Zheng Xian-Yun, Duan Yi-Hao, Li Chun-Xuan, Ma En-Bo
College of Life Science and Technology, Shanxi University, Taiyuan 030006, China.
Yi Chuan Xue Bao. 2002;29(11):966-71.
The allozyme analysis using horizontal starch gel electrophoresis was employed to compare the genetic structure in the population of oriental migratory locust Locusta migratoria manilensis from two breeding areas, Beidagang(Tianjin) and Huanghua(Hebei). The two areas are adjacent but with distinct ecological features, with the recorded locust outbreaks and migration. The zymograms showed that among nineteen loci four (Mdh-1, Pgm, Adk and G3pd) showed extremely low variability level with the frequency of the most common allele higher than 0.95 in the populations from both sites. The rest loci had 2 to 4 alleles but the allele frequencies between the two populations were all similar except Fbp and Got-2 loci. In the 27 chi 2-tests for the genotypes at polymorphic loci only two (Pgi and Got-1) of beidagang population did fit the Hardy-Weinberg's expectations. This is due to high frequencies of the most common homozygotes and the corresponding heterozygote deficiency. The allozyme data demonstrated that the locusts had remarkable genetic variability within each population, but little divergence between the populations. The genetic variability measurements were found similar: Percentage of polymorphic loci (P) was between 73.7% and 78.9%; The mean number of alleles per locus (A) was from 2.9 to 3.1; and the mean heterozygosity (Ho) was nearly identical (about 0.138). The F-statistics (FST = 0.053) also showed the genetic uniformity of the populations, corresponding to the high Nei's genetic identity (I = 0.938). These results of the allozyme analysis suggested that the two populations appeared to be a part of a large population. It is reasoned that the genetic polymorphism and differentiation at certain loci between the two populations may depend on at least two agnostic factors that are all related to migration. First, the unusual dispersal capability of L. m. manilensis tends to make a continuous genetic structure distribution. Second, the frequent migration also results in the individuals to be exposed to drastically various environments. Since the broad adaptability is crucial to survive the changing environments, the genetic variation at population level is necessarily required to offer the population resilience for successful survival and reproduction under those ecologically divergent abiotic and biotic conditions. Thus, the migration contributes to the maintenance of dynamic equilibrium of genetic polymorphism in this highly specialized subspecies.
采用水平淀粉凝胶电泳进行等位酶分析，以比较来自两个繁殖地（天津北大港和河北黄骅）的东亚飞蝗Locusta migratoria manilensis种群的遗传结构。这两个地区相邻，但生态特征不同，有蝗虫爆发和迁飞的记录。酶谱显示，在19个基因座中，有4个（Mdh-1、Pgm、Adk和G3pd）的变异水平极低，两个地点种群中最常见等位基因的频率均高于0.95。其余基因座有2至4个等位基因，但除Fbp和Got-2基因座外，两个种群之间的等位基因频率都相似。在对多态性基因座基因型进行的27次卡方检验中，北大港种群只有2个（Pgi和Got-1）符合哈迪-温伯格预期。这是由于最常见纯合子的高频率以及相应的杂合子缺失。等位酶数据表明，蝗虫在每个种群内具有显著的遗传变异性，但种群之间的差异很小。遗传变异性测量结果相似：多态性基因座百分比（P）在73.7%至78.9%之间；每个基因座的平均等位基因数（A）为2.9至3.1；平均杂合度（Ho）几乎相同（约0.138）。F统计量（FST = 0.053）也表明种群的遗传一致性，与高奈氏遗传同一性（I = 0.938）相对应。这些等位酶分析结果表明，这两个种群似乎是一个大种群的一部分。据推测，两个种群之间某些基因座的遗传多态性和分化可能至少取决于两个与迁飞相关的未知因素。第一，东亚飞蝗的非凡扩散能力倾向于形成连续的遗传结构分布。第二，频繁的迁飞也导致个体暴露于截然不同的环境中。由于广泛的适应性对于在不断变化的环境中生存至关重要，因此在种群水平上的遗传变异对于在那些生态不同的非生物和生物条件下成功生存和繁殖提供种群恢复力是必不可少的。因此，迁飞有助于维持这个高度特化亚种遗传多态性的动态平衡。
