An autoradiography study of myogenic cell movement in avian limb buds following heterospecific and homospecific transplantation.

Species specificity and the use of quail cells as a marker in the study of myogenic cell movement in the developing avian limb was investigated. In order to establish whether or not observed myogenic cell movement in quail/chick limb transplantation experiments might be an artefact produced by cellular interaction between these cell types a series of homospecific and heterospecific transplantations was performed. Chick wing fragments (staged 20-25 H.H.) were labelled with tritiated thymidine and inserted into unlabelled chick wing bud (homospecific) in ovo. In addition, quail wing fragments were also labelled with tritiated thymidine and transplanted in the same manner into chick (heterospecific), so that the effectiveness of tritium as a marker could be assessed. After 4 days post-incubation, myogenic cell movement was detected in eight out of the ten homospecific transplantations performed. Myogenic cell movement in avian limbs is therefore not produced by interaction between chick and quail cells, as migration was also detected in the chick/chick transplants. Nonetheless, heterospecific transplantation results revealed that autoradiographic methods failed to reveal completely the true extent to which myogenic cell movement occurred, because tritiated thymidine was subject to dilution.