Sheep-goat chimera

:"Geep can also refer to a series of railroad locomotives"A sheep-goat chimera (sometimes called a "geep" in popular media) is a chimera produced by combining the embryos of a goat and a sheep; the resulting animal has cells of both sheep and goat origin. A geep should not be confused with a sheep-goat hybrid, which can result when a goat mates with a sheep.

History

The first sheep-goat chimera was bred in Manumbar, Queensland, Australia. It was artificially inseminated into 3 goats and 3 sheep in the year 1982. [cite web | title=It's a Geep | url=http://www.time.com/time/magazine/article/0,9171,921546,00.html | publisher = TIME magazine | accessdate = July 21 | accessyear= 2007] Researchers fused a sheep embryo with a goat embryo. The resulting creature was a mosaic of goat and sheep tissue. Those parts which grew from the sheep embryo were woolly. Those which grew from the goat embryo were hairy.

Characteristics

In a chimera, each set of cells (germ lines) keeps their own species identity instead of being intermediate in type between the parental species. It has four parents, whereas a hybrid has two parents.

A sheep-goat chimera may be fertile, but it will pass on either sheep or goat genes, depending on whether its reproductive (organs) system were formed from the goat embryo or from the sheep embryo (i.e., which germ-line formed the ovaries or testes).

The term "shoat" is sometimes erroneously used for sheep-goat hybrids and chimeras. The term "shoat" actually means a young piglet.

See also

*Sheep-goat hybrid

References