Question

Suppose scientists studying pigmentation in Arabidopsis attempted to alter expression of a pigment gene. Using transgenic techniques, multiple copies of the pigment gene were inserted into homozygous and heterozygous individuals. This was expected to darken the pigmentation of the plants. Instead of increased pigment production, the additional gene copies often reduced or completely inhibited the pigment gene expression. One explanation for this unexpected result is that high concentrations of mRNA are produced. This, in turn, increases the likelihood of homologous regions of mRNA binding with one another and forming double stranded molecules. Double stranded RNA is often unstable and rapidly degraded by enzymes in the cell. Choose a term that describes this mechanism of reduced gene expression.

Answer 1

The correct answer would be RNAi or RNA interference.

It is a technique to down regulate the gene expression, especially at translation level.

In this method, short sequence RNA such as miRNA or siRNA which are complementary to targeted mRNA are used. These are inserted into the cell after which they bind to the mRNA to form a double-stranded mRNA molecule.

Due to double-strand configuration, translation factors and other machinery can not attach to the mRNA.

Consequently, translation can not proceed.

The same is observed in the experiment in which complementary mRNAs bind to each other and prevent translation.