Embryonic diapause

Part of a series on
Animal dormancy
Torpor Hibernation Hibernaculum HIT Aestivation Cryptobiosis Brumation Diapause Embryonic diapause Winter rest Critical thermal maximum Sleep Developmental biology
v t e

Embryonic diapause^[a] (delayed implantation in mammals) is a reproductive strategy used by a number of animal species across different biological classes. In more than 130 types of mammals where this takes place, the process occurs at the blastocyst stage of embryonic development,^[1] and is characterized by a dramatic reduction or complete cessation of mitotic activity, arresting most often in the G₀ or G₁ phase of division.^[2]

In placental embryonic diapause, the blastocyst does not immediately implant in the uterus after sexual reproduction has resulted in the zygote, but rather remains in this non-dividing state of dormancy until conditions allow for attachment to the uterine wall to proceed as normal.^[3] As a result, the normal gestation period is extended for a species-specific time.^[4][5]

Diapause provides a survival advantage to offspring, because birth or emergence of young can be timed to coincide with the most hospitable conditions, regardless of when mating occurs or length of gestation; any such gain in survival rates of progeny confers an evolutionary advantage.

Cite error: There are <ref group=lower-alpha> tags or {{efn}} templates on this page, but the references will not show without a {{reflist|group=lower-alpha}} template or {{notelist}} template (see the help page).