Stinson J R, Eisenberg A J, Willing R P, Pe M E, Hanson D D, Mascarenhas J P
Department of Biological Sciences, State University of New York at Albany, Albany, New York 12222.
Plant Physiol. 1987 Feb;83(2):442-7. doi: 10.1104/pp.83.2.442.
Recombinant cDNA libraries to poly(A)RNA isolated from mature pollen of Zea mays and Tradescantia paludosa have been constructed. Northern blot analyses indicate that several of the clones are unique to pollen and are not expressed in vegetative tissues. The majority, however, are expressed both in pollen and vegetative tissues. Southern hybridizations show that the pollen specific sequences in corn are present in one or a very few copies in the genome. By using several of the clones as probes, it was found that there are at least two different groups of mRNAs with respect to their synthesis. The mRNAs of the first group represented by the pollen specific clones are synthesized after microspore mitosis and increase in concentration up to maturity. The second group, exemplified by actin mRNA, begins to accumulate soon after meiosis, reaches its maximum by late pollen interphase, and decreases thereafter. Although the actin mRNA and the pollen specific mRNAs studied show very different patterns of initiation of synthesis and accumulation during pollen development, the rates of decline of these mRNAs during the first 60 minutes of germination and pollen tube growth in Tradescantia are similar and reflect the previously observed declines in rates of protein synthesis during this period.
已构建了从玉米和紫露草成熟花粉中分离的聚腺苷酸RNA的重组cDNA文库。Northern印迹分析表明，其中几个克隆是花粉特有的，在营养组织中不表达。然而，大多数克隆在花粉和营养组织中都有表达。Southern杂交显示，玉米中的花粉特异性序列在基因组中以一个或极少数拷贝存在。通过使用几个克隆作为探针，发现就其合成而言，至少有两组不同的mRNA。以花粉特异性克隆为代表的第一组mRNA在小孢子有丝分裂后合成，并在成熟前浓度增加。第二组以肌动蛋白mRNA为例，在减数分裂后不久开始积累，在花粉间期后期达到最大值，此后下降。尽管所研究的肌动蛋白mRNA和花粉特异性mRNA在花粉发育过程中显示出非常不同的合成起始和积累模式，但在紫露草中，这些mRNA在萌发和花粉管生长的前60分钟内的下降速率相似，反映了在此期间先前观察到的蛋白质合成速率的下降。
