What are horizontal and vertical gene transfer?

Horizontal gene transfer is the transfer of genetic material between organisms that are not parent and offspring.

Horizontal gene transfer (HGT) is the movement of genetic material between organisms that are not related by descent. This transfer can occur through three mechanisms: transformation, transduction, and conjugation. Transformation is the uptake of free DNA from the environment by a bacterial cell. Transduction is the transfer of DNA between bacteria by a bacteriophage, a virus that infects bacteria. Conjugation is the transfer of DNA between bacteria through a physical connection called a pilus.

HGT can have significant impacts on the evolution of organisms. It can provide new genetic material that can be beneficial for adaptation to new environments or for the acquisition of new functions. For example, antibiotic resistance genes can be transferred between bacteria, leading to the spread of antibiotic resistance. HGT can also have negative consequences, such as the transfer of virulence factors that can make bacteria more pathogenic.

Vertical gene transfer, on the other hand, is the transfer of genetic material from parent to offspring. This occurs through the processes of meiosis and fertilization in sexually reproducing organisms. Vertical gene transfer is the primary mechanism for the transmission of genetic information from one generation to the next and is responsible for the inheritance of traits from parents to offspring.