刘昊昕, Sadaf RIAZ, 刘源, Anam KHURSHID, 张巍, 隋正红
中国海洋大学 海洋生物遗传学与育种教育部重点实验室, 山东 青岛 266003

摘要:
链状亚历山大藻（Alexandrium catenella）是一种典型的产毒赤潮甲藻。甲藻曾被认为没有组蛋白，但近年来在多种甲藻中检测到全部四个核心组蛋白的活跃转录，而目前对甲藻中组蛋白表达模式与具体功能还缺乏深入的研究。本文报道了链状亚历山大藻组蛋白H3变体之一H3.c的全长ORF序列的克隆和分析；分析了链状亚历山大藻生长过程中组蛋白H3在基因和蛋白水平的表达。目前研究发现的链状亚历山大藻H3变体共三个，其中H3.b在N末端序列与其他物种差异最大，为链状亚历山大藻特有的H3变体。对数生长期的组蛋白H3在基因与蛋白水平上均活跃表达，但表达量并不会随着爆发性增长而显著变化，其中H3.b的基因表达在对数末期呈现上调；培养至衰亡期，各H3变体表达均下调，尤其在蛋白水平上呈现明显衰减。结合前期研究，本文认为链状亚历山大藻三个H3均为复制非依赖型（RI）变体，一些变体可响应伴随藻不断生长而逐渐增强的细胞密度等复杂胁迫，推测其参与某些表观遗传修饰，调控生长进程；而衰亡期基于H3的表观遗传调控受到抑制。
关键词:链状亚历山大藻组蛋白H3表观遗传调控实时荧光定量PCR蛋白免疫印记杂交
DOI：10.11759/hykx20190401001
分类号:Q943.2
基金项目:国家自然科学基金项目（41676091，41176098）

Cloning and expression analysis of histone H3 in Alexandriumcatenella during the growth process
LIU Hao-xin, Sadaf RIAZ, LIU Yuan, Anam KHURSHID, ZHANG Wei, SUI Zheng-hong
Key Laboratory of Marine Genetics and Breeding, Ministry of Education, Ocean University of China, Qingdao 266003, China
Abstract:
Alexandrium catenella is a typical toxic red tide dinoflagellate. Dinoflagellates were once thought to have no histones. However, active transcription of all four core histones has been detected in a variety of dinoflagellates in recent years. At present, the expression pattern and specific function of histones in dinoflagellates have not been thoroughly studied. Our research reported the cloning and analysis of the full-length ORF sequence of H3.c, one of the H3 variants of Alexandrium catenella. We further analyzed the expression of histone H3 at the gene and protein levels during different growth stages of A. catenella. Studies have shown that three H3 variants have been found in A. catenella, among which H3.b differs the most from those of other species in the N-terminal sequence, which is the unique H3 variant of A. catenella. Histone H3 genes were actively expressed at both gene and protein levels in the log growth phase, but the expression level did not change significantly with explosive growth, in which the gene expression of H3.b was upregulated at the late log phase. In the death phase, the expression of H3 variants was downregulated, especially at the protein level. Considering our results together with those of previous studies, we believe that all three H3 variants of A. catenella are replication-independent variants, some of which could respond to the increasing population pressure and various stresses accompanying the continuous growth of dinoflagellates. We speculate that they are involved in epigenetic modifications that regulate the growth process and that said epigenetic regulation based on H3 is inhibited in the death phase.
Key words:Alexandrium catenellahistone H3epigenetic regulationreal-time PCRwestern blot





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