POPULATION GENETICS OF TRANSPOSABLE ELEMENTS

果蝇Copia样转座子的群体遗传学研究 将被调查，特别是他们是否有能力 在物种间的水平转移及其顺序程度 近缘种间的分化。我们会追求三个具体目标： 1.开展异源转化，以转移 物种间的转座因子。最初，P-元件介导的 利用ROSY转化系统对拟态石杉进行DNA转化 来自D.Blackogaster。成功的转型将建立起 P的转座发生在非黑腹金龟子的基因组中。 随后的实验将确定果蝇物种的分布范围有多广。 这一元件可以传播，但仍然可以转座。在……里面 此外，将研究含磷共转化体，以确定 无论是杂交性发育不良，还是生殖系异常的复杂综合征 与黑腹金龟子中的P元素有关，也存在于其他物种中 其中P已被引入。这些实验将提供 关于主体-元素在换位中的相互作用的信息，它们将 允许对类P元素在物种形成中的假定作用进行评估。 2.将研究毛叶石杉中一种高度不稳定的白色等位基因 在基因和分子水平上对插入的DNA进行表征 元素。这个突变体之所以令人感兴趣，是因为毛氏假丝核菌和拟南氏假丝酵母 与它们的兄弟物种D相比，有更少的类似复制的元素。 黑猩猩。保留在毛叶杜鹃和马尾藻中的转座元件 因此，拟人猿可能具有某些不同寻常的特性。这些研究 可以解释为什么某个家族的转座元件不是分布的 物种之间的关系，从它们的系统发育关系可以预料到的。在……里面 从长远来看，不稳定的白色等位基因将转化为D。 以研究其在外星人身上的突变特征 基因组。 3.转座子COPIA将在相关物种中进行研究 为了确定果蝇限制性内切酶图谱变异的程度 在物种内部和物种之间。限制性内切酶图谱不同的几个副本 在黑腹盘藻中发生，而在毛盘盘藻中的复制不同于 D.黑腹蛇。我们的研究将集中在相对收集到的菌株上 最近。这些研究将揭示协同进化是否发生在 分散的重复多基因家族，这将在 评估影响的进化力量的相对作用 这样的元素。

The population genetics of copia-like transposable elements in Drosophila will be investigated, with special reference to their ability to be transferred horizontally among species and their extent of sequence divergence among related species. Three specific aims will be pursued: 1. Heterologous transformation will be developed in order to transfer transposable elements among species. Initially, the P-element-mediated rosy transformation system will be used to transform D. simulans with DNA from D. melanogaster. Successful transformation will establish the ability of P to transpose in genomes other than that of D. melanogaster. Subsequent experiments will determine how widely among Drosophila species this element can be disseminated and still remain transposable. In addition, P-bearing cotransformants will be studied in order to determine whether hybrid dysgenesis, a complex syndrome of germ-line abnormalities associated with P element in D. melanogaster, also occurs in other species into which P has been introduced. These experiments will provide information about host-element interactions in transposition, and they will permit evaluation of the postulated role of P-like elements in speciation. 2. A highly unstable white allele in D. mauritiana will be studied genetically and at the molecular level to characterize an inserted DNA element. This mutant is of interest because D. mauritiana and D. simulans have many fewer copia-like elements than their sibling species D. melanogaster. Transposable elements that are retained in D. mauritiana and D. simulans may therefore have certain unusual properties. These studies may explain why transposable elements of a given family are not distributed among species as would be expected from their phylogenetic affiliation. In the long run the unstable white allele will be transformed into D. melanogaster in order to study its mutational characteristics in an alien genome. 3. The transposable element copia will be studied among related species of Drosophila in order to determine the extent of restriction-map variation within and among species. Several copias differing in restriction map occur in D. melanogaster, and copia in D. mauritiana differs from that in D. melanogaster. Our studies will focus on strains collected relatively recently. These studies will reveal whether concerted evolution occurs in dispersed repeated multigene families, which will be important in evaluating the relative role of the evolutionary forces that impinge upon such elements.