MESSENGER-RIBONUCLEIC-ACID FOR TRANSFORMING GROWTH FACTOR-ALPHA, BUT NOT FOR EPIDERMAL GROWTH-FACTOR, IS EXPRESSED IN FETAL AND NEONATAL MOUSE-BRAIN

OBJECTIVE: Little is known concerning the presence of transforming growth factor-alpha in fetal and neonatal tissues. Our objective was to analyze messenger ribonucleic acid expression for transforming growth factor-alpha and epidermal growth factor, the structural and biochemical analog of transforming growth factor-alpha in fetal and neonatal murine brain. STUDY DESIGN: Messenger ribonucleic acid was prepared from whole brains of mice from these developmental stages: embryonic days 14, 15, and 17, postnatal days 0, 4, 10, and adult. Polymerase chain reaction was performed on the complementary deoxyribonucleic acid obtained from reverse transcription of messenger ribonucleic acid with transforming growth factor-alpha and epidermal growth factor primers. In addition, ribonuclease protection assay was used to identify transforming growth factor-alpha transcripts. RESULTS: We found messenger ribonucleic acid encoding transforming growth factor-alpha in all stages of development used. Epidermal growth factor messenger ribonucleic acid was not found in any stage. Ribonuclease protection assay confirmed transforming growth factor-alpha transcripts in these tissues. CONCLUSION: Transforming growth factor-alpha may play an autocrine or paracrine role in the differentiation or maintenance of murine fetal and neonatal brains.