Fig. 1

Description of early embryogenesis in O. dioica. The developmental stages included are: vegetal views of an 8 cell-stage embryo (a), a 16-cell stage embryo (b), and an embryo which has completed stage one of gastrulation (c). The gastrulation stage shown here corresponds to the transition from 32-cell to 62-cell stage. This stage is easily recognizable due to the star-like organization of the blastomeres on the vegetal surface. The nomenclature is according to the nomenclature of Conklin (see [9]). B4.1 and B5.2 are germ line precursor cells. The small B5.2 cell and the large B5.1 cells are daughter cells of the germ line precursor cell B4.1. The white asterisks mark each of the two detected refractive structures within one of the B6.4 cells. The black asterisk marks one observed refractive structure in the other B6.4 cell. The small sized germ line cell B6.4 and the larger somatic B6.3 blastomeres are sibling cells and daughter cells of the germ line precursor cell B5.2 [9, 10]. Scale bar: 50 μm