Mesoderm invagination

C. Genes Regulating Mesoderm Invagination concertina, folded gastrulation, Rbo, RhoCEF... 

Pouille, P.-A Ahmadi, P. Brunet, A-C. Farge, E. Sci. Signal. 2009,2 Mechanical Signals Trigger Myosin II Redistribution and Mesoderm Invagination in Drosophila Embryos. 

The cephalic fold forms domain 10 (mesoderm) invaginates (55-62 min). 

Invagination of these cells results in formation of the mesoderm and replacement of some of the hypoblast cells to produce the definitive endoderm. 

The determination of the anlagen of different mesodermal derivatives and their morphogenesis is initiated shortly after the dorsal migration of the invaginated mesoderm has been completed (see IV.). As a result of morphological studies and the availability of early molecular markers for these derivatives, we now have a... 

Initial tinman expression occurs at cellular blastoderm in the prospective mesoderm and is confined to the trunk mesoderm where it is initally modulated in a peri-t)dic pair-rule pattern (Bodmer et ah, 1990 Azpiazu and Frasch. 1993). During invagination and dorsal migration of the mesoderm, the entire trunk mesoderm expresses tinman mRNA in a uniform pattern. However, shortly before the mesoderm reaches the dorsal border of the ectoderm, tinman expression decreases in the ventral portions and its levels increase in the dorsaimost cells of the mesoderm. Be-... 

Fig. 12.3. Stages in the development of the chick embryo, (a) Blastoderm before invagination of the mesoderm, (b) Blastoderm after the formation of the primitive streak and Henson s node, mesoderm cells forming from the epiblast. (c) Neural fold stage, (d) Differentiation of the somites into sderoderm, myotome and dermatome.

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