Question

A central question in biology is, how do we have > 200 different cell types, complete with unique cell morphologies and functions, when all cells have the same DNA (the concept of genomic equivalence). Epigenetic regulation of gene transcription is one way to explain this. Define what is meant by epigenetic regulation of gene transcription, including different general epigenetic mechanisms, and describe three different contexts of a developmental process that is associated with epigenetic changes that we have discussed in class.

Answer 1

Ans

Epigenetic processes regulate gene expression by modulating the frequency, rate, or extent of gene expression in a mitosis or meiosis. These processes do not change the DNA sequence, but instead, they affect how cells read the genes.

The general epigenetic mechanisms are DNA methylation, modifications to chromatin structure, loss of imprinting, and non-coding RNA.

1. Epigenetic mechanism influence the genomic activities in the brain to produce long term changes in synaptic signaling, organization, and morphology which supports learning and memory

2. Diseases can be caused by direct changes in epigenetic marks like DNA methylation, affect the imprinted gene regulation.

3. Epigenetics play a role in cancer development. Epigenetic change can turn off the genes that help repair the damaaged DNA which leads to increase innDNA damage and thusbincreases cancer risk.

Also Epigenetic control of the proto-onco regions and the tumor suppressor sequences by conformational changes in histones plays a role in the formation and progression of cancer.