Preferential Retention of Circadian Clock Genes during Diploidization following Whole Genome Triplication in Brassica rapa
Preferential Retention of Circadian Clock Genes during Diploidization following Whole Genome Triplication in Brassica rapa
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DOI：
10.1105/tpc.112.099499
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发表时间：
2012-06-01
期刊：
影响因子：
11.6
通讯作者：
McClung, C. Robertson
中科院分区：
文献类型：
--
作者：
Lou, Ping;Wu, Jian;McClung, C. Robertson
作为植物昼夜节律的模型，拟南芥的昼夜节律钟的结构和功能已经有了很大的了解。昼夜节律有助于进化适应性，这表明昼夜节律性也可能有助于农业生产力。因此，我们将我们对植物生物钟的研究扩展到农业作物芜菁。自拟南芥分离以来，B.芜菁经历了全基因组三倍化和随后的二倍化，这涉及相当多的基因丢失。我们发现，生物钟基因优先保留相对于比较组的相邻基因，一组随机选择的基因，和一组管家基因广泛保守的真核生物。时钟基因的优先保留与基因剂量假说一致，该假说预测高度网络化或剂量敏感的基因的优先保留。编码在植物核心转录因子中起重要作用的转录因子的两个基因家族--假应答调节因子，包括CAB表达的定时1，和揭示家族，包括昼夜节律相关1和晚伸长下胚轴--表现出与基因剂量假说一致的优先保留，但是第三个基因家族，包括ZEITLUPE，编码调节翻译后蛋白质稳定性的F-Box蛋白的基因提供了一个例外。
Much has been learned about the architecture and function of the circadian clock of Arabidopsis thaliana, a model for plant circadian rhythms. Circadian rhythms contribute to evolutionary fitness, suggesting that circadian rhythmicity may also contribute to agricultural productivity. Therefore, we extend our study of the plant circadian clock to Brassica rapa, an agricultural crop. Since its separation from Arabidopsis, B. rapa has undergone whole genome triplication and subsequent diploidization that has involved considerable gene loss. We find that circadian clock genes are preferentially retained relative to comparison groups of their neighboring genes, a set of randomly chosen genes, and a set of housekeeping genes broadly conserved in eukaryotes. The preferential retention of clock genes is consistent with the gene dosage hypothesis, which predicts preferential retention of highly networked or dose-sensitive genes. Two gene families encoding transcription factors that play important roles in the plant core oscillator-the PSEUDO-RESPONSE REGULATORS, including TIMING OF CAB EXPRESSION1, and the REVEILLE family, including CIRCADIAN CLOCK ASSOCIATED1 and LATE ELONGATED HYPOCOTYL-exhibit preferential retention consistent with the gene dosage hypothesis, but a third gene family, including ZEITLUPE, that encodes F-Box proteins that regulate posttranslational protein stability offers an exception.