To answer your question, it does not appear
to be possible to insert the somatic nucleus of
an animal into the egg of an animal of a
different species and generate a live clone.
The reason for this is that development of an
embryo is an incredibly sensitive process even
in regards to naturally occurring
fertilization. When an embryo initially begins
to divide, many proteins present in the egg are
responsible for ensuring that cell division
occurs properly and that those cells begin to
express the correct genes at the correct
When development begins, cells must
differentiate from being a general cell type, to
a specific tissue that only expresses a small
number of the genes present in the nucleus.
This happens early, and is stimulated by signals
already present inside the original egg. For
this to work, the proteins present in the egg
must recognize specific sequences found in the
DNA of the nucleus. In the case of cloning, the
DNA being inserted into the egg must come from
the same species, or the proteins inside the egg
won’t recognize the sequences they are supposed
to interact with. Imagine that the DNA of each
animal is a set of instructions for the creation
of that animal, and each is written in a unique
language that only animals of that species can
understand. For example, if you were a protein
in the egg and the only language you knew was
English, it would be pretty hard to put together
an animal whose instructions were written in
Japanese. Essentially, if you put the nucleus
of one species into the egg of another species,
the proteins in the egg won’t understand how to
read the DNA instructions that tell it how to
put the new animal together.
Also, there is a second set of DNA inside the
egg called “mitochondrial DNA”. This DNA is
always inherited directly from the mother and
encodes another special set of genes that are
involved in generating energy for the cell.
This DNA must also match the species that the
nucleus comes from or the cell will have
difficulties creating energy, and without energy
the cell can’t survive.
Even when using an egg from the same species,
cloning is a very difficult process with a very
low success rate because of all the problems
that arise from using a differentiated nucleus
to create all the tissue types in the body.
When scientists cloned Dolly the sheep click here in dolly
they had to
generate 98 embryos to get 16 that were able to
divide into a multicellular embryo, of these
only 8 developed into fetuses and only 1 (Dolly)
survived more than a few days after being born.
So you can see that even when using the same
species for the egg and nuclear DNA, cloning is
still an imperfect process that requires many
attempts to actually work. Hope that helped!