Characterization of duplicated Dunaliella viridis SPT1 genes provides insights into early gene divergence after duplication |
| |
Authors: | Guan Zhenwei Meng Xiangzong Sun Zhenhua Xu Zhengkai Song Rentao |
| |
Affiliation: | Shanghai Key Laboratory of Bio-energy Crops, School of Life Sciences, Shanghai University, Shanghai 200444, China. |
| |
Abstract: | The sodium-dependent phosphate transporter gene from unicellular green algae Dunaliella viridis, DvSPT1, shares similarity with members of Pi transporter family. Sequencing analysis of D. viridis BAC clone containing the DvSPT1 gene revealed two inverted duplicated copies of this gene (DvSPT1 and DvSPT1-2 respectively). The duplication covered most of both genes except for their 3' downstream region. The duplicated genomic sequences exhibited 97.9% identity with a synonymous divergence of Ks=0.0126 in the coding region. This data indicated very recent gene duplication in D. viridis genome, providing an excellent opportunity to investigate sequence and expression divergence of duplicated genes at an early stage. Scatted point mutations and length polymorphism of simple sequence repeats (SSRs) were predominant among the sequence divergence soon after gene duplication. Due to sequence divergence in the 5' regulatory regions and a swap of the entire 3' downstream regions (3'-UTR), DvSPT1 and DvSPT1-2 showed expression divergence in response to extra-cellular NaCl concentration changes. According to their expression patterns, the two diverged gene copies would provide better adaptation to a broader range of extra-cellular NaCl concentration. Furthermore, Southern blot analysis indicated that there might be a large phosphate transporter gene family in D. viridis. |
| |
Keywords: | BAC, bacterial artificial chromosome SPT, sodium-dependent phosphate transporter SSR, simple sequence repeat UTR, untranslated region |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|