In this video, we're going to introduce the sex pilus. The sex pilus is also referred to as the conjugation pilus. It connects two cells directly for a special type of DNA transfer known as conjugation. Conjugation can be defined as the process by which DNA is transferred from one bacterial cell to another by using direct contact through the sex pilus or the conjugation pilus. This transferred DNA, occurring via conjugation, can add new functions to a cell, such as resistance to antibiotics.
Looking at the image below, we can better understand how the sex pilus can bring two cells together to directly transfer genetic material. In this part of the image, we see two bacterial cells; bacterial cell A and bacterial cell B. Bacterial cell A has a yellow circle representing a DNA plasmid, possibly conferring antibiotic resistance. However, cell B does not have this yellow circle, indicating sensitivity to antibiotics.
The green structure seen here is the sex pilus itself, which brings the two cells into closer proximity. This action allows the DNA plasmid to be copied and transferred to cell B. Both cells A and B eventually possess the plasmid, highlighting its transfer through the action of the sex pilus. Now, cell B can also transfer this DNA to other cells. This is accomplished through the action of their own sex pili, demonstrating the recurring potential of this process. This concludes our lesson here, and I'll see you all in our next video.
