SGER: Exploratory Comparison of Eight Nuclear and mtDNA Sequences Among Selected Taxa of Deltocephaline Leafhoppers (Homoptera: Cicadellidae)

类似三角头的叶蝉属已经构成了一个 由于缺乏系统发育， 信息和确定性的字符所必需的通用 分居 为了更清楚地了解 研究人员希望对这一群体进行支序分类， 分子分析的一个子集的24个narctic属，其中 连接物和aedeagus的融合似乎代表了 亚群的突触形态特征。 目前的问题是， 分子系统学领域的一个问题是， 哪些DNA序列可用于昆虫分类学研究， 一般水平。 迄今为止几乎所有的分子系统学研究 在更高的分类学水平上比较物种。 大部分 在这些层次上考察过的层序都是单形的 在较低的分类水平上。 在另一个极端， 这些序列表现出广泛的种内变异， 其在更高的分类学上可能不存在可识别的同源性 程度. 要求提供一年的资金，以审查八个不同的 在四个分类水平上选择叶蝉的DNA序列。 五个候选核区域和三个mtDNA区域已经被确定。 鉴定 核DNA区域包括：1，2）两个内部区域 间隔区（ITS 1和ITS 2）在rDNA顺反子，3）高变 rDNA顺反子的28 s区域，4）rDNA顺反子中的内含子， 不变组蛋白H2 A基因和5）核糖体S14蛋白基因 及其内含子。 线粒体基因是：1）线粒体的一个区域， 12 s rDNA，2）16 s rDNA和3）细胞色素氧化酶区域 III基因。 所有区域将用PCR扩增并测序。 这些区域将首先在三个物种之间进行比较， 三个部落在叶蝉亚科Deltocephalinae，如果 序列显示在这个水平上的变化，两个额外的物种将 在三个部落中的两个部落中进行比较。 如果属间 在部落内检测到变异，然后在一个物种内检测到两个物种。 将对属进行检查。 如果在该水平检测到变化， 那么种内变异的检查将需要收集 来自同一物种的不同地理种群。 与此 协议的分类水平，在这些序列中的每一个可以 可以使用它来确定。 目标是识别2-3个DNA 序列，可用于24属的密集调查， 类似三角头的叶蝉属。

The Deltocephalus-like genera of leafhoppers have posed a difficult problem for workers because of an absence of phylogenetic information and definitive characters necessary for generic separation. Towards obtaining a clearer picture of phylogenies in this group, the investigators hope to perform cladistic and molecular analyses of a subset of 24 nearctic genera in which fusion of the connective and aedeagus appears to represent a synapomorphic character of the subset. A current problem in the field of molecular systematics is that there is no agreement as to which DNA sequences can be used in insect taxonomic studies at the generic level. Almost all molecular systematic studies to date have compared species at higher taxonomic levels. Most of the sequences which have been examined at these levels are monomorphic at lower taxonomic levels. At the other extreme there are sequences which demonstrate extensive intraspecific variation but which may present no recognizable homology at higher taxonomic levels. Funding is requested for one year to examine eight different DNA sequences in leafhoppers selected at four taxonomic levels. Five candidate nuclear regions and three mtDNA regions have been identified. The nuclear DNA regions include: 1,2) two internal spacers (ITS1 and ITS2) in the rDNA cistron, 3) a hypervariable region of the 28s from the rDNA cistron, 4) an intron in the invariant histone H2A gene and 5) the ribosomal S14 protein gene and its intron. The mitochondrial genes are: 1) a region of the 12s rDNA 2) the 16s rDNA and 3) a region of the cytochrome oxidase III gene. All regions will be amplified with PCR and sequenced. These regions will be initially compared among three species in three tribes in the leafhopper subfamily Deltocephalinae, if the sequences show variation at this level, two additional species will be compared within two of the three tribes. If intergeneric variation is detected within tribes then two species within one genus will be examined. If variation is detected at this level then an examination of intraspecific variation will take collection from different geographic populations of one species. With this protocol the taxonomic level at which each of these sequences can be used can be determined. The goal is to identify 2-3 DNA sequences which can be used in an intensive survey of 24 genera of the Deltocephalus-like genera of leafhoppers.