Functional Genomic Analysis of C. elegans Using RNA Interference Essay

Introduction Before we talk about this important experiment, do you know what a nematode is? Specifically, this experiment used Caenorhabditis elegans, C. elegans for short. C. elegans is a little worm (just like the kind you find in the ground), but has a very special place in modern biochemistry: scientists have mapped its entire genomic sequence. This sequence lets scientists know the character and location of all C. elegans' genes. However, biochemists do not yet fully understand what each gene does and the goal of this experiment is to find the function of each gene within the worm. The connection between a worm's genotype and phenotype is important, because, believe it or not, human beings and worms share many of the same genes. Scientists can use information about nematode genes and their phenotypic expression (the worm's physical traits) to better understand how human genes function in the body. The researchers who performed this study "fed" the worms double stranded RNA that encodes for a particular gene. The cells of the nematode's body recognize the double stranded RNA as foreign genetic material and delete all proteins associated with that RNA. Therefore, the C. elegans will not express the targeted gene, and in its absence, scientists can identify the normal phenotypic expression of that gene. For example, if the inhibited gene was supposed to create raised eyes in the nematode, then the organism would not have raised eyebrows, because it cannot manufacture the proteins that make this trait physically possible. This experiment inhibits the majority of C. elegans' genes in an effort to find what each gene does in the organism. The C. elegans is an ideal species to use in this process because it grows and... ...nucleic acid interference. RNAi uses fragments of double-stranded RNA (dsRNA) which induces the degradation of mRNA. Hopefully, one is beginning to see the similarities of the functions of RNAi and antisense pharmaceuticals. I have mentioned before that antisense drugs work by temporarily inhibiting the mRNA from manufacturing specific proteins. Future RNAi technology could be used to permanently degrade the mRNA. This is not only an exciting possibility; it is a near-future reality. Isis Pharmaceuticals has already five antisense drugs in clinical trails! Who knows when they or another pharmaceutical company will begin to utilize RNAi! References Ahringer, J., Fraser, A.G., Kamath, R.S., Martinez-Campos, M., Sohrmann, Marc., Zipperlen, Peder. "Functional genomic analysis of C. elegans chromosome I by systematic RNA interference". Nature 2000; 408: 325-330.