L3 Flashcards
DNA methylation and gene expression
Methylation prevents transcription because transcription factors can’t get to it - thus decreased gene expression
Early life modifications to DNA methylation
- cellular/genetic
- stress
- food/nutrition
- maternal behaviour
Genomic imprinting and examples
Silencing of one parental copy of each gene, depending on the sex of the parent from which it was inherited
eg timing of parturition denoted by paternally imprinted genes
placenta made by paternally imprinted genes
X silencing
turn off expression of one copy of X chromosome in each cell to avoid producing double quantities - varies cell-to-cell whether it is maternal or paternal X that is silenced (CALICO CATS)
Paternal diet effects on daughters
Paternal environmental expression can induce intergenerational transmission of impaired glucose-insulin homeostasis in female offspring
Maternal depression
Increased methylation in foetal cord blood so decreased expression of glucocorticoid receptor gene and ths heightened infant stress response
Imprinting genes
Genes that, when expressed in offspring, retain their identity regarding their parent of origin