The small genome of the carnivorous, aquatic bladderwort packs a gene-rich punch that provides the unique plant with many of its special adaptations, according to a study published in Molecular Biology and Evolution in January.
The Utricularia gibba genome contains 28,500 protein-coding genes, roughly the same amount as that of the Norway spruce, even though the spruce’s genome is nearly 250-fold larger. Researchers from the University of Buffalo, the University of Barcelona, and the National Genomics Lab for Biodiversity in Mexico, found evidence that the bladderwort genome had been duplicated three times, suggesting the plant had also undergone massive deletion events, resulting in its compact genome. Unlike many organisms, few of the bladderwort’s genes belong to larger gene families grouped by function, and its more than 10,000 “singleton” genes—where only one gene is responsible for a particular function—represent a larger proportion of the genome than in other plants.
“When you have the kind of rampant DNA deletion that we see in the bladderwort, the genes that remain—and their functions—are the ones that were able to withstand this deletion pressure, so the selective advantage of having these genes must be pretty high,” study coauthor Victor Albert of Buffalo said in astatement.
Among the bladderwort-specific adaptations the scientists found in a comparative analysis were unique versions of genes involved in cell-wall biosynthesis and the regulation of leaf and root development, which may be responsible for bladderwort’s adaptations to a watery environment. The researchers also identified genes that encode meat-digesting enzymes, including some similar to the pepsin found in human stomachs…..
