Exam 5 Notes Final Exam 5 Notes Final 11 11 2013 11 08 13 How do we obtain totipotent stem cells Pretty much forgotten How do we obtain Pluripotent stem cells Blastocysts inner mass cells All we need are blastocyts They are around for four days Not too reliable to have a donor What is a ready source though Discarded blastocysts abortion clinics They throw lots away Another source fertility clinics usually make too many for a particular patient and then just throw away Getting this is not that difficult Abbreviations FIRS full ICM in the blastocysts removal take them out and then they divide like crazy take 100 out and make 100 000 Two problems of FIRS 1 the cells are going to become the gastrula means that it is killing an embryo lots don t agree even though the blastocsysts will be thrown away best way to get pluripotent stem cells 2 Those cells are the person s own cells does not match up with another person s why not use John s John does not make blastocysts a woman could make her own blastocyts and use them for stem cell scientists have been working like crazy to fix this one approach PIRS Partial ICM removal don t take them all only take half the other half of the ICM will replace those cells had to poke a whole in the blastocyst to do this will it disturb this and cause problems in mice and rats it has no affects cannot experiment with humans shows a lot of promise but do not know for sure seems to have no negative effect on their gastrula s and fetus TCS therapeutic cloning stem cells get a woman s egg donors take the nucleus and suck it out remove it going to take a skin cell nucleus from a boy throw away the egg nucleus put the skin cell nucleus into the egg without the nucleus that egg cell became a zygote and it became a morula and a blastula with ICMs 11 11 13 Topic 16 Daily Question At the end of our class time on Friday we were considering Therapeutic Cloning TCS as an approach to obtaining stem cells without using blastocysts that resulted from fertilization Instead of the latter we made a Lei blastocyst using one of his nuclei inserted into one of Danielle s eggs Assuming that Danielle was cool about giving up one of her eggs for a hefty price what potential problem do you see with this approach to getting some pluripotent ICM cells for poor Lei s damaged spine Hint the answer is in your lecture notes from about a month ago it is possible that it could reject the cells endosymbiotic theory the mitochondria come from Danielle if problems with her mitochondrial genes DNA then they will get put into Lei this is also true when we use normal fertilization between a man and a woman all mitochondria in that zygote are from the mother Daily News Research would be restricted to 100 cell line 1 embryo When Bush was president there were about 50 He said he would not tolerate anymore When Obama became president he said there was no longer a limit Some scientists sued Obama was not right to continue to kill these embryos Still no limit Have gotten ICM tells were made viable mouse egg cells made embryos Mini brains to study brain diseases Scientists have now found pluripotent stem cells in sperm the ethics killing an embryo regardless if you were going to throw it away or not immune rejection putting someone else s cells into your body Full ICM Removal Stem cells FIRs Pros easy kind of easy to get easy to grow in the lab pluripotent most effective for research Cons Partial ICM Removal Stem Cells PIRs Pros about as easy as last one easy to grow pluripotent no ethical problems Cons not proven to destroy embryo still have the immune rejection problem TCS therapeutic cloning stem cells easy to get cost a lot opinion on easy or not easy to get no immune problem because they are genetically Lei s cells exception is mitochondria but ethics making an artificial embryo say it could not grow into Lei Pros making pluripotent stem cells easy to grow that is always a problem Cons ethics making an artificial embryo some say it could grow into Lei hard to get the eggs costly difficult technique A scientist in Oregon has cloned a human up to the blastocysts if he has taken that blastocyts and put it in a surrogate mother would have become a clone Dolly the sheep was made by therapeutic cloning very difficult to make ITCS InterSpecies Therapeutic Cloning Stem Cell we can take a cows egg skin cell from a mouse put into egg that does not have a nucleus and we clone that mouse using another species for the source of egg Pros get pluripotent easy to get easy to grow Cons no immune rejects still destroying that embryo ethics ethics farming animals for eggs inject into the brain now we have mitochondrial DNA from a mouse in human stem cells that we are going to Why do we get rid of Danielle s eggs nucleus and then put a skin cell nucleus no one predicted that the egg would act like a fertilized egg zygote morula blastocyst no one has let it go beyond blastocyts in humans What is going on to trigger the formation of a zygote Love to solve mysteries If we can find out the reason we can simplify the whole thing iPS iPS induced Pluripotent Stem Cells there are only four genes that control this process took all of Danielle s genes out Lei s skin cell nucleus has the genes Because the transfer four of his genes turned on We all have these four genes but are turned off Turn on when example of Danielle and Lei We don t need an egg anymore We can take any cell even differentiated cell like skin cell If we just put the four genes into that cell put with the same four genes 8 genes We take out the four genes even though they are inactive This turns the 4 genes on creates zygote The four genes differentiate These four genes are involved in causing determination in the early blastocyst to make the ICM different from the trophoblast Involved in embryonic development Pros Pluripotent stem cells Easy to grow Now super easy to get Immune compatible no immune problem can use own cells and own genes Cons Nagging embryo ethical issue still making a blastcyst Could grow into a person even though it is a really bizarre embryo Putting viral genes in the cell some of the virus might get into the pluripotent stem cells 1 of those 4 genes is a proto oncogene cancer gene everyone has one normal function in your body when you mess with this gene it turns into a cancer causing gene 11 13 13 Topic 16 Growth and Development in Animals Daily Question As you know our focus thus far has been on the medical …