ISSN:
0192-253X
Keywords:
Pattern regulation
;
cell sorting
;
transplantation
;
Life and Medical Sciences
;
Genetics
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
Notes:
In classical transplantation experiments, we have attempted to distinguish between cell sorting and position-dependent mechanisms of pattern formation during the regulation of amputated prespore regions of Dictyostelium slugs. Host and transplanted tissue were distinguished by prior labelling with 14C and 3H, and their distributions in the manipulated slugs were determined by double-label scintillation counting of serial sections of the slugs. First, we showed that the regenerated prestalk region is formed predominantly from the anterior of a prespore isolate. This disproves extreme cell sorting models, which hold that the new prestalk cells arise at random in the prespore mass, before sorting to the prestalk zone. Second, we showed that a proportion of posterior cells, which are not normally recruited into the new prestalk region, can be recruited into it if they are transplanted into the anterior of the prespore isolate. Recruitment of these cells occurs only during the first hour of regulation. We believe that these experiments prove a position-dependent mechanism of pattern formation during slug regulation. This in turn implies the existence of localized inductive signals in the regulating fragments. Although cell sorting occurs efficiently when cells are misplaced in the slug, it does not appear to play a major role in reforming the prestalk/prespore pattern.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/dvg.1020110520
