抄録
The purpose of this study was to compare the availability of fetal DNA in cells and plasma of maternal blood from cynomolgus monkey as an important biomedical model. We also aimed to detect fetal DNA more effectively in maternal blood plasma by amplifying highly repetitive DYS14 (Y chromosome) sequence. PCR detection was performed by using extracted DNA from plasma and cells in blood from pregnant monkeys at the 22nd weeks of gestational age and cord blood. These quantifications were compared by using established real-time PCR assay designed for multi-plex detection of the single-copy SRY gene and DYS14 sequence, and also for uni-plex detection of the NQO1 (NAD(P)H dehydrogenase, quinine 1) gene on chromosome 20. The calculated relative fetal DNA percentages in total DNA based on NQO1 quantification were higher (around SRY-3.17% and DYS14-22.8 %) in per mL blood plasma than in blood cell DNA (around SRY-0.0028 % and DYS14-0.039 %). Our results also indicate that the multi-copy DYS14 sequence detection in low template dilution of male DNA had at least 10-fold more sensitivity than the detection of single copy SRY. Similarly in cell-free fetal DNA detection, DYS14 could be able to detect easily while SRY showed limited copies. Cell-free DNA from maternal blood plasma is the best source to detect fetal DNA in cynomolgus monkey. DYS14 assay is the improvement for quantifying rare cell-free male fetal DNA in maternal blood plasma.
