Destabilizing mutations encode nongenetic variation that drives evolutionary innovation

Science ◽  
2018 ◽  
Vol 359 (6383) ◽  
pp. 1542-1545 ◽  
Author(s):  
Katherine L. Petrie ◽  
Nathan D. Palmer ◽  
Daniel T. Johnson ◽  
Sarah J. Medina ◽  
Stephanie J. Yan ◽  
...  
Keyword(s):  
Host Recognition ◽  
General Mechanism ◽  
Protein Variation ◽  
Evolutionary Innovation ◽  
Multiple Phenotypes ◽  
Single Genotype ◽  
Enhanced Adsorption ◽  
Phenotypic Forms

Evolutionary innovations are often achieved by repurposing existing genes to perform new functions; however, the mechanisms enabling the transition from old to new remain controversial. We identified mutations in bacteriophage λ’s host-recognition gene J that confer enhanced adsorption to λ’s native receptor, LamB, and the ability to access a new receptor, OmpF. The mutations destabilize λ particles and cause conformational bistability of J, which yields progeny of multiple phenotypic forms, each proficient at different receptors. This work provides an example of how nongenetic protein variation can catalyze an evolutionary innovation. We propose that cases where a single genotype can manifest as multiple phenotypes may be more common than previously expected and offer a general mechanism for evolutionary innovation.

Homology, Genes, and Evolutionary Innovation

2014 ◽  
Author(s):  
Günter P. Wagner
Keyword(s):  
Evolutionary Biology ◽  
Regulatory Networks ◽  
Biological Diversity ◽  
Cell Types ◽  
Origin And Evolution ◽  
Major Transitions ◽  
Form And Function ◽  
Historical Continuity ◽  
Evolutionary Innovation ◽  
Character Identity

Homology—a similar trait shared by different species and derived from common ancestry, such as a seal's fin and a bird's wing—is one of the most fundamental yet challenging concepts in evolutionary biology. This book provides the first mechanistically based theory of what homology is and how it arises in evolution. The book argues that homology, or character identity, can be explained through the historical continuity of character identity networks—that is, the gene regulatory networks that enable differential gene expression. It shows how character identity is independent of the form and function of the character itself because the same network can activate different effector genes and thus control the development of different shapes, sizes, and qualities of the character. Demonstrating how this theoretical model can provide a foundation for understanding the evolutionary origin of novel characters, the book applies it to the origin and evolution of specific systems, such as cell types; skin, hair, and feathers; limbs and digits; and flowers. The first major synthesis of homology to be published in decades, this book reveals how a mechanistically based theory can serve as a unifying concept for any branch of science concerned with the structure and development of organisms, and how it can help explain major transitions in evolution and broad patterns of biological diversity.

Further Evidence for Energy Landscape Flattening in the Superionic Argyrodites Li6+xP1−xMxS5I (M = Si, Ge, Sn)

2019 ◽  
Author(s):  
Saneyuki Ohno ◽  
Bianca Helm ◽  
Till Fuchs ◽  
Georg Dewald ◽  
Marvin Kraft ◽  
...  
Keyword(s):  
Solid State ◽  
Activation Barrier ◽  
Energy Landscape ◽  
General Mechanism ◽  
Ionic Conductors ◽  
Energy Storage Devices ◽  
Ion Conductor ◽  
Storage Devices ◽  
Open Questions ◽  
Sudden Decrease

<p>All-solid-state batteries are promising candidates for next-generation energy storage devices. Although the list of candidate materials for solid electrolytes has grown in the past decade, there are still many open questions concerning the mechanisms behind ionic migration in materials. In particular, the lithium thiophosphate family of materials has shown very promising properties for solid-state battery applications. Recently, the Ge-substituted Li<sub>6</sub>PS<sub>5</sub>I argyrodite was shown to be a very fast Li-ion conductor, despite the poor ionic conductivity of the unsubstituted Li<sub>6</sub>PS<sub>5</sub>I. Therein, the conductivity was enhanced by over three orders of magnitude due to the emergence of I<sup>−</sup>/S<sup>2−</sup>exchange, <i>i.e.</i>site-disorder, which led to a sudden decrease of the activation barrier with a concurrent flattening of the energy landscapes. Inspired by this work, two series of elemental substitutions in Li<sub>6+<i>x</i></sub>P<sub>1−<i>x</i></sub><i>M<sub>x</sub></i>S<sub>5</sub>I (<i>M</i>= Si and Sn) were investigated in this study and compared to the Ge-analogue. A sharp reduction in the activation energy was observed at the same <i>M</i><sup>4+</sup>/P<sup>5+</sup>composition as previously found in the Ge-analogue, suggesting a more general mechanism at play. Furthermore, structural analyses with X-ray and neutron diffraction indicate that similar changes in the Li-sublattice occur despite a significant variation in the size of the substituents, suggesting that in the argyrodites, the lithium substructure is most likely influenced by the occurring Li<sup>+</sup>– Li<sup>+</sup>interactions. This work provides further evidence that the energy landscape of ionic conductors can be tailored by inducing local disorder.</p>

Engagement patterns of users and providers: a study of messaging on app usage in a smartphone app for the treatment of eating disorders (Preprint)

2020 ◽  
Author(s):  
Jane Kim ◽  
Jisung Park ◽  
Jenna Tregarthen
Keyword(s):  
Eating Disorders ◽  
Health Care Providers ◽  
Digital Health ◽  
Communication Styles ◽  
Care Providers ◽  
Digital Tool ◽  
Self Monitoring ◽  
Multiple Phenotypes ◽  
Monitoring Tools ◽  
Level Data

BACKGROUND By offering the ability to immediately communicate with health care providers, digital health apps may significantly bolster the therapeutic relationship. Increasing opportunities of engagement with a digital tool, self-monitoring tools show confer promise in allowing patients to go through periods in between in-clinic visits. Little is known however, regarding the usage of the apps and whether communication between providers and app users in fact encourages usage. OBJECTIVE The objective of this study was to investigate the users of an app for eating disorders and summarize the characteristics of usage, characteristics of communication (i.e. messages sent and received), and assess whether the degree of communication and the degree of app usage (of the main features of the app precluding provider contact) were related. METHODS Users of an app for eating disorders (Tregarthen et al) consented for their de-identified, aggregate level data to be utilized for research. Records of five hundred users were randomly sampled from May 2017 to July 2017. All users in the sampled cohort were linked to a clinician. Raw data included 97,732 observations of meal logs submitted via app across 500 individuals. RESULTS Our data demonstrated a high degree of variability across users in their engagement patterns of the app. Receiving more messages on average had a greater effect on usage than sending messages, implying that being checked in on by clinicians may encourage users to engage more with their app. Data also demonstrated that there were multiple phenotypes in terms of preferences regarding communication – while a portion of users seemed to benefit, a large minority did not demonstrate a change in usage based on the frequency of communication. CONCLUSIONS Understanding usage phenotypes can be instrumental in helping clinician and apps understand who their user is. This work demonstrates that variability among the user population in terms of usage and communication styles, as well as usage and behavior. This information can ultimately be leveraged for guiding effective treatment delivery.

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