In this video, we're going to begin our introduction to eukaryotic gene regulation. Gene regulation in eukaryotes is extremely important to allow for a process known as differential gene expression. Differential gene expression is a process that allows multicellular organisms to express genes differently in different cells, which is going to allow multicellular organisms to have different cell types. It's important to note that all cells of a multicellular organism have the same genome or the same set of DNA, but they have a different proteome or a different set of proteins. The reason these different cell types have a different proteome is because their genes are being regulated differently. There is differential gene expression and different forms of regulation occurring in different cells. As we move forward in our course, we'll be able to discuss all of the different types of gene regulation that can occur inside of eukaryotes. But for now, let's take a look at our image down below, which will help us better understand differential gene expression and how it can lead to different cell types within a multicellular organism.
For example, liver cells and skin cells of a multicellular organism have the same DNA or the same genome, but those genes will be expressed differently. Different genes are going to be expressed, which leads to a different proteome or a different set of proteins, resulting in different cell types. Over here on the far left-hand side, notice that we're showing you a single eukaryotic cell. Eukaryotic multicellular organisms, like humans, for example, start off as a single eukaryotic cell. This single eukaryotic cell is, of course, going to divide to create trillions of cells, but it is also going to undergo differential gene expression, where different cells are going to regulate their genes differently, leading to different proteins being expressed, which leads to different cell types. The liver cell is going to have the same DNA as the red blood cell, which has the same DNA as the neuron, skin cell, and kidney cell. The DNA of all these cell types is the same, but what is different is the expression of those genes. The expression of the DNA is different, and the expression of the DNA leads to a different proteome, a different set of proteins. Although the liver cell has the same DNA as all these other ones, it has a unique proteome in comparison to these other cell types. And so, a eukaryotic multicellular organism like a human is going to have a whole bunch of different cell types, all thanks to differential gene expression. Again, differential gene expression is possible through all the different forms of gene regulation that eukaryotes are capable of performing. This concludes our introduction to eukaryotic gene regulation, and I'll see you guys in our next video.