Nature 294, 450 - 451 (03 December 1981); doi:10.1038/294450a0

Evidence for expression of the paternal genome in the two-cell mouse embryo

Janet A. Sawicki, Terry Magnuson & Charles J. Epstein

Departments of Pediatrics and of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, California 94143, USA

Although there is strong evidence that the paternal genome is activated at the four- to eight-cell stage of mouse embryogenesis^1–12, studies to date have been restricted because of their dependence on the manifestations of gene products, such as enzyme activity and cell-surface expression, rather than on direct assay of their synthesis. ₂-microglobulin ( ₂M), a 12,000-molecular weight (M _r) peptide associated with several of the gene products encoded by the H–2–Tla complex in the mouse^13–17, is synthesized by early cleavage stage embryos (J.A.S., T.M. and C.J.E., unpublished). The existence of an electrophoretic variant of ₂M in inbred strains has recently been described^18–20, and tryptic peptide mapping¹⁹ and amino acid sequencing data₂₁ indicate that the primary sequences of these variants differ by a single amino acid, thus establishing the genetic basis for this variation. Mice heterozygous at the ₂m locus synthesize both forms, ₂M^a and ₂M^b (refs 18, 20). Using direct immunoprecipitation and two-dimensional gel electrophoresis, we have used this variation at the ₂m locus to distinguish between maternal and paternal ₂M and have now established that the synthesis of paternally derived ₂M is first detectable at the two-cell stage. This is the earliest stage at which expression of the mammalian embryonic genome has been established²².

References

1.	Epstein, C. J. Science 175, 1467−1468 (1972). | PubMed | ISI | ChemPort |
2.	Brinster, R. L. Biochem. Genet. 9, 187−191 (1973). | PubMed | ISI | ChemPort |
3.	Krco, C. J. & Goldberg, E. H. Transplant Proc. 9, 1367−1370 (1977). | PubMed | ISI | ChemPort |
4.	Muggleton-Harris, A. L. & Johnson, M. H. J. Embryol. exp. Morph. 35, 59−72 (1976). | PubMed | ChemPort |
5.	Wudl, L. & Sherman, M. I. Cell 9, 523−531 (1976). | Article | PubMed | ISI | ChemPort |
6.	Adler, D. A., West, J. D. & Chapman, V. M. Nature 267, 838−839 (1977). | PubMed | ISI | ChemPort |
7.	Epstein, C. J., Smith, S., Travis, B. & Tucker, G. Nature 274, 500−503 (1978). | PubMed | ISI | ChemPort |
8.	Kratzer, P. G. & Gartler, S. M. Nature 274, 503−504 (1978). | PubMed | ISI | ChemPort |
9.	Monk, M. in Development in Mammals Vol. 1 (ed. Johnson, M. H.) 189−223 (North-Holland, Amsterdam, 1978).
10.	Monk, M. & Harper, M. J. Embryol. exp. Morph. 46, 53−64 (1978). | PubMed | ISI | ChemPort |
11.	Epstein, C. J., Smith, S. & Travis, B. Tissue Antigens 15, 63−67 (1980). | PubMed | ISI | ChemPort |
12.	Esworthy, S. & Chapman, V. M. Devl Genet. 2, 1−12 (1981). | ChemPort |
13.	Rask, L., Lindblom, B. & Peterson, P. A. Nature 249, 833−834 (1974). | PubMed | ISI | ChemPort |
14.	Silver, J. & Hood, L. Nature 249, 764−765 (1974). | PubMed | ISI | ChemPort |
15.	Armeding, D., Kubo, R. T., Grey, H. M. & Katz, D. H. Proc. natn. Acad. Sci. U.S.A. 72, 4577−4581 (1975).
16.	Capra, J. D., Vitetta, E. & Klein, J. J. exp. Med. 142, 664−672 (1975). | Article | PubMed | ISI | ChemPort |
17.	Vitetta, E., Uhr, J. W. & Boyse, E. A. J. Immun. 114, 252−254 (1975). | PubMed | ISI | ChemPort |
18.	Michaelson, J., Rothenberg, E. & Boyse, E. A. Immunogenetics 11, 93−95 (1980). | PubMed | ISI | ChemPort |
19.	Robinson, P. J., Graf, L. & Sege, K. Proc. natn. Acad. Sci. U.S.A. 78, 1167−1170 (1981). | ChemPort |
20.	Goding, J. W. & Walker, I.D. Proc. natn. Acad. Sci. U.S.A. 77, 7395−7399 (1980). | ChemPort |
21.	Gates III, F. T., Coligan, J. E. & Kindt, T. J. Proc. natn. Acad. Sci. U.S.A. 78, 554−558 (1981). | ChemPort |
22.	Magnuson, T. R. & Epstein, C. J. Biol. Rev. 56, 369−408 (1981). | PubMed | ISI | ChemPort |
23.	Sawicki, J. A. & Epstein, C. J. Immunogenetics 12, 141−151 (1981). | PubMed | ISI | ChemPort |
24.	O'Farrell, P. H. J. biol. Chem. 250, 4007−4021 (1975). | PubMed |
25.	O'Farrell, P. Z., Goodman, H. M. & O'Farrell, P. H. Cell 12, 1133−1142 (1977). | Article | PubMed | ChemPort |
26.	Epstein, C. J., Wegienka, A. & Smith, C. W. Biochem. Genet. 3, 271−281 (1969). | ISI | ChemPort |
27.	Golbus, M. S. & Epstein, C. J. Differentiation 2, 143−149 (1974). | PubMed | ISI | ChemPort |