Max Perutz (1914–2002)

AbstractWalter Gratzer salutes the life of a founder of molecular biology who died last month and will be remembered as one of an illustrious breed of scientists who led from the bench

αI-spectrin represents evolutionary optimization of spectrin for red blood cell deformability

Spectrin tetramers of the membranes of enucleated mammalian erythrocytes play a critical role in red blood cell survival in circulation. One of the spectrins, αI, emerged in mammals with enucleated red cells following duplication of the ancestral α-spectrin gene common to all animals. The neofunctionalized αIspectrin has moderate affinity for βI-spectrin, while αII-spectrin, expressed in non-erythroid cells, retains ancestral characteristics and has a 10-fold higher affinity for βI-spectrin. It has been hypothesized that this adaptation allows for rapid make-and-break of tetramers to accommodate membrane deformation. We have tested this hypothesis by generating mice with high-affinity spectrin tetramers formed by exchanging the site of tetramer formation in αI-spectrin (segments R0 and R1) for that of αII-spectrin. Erythrocytes with αIIβI presented normal hematologic parameters yet showed increased thermostability and their membranes were significantly less deformable: under low shear forces they displayed tumbling behavior, rather than tank-treading. The membrane skeleton is more stable with αIIβI and shows significantly less remodeling under deformation than red cell membranes of wild-type mice. These data demonstrate that spectrin tetramers undergo remodeling in intact erythrocytes and that this is required for the normal deformability of the erythrocyte membrane. We conclude that αI-spectrin represents evolutionary optimization of tetramer formation: neither higher affinity tetramers (as shown here) nor lower affinity (as seen in hemolytic disease), can support the membrane properties required for effective tissue oxygenation in circulation

MASTREE+: Time-series of plant reproductive effort from six continents.

Significant gaps remain in understanding the response of plant reproduction to environmental change. This is partly because measuring reproduction in long-lived plants requires direct observation over many years and such datasets have rarely been made publicly available. Here we introduce MASTREE+, a data set that collates reproductive time-series data from across the globe and makes these data freely available to the community. MASTREE+ includes 73,828 georeferenced observations of annual reproduction (e.g. seed and fruit counts) in perennial plant populations worldwide. These observations consist of 5971 population-level time-series from 974 species in 66 countries. The mean and median time-series length is 12.4 and 10 years respectively, and the data set includes 1122 series that extend over at least two decades (≥20 years of observations). For a subset of well-studied species, MASTREE+ includes extensive replication of time-series across geographical and climatic gradients. Here we describe the open-access data set, available as a.csv file, and we introduce an associated web-based app for data exploration. MASTREE+ will provide the basis for improved understanding of the response of long-lived plant reproduction to environmental change. Additionally, MASTREE+ will enable investigation of the ecology and evolution of reproductive strategies in perennial plants, and the role of plant reproduction as a driver of ecosystem dynamics

L’affaire Lyssenko, une éclipse de la raison

L’influence néfaste de Trofim Lyssenko (1898-1976) domina la biologie dans l’empire soviétique durant le règne de Staline. Lyssenko assura son succès en promettant de sauver l’agriculture soviétique de la catastrophe où elle se trouvait à la suite de la politique désastreuse de collectivisation et d’une succession de mauvaises récoltes. Lyssenko affirmait avoir mis au point des méthodes permettant d’imposer des caractères héréditaires voulus à des plantes, et même de transformer à volonté une espèce en une autre. Il dénonçait la « génétique bourgeoise » comme une imposture et finit par étouffer tout débat scientifique et toute opposition en faisant arrêter ou exécuter nombre de scientifiques éminents. Les théories absurdes de Lyssenko contaminèrent les milieux scientifiques en Europe de l’ouest et furent saluées par beaucoup d’intellectuels communistes, notamment en France. Le phénomène Lyssenko est un exemple extrême de la perversion de la science par l’idéologie, souvent avec l’assentiment de la communauté scientifique. Est-il aussi certain que ce type d’événement ne puisse arriver aujourd’hui ?Trofim Lysenko was a Ukrainian peasant whose malign influence dominated biology in the Soviet Union and its imperium through most of Stalin’s reign. Lysenko owed his ascendancy to repeated promises that he would rescue Soviet agriculture from the catastrophic state into which it had sunk, following Stalin’s disastrous policy of collectivisation of the farms, and a succession of bad harvests. He claimed to have devised methods of imposing desirable hereditary characteristics on plants, and even of converting one species into another at will. He noisily denounced modern genetics as a bourgeois imposture, a view that resonated well with Marxist doctrine. As Lysenko’s power grew he was able to smother scientific debate, and to crush all opposition through the arrest and often execution of many leading scientists. Lysenko’s preposterous theories became the accepted orthodoxy in the academies and universities of Eastern Europe, and were greeted with enthusiasm by many Communist intellectuals in the West, not least in France. The Lysenko phenomenon is the most extreme, but by no means the only example of the perversion of science by ideology, often with the acquiescence of the scientific community. Nor can we be confident that nothing of the kind could happen today

L’affaire Lyssenko, une éclipse de la raison

L’influence néfaste de Trofim Lyssenko (1898-1976) domina la biologie dans l’empire soviétique durant le règne de Staline. Lyssenko assura son succès en promettant de sauver l’agriculture soviétique de la catastrophe où elle se trouvait à la suite de la politique désastreuse de collectivisation et d’une succession de mauvaises récoltes. Lyssenko affirmait avoir mis au point des méthodes permettant d’imposer des caractères héréditaires voulus à des plantes, et même de transformer à volonté une espèce en une autre. Il dénonçait la « génétique bourgeoise » comme une imposture et finit par étouffer tout débat scientifique et toute opposition en faisant arrêter ou exécuter nombre de scientifiques éminents. Les théories absurdes de Lyssenko contaminèrent les milieux scientifiques en Europe de l’ouest et furent saluées par beaucoup d’intellectuels communistes, notamment en France. Le phénomène Lyssenko est un exemple extrême de la perversion de la science par l’idéologie, souvent avec l’assentiment de la communauté scientifique. Est-il aussi certain que ce type d’événement ne puisse arriver aujourd’hui ?Trofim Lysenko was a Ukrainian peasant whose malign influence dominated biology in the Soviet Union and its imperium through most of Stalin’s reign. Lysenko owed his ascendancy to repeated promises that he would rescue Soviet agriculture from the catastrophic state into which it had sunk, following Stalin’s disastrous policy of collectivisation of the farms, and a succession of bad harvests. He claimed to have devised methods of imposing desirable hereditary characteristics on plants, and even of converting one species into another at will. He noisily denounced modern genetics as a bourgeois imposture, a view that resonated well with Marxist doctrine. As Lysenko’s power grew he was able to smother scientific debate, and to crush all opposition through the arrest and often execution of many leading scientists. Lysenko’s preposterous theories became the accepted orthodoxy in the academies and universities of Eastern Europe, and were greeted with enthusiasm by many Communist intellectuals in the West, not least in France. The Lysenko phenomenon is the most extreme, but by no means the only example of the perversion of science by ideology, often with the acquiescence of the scientific community. Nor can we be confident that nothing of the kind could happen today