The present state in the phylogeny and ontogeny of hormone receptors.

Presence of signal receivers (for food, toxic, substances, "hostile" cells etc.) is essential at all levels of phylogenesis. The first encounter of a "hormone to be" with an aspecific membrane structure ("receptor to be") could result in the formation of a lasting receptor-hormone connection if it is adventageous for the cell or organism (which contains the cell), during phylogeny. At higher levels of phylogenesis receptors (ontogenetically) develop according to the differentiation program of the cell, however reinforcement (by the hormone) is necessary in a critical (neonatal) period of receptor development. This is the hormonal imprinting. In that time the receptor could be damaged by the presence of molecules analogous to the hormone. The hormonal imprinting belongs to the perinatal recognition mechanisms of organisms. The possible mechanisms of receptor development are also discussed.