germ layer


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Related to germ layer: germ layer theory

germ layer

[′jərm ‚lā·ər]
(embryology)
One of the primitive cell layers which appear in the early animal embryo and from which the embryo body is constructed.
References in periodicals archive ?
It is likely that these tumors are the result of improper regulation of pluripotency in which reacquisition of epiblast-like pluripotency during improper PGC specification results in cells that attempt to recapitulate embryonic development, including creation of the three germ layers. Cells in teratomas may not, however, receive the very specific spatial and temporal differentiation cues needed for proper embryogenesis, resulting in disorganized development.
(A) In utero exposure to BaP induced a significant dose-dependent increase in mutant frequencies in somatic tissues originating from distinct primary germ layers, including the bone marrow (mesoderm), brain (ectoderm), and liver (endoderm).
(b) EB formation and spontaneous differentiation of reprogrammed cells into cells of the three germ layers by VPA in normoxia (5 mg/mL).
Our results do not allow us to determine which of these features best explains the shift in germ layer allocation we observed.
In this stage, ESCs or IPSCs maintain pluripotency and EB-like masses harbor three germ layers (ectoderm, mesoderm, and endoderm).
Embryonic stem cells (ESCs) are pluripotent cells, that is, they possess an infinite self-renewal potential and can differentiate into cells of all three germ layers (ectoderm, endoderm, and mesoderm) and the germline, ultimately contributing to all lineages of the mature organism [8].
No one has yet been able to induce the cells to form the three distinct germ layers, in the correct order: endoderm on the inside, mesoderm in the middle and ectoderm on the outside.
A more recent elaborate definition, perhaps more appropriate is an encapsulated tumor with tissue or organ components that can be traced to derivatives of the three primordial germ layers; ectoderm, mesoderm, and endoderm.
Mesoderm and endoderm are two of the three primary early precursors, "germ layers," which develop into all of the non-neuronal cells of the body.
miRNA-335, a messenger nucleic acid, regulates the endodermal transcription factors Sox 17 and Foxa2 and is essential for the differentiation of cells within this germ layer and their demarcation from the adjacent mesoderm.
This facilitates the switch from the mesenchymal to the ectodermal germ layer gene expression [52].
In the current study, we provide proof of the concept that plucked human hair-derived iPSCs are highly potent in their capacity to commit not only towards mesoderm [3]and neuroectoderm [25] but also towards the endodermal germ layer, particularly definitive endoderm.