Molecular evolution and epidemiology of SARS-CoV-2 virus

Koronavirusi često uzrokuju bolesti u ljudi, a jedan od njih, virus SARS-CoV-2, nakon pojave u Kini 2019. postao je problem svjetskih razmjera. S obzirom na to da je njegov genom pozitivna jednolančana RNA molekula, ovaj virus ima relativno visoku stopu mutacija. Brojne mutacije kao glavna pokretačka sila uzrokuju brzu evoluciju što sa sobom često nosi promjene u biološkim karakteristikama virusa. Posebno su česte i problematične one u dijelu genoma koji kodira za protein šiljka jer promjena samo jedne aminokiseline može značajno utjecati na interakcije između proteina šiljka i receptora na stanici domaćina čime se mijenja infektivnost samog virusa. S obzirom na prisutnost određenih mutacija do sada je identificirano pet varijanti koje izazivaju zabrinutost zbog povećane sposobnosti rasprostranjivanja. Praćenjem virusne filodinamike, koja se bavi utjecajem epidemioloških, imunoloških i evolucijskih procesa na gensku raznolikost virusa moguće je dobiti uvid u geografsku rasprostranjenost i patogenezu spomenutih varijanti te procijeniti eventualnu opasnost od razvoja novih. S ciljem olakšavanja istraživanja i boljeg razumijevanja evolucije i rasprostranjivanja virusa gripe i koronavirusa pokrenuta je platforma GISAID u sklopu koje su javno dostupne brojne nukleotidne sekvence te epidemiološki podatci. Upravo na temelju tih podataka provode se mnoge analize koje doprinose razumijevanju evolucije i patogeneza virusa SARS-CoV-2.After its appearance SARS-CoV-2 virus shortly became a global problem. Given that its genome is a positive single-stranded RNA, this virus has a relatively high mutation rate. Numerous mutations as the main driving force cause rapid evolution, which often brings changes in the biological characteristics of virus. Mutations in the part of genome that codes for spike protein are especially common and problematic. The reason for this is that changing a single amino acid can significantly affect interactions between spike protein and receptor on the host cell, thus changing the infectivity. Due to the presence of certain mutations there are until now identified five variants of concearn. By monitoring viral phylodynamics, which deals with the influence of epidemiological, immunological and evolutionary processes ongenetic variability, it is possible to gain insight into the geographical distribution and pathogenesis of variants and assess the eventual risk of developing new variants. With the aim of facilitating better understanding of the evolution of viruses and spread of influenza and coronaviruses, GISAID platform was launched, within which nucleotide sequences and epidemiological data are publicly available. Based on these data, many analyzes are carried out that contribute to the understanding of the evolution and pathogenesis of SARS-CoV-2