Chopra Vivek S, Mishra Rakesh K
Centre for Cellular and Molecular Biology, Hyderabad, India.
Bioessays. 2006 May;28(5):445-8. doi: 10.1002/bies.20401.
Micro RNAs (miRNAs) have been shown to control many cellular processes including developmental timing in different organisms. The prediction that miRNAs are involved in regulating hox genes of flies and mouse is quite a recent idea and is supported by the finding that mir-196 represses Hoxb8 gene expression. The non-coding regions that encode these miRNAs are also conserved across species in the same way as other mechanisms that regulate expression of hox genes. On the contrary, until now no homeotic phenotype, a hallmark of any hox gene mutation, had been associated with any hox miRNA. Recent work on bithorax complex miRNA (miR-iab-4-5p) shows, for the first time, that miRNAs can lead to homeotic transformation. This miRNA regulates Ultrabithorax (Ubx) and results in the transformation of haltere to wing. This study unveils a new complexity and finesse to the regulation of hox gene expression pattern that is needed for determining the anteroposterior body axis in all bilaterians.
微小RNA（miRNA）已被证明可控制许多细胞过程，包括不同生物体中的发育时间。miRNA参与调节果蝇和小鼠的同源框基因这一预测是相当新的观点，并且得到了mir-196抑制Hoxb8基因表达这一发现的支持。编码这些miRNA的非编码区域在物种间也像其他调节同源框基因表达的机制一样保守。相反，到目前为止，尚未发现任何同源异型表型（任何同源框基因突变的标志）与任何同源框miRNA相关。最近关于双胸复合体miRNA（miR-iab-4-5p）的研究首次表明，miRNA可导致同源异型转化。这种miRNA调节超双胸基因（Ubx），并导致平衡棒向翅膀的转化。这项研究揭示了同源框基因表达模式调控的新复杂性和精细度，而这种调控对于确定所有两侧对称动物的前后体轴是必需的。
