Re: can an 'activated'egg be injected with the nucleus from another egg?

  First off, I believe that any egg must first be activated before nuclear 
transplantation can be carried out.  This can be done in several ways, 
depnding on the organism.  Because activation begins the process of 
cleavage and maturation of the embryo, an inactivated egg will not be 
capable of responding normally after nuclear transplantation.  However, 
after activation has occurred, it IS possible to transplant a different 
nucleus into the oocyte and basically "create" a normal, healthy animal.  
This is the exact proceedure that was carried out to clone the sheep Dolly 
and her subsequent "sisters."  The current thinking is that the chromosomes 
of the donor nucleus are remodeled by the recipient oocyte, thereby erasing 
the information of the differentiated state from the donor DNA.  AS an 
example, sperm nuclei which enter an egg cell undergo very specific and 
rapid alterations to chromatin structure.  Their nuclear envolope breaks 
down, and the highly condensed sperm chromosomes rapidly decondense, 
followed by recondensation in sync with the oocyte cell cycle.  This 
mechanism could easily be the same way in which a differentiated donor 
nucleus is able to regain totipotency and contribute to formation of a 
cloned animal.  (Especially since the efficiency of nuclear transplantation 
is known to be cell cycle dependant.)  Since your question seems to be 
directed towards the recent cloning of sheep, there are several reviews and 
articles in Nature which might interest you:

Mitchell A., Nuclear transplantation.  The science of the lambs [news]., 
Nature 391 (6662): 21, 1998 Jan 1.

Stewart C., Nuclear Transplantation.  An udder way of making lambs [news]., 
Nature 385 (6619): 769, 771, 1997 Feb. 27.

Campbell KH. McWhir J. Ritchie WA. Wilmut I., Sheep cloned by nuclear 
transfer from a cultured cell line., Nature 380 (6569): 64-6, 1996 Mar. 7

Sun FZ. Moor RM., Nuclear transplantation in mammalian eggs and embryos. 
[review]., Current Topics in Developmental Biology. 30: 147-76, 1995

  Hope this helps.