Genome sequencing uncovers the adaptability of water bear in extreme environment

Water Bear is a small aquatic animal, also known as tardigrade. The issue of Nature - Communications published an article of latest research results on its genome sequence on September 20th. Through research using recombinant proteins, the study found that a kind of gene in the body of tardigrade, its protein can resist the DNA damage in human-cultured cells. This suggests that this protein which is specific for tardigrades may help cells to resist DNA damage sources.

Tardigrada can survive in extremely stressful environment (including vacuum), but scientists didn't know specifically how it survives in extreme environments. This ability of tardigrada prompted researchers to investigate its genome. The first genome sequencing results show that in the process of evolution of tardigrade, it obtains a large number of genes from other species by horizontal gene transfer (DNA transfer among genomes of different species). However, the rooted reason of tardigrada showing tolerance in extreme environment is still an unsolved mystery.

Takekazu Kunieda and colleagues at the University of Tokyo, Japan, presented to the high-quality genome of water bears which are known to tolerate high-pressure environment, and they found no evidence of large-scale horizontal gene transfer. But compared with flies and worms, the number of genes which are responsible for tolerating high-pressure environment was much more. In addition, they found a protein which binds to DNA and helps to protect cultured human cells from being affected by X-ray radiation, and they believed that the protein is unique for Tardigrada. Through a detailed comparison of tardigrada genes and genes from other species, the authors found that the gene designated as the genetic code of this protective protein may be specific to Tardigrada. These results don't support the viewpoint of the tolerance coming from horizontal gene transfer.

Although it remains unclear how tardigrada's unique adaptability play a role in the molecular level or organism level, the results of the study show that tardigrada has evolved and obtained unique "cheats" against high-pressure condition. Flarebio provides superior recombinant proteins such as recombinant Nrg2 at good prices.