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Uebbing, S.

Publications and source records attributed to Uebbing, S..

2 recordsLinked to original sources

Evaluation of RNA-seq normalization methods using challenging datasets

RNA-seq is a powerful tool for both discovery and experimentation. Most RNA-seq studies rely on library normalization to compare samples or to reliably estimate quantitative gene expression levels. Over the years a number of RNA-seq normalization methods have been proposed. Review studies testing these methods have provided evidence that commonly used methods perform well in simple normalization tasks, but their performance in challenging normalization tasks has yet to be evaluated. Here I test RNA-seq normalization methods using two challenging normalization scenarios. My assessment reveals surprising shortcomings of some commonly used methods and identifies an underappreciated method as the most promising normalization strategy for common, yet challenging RNA-seq experiments.

genomics

Disrupting Pitx1 Regulatory Topology Results In Overtly Normal Limb Development

Gene expression patterns during development are orchestrated in part by thousands of distant-acting transcriptional enhancers. However, identifying enhancers that are essential for expression of their target genes has proven challenging. Genetic perturbation of individual enhancers in some cases results in profound molecular and developmental phenotypes, but in mild or no phenotypes in others. Topological maps of long-range regulatory interactions may provide the means to identify enhancers critical for developmental gene expression. Here, we leveraged chromatin topology to characterize and disrupt the major promoter-enhancer interaction for Pitx1, which is essential for hindlimb development. We found that Pitx1 primarily interacts with a single distal enhancer in the hindlimb. Using genome editing, we deleted this enhancer in the mouse. Although loss of the enhancer completely disrupts the predominant topological interaction in the Pitx1 locus, Pitx1 expression in the hindlimb is only reduced by ~14%, with no apparent changes in spatial distribution or evidence of regulatory compensation. Pitx1 enhancer null mice did not exhibit any of the characteristic morphological defects of the Pitx1-/- mutant. Our results indicate that Pitx1 expression is robust to the loss of its primary enhancer interaction, suggesting disruptions of regulatory topology at essential developmental genes may have mild phenotypic effects.

genetics