BIOLOGY 2C03 Lecture Notes - Attention Deficit Hyperactivity Disorder, Ubiquitin, Intellectual Disability
Document Summary
Lecture 1 x chromosome inactivation (march 26) Genes affected by x inactivation or imprinting are expressed from a single allele as a result of silencing of the second allele. Genes affected by these processes tend to be clustered. X inactivation a whole chromosome is selected and inactivated. Imprinting one of two alleles is silenced depending on whether it is inherited from the mother or the father. Silencing depends on a master control region lncrnas act as master regulators of silencing. X-inactivation and imprinting regulate 5-10% of the genes of the genome. Several diseases are determined by genes controlled by x inactivation or imprinting. Fragile x (x-linked disorder: rett syndrome (x-linked disorder, hemophilia (x-linked disorder, testicular feminization (x-linked disorder, prader-willi/angelman (due to imprinting, backwith-widemann (due to imprinting) Females 2 x chromosomes two copies (doses) of each gene. Males 1 x chromosome one copy (dose) of each gene. Dosage compensation way of equalizing gene expression in the face of different gene dosage.
