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Sunday, January 16, 2011

social networking bacteria, cellulosaic structures, and greenbeard genes

I was surprised this past week when after writing the “unicellular” blog to find a paper titled “social interactions in a unicellular world. “ Fascinating.  The authors seem to struggle in a way with the concept, because it appears that many “social” interactions among microbes appear to be beneficial and not necessarily competitive.  They even mentioned that Darwin struggled with the concept that living creatures can benefit another creature, without receiving a benefit in return.
One example they used was the cooperation among “unicellular”  DIctyostelium discoideum an amoeba which assembles multicellular structures via cooperation.  The structure they form is a fruiting body which culminates in a spore forming tip. So in the soil this microbe can be very happy living as a disorganized mob, but when it comes time to start a colony somewhere in the beyond, they get organized and form a fruiting body. The authors note that when they get together to organize a multicellular fruiting body, 20% of the cells lyse (kill themselves) to form a cellulosaic structure ( I like that word cellulosaic for some reason).  The cellulosaic structure is apparently a dead stalk which supports the fruiting body.  So how do we explain this apparent act of selfless behavior in this slime mold?  Can slime molds really exhibit  selfless behavior?  Do we really care?  I find it fascinating that biologists are interested in this.  It appears to me that the ideas which embody evolution drive them to see these ideas of selfless or selfish behavior in living organism.  Why are biologists interested in these concepts?
The authors also discuss the discovery of genes which are thought to be responsible for co-operation; these genes are called "greenbeard genes."  They mention the discovery  of the greenbeard gene Flo-1 in yeast which codes for a protein which makes yeast work together.
1 Find out more about DIctyostelium discoideum.  What role does it play in nature? 
2 What advantages are there to living as an organism which can experience both a closely nit multicellular stage and a loosely nit unicellular-like stage? i.e.  what could organisms  accomplish living in this way?
3 Why are biologists interested in the concepts of selfless behavior or selfish behavior as demonstrated at the cellular level?
4 How does the Flo-1 gene promote yeast communities?


  1. 1. Oh wow, in nature it's found in soil and is known for eating bacteria such as E. Coli..fascinating...been used for the study of interaction (makes sense) and signalling. Also "noteworthy" of "as representing one of the earliest branches from the last common ancestor of all eukaryotes." also has qualities that can help the research of human cancer..
    2. I would think that an advantage of being able to live both as unicellular and multicellular would be that you wouldn't be as dependant on other organisms as being just multicellular, but I'm not sure..I would think that it would make you able to live in a variety of environments, but I'm also unsure on that..and then I'm not sure about number 3 and 4., but I must say very interesting Dr. Francis! Praise the Lord for a teacher who can get me thinking more about the complexity of God's creation! And I must say, I also like the word "cellulosaic". :) Thank you!

  2. Great work Bethany...I like your ideas...feel free to expand them...I did not know about the cancer link...feel free to elaborate on that.

    Dr Francis

  3. mmm well the cancer part came from wikipedia so who knows if that is correct. XD and I shall think about it more today!

  4. this is what I found on number 4 from a website called

    the actual link is

    Summary of Flo-1:
    "Flocculation, the calcium-dependent, non-sexual aggregation of yeast cells into 'flocs', is stimulated by nutrient limitation and is a process of great importance to the brewing characteristics of yeast strains.

    Flo1p is a lectin-like cell-surface protein which aggregates cells into 'flocs' by binding to mannose sugar chains on the surfaces of other cells.

    Floc-forming ability conferred by FLO1 is chymotrypsin-sensitive and heat-resistant"

    It sounds like Flo-1 promotes yeast communities by binding the cells to one another and allowing them to be heat resistant as a community. I am not sure that I understand all the technical wording of the entire paragraph in the website, but that was what I got out of it :)

  5. This comment has been removed by the author.

  6. 1) Find out more about DIctyostelium discoideum.  What role does it play in nature? 

    Dictyostelium discoideum resides in decaying organic material and consumes bacteria. They are often used by scientists to study cytokinesis, chemotaxis, cell motility, and other various cell functions.

    2) What advantages are there to living as an organism which can experience both a closely knit multicellular stage and a loosely knit unicellular-like stage? i.e.  what could organisms  accomplish living in this way?

    In the case of Dictyostelium discoideum, living in a multicellular stage is beneficial for reproduction. Another possible advantage to multicellular existence would be that as one cell died and began to break itself down, the nutrients released by that dead cell could be utilized by the cells surrounding it.
    An advantage to living alone would be that the individual cells would be more dispersed and not competing as closely for food sources. Also, a spread-out population is more difficult to eradicate than a population that is lumped together and can easily be destroyed all at once.

  7. 1. The DIctyostelium discoideum slime mold is an extremely important example of versatility in God’s creation. During its life time, this slime mold changes from a collection of unicellular amoebas, to a multi cellular slug, and then into a fruiting body. It’s primary propose in nature is consuming the bacteria that digest decaying matter, especially under forests.

    2. They could efficiently adapt to a variety of situations. For example, during the winter the organisms could lump together in a multicellular stage. This would accomplish efficient spread of nutrients and increased heat conserving. In the other seasons, they could spread out to gain as much nutrients as the can.

    3. According to secular biologists, an organism's primary propose should be to promote their own survival. According to a biologist who has a Godly worldview, everything in creation brings glory to God. This organism could be a prime example of how Christ laid down His life for us.

  8. 1. In nature, the DIctyostelium discoideum is a decomposer that lives in moist environments such as forest floors. It decomposes bacteria and dead plant materials. When the food source of bacteria is gone, the amoebas then aggregate to form a group of cells that is later used for reproduction by releasing spores once the cells have been differentiated and matured.

    2. Since the amoeba only congregates when the bacterial food supply is gone, it looks like having a multicellular stage helps it survive in a situation where it would otherwise be unable to. The spores that are released during this stage then become the unicellular versions of the amoeba, that stay this way until conditions again force it to make a multicellular organism again.

    3. At the cellular level, if every organism is truly independent, there seems to be no reason for selfless behavior. The only reason for sacrifice would be if that cell was the part of a greater whole, which is the multicellular stage of the organism’s lifestyle.

    4. The Flo-1 gene codes for a protein that forms an adhesive layer on the outside of the yeast cell, which helps yeast to stick together. When thousands of yeast cells are put together, the ones on the inside are better protected against possible threats to the community, while the cells on the outside are exposed to them and die.

  9. I like your answers 3 and 4 are making me think....Dr Francis

  10. 3.) I think that biologists are interested in the concepts of these behaviors in cellular level because this is where the argument of evolution begins. We've all heard the "it all started with a single-celled organism" or something like that. I also believe that people have a tendency to find joy in controversies--taking an idea or theory that is widely accepted and looking for an error or loophole in it. They may be trying to question the very foundation of evolution. That's my opinion. :)

    Also, frendtem has given really good points. Would like to know who you are! haha.

  11. This is the third time I have tried to post the second half to my answer... not sure why it won't stay posted...

    3) Why are biologists interested in the concepts of selfless behavior or selfish behavior as demonstrated at the cellular level?

    As mentioned in the article linked in the blog, any form of life that demonstrates selfless behavior would be highly contradictory to Darwinian evolution. Darwin himself said, “‘If it could be proved that any part of the structure of any one species had been formed for the exclusive good of another species, it would annihilate my theory, for such could not have been produced through natural selection’ (from On the Origin of Species, Chapter 6: Difficulties on Theory).” Scientists, then, would most certainly be interested in cellular behavior that has implications as big as disproving or casting serious doubt on their entire premise regarding of the origins and development of life.

  12. 4) How does the Flo-1 gene promote yeast communities?

    According to, “FLO1 produces an adhesive protein on the cell surfaces that causes individual yeast cells to stick together and form vast clumps (also known as 'flocs') containing thousands of cells.” However, a yeast cell only produces this protein when chemically alerted to to the presence of other yeast cells.

  13. 1. It said that it lives in soil and helps withe research of cancer with genetics which is kind of cool.
    2. Being multicellular and unicellular coulkd possibly help wiht the organism not being dependant on so many other organisms, helping in survival rates. Possibly affecting homeostasis.

  14. 3. I think scientist are interested in cell's selfish/selfless behavior because they are interested on how the cell can live on its own and live with others, almost basing it off human society how we all live alone or together.
    4. The Flo-1 gene sticks together to protect each other from other threats. And the ones that doesn't contain the Flo-1 gene are excluded from the other yeast cells.

  15. 1. I cant really find an answer as to what role it plays in nature but is used as a model organism to study cell differentiation, chemotaxis, and programmed cell death.
    2. By living as an organism which can experience both multicellular an unicellular stages, living as a unicellular organism, it doesn’t need as much nutrients to sustain it which would be beneficial in times of the year when there possibly might not be an abundance of nutrients. However, it would be beneficial to be multicellular because it could spread itself out to engulf as much nutrients as it can in a smaller amount of time than if it was unicellular.
    3. I think that biologists are interested in the concepts of selfless behavior and selfish behavior because they’re trying to figure out which organisms can survive on their own and which organisms rely on others for survival.
    4. The flo-1 gene is cloned and sequenced. I’m having a hard time finding information about this but it seems like it acts as some sort ‘bind-er’ to the cell wall protein and causes heat to be produced which would cause yeast communities to grow like wild fire with those perfect conditions.

  16. 1. Dictyostelium discoideum grows by themselves and help decaying leaves.
    2. The benefit of being multicellular and unicellular is they can survive and still reproduce through harsh conditions.
    3. I think since Dictyostelium discoideum is similar to human genes, it is helpful to do research on how cell's selfless behavior in order to find solution to replace the damage human genes which causes cancer with the life cycles of Dictyostelium discoideum.

  17. 3) I think the biologists want to found out can an organism live by itself. Human will die if we live in an environment that has no other organism. And I wonder can photosynthesis algae live by itself?

  18. 1 The DIctyostelium discoideum is a eukaryotic slime mold. Its main role in nature is played as a decomposer, eating through harmful bacteria in its habitat.

    2. In its multi-cellular state, the cells are able to work together to reach a common goal. Also when they exist in the multi-cellular state, each cell can individually work on something such as reproduction, hormone secretion, etc. Thus they help the other cells and the other cells help them toward a common goal. But as a unicellular state, I guess maybe the cell is more independent and can perhaps survive easier in an environment, it can feed easier (eating only for one instead of for thousands) thus they can survive in harsher conditions.

    3 Biologists are interested in the concept of selfless behavior or selfish behavior as demonstrated at the cellular level because this totally contradicts the rule of natural selection in that all cells (multicellular or unicellular) are competing for survival and the strongest will survive, but only for themselves, not for others. As the article quoted Darwin, this totally debunks his theory.

    4 "Flo1 gene is responsible for the production of a cell-wall protein allowing cells to flocculate or clump together. This clumping together provides protection from the stresses of the environment"
    Basically it is saying that the cells (because of this Flo-1 gene) secrete this hormone that clumps the cells together, thus forming a community of similar flo-1 "geened" cells.

  19. 3 ) also the scientists are interested in this topic because they are hoping to learn more about this subject so they can apply it to medicine. Because of these cells' selfless suicides the whole community benefits. They are learning more about this and also in the area of the "cheaters". Because of these interesting concepts and observations, scientists are learning more about the cellular world

  20. 1)The DIctyostelium discoideum is commonly used as a model organism. It is used to study cell differentiation, chemotaxis and programmed cell death. It also has the role of a decomposer. What was very interesting was that the cells involved in the life cycle of the DIctyostelium discoideum are applicable to human cancer research.
    2)I think living in two different stages like that can "prepare" the organism for any kind of situation it will live in. It can function in both a closely nit stage as well as a loosely nit stage.
    3)I think scientists find this fascinating because it makes them view the cells in a different way. Not just looking at cells competing with one another for survival, but rather "giving" themselves up.
    4)Yeast cells that have the gene FLO1 will literally stick together to protect each other from threats such as antibiotics or alcohol. the findings could prove useful in the brewing industry and in hospitals, where many disease-causing types of yeast also clump together, making them extremely difficult to treat. FLO1 produces an adhesive protein on the cell surfaces that causes individual yeast cells to stick together and form vast clumps (also known as 'flocs') containing thousands of cells. Cells on the inside of the clump are shielded from stress, antibiotics and other dangers by the cells on the outside, which sacrifice themselves for the common good.

    Makes you think cells have a personality :)

  21. 1. The Dictyostelium discoideum is a slime mold. It is used to consume the bacteria and decaying leaves in deciduous forests.
    2. An advantage to having both a unicellular and multicellular stage is that it prepares the organism for both an easy to live in environment and a more hostile environment. In a hostile environment, the slime mold could become unicellular, meaning there is less to sustain from the sparse nutrients. However in the more fertile times of the year, the climate can iinduce a multicellular stage. As there are more than enough nutrients, the slime mold could then reproduce from the multicellular stage.This inculdes exchanging genetic material, thus adding genetic differences between the organisms. This could prevent an annihilation of the species.
    3. There is no reason for selfless behavior for a unicellular organism, as its main purpose is for it to survive.
    4. The Flo-1 gene is a gene which codes for integral membrane proteins. This means that it could keep the yeast together in a colonial structure and causing a colony to form.

  22. Dictyoselium discoideum decomposes bacteria. It is used to study genetic, cellular, and biochemical processes in other organisms.
    At the multi-cellular level, the organism has numerous cells working together to bring a more efficient system. At the uni-cellular level, the organism can become more independent. The combination of these two would provide the cell with more stability, efficiency, and possibly a higher survival rate

  23. 1. The DIctyostelium discoideum lives in the forest soil where it hunts bacteria and yeast. They have been used to stuffy how cells can sense towards the bacteria or yeast.
    2. When it can’t find bacteria for food, it can come together and form a “fruiting body” for survival. It releases spores that are important for when it wants to become multicellular once again.
    3. This goes against survival of the fittest. Instead of killing itself off or its counterpart, it comes together for survival together.
    4. Flo-1 has a code that signals certain proteins that form a layer outside of the yeast cell that causes other cells to stick together to protect each other from threats.

  24. 1 Find out more about DIctyostelium discoideum. What role does it play in nature?

    it plays a major role in the decomposing process of the old cells in the cell they decompose them and recycle the nutrients/ materials in the cell for cell growth.

    2 What advantages are there to living as an organism which can experience both a closely nit multicellular stage and a loosely nit unicellular-like stage? i.e. what could organisms accomplish living in this way?

    being that it is multicellular it is repair itself much faster then a single cell organism can, it also it able to do many functions that would require a lot of time in a single celled organism but be a matter of seconds in a multicllur cell.

    3 Why are biologists interested in the concepts of selfless behavior or selfish behavior as demonstrated at the cellular level?

    they are interested in this because it could possible be a cure in the future for diseases like cancer and other cell diseases.

    4 How does the Flo-1 gene promote yeast communities?

    the flo-1 gene acts as a receptor for which the yeast community could then reconize and allow the the single yeast into the community.

    ps i love doing things twice errr i hate this computer lol

  25. 1 Dictyostelium discoideum also called slime mold is a model organism that eats bacteria which grow in rich organic decaying matter such as leaves.

    2 In a unicellular stage this organism is separate and can cover more area with a higher surface area which will allow the organism to consume more bacteria. In a close nit multicellular stage the organism will congregate which would allow the organisms to utilize less energy by specializing in tasks as movement, disposal, and eating would all become more efficient.

    3 Selfless behaviors would be a new concept to most biologists seeing that nearly all organisms work for their own benefit. A fallen world is mostly what we see yet God may have left some things for us to observe to show his character. Selfless behavior benefits the whole shown in this example when the organisms come together to form one larger body.

    4 the flo 1 gene works with yeast to make yeast flocculate using an adhesive which benefits the yeast causing it to resist heat and other outside extremities which could individually destroy every cell.

  26. 1. Dictyostelium discoideum and slime molds in general decompose dead organic material and bacteria. Decomposition is vital in nature, for obvious reasons. Dictyostelium discoideum has a unique asexual lifecycle that consists of four stages. Its primary diet is E. coli. Because of D. discoideums relatively simple life cycle, it is often considered a “model organism.”
    2. You get the “best of both worlds” because it allows diversity and self sufficiency, while also cooperation to increase the gene pool and other aspects that increase survival rates. When organisms are unicellular, they aren’t necessarily tied to other organism’s fates. It could also allow them to spread and reproduce rapidly, while larger organisms usually don’t disseminate as quickly.
    3. Because it goes against evolutionary tendencies to compete and the whole idea of “survival of the fittest.” These have direct implications to the theory of evolution and the complexity of seemingly non-complex organisms. If even the simplest organisms show a remarkable amount of complexity, it could challenge the theory of evolution and the idea that all life came from one source.
    4. “FLO1 produces an adhesive protein on the cell surfaces that causes individual yeast cells to stick together and form vast clumps (also known as 'flocs') containing thousands of cells. Cells on the inside of the clump are shielded from stress, antibiotics and other dangers by the cells on the outside, which sacrifice themselves for the common good.” Those without the Flo-1 gene are excluded from the group.

  27. Find out more about DIctyostelium discoideum. What role does it play in nature?
    Dictyostelium discoideum is a species of soil-living amoeba belonging to the phylum Mycetozoa. D. discoideum, commonly referred to as slime mold, is a eukaryote that transitions from a collection of unicellular amoebae into a multicellular slug and then into a fruiting body within its lifetime. D. discoideum has a unique asexual lifecycle that consists of four stages: vegetative, aggregation, migration, and culmination. The life cycle of D. discoideum is relatively short, which allows for timely viewing of all life stages. The cells involved in the life cycle undergo movement, chemical signaling, and development, which are applicable to human cancer research. The simplicity of its life cycle makes D. discoideum a valuable model organism to study genetic, cellular, and biochemical processes in other organisms.

  28. 1. Dictyostellium discoideum, commonly known as slime mold, has a short life cycle that makes it suitable for it's articial purpose--research. In nature, it is a decomposer, feeding on bacteria.
    2. Survival and increased reproduction are the main advantages of having both a unicelluar and multicellular stage in its life cycle. This also makes it ideal for cancer research because cancerous cells live together as tumors and then spread as smaller pieces.
    3. The interest in selfless cells is that it points to intelligent design. Evolution could not produce selflessness as it is based on competition and natural selection.
    4. It has been suggested in Molecular cloning and analysis of the yeast flocculation gene Flo-1 by J Watari and his research team that Flo-1 codes for an integral membrane protein and a part of the cell wall. It may be similar to extracellular matrix proteins which connect cells, as it is known to bind cells together.

  29. 1) Dictyostelium discoideum is a decayer that consumes bacteria found in rotting vegetable matter. It helps the evironment by getting rid of harmful bacteria.

    2)There are different advantages to the unicellular and multicellular stages of life, so living as both of them gives an organism all of the advantages. A unicellular being doesn't have to rely on other cells to do tasks for it. However, reproduction is a complex task, and if you mess it up, some serious consequences can result. It is easier for cells to reproduce with the help of other cells, so that is why Dictyostelium discoideum starts to live as a multicellular creature.
    3) Biologists are interedted in the ideas of selfless and selfish behavior because of evolution. The main thesis of evolution is that organisms do whatever they can to reproduce and stay alive. It makes no sense to them then that a creature would willingly sacrifice itself for another. Another thing that they are interested in is where human ethics came from. Evolution can possibly explain where are bodies originated from, but it offers no explanation for the origin of our sense of right and wrong, love, and selflessness. If we are all just grown up germs, and it will help me to further the species to kill you, then who is to say that i'm wrong for committing murder? all types of species do it, so why don't humans? Evolution has no answer for this, and biologists are searching for one desperately so that they can continue to deny that there is a God that created morals.

    4) Flo 1 alters the yests phenotype by activating flocculation. Flocculation is the grouping together of yeast cells so that they can protect each other from outside causes of stress.Since yeast can survive better, colonies grow more easily and cellular life spreads.

  30. 1. It has an asexual lifecycle with four stages: vegetative, aggregation, migration, and culmination and it is relatively short. During their life cycle they undergo movement, chemical signaling, and development and all of them are applicable to cancer research. This amoeba is valuable in studying genetic, cellular, and biochemical processes in other organisms. In nature, they eat decaying leaves, which keeps the forests “clean.”
    2. In a unicellular-like stage movement is a lot more feasible, while in a closely nit multicellular stage a lot more effort is put into movement. But, in a multicellular stage there is a lot more protection, especially for those cells situated in the middle, they are not subject to the outside forces. Competition is also a problem. In the multicellular stage food would be scarce, but in the unicellular stage food would be more easily accessed and competition would not be as much of a problem.
    3. Evolution is based upon selfish activity. The reason we all evolved was because we were selected, we were the fittest organism and were able to survive. But this is a prime example of that being wrong, these cells give up of themselves to ensure the organism survives. If this is happening at the cellular level, they have to rethink their evolutionist views or change the theory to accommodate this fact. Essentially they have to admit they’re wrong and they do not want to do that.
    4. Flo-1 gene causes yeast to flocculate, or form into clumps. It directs cooperation toward other carriers of the same gene, so due to this gene yeast stays together. Without it it would just fall apart, we would not have bread.

  31. 1. It is a decomposer so it is important in the food web. It's also a colonial reproducer.

    2. In the multicellular phase they are able to reproduce easily and when they are on their own it makes it easier for them to get nutrients and also makes the species more resilient as a whole- it's hard to wipe them out if they are dispersed. Being able to live on your own or in a group means more adaptibility, just like a person who can live in a city ok is better than a mountain hermit or a city slicker.

    3. I think this matter interests biologists because surviving means doing whatever you can for yourself. But if an organism is selfless, then it means that the organism is programmed to be responsible for its species as a whole. If we all came from the same "stuff" or common ancestor then shouldn't all organisms be independent and selfish OR dependent and selfless?

    4. Flo-1 codes for an adhesive protein that makes yeast cells stick to each other, making them form clumps. This is the perfect example of a "selfless" behavior pattern since the yeast that are stuck on the outside are exposed to much more than those on the inside of the clump and usually die as a result. The inside cells, in turn, get a safe, protected environment to grown and reproduce in.

  32. 1
    The DIctyostelium discoideum is an amoeba that colonizes to form a slug-like colony. They are important in decaying dead things in nature and consuming potentially dangerous bacteria on decaying matter.
    The advantage of living a somewhat multicellular but not confined to it is that they can reproduce easier and get nutrients better but at the same time, they are not completely dependent on multicellularity so that if the colony is damaged, the whole thing does not die.
    DIctyostelium discoideum are useful for scientific study because they are good for genetic studies. They contain genes that are homologous to some in higher eukaryotes that promote multicellularity.
    Flo-1 is a gene for an adhesive protein. Generally cells with this protein are more likely to adhere to each other so the amoeba withe these proteins will stick to each other upon cell division.

  33. Wellskies...I think this website was quite informative and answered two questions for the most part. :/

    "Dictyostelium avidly engulf and kills most of the bacteria. Indeed, bacterial pathogenicity was largely developed to resist predatory amoebae in the environment. The basic strategies of phagocytic cells, invented in primitive protozoan, are still used in both amoebae and mammalian phagocytic cells. It can be said that Dictyostelium is a primitive macrophage. This is why the organism is used for maintaining cultures or as a host model for several pathogens including Pseudomonas aeruginosa, Cryptococcus neoformans (at MetaPathogen), Mycobacterium spp. and Legionella pneumophila...."

    "Dictyostelium discoideum (slime mold) are a free living amoebae whose natural habitat is the upper layer of soil rich in decaying organic material. Bacteria are the main source of food of the D. discoideum. When the food supply is abundant the slime mold organisms live in unicellar form. Once the food becomes sparse they aggregate to form a multicellular fruiting body composed of two main cell types: stalk cells that support a spore-containing sorus. Spores are protected by a tough cell wall. The stalk raises the spore head high enough for the spores to be scattered away to maximize the possibility of germination in a more favorable environment. The dispersion of spores in an environment favorable for successful germination and survival is granted by the ability of the slug to migrate towards light and heat."
    -Sarah Gonzales

  34. 1. Dictyostelium discoideum is a soil-living amoeba. The hereditary information is carried on six chromosomes with sizes ranging from 4 to 7 Mb resulting in a total of about 34 Mb of DNA, a multicopy 90 kb extrachromosomal element that harbors the rRNA genes, and the 55 kb mitochondrial genome. The estimated number of genes in the genome is 8,000 to 10,000 and many of the known genes show a high degree of sequence similarity to genes in vertebrate species.
    Dictyostelium amoebae grow as separate, independent cells but interact to form multicellular structures when challenged by adverse conditions such as starvation. Up to 100,000 cells signal each other by releasing the chemoattractant cAMP and aggregate together by chemotaxis to form a mound that is surrounded by an extracellular matrix. This mechanism for generating a multicellular organism differs radically from the early steps of metazoan embryogenesis. However, subsequent processes depend on cell-cell communication in both Dictyostelium and metazoans. Many of the underlying molecular and cellular processes appear to have arisen in primitive precursor cells and to have remained fundamentally unchanged throughout evolution. Basic processes of development such as differential cell sorting, pattern formation, stimulus-induced gene expression, and cell-type regulation are common to Dictyostelium and metazoans. D. discoideum has four life cycles which are the vegetative, developmental, and sexual life cycles.

    2.It is a eukaryote that transitions from a collection of unicellular amoebae into a multicellular slug and then into a fruiting body within its lifetime. When starving, the normally solitary amoebae aggregate to form a differentiated multicellular slug that migrates towards light and forms a fruiting body, facilitating the dispersal of spores. When food is scarce, either the sexual cycle or the social cycle begins. Under the social cycle, amoebae aggregate to cAMP by the thousands, and form a motile slug, which moves towards light. Ultimately the slug forms a fruiting body in which about 20% of the cells die to lift the remaining cells up to a better place for sporulation and dispersal. When the creature is under stress then it multiples and that is just one of the benefits of having both unicellularity and multicellularity in one organism.

    3. I think that biologists are interested in that at the cellular level because then they can work up from there up to where we are now and prove evolution. They can also prove where they think sin came from if they can prove there is selfish behavior on the cellular level. The fact really is that there is one problem that has affected all of nature and that would be the only reason for any of the similarities in selfishness that they find between humans and these organisms.

    4. Scientists have found a single gene, Flo-1, which drives the social behavior that yeast has. For instance, if yeast cells have the Flo-1 gene then they will stick together in one group and be buddies. By doing this, they will stay away from harmful particles or substances such as alcohol or antibiotics. But, if the yeast does not have the Flo-1 gene, then it gets excluded from the group and he is a loner all by himself and will most likely die if something harmful comes along. Researchers have suggested that the mechanism involved could be quite simple: two cells with FLO1 proteins can form two-way attachments that are stronger than the one-way interactions between a cell with the sticky proteins and a cell lacking them.

  35. (1)Due to Dictyostelium being known as a primitive macrophage, Dictyostelium can be used to maintain culture or as a host model for several pathogens. Furthermore, this organism can be used to study the dynamics of the actin cytoskeleton, determine cell type, and spatial patterning. It is used as a model organism. It can be observed at organismic, cellular, and molecular levels due to their restricted number of cell types, behaviors, and their rapid growth” (Tyler).

    (4)Yeast communities are crucial in the fungal kingdom. It is crucial for the growth and survival of the fungal kingdom. When talking about yeast communities, do you mean by the term flocculation? Because flocculation refers to the clumping together. Flocculation in the Flo-1 gene is controlled by specific cell surface lectins that are able to bind directly to mannose. When this binding occurs, this leads to cellular aggregation, and then yeast cells rise to the surface of the substrate

  36. 4."In this latest study, scientists from Belgium, France and the US explain how a single gene, FLO1, is responsible for yeast's clumping behaviour. FLO1 produces an adhesive protein on the cell surfaces that causes individual yeast cells to stick together and form vast clumps (also known as 'flocs') containing thousands of cells. Cells on the inside of the clump are shielded from stress, antibiotics and other dangers by the cells on the outside, which sacrifice themselves for the common good."

  37. 1 Find out more about DIctyostelium discoideum.  What role does it play in nature? 
    this is a cleaner upper organism. It cleans up the bacteria that clean up the dead organisms. some sources have linked it to the research of cancer, but that doesn't completely add up to me.

    2 What advantages are there to living as an organism which can experience both a closely nit multicellular stage and a loosely nit unicellular-like stage? i.e.  what could organisms  accomplish living in this way?
    the versatility of that lifestyle is a huge advantage. It can survive in almost any amount of population. It can live both alone and in a highly populated area.

    3 Why are biologists interested in the concepts of selfless behavior or selfish behavior as demonstrated at the cellular level?
    biologists are interested in it because it is completely against all normal life. The world teaches to look out for number one, and only watch out for yourself. Essentially that is what natural selection is all about. it is almost like it freaks biologists out! they study it because it is different. It is a display of the character of God almost, it contradicts the worlds philosophy completely.

    4 How does the Flo-1 gene promote yeast communities?
    Flo-1 codes for an adhesive protein that causes the yeast cells to adhere to each other to form clumps for their communities.

  38. 1. Dictyostelium discoideum is an organism that eats all the bacteria found in soil, I mean, thats about as simple as it gets. It moves around, and has different stages as well.

    2. This is better explained by example. A society runs better when there are multiple people looking for food, rather than just one person looking for food. If everybody had to find food, water, energy, etc. then society would not progress. So when food is abundant, a unicellular organism would work fine, but when food is scarce, a multicellular organism would work better, because more cells are working together for the whole.

    3. This is somewhat of a generalized question, obviously my answer will never apply to the whole, but it might include some biologists. I believe they like to study the selfish/selfless nature of organisms because it shows a form of intelligence that can only be seen in humans. A human quality (to us believers) seen in cells and organisms, is obviously intelligent design and not evolution, so although it is very fascinating, we still have an answer(:

    4. Basically what the flo-1 gene helps protect the yeast from heat so that it doesn't die. It does so by binding to other cells so that it becomes bigger and more insulated from the crazy temperatures on the outside of the organism. I think thats it.

  39. This comment is from a student, Saratha and I'm currently pursuing my B.Tech. Cell biology and Genetics is my cores. I stumbled across this blog and eventually found it extremely useful in aiding my studies towards this subject. Now my question is that, since Flo-1 is an integral membrane protein, does it also have a tendency to exhibit modified characteristics on interactions with other peripheral proteins or get affected by various cell signalling mechanisms? If so how are these activities being performed without miscommunication?

    Thank you for your time in answering my question, professor.

    1. Hello! I am currently pursing my PhD from Philadelphia and I'm doing research on this topic, the functioning of Flo1 as an integral membrane protein on E.coli and we have noted that it does get affected by cell signalling mechanisms. If there is a miscommunication in the cell cycling mechanisms, it has a direct effect on the metabolism of the microbe. We are conducting further research to draw the link as to why is there a metabolic dysfunction due to cell signalling miscommunications.

      I hope I've helped to clear your doubts to some extent.

  40. Thanks Saratha and PHD pursuer in Philadelphia...fascinating...I am an professor of undergraduate microbiology courses and have not done any research on this..PHD in Philadelphia are you saying that Flo-1 responds to cell cycle miscommunication or is turned on by it? If so could it be that Flo-1 is used to correct the miscommunication or deleterious function by recruiting neighbor cells to help overcome the problem since they will secrete correct factors? I am just totally guessing ...I appreciate your communication on this. J Francis