Ramírez Oscar, Gigli Elena, Bover Pere, Alcover Josep Antoni, Bertranpetit Jaume, Castresana Jose, Lalueza-Fox Carles
Institute of Evolutionary Biology (UPF-CSIC), Barcelona, Spain.
PLoS One. 2009 May 22;4(5):e5670. doi: 10.1371/journal.pone.0005670.
Numerous endemic mammals, including dwarf elephants, goats, hippos and deers, evolved in isolation in the Mediterranean islands during the Pliocene and Pleistocene. Most of them subsequently became extinct during the Holocene. Recently developed high-throughput sequencing technologies could provide a unique tool for retrieving genomic data from these extinct species, making it possible to study their evolutionary history and the genetic bases underlying their particular, sometimes unique, adaptations. METHODOLOGY/PRINCIPALS FINDINGS: A DNA extraction of a approximately 6,000 year-old bone sample from an extinct caprine (Myotragus balearicus) from the Balearic Islands in the Western Mediterranean, has been subjected to shotgun sequencing with the GS FLX 454 platform. Only 0.27% of the resulting sequences, identified from alignments with the cow genome and comprising 15,832 nucleotides, with an average length of 60 nucleotides, proved to be endogenous.
A phylogenetic tree generated with Myotragus sequences and those from other artiodactyls displays an identical topology to that generated from mitochondrial DNA data. Despite being in an unfavourable thermal environment, which explains the low yield of endogenous sequences, our study demonstrates that it is possible to obtain genomic data from extinct species from temperate regions.
众多地方性哺乳动物,包括矮象、山羊、河马和鹿,在新近纪和更新世期间于地中海诸岛孤立进化。它们中的大多数随后在全新世灭绝。最近发展起来的高通量测序技术可为从这些已灭绝物种中检索基因组数据提供独特工具,从而有可能研究它们的进化历史以及其特殊的、有时是独特的适应性背后的遗传基础。
方法/主要发现:对来自西地中海巴利阿里群岛的一只已灭绝山羊(巴氏摩弗伦羊)的约6000年前的骨样本进行了DNA提取,并使用GS FLX 454平台进行鸟枪法测序。与牛基因组比对后鉴定出的所得序列中,只有0.27%(共15832个核苷酸,平均长度为60个核苷酸)被证明是内源性的。
用巴氏摩弗伦羊序列和其他偶蹄目动物序列构建的系统发育树与基于线粒体DNA数据构建的系统发育树具有相同的拓扑结构。尽管处于不利的热环境中,这解释了内源性序列产量较低的原因,但我们的研究表明,从温带地区的已灭绝物种中获取基因组数据是可能的。