Expression & Regulation
Each cell expresses only a limited amount of its full genetic potential. ~ American biochemist Gordon Tomkins et al
The value of a gene is in its expression: the process of using the genetic information to synthesize a functional protein or other bioproduct.
The conventional view has been that traits manifest on a gene-by-gene basis. Instead, many genes are expressed in groups, and their expressions are affected by innumerable interactions, even contact among DNA strands.
DNA is coiled and tangled like spaghetti inside the cell. So there are many places where the DNA touches and intersects. These interactions could be crucial to how the information in the DNA is read and interpreted by the cell. ~ South African geneticist Marc Weinberg
Regulation is the control of gene expression. There are many ways in which expression may be modified or silenced.
Conventional wisdom holds that modifying a gene to make the encoded protein inactive — ‘knocking out’ the gene — will have more severe effects than merely reducing the gene’s expression level. However, there are many cases in which the opposite occurs. In fact, the knockout of a gene sometimes has no discernible impact, whereas the reduction of expression (knockdown) of the same gene causes major defects. ~American obstetrician Miles Wilkinson