Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Autónoma de Buenos Aires, Argentina.
Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina.
BMC Genomics. 2022 Jul 16;23(1):515. doi: 10.1186/s12864-022-08745-9.
The chance to compare patterns of differential gene expression in related ecologically distinct species can be particularly fruitful to investigate the genetics of adaptation and phenotypic plasticity. In this regard, a powerful technique such as RNA-Seq applied to ecologically amenable taxa allows to address issues that are not possible in classic model species. Here, we study gene expression profiles and larval performance of the cactophilic siblings Drosophila buzzatii and D. koepferae reared in media that approximate natural conditions and evaluate both chemical and nutritional components of the diet. These closely related species are complementary in terms of host-plant use since the primary host of one is the secondary of the other. D. koepferae is mainly a columnar cactus dweller while D. buzzatii prefers Opuntia hosts.
Our comparative study shows that D. buzzatii and D. koepferae have different transcriptional strategies to face the challenges posed by their natural resources. The former has greater transcriptional plasticity, and its response is mainly modulated by alkaloids of its secondary host, while the latter has a more canalized genetic response, and its transcriptional plasticity is associated with the cactus species.
Our study unveils a complex pleiotropic genetic landscape in both species, with functional links that relate detox responses and redox mechanisms with developmental and neurobiological processes. These results contribute to deepen our understanding of the role of host plant shifts and natural stress driving ecological specialization.
比较相关生态差异物种中差异基因表达模式的机会对于研究适应和表型可塑性的遗传学特别有成效。在这方面，RNA-Seq 等强大技术应用于生态适宜的分类群，可以解决经典模式物种不可能解决的问题。在这里，我们研究了在接近自然条件的培养基中饲养的嗜仙人掌果蝇 buzzatii 和 D. koepferae 的基因表达谱和幼虫表现，并评估了饮食的化学和营养成分。这两个密切相关的物种在宿主植物的利用上是互补的，因为一个物种的主要宿主是另一个物种的次要宿主。D. koepferae 主要是柱状仙人掌的居住者，而 D. buzzatii 则更喜欢 Opuntia 宿主。
我们的比较研究表明，D. buzzatii 和 D. koepferae 有不同的转录策略来应对其自然资源带来的挑战。前者具有更大的转录可塑性，其反应主要由其次要宿主的生物碱调节，而后者具有更趋同的遗传反应，其转录可塑性与仙人掌物种有关。
我们的研究揭示了这两个物种中复杂的多效遗传景观，其中与解毒反应和氧化还原机制有关的功能联系与发育和神经生物学过程有关。这些结果有助于加深我们对宿主植物转移和自然胁迫驱动生态特化作用的理解。
