Control of eukaryotic gene expression -miRNA (approximately 500 words)
The model organism Caenorhabditis elegans is a roundworm and is frequently used to understand

function of eukaryotic genes. The genome of C. elegans encodes a microRNA (miRNA) called lin4 – the

first miRNA ever discovered. The lin-4 miRNA controls the expression of a gene called lin-14, which is

involved in the development of C. elegans. Using the miRNA lin4 as the example, answer the following

questions:

1.What is a miRNA?
2.Where within a cell does a miRNA control gene expression?
3.Describe the steps involved in creating a miRNA.
4.Describe how lin-4 regulates the expression of the lin-14 gene.
a.Does lin-4 miRNA bind to the lin-14 gene, its hnRNA or its mRNA?
b.Where within the lin-14 sequence does lin-4 bind?
c.How does the binding of lin-4 influence the expression of the lin-14 gene?

5. Briefly discuss why this regulation is important.