Rebecca A Mosher

Rebecca A Mosher

Associate Professor, Plant Sciences
Associate Director, School of Plant Sciences
Associate Professor, Applied BioSciences - GIDP
Associate Professor, Genetics - GIDP
Associate Professor, BIO5 Institute
Primary Department
Department Affiliations
Contact
(520) 626-4185

Work Summary

Dr. Mosher studies methylation of DNA in plants and how these epigenetic marks are transmitted from parent to offspring.

Research Interest

Rebecca Mosher, PhD, studies how epigenetic information is passed from parent to offspring. Epigenetic information refers to signals laid on top of DNA sequence that affect how and when genes are turned on. Examples of epigenetic signals include chemical modifications of DNA, packaging of DNA around proteins, or the position of DNA in the nucleus. Beginning with Mendel’s observations of pea plants, we have developed a robust understanding of how genetic information in the form of DNA is passed from parent to offspring, but we are only beginning to comprehend how and when epigenetic information is passed from generation to generation. Some epigenetic marks are erased and re-established during reproduction, while others are inherited for many generations. Using plants as models, the Mosher lab studies how tiny RNA molecules place and erase epigenetic marks during reproduction and how the epigenetic marks from the maternal and paternal genomes interact after fertilization.

Publications

Grover, J., Kendall, T., Baten, A., King, G. J., & Mosher, R. A. (2017). Maternal RNA-directed DNA methylation is required for seed development in Brassica rapa. bioRxiv.

This preprint has been reviewed and is currently being revised for publication at Plant Journal.

Wang, Y., Tsukamoto, T., Noble, J. A., Liu, X., Mosher, R. A., & Palanivelu, R. (2017). Arabidopsis LORELEI, a Maternally Expressed Imprinted Gene, Promotes Early Seed Development. PLANT PHYSIOLOGY, 175(2), 758-773.
Bowman, J. L., Kohchi, T., Yamato, K. T., Jenkins, J., Shu, S., Ishizaki, K., Yamaoka, S., Nishihama, R., Nakamura, Y., Berger, F., Adam, C., Aki, S. S., Althoff, F., Araki, T., Arteaga-Vazquez, M. A., Balasubrmanian, S., Barry, K., Bauer, D., Boehm, C. R., , Briginshaw, L., et al. (2017). Insights into Land Plant Evolution Garnered from the Marchantia polymorpha Genome. Cell, 171(2), 287-304.e15.
Rhind, N., Chen, Z., Yassour, M., Thompson, D. A., Haas, B. J., Habib, N., Wapinski, I., Roy, S., Lin, M. F., Heiman, D. I., Young, S. K., Furuya, K., Guo, Y., Pidoux, A., Chen, H. M., Robbertse, B., Goldberg, J. M., Aoki, K., Bayne, E. H., , Berlin, A. M., et al. (2011). Comparative functional genomics of the fission yeasts. Science, 332(6032), 930-936.

PMID: 21511999;PMCID: PMC3131103;Abstract:

The fission yeast clade - comprising Schizosaccharomyces pombe, S. octosporus, S. cryophilus, and S. japonicus - occupies the basal branch of Ascomycete fungi and is an important model of eukaryote biology. A comparative annotation of these genomes identified a near extinction of transposons and the associated innovation of transposon-free centromeres. Expression analysis established that meiotic genes are subject to antisense transcription during vegetative growth, which suggests a mechanism for their tight regulation. In addition, trans-acting regulators control new genes within the context of expanded functional modules for meiosis and stress response. Differences in gene content and regulation also explain why, unlike the budding yeast of Saccharomycotina, fission yeasts cannot use ethanol as a primary carbon source. These analyses elucidate the genome structure and gene regulation of fission yeast and provide tools for investigation across the Schizosaccharomyces clade.

Harris, R. A. (2011). Pol IV-Dependent siRNAs in Plants. NON CODING RNAS IN PLANTS, 419-445.

In plants, the most abundant class of small RNAs are 24-nucleotide short interfering (si)RNA. These siRNAs are produced at thousands of discrete genomic locations through the action of the plant-specific DNA-dependent RNA polymerase IV (Pol IV). Pol IV-dependent siRNAs catalyze repressive DNA methylation on transposable elements and other repetitive sequences, but might trigger diverse chromatin modifications at distinct genomic locations, such as DNA demethylation or histone modification. Pol IV-dependent siRNAs are expressed abundantly, and sometimes exclusively, in the developing endosperm, where they are produced from only the maternal chromosomes. The biological role of Pol IV-dependent siRNAs is unclear, but might involve interaction between different genomes or alleles, or stabilizing and buffering the genome from genetic and epigenetic modifications.