Final answer:
During gamete formation in mammals, methylation patterns of DNA are reset. Differences in methylation patterns between sperm and eggs can lead to gene silencing that is specific to one gender. Incorrect methylation patterns during gamete formation can lead to mutations and health concerns.
Step-by-step explanation:
During gamete formation in mammals, the methylation patterns of DNA undergo resetting. Methylation is the addition of a methyl group to the cytosine of CpG islands, which are found in the promoter regions of genes. Methylation usually leads to gene silencing. In mammals, there are potential differences in methylation patterns between sperm and eggs due to differences in the way they are formed. This can lead to certain genes being transcriptionally inactive in one gender but active in the other.
X-chromosome inactivation is a process in females where one of the two X chromosomes is randomly inactivated. Epigenetic changes to the chromatin result in one of the X chromosomes being tightly condensed into a dormant structure called a Barr body. This compensation for the double genetic dose of X-chromosome ensures equal gene expression in both males and females.
If the process of resetting methylation patterns during gamete formation is incorrect, it can lead to mutations. Incorrect methylation patterns can also result in the incorrect activation or silencing of genes, which can have various health implications.