Methylation of progesterone receptor isoform A and B promoters in the reproductive system of cows

Abstract

The aim of this study was to investigate whether the promoters of progesterone receptor isoform A (PGRA) and B (PGRB) are methylated and to determine the percentage of methylation occurring for each isoform. Genomic DNA was isolated from the corpora lutea (CL) and endometrial slices from cows on Days 2-5, 6-10, 11-16 and 17-20 of the oestrous cycle. DNA was bisulphite-converted and amplified using methyl-specific polymerase chain reaction (PCR) with primers that detect both methylated and unmethylated sequences. The determination of the percentage of the methylation was performed using HpaII and MspI restriction enzymes. Methyl-specific PCR showed partial methylation of PGRA and PGRB promoters in the CL and endometrium during the oestrous cycle. Methylation for PGRA was between 15 and 17% and for PGRB was in the range of 6 to 7.7% during the oestrous cycle in the CL. In the endometrium, the methylation for PGRA was between 6 and 7.3% and for PGRB was between 3 and 4.8% during the oestrous cycle. The data obtained indicate that the higher promoter methylation of the PGRA isoform could be a mechanism for regulation of PGRA inhibitory activity against PGRB and, in this way, methylation may influence the regulation of progesterone action in the CL and endometrium.

The Identification of RPL4 as a Hub Gene Associated with Goat Litter Size via Weighted Gene Co-Expression Network Analysis

“…Reproductive traits are complex quantitative traits encompassing important indicators such as litter size and ovulation rate, which are regulated by major effect genes and multiple minor effect genes, often referred to as reproductive genes [18,19]. Through traditional molecular marker techniques such as restriction fragment length polymorphism (RFLP), microsatellites, and single nucleotide polymorphisms (SNPs), some major effect genes such as progesterone receptor (PGR), estrogen receptor (ESR), follicle-stimulating hormone (FSHR), prolactin receptor (PRLR), etc., have been identified [20][21][22]. It is not difficult to find that these genes are more or less related to the regulation function of the neuroendocrinereproductive system and have significant impacts on reproductive performance.…”

Effects of DNA Methylation on Gene Expression and Phenotypic Traits in Cattle: A Review

“…The results indicate that the restricted expression of the bovine KPNA7 gene in oocytes is regulated by DNA methylation of its proximal promoter and that demethylation of three CpG sites was closely associated with the tissue specificity of the KPNA7 gene [106]. Rekawiecki et al assessed the percentage of methylation in the promoters of progesterone receptor isozymes A (PGRA) and B (PGRB) and determined that the hypermethylation level of the promoter region of the PGRA subtype might be a mechanism for regulating the inhibition of PGRB activity by PGRA, which may affect the regulation of progesterone in the luteum and endometrium [107]. Takeda used frozen semen samples from Japanese black bulls to record the sire conception rate (SCR), and a human methylation gene chip was used to analyze the methylation level of each CpG site [108].…”