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What I'm actually interested about is whether a modification in one cell during the life of an asexually reproducing organism affects its genetic information? Which cell's genetic information is used during reproduction like budding, for example in the case of Hydra.

Or does the incidental advantage it could have given rise to disappear with the death of the organism?

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  • $\begingroup$ What kind of organism? Multicellular or unicellular? If the former, what cell? A random cell of a multicellular organism? A gamete? $\endgroup$
    – terdon
    Commented Mar 22, 2015 at 13:50

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In multicellular organisms there are specialised cells called gametes that are responsible for sexual reproduction (sperm/ egg cells). Mutations occurring in these cells can be passed on to offspring (germ line mutations). Mutations occurring in others cells affect only the given individual (somatic mutations).

Edit: For unicellular organisms it is pretty straight forward, the daughter cells formed through fission are identical. As for multicellular organisms here are many forms of asexual reproduction, and even these may involve the formation of specialized cells (eg. spores). So my answer is: it depends on the type of asexual reproduction and the actual cell(s) that accumulate mutation(s). For example in parthenogenesis - where the unfertilized egg cell develops into a new individual - , a mutation can be inherited if it occurs in the germ line cells generating the egg cell, but any somatic mutation would stay in the parent. You can find detailed info on asexual reproduction with details on each form on this wiki page

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    $\begingroup$ Thx for editing my typos,.I wrote my answer on a phone. $\endgroup$
    – Nandor Poka
    Commented Mar 22, 2015 at 10:00
  • $\begingroup$ I'm sorry for undoing the acceptance of your answer, even though it was correct for the previous question, but I realised that what I asked was wrong to begin with. $\endgroup$
    – FloriOn
    Commented Mar 22, 2015 at 22:12
  • $\begingroup$ @FloriOn - No worries :) Since my answer does not fit to the question I shall edit it. $\endgroup$
    – Nandor Poka
    Commented Mar 23, 2015 at 13:08
  • $\begingroup$ @FloriOn - I hope my edit helps a little bit. $\endgroup$
    – Nandor Poka
    Commented Mar 23, 2015 at 19:57
  • $\begingroup$ Yes, it certainly does. But aren't the cells used for budding somatic ones? Or do they change into germline cells before reproduction, in which case they might integrate the mutation they might have experienced during their "somatic life"? $\endgroup$
    – FloriOn
    Commented Mar 23, 2015 at 20:08
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Would something like CRISPR fit your criteria? CRISPR is essentially an adaptive immune system for bacteria. When a bacteria encounters foreign DNA (usually from an invading bacteriophage), it can cut it up and insert part of it in between palindromic repeats called CRISPRs. This small piece of DNA can be transcribed and then used as a template to recognize other copies of the foreign DNA. When a match is found, the foreign DNA is degraded, impairing the invading virus. Because a record of this foreign DNA is stored in the bacterial chromosome, it is transmitted to daughter cells, which will now have some protection against the offending virus in the future.

In the same vein, when certain bacteriophages invade bacteria, they integrate their viral genomes into the host bacterial genome---phage lambda is the classic example. At this juncture, the phage can choose between two lifestyles: lysis, in which the virus replicates like crazy, killing the host cell and spreading to other cells; or lysogeny, in which the virus lies dormant, allowing its genome to hitch a ride in the host genome, getting replicated and passed on to daughter cells just like any other piece of chromosomal DNA. When the time is right, the virus can switch back to lysis, proliferate, and infect new cells. Thus viral invasion of an asexually reproducing organism can lead to heritable changes in the host genome.

I'm sure you've heard of epigenetics, in which environmental factors can cause heritable changes to an organism without specifically mutating genes. While typically appreciated in eukaryotic organisms, asexually reproducing bacteria also have epigenetic mechanisms (1).

(1): Casadesus J and Low D. (2006). Epigenetic gene regulation in the bacterial world. Microbiol. Mol. Biol. Rev. 70(3): 830-56.

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  • $\begingroup$ Just saw your restriction to multicellular organisms. Less familiar with that, I'll let someone else answer that then! $\endgroup$
    – A. Kennard
    Commented Mar 23, 2015 at 10:01

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