Ricardo M. Zayas

Photo of Ricardo Zayas

Associate Professor of Biology
Ph.D., Tufts University
Postdoc., University of Illinois at Urbana-Champaign

Department of Biology
Cell & Molecular Doctoral Program
Evolutionary Biology Doctoral Program
Molecular Biology Master’s Program


North Life Sciences 306A
Office: (619) 594-2698
Lab: (619) 594-3042

Planarian Regeneration, Stem Cell Biology

My laboratory studies the molecular and cellular mechanisms underlying tissue regeneration.  To investigate this long-standing biological problem we examine the process of regeneration in freshwater planarians.  These animals are able to form entire worms and replace lost body parts from very small body pieces.  Planarians are endowed with a population of adult pluripotent stem cells (called neoblasts) that serve to replace cells lost during physiological cell turnover and after amputation.  Thus, planarians provide an excellent opportunity to explore conserved molecular mechanisms that regulate maintenance, proliferation and differentiation of stem cells in vivo.

Selected Publications:

Hubert, A., Henderson, J.M., Cowles, M.W., Anderson, C., Szeterlak, C., Hagen, M., and Zayas, R.M. (2015). A functional genomic screen identifies an importin-alpha homolog as a regulator of stem cell function and regeneration in planarians. BMC Genomics (in press).

Henderson, J.M., Nisperos, S.V., Weeks, J., Ghulam, M., Marín, I. and Zayas, R.M. (2015). Identification of HECT E3 ubiquitin ligase family genes involved in stem cell regulation and regeneration in planarians. Dev. Biol. 404, 21-34.

Ross, K.G., Omuro, K.C., Taylor, M.R., Munday, R.K., Hubert, A., King, R.S., and Zayas, R.M. (2015). Novel antibodies to study tissue regeneration in planarians. BMC Dev. Biol. 15: 2.

Cowles, M.W., Omuro, K.C., Stanley, B.N., Quintanilla, C.G., and Zayas, R.M. (2014). COE loss-of-function analysis reveals a genetic program underlying maintenance and regeneration of the nervous system in planarians. PLoS Genetics 10, e1004746.

Cowles, M.W., Brown, D.D.R., Stanley, B., Nisperos, S.V., Pearson, B.J., and Zayas, R.M. (2013). Genome-wide analysis of the basic Helix-Loop-Helix gene family in planarians identifies factors involved in adult neurogenesis and neuronal regeneration. Development 140, 4691-4702.

Hubert, A., Henderson, J.M., Ross, K.G., Cowles, M.W, Torres, J., and Zayas, R.M. (2013).
Epigenetic regulation of planarian stem cells by the SET1/MLL family of histone methyltransferases. Epigenetics 8, 79-91.

Cowles, M.W., Hubert, A., and Zayas, R.M. (2012). A Lissencephaly-1 homologue is essential for mitotic progression in the planarian Schmidtea mediterranea. Dev. Dyn. 241, 901-910.

Zayas, R.M., Cebrià, F., Guo, T., Feng, J., and P. A. Newmark. (2010). The use of lectins as markers for differentiated secretory cells in planarians.  Dev. Dyn. 239, 2888-2897.

Wang, Y., Zayas, R.M., Guo, T., and Newmark, P.A. (2007). nanos function is essential for development and regeneration of planarian germ cells. Proc. Natl. Acad. Sci. U S A 104, 5901-5906.

Zayas, R.M., Hernandez, A., Habermann, B., Wang, Y., Stary, J.M., and Newmark, P.A. (2005). The planarian Schmidtea mediterranea as a model for epigenetic germ cell specification: analysis of ESTs from the hermaphroditic strain. Proc. Natl. Acad. Sci. U S A 102, 18491-18496.

Zayas, R.M., Bold, T.D., and Newmark, P.A. (2005). Spliced-leader trans-splicing in freshwater planarians. Mol. Biol. Evol. 22, 2048-2054.

Zayas Lab Homepage