Nature子刊：北京大學姚蒙實驗室報導白頭葉猴種群遺傳學及棲息地破碎化對種群遺傳結構

2017年5月，國際學術權威刊物自然出版集團旗下子刊《Heredity》線上發表了北京大學生命科學學院姚蒙研究組題為“Low genetic diversity and strong population structure shaped by anthropogenic habitat fragmentation in a critically endangered primate,Trachypithecus leucocephalus”的封面文章。研究首次利用微衛星和線粒體DNA全面分析了野生白頭葉猴種群的遺傳多樣性、遺傳結構及導致遺傳分化的環境因素。

博士生王魏然為第一作者，姚蒙研究員為本文通訊作者。

棲息地片段化很可能造成野生種群遺傳多樣性降低、遺傳分化加劇。白頭葉猴(Trachypithecus leucocephalus)是生活在廣西壯族自治區西南部喀斯特石山地區的我國特有物種。其野生種群目前僅餘約1, 000只，只分佈在由左江、明江和四方嶺圍繞的狹小地區，已被列為我國一級保護動物和世界自然保護聯盟(International unio for Conservation of Nature, IUCN)紅色名錄的極危級(Critically Endangered, CR)物種。

然而，隨著人口增加、人類對耕地和資源需求量的增加，石山之間的平地逐漸被開採成為農田，破壞了白頭葉猴棲息地的連續性。該研究即針對人類活動引起的棲息地片段化對白頭葉猴的遺傳多樣性和遺傳結構造成的影響進行了研究，並根據研究結果提出相應的保護和管理建議。

研究分析了來自白頭葉猴主要分佈區崇左和扶綏的41個社群(social groups)的214份獨立個體樣品，

獲得15個物種特異的多態性微衛星位點、1個性別差異位點(Dead-box)和一段線粒體DNA控制區的基因型資料。結果顯示白頭葉猴的遺傳多樣性水準與瀕危狀態和種群數量相似的其他靈長類物種相比更低。白頭葉猴種群表現出崇左(CZ)-扶綏九重山(FS-JCS)-扶綏布噂(FS-BZ)的遺傳結構劃分，這三個遺傳種群間已經出現了顯著的遺傳分化，它們之間個體遷移率低。大片非棲息地區域(農田、村莊等)和地理距離是造成種群遺傳結構最主要的景觀因數。因此，建議通過恢復棲息地植被、減少棲息地內人為活動以及在相鄰棲息地片區之間建立遷移廊道等方法，促進猴群間的自然基因交流，避免小種群遺傳隔離，以保護種群遺傳多樣性，保障該物種的長期生存和進化潛力。

封面圖片

白頭葉猴的主要分佈範圍及採樣地點。

原文連結：

原文摘要：

Habitat fragmentation may strongly impact population genetic structure and reduce the genetic diversity and viability of small and isolated populations. The white-headed langur (Trachypithecus leucocephalus) is a critically endangered primate species living in a highly fragmented and human-modified habitat in southern China. We examined the population genetic structure and genetic diversity of the species and investigated the environmental and anthropogenic factors that may have shaped its population structure. We used 214 unique multi-locus genotypes from 41 social groups across the main distribution area of T. leucocephalus, and found strong genetic structure and significant genetic differentiation among local populations. Our landscape genetic analyses using a causal modelling framework suggest that a large habitat gap and geographical distance represent the primary landscape elements shaping genetic structure, yet high levels of genetic differentiation also exist between patches separated by a small habitat gap or road. This is the first comprehensive study that has evaluated the population genetic structure and diversity of T. leucocephalus using nuclear markers. Our results indicate strong negative impacts of anthropogenic land modifications and habitat fragmentation on primate genetic connectivity between forest patches. Our analyses suggest that two management units of the species could be defined, and indicate that habitat continuity should be enforced and restored to reduce genetic isolation and enhance population viability.