
15 Worrying Things About the CRISPR Babies Scandal - devy
https://www.theatlantic.com/science/archive/2018/12/15-worrying-things-about-crispr-babies-scandal/577234/
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aurizon
We have to consider a few things. CRISPR is a bacterial immune sysyem against
bacterial viruses (phages) and it has evolved to toss a monkey wrench into the
phage duplication machinery. It must act fast - too slow and machinery wins
the race. This means it must act on rumor - as it were. This may lead to erros
when attached to another molecule CAS, which may well want precision. A phage
has it's genome well spread out and accessible, but human cells are tightly
involved with chromatic - which means finding the needle in the haystack is
very slow and hard work - and error prone. So am embryo starts as one cells,
divides, 2, 4, 8, 16 in the initial stages - and that is when the genome is
accessible to be sieved, during mitosis. So this researcher must wait until
the embryoe is in mitosis before adding the gene correcting vector. He also
needs to add an excess to make sure it finds the correct place to cut out a
gene and spilce in a gene (or gene fraction). He then has to test this cell
for correct placement (proof reading), he also has to make sure it has only a
single edit, that there are no others scattered here and there. So he must
allow this cell to divide a few times. and also keep one or more aside to use
for a child if that line meets the quality required. I do not know what his
error rate was? Di he make hundreds to find a few? The fact we have twins
leads me to feel that there was a process of testing and making up of many
multiples, and even possibly hundreds of discarded batches - full of errors
etc. I ex[ect this news to filter out. He may not tell us, he may not live to
tell - there are rumors...

