)90357-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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26
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Koch G. Synthesis of the mitochondrial inner membrane in cultured Xenopus laevis oocytes. J Biol Chem 1976. [DOI: 10.1016/s0021-9258(17)33064-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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