Hematopoietic cell development in the zebrafish embryo (original) (raw)

Definitive hematopoietic stem/progenitor cells manifest distinct differentiation output in the zebrafish VDA and PBI

Development, 2009

One unique feature of vertebrate definitive hematopoiesis is the ontogenic switching of hematopoietic stem cells from one anatomical compartment or niche to another. In mice, hematopoietic stem cells are believed to originate in the aorta-gonadmesonephros (AGM), subsequently migrate to the fetal liver (FL) and finally colonize the bone marrow (BM). Yet, the differentiation potential of hematopoietic stem cells within early niches such as the AGM and FL remains incompletely defined. Here, we present in vivo analysis to delineate the differentiation potential of definitive hematopoietic stem/progenitor cells (HSPCs) in the zebrafish AGM and FL analogies, namely the ventral wall of dorsal aorta (VDA) and the posterior blood island (PBI), respectively. Cell fate mapping and analysis of zebrafish runx1 w84x and vlad tepes (vlt m651 ) mutants revealed that HSPCs in the PBI gave rise to both erythroid and myeloid lineages. However, we surprisingly found that HSPCs in the VDA were not quiescent but were uniquely adapted to generate myeloid but not erythroid lineage cells. We further showed that such distinct differentiation output of HSPCs was, at least in part, ascribed to the different micro-environments present in these two niches. Our results highlight the importance of niche in shaping the differentiation output of developing HSPCs.

The caudal dorsal artery generates hematopoietic stem and progenitor cells via the endothelial-to-hematopoietic transition in zebrafish

Journal of genetics and genomics = Yi chuan xue bao, 2018

Zebrafish hematopoietic stem and progenitor cells (HSPCs) originate from the hemogenic endothelium of the ventral wall of the dorsal aorta (DA) through the endothelial-to-hematopoietic transition (EHT) from approximately 30 to 60 hours post fertilization (hpf). However, whether other artery sites can generate HSPCs de novo remains unclear. In this study, using live imaging and lineage tracing, we found that the caudal dorsal artery (CDA) in the caudal hematopoietic tissue directly gave rise to HSPCs through EHT. This process initiated from approximately 60 hpf and terminated at approximately 156 hpf. Compared with that in the DA, fewer EHT events were observed in the CDA. The EHT events in the DA and CDA were similarly regulated by Runx1 but differentially influenced by blood flow (i.e., the EHT frequency in CDA was affected to a lesser extent when circulation was compromised in the tnnt2a mutant). Therefore, the whole artery, including both DA and CDA, was endowed with the ability ...

Zebrafish Caudal Haematopoietic Embryonic Stromal Tissue (CHEST) Cells Support Haematopoiesis

Scientific reports, 2017

Haematopoiesis is an essential process in early vertebrate development that occurs in different distinct spatial locations in the embryo that shift over time. These different sites have distinct functions: in some anatomical locations specific hematopoietic stem and progenitor cells (HSPCs) are generated de novo. In others, HSPCs expand. HSPCs differentiate and renew in other locations, ensuring homeostatic maintenance. These niches primarily control haematopoiesis through a combination of cell-to-cell signalling and cytokine secretion that elicit unique biological effects in progenitors. To understand the molecular signals generated by these niches, we report the generation of caudal hematopoietic embryonic stromal tissue (CHEST) cells from 72-hours post fertilization (hpf) caudal hematopoietic tissue (CHT), the site of embryonic HSPC expansion in fish. CHEST cells are a primary cell line with perivascular endothelial properties that expand hematopoietic cells in vitro. Morphologic...