[
Nature Reviews Genetics,
2004]
MicroRNAs are a family of small, non-coding RNAs that regulate gene expression in a sequence-specific manner. The two founding members of the microRNA family were originally identified in Caenorhabditis elegans as genes that were required for the timed regulation of developmental events. Since then, hundreds of microRNAs have been identified in almost all metazoan genomes, including worms, flies, plants and mammals. MicroRNAs have diverse expression patterns and might regulate various developmental and physiological processes. Their discovery adds a new dimension to our understanding of complex gene regulatory networks.
[
Nature Reviews Genetics,
2002]
Imagine being able to knock out your favourite gene with only a day's work. Not just in one model system, but in virtually any organism: plants, flies, mice or cultured cells. This sort of experimental dream might one day become reality as we learn to harness the power of RNA interference, the process by which double-stranded RNA induces the silencing of homologous endogenous genes. How this phenomenon works is slowly becoming clear, and might help us to develop an effortless tool to probe gene function in cells and animals.
[
Ann N Y Acad Sci,
1992]
The freeze-fracture technique offers a unique view of intramembrane particles (IMPs), which derive from large membrane-associated molecules such as gap junctions, receptors, and ion channels. We are particularly interested in the gap junction (gj) and its role in intercellular communication. The anatomy of the soil nematode, C. elegans, has been studied extensively in serial thin sections and gjs have been noted in many cell types. Although gjs vary in frequency and extent, their appearance in sectioned material is rather uniform. The freeze-fracture technique can be used to identify and differentiate gjs according to IMP size, packing density, and preferred fracture face. For instance, in the planarian, Dugesia, this technique revealed three classes of gjs occurring in different tissues. The nematode usually fractures lengthwise; the fracture plane preferentially travels along membranes, splitting the unit membrane into two opposing halves (the P- and E-faces). Many tissues are recognizable: hypodermis, muscle, neurons, nerve cords, intestine, and so forth...