Analysis of RNA sorting mechanisms in the ascidian embryos.

海鞘胚胎中 RNA 分选机制的分析。

• 批准号: 14580710
• 负责人: MAKABE Kazuhiro
• 金额: $ 2.3万
• 依托单位: The University of Tokushima (2003)Kyoto University (2002)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14580710/
• 关键词: ascidian; matenal factors; EST; RNA; localization; UTR; 後極

We have isolated many RNAs localized in the ascidian eggs. It is noteworthy to have found RNAs as localized functional molecules in the ascidian eggs, which are known to be "mosaic" eggs. Six RNAs we studied are localized at the posterior-vegetal region of the egg, named the postplasm. This region is reported to be involved in the anterior-posterior axis formation and generation of unequal cleavages of early blastomeres. We, therefore, designated these RNAs the postplasmic RNAs. The detailed analysis of their expression patterns revealed that they are categorized into two groups (type I and type II) based on their transport pathways. Microinjection experiments of labeled synthetic RNAs into the unfertilized eggs suggested that small elements in the 3 'UTR of the RNAs are necessary and sufficient to proper localization. There is no obvious conserved sequence in the regions, but the injection assay. using portions of the 3'UTRs identified 50-nucleotide elements responsible for the localization. In order to investigate molecular mechanisms of RNA sorting in the ascidian eggs and embryos, we are currently trying to isolate sequence-specific RNA-binding proteins which bind to the identified elements from the ascidian egg extract using gel shift, east-western and UV-cross link techniques and analyze on the biochemical characteristics of the proteins. On the other hand, we revealed that the postplasmic RNAs distribute at specific sites in the CAB region of the embryo at the electron microscopic level. These will shed a light to the whole molecular mechanisms on the RNA sorting in the ascidian eggs and embryos.

我们已经分离出许多海鞘卵中的RNA。值得注意的是，在海鞘卵中发现了RNA作为定位的功能分子，海鞘卵被称为“马赛克”卵。我们研究的六个RNA位于卵的后植物区，称为postplasma。据报道，这一区域参与了前-后轴的形成和早期卵裂球不均等卵裂的产生。因此，我们将这些RNA命名为后质RNA。对它们的表达模式的详细分析表明，它们根据其转运途径分为两组（I型和II型）。将标记的合成RNA显微注射到未受精卵中的实验表明，RNA的3 'UTR中的小元件对于适当的定位是必要的和足够的。在这些区域中没有明显的保守序列，但注射试验显示。使用3 'UTR的部分鉴定了负责定位的50个核苷酸的元件。为了研究海鞘卵和胚胎中RNA分选的分子机制，我们利用凝胶迁移、东西向电泳和紫外交联等技术从海鞘卵提取物中分离出序列特异性RNA结合蛋白，并对其生化特性进行分析。另一方面，我们发现，postplasma RNA分布在特定的位点在CAB区域的胚胎在电子显微镜水平。这些结果将为海鞘卵和胚胎RNA分选的分子机制研究提供新的思路。

项目成果

Wang, C-P.^*, K.Yagi^*: "Identification of a gene encoding a typical carboxy-glutamic acid domain in the tunicate Halocynthia roretzi."J.Thrombosis and Hemostasis.. 1. 118-123 (2003)

Wang, C-P.^*, K.Yagi^*：“被囊动物 Halocynthia roretzi 中编码典型羧基谷氨酸结构域的基因的鉴定。”J.Thrombosis and Hemostasis.. 1. 118-123 (2003)

Nakamura, Y.: "Localization and expression pattern of type 1 postplasmic mRNAs in embryos of the ascidian Halocynthia roretzi"Mech. Dev.. (In press). (2003)

Nakamura, Y.：“海鞘类 Halocynthia roretzi 胚胎中 1 型后质 mRNA 的定位和表达模式”Mech。

Yagi, K.: "Retinoic acid differently affects the formation of palps and surrounding neurons in the ascidian tadpole."Dev.Genes Evol.. 212. 288-292 (2002)

Yagi, K.：“视黄酸对海鞘蝌蚪触须和周围神经元的形成有不同的影响。”Dev.Genes Evol.. 212. 288-292 (2002)

Sasakura, Y.: "Identification of the cis elements which direct the localization of maternal mRNAs to the posterior pole of ascidian embryos."Dev.Biol.. 250. 128-144 (2002)

Sasakura, Y.：“识别将母体 mRNA 定位到海鞘胚胎后极的顺式元件。”Dev.Biol.. 250. 128-144 (2002)

Nakamura, Y.: "Localization and expression pattem of type 1 postplasmic mRNA in embryos of the ascidian Halocynthia roretzi."Gene Exp.Patterns. 3. 71-75 (2003)

Nakamura, Y.：“海鞘类 Halocynthia roretzi 胚胎中 1 型后质 mRNA 的定位和表达模式。”基因实验模式。