Chromosomal analysis of DDT-resistance in a long-term selected population of Drosophila melanogaster.
Chromosomal analysis of DDT-resistance in a long-term selected population of Drosophila melanogaster.
复制标题
长期选定的黑腹果蝇群体的 DDT 抗性染色体分析。
作者：
D. Dapkus;D. J. Merrell
研究了黑腹果蝇对DDT抗性的遗传基础。这一种群的独特之处在于，自1952年以来，它一直被选为抗滴滴涕的种群，并达到了非常高的抗药性水平。用染色体分析的方法研究了抗性的遗传基础。用基于时间的滴滴涕试验测试了15个抗性染色体和对照染色体的组合。对数据的分析表明，抗性是多因素的，涉及到三条主要染色体。显性和隐性的第二和第三染色体效应比第一染色体的效应要重要得多，第一染色体没有明显的隐性效应。第二、三号染色体抗性基因表现不完全显性。第二条染色体的平均显性远小于第三条染色体。染色体效应和平均显性之间的这些大规模差异可能表明，参与其中的是少数抗性基因。在染色体之间发现了两个显著的相互作用。尺度上的困难使得在没有进一步数据的情况下很难解释相互作用。通过长期的定向选择，抗性之间的正向交互作用可能已经在该种群中发展起来。
The genetic basis of DDT-resistance was studied in a population of Drosophila melanogaster. This population was unique in that it had been continually selected for DDT-resistance since 1952 and had achieved a very high level of resistance. The genetic basis of resistance was studied by means of a chromosomal analysis. Fifteen combinations of resistant and control chromosomes were tested using a time-based DDT test. The analysis of the data showed that resistance was multifactorial with each of the three major chromosomes involved. Dominant and recessive second and third chromosome effects were found to be much more important than those of the first chromosome, which had no detectable recessive effects. Second and third chromosome resistance genes showed incomplete dominance. The average dominance of the second chromosome was much less than that of the third chromosome. These large-scale differences between chromosomes' effects and average dominance may indicate that a small number of resistance genes are involved. Two significant interactions between chromosomes were found. Scaling difficulties make the interactions difficult to interpret without further data. It seems possible that positive interactions between resistance have been developed by the long-term directional selection in this population.