GIM 14 - Genome Imprinting Flashcards
what is androgenesis
development of an embryo containing only paternal chromosomes due to failure of the egg to participate in fertilization
what is parthenogenesis
reproduction from an ovum without fertilization
why is androgenesis, 46,XX
46, YY would not be able to survive
what is hydatidiform mole
A hydatidiform mole is a growing mass of tissue inside your womb (uterus) that will not develop into a baby. It is the result of abnormal conception.
what is the cause of hydatidiform mole?
androgenetic
what can parthenogenesis cause?
benign ovarian teratomas - derived from oocytes which have completed first or both meiotic divisons
why do uniparental conceptions fail?
different roles of maternal vs paternal genes in determining developmental fate -
paternal - extra-embryonic structure
maternal - the embryo itself
what is genomic imprinting
a mechanism that ensure the functional non-equivalence of the maternal and peternal genomes
what is epigenetic
genetic material which is not encoded within the DNA sequence
what is an example for epigenetic?
DNA methylation
what carry out DNA methylation?
DNA methyltransferases
how can maternal and paternal DNA be distinguished?
DNA methylation - methylated of the promoter regions when not used
how can imprint switch happen?
imprinting forget before gametogenesis - erasure of grandparental imprint and establishment of new parental imprint during gametogenesis
what does X inactivation happen
dosage compensation - to ensure equivalent dosage of chromosome X
how is inactivation of X achieved ?
epigenetic silencing
