Picture of the week

bimaternal pups

Healthy adult bimaternal mouse (born to two mothers) with offspring of her own.
Credit: Leyun Wang

Single-gender worlds will remain a sci-fi fantasy. Gay and lesbian couples won’t become parents this way for the foreseeable future. This kind of manipulation is just too risky for humans. But unisexually reproducing mice are an impressive accomplishment, and CRISPR stands out again as a powerful research tool, opening up brand new possibilities for the study of genomic imprinting. For further details, please see the STAT News article about the Cell Stem Cell paper by Zhi-Kun Li.

Gene drives & the trolley dilemma

malaria kills

The trolley problem is a classic philosophical dilemma, and its variants have been used extensively to test moral intuitions. Scanning the brain of human subjects with functional MRI during task performance has proven useful to understand how emotion and reason interact when we ponder bioethical issues. It would be interesting to adopt those approaches to study the psychological barriers towards controversial innovations such as gene drives. Just imagine you alone are responsible for pressing a button and switching on gene drives in malaria-spreading mosquitoes. Someone is going to die, and you must decide whom to save. Continue reading

CRISPR diving the coral reef

coral-bleachingThey are not super-corals genetically edited to repopulate the reef. However, the Acropora millepora described in PNAS last week are the first baby polyps ever CRISPRed in a lab, by a team involving Stanford University, UT-Austin and the Australian Institute of Marine Science in Townsville. These uncontroversial organisms pave the way for future experiments to reveal the molecular basis of vulnerability to bleaching, the fatal loss of algal symbionts triggered by global warming. Most corals reproduce once or twice a year, ejecting huge quantities of sex cells resembling underwater snowflakes. The time window of these spawning events can be predicted quite accurately, so researchers can sample the reef at the right moment and collect early embryos for genetic manipulation. We discussed the experiment results and future perspectives of gene editing in corals with the paper’s first author Phil Cleves.

Continue reading

CRISPR animals knock on regulator’s door

Roslin CRISPR pigs

When you hear the word GMOs, chances are high that you think of plants, not animals. In the last 20 years, indeed, the Frankenfood controversy has forestalled the use of genetic engineering in animal breeding. To date, only a single food animal can be eaten in a single country (the fast-growing AquAdvantage salmon approved in Canada), while transgenic plants are grown on more than 180 million hectares in over twenty countries. Genome editing is now knocking at animal farms, will the door open? Continue reading

Epigenetic editing hits hat-trick

editing epigenetico Cell

Reversing three genetic diseases in the animal model without even changing a single DNA letter. A Salk Institute team did it by bringing together two of biomedicine’s hottest trends. One is the CRISPR technique, which edits target genes through a programmable molecular machine named Cas9. The other is epigenetics, i.e., the study of chemical modifications that switch genes on and off without altering their sequence. It’s called epigenetic editing, because corrections are precise as in manuscript revision and occur at a level that is over (epi- in Greek) genetics. 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