SRG3, a core component of mouse SWI/SNF complex, is essential for extra-embryonic vascular development

• DOI: 10.1016/j.ydbio.2007.12.024
• Publication Date: 2007-12-28T15:51:33Z
• Authors: Daehee Han; Shin Jeon; Dong Hyun Sohn; Changjin Lee; Sangil Ahn; Won Kyu Kim; Heekyoung Chung; Rho Hyun Seong
• Keywords: Vascular Endothelial Growth Factor A; Transgene-rescue; Chromosomal Proteins, Non-Histone; Embryonic Development; Neovascularization, Physiologic; Mice, Transgenic; SRG3; Visceral endoderm; Mice; 03 medical and health sciences; Angiopoietin-1; Animals; Transgenes; Molecular Biology; Yolk Sac; 0303 health sciences; Models, Genetic; Gene Expression Regulation, Developmental; Cell Biology; Embryo, Mammalian; Immunohistochemistry; Specific Pathogen-Free Organisms; Platelet Endothelial Cell Adhesion Molecule-1; Blood Vessels; Blood vessel; Angiogenesis; SWI/SNF complex; Yolk sac; Developmental Biology; Transcription Factors

The SWI/SNF chromatin-remodeling complex functions as a transcriptional regulator and plays a significant role in cell proliferation, differentiation and embryonic development. SRG3, a homologue of human BAF155, is a core component of the mouse SWI/SNF chromatin remodeling complex. Mutant mice deficient in Srg3 expression are peri-implantation lethal. To investigate the role of SRG3 in the post-implantation stage, we generated SRG3 transgene-rescued (Srg3-/-Tg+) embryos by inducing exogenous gene expression. These Srg3-/-Tg+ embryos overcame early embryonic lethality and extended the life span until mid-gestation. However, the embryos displayed significant defects in blood vessel formation and fetal circulation within the yolk sac around embryonic day 10.5, which led to developmental retardation and death. We found that SRG3 expression was absent in the visceral endoderm of Srg3-/-Tg+ yolk sacs, while SRG3 was normally expressed in wild-type embryos. In addition, expression of angiogenesis-related genes, including Angiopoietin1, Tie2, EphrinB2, Ihh and Notch1, was markedly reduced in Srg3-/-Tg+ yolk sacs. During normal angiogenesis, maturation of the visceral endoderm development is observed in the yolk sac. However, in Srg3-/-Tg+ yolk sacs, the visceral endoderm did not develop normally. Our results indicate that SRG3 is required for angiogenesis and visceral endoderm development in the yolk sac.