Epigenetics I and II Flashcards
when can epigenetic changes be transmitted?
during gametogenesis
what 2 factors result in an increased level of cortisol exposure to a fetus?
lack of placental 11beta hydroxycortisteroid dehydrogenase type 2 (the enzyme that catalyzes rapid conversion of maternal cortisone to inert cortisone
what can increased cortisone exposure to a fetus cause?
low birth weight and subsequent development of metabolic syndrome and other diseases
what can epigenetics modify?
it can modify the activation of certain genes but not the sequence of genes
do most epigenetic changes affect the individual or subsequent generations?
both - most only occur w/in individual organism but if a mutation in DNA has happened in the sperm or egg cell that results in fertilization then can be inherited from one generation to the next
how does gene therapy work?
gene inserted into a nonspecific location or carrier molecule called a vector must be used to deliver the therapeutic gene to the patient’s target cells, vector then unloads genetic material into target cell then generation of functional protein is made from the therapeutic gene therapy so as to return the cell to normal state
different types of vectors for gene therapy?
retroviruses - class of viruses that can create double-stranded DNA copies of their RNA genomes, can be integrated into chromosomes of host cells, HIV is an example adenoviruses- class of viruses with dsDNA- these work the best can also use direct introduction of therapeutic DNA into target cells
problems why gene therapy haven’t worked thus far?
because the cells the therapeutic DNA is inserted to may become dysfunctional, have too short of a life cycle so would have to undergo multiple rounds of gene therapy as well as any foreign material usu initiates an immune response which then makes it more difficult to repeat gene therapy
what is a major concern with viral vectors?
the fact that it could trigger an immune response, cause toxicity or inflammation as well as potentially revert to being an active virus
what is gene editing and CRISPR?
taking cells from patients, editing the chromosome then returning the transformed cells to patients
potential applications of CRISPR?
genome editing, potential to be gene therapy mechanism, screening drug targets, synthetic biology, agriculture, programmable RNA targeting and viral gene disruption
what is RNA interference?
process w/in living cells that moderates the activity of their genes
also known as co-suppression, post transcriptional gene silencing and quelling
what is post-transcription gene silencing?
guide strand base pairs w/a complimentary sequence in a messenger RNA molecule and induces cleavage
what process serves to down or up regulate genes pre-transcriptionally?
modification and associated induction of heterochromatin - RNA induced transcriptional silencing
