October 27, "BMC evolutionary biology" online published the research results with the title "Genome-wide identification and evolution of ATP-binding cassette transporters in the ciliate Tetrahymena thermophila”, which was fulfilled by XIONG Jie from the Research Group of Protozoa Functional Genomics of Institute of Hydrobiology, Chinese Academy of Sciences (IHB). In this study, a total of 165 ABC transporter genes have been identified, and made it the largest family of ABC transporter genes described in any eukaryotes to date. The result of phylogeny, conserved introns information and comparison to paramecium showed that most of the Tetrahymena ABC transporters were arisen after the divergence of these two species (about 800 Mya). Further investigation on the gene expression and expression evolution indicated that the expression and function of some Tetrahymena ABC transporter genes have been diverged after duplication, and the retention of many these duplicates in genome corresponded to the neofunctionalization and dosage balance model. This work is the advancesin molecular evolution of gene family which sense of and respond to environmental changes in Tetrahymena after the cytochrome P450 work of this team last year, and validated the team’s view that Tetrahymena is a good organism to study the molecular evolution of these families. 

This work was supported by grants from the National Natural Science Foundation of China and the Knowledge Innovation Program of CAS.