[CITATION][C] Migration patterns of the precardiac mesoderm in the early chick embryo

RL DeHaan - Experimental Cell Research, 1963 - Elsevier
RL DeHaan
Experimental Cell Research, 1963Elsevier
This concept received major support with the development of techniques for dissociating
embryonic tissues [27, 37, 561 and the discovery that reaggregates of such dissociated cells
were capable of reorganizing themselves by a combination of active random cell
movements and selective intercellular adhesion [35, 47, 48]. In addition, the use of time-
lapse microcinematography on living systems has made it feasible to observe and carefully
analyze the movements and behavioral interactions of individual cells and small cell groups …
This concept received major support with the development of techniques for dissociating embryonic tissues [27, 37, 561 and the discovery that reaggregates of such dissociated cells were capable of reorganizing themselves by a combination of active random cell movements and selective intercellular adhesion [35, 47, 48]. In addition, the use of time-lapse microcinematography on living systems has made it feasible to observe and carefully analyze the movements and behavioral interactions of individual cells and small cell groups in vitro (eg,[1, 2, 31) and in the intact embryo [13, 22, 23, 381.
An analysis of the initial processes of cardiogenesis has recently been completed utilizing time-lapse cinematography on early chick embryos in culture [15, 16]. The movements and changes of topographical configuration of the mesodermal heart-forming regions were described for the period from stage 5 to stage 10 (Hamburger-Hamilton series,[24!). In brief, it was shown in this work that the precardiac material is present at stage 5 (headprocess stage), as a pair of indistinct regions in the lateral mesoderm on each side of the forming notochord. These cell masses arrange themselves into a crescent-shaped cardiogenic plate by stage 6 to 7, and then, some 10 hr later, form the median primitive tubular heart, ready to begin pulsating at stage 10. It was further noted that the cardiogenic mesoderm is composed of small groups or clusters of cells which appeared to migrate actively and independently of each other. These clusters frequently maintain their integrity during the entire period of observation, and can be identified and" tracked" in their movements from their initial site in the lateral heartforming regions to the time they are lost in the opacity of the forming tubular heart. In this migration, as will be seen, at least two types of motile behavior are involved: the folding movements of the endoderm, and intrinsic mass cell movements of the precardiac mesoderm. Several specific questions appear pertinent to these observations.(1) Is there any correlation between the position of a cell in the lateral heart-forming region at the head-process stage, and the position it takes up later in the tubular heart; that is, is there a spatial preorganization or prepattern in the heart-forming mesoderm?(2) Do these cell clusters move of their own volition, or are they carried by the folding substratum of endoderm with which they are normally in contact?
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