[zemaxe7]

Model Organisms

Roundworm (Caenorhabditis elegans)

C. elegans is in the group of nematode worms (they are basically unsegmented worms with elongated rounded body pointed at both ends) and it is great target for genetic engineering since it is multicellular organism but still very simple. It has small number of cells arranged in nearly identical way in every worm, making it perfect target for studying embryonic development. Basically, it has been used to trace the formation of each individual cell, to study the development of the whole body plan and to study the cell lineage.

C. elegans was also the first organism to have given us the insight into RNAi (RNA interference), which refers to the control of gene expression by blocking the translation of specific mRNA molecules and targeting them for degradation with the help of siRNA (small interfering RNA) molecules.

Moreover, formation and the function of nervous system is well studied through C. elegans, as well as muscle development, mostly due to the simplicity of its body, making it easy to track the development of these tissues and compare them among different individuals from the population. The research about muscle and nerve cells extends to the identification, isolation and study of mutants, focusing on their problems with development and function.

Having relatively simple multicellular body has many other advantages. Chromosome structure has been studied in C. elegans but, more importantly, gene regulation, as it is very complex process, making it pretty complicated to study in more advanced organisms. Knowledge on gene regulation has led to additional research of the regulation of cell cycle, cell aging and programmed cell death, also known as apoptosis. Any mutations here can lead to uncontrolled cell proliferation and cancer, so this worm has also been used to identify and study potential cancer genes responsible for the “immortality” of cells.