|BA||Oxford University||Oxford, England||Botany|
|PhD||Oxford University||Oxford, England||Plant Physiology/Biochemistry|
Dr. Roberts’ laboratory conducts research in four main areas.
A first area of interest is a study of the transcriptional control of expression of the interferon-tau genes (IFNT), whose protein products play a crucial role in establishing communication between the conceptus and mother during early pregnancy of cattle. With Angela Walker, a postdoctoral fellow, we have also recently initiated research on the evolution of the IFNT and the entire type 1 interferon locus in ruminant species and discovered an entirely new sub-family of interferon genes.
A second research area is utilizing human embryonic stem cells (hESC) as models for trophoblast differentiation. These cells can be directed to form colonies with many features of trophoblast when they are exposed to the growth factor BMP4. We are using this model system to explore the initial events that specify trophoblast, the progressive conversion of these cells to more differentiated lineages (especially one with the invasive phenotype of extra-villous trophoblast), and the role of oxygen in the differentiation process.
In a third area with Toshihiko Ezashi, a Research Assistant Professor, the laboratory has created induced pluripotent stem cells (iPSC) from porcine embryonic fibroblasts by re-programming. We are attempting to improve the efficiency of this process and exploring the possible use of such cells for tissue grafts of pigs. Reprogramming also led to the production of cell lines with the properties of trophoblast, thereby providing a potential source of trophoblast stem cells and a means for studying trophoblast specification.
Our fourth interest is in the manner by which maternal diet can influence the sex of offspring in mice and livestock species, and particularly why in mice a diet high in saturated fats can skew sex ratio of pups towards sons while a diet very low in fat favors the birth of daughters.
Amita, M. Adachi, K, Alexenko A.P., Sinha, S., Schust, D.J., Schulz, L.C., Roberts R.M. Ezashi, T. Complete and unidirectional conversion of human embryonic stem cells to trophoblast by BMP4. Proc. Nat. Acad. Sci.111 In Press. PMID 23493551 (2013).
Cibelli, J., Emborg, M., Prockop, D.J., Roberts, R.M., Schatten, G., Rao, M., Harding, J., and Mirochnitchenko, O. Strategies for improving animal models for regenerative medicine. Cell Stem Cell. In Press. PMID 23472868 (2013).
Rosenfeld, C.S., Sieli, P.T., Warzak, D.A., Ellersieck, M.R., Pennington, K.A., and Roberts, R.M. Maternal exposure to bisphenol A and genistein has minimal effect on Avy/a offspring coat color but favors birth of agouti over nonagouti mice. Proc. Nat. Acad. Sci. 110(2): 537-542. PMID 23267115 (2013).
Jasarevic, E., Williams, S.A., Vandas, G.M., Ellersieck, M.R., Liao, C., Kannan, K., Roberts, R.M., Geary, D.C., and Rosenfeld, C.S. Sex and dose-dependent effects of developmental exposure to bisphenol A on anxiety and spatial learning in deer mice (Peromyscus maniculatus bairdii) offspring. Hormones and Behavior 63: 180-189. PMID 23051835 (2012).
Jasarevic, E., Williams, S.A., Roberts, R.M., Geary, D.C., and Rosenfeld, C.S. Spatial navigation strategies in Peromyscus: a comparative study. Animal Behaviour 84(5): 1141-1149. PMID 23355748 (2012).
Ezashi, T., Telugu, B.P., and Roberts, R.M. Induced pluripotent stem cells from pigs and other ungulate species: An alternative to embryonic stem cells? Reproduction in Domestic Animals 47(Suppl. 4): 92-97. PMID 22827356 (2012).
Bermejo-Alvarez, P., Rosenfeld, C.S., and Roberts, R.M. Effect of maternal obesity on estrous cyclicity, embryo development and blastocyst gene expression in a mouse model. Human Reproduction 27: 3513-3522. PMID 23001779 (2012).
Bermejo-Alvarez, P., Roberts, R.M., and Rosenfeld, C.S. Effect of glucose concentration during in vitro culture of mouse embryos on development to blastocyst, success of embryo transfer, and litter sex ratio. Molecular Reproduction and Development 78(5): 329-36. PMID 22431414 (2012).
Gupta, R., Ezashi, T.E., and Roberts, R.M. POU5F1-directed silencing of the CGA subunit gene of human chorionic gonadotropin in human choriocarcinoma and embryonic stem cells through squelching of the transactivational properties of ETS2. Molecular Endocrinology 26: 859-872.PMID 22446105 (2012).
Ezashi, T.E., Telugu, B.P., and Roberts, R.M. Model Systems for Studying Trophoblast Differentiation from Human Pluripotent Stem Cells. Cell & Tissue Research 249: 809-824. PMID 22427062 (2012).
Jasarevic, E., Sieli, S., Twellman, E.E., Welsh, T.H., Schachtman, T.R., Roberts, R.M., Geary, D.C., and Rosenfeld, C.S. Disruption of adult expression of sexually selected traits by developmental exposure to bisphenol A. Proceedings of the National Academy of Sciences USA 108(28): 11715-20. PMID 21709224 (2011).
Telugu, B.P., Ezashi, T.E., Alexenko, A.P., Spate, L., Prather, R.S., and Roberts, R.M. LIF- Dependent, Pluripotent Stem Cells Established from Inner Cell Mass of Porcine Embryos. The Journal of Biological Chemistry 286(33): 28948-53. PMID 21705331 (2011).
Ezashi, T.E., Matsuyama, H., Telugu, B.P., and Roberts, R.M. Generation of colonies of induced trophoblast cells during standard reprogramming of porcine fibroblasts to induced pluripotent stem cells. Biology of Reproduction 85(4): 779-87. PMID 21734265 (2011).
Schulz, L.C. and Roberts, R.M. Dynamic changes in leptin distribution in the progression from ovum to blastocyst of the pre-implantation mouse embryo. Reproduction 141(6): 767-77. PMID 21444625 (2011).
Roberts, R.M. and Fisher, S.J. Trophoblast Stem Cells. Biology of Reproduction 84(3): 412-21. PMID 21106963 (2011).
Roberts, R.M., Katayama, M., Magnuson, S.R., Falduto, M.T., and Torres, K.E. (2011). Transcription profiling of individual twin blastomeres derived by splitting two-cell stage murine embryos. Biology of Reproduction 84(3): 387-94. PMID 21076082
Telugu, B.P., Ezashi, T.E., and Roberts, R.M. The Promise of Stem Cell Research in Pigs and Other Ungulate Species. Stem Cell Review 6(1): 31-41. PMID 19949895 (2010).
Telugu, B.P., Ezashi, T.E., and Roberts, R.M. Porcine Induced Pluripotent Stem Cells Analogous to Naïve and Primed Embryonic Stem Cells of the Mouse. The International Journal of Developmental Biology 54(11-12): 1703-11 (Special issue on Animal Cloning and Cell Reprogramming).PMID 21305472 (2010).
Katayama, M., Ellersieck, M., and Roberts, R.M. Development of monozygotic twin mouse embryos from the time of blastomere separation at the two-cell stage to blastocyst. Biology of Reproduction 82(6): 1237-47. PMID 20181620 (2010).
Katayama, M. and Roberts, R.M. The effect of superovulation on the contributions of individual blastomeres from 2-cell stage CF1 mouse embryos to the blastocyst. The International Journal of Developmental Biology 54(4): 675-81. PMID 20209440 (2010).
Roberts, R.M., Telugu, B.P.L, and Ezashi, T. Induced pluripotent stem cells from swine (Sus scrofa): why they may prove to be important. Cell Cycle 8(19): 3078-81. PMID 19738434 (2009).
Tanasijevic, B., Dai, B., Ezashi, T., Livingston, K., Roberts, R.M., and Rasmussen, T.P. Progressive accumulation of epigenetic heterogeneity during human ES cell culture. Epigenetics 4(5): 330-8. PMID 19571681 (2009).
Ezashi, T., Telugu, B., Alexenko, A., Shrikesh S., Sinha, S., and Roberts, R.M. Derivation of induced pluripotent stem cells from pig somatic cells. Proceedings of the National Academy of Sciences USA 106(27): 10993-8. PMID 19541600 (2009).
Walker, A. and Roberts, R.M. Characterization of the bovine type I IFN Locus: Rearrangements, expansions, and novel subfamilies. BMC Genomics 10:187-202. PMID 19393062 (2009).
Walker, A., Kimura, K., and Roberts, R.M. Expression of bovine interferon-tau variants according to sex and age of conceptuses. Theriogenology 72(1): 44-53. PMID 19324401 (2009).
Egen, T.E., Ealy, A.D., Landon, L.A., Roberts, R.M., and Green, J.A. Autoimmunization of ewes against pregnancy-associated glycoproteins does not interfere with the establishment and maintenance of pregnancy. Animal 3(6): 850-7. PMID 22444772 (2009).
Schulz, L.C, Widmaier, E.P, Qiu, J, and Roberts, R.M. Effect of leptin on mouse trophoblast giant cells. Biology of Reproduction 80(3): 415-24. PMID 19038858 (2009).