The two tephritid fruit fly pests, Bactrocera tryoni and Bactrocera neohumeralis, are unusually well suited to the study of the genetics of reproductive isolating mechanisms. Sequence difference between the species is no greater than between a pair of conspecific Drosophila melanogaster populations. The two species exist in close sympatry, yet do not hybridize in the field, apparently kept separate by a strong premating isolation mechanism involving the time of day at which mating occurs. This spurred us to search for key genes for which time of day expression is regulated differently between the species. Using replicated, quantitative transcriptomes from head tissues of males of the two species, sampled in the day and night, we identified 141 transcripts whose abundance showed a significant interaction between species and time of day, indicating a difference in gene regulation. The brain transcripts showing this interaction were enriched for genes with a neurone function and 90% of these were more abundant at night than day in B. tryoni. Features of the expression patterns suggest that there may be a difference in the regulation of sleep–wake cycles between the species. In particular several genes, which in D. melanogaster are expressed in circadian pacemaker cells, are promising candidates to further explore the genetic differentiation involved in this prezygotic reproductive isolation mechanism.

中文翻译：

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在合子前生殖分离的特非替尼模型中基因调控的差异。

两种拟蝇类果蝇害虫Bactrocera tryoni和Bactrocera neohumeralis非常适合用于生殖分离机制的遗传学研究。物种之间的序列差异不大于一对同种的果蝇（Drosophila melanogaster）之间的序列差异人口。这两个物种紧密交配地存在，但并未在野外杂交，显然是通过涉及一天中发生交配时间的强大的过早隔离机制而分开的。这促使我们寻找关键基因，这些基因在一天中的表达在物种之间受到不同的调节。使用白天和黑夜从两个物种的雄性头部组织中复制，定量的转录组，在白天和晚上进行采样，我们鉴定出141个转录本，这些转录本的丰度表明物种与一天中的不同时间之间存在显着的相互作用，表明基因调控方面存在差异。显示这种相互作用的大脑转录本富含具有神经元功能的基因，其中90％的夜里白天比白天丰富。。表达模式的特征表明，物种之间的睡眠-觉醒周期的调节可能有所不同。特别地，在昼夜节律性起搏器细胞中表达的在黑腹果蝇中的几个基因是有希望的候选者，以进一步探索参与这种合子前生殖分离机制的遗传分化。