article published yes Tamar Friedlander author 36A5845C-F248-11E8-B48F-1D18A9856A87 Avraham Mayo author Tsvi Tlusty author Uri Alon author GaTk department International IST Postdoc Fellowship Programme project Bow-tie or hourglass structure is a common architectural feature found in many biological systems. A bow-tie in a multi-layered structure occurs when intermediate layers have much fewer components than the input and output layers. Examples include metabolism where a handful of building blocks mediate between multiple input nutrients and multiple output biomass components, and signaling networks where information from numerous receptor types passes through a small set of signaling pathways to regulate multiple output genes. Little is known, however, about how bow-tie architectures evolve. Here, we address the evolution of bow-tie architectures using simulations of multi-layered systems evolving to fulfill a given input-output goal. We find that bow-ties spontaneously evolve when the information in the evolutionary goal can be compressed. Mathematically speaking, bow-ties evolve when the rank of the input-output matrix describing the evolutionary goal is deficient. The maximal compression possible (the rank of the goal) determines the size of the narrowest part of the network—that is the bow-tie. A further requirement is that a process is active to reduce the number of links in the network, such as product-rule mutations, otherwise a non-bow-tie solution is found in the evolutionary simulations. This offers a mechanism to understand a common architectural principle of biological systems, and a way to quantitate the effective rank of the goals under which they evolved. https://research-explorer.ista.ac.at/download/1827/5161/IST-2016-452-v1+1_journal.pcbi.1004055.pdf application/pdfno Public Library of Science2015 eng 00035219570000610.1371/journal.pcbi.1004055 113 https://research-explorer.ista.ac.at/record/9718 https://research-explorer.ista.ac.at/record/9773 T. Friedlander, A. Mayo, T. Tlusty, and U. Alon, “Evolution of bow-tie architectures in biology,” <i>PLoS Computational Biology</i>, vol. 11, no. 3. Public Library of Science, 2015. Friedlander T, Mayo A, Tlusty T, Alon U. Evolution of bow-tie architectures in biology. <i>PLoS Computational Biology</i>. 2015;11(3). doi:<a href="https://doi.org/10.1371/journal.pcbi.1004055">10.1371/journal.pcbi.1004055</a> Friedlander, Tamar, Avraham Mayo, Tsvi Tlusty, and Uri Alon. “Evolution of Bow-Tie Architectures in Biology.” <i>PLoS Computational Biology</i>. Public Library of Science, 2015. <a href="https://doi.org/10.1371/journal.pcbi.1004055">https://doi.org/10.1371/journal.pcbi.1004055</a>. Friedlander, T., Mayo, A., Tlusty, T., &#38; Alon, U. (2015). Evolution of bow-tie architectures in biology. <i>PLoS Computational Biology</i>. Public Library of Science. <a href="https://doi.org/10.1371/journal.pcbi.1004055">https://doi.org/10.1371/journal.pcbi.1004055</a> T. Friedlander, A. Mayo, T. Tlusty, U. Alon, PLoS Computational Biology 11 (2015). Friedlander, Tamar, et al. “Evolution of Bow-Tie Architectures in Biology.” <i>PLoS Computational Biology</i>, vol. 11, no. 3, Public Library of Science, 2015, doi:<a href="https://doi.org/10.1371/journal.pcbi.1004055">10.1371/journal.pcbi.1004055</a>. Friedlander T, Mayo A, Tlusty T, Alon U. 2015. Evolution of bow-tie architectures in biology. PLoS Computational Biology. 11(3). 18272018-12-11T11:54:14Z2025-09-23T08:43:16Z