Since its outbreak in 2019,Severe Acute Respiratory Syndrome Coronavirus 2(SARS-CoV-2)keeps surprising the medical community by evolving diverse immune escape mutations in a rapid and effective manner.To gain deeper insight into mutation frequency and dynamics,we isolated ten ancestral strains of SARS-CoV-2 and per-formed consecutive serial incubation in ten replications in a suitable and common cell line and subsequently analysed them using RT-qPCR and whole genome sequencing.Along those lines we hoped to gain fundamental insights into the evolutionary capacity of SARS-CoV-2 in vitro.Our results identified a series of adaptive genetic changes,ranging from unique convergent substitutional mutations and hitherto undescribed insertions.The re-gion coding for spike proved to be a mutational hotspot,evolving a number of mutational changes including the already known substitutions at positions S:484 and S:501.We discussed the evolution of all specific adaptations as well as possible reasons for the seemingly inhomogeneous potential of SARS-CoV-2 in the adaptation to cell culture.The combination of serial passage in vitro with whole genome sequencing uncovers the immense muta-tional potential of some SARS-CoV-2 strains.The observed genetic changes of SARS-CoV-2 in vitro could not be explained solely by selectively neutral mutations but possibly resulted from the action of directional selection accumulating favourable genetic changes in the evolving variants,along the path of increasing potency of the strain.Competition among a high number of quasi-species in the SARS-CoV-2 in vitro population gene pool may reinforce directional selection and boost the speed of evolutionary change.

Sissy Therese Sonnleitner;Stefanie Sonnleitner;Eva Hinterbichler;Hannah Halbfurter;Dominik B.C.Kopecky;Stephan Koblmüller;Christian Sturmbauer;Wilfried Posch;Gernot Walder

Dr.Gernot Walder GmbH,Medical Laboratory,Department of Virology,Ausservillgraten,9931,Austria;Division of Hygiene and Medical Microbiology,Medical University of Innsbruck,Innsbruck,6020,Austria;Institute of Biology,University of Graz,Graz,8010,Austria

中国病毒学

[1]Sissy Therese Sonnleitner;Stefanie Sonnleitner;Eva Hinterbichler;Hannah Halbfurter;Dominik B.C.Kopecky;Stephan Koblmüller;Christian Sturmbauer;Wilfried Posch;Gernot Walder-.The mutational dynamics of the SARS-CoV-2 virus in serial passages in vitro)[J].中国病毒学,2022(02):198-207

mutational,dynamics,SARS,CoV,serial,passages,vitro,Since,its,outbreak,Severe,Acute,Respiratory,Syndrome,Coronavirus,keeps,surprising,medical,community,by,evolving,diverse,immune,escape,mutations,rapid,effective,manner,To,gain,deeper,into,frequency,isolated,ancestral,strains,formed,consecutive,incubation,replications,suitable,common,cell,subsequently,analysed,them,using,qPCR,whole,genome,sequencing,Along,those,lines,hoped,fundamental,insights,evolutionary,capacity,Our,results,identified,series,adaptive,genetic,changes,ranging,from,unique,convergent,substitutional,hitherto,undescribed,insertions,gion,coding,spike,proved,hotspot,number,including,already,known,substitutions,positions,We,discussed,all,specific,adaptations,well,possible,reasons,seemingly,inhomogeneous,potential,culture,combination,uncovers,immense,some,observed,could,not,explained,solely,selectively,neutral,but,possibly,resulted,action,directional,selection,accumulating,favourable,variants,along,path,increasing,potency,Competition,among,high,quasi,species,population,pool,may,reinforce,boost,speed

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