臺灣梅花鹿遺傳多樣性與族群遺傳結構研究

外文標題: 
The genetic diversity and population genetic structure of Formosan sika deer
校院系所: 
臺灣大學動物科學技術學研究所
指導教授: 
朱有田
姜延年
出版年份: 
2014年
主題類別: 
摘要: 

臺灣梅花鹿 (Cervus nippon taiouanus) 為臺灣特有亞種,約於西元1969年在野外絕跡。臺灣梅花鹿復育計畫在西元1984年展開,由臺北市立動物園圓山舊址引入5雄17雌梅花鹿於墾丁國家公園進行復育,而後又加入少數民間鹿群。現今野外族群已成長到1,500隻左右。原始復育族群個體數目少、非源自野外且來源分歧等因素,因此族群遺傳結構、遺傳多樣性與外來鹿科動物之基因滲入問題需要被研究。
本研究以跨物種微衛星DNA標記為分析工具。自牛科微衛星標記篩選11組在臺灣梅花鹿具微衛星特徵與多形性之標記,分析墾丁國家公園90頭臺灣梅花鹿、金門畜試所36頭、大坵島39頭、壽山動物園8 頭及民間飼養梅花鹿23頭進行遺傳多樣性檢測。同時,分析族群內遺傳多樣性及族群間分化指數,並以遺傳距離建構族群親緣關係樹。另外,本研究整合粒線體母系遺傳資訊與Y染色體Zfy (zinc-finger gene in Y-chromosome) 鋅指基因父系遺傳資訊,進行物種鑑定並和11組微衛星資料做比對,以探討過去基因滲入鹿群的現象。
檢測11組微衛星標記在196頭臺灣梅花鹿整體之個體鑑別率為 (P(ID))為2.06×10-6,多態性訊息含量(PIC)為0.439,顯示所選微衛星標記適合進行臺灣梅花鹿遺傳多樣性分析。在遺傳多樣性分析結果,顯示墾丁梅花鹿族群較臺灣其他族群含有較高遺傳多形性與異型合子歧異度。墾丁國家公園梅花鹿復育族群與金門畜試所、馬祖大坵梅花鹿族群三者在親緣遺傳關係上較近,與圈養族群親緣較遠。另外,兩民間飼養鹿群間分化指數與遺傳距離小,顯示互有基因交流。在基因滲入情況研究上,本研究亦建立臺灣梅花鹿與紅鹿或其他外來鹿科動物之母系Cyt b與Y染色體上父系Zfy序列資料庫做為初步物種鑑定依據,並配合微衛星標記基因型分析,結果顯示民間鹿場有較明顯的紅鹿基因滲入,墾丁國家公園梅花鹿復育族群與金門畜試所、馬祖大坵梅花鹿族群沒有顯著紅鹿基因滲入。
綜上所述,本研究所篩選11組跨物種微衛星標記適合研究臺灣梅花鹿遺傳多樣性,輔以Cyt b與Zfy序列更可分析外來鹿科動物基因滲入情況。墾丁國家公園梅花鹿族群、金門畜試所及大坵島族群紅鹿基因滲入比例極低,且與民間飼養梅花鹿已有明顯遺傳分化現象,彰顯過去臺灣梅花鹿復育重要性。本研究提供臺灣臺灣梅花鹿遺傳結構、分化與多樣性基本資訊。提供族群遺傳管理與防範外來鹿科動物基因滲入、遺傳監控與法醫學鑑定方法。

外文摘要: 

Formosan sika deer (C. n. taiouanus) is endemic to Taiwan, and was widely distributed in the woodlands under 300 m elevation. The wild Formosan sika deer was extinct in 1960, while some individuals were conserved in Taipei Zoo and deer farm. The Recovering Program of Formosan sika deer started in 1986, and Twenty-two individuals were chosen from Taipei zoo and conserved in the wild of Kenting National Park. The population size of wild deer in Kenting National Park has increased to about 1,500 nowadays (2010). However, the genetic structure of the wild Formosan sika deer is not clear. The research aim to select applicable microsatellite markers for Formosan sika deer; to investigate the genetic diversity and genetic structure of Formosan sika deer conserved population for population management; to analyze the introgression from red deer to sika deer populations.
A total 196 sika deer samples form 6 sites were collected (90 from Kenting National Park, 36 from Kinmen Livestock Research Institute, 39 from Ta Chiu islet, 8 from Shou Shan Zoo, 10 form Taitung deer farm and 13 from Tainan deer farm) for population study. The cross-species microsatellite markers were selected form 22 bovine and ovine markers. The markers with short tandem repeat sequences were examined cloning to separate sequences and sequencing. The genetic diversity and genetic structure of Formosan sika deer was examined by 11microsatellite markers. Identification of species is conducted by Zfy gene and cytochrome b for investigating cultivated deer populations.
The selected 11 crossed-species markers showed medium level of polymorphic information content in whole Formosan sika deer population. And the probability of identity (P(ID)) is less than 0.0001. These results reveal The selected 11 crossed-species markers are polymorphic and achieve a very low probability of finding two random individuals with identical genotypes. The average polymorphic information is 0.439 in Kenting National Park population (KNP). The average expected heterozygosity (He) and observed heterozygosity (Ho) were both 0.512. It showed KNP population maintained more alleles and heterozygosity than other conservation populations. The result of Neighbor-Joining tree showed KNP, Kinmen and Ta Chiu islet population can cluster together. It agrees with the process of introduced founder populations. Utilizing Zfy gene and Cytochrome b gene can acquire maternal and paternal genetic information. The genetic structure showed red deer population has different pattern with sika deer population. And only a few individuals in deer farm showed introgression.
In conclusion, this study can provide the applicable method to investigate population genetic structure of Formosan sika deer with microsatellite markers. The information of genectic diversity in Kenting National Park population can be refer as population management. With microsatellite, Zfy and Cytochrome b gene, the futher study of introgression from red deer to sika deer population can be implemented.