Discovery and profiling of bovine microRNAs from immune-related and embryonic tissues
Discovery and profiling of bovine microRNAs from immune-related and embryonic tissues
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DOI：
10.1152/physiolgenomics.00081.2006
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发表时间：
2007-03-14
影响因子：
4.6
通讯作者：
Smith, Timothy P. L.
中科院分区：
文献类型：
--
作者：
Coutinho, Luiz L.;Matukumalli, Lakshmi K.;Smith, Timothy P. L.
MicroRNA是一种小的类似于22个核苷酸长的非编码RNA，能够通过抑制翻译来控制基因表达。人类microRNA茎环序列（mir）与牛基因组的最新序列组装草案的比对，鉴定出334个预测的牛mir。我们对来自牛胚胎、胸腺、小肠和淋巴结的小RNA组分的5个组织特异性cDNA文库进行测序，以验证这些预测并鉴定新的miR。该策略结合比较序列分析确定了129个对应于成熟microRNA（miR）的序列。共有107个序列与已知的人类mir比对，其中100个匹配表达的miR。其他7个序列代表了从先前表征的人mir的互补链表达的新型miR。没有匹配的22个序列显示特征性的米尔二级结构时，在电脑中折叠，其中10个保留序列保守与其他脊椎动物物种。基于序列同一性计数的表达分析显示，一些miR在某些组织中优先表达，而bta-miR-26 a和bta-miR-103在所有检查的组织中普遍存在。这些结果支持的前提是，物种差异的基因表达调控的miR主要发生在表达和加工的水平。
MicroRNAs are small similar to 22 nucleotide-long noncoding RNAs capable of controlling gene expression by inhibiting translation. Alignment of human microRNA stem-loop sequences (mir) against a recent draft sequence assembly of the bovine genome resulted in identification of 334 predicted bovine mir. We sequenced five tissue-specific cDNA libraries derived from the small RNA fractions of bovine embryo, thymus, small intestine, and lymph node to validate these predictions and identify new mir. This strategy combined with comparative sequence analysis identified 129 sequences that corresponded to mature microRNAs (miR). A total of 107 sequences aligned to known human mir, and 100 of these matched expressed miR. The other seven sequences represented novel miR expressed from the complementary strand of previously characterized human mir. The 22 sequences without matches displayed characteristic mir secondary structures when folded in silico, and 10 of these retained sequence conservation with other vertebrate species. Expression analysis based on sequence identity counts revealed that some miR were preferentially expressed in certain tissues, while bta-miR-26a and bta-miR-103 were prevalent in all tissues examined. These results support the premise that species differences in regulation of gene expression by miR occur primarily at the level of expression and processing.