Chapter 11
Control of Gene Expression
Multicellular organisms contain a variety of structurally and functionally distinct cell types, but the DNA in all the cells originated from the same…
Gene expression can be regulated at almost every step from gene to protein. Transcription is the step that is most commonly regulated. This involves…
Cis-regulatory sequences are short fragments of non-coding DNA that are present on the same chromosomes as the genes that they regulate. These…
Transcriptional regulators bind to specific cis-regulatory sequences in the DNA to regulate gene transcription. These cis-regulatory sequences…
The organization of prokaryotic genes in their genome is notably different from that of eukaryotes. Prokaryotic genes are organized, such that the…
The eukaryotic promoter region is a segment of DNA located upstream of a gene. It contains an RNA polymerase binding site, a transcription start…
Gene transcription is regulated by the synergistic action of several proteins that form a complex at a gene regulatory site. This is observed in…
Master transcription regulators are regulatory proteins that are predominantly responsible for regulating the expression of multiple genes. Often…
In eukaryotes, transcription and translation are compartmentalized; an mRNA is first synthesized in the nucleus and then selectively transported to…
The structure and stability of mRNA molecules regulates gene expression, as mRNAs are a key step in the pathway from gene to protein. In eukaryotes,…
MicroRNA (miRNA) are short, regulatory RNA transcribed from introns (non-coding regions of a gene) or intergenic regions (stretches of DNA present…
Small interfering RNAs, or siRNAs, are short regulatory RNA molecules that can silence genes post-transcriptionally, as well as the transcriptional…
In humans, more than 80% of the genome gets transcribed. However, only around 2% of the genome codes for proteins. The remaining part produces…
Epigenetic changes alter the physical structure of the DNA without changing the genetic sequence and often regulate whether genes are turned on or…
Epigenetic regulation plays central roles in gene expression. Since histone modification was discovered in the 1960s, its physiological and…
Fluorescence-based imaging techniques, in combination with developments in light microscopy, have revolutionized how cell biologists conduct live…
Half of all human transcripts are thought to be regulated by microRNAs. Therefore, quantifying microRNA expression can reveal underlying mechanisms…
