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 ut erus during late pregnancy. STUDY DESIGN: A complementary deoxyribonuc leic acid library constructed from late pregnancy mouse uterus was scr eened by differential hybridization with complementary deoxyribonuclei c acid probes constructed from late pregnancy mouse uterus and nonpreg nant mouse uterus. Radiolabeled complementary deoxyribonucleic acid pr obes derived from one of the complementary deoxyribonucleic acids isol ated were used in northern hybridizations against ribonucleic acid col lected from pregnant and nonpregnant uterus and a variety of other mou se 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 o f the complementary deoxyribonucleic acid predicted a novel protein of 154 amino acids that is proline rich and acidic (pregnancy-specific u terine protein). Northern hybridizations demonstrated that message is abundant in the uterus during late pregnancy. After birth expression r apidly decreased and message was no longer found in the uterus by the third day. A minimal amount of message is present in placental ribonuc leic acid, but expression is otherwise not detected in a variety of ad ult and fetal tissues surveyed, suggesting that expression of this gen e is limited to the pregnant uterus. CONCLUSIONS: The abundance of mes sage and expression apparently limited to the pregnant uterus suggests that the protein represented by this complementary deoxyribonucleic a cid may play an important role in pregnancy.