From chili pepper to hot tomato?

this image shows jalapeño peppers (a cultivated variety of capsicum annuum) credit emmanuel rezende naves

Chili peppers have happily entered our kitchens with their capsaicinoid content, since Cristoforo Colombo brought then back from Central America. Capsicum species however are labour-intensive and difficult to grow. They are also notoriously recalcitrant to biotechnological intervention. Tomatoes are much handier in comparison. The Capsicum and Solanum clades split at least 19 Mya ago but comparative genomics has revealed that tomatoes retain all the necessary genes for pungency. Why not to harness CRISPR power to turn tomatoes into capsaicinoid biofactories then? Continue reading

CRISPR best and worst in 2018

CRISPR contributed to Science’s Breakthrough of the Year and was also nominated for the Breakdown category by the same journal. The second nomination was an easy guess: He Jiankui and its baby-editing claim were also mentioned in Nature’s 10 for 2018. Much more interesting is the decision to celebrate cell-barcoding, the CRISPR-based technique used to track embryo development in stunning detail and over time. Continue reading

CRISPR seeds: the asexual revolution is now

apomictic rice UC Davis

Imtiyaz Khanday (left), Venkatesan Sundaresan (right)  with their apomictic rice  (credit: KARIN HIGGINS/UC DAVIS)

“To make a seed it takes a fruit,” pupils use to sing in Italy. Then students learn that there is an embryo inside seeds and it takes a pollen fertilized egg to make it. The dream of plant scientists, however, has always been to be able to produce seeds using only the cell egg. This dream has finally come true: a group led by Venkatesan Sundaresan, at UC Davis, has developed a rice variety capable of cloning its seed. Continue reading

Another CRISPR havoc? That’s science, baby

keep-calm-and-sequence-dna

A paper published in Nature Biotechnology by Allan Bradley and colleagues from the Wellcome Sanger Institute in Hinxton, UK, shows that classical CRISPR editing can cause large rearrangements of DNA near the target site in actively dividing cells. We may think of it as the latest CRISPR alarm, but also as a demonstration of how biomedical research works. Firstly: no technology is perfect, but the best ones are perfectible. CRISPR belongs to this category because it is an extraordinarily versatile and fast-evolving biotech platform. When reading news like “CRISPR causes this or that problem,” the first question to ask is: which CRISPR variant are we talking about? Continue reading

CRISPRing the Neanderthal’s mind

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Sapiens vs Neanderthalized brain organoids (credit A. Muotri)

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.

The CRISPR world we live in

crispr distribution

“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]

CRISPR boosts rice yield

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Jian-Kang Zhu (courtesy of Purdue University)

Around 30% more grain. This is the result announced in PNAS by Chinese researchers that have made the most of CRISPR’s multiplexability in rice. By simultaneously targeting multiple genes, the editing technique is a boon for scientists struggling with plants’ genetic redundancies. Continue reading