The Study on Expression of Mous Oocyte and Preimplantation Embryc Mct1 and Mct3 Genes in Vivo and in Vitro

Purpose: The aim of this study was to assay the profile of MCT1 & MCD in mouse unfertilized & fertilized oocytes and preimplantation embryos In vivo and In vitro. Materials and Methods: The presence of mRNAs encoding MCT1 & MCD3 were determined On unfertilized and fertilized oocytes, 2-cell, morulae, blastocyst and cultured embryos in plus glucose KSOM, minus glucose KSOM and pulse glucose KSOM by using RNeasy mini column kit. Fertilized oocytes and mentioned embryos were collected 24, 48, 72 & 96 hr. post-hCG injection respectively. In experiments requiring in vitro derived embryos, zygotes were collected and denuded at 18 hr. post-hCG. The culture medium used was KSOM modified to be either glucose-free (KSOM-G) or containing 1mM glucose. Embryos cultured in KSOM-G group were exposed to 27mM glucose at 65 hr. post-hCG for 2 hours (pulse G). Embryos of these three groups were collected at 90 hr. post-hCG injection. Transcripts encoding MCT1 & MCT3 were reversed transcribed in total 201 reaction mixture. PCR products were electrophorized on %2 agarose gel, stained by ethidium bromide and visualized by UV transiluminator. Density of the obtained DNA bands was determined by using Worklab & Excel soft wares. Results: MCT3 transcripts are not detected in mouse oocytes & embryos. MCT1 transcripts were present in oocytes, mentioned developmental stages and cultured embryos except KSOM-G group. DNA density is minimum in 2-C stage and maximum in blastocyst. Conclusion: It can be concluded that MCT1 gene which plays an important role in transport lactate & pyruvatein embryos, can be expressed in mouse oocyte and perimplantation embryos. The Presence of MCT1 mRNA in cultured embryos with glucose and exposed to glucose about 2- or 4-cell stage suggests that exposure of embryos to glucose during movement in oviduct is very important for expression of this gene and maybe is important for continuating transport of pyruvate and lactate across the cell membrane.