Mammalian Development

Mammalian Development

oocyte-to-embryo transition, reprogramming, mouse/human embryonic stem cell differentiation

Principal Investigator

Prof Davor Solter & Prof Barbara Knowles

Group Members

Senior Research Fellows: Stuart AVERY, Katie AVERY, LIM Chin Yan
Research Fellows: CHEW Ting Gang, Chanchao LORTHONGPANICH, MESSERSCHMIDT, Daniel
Senior Research Officer: THAM Puay Yoke Doris
Research Officers: Sathish BALU, LING Ka Yi
Asst Laboratory Officer: CHOO Siew Chin
Student: Di DONG (NUS)

Our Research

Unraveling the molecular complexity that underlies plasticity between the embryonic stem cell/differentiated cell state has become one of the major scientific themes of our time. The transcriptome, the signal transduction mechanisms regulating its stability and translation, and chromatin modifications are inter-related mechanisms that control this change of cell fate. In earlier times we investigated cell surface molecules and extracellular matrix changes accompanying embryonic stem cell differentiation. In recent years we have focused on the oocyte-to-embryo transition, gaining knowledge of the transcriptome and molecular processes that govern activation of the embryonic genome. We now propose to reciprocally study these processes in vivo in mouse oocytes and embryos and in vitro in human and mouse embryonic stem cells.

The first cleavage plane is specified by topology of the two apposing pronuclei in the ooplasm

There is no transcription during the oocyte to embryo transition. Accordingly, the molecular processes driving the nuclei of the gametes to a functional totipotent stem cell is driven by signal transduction, selective destruction of proteins and RNAs and controlled mRNA translation. Through analysis of the full grown oocyte transcriptome we discovered a new mammalian oocyte-specific eukaryotic translation initiation factor, 4E (Eif4eoo), suggesting a novel regulation of translation in the oocyte and early embryo, an hypothesis which awaits serious functional analysis.

We are also investigating motifs in the 3’-untranslated regions of maternal mRNAs that may serve as binding motifs for miRNAs and proteins that control translation during progression through ovulation, fertilization and genome activation. Detailed analysis of the interaction of these motifs with their RNA and protein recognition molecules is another planned area of research.

Signal transduction through the SMADs, members of the TGFβ super family, is crucial to maintaining the undifferentiated, pluripotent state of mouse embryonic stem cells. We are currently investigating the role of SMAD4 in regulating differentiation of human embryonic stem cells and are planning to extend this research to other members of the SMAD complex. Understanding the role of these signal transduction factors and the complexity of their interaction is central to the use of human embryonic stem cells in cell replacement therapy.

We also plan to investigate reprogramming, introducing differentiated human fibroblasts into enucleated mouse oocytes, comparing the process to that accomplished by specific genes or chemical treatment of fibroblasts to make iPS cells. Epigenetic changes occurring during oogenesis will be a focus, starting from exploration of the mode of action of a maternal effect gene influencing normal germ cell development in subsequent generations.

Staff Profiles

Representative Publications

Evsikov AV, de Vries WN, Peaston A, Fancher K, Chen F, Radford E, Latham K, Blake J, Bult C, Solter D, Knowles BB. 2004. Systems biology of the 2-cell embryo. Cytogenet. Genome. Res., 105:240-250.

Solter, D., Hiiragi, T., Evsikov, A.V., Moyer, J., de Vries, W.N., Peaston, A.E., and Knowles, B.B. 2004. Epigenetic mechanisms in early mammalian development. Cold Spring Harbor Symposia on Quantitative Biology 69: 11-17.

Hiiragi, T. and Solter, D. 2004. First cleavage plane of the mouse egg is not predetermined but defined by the topology of the two apposing nuclei. Nature 430: 360-364.

Chen W, Masterman K-A, Basta S, Dimopoulos N, Knowles BB, Bennink, JR and Jonathan W. Yewdell.2004. Cross-Priming of CD8 + T Cells to Viral and Tumor Antigens is a Robust Phenomenon Europ.J. Immunol, 34:194-9.

de Vries WN, Evsikov AV, Fancher K, Haac BE, Solter D, Kemler R, Knowles BB. 2004. Development of mouse preimplantation embryos lacking maternal β-catenin and E-cadherin: insights into zygotic genome activation. Development,131: 4435-45.

Peaston AE, Evsikov AV, Graber J, de Vries WN, Solter D, and Knowles BB. 2004. Retrotransposons regulate host genes in mouse oocytes and preimplantation embryos. Developmental Cell, 7: 597-606.

Kemler, R, Hierholzer A, Kanzler B, Kuppig S, Hansen K, Taketo M, de Vries WN, Knowles BB, and Solter, D. 2004. Stabilization of β-catenin in the mouse zygote leads to premature epithelial-mesenchymal transition in the epiblast. Development,131:4435-45.

Mikaelian I, Blades N, Churchill GC, Fancher K, Knowles BB, Eppig JT, Sundberg JP. 2004. Classification of spontaneous and transgenic mammary neoplasms, Breast Cancer Res. 6:668-79.

Mehlmann,LM, Saeki Y, Tanaka S,. Brennan TJ, Evsikov AV, Pendola F, Knowles BB, EppigJJ, Jaffe LA. 2004. The Gs-linked receptor GPR3 maintains meiotic arrest in mammalian oocytes Science, 306:1947-50.

Kemler, R, Hierholzer A, Kanzler B, Kuppig S, Hansen K, Taketo M, de Vries WN, Knowles BB, and Solter, D. 2004. Stabilization of b-catenin in the mouse zygote leads to premature epithelial-mesenchymal transition in the epiblast. Development131:5817-24.

Solter, D. 2005. Politically correct human embryonic stem cells? N. Engl. J. Med. 353: 2321-2323.

Motosugi, N., Bauer, T., Polanski, Z., Solter, D., and Hiiragi, T. 2005. Polarity of the mouse embryo is established at blastocyst and is not prepatterned. Genes Dev. 19: 1081-1092.

Solter, D. 2006. From teratocarcinomas to embryonic stem cells and beyond: a history of embryonic stem cell research. Nat. Rev. Genet. 7: 319-327.

Motosugi, N., Dietrich, J.-E., Polanski, Z., Solter, D., and Hiiragi, T. 2006. Space asymmetry directs preferential sperm entry in the absence of polarity in the mouse oocyte. PloS Biology 4: e135.

Otahal P, Schell TD, Hutchinson SC, Knowles BB and Tevethia SS. 2006. Early immunization induces persistent tumor-infiltrating CD8+ T cells against an immunodominant epitope and promotes life-long control of pancreatic tumor progression in SV40 T antigen transgenic mice. J Immunol, 177: 3089-3099.

Evsikov AV, Graber JH, Holbrook AE, Hampl A, Oh, B, Eppig JJ, Solter D, Knowles BB. 2006. Cracking the egg: molecular dynamics and evolutionary aspects of the mouse oocyte-to-embryo transition. Genes and Development, 20: 2713 - 2727.

Peaston AE, Knowles BB Hutchison K. 2007. Genome constancy and plasticity during the oocyte to embryo transition. Human Fertility 10:55-69.

The International Stem Cell Initiative Consortium. 2007. Characteristics of human embryonic stem cell lines: Results from the International Stem Cell Initiative, Nature Biotech. 25: 803-814.

Otahal, P. Knowles BB, Tevethia SS & Schell TD. 2007. Anti-CD40 Conditioning Enhances the TCD8 Response to a Highly Tolerogenic Epitope and Subsequent Immunotherapy of SV40 T Antigen-Induced Pancreatic Tumors. J Immunol. 179: 6686-6695.

Naxerova K, Bult CJ, Peaston A, Fancher K, Knowles BB, Kasif S, and Kohane IS. 2008. Analysis of gene expression in a developmental context emphasizes distinct biological leitmotifs in human cancers. Genome Biology 9: R108.

Knowles B. 2009. Balancing work and life: a conversation with Barbara Knowles. Interview by Majlinda Lako and Susan Daher. Stem Cells. 27(5): 989-90.

Lopez-Terrada D, Cheung SW, Finegold MJ, Knowles BB. 2009. Hep G2 is a hepatoblastoma-derived cell line. Hum Pathol. 40(10): 1512-5.

Knowles B et al. 2009. Consensus guidance for banking and supply of human embryonic stem cell lines for research purposes. Stem Cell Rev. 5(4): 301-14.

International Stem Cell Initiative Consortium, Akopian V, Andrews PW, Beil S, Benvenisty N, Brehm J, Christie M, Ford A, Fox V, Gokhale PJ, Healy L, Holm F, Hovatta O, Knowles BB, Ludwig TE, McKay RD, Miyazaki T, Nakatsuji N, Oh SK, Pera MF, Rossant J, Stacey GN, Suemori H. 2010. Comparison of defined culture systems for feeder cell free propagation of human embryonic stem cells. In Vitro Cell Dev Biol Anim. 46(3-4):247-58.

Theisen JW, Lim CY, Kadonaga JT. 2010. Three Key Subregions Contribute to the Function of the Downstream RNA Polymerase II Core Promoter. Mol Cell Biol. Mol Cell Biol. 2010 Jul;30(14):3471-9.

Avery S, Zafarana G, Gokhale PJ, Andrews PW. 2010. The role of SMAD4 in human embryonic stem cell self-renewal and stem cell fate. Stem Cells. 2010 May;28(5):863-73.

Varlakhanova N, deVries WN, Cotterman RF, Donahue LR, Murray S, Knowles BB & Knoepfler P. 2010. myc maintains embryonic stem cell survival, self-renewal and pluripotency. Differentiation. 2010 Jul;80(1):9-19.

Messerschmidt DM, Kemler R. 2010. Nanog is required for primitive endoderm formation through a non-cell autonomous mechanism. Dev Biol. 2010 Aug 1;344(1):129-137.