Cardiac abnormalities cause early lethality of jumonji mutant mice

Area of Science:

• Developmental biology
• Genetics
• Cardiovascular research

Background:

• Jumonji (jmj) mutant mice display morphological abnormalities and embryonic lethality around embryonic day 11.5.
• The precise cause of embryonic lethality in jmj mutant mice remains undetermined.

Purpose of the Study:

• To investigate the role of the jumonji (jmj) gene in embryonic development, specifically focusing on cardiac defects.
• To determine if cardiac abnormalities are the cause of early embryonic lethality in jmj mutant mice.

Main Methods:

• Generation of jumonji (jmj) mutant mice using a gene trap strategy.
• Exogenous expression of the jmj gene in the cardiac tissue of jmj mutant embryos.
• Assessment of morphological phenotypes and survival rates of rescued embryos.

Main Results:

• Exogenous expression of the jmj gene in the heart rescued morphological cardiac defects in jmj mutant mice.
• Embryos with rescued cardiac phenotypes survived until embryonic day 13.5, indicating a delay in lethality.
• These findings suggest that cardiac abnormalities are a primary cause of the earlier embryonic lethality in jmj mutant mice.

Conclusions:

• Mutation of the jumonji (jmj) gene leads to severe cardiac abnormalities and embryonic lethality.
• The jumonji (jmj) gene plays a critical role in cardiac development.
• Jmj mutant mice experience at least two periods of lethality, with cardiac defects contributing to the earlier phase.