Epigenetics: The Science of Change
The study of heritable changes in gene expression that do not involve changes to the underlying DNA sequence is known as epigenetics.
A single or multiple change in phenotype without a changing the genotype which results affects the cells that can read the genes.
One example of an epigenetic change in eukaryotic biology is the process of cellular differentiation. During morphogenesis, totipotent stem cells become the various pluripotent cell lines of the embryo, which in turn become fully differentiated cells.
In other words, as a single fertilized egg cell – the zygote – continues to divide, the resulting daughter cells change into all the different cell types in an organism, including neurons, muscle cells, epithelium, endothelium of blood vessels, etc., by activating some genes while inhibiting the expression of others.
MicroRNAs (miRNAs) are members of non-coding RNAs that range in size from 17 to 25 nucleotides. miRNAs regulate a large variety of biological functions in plants and animals.
So far, in 2013, about 2000 miRNAs have been discovered in humans and these can be found online in a miRNA database. Each miRNA expressed in a cell may target about 100 to 200 messenger RNAs(mRNAs) that it downregulates. Most of the downregulation of mRNAs occurs by causing the decay of the targeted mRNA, while some downregulation occurs at the level of translation into protein.
Developmental epigenetics can be divided into predetermined and probabilistic epigenesis. Predetermined epigenesis is a unidirectional movement from structural development in DNA to the functional maturation of the protein. "Predetermined" here means that development is scripted and predictable. Probabilistic epigenesis on the other hand is a bidirectional structure-function development with experiences and external molding development.[91]
- Medicine
Epigenetics has many and varied potential medical applications. In 2008, the National Institutes of Health announced that $190 million had been earmarked for epigenetics research over the next five years.
In announcing the funding, government officials noted that epigenetics has the potential to explain mechanisms of aging, human development, and the origins of cancer, heart disease, mental illness, as well as several other conditions. Some investigators, like Randy Jirtle, Ph.D., of Duke University Medical Center, think epigenetics may ultimately turn out to have a greater role in disease than genetics.
Cancer
A variety of epigenetic mechanisms can be perturbed in different types of cancer. Epigenetic alterations of DNA repair genes or cell cycle control genes are very frequent in sporadic (non-germ line) cancers, being significantly more common than germ line (familial) mutations in these sporadic cancers.
Epigenetic alterations are important in cellular transformation to cancer, and their manipulation holds great promise for cancer prevention, detection, and therapy. Several medications which have epigenetic impact are used in several of these diseases. These aspects of epigenetics are addressed in cancer epigenetics.
The Global Epigenetics Market is expected to reach US$ 2,611.57 Mn in 2025 from US$ 991.45 in 2017 and estimated to grow with a CAGR of 13.6% from 2018-2025.
The prominent players operating in the market of epigenetics across the globe includes Merck KGaA, Thermo Fisher Scientific, Inc., Abcam plc, Agilent Technologies, Active Motif, QIAGEN, Bio-Rad Laboratories, Inc., PerkinElmer Inc., New England Biolabs (NEB), and Illumina, Inc. among others.