|Matteri, Robert - Bob|
Submitted to: Society for the Study of Reproduction Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 7/27/1996
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Intensive studies revealed that insulin-like growth factors (IGFs), their receptors as well as their binding proteins play important roles in regulating mammalian embryonic development. IGF-2 and IGF-1R (receptor of IGF-1) are maternally imprinted in mice during embryo-genesis, and IFG-2R is paternally imprinted. In order to examine their transcriptional activities systematically, porcine pre-implantation embryos derived from IVM and IVF at various stages (2-cell to blastocyst) as well as in vivo derived blastocysts were analyzed through RT-PCR for the presence of mRNA specific to IGF-1R, -2 and -2R. IVM oocytes and electrically activated (EA) oocytes were also studied to evaluate maternal imprinting. All RT-PCR were balanced to 5 embryos in approximately 13 ul reverse transcription reaction and 50 ul PCR reaction. As an internal control, beta-actin was tested and, as a result, its transcripts were detected in all oocytes/ embryos and transcript levels across different developmental stages or periods of time in vitro were approximately the same. IGF-1R mRNA was detected throughout the pre-implantation period among IVM+IVF embryos and in vivo blastocysts. Oocytes and EA oocytes also had transcripts, indicating that IGF-1R might not be maternally imprinted in pig as is in mice. RT-PCR of IGF-2 revealed a very low level of transcripts among IVM+IVF embryos from 4-cell to blastocyst stages. No IGF-2 transcripts were detected from oocytes or EA oocytes at all stages, indicating that it might be maternally imprinted in swine as in mice. Transcripts for IGF-2R were detected throughout the pre-implantation period among IVM+IVF embryos, in vivo derived blastocysts, and oocytes. The transcriptional activities tended to increase at later stages of embryonic development.