Mechanisms of Initiation of DNA replication after fertilization in Starfish eggs

海星卵受精后 DNA 复制启动机制

• 批准号: 17570157
• 负责人: TACHIBANA Kazunori
• 金额: $ 2.3万
• 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: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17570157/
• 关键词: DNA replication; Lisence; meiosis; fertilization; Mcm; Cdc6; Cdc45; oocyte maturation; ライセンス

Cdc6 is a member of nucleotide-dependent loading factors of Mcm (mini-chromosome maintenance) proteins. We have cloned starfish Cdc6 cDNA and raised its antibody that recognized Cdc6 protein on chromatin by immuno fluorescent microscopy. Very low level of Cdc6 protein was identified in immature oocytes of starfish. After resumption of meiosis Cdc6 increased 5-10 times of initial level. Using morpholino oligonucleoties(M0) to knockdown Cdc6. Microinjection of MO inhibited more than 90% of expression of Cdc6 during oocyte, maturation. Surprisingly, Cdc6 on the chromatin in the Cdc6 knockdown oocytes, eggs and embryos was same level as in the control eggs that were injected with control (beta-globin) morpholino. Furthermore, the Ced6 knocked down embryos developed at least gastrula. These results suggest that cells require very small amount of Cdc6 (1/5-1110 of normal level) to replicate DNA.

Cdc6是Mcm（迷你染色体维持）蛋白的核苷酸依赖装载因子的成员。我们克隆了海星Cdc6 cDNA，并在免疫荧光显微镜下获得了在染色质上识别Cdc6蛋白的抗体。在海星未成熟卵母细胞中发现了极低水平的Cdc6蛋白。减数分裂恢复后，Cdc6增加5-10倍于初始水平。利用morpholino寡核（M0）敲除Cdc6。在卵母细胞成熟过程中，微量注射MO可抑制Cdc6 90%以上的表达。令人惊讶的是，Cdc6敲除的卵母细胞、卵子和胚胎中染色质上的Cdc6与注射了对照（β -珠蛋白）morpholino的对照卵子中的Cdc6水平相同。此外，敲除Ced6的胚胎至少发育出原肠胚。这些结果表明细胞需要非常少量的Cdc6（正常水平的1/5-1110）来复制DNA。

项目成果

p90Rsk is required for G1 phase arrest in unfertilized starfish eggs.

p90Rsk 是未受精海星卵 G1 期停滞所必需的。

• 发表时间: 2006
• 期刊: Development (in press)
• 作者: Mori;M.;Hara;M.;Tachibana;K.;Kishimoto;T.
• 通讯作者: T.

p9ORsk is required for Gl arrest in unfertilized starfish eggs

p9ORsk 是未受精海星卵中 GL 阻滞所必需的

• 发表时间: 2006
• 期刊: Development 133
• 作者: Mori;M.;Hara;M.;Tachibana;K.;Kishimoto;T.
• 通讯作者: T.

Intracellular Ca2+ increase induces post-fertilization events via MAP kinase dephosphorylation in eggs of the hydrozoan jellyfish Cladonema pacificum

• DOI: 10.1016/j.ydbio.2006.02.005
• 发表时间: 2006-05-01
• 期刊: DEVELOPMENTAL BIOLOGY
• 影响因子: 2.7
• 作者: Kondoh, E;Tachibana, K;Deguchi, R
• 通讯作者: Deguchi, R