Mesenchyme in Vertebrates
- Mesenchyme is characterized by a ground substance matrix with reticular fibers and mesenchymal stem cells.
- Mesenchymal cells can migrate easily compared to epithelial cells.
- Mesenchyme originates from the mesoderm.
- Mesenchyme develops into lymphatic and circulatory systems, as well as the musculoskeletal system.
- Mesenchymal cells can give rise to sarcomas.

Epithelial-Mesenchymal Transition (EMT)
- Mesenchyme emerges from the epithelial-mesenchymal transition (EMT) process.
- EMT involves the loss of epithelial cadherin and tight junctions.
- Mesenchyme can migrate along the extracellular matrix (ECM).
- Protein S100-A4 and c-Fos are expressed in embryological mesenchymal cells.
- Wnt/β-catenin pathway is involved in the formation of the primitive streak and mesenchymal tissue.
- EMT is activated by c-Fos estrogen receptor activation.
- EMT involves nuclear translocation of beta-catenin.
- EMT leads to upregulation of beta-catenin/lymphoid enhancer binding factor-1 transcriptional activity.
- EMT is orchestrated by complex networks.
- EMT is a process that involves the transformation of epithelial cells into mesenchymal cells.

Mesenchyme in Embryonic Development
- Extra-embryonic cells of the trophectoderm undergo EMT to form mesenchyme.
- These cells migrate into the endometrial layer of the uterus to contribute to placenta formation.
- Primary mesenchyme is the first embryonic mesenchymal tissue to emerge.
- WNT3 is essential for the formation of primary mesenchyme.
- Deficiencies in signaling pathways like Nodal can lead to defective mesoderm formation.
- Neural mesenchyme forms after primary mesenchyme formation.
- It is induced by ectoderm and somite-forming morphogenic factors.
- Neural mesenchyme undergoes a mesenchymal-epithelial transition to form somites.
- Neural crest cells (NCCs) form from neuroectoderm and undergo EMT.
- NCCs migrate throughout the body to form peripheral nervous system cells and melanocytes.

Mesenchyme in Invertebrates
- In some invertebrates, mesenchyme refers to a loosely organized tissue between the epidermis and gastrodermis.
- Mesenchyme in sponges is called mesohyl.
- In diploblasts, mesenchyme is fully ectodermally derived and called ectomesodermal.
- Triploblastic acoelomates have mesenchyme derived from both ectoderm and entomesoderm.
- Mesenchyme in cnidarians may be called collenchyma or parenchyma depending on cellular material.

Mesenchymal Cell Signaling
- Mesenchymal cells exhibit remarkable signaling mechanisms.
- The mesenchymal cell plays a crucial role in embryonic development.
- Mesenchymal stem cells can differentiate into neural cells.
- Neural differentiation of mesenchymal stem cells involves the expression of neural markers.
- Eag K+ channel types are expressed in neural-differentiated mesenchymal stem cells.

Primitive Streak Formation
- Beta-catenin signaling marks the prospective site of primitive streak formation in mouse embryos.
- The primitive streak is an important structure in embryonic development.
- The formation of the primitive streak is crucial for gastrulation.
- The primitive streak is involved in the establishment of the three germ layers.
- The primitive streak plays a role in determining body axis formation.

Segmental Plate Mesoderm and Somite Formation
- Wnt 6 regulates the epithelialization process of the segmental plate mesoderm.
- Somite formation is influenced by the epithelialization process of the segmental plate mesoderm.
- The segmental plate mesoderm gives rise to somites.
- Somites are important structures in vertebrate development.
- Avian somite development involves complex molecular and cellular processes.

Neural Crest Cell Formation and Migration
- Neural crest cells are formed during embryonic development.
- Neural crest cells migrate to various locations in the embryo.
- Neural crest cell formation and migration are crucial for the development of the peripheral nervous system.
- Neural crest cells give rise to a variety of cell types, including neurons and glial cells.
- Neural crest cell specification and migration are tightly regulated processes.

Mesenchyme (Wikipedia)

"Mucoid" redirects here. For the Ninjago characters, see Mucoids.

Mesenchyme (/ˈmɛsənkaɪm ˈmiːzən-/) is a type of loosely organized animal embryonic connective tissue of undifferentiated cells that give rise to most tissues, such as skin, blood or bone. The interactions between mesenchyme and epithelium help to form nearly every organ in the developing embryo.

Mesenchyme
Transmission electron micrograph of mesenchyme displaying the ultrastructure of a typical cell and matrix.
Mesenchyme (pointer) stained with H&E
Details
Carnegie stage	6b
Precursor	lateral mesoderm
Identifiers
TE	E5.16.4.0.3.0.18
Anatomical terminology [edit on Wikidata]