Researchers from Nanjing Normal University and BGI report their original genomic research on Baiji, also known as Yangtze River dolphin (Lipotes vexillifer). The study gives new insight into the genetic and evolutionary adaptations of Dolphin, and provides valuable resources for the conservation of mammals and cetaceans in particular. The latest study was published online in the journal Nature Communications. Nicknamed “Goddess of the Yangtze,” the baiji was regarded as the goddess of protection by local fishermen and boatmen in China. Unfortunately, this species has suffered huge losses in recent decades largely due to the extreme pressures brought by human’s activities. There have been many great efforts made to conserve the baiji, but most of them failed.
In this study, researchers presented a high-quality draft genome and three re-sequenced genomes of the baiji using next-gen sequencing technology. Comparative genomic analysis revealed that cetaceans (baiji and the bottlenose dolphin) have a slower molecular clock than previous thought. The further analysis reveals that the genes involved in oxidoreductase activity, ferric iron binding, metabolic processes and ATPase activity show significant expansion, whereas the genes involved in olfactory receptor activity decreased most significantly. Researchers suggested that these changes of genes maybe related with the baiqi’s basic physiological activities required for underwater living, such as oxygen carrying and sensing.
Fengming Sun, project manager from BGI, said, “We not only found some special evolutionary characterics of baiji, but also found that the functionally extinct of this species was mainly due to human activities. The high-quality draft genome of baiji will provide a valuable resource for researchers to uncover the genetic mechanisms underlying extinct species, and will make a great contribution to the protection of endangered species.”