Cellular characterization of thrombocytes in Xenopus laevis with specific monoclonal antibodies

Establishment of a sticky, large, oval-shaped thrombocyte cell line from tree frog as an ancestor of mammalian megakaryocytes

“…However, the bone marrow has been reported to be the main site of differentiation of neutrophilic granulocytes but not the main site of hematopoiesis. In addition, recent histological research using antibodies against Xenopus thrombocytes demonstrated the existence of thrombocytes in both the hepatic sinusoids and splenic red pulp (Tanizaki et al 2015 ). In contrast, it was reported in another study that the thrombocytic lineage occurred near the sinusoids of the bone marrow in bullfrogs (de Abreu Manso et al 2009 ).…”

“…CD41 (glycoprotein αIIb) is one of the major markers of megakaryocytes and thrombocytes (Tanizaki et al 2015 ; Finkielsztein et al 2015 ). Studies that identified and characterized thrombocytes in zebrafish reported that thrombocytes represent the hemostatic homolog of mammalian platelets (Jagadeeswaran et al 1999 ).…”

Using Xenopus to understand human disease and developmental disorders

“…Xenopus also has greatly enhanced our understanding of DNA replication and repair (Kalb, Mallery, Larkin, Huang, & Hiom, ; Long, Joukov, Budzowska, & Walter, ; Räschle et al, ; Shintomi, Takahashi, & Hirano, ; Zhang et al, ), and the mechanisms of genome organization, transcriptional regulation, and epigenetics (Belikov, Berg, & Wrange, ; Bogdanović et al, ; Buisine et al, ; Gazdag, Jacobi, van Kruijsbergen, Weeks, & Veenstra, ; Gao et al, ; Hontelez et al, ; Owens et al, ; Tamaoki et al, ; Wang et al, ; Wen, Fu, Guo, Chen, & Shi, ). Numerous studies in Xenopus elucidate mechanisms of morphogenesis and organogenesis ( Agricola et al, ; Bestman, Huang, Lee‐Osbourne, Cheung, & Cline, ; Metikala, Neuhaus, & Hollemann, ; Mimoto, Kwon, Green, Goldman, & Christian, ; Nie & Bronner, ; Okada, Wen, Miller, Su, & Shi, ; Ossipova et al, ; Tanizaki, Ishida‐Iwata, Obuchi‐Shimoji, & Kato, ). Many of the components of the well‐known signaling pathways were discovered in Xenopus and fly, and new discoveries in this field continue to rely on Xenopus (e.g., Lee et al, ; Lee, Shi, & Zheng, ; Park et al, ; Zhang et al, ; Zhao, Shi, Winey, & Klymkowsky, ).…”

Hematologic reference intervals for Rana sylvatica (Lithobates sylvaticus) and effect of infection with Frog Virus 3 (Ranavirus sp., Iridoviridae)

“…Thrombocytes were mostly small and round, with a very dark nucleus whose chromatin was particularly dense at its core, a ragged cytoplasmic membrane, and little pale to clear cytoplasm that occasionally contained a red-magenta vacuole (activated thrombocytes) (Figure 2). 34,35 Elliptical (nonactivated) thrombocytes were less frequently observed; they had a dark ovoid nucleus whose chromatin was darkest and most dense along the nuclear long axis. Cytoplasm in elliptical thrombocytes was very pale blue to clear, and the cytoplasmic membrane was smooth, sometimes tapered at the edges, giving the cell a fusiform shape (Figure 4).…”