Differential expression of the full-length and truncated forms of the epidermal growth factor receptor in the preimplantation mouse uterus and blastocyst.
The present investigation examined the differential expression of the full-length (fl) and the truncated (tr) forms of the epidermal growth factor receptor (EGFr) in the preimplantation mouse uterus and blastocyst. Northern blot hybridization using a complementary RNA probe specific to the full-length form (EGFr-fl) detected a 6.5-kb transcript, whereas that of the truncated form (EGFr-tr) detected a 2.7-kb transcript in the preimplantation mouse uterus on days 1 and 4 of pregnancy (day 1 = vaginal plug). In situ hybridization using these probes detected the EGFr-fl transcripts only in the stroma and myometrium, but not in the epithelium, whereas EGFr-tr transcripts were detected in all major uterine cell-types. To confirm the results of in situ hybridization, RT-PCR was performed on RNA isolated from separated uterine cell-types on day 4 of pregnancy using sequence specific primers for the two forms of the receptor. The results concur that the EGFr-tr transcript is expressed in the epithelium, stroma and myometrium, whereas that of the EGFr-fl transcript is not expressed in the epithelium. In the preimplantation blastocyst, RT-PCR detected the EGFr-fl messenger RNA, but not the EGFr-tr messenger RNA. These results suggest that the blastocyst, not the uterine epithelium, is the target for EGF family of growth factors in embryo-uterine interaction during implantation.
Tong
B J
BJ
Department of Physiology, Ralph L. Smith Research Center, University of Kansas Medical Center, Kansas City, 66160, USA.
Das
S K
SK
Threadgill
D
D
Magnuson
T
T
Dey
S K
SK
D000818:Animals; D001483:Base Sequence; D001755:Blastocyst / Q000737:chemistry*; D015152:Blotting, Northern; D018076:DNA, Complementary; D047108:Embryonic Development; D066246:ErbB Receptors / Q000378:metabolism*; D005260:Female; D017403:In Situ Hybridization; D051379:Mice; D008815:Mice, Inbred Strains; D015335:Molecular Probes / Q000235:genetics; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000378:metabolism*; D016133:Polymerase Chain Reaction / Q000379:methods; D011247:Pregnancy; D014158:Transcription, Genetic; D014599:Uterus / Q000737:chemistry*
D018076:DNA, Complementary; D015335:Molecular Probes; D010446:Peptide Fragments; D066246:ErbB Receptors