透過您的圖書館登入
IP:18.217.144.32
  • 學位論文

以微衛星DNA探討澳洲東部三種淡水鰻(澳洲花鰻、澳洲短鰭鰻和紐西蘭大鰻)的族群遺傳結構及其演化史

The population genetic structure and evolutionary scenario of three freshwater eels Anguilla reinhardtii, A. australis and A. dieffenbachii in the eastern Australia as revealed by microsatellites

指導教授 : 曾萬年

摘要


為了瞭解澳洲東部的三種淡水鰻 (Anguilla spp):熱帶性澳洲花鰻 (A. reinhardtii, Steindachner 1867),以及溫帶性澳洲短鰭鰻 (A. australis, Richardson 1841) 和紐西蘭大鰻 (A. dieffenbachii, Gray 1842) 的族群遺傳結構及其演化關係,本研究以微衛星DNA為遺傳標記,分析6-7個微衛星基因座的遺傳變異性。總共使用了1277尾鰻線標本,分別是1997-1999年採自澳洲六個河口的澳洲花鰻 (799尾) 和澳洲短鰭鰻 (287尾) 以及1995-1996年採自紐西蘭南北島的三個河口澳洲短鰭鰻 (101尾) 和紐西蘭大鰻 (90尾)。其中,澳洲東岸Albert River的澳洲花鰻標本連續採集12個月以上。 分析結果發現澳洲花鰻雖然終年產卵,但其族群遺傳結構並無時間或空間的分化現象,這可能和其仔魚浮游期短、散佈範圍窄以及終年產卵基因容易交流有關。相反地,澳洲短鰭鰻的仔魚漂浮期長、分佈域含蓋澳洲及紐西蘭兩地,地區間卻有明顯的族群遺傳分化現象。紐西蘭大鰻為已知仔魚浮游期最長的淡水鰻,但族群分化情形並不明顯,可能和可散佈陸域範圍太小 (僅局限於紐西蘭島) 有關。紐西蘭大鰻的外部型態及其基因結構比同一個演化支序的澳洲短鰭鰻保留更多的祖徵。顯示溫帶性紐西蘭大鰻可能是上述鰻鱺屬 (Anguilla) 的三個種類中最早抵達紐澳地區的的淡水鰻。本研究結果顯示微衛星基因座的等位基因變異特性,可以提供澳洲三種淡水鰻的族群擴散及演化的部分訊息。

並列摘要


Population genetic structure and evolutionary scenario were investigated with the microsatellites analysis for three species of the freshwater eels, tropical Anguilla reinhardtii (Steindachner 1867), and temperate Anguilla australis (Richardson 1841) and Anguilla dieffenbachii (Gray 1842) in Australia and New Zealand. A total of 1277 glass eel specimens were used: 388 from East Australia and New Zealand for A. australis, 90 from both North and South Island of New Zealand for A. dieffenbachii, and 799 from East Australia for A. reinhardtii, including a series of monthly collections for over 12 months from the Albert River estuary. The specimens were collected from East Australis in 1997-1999 and New Zealand in 1995-1996. For A. reinhardtii there was no significant spatial and temporal differentiation in the genetic structure. This may be due to the fact that it has a short pelagic larval duration, narrow distribution range, but a long, all the year round spawning period, that facilitate the gene flow. For A. australis that has comparatively longer pelagic larval duration than that of A. reinhardtii, two geographical populations were recognized in East Australia and New Zealand, respectively. For A. dieffenbachii in New Zealand that has the longest duration of the pelagic larval stage has no population genetic differentiation due to the small land mass for dispersal. A. dieffenbachii is characterized with more ancient morphological and genetic characters than the A. australis in the same evolutionary lineage. These may suggest that temperate eel A. dieffenbachii is the earliest arrival of the freshwater eel in Oceania. Genetic variation in microsatellite loci may provide a useful tool in examining evolution and population dispersal of freshwater eels.

參考文獻


Allen AP, Brown JH, Gillooly JF (2002) Global Biodiversity, Biochemical Kinetics and the Energetic-Equivalence Rule. Science 297:1545-1548.
Aoyama J, Kobayashi T, Tsukamoto K (1996) Phylogeny of eels suggested by mitochrondrial DNA sequences. Nippon Suisan Gakkaishi 62: 370-375.
Aoyama J, Mochioka N, Otake T, Ishikawa S, Kawakami Y, Castle P, Nishida M, Tsukamoto K (1999) Distribution and dispersal of anguillid leptocephali in the western Pacific Ocean revealed by molecular analysis. Mar Ecol Prog Ser 188: 193-200.
Aoyama J, Mutsumi N, Tsukamoto K (2001) Molecular phylogeny and evolution of the freshwater eel, genus Anguilla. Mol Phylogenet Evol 20: 450-459.
Aoyama J, Tsukamoto K (1997) Evolution of the freshwater eels. Naturwissenschaften 84: 17–21.

延伸閱讀