Newmark Phillip A, Reddien Peter W, Cebrià Francesc, Sánchez Alvarado Alejandro
Department of Cell and Structural Biology, University of Illinois at Urbana-Champaign, B107 Chemical Life Sciences Laboratory, 601 South Goodwin Avenue, Urbana, IL 61801, USA.
Proc Natl Acad Sci U S A. 2003 Sep 30;100 Suppl 1(Suppl 1):11861-5. doi: 10.1073/pnas.1834205100. Epub 2003 Aug 13.
Freshwater planarian flatworms are capable of regenerating complete organisms from tiny fragments of their bodies; the basis for this regenerative prowess is an experimentally accessible stem cell population that is present in the adult planarian. The study of these organisms, classic experimental models for investigating metazoan regeneration, has been revitalized by the application of modern molecular biological approaches. The identification of thousands of unique planarian ESTs, coupled with large-scale whole-mount in situ hybridization screens, and the ability to inhibit planarian gene expression through double-stranded RNA-mediated genetic interference, provide a wealth of tools for studying the molecular mechanisms that regulate tissue regeneration and stem cell biology in these organisms. Here we show that, as in Caenorhabditis elegans, ingestion of bacterially expressed double-stranded RNA can inhibit gene expression in planarians. This inhibition persists throughout the process of regeneration, allowing phenotypes with disrupted regenerative patterning to be identified. These results pave the way for large-scale screens for genes involved in regenerative processes.
淡水涡虫纲扁形虫能够从其身体的微小片段再生出完整的生物体；这种再生能力的基础是成年涡虫体内存在的一种可通过实验获取的干细胞群体。这些生物体作为研究后生动物再生的经典实验模型，通过现代分子生物学方法的应用得以复兴。数千个独特的涡虫ESTs的鉴定，加上大规模的全组织原位杂交筛选，以及通过双链RNA介导的基因干扰抑制涡虫基因表达的能力，为研究调节这些生物体组织再生和干细胞生物学的分子机制提供了丰富的工具。我们在此表明，与秀丽隐杆线虫一样，摄入细菌表达的双链RNA可抑制涡虫中的基因表达。这种抑制在整个再生过程中持续存在，从而能够鉴定出再生模式被破坏的表型。这些结果为大规模筛选参与再生过程的基因铺平了道路。
