scholarly journals SARS-CoV-2 Spike Affinity and Dynamics Exclude the Strict Requirement of an Intermediate Host

2021 ◽  
Author(s):  
Matteo Castelli ◽  
Luigi Scietti ◽  
Nicola Clementi ◽  
Mattia Cavallaro ◽  
Silvia Faravelli ◽  
...  

SARS-CoV-2 proximal origin is still unclear, limiting the possibility of foreseeing other spillover events with pandemic potential. Here we propose an evolutionary model based on the thorough dissection of SARS-CoV-2 and RaTG13 - the closest bat ancestor - spike dynamics, kinetics and binding to ACE2. Our results indicate that both spikes share nearly identical, high affinities for Rhinolophus affinis bat and human ACE2, pointing out to negligible species barriers directly related to receptor binding. Also, SARS-CoV-2 spike shows a higher degree of dynamics and kinetics optimization that favors ACE2 engagement. Therefore, we devise an affinity-independent evolutionary process that likely took place in R. affinis bats and limits the eventual involvement of other animal species in initiating the pandemic to the role of vector.

Author(s):  
Witold Kwasnicki

AbstractThis paper presents an evolutionary model of industry development, and uses simulations to investigation the role of diversity and heterogeneity in firms’ behaviour, and hence industrial development. The simulations suggest that economic growth is increased with greater variety, in the sense of the evolutionary process approaching the equilibrium faster and also, in the long run, moving faster from one equilibrium to a new, more advanced, equilibrium. This occurs due to higher variety caused by a more tolerant environment, and due to the higher probability of emergence of radical innovations.


Author(s):  
V.I. Bol’shakov ◽  
◽  
Yu.I. Dubrov ◽  
Keyword(s):  

2019 ◽  
Vol 14 (7) ◽  
pp. 598-606
Author(s):  
Sarah Albogami

Background:: Regeneration is the process by which body parts lost as a result of injury are replaced, as observed in certain animal species. The root of regenerative differences between organisms is still not very well understood; if regeneration merely recycles developmental pathways in the adult form, why can some animals regrow organs whereas others cannot? In the regulation of the regeneration process as well as other biological phenomena, epigenetics plays an essential role. Objective:: This review aims to demonstrate the role of epigenetic regulators in determining regenerative capacity. Results:: In this review, we discuss the basis of regenerative differences between organisms. In addition, we present the current knowledge on the role of epigenetic regulation in regeneration, including DNA methylation, histone modification, lysine methylation, lysine methyltransferases, and the SET1 family. Conclusion:: An improved understanding of the regeneration process and the epigenetic regulation thereof through the study of regeneration in highly regenerative species will help in the field of regenerative medicine in future.


Author(s):  
Bipin Singh

: The recent outbreak of novel coronavirus (SARS-CoV-2 or 2019-nCoV) and its worldwide spread is posing one of the major threats to human health and the world economy. It has been suggested that SARS-CoV-2 is similar to SARSCoV based on the comparison of the genome sequence. Despite the genomic similarity between SARS-CoV-2 and SARSCoV, the spike glycoprotein and receptor binding domain in SARS-CoV-2 shows the considerable difference compared to SARS-CoV, due to the presence of several point mutations. The analysis of receptor binding domain (RBD) from recently published 3D structures of spike glycoprotein of SARS-CoV-2 (Yan, R., et al. (2020); Wrapp, D., et al. (2020); Walls, A. C., et al. (2020)) highlights the contribution of a few key point mutations in RBD of spike glycoprotein and molecular basis of its efficient binding with human angiotensin-converting enzyme 2 (ACE2).


Author(s):  
Sergio F. A. Batista ◽  
Deepak Ingole ◽  
Ludovic Leclercq ◽  
Monica Menendez

2019 ◽  
Vol 33 (2) ◽  
pp. 370-375 ◽  
Author(s):  
Camilla de Carvalho de Brito ◽  
Washington Soares Ferreira-Júnior ◽  
Ulysses Paulino Albuquerque ◽  
Marcelo Alves Ramos ◽  
Taline Cristina da Silva ◽  
...  

2019 ◽  
Vol 7 (4) ◽  
pp. 929-947 ◽  
Author(s):  
Michele Delchiaro ◽  
Marta Della Seta ◽  
Salvatore Martino ◽  
Maryam Dehbozorgi ◽  
Reza Nozaem

Abstract. The Seymareh landslide, detached ∼10 ka from the northeastern flank of the Kabir-kuh fold (Zagros Mts., Iran), is recognized worldwide as the largest rock slope failure (44 Gm3) ever recorded on the exposed Earth surface. Detailed studies have been performed that have described the landslide mechanism and different scenarios have been proposed for explaining the induced landscape changes. The purpose of this study is to provide still missing time constraints on the evolution of the Seymareh River valley, before and after the emplacement of the Seymareh landslide, to highlight the role of geomorphic processes both as predisposing factors and as response to the landslide debris emplacement. We used optically stimulated luminescence (OSL) to date lacustrine and fluvial terrace sediments, whose plano-altimetric distribution has been correlated to the detectable knickpoints along the Seymareh River longitudinal profile, allowing the reconstruction of the evolutionary model of the fluvial valley. We infer that the knickpoint migration along the main river and the erosion wave propagation upstream through the whole drainage network caused the stress release and the ultimate failure of the rock mass involved in the landslide. We estimated that the stress release activated a mass rock creep (MRC) process with gravity-driven deformation processes occurring over an elapsed time-to-failure value on the order of 102 kyr. We estimated also that the Seymareh damming lake persisted for ∼3500 years before starting to empty ∼6.6 ka due to lake overflow. A sedimentation rate of 10 mm yr−1 was estimated for the lacustrine deposits, which increased up to 17 mm yr−1 during the early stage of lake emptying due to the increased sediment yield from the lake tributaries. We calculated an erosion rate of 1.8 cm yr−1 since the initiation of dam breaching by the Seymareh River, which propagated through the drainage system up to the landslide source area. The evolutionary model of the Seymareh River valley can provide the necessary constraints for future stress–strain numerical modeling of the landslide slope to reproduce the MRC and demonstrate the possible role of seismic triggering in prematurely terminating the creep-controlled time-to-failure pathway for such an extremely large case study.


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