動物的品種不同,其特徵亦會有所不同。以狗為例的話,金毛尋羊犬以及臘腸狗就是非常鮮明的例證。539Please respect copyright.PENANA7jkBsMjzj3539Please respect copyright.PENANAChIcVhYiky
539Please respect copyright.PENANAkJucqSNPmX
至於牛隻,農場飼養用的大致分為兩種,主力出產牛奶的乳牛(Dairy Cattle)和主力屠宰成肉類出售的肉用牛(Beef Cattle)。539Please respect copyright.PENANADIz6NxvcFd
539Please respect copyright.PENANAjIB4UbuT0J
各舉一例的話,前者品種例子為Holstein(荷斯坦),而後者則為較為廣泛認識的Angus(安格斯)。539Please respect copyright.PENANAJIBW9k7YGf
539Please respect copyright.PENANAdwuA3xF4uO
牛天生會否長角,將視乎品種而定。大多數的乳牛品種天生均長有角,而食用牛多數的品種則天生無角。539Please respect copyright.PENANAWEGtsC1NQw
539Please respect copyright.PENANAv68N0xhfy2
這裡讓農夫感到煩惱的是,乳牛隻會利用頭上的角互相攻擊對方甚至自己。539Please respect copyright.PENANA8kbuM2dsHs
因此慣常的做法會麻醉牛隻然後再進行除角手術,以免牛隻受傷因而損失獲利,但這做法引起動物權益成員的關注及爭議,認為此舉會對牛隻帶來創傷。539Please respect copyright.PENANAOP7q98RvtV
539Please respect copyright.PENANApb8ZEaiJbw
(圖2)最為有效率及一勞永逸的解決辦法,自當然就是培育沒有長角的品種,一直傳遞下去。539Please respect copyright.PENANAbqFTX80vgU
有科學家致力尋求發現,發現牛隻基因染色體1的某一段位置的重覆區域,將會導致乳牛品種不會長出牛角。539Please respect copyright.PENANA9Dpr4zJh7p539Please respect copyright.PENANAZjasdX3PvB
539Please respect copyright.PENANALAMrIypC2k
(圖3)因此,他們嘗試抽取長角品種的皮膚細胞,利用CRISPR基因編輯技術在那段基因區域上加添重覆區域(Ref1),再經過一系列的工序,將已編輯的細胞人工培植到牛隻身上,觀察誕下的胎兒會否長出牛角。539Please respect copyright.PENANA48zQWJu0yq539Please respect copyright.PENANAdnwzKGvfxx
539Please respect copyright.PENANAyHgwTCQA2T
(圖4)最終所誕下的牛隻的而且確沒有長角,但因器官衰竭等問題很快便與世長辭。539Please respect copyright.PENANA8nHT5Q38gd539Please respect copyright.PENANAKiiHRJpv99
539Please respect copyright.PENANAqoSV8TbJ7U
539Please respect copyright.PENANA9KDNahwfTY
這研究確實了CRISPR技術在牛隻的應用,但顯然仍有一系列的應用問題需要改善。在這實驗中,6隻人工培植受孕的牛隻中,只有一隻成功誕下嬰兒。539Please respect copyright.PENANAwdccWX7oHa
539Please respect copyright.PENANAdnkpIJSIDs
至於為何不重點培育沒有長角品種的乳牛,原因是牠的產奶量較其他有角品種的最少。539Please respect copyright.PENANAHC3HT0toYI
539Please respect copyright.PENANAOxQfQkbqPK
農父及科學家的最終目標,當然就是希望培植沒有長角而產奶量豐盛的牛隻。但這做法是否符合動物權益,這又會是一場永無休止的辯論。539Please respect copyright.PENANAOe7YKxanlF
539Please respect copyright.PENANAgd6I0E3d77
539Please respect copyright.PENANAZ8IKEzJST7
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。539Please respect copyright.PENANAoI1Y8X7SZ8
539Please respect copyright.PENANALr3lZMIU5P
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/toc539Please respect copyright.PENANALJpqFtK04S
539Please respect copyright.PENANAQXGUVD6qRX
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。539Please respect copyright.PENANApH561RXjWP
539Please respect copyright.PENANAYwUN1Jr95g
Link:539Please respect copyright.PENANAA0T8L6VNej
https://www.penana.com/user/27349/%E8%96%AF%E4%BB%94%E8%81%9E%E8%8C%B1%E8%8E%89/portfolio539Please respect copyright.PENANAOvl4E52gDU
539Please respect copyright.PENANAP0TCESoGt6
539Please respect copyright.PENANAPmdp8FiU2Q
有興趣接收科學資訊的話,歡迎follow IG: potatopigtongue。539Please respect copyright.PENANAaJL8G04quZ
539Please respect copyright.PENANAs9mBY3lOXY
Ref1:https://www.nature.com/articles/s41598-020-70531-y539Please respect copyright.PENANA3iNrDbXbLK