Genetic variability in a bacteria species

Something I've wondered about for quite a while, with this topic being triggered by this message elsewhere.Now, bacteria reproduce via fission - One bacteria turns into two.The question is, will these two be genetically identical? My uneducated guess would be "maybe, maybe not".Moose

Thread copied here from the Genetic variability in a bacteria species thread in the Proposed New Topics forum.

Your uneducated guess would be correct.Errors are introduced roughly 1 per 1000 divisions (that is, if a cell has a thousand daughter cells, 1 of those 1000 will have an error, not 1 error will occur in a thousand generations which obviously can include an incredible number of bacteria cells).

Right, the daughter bacteria are only going to be different right then if there's a transcription error (standard mutation.) BUT if they eat other bacteria not closely related to them, there's a very good chance that they won't be that similar to their parent or each other by the time they each split. Contrariwise, if they are the ones who get eaten, some of their own traits are liable to survive in bacterial lineages not descended from them in the usual way. Bacteria are the living spirit of miscegenation

Hmm... it can happen, but I wouldn't describe it as "a very good chance". It's not even the primary means of lateral gene transfer. And lateral gene transfer in bacteria is rare (at the individual level, at the population level there are so very, very many bacteria involved that it happens a lot).

Would you say that transduction (bacteriophages) and true conjugation are more likely than transformation then? That surprises me, but my opinions are about 10 years old. I just tried looking up current work, but everyone is all gay about what's happening in eukaryotes now, and that is mostly conjugation as I understand it.Feel free to link me somewhere if you don't feel up to teaching preschool.

Hi everyone,In Message 69 I comented to Jeff Davis saying "Penicillin was first used in 1871 but was not mass produced until just before the invasion of Normandy. It was great for colds in the 50's.So bacteria had 40 years to raise immunities before the ninties.Now where those immunities came from is another question."jar promptly informed me the immunities came from mutations.I then introduced a paraphrased Lederberg experiment in Message 71.After which I made the following statement: To which Moose pointed me to this thread.Anybody game to clear my misconceptions up?God Bless,

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"John 5:39 (KJS) Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me."

I've done so in the other thread.

Hi crash, No really.I will bring my last post over here and you can answer it here.God Bless,

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"John 5:39 (KJS) Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me."

Hi crash,Here is my post at Message 80.Hi crash, Check out the experiment I was pharaphasing HereThe experiment was started with a lot of bacteria in the beginning.They were allowed to grow into several different colonies.Then the colonies were stamped and stamped on a plate with penicillin on it.Some colonies survived and some did not.Penicillin was then introduced on the original plate and the same colonies on it died.Thus my conclusion that some of the original bacteria had immunity and some did not.The immunity had to exist in their DNA and was not acquired during the experiment.I moved my questions to the thread Moose mentioned so lets go over there.God Bless,

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"John 5:39 (KJS) Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me."

Yes. All clones of a single individual, called the "founding individual." Right, that's "replica plating." A sterilized piece of velveteen acts as a huge "paintbrush", picking up individuals from each colony on the plate and then stamping them down in the exact same relative position on the replica plate.That enables a researcher to positively identify replica colonies with their original culture. The antibiotic resistance was acquired during the initial culture - the step you describe as "they were allowed to grow into several different colonies." We know that this is true because of the proportion of colonies that survived vs. those that died. If no colonies survived then we would have known that none of the bacteria had developed any resistance. If the bacteria had an inherent resistance they inherited from the founding individual then all colonies would have survived on both plates, because the vast majority of organisms would have been resistance-positive.We observed neither of those. We observed that some colonies replicated and some did not - thus proving that resistance was an acquired trait, acquired during the "log phase" of the experiment (the initial culture, when bacterial growth is exponential) by a mechanism other than inheritance, which is so unlikely that across tens of billions of individuals only 20-30 actually developed the trait.This proves that random mutation was the source of the acquired resistance. The mutation in question occurred during the initial culture of the original plate, as proven by the fact that the same colonies on both plates are resistant.Edited by crashfrog, : No reason given.

Not actually. You misunderstood. Many colonies were derived from a single source. I'm not sure what "stamped and stamped" means. I do know what it means to stamp one plate with another. OK. So the colonies that died did not have the mutation that made them resistant to penicillin. But the original bacteria were from the same source. Actually, this experiment has been done so many times under so many restrictions that there is little doubt that the immunity to antibiotics arises anew during the experiment from genetic mutations.How do you explain a strain of bacterium that is able to metabolize waste products from the manufacture of nylon 6?To quote Wikipedia:

quote:

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In 1975 a team of Japanese scientists discovered a strain of Flavobacterium, living in ponds containing waste water from a nylon factory, that was capable of digesting certain byproducts of nylon 6 manufacture, such as the linear dimer of 6-aminohexanoate, even though those substances are not known to have existed before the invention of nylon in 1935. Further study revealed that the three enzymes the bacteria were using to digest the byproducts were significantly different from any other enzymes produced by other Flavobacterium strains (or any other bacteria for that matter), and not effective on any material other than the manmade nylon byproducts.

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Are you trying to tell us that these bacteria, that don't exist anywhere else in the world, have existed since the creation of the earth in this one spot, even though this one spot was not always a waste pond from this nylon production facility?Really? You aren't aware that mutations in a variety of organisms have been observed and documented? If all humans arose from a single created pair, and if genetic diversity were not increased by several mechanisms of evolution (primarily mutation), then the genetic difference between all humans would be less than the difference between 1st cousins. Given any two individuals (a male and a female), it is only possible that they carry 4 alleles for any gene. On average, for every gene in the human genome there are 14 alleles (some more, some less). Where did they come from? The original humans could not have possibly have carried all of these alleles.It borders on idiocy to deny that mutations occur in reproducing organisms. Especially since bacterial resistance to penicillin was non-existent back in the 40s. And now there are strains of bacteria that are resistant to most antibiotics that we have. And most antibiotics we have have been developed during my lifetime. Ever heard of MRSA? I recently had a major spinal surgery. Even though I was heavily drugged during my hospital stay (I had surgery on Monday morning and was discharged on Saturday morning - I remember only bits and pieces), I was sent home before I was able to walk. The danger from mutant strains of infectious bacteria in hospitals is so great that that it is better to send the patient home than stay in the hospital.By the way, that hospital has a very low rate of hospital acquired infections.Edited by pandion, : To add comment.

im guessing you all asume that penicilin was the first antibiotic that bacteria have ever encounterd to name a few natural antibioticsgarlic, honey, Carob powder, Aloe Vera, Grapefruit seed extract, ....all bacteria have had ample time in human history to develope a resistance to these natural antibiotics, that resistence could have helped them to evolve a resistance to industrial antibiotics.
in short they did not haveto invent a way to defend themselves from a totaly new substance they only hadto invent a way to defend themselves from a more powerful substance that kills them.

All "industrial antibiotics" are natural antibiotics too. Almost all of them are compounds originally derived from soil fungi. Penicillin for example was originally produced by Penicillium chrysogenum

i know you just cant get them that pure in nature. so all bacteria could have had a small resistance to them already and they did not have to find the resistance only straighten it.