In this video, we're going to briefly discuss the integration of DNA via homologous recombination. Homologous recombination is really just referring to the process of genetic exchange between two similar strands of DNA. It allows molecules to integrate into other segments of DNA. Homologous recombination can only occur if the donor DNA actually has a similar nucleotide sequence to the recipient cell's chromosome.
If we take a look at our image down below, we can get a better understanding of homologous recombination. What you'll notice on the left is the chromosomal DNA of, say, the bacteria. The chromosomal DNA is the original DNA that's found in the bacteria. What we're showing you down below is the donor DNA that could have potentially been obtained through horizontal gene transfer. The donor DNA has some regions highlighted in orange that have similar sequences to the chromosomal DNA. These yellow highlighted regions represent areas of similarity. When these regions have similarity, it creates the possibility for homologous recombination.
What can happen is the donor DNA, which I'll highlight here like this, can be incorporated and replace the chromosomal DNA at this region. The chromosomal DNA can be removed, whereas the donor DNA can be integrated. This is what we are seeing here. The donor DNA can be integrated into the chromosomal DNA and it replaces a region of the chromosomal DNA. This is what we call homologous recombination, and it can allow donor DNA to be incorporated and integrated into the chromosomal DNA.
This here concludes our brief lesson on the integration of DNA via homologous recombination. We'll be able to get some practice applying this as we move forward. So I'll see you all in our next video.