Marja Timmermans

miRNAs as Mobile Signals in Development

University of Tübingen
Faculty in: IMPRS

Portrait of Marja Timmermans in front of a mountain.

Vita

PhD studies at Rutgers University, 1990-1996
Postdoctoral training at Yale University, 1996-1998
Assistant, Associate, and Full Professor at Cold Spring Harbor Laboratory, 1998-2015
Alexander von Humboldt Professor at the University of Tübingen since 2015

Research Interest
The focus of our research is on pattern formation in development. We investigate how new tissues and organs arise at plant stem cell niches. We combine molecular genetics with single cell genomic approaches, quantitative time-lapse imaging, and theoretical modeling to discern the spatiotemporal patterns of gene regulation driving cell fate decisions. Please see here for more detail.

Microscopic images of leaf primordia with highlighted morphogen-like patterning activities of mobile small RNAs. — Figure 1. Gradients of mobile small RNAs have morphogen-like patterning activities. Mobility of miRNAs from their site of biogenesis in the bottom epidermis (A) yields a miRNA gradient (B) that through a threshold-based read-out establishes an on-off pattern of target gene expression (C, D).

Figure 1. Gradients of mobile small RNAs have morphogen-like patterning activities. Mobility of miRNAs from their site of biogenesis in the bottom epidermis (A) yields a miRNA gradient (B) that through a threshold-based read-out establishes an on-off pattern of target gene expression (C, D).

Close-ups of Arabidopsis seedlings with fluorescent reporters in their leaves. — Figure 2. Synthetic system to study miRNA mobility. In seedlings expressing fluorescent reporters (A), artificial miRNAs targeting these reporters are expressed in a regulated often tissue-specific manner (B) to arrive at the parameters and mechanisms of miRNA mobility (C)

Figure 2. Synthetic system to study miRNA mobility. In seedlings expressing fluorescent reporters (A), artificial miRNAs targeting these reporters are expressed in a regulated often tissue-specific manner (B) to arrive at the parameters and mechanisms of miRNA mobility (C)

Available PhD Projects

Selected Reading

Scacchi et al. (2024) A diffusible small-RNA-based Turing system dynamically coordinates organ polarity. Nat Plants 10, 412–422.
Burian A., et al. (2022) Specification of leaf dorsiventrality via a prepatterned binary readout of a uniform auxin input. Nat Plants 8, 269-280.
Denyer, T., et al. (2019) Spatiotemporal developmental trajectories in the Arabidopsis root revealed using high-throughput single cell RNA sequencing. Dev Cell 48, 840-852.
Skopelitis, D., et al. (2018) Gating of miRNA movement at defined cell-cell interfaces governs their impact as positional signals. Nat Commun. 9, 3107.
Skopelitis, D., et al. (2017) Boundary formation through a direct threshold-based readout of mobile small RNA gradients. Dev Cell 43, 265-273.