The genetic information is packed as a ribonucleoprotein complex in which RNA is tightly bound by the viral nucleoprotein. The RNA genome of the virus encodes five genes whose order is highly conserved: nucleoprotein (N), phosphoprotein (P), matrix protein (M), glycoprotein (G), and the viral RNA polymerase (L).To enter cells, trimeric spikes on the exterior of the membrane of the virus interact with a specific cell receptor, the most likely one being the acetylcholine receptor. The cellular membrane pinches in a procession known as pinocytosis and allows entry of the virus into the cell by way of an endosome. The virus then uses the acidic environment, which is necessary, of that endosome and binds to its membrane simultaneously, releasing its five proteins and single-strand RNA into the cytoplasm.Once within a muscle or nerve cell, the virus undergoes replication. The L protein then transcribes five mRNA strands and a positive strand of RNA all from the original negative strand RNA using free nucleotides in the cytoplasm. These five mRNA strands are then translated into their corresponding proteins (P, L, N, G and M proteins) at free ribosomes in the cytoplasm. Some proteins require post-translative modifications. For example, the G protein travels through the rough endoplasmic reticulum, where it undergoes further folding, and is then transported to the Golgi apparatus, where a sugar group is added to it (glycosylation).When there are enough viral proteins, the viral polymerase will begin to synthesize new negative strands of RNA from the template of the positive-strand RNA.
Other bird species have been known to develop rabies antibodies, a sign of infection, after feeding on rabies-infected mammals.The virus has also adapted to grow in cells of cold-blooded vertebrates. Most animals can be infected by the virus and can transmit the disease to humans. Worldwide, about 99% of human rabies cases come from domestic dogs. Other sources of rabies in humans include bats, monkeys, raccoons, foxes, skunks, cattle, wolves, coyotes, cats, and mongooses (normally either the small Asian mongoose or the yellow mongoose).Rabies may also spread through exposure to infected bears, domestic farm animals, groundhogs, weasels, and other wild carnivorans. However, lagomorphs, such as hares and rabbits, and small rodents, such as chipmunks, gerbils, guinea pigs, hamsters, mice, rats, and squirrels, are almost never found to be infected with rabies and are not known to transmit rabies to humans. Bites from mice, rats, or squirrels rarely require rabies prevention because these rodents are typically killed by any encounter with a larger, rabid animal, and would, therefore, not be carriers. The Virginia opossum (a marsupial, unlike the other mammals named in this paragraph, which are all eutherians/placental), has a lower internal body temperature than the rabies virus prefers and therefore is resistant but not immune to rabies. Marsupials, along with monotremes (platypuses and echidnas), typically have lower body temperatures than similarly sized eutherians.The virus is usually present in the nerves and saliva of a symptomatic rabid animal. The route of infection is usually, but not always, by a bite.