105 Sexual dimorphism in equine D8 blastocysts

In mammals, male embryos grow faster. Equine embryo size is highly variable for same developmental stage, with no reported relation to sex nor gene expression. Our objective was evaluate expression sexual dimorphism on equine D8 blastocysts. Non-nursing, Saddlebred mares located 2 experimental farms were inseminated the semen of one unique stallion per farm. At 8 d post ovulation, 17 and 11 from each farm, a different dam, recovered by uterine flushing bissected obtain samples pure (TE) or inner cell mass enriched (TE-ICM) trophoblast. RNA analyzed separately in TE-ICM TE 16 female 12 using paired end, non-oriented sequencing (Illumina, NextSeq500). To discriminate ICM that TE, deconvolution (DeMixT R package) used data. Differential (DESeq2) farm as cofactors false discovery rate (FDR) < 0.05 cutoff. Gene Set Enrichment Analysis performed KEGG GO BP databases. Out 13,786 13,210 genes expressed respectively, only 184 (51.1% X chromosome) 415 (39.0% differentially expressed, 111 common. Overall, 145 312 significantly upregulated female. As bovine embryos, glucose-6-phosphate dehydrogenase (G6PD) (log2 Fold Change = 0.96 0.83 TE; both FDR <0.001). G6PD required detoxification oxygen radicals have cellular damage growth-stimulant effects. Reduced levels been hypothesized be responsible growth delay embryos. cells, 1 sets KEGG, respectively while 3 pathways ICM. part, 27 6 pathway Biological processes are mostly common between related translation spliceosome, ribosome biogenesis, mitochondrial function, cytoskeleton organization amino acid metabolism. Pathways relate potassium ion homeostasis they protein export. females, Krebs cycle, glycosaminoglycan degradation lysosome. Thus, although retardation has observed embryo, unrelated chromosomes observed.