Analysis of determinants for epidermis and muscle differentiation in ascidian egg cytoplasm.

海鞘卵细胞质中表皮和肌肉分化的决定因素分析。

• 批准号: 07680796
• 负责人: NISHIDA Hiroki
• 金额: $ 1.41万
• 依托单位: TOKYO INSTITUTE OF TECHNOLOGY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07680796/
• 关键词: Ascidian embryogenesis; endoderm differentiation; Alkaline phosphatase; Cytoplasmic determinant; gene expression; 原索動物; ホヤ; 胚発生; 発生運命; 細胞質内決定因子; 内胚葉; 組織分化

Alkaline phosphatase (AP) activity is expressed in endodermal cells of ascidian larvae. It was reported previously that the expression of AP activity is resistant to treatment with actinomycin D,a transcription inhibitor. The resistance of AP expression to actinomycin D treatment suggests that appearance of AP activity does not depend on zygotic transcription and that its appearance is mediated by the translational activation of maternal AP mRNA present in ascidian eggs. To directly examine whether or not maternal AP transcripts are present in the cytoplasm of eggs, the endoderm-specific alkaline phosphatase was purified and its N-terminal amino acid sequence was determined in Halocynthia roretzi. Based on this sequence, we isolated a cDNA of this enzyme (HrES-AP) which is 3017-bp long and contains the complete open reading frame and polyadenvlic acid. HrES-AP exhibited a 52.6% homology to a non-specific mouse AP and is specificaly expressed in endoderm precursor cells of the tailbud embryos. As the results of northern blots and in situ hybridization, AP transcripts were not detected in the cytoplasm of unfertilized eggs and they were first detected at the neurula stage in endoderm precursor cells. These results indicate that at least in Halocynthia, embryonic AP activity exclusively depends on the activation of zygotic AP genes, presumably by cytoplasmic determinants present in eggs.

碱性磷酸酶（AP）活性在海鞘幼虫的内胚层细胞中表达。先前报道AP活性的表达对转录抑制剂放线菌素D的治疗具有抵抗力。 AP 表达对放线菌素 D 处理的抗性表明 AP 活性的出现不依赖于合子转录，并且其出现是由海鞘卵中存在的母体 AP mRNA 的翻译激活介导的。为了直接检查母体 AP 转录物是否存在于卵的细胞质中，纯化了 Halocynthia roretzi 中的内胚层特异性碱性磷酸酶并测定了其 N 末端氨基酸序列。基于该序列，我们分离出了该酶的cDNA（HrES-AP），其长度为3017bp，包含完整的开放阅读框和聚腺苷酸。 HrES-AP与非特异性小鼠AP表现出52.6%的同源性，并在尾芽胚胎的内胚层前体细胞中特异性表达。 Northern印迹和原位杂交的结果表明，在未受精卵的细胞质中未检测到AP转录本，并且在内胚层前体细胞的神经胚阶段首次检测到AP转录本。这些结果表明，至少在盐藻中，胚胎 AP 活性完全取决于合子 AP 基因的激活，大概是通过卵中存在的细胞质决定簇。

项目成果

Satoshi Kawaminami,Hiroki Nishida: "Induction of trunk lateral cells,the blood cell precursors,during ascidian embryogenesis" Developmental Biology. (印刷中). (1997)

Satoshi Kawaminami、Hiroki Nishida：“海鞘胚胎发生过程中躯干侧细胞的诱导”（出版中）。

Noriyuki Satoh: "Morphogenetic determinants in the early ascidian embryo." BioEssays. (印刷中). (1996)

Noriyuki Satoh：“早期海鞘胚胎的形态发生决定因素”（BioEssays）（1996 年）。

Satoshi Kawaminami and Hiroki Nishida: "Induction of trunk lateral cells, the blood cell precursors, during ascidian embryogenesis" Developmental Biology. 181. 14-20 (1997)

Satoshi Kawaminami 和 Hiroki Nishida：“海鞘胚胎发生过程中躯干侧细胞（血细胞前体）的诱导”发育生物学。

Hiroki Nishida: "Vegetal egg cytoplasm promotes gastrulation and is responsible for specification of vegetal blastomeres in embryos of the ascidian Halocynthia roretzi" Development. (印刷中). (1996)

Hiroki Nishida：“植物卵细胞质促进原肠胚形成，并负责海鞘类 Halocynthia roretzi 胚胎中植物卵裂球的规范”（正在出版）。

Hiroki Nishida: "Vegetal egg cytoplasm promotes gastrulation and is responsible for specification of vegetal blastomeres in embryos of the ascidian Halocynthia roretzi." Development. Vol.122. 1271-1279 (1996)

Hiroki Nishida：“植物卵细胞质促进原肠胚形成，并负责海鞘类 Halocynthia roretzi 胚胎中植物卵裂球的规范。”