Question about transgenic mice and lethal mutation

[perrinekkk]

Hi,

I have a question that tickles me: imagine a mutation that's lethal when it's expressed homozygously. To comprehend in vivo the mechanism of the mutation, i'll try to obtain heterozygous mice. But will the chimeric mouse obtained after electroporation of the vector and homologous recombination be viable? If the mutation is expressed in the germinal cells (which i want, to go on with the protocol), will the mouse be fertile and able to procreate the heterozygous mice i wanted? Here an image to illustrate the question:

Thank you!