ABSTRACT
Background: DNA methylation is one the epigenetic mechanisms, which is critically involved in gene expression. This phenomenon is mediated by DNA methyl-transferases and is affected by environmental stress, including in vitro maturation [IVM] of oocytes. Melatonin, as an antioxidant, may theoretically be involved in epigenetic regulation via reductions of reactive oxygen species. This study was performed to investigate DNA methylation and the possibility of goat oocyte development after treatment with different concentrations of melatonin
Materials and Methods: This experimental study was performed to investigate DNA methylation and the possibility of goat oocyte development after treatment with different concentrations of melatonin. For this purpose, oocytes with granulated cytoplasm were selected and co-cultured with at least two layers of cumulus cells in maturation medium with 10-6M, 10-9M, 10-12M and 0-M [as control group] of melatonin. Nucleus status, glutathione content and developmental competence of the oocytes in each experimental group were assessed. Also, expression of genes associated with DNA methylation, including DNA methyltransferase 1 [DNMT1], DNA methyltransferase 3b [DNMT3b] and DNA methyltransferase 3a [DNMT3a] was evaluated by quantitative real time-polymerase chain reaction [RT-PCR]
Results: According to our findings, the percentage of oocytes that reached the M-II stage significantly increased in the 10-12 M group [P<0.05]. Also, a significant elevation of glutathione content was observed in melatonin-treated oocytes [P<0.05]. Analysis of blastocyst formation revealed that developmental competence of the oocytes was higher than the control group [P<0.05]. It was observed that melatonin treatment decreased expression levels of DNA methyltransferases [DNMTs] and global DNA methylation [P<0.05]. In addition, the expression of melatonin receptor1A [MTNR1A] was detected in both cumulus and oocyte by RT-PCR
Conclusion: The results suggested that in goat model melatonin affects DNA methylation pattern, leading to an improvement in the developmental competence of the oocytes
ABSTRACT
Quinazolinones are heterocyclic compounds, with biological and pharmacological activities, such as inhibiting some proteins, enzymes and reducing blood lipids. Following previous results of our group, effects of two new derivatives of quinazolinones 9 [3]-quinazolinone-2-propyl-2-phenylethyl [QPPE] and 9 [3]-quinazolinone-2-ethyl-2-phenylethyl [QEPE] on livers, intestines and kidneys of newborn Balb/C mice were investigated. Pregnant mice were divided into four groups of control, sham, experimental 1, treated with QPPE, and experimental 2, treated with QEPE. Experimental groups received 100 mg/kg body weight [most effective dose] of QPPE and QEPE, sham groups received methyl cellulose 0.05% [the solvent] and control groups received distilled water, intraperitoneally [IP], on day 8 of gestation. Five days after birth, livers, intestines and kidneys were removed, fixed in formalin 10%, stained with hematoxylene and eosin for histological and pathological studies. Results showed appearance of fatty changes in livers, an increase in diameters of hepatocytes and central veins of livers, and reduction in the lengths of villi of proximal, middle and distal segments of newborn Balb/C mice intestines. Furthermore, there was a diminished diameter of the lumen of the proximal tubules, and average diameter of the lumen of distal tubules which led to an increase in the number of glomeruli cells of newborn Balb/C mice kidneys. Regarding inflammation in different parts of the kidneys, livers and intestines, our investigations suggest that quinazolinones may have some toxic effects on embryos