Maternal Effect Genes and Genomic Imprinting Flashcards
What are maternal effect genes?
Genes from the mother’s genotype that affect the offspring’s phenotype. The paternal and individual’s genotypes do not affect the phenotype.
Do maternal effect genes affect the mother herself?
No, only the offspring.
What is genomic imprinting?
Chromosomal events that silence the expression of genes inherited from one of the two parents.
Does imprinting occur in the maternal or paternal chromosome or both?
Can occur in either depending on the gene, but not in both.
What is the epigenetic effect?
Alteration of the DNA chromatin but no chance in the actual DNA (in imprinting).
How long does the imprint last in the offspring?
Throughout their life, but is erased during production of gametes.
What changes in chromatin occur during imprinting?
DNA is methylated at the CpG islands and histones are deacetylated so that the involved genes cannot be transcribed due to tight chromatic packaging.
What is monoallelic inheritance?
Only one allele, maternal or paternal, is expressed, but not both.
Does genomic imprinting follow Mendelian inheritance?
No
What is Prader-Willi syndrome?
7 genes on chromosome 15 are deleted or not expressed on paternal chromosome, while the mother’s is imprinted.
What is Angelman syndrome?
Deletion or inactivation of maternally inherited chromosome 15, while the paternal is imprinted.
What gives rise to the differences between a tigon (male tiger x female lion) and a liger (female tiger x male lion)?
Genomic imprinting.
