The paper "The New Genetics of Mental Illness by Edmund S. Higgins" is a brilliant example of an article on biology. Proteins, which are produced as a result of gene expression, are primarily involved in the maintenance of the brain and body. There are various factors that contribute to gene expression as a result of which the same genes are expressed to a different extent or not expressed at all in certain cells. The DNA is transcribed into an intermediate molecule termed RNA, which in turn is translated into proteins. However, only certain genes within a cell are transcribed and translated through a process called gene expression.
Epigenetic mechanisms which involve addition or removal of certain molecules to the DNA or its proteins are mainly involved in the process of selective gene expression. These mechanisms initiate the binding of molecules such as methyl groups to the DNA thus preventing the transcription machinery from gaining access to the DNA. These changes, however, do not affect the DNA or the genetic code. On the other hand molecules such as acetyl groups tend to expand the chromosome and thus facilitate the binding of the transcription machinery.
From one of the research carried out to study epigenetic mechanisms, it has been shown that they may play a role in stress. The study indicates that those children who had received normal physical care and affection tend to be less prone to stress later in life compared to children who have suffered sexual and physical abuse. A similar stress response studied in rats has revealed that lesser corticosterone hormone receptor is produced in rats that received less nurturing by their mothers.
The reason was traced to the presence of more methyl groups in the corticosterone receptor gene in the hypothalamus. In studies carried out to unravel the genetics of depression, it was found that low levels of brain-derived neurotrophic growth factors (BDNF) were found in the blood of a depressed person. Studies carried out with mice have shown that mice subjected to stressful experiences had the number of methyl groups near the histones of the gene for BDNF, thus silencing the gene. Latest research shows that increasing the number of acetyl groups and subsequently reducing the methyl groups on rat chromosomes helped them to combat stress as their levels of stress hormones increased.
Thus erasing the epigenetic markings can help reduce the occurrence of mental disorders and suitable drugs need to be developed for the treatment of humans.