Dolphins are well-known aquatic mammals that evolved from ungulates about 50 million years ago. Reporter learned from the Kunming Institute of animal studies, the scientists recently conducted a systematic analysis of the dolphin genome, further reveals the evolution and the secrets of their cetacean animal "into the water".
Is a rare animal cetacean mammals aquatic species, the dolphin is one of them. They are composed of terrestrial animal evolution in mammals and Artiodactyla, about 50 million years ago to return to the water of life.
Cetace animal "two water" event is to change the life history of mammalian evolution in the history of a rare, they live by terrestrial to fully aquatic. Severe environmental changes resulting in physiological and structure have undergone significant changes to adapt to aquatic life, such as thickening of the subcutaneous fat layer ("oil"), the ability of long time diving and echolocation, also has a powerful system to support muscle water movement. Although many physiological morphological adaptations have been understood, the molecular basis of these features has not been systematically addressed.
In recent years, with the rapid increase of genomic data, the genetic basis of adaptive evolution of species is studied by comparative genomics and bioinformatics.
Kunming Institute of Animal Research Institute Zhang Yaping research group for academicians published by dolphin genome, and other species genome comparison, systematically identified genes and loci experienced positive selection of dolphins, dolphins and other cetaceans for understanding aquatic animal to lay a foundation, but also provide clues for the further study of these gene function.
Study on the personnel in charge of the project, through the construction of close relatives of high quality sequences among species (including dolphins, cattle, dog, panda, and people, a total of 11838 orthologous genes), the dolphin was detected in 368 experienced positive selection of genes. The results of functional cluster analysis showed that these positive selection genes were significantly enriched in functions such as muscle contraction, ATP enzyme, fat transport and localization, perception of sound, and glycolysis.
The molecular mechanism of the adaptation and evolution of aquatic animal reveal cetaceans has important reference value.