The metabolic growth limitations of petite cells lacking the mitochondrial genome.

Eukaryotic cells can survive the loss of their mitochondrial genome, but consequently suffer from severe growth defects. ‘Petite yeasts’, characterized by mitochondrial genome loss, are instrumental for studying mitochondrial function and physiology. However, the molecular cause of their reduced growth rate remains an open question. Here we show that petite cells suffer from an insufficient capacity to synthesize glutamate, glutamine, leucine and arginine, negatively impacting their growth. Using a combination of molecular genetics and omics approaches, we demonstrate the evolution of fast growth overcomes these amino acid deficiencies, by alleviating a perturbation in mitochondrial iron metabolism and by restoring a defect in the mitochondrial tricarboxylic acid cycle, caused by aconitase inhibition. Our results hence explain the slow growth of mitochondrial genome-deficient cells with a partial auxotrophy in four amino acids that results from distorted iron metabolism and an inhibited tricarboxylic acid cycle.We thank our laboratory members and J. Bähler for critical discussion and comments on the manuscript, and C. Kilian for technical support. This work was supported by the Francis Crick Institute, which receives its core funding from Cancer Research UK (FC001134), the UK Medical Research Council (FC001134) and the Wellcome Trust (FC001134), and received specific funding from the European Research Council (StG 260809 and SYG 951475) and the Wellcome Trust (IA 200829/Z/16/Z), as well as the FWF (Austria) for project P26713 (to M.B.) and a Swiss National Science Foundation Postdoc Mobility fellowship (191052 to J.H.)

Conceptual Readings into the Cold War: Towards Transnational Approaches from the Perspective of Latin American Studies in Eastern and Western Europe

This bibliographical and conceptual essay summarizes recent research in Cold War Studies in Europe and the Americas, especially on smaller states in historiographical studies. Against the background of an increasing connectedness and globalization of research about the Cold War, the authors highlight the importance of the full-scale integration of countries and regions of the 'Global South' into Cold War Studies. Critical readings of the newly available resources reveal the existence of important decentralizing perspectives resulting from Cold War entanglements of the 'Global South' with the 'Global North.' As a result, the idea that these state actors from the former 'periphery' of the Cold War should be considered as passive recipients of superpower politics seems rather troubled. The evidence shows (at least partially) autonomous and active multiple actors