What is the significance of horizontal gene transfer in
prokaryotes?
Horizontal gene transfer (HGT) is the movement of genetic information between
organisms that do not have a parent-offspring relationship. The significance of HGT
in prokaryotes is vast, as it facilitates the acquisition of new genetic material,
enabling prokaryotes to rapidly adapt to changing environments. HGT is a critical
driver of bacterial evolution, and it occurs via three mechanisms: transformation
(uptake of free DNA), conjugation (transfer of genetic material between bacterial
cells), and transduction (transfer of genetic material by bacteriophages).
HGT can confer various benefits to prokaryotes, including antibiotic resistance,
virulence factors, and metabolic pathways that allow them to utilize novel energy
sources or survive in extreme environments. For instance, the presence of antibiotic
resistance genes in microbial communities dramatically increases the prevalence of
antibiotic-resistant pathogens. Antibiotic resistance genes can be transferred
between different bacterial strains or species, leading to the emergence of multidrugresistant bacteria that pose a significant threat to public health.
HGT also plays a significant role in shaping microbial communities and
biogeochemical cycles. Some prokaryotes can acquire genes that allow them to
degrade pollutants, such as heavy metals, organic compounds, or xenobiotics. The
acquisition of these genes enhances the ability of prokaryotes to tolerate and
detoxify environmental contaminants, thereby shaping ecosystems and influencing
global biogeochemical cycles.
In conclusion, horizontal gene transfer has a profound impact on the diversity and
versatility of prokaryotic genomes. It is a key mechanism of prokaryotic evolution and
adaptation, enabling them to survive and thrive in various habitats and challenging
conditions.
References:
1. Frost, L. S., Leplae, R., Summers, A. O., & Toussaint, A. (2005). Mobile genetic elements:
the agents of open source evolution. Nature Reviews Microbiology, 3(9), 722-732.
2. Normile, D. (2013). Antibiotic resistance: Moving the environment. Science, 342(6163),
1065-1067.
3. Thomas, C. M., & Nielsen, K. M. (2005). Mechanisms of, and barriers to, horizontal gene
transfer between bacteria. Nature Reviews Microbiology, 3(9), 711-721.
4. Zhang, Q., & Lambert, G. (2019). Lateral gene transfer in microbial ecology. Advances in
Experimental Medicine and Biology, 1157, 1-27.