SEARCH:   Advanced

Blood, 1 January 2006, Vol. 107, No. 1, pp. 111-117. Prepublished online as a Blood First Edition Paper on September 15, 2005; DOI 10.1182/blood-2005-05-1970. This Article Full Text (PDF) All Versions of this Article: 2005-05-1970v1 107/1/111    most recent Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Rights and Permissions Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Ema, M. Articles by Rossant, J. Search for Related Content PubMed PubMed Citation Articles by Ema, M. Articles by Rossant, J. Related Collections Related Article in Blood Online Social Bookmarking                   What's this?  Previous Article  |  Next Article  Submitted May 17, 2005 Accepted August 8, 2005 Deletion of selection cassette but not cis-acting elements in targeted Flk1-lacZ allele reveals Flk1 expression in multipotent mesodermal progenitors Masatsugu Ema, Satoru Takahashi, and Janet Rossant* Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada; Department of Anatomy and Embryology, Institute of Basic Medical Sciences, The University of Tsukuba, Tsukuba, Ibaraki, Japan Department of Anatomy and Embryology, Institute of Basic Medical Sciences, The University of Tsukuba, Tsukuba, Ibaraki, Japan Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada; Department of Medical Genetics and Microbiology, University of Toronto, Toronto, Ontario, Canada * Corresponding author; email: janet.rossant{at}sickkids.ca. Flk1, the gene encoding the vascular endothelial growth factor receptor, VEGFR2, is a well-known marker for vascular and hematopoietic progenitors and is indispensable for normal hematopoiesis and vasculogenesis. Here we show that Flk1 expression in the early mouse embryo marks a broad spectrum of mesodermal progenitors exiting the primitive streak as well as later mesodermal cell types including some cardiomyocytes, portions of the somites and all extraembryonic mesoderm cells. These findings made use of a Flk1-lacZ knock-in allele in which the neomycin selection cassette was removed, which resulted in full replication of the endogenous expression of Flk1. Targeted deletion of a region in intron 1 that has been proposed to direct endothelial expression produced no alteration in either endothelial or broader mesodermal expression of the Flk1-lacZ allele. Examination of lacZ expression in homozygotes for the Flk1lacZ neo-out allele revealed that lacZ-expressing mesodermal cells persisted in non-vascular regions. Thus Flk1 expression marks progenitors with broad mesodermal potential but is not absolutely required for the development of all mesodermal lineages in which it is expressed. CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this? Related Article in Blood Online: Flk1 expression: promiscuity revealed Victoria L Bautch Blood 2006 107: 3-4. [Full Text] [PDF] This article has been cited by other articles: T. J. Nelson, R. S. Faustino, A. Chiriac, R. Crespo-Diaz, A. Behfar, and A. Terzic CXCR4+/FLK-1+ Biomarkers Select a Cardiopoietic Lineage from Embryonic Stem Cells Stem Cells, June 1, 2008; 26(6): 1464 - 1473. [Abstract] [Full Text] [PDF] K. Kawasaki, T. Watabe, H. Sase, M. Hirashima, H. Koide, Y. Morishita, K. Yuki, T. Sasaoka, T. Suda, M. Katsuki, et al. Ras signaling directs endothelial specification of VEGFR2+ vascular progenitor cells J. Cell Biol., April 3, 2008; 181(1): 131 - 141. [Abstract] [Full Text] [PDF] Y. Lan, B. Liu, H. Yao, F. Li, T. Weng, G. Yang, W. Li, X. Cheng, N. Mao, and X. Yang Essential Role of Endothelial Smad4 in Vascular Remodeling and Integrity Mol. Cell. Biol., November 1, 2007; 27(21): 7683 - 7692. [Abstract] [Full Text] [PDF] M. M. Bakre, A. Hoi, J. C. Y. Mong, Y. Y. Koh, K. Y. Wong, and L. W. Stanton Generation of Multipotential Mesendodermal Progenitors from Mouse Embryonic Stem Cells via Sustained Wnt Pathway Activation J. Biol. Chem., October 26, 2007; 282(43): 31703 - 31712. [Abstract] [Full Text] [PDF] A. C. White, K. J. Lavine, and D. M. Ornitz FGF9 and SHH regulate mesenchymal Vegfa expression and development of the pulmonary capillary network Development, October 15, 2007; 134(20): 3743 - 3752. [Abstract] [Full Text] [PDF] R. C. R. Perlingeiro Endoglin is required for hemangioblast and early hematopoietic development Development, August 15, 2007; 134(16): 3041 - 3048. [Abstract] [Full Text] [PDF] T. Haremaki, S. T. Fraser, Y.-M. Kuo, M. H. Baron, and D. C. Weinstein Vertebrate Ctr1 coordinates morphogenesis and progenitor cell fate and regulates embryonic stem cell differentiation PNAS, July 17, 2007; 104(29): 12029 - 12034. [Abstract] [Full Text] [PDF] A. T. Naito, I. Shiojima, H. Akazawa, K. Hidaka, T. Morisaki, A. Kikuchi, and I. Komuro Developmental stage-specific biphasic roles of Wnt/beta-catenin signaling in cardiomyogenesis and hematopoiesis PNAS, December 26, 2006; 103(52): 19812 - 19817. [Abstract] [Full Text] [PDF] M. Ema, T. Yokomizo, A. Wakamatsu, T. Terunuma, M. Yamamoto, and S. Takahashi Primitive erythropoiesis from mesodermal precursors expressing VE-cadherin, PECAM-1, Tie2, endoglin, and CD34 in the mouse embryo Blood, December 15, 2006; 108(13): 4018 - 4024. [Abstract] [Full Text] [PDF] R. C. Lindsley, J. G. Gill, M. Kyba, T. L. Murphy, and K. M. Murphy Canonical Wnt signaling is required for development of embryonic stem cell-derived mesoderm Development, October 1, 2006; 133(19): 3787 - 3796. [Abstract] [Full Text] [PDF]

	Blood Online is supported in part by Genentech BioOncology and Biogen Idec
	Copyright © 2005 by American Society of Hematology         Online ISSN: 1528-0020