A quantitative analysis of regeneration from chimaeric limb stumps in the axolotl.

We have analysed the cellular contribution and cellular displacement which occur during regeneration from chimaeric (half triploid, half diploid) lower arms in the axolotl. In general both anterior and posterior halves contribute approximately 50% of the regenerated limb cells. Deviations from equal contribution were observed only when anterior tissue was grafted, suggesting that anterior tissue is more sensitive to grafting operations. Approximately 25% of all cells in the regenerated limb were found to be displaced to the opposite side of the limb. Cellular displacement was not random; 63% of all displaced cells were found in regions adjacent to the tissue of origin.