mRNAs for insulin-like growth factor-II (IGF-II) and variant IGF-II are co-expressed in human fetal ovary and uterus.
Insulin-like growth factor-II (IGF-II) is postulated to have autocrine and/or paracrine functions in developing fetal tissues, but has never been reported in human fetal reproductive organs. The forms of IGF-II found in normal human serum include a 67 amino acid form and a variant form resulting from alternate splicing of the mRNA such that Ser-29 is replaced by four other amino acid residues. We studied the expression of mRNA encoding IGF-II in human fetal ovaries and uteruses of 10, 15, 19 and 22 weeks of gestation. By reverse transcription followed by polymerase chain reaction (PCR), we identified the co-expression of two mRNAs encoding IGF-II in all developmental stages of fetal ovaries and uteruses tested. One of the PCR amplified fragments was 9 nucleotides larger than the other. The PCR amplified ovarian and uterine DNA fragments were mapped by digestion with the restriction endonucleases AvaII and PvuII and both the IGF-II fragment and the larger IGF-II fragment produced the anticipated DNA patterns by gel electrophoresis. The PCR amplified DNA fragments were cloned and sequenced to confirm that the expressed mRNAs encoded IGF-II and variant IGF-II. We conclude that IGF-II and variant IGF-II mRNA co-expression occurs in the human fetal female genital tract and that the two forms of the growth factors may have physiologic roles in reproductive tract development.
Yeh
J
J
Department of Obstetrics, Gynecology and Reproductive Biology, Brigham and Women's Hospital, Boston, MA 02115.
Danehy
F T
FT
Osathanondh
R
R
Villa-Komaroff
L
L
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA; D005260:Female; D014644:Genetic Variation; D006801:Humans; D007335:Insulin-Like Growth Factor II / Q000235:genetics*; D008969:Molecular Sequence Data; D010053:Ovary / Q000196:embryology / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D014599:Uterus / Q000196:embryology / Q000378:metabolism*
D012333:RNA, Messenger; D007335:Insulin-Like Growth Factor II; D004247:DNA