During embryonic development, the movement and rearrangement of cells is vital to the establishment of body axes and the differentiation of cells into their proper cell types. The ectoderm-derived neural crest cells are known for their high motility during the neuralation of vertebrate embryos, ultimately resulting in many diverse cell types arising in areas of the embryo distant from the origin of the NC cells. The characteristic transition that allows for the movement of neural crest cells, known as EMT or epithelial-to-mesenchymal transition, features the destruction of the cells’ basement membrane which anchors them to surrounding tissues and the digestion of the extracellular matrix restricting the cells. This characteristic pattern is also observed in metastasizing cancer cells, allowing them to spread rapidly to distant areas of the body.
My current gene of interest that holds a vital role in the migration of neural crest cells is the Xenopus laevis variant of MMP-14 (MT1-MMP or matrix metalloproteinase-14). The product of this gene is a transmembrane protein that acts as the primary enzyme responsible for the cleavage of type-I collagen fibers present in the extracellular matrix surrounding a cell. This protein is an endopeptidase, meaning that it digests collagen fibers by the breaking of peptide bonds within the interior of an amino acid chain between nonterminal amino acids (Christian et al. 2013).
Within Xenopus laevis, the expression of MMP-14 is primarily localized to cranial neural crest tissues, especially within rhombomeres 3 and 5 of the hindbrain (Harrison et al. 2004). Expression prior to gastrulation is fairly limited, however it features a dramatic increase from stages 8 to 14. After stage 14, which features neurulation and the specification of neural crest cells, the expression of MMP-14 increases slightly (Yanai et al. 2011).
The protein product of this gene is distinguished by its reliance on metal ions as cofactors within its active site, specifically zinc ions. This opens the opportunity of investigating the possible effects and implications of removing zinc ions using a metal chelating agent (such as EDTA) on the specification and migration of neural crest cells along with the general survivability of the embryo.
References:
Images:
http://www.xenbase.org/gene/expression.do?method=displayGenePageExpression&geneId=485642&tabId=1
My current gene of interest that holds a vital role in the migration of neural crest cells is the Xenopus laevis variant of MMP-14 (MT1-MMP or matrix metalloproteinase-14). The product of this gene is a transmembrane protein that acts as the primary enzyme responsible for the cleavage of type-I collagen fibers present in the extracellular matrix surrounding a cell. This protein is an endopeptidase, meaning that it digests collagen fibers by the breaking of peptide bonds within the interior of an amino acid chain between nonterminal amino acids (Christian et al. 2013).
Within Xenopus laevis, the expression of MMP-14 is primarily localized to cranial neural crest tissues, especially within rhombomeres 3 and 5 of the hindbrain (Harrison et al. 2004). Expression prior to gastrulation is fairly limited, however it features a dramatic increase from stages 8 to 14. After stage 14, which features neurulation and the specification of neural crest cells, the expression of MMP-14 increases slightly (Yanai et al. 2011).
The protein product of this gene is distinguished by its reliance on metal ions as cofactors within its active site, specifically zinc ions. This opens the opportunity of investigating the possible effects and implications of removing zinc ions using a metal chelating agent (such as EDTA) on the specification and migration of neural crest cells along with the general survivability of the embryo.
References:
- Christian LBW, Shuo. 2013. Extracellular metalloproteinases in neural crest development and craniofacial morphogenesis. Critical Reviews in Biochemistry and Molecular Biology 48:544-560.
- Harrison MA-E, Muhammad; Grocott, Timothy; Yates, Clara; Gavrilovic, Jelena; Wheeler, Grant. 2004. Matrix metalloproteinase genes in Xenopus development Developmental Dynamics 231:214-220.
- Yanai IP, Leonid; Jorgensen, Paul; Kirchner, Marc W. 2011. Mapping gene expression in two Xenopus species: evolutionary constraints and developmental flexibility Developmental Cell 20:483-496.
Images:
http://www.xenbase.org/gene/expression.do?method=displayGenePageExpression&geneId=485642&tabId=1