Carnivorous bladderwort’s tiny genome contains loads of genes. Scientists think they can explain the phenomenon. Victor Albert from the University of Buffalo’s Biological Sciences Department described bladderwort (Utricularia Gibba) to be a “marvel of Nature”. The bladderwort (Utricularia gibba) lives in water and has no roots. It also has tiny traps using suction pressure to catch prey. The authors of this new study published their results and conclusions in the scientific journal Molecular Biology and Evolution. Citation below. A scanning electron micrograph taken of Utricularia gibba’s bladder, a humped bladderwort-plant. Image: University of Buffalo. The bladderwort’s genome is smaller than many other well-known species of plants, including grape, papaya, and coffee. Professor Albert, the Rampant DNA Deletion Study Leader explained that the bladderwort’s remarkable compact structure was due to a history in “rampant DNA deletion” whereby genetic material was added and deleted at an extremely rapid pace. The study included several partners, including the Instituto de Ecologia, Laboratorio Nacional de Genomica para la Biodiversidad in Mexico and the Universitat de Barcelone in Spain. Professor Albert stated that the story was that the bladderwort had a history of shedding and gaining a lot of DNA. “With a shrinking genome, we might expect to find what I call a minimal complement to our DNA: A plant with relatively few genes, only those that are necessary to create a simple plant. However, this is not the case. Professor Albert’s team discovered that U. gibba had more genes than other plants, such as grape and Arabidopsis. This, contrary to minimalist plant theory. U. gibba has many genes that enable carnivory, specifically those that allow it to create enzymes that are similar to papain. This protein helps in the breakdown of meat fibers. The gene pool is rich in genes that are involved with cell wall biosynthesis, which is vital for aquatic species. Professor Albert stated that genes that are not as important or redundant can be easily deleted when there is a lot of DNA loss like the one seen in bladderwort. Professor Albert stated that the genes that survived the deletion were the genes with the most functions. “The majority of bladderwort’s DNA was lost over time, and was called “junk DNA,” which is essentially a non-gene. They set out to discover how bladderwort developed its current genetic structure. It was compared to four closely related species, and they discovered that there is a rapid pattern of DNA modification. Professor Albert said: “When looking at bladderwort’s past, you’ll see that it’s losing genes but also gaining them at a rapid rate. This allows it to remain alive and make appropriate adaptations for its environment.” The entire genome was duplicated by the researchers. They discovered that U. gibba had experienced three duplication events, which resulted in the creation of redundant copies. Fast-paced deletion countered this rapid gene growth. This phenomenon is evident in the fact that the genome of the plant is small despite having a history of genetic duplicates. The authors noted that the plant also contains a large percentage of genes not related to each other in the genome. This suggests that the plant rapidly deleted duplicate DNA from duplication events. Citation: “High gene families turnover rates and gene spaces adaptation in the compact genome Utricularia gibba,” Lorenzo Carretero–Paulet and Pablo Librado. Luis Herrera–Estrella, Julio Rozas and Victor A. Albert. Mol Biol Evol was first published online in January 31, 2015. DOI: 10. 1093/molbev/msv020.
