Pathways in blood and vessel development revealed through zebrafish genetics.
Studies in zebrafish have potential to contribute to understanding of the vertebrate hematopoietic and vasculogenic systems. Our research has examined the roles of several molecules in pathways that lead to the development of blood and vessels in zebrafish, and has provided insights into the regulation of these processes. Gdf6a/radar, a member of the bone morphogenetic protein (BMP) family, is expressed in the zebrafish hypochord and primitive gut endoderm; structures that flank the developing dorsal aorta and posterior cardinal vein. This pattern of expression positions Gdf6a/radar as a candidate regulator of vasculogenesis. Support for such a role has come from experiments where Gdf6a/radar function was depleted with antisense morpholino oligonucleotides. This resulted in vascular leakiness, suggesting that Gdf6a/radar is involved in maintenance of vascular integrity. The transcription factor Runx1 is known to play a critical role in mammalian definitive hematopoiesis. When Runx1 expression domains and function were analyzed in zebrafish, the importance of this gene in definitive hematopoiesis was confirmed. However there was also evidence for a wider role, including involvement in vascular development and neuropoiesis. This work has laid the foundation for an ethylnitrosourea (ENU) mutagenesis screen based on runx1 whole-mount in situ hybridzation, that aims to identify genes operative in the runx1 pathway. An additional member of the Runx family, Runx3, is also involved in developmental hematopoiesis, with a function distinct from that of Runx1. We hypothesize that Runx1 and Runx3 form a continuum of transcriptional control within the hematopoietic system. An added attraction of zebrafish is that models of human disease can be generated, and we have shown that this system has potential for the study of Runx1-mediated leukemogenesis.
Division of Molecular Medicine, Faculty of Medical and Health Sciences, The University of Auckland, New Zealand. ps.crosier@auckland.ac.nz
Philip S
PS
Crosier
Maggie L
ML
Kalev-Zylinska
Christopher J
CJ
Hall
Maria Vega C
MV
Flores
Julia A
JA
Horsfield
Kathryn E
KE
Crosier
D000818:Animals; D019485:Bone Morphogenetic Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D050676:Core Binding Factor Alpha 2 Subunit; D050677:Core Binding Factor Alpha 3 Subunit; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D055431:Growth Differentiation Factor 6; D006412:Hematopoietic Stem Cells / Q000166:cytology; D017403:In Situ Hybridization; D008954:Models, Biological; D009389:Neovascularization, Pathologic; D011518:Proto-Oncogene Proteins; D015398:Signal Transduction; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D019076:Transgenes; D015027:Zebrafish / Q000196:embryology* / Q000235:genetics* / Q000502:physiology; D029961:Zebrafish Proteins
D019485:Bone Morphogenetic Proteins; D050676:Core Binding Factor Alpha 2 Subunit; D050677:Core Binding Factor Alpha 3 Subunit; D004268:DNA-Binding Proteins; D055431:Growth Differentiation Factor 6; D011518:Proto-Oncogene Proteins; D014157:Transcription Factors; D029961:Zebrafish Proteins; C420987:gdf6a protein, zebrafish