Lord Winston Cloning Babies

The lecture began by Lord Winston explaining that humans are quite an infertile species and, although he did not recommend random testing of this, at any one time there is only an 18% chance of becoming pregnant by conventional means! Numerous fertilised eggs are lost during the very early stages of pregnancy; many of these due to chromosomal abnormalities. In vitro fertilisation (IVF) is regularly used to help couples who have difficulty conceiving naturally, but even then there is only 15-18% chance of success. An important factor is the quality of eggs available and here the age of the female is critical, 24-30 years old being the optimal age for IVF. Many women are very infertile by the age of 40 and, over 40 a lot of chromosome defects become evident. The incidence of Downs syndrome (trisomy 21, an extra chromosome 21) is relatively common in mothers over the age of 40. There are only three chromosomes, 13, 18 and 21, for which trisomy is viable. Trisomies of all other chromosomes spontaneously abort. Downs syndrome babies are the most common of the viable trisomies probably due to the small size of the chromosome involved. If donor eggs from young females are employed for IVF then the age of the mother becomes far less critical, hence the birth in Rome to a female at the age of 65.

The advent of preimplantation diagnostic techniques has opened up vast new opportunities. These procedures allow the removal by microsurgery of one or two cells from an 8-cell embryo for subsequent DNA or chromosome analysis. If the biopsied cells prove normal then the embryo can be implanted into the mother with a reasonable chance of a successful pregnancy, subsequently resulting in the birth of a healthy child. Unfortunately, this technology can cause controversy and has led to the public notion of "designer babies".

Here, Lord Winston went on to say that public attitudes are very important and are easily influenced by emotive or inaccurate reporting in the press. The controversial subject of possible human cloning was then discussed.

However, he did not envisage human cloning likely in the near future as animal cloning currently produces mostly abnormal embryos and foetuses.

Lord Winston also talked about the use of animals in research and said that properly conducted and regulated animal research was absolutely essential to scientific progress in medicine. A new House of Lords Select Committee will examine the working of the Animals (Scientific Procedures) Act 1986 and he explained that all members of this committee were non-scientists. Lord Winston felt that this was probably a good thing as prejudice will be limited. He stressed the importance of the need to study gene function and how mutagenesis experiments such as those carried out at Harwell were critical in generating new mouse models of human genetic disorders.

Lord Winston ended his fascinating lecture by talking about his role in the House of Lords and advised scientists that communication is all. He warned that scientists must improve communication with the general public or we will face a more difficult time in future years.

The afternoon concluded with a buffet and drinks at which Lord Winston took the opportunity to chat to the many students from local schools that attended the lecture.