Molecular population-genetic studies on adaptive evolution of Drosophila population.

为了了解适应性进化的分子基础，我们进行了四个实验，得到了以下结果：1.我们报道了生存能力存在从北到南的加性遗传变异，南方种群的过剩是通过基因型-环境互作来维持的。为了获得分子基础，对小川(南部)和青森(北部)种群进行了Southern杂交分析。利用包括Gpdh、adn、Amy和Pu基因在内的4个证据，用8种限制性内切酶对每个群体的43条第二染色体进行了分析。南方种群与北方种群间差异不显著，南方种群的唯一插入/缺失数量显著多于北方种群。因此，插入/缺失可能是多基因活性的重要条件之一。2.在自然人群中检测到sn甘油-3-磷酸脱氢酶基因(Gpdh)的复制和三倍体。前者在每个受试人群中都是多态的。后者仅在青森和小川种群中是多态的。3.利用先前在北卡罗来纳州罗利人群中发现的In(2L)t年龄，进行了有益突变的搜索。在大约4000代以前，人们检测到这种倒位发生了一些有益的突变，其在携带In(2L)t的染色体中的频率已增加到18%。4.对CopiA、CopiA样元件(17、6、412)、HOBO和I__-元件的转座率进行了估算。Copia和Copia类分子在其不正常的条件下不会随着hogo分子的移动而交叉动员。此外，Yamaguchi和Mukai(1974)的突变因子被发现是流浪者分子。

To understand the molecular basis of adaptive evolution, four experiments were conducted and the following results were obtained: 1. We have reported that there is a north-to-south cline of additive genetic variance for viability and that the excess in the southern population has been maintained by genotype-environment interaction. To obtain the molecular basis, southern blot analysis was conducted for the Ogasawara (south) and Aomori (north) populations. Forty-three second chromosomes were analyzed for each population using four proves inclusing the Gpdh, Adn, Amy and Pu genes, with eight restriction enzymes. Significant difference was not detected between the northern and southern populations except the following; in the southern population, the number of unique insersion/deletions was significantly larger than that in the northern population. Thus, insertions/deletions may be one of the important condidates of viability polygenes. 2. Duplication and triplication of the sn glycerol-3-phosphate dehydrogenase gene (Gpdh) were detected in natural populations. The former were found to be polymorphic in every population tested. The latter were polymorphic only in the Aomori and Ogasawara populations. 3. Using the previous finding of the age of In(2L)t in the Raleigh, N.C. population, search for beneficial mutations was conducted. It was detected that some beneficial mutation occurred in this inversion about 4000 generations ago and that its frequency has increased to 18% in the In(2L)t-carrying chromosomes. 4. The transposition rates, both the exision and insertion rates, were estimated for copia, copia-like elements (17,6, 412), hobo and I__- elements. Copia and copia-like elements are not cross-mobilized with the movement of hogo elements under their dysgenic condition.Furthermore, it was found that the mutator factor of Yamaguchi and Mukai (1974) is hobo elements.