Notices
Results 1 to 31 of 31
Like Tree1Likes
  • 1 Post By Bsquared

Thread: Inserting Chloroplasts into Animal Cells

  1. #1 Inserting Chloroplasts into Animal Cells 
    New Member IHaveAQuestion?'s Avatar
    Join Date
    Aug 2008
    Posts
    2
    Okay, I'm not sure if this qualifies more as pseudoscience, I'll be fine with having it moved.

    There's a theory floating around in the scientific community known as "Endosymbiotic Theory". Basically, it says that mitochondria (energy producing organelles in animal cells) and chloroplasts (responsible for photosynthesis in plant cells) were originally seperate organisms that other single-celled organisms would take into themselves to utilize their energy-producing abilities. Evidence for this is the fact that mitochondria and chloroplasts have their own DNA and reproduce by themselves when the cell undergoes mitosis.

    Even if endosymbiotic theory is incorrect ( I believe it) chloroplasts are basically seperate organisms, even if they didn't evolve as seperate organisms.

    So my question is this:

    Could you take a chloroplast from a plant cell and insert it into an animal cell, making it capable of photosynthesis?

    If you could, the implications are huge. It could eliminate, or at least alleviate, world hunger; You just drink a few bottles of water, then lie out in the sun for a while, and you're set for the day.

    It doesn't even come with the same religious problems as genetic engineering, since it wouldn't be tampering with human DNA; Though, the chloroplasts would probably have to be inserted just after the sperm fertilizes the egg, to let them spread fully throughout the body. But after the first few women born it would continue by itself; Your mitochondrial DNA comes from your mother, I can only assume this would work the same way.

    What do you guys think? Am I nuts? Could this work?


    Reply With Quote  
     

  2.  
     

  3. #2  
    Forum Cosmic Wizard paralith's Avatar
    Join Date
    Jun 2007
    Posts
    2,190
    Hi,

    The endosymbiotic theory is definitely not pseudoscience, and has quite a good deal of evidence in support of it. Nor is your idea pseudoscientific, but several problems jump out at me right away.

    1, an animal has MUCH higher energy requirements than plants. Animals have expensive tissues like muscle, hearts, livers, kidneys, guts, and in particular the brain, that require much higher levels of energy than any plant with similar overall mass. Just think about it - plants don't move. Animals do.

    2, only chloroplasts on the surface of our skin would do us any good. There's a reason why leaves are flat - plants are trying to maximize the surface area that is exposed to the sun. Humans have relatively very little surface area exposed to the sun, and what chloroplasts that would get exposed what not be enough to create enough energy to satisfy all our needs.

    3, plants need more than water, sun, and CO2 to grow. They require minerals and other nutrients, in particular nitrogen. Plants get nitrogen from the soil through their roots - we humans don't have roots. We'd probably need to consume nitrogen sources and a variety of other supplements through ingestion.

    4, remember that plants have evolved with chloroplasts for hundreds of millions of years. At this point chloroplasts are obligate parasites of plants - they can't survive on their own, and they need to be in a plant. In order to work in coordination with the rest of the cell, the necessary signaling mechanisms had to evolve in both ancient chloroplasts and ancient plants. Simply transplanting chloroplasts from plants to animals doesn't mean animal cells will "know" how to communicate with chloroplasts to give them what they need to function, and vice versa.


    You're not nuts, there's just some important biological details that you didn't take into consideration.


    Man can will nothing unless he has first understood that he must count on no one but himself; that he is alone, abandoned on earth in the midst of his infinite responsibilities, without help, with no other aim than the one he sets himself, with no other destiny than the one he forges for himself on this earth.
    ~Jean-Paul Sartre
    Reply With Quote  
     

  4. #3  
    Forum Professor Zwirko's Avatar
    Join Date
    Sep 2008
    Location
    55 N, 3 W
    Posts
    1,082
    Just to expand briefly on Point 4 (above):

    Organelles such as chloroplasts and mitochodria have their own small genomes. However, many chloroplast genes have been transferred over to the nuclear genome. For example, Photosystem I & II, ATPase, the cytochrome complex and the RUBISCO enzyme all have subunits that are encoded by the nucleus as well as by the chloroplast genome.

    A chloroplast dumped in to an animal would eventually die off without support from the nuclear-encoded protein products that are essential to its functioning. This is likely why some animal species maintain photosynthetic organisms within their bodies rather than just stealing their chloroplasts.

    However, just to contradict myself, there are species of sea slug (such as Elysia chlorotica) that sucks chloroplasts out from their algal prey and uses them as camouflage and as an energy source. Apparently it can keep its captured chloroplasts viable for up to 9 months.

    Here's a nice one, looking pretty much like a leaf:

    Reply With Quote  
     

  5. #4  
    Forum Cosmic Wizard paralith's Avatar
    Join Date
    Jun 2007
    Posts
    2,190
    Quote Originally Posted by Zwirko
    However, just to contradict myself, there are species of sea slug (such as Elysia chlorotica) that sucks chloroplasts out from their algal prey and uses them as camouflage and as an energy source. Apparently it can keep its captured chloroplasts viable for up to 9 months.
    Still not a permanent solution, as you pointed out. Are the chlorplasts of algae identical to the chloroplasts of land plants? By which I mostly mean, has the same amount of transfer of genes from chloroplast to nucleus occurred? It may also be possible that the sea slug has itself evolved some proxy genes capable of supporting chloroplasts for a certain amount of time.
    Man can will nothing unless he has first understood that he must count on no one but himself; that he is alone, abandoned on earth in the midst of his infinite responsibilities, without help, with no other aim than the one he sets himself, with no other destiny than the one he forges for himself on this earth.
    ~Jean-Paul Sartre
    Reply With Quote  
     

  6. #5  
    Forum Professor Zwirko's Avatar
    Join Date
    Sep 2008
    Location
    55 N, 3 W
    Posts
    1,082
    Different lineages of chloroplast bearing organisms have transferred varying amounts of their genes over to the nuclear genome, so it's quite likely that this particular algae that is preyed upon by this sea slug has not transferred as much as others. Maybe that is why Elysia chlorotica feeds upon it? To be honest, I don't know how it works in this case. I did manage to quickly read that the chloroplast genes in these sea slugs are being actively transcribed and translated. So, we've got chloroplast genes functioning in an animal host - quite amazing really.

    I found a short review article on these so-called "solar-powered sea slugs" in Plant Physiology.
    I've not read it myself yet, but will do so tomorrow - this topic has piqued my interest.
    Reply With Quote  
     

  7. #6  
    Forum Professor Zwirko's Avatar
    Join Date
    Sep 2008
    Location
    55 N, 3 W
    Posts
    1,082
    This weeks issue of PNAS has a photosynthetic sea slug on the cover.

    The article itself is called "Horizontal gene transfer of the algal nuclear gene psbO to the photosynthetic sea slug Elysia chlorotica". (Abstract only, unless you are subscriber).


    Another article I read recently suggested that a retrovirus (that ultimately kills the adult sea slug) may be involved in the lateral gene transfer of genes from plastid to nucleus.
    Reply With Quote  
     

  8. #7  
    WYSIWYG Moderator marnixR's Avatar
    Join Date
    Apr 2007
    Location
    Cardiff, Wales
    Posts
    5,760
    on the other hand, several types of organisms have established a symbiotic relationship with algae (e.g. corals, tridacna), which in a way has the same effect
    "Reality is that which, when you stop believing in it, doesn't go away." (Philip K. Dick)
    Reply With Quote  
     

  9. #8  
    WYSIWYG Moderator marnixR's Avatar
    Join Date
    Apr 2007
    Location
    Cardiff, Wales
    Posts
    5,760
    + there's actually quite an interesting article in New Scientist on a related topic :

    Solar-powered sea slug harnesses stolen plant genes
    "Reality is that which, when you stop believing in it, doesn't go away." (Philip K. Dick)
    Reply With Quote  
     

  10. #9  
    Forum Freshman
    Join Date
    Dec 2008
    Posts
    10
    I think it could work, to lessen the need for food, but not to replace it. That would take care of paralith's first 3 problems. As for the problem about some of the chloroplast's DNA being nuclear, I think the best solution would be to use the least evolved plant still alive today. It might also be possible to insert any missing DNA into the chloroplast's genome. Also, I think the first test subject should be some sort of transparent fish.
    Reply With Quote  
     

  11. #10  
    Forum Sophomore
    Join Date
    Jan 2007
    Posts
    158
    It's a while since I did biology, so maybe someone with more expertise can help me on this (or just tell me to shut up if I'm completely missing the mark).

    If I recall, plants cannot photosynthesise and respire at the same time- once requires CO2, one requires O2. Therefore they photosynthesise at day, closing their stomata, and at night they open them allowing respiration to occur. Would I be right in thinking that if an animal with chloroplasts was respiring (which we do constantly), it would be unable to photosynthesise at the same time?
    Reply With Quote  
     

  12. #11  
    Forum Cosmic Wizard paralith's Avatar
    Join Date
    Jun 2007
    Posts
    2,190
    Quote Originally Posted by The Matt
    It's a while since I did biology, so maybe someone with more expertise can help me on this (or just tell me to shut up if I'm completely missing the mark).

    If I recall, plants cannot photosynthesise and respire at the same time- once requires CO2, one requires O2. Therefore they photosynthesise at day, closing their stomata, and at night they open them allowing respiration to occur. Would I be right in thinking that if an animal with chloroplasts was respiring (which we do constantly), it would be unable to photosynthesise at the same time?
    Sorry Matt, plants do indeed photosynthesize and respire at the same time. Photosynthesis requires CO2, but remember: at the end of the photosynthesis process water is split, resulting in O2. Not to mention that as long as stomata are open, both CO2 and atmospheric O2 can enter.

    What you're thinking of is the CAM pathway, a particular process evolved by plants who live in extremely dry conditions. The stomata need to open in order to absorb CO2 - but, as long as the stomata are open, precious water is also being lost to the air! In a dry environment, the humidity differential between the stomata and the air is huge, pulling way more water than would more humid air. Thus, the plants only open their stomata at night, and store the CO2 they absorb until daytime, when light is available for photosynthesis.
    Man can will nothing unless he has first understood that he must count on no one but himself; that he is alone, abandoned on earth in the midst of his infinite responsibilities, without help, with no other aim than the one he sets himself, with no other destiny than the one he forges for himself on this earth.
    ~Jean-Paul Sartre
    Reply With Quote  
     

  13. #12  
    Forum Sophomore
    Join Date
    Jan 2007
    Posts
    158
    haha oops, that must have been what I was thinking of.
    Not done biology since 2003/4.
    Reply With Quote  
     

  14. #13  
    Forum Freshman SlugMan's Avatar
    Join Date
    Dec 2008
    Posts
    26
    I like this idea. It would be preety sweet to have green sperm. Maybe this could be better explored by injecting hairless rat cells with chloroplast like how they grow ears on them.
    Reply With Quote  
     

  15. #14  
    Forum Cosmic Wizard paralith's Avatar
    Join Date
    Jun 2007
    Posts
    2,190
    Quote Originally Posted by SlugMan
    I like this idea. It would be preety sweet to have green sperm. Maybe this could be better explored by injecting hairless rat cells with chloroplast like how they grow ears on them.
    lol - why would the sperm need to have chloroplasts? They come packed with the energy they already need, and if reproduction happens the way its supposed to they never get significant exposure to sunlight.
    Man can will nothing unless he has first understood that he must count on no one but himself; that he is alone, abandoned on earth in the midst of his infinite responsibilities, without help, with no other aim than the one he sets himself, with no other destiny than the one he forges for himself on this earth.
    ~Jean-Paul Sartre
    Reply With Quote  
     

  16. #15  
    New Member
    Join Date
    Dec 2008
    Location
    England
    Posts
    1
    Wouldn't our skin turn slightly green as well because of the chlorophyll in the chloroplasts lol?
    Reply With Quote  
     

  17. #16  
    Forum Freshman
    Join Date
    Jun 2009
    Posts
    19
    Oh yeah, it would be awesome. I think anyone with the oppertunity would love to become slightly green
    Reply With Quote  
     

  18. #17  
    New Member
    Join Date
    Aug 2009
    Posts
    1
    The idea of enabling the animal kingdom to share the secrets of the plant kingdom may just be the one that saves the planet, turning all 6 billion of us into CO2 filters plus solving world hunger!!
    I have bounced this concept past a number of learned folk in my circle and I get the same "if man was born to fly he'd have wings" arguement cutting the idea off at the source. Let these naysayers join the queue for an injection in 30 years when we've cracked the code!!
    A number of practical steps in the meantime could be:
    1) Better understanding of replication of mitchondria & chloroplasts vis-a-vis straight nucleic replication
    2) Better understanding of that sea slug !
    3) See if fungi can be injected with sustainable chloroplasts - they may represent a step closer to plants.
    Lets keep this forum going - we are the Leonardos of our time !
    green shoulders
    Reply With Quote  
     

  19. #18 Re 
    New Member
    Join Date
    Oct 2009
    Location
    Northeast, USA
    Posts
    1
    Wouldn't the CO2/O2 concentrations affect the H2C03/H+ and HCO3- balance in the blood, adjusting the pH and damaging the body, or at the least, stressing the system? Other than a decent percentage of the endosymbiont DNA being encoded by the nuclear DNA in the eukaryotic cell, chloroplasts require stimuli to grow - such as cytokinins - are there similar biomolecules in the human body? Would they have the same effect and would they have them to the same degree? To my knowledge, most plant hormones (probably mostly auxins, but maybe cytokinins as well) are toxic and potential carcinogens at the least.
    SASulewski
    Reply With Quote  
     

  20. #19  
    Forum Freshman
    Join Date
    Jul 2009
    Posts
    19
    I dug up this topic and, as I like to walk the line between reality and pseudoscience, I have an idea to throw into the mix.
    Assuming I'm right in thinking that heart tissue beats independantly of any nerves, it should be theoretically possible for a heart to exist alone if provided with energy. So, by adding chloroplasts to a heart, it will beat using energy from the sun. Then we have fields of hearts which take light from the sun, pump water which powers a turbine and solves our fossil fuel problems
    Reply With Quote  
     

  21. #20  
    Forum Freshman
    Join Date
    Nov 2009
    Posts
    16
    Your question is interesting and I have also thought of it a long time ago.
    But, some genetic problems need to be considered.
    For mitochondria, the organelles replication during mitosis not only require the mtDNA, but also the nuclear DNA. So, it seems that to maintain the function of mitochondria, both genome need to be compatabile.
    Chloroplast is simialr in case, in plant nuclear genome, there are some genes for chloroplast synthesis and function. To inject the chloroplast into animals ' cell, we need to ensure the cell will not degrade the foreign things and let the chloroplast be functional. So, some plant nuclear gene is required to incoporated into aniaml nuclear genome.
    Reply With Quote  
     

  22. #21  
    Forum Freshman
    Join Date
    Oct 2009
    Posts
    20
    Great posts Zwirko. That sea slug is fascinating!
    Reply With Quote  
     

  23. #22 chloroplasts into animals 
    Forum Freshman
    Join Date
    Jul 2010
    Location
    Arizona
    Posts
    17
    Considering humans are here, I don't see why this could not evolve in the future. I mean the sun is going to get stronger so why not.
    Reply With Quote  
     

  24. #23  
    New Member flush54101's Avatar
    Join Date
    May 2012
    Location
    America
    Posts
    3
    If chloroplast could some how be put inside of our cells, wouldn't our immune system attack it?
    Reply With Quote  
     

  25. #24  
    Forum Freshman
    Join Date
    Jun 2012
    Posts
    59
    I've actually read an article about this the amount of energy produced by photosynthesis is very low, which is why plants aren't mobile. the amount of energy produced by photosynthesis is equivalent of one sixth of an apple. it would be a wonderful concept, but not very practical.

    besides, wouldn't you miss the taste of food?
    Reply With Quote  
     

  26. #25  
    New Member
    Join Date
    Jun 2012
    Posts
    1
    There have actually been a few studies on this already. In one of them they inserted Synechoccous elongatus into some zebrafish embryos, and found that the aglea successfully grew with the fish, and became distributed more or less throughout the tissues of the fish. The solution to the nuclear genes problem is to use some of the types of endosymbiotic picoplankton, such as S. elongatus, and the larger Chlorella species. Chlorella particularly is able to endosymbiotise a relatively wide variety of organisms from paramecium bursaria (and a few other paramecia species), to hydras. In the paramecium bursaria, and most likely in the other organisms in which endosymbiosis is sucessful, the chlorella is able to convert the digestive vacuoles into perialgal membranes which serve to mask the LPS on the surface of the algea. These algea then proceed to exude small amounts of maltose sugar which can then be used directly by the cell for feeding purposes. LPS is the chemical that elicits a very strong immune response in humans since it is associated with deadly pathogens. A potential mechanism for introducing small algal cells into the skin of adult people would be to inoculate melanocytes with small celled algea such as synechoccous. The melanocytes would then travle throughout the basal dermis, and insert these algea into the keratocyte cells, thereby spreading the algea. Also you are correct in saying that under normal circumstances the algea would not provide significant energy to the person. However if we take things to an extreme an average adult has a surface area of 1.5 square meters, chlorophyl is about 5% efficient, and the sun puts out ~1000w/m2. So with the sun hitting both sides (front and back) of a naked person, with a concentration factor of 2, the algea would produce enough sugar for the entire caloric intake of that person (~2100Kcals) in about 6 to 8 hours. Of course you would have to keep yourself from overheating during all of this. In fact though if you made a tank of water with mirrors on its sides and lay in there with a air hose or something, that would be enough to keep you cool. And whats more the chlorophyl is even more efficient at lower temps so if the water (and skin temp) was about 60F the efficiency would rise to about 8%. So basically it could be done in theory, but it would be somthing of a drastic change. Another issue that might be a problem is the high level of blood sugar that would result from this. Basically more research needs to be done, but its anything but a dead end.
    Reply With Quote  
     

  27. #26  
    Forum Freshman
    Join Date
    May 2012
    Posts
    7
    1, an animal has MUCH higher energy requirements than plants. Animals have expensive tissues like muscle, hearts, livers, kidneys, guts, and in particular the brain, that require much higher levels of energy than any plant with similar overall mass. Just think about it - plants don't move. Animals do.
    Don't plants take in a higher amount of energy? If we were to look at an energy pyramid, plants would be at the bottom due to the fact that they have the most energy and the consumer that eats that plant would only take 10% of it's energy. So, if we were producing our own energy using photosynthesis wouldn't we be getting the maximum amount of energy?
    Reply With Quote  
     

  28. #27  
    Forum Freshman
    Join Date
    Jun 2012
    Posts
    5
    Brilliant! Way to break it down. I've been thinking about this for a while too! You all broke it down nicely. I need to catch up on molecular bio.

    Here are some scientists mimicking chloroplasts to construct 40% efficient photovoltaics (but still under research).

    http://www.science20.com/news_articl...fix_themselves

    Maybe it would be better if we constructed our own chloroplasts from rather than using pre-existing complex ones? This, though, might be more difficult than using plant chloroplasts... what do you all think?
    Last edited by Bsquared; June 11th, 2012 at 10:57 PM.
    Reply With Quote  
     

  29. #28  
    Forum Freshman
    Join Date
    Jun 2012
    Posts
    5
    Also, another blog addressed the same question. They also came upon some of the same problems and solutions.

    Mad Scientist Dreams: Chloroplasts in Animal Cells On the Shoulders of Giants

    G
    ene splicing to insert the predetermination of Chloroplasts is also an option, provided we address the same concerns (high blood-glucose, temp, and many others).

    Awesome.
    Charles Bensinger likes this.
    Reply With Quote  
     

  30. #29  
    New Member
    Join Date
    Dec 2012
    Posts
    1
    The incorporation of photosynthetic capability in humans actually may become a necessity in the next few decades if climate change drastically reduces the planet's agricultural capacity. If that's the case billions will starve. Photosynthetic humans could reduce the competition for ever-scarcer food resouces.
    Reply With Quote  
     

  31. #30  
    Life-Size Nanoputian Flick Montana's Avatar
    Join Date
    Jul 2012
    Location
    Flatland
    Posts
    5,438
    Quote Originally Posted by Charles Bensinger View Post
    The incorporation of photosynthetic capability in humans actually may become a necessity in the next few decades if climate change drastically reduces the planet's agricultural capacity. If that's the case billions will starve. Photosynthetic humans could reduce the competition for ever-scarcer food resouces.
    Dammit. And I spent all those years specifically avoiding the Sun for fear of cancer.
    "Sometimes I think the surest sign that intelligent life exists elsewhere in the universe is that none of it has tried to contact us." -Calvin
    Reply With Quote  
     

  32. #31  
    New Member
    Join Date
    Dec 2012
    Posts
    1
    Here's an issue I am considering if this became possible and mainstream. Wouldn't the earth's supply of CO2 go through the roof if this happened? How would this affect the global climate? The debate for global warming comes down to the % of heat reflection/absorption of CO2 wouldn't this just compound all these kind of issues?

    Side thought hypothetically
    How would humans or any animals evolve differently if we gave the primary food support over to this kind of process? Given that any animal develops to reproduce and sustain itself and this process all but eliminates the issue of self sustaining oneself which is why/how we developed things like mouths, digestive systems and systems to hunt or find sustenance how would animals/humans develop differently on an ecological scale? just a fun thought
    Reply With Quote  
     

Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •