Department of Life Science, College of Natural Sciences, Hanyang University, Seoul, Republic of Korea.
Hanyang Institute of Advanced BioConvergence, Hanyang University, Seoul, Republic of Korea.
PLoS Genet. 2023 Dec 19;19(12):e1011077. doi: 10.1371/journal.pgen.1011077. eCollection 2023 Dec.
Drosophila hemocytes serve as the primary defense system against harmful threats, allowing the animals to thrive. Hemocytes are often compared to vertebrate innate immune system cells due to the observed functional similarities between the two. However, the similarities have primarily been established based on a limited number of genes and their functional homologies. Thus, a systematic analysis using transcriptomic data could offer novel insights into Drosophila hemocyte function and provide new perspectives on the evolution of the immune system. Here, we performed cross-species comparative analyses using single-cell RNA sequencing data from Drosophila and vertebrate immune cells. We found several conserved markers for the cluster of differentiation (CD) genes in Drosophila hemocytes and validated the role of CG8501 (CD59) in phagocytosis by plasmatocytes, which function much like macrophages in vertebrates. By comparing whole transcriptome profiles in both supervised and unsupervised analyses, we showed that Drosophila hemocytes are largely homologous to vertebrate myeloid cells, especially plasmatocytes to monocytes/macrophages and prohemocyte 1 (PH1) to hematopoietic stem cells. Furthermore, a small subset of prohemocytes with hematopoietic potential displayed homology with hematopoietic progenitor populations in vertebrates. Overall, our results provide a deeper understanding of molecular conservation in the Drosophila immune system.
果蝇血细胞作为抵御有害威胁的主要防御系统，使动物得以茁壮成长。由于观察到两者之间存在功能相似性，血细胞常被比作脊椎动物先天免疫系统细胞。然而，这些相似性主要是基于有限数量的基因及其功能同源性建立的。因此，使用转录组数据进行系统分析可以为果蝇血细胞功能提供新的见解，并为免疫系统的进化提供新的视角。在这里，我们使用来自果蝇和脊椎动物免疫细胞的单细胞 RNA 测序数据进行了跨物种比较分析。我们在果蝇血细胞中发现了几个与分化群（CD）基因相关的保守标记，并验证了 CG8501（CD59）在吞噬作用中的作用，该作用类似于脊椎动物中的巨噬细胞。通过比较监督和无监督分析中的全转录组谱，我们表明果蝇血细胞在很大程度上与脊椎动物髓样细胞同源，尤其是浆血细胞与单核细胞/巨噬细胞同源，原血细胞 1（PH1）与造血干细胞同源。此外，一小部分具有造血潜能的原血细胞与脊椎动物造血祖细胞群体具有同源性。总的来说，我们的研究结果为果蝇免疫系统的分子保守性提供了更深入的了解。
