Gene expression in Day-8 equine embryos from young nulliparous mares

The aim of the global study was to compare the effects of maternal age and parity on gene expression of equine embryos. For that, 17 embryos were collected at 8 days post ovulation (expanded blastocyst stage) from 3 groups of young or old nulliparous or multiparous mares: 6 from young nulliparous mares (5 or 6 year-old, never foaled before), 5 from young multiparous mares (6 year-old and foaled at least once) and 6 from old multiparous (10-16 year-old and foaled at least once). 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. Data for young and old multiparous mares had been already published in [accession: GSE162893; https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE162893]. Only data for embryos collected from young nulliparous mares are deposited here Overall design: 6 embryos cut in ICM and TE parts analyzed according to maternal parity (Nulliparous or multiparous mares)