Leg regeneration is epigenetically regulated by histone H3K27 methylation in the cricket Gryllus bimaculatus
Leg regeneration is epigenetically regulated by histone H3K27 methylation in the cricket Gryllus bimaculatus
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DOI：
10.1242/dev.122598
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发表时间：
2015-09-01
期刊：
影响因子：
4.6
通讯作者：
Ohuchi, Hideyo
中科院分区：
文献类型：
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作者：
Hamada, Yoshimasa;Bando, Tetsuya;Ohuchi, Hideyo
半代谢昆虫，如蟋蟀Gryllus bimaculatus，使用胚芽细胞再生丢失的组织部分，胚芽细胞是一群去分化的增殖细胞。与分化组织相比，控制表观遗传修饰的几个因子在胚泡中的表达上调，这表明基因表达的表观遗传变化可能控制了胚泡细胞在再生过程中的分化状态。为了阐明再生过程中表观遗传调控的分子基础，我们重点研究了ZEST的Gryllus增强子[GB‘e(Z)]和X染色体上普遍转录的四肽重复序列基因(GB’Utx)的功能，它们分别调节组蛋白H3赖氨酸27(H3K27)的甲基化和去甲基化。Gb‘e(Z)(RNAi)使再生小腿中甲基化的组蛋白H3K27减少，而Gb’Utx(RNAi)增加。再生的Gb‘e(Z)(RNAi)蟋蟀腿在胫骨和颧骨之间表现出额外的腿部节段形成，而再生的GB’Utx(RNAi)板球腿部表现出膝部关节形成的缺陷。在Gb‘e(Z)(RNAi)再生腿中，Gb’dac表达结构域在眼睑扩张。相比之下，在Gb‘Utx(RNAi)再生小腿中，Gb’Egfr在踝关节中部的表达减少。这些结果表明，组蛋白H3K27甲基化状态的调控参与了蟋蟀种间腿部再生过程中的重塑过程，这是通过对腿部纹饰基因表达的表观遗传调节来实现的。
Hemimetabolous insects such as the cricket Gryllus bimaculatus regenerate lost tissue parts using blastemal cells, a population of dedifferentiated proliferating cells. The expression of several factors that control epigenetic modification is upregulated in the blastema compared with differentiated tissue, suggesting that epigenetic changes in gene expression might control the differentiation status of blastema cells during regeneration. To clarify the molecular basis of epigenetic regulation during regeneration, we focused on the function of the Gryllus Enhancer of zeste [Gb'E(z)] and Ubiquitously transcribed tetratricopeptide repeat gene on the X chromosome (Gb'Utx) homologues, which regulate methylation and demethylation of histone H3 lysine 27 (H3K27), respectively. Methylated histone H3K27 in the regenerating leg was diminished by Gb'E(z)(RNAi) and was increased by Gb'Utx(RNAi). Regenerated Gb'E(z)(RNAi) cricket legs exhibited extra leg segment formation between the tibia and tarsus, and regenerated Gb'Utx(RNAi) cricket legs showed leg joint formation defects in the tarsus. In the Gb'E(z)(RNAi) regenerating leg, the Gb'dac expression domain expanded in the tarsus. By contrast, in the Gb'Utx(RNAi) regenerating leg, Gb'Egfr expression in the middle of the tarsus was diminished. These results suggest that regulation of the histone H3K27 methylation state is involved in the repatterning process during leg regeneration among cricket species via the epigenetic regulation of leg patterning gene expression.