Skip to main content
Fig. 4 | BMC Biology

Fig. 4

From: From spiral cleavage to bilateral symmetry: the developmental cell lineage of the annelid brain

Fig. 4

The developmental origin of the accessory prototroch cells and the cells in the apical organ. a The overview of the development of the apical rosette (1m-111, orange dashed line) and the primary (1m-2, yellow) and accessory (1m-12, pink) prototroch cells at 5, 8, and 30 hpf. b Schematic diagram showing the lineage origin of the prototroch cells. Only the 1a quadrant lineage tree is shown here for simplicity. The cells in the scheme are color-coded by their quadrant of origin. The black dashed lines indicate sister cells. Each quadrant contributes three primary prototroch cells (1m-221, 1m-222, 1m-212) and three accessory prototroch cells (1m-211—a sister cell of one of the primary prototroch cells, 1m-1212 and 1m-122). The only exception is the 1d quadrant producing only two accessory prototroch cells, due to the migration of the 1d-121 clone out of the episphere (see main text for details). Note that the triplet of the accessory prototroch cells originating from a given quadrant does not associate with the triplet of the primary prototroch cells of the same quadrant, but is rotated by one cell counter-clockwise. c A detailed scheme of the lineage origin of the apical organ cells

Back to article page