Lysogeny, or the
lysogenic cycle, is one of two cycles of viral reproduction (the
lytic cycle is the other). Lysogeny is characterized by integration of the
bacteriophage nucleic acid into the host bacterium's genome or formations of a circular
replicon in the bacterium's cytoplasm. In this condition the bacterium continues to live and reproduce normally. The genetic material of the bacteriophage, called a
prophage, can be transmitted to daughter cells at each subsequent cell division, and a later event (such as
UV radiation or the presence of certain chemicals) can release it, causing proliferation of new phages via the
lytic cycle. Lysogenic cycles can also occur in
eukaryotes, although the method of DNA incorporation is not fully understood.