Adding the RNA string to the CRISPR bow


So far we have learned that CRISPR may turn a faulty gene off by cutting and mutating its sequence. But what if we want to proceed more cautiously and avoid permanent changes to the genome? We could leave the target gene intact but ineffective, by intercepting and destroying the RNA messages with which it gives the wrong orders to the diseased cells. In this way it would be easier to go back if necessary. The good news is that CRISPR is a jack-of-all-trades, well-suited for the task, and the new approach (call it RNA targeting with CRISPR) is going to help to study human biology and diseases. One of the technique pioneer, Feng Zhang, has demonstrated in Nature last week that it can efficiently target RNA in mammalian cells (and also plants), equalizing and even surpassing the performance of the current tool of choice for RNA knockdown (RNA interference). In short, besides advancing its career as DNA editor, CRISPR has also found a second job in the RNA business. Continue reading

3 questions on CRISPR butterflies

19TB-BUTTERFLIES3-master675Biodiversity is a wonderful interplay between genetics and evolution, and butterflies are a fascinating example with their variety of patterns and colors. Understanding how the same gene networks engender visual effects so diverse in thousands of Lepidoptera species is a longtime ambition  for many entomologists and evolutionary biologists. The good news is that scientists nowadays have a straightforward technique working with organisms that were difficult to manipulate with conventional biotech tools. Obviously, we are talking about CRISPR. Two papers published in PNAS last week describe how genome editing was used to alter the genetic palette of colors in butterflies and how their wings changed as a result. We’ve asked the entomologist Alessio Vovlas, from the Polyxena association, to comment these stunning experiments. Continue reading

A CRISPR punch makes ants asocial

egg laying ant 700x363In horror films of the 1950s mutant insects were a nightmare. Now they are a dream that is becoming a reality, at least for those interested in studying the molecular bases of social behaviors. Two teams have just succeeded in modifying ants DNA by knocking down their olfactory system and consequently putting their social interactions in disarray. The experiments, published in August in Cell, herald the beginning of a new scientific adventure: ants are set to become the model organism for eusociality studies in the post-genomic era. Continue reading

CRISPR in RNA Wonderland

doudna_crispr_wide-cb9478286d39615ed64291ea95d4cfe022596aa2-s900-c85This week our journey among leading labs takes us to meet a pioneer of gene silencing. Pino Macino contributed to the birth of RNA interference, a field awarded a Nobel prize in 2006, and teaches cell biology at Sapienza University of Rome.  He thinks CRISPR is a great leap forward in understanding the function of genes. Continue reading