[Quantitative expression of BAG1, BAX and BCL-2 genes in human embryos with different fragmentation grades derived from ART]

ABSTRACT

The purpose of this study was to evaluate the quantitative expressions of BAG1, BAX and BCL-2 in human embryos with different fragmentation grades as derived from assisted reproduction technology [ART]. Fragmented and normal human 8-cell embryos were scored according to the degree of fragmentation with an inverted microscope and divided into four grades [grade I no or minimal fragmentation [<5%], grade II embryos with <25% fragmentation, grade III embryos with >25% fragmentation and grade IV apoptotic induced embryos with actinomycin D]. In this study, TUNEL labeling was initially used to detect apoptosis, and then revers transcription polymerase chain reaction [RT-PCR] and quantitative PCR were used to define the quantitative expressions of experimental genes in human embryos with different fragmentation grades. The results of TUNEL labeling showed that embryos with higher fragmentation had a high number of apoptotic bodies. The results of RT-PCR and q-PCR analyses showed a significantly decreased amount of BAGI transcript expression from group I to group IV. The highest expression of BAX gene was observed in group II, however, the transcript of BCL-2 gene was not observed in any of the experimental groups. The effect of actinomycin D on transcript expression amounts of experimental genes in apoptotic induced embryos [group IV] compared to control embryos [group I] showed a significant decrease. mRNA expression of BAG1 gene can be used as a good marker to detect apoptosis in human embryos. However, the transcript of BCL-2 gene does not play a role in the detection of apoptosis in human embryos at the 8-cell stage