Data_Sheet_5_The Transcriptomic and Bioinformatic Characterizations of Iron Acquisition and Heme Utilization in Avibacterium paragallinarum in Response to Iron-Starvation.XLS

Avibacterium paragallinarum is the pathogen of infectious coryza, which is a highly contagious respiratory disease of chickens that brings a potentially serious threat to poultry husbandry. Iron is an important nutrient for bacteria and can be obtained from surroundings such as siderophores and hemophores. To date, the mechanisms of iron acquisition and heme utilization as well as detailed regulation in A. paragallinarum have been poorly understood. In this study, we investigated the transcriptomic profiles in detail and the changes of transcriptomes induced by iron restriction in A. paragallinarum using RNA-seq. Compared with the iron-sufficiency control group, many more differentially expressed genes (DEGs) and cellular functions as well as signaling pathways were verified in the iron-restriction group. Among these DEGs, the majority of genes showed decreased expression and some were found to be uniquely present in the iron-restriction group. With an in-depth study of bioinformatic analyses, we demonstrated the crucial roles of the Hut protein and DUF domain-containing proteins, which were preferentially activated in bacteria following iron restriction and contributed to the iron acquisition and heme utilization. Consequently, RT-qPCR results further verified the iron-related DEGs and were consistent with the RNA-seq data. In addition, several novel sRNAs were present in A. paragallinarum and had potential regulatory roles in iron homeostasis, especially in the regulation of Fic protein to ensure stable expression. This is the first report of the molecular mechanism of iron acquisition and heme utilization in A. paragallinarum from the perspective of transcriptomic profiles. The study will contribute to a better understanding of the transcriptomic response of A. paragallinarum to iron starvation and also provide novel insight into the development of new antigens for potential vaccines against infectious coryza by focusing on these iron-related genes.

禽副嗜血杆菌是传染性鼻炎的病原体，该病是一种高度传染性的鸡呼吸道疾病，对家禽养殖业构成潜在严重威胁。铁是细菌的重要营养素，可从环境中的铁载体和血纤维蛋白中获取。迄今为止，关于禽副嗜血杆菌中铁的获取机制和血红素利用，以及详细的调节作用仍了解不多。在本研究中，我们详细调查了转录组特征，并利用RNA测序技术分析了铁限制条件下禽副嗜血杆菌转录组的改变。与铁充足对照组相比，铁限制组中验证了更多差异表达基因（DEGs）、细胞功能和信号通路。在这些DEGs中，大多数基因表达量降低，其中一些仅在铁限制组中发现。通过对生物信息学分析的深入研究，我们揭示了Hut蛋白和DUF结构域蛋白在细菌铁限制后的关键作用，这些蛋白在细菌中优先激活，并参与铁的获取和血红素的利用。因此，实时定量PCR结果进一步验证了铁相关DEGs，并与RNA测序数据一致。此外，禽副嗜血杆菌中存在几种新型小RNA，它们在铁稳态调节中具有潜在的调控作用，特别是在调节Fic蛋白以确保其稳定表达方面。这是首次从转录组特征的角度报道禽副嗜血杆菌铁获取和血红素利用的分子机制。本研究将有助于更好地理解禽副嗜血杆菌对铁剥夺的转录组反应，并通过对这些与铁相关的基因的关注，为开发针对传染性鼻炎的新抗原疫苗提供新的见解。