Genetic marking of hematopoietic stem and endothelial cells: identification of the Tmtsp gene encoding a novel cell surface protein with the thrombospondin-1 domain.
Using an in silico database search, we identified a novel gene encoding a cell surface molecule with a thrombospondin domain, and designated the gene as transmembrane molecule with thrombospondin module (Tmtsp). Expression profiling of Tmtsp using specific monoclonal antibodies and Venus, a variant of yellow fluorescent protein knock-in mice in the Tmtsp locus, demonstrated its specific expression in hematopoietic and endothelial cells. In lymphohematopoietic cells, Tmtsp was predominantly expressed in hematopoietic stem and progenitor cells, and the level of expression gradually declined as the cells differentiated. Venus expression faithfully traced the expression of Tmtsp, and the level of Venus expression correlated well to the in vitro hematopoietic activity as well as the in vivo bone marrow repopulating capacity. Notably, Venus expression marked the development of definitive hematopoiesis in both the extraembryonic yolk sac and the intraembryonic aorta-gonad-mesonephros (AGM) region and, in combination with CD41, strikingly promoted the enrichment of developing progenitors in the CD41(+)Venus(high) fraction at embryonic day 10.5 (E10.5). In this context, Tmtsp is a novel marker gene for primitive hematopoietic cells and endothelial cells, and Tmtsp(Venus/)(+) mice would serve as a valuable mouse model for the analysis of both embryonic and adult hematopoiesis, as well as for vascular biology.
Takayanagi
Shin-ichiro
S
Laboratory of Stem Cell Therapy, Center for Experimental Medicine, University of Tokyo, Japan.
Hiroyama
Takashi
T
Yamazaki
Satoshi
S
Nakajima
Tomoko
T
Morita
Yohei
Y
Usui
Joichi
J
Eto
Koji
K
Motohashi
Tsutomu
T
Shiomi
Kensuke
K
Keino-Masu
Kazuko
K
Masu
Masayuki
M
Oike
Yuichi
Y
Mori
Shigeo
S
Yoshida
Nobuaki
N
Iwama
Atsushi
A
Nakauchi
Hiromitsu
H
D000595:Amino Acid Sequence; D000818:Animals; D001853:Bone Marrow / Q000502:physiology; D004622:Embryo, Mammalian / Q000166:cytology; D042783:Endothelial Cells / Q000737:chemistry*; D015723:Gene Library; D005819:Genetic Markers; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells / Q000737:chemistry*; D006801:Humans; D008565:Membrane Proteins; D051379:Mice; D008969:Molecular Sequence Data; D013154:Spleen; D019700:Thrombospondin 1 / Q000032:analysis / Q000737:chemistry / Q000235:genetics; D019699:Thrombospondins / Q000032:analysis / Q000737:chemistry / Q000235:genetics*; D014018:Tissue Distribution
D005819:Genetic Markers; D008565:Membrane Proteins; C511241:THSD1 protein, human; D019700:Thrombospondin 1; D019699:Thrombospondins; C511242:Tmtsp protein, mouse