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Most autosomal genes in the placenta show a biallelic expression pattern. However, some genes exhibit allele-specific transcription depending on the parental origin of the chromosomes on which the copy of the gene resides. Parentally expressed genes are involved in the reciprocal interaction between maternal and paternal genes, coordinating the allocation of resources between fetus and mother. One of the main challenges of studying parental-specific allelic expression (allele-specific expression [ASE]) in the placenta is the maternal cellular remnant at the fetomaternal interface. Horses (Equus caballus) have an epitheliochorial placenta in which both the endometrial epithelium and the epithelium of the chorionic villi are juxtaposed with minimal extension into the uterine mucosa, yet there is no information available on the allelic gene expression of equine chorioallantois (CA). In the current study, we present a dataset of 1,336 genes showing ASE in the equine CA (https://pouya-dini.github.io/equine-gene-db/) along with a workflow for analyzing ASE genes. We further identified 254 potentially imprinted genes among the parentally expressed genes in the equine CA and evaluated the expression pattern of these genes throughout gestation. Our gene ontology analysis implies that maternally expressed genes tend to decrease the length of gestation, while paternally expressed genes extend the length of gestation. This study provides fundamental information regarding parental gene expression during equine pregnancy, a species with a negligible amount of maternal cellular remnant in its placenta. This information will provide the basis for a better understanding of the role of parental gene expression in the placenta during gestation.

Grapevine domestication has traditionally been based in clonal propagation, with the aim of enhancing and selecting grapes traits (like fruit size or berry sugar content) and reducing heterogeneity in the vineyard. Due to the domestication process, Vitis vinifera L. was separed in two subspecies based on morphological differences: Vitis vinifera ssp sylvestris and Vitis vinifera ssp vinifera, which differences concentrate in reproductive phenotype and environmental adaptations. These phenotypic differences could be explained both by the selection of genetic and epigenetic variation occured during species evolution. The contribution of genetic variability towards the observed phenotypic diversity and plasticity of cultivated and wild V. vinifera, has been extensively studied. However, very little effort has been directed at the selection of epialleles during grapevine's domestication. To explore the epigenomic differences between the two subspecies, we characterized the methylome across 8 wild accessions (WT) of Vitis vinifera ssp sylvestris and 10 cultivated varieties (CV) of Vitis vinifera L. ssp vinifera using a reduced-representation genome sequening approach (epiGBS). Genome-wide analysis of differentially methylated regions (DMRs) identified a total of 9955 DMRs, of which, 7793 were hypermethylated and 2162 hypomethylated in cultivated varieties in comparison to wild accessions. Additionally, study of the location of DMRs in relation to genomic features, showed higher DNA methylation levels in intergenic regions in WT than in CV in all methylation contexts (i.e., CG, CHG, and CHH). Conversely, we found a higher percentage of methylated regions (in all contexts) in gene promoters of the CV group (and different methylation rates in intron and exon between CV and WT groups). The results suggested that, although the methylome of CV and WT groups were modelled under the same environmental conditions, we showed that regions harboring polymorphic methylation could contribute to functionally relevant phenotypic variation across them. [ABSTRACT FROM AUTHOR]