A. C. elegans is an ideal organism to use for studying aging because it is generally small in size and has a rapid lifespan. (http://cmgm.stanford.edu/~kimlab/index_wormaging.html). The organism also shares many essential biological characteristics that cause problems in human biology.(Edgley 2014). Worms can be genetically mutated fairly easily because of their 4-day generation time, where it develops from an egg to an adult with a maximum length of 1.5mm, while maintaining transparency. C. elegans being transparent throughout its life stage allows for better inspection and can be seen with easier access. (Hodgkins). With the small size, it allows culture and screening of thousands of animals, compactly and cheaply. They also come with a “toolkit” of genetic and molecular techniques where gene function can be experimentally dissected (Lundquist). Certain mutants and treatments can either extend or shorten the lifespan on C. elegans so it can be assessed faster compared to other animal models. C. elegans small size and fast lifespan is why it is an ideal organism to use for studying aging.
B. The daf-2 gene is an insulin-like receptor that is required for reproductive growth and normal adult life span. (Piecre et al. 2001). Longevity is regulated by the daf-2 gene network, where it regulates oxidative stress resistance and Mn-superoxide dismutase gene expression in C. elegans. The age phenotype is mutually potentiated by two life extension mutations in the daf-2 gene and the clk-1 gene. (Honda 1999). The daf-2 insulin-like signalling pathway plays a major role in C. elegans longevity, this pathways connects on the daf-16 transcription factor and may regulate life span by controlling genes. Some genes controlled are free-radical detoxifying genes, stress resistance genes, pathogen resistance genes, innate immunity and metabolism, which all help with the protection and repairing of tissues.(Samuelson, Carr, Ruvkun 2007).