- [Narrator] This cat is a clone.
- [Kelly] I just wanted to carry on a piece of Chi.
I never wanted to bring her back from the dead.
And Bell is literally a piece of her.
They share the same genetic makeup.
- [Narrator] When Chi, a young cream bicolor Ragdoll cat,
died unexpectedly, Kelly Anderson sent skin samples
to a company in Texas to make a genetic replica of her cat.
But genes may be the only thing
these two cats have in common.
- Just couldn't be any more different.
Definitely more outgoing,
more comfortable around people and other animals.
Everything that Chi never had the chance to be.
- [Narrator] Cloning has come a long way
since Dolly the sheep was born in 1996,
cloned from a cell of a mammary gland
of a six year old female sheep.
And it's not just house pets that are being cloned now.
Cows, pigs, even horses have been cloned.
Cloned animals are used in agriculture,
primarily for breeding,
to increase preferred characteristics in a herd.
And scientist hope reproductive cloning
may one day even help bring back endangered species.
But like with Chi and Bell,
personality isn't always inherited.
Scientists don't fully understand the role of genes
in forming personality.
- [Robert] The evidence suggests that many things about us
are in fact cognitively half genetic and half other stuff,
environment, rearing, et cetera.
- [Narrator] And like humans, animal's personalities
are shaped by lived experience.
But some high performing animals,
like police dogs or prized polo ponies,
may pass on some abilities to their clones.
- [Katrin] Part of their behavior
could be innate in their DNA,
but part of it could also be how they responded
to how they were trained.
I talked to some horse breeders once that said,
"Well, we actually have an advantage if we have a clone foal
and we know the original horse,
because we now know this foal has the potential
to be a champion and we will do everything we can
for this foal."
And so, that's a concept too.
They could theoretically be better than the original.
- [Narrator] Clone means copy.
In invertebrates, cloning is done
by basically swapping the nucleus of a mature egg cell
with that of a desired animal from the same species.
- It is actually very incredible that this works.
- [Narrator] But there are still a number of challenges
to this kind of research.
For one, the success rate is pretty low.
- [Jose] In most cases, it's about 20%.
So, you still have to transfer five cows
to get a one healthy calf.
You actually may get good pregnancy rate,
but then the the losses are
at the beginning of the pregnancy.
And then, you get some losses right before birth
or sometimes the animals are born, but they don't survive.
They don't thrive.
- [Narrator] It starts with the nucleus,
the part of the cell that contains the genetic instructions
for building an operating organism.
Packaged in the form of chromosomes.
- [Katrin] You get a mature oocyte
that knows how to make an embryo,
take its chromosomes out, put the chromosomes
from a cell of your donor animal in,
and then you give it a signal you've been fertilized.
And off the oocyte goes working
with these chromosomes to make an embryo.
- [Narrator] Cells located just under the skin
are commonly used in cloning,
because they're fairly easy to collect.
But they're not the only kinds of cells used.
- [Jose] Animals have been clone
from all types of cell types in the body.
Practically people have tried everything
and everything seems to work at different efficiencies.
- [Narrator] And in theory, this works
because every cell in your body has the same DNA,
but they just don't all use every part of it.
- [Katrin] Like if you had a huge blueprint
for a 200 story building.
You're plumbing the bathroom on the Northeast corner
of the 148th floor,
you go through the blueprint.
You find out where the instructions for doing that.
- [Narrator] So to produce a clone,
those signals that tell the cell
which part of the DNA to use need to be reprogrammed.
- [Jose] We're still working on how
to remove all the proteins that are around the chromosomes
to erase the memory of the original cell.
That we need to make sure that the memory is erased.
And then, we can reestablish
a memory that is unique for an embryo.
- [Narrator] Once new genetic information is in the egg,
scientists try to coax the cell to become an embryo
in the lab.
If that works, it's implanted into the womb of a female,
usually of the same species.
One of the most common complications with producing a clone
has to do with the development of the placenta.
- [Jose] And when placenta is now properly formed,
you get issues that are complications
in the cardiovascular system of the fetus.
- You'd think that that making an embryo,
making the individual is the hard part
but there's certain aspects of how genes
are turned on and off in the placenta
that makes it even more difficult
for the oocyte to get it right.
- [Narrator] Because of some of the complications,
it might take a number of attempts
to produce a single healthy clone.
And the burden place on other animals
during cloning procedures
and during pregnancy raises ethical concerns.
- [Robert] Whether it's with horses or dogs or cats,
maybe half will die at birth or shortly after birth.
And they have major deformities
and they're gonna suffer.
Problems also rise
because to make 30 or 40 or 50 cats pregnant
also put strain on those cats.
So, pregnancy is not a benign endeavor
for a human or for a cat.
So, it's definitely putting a burden
on a lot of different animals
to produce one take home healthy animal.
- [Narrator] And private companies
that offer cloning services of pets
aren't always transparent about success rates.
- [Robert] So, I understand people's attachment to animals
but I think we need to be concerned
about what kind of risks and strains
we're putting on the animals.
And I think there's an ethical concern
that comes up given that there are millions of cats
and dogs that are available for adoption every day.
(mellow music)