Page Banner

United States Department of Agriculture

Agricultural Research Service

Title: Global Gene Expression Analysis of the Living Human Fetus Using Cell-Free Messenger Rna in Amniotic Fluid

Authors
item Larrabee, Paige - TUFTS-NEW ENGLAND MED CTR
item Johnson, Kirby - TUFTS-NEW ENGLAND MED CTR
item Lai, Chao Qiang
item Ordovas, Jose
item Cowan, Janet - TUFTS-NEW ENGLAND MED CTR
item Tantravahi, Umadevi - BROWN UNIVERSITY, R.I.
item Bianchi, Diana - TUFTS-NEW ENGLAND MED CTR

Submitted to: Journal of the American Medical Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 1, 2005
Publication Date: February 16, 2005
Citation: Larrabee, P.B., Johnson, K.L., Lai, C., Ordovas, J.M., Cowan, J.W., Tantravahi, U., Bianchi, D.W. 2005. Global gene expression analysis of the living human fetus using cell-free messenger RNA in amniotic fluid. Journal of the American Medical Association. 16;293(7):836-42.

Interpretive Summary: Currently, there are no molecular biologic tests available to monitor the ongoing development of human fetuses in vivo. The purpose of this research was to determine whether fetal messenger RNA (mRNA) could be detected in amniotic fluid using oligonucleotide microarrays to study large-scale gene expression in living human fetuses, analyzing gender, gestational age and fetal pathology as variables. Our results demonstrate for the first time the technical ability to measure fetal mRNA in amniotic fluid. Moreover, we demonstrate that 36% of the mRNA represented in the microarrays were present in the amniotic fluid. Only male samples expressed one Y chromosome transcript. The expression of some developmental transcripts, such as surfactant proteins, mucins and keratins, changed with gestational age by up to 64-fold. Placental gene transcripts were not present in any samples. In conclusion, this pilot study demonstrates that cell-free fetal mRNA can be extracted from amniotic fluid and successfully hybridized to gene expression microarrays. Preliminary analysis suggests that gene expression changes can be detected in fetuses of different genders, gestational age, and disease status. Cell-free mRNA in amniotic fluid appears to originate from the fetus and not the placenta.

Technical Abstract: Currently, there are no molecular biologic tests available to monitor the ongoing development of human fetuses in vivo. Our objective was to determine whether cell-free fetal messenger RNA (mRNA) in amniotic fluid could be detected using oligonucleotide microarrays to study large-scale gene expression in living human fetuses, analyzing gender, gestational age and fetal pathology as variables. Four samples of cell-free amniotic fluid were analyzed from pregnant women between 20-32 weeks undergoing amnioreduction for polyhydramnios associated with twin-twin transfusion syndrome or hydrops fetalis (cases). The control consisted of 6 pooled amniotic fluid samples from women at 17 weeks undergoing genetic amniocentesis. After extraction from the normally discarded fraction of amniotic fluid, RNA was amplified twice, labeled and analyzed using gene expression microarrays. The main outcome measures were relative mRNA expression in cell-free samples of amniotic fluid from fetuses with polyhydramnios at different gestational ages versus cell-free amniotic fluid from a pooled control at 17-weeks' gestation. Thirty-six percent of probe sets represented on the arrays were present in the cell-free amniotic fluid and 20% of all transcripts differed between cases and the pooled control. Only male samples expressed one Y chromosome transcript. The expression of some developmental transcripts, such as surfactant proteins, mucins and keratins, changed with gestational age by up to 64-fold. A water transporter gene transcript was increased up to 20-fold in both twin-twin transfusion samples. Placental gene transcripts were not present in any samples. This pilot study demonstrates that cell-free fetal mRNA can be extracted from amniotic fluid and successfully hybridized to gene expression microarrays. Preliminary analysis suggests that gene expression changes can be detected in fetuses of different genders, gestational age, and disease status. Cell-free mRNA in amniotic fluid appears to originate from the fetus and not the placenta.

Last Modified: 12/17/2014
Footer Content Back to Top of Page