In a typical gene bombardment procedure, approximately how many cells (somatic plus gonad) per bombarded worm (the mosiac P0) will take up and express the transgene? Is it empirically related to the bombardment pressure?
When one makes a transgenic by either injection or bombardment, it typically is not the P0 that one studies. Instead if the F2 progeny inherit the array, they are considered to be stable lines. For this to happen, the DNA is magically turned into an extrachromosomal array in the shared cytoplasm of the germline, and during cellularization the hope is for the array to be captured and thus transmitted to the next generation. For it to become stable, the array must make it into the future germline cell ยง in the 1st embryonic division. For bombardment, the additional consideration is an integration event. If the array becomes integrated in the germline of the P0, then all the cells of the F1 generated from that nucleus will inherit the exogenously provided DNA, and provide it to future generations as well.
So in sum, the number of cells that get the DNA in a bombarded P0 is not what matters. What matters is the DNA getting into oocytes, and then into P, to generate stable lines.