Epigenetic Tags Are Mostly Erased During The Formation of Gametes
- This erasure ensures a "clean slate" for the next generation.
- Chemical modifications, such as DNA methylation and histone acetylation, do this by without altering the DNA sequence.
- However, about 1% of these tags persist, leading to genomic imprinting a process where certain genes are silenced based on their parental origin.
Definition
Genomic imprinting
Genomic imprinting is a form of epigenetic inheritance, where the expression of a gene depends on whether it is inherited from the mother or the father.
Epigenetic Tags Persist To Regulate Genes Involved in Growth, Development, and Metabolism
- These tags ensure that imprinted genes are expressed in a parent-specific manner.
- The differences in ligers and tigons highlight how epigenetic tags inherited from parents can influence gene expression in offspring.
- In lions and tigers, these tags have evolved to suit their reproductive strategies:
- Lions: Males compete to sire the largest cubs, so their genes promote growth.
- Tigers: Females raise cubs alone, so their genes limit growth to conserve resources.
- Think of genomic imprinting as a tug-of-war between parental genes.
- In ligers, the father's genes win, promoting growth.
- In tigons, the mother's genes balance the effect, resulting in a smaller size.
- How does the concept of epigenetic inheritance challenge traditional Mendelian genetics?
- What ethical considerations arise when studying epigenetic changes in humans?
