Prenatal fetal head and placental gene expression in a mouse model of advanced maternal age. Prenatal fetal head and placental gene expression in a mouse model of advanced maternal age

Advanced maternal age is a risk factor for neurodevelopmental disorders in offspring. The present study aimed to investigate differences in placental and fetal head gene expression between old and young C57BL6/J female mice. Conceptuses were collected at E12.5 and processed for transcriptomic mRNA gene expression microarray analyses. The most significant differences between old and young females were found in gene expression of the fetal heads (398 differentially expressed genes, DEG) as compared with the placenta (51 DEG). Overall design: Fetuses with their placentas were collected from pregnant BTBR and B6 advanced maternal aged females (42-65 weeks old, AMA) and young (10-23 weeks old, YMA) females. RNA for transcriptomic analyses was extracted from placentas and fetal heads following the manufacturers’ instructions. Total RNA extraction was conducted using the Universal RNA Purification Kit (Eurx, Poland), and included a DNase treatment (Eurx, Poland). The quantity and purity of isolated nucleic acids were validated using a Nanodrop 1000 spectrophotometer (Thermo Fisher Scientific, USA). RNA integrity of selected samples was additionally validated using a Bioanalyzer 2100 microcapillary electrophoresis device (Agilent, USA). Genome-wide transcriptomic analysis was performed using SurePrint G3 Mouse GE v2 8x60K microarrays (GPL21163, Agilent Technologies, USA) and Agilent Technologies Reagent Set according to the manufacturer’s instructions. 100 ng of RNA of each sample (n=4 fetuses and placentas per maternal age group per tissue, only male offspring were selected for microarrays purposes) was labeled using Low Input QuickAmp Labeling Kit One-Color (Agilent Technologies, USA) and hybridized on the microarrays according to the manufacturer’s protocol. Statistical analysis of raw data was carried out using the default protocol of the Partek Genomics Suite. Microarrays analyses were conducted in n=4 conceptuses per maternal age group, obtained from 4 different litter of old and young mothers.