We have identified a subcortical maternal complex (SCMC) that assembles during oocyte growth and is essential for zygotes to progress beyond the first embryonic cell divisions. At least four maternally encoded proteins contribute to this MDa complex: FLOPED, MATER and TLE6 interact with each other while Filia binds independently to MATER. Although the transcripts encoding these proteins are degraded during meiotic maturation and ovulation, the SCMC proteins persist in the early embryo. The SCMC, located in the subcortex of eggs, is excluded from regions of cell-cell contact in the cleavage-stage embryo and segregates to the outer cells of the morulae and blastocyst. Floped null and/or Mater null eggs lack the SCMC, but can be fertilized. However, these embryos do not progress beyond cleavage stage development and female mice are sterile. The proteins are conserved in humans and similar maternal effect mutations may result in recurrent embryonic loss.
| Li, Lei; Baibakov, Boris; Dean, Jurrien (2008) A subcortical maternal complex essential for preimplantation mouse embryogenesis. Dev Cell 15:416-25 |
| Ohsugi, Mami; Zheng, Ping; Baibakov, Boris et al. (2008) Maternally derived FILIA-MATER complex localizes asymmetrically in cleavage-stage mouse embryos. Development 135:259-69 |
| Zheng, Ping; Dean, Jurrien (2007) Oocyte-specific genes affect folliculogenesis, fertilization, and early development. Semin Reprod Med 25:243-51 |
