Quantification of TFAM Expression in Pig

Biogenesis of mitochondria is a complex process, which involves a number of regulatory mechanisms at transcriptional and posttranscriptional level. The replication and transcription of mtDNA greatly depends on mitochondrial transcription factor TFAM. Differences in expression level, mutations in the gene TFAM coding region and alternative splicing of TFAM primary transcripts affect mitochondrial biogenesis and function of mitochondria. Because of its central role in mitochondrial biogenesis the differences in expression level of TFAM can lead to a wide range of phenotypes at cellular and at the organ level.  In our study we established expression profile of TFAM in different tissues (brain, muscle (longissimus dorsi, semispinalis capitis and semimembranosus), liver, kidney and spleen) and developed qPCR assay for absolute quantification of both splice forms (whole length transcript and short (skipped exon 4) form) in different tissues. The absolute level of expression varied between 100 and 10⁸ copies per 50 mg of tissue. We could also confirm results from our previous experiments, which suggested the presence of two different splicing forms of TFAM in different tissues. In addition, the expression of TFAM plays also an important role in muscle type determination and establishment of oxidative potential of cells in different tissues. Our results confirm the presence of the long and short splice forms in all analyzed tissues.