A MOLECULAR APPROACH FOR THE IDENTIFICATION OF MEIOFAUNAL TURBELLARIANS (PLATYHELMINTHES, TURBELLARIA)
A MOLECULAR APPROACH FOR THE IDENTIFICATION OF MEIOFAUNAL TURBELLARIANS (PLATYHELMINTHES, TURBELLARIA)
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DOI：
10.1007/bf00680218
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发表时间：
1994-10-01
期刊：
影响因子：
2.4
通讯作者：
KOCHER, TD
中科院分区：
文献类型：
--
作者：
LITVAITIS, MK;NUNN, G;KOCHER, TD
在缺乏可靠的形态特征，或结合基于形态学的鉴定，小型底栖涡虫也可以使用核糖体RNA大亚基（26/28 S rRNA）的一部分的核苷酸序列进行鉴定。从原序列目（Proseriata）、巨口目（Macrostomida）、原石首鱼目（Prolecithophora）和无腔目（Acoela）10种涡虫的基因组DNA中，发现了26/28 SrRNA的一个284碱基对长的区域。这些原丝氨酸是从欧洲和以色列的一些地方收集来的，并保存在乙醇中。其余的Turbellarians分离的潮间带沉积物样品收集于1992年的两个地点在缅因州和新罕布什尔州海岸，美国。使用两种引物进行基因组DNA扩增，所述引物设计为匹配陆生线虫秀丽隐杆线虫（Caelophabditis elegans）的26/28 S rDNA基因的一部分的核苷酸序列（Maupas 1900）。这个区域由一个高度可变的，约150个碱基对长的区域组成，称为D3扩展片段，随后是一段非常保守的序列。当折叠成其二级结构时，保守区将形成对应于C的螺旋15至18的茎结构。elegans结构模型使用序列比对程序PILEUP对序列进行聚类分析（使用算术平均值的未加权对组方法，UPGMA）。该分析表明，螺旋允许在家庭和以上的水平上的Turbellarians的分类，而如果D3扩展段本身包括在分析中，可以建立属内和种内分组。
In the absence of reliable morphological characters, or in conjunction with morphology-based identifications, meiofaunal turbellarians may also be identified using the nucleotide sequence of a portion of the large subunit of the ribosomal RNA (26/28S rRNA). A 284 base pair-long region of the 26/28S rRNA has been identified by isolating genomic DNA from ten species of turbellarians belonging to four orders, namely, the Proseriata, Macrostomida, Prolecithophora and Acoela. The proseriates had been collected from localities in Europe and Israel and were preserved in ethanol. The remaining turbellarians were isolated from intertidal sediment samples collected from two sites on the Maine and New Hampshire coast, USA in 1992. Amplification of the genomic DNA was carried out using two primers designed to match the nucleotide sequence of a portion of the 26/28S rDNA gene of the terrestrial nematode, Caenorhabditis elegans (Maupas 1900). This area consists of a highly variable, about 150 base pair-long region, called the D3 expansion segment, followed by a very conserved stretch of sequence. When folded into its secondary structure, the conserved region will form stem structures that correspond to helices 15 to 18 of the C. elegans structural model. The sequence alignment program PILEUP was used to perform a cluster analysis (unweighted pair group method using arithmetic averages, UPGMA) on the sequences. This analysis revealed that the helices allow for the classification of the turbellarians at the level of families and above, whereas if the D3 expansion segment itself was included in the analysis, intrageneric and intraspecific groupings could be established.