Gut bacteria share ability to acquire vitamin B12 by “hugging” each other
- Mobile genetic elements or MGEs are genetic materials that can move around within a genome or move across different genomes.
- One popular example of mobile genetic elements in evolutionary context is the transfer of antibiotic resistance genes to another bacteria.
- Horizontal transfer refers to the transfer of genetic material between organisms rather than the transmission of DNA from parent to offspring.
- Horizontal transfer of mobile genetic elements can shape the diversity of the human gut microbiome.
- Mobile genetic elements can encode genes which benefits their host such as providing self-defense or the ability to compete for limited resources.
- Vitamin B12 is an important nutrient required to enable gut colonization of Bacteriodetes.
- Bacteriodetes are Gram-negative bacteria found anywhere in gastrointestinal tract, including the mouth and stomach, despite the presence of gastric juices and digestive enzymes.
- Researchers discovered a distinct type of mobile genetic elements in the Bacteriodetes responsible for the movement and exchange of the genes required for the transport of corrinoids.
- Corrinoid is cobalt-containing molecule that function as enzyme cofactors in many organisms.
- An example of corrinoid is vitamin B12 (cobalamin).
- The newly discovered mobile genetic elements include two distinct groups of conjugative transposons and one group of bacteriophage.
- Conjugative transposons are elements that can move from one bacterial cell to another through cell to cell contact.
- Researchers confirmed the activity of two of the conjugative transposons in vitro and in vivo.
- The study highlights the importance of mobile genetic elements in distribution of corrinoid transporters in gut bacteria.
Frye, K. A., Piamthai, V., Hsiao, A., & Degnan, P. H. (2021). Mobilization of vitamin B12 transporters alters competitive dynamics in a human gut microbe. Cell reports, 37(13), 110164. https://doi.org/10.1016/j.celrep.2021.110164