Pegueroles G, Mestres F, Serra L
Departament de Genètica, Facultat de Biologia, Universitat de Barcelona, Spain.
Genetica. 1996;98(3):289-96. doi: 10.1007/BF00057593.
An analysis of the effects of inbreeding on the genetic structure of a colonizing population of Drosophila subobscura has been carried out. Species of Drosophila, particularly D. subobscura, may have lethal alleles associated with chromosomal inversions and our aim was to assess the extent to which the genome is balanced in this way. The frequencies of chromosomal inversions were compared between a large population and a set of 72 lines that were maintained by brother-sister mating for 10 generations. Fisher's matrix method was used to calculate the expected homozygosity in these inbred lines for 5 allozyme loci (Aph, Hk-1, Lap, Odh, and Pept-1) used as markers of large chromosomal segments. Furthermore, the expected rates of fixation corresponding to these allozyme loci were also calculated. The results show that the amount of homozygosis observed did not differ significantly from expectations (with the corresponding loss of lines as a consequence of the reduction in viability). However, two deviations from strict neutrality were observed: there was a heterozygote excess at the Lap locus, and the frequency of the O5 inversion (always associated with a lethal gene in colonizing populations) was higher than expected.
对近亲繁殖对暗果蝇定殖种群遗传结构的影响进行了分析。果蝇物种，特别是暗果蝇，可能具有与染色体倒位相关的致死等位基因，我们的目的是评估基因组以这种方式保持平衡的程度。比较了一个大种群与一组通过亲兄妹交配维持10代的72个品系之间的染色体倒位频率。使用费舍尔矩阵法计算这些近交系中5个等位酶基因座（Aph、Hk-1、Lap、Odh和Pept-1）的预期纯合度，这些基因座用作大染色体片段的标记。此外，还计算了与这些等位酶基因座相对应的预期固定率。结果表明，观察到的纯合程度与预期没有显著差异（由于活力降低导致相应品系的损失）。然而，观察到两个偏离严格中性的情况：Lap基因座存在杂合子过剩，O5倒位（在定殖种群中总是与一个致死基因相关）的频率高于预期。
