Department of Biology
Dr. Wenyan Xiao
Assistant Professor - Ph.D., The Ohio State University
Phone: (314) 977-2547
Fax: (314) 977-3658
Mail: Department of Biology, St. Louis University, 3507 Laclede Ave. St. Louis, MO 63103-2010
Courses offered: Genetics, Plant Physiology, and Molecular Technique Lab
Research interests: My laboratory studies the mechanisms underlying DNA methylation and demethylation in regulating imprinting and reproduction in plants. DNA methylation is a covalent modification of DNA by addition of a methyl group to the 5-position of cytosine. This is a heritable epigenetic process that plays an important role in genome integrity, X chromosome inactivation, silencing of transposons, gene expression and imprinting. We are employing genetic and molecular approaches to investigate how gene imprinting is controlled and how imprinted genes regulate development in the flowering plant Arabidopsis thaliana. Imprinting, occurring in both mammals and plants, results in gene alleles being expressed or silenced according to their parental origins, and plays an important role in reproductive strategies. In Arabidopsis, DNA methyltransferase1 (MET1), an ortholog of Dnmt1 in mammals, is responsible for maintaining genomic DNA methylation patterns. It has been shown that the MET1 DNA methyltransferase and another DNA-modifying enzyme, Demeter (DME) demethylase, antagonistically regulate gene imprinting and reproduction. Interestedly, we also discovered that genomic hypomethylation affects embryogenesis and seed size in Arabidopsis. Embryos with mutations in MET1 develop improperly, display altered planes and numbers of cell division, and have reduced viability. Furthermore, our results indicate that maternal and paternal genomes play distinct roles in the regulation of seed size. Our current research is focused on how DME finds its targets and how specificity of DNA methylation in regulating gene transcription is achieved.
Research Opportunities: Research opportunities are currently available for both undergraduate and graduate students in the lab. Students can learn basic and useful skills of molecular biology and genetics. Students are encouraged to think and conduct research independently while I provide my advice and input as needed. I intend to see every undergraduate and graduate student reach his or her full potential. Interested undergraduate or graduate students are welcome to send me an email or stop by the lab to discuss research projects.
Wenyan Xiao, Mary Gehring, Yeonhee Choi, Linda Margossian, Hong Pu, John J. Harada, Robert B. Goldberg, Roger I. Pennell, and Robert L. Fischer. 2003. Imprinting of the MEA polycomb gene is controlled by antagonism between MET1 methyltransferase and DME glycosylase. Developmental Cell 5: 891-901.
Wenyan Xiao, Kendra D. Custard, Roy C. Brown, Betty E. Lemmon, John J. Harada, Robert B. Goldberg and Robert L. Fischer. 2006. DNA methylation is critical for Arabidopsis embryogenesis and seed viability. Plant Cell 18: 805-814.
Wenyan Xiao, Roy C. Brown, Betty E. Lemmon, John J. Harada, Robert B. Goldberg, Robert L. Fischer. 2006. Regulation of Seed Size by Hypomethylation of Maternal and Paternal Genomes. Plant Physiology 142: 1160-1168.
Matthew Rea, Ming Chen, Shan Luan, Drutdaman Bhangu, Christopher Braud, Wenyan Xiao. 2011. Determination of DNA methylation of imprinted genes in Arabidopsis endosperm. http://www.jove.com/details.stp?id=2327. Journal of Visualized Experiments 47: doi: 10.3791/2327.
Matthew Rea1, Wenguang Zheng1, Ming Chen, Christopher Braud, Drutdaman Bhangu, Tara N. Rognan, and Wenyan Xiao. 2012. Histone H1 affects gene imprinting and DNA methylation in Arabidopsis. The Plant Journal 71: 776-786. 1M.R. and W.Z. contributed equally to this work.
Christopher Braud1, Wenguang Zheng1, and Wenyan Xiao. 2012. LONO1 encoding a nucleoporin is required for embryogenesis and seed viability in Arabidopsis. Plant Physiology 160: 823-836. 1C.B. and W.Z. contributed equally to this work.
Wenyan Xiao. 2012. Specialized technologies for epigenetics in plants. In: Methods in Molecular Biology: Genomic Imprinting (ed. N. Engel), Humana Press, New York. Page 231-247.Updated 10/31/2012