Taking a peek into the brain of a Neanderthal specimen would be a dream for whoever is interested in the evolution of human intelligence. To get an idea of the cognitive abilities of our closest relatives, so far, anthropologists and neuroscientists could only study the fossil and archaeological record, but a new exciting frontier is opening up where paleogenetics meets organoids and CRISPR technologies. By combining these approaches, two labs are independently developing mini-brains from human pluripotent stem cells edited to carry Neanderthal mutations. Alysson Muotri did it at UC San Diego, as Jon Cohen reported in Science last week. Svante Pääbo is doing it at the Max Planck Institute in Leipzig, as revealed by The Guardian in May. Forget George Church’s adventurous thoughts on cloning Neanderthals. The purpose here is to answer one of the most captivating questions ever asked: did the mind of these ancient men and women, who interbred with our sapiens ancestors before going extinct, work differently from ours? Last but not least, with respect to the ethics of experimenting with mini-brains, don’t miss the perspective published in Nature.
“As of January 2018 Addgene has distributed more than 100,000 CRISPR plasmids to 3,400 laboratories worldwide. More than 6,300 CRISPR-related plasmids have been developed by over 330 academic labs and deposited into Addgene’s collection. Geographically, new CRISPR plasmids have been developed and deposited to Addgene’s collection from the Americas (led by the United States), Europe (led by Denmark), Asia (led by China), and Oceania (led by Australia), and shipped to some 75 countries.” [Reference: Enabling the Rise of a CRISPR World, Caroline M. LaManna and Rodolphe Barrangou, The CRISPR Journal, Vol. 1, n. 3, 2018]
As far as we know, the passing of controversial DIY-bioentrepreneur Aaron Traywick has nothing to do with CRISPR. The cause of death is still unknown, and there is not even much information about the alleged herpes vaccine he self-injected a few months ago. According to media reports, it consisted of “live attenuated virus with a missing protein” or maybe contained “engineered copies of the virus DNA code.” Injecting yourself with an unproven concoction is obviously a bad idea, with or without CRISPR. The death news indeed puts biohacking at a crossroads, according to the Atlantic. But even more worrying is the MIT Technology Review scoop that Traywick has been planning human tests of a CRISPR therapy for lung cancer at a wellness center in Tijuana, Mexico. Stem cells researchers have raised the alarm over and over again in the past on unregulated clinics preying on desperate patients in lenient countries. The specter of nascent CRISPR-medical tourism in search of unproven treatments is an urgent issue to tackle.
Off-target paper retraction: Nature Methods has retracted a controversial study questioning CRISPR precision, after its authors admitted they were probably wrong. This blog’s wish is that future studies on CRISPR flaws and virtues are as reliable as the genome-editing technique.
Deregulation statement: US Secretary of Agriculture Sonny Perdue has announced that USDA will not regulate edited plants as long as they could have been created through conventional breeding. Let’s hope Europe will follow the example.
Gene therapy going “organic”: that’s the hope expressed by Merlin Crossley, when commenting his Nature Genetics paper on mutations beneficial to patients with β-thalassemia and sickle cell anemia. The word organic here means that fetal hemoglobin production can be boosted without inserting foreign DNA.
CRISPR needs to anchor itself near a short sequence called PAM to do its job. In the book “Modern Prometheus” (Cambridge University Press) James Kozubek says a PAM is like a shoehorn, where the Cas9 nuclease begins to clasp down to recognize the right site and cut. In order to fit every gene, a super-adjustable shoehorn would be needed. Think of it as the equivalent of a bump key that can open any door. A Broad Institute group led by David Liu has almost reached the goal with xCas9, the new super-adjustable Cas9 variant described in Nature this week. Continue reading