Kruangkum Thanapong, Söderhäll Kenneth, Söderhäll Irene
Department of Organismal Biology, Uppsala University, Norbyvägen 18A, 75236, Uppsala, Sweden.
Department of Anatomy, Faculty of Science, Mahidol University, Bangkok, Thailand.
Cell Tissue Res. 2025 Mar;399(3):303-322. doi: 10.1007/s00441-024-03943-1. Epub 2025 Jan 4.
The hematopoietic tissue (HPT) and anterior proliferation center (APC) are the main hemocyte-producing organs of the freshwater crayfish, Pacifastacus leniusculus. To deepen our understanding of immune responses to various pathogens, it is essential to identify distinct hemocyte subpopulations with specific functions and to further explore how these cells are generated. Here we provide an in-depth histological study of the HPT and APC in order to localize cell types in different developmental stages, and to provide some information regarding the hemocyte differentiation in the crayfish. We localized mRNA expression of previously identified genes in the HPT/APC and hemocytes by RNA-FISH. The expression of hemolectin and transglutaminase 1 was shown to be co-localized in a high number of the HPT cells, while transglutaminase 2 was expressed in different cell types mainly associated with epithelium or endothelium. Furthermore, by double RNA-FISH for hemolectin and a previously unidentified PDGF-like factor, combined with immunostaining for prophenoloxidase, we could identify several different subtypes of hemocytes, indicating that the immune function of hemocytes in crayfish is more diversified and complex than previously appreciated.
造血组织（HPT）和前增殖中心（APC）是淡水小龙虾美洲鳌虾主要的血细胞生成器官。为了加深我们对各种病原体免疫反应的理解，识别具有特定功能的不同血细胞亚群并进一步探索这些细胞是如何产生的至关重要。在此，我们对HPT和APC进行了深入的组织学研究，以便定位不同发育阶段的细胞类型，并提供有关小龙虾血细胞分化的一些信息。我们通过RNA荧光原位杂交（RNA-FISH）在HPT/APC和血细胞中定位先前鉴定基因的mRNA表达。血凝集素和转谷氨酰胺酶1的表达显示在大量HPT细胞中共定位，而转谷氨酰胺酶2在主要与上皮或内皮相关的不同细胞类型中表达。此外，通过对血凝集素和一种先前未鉴定的血小板衍生生长因子（PDGF）样因子进行双重RNA-FISH，并结合对前酚氧化酶的免疫染色，我们可以识别几种不同的血细胞亚型，这表明小龙虾血细胞的免疫功能比以前认识到的更加多样化和复杂。
