Bowen T, Dover G A
Department of Genetics, University of Leicester, UK.
Mol Ecol. 1995 Aug;4(4):419-27. doi: 10.1111/j.1365-294x.1995.tb00235.x.
A recently described PCR-based method for the analysis of intergenic spacer (IGS) length variation in the ribosomal (r) DNA of Drosophila melanogaster was used to analyse the distribution of IGS length variants in the rDNA of a number of recently collected D. melanogaster populations. One group of populations, from Europe and North Africa, was shown to have low intrapopulation IGS length variation following maintenance of massed populations in the laboratory for an extended period. However, a greater degree of IGS profile variability was detected at a number of levels in the majority of laboratory-maintained isofemale lines from two of these populations plus a second group of populations which were collected more recently from the eastern coast of Australia; all of which were immediately divided into isofemale lines following collection. Interestingly, PCR analysis of pooled DNA extracts from 30 individuals of either sex showed almost identical PCR profiles from each of the Australian populations. These preliminary results are discussed with regard to the possible combinations of forces (natural selection, neutral drift and genomic molecular drive) on the patterns of IGS length variation.
一种最近描述的基于聚合酶链反应（PCR）的方法，用于分析黑腹果蝇核糖体（r）DNA中基因间隔区（IGS）长度变异，该方法被用于分析一些最近采集的黑腹果蝇种群rDNA中IGS长度变异体的分布情况。结果显示，来自欧洲和北非的一组种群，在实验室中长期维持大规模种群后，其种群内IGS长度变异较低。然而，在来自这些种群中的两个种群以及最近从澳大利亚东海岸采集的第二组种群的大多数实验室维持的同雌系中，在多个水平上检测到了更高程度的IGS图谱变异性；所有这些种群在采集后立即被分成同雌系。有趣的是，对来自30只不同性别的个体的混合DNA提取物进行PCR分析，结果显示来自每个澳大利亚种群的PCR图谱几乎相同。本文就影响IGS长度变异模式的各种可能因素组合（自然选择、中性漂变和基因组分子驱动）对这些初步结果进行了讨论。
