Later, the structure is found in close proximity to microtubules. Its translocation to the distal furrows is microtubule dependent. It is proposed that vasa RNA but not Vasa protein is a component of the zebrafish germ plasm. To address this question, germ plasm-positive cells were followed during early embryogenesis. In 1,000-cell stage embryos, germ plasm is still seen as a tight structure restricted to one part of the cell.
Germ plasm is localized to one side of the division plane during early cell divisions.
Most frequently, the axis of cellular division to the animal-vegetal axis is seen with the germ plasm segregated to the vegetal spindle pole. The germline-specific expression of CVH protein throughout all stages of development is demonstrated. During the early cleavages, CVH protein was restrictively localized in the basal portion of the cleavage furrow. A mouse homolog to vasa is an essential maternal determining factor for the formation of mouse germ cell precursors. Mvh encodes a DEAD-family protein that shows a much higher degree of similarity with the product of the Drosophila vasa gene than previously reported mouse genes.