Higher Level Taxonomy and Molecular Phylogenetics of the Choanoflagellatea
Higher Level Taxonomy and Molecular Phylogenetics of the Choanoflagellatea
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DOI：
10.1111/j.1550-7408.2011.00572.x
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发表时间：
2011-09-01
影响因子：
2.2
通讯作者：
Leadbeater, Barry S. C.
中科院分区：
文献类型：
--
作者：
Nitsche, Frank;Carr, Martin;Leadbeater, Barry S. C.
领鞭毛虫（Choanoflagellatea）包括主要的一类纳米鞭毛虫，其在水生环境中普遍存在。最近的分子生物学研究表明它们是后生动物的姐妹群。然而，领鞭毛虫的生殖发育仍远未被理解。我们在这里提出了一个29个分类群，多基因系统发育，有力地将根的choanoflagellates。Codonosigidae是原始的无甲科之一，被证明是一个多系组合，嵌套在Salpingoecidae内。我们详细介绍了一个修订的分类，分为两个命令：Craspedida和Acanthoecida的Choanoflatea。Craspedida由具有有机细胞涂层的物种组成，并包含单一的Salpingoecidae科。主要为海生刺壳纲的成员除了有一层有机的外壳外，还产生一层硅质的洛里卡，并包含在两个家族中-刺壳科和千金藤科。n.以往对领鞭毛虫的研究一直受到分类错误和18 S小亚基（SSU）rDNA序列分辨率有限的阻碍。不幸的是，文献中大量重复出现错误识别的案例。为了避免进一步的混乱，我们强调了已知的命名错误的类群的实例。我们还研究了SSU rDNA序列单独用于领鞭毛虫遗传学的适用性，并建议尽可能使用蛋白质编码基因，如HSP 90和tubA。
The choanoflagellates (Choanoflagellatea) comprise a major group of nanoflagellates, which are ubiquitous in the aquatic environment. Recent molecular phylogenies have shown them to be the sister group to the Metazoa. However, the phylogeny of the choanoflagellates is still far from understood. We present here a 29 taxon, multigene phylogeny that robustly places the root of the choanoflagellates. One of the original nonloricate families, Codonosigidae is shown to be a polyphyletic assemblage nested within the Salpingoecidae. We elaborate on a revised taxonomy that divides Choanoflagellatea into two orders: Craspedida and Acanthoecida. Craspedida is composed of species that possess an organic cell coating and contains the single family Salpingoecidae. Members of the predominantly marine Acanthoecida produce a siliceous lorica in addition to an organic coat and are contained in two families-the Acanthoecidae and Stephanoecidae fam. n. Previous studies of choanoflagellates have been hindered by cases of taxon misidentification as well as the limited resolution of 18S small subunit (SSU) rDNA phylogenies. Unfortunately, cases of misidentification have been heavily repeated in the literature. In an attempt to avoid further confusion, we highlight known instances of misnamed taxa. We also examine the suitability of SSU rDNA sequences alone for choanoflagellate phylogenetics and recommend the use of protein-coding genes, such as hsp90 and tubA, whenever possible.