2009-08-012024-05-18https://scholars.lib.ntu.edu.tw/handle/123456789/698699摘要：當DNA受到傷害時，會啟動偵測系統ATM/ATR、Chk1/Chk2蛋白質磷酸&#37238;對下游受質(如Cdc25, p53, and E2F)進行磷酸化作用，藉已停止或延長細胞週期運轉來等待DNA被修復或直接活化細胞凋亡機制。天生缺乏ATM基因表現的病人在臨床上顯示出神經系統衰退、免疫能力缺乏、對放射線或化療藥物極度敏感有發展成癌症的可能性，這些病人的生殖細胞因有缺陷的減數分裂重組反應因而導致不孕。在ATM基因剔除鼠的生殖細胞也看到了有缺陷的減數分裂細胞，伴隨著染色體斷裂的現象，同樣地，ATM基因剔除鼠也有精卵發育不全的現象。 我們在第一年的研究中，已將p29基因送進缺乏ATM表現的AT細胞表現，結果發現在穩定高度表現p29的 AT細胞對於化療藥物cisplatin具有較高的耐受度，證明p29穩定高度表現時可以部分地補償ATM缺乏時細胞對藥物反應的缺陷。為了探討mp29基因轉殖鼠是否能補救ATM基因剔除鼠不孕的現象，我們在第二年的計畫中將開始進行mp29基因轉殖鼠與ATM基因剔除鼠交配，希望取得高度表現mp29的ATM基因剔除鼠後，觀察其子代精虫發育情形並研究其可能機制，同時我們將進行mp29 gene trap的實驗，希望取得缺乏mp29表現的基因剔除鼠。 <br> Abstract: Maintenance of genomic integrity and protection against harmful mutagenic effects of DNA damage rely on DNA damage response machinery, a complex network of signaling and effector pathways that coordinate cell cycle checkpoints with DNA repair and cell death mechanisms. In response to DNA lesions, the signal transducing kinases, ATM (ataxia telangiectasia-mutated), ATR(ataxia telangiectasia and Rad3-related), Chk1, and Chk2, phosphorylate downstream checkpoint effector proteins, such as Cdc25, p53, and E2F, to regulate cellular responses and ensure error-free DNA replication. In Atm-deficient mice, male and female gametogenesis is severely disrupted as early as leptonema of prophase I with significant chromosome fragmentation, and apoptotic degeneration. In our first-year experiments, we have established p29 stable expression in AT cells. Preliminary data showed a higher survival rate in p29 stably expressing AT cells than in control cells when these cells were treated with cisplatin, indicating that p29 could partially complement cellular defects resulted from ATM-deficiency. In the second year proposal, we will inbreed mp29 transgenic mice with ATM-deficient mice to generate mp29 Tg/+ ATM-/- littermates in an effort to investigate whether mp29 overexpression could rescue the prophase-I arrest characteristics of Atm-deficient spermatocytes. In addition, we will study the mp29-deficient mice using the gene-trap method.p29ATM基因轉殖精蟲發生p29ATMtransgenespermatogenesis