[Animal experiments]-Discover new mechanisms that lead to phenotypic convergent evolution through mammalian research

  Convergent evolution is a research hotspot in the field of evolutionary biology, and it is usually manifested as the same survival strategy formulated by different species for similar habitats. Therefore, it is generally believed that the convergent changes in phenotype are the result of adaptive evolution. The explanation of the molecular mechanism of convergent phenotype not only provides a new way to connect genotype and adaptive phenotype, but also allows us to study the predictability and reproducibility of genes in the evolutionary process.

  Shi Peng's research group at the Kunming Institute of Zoology, Chinese Academy of Sciences has always used mammalian echolocation as a research model, and used molecular evolution theory and analysis techniques to study the occurrence of this complex convergent phenotype. We are exploring internal molecular mechanisms that promote development. Considering the close relationship between echolocation and auditory performance, previous studies have shown that multiple auditory genes in mammals are selected for echolocation through parallel evolution, and multiple parallel evolutionary sites mainly represent these auditory genes. It has been identified that it is closely related to mammalian echolocation (Lietal.CurrBiol20(2): R55-56,2010; Liuet.al.PLoSOne6(10):e26618,2011). In order to further support the functional experiments of the parallel evolution gene Prestin, the identified parallel sites can fully explain the functional convergence of this gene in echolocation mammals (Liuetal.MolBiolEvol31(9): 2415-2424, 2014, ).

  Recently, further studies have shown that bats with different echolocation characteristics, especially FM bats that are parallel in the phylogenetic tree of this species, have different prestin functions. Compared with the relatively close constant frequency bat, the function of FM Bat Prestin shows the same trend change. The results of this study strongly support that the places that lead to the same trend change in function are not places of convergence or parallel evolution. The decisive role is fixed in the branch of FM bat ancestors. The polymorphic site originated from the common ancestor of bats, and the immobilization of the polymorphic site may be affected by natural selection. This result indicates that not all convergent phenotypes are caused by genes that have undergone convergence or parallel evolution and their convergent or parallel sites. At the same time, the researchers recalled that in different species, especially those undergoing adaptive radiation, one must be careful to distinguish between different formation mechanisms when inferring and analyzing genetic convergence or parallel evolution.