Stem Cells and Viruses Lecture

hello cell bio students let&#39;s take a look at our last set of lecture slides for this semester stem cells and viruses we&#39;re just hitting some highlights as you can see a stem cells is covered in chapter 19 but we&#39;re just taking a look at parts of 19.3 and 19.4 and then we get into viruses we&#39;ll be focusing on material from 26.1 and 26 6.4 starting with the stem cells I actually grabbed this image out of the book I&#39;ve used in anatomy class and stem cells when we&#39;re looking at embryonic stem cells the embryo of course is going to be formed from fertilization between sperm and egg that forms the zygote now you see 2 N the zygote is diploid that is the single cell that we all were when we first started our life and then that zygote under goes some mitosis to make identical daughter cells during this initial development process called cleavage and eventually reaches this blast assist stage now if a couple is doing invitro fertilization this fertilization is done in the lab in the you know test tube in the petri dish and then then the zygote and development starts to happen for a couple of days until it reaches this blastus stage now the blasticus would be what would be implanted in either a surrogate or into the mother if invitro fertilization is taking place but what&#39;s important about this blast assist is that is the component which contains the embryonic stem cells now from there you can see the blasticus would develop into the growing embryo into the baby but we will be focusing on kind of this stage right here taking a look at those embryonic stem cells here&#39;s the zygote the zygote of course is a single cell and the DNA in there comes half the genetic information from the sperm half the genetic information from the oite or the egg and these polar bodies are just extra DNA um that is not needed right because the each sperm and egg each gamet only needed half the amount of genetic information so those polar bodies are separate that would be extra DNA and then initially some mitosis so that single cell zygote becomes two cells becomes four becomes eight and then forms this morula now the morula in development is the last stage where all of the cells are identical and notice that all throughout this from the zygote all the way to the morula even the morula is a ball of 16 to 32 identical cells notice that the overall size has not changed now the morula is the last structure where all of the cells will be identical and right after the morula is the blasy the blasy here we see now actually has two different distinct Parts the outer cell layer is called the troob blast now autotrof heter trro anytime you hear tro think nutrition now remember an autot Trove made their own nutrition heter trro gets nutrition from another source but in this case trophoblast that is the outer layer that is the layer that if there is implantation in the uterus for a human you know embryo it would burrow into that lining of the uterus called the endometrium and the Tropa blast would be helping to provide nourishment before the placenta is formed so Tropa blast that is the outer cell layer of the blasticus and that is what will provide nutrition to a growing embryo during those first you know eight or nine weeks before the placenta has developed now what&#39;s here on the inside is called the embryo blast or the Inner Cell mass now the embryoblast those are all the cells that will give rise to the growing embryo or the growing baby um also referred to as Inner Cell Mass but these are the cells here of the embryoblast that are also referred to as the embryonic stem cells let&#39;s take a look at those all right so stem cells those are capable of division but can also give rise to differentiated cells the thing with stem cells is they are not specialized they have not been given a fate yet on what they will become differentiated means it is going to be a muscle cell or it&#39;s going to be a nerve cell for example or an epithelial cell like a skin cell um and that hasn&#39;t happened yet so the potential of these stem cells these embryonic stem cells is the fact that they have not been determined to be any particular cell type in the body now when it comes to cell stem cells there are some different types now totop poent totop poent you can see here is a cell that can give rise to any tissue in an organism and those were the those early cells those early cells like in the morula that were all identical those are still toap poent cells that they can give rise to any tissue in an organism by the time they&#39;ve reached the embryoblast stage right when they&#39;re in the blast toist they have become hurop poent now those embryonic stem cells have the ability to give rise to all cells in the adult organism body so that means just kind of our major tissue types again nervous tissue muscle tissue um connective tissue epithelial tissue so those are our four main tissue types everything in the adult organism that would come from plop poent and again that would be embryonic stem cells now multi poent that would give rise to a limited number of cells and what we tend to see in the adult body like our body um we have stem cells in our bone marrow that make all of our uh blood cells and those would be considered multi- poent because they&#39;re giving rise not only to red blood cells but also to our white blood cells so multi poent would be found in an area like our bone marrow unipotent those would be stem cells that are really only going to give rise to one cell type and that would be found like in our epidermis so we do have epidermal stem cells but they are considered unipotent because those stem cells would only give rise to other epidermal cells here are the embryonic stem cells you can see they&#39;re a form of plop poent plop poent from mamalian blasticus and this is going to be the source is the that inner cell mass or the embryo blast of the blasticus and the fact is that these cells have not been determined to be any particular cell type uh lots of experiments have been done on these cells you can see you can take them out of an embryo it wouldn&#39;t grow up into an embryo but you can remove them from here place them in a dish and they can be utiliz for lots of different experiments and lots of different uses that could could hold some really important potential therapeutic uses now why are individuals studying embryonic stem cells because they have that potential to become any cell type what can we do with them you know Recent research shows stem cells can be utilized to grow new healthy pancreatic eyelet cells pancreatic eyelid cells are where insulin is produced therefore in individuals with diabetes that are not making insulin maybe we can help them to make some healthy pancreatic eyelid cells and be able to produce insulin another area you can see hematopoetic cells if individuals have anemia like sickle cell anemia and they&#39;re not producing good hemoglobin not getting good red blood cells maybe we can introduce stem cells and they can start to make those healthy blood cells cardyes all right heart that&#39;s heart muscle right there um they did a a surgery in Italy where they injected about 20,000 injections of stem cells into an individual&#39;s heart and they were able to grow healthy heart muscle cells and that heart was able to return you know in a 60-year-old to the heart of like a 20year old um and so it showed great promise now also of course neuronal diseases neuronal degeneration or spinal cord injuries can we take stem cells and grow new neurons absolutely that potential is there and then the last one here hepatocytes liver think about you know the liver is our detox organ the liver can be damage sometimes liver transplants are not successful is there a way we can use stem cells grow healthy liver cells and help that with treatment so that&#39;s the big promise of stem cell research if there are embryos that are not going to be used to grow into healthy human babies then we can use those cells for stem cell research um I gave that link in the canvas uh site for the UCSB stem cell research center and a big area of study there is actually with eye disorders um they&#39;re doing a lot of work with kind of you know retinal um retinol kind of therapies and detached retina and all that sort of stuff that is being worked at at UCSB with stem cells seeing if we can help with eye disorders in that area now one of the challenges though however is of course when you&#39;re using embryonic stem cells that that embryo cannot grow up to be a baby therefore one of the challenges for scientists was how can you get those stem cells by not using embryos and so after that scientists were like okay is there a way that we can kind of reprogram actually an adult cell or an adult nucleus to give rise to embryonic stem cells so a couple of ways you can see reprogram adult cells so that means you&#39;re not wasting embryos um to do that maybe you just transfer the nucleus just take the nucleus out transfer that make some new cells from there you can see see a fusion a fusion of a somatic just a regular body cell and maybe some you know embryonic stem cells bring those together um introduce some different genes so there has been work where they&#39;ve taken skin cells they&#39;ve introduced a few different genes and have been able to induce um plop poent stem cells from there and then even you know take kind of cultures of germ cells or other adult stem cells and trigger them to become these plop poent cells so after that initial you know promise of embryonic stem cells there was then the challenge of can we figure out how we can get plop poent cells without um the loss of an embryo and where does that come into play now one thing with therapeutic cloning especially if you&#39;re taking a cell from that individual the big benef benefit is the individual will be less likely to reject it right when we get things like organ transplants or a skin graft one of the big risks is that that individual&#39;s body will reject the new organ or the skin graft and so though is individuals take a lot of immunosuppressant medications to not attack well if we&#39;re able to make stem cells from an individual&#39;s own cells then we really reduce that rejection risk so here that goal of maybe some therapeutic cloning you take a diabetic patient you take their own cells and then grow up embryonic stem cells that actually originated from their own cells use those to make maybe a healthy pancreatic eyelet then introduce that and the fact that those cells originally came from the patient really help with that rejection issue so that potential therapeutic cloning is a huge driving force for stem cell research now there is also reproductive cloning and in 1996 Dolly um was the first um mammal to be cloned from an adult cell so this process is called somatic cell nuclear transfer or scnt and here&#39;s what happened um a regular adult cell was taken from a white-faced sheep and then the nucleus was taken from the adult cell placed into uh the like a surrogate cell like a surrogate type embryo and then that surrogate was actually a black-faced sheep what you&#39;re seeing in this image here is you&#39;re seeing the surrogate notice the surrogate is a blackface sheep and then this is Dolly right here the white face sheep that was born they very purposely wanted to use a blackface sheep as the surrogate so they would know that if a white face sheep was born that it was from the DNA that was utilized if they used a white face sheep they wouldn&#39;t necessarily know for sure it was from the reproductive cloning so you&#39;re seeing the blackface sheep surrogate that&#39;s what this the embryo was placed into gave birth to Dolly here is Dolly now on the left side this is Dolly as well a dolly matured into a fertile adult this is Dolly this is one of Dolly&#39;s Offspring so Dolly did have by regular reproduction the old-fashioned way um Offspring and Dolly was formed as a full clone from atic cell nuclear transfer just taking the nucleus of an adult cell from another sheep and then growing that up into a whole new um member of their species and just incredible and the fact that dolly was fertile matured to an adult was able to have Offspring um was just a huge huge revolutionary step for Reproductive cloning now there are also some companies that are doing reproductive cloning in terms of like cloning your pets you know maybe cloning your dog or cloning your horse um there is still this kind of stuff going on it&#39;s a it&#39;s a hefty price if you want to you know clone your dog but absolutely um reproductive cloning is happening here&#39;s the example from our book showing the whole process going on so you&#39;ve got so the mamory cell so it was just an adult regular adult cell taken from the white white face sheep take a regular cell and then that nucleus was exchanged for the nucleus that would have been in an egg cell so the egg cell of the the blackface sheep take that egg remove the DNA from the blackface sheep insert that nucleus and then obviously it hasn&#39;t been uh fertilized so this is an egg cell but it hasn&#39;t been fertilized by sperm and so they needed to figure out okay what is the you know chemical makeup what what kind of you know process do we need to really trick this egg to thinking that it has been fertilized and undergoing development so that was a big part of the process it took a lot a long time um to figure this out but they figured out the right you know makeup to get this egg to think okay it&#39;s time to develop underwent the cleavage process the cell division we&#39;re able to develop an embryo from it and then they go implementation into the the darkface Sheep where the O site originally came from and birth of Dolly from that now reproductive cloning you can see the efficiency is quite low and some of the Clones do have complications now I think with Dolly it actually took like 276 tries to finally get Dolly um and one of the things is that ol despite being a fertile adult actually only lived about half of the typical LIF span of a sheep so one of the things that was a concern was maybe maybe the tiir right we know those ends of chromosomes those can tend to shorten over time dolly was formed from already adult DNA maybe the tiir had shortened um but also there are a lot of cloned organisms that do live a full lifespan so we&#39;re still trying to figure out um what&#39;s going on there but you can see the efficiency is still quite low it took a lot of tries um to get that result to get the result of Dolly and then as I mentioned many of the animals do have kind of some age Associated um conditions where they do just seem to age quicker and then one of the things lacking from like the lack of fertilization or the lack of kind of a male female um interaction ction that&#39;s taking place to form the embryo is that genomic imprinting now genomic imprinting is when you get things like the DNA methylation the genomic imprinting doesn&#39;t have to do with the genetic code but it does have to do with what&#39;s turned on and off in the genes and they&#39;re seeing that that is obviously changed when they are making the reproductive clones so just a couple of considerations um but again there have been cloned puppies um that companies are doing um I&#39;ve heard of a cloned horse that not only looked exactly like the Clone but even behaved exactly like um you know the horse that they were cloned from so just really interesting science going on here however of course for humans we are not looking at this technology in terms of doing reproductive cloning and cloning ourselves um but that whole therapeutic aspect of using the stem cells is certainly very beneficial for us all right just taking a quick jump to our review slide for this video so we&#39;re taking a look at the cleavage remember the cleavage was um the cell division making those identical cells starting with the zygote the Single Cell undergoing that cleavage becoming the morula and then giving rise to the blasticus we took a look at the different types of stem cells and all those different definitions and then of course focusing on embryonic stem cells and then differentiating between that reproductive cloning where we get organisms like Dolly and then therapeutic cloning where we can make maybe brand new healthy tissue that can help to cure disease so that&#39;s it for this first video focusing on stem cells and then the next one we&#39;ll take a look look at viruses

hello cell bio students let&amp;#39;s take a look at our last set of lecture slides for this semester stem cells and viruses we&amp;#39;re just hitting some highlights as you can see a stem cells is covered in chapter 19 but we&amp;#39;re just taking a look at parts of 19.3 and 19.4 and then we get into viruses we&amp;#39;ll be focusing on material from 26.1 and 26 6.4 starting with the stem cells I actually grabbed this image out of the book I&amp;#39;ve used in anatomy class and stem cells when we&amp;#39;re looking at embryonic stem cells the embryo of course is going to be formed from fertilization between sperm and egg that forms the zygote now you see 2 N the zygote is diploid that is the single cell that we all were when we first started our life and then that zygote under goes some mitosis to make identical daughter cells during this initial development process called cleavage and eventually reaches this blast assist stage now if a couple is doing invitro fertilization this fertilization is done in the lab in the you know test tube in the petri dish and then then the zygote and development starts to happen for a couple of days until it reaches this blastus stage now the blasticus would be what would be implanted in either a surrogate or into the mother if invitro fertilization is taking place but what&amp;#39;s important about this blast assist is that is the component which contains the embryonic stem cells now from there you can see the blasticus would develop into the growing embryo into the baby but we will be focusing on kind of this stage right here taking a look at those embryonic stem cells here&amp;#39;s the zygote the zygote of course is a single cell and the DNA in there comes half the genetic information from the sperm half the genetic information from the oite or the egg and these polar bodies are just extra DNA um that is not needed right because the each sperm and egg each gamet only needed half the amount of genetic information so those polar bodies are separate that would be extra DNA and then initially some mitosis so that single cell zygote becomes two cells becomes four becomes eight and then forms this morula now the morula in development is the last stage where all of the cells are identical and notice that all throughout this from the zygote all the way to the morula even the morula is a ball of 16 to 32 identical cells notice that the overall size has not changed now the morula is the last structure where all of the cells will be identical and right after the morula is the blasy the blasy here we see now actually has two different distinct Parts the outer cell layer is called the troob blast now autotrof heter trro anytime you hear tro think nutrition now remember an autot Trove made their own nutrition heter trro gets nutrition from another source but in this case trophoblast that is the outer layer that is the layer that if there is implantation in the uterus for a human you know embryo it would burrow into that lining of the uterus called the endometrium and the Tropa blast would be helping to provide nourishment before the placenta is formed so Tropa blast that is the outer cell layer of the blasticus and that is what will provide nutrition to a growing embryo during those first you know eight or nine weeks before the placenta has developed now what&amp;#39;s here on the inside is called the embryo blast or the Inner Cell mass now the embryoblast those are all the cells that will give rise to the growing embryo or the growing baby um also referred to as Inner Cell Mass but these are the cells here of the embryoblast that are also referred to as the embryonic stem cells let&amp;#39;s take a look at those all right so stem cells those are capable of division but can also give rise to differentiated cells the thing with stem cells is they are not specialized they have not been given a fate yet on what they will become differentiated means it is going to be a muscle cell or it&amp;#39;s going to be a nerve cell for example or an epithelial cell like a skin cell um and that hasn&amp;#39;t happened yet so the potential of these stem cells these embryonic stem cells is the fact that they have not been determined to be any particular cell type in the body now when it comes to cell stem cells there are some different types now totop poent totop poent you can see here is a cell that can give rise to any tissue in an organism and those were the those early cells those early cells like in the morula that were all identical those are still toap poent cells that they can give rise to any tissue in an organism by the time they&amp;#39;ve reached the embryoblast stage right when they&amp;#39;re in the blast toist they have become hurop poent now those embryonic stem cells have the ability to give rise to all cells in the adult organism body so that means just kind of our major tissue types again nervous tissue muscle tissue um connective tissue epithelial tissue so those are our four main tissue types everything in the adult organism that would come from plop poent and again that would be embryonic stem cells now multi poent that would give rise to a limited number of cells and what we tend to see in the adult body like our body um we have stem cells in our bone marrow that make all of our uh blood cells and those would be considered multi- poent because they&amp;#39;re giving rise not only to red blood cells but also to our white blood cells so multi poent would be found in an area like our bone marrow unipotent those would be stem cells that are really only going to give rise to one cell type and that would be found like in our epidermis so we do have epidermal stem cells but they are considered unipotent because those stem cells would only give rise to other epidermal cells here are the embryonic stem cells you can see they&amp;#39;re a form of plop poent plop poent from mamalian blasticus and this is going to be the source is the that inner cell mass or the embryo blast of the blasticus and the fact is that these cells have not been determined to be any particular cell type uh lots of experiments have been done on these cells you can see you can take them out of an embryo it wouldn&amp;#39;t grow up into an embryo but you can remove them from here place them in a dish and they can be utiliz for lots of different experiments and lots of different uses that could could hold some really important potential therapeutic uses now why are individuals studying embryonic stem cells because they have that potential to become any cell type what can we do with them you know Recent research shows stem cells can be utilized to grow new healthy pancreatic eyelet cells pancreatic eyelid cells are where insulin is produced therefore in individuals with diabetes that are not making insulin maybe we can help them to make some healthy pancreatic eyelid cells and be able to produce insulin another area you can see hematopoetic cells if individuals have anemia like sickle cell anemia and they&amp;#39;re not producing good hemoglobin not getting good red blood cells maybe we can introduce stem cells and they can start to make those healthy blood cells cardyes all right heart that&amp;#39;s heart muscle right there um they did a a surgery in Italy where they injected about 20,000 injections of stem cells into an individual&amp;#39;s heart and they were able to grow healthy heart muscle cells and that heart was able to return you know in a 60-year-old to the heart of like a 20year old um and so it showed great promise now also of course neuronal diseases neuronal degeneration or spinal cord injuries can we take stem cells and grow new neurons absolutely that potential is there and then the last one here hepatocytes liver think about you know the liver is our detox organ the liver can be damage sometimes liver transplants are not successful is there a way we can use stem cells grow healthy liver cells and help that with treatment so that&amp;#39;s the big promise of stem cell research if there are embryos that are not going to be used to grow into healthy human babies then we can use those cells for stem cell research um I gave that link in the canvas uh site for the UCSB stem cell research center and a big area of study there is actually with eye disorders um they&amp;#39;re doing a lot of work with kind of you know retinal um retinol kind of therapies and detached retina and all that sort of stuff that is being worked at at UCSB with stem cells seeing if we can help with eye disorders in that area now one of the challenges though however is of course when you&amp;#39;re using embryonic stem cells that that embryo cannot grow up to be a baby therefore one of the challenges for scientists was how can you get those stem cells by not using embryos and so after that scientists were like okay is there a way that we can kind of reprogram actually an adult cell or an adult nucleus to give rise to embryonic stem cells so a couple of ways you can see reprogram adult cells so that means you&amp;#39;re not wasting embryos um to do that maybe you just transfer the nucleus just take the nucleus out transfer that make some new cells from there you can see see a fusion a fusion of a somatic just a regular body cell and maybe some you know embryonic stem cells bring those together um introduce some different genes so there has been work where they&amp;#39;ve taken skin cells they&amp;#39;ve introduced a few different genes and have been able to induce um plop poent stem cells from there and then even you know take kind of cultures of germ cells or other adult stem cells and trigger them to become these plop poent cells so after that initial you know promise of embryonic stem cells there was then the challenge of can we figure out how we can get plop poent cells without um the loss of an embryo and where does that come into play now one thing with therapeutic cloning especially if you&amp;#39;re taking a cell from that individual the big benef benefit is the individual will be less likely to reject it right when we get things like organ transplants or a skin graft one of the big risks is that that individual&amp;#39;s body will reject the new organ or the skin graft and so though is individuals take a lot of immunosuppressant medications to not attack well if we&amp;#39;re able to make stem cells from an individual&amp;#39;s own cells then we really reduce that rejection risk so here that goal of maybe some therapeutic cloning you take a diabetic patient you take their own cells and then grow up embryonic stem cells that actually originated from their own cells use those to make maybe a healthy pancreatic eyelet then introduce that and the fact that those cells originally came from the patient really help with that rejection issue so that potential therapeutic cloning is a huge driving force for stem cell research now there is also reproductive cloning and in 1996 Dolly um was the first um mammal to be cloned from an adult cell so this process is called somatic cell nuclear transfer or scnt and here&amp;#39;s what happened um a regular adult cell was taken from a white-faced sheep and then the nucleus was taken from the adult cell placed into uh the like a surrogate cell like a surrogate type embryo and then that surrogate was actually a black-faced sheep what you&amp;#39;re seeing in this image here is you&amp;#39;re seeing the surrogate notice the surrogate is a blackface sheep and then this is Dolly right here the white face sheep that was born they very purposely wanted to use a blackface sheep as the surrogate so they would know that if a white face sheep was born that it was from the DNA that was utilized if they used a white face sheep they wouldn&amp;#39;t necessarily know for sure it was from the reproductive cloning so you&amp;#39;re seeing the blackface sheep surrogate that&amp;#39;s what this the embryo was placed into gave birth to Dolly here is Dolly now on the left side this is Dolly as well a dolly matured into a fertile adult this is Dolly this is one of Dolly&amp;#39;s Offspring so Dolly did have by regular reproduction the old-fashioned way um Offspring and Dolly was formed as a full clone from atic cell nuclear transfer just taking the nucleus of an adult cell from another sheep and then growing that up into a whole new um member of their species and just incredible and the fact that dolly was fertile matured to an adult was able to have Offspring um was just a huge huge revolutionary step for Reproductive cloning now there are also some companies that are doing reproductive cloning in terms of like cloning your pets you know maybe cloning your dog or cloning your horse um there is still this kind of stuff going on it&amp;#39;s a it&amp;#39;s a hefty price if you want to you know clone your dog but absolutely um reproductive cloning is happening here&amp;#39;s the example from our book showing the whole process going on so you&amp;#39;ve got so the mamory cell so it was just an adult regular adult cell taken from the white white face sheep take a regular cell and then that nucleus was exchanged for the nucleus that would have been in an egg cell so the egg cell of the the blackface sheep take that egg remove the DNA from the blackface sheep insert that nucleus and then obviously it hasn&amp;#39;t been uh fertilized so this is an egg cell but it hasn&amp;#39;t been fertilized by sperm and so they needed to figure out okay what is the you know chemical makeup what what kind of you know process do we need to really trick this egg to thinking that it has been fertilized and undergoing development so that was a big part of the process it took a lot a long time um to figure this out but they figured out the right you know makeup to get this egg to think okay it&amp;#39;s time to develop underwent the cleavage process the cell division we&amp;#39;re able to develop an embryo from it and then they go implementation into the the darkface Sheep where the O site originally came from and birth of Dolly from that now reproductive cloning you can see the efficiency is quite low and some of the Clones do have complications now I think with Dolly it actually took like 276 tries to finally get Dolly um and one of the things is that ol despite being a fertile adult actually only lived about half of the typical LIF span of a sheep so one of the things that was a concern was maybe maybe the tiir right we know those ends of chromosomes those can tend to shorten over time dolly was formed from already adult DNA maybe the tiir had shortened um but also there are a lot of cloned organisms that do live a full lifespan so we&amp;#39;re still trying to figure out um what&amp;#39;s going on there but you can see the efficiency is still quite low it took a lot of tries um to get that result to get the result of Dolly and then as I mentioned many of the animals do have kind of some age Associated um conditions where they do just seem to age quicker and then one of the things lacking from like the lack of fertilization or the lack of kind of a male female um interaction ction that&amp;#39;s taking place to form the embryo is that genomic imprinting now genomic imprinting is when you get things like the DNA methylation the genomic imprinting doesn&amp;#39;t have to do with the genetic code but it does have to do with what&amp;#39;s turned on and off in the genes and they&amp;#39;re seeing that that is obviously changed when they are making the reproductive clones so just a couple of considerations um but again there have been cloned puppies um that companies are doing um I&amp;#39;ve heard of a cloned horse that not only looked exactly like the Clone but even behaved exactly like um you know the horse that they were cloned from so just really interesting science going on here however of course for humans we are not looking at this technology in terms of doing reproductive cloning and cloning ourselves um but that whole therapeutic aspect of using the stem cells is certainly very beneficial for us all right just taking a quick jump to our review slide for this video so we&amp;#39;re taking a look at the cleavage remember the cleavage was um the cell division making those identical cells starting with the zygote the Single Cell undergoing that cleavage becoming the morula and then giving rise to the blasticus we took a look at the different types of stem cells and all those different definitions and then of course focusing on embryonic stem cells and then differentiating between that reproductive cloning where we get organisms like Dolly and then therapeutic cloning where we can make maybe brand new healthy tissue that can help to cure disease so that&amp;#39;s it for this first video focusing on stem cells and then the next one we&amp;#39;ll take a look look at viruses

Transcript for:Stem Cells and Viruses Lecture

Transcript for:
Stem Cells and Viruses Lecture