Figure 3.
Northern blotting analysis of mitochondrial tRNA under denaturing conditions. (A) Two micrograms of total mitochondrial RNA from various cell lines were electrophoresed through a denaturing polyacrylamide gel, electroblotted, and hybridized with DIG-labeled oligonucleotide probes specific for the tRNAThr, tRNALys, tRNAGlu, tRNALeu(CUN) and tRNASer(AGY), respectively. (B) Quantification of tRNA levels. The average tRNAThr content per cell, normalized to the average content per cell of tRNALys, tRNAGlu, tRNA Leu(CUN), and tRNASer(AGY) in three cybrid cell lines derived from one affected subject (IV-3) carrying the m.15927 G > A mutation and three cybrid cell lines derived from one Chinese control individual (HZC25) belonging to the same mtDNA haplogroup (B5) but lacking this mutation. The values for the cybrid cell lines are expressed as percentages of the average value for the control cell lines. The calculations were based on three independent determinations. The error bars indicate two standard errors of the means, the horizontal dashed lines represent the average value for each group. P indicates the significance, according to the t-test, of the differences between mutant and control cybrid cell lines.