Original story from Osaka Metropolitan University (Japan). When cultivated tobacco is crossed with a wild relative it erases lethal genes, allowing normally fatal hybrids to survive. In the plant world, when two different species mate, their offspring often don’t survive. The reason lies in their DNA: incompatible genes often mix in their offspring, triggering a fatal breakdown known as ‘hybrid lethality’ that acts as a reproductive barrier to keep species separate. Using tobacco plants and their wild relatives, a research group led by graduate student Shota Nagai and Associate Professor Takahiro Tezuka at the Graduate School of Agriculture, Osaka Metropolitan University (Japan), explored what happens when two species with a long evolutionary history attempt to hybridize. As expected, many of the resulting seedlings died shortly after sprouting, turning brown and collapsing from hybrid lethality. However, a larger-than-expected number of hybrids survived and grew normally. By carefully cross-pollinating cultivated tobacco (Nicotiana tabacum) with a wild species (Nicotiana amplexicaulis), the researchers tracked which seedlings lived and which died. They then examined the plants’ DNA, focusing on two genes known to trigger hybrid lethality when they interact; one from each parent species. Nature’s medicine cabinet: alkaloid biosynthesis breakthrough may plant seed for drug discovery A step forward in our understanding of how plants produce alkaloids could herald new pharmaceuticals. They found that in many of the surviving hybrids, one of the lethal genes had vanished. This disappearance appeared to be the result of a gene reshuffling process known as ‘genome shock’. When two…
