Mouse Embryology Laboratory
- Environmental factors in clonal embryo development of the mouse
- Chromosomal (aneuploidy) vs epigenetic causes of abnormal development in clonal mouse embryos
- Facilitating de-programming of somatic cell features in mouse clones and derivative ES cells
Governing cell lineage decision in cloned mouse embryos
Michele Boiani, Sebastian Balbach
A single cell cannot be pluripotent unless it divides and its progeny give rise to the three germ layers. Can a nucleus be completely reprogrammed as one? It has been known that after nuclear transfer into an oocyte, reprogramming is not instantaneous but it unfolds during the embryonic cell cycles. Our data show that it is not simply a matter of time in order for the nucleus to become reprogrammed, but also of cell-cell interactions and cell signaling.
Genetic stability and pluripotency of 2N and 4N cloned mouse embryos and derivative cell lines
Sebastian Balbach, Martin Pfeiffer, Michele Boiani
When a somatic nucleus is re-activated by transplantation into an ooplasm, the mechanisms to maintain genome stability also need to be re-activated. Our data show that the ooplasm can reprogram not just one but also two nuclei without affecting the quality. Resultant diploid (2N) and tetraploid (4N) cloned embryos have less aneuploidy than fertilized embryos and can be derived into 2N and 4N ES cell lines, respectively. These are able to differentiate into the three germ layers but are unable to form teratomas. However, small mutations known to frequently occur in somatic cells may give rise to phenotypes due to the increased potency after reprogramming. Our data warn against the temptation to think that all conditions of clones are epigenetic and recover during gametogenesis.
Ageing and metabolism of cloned and fertilized mouse embryos
Telma Esteves, Michele Boiani
The mechanisms underlying “reprogramming” likely involve not only genetic modifications of the transferred somatic nucleus, but also changes in cell physiology, namely in energy metabolism. Whether these changes are the cause or the consequence of “reprogramming” events after nuclear transfer is a topic of our research. In this context, we are also investigating the impact of alterations in the cytoplasm of the oocyte (for example due to ageing) in “reprogramming” efficiency after cloning in the mouse. We propose that oocytes that are ‘too old’ for reproduction may still be adequate for somatic reprogramming.
Induction of pluripotency by protein gain-of-function in cloned mouse embryos
Martin Pfeiffer, Nicola Crosetto, Michele Boiani
By transferring the nucleus of a fully differentiated cell into the environment of an enucleated oocyte, the expression pattern and the epigenetics of the donor nucleus can be changed back to the pluripotent state. The meager efficiency of this process may be due to the lack of proper amounts of specific factors or co-factors in oocytes, which are essential for reprogramming. By identifying and complementing oocytes with the missing (co)factors, we can improve our understanding of the molecular mechanisms of oocyte mediated reprogramming. Our data suggest that not the classical reprogramming factors (Oct4, Sox2, Klf4, cMyc) rather other, yet undiscovered factors account for the reprogramming ability of the oocyte.
People in the lab
- Sebastian Balbach (PhD),
- Telma Esteves (PhD, and
- Martin Pfeiffer (PhD student) join the endeavors to these projects.
- Dr. Yong Mahn Han, KAIST, Daejeon, KOREA
- Dr. Jan Ellenberg, EMBL, Heidelberg, GERMANY
- Dr. Anna Jauch, Klinikum Uni. Heidelberg, GERMANY
Outreach and downloads
Extramural financial support from:
DFG SPP 1356
Interactions and collaborations:
James Adjaye - Berlin (D)
Konstantinos Anastassiadis - Dresden (D)
Nicola Crosetto - Frankfurt a/M (D)
Frank Edenhofer - Bonn (D)
Franchesca Houghton - Southampton (UK)
Anna Jauch - Heidelberg (D)
Severine Le Gac - Enschede (NL)
K. John McLaughlin - Columbus (USA)
CarloAlberto Redi - Pavia (I)
Stefan Schlatt & Verena Nordhoff - Muenster (D)
Documents from the lab:
Doctoral Theses, protocols, publications… coming soon.
Kishigami S, Wakayama S, Van Thuan N, Ohta H, Mizutani E, Hikichi T, Bui HT, Balbach S, Ogura A, Boiani M, Wakayama T (2006).Production of cloned mice by somatic cell nuclear transfer.Nature Protocols 1:125-138.
Boiani M, Gentile L, Gambles V, Cavaleri F, Redi CA, Schöler HR (2005) Variable "reprogramming" of the pluripotent stem cell marker Oct4 in mouse clones: distinct developmental potentials in different culture environments. Stem Cells 23:93-108.
Boiani M, Eckardt S, Leu AN, Schöler HR, McLaughlin KJ (2003).Pluripotency deficit in clones overcome by clone-clone aggregation: epigenetic complementation? The EMBO Journal 22: 5304-5312
Hübner K, Fuhrmann G, Christenson LK, Kehler J, Reinbold R, De La Fuente R, Wood J, Strauss JF 3rd, Boiani M, Schöler HR (2003).Derivation of oocytes from mouse embryonic stem cells. Science 300:1251-1256.
Boiani M, Eckardt S, Schöler HR, McLaughlin KJ (2002). Oct4 distribution and level in mouse clones: consequences for pluripotency. Genes and Development 16:1209-1219.
Boiani M, McLaughlin KJ and Schöler HR. Compositions and methods for the efficient and reproducible generation of clone animals of all developmental stages and methods of use thereof. U.S. Patent Application No. 10/865,369