 |
| Panhandle Slim Clones - Photo courtesy of Scott Accomazzo |
Clones are not common in the bucking bull world, but with the appearance of the Panhandle Slim clones on the PBR Built Ford Tough tour, and the amount of controversy they have created in the bucking bull industry, it's worth talking about them. So this week's feature is a series on clones and cloning, beginning with the question that's fundamental to the issue: How you make a baby without a sperm and an egg? The short answer? You do need the egg.
Here, in a very simplified form, is how it’s done.
1. The genetic material (DNA) is removed from an unfertilized donor egg.
2. It is replaced with a fibroblast cell from the animal that is being cloned (sometimes called the founder animal). This cell contains the DNA of the founder animal. (Fibroblasts are a kind of stem cell. The cell used from the founder animal is not a sperm cell.)
3. So far we just have a donor cell in a donor egg. To turn it into an embryo, an electrical stimulus is applied to fuse the nucleus of the fibroblast cell (with the DNA of the founder animal) to the cytoplasm of the donor egg. The egg now kicks into action and does it's job just as if it were a normal fertilized egg. It's worth saying that this is the critical moment in the whole process, the point where a simple non-reproductive cell becomes a growing embryonic animal.
4. The embryo is incubated for several days and then implanted in a recipient cow - if we were talking about humans, we'd call it a surrogate - where it grows and develops just like any other embryo. And then the cloned calf is born, just like any other calf. The recipient cow will go with the cloned calf when it leaves the cloning facility and goes to its home, usually at 60 days old.
That’s it in a nutshell. If you'd like to read more about clones, check out Questions and Answers about Clones and The Clone Controversy.
Photo credit: Scott Accomazzo
