Cellular and Immune Adaptations at the Maternal-Fetal Interface in Bats

Area of Science:

• Reproductive biology and immunology
• Mammalian placental evolution
• Comparative genomics

Background:

• Bats face unique physiological challenges during pregnancy, including extended gestation and high metabolic demands.
• The cellular and molecular basis of placental adaptations in bats remains largely unexplored.
• Understanding these adaptations is crucial for insights into pregnancy under extreme conditions and evolutionary biology.

Purpose of the Study:

• To map the cellular landscape of the Jamaican fruit bat placenta.
• To identify unique cellular and molecular adaptations supporting bat pregnancy.
• To compare placental development and immune regulation with other mammals.

Main Methods:

• Single-nucleus RNA sequencing (snRNA-seq) of bat placenta.
• Histological and immunohistochemical analyses.
• Derivation of trophoblast and decidual gland organoids for in vitro modeling.
• Cross-species transcriptomic comparisons with human and mouse placentas.

Main Results:

• Identification of diverse trophoblast, stromal, and immune cell populations in the bat placenta.
• Discovery of dynamic trophoblast differentiation trajectories and specialized macrophages.
• Uncovering of bat-specific gene programs and attenuated antiviral signaling in trophoblast organoids compared to human counterparts.

Conclusions:

• Bat placentas possess unique cellular strategies to support pregnancy under extreme physiological stress.
• Species-specific modulation of innate immunity at the maternal-fetal interface is evident in bats.
• This study provides a framework for investigating placental evolution across mammals.