The mRNA Expression of PAPPA, PLAC8 and PAG in Pregnant Diary Cows
|School||Nanjing Agricultural College|
|Course||Animal Genetic Breeding and Reproduction|
|Keywords||pregnancy cows free RNA PAPPA PLAC8 PAG pregnancy diagnosis|
Pregnancy-specific proteins can be the molecular markers of the pregnant cows. To provide references to early pregnancy diagnose, the mRNA expression of the three pregnancy-specific proteins were investigated in the peripheral blood of the pregnant cows, which including pregnancy-associated plasma protein (PAPPA), placenta-specific gene 8 protein (PLAC8) and pregnancy-associated glycoprotein (PAG). The peripheral blood of the pregnant cows were collected on gestation D30, D60, D90, D150 and D240, as well as the samples of no pregnant cows were collected as negative control. To acquire RNA with high quality method of Column Vrial RNAout was adopted in this study. RT-PCR was adopted to detect the mRNA expression of the pregnancy-specific proteins.This study could be divided into two parts:1. Extraction of fetal free RNA from peripheral blood of pregnant cowsIsolating fetal free RNA is the key point of the research, for it is very difficult to extract high quality RNA because of the small quantity and special existence formality of the fetal free RNA. The experiment compared with routine RNA extraction method and Column Vrial RNAout, results showed that fetal free RNA could not be acquired by routine method but by Column Vrial RNAout.2. The mRNA expression of PAPPA, PLAC8 and PAG in the peripheral blood of the pregnant cowsPAPPA, PLAC8 and PAG are considered as the molecular markers of pregnant cows. Many previous researches reported that PLAC8 and PAG were secreted and expressed in the placenta during gestational period in cows. However PAPPA are not exclusively expressed in the placenta but also in other tissues, but the expression level of placenta was fairly higher than the other tissues. The results showed that:(1) the mRNA expression level of PAPPA in peripheral blood of the pregnant cows are raised compared to the non-pregnancy (p<0.05), and it increased significantly on the D150 (p<0.01); (2) Since PLAC8 were not detected in non-pregnant cows, the expression on D30 data was set as negative control, mRNA expression of PLAC8 was peaked on D150, and it was lowest on D240. In early trimester of pregnancy, the level of PLAC8 mRNA on D60 is higher than both D30 and D90; (3) PAG mRNA level was increased during the whole gestational period. The expressions on D30, D90 and D150 were higher compared with the one of non-pregnant cows (p<0.05), while the level on D60 and D240 were significantly higher (p<0.01).According to the study, it was suggested that PAG could be chosen as the dominant protein in early trimester of pregnant. However, further researches about PAG are needed to elucidate its biological function and transcription regulation mechanisms, which ultimately provide a new prospective and important references to its utilization in the early pregnancy noninvasive diagnosis of dairy cows.