Evidence for the independent evolution of "functional progesterone withdrawal" in primates and guinea pigs: a comparative transcriptomic study

Cervix remodeling (CRM) is a critical process in preparation for parturition. Early cervix shortening is a powerful clinical predictor of preterm birth, and thus understanding how CRM is regulated is important for the prevention of prematurity. Humans and other primates differ from most other mammals by the maintenance of high levels of systemic progesterone concentrations and thus differ dramatically from most model species. Humans have been hypothesized to perform functional progesterone withdrawal (FPW), but the mechanisms of FPW are not known. Guinea pigs are similar to humans as they also maintain high progesterone concentrations through parturition. The aim of this study is to document gene expression during pregnancy in the guinea pig uterine cervix in order to assess whether guinea pig can be used as a model for human FPW Overall design: Total RNA obtained from isolated cervical tissues from non-pregnant and two genstation stages (mid-term, and late-term but not in labor).