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Published on: January 13, 2018
Mcl-1 deficiency results in peri-implantation embryonic lethality
J L Rinkenberger1, S Horning, B Klocke
1Departments of Medicine and Pathology, Howard Hughes Medical Institute, Washington University School of Medicine, St. Louis, Missouri 63110 USA.
Abstract:
We disrupted the Mcl-1 locus in murine ES cells to determine the developmental roles of this Bcl-2 family member. Deletion of Mcl-1 resulted in peri-implantation embryonic lethality. Mcl-1(-/-) embryos do not implant in utero, but could be recovered at E3.5-4.0. Null blastocysts failed to hatch or attach in vitro, indicating a trophectoderm defect, although the inner cell mass could grow in culture. Of note, Mcl-1(-/-) blastocysts showed no evidence of increased apoptosis, but exhibited a delay in maturation beyond the precompaction stage. This model indicates that Mcl-1 is essential for preimplantation development and implantation, and suggests that it has a function beyond regulating apoptosis.
Insights
Mcl-1 is crucial for early embryonic development and successful implantation. Its absence causes peri-implantation lethality due to trophectoderm defects, not increased apoptosis.
Area of Science:
- Developmental Biology
- Cell Biology
- Genetics
Background:
- Bcl-2 family proteins regulate apoptosis.
- Mcl-1 is a key anti-apoptotic member of this family.
- Its specific role in early mammalian development is not fully understood.
Purpose of the Study:
- To investigate the developmental roles of Mcl-1 during murine preimplantation development and implantation.
- To determine the consequences of Mcl-1 gene deletion on embryonic development.
Main Methods:
- Gene targeting to disrupt the Mcl-1 locus in murine embryonic stem cells.
- In vitro culture and analysis of blastocysts.
- Assessment of embryonic lethality and developmental defects.
Main Results:
- Mcl-1 deletion resulted in peri-implantation embryonic lethality.
- Mcl-1(-/-) embryos failed to implant in utero and could be recovered at E3.5-4.0.
- Null blastocysts exhibited trophectoderm defects, failing to hatch or attach in vitro, despite inner cell mass viability.
- Mcl-1(-/-) blastocysts showed delayed maturation and no increased apoptosis.
Conclusions:
- Mcl-1 is essential for successful preimplantation development and implantation in mice.
- The function of Mcl-1 extends beyond apoptosis regulation, impacting embryonic maturation and trophectoderm development.
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