April 9, 2014

expert reaction to dog cloning

Korean company Sooam Biotech produced the UK’s first cloned dog for the winner of a competition.

Dr Dusko Ilic, Reader in Stem Cell Science, King’s College London, said:

“Cloned animals are like monozygotic twins – similar, but never the same. As time passes by, the differences will be more and more pronounced, especially personality traits. It is absolute waste of money.”

Prof Robin Lovell-Badge, Head of Developmental Genetics, MRC National Institute for Medical Research (NIMR), said:

“Apart from similarity in outward appearance, you would have about as much chance of replicating your favourite pet by choosing one from Battersea Dog’s home as you would from cloning it. And the former is likely to be loved more as it will not fail your expectations.

“Dogs, like humans, are not just a product of their DNA sequence and the genes this contains, which is all that the cloning procedure copies. Importantly, it is the activity of these genes in different tissues, from development of the embryo to the adult, that determines the physical characteristics of an individual. While much of this is programmed within the DNA, gene activity can be influenced by external factors, from the mother’s diet and levels of hormones during pregnancy and lactation, to what the animal itself eats and drinks. Levels of gene activity within cells are also never precisely controlled, there is always an element of chance. This can be further compounded by random mutations in DNA, which occur at a low level during cell division.

“These effects on gene activity explain why identical twins, which develop by the splitting of a single early embryo, do exhibit differences in appearance, and sometimes these are quite pronounced. Cloned animals are likely to be even more distinct from one another. They are derived from adult cells that may have accumulated different mutations in DNA sequence, the reprogramming process to revert the activity of the cell’s genes back into an early embryonic state is not perfect and this may affect how the genes behave in the liveborn animal, moreover, each embryo may have developed in a different mother at a different time. Cows cloned from the same original animal with, for example, a high milk yield, can show quite different patterns of skin pigmentation, and why they may yield higher than normal levels of milk, this is unlikely to be the same in each clone.

“The behaviour of an animal, and aspects of its physiology, are also determined in part by genes and therefore subject to the same issues promoting variability among twins and cloned animals. But of course they are also strongly influenced by “nurture”. Early life experiences, including interactions with the mother (and father if present), siblings, and human carers, can have a significant effect on the personality and behaviour of many animals and notably of dogs. Dogs are social, hierarchical, and can learn much from humans as well as other dogs. It is extremely unlikely that a puppy cloned from a favourite pet will grow up to behave the same way. Even the expectation of the owner that it might (because it looks similar), will probably guarantee that it will not, especially if it is chastised when it responds differently from the original.

“Given the frequency with which the cloning procedure is known to go wrong, leading to abnormally developing embryos, with consequences to the mothers carrying them, to stillborn, or live born animals with defects, and to adults with compromised anatomy, physiology, or health, and the inevitability that even a normal heathy clone will not be identical to the original animal in appearance and especially in their behaviour, I see no valid justification for cloning pets. It is a ridiculous waste of money and hope as well as being ethically very dubious.

“It has been proposed that there may be some rationale in cloning certain working dogs, for example to “replicate” individuals that are particularly good sniffer dogs – able to detect trapped or missing people, or perhaps for law enforcement. However, is this really better than standard breeding techniques ? I personally think that cloning even remarkable working dogs would still be hard to justify, given the inevitable suffering associated with failed attempts – and I doubt that all clones would be comparable to the original, both in the property that prompted their cloning, such as sense of smell, and particularly in their ability to carry out the desired task, namely the way they behave.”