Identification of gestationally regulated genes in rat myometrium by use of messenger ribonucleic acid differential display

OBJECTIVE: We hypothesized that the proteins contributing to myometrial changes during gestation could be identified indirectly by analyzing the changing pattern of messenger ribonucleic acid expression in the myometrium during pregnancy, STUDY DESIGN: Ribonucleic acid was extracted from myometrium of timed pregnant Sprague-Dawley rats on days 12, 16, 20, 21, and 22 of pregnancy and on day 1 post partum. The technique of messenger ribonucleic acid differential display, a simple and sensitive polymerase chain reaction-based method for rapidly identifying messenger ribonucleic acids whose levels increase or decrease, was performed with the nine different anchoring primers (oligodeoxythymidine(11) VN: V = G, A, or C; N = G, A, or C) in combination with 24 different 10-base oligonucleotides of random sequence. The polymerase chain reaction products were separated by electrophoresis on a 5% polyacrylamide sequencing gel, and those whose levels changed were then cloned, sequenced, and compared with those in the GenBank database to determine whether they corresponded to a known sequence in the database or were novel. Semiquantitative reverse transcriptase-polymerase chain reaction was used to confirm differential expression of selected products. RESULTS: Messenger ribonucleic acid differential display revealed >500 polymerase chain reaction products that were differentially expressed during gestation, 179 of which were cloned and sequenced. Of these, 157 were from messenger ribonucleic acids whose levels increased during gestation, and 22 were from transcripts that decreased. Eighty-seven (49%) were related to sequences in the GenBank database, of which 62 (35%) were from messenger ribonucleic acids encoding known proteins and 25 (14%) corresponded to known expressed sequence tags. The technique of semiquantitative reverse transcriptase-polymerase chain reaction confirmed the increased expression of messenger ribonucleic acids encoding beta-tropomyosin, type II phosphatidyl inositol-4-phosphate 5-kinase, and a novel myometrial messenger ribonucleic acid named RPU0901AC. CONCLUSION: Messenger ribonucleic acid differential display is a simple and sensitive method for rapidly identifying myometrial messenger ribonucleic acids that are differentially regulated during pregnancy. The identification of these differentially expressed messenger ribonucleic acids may lead to a better understanding of the molecular basis of normal and abnormal parturition.