Humster

A hybrid cell line made from hamster oocyte fertilized with human sperm routinely created for mainly two reasons:
 * To avoid legal issues with working with pure human embryonic stem cell lines.
 * To assess the viability of human sperm for in vitro fertilization.

Somatic cell hybrids between hamster or mouse and man have been used for mapping of various traits at least since the 1970s.

Ethical discussions
Several, primarily Catholic, countries have banned in vitro generation of hybrid cell lines. The ethical issues ofter raised is the idea:


 * human embryos get their inherently "human" qualities (soul) at the moment of fertilization - a philosophy adopted to a varying extent by many countries in their legal regulations about ES cell lines.
 * Animals lack a soul (but some say that, animals do have souls)

Generation of hybrid cell lines causes a big problem for people that hold the two above mentioned statements for true.