Differential expression patterns of peroxiredoxins in olfactory neurons

Abstract

Peroxiredoxins (Prdxs) comprise a large family of cysteine-based peroxidases that are involved in a wide variety of physiological processes. At the single-cell level co-expression of Prdxs has not been studied. We performed gene expression profiling in mouse olfactory neurons and found that individual cells express distinct prdxs in multiple combinations. In the case of conventional interpretation of RT-PCR data, differential expression patterns indicate that each olfactory neuron selects specific set of prdxs to express. However, a new concept of stochastic dynamics of gene expression may provide an alternative interpretation of our data. Here we suggest that the lack of synchronization in transcriptional states of individual genes may give rise to temporal shifts in gene expression pattern, thus constituting a plausible source of variability detected at the single-cell level. If so, the olfactory neuron is likely to transcribe genes for each of the six Prdxs yet with entirely different transcriptional phases. Based on the discontinuous mode of gene expression, the composition of Prdx transcripts within a cell may be variable, and therefore, the outcome of gene expression analysis is likely to depend on the moment of cell harvesting. This assumption easily reconciles the apparent discrepancy between transcriptional profiles derived from single cells and from population of cells.