水稻基因组中的tRNA和rRNA基因(英文)

The tRNA and rRNA Genes in the Oryza sativa Genome

在最近完成测序的水稻籼稻和粳稻两个亚种基因组中 ,各找到 5 6 4和 5 19个较为可靠的tRNA基因 ,进一步证实了于 2 0 0 2年发表的基于基因组序列草图的分析结果。修正的摆动假设 ,即至少需要 4 6种tRNA基因才能译出 6 1种可能的反密码子 ,在这两个亚种中均准确成立。在这 4 6种tRNA中 ,有些在籼稻和粳稻中的序列均全同。有 18种水稻tRNA与拟南芥中的相应序列全同。在籼稻基因组序列中还发现了 384个 5SrRNA基因 ,一批 17S和5 .8SrRNA基因以及一个 2 5SrRNA基因。这些rRNA基因的不完备是由于它们通常以串接阵列形式存在于异染色质区域 ,而后者在全基因组霰弹法测序中不易完整测出。在tRNA和rRNA基因序列之间发现了多处互补片段 ,这将有助于研究它们的进化和相互作用。

In the recently assembled genomes of rice Oryza sativa ssp. indica and japonica ,we identified 564 and 519 tRNA genes,respectively.The modified wobble hypothesis,namely,at least 46 tRNA species must present in order to decode all 61 possible anticodons,is perfectly observed in both subspecies.Among the 46 tRNA species, indica and japonica have many identical ones in sequence.There are 18 rice tRNA species that have identical counterparts in Arabidopsis .In the indica superscaffold dataset,384 5S rRNA genes,dozens of 17S and 5.8S rRNA genes and one 25S rRNA gene were discovered.The incompleteness of observed rRNA genes is mainly caused by the fact that the rRNA genes always exist as tandem arrays in heterochromatic regions that are not successfully sequenced in a whole-genome shotgun approach.