Talk:Axenic

Horizontal gene transfer

Why horizontal gene transfer is included as a variability introducing process in an asexual axenic culture? If there is a single species or strain in the culture this transfer is not possible. I think the variability results from mutation and not from horizontal gene transfer (in this case).--Miguelferig (talk) 11:57, 15 June 2013 (UTC)[reply]

Hi there. I'm not an expert, but my understanding of HGT is that it can happen in ostensibly "asexual" species, and that the transferred segments of DNA can be fairly arbitrary. So while one might start with a culture of organisms with identical genomes of identical size, HGT would lead to a culture of organisms in which, while there may be no new genes, there might be organisms with a range of genome sizes. This is quite different from the situation in which only mutation occurs - which may well be the case in an axenic culture of organisms that don't, or can't, exhibit HGT. And once organisms start to have multiple copies of the same (functional) genes, the possibility exists for mutation to work on these extra copies without harming the organism. Anyway, have a read of the HGT article and see if that helps. Cheers, --PLUMBAGO 07:38, 16 June 2013 (UTC)[reply]

Another nuance is that axenic cultures are not necessarily clonal (all identical). They are simply confined to a single species or strain (these are surprisingly vague concepts in microbiology), but there may be a few slightly different individuals in the founding population of an axenic culture. So even without invoking duplication (which does happen), simple homologous recombination can shuffle differences from the founding few genomes into many different combinations. Jmeppley (talk) 20:18, 10 February 2014 (UTC)[reply]