Department of Vector Biology and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.
PLoS One. 2012;7(8):e43479. doi: 10.1371/journal.pone.0043479. Epub 2012 Aug 29.
Although mammals are a well-studied group of animals, making accurate field identification of small mammals is still complex because of morphological variation across developmental stages, color variation of pelages, and often damaged osteological and dental characteristics. In 2008, small mammals were collected for an epidemiological study of a spotted fever outbreak in Hainan, China. Ten species of small mammals were identified by morphological characters in the field, most using pelage color characters only. The study is extended here, in order to assess whether DNA barcoding would be suitable as an identification tool in these small mammals. Barcode clusters showed some incongruence with morphospecies, especially for some species of Rattus and Niviventer, so molecular delineation was carried out with an expanded dataset of combined cytochrome b (Cyt-b) and cytochrome c oxidase subunit I (COI) sequences. COI sequences were successfully amplified from 83% of collected mammals, but failed in all specimens of Suncus murinus, which were thus excluded in DNA barcoding analysis. Of note, ten molecular taxonomic units were found from samples of nine morphologically identified species. Accordingly, 11 species of small mammals were present in the investigated areas, including four Rattus species, three Niviventer species, Callosciurus erythraeus, Neohylomys hainanensis, Tupaia belangeri, and Suncus murinus. Based on the results of the phylogenetic and molecular delineation analyses, the systematic status of some rodent species should be redefined. R. rattus hainanicus and R. rattus sladeni are synonyms of R. andamanensis. R. losea from China and Southeast Asia comprises two independent species: R. losea and R. sakeratensis. Finally, the taxonomic status of three putative species of Niviventer should be further confirmed according to morphological, molecular and ecological characters.
尽管哺乳动物是一组研究得很好的动物，但由于发育阶段的形态变异、皮毛颜色的变异以及骨骼和牙齿特征经常受损，准确地对小型哺乳动物进行野外鉴定仍然很复杂。2008 年，在中国海南的斑疹热爆发的流行病学研究中收集了小型哺乳动物。在野外通过形态特征鉴定了十种小型哺乳动物，大多数只使用皮毛颜色特征。本研究在此基础上进一步扩展，以评估 DNA 条形码是否适合作为这些小型哺乳动物的鉴定工具。条形码聚类与形态种有些不一致，特别是对于某些 Rattus 和 Niviventer 物种，因此使用结合细胞色素 b（Cyt-b）和细胞色素 c 氧化酶亚基 I（COI）序列的扩展数据集进行了分子划分。COI 序列成功地从采集到的哺乳动物中扩增出 83%，但在所有的白腹巨鼠标本中均未成功，因此在 DNA 条形码分析中被排除。值得注意的是，从 9 种形态鉴定物种的样本中发现了 10 个分子分类单元。因此，在所研究的区域内存在 11 种小型哺乳动物，包括四种 Rattus 物种、三种 Niviventer 物种、赤腹松鼠、海南水鹿、白胸苦恶鸟和白腹巨鼠。根据系统发育和分子划分分析的结果，一些啮齿动物物种的系统地位需要重新定义。海南变色树蜥和斯氏变色树蜥是安氏变色树蜥的同义词。来自中国和东南亚的洛氏树蜥包括两个独立的物种：洛氏树蜥和薮羚树蜥。最后，根据形态、分子和生态特征，进一步确认三个拟议的 Niviventer 物种的分类地位。
