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Influence of paternally imprinted genes on development
S C Barton1, A C Ferguson-Smith, R Fundele
1Department of Molecular Embryology, AFRC Institute of Animal Physiology and Genetics Research, Babraham, Cambridge, UK.
Development (Cambridge, England)
|October 1, 1991
Summary
Introducing paternal genome cells (AG) into mouse blastocysts significantly increased embryonic growth but proved lethal above 50% contribution. Resulting chimeras showed skeletal abnormalities, reciprocal to maternal genome effects.
Area of Science:
- Developmental Biology
- Genetics
- Epigenetics
Background:
- Genomic imprinting is crucial for mammalian development, with parental chromosome origin influencing gene expression.
- Aberrant gene dosage from duplicated paternal (androgenones, AG) or maternal (gynogenones/parthenogenones, GG/PG) genomes causes developmental abnormalities.
Purpose of the Study:
- To investigate the developmental effects of introducing AG inner cell mass into normal mouse blastocysts.
- To understand the impact of paternally imprinted genes on embryonic and post-natal development.
Main Methods:
- Creation of chimeric mouse embryos by aggregating AG inner cell mass with normal blastocysts.
- Analysis of embryonic growth, morphology, cell distribution, and post-natal survival and phenotype.
Main Results:
- AG cell contribution led to up to 50% increased embryonic growth and altered embryonic shape (e12-e15).
- Contributions exceeding 50% from AG cells were lethal by e15; low contributions allowed limited full-term development.
- AG cells preferentially populated mesodermal tissues, particularly heart and skeletal muscle, with reduced brain presence.
- Post-natal survivors exhibited severe skeletal defects, including rib malformations and lack of ossification.
Conclusions:
- Paternally imprinted genes significantly influence embryonic growth and tissue distribution.
- Excessive paternal genome contribution is detrimental, leading to lethality and severe skeletal abnormalities.
- These findings highlight the critical balance of parental genomic contributions for normal development and reciprocal effects of paternal and maternal imprinting.