asked Her Majesty's Government:

Further to the Written Answer by Lord Darzi of Denham on 1 July (WA 28) regarding Clause 4 of the Human Fertilisation and Embryology Bill, to what extent the quantitative criterion underlying that clause (whereby it has been stressed that animal DNA does not predominate in the resulting embryos) reflects the mixing of human sperm with eggs of Mesocricetus auratus, in light of what is known about the nuclear genome size (in base pairs) of each respective species and the total mass (in picograms) of mitochondrial DNA typically found in mammalian eggs.

Provision regarding the mixing of human gametes with the gametes of an animal for research purposes is provided for under new Section 4A(6)(b) of the Human Fertilisation and Embryology Act, as introduced by Clause 4 of the Human Fertilisation and Embryology Bill (HFE). The "hamster test" is also provided for separately in the HFE Bill through provisions in Schedule 2 to the HFE Bill. The "predominantly human" provision is only a specific requirement of new Section 4A(6)(e).