1: Dev Biol. 1998 May 15;197(2):248-69. 

The cloche and spadetail genes differentially affect hematopoiesis and
vasculogenesis.

Thompson MA, Ransom DG, Pratt SJ, MacLennan H, Kieran MW, Detrich HW 3rd, Vail
B, Huber TL, Paw B, Brownlie AJ, Oates AC, Fritz A, Gates MA, Amores A, Bahary
N, Talbot WS, Her H, Beier DR, Postlethwait JH, Zon LI.

Howard Hughes Medical Institute, Children's Hospital, Boston, Massachusetts
02115, USA.

In vertebrates, hematopoietic and vascular progenitors develop from ventral
mesoderm. The first primitive wave of hematopoiesis yields embryonic red blood
cells, whereas progenitor cells of subsequent definitive waves form all
hematopoietic cell lineages. In this report we examine the development of
hematopoietic and vasculogenic cells in normal zebrafish and characterize
defects in cloche and spadetail mutant embryos. The zebrafish homologs of lmo2,
c-myb, fli1, flk1, and flt4 have been cloned and characterized in this study.
Expression of these genes identifies embryonic regions that contain
hematopoietic and vascular progenitor cells. The expression of c-myb also
identifies definitive hematopoietic cells in the ventral wall of the dorsal
aorta. Analysis of b316 mutant embryos that carry a deletion of the c-myb gene
demonstrates that c-myb is not required for primitive erythropoiesis in
zebrafish even though it is expressed in these cells. Both cloche and spadetail
mutant embryos have defects in primitive hematopoiesis and definitive
hematopoiesis. The cloche mutants also have significant decreases in vascular
gene expression, whereas spadetail mutants expressed normal levels of these
genes. These studies demonstrate that the molecular mechanisms that regulate
hematopoiesis and vasculogenesis have been conserved throughout vertebrate
evolution and the clo and spt genes are key regulators of these programs.

PMID: 9630750 [PubMed - indexed for MEDLINE]


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