1. Postimplantation Mga expression and embryonic lethality of two gene-trap alleles
- Author
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Andrew J. Washkowitz, Virginia E. Papaioannou, Svetlana Gavrilov, and Sally F. Burn
- Subjects
0301 basic medicine ,Organogenesis ,Embryonic Development ,Biology ,Article ,03 medical and health sciences ,Mice ,0302 clinical medicine ,Genetics ,medicine ,Basic Helix-Loop-Helix Transcription Factors ,Inner cell mass ,Animals ,Blastocyst ,Embryo Implantation ,Progenitor cell ,Molecular Biology ,Transcription factor ,Alleles ,Cells, Cultured ,Embryonic Stem Cells ,Gene Expression Regulation, Developmental ,Embryo ,Embryo, Mammalian ,Embryonic stem cell ,Cell biology ,030104 developmental biology ,medicine.anatomical_structure ,Epiblast ,embryonic structures ,Embryo Loss ,Female ,030217 neurology & neurosurgery ,Developmental Biology ,Transcription Factors - Abstract
Background The dual-specificity T-box/basic helix-loop-helix leucine zipper transcription factor MGA is part of the MAX-interacting network of proteins. In the mouse, MGA is necessary for the survival of the pluripotent epiblast cells of the peri-implantation embryo and a null, gene-trap allele MgaGt results in embryonic lethality shortly after implantation. We have used this allele to document expression of Mga in postimplantation embryos and also investigated a second, hypomorphic gene-trap allele, MgaInv. Results Compound heterozygotes, MgaGt/MgaInv, die prior to midgestation. The extraembryonic portion of the embryos appears to develop relatively normally while the embryonic portion, including the pluripotent cells of the epiblast, is severely retarded by E7.5. Mga expression is initially limited to the pluripotent inner cell mass of the blastocyst and epiblast, but during organogenesis it is widely expressed, notably in the central nervous system and sensory organs, reproductive and excretory systems, heart, somites and limbs. Conclusions Widespread yet specific areas of expression of Mga during organogenesis raise the possibility that the transcription factor may play roles in controlling proliferation and potency in the progenitor cell populations of different organ systems. Documentation of these patterns sets the stage for the investigation of specific progenitor cell types. more...
- Published
- 2017