本周《自然—通訊》期刊發(fā)表了白鰭豚（又名白暨豚）的基因組序列 ,。這項研究有助于了解白鰭豚的生活習(xí)性與其被滅絕原因。
白鰭豚是世界上已知五種淡水豚（拉河豚,、亞河豚、恒河豚、印河豚、白鰭豚）中存活頭數(shù)最少的一種,，已被公認為“功能性滅絕”,。它也是鯨類動物中因人類活動而被滅絕的第一種物種。南京師范大學(xué)楊光教授與其科研團隊為一頭雄性白鰭豚進行了基因組測序,，也同時為三頭白鰭豚進行了基因組重測序,，以便了解鯨類動物的進化適應(yīng)和導(dǎo)致其數(shù)量下降的遺傳原因,。
通過比較分析,，作者發(fā)現(xiàn)了一籃子幫助哺乳動物適應(yīng)水中生活的基因，包括和嗅覺,、味覺,、視覺、聽覺和大腦擴張有關(guān)的基因,。盡管有證據(jù)表明一萬年前白鰭豚曾遭遇過‘人口瓶頸’（人口或數(shù)量因突然的災(zāi)難或不能生育造成而減少50%以上）,，但是研究結(jié)果顯示，白鰭豚最終被滅絕的原因不是由‘人口瓶頸’造成,，而是由人類在長江的活動而造成,。這項研究為研究水生哺乳動物進化和保護提供了寶貴的數(shù)據(jù)。(生物谷Bioon.com)
生物谷推薦的英文摘要
Nature Communications doi:10.1038/ncomms3708
Baiji genomes reveal low genetic variability and new insights into secondary aquatic adaptations
Xuming Zhou,Fengming Sun,Shixia Xu, Guangyi Fan, Kangli Zhu,Xin Liu,Yuan Chen,Chengcheng Shi,Yunxia Yang, Zhiyong Huang,Jing Chen,Haolong Hou,Xuejiang Guo,Wenbin Chen,Yuefeng Chen, Xiaohong Wang,Tian Lv,Dan Yang, Jiajian Zhou,Bangqing Huang
The baiji, or Yangtze River dolphin (Lipotes vexillifer), is a flagship species for the conservation of aquatic animals and ecosystems in the Yangtze River of China; however, this species has now been recognized as functionally extinct. Here we report a high-quality draft genome and three re-sequenced genomes of L. vexillifer using Illumina short-read sequencing technology. Comparative genomic analyses reveal that cetaceans have a slow molecular clock and molecular adaptations to their aquatic lifestyle. We also find a significantly lower number of heterozygous single nucleotide polymorphisms in the baiji compared to all other mammalian genomes reported thus far. A reconstruction of the demographic history of the baiji indicates that a bottleneck occurred near the end of the last deglaciation, a time coinciding with a rapid decrease in temperature and the rise of eustatic sea level.
