Dolly was big news in the 90s as being the first successfully cloned sheep. I have heard literally nothing about cloning since then. What happened?
Hi!
Sorry, I can't find if this was already asked.
Why did they use 3 sheep to create Dolly and not just one? They could have used the same sheep to extract the nucleus from a somatic cell, the egg cell from that same sheep and use the same sheep to grow the newborn. Why did they use three?
Hiram Caton writes: “I mentioned that the highly touted breakthrough was 'science by press conference'. It's bad ethics because the pre-publication publicity instills broad public belief before experts have the opportunity to examine the findings. This tends to cut critical thought out of the loop. Would-be critics are cast in the role of spoilsports. This is what happened to Wilmut's claims about Dolly. Questions were raised soon after publication; by the year's end, a number of scientists, among them a Nobelist or two, had found the Roslin research to be seriously flawed. Here are their criticisms. a) Roslin should have replicated the experiment before publishing because a sample of one is an anecdote, not an experiment. It's especially not good enough when Dolly was the only animal produced from 277 attempts. Embryos were achieved in only eight attempts. No other laboratory replicated the results and Roslin has no plans to replicate.
b) The Institute could not document that the nuclear material derived from adult stem cells. Doubt arose because the cell donor was pregnant at the time of cell collection, which meant that the fetal cells could have been included in the collected cell sample. The possibility could be excluded had Roslin tested the cell sample for the presence of fetal cells. It did not conduct that test.
c) These uncertainties could be eliminated by direct DNA comparison between the donor animal and Dolly. Alas, the donor animal had died three years prior to Dolly's birth and Roslin had no means of making the DNA test. This evidence gap prompted critic Richard Gardner, an Oxford University embryologist, to style the team's negligence as 'staggering'. The Institute's excuse only increased Gardner's skepticism. It apologised that the cells used in the cloning study were prepared for a different purpose (investigating the expression of milk proteins). The cloning experiment was an afterthought; hence the team didn't conduct the tests needed to authenticate the experiment. Gardner rated the face validity of this excuse at nil.
d) In his criticism, Rockefeller University geneticist Norton Zinder called the experimental sample an 'anecdote, not a result' and declared that despite the hullabaloo 'the emperor has no clothes': cloning not proved.
Criticisms so fundamental were a whisker away from allegation of fraud. That sounded the trumpet for the fertility fraternity to close ranks behind the embattled Wilmut. The rebuttals did little to dam
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Hi all,
I don't often make top-level posts here, but I've been toying with a rebuttal to the "life begins at conception" argument that is commonly used by conservatives. I would like to present it here and request that conservatives review & criticize it, please. I have reviewed this with some close conservative friends who were surprisingly receptive to the idea and now I would like to refine it further by having it challenged by you guys.
My rebuttal centers around the creation of Dolly the sheep, which some of you may remember hearing about over a decade ago. Borrowing from (https://www.statnews.com/2020/02/21/human-reproductive-cloning-curious-incident-of-the-dog-in-the-night-time/):
> Creating Dolly meant taking an egg from one sheep, removing its DNA-carrying nucleus, fusing into the egg a cell from another sheep (in this case, from a cell line from a sheep that had been dead for several years), then hitting the resulting cell with a jolt of electricity. When this technique finally worked — the researchers tried it unsuccessfully 250 times — the resulting cell began to grow and divide. It was successfully implanted in a sheep’s uterus and eventually became a healthy lamb.
In case you missed it, this new life was created without conception and with one set of DNA. If life begins at conception, was Dolly the sheep never alive?
Why did Dolly the sheep die so early if the explanation involving telomeres is wrong?
I was wondering about cloning after hearing about dolly the sheep was cloned. I thought a similar method could be tried with humans, but I am not sure if anyone has tried to do so before.
Is there a legal barrier, an ethical barrier, or a cost barrier (or combination of the three) to cloning humans if I want a little me as my kid?
Also info on the sheep here in case someone hasn't heard of her before: https://en.wikipedia.org/wiki/Dolly_(sheep)
Dolly the Sheep was a clone. These days the clone is lessened taboo, easier finance, better DNA understanding etc. What are the hangups? George Church wants to clone a mammoth and I'm sure other scientists wants to do the same for other mammals.
I don't need Jurrasic Park, just a Dolly Dinosaur.
Thank you.
I just simply don’t fully understand how it works. Thank you 😊
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