[9] The surface molecules undergo endocytosis and the microtubule cytoskeleton loses shape, enabling mesenchyme to migrate along the extracellular matrix (ECM).

[14] Specific markers of mesenchymal tissue include the additional expression of ECM factors such as fibronectin and vitronectin.

These migrate from the body of the blastocyst into the endometrial layer of the uterus in order to contribute to the formation of the anchored placenta.

In the epiblast, it is induced by the primitive streak through Wnt signaling, and produces endoderm and mesoderm from a transitory tissue called mesendoderm during the process of gastrulation.

The EMT occurs as a result of Wnt signaling, the influence of Sox genes and the loss of E-cadherin from the cell surface.

NCCs ingress into the embryo from the epithelial neuroectodermal layer and migrate throughout the body in order form multiple peripheral nervous system (PNS) cells and melanocytes.

[22][23] In some invertebrates, such as Porifera, Cnidaria, Ctenophora, and some triploblasts (namely the acoelomates), the term "mesenchyme" refers to a more-or-less solid but loosely organized tissue that consists of a gel matrix (the mesoglea) with various cellular and fibrous inclusions, located between the epidermis and the gastrodermis (non-triploblast animals usually are considered to lack "connective" tissue).

[24] When cellular material is sparse or densely packed, as in cnidarians, the mesenchyme may sometimes be called collenchyma, or parenchyma in flatworms.