Assisted Reproductive Technology Flashcards
What are considered natures clones? How does this occur?
Identical twins; the embryo splits where you have two different copies with the exact same mitochondrial and nuclear DNA
What are the two ways to produce a clone?
Embryo splitting
Nuclear transfer
Embryo splitting?
You split the embryo by hand so that each embryo has identical genetics
Nuclear transfer?
An embryonic, fetal, and/or somatic nucleus is inserted into a bag of cytoplasm (enucleated cell) to get an active form
T/F: nuclear transfer clones are true clones.
F: they do not share the same mitochondrial DNA
Who first proposed cloning?
Hans Spemann
The first animal successfully cloned was what?
frog
Clones before 1996 used what two types of cells?
embryonic; differentiated
Of the cell types used in cloning before 1996, which were most successful?
embryonic (before differentiation of cell types occurred) because differentiated cells failed miserably
What is the dogma of cloning?
it is biologically impossible to clone mammals by nuclear transplantation
What disproved the dogma of cloning?
the cloning of Dolly the sheep by somatic cell nuclear transfer
How was Idaho Gem cloned? What species?
mule fetal cells; horse
Who is Prometea?
a foal that is genetically identical to its surrogate mother; somatic cell donor where the mother carried her own clone
Who is Ralph? Significance?
a cloned rat; a first for the species which is important in research on human diseases including diabetes and hypertension
Who is Dewey?
Texas A&M first clone of a deceased white tailed buck
Name a few applications for cloning by somatic cell nuclear transfer.
1) Replicate farm animals of high genetic merit-agricultural use 2) rescue genetics of endangered or exotic species 3) Clone companion animals 4) research tool for study of embryonic development and loss 5) genetically modify farm animals 6) increase efficiency of producing genetically modified animals
What does the US FDA say about cloning agricultural animals for food?
food products derived from animals clones are safe for human consumption
100% of clones will be ___.
transgenic
What are two ways that transgenic farm animals will benefit human health?
1) new form of farming (pharming) 2) genetically modified farm animals will lead to pharmaceutical proteins and organ donor availabilities
What was unique about Polly?
while cells were growing in culture, they inserted a genetic code with a blood clotting factor – biochemists could then use Polly’s milk to study diseases where this blood clotting factor was important
How will the use of cows for biopharmaceuticals affect the economy?
leads to greater profits because more specific genes can be coded for that can lead to (for example) greater milk recovery and greater profits
How can genetically altered swine provide an answer to the growing organ shortage?
one can alter carbohydrate molecules on pig cells so that human antibodies would not recognize the pig cells as foreign
What are the problems of using genetically modified pig organs for humans?
inefficient, death of embryos and fetuses throughout pregnancy, large offspring, death of offspring (all in pigs when altered)
What are some of the genetic affects of the clones in the female reproductive tract?
hypoplastic placentas, rudimentary cotyledons, and IVF placentas
Hypoplastic placentas lead to what?
retarded fetuses
Spontaneous abortions typically occur in which stage of the pregnancy?
second trimester
Hydrops?
excessive accumulation of allantoic or amnionic fluid in the uterus during the latter half of gestation
What can be done to fix hydrops?
euthanasia; the fetus cannot survive so abort the fetus (the recipient often dies as well)
What are a few problems with cloned offspring?
high mortality, large offspring, enlarged umbilicus, hypothermic, hypoxic, lethargic, lung dysmaturity, metabolic disorders, pulmonary hypertension, others
What are the risks associated with cloning humans?
inefficiency of procedure; many cases where cloned fetuses die late in pregnancy or immediately following birth; possible death of woman carrying pregnancy; complications with resulting offspring?
Therapeutic cloning?
use of cloning procedures to reprogram one’s own cells to generate replacement tissue to correct injuries and/or diseases; avoid concerns with tissue rejection; does not allow cloned embryo to establish a pregnancy (harvest stem cells and use for generating replacement tissues)
What is a clone?
a genetic replica of an existing individual
Does cloning maintain genetic diversity?
no; but if technology was used to clone the best genetic lines in an individual then used to create new genetic lines, this would allow for maximum genetic diversity
Nature’s truest form of clones?
identical twins
What is important to note about the process of nuclear transfer?
transfer of nucleus by any somatic cell (body cell) into a bag of oocyte cytoplasm because it was previously an oocyte arrested at Metaphase II (stage that gets fertilized)
What is the importance of calcium in nuclear transfer?
something needs to come in and induce calcium oscillation by electrical pulse or expose it to chemicals that will mimic what sperm does to initiate the calcium spike
Embryonic cells were used for nuclear transfer before ___.
the trophectoderm and ICM
What was the first ever clone of an adult mammal?
Dolly (1/277 attempts)
What is the purpose of fetal fibroblasts in transgenics?
they will make the protein product of interest
T/F: What can be done in one species is equal to what can be done in other species, including humans.
T
___% of clones are lost early on.
90%
Name a few placental problems known to occur with clone fetuses?
1) they lack blood vessels in some cases 2) the placenta doesn’t form properly resulting in a retarded fetus because the placenta is not sufficient; fetal cotyledon numbers were extremely decreased
T/F: Problems with cloning stop after birth.
False
T/F: Incidence of loss is greater in clones.
T
Reproductive cloning?
used as a tool to replace an individual which is illegal in humans
Difference between reproductive and therapeutic cloning?
therapeutic cloning must destroy the embryo to have its effects (different from reproductive cloning)
