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Tracking Periocular Mesenchyme (POM) Development with Gli1‐CreERT2; tdTomato flox Labeled Cells in Mice
Author(s) -
Svoboda Kathy K. H.,
Zhao Hu,
Petroll Matthew
Publication year - 2018
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2018.32.1_supplement.776.4
Subject(s) - mesenchyme , pax6 , eye development , biology , trabecular meshwork , anatomy , microbiology and biotechnology , sonic hedgehog , neural crest , cornea , ciliary body , mesenchymal stem cell , transcription factor , glaucoma , signal transduction , neuroscience , gene , genetics , embryo
The periocular mesenchyme (POM) cells contribute to the development of the ciliary body, trabecular meshwork and the iridocorneal angle. It is known that cells expressing the Sonic hedgehog signaling pathway play a key role in anterior eye development. This pathway is mediated by the Gli transcription factors (Gli1, Gli2, and Gli3) that deferentially activate and repress the expression of specific eye development genes (Pax6, Pax2 and Vax1). The objective of this project was to determine if Gli1 positive cells contribute to the POM and anterior eye structures by using inducible Gli1‐CreERT2; tdTomato flox mouse model, and thus could serve as a new probe for studying anterior eye development. The Gli1 marker produced a protein that fluorescently labeled cells from a mesenchymal or mesodermal origin, and did not label the neural crest cells. Transgenic mice using a Gli1‐Cre‐ERT2;Rosa26‐tdTomato flox construct were bred. The tdtomato fluorescence was induced at specific developmental stages with tamoxifen and cells tracked. Eyes from mice that were induced on post‐natal day 3 or 7, and sacrificed on day P10 were examined with confocal microscopy on frozen sections and whole mounts to determine the spatial distribution of the cells derived from Gli1+ progenitors. We found that the labeled cells were in the optic nerve head and tissues surrounding the eye, called the periocular mesenchyme (POM). The labeled cells appeared to be migrating into the tissues between the peripheral cornea and the anterior retina. This area is where the ciliary body, trabecular meshwork and the iridocorneal angle develops. In contrast, the cornea and sclera did not show any positive cells. In conclusion, this new inducible Gli1‐CreERT2; tdTomato flox mouse model appears to be an excellent system for determining the role of periocular mesenchyme in anterior eye development. The elegance of this model is it can be activated at specific developmental stages and Gli1+ cells derivatives can be tracked and other detection probes (EDU, GFPCol1, calcein, nuclear stains, etc), can be incorporated to determine cell division, collagen expression, bone deposition and over all tissue structure. Our initial results suggest that POM cells may be contributing to the development of the anterior angle chamber that forms between P4–P10. Support or Funding Information The Department of Biomedical Sciences, Texas A&M College of Dentistry.Frozen section of the anterior eye angle from a mouse treated with tamoxifen on P7 and sacrificed on P10. The Gli1 positive cells (red) are in the mesenchyme area. Nuclei in other eye structures are labeled with DAPI (green). The lens was displaced in processing.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .