Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Müggelseedamm 301, D-12587 Berlin, Germany.
Department of Biology, Faculty of Sciences, Shahid Chamran University of Ahvaz, Ahvaz 61357-43135, Iran.
Genes (Basel). 2019 Apr 18;10(4):306. doi: 10.3390/genes10040306.
The Hyrcanian Forests present a unique Tertiary relict ecosystem, covering the northern Elburz and Talysh Ranges (Iran, Azerbaijan), a poorly investigated, unique biodiversity hotspot with many cryptic species. Since the 1970s, two nominal species of Urodela, Hynobiidae, (later: ) have been described: from northwestern and from northeastern Iran. Although has been involved in studies on phylogeny and development, there is little data on the phylogeography, systematics, and development of the genus throughout the Hyrcanian Forests; genome-wide resources have been entirely missing. Given the huge genome size of hynobiids, making whole genome sequencing hardly affordable, we aimed to publish the first transcriptomic resources for from an embryo and a larva (9.17 Gb RNA sequences; assembled to 78,918 unigenes). We also listed 32 genes involved in vertebrate sexual development and sex determination. Photographic documentation of the development from egg sacs across several embryonal and larval stages until metamorphosis enabled, for the first time, comparison of the ontogeny with that of other hynobiids and new histological and transcriptomic insights into early gonads and timing of their differentiation. Transcriptomes from central Elburz, next-generation sequencing (NGS) libraries of archival DNA of topotypic , and GenBank-sequences of eastern allowed phylogenetic analysis with three mitochondrial genomes, supplemented by PCR-amplified mtDNA-fragments from 17 museum specimens, documenting <2% uncorrected intraspecific genetic distance. Our data suggest that these rare salamanders belong to a single species s.l. Humankind has a great responsibility to protect this species and the unique biodiversity of the Hyrcanian Forest ecosystems.
伊朗和阿塞拜疆交界的北厄尔布尔士山脉和塔利什山脉的北缘是胡拉桑森林，这里拥有独特的第三纪遗留生态系统，是一个生物多样性热点地区，拥有许多隐种，但研究甚少。自 20 世纪 70 年代以来，已描述了两种有尾目（蝾螈）胡拉桑特有种，即分布于伊朗西北部的 和分布于伊朗东北部的 。虽然 已被用于研究系统发育和发育，但有关该属在整个胡拉桑森林的系统发育、分类学和发育的数据很少；基因组资源完全缺失。由于胡拉桑蝾螈的基因组很大，使得全基因组测序几乎无法承受，我们旨在发表首个胡拉桑蝾螈胚胎和幼体的转录组资源（9.17Gb RNA 序列；组装到 78918 个基因）。我们还列出了 32 个参与脊椎动物性发育和性别决定的基因。从卵囊到几个胚胎和幼体阶段，直至变态发育的发育过程的照片记录，首次使我们能够比较该物种与其他胡拉桑蝾螈的个体发生，并深入了解早期性腺及其分化的时间。从中部厄尔布尔士山脉获得的转录组、档案 DNA 的下一代测序（NGS）文库和东部 的 GenBank 序列，结合从 17 个博物馆标本中扩增的 mtDNA 片段，对 3 个线粒体基因组进行了系统发育分析，表明该物种的种内遗传距离 <2%，无需校正。我们的数据表明，这些稀有的蝾螈属于单一物种 s.l. 人类有责任保护该物种和胡拉桑森林生态系统的独特生物多样性。
