Department of Bioscience and Bioinformatics, Kyushu Institute of Technology.
RIKEN Center for Sustainable Resource Science.
Genes Genet Syst. 2023 Nov 21;98(5):283-286. doi: 10.1266/ggs.23-00019. Epub 2023 Sep 29.
Duplicated genes show various degrees of functional diversification in plants. We previously identified 1,052 pairs of high diversified duplicates (HDDs) and 600 pairs of low diversified duplicates (LDDs) in Arabidopsis thaliana. Single knock-down of HDDs induced abnormal phenotypic changes because the other gene copy could not compensate for the knock-down effect, while single knock-down of LDDs did not induce abnormal phenotypic changes because of functional compensation by the copy gene. Here, focusing on one pair each of HDDs and LDDs, we performed transcriptome analyses in single-knock-down transgenic plants. The numbers of differentially expressed genes in single-knock-down transgenic plants were not different between HDDs and LDDs. Thus, functional compensation inferred by transcriptomics was similar between HDDs and LDDs. However, the trend of differentially expressed genes was similar in the pair of LDDs, while expression profiles were dissimilar in the pair of HDDs. This result indicates that a pair of LDDs tends to share similar functions but a pair of HDDs tends to have undergone functional divergence. Taking these findings together, as the reason for no phenotypic changes in single knock-down of LDDs but phenotypic changes in double knock-down of LDDs, we concluded that phenotypic changes of LDDs were induced by decreasing gene dosage.
在植物中，重复基因表现出不同程度的功能多样化。我们之前在拟南芥中鉴定了 1052 对高度多样化重复（HDD）和 600 对低度多样化重复（LDD）。HDD 的单个敲除会引起异常表型变化，因为另一个基因副本无法补偿敲除效应，而 LDD 的单个敲除不会引起异常表型变化，因为拷贝基因的功能补偿。在这里，我们聚焦于每对 HDD 和 LDD 各一对，在单敲除转基因植物中进行了转录组分析。单敲除转基因植物中转录组分析中差异表达基因的数量在 HDD 和 LDD 之间没有差异。因此，HDD 和 LDD 之间的转录组推断出的功能补偿是相似的。然而，LDD 对中差异表达基因的趋势相似，而 HDD 对中表达谱则不同。这一结果表明，一对 LDD 倾向于具有相似的功能，而一对 HDD 则倾向于经历功能分化。综合这些发现，由于 LDD 单敲除没有表型变化而 LDD 双敲除则有表型变化，我们得出结论，LDD 的表型变化是由基因剂量减少引起的。
