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 ?
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).
Although diagrams of sea urchin cell lineage are presented with clear lines distinguishing germ layer boundaries, variation occurs in normal embryos.
First, the ball of generalized cells separates into three different cell lines, called germ layers, which will become different systems of the body.
Endoderm is the innermost of the three primary developmental germ layers, and develops into the gastrointestinal tract, including the major cells of the liver and pancreas, respiratory tracts of the lungs, other endocrine glands and organs, such as the thyroid and thymus glands, the major cells of the kidney and the auditory and urinary systems.
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.
In humans, embryonic stem cells differentiate into three families, or germ layers, of cells.
They are composed of multiple cell types derived from one or more of the three germ layers.
Ovarian teratomas present unique histological features, as tissues derived from more than one of the three germ layers are present, including neural tissue, adipose tissue, bone, teeth, and respiratory epithelium.
The histopathology report was mature GT composed of tissues derived from all three germ layers.
Magnesium intake reportedly declined from a high of 500 mg per day in 1900 to just 175 mg to 225 mg per day today, attributed to grain processing that removes the magnesium-rich bran and germ layers and to fast food menus that are typically deficient in magnesium-rich vegetables, whole grains and legumes.
During gastrulation, the embryo folds inwards into a cup-like shape, forming the primary germ layers that give rise to all the organs in the body.
It contains structures which are derivatives of all three germ layers.