Larkin J C, Hunsperger J P, Culley D, Rubenstein I, Silflow C D
Department of Genetics, University of Minnesota, St. Paul 55108-1095.
Genes Dev. 1989 Apr;3(4):500-9. doi: 10.1101/gad.3.4.500.
We have isolated several Zea mays cDNAs encoding the 40S subunit ribosomal protein S14. In maize, this ribosomal protein is encoded by a small multigene family, at least three members of which are expressed. S14 transcript levels are highest in mitotically active tissues, such as seedling shoot, developing endosperm, and tassel primordia, and lowest in tissues with little cell division, such as mature leaf and root. Very little S14 RNA is present in pollen, suggesting that translation of pollen mRNAs during pollen germination uses preformed ribosomes. During kernel development, the highest levels of S14 transcripts in endosperm tissue are found at 10-12 days postpollination; S14 RNA levels decline continuously from this point onward. The period of maximal expression of the S14 ribosomal protein gene appears to precede the onset of storage protein synthesis and does not correlate with the reported times of increased nucleolar volume or genome amplification.
我们已经分离出了几个编码40S核糖体亚基蛋白S14的玉米cDNA。在玉米中，这种核糖体蛋白由一个小的多基因家族编码，其中至少有三个成员表达。S14转录本水平在有丝分裂活跃的组织中最高，如幼苗茎尖、发育中的胚乳和雄穗原基，而在细胞分裂很少的组织中最低，如成熟叶片和根。花粉中几乎没有S14 RNA，这表明花粉萌发期间花粉mRNA的翻译使用预先形成的核糖体。在籽粒发育过程中，胚乳组织中S14转录本的最高水平出现在授粉后第10 - 12天；从这一点开始，S14 RNA水平持续下降。S14核糖体蛋白基因的最大表达期似乎先于贮藏蛋白合成的开始，并且与报道的核仁体积增加或基因组扩增的时间无关。
