Mutation Buffering

Each of us has come in contact with a person who has been taken captive by a harmful disease by no fault of their own but instead their adversity it at the hands of chance. We clearly see the detrimental effects mutations have on humans. Huntington’s disease and cystic fibrosis, for example, are familiar genetic diseases that affect humans in an array of severity. One person may have a mild case of cystic fibrosis whereas another individual suffers from the most severe case. Is this by chance? The research article, Trade-Offs and Environmentally Induced Mutation Buffering in Isogenic Caenorhabditis elegans, studied whether environmental stress changed the frequency of mutations’ harmful effects. Caenorhabditis elegans, abbreviated C. elegans, are nematodes or roundworms. The environmental stress levels of the organisms were increased by overexpressing the heat shock factor. The results of the environmental stimulus were that the harmful effects of mutations were lessened. For example, a generally lethal mutation, meaning deadly, among C. elegans resulted in a lethality rate of 17% that was normally 33%. Chaperone proteins were found to be a variable that affected the consequences of mutations. Environmentally induced stress resulted in the expression of chaperone proteins. Chaperone proteins are proteins that assist in the folding and unfolding of macromolecules. Chaperones decrease the likelihood of misfolding or the aggregation or grouping together of proteins. Therefore, temporary induced stress stimulus can promote mutation protection by increasing stress resistance.
The consequences of mutations vary individually. Hence, if a mutation is inherited, the affects the mutation will have on the individual depends on the chaperone levels within the individual and not the inherited mutation itself. The same holds true if chaperone levels were already higher in one individual than another without being induced, the individual with higher chaperone levels will have greater stress resistance. Chaperones were found to have a direct correlation with lifespan among C. elegans meaning, higher levels of chaperones resulted in a longer lifespan and the reverse also proved to be true.
Undoubtedly, all C. elegans could benefit from stress resistance in relation to susceptibility to mutations. However, stress resistance effects several other genes related to fitness. Fertility, for example is affected in that high stress resistance yields less offspring and low stress resistance yields more offspring. The organism C. elegans undergo diverse environmental conditions therefore their survival rate is increased by having both high and low stress resistance organisms within their environment. Misfortune
If the research conducted on round worms can be applied to human genetic diseases, then the importance of this study is clear. The ability to buffer the effects of mutations in humans would be a life changing discovery. Although the effects of mutations vary among individuals, the capacity to protect individuals from the consequences of mutations is predictable according to this study and its concepts may be applied to human genetics. This study was of interest to me because my healthiness is a mere grain of sand compared to the ocean of those suffering from the dire consequences of mutations. Any scientific step toward alleviating the effects of mutations is research worth reading, understanding, and applying.

Citation: M. O. Casanueva, A. Burga, B. Lehner, Science 335, 82 (2012); 10.1126/science.1213491.

Quanytta Johnson