P-30: The Investigation of Transcript Expression Level of Mitochondrial Transcription Factor A (TFAM) during In Vitro Maturation (IVM) in Single Human Oocytes
In vitro maturation (IVM) of human oocytes has acquired increasing attention in infertility treatment with great promise. This technique is an alternative conventional in vitro fertilization-embryo transfer (IVF-ET), and can be reduced the side effects of gonadotropin stimulation such as ovarian hyperstimulation (OHSS). Oocyte maturation is a complex process including cytoplasmic and nuclear maturation which essential for the acquisition of oocyte competence. Mitochondria are the most predominant organelle in human oocytes.Mitochondria are maternally inherited organelles that supply ATP to the cell by oxidative phosphorylation. Mitochondria have their own genomes. Little is known about the transcript expression of mitochondrial related genomes during oocyte maturation. This study was to identify mitochondrial transcription factor A (TFAM) during IVM in single human oocytes.
Materials and methods
Oocytes at various stages of germinal vesicle(GV) and metaphase I (MI) maturation obtained from 27 consenting women (age 21–35 years), with male factors who were selected for ovarian stimulation and ICSI procedures. Matured oocytes (MII) were generated following IVM. The mRNA level of TFAM identified using single cell taqman Real time-PCR.
The expression level of the target TFAM gene was low at the germinal vesicle (GV) and MI stages (P>0.05). Although, the mRNA level of TFAM gene remained stable in metaphase II (MII) following IVM, the mRNA level of TFAM increased significantly at the stage of MII in in vivo (P<0.05).
Key regulators of cytoplasmic maturation including mitochondrial gene expression were explored to characterize the important components of IVM so that the culture medium with mitochondrial supplemented may be further optimized in oocyte competence.