Hello World.
I'm Imagination.
Today I'm going to talk about Genome Editing.
Genome editing, or genome engineering, or
gene editing, is a type of genetic engineering
in which DNA is inserted, deleted, modified,
or replaced in the genome of a living organism.
Unlike early genetic engineering techniques
that randomly insert genetic material into
a host genome, genome editing targets the
insertions to site-specific locations.
Nine genome editors were available as of 2017.
In 2018, the common methods for such editing
used engineered nucleases, or "molecular scissors".
These nucleases create site-specific double-strand
breaks at desired locations in the genome.
The induced double-strand breaks are repaired
through nonhomologous end-joining or homologous
recombination, resulting in targeted mutations
edits.
In May 2019, lawyers in China reported, in
light of the purported creation by Chinese
scientist He Jiankui of the first gene-edited
humans, the drafting of regulations that anyone
manipulating the human genome by gene-editing
techniques, like CRISPR, would be held responsible
for any related adverse consequences.
A cautionary perspective on the possible blind
spots and risks of CRISPR and related biotechnologies
has been recently discussed, focusing on the
stochastic nature of cellular control processes.
In February 2020, a US trial safely showed
CRISPR gene editing on 3 cancer patients.
Genetic engineering as a method of introducing
new genetic elements into organisms has been
around since the 1970s.
One drawback of this technology has been the
random nature with which the DNA is inserted
into the host's genome.
This can impair or alter other genes within
the organism.
Methods were sought which targeted the inserted
genes to specific sites within an organism
genome.
As well as reducing off-target effects it
also enabled the editing of specific sequences
within a genome.
This could be used for research purposes,
by targeting mutations to specific genes,
and in gene therapy.
By inserting a functional gene into an organism
and targeting it to replace the defective
one it could be possible to cure certain genetic
diseases.
Researchers have used CRISPR-Cas9 gene drives
to modify genes associated with sterility
in A.gambiae, the vector for malaria.
This technique has further implications in
eradicating other vector-borne diseases such
as yellow fever, dengue, and Zika.
The CRISPR-Cas9 system can be programmed to
modulate the population of any bacterial species
by targeting clinical genotypes or epidemiological
isolates.
It can selectively enable the beneficial bacterial
species over the harmful ones by eliminating
pathogens, which gives it an advantage over
broad-spectrum antibiotics.
In January 2019, scientists in China reported
the creation of five identical cloned gene-edited
monkeys, using the same cloning technique
that was used with Zhong Zhong and Hua Hua
– the first-ever cloned monkeys - and Dolly
the sheep, and the same gene-editing Crispr-Cas9
technique allegedly used by He Jiankui in
creating the first-ever gene-modified human
babies Lulu and Nana.
The monkey clones were made in order to study
several medical diseases.
In the near future, the new CRISPR system
will also be able to eradicate diseases and
conditions that humans are predisposed to.
With this new technology, scientists will
be able to take the genes of a human sperm
cell and egg and replace the genes that activate
cancer or other abnormal or unwanted defects.
This will take the stress off from parents
worrying about having a child and not able
to live a normal life.
After just one generation of this process,
the entire future of the human race would
never have to worry about the problems of
deformities or predisposing conditions.
Many transhumanists see genome editing as
a potential tool for human enhancement.
Australian biologist and Professor of Genetics
David Andrew Sinclair notes that "the new
technologies with genome editing will allow
it to be used on individuals to have healthier
children" – designer babies.
According to a September 2016 report by the
Nuffield Council on Bioethics in the future
it may be possible to enhance people with
genes from other organisms or wholly synthetic
genes to for example improve night vision
and sense of smell.
The American National Academy of Sciences
and National Academy of Medicine issued a
report in February 2017 giving qualified support
to human genome editing.
They recommended that clinical trials for
genome editing might one day be permitted
once answers have been found to safety and
efficiency problems "but only for serious
conditions under stringent oversight."
Genome editing tools such as CRISPR are beginning
to reshape the physical world around us, one
base pair at a time.
That's all for today.
Thanks for watching.
