In heterozygote state, we interogressed three chromosomal segments of Drosophila koepferae in D. buzzatii. The effect of each introgression was evaluated in the fertility of the segmental males, quantifying the amount of offspring produced. Through specific crosses method, we generated Drosophila segmental isolines carrying specific chromosomal introgression segments. The introgressions were monitored cytogenetically by the method of molecular markers of chromosomal asynapsis. The statistical analysis showed that none of the three segments evaluated, introgressed individually or in pairs, as well as cis or trans, do not produce sterility in the segmental males, as determined by the normal productions of offspring. Additional introgressions using other larger segments show that when the introgressions reach a minimum size of 31.15%, they produce sterility. It is concluded that the hybrid sterility genes present in the three segments evaluated did not act in strong epistasis, but show a pattern of gradual additive behaviour by requiring a minimum threshold size to produce sterility. Finally, we also isolated the smallest introgressing segment that has been reported for these species (2.19%), and for the first time we have managed to place it in homozygous state (data not shown), so we are now in the process of evaluating the ability to these segments in homozygous state.

中文翻译：

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通过模拟拥有来自生殖隔离的杂种不育基因而提出的果蝇染色体片段的评价

在杂合子状态下，我们在 D. buzzatii 中对 Drosophila koepferae 的三个染色体片段进行了互渗。在节段雄性的生育力中评估每个基因渗入的影响，量化产生的后代数量。通过特定的杂交方法，我们生成了携带特定染色体基因渗入片段的果蝇节段等值线。基因渗入通过染色体不联触的分子标记方法进行细胞遗传学监测。统计分析表明，评估、单独或成对渗入以及顺式或反式渗入的三个节段都不会在节段雄性中产生不育，这取决于后代的正常生产。使用其他较大片段的额外渗入表明，当渗入达到 31.15% 的最小大小时，它们产生不育性。得出的结论是，所评估的三个片段中存在的杂种不育基因没有在强上位性中起作用，而是通过要求产生不育的最小阈值大小而显示出逐渐累加行为的模式。最后，我们还分离出了这些物种报告的最小基因渗入片段 (2.19%)，并且我们第一次设法将其置于纯合状态（数据未显示），因此我们现在正在评估这些片段处于纯合状态的能力。