Boothroyd J C, Wang A, Campbell D A, Wang C C
Nucleic Acids Res. 1987 May 26;15(10):4065-84. doi: 10.1093/nar/15.10.4065.
The ribosomal RNA (rRNA) genes of the protozoan parasite Giardia lamblia have been analyzed with respect to size, composition and copy number. They are found to be remarkable in several respects. First, the rRNAs themselves are the smallest yet reported for any eukaryotic organism. Second, the genes encoding them are found as an exceptionally small tandemly repeated unit of only 5.4 kilobase-pairs. Third, the genes are extraordinarily G:C rich, even in regions which are highly conserved between all other eukaryotic rRNA genes. Finally, by analogy to other organisms, the 5.8S RNA appears to lack about 15 nucleotides from its 3'-end, a region previously thought to be essential for 5.8S RNA function. We also provide the first estimates of the genomic complexity and total G:C content of this important protozoan pathogen.
已对原生动物寄生虫蓝氏贾第鞭毛虫的核糖体RNA（rRNA）基因的大小、组成和拷贝数进行了分析。结果发现它们在几个方面引人注目。第一，rRNA本身是迄今报道的所有真核生物中最小的。第二，编码它们的基因以仅5.4千碱基对的异常小的串联重复单元形式存在。第三，这些基因的G:C含量极高，即使在所有其他真核rRNA基因之间高度保守的区域也是如此。最后，与其他生物类似，5.8S RNA的3'端似乎缺少约15个核苷酸，该区域以前被认为对5.8S RNA功能至关重要。我们还首次估算了这种重要的原生动物病原体的基因组复杂度和总G:C含量。
