TY - JOUR
T1 - Disruption of gastrulation and heparan sulfate biosynthesis in EXT1-deficient mice
AU - Lin, Xin
AU - Wei, Ge
AU - Shi, Zheng-Zheng
AU - Dryer, Laurence
AU - Esko, Jeffrey D.
AU - Wells, Dan E.
AU - Matzuk, Martin M.
N1 - Funding Information:
We thank Qiuxia Guo and Pei Wang for expert technical assistance, Drs. William Klein and Lin Gan for pLGII vector and helpful comments about this work, Dr. Richard Behringer for the Brachyury probe, and Dr. Scott Selleck for his invaluable discussions and support. This work was supported by NIH Grant HD27981 to D.E.W. and NIH Grants GM 33063 and PPG HL57345 to J.D.E.
PY - 2000/8/15
Y1 - 2000/8/15
N2 - Mutations in the EXT1 gene are responsible for human hereditary multiple exostosis type 1. The Drosophila EXT1 homologue, tout-velu, regulates Hedgehog diffusion and signaling, which play an important role in tissue patterning during both invertebrate and vertebrate development. The EXT1 protein is also required for the biosynthesis of heparan sulfate glycosaminoglycans that bind Hedgehog. In this study, we generated EXT1-deficient mice by gene targeting. EXT1 homozygous mutants fail to gastrulate and generally lack organized mesoderm and extraembryonic tissues, resulting in smaller embryos compared to normal littermates. RT-PCR analysis of markers for visceral endoderm and mesoderm development indicates the delayed and abnormal development of both of these tissues. Immunohistochemical staining revealed a visceral endoderm pattern of Indian hedgehog (Ihh) in wild-type E6.5 embryos. However, in both EXT1-deficient embryos and wild-type embryos treated with heparitinase I, Ihh failed to associate with the cells. The effect of the EXT1 deletion on heparan sulfate formation was tested by HPLC and cellular glycosyltransferase activity assays. Heparan sulfate synthesis was abolished in EXT1 -/- ES cells and decreased to less than 50% in +/- cell lines. These results indicate that EXT1 is essential for both gastrulation and heparan sulfate biosynthesis in early embryonic development. (C) 2000 Academic Press.
AB - Mutations in the EXT1 gene are responsible for human hereditary multiple exostosis type 1. The Drosophila EXT1 homologue, tout-velu, regulates Hedgehog diffusion and signaling, which play an important role in tissue patterning during both invertebrate and vertebrate development. The EXT1 protein is also required for the biosynthesis of heparan sulfate glycosaminoglycans that bind Hedgehog. In this study, we generated EXT1-deficient mice by gene targeting. EXT1 homozygous mutants fail to gastrulate and generally lack organized mesoderm and extraembryonic tissues, resulting in smaller embryos compared to normal littermates. RT-PCR analysis of markers for visceral endoderm and mesoderm development indicates the delayed and abnormal development of both of these tissues. Immunohistochemical staining revealed a visceral endoderm pattern of Indian hedgehog (Ihh) in wild-type E6.5 embryos. However, in both EXT1-deficient embryos and wild-type embryos treated with heparitinase I, Ihh failed to associate with the cells. The effect of the EXT1 deletion on heparan sulfate formation was tested by HPLC and cellular glycosyltransferase activity assays. Heparan sulfate synthesis was abolished in EXT1 -/- ES cells and decreased to less than 50% in +/- cell lines. These results indicate that EXT1 is essential for both gastrulation and heparan sulfate biosynthesis in early embryonic development. (C) 2000 Academic Press.
KW - Embryonic development
KW - EXT1
KW - Gene targeting
KW - Heparan sulfate biosynthesis
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U2 - 10.1006/dbio.2000.9798
DO - 10.1006/dbio.2000.9798
M3 - Article
C2 - 10926768
AN - SCOPUS:0034663225
SN - 0012-1606
VL - 224
SP - 299
EP - 311
JO - Developmental Biology
JF - Developmental Biology
IS - 2
ER -