piRNA於基因組中扮演守衛的角色，辨認外來基因並引發基因沉默現象，抵禦外來病毒的入侵。但此現象於實驗研究中卻是長年困擾著學者們，piRNA的標靶致使轉殖基因遭受基因沉默，其性狀因此無法表現。線蟲piRNA標靶規則的發現為此帶來一線曙光，根據此規則我們即可較準確的預測piRNA對轉殖基因標靶之情況，並設法修改轉殖基因序列避免其遭piRNA標靶而致使基因沉默。我們研究開發pirScan網頁工具，提供生物學家線蟲物種之piRNA標靶位置預測，並根據預測結果，提供使用者序列修改之建議，以逃脫piRNA的標靶，使用者僅須透過簡單操作即可獲得修改之序列，此序列經過再次預測piRNA標靶位置，確認其不只能逃脫piRNA之標靶，亦不會造成新的piRNA標靶位置。本文首先對於線蟲piRNA做簡介，說明研究動機以及pirScan運作流程，接著討論本研究所運用的資料及其處理方式，再來介紹pirScan網頁工具實際於網頁呈現之結果，最後以實例探討比較人工測試修改序列與pirScan提供之序列修改建議，討論我們所研究開發的pirScan網頁工具之實用性。相信有了pirScan的輔助，能使生物學家在線蟲相關研究上更加順利，並使更多未知的piRNA運作機制能夠被研究探明。
pirScan網址:http://cosbi4.ee.ncku.edu.tw/pirScan/
pirScan備用網址:http://cosbi2.ee.ncku.edu.tw/pirScan/ 與http://cosbi5.ee.ncku.edu.tw/pirScan/

The piRNA-mediated transcriptional silencing mechanism lead the mRNA target site to inhibit gene expression or translation. It impediment to C. elegans researchers to observe the changes of phenotype. Biologists used to do try and error to modify sequences in order to avoid piRNA targeting. It’s not that effectively. Therefore, we developed pirScan which is a web tool for predicting C. elegans piRNA target site of a given sequence that provided by user. Subsequently, pirScan offers modify suggestions to introduce silent mutations into the input sequence. We implement these two features of pirScan according to piRNA sequences and codon usage table of C. elegans. pirScan web-based tool back-end is constructed by python script. With pirScan, C. elegans related researchers can predict the targeting site of their input sequences and obtain sequence silent mutation modify suggestions quickly. In this thesis, we will compare real experiment and pirScan to verify the practicality of pirScan. pirScan is available at http://cosbi4.ee.ncku.edu.tw/pirScan/.

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