English: Generalization of Nidovirales life cycle, based on the information acquired studying Arteriviruses and Coronaviruses. Infection starts with the binding of the viral particle to a cell surface receptor and subsequent cell entry through membrane fusion in endosomes upon endocytosis (step 1). Translation of the released genomic RNA (gRNA) yields replicase polyproteins (step 2), i.e., polyprotein 1a (pp1a) and polyprotein 1ab (pp1ab), which undergo autoproteolytic processing to generate nonstructural proteins that assemble into replication-transcription complexes (RTCs). The RTCs are part of a complex membranous network composed of double membrane vesicles (DMVs) and convoluted membranes (step 4). The RTCs first engage in minus-strand RNA synthesis to produce both single strand full-length and subgenomic (sg) minus-strand RNAs (step 5). Subsequently, they use sg mRNAs as templates for the production of the gRNA and plus-strand sg mRNAs required to express the structural protein genes (step 6). Newly synthesized S, E, and M structural proteins are inserted in the endoplasmic reticulum (ER) (steps 7 and 8), whereas the N nucleocapsides are translated and oligomerize in the cytosol, where they interact with RTCs and associate with the gRNA to form the ribonucleoprotein complexes (step 7). Virion assembly takes place in the ER and/or Golgi (step 9), and involves the inward budding of the limiting membrane of these compartments, which is triggered by the interaction between the structural proteins and the ribonucleoprotein complexes. Mature virions are released extracellularly by exocytosis (step 10).