Mammalian development in space.

Area of Science:

• Space biology
• Developmental biology
• Mammalian reproduction

Background:

• Mammalian life evolved under Earth's gravity, raising questions about reproduction and development in space.
• Spaceflight impacts critical reproductive and developmental phases, including fertilization, embryogenesis, pregnancy, birth, and postnatal maturation.

Purpose of the Study:

• To review the current knowledge of spaceflight effects on mammalian reproduction and development.
• To emphasize fetal and early postnatal life, where most mammalian spaceflight data exists.
• To highlight the importance of the maternal-offspring system in interpreting spaceflight effects.

Main Methods:

• Review of existing mammalian spaceflight data, focusing on fetal and early postnatal development.
• Analysis of studies on rats at different developmental stages (mid-pregnant, early postnatal).
• Consideration of challenges in in-flight caging and maternal-offspring interactions.

Main Results:

• Spaceflight alters maternal-offspring interactions, affecting the interpretation of developmental effects.
• Studies of mid-pregnant rats in space have been successful.
• Studies of early postnatal rodents have faced challenges due to caging and compromised maternal care.

Conclusions:

• Biologically meaningful maternal-offspring interactions are changed in weightlessness.
• There is a strong need for new studies on mammalian reproduction and development in space.
• Habitat development and ground-based testing are crucial for future research, especially with young rodents.