Determining the association between mitochondrial DNA methylation and transcription

Sammanfattning

Unlike DNA methylation in nuclear DNA, which has been extensively studied, mitochondrial DNA methylation is still at a preliminary stage of research. Moreover, the relationship between mitochondrial DNA methylation and the expression of mitochondrial genes has not yet been thoroughly explored. This study investigates mitochondrial DNA methylation and its impact on gene expression in adult chickens (Gallus gallus) subjected to developmental hypoxia, hypothermia, and combined treatments. Using quantitative PCR, we analyzed mitochondrial copy number and gene expression, while Oxford Nanopore sequencing was used to assess DNA methylation levels. Results indicate that mitochondrial gene expression linked to the electron transport chain complex IV changes with treatment, prior to copy number normalization. However, methylation analysis revealed very low levels of mitochondrial DNA methylation, predominantly at CpG sites. Due to these minimal methylation levels, the relationship between DNA methylation and transcription in mitochondria could not be established. This research underscores the complexity of mitochondrial epigenetics and highlights its potential role in response to environmental stress, providing insights into the subtle yet detectable effects of mitochondrial DNA methylation on mitochondrial activity.