Dataset Information

Comparative genomic and transcriptomic analysis of tandemly and segmentally duplicated genes in rice.

ABSTRACT: Tandem and segmental duplications significantly contribute to gene family expansion and genome evolution. Genome-wide identification of tandem and segmental genes has been analyzed before in several plant genomes. However, comparative studies in functional bias, expression divergence and their roles in species domestication are still lacking. We have carried out a genome-wide identification and comparative analysis of tandem and segmental genes in the rice genome. A total of 3,646 and 3,633 pairs of tandem and segmental genes, respectively, were identified in the genome. They made up around 30% of total annotated rice genes (excluding transposon-coding genes). Both tandem and segmental duplicates showed different physical locations and exhibited a biased subset of functions. These two types of duplicated genes were also under different functional constrains as shown by nonsynonymous substitutions per site (Ka) and synonymous substitutions per site (Ks) analysis. They are also differently regulated depending on the tissues and abiotic and biotic stresses based on transcriptomics data. The expression divergence might be related to promoter differentiation and DNA methylation status after tandem or segmental duplications. Both tandem and segmental duplications differ in their contribution to genetic novelty but evidence suggests that they play their role in species domestication and genome evolution.

SUBMITTER: Jiang SY

PROVIDER: S-EPMC3656045 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature

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Comparative genomic and transcriptomic analysis of tandemly and segmentally duplicated genes in rice.

Jiang Shu-Ye SY González José M JM Ramachandran Srinivasan S

PloS one 20130516 5

Tandem and segmental duplications significantly contribute to gene family expansion and genome evolution. Genome-wide identification of tandem and segmental genes has been analyzed before in several plant genomes. However, comparative studies in functional bias, expression divergence and their roles in species domestication are still lacking. We have carried out a genome-wide identification and comparative analysis of tandem and segmental genes in the rice genome. A total of 3,646 and 3,633 pair ...[more]

PMID: 23696832

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Project description:The plant hormone ABA (abscisic acid) regulates plant responses to abiotic stresses by regulating the expression of ABA response genes. However, the functions of a large portion of ABA response genes have remained unclear. We report in this study the identification of ASDs (ABA-inducible signal peptide-containing DUF538 proteins), a subgroup of DUF538 proteins with a signal peptide, as the regulators of plant responses to ABA in Arabidopsis. ASDs are encoded by four closely related DUF538 genes, with ASD1/ASD2 and ASD3/ASD4 being two pairs of duplicated tandemly repeated genes. The quantitative RT-PCR (qRT-PCR) results showed that the expression levels of ASDs increased significantly in response to ABA as well as NaCl and mannitol treatments, with the exception that the expression level of ASD2 remained largely unchanged in response to NaCl treatment. The results of Arabidopsis protoplast transient transfection assays showed that ASDs were localized on the plasma membrane and in the cytosol and nucleus. When recruited to the promoter of the reporter gene via a fused GD domain, ASDs were able to slightly repress the expression of the co-transfected reporter gene. Seed germination and cotyledon greening assays showed that ABA sensitivity was increased in the transgenic plants that were over-expressing ASD1 or ASD3 but decreased in the transgenic plants that were over-expressing ASD2 or ASD4. On the other hand, ABA sensitivity was increased in the CRISPR/Cas9 gene-edited asd2 single mutants but decreased in the asd3 single mutants. A transcriptome analysis showed that differentially expressed genes in the 35S:ASD2 transgenic plant seedlings were enriched in several different processes, including in plant growth and development, the secondary metabolism, and plant hormone signaling. In summary, our results show that ASDs are ABA response genes and that ASDs are involved in the regulation of plant responses to ABA in Arabidopsis; however, ASD1/ASD3 and ASD2/ASD4 have opposite functions.

Dataset Information

Comparative genomic and transcriptomic analysis of tandemly and segmentally duplicated genes in rice.

Publications

Comparative genomic and transcriptomic analysis of tandemly and segmentally duplicated genes in rice.

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