Effects of neonatal methoxychlor exposure on the ovarian transcriptome in piglets

Area of Science:

• Endocrinology
• Toxicology
• Genomics

Background:

• Methoxychlor (MXC) is an organochlorine insecticide with endocrine-disrupting properties.
• Previous studies noted retarded follicle development in neonatal pigs exposed to MXC.
• The precise mechanism of MXC's ovarian action requires further elucidation.

Purpose of the Study:

• To investigate the molecular mechanisms underlying MXC's effects on the neonatal piglet ovary.
• To analyze changes in both protein-coding (mRNA) and long non-coding RNA (lncRNA) expression following MXC exposure.
• To identify specific genes and lncRNAs involved in MXC-induced ovarian dysregulation.

Main Methods:

• Neonatal piglets were treated daily with MXC (100 mg/kg) or corn oil from postnatal days 1-10.
• Ovaries were collected from 11-day-old piglets for total RNA isolation.
• RNA sequencing (RNA-Seq) was performed to profile mRNA and lncRNA expression.

Main Results:

• 460 differentially expressed genes (DEGs) and 143 differentially expressed lncRNAs (DELs) were identified in MXC-treated piglets (P-adj < 0.05; |log2FC| > 1).
• Functional enrichment analysis revealed MXC impacts genes related to intracellular transport, intra-ovarian signaling, and cell-cell communication.
• Correlations between DEGs and DELs suggest a potential role for lncRNAs in mediating MXC's effects.

Conclusions:

• MXC exposure alters gene expression critical for neonatal ovarian folliculogenesis.
• These molecular changes in the neonatal ovary may contribute to future fertility problems.
• lncRNAs may play a role in mediating the endocrine-disrupting effects of MXC in the ovary.