Jiménez-Florido Patricia, Aquilino Mónica, Buckley David, Bella José L, Planelló Rosario
Departamento de Biología (Genética), Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain.
Centro de Investigación en Biodiversidad y Cambio Global (CIBC-UAM), Universidad Autónoma de Madrid, Madrid, Spain.
Insect Sci. 2024 Nov 29. doi: 10.1111/1744-7917.13481.
Distinct lineages of the grasshopper Chorthippus parallelus (Orthoptera: Acrididae) form well-known hybrid zones (HZs) both in the Pyrenees and the Alps mountain ranges in South Europe. These HZs represent unique experimental systems to identify "key genes" that maintain genetic boundaries between emerging species. The Iberian endemism C. p. erythropus (Cpe) and the subspecies C. p. parallelus (Cpp), widely distributed throughout the rest of Europe, overlap and form the Pyrenean HZ. Both subspecies differ morphologically, as well as in behavioral, mitochondrial, nuclear, and chromosomal traits, and in the strains of the maternally transmitted bacterial endosymbiont Wolbachia infecting them. This results in either unidirectional and bidirectional cytoplasmic incompatibility between both grasshopper subspecies, pointing out that Wolbachia clearly affects gene expression in the infected individuals. Here we explore how Wolbachia may modify the expression of some major genes involved in relevant pathways in Cpp in the Pyrenean HZ. We have analyzed, through molecular biomarkers, the physiological responses in C. parallelus individuals infected by Wolbachia, with particular attention to the energy metabolism, the immune system response, and the reproduction. qPCR was used to evaluate the expression of selected genes in the gonads of infected and uninfected adults of both sexes, since this tissue constitutes the main target of Wolbachia infection. Transcriptional analyses also showed differential sex-dependent responses in most of the analyzed biomarkers in infected and noninfected individuals. We identified for the first time new sensitive biomarkers that might be involved in the reproductive barrier induced by Wolbachia in the hybrid zone.
草蜢Chorthippus parallelus（直翅目：蝗科）的不同谱系在南欧的比利牛斯山脉和阿尔卑斯山脉形成了著名的杂交区（HZs）。这些杂交区代表了独特的实验系统，用于识别维持新出现物种之间遗传边界的“关键基因”。伊比利亚特有种C. p. erythropus（Cpe）和亚种C. p. parallelus（Cpp）广泛分布于欧洲其他地区，它们相互重叠并形成了比利牛斯杂交区。这两个亚种在形态上以及行为、线粒体、核和染色体特征，以及感染它们的母系传播细菌内共生体沃尔巴克氏体的菌株方面都有所不同。这导致了两个草蜢亚种之间单向和双向的细胞质不相容，表明沃尔巴克氏体明显影响受感染个体的基因表达。在这里，我们探讨沃尔巴克氏体如何可能改变比利牛斯杂交区Cpp中参与相关途径的一些主要基因的表达。我们通过分子生物标志物分析了感染沃尔巴克氏体的C. parallelus个体的生理反应，特别关注能量代谢、免疫系统反应和繁殖。定量聚合酶链反应（qPCR）用于评估感染和未感染的成年两性性腺中选定基因的表达，因为该组织是沃尔巴克氏体感染的主要靶标。转录分析还显示，在感染和未感染个体中，大多数分析的生物标志物存在性别依赖性差异反应。我们首次鉴定出可能参与杂交区中由沃尔巴克氏体诱导的生殖屏障的新的敏感生物标志物。
