An analysis of the quantity and diversity of messenger RNAs from pollen and shoots of Zea mays
The mRNAs of the mature pollen grain of Zea mays and of vegetative shoots were analyzed by comparing the kinetics of hydridization between homologous and heterologous reactions of cDNA to poly-(A)RNA in excess. The total complexity of pollen poly-(A)RNA i s 2.4×107 nucleotides, whereas in the seedling shoot it is 4.0×107 nucleotides. This corresponds to 24,000 different sequences in pollen and about 31,000 diverse mRNAs in shoots. The mRNAs in pollen can be divided into three abundance classes that constitute 35%, 49% and 15% of the total mRNAs having complexities of 2.1×105, 6.4×106 and 1.8×107 nucleotides, respectively. Estimates have been made of the number of copies of each sequence per pollen grain or shoot cell, and also of the pollen mRNA sequences shared with those of the shoot.
Key wordsHybridization kinetics mRNA copy numbers Pollen mRNA complexity
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- Frankis R, Mascarenhas JP (1980) Messenger RNA in the ungerminated pollen grain: a direct demonstration of its presence. Ann Bot 45:595–599Google Scholar
- Goldberg RB, Hoschek G, Kamalay JC, Timberlake WE (1978) Sequence complexity of nuclear and polysomal RNA in leaves of the tobacco plant. Cell 14:123–131Google Scholar
- Mascarenhas JP (1975) The biochemistry of angiosperm pollen development. Bot Rev 41:259–314Google Scholar
- Mascarenhas NT, Bashe D, Eisenberg A, Willing RP, Xiao CM, Mascarenhas JP (1984) Messenger RNAs in corn pollen and protein synthesis during germination and pollen tube growth. Theor Appl Genet 68:323–326Google Scholar
- Maxwell IH, Van Ness J, Hahn WE (1978) Assay of DNA/RNA hybrids by S-1 nuclease digestion and adsorption to DEAE-cellulose filters. Nucleic Acids Res 5:2033–2038Google Scholar
- Mulcahy DL (1979) The rise of the angiosperms: a genecological factor. Science 26:20–23Google Scholar
- Pearson WR, Davidson EH, Britten RJ (1977) A program for least squares analysis of reassociation and hybridization data. Nucleic Acids Res 4:1727–1737Google Scholar
- Sari-Gorla M, Frova C, Binelli G, Ottaviano E (1986) The extent of gametophytic-sporophytic gene expression in maize. Theor Appl Genet 72:42–47Google Scholar
- Tanksley SD, Zamir D, Rick CM (1981) Evidence for extensive overlap of sporophytic and gametophytic gene expression in Lycopersicon esculentum. Science 213:453–455Google Scholar
- Tupy J (1982) Alterations in polyadenylated RNA during pollen maturation and germination. Biol Plant 24:331–340Google Scholar
- Van Ness J, Hahn WE (1982) Physical parameters affecting the rate of completion of RNA driven hybridization of DNA: new measurements relevant to quantitation based on kinetics. Nucleic Acids Res 10:8061–8077Google Scholar
- Willing RP, Mascarenhas JP (1984) Analysis of the complexity and diversity of mRNAs from pollen and shoots of Tradescantia. Plant Physiol 75:865–868Google Scholar