Maternal age affects D8 embryo gene expression both in trophoblast and inner cell

The aim of the study was to compare the effects of maternal age on embryos in horses. For that, 11 embryos were collected at 8 days post ovulation (expanded blastocyst stage) from 2 groups of multiparous mares of different age: 5 from young mares (<10 years old) and 6 from old mares (10-17 years old). Embryos collected were cut in 2 parts: one hemi-embryo containing pure trophoblast and the other one containing trophoblast + inner cell mass. ARN extractions were performed for all samples using PicoPure RNA isolation kit (Applied Biosystem). Five nanograms of both parts of each embryo were sequenced in paired-end with a length of 30-50bp separately using Illumina NextSeq 500 High. Data were trimmed using Cutadapt. Sequences with less than 10bp were removed. 11 embryos cut in ICM and TE parts analyzed according to maternal age (Old or young mares)