postzygotilised

Postzygotilised is an adjective used in biology to describe processes, states, or outcomes that occur after fertilization and zygote formation. It designates phenomena arising in the postzygotic stage, as distinct from prezygotic events that prevent zygote formation. The term is a variant of postzygotic, but appears in some texts with the -ilised suffix reflecting older or regional spelling conventions.

In embryology and developmental biology, postzygotilised conditions cover events that take place after the zygote forms, including later stages of embryo development, cellular differentiation, and patterns of gene expression that emerge during early development. In evolutionary biology, the concept is closely connected to postzygotic isolation, where hybrids between species may be inviable, sterile, or exhibit reduced fitness, thereby limiting gene flow between species.

Examples of postzygotic phenomena include reduced viability of hybrid offspring, hybrid sterility, and developmental abnormalities that manifest after fertilization. In plants, postzygotic barriers can include embryo or seed abortion and abnormal hybrid growth. These postzygotic effects contrast with prezygotic barriers, which act before fertilization to prevent the formation of a zygote altogether.

Usage notes: postzygotilised is relatively uncommon in modern literature; many writers prefer postzygotic or post-zygotic. When encountered, it is usually understood in the same sense as postzygotic, describing processes after zygote formation.

See also: postzygotic isolation, prezygotic isolation, zygote, embryo development.