A novel complementary deoxyribonucleic acid is abundantly and specifically expressed in the uterus during pregnancy.

OBJECTIVE

Our purpose was to identify novel genes expressed by the uterus during late pregnancy.

STUDY DESIGN

A complementary deoxyribonucleic acid library constructed from late pregnancy mouse uterus was screened by differential hybridization with complementary deoxyribonucleic acid probes constructed from late pregnancy mouse uterus and nonpregnant mouse uterus. Radiolabeled complementary deoxyribonucleic acid probes derived from one of the complementary deoxyribonucleic acids isolated were used in northern hybridizations against ribonucleic acid collected from pregnant and nonpregnant uterus and a variety of other mouse tissues.

RESULTS

A total of 40 positive clones were isolated; half were identified as cytotoxic T-lymphocyte antigen-2 alpha (a putative inhibitor of the protease cathepsin L) and the other half represented a novel complementary deoxyribonucleic acid. Conceptual translation of the complementary deoxyribonucleic acid predicted a novel protein of 154 amino acids that is proline rich and acidic (pregnancy-specific uterine protein). Northern hybridizations demonstrated that message is abundant in the uterus during late pregnancy. After birth expression rapidly decreased and message was no longer found in the uterus by the third day. A minimal amount of message is present in placental ribonucleic acid, but expression is otherwise not detected in a variety of adult and fetal tissues surveyed, suggesting that expression of this gene is limited to the pregnant uterus.

CONCLUSIONS

The abundance of message and expression apparently limited to the pregnant uterus suggests that the protein represented by this complementary deoxyribonucleic acid may play an important role in pregnancy.