無病無痛，沒有任何交通或人為意外的話，人類是否會進入不死永生狀態呢？684Please respect copyright.ＰＥＮＡＮＡIr1SmDA7DM
684Please respect copyright.ＰＥＮＡＮＡW5ZTlQbvNy
答案是，不會。684Please respect copyright.ＰＥＮＡＮＡbbzPFPQc2T
684Please respect copyright.ＰＥＮＡＮＡdwJOx2UBRS
箇中的原因，就是在於染色體亦即是DNA的運作機制之上。684Please respect copyright.ＰＥＮＡＮＡX4s8dd0wnk
684Please respect copyright.ＰＥＮＡＮＡABFXhluUPt
684Please respect copyright.ＰＥＮＡＮＡe6VxpIP4PB
（圖1）正常人體細胞分裂的時候，染色體的長度會越來越短。684Please respect copyright.ＰＥＮＡＮＡXjyFkVBQhw
684Please respect copyright.ＰＥＮＡＮＡqzrMzTZhwM
684Please respect copyright.ＰＥＮＡＮＡeDk70t4w0Q
684Please respect copyright.ＰＥＮＡＮＡOXyFkQ1Fsd
（圖2）染色體的頂端區域，我們稱之為Telomere。正常細胞分裂後，Telomere的長度便會越來越短，所以導致染色體的總長度亦會有所減少。684Please respect copyright.ＰＥＮＡＮＡNDPv99fUJI
684Please respect copyright.ＰＥＮＡＮＡWl84js6Wbg
684Please respect copyright.ＰＥＮＡＮＡHsNFOrqcnk
（圖3）而幹細胞進行分裂的時候，則會有著Telomerase的協助，導致Telomere的長度便並不會有所減少。684Please respect copyright.ＰＥＮＡＮＡqjoUFe1NKf
然而，當幹細胞變成正常細胞後，Telomerase的功能便會消失。684Please respect copyright.ＰＥＮＡＮＡPRAcdGHypu
684Please respect copyright.ＰＥＮＡＮＡTYEpydC1Ns
684Please respect copyright.ＰＥＮＡＮＡzBiZ4Gn0SH
684Please respect copyright.ＰＥＮＡＮＡYNY5JU1vwv
（圖4）當Telomere長度削減到一定程度的時候，細胞便會自行啟動機制滅亡，又或者陷入衰老(Senescence)狀態。684Please respect copyright.ＰＥＮＡＮＡCeURsl6LHA
684Please respect copyright.ＰＥＮＡＮＡbioTJYJK4Q
細胞滅亡或衰老的話，器官的功能便會衰退，最後亦會支撐不住，無法正常運作，促成死亡。684Please respect copyright.ＰＥＮＡＮＡZX2S9bZBBG
684Please respect copyright.ＰＥＮＡＮＡi5OlMk5tAJ
684Please respect copyright.ＰＥＮＡＮＡhyxFNvsNFN
你可能會問，現在科技如此倡明，那麼我們只要學習幹細胞的那一套方式，動用外力重啟Telomerase功能，那不就能踏入永生嗎？684Please respect copyright.ＰＥＮＡＮＡqn0r7dXUJZ
684Please respect copyright.ＰＥＮＡＮＡOhm6AJ0AWS
這個思路並沒有錯，只不過代價就是會增加患癌的風險。684Please respect copyright.ＰＥＮＡＮＡ3LPAqp1F1K
684Please respect copyright.ＰＥＮＡＮＡmBRX50r7gV
事實上，不少癌細胞的特徵就是Telomere長度非常之短，但又有著一定水平的Telomerase功能穩定維持著Telomere的長度，逃避進入滅亡的命運。684Please respect copyright.ＰＥＮＡＮＡYcOQ2jlBrL
684Please respect copyright.ＰＥＮＡＮＡx1p5nhG2WM
另一方面的想，如果細胞真的是踏入「永生」狀態的話，終有一天無可避免會累積各種的DNA變異，促成癌細胞的誕生。684Please respect copyright.ＰＥＮＡＮＡdsKqMWhyr9
684Please respect copyright.ＰＥＮＡＮＡrZS9tsQFMf
（圖5）既然Telomere對細胞的壽命有著重要影響的話，那麼一些較為長壽的物種是否擁有較長的Telomere呢？684Please respect copyright.ＰＥＮＡＮＡjitzGNT4Eq
684Please respect copyright.ＰＥＮＡＮＡzfpG3jnb9c
科學家比較各物種的Telomere後（Ref1)，發現海豚的起始Telomere長度比人類高出6倍以上，但壽命長度始終是人類佔優。684Please respect copyright.ＰＥＮＡＮＡKsqNfVsXb3
684Please respect copyright.ＰＥＮＡＮＡuh3aWwDcpw
684Please respect copyright.ＰＥＮＡＮＡvCy1nhX9Yu
反而，決定物種壽命長度的其中一種因素，則是Telomere衰減的速度；684Please respect copyright.ＰＥＮＡＮＡnnNIychbmo
Telomere衰減的速度只是一個參考性的指標，並非絕對。物種的大小、新陳代謝機制的不同等等均會對壽命長度有著影響。684Please respect copyright.ＰＥＮＡＮＡS71rfjsQb6
684Please respect copyright.ＰＥＮＡＮＡq9nUPctChE
人類每年約會減少71單位Telomere的長度，最高壽命為120歲。684Please respect copyright.ＰＥＮＡＮＡ6GEiFqsLYg
而老鼠每年會減少7000單位Telomere長度，最高壽命為5歲。684Please respect copyright.ＰＥＮＡＮＡ2iVyjYBcrE
684Please respect copyright.ＰＥＮＡＮＡDnNKT4J81N
人類：每年減少71；120歲684Please respect copyright.ＰＥＮＡＮＡ2Wn3eMVWLA
大象：每年減少109；66歲684Please respect copyright.ＰＥＮＡＮＡ85McevCWiN
紅鸛：每年減少105；60歲684Please respect copyright.ＰＥＮＡＮＡxx0VpiVaFL
海豚：每年減少766；52歲684Please respect copyright.ＰＥＮＡＮＡaN1C0CgKaV
兀鷲：每年減少209；41歲684Please respect copyright.ＰＥＮＡＮＡ1SPjR4D4Zd
海鷗：每年減少771；25歲684Please respect copyright.ＰＥＮＡＮＡiTJ2lVnyVA
馴鹿：每年減少531；22歲684Please respect copyright.ＰＥＮＡＮＡKE9ssjBRh6
山羊：每年減少363；21歲684Please respect copyright.ＰＥＮＡＮＡITuTBbdAqs
老鼠：每年減少7000；5歲684Please respect copyright.ＰＥＮＡＮＡoH4FdmQ46K
684Please respect copyright.ＰＥＮＡＮＡv84yxuvrso
684Please respect copyright.ＰＥＮＡＮＡXIwOcJyOTF
龜又是每年減少幾多呢？有待有心人發掘。684Please respect copyright.ＰＥＮＡＮＡKqtCHCALce
684Please respect copyright.ＰＥＮＡＮＡSX0JBs0O9c
684Please respect copyright.ＰＥＮＡＮＡyIBWUvO1rE
如果想我快啲出文的話，請入去Penana網站科普專欄–薯不揀單俾一個like以及Bookmark，這對我非常之重要。684Please respect copyright.ＰＥＮＡＮＡz1oiYEYLUL
684Please respect copyright.ＰＥＮＡＮＡSbpZWC2RxD
Link: https://www.penana.com/story/66244/%E7%A7%91%E6%99%AE%E5%B0%88%E6%AC%84-%E8%96%AF%E4%B8%8D%E6%8F%80%E5%96%AE/toc684Please respect copyright.ＰＥＮＡＮＡwnQRsY7CQe
684Please respect copyright.ＰＥＮＡＮＡqzeqS9Rffe
同時亦可以在Penana網站裡按「買一嚿/半嚿薯仔」，以課金的方式推動我繼續搜羅資料寫文，多謝。684Please respect copyright.ＰＥＮＡＮＡil3D3LSkEX
684Please respect copyright.ＰＥＮＡＮＡvSdmj3d49y
Link:684Please respect copyright.ＰＥＮＡＮＡmrV8dVrHoN
https://www.penana.com/user/27349/%E8%96%AF%E4%BB%94%E8%81%9E%E8%8C%B1%E8%8E%89/portfolio684Please respect copyright.ＰＥＮＡＮＡd8OAme0qw4
684Please respect copyright.ＰＥＮＡＮＡr2LIAUs4Pj
684Please respect copyright.ＰＥＮＡＮＡvcLuQdnIxd
有興趣接收科學資訊的話，歡迎follow IG: potatopigtongue。684Please respect copyright.ＰＥＮＡＮＡlnlW3WgUs6
684Please respect copyright.ＰＥＮＡＮＡxVSopurD2G
684Please respect copyright.ＰＥＮＡＮＡS2cZQ7bcto
Ref1:https://www.pnas.org/content/116/30/15122684Please respect copyright.ＰＥＮＡＮＡMJYc8j6TJ9
Penana
search
登入arrow_drop_down
註冊arrow_drop_down
