Toggle light / dark theme

In October 2019, Liu and his colleagues published a paper in Nature, describing an even newer technology, called prime editing. Prime editing can not only make all twelve of the possible base substitutions, it can also make multiple-base insertions or deletions, without requiring a double-strand break. It achieves this with a multi-step operation that first cuts one strand, then performs the appropriate substitution, insertion, or deletion, and then nicks the second strand to allow the bases on the second strand to be replaced by bases that complement the ones substituted, inserted into or deleted from the first strand. The result is a modified stretch of DNA that had never been completely separated. This has the effect of massively reducing the number of off-target modifications.

This new prime editing variant of CRISPR technology, can make the same corrections to the defects that cause sickle cell disease and beta-thalassemia that standard CRISPR/Cas9 has now made in human subjects, but with less opportunity for unwanted off-target changes. Furthermore, its possible applicability is much wider. The ClinVar database lists over 75,000 pathogenic mutations in the human genome. Of these, over 89% are potentially correctable by prime editing.

From zinc fingers to TALE, to CRISPR/Cas9 to base editing and now to prime editing, progress in gene editing has been accelerating. The next advances are currently being aggressively pursued in laboratories all over the world. It will probably be several years before the therapies that are currently being researched are applied routinely in a clinical setting. However, for people who up until recently have had no hope for a cure to a disease suffered by their child, or even themselves, these are exciting times. The prospect of effective treatments, or even cures, is now a valid cause for hope.

The Human Genome Project is probably the most ambitious scientific proposal ever made.


ii. writing DNA

Synthesising short, single stranded fragments of DNA, called oligonucleotides (oligos for short) has been automated and affordable for a number of years now, and almost every biology laboratory in the world uses these short fragments (usually 18–25 base-pairs — compare this to the human genome which is 3 billion base-pairs long) for applications ranging from disease diagnostics to making genetically modified plants. What really has been a game-changer in DNA synthesis is the ability to synthesise longer pieces of DNA and the ability to join these together efficiently to form synthetic gene length fragments.

How close are we to creating a synthetic human genome?


Creating humans is also an ethical minefield. Unsettled questions about who might own a synthetic human genome abound. Boeke warns that ownership could come down to who ends up funding the project development. Rob Carlson, a co-author of the GP-Write proposal, is even more skeptical of the idea of a patented artificial human genome, pointing out via email that “as soon as there is any possibility of a synthetic genome being used to germinate a live human, then ownership is obviously out of the question anyway…because you are now talking about owning a person.”

So far the GP-write project has been more talk than action, with large consultation meetings held between scientists and policy experts. The project has yet to attract significant funding. Perhaps successes in other organisms like yeast will embolden governments and private industry to open up to the idea of a man-made human genome.

Afghanistan’s first-ever robot waitress glides up to a table of curious diners in central Kabul and presents them with a plate of French fries.

“Thank you very much,” the machine says in Dari, one of Afghanistan’s two main languages.

Restaurant manager Mohammad Rafi Shirzad says the humanoid robot, imported from Japan and designed to look vaguely like a women wearing a hijab, has already pulled in new customers since it started working last month.

Newborn screening covers more than 30 conditions. Yet, with genome sequencing, we could screen newborns for several thousand genetic conditions.


In the surveys’ open-ended responses about risks of genome sequencing, parents and clinicians both expressed concerns about psychological distress related to difficult or uncertain results. Clinicians were more likely to raise concerns about returning results for adult-onset conditions, unnecessary parental stress over health problems that might never actually occur, and the possibility of future discrimination against the child on the basis of their genomic information.

On the other hand, parents mentioned a broader range of benefits than clinicians. Both parents and clinicians saw potential health benefits of genome sequencing, such as the ability to search for more conditions compared to standard newborn screening and the ability to predict a child’s future disease risks. Parents went further, though, seeing benefits in family planning, preparing for the child’s future, and knowledge just for the sake of knowing. Those potential benefits fall outside of traditional definitions of clinical utility, which means they are less likely to be considered in the professional guidelines that steer adoption of practices like genome sequencing.

Superb piece.

“But, I say we should pursue science and technology because, like Prometheus, the fires of invention burn bright, and although we may not always know where it leads us, a world darkened by the fear of treading upon the unknown, is unimaginable.”


Yet we can look to a brighter side, one I could never have imagined in the ’60’s when the chromosomes we karyotyped would be uncoiled to lay bare the genome as an instrument for critical medical diagnoses, to set free those erroneously convicted of crime, or enlighten us about Mitochondrial Eve our common mother, and the long journey that began two hundred thousand years ago; the journey that brought me into the world of physical things, air, table and chairs, and beyond into the space of the geometries and cohorts, like Golay and Bolsey, who helped me better understand my Universe, the one either too small or too far to see, unless aided by the eyes of science and technology. I once wondered how I got here, and now I think I know, but I am afraid my second query, “where will it lead,” will remain an open question.

An auditory illusion thought to synchronize brain waves and alter mood is no more effective than other sounds, according to research in adults recently published in eNeuro. The effect reported in other studies might be a placebo but could still have helpful effects for some people.

Binaural beats are an auditory illusion caused by listening to two tones of slightly different frequency, one in each ear. The difference in frequencies creates the illusion of a third sound — a rhythmic beat. Neurons throughout the brain begin to send electrical messages at the same rate as the imaginary beat. Many unsupported claims surround binaural beats, including that listening to them decreases anxiety, increases focus, and improves mood.

Orozco Perez et al. played binaural and monoaural beats to healthy adults and measured their brain activity with electroencephalography. Monoaural beats don’t rely on the illusion to create the beats because they consist of edited audio tracks of the two different tones together. Both ears hear all three sounds. Brain activity synchronized with both types of beats, but the effect was stronger with monoaural beats. Neither type of beat affected mood. When the binaural beat played, far apart brain areas synchronized with each other at a different frequency than the beat. This may be how binaural beats improve memory and focus.