High level of microsynteny and purifying selection affect the evolution of WRKY family in Gramineae
High level of microsynteny and purifying selection affect the evolution of WRKY family in Gramineae
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高水平的微同线性和纯化选择影响禾本科WRKY家族的进化
DOI：
10.1007/s00427-015-0523-2
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发表时间：
2016-01-01
影响因子：
2.4
通讯作者：
Jiang, Haiyang
中科院分区：
文献类型：
--
作者：
Jin, Jing;Kong, Jingjing;Jiang, Haiyang
WRKY基因家族是高等植物中最大的转录因子家族之一，编码不同发育阶段调控过程中的蛋白质。在这项研究中，通过寻找种间基因共线性(微共线)和重复基因的年龄分布，我们发现WRKY家族I亚组基因(WRKY I)的35个染色体片段在4个禾本科植物(Brachypodium、水稻、高粱和玉米)中形成了8个直系类群。在对WRKY基因两侧的所有蛋白质序列进行逐个基因的相互比较后，发现在四个禾本科植物中存在高度保守的微同步区域。大多数基因对在同线基因组区域内表现出保守的取向。此外，串联复制事件在基因扩增中起主导作用。最后，环境选择压力分析表明，WRKY I基因在禾本科植物中有很强的净化选择，随后可能发生了基因丢失和重排。本研究结果提供了禾本科植物WRKY基因的基本信息，并为进一步研究这些基因的功能奠定了基础。这四个草种的高水平微同步性进一步证明，大规模的基因组复制事件发生在物种形成之前。
The WRKY gene family, which encodes proteins in the regulation processes of diverse developmental stages, is one of the largest families of transcription factors in higher plants. In this study, by searching for interspecies gene colinearity (microsynteny) and dating the age distributions of duplicated genes, we found 35 chromosomal segments of subgroup I genes of WRKY family (WRKY I) in four Gramineae species (Brachypodium, rice, sorghum, and maize) formed eight orthologous groups. After a stepwise gene-by-gene reciprocal comparison of all the protein sequences in theWRKY Igene flanking areas, highly conserved regions of microsynteny were found in the four Gramineae species. Most gene pairs showed conserved orientation within syntenic genome regions. Furthermore, tandem duplication events played the leading role in gene expansion. Eventually, environmental selection pressure analysis indicated strong purifying selection for theWRKY Igenes in Gramineae, which may have been followed by gene loss and rearrangement. The results presented in this study provide basic information of GramineaeWRKY Igenes and form the foundation for future functional studies of these genes. High level of microsynteny in the four grass species provides further evidence that a large-scale genome duplication event predated speciation.