Annual Report 2014–15

發現新DNA 生命科學學院許浩霖教授（中）及其 研究小組成功利用一種被視為沒有實 際功能的「垃圾」DNA，揭示不同動 物之間的關係。 人體細胞內通常含有二十三對染色 體，當中只有極少數DNA（約1–3%） 可組成蛋白質，決定細胞的結構。科 學家通常會用蛋白質或其基因，來揭 示生物體之間的關係，其餘的DNA 都一直被視為沒有功能的「垃圾」 DNA。近年科學界正在改變這種觀 念，並發現大多數DNA會轉譯成非蛋 白質編碼RNA。非蛋白質編碼RNA主 要負責調控基因的表達，其中一種命 名為小分子RNA。許教授是研究小分 子RNA的專家，他與團隊發現圍繞小 分子RNA的DNA，原來並非垃圾。 研究小組利用這種新發現的DNA揭示 不同動物的關係。他們首先比較人類 及黑猩猩、大猩猩、婆羅洲猩猩、普 通獼猴的該種DNA，並推算出人類 與其近親品種的演化歷史：人類的最 近親為黑猩猩，其次順序是大猩猩、 婆羅洲猩猩和普通獼猴。他們還利 用新方法成功了解其他物種之間的關 係，如昆蟲及線蟲等。研究成果在 2015年3月發表於《英國皇家學會學 報》。 最準確人面識別系統 信息工程學系湯曉鷗教授及電子工程 學系王曉剛教授領導的研究團隊， 研發出嶄新的自動人面識別系統， 準確度為全球之冠。該系統在人面 Discovery of New DNA Prof. Jerome H.L. Hui ( centre ) and his team members at the School of Life Sciences discovered and utilized a new type of ‘junk DNA’ in revealing the relationships among different animals. Majority of cells in the human usually contains 23 pairs of chromosomes, and very few of these DNA (approximately 1–3%) will become protein and form the cell structure. Scientists usually make use of the proteins or their encoding DNA sequences to reveal the different organisms’ relationships, while the rest of the genome or DNA are regarded as useless ‘junk’. In recent years, this concept is rapidly changing, and scientists have discovered that the majority of our DNA will become non-coding RNAs that do not encode for proteins. The non-coding RNAs are mainly responsible for regulating the gene expression, with one class known as the micro RNAs. Prof. Jerome Hui is one of the experts on microRNAs. He and his team members have discovered that the DNA surrounding microRNAs are in fact not junk. By comparing these sequences between human, chimpanzee, gorilla, orangutan, and macaque, the team successfully recovered the evolutionary history of human and our close relatives—whereas chimpanzee share the closest common ancestor with human, followed by gorilla, orangutan, and then macaque being the more distant relatives. They have also used this new method to reveal the relationships of other animals, such as insects and nematodes. Their findings were published in the Proceedings of the Royal Society B in March 2015. Most Accurate Face Recognition System A research team led by Prof. Tang Xiaoou of the Department of Information Engineering and Prof. Wang Xiaogang of the Department of Electronic Engineering has built a novel facial recognition system with the highest accuracy in the world. Tested with thousands of picture sets, this recognition system could recognize faces at an accuracy rate of 99.15%, regardless of changes in lighting, make-up and camera angles, compared to the accuracy rate of 97.53% of humans. 24 開拓人類知識的版圖 Pushing Knowledge Frontiers