Maternally derived FILIA-MATER complex localizes asymmetrically in cleavage-stage mouse embryos.
Initial cell lineages that presage the inner cell mass and extra-embryonic trophectoderm are established when eight blastomeres compact to form polarized morulae in preimplantation mouse development. FILIA has been identified as a binding partner to MATER (maternal antigen that embryos require; also known as NLRP5), which is encoded by a maternal effect gene. Products of each gene are detected in growing oocytes and, although transcripts are degraded before fertilization, the cognate proteins persist in early blastocysts. The two proteins co-localize to the cytocortex of ovulated eggs, where the stability of FILIA is dependent on the presence of MATER. After fertilization, FILIA-MATER complexes become asymmetrically restricted in the apical cytocortex of two-cell embryos due to their absence in regions of cell-cell contact. This asymmetry is reversible upon disaggregation of blastomeres of the two- and four-cell embryo. Each protein persists in cells of the preimplantation embryo, but the continuous cell-cell contact of ;inner' cells of the morulae seemingly precludes formation of the subcortical FILIA-MATER complex and results in cell populations that are marked by its presence (;outer') or absence (;inner'). Thus, the FILIA-MATER complex provides a molecular marker of embryonic cell lineages, but it remains to be determined if the molecular asymmetry established after the first cell division plays a role in cell fate determinations in the early mouse embryo. If so, the plasticity of the FILIA-MATER complex localization may reflect the regulative nature of preimplantation mouse development.
Laboratory of Cellular and Developmental Biology, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA.
Mami
M
Ohsugi
Ping
P
Zheng
Boris
B
Baibakov
Lei
L
Li
Jurrien
J
Dean
D017398:Alternative Splicing / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D000941:Antigens / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001755:Blastocyst / Q000166:cytology / Q000378:metabolism; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002970:Cleavage Stage, Ovum / Q000166:cytology / Q000378:metabolism*; D004527:Egg Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004622:Embryo, Mammalian / Q000166:cytology / Q000378:metabolism*; D047108:Embryonic Development; D005260:Female; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009865:Oocytes / Q000166:cytology / Q000378:metabolism; D011485:Protein Binding; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D021381:Protein Transport; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
D000941:Antigens; D002352:Carrier Proteins; D004527:Egg Proteins; C416503:Nalp5 protein, mouse; D020033:Protein Isoforms; D012333:RNA, Messenger