21. First the epithelium signals the mesenchyme, then the mesenchyme induces the epithelial sheet to bud into it. 22. The mesenchyme contains all the internal organs and allows the passage of oxygen, nutrients and waste products. 23. The importance of mesenchyme -to-epithelial signaling is to maintain AMHR-II expression in the mesenchyme. 24. The importance of mesenchyme-to-epithelial signaling is to maintain AMHR-II expression in the mesenchyme . 25. The paramesonephric ducts and the mesonephric ducts share a majority of the same mesenchyme due to Hox gene expression. 26. The endoderm sends a fibroblast growth factor ( FGF ) signal to specify the notocord and the mesenchyme fates. 27. The prechordal mesenchyme proliferates laterally over the junction of the dorsal aorta and first aortic arch on each side. 28. Primary mesenchyme is the first embryonic mesenchymal tissue to emerge, and it is produced from EMT in epiblast cells. 29. Neural mesenchyme soon undergoes a mesenchyme to epithelial transition under the influence of Wnt6 produced by ectoderm to form somites. 30. Neural mesenchyme soon undergoes a mesenchyme to epithelial transition under the influence of Wnt6 produced by ectoderm to form somites.
