Some Mammals Can Just… Pause Pregnancy

Embryonic diapause is a process where over 130 mammal species can pause pregnancy, delaying embryo development. This occurs during the blastocyst stage and can last months or years, allowing animals to optimize offspring production or delay birth until conditions are favorable. Diapause is influenced by environmental cues like hunger and temperature, affecting the mTOR enzyme, which regulates cell growth based on nutrient availability. While humans have mTOR, we cannot pause pregnancies, indicating other factors are involved. Understanding this process could have future applications.

What is embryonic diapause?

• A phase of rapid fetal development

• A stage where the embryo grows rapidly

• A pause in pregnancy development

• A condition where the embryo is expelled

Why might an animal delay the implantation of an embryo?

• To reduce the number of offspring

• To synchronize birth with favorable conditions

• To avoid competition with other species

• To ensure the embryo grows faster

Which animals are most likely to experience embryonic diapause due to environmental cues?

• Herbivores

• Carnivores

• Omnivores

• Insects

What role does the enzyme mTOR play in embryonic diapause?

• It detects nutrient levels and can suppress growth

• It accelerates embryo growth

• It causes the embryo to implant immediately

• It has no role in embryonic diapause

What happens to mTOR levels during a food shortage?

• They decrease, leading to a pause in pregnancy

• They increase, causing rapid growth

• They remain unchanged

• They cause the embryo to be expelled