DNA methylation is a well-studied epigenetic modification that regulates gene expression, maintains genome integrity, and influences cell fate. It is strictly regulated by a group of enzymes known as DNA methyltransferases (DNMTs). Most DNA methylation occurs at cytosines within symmetrical CpG dinucleotide base pairs, often located at gene promoters or other regulatory elements. Thus, methylation of a promoter CpG island leads to stable transcriptional repression of the associated gene. Nonetheless, abnormal gene expression caused by alterations in DNA methylation has been linked to infertility in both males and females, as well as to reproductive potential and improper post-fertilization embryo development. Recent epigenetic advancements have highlighted the significant association between epigenetic modification and reproductive health outcomes, garnering considerable attention. In this review, we explore significant advancements in understanding DNA methylation, emphasizing its establishment, maintenance, and functions in male and female reproductive sex cells. We also shed light on the recent discoveries on the influence of environmental exposures, nutrition, infection, stress, and lifestyle choices on DNA methylation. Finally, we discuss the latest insights and future directions concerning the diverse functions of DNA methylation in reproductive outcomes.

Fertilizers play an important role in enhancing crop yield, growth, and fertility of the soil. This research was conducted at the Faculty of Agriculture teaching and research farm, University of Port Harcourt, Nigeria to investigate the influence of inorganic fertilizer (urea) and organic manure (spent mushroom substrate and poultry manure) on the yield and growth parameters of three okra cultivars (Clemson Spineless, Perkin Long Pod and the Local Assertion). The urea was applied at the rate of 4g per 10kg of soil, while spent mushroom substrate and poultry manure were applied at the rates of 200g and 150g per 10kg of soil respectively at 4 weeks after planting. The treatments were laid in a completely randomized design (CRD) with 3 replications. The results revealed that the okra cultivars responded positively to both organic manures when compared with urea and the control group where no fertilizer was applied. Furthermore, varieties grown with poultry manure generally had the highest fresh fruit weight, plant height, fruit length, number of fruits, and fresh fruit yield. Spent mushroom substrate influenced the number of fruits and fruit yield while urea influenced the leaf area, number of leaves, and leaf area index. Poultry manure was recorded as the best organic manure for okra growth and yield and is recommended to be used to grow okra plants. Also, the Perkin Long Pod variety is recommended to be the best for cultivation.