Blair S S
Dev Biol. 1983 Jan;95(1):65-72. doi: 10.1016/0012-1606(83)90007-6.
Ablation of different identifiable blastomeres of the early embryo of the leech Helobdella triserialis was found to lead to the absence of different sets of segmentally iterated monoamine-containing neurons in subsequent development. Thus the ablation of one of the paired N ectoteloblasts leads to the absence of one member of each of the three bilateral pairs of serotonin-containing neurons (one of which is the Retzius cell) from each segmental ganglion. The ablation of one of the paired OP blastomeres (precursors of the paired O and P ectoteloblasts) leads to the absence of one member of each of the two bilateral pairs of lateral dopamine-containing neurons that lie in the body wall of each segment. And the ablation of one of the paired Q ectoteloblast leads to the absence of one member of the bilateral pair of medial dopamine-containing neurons that lie in the body wall of each segment. These results suggest that each of these sets of monoamine-containing neurons is derived from a particular blastomere. Upon ablation of that blastomere the set does not develop from any other source.
人们发现，切除三带盾蛭早期胚胎中不同的可识别卵裂球，会导致后续发育过程中不同组的节段重复含单胺神经元缺失。因此，切除一对N外胚层母细胞中的一个，会导致每个节段神经节中三对含5-羟色胺神经元（其中一对是雷祖斯细胞）的每一对中的一个缺失。切除一对OP卵裂球（成对的O和P外胚层母细胞的前体）中的一个，会导致位于每个节段体壁中的两对含外侧多巴胺神经元的每一对中的一个缺失。切除一对Q外胚层母细胞中的一个，会导致位于每个节段体壁中的一对含内侧多巴胺神经元中的一个缺失。这些结果表明，这些含单胺神经元组中的每一组都源自特定的卵裂球。切除该卵裂球后，该组神经元不会从任何其他来源发育而来。
